CA1186162A - Concrete reinforcing rod chair - Google Patents
Concrete reinforcing rod chairInfo
- Publication number
- CA1186162A CA1186162A CA000393143A CA393143A CA1186162A CA 1186162 A CA1186162 A CA 1186162A CA 000393143 A CA000393143 A CA 000393143A CA 393143 A CA393143 A CA 393143A CA 1186162 A CA1186162 A CA 1186162A
- Authority
- CA
- Canada
- Prior art keywords
- troughs
- body member
- pair
- chair
- reinforcing rod
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
- E04C5/16—Auxiliary parts for reinforcements, e.g. connectors, spacers, stirrups
- E04C5/20—Auxiliary parts for reinforcements, e.g. connectors, spacers, stirrups of material other than metal or with only additional metal parts, e.g. concrete or plastics spacers with metal binding wires
- E04C5/206—Spacers having means to adapt the spacing distance
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
- E04C5/16—Auxiliary parts for reinforcements, e.g. connectors, spacers, stirrups
- E04C5/162—Connectors or means for connecting parts for reinforcements
- E04C5/166—Connectors or means for connecting parts for reinforcements the reinforcements running in different directions
- E04C5/167—Connection by means of clips or other resilient elements
Landscapes
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Reinforcement Elements For Buildings (AREA)
- Rod-Shaped Construction Members (AREA)
- Manufacturing Of Tubular Articles Or Embedded Moulded Articles (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A concrete reinforcing rod chair comprises a frusto-conical tubular body or hollow tapered body with open ends to permit mutual stacking, the body having two pairs of diametrically opposed troughs in one or both ends thereof, with each pair having a different depth. The troughs are arranged on the body so that a continuous strip of body member material extends in the longitudinal direction, either from end to end between adjacent troughs or from the bottom of each trough to the opposite end of the body. The continuous strips of material provide strength against axially directed compressive forces. In addition, a continuous strip of material is provided in the circumferential direction intermediate the two ends, to provide additional strength.
A concrete reinforcing rod chair comprises a frusto-conical tubular body or hollow tapered body with open ends to permit mutual stacking, the body having two pairs of diametrically opposed troughs in one or both ends thereof, with each pair having a different depth. The troughs are arranged on the body so that a continuous strip of body member material extends in the longitudinal direction, either from end to end between adjacent troughs or from the bottom of each trough to the opposite end of the body. The continuous strips of material provide strength against axially directed compressive forces. In addition, a continuous strip of material is provided in the circumferential direction intermediate the two ends, to provide additional strength.
Description
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BACKGROUND OF THE INVENTION
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The pre~ent invention relates to a spacer, commonly referred t~ as a chair, for positioning reinforcing rod at predetermined distances from the surfaces of molding forms Eor concrete.
Conventional spacers used in positioning reinforcing rods a pre~electad distance above a base, or adjacent a vertical wall, have been formed of concrete into structures known as dobies. Dobies for use on~vertical surfaces -typically have a wire embedded in the concrete with its two ends projecting out on either side of the dobie. A
reinforcing rod is placed on one end surface of the dobie and the two ends of the wire are wrapped around the rod to tie the rod ~o ~he end surface.
Because Qf the nature of its design, each concrete dobie is capable of providing only one spacing distance between a reinforcing rod and the concrete form. A typical project where reinforcing rods are used might require a number of different spacings to be provided. Consequently, a variety of different sizes of dobies must be kept on hand at the projèrt site. For small spacing requirements concrete dobies may weigh only a few ounces, but for larger spacings they may weigh several pounds. The bulk and weight of larger dobies maXe it difficult for an installer to carry several dobie~ with him during installation. For example, a typical 100 pound bag of 4" dobies may contain a relatively small number of spacers, because of each dobie' 5 bul~ and weight. Consequently, relatively large numbers of bags are ,i-"c~, .
~186162 needed Eor any given project and~large numbers of bags C05t money -to moveO Bags of dobias are moved with manpower or, -in -the case where quantities o bags are required, by cranepower. On jobs where hundreds r thousands, and millions of dobies are required. the transporting/handling problems for all ~izes of concrete dobie are extremely significant and add to the real, or end cost of the dobies, Furthermore, dobies must be individually handled once any package in which they are contained is broken.
_~ The difficulty in using concrete dobies is mul-tiplied when installations are in such an area as along the vertical face of a dam site. In such installations, it is necessary or the installer to hold the concrete dobie in place wi.th one hand and attempt to tie the reinforcing rod to i-t with the other hand. This procedure is cumbersome and time consuming. Moreover, because of the weight of the dobie and the fact that it is fastened to the rod at only one end, the dobie tends to droop at its unattached end, resulting in variations from one dobie to another in spacin~
from -the form, depending upon the amount of the droop.
Where ~he project site is in a remote and/or inac-cessible area, the real cost o the dobies i5 compounded by the added requirement of fabricating the dobies at t~e site.
The extra manpower, transportation, and crane-time costs required on such projects, because of the nature of concrete dobies, add again to the end costs o the dobies. Despite this, and the existence of several alternative forms of spacer made of material other than concrete, the concrete spacer still is the one most commonly used, because of other 16~
disadvantayss inherent in the alternative forms o spacer.
One prior art attempt at providing an alternative . :
form of spacer is disolosed in French Patent No. 1,420,975 issued to Ingeborg Schwachula K.G. ~The disclosed spacer is a tubular or conlcal structure~hav:ing a number of pairs of troughs formed in each end thereof, with each pair being of a diferent depth than each of the other pairs. The struc-ture further includes narrow eyelets below each set of troughs and a pair of oblique eyelets, one on each side of a deep trough and opening into the trough, to permit passage therethrough of a special tie band that is wrapped around a reinforcing rod when in place in an associated pair o troughs. The procedure suggested to attach the tie band is to firs-t insert it through the appropriate eyelet up to a head at one of its ends, place the rod in the desired troughs, wrap the tie band around the reinforcing rod, and hook the tie band in one of the oblique eyelets.
While the spacer disclosed in the French patent embodies certain concepts that theoretically overcome some oE the previously mentioned difficulties associated with concrete dobies, it also possesses a number of drawbacks that provide impediments to its use in a practical applica-tion. For example, it is unlikely that an ironworker on an actual job site would use the tie band associated with the spacer because of the timè and dexterity required to mani-pulate the tie band through the eyelet, around the placed reinforcing rod, and through the second eyelet.
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86~62 An objective set forth in the French patent is to provide as many troughs of diferent depths as possible on a single spacer body. Ih addition, it states that -the prefer-red design for the troughs i~ a V-shapeO Consequently, relatively long and narrow V-shaped legs of body material are formed between adjacent troughs, connecting the upper and lower portions of the spacer. The relative Fragility of these narrow, angled legs constitutes a sec~nd impractical-ity of the spacer disclosed in the French patent. It is quite common for workers to walk on the mesh of reinforcing rods prior to the time the concrete is poured. Conse-quently, a substantial axial or longitudinal force is exer-ted on the spacers. It does not appear that the relatively small amount of material provided between the bottom of a trough and the surface of a concrete form, coupled with the angular disposition of this material relative to the axial or longitudinal direction, would provide sufficient resis-tance to such forces. Hence, the spacer would be subject to buckling under pressure, or similar such failure.
In accordance with the previously noted objective of providing as many different troughs as possible i~ one spacer, the French patent discloses six individual troughs of varying depths at one end oOthe spacer, so as to theo-re-tically provide for several variations of concrete slab depth. In reality, this will only b practically possible where small diameter reinforcing rods are used. Larger diameter rods would require wide troughs. Increasing the trough 5ize, while retaining several variations of trough dep-th, would result in a spacer having a very large top .
diameter. To balance this, the overall size of the spacer would have to be increased. The resulting spacar that can be used with large-diameter rods and provide for variations of slab depth would be ~nreasonably large and cumbersome to use.
Xn addition, the use of the preferred V-shaped troughs presents a structural defect when large diameter rods are used. If the radius of curvature of the bottom of the trough is less than that of the rod, the rod will not rest in the bo~tom of the trough but will rest against the converging side walls of the trough. When force is applied to the rod, for example the weight of the worker, the rod will exert pressure on the side walls having a component o force in the circumEerential direction of the spacer. If sufficient, this force can cause the spacer to crack or split at the apex of the trough.
SUMMARY OF THE INVENTION
--In accordance with the present inventionl a spacer for positioning reinforcing rods used in molding forms for concrete includes a substantially frusto-conical body having two pairs of diametrically opposed troughs on at least one end thereo for receiving reinforcing rods and retaining them in place. The deep troughs are preferably U-shaped~
and the radius of curvature, or width, of each -trough is equal to that of the largest diameter rod that is expected to be positioned by the spacer. Advantageously, each pair of opposed troughs is a different preselected depth below 6~
the end of the body in which they are located so as to engage a rod at a predetermined distanca from the other end of the spacer. In one embodiment of the invention, the troughs are located relative to one another so as to provide a substantially continuous strip of body material extending along the length of the body mem~er between adjacent troughs. The continuous strip of bocly material provides a spacer configuration which exhibits a high degree of strength against axially directed compressive forces.
Preferably, the body material is resilient. For spacers intended to be used on vertical faces, the troughs oE at least one o the pairs of troughs on each end of the body may have a neck located away from the bottom of the trough a distance such that the neck resists entry and removal of a rod of substantially the same diameter as that of the trough and retains the rod in place in the trough.
The use of the narrow neck on a ~air of the troughs allows the rod to be snapped into those troughs and held in posi-tion by -the tightness of the fit of the trough to the rod until a wire can be wrapped around the rod. The narrow nech thus allows the installer to snap on the spacer with one hand and then free that hand and use both hands to tie the rod to the spacer, as would he done when the spacers are installed along a vertical face ~f à retaining wall or dam site form.
The spacer may further include a circular or oval aperture in ~he body intermediate the troughs for permitting entry into the interior of the body of a fluid concrete mix.
Preferably, four troughs are located on each end lP~
so that a first imaginary line.bisecting a pair of troughs on one end of the body is di~placed 90 about the body axis from a second imaginar~ line bisecking the other palr of troughs on the same end.- This con~iguration may allow one end of the spacer to position two rod~ at right angles when one pair of troughs is recessed a depth suficiently greater than that of the other pair.
For spacers designed to position ~ods short dis-tances away from a deck and having two pairs of troughs on each Qnd with each pair on a given end being displaced 90 relative to the other pair on that end, the troughs on one end rnay be displaced about the axis of the body relative to -those on the opposite end so as to provide a conti.nuous strip of body material from the bottom of each trough to the end opposite that trough. Moreover, each such strip may be thickened in order to enhance its strength. The width and thickness of ~he strip so formed may be such as to allow the spacer to support heavy, large diameter rods without buckling.
The location of the troughs relative to one another and to any apertur~s which may be incorporated into the structure is also preferably such as to ensure that there is a continuous strip of material disposed in the circumferential direction of the body between the troughs and the apertures so as to provide considerable strength in concer-t with the longitudianl strips of material.
The frusto-conical shape of the spacers allows efficient stacking of a plurality of spacers and enables the ins-taller -to carry with him a considerable number of spacers during installation. Optimally the spacer can be made of a relatively light plastic material which further facilitates efficient transportation, packaging and installation of the spacers.
As used in the context of the present invention, the term "frusto-conicall', as applied to the tubular body, is synonymous with a hollow frustum, i.e., a tapered tube with open ends to permit mutual stacking, and includes not only a body having a circular cross section, but other forms of hollow tapered bodies as well. For example, the body can have four or more straight sides, i.e., be a truncated pyramid, concave or convex sides, or an elliptical or oval cross section. For those body forms having sides that intersect at corners, the corners are preferably rounded or mitred so that the poured concrete can easily fill the entire interior of the form, rather than leave spaces in the corners that can lead to subsequent erosion.
The use of troughs of different depths on both ends of a spacer provides for a greater variety of possible spacings from a concrete form to be achieved with a single spacer.
For example, spacers that are designed to be used on horizontally disposed forms, commonly known as deck chairs, can each provide four different sizes of clearance between the surface of the form and the underside of a reinforcing rod. This enables one spacer to accommodate varying concrete slab depths, rather than requiring a different spacer for each size. The additional troughs that are not used also provide apertures through which fluid concrete mix can enter the interior of the spacer. The provision in the spacer of continuous strips of body material in the longitudinal and circumferential directions _g_ .
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for streng~h, a frusto-conical~shaped body for permitting efficien-t stacking of several spacers, and pairs of troughs .
Eor both ends for enabling several different possible spacings to be achieved with a relatively small single spacer makes the present invention a more versatile, easier to install and less~expensive device to produce than any hitherto known spacer~.
~ nother advantage as~ociated with.the use of a tubular spacer, as opposed to a solid one, is the fact that a relatively small amount of the spacer material is visible on the finished concrete surface when the form is removed.
Solid dobies present a substantiaI solid area of material on the surface of the concrete. The dobies do not always adhere well to the poured concrete, resulting in cracks or holes that can interrupt the flow o water and in which ice can form, leading to erosion of the dobies and/or the fin-ished surface and the formation o holes. In contrast, the relatively small amount of visible spacer material presented by a tubular spacer, combined with the act that the inter-ior of -the spacer is completely filled with the poured con-crete, substantially reduces the likelihood that interrup-tions to the flow of water will be formedO
In order ~o facilitate a greater appreciation of the present .invention and the manner in which i-t achieves the previously noted advantages, preferred embodiments thereof are described hereinater in greater detail with reference to the accompanying illustrations.
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BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is a perspective view of a reinforce,ment rod spacer, or chair, constructed in-àccordance with th'e present invention;: ~
Figure 2 is a front elevation view of the reinforcement rod spacer of Figure 1, Figure 3 is a side elevation view of the spacer o Figure l;
~~~ , Figure 4 is a perspective view of a $econd embodiment of a reinforcement rod spacer according'to the present invention, Figure 5 is a front elevation view of the spacer of Figure 4;
Figure 6 is a side elevation view of the spacer of Figure 4; .
Figure 7 is a perspective view of a third embodiment of a spacer implementing the present invention;
Figure 8 is a front elevation view of the spacer of Figure 7;
Figure 9 is a side elevation view of -the spacer of Figure 7, Figure 10 is a perspective view of a fourth embodiment oE a spacer implementing the present invention, Figure 11 is a front elevation view of the spacer of Figure 10: and Figure 12 is a side elevation view o the spacer of Figure 10.
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DETAIL,ED DESC~IPTION OF THE PREFERRED ~MBODIMENTS
Referring to Figures 1, 2 and 3, a spacer or chair is formed from a frusto-conical tubular body 10 having a pair of diametrically opposed shallow troughs 12 and a pair of dialnetrically opposed deeper troughs 14, circumferentially displaced 90 relative to the troughs 12, at one end 13 of the body 10. On the opposite end of the body 10 there are formed four additional troughs 16 and 18 that are aligned with the,trouyhs 12 and 14, respectively. The depth of the troughs 18 is slightly greater than that of the troughs 14 and the depth of the troughs 16 is greater than that of the troughs 18. As shown in Figure 1, the diameter of the troughs is preEerably approximately the same as that of the largest sized rod 15 that is expected to be positioned therein. The shallowest troughs 12 have a depth that is approximately the same as the radius of the largest rod, and therefore these trcughs have the shape of a semicircle, as best seen in Figure 2. The deeper troughs 14-18 have sub-stantially parallel side walls in addition to the se~icir-cular bottom. In the context of the present invention, the term "U-shaped" is intended to refer to the shallower troughs 12 having the semicirc~lar shape as well as the deeper troughs having the substantially parallel side walls. The lower end 17 of the body 10 rests on a planar b~se support 19 such as the deck for a concrete slab.
The four pairs of troughs 12, 14, 16 and 18, each having a di~ferent depth, enable a single spacer to provide four different clearance distances between the surface deck "
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form 19 and the underside of the rod 15. In other words, the clearance distance can be easily varied with the same spacer by simply rotating it 90 to position the roct in the other pair of trouyhs in the same end, or turning it so that its other end re~ts on the form and the rod is disposed in a pair of troughs of different depth on the opposite end.
Apertures 20 and 22 are formed intermediate the troughs disposed on ends 13 and 17 of the body. The aper-tures can be circular, as shown, oval, or some other shape, depending on space, size and strength requirements. The location of the apertures 20 and 22 are such that`a maximum dis-tance is prov.ided between each of the apertures and each of the -troughs. The alignment of the troughs on one end 13 with respect to those formed in the other end 17, and the further alignment o the apertures 20 and 22 with the troughs, provides for continuous sections 21 of body material in the longitudinal direction from one end 13 to the other end 17. These sections are joined by continuous circumfer-ential strips 23 of body material intermediate the aperturesand the troughs. The resultant structure exhibits consid-erable stren~th against compression forces applied axially with respect to the body, such as when workers walk upon a array of reinforcing rods positioned by the spacers. If ~esired, reinEorcing ribs (no~ shown) can be provided on the body along ~he continuous longitudinal strips for added strength.
The embocliment of the Qpacer illustrated in Figures 1-3 is primarily intended for use with horizontal concrete forms, wherein the base of the spacer rests upon the form surface. A second embodiment of a spacer, illus-trated in Figures 4-6,~is designed for use in spacing rein-forcing rods from vertical form sùrfaces. The spacer includes a tubular ~rusto-conical ~ody 30 having a wide end 42 without trough~; or notches~. The narrow end 35 has -two pairs of diametrially opposed`troughs 36 and 32 disposed 90 relative to one another. The deeper troughs 32 are open towards the narrow end 35 by mean~ of a pair of diverging spaced apart sides 34 whose intersection with the troughs 32 form necks which are narrower than the bottom diameter of troughs. The body material 30 is selected to be resilient so that when a reinforcing rod of substantially the same diameter as the dia~eter of the troughs 32 is pressed into the opening formed by the diverging sides 34, it can be pushed through the narrow neck into troughs 32 and be retained therein. This feature frees the hands of the worker to tie the rod to the spacer. The lower troughs 32 are preferably deeper than the upper troughs 36 by at least the diameter of a reinforcing rod, so that when a rod 37 is in place in the lower troughs, a second perpendicularly disposed rod 39 may be supported by the upper troughs 36 above the rod 37. Thus, during assembly, when the vertical rod 37 is snapped into place in the troughs 32 of the spacer, the spacer is vertically stabilized. Thereafter, -t~e horizon~al rod 39 is secured ~o the spacer, for example by tying, to provide lateral stability as well.
Pairs of opposed apertures 38 and 40 are formed around the body 30 intermecliate the troughs 32 and 36, re~pectively, and the wide end 42. The apertures are 16~
located below corresponding troughs so that continuous strips 43 of body material are formed in a longitudinal direction between the narrow end 35 and the wide end 42~ The strips thus formed are joined by continuous circumferential strips 45 of material defined by the area between the troughs 32,36 and the apertures 38, 40. The apertures are formed in order to permit entry of a fluid concrete mix into the interior of the spacer when the reinforcing rods are in place and the spacer is resting on or against a flat form.
The positioning of the apertures 38 and 40 and the troughs 32 and 36 is such as to provide a maximum resistance to buckling under compressive loads.
A third embodiment of the spacer is shown in Figures 7, 8 and 9. In this embodiment, two pairs of opposed troughs, similar to those in the narrow end 35 of the embodiment of Figures 4 - 6, are formed in both ends of the body 50. In the narrow end 52 there is formed a shallow set of diametrically opposed troughs 54 and a deeper set 56 opening to end 52 by means of the diverging spaced apart sides 58. At the wide end 59 are disposed shallow troughs 60 oriented to be in line with the deep troughs 56 of the narrow end, and deep troughs 62 which open by means of diverging sides 64 to the wide end 59 and are aligned with the shallow troughs 54 on the narrow end. This structure can be utilized in the same manner as that illustrated in Figure 1, with either -the wide end 59 resting on or against a flat form and the rods engaged on the opposite end 52 or vice versa.
~L~86i62 A ourth embodiment oE the device, illustrated in Figures 10-12, is adapted to be positioned on a horizontal deck and to support the reinforcing rod at relatively small distances away from the deck. The spacer, made up of a frusto-conical tubular structure 70 haviny a narrow end 72 and a wide end 74, includes relatively shallow troughs 76 and 78 formed in the narrow end, and deeper troughs 80 and 82 formed in the wide end. The positioning of the troughs on one end relative to ~hose on the other i9 such as to provide a continuous strip 7~ of body material between the bottom of each trough and the opposite end of the spacer.
Specifically, the troughs 80 and 82 on the bottom end are displaced 45 relative to the troughs 76 and 78 on the upper end. ~ecause of the small height of this spacer, it may be desirable to incorporate additional material for stiffening the structure so as to provide adequate strength against the application of compressional forces exerted axially of the body 70 by larger rods. For example, the material at the wide end 74 located proximate the deep troughs can be thicker than the material at the narrow end 72. The thickening of material in this way helps to prevent buckling of the long legs formed by the deep troughs at the wide end 74.
Since this embodiment-of the spacer is designed for small clearance distances, it may not be tall enough to accomodate four different depths of troughs and still pro-vide sufficient s~ructural strength. For example, the two upper pairs of troughs may be designed for spacing distances of 3/4 inch and one inch, respectively. In such a c~se, the ~ ~186~62 spacer would not be reversible, and the lower -troughs 80 and 82 are primarily intended to admit concrete into the inter-,. . .
ior of the spacer.
The present invention may be embodied in o-ther speciic forms withoùt departing from the spirit or essen-tial characteristics thereof. T~e presently disclosed embodiments are therefore considered in all respects as illustrative and not restrictive. The scope o the inven-tion is indicated by the appended claims rather than the Eoregoing description, and all changes which come within the meaning and range of equivalency of the claims are thereore intended to be embraced therein.
BACKGROUND OF THE INVENTION
~ . _. . ~ .
The pre~ent invention relates to a spacer, commonly referred t~ as a chair, for positioning reinforcing rod at predetermined distances from the surfaces of molding forms Eor concrete.
Conventional spacers used in positioning reinforcing rods a pre~electad distance above a base, or adjacent a vertical wall, have been formed of concrete into structures known as dobies. Dobies for use on~vertical surfaces -typically have a wire embedded in the concrete with its two ends projecting out on either side of the dobie. A
reinforcing rod is placed on one end surface of the dobie and the two ends of the wire are wrapped around the rod to tie the rod ~o ~he end surface.
Because Qf the nature of its design, each concrete dobie is capable of providing only one spacing distance between a reinforcing rod and the concrete form. A typical project where reinforcing rods are used might require a number of different spacings to be provided. Consequently, a variety of different sizes of dobies must be kept on hand at the projèrt site. For small spacing requirements concrete dobies may weigh only a few ounces, but for larger spacings they may weigh several pounds. The bulk and weight of larger dobies maXe it difficult for an installer to carry several dobie~ with him during installation. For example, a typical 100 pound bag of 4" dobies may contain a relatively small number of spacers, because of each dobie' 5 bul~ and weight. Consequently, relatively large numbers of bags are ,i-"c~, .
~186162 needed Eor any given project and~large numbers of bags C05t money -to moveO Bags of dobias are moved with manpower or, -in -the case where quantities o bags are required, by cranepower. On jobs where hundreds r thousands, and millions of dobies are required. the transporting/handling problems for all ~izes of concrete dobie are extremely significant and add to the real, or end cost of the dobies, Furthermore, dobies must be individually handled once any package in which they are contained is broken.
_~ The difficulty in using concrete dobies is mul-tiplied when installations are in such an area as along the vertical face of a dam site. In such installations, it is necessary or the installer to hold the concrete dobie in place wi.th one hand and attempt to tie the reinforcing rod to i-t with the other hand. This procedure is cumbersome and time consuming. Moreover, because of the weight of the dobie and the fact that it is fastened to the rod at only one end, the dobie tends to droop at its unattached end, resulting in variations from one dobie to another in spacin~
from -the form, depending upon the amount of the droop.
Where ~he project site is in a remote and/or inac-cessible area, the real cost o the dobies i5 compounded by the added requirement of fabricating the dobies at t~e site.
The extra manpower, transportation, and crane-time costs required on such projects, because of the nature of concrete dobies, add again to the end costs o the dobies. Despite this, and the existence of several alternative forms of spacer made of material other than concrete, the concrete spacer still is the one most commonly used, because of other 16~
disadvantayss inherent in the alternative forms o spacer.
One prior art attempt at providing an alternative . :
form of spacer is disolosed in French Patent No. 1,420,975 issued to Ingeborg Schwachula K.G. ~The disclosed spacer is a tubular or conlcal structure~hav:ing a number of pairs of troughs formed in each end thereof, with each pair being of a diferent depth than each of the other pairs. The struc-ture further includes narrow eyelets below each set of troughs and a pair of oblique eyelets, one on each side of a deep trough and opening into the trough, to permit passage therethrough of a special tie band that is wrapped around a reinforcing rod when in place in an associated pair o troughs. The procedure suggested to attach the tie band is to firs-t insert it through the appropriate eyelet up to a head at one of its ends, place the rod in the desired troughs, wrap the tie band around the reinforcing rod, and hook the tie band in one of the oblique eyelets.
While the spacer disclosed in the French patent embodies certain concepts that theoretically overcome some oE the previously mentioned difficulties associated with concrete dobies, it also possesses a number of drawbacks that provide impediments to its use in a practical applica-tion. For example, it is unlikely that an ironworker on an actual job site would use the tie band associated with the spacer because of the timè and dexterity required to mani-pulate the tie band through the eyelet, around the placed reinforcing rod, and through the second eyelet.
, , . ~
86~62 An objective set forth in the French patent is to provide as many troughs of diferent depths as possible on a single spacer body. Ih addition, it states that -the prefer-red design for the troughs i~ a V-shapeO Consequently, relatively long and narrow V-shaped legs of body material are formed between adjacent troughs, connecting the upper and lower portions of the spacer. The relative Fragility of these narrow, angled legs constitutes a sec~nd impractical-ity of the spacer disclosed in the French patent. It is quite common for workers to walk on the mesh of reinforcing rods prior to the time the concrete is poured. Conse-quently, a substantial axial or longitudinal force is exer-ted on the spacers. It does not appear that the relatively small amount of material provided between the bottom of a trough and the surface of a concrete form, coupled with the angular disposition of this material relative to the axial or longitudinal direction, would provide sufficient resis-tance to such forces. Hence, the spacer would be subject to buckling under pressure, or similar such failure.
In accordance with the previously noted objective of providing as many different troughs as possible i~ one spacer, the French patent discloses six individual troughs of varying depths at one end oOthe spacer, so as to theo-re-tically provide for several variations of concrete slab depth. In reality, this will only b practically possible where small diameter reinforcing rods are used. Larger diameter rods would require wide troughs. Increasing the trough 5ize, while retaining several variations of trough dep-th, would result in a spacer having a very large top .
diameter. To balance this, the overall size of the spacer would have to be increased. The resulting spacar that can be used with large-diameter rods and provide for variations of slab depth would be ~nreasonably large and cumbersome to use.
Xn addition, the use of the preferred V-shaped troughs presents a structural defect when large diameter rods are used. If the radius of curvature of the bottom of the trough is less than that of the rod, the rod will not rest in the bo~tom of the trough but will rest against the converging side walls of the trough. When force is applied to the rod, for example the weight of the worker, the rod will exert pressure on the side walls having a component o force in the circumEerential direction of the spacer. If sufficient, this force can cause the spacer to crack or split at the apex of the trough.
SUMMARY OF THE INVENTION
--In accordance with the present inventionl a spacer for positioning reinforcing rods used in molding forms for concrete includes a substantially frusto-conical body having two pairs of diametrically opposed troughs on at least one end thereo for receiving reinforcing rods and retaining them in place. The deep troughs are preferably U-shaped~
and the radius of curvature, or width, of each -trough is equal to that of the largest diameter rod that is expected to be positioned by the spacer. Advantageously, each pair of opposed troughs is a different preselected depth below 6~
the end of the body in which they are located so as to engage a rod at a predetermined distanca from the other end of the spacer. In one embodiment of the invention, the troughs are located relative to one another so as to provide a substantially continuous strip of body material extending along the length of the body mem~er between adjacent troughs. The continuous strip of bocly material provides a spacer configuration which exhibits a high degree of strength against axially directed compressive forces.
Preferably, the body material is resilient. For spacers intended to be used on vertical faces, the troughs oE at least one o the pairs of troughs on each end of the body may have a neck located away from the bottom of the trough a distance such that the neck resists entry and removal of a rod of substantially the same diameter as that of the trough and retains the rod in place in the trough.
The use of the narrow neck on a ~air of the troughs allows the rod to be snapped into those troughs and held in posi-tion by -the tightness of the fit of the trough to the rod until a wire can be wrapped around the rod. The narrow nech thus allows the installer to snap on the spacer with one hand and then free that hand and use both hands to tie the rod to the spacer, as would he done when the spacers are installed along a vertical face ~f à retaining wall or dam site form.
The spacer may further include a circular or oval aperture in ~he body intermediate the troughs for permitting entry into the interior of the body of a fluid concrete mix.
Preferably, four troughs are located on each end lP~
so that a first imaginary line.bisecting a pair of troughs on one end of the body is di~placed 90 about the body axis from a second imaginar~ line bisecking the other palr of troughs on the same end.- This con~iguration may allow one end of the spacer to position two rod~ at right angles when one pair of troughs is recessed a depth suficiently greater than that of the other pair.
For spacers designed to position ~ods short dis-tances away from a deck and having two pairs of troughs on each Qnd with each pair on a given end being displaced 90 relative to the other pair on that end, the troughs on one end rnay be displaced about the axis of the body relative to -those on the opposite end so as to provide a conti.nuous strip of body material from the bottom of each trough to the end opposite that trough. Moreover, each such strip may be thickened in order to enhance its strength. The width and thickness of ~he strip so formed may be such as to allow the spacer to support heavy, large diameter rods without buckling.
The location of the troughs relative to one another and to any apertur~s which may be incorporated into the structure is also preferably such as to ensure that there is a continuous strip of material disposed in the circumferential direction of the body between the troughs and the apertures so as to provide considerable strength in concer-t with the longitudianl strips of material.
The frusto-conical shape of the spacers allows efficient stacking of a plurality of spacers and enables the ins-taller -to carry with him a considerable number of spacers during installation. Optimally the spacer can be made of a relatively light plastic material which further facilitates efficient transportation, packaging and installation of the spacers.
As used in the context of the present invention, the term "frusto-conicall', as applied to the tubular body, is synonymous with a hollow frustum, i.e., a tapered tube with open ends to permit mutual stacking, and includes not only a body having a circular cross section, but other forms of hollow tapered bodies as well. For example, the body can have four or more straight sides, i.e., be a truncated pyramid, concave or convex sides, or an elliptical or oval cross section. For those body forms having sides that intersect at corners, the corners are preferably rounded or mitred so that the poured concrete can easily fill the entire interior of the form, rather than leave spaces in the corners that can lead to subsequent erosion.
The use of troughs of different depths on both ends of a spacer provides for a greater variety of possible spacings from a concrete form to be achieved with a single spacer.
For example, spacers that are designed to be used on horizontally disposed forms, commonly known as deck chairs, can each provide four different sizes of clearance between the surface of the form and the underside of a reinforcing rod. This enables one spacer to accommodate varying concrete slab depths, rather than requiring a different spacer for each size. The additional troughs that are not used also provide apertures through which fluid concrete mix can enter the interior of the spacer. The provision in the spacer of continuous strips of body material in the longitudinal and circumferential directions _g_ .
~ L6~
t ` ` '~
for streng~h, a frusto-conical~shaped body for permitting efficien-t stacking of several spacers, and pairs of troughs .
Eor both ends for enabling several different possible spacings to be achieved with a relatively small single spacer makes the present invention a more versatile, easier to install and less~expensive device to produce than any hitherto known spacer~.
~ nother advantage as~ociated with.the use of a tubular spacer, as opposed to a solid one, is the fact that a relatively small amount of the spacer material is visible on the finished concrete surface when the form is removed.
Solid dobies present a substantiaI solid area of material on the surface of the concrete. The dobies do not always adhere well to the poured concrete, resulting in cracks or holes that can interrupt the flow o water and in which ice can form, leading to erosion of the dobies and/or the fin-ished surface and the formation o holes. In contrast, the relatively small amount of visible spacer material presented by a tubular spacer, combined with the act that the inter-ior of -the spacer is completely filled with the poured con-crete, substantially reduces the likelihood that interrup-tions to the flow of water will be formedO
In order ~o facilitate a greater appreciation of the present .invention and the manner in which i-t achieves the previously noted advantages, preferred embodiments thereof are described hereinater in greater detail with reference to the accompanying illustrations.
, I , ~8616;~:
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is a perspective view of a reinforce,ment rod spacer, or chair, constructed in-àccordance with th'e present invention;: ~
Figure 2 is a front elevation view of the reinforcement rod spacer of Figure 1, Figure 3 is a side elevation view of the spacer o Figure l;
~~~ , Figure 4 is a perspective view of a $econd embodiment of a reinforcement rod spacer according'to the present invention, Figure 5 is a front elevation view of the spacer of Figure 4;
Figure 6 is a side elevation view of the spacer of Figure 4; .
Figure 7 is a perspective view of a third embodiment of a spacer implementing the present invention;
Figure 8 is a front elevation view of the spacer of Figure 7;
Figure 9 is a side elevation view of -the spacer of Figure 7, Figure 10 is a perspective view of a fourth embodiment oE a spacer implementing the present invention, Figure 11 is a front elevation view of the spacer of Figure 10: and Figure 12 is a side elevation view o the spacer of Figure 10.
.
DETAIL,ED DESC~IPTION OF THE PREFERRED ~MBODIMENTS
Referring to Figures 1, 2 and 3, a spacer or chair is formed from a frusto-conical tubular body 10 having a pair of diametrically opposed shallow troughs 12 and a pair of dialnetrically opposed deeper troughs 14, circumferentially displaced 90 relative to the troughs 12, at one end 13 of the body 10. On the opposite end of the body 10 there are formed four additional troughs 16 and 18 that are aligned with the,trouyhs 12 and 14, respectively. The depth of the troughs 18 is slightly greater than that of the troughs 14 and the depth of the troughs 16 is greater than that of the troughs 18. As shown in Figure 1, the diameter of the troughs is preEerably approximately the same as that of the largest sized rod 15 that is expected to be positioned therein. The shallowest troughs 12 have a depth that is approximately the same as the radius of the largest rod, and therefore these trcughs have the shape of a semicircle, as best seen in Figure 2. The deeper troughs 14-18 have sub-stantially parallel side walls in addition to the se~icir-cular bottom. In the context of the present invention, the term "U-shaped" is intended to refer to the shallower troughs 12 having the semicirc~lar shape as well as the deeper troughs having the substantially parallel side walls. The lower end 17 of the body 10 rests on a planar b~se support 19 such as the deck for a concrete slab.
The four pairs of troughs 12, 14, 16 and 18, each having a di~ferent depth, enable a single spacer to provide four different clearance distances between the surface deck "
\~, .
6~Z
form 19 and the underside of the rod 15. In other words, the clearance distance can be easily varied with the same spacer by simply rotating it 90 to position the roct in the other pair of trouyhs in the same end, or turning it so that its other end re~ts on the form and the rod is disposed in a pair of troughs of different depth on the opposite end.
Apertures 20 and 22 are formed intermediate the troughs disposed on ends 13 and 17 of the body. The aper-tures can be circular, as shown, oval, or some other shape, depending on space, size and strength requirements. The location of the apertures 20 and 22 are such that`a maximum dis-tance is prov.ided between each of the apertures and each of the -troughs. The alignment of the troughs on one end 13 with respect to those formed in the other end 17, and the further alignment o the apertures 20 and 22 with the troughs, provides for continuous sections 21 of body material in the longitudinal direction from one end 13 to the other end 17. These sections are joined by continuous circumfer-ential strips 23 of body material intermediate the aperturesand the troughs. The resultant structure exhibits consid-erable stren~th against compression forces applied axially with respect to the body, such as when workers walk upon a array of reinforcing rods positioned by the spacers. If ~esired, reinEorcing ribs (no~ shown) can be provided on the body along ~he continuous longitudinal strips for added strength.
The embocliment of the Qpacer illustrated in Figures 1-3 is primarily intended for use with horizontal concrete forms, wherein the base of the spacer rests upon the form surface. A second embodiment of a spacer, illus-trated in Figures 4-6,~is designed for use in spacing rein-forcing rods from vertical form sùrfaces. The spacer includes a tubular ~rusto-conical ~ody 30 having a wide end 42 without trough~; or notches~. The narrow end 35 has -two pairs of diametrially opposed`troughs 36 and 32 disposed 90 relative to one another. The deeper troughs 32 are open towards the narrow end 35 by mean~ of a pair of diverging spaced apart sides 34 whose intersection with the troughs 32 form necks which are narrower than the bottom diameter of troughs. The body material 30 is selected to be resilient so that when a reinforcing rod of substantially the same diameter as the dia~eter of the troughs 32 is pressed into the opening formed by the diverging sides 34, it can be pushed through the narrow neck into troughs 32 and be retained therein. This feature frees the hands of the worker to tie the rod to the spacer. The lower troughs 32 are preferably deeper than the upper troughs 36 by at least the diameter of a reinforcing rod, so that when a rod 37 is in place in the lower troughs, a second perpendicularly disposed rod 39 may be supported by the upper troughs 36 above the rod 37. Thus, during assembly, when the vertical rod 37 is snapped into place in the troughs 32 of the spacer, the spacer is vertically stabilized. Thereafter, -t~e horizon~al rod 39 is secured ~o the spacer, for example by tying, to provide lateral stability as well.
Pairs of opposed apertures 38 and 40 are formed around the body 30 intermecliate the troughs 32 and 36, re~pectively, and the wide end 42. The apertures are 16~
located below corresponding troughs so that continuous strips 43 of body material are formed in a longitudinal direction between the narrow end 35 and the wide end 42~ The strips thus formed are joined by continuous circumferential strips 45 of material defined by the area between the troughs 32,36 and the apertures 38, 40. The apertures are formed in order to permit entry of a fluid concrete mix into the interior of the spacer when the reinforcing rods are in place and the spacer is resting on or against a flat form.
The positioning of the apertures 38 and 40 and the troughs 32 and 36 is such as to provide a maximum resistance to buckling under compressive loads.
A third embodiment of the spacer is shown in Figures 7, 8 and 9. In this embodiment, two pairs of opposed troughs, similar to those in the narrow end 35 of the embodiment of Figures 4 - 6, are formed in both ends of the body 50. In the narrow end 52 there is formed a shallow set of diametrically opposed troughs 54 and a deeper set 56 opening to end 52 by means of the diverging spaced apart sides 58. At the wide end 59 are disposed shallow troughs 60 oriented to be in line with the deep troughs 56 of the narrow end, and deep troughs 62 which open by means of diverging sides 64 to the wide end 59 and are aligned with the shallow troughs 54 on the narrow end. This structure can be utilized in the same manner as that illustrated in Figure 1, with either -the wide end 59 resting on or against a flat form and the rods engaged on the opposite end 52 or vice versa.
~L~86i62 A ourth embodiment oE the device, illustrated in Figures 10-12, is adapted to be positioned on a horizontal deck and to support the reinforcing rod at relatively small distances away from the deck. The spacer, made up of a frusto-conical tubular structure 70 haviny a narrow end 72 and a wide end 74, includes relatively shallow troughs 76 and 78 formed in the narrow end, and deeper troughs 80 and 82 formed in the wide end. The positioning of the troughs on one end relative to ~hose on the other i9 such as to provide a continuous strip 7~ of body material between the bottom of each trough and the opposite end of the spacer.
Specifically, the troughs 80 and 82 on the bottom end are displaced 45 relative to the troughs 76 and 78 on the upper end. ~ecause of the small height of this spacer, it may be desirable to incorporate additional material for stiffening the structure so as to provide adequate strength against the application of compressional forces exerted axially of the body 70 by larger rods. For example, the material at the wide end 74 located proximate the deep troughs can be thicker than the material at the narrow end 72. The thickening of material in this way helps to prevent buckling of the long legs formed by the deep troughs at the wide end 74.
Since this embodiment-of the spacer is designed for small clearance distances, it may not be tall enough to accomodate four different depths of troughs and still pro-vide sufficient s~ructural strength. For example, the two upper pairs of troughs may be designed for spacing distances of 3/4 inch and one inch, respectively. In such a c~se, the ~ ~186~62 spacer would not be reversible, and the lower -troughs 80 and 82 are primarily intended to admit concrete into the inter-,. . .
ior of the spacer.
The present invention may be embodied in o-ther speciic forms withoùt departing from the spirit or essen-tial characteristics thereof. T~e presently disclosed embodiments are therefore considered in all respects as illustrative and not restrictive. The scope o the inven-tion is indicated by the appended claims rather than the Eoregoing description, and all changes which come within the meaning and range of equivalency of the claims are thereore intended to be embraced therein.
Claims (22)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A concrete reinforcing rod chair for position-ing rods at different selectable spacings from the surface of a concrete molding form, comprising:
a tapered tubular body member having spaced apart ends;
a first pair of diametrically opposed troughs on one end of said body member having a first predetermined depth;
a second pair of diametrically opposed troughs on said one end of said body member, said second pair of troughs having a second predetermined depth which differs from the first predetermined depth, the second pair of troughs being circumferentially spaced 90°
around said body member from said first pair of troughs, such that a section of body member material disposed between adjacent troughs extends continuously from said one end to the other end of the body member along a longitudinal line on the surface of the said body.
a tapered tubular body member having spaced apart ends;
a first pair of diametrically opposed troughs on one end of said body member having a first predetermined depth;
a second pair of diametrically opposed troughs on said one end of said body member, said second pair of troughs having a second predetermined depth which differs from the first predetermined depth, the second pair of troughs being circumferentially spaced 90°
around said body member from said first pair of troughs, such that a section of body member material disposed between adjacent troughs extends continuously from said one end to the other end of the body member along a longitudinal line on the surface of the said body.
2. The reinforcing rod chair of Claim 1 further including a third pair of diametrically opposed troughs on said other end of said body member having a third predetermined depth, and a fourth pair of diametrically opposed troughs on said other end of said body member having a fourth predetermined depth, said third and fourth pairs of troughs being longitudinally aligned with said first and second pairs of troughs, respectively, to thereby provide said continuous sections of body member material.
3. The reinforcing rod chair of Claim 2 further including an aperture disposed in said body member between at least one of the troughs in said one end and the aligned trough in said other end.
4. The reinforcing rod chair of Claim 2 wherein said second predetermined depth is greater than said first predetermined depth, and said third predetermined depth is greater than said fourth predetermined depth.
5. The reinforcing rod chair of Claim 4 wherein said fourth predetermined depth is greater than said second predetermined depth.
6. The reinforcing rod chair of Claim 1 wherein one said pair of troughs is substantially U-shaped.
7. The reinforcing rod chair of Claim 2 wherein one pair of troughs on each end of said body member is substantially U-shaped.
8. The reinforcing rod chair of Claim 1 or 2 wherein all of said pairs of troughs are substantially U-shaped.
9. The reinforcing rod chair of Claim 1 wherein the side walls of at least one of said pairs of troughs define neck portions with openings that are smaller than the diameter of the openings at the bottom of the troughs to thereby resiliently hold a reinforcing rod in said troughs.
10. The reinforcing rod chair of Claim 9 wherein the side walls of said at least one pair of troughs diverge towards the end of the body to form said neck portion.
11. The reinforcing rod chair of Claim 1 wherein said second predetermined depth is greater than said first predetermined depth by at least the diameter of a reinforcing rod to be positioned by the chair, to thereby enable the chair to position two intersecting rods.
12. A concrete reinforcing rod chair for position-ing reinforcing rods at different selectable spacings from the surface of a concrete moulding form, comprising:
a tapered tubular body member having spaced apart ends;
a first pair of diametrically opposed troughs on one end of said body member having a first predetermined depth;
a second pair of diametrically opposed troughs on said one end of said body member having a second predetermined depth, said second pair of troughs being circumferentially spaced 90° around said body member from said first pair of troughs;
a third pair of diametrically opposed troughs on the other end of said body member;
a fourth pair of diametrically opposed troughs on said other end of said body member, said fourth pair of troughs being circumferentially spaced 90° around said body member from said third pair of troughs;
said third and fourth pairs of troughs being circumferentially spaced about the surface of said body member relative to said first and second pairs of troughs by an amount sufficient to provide a continuous strip of body material extending from at least the bottom of each trough to the opposite end of said body member.
a tapered tubular body member having spaced apart ends;
a first pair of diametrically opposed troughs on one end of said body member having a first predetermined depth;
a second pair of diametrically opposed troughs on said one end of said body member having a second predetermined depth, said second pair of troughs being circumferentially spaced 90° around said body member from said first pair of troughs;
a third pair of diametrically opposed troughs on the other end of said body member;
a fourth pair of diametrically opposed troughs on said other end of said body member, said fourth pair of troughs being circumferentially spaced 90° around said body member from said third pair of troughs;
said third and fourth pairs of troughs being circumferentially spaced about the surface of said body member relative to said first and second pairs of troughs by an amount sufficient to provide a continuous strip of body material extending from at least the bottom of each trough to the opposite end of said body member.
13. The reinforcing rod chair of Claim 12 wherein said body member is thicker at said other end than at said one end.
14. The reinforcing rod chair of Claim 12 wherein said third and fourth troughs are displaced 45° relative to said first and second troughs.
15. The reinforcing rod chair of Claim 12 wherein at least one of said pairs of troughs is substantially U-shaped.
16. The reinforcing rod chair of Claim 12 wherein all of said troughs are substantially U-shaped.
17. A chair for spacing reinforcing rods from the surface of a concrete form, comprising a tubular body member formed as a tapered shell, each end of said shell having formed therein a pair of diametrically opposed troughs, each trough having an arcuate bottom with a substantially identical radius of curvature, with the length of the side walls of one pair of said troughs at one end of said shell being greater than length of the side walls of the troughs in the other end, said pairs of troughs being positioned on said tubular body member relative to each other so that a continuous strip of body material extends in the longitudinal direction between the two ends of said body member.
18. A chair for spacing reinforcing rods from the surface of a concrete form, comprising a tubular body member formed as a tapered shell, one end of said shell having formed therein two pairs of diametrically opposed U-shaped troughs, each trough having an arcuate bottom with a substantially identical radius of curvature, with the length of the side walls of one pair of said troughs being greater than the length of the sidewalls of the other pair of troughs, and at least one pair of troughs on the other end of said body member, said troughs being positioned on said tubular body member relative to each other so that a continuous strip of body material extends in the longitudinal direction from the bottom of each trough to the opposite end of the body member.
19. The chair of Claim 17 or 18 wherein said troughs are also disposed on said body member so that a continuous strip of body material is provided in the circumferential direction around the body member intermediate the two ends thereof.
20. A chair for spacing reinforcing rods from the surface of a concrete form, comprising a tapered tubular body member, a first pair of diametrically opposed troughs having a first depth in one end of said body member, a second pair of diametrically opposed troughs having a second depth in said one end of said body member disposed at 90° relative to said first pair of troughs, the second depth differing from the first depth, and at least one pair of troughs at the other end of said body member, said troughs being disposed on said body member so that a continuous strip of body material is provided in the circumferential direction around the body member intermediate the two ends thereof.
21. The spacing chair of Claim 20 further including apertures disposed around the circumference of said body member intermediate the two ends thereof such that at least two continuous circumferential strips of body material are provided on said body member.
22. A chair for spacing reinforcing rods from the surface of a concrete form, comprising a tapered tubular body member, a first pair of diametrically opposed troughs having a first depth in one end of said body member, a second pair of diametrically opposed troughs having a second depth in said one end of said body member disposed at 90° relative to said first pair of troughs, and apertures disposed around the circumference of said body member intermediate the two ends thereof, said throughs and apertures being arranged such that at least one continuous strip of body material is provided in the circumferential direction around the body member intermediate the two ends thereof.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000393143A CA1186162A (en) | 1981-12-23 | 1981-12-23 | Concrete reinforcing rod chair |
| EP82307052A EP0082737B1 (en) | 1981-12-23 | 1982-12-22 | Concrete reinforcing rod chair |
| AT82307052T ATE25729T1 (en) | 1981-12-23 | 1982-12-22 | SPACERS FOR CONCRETE REINFORCEMENT. |
| DE8282307052T DE3275571D1 (en) | 1981-12-23 | 1982-12-22 | Concrete reinforcing rod chair |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000393143A CA1186162A (en) | 1981-12-23 | 1981-12-23 | Concrete reinforcing rod chair |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1186162A true CA1186162A (en) | 1985-04-30 |
Family
ID=4121700
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000393143A Expired CA1186162A (en) | 1981-12-23 | 1981-12-23 | Concrete reinforcing rod chair |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0082737B1 (en) |
| AT (1) | ATE25729T1 (en) |
| CA (1) | CA1186162A (en) |
| DE (1) | DE3275571D1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USD421709S (en) | 1998-10-02 | 2000-03-21 | Aztec Concrete Accessories, Inc. | Tower chair |
| US6089522A (en) * | 1998-10-02 | 2000-07-18 | Aztec Concrete Accessories, Inc. | Method and apparatus for supporting reinforcement members |
| USD428501S (en) | 1998-10-02 | 2000-07-18 | Aztec Concrete Accessories, Inc. | Chair |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU4257885A (en) * | 1984-05-25 | 1986-10-30 | Gie, Loa Tjhong | Plastics spacers for concrete reinforcement |
| GB8805547D0 (en) * | 1988-03-09 | 1988-04-07 | Crosby J S | Insert for concrete structures |
| DE29812111U1 (en) * | 1998-07-09 | 1999-11-18 | Adolf Würth GmbH & Co. KG, 74653 Künzelsau | Formwork stop |
| AU2012100930B4 (en) * | 2010-10-27 | 2013-09-26 | Luke Aiden Knight | Spacer for supporting a reinforcing bar |
| RU2458216C1 (en) * | 2011-02-28 | 2012-08-10 | Сергей Владимирович Руттер | Fixator of reinforcement rods to create protective concrete layer |
| IL292694B2 (en) * | 2022-05-02 | 2023-10-01 | Ber Ilan | Method and accessory for laying welded reinforcement nets |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1659233A1 (en) * | 1967-06-08 | 1971-01-07 | Ingeborg Schwachula Kg | Spacer for intersecting reinforcement bars and reinforcement mats in reinforced concrete |
| DE1913104A1 (en) * | 1968-03-15 | 1969-10-02 | Alplast Produkter | Tubular spacer |
| GB1276874A (en) * | 1969-07-01 | 1972-06-07 | Olav Dale | A method for the production of bar spacers for use in reinforced concrete structures |
| NL147503B (en) * | 1970-02-12 | 1975-10-15 | Attema Kunststoffenind | STACKABLE SPACER FOR REINFORCED CONCRETE. |
| FR2081758B3 (en) * | 1970-03-06 | 1973-12-28 | Keller August | |
| DE2052100A1 (en) * | 1970-10-23 | 1972-04-27 | Gebr. Seifert, 5880 Lüdenscheid | Spacer for reinforcement in concrete construction |
-
1981
- 1981-12-23 CA CA000393143A patent/CA1186162A/en not_active Expired
-
1982
- 1982-12-22 AT AT82307052T patent/ATE25729T1/en not_active IP Right Cessation
- 1982-12-22 EP EP82307052A patent/EP0082737B1/en not_active Expired
- 1982-12-22 DE DE8282307052T patent/DE3275571D1/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USD421709S (en) | 1998-10-02 | 2000-03-21 | Aztec Concrete Accessories, Inc. | Tower chair |
| US6089522A (en) * | 1998-10-02 | 2000-07-18 | Aztec Concrete Accessories, Inc. | Method and apparatus for supporting reinforcement members |
| USD428501S (en) | 1998-10-02 | 2000-07-18 | Aztec Concrete Accessories, Inc. | Chair |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3275571D1 (en) | 1987-04-09 |
| ATE25729T1 (en) | 1987-03-15 |
| EP0082737B1 (en) | 1987-03-04 |
| EP0082737A1 (en) | 1983-06-29 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |
