US3246583A - Joint rake - Google Patents

Description

April 19, 1966 A. c. SCHILLER JOINT BAKE Filed Oct. 15, 1962 i i .Ii

United States Patent O 3,246,583 JONT RAKE Albert C. Schiller, 829 Henry St., Collinsville, Ill. Filed Oct. 15, 1962, Ser. No. 23),e31 11 Ciairns. (Cl. 94-39) This invention relates to bituminous paving devices, and in particular to a mechanical joint rake for use on and in connection with a so-called asphalt spreader.

In resurfacing roads, `or laying a new road on la prepared bed, it is common practice to lay a so-called mat of asphalt, filler and rock, the Width of an asphalt spreader, to roll the mat, and because of the pressure of traffic, to -permit the mat to be used for -trafiic before a second, parallel mat is laid to complete the width of the road. When, later, the second mat is laid parallel with the first, the first mat has completely lcooled and set, the edge contiguous the second mat has been beaten down in spots by traffic, and the problem of producing a tight joint between the first and sec-ond mats, is one which has proved extremely troublesome heretofore.

In present practice, the spreader is run about three inches over the edge of the first mat. It can be appreciated, that if the freshly laid material is permitted to lie on top of the set first mat, when a three wheel compactor is run ralong the joint, the set mat, supporting the wheel of the compactor, will prevent effective compaction of the joint. Accordingly, in present practice, a laborer, with a rake, pushes the fresh material from the set mat to the edge of the new mat, i.e., to the very edge of the joint. It can be seen that this involves much manual labor, and that, unless the laborer is especially skillful and conscientious, it is extremely unlikely that a uniform distribution of material along the joint will be obtained or that the material will be positioned immediately contiguous the edge of the joint. As a result of the natural inconsistencies of the raker in the present practice, and in the very nature of the action of the rake, which is to lift and chill the hot fresh material, when the material is pushed by the rake, 1a joint is very frequently produced which carries in it the ingredients of its own destruction, because the material is frequently not properly compacted by the three wheeled roller (when not all of the material is moved beyond the upper edge of the set mat) and even more frequently, 4because the material `is aerated and chilled by the humping action of the rake, the material, even when properly compacted, does not bond properly to the set mat. This permits the ingress of water, and the peeling of the material along the joint, by the action of the vehicles passing over it.

These problems are met in the application of both the sfo-called binder coat, which is the base coat, and the surface coat.

One of the objects of this invention is to provide a mechanical joint rake for application to an asphalt spreader, which can lbe operated from the spreader itself, which eliminates the need for manual raking, which produces a uniform distribution of material immediately contiguous the edge of the joint, which does not aerate and chill the fresh material, and which facilitates the ow of traffic on the laid and set part of the road, thus contributing to the safety both of the crew laying the road, and of the vehicles using the set part of the road.

Another object is to provide a device which makes apparent an improper adjustment of the screed.

@ther objects will become apparent to those skilled in the `art in the light of the following description.

In accordance with this invention, generally stated, a mechanical joint rake is provided, attached to a spreader, which includes a scraper blade which rides along the surface of a set mat, scraping freshly laid material to the edge of the joint, a `strike-olf blade, adjustable vertically with respect to the scraper blade, which regulates the height of fresh laid material along the joint and feathers the scraped off material Ionto the new material, `and means for extending and retracting the two blades laterally of the spreader. The strike-off blade also serves to classify the fresh material, so as to leave `along the joint a higher percentage of fine material than is present in the fresh mix as it emerges from the spreader. In this, in one embodiment, the strike-olf blade is assisted by the scraper blade.

Preferably, both scraper and strike-off blades are resiliently biased, to permit their accommodation to irregularities in the surface, and to guard against breakage.

An important feature of the joint of rake of this invention, is the adjustability of the reach of the scraper blade (accompanied by they strike-off blade) transversely of the spreader, to accommodate variations in the posi tion of the edge of the joint, yas the spreader moves. In this connection, another important feature of the preferred embodiment of this invention is an arrangement of the supporting mechanism for the blade, which permits the maintenance of substantially the same angular relationship between the blade and the axis of the spreader, with variation in the t-ransverse reach of the blade.

These latter features are highly important, because the edge of the set mat is never absolutely square and straight, and the problem is complicated by the fact that in laying a second mat, the engineer on the spreader frequently is required to guide along a line defining the outer margin of the road, instead of along the edge of the set mat. Accordingly, in order to ensure that -a proper joint is made, the overlap of the joint is likely to vary from su=bstantial-ly zero to six or more inches, and a rake fixed with a three inch reach of the scraper blade with respect to the machine would accordingly either scrape off three inches of freshly laid material, leaving no material at all f-or compaction along the joint, when the overlap is nil, or it would leave three inches of overlap material on top of the set mat, when there is a six inch overlap, which would prevent any effective compaction along that part of the joint. With the joint rake `of this invention, the oiler, who controls the depth of the material being spread, can move the scraper blade transversely to keep the material at the very edge of the set mat. The arrangement by which the angular relation of the blade and the machine remains constant with a change in the transverse reach of the blade provides a substantially uniform distribution of material along the edge of the joint. It can be seen, that if the angularity changed markedly, there would be either a dip or a hump when the angularity was changed, and the effectiveness of the blades, las classifying means, yand even in the scraping and feathering functions, would be altered.

In the drawing, FIGURE 1 is a view -in perspective of a typical asphalt spreader to which one illustrative embodiment of joint rake of this invention is attached;

FIGURE 2 is a fragmentary sectional view taken along the line 2 2 of FIGURE 1;

FIGURE 3 is a fragmentary view in side elevation taken along the line 3 3 of FIGURE 2;

FIGURE 4 is a sectional View taken along the line 4 4 of FIGURE 2; and

FIGURE 5 is a sectional view taken along the line 5 5 of FIGURE 3.

Referring now to the drawing for one illustrative embodiment of the device of this invention, reference numeral 1l indicates an asphalt spreader of a well known commercial manufacture, with a side rail 2 and a walkway 3. A joint rake 10 of this invention is mounted on the spreader, by means of a side bracket 12 and a walk bracket 2t). The side bracket 12 consists `or" an angle 13 bolted 3 to the rail 2. A at plate 14, welded parallel with and in spaced relation to the outwardly projecting shelf of the angle 13, serves to provide, with the shelf, a knuckle, through aligned holes in which a hinge pin extends. The hinge pin 15 is slidably received in the holes in the side bracket knuckle, so as to permit its quick removal.

The walk bracket consists of a hinge leaf 21, secured to the walkway 3, with a pintle shaft 22 welded to it along its outer edge.

An open-sided box-like support 30 is hingedly mounted on the pintle shaft 22, by means of a knuckle 23. The support 30 is made -up of a top-plate 25, a bottom plate 26 and a heavy end-piece '27. The knuckle 23 is split, and is made up of an upper half 2S, welded to the underside of the top-plate along the edge opposite the end-piece 27, and a lower half 29, welded to the upper side of the bottom plate 26. Bolts 31, upon which nuts 32 are threaded, extend ybetween and through holes in the upper plate 25 and the lower plate Z6, and serve to h-old the upper and lower halves of the knuckle 23 in adjustable frictional engagement with the pintle shaft 22.

The end piece 27 serves the double function of spacer 'between upper and lower plates, and, on its inside surface, of a bearing surface for a transversely extending rack 35. The rack 35 has a smooth side 36, in slidingy contact with the inner surface of the end piece 31, teeth 37, on its opposite face, and ears 3S at each end. The ears 38 `serve as stops, and also as means for mounting a bladesupporting bracket 45.

In the embodiment shown, the joint rake is attached to the right side of the spreader, as viewed in FIGURE 1, and the blade bracket 45 is therefore mounted on the right ear 38, as viewed in FIGURE 2. A joint rake mounted on the left side of the machine will have its bracket 45 mounted on the left ear.

A pinion 50, on the lower end of an upwardly projecting stub shaft 51, is journaled between the upper and lower plates 25 and 26, in operative engagement with the teeth 37 of the rack 35. The upper end of the shaft 51, in the embodiment shown, is squared to fit a complementarily shaped socket 55 on the lower end of a shank 56. A handwheel 57 is secured to the upper end of the shank 56. The shank 56 and handwheel 57 are so proportioned and positioned as to make the manipulation of the handwheel, hence rotation of the pinion 50, easy for an operator on the walkway 3.

An arm 60 is pivoted at its inner end on the hinge pin 15, and at its outer end, on a post 65. The post 65 is mounted on and projects vertically from an upper face 75 of a scraper blade 70. The past 65 has a head or cap 66, above the arm 60. A heavy helical spring 67, positioned around the post 65 and between the arm 60 and the upper face 75 of the blade 70, biases the blade downwardly with respect to the arm 60. Near the inner end of the scraper blade 70, another post 71, mounted on and projecting upwardly from the upper face 75 of the blade 70 extends slidably through a hole in a horizontal leg 46 of the bracket 45. A helical spring 72 is positioned between yand bears against the upper face of the scraper blade 70 and the underside of the leg 46, biasing the scraper blade 70 downwardly with respect to the bracket 45. A head 73 on the post 71 serves as a stop.

The scraper blade 70, has, in addition to its flat upper face 75, a front face 76, backface 77, a relatively narrow bottom edge 7S, an arris 79 between the backface 77 and the bottom edge 78, as shown particularly in FIGURE 5, a vertical outboard edge 90 and a vertical inboard edge 91. Near its inboard edge 91, the blade 70 has a tapped and threaded hole, not here shown, to receive a stud bolt 81. The stud bolt 81 extends through a vertical slot 83 in the inner end of a strike-off blade 80. The strike-off :blade 8f) is vertically oiset from the lower edge of the scraper blade 70, 'and its height can be adjusted by virtue of the provision of the vertically extending slot 83. The stud 81 is merely loosened, the height of the strike-off 4 blade adjusted, and the stud 81 tightened. To inhibit unintentional loosening, a lock washer 84 can be interposed between the head of the stud 81 and the strike-off blade Sil.

The proportions and the positions of the blades 70 and 8G, the arm 60, and the various pivot points, are such that lateral movement of the blades with respect to the machine, in response to the movement of the rack 35, has practically no effect upon the angular relation of the blades and the spreader. Normally, it is desirable that the blades be set at an angle of about 45 to the axis of the machine, hence to the edge of the mat being laid.

In operation, as the spreader moves forward, the lateral reach of the blades is adjusted by turning the handwheel 57, until the inboard edge 91 of the scraper blade 70 is immediately contiguous the edge of a previously laid mat 100. The spreader will ordinarily be so oriented with respect to the already laid mat, as to provide two to six inches of overlap of new material 101 on top of the laid mat. The scraper blade 70, which is biased by the springs 67 and 72 downwardly into scraping engagement with the top of the laid mat, moves the fresh material, immediately after it is deposited by the spreader, to the very edge of the laid mat. The strike-off blade 80 then moves the upper part of the joint material beyond the edge of the laid mat, onto the fresh laid material behind the spreader. The strike-off blade is, with respect to the scraper blade, at a height which accomplishes two purposes: first, to provide suflicient material so that when the fresh bed is compacted by a compactor, the joint is level and at the same time the joint material is thoroughly and tightly compacted into initial contact not only with the new material of the fresh laid mat, but with the material defining the edge of the previously laid mat; and second, to classify the loose material so as to leave a somewhat finer, denser mix in the joint. This is accomplished by setting the height of the strike-olf blade a little less than the diameter of the coarser stone used in the particular coating being applied. Thus, for example, in laying a binder coat, in which one inch stone is used, the strike-olf blade may be set at 3A inch above the grade level, so as to tend to move the 1 inch stone away from the joint, toward the free end of the strike-off blade. When the surface coat is applied with 1/2 inch stone, the strike-off blade can be set 1A to 3A; inch above the grade level, again to move the coarser stone away from the joint.

The strike-off blade also serves another important function. Since it provides a guage of the relative heights of the previously laid mat and newly laid bed, if the screed bar of the spreader has been set too high, the strike-olf blade will begin to scrape and move not only the excess material delivered by the scraper blade, but also the newly laid bed itself, to form a noticeable windrow at the free end of the strike-off blade. Since it is not uncommon for a spreader to deliver material at the rate of two tons a minute, in operation, it can be seen that the prompt detection of an improper screed level can be of great practical importance.

As the spreader moves forward, the oiler or raker or eigineer, `as the case may be, keeps an eye on the position of the joint rake with respect to the edge of the previously laid mat, adjusting the lateral reach of the inboard edge 91 of the scraper blade 70 to keep it on the edge of the previously laid mat. Commonly, the overlap of the spreader onto the previously laid mat will not exceed 6 to 9 inches. However, the scraper blade 70 can be of any desired length, and an overlap of 15 inches to 2 feet can be accommodated if necessary.

If the spreader should have to leave a gap between the material which is being freshly laid and the previously laid mat, the joint rake of this invention can be utilized to fill this gap. If there is provision for the delivering of material from the side of the spreader, this is done. Otherwise, material can be deposited from another source immediately along the edge and slightly overlapping the edge of the previously laid mat. The reach of the scraper blade is then adjusted to bring the inboard edge 91 of the blade to the edge of this mat, and the extra material is then moved to its proper position and any excess, feathered by the strike-off blade. It may, under these circumstances, be desirable to make the vertical offset of the strike-off blade from the scraper blade a little greater to `allow for greater compaction by the following compactor, since the material in the gap has not had the preliminary tamping by the spreader which is given the fresh laid bed deposited by the spreader in the usual way.

Ordinarily, it is advantageous to make the scraper blade 18 to 30 inches long, so that it projects from the side rail 2 of the spreader a foot or so, because, in this arrangement, the scraper blade extends little if any beyond the farthest projection of the spreader itself. Thus, instead of having a man with a rake standing in the lane of tr-aiiic as he does in present practice, with the use of the joint rake of this invention, the blade provides no obstruction at all as far as trai-lic is concerned.

It might be thought that the turbulence and classifica- -tion of the scraped material might lead to the aeration and chilling which have been among the undesirable features of manual raking. However, it is to be observed that the joint rake of this invention is immediately behind the machine, in constant contact with the hot material, so that the blade, hence the material does not have a chance to chill, the strike-off blade exerts some immediate compacting effect, the fresh material deposited by the spreader against the more or less vertical face of the previously laid mat is undisturbed, and the three wheeled compactor can follow immediately, whereas, in the manual raking, there was frequently a considerable time lapse between the spreading and the raking, as compared with the lapse in the use of the present invention, the rake was not in constant contact with the hot material, hence cooled between contacts, and the bumping of the rake lifted the yfresh material which had been deposited by the spreader against the side face of the cooled rst mat, thus contributing to the aeration land chilling of the material in immediate contact with the joint.

The provision of the slidable hinge pin and the socket type of slidable connection between the stub shaft 51 and shank 56, permits the blade to be raised when the Spreader is traveling over a cross street, or the like, with practically no delay. The hinge pin 15 is merely slipped out and the arm 60 turned out of the way, the shank 56 removed and the support 30, with the blade, raised manually. Alternatively to raising the blades, the hinge leaf 21 can be mounted Von the walkway 3 with quick disconnect clamps or the like, and the entire rake removed.

Simply by way of illustration, and not oflimitation, the scraper blade can be twenty-seven inches long, and the strike-off blade seventeen inches long. The rack can be thirty inches long, the arm 60, two feet long, and the support 30, thirteen inches long. The scraper blade can be made of one inch hardened steel stock, four inches high, with a one inch chamfer at the bottom.

It can be seen from examination of FIGURE 2, that as the blade 76 is moved inwardly and outwardly by the rack 35, the outboard end of the blade 70 will be guided by the arm 66 in such a Way that the angle of the blade to the spreader will remain substantially the same.

As has already been suggested, the joint rake of this invention can be mounted on either side of the spreader. In the preferred embodiment shown, this left-for-rightside switching can be accomplished with the same parts by mounting the strike-off blade, turned around, on the other end of the scraper blade (a threaded hole being provided at each end of the scraper blade for this purpose), inverting the arm and mounting its inner end on a side bracket on the other (left) side of the spreader and mounting its outer end on the post 71 of the scraper blade. The post is mounted in the blade bracket 45,

which is mounted on the left ear 38 of the rack 35. The hinge leaf 21 is mounted on the walkway at the left end of the walkway, and the rake is ready for operation, since the rack and pinion work both directions. Of course two rakes can be provided, one for the right side, the other, for the left. All or part of either orboth may be mounted on the spreader at any one time.

Numerous variations in the device of this invention within the scope of the appended claims, will occur to those skilled in the art in the light of the foregoing disclosure. For example, the manual adjustment of the lateral reach of the blades by means of the handwheel 57 may be eliminated, and the adjustment achieved either by an electric or fluid motor operating the pinion 50, or by the use of a direct acting power means, such as a fluid cylinder and piston arrangement. In any such arrangement, however, it is important that the angularity of the blade with respect to the spreader be maintained substantially constant, and that the scraper blade be resiliently biased downwardly at essentially two spaced points. The controls for a iluid or electric drive may, of course, be located in any desired place. The particular shapes and dimensions of the various parts described and illustrated have been found excellently adapted to successful operation of the joint rake of this invention, but they are not absolutely essential, as long as the relationships which have been described as necessary, are maintained.

Having thus described the invention what is claimed and desired to be secured by Letters Patent is:

1. In a bituminous paving device including a spreader from which a dimensionally dened bed of fresh bituminous material is discharged, the improvement comprising a mechanical joint rake attached to said spreader, said joint rake having a scraper blade adapted to extend laterally outboard of the bed of fresh material and forwardly at an acute angle to the direction of travel of the spreader and positioned vertically -for scraping fresh material from the surface of a set mat contiguous the fresh bed; a strike-off blade attached to said scraper blade and adapted to be positioned with its lower edge vertically above the lower edge of the scraper blade and extending substantially parallel thereto with its inner end trailing with respect to the direction of travel of the spreader, means operatively connected to said blades for moving said blades laterally with Vrespect to said spreader during travel of said spreader, and means operatively connected to said blades for maintaining the angularity of said blades substantially constant upon lateral movement of the blades.

2. The joint rake of claim 1 wherein the means for Amoving the blades laterally include a support carried by `the spreader, a pinion journaled in the support, a rack journaled in the support in engagement with the pinion, and a bracket carried by the rack and connected with the scraper blade.

3. The joint rake of claim 1 wherein the means for maintaining the angularity of the blades is an arm pivoted at one end to a side of the spreader, and at the other end to one end of the scraper blade.

4. The joint rake of claim 1 wherein the strike-off blade is mounted directly on the scraper blade near the inboard end thereof, for vertical adjustment of the strikeoff blade with respect to the scraper blade.

5. The joint rake of claim 1 wherein a vertically elongate slot is provided in the strike-off blade, through which a bolt extends.

6. The joint rake of claim 1 wherein the blades are carried by support means hingedly connected to the spreader, and means are provided for selectively inhibiting the hinging movement of said support.

7. The joint rake of claim 6 wherein the hinging inhibiting means comprise a fixed pintle shaft carried by one hinge part, a split knuckle carried by another hinge part, the two halves of said knuckle embracing opposite sides of said pintle shaft, and means for clamping said knuckle halves with varying pressures about said pintle shaft.

8. In a bituminous paving device including a spreader from which a dimensionally defined bed of fresh bituminous material is discharged, the improvement comprising a mechanical joint rake attached to said spreader, said joint rake having a scraper blade; mounting means for said scraper blade carrying said scraper blade at two points of connection, with resilient biasing means at said two points biasing said scraper blade downwardly, said scraper blade adapted to extend laterally outboard of the bed of fresh material and forwardly at an acute angle to the direction of travel of the spreader and positioned vertically for scraping fresh material from the surface of a set mat contiguous the fresh bed; a strike-off blade attached to said scraper blade and adapted to be positioned with its lower edge vertically above the lower edge of the scraper blade and extending substantially parallel thereto with its inner end trailing with respect to the direction of travel of the spreader; means operatively connected to said blades for moving said blades laterally with respect to said spreader; and means operatively connected to said blades for maintaining the angularity of said blades substantially constant upon lateral movement of the blades.

9. The joint rakerof claim 8, wherein the scraper blade biasing means are coil springs interposed between said blade and said mounting means.

10. In a bituminous paving device including a spreader from which a dimensionally defined bed of fresh bituminous material is discharged, the improvement comprising a mechanical joint rake attached to said spreader, said joint rake comprising a leaf mounted on a rear part of said spreader; a horizontal pintle shaft secured to said leaf; an upper knuckle secured to an upper plate of a support and embracing the upper surface of said pintle shaft; a lower knuckle secured to a lower plate of said support and embracing the lower surface of said pintle shaft; means for clamping said upper and lower knuckles on said pintle shaft; a pinion journaled in said support; means connected to said pinion by which said pinion can be controlledly rotated; a rack, journaled in operative engagement with said pinion in said support; a bladesupporting bracket connected to one end of said rack; a scraper blade mounted at one end for limited vertical movement on said blade-supporting bracket with the outboard end of said blade extending forwardly and at an acute angle with respect to the direction of travel of said spreader; a coil spring positioned between and bearing upon said bracket and said blade, biasing said blade downwardly; a strike-off blade mounted upon and supported by the scraper blade near the inboard end thereof, but adjustable vertically with respect thereto, the inboard end of said strike-off blade trailing with respect to the direction of travel of said spreader; an arm pivoted at its inner end to the side of the spreader and at its outer end to a post on and near the outboard end of the scraper blade, and so positioned and shaped as to move the outboard end of the scraper blade inwardly and outwardly substantially the same distance as the inboard end is moved inwardly and outwardly in response to movement of the rack, whereby the relative angularity of the blades and spreader are maintained substantially constant; and a coil spring about the post, between and bearing upon the arm and the blade, to bias the said blade downwardly.

11. The method of laying a bituminous mat of a mixture containing bitumen, filler and relatively coarse stone immediately adjacent a previously laid mat which has set, comprising discharging said mixture in a dimensionally defined bed from a spreader, with a portion of mixture on top of the said previously laid mat along the adjacent edge thereof; continuously moving said portion laterally to and slightly beyond the surface defining the uppermost contiguous edge of said previously laid mat, while maintaining the material within the fresh bed contiguous the previously laid mat substantially undisturbed; moving a part of the material moved from the previously laid mat which contains a larger proportion of the coarse stones than is present in the mixture as it issues from the spreader, away from said edge onto the bed of freshly discharged material, leaving the freshly discharged material at a higher level immediately along the said edge than the level of the previously laid mat, and subsequently compacting the said freshly discharged material.

References Cited by the Examiner UNITED STATES PATENTS 1,773,431 8/1930 Mosel 94-45 X 1,926,895 9/ 1933 Fischer 94--45 2,054,437 9/ 1936 Mosel 94-46 2,164,446 7/1939 Clamp 94-45 X 2,832,273 4/ 1958 Calabrese 94-46 2,914,995 12/1959 Odell 94-46 2,945,427 7/ 1960 Gerk 94-45 3,031,938 5/1962 Bero 94-46 OTHER REFERENCES Barber-Greene Asphalt Paving Pacemakers, copyright 1960, page 20.

CHARLES E. OCONNELL, Primary Examiner.

JACOB L. NACKENOFF, Examiner.

Claims (1)

1. IN A BITUMINOUS PAVING DEVICE INCLUDING A SPREADER FROM WHICH A DIMENSIONALLY DEFINED BED OF FRESH BITUMINOUS MATERIAL IS DISCHARGED, THE IMPROVEMENT COMPRISING A MECHANICAL JOINT RAKE ATTACHED TO SAID SPREADER, SAID JOINT RAKE HAVING A SCRAPER BLADE ADAPTED TO EXTEND LATERALLY OUTBOARD OF THE BED OF FRESH MATERIAL AND FORWARDLY AT AN ACUTE ANGLE TO THE DIRECTION OF TRAVEL OF THE SPREADER AND POSITIONED VERTICALLY FOR SCRAPING FRESH MATERIAL FROM THE SURFACE OF A SET MAT CONTIGUOUS THE FRESH BED; A STRIKE-OFF BLADE ATTACHED TO SAID SCRAPER BLADE AND ADAPTED TO BE POSITIONED WITH ITS LOWER EDGE VERTICALLY ABOVE THE LOWER EDGE OF THE SCRAPER BLADE AND EXTENDING SUBSTANTIALLY PARALLEL THERETO WITH ITS INNER END TRAILING WITH RESPECT TO THE DIRECTION OF TRAVEL OF THE SPREADER,

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