US3651839A

US3651839A - Portable motor saw

Info

Publication number: US3651839A
Application number: US29763A
Authority: US
Inventors: Andreas Stihl; Ewald Abt; Albrecht Rauh
Original assignee: Andreas Stihl AG and Co KG
Current assignee: Andreas Stihl AG and Co KG
Priority date: 1966-12-03
Filing date: 1970-04-27
Publication date: 1972-03-28
Anticipated expiration: 1989-03-28
Also published as: CH473655A; DE1528034C3; FR1549639A; DE1528034A1; NO130816C; BE707383A; AT279139B; NO130816B; DE1528034B2; GB1152547A

Abstract

A portable motor saw having a housing, front and rear handle means and frame means rigidly interconnecting said housing and rear handle means in spaced relationship, said frame means when seen in plan view having a contour substantially corresponding to the contour of said housing, while a plurality of elastic vibration damping means is interposed between said housing and said handle means.

Description

[151 3,651,39 Stihl et a1. 5] at. 2%, W72

[54] PURTALE MOTOR SAW [56] Reierences Cited [72] Inventors: Andreas Stlhl, Rohrbronn, Am UNITED STATES PATENTS kirschberg; Ewald Albt, Stuttgart-Bad Gannstatt; Albrecht IRauh, lqei h h, 1,720,545 7/1929 Dickey ..l6/l16 UX all of Germany 3,372,718 3/1968 lrgens 4 2 [73] Assignee: Andreas Stlhl Muschinenfabrik, Neustadt 34O9'056 11/1968 Rauh 1 3/3 near 'b Germany Primary Examinef-D0nald R. Schran [22] Filed: Apr. 27, 1970 Attorney-Walter Becker [21] Appl. No.: 29,763 [57] ABSTRACT Related Application Data A portable motor saw having a housing, front and rear handle [63] Continuation of sen 687 703 4 1967 aban means and frame means rigidly interconnecting said housing doned and rear handle means in spaced relationship, said frame means when seen in plan view having a contour substantially 30] Foreign Application Priority Dam corresponding to the contour of said housing, while a plurality of elastic vibration damping means is interposed between said NOV. 24, Germany .-St housing and said handle means,

[52] US. Cl. ..l43/32 R, 173/162 24 Claims, 6 Drawing Figures [51] Int. Cl ..B27b 17/02 A [58] Field oiSearch ..143/32,43,68; 173/162;

PATENTED M28 I972 SHEET 1 OF 6 In ventors: 4/7091905 S/Ms/ We d A6.-

.PATENTEUMAR28 I972 3,651,839

SHEET 2 [1F 6 Fig. la

Inventors PATENTEDMARZB m2 a, 651 ,839

SHEET 8 BF 6 Inventors I M-ees sf// flro/d PORTABLE MOTOR SAW This is a continuation of application Ser. No. 687,703 filed Dec. 4, 1967, now abandoned.

The present invention relates to a portable motor saw with a handle member at the front portion of the saw and a handle member at the rear portion of the saw while a rigid connection is provided between said handle members. The handles are of an elastic material and are separated from the respective adjacent housing portion of the saw by vibration damping hearing means.

It is an object of the present invention to provide the portable motor saw in such a way that on one hand a considerable damping of the oscillations of the motor relative to said handle members will be realized while on the other hand the necessary rigidity, which will assure a safe working with the motor saw, will be maintained between the handle members and the saw including the guiding rail means therefor.

It is another object of this invention to provide a simple structure and arrangement of the vibration damping guiding means.

It is still another object of this invention so to design the portable motor saw that sensitive motor parts, such as air filter, carburetor, or the like, are so protected that even when handled roughly and carelessly, said motor parts will not be damaged, for instance in densely wooded areas by tree branches, trunks, or the like.

It is a still further object of this invention to provide a motor saw as set forth above which will have a relatively low weight and which can be handled in a simple manner.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIG. 1 illustrates a motor chain saw according to the invention, partially in view and partially in section.

FIG. 1a is a cutout from the front handle portion.

FIG. 2 is a top view of the motor chain saw according to FIG. 1, partially in view and partially in section.

FIG. 3 illustrates a further embodiment of the present invention as seen from the top.

FIG. 4 is a top view of the motor chain saw of FIG. 3.

FIG. 5 shows the motor chain saw of FIG. 3 as seen from the rear.

The portable motor chain saw according to the present invention is characterized primarily in that the rigid connection between the handle members is formed by a circumferential frame arranged above the motor chain saw and, when seen from the top, approximately conforming to the contour of the plan view of the motor housing. The relatively considerable mass of the handle members in view of the circumferential frame further improves the damping of the motor vibrations. In addition thereto, the circumferential frame protects the air filter located near the top side of the motor housing and also protects the carburetor against shock and damage so that these elements are protected against damage even when handled roughly and when the motor chain saw is carelessly used.

According to a further feature of the invention, the circumferential frame extends substantially parallel to the surface of the motor housing so that the said frame will not interfere with the operation and handling of the motor chain saw. The motor housing and the saw unit will even be better protected against shocks when the circumferential frame protrudes somewhat beyond the plan view of the housing.

Advantageously, the front portion of the circumferential frame is through the intervention of vibration damping bearing means mounted on the motor housing. In this way, the circumferential frame itself is safely supported while resting on the motor housing in such a manner that it is cushioned against vibrations.

With a motor chain saw having a guiding rail, the degree of freedom of the vibration damping bearing means is preferably parallel to the guiding rail for the saw chain so that the guiding rail will be able relative to the handle members to vibrate only parallel to its plane. In this way an accidental tilting of the guiding rail during the cutting operation will be prevented, in other words, the guiding rail is prevented from getting out of the cutting plane and jamming in the cutting groove.

According to a further suggestion in confonnity with the present invention, the vibration damping bearing means are formed by two sleeves coaxially arranged with regard to each other and formed of vibration damping material. The outside of said sleeves rests on the motor housing. The handle members or the supporting frame are, preferably by means of a clamp, connected to the central portion of said sleeves. Such an arrangement results in a simple but highly effective vibration damping bearing means which can easily be mounted.

The circumferential frame excels by a high stability and low weight and can be produced particularly simply when its cross section has a downwardly opening U-shaped profile, preferably castable profile. In order to be able from the inside of the circumferential frame to engage the circumferential frame in a simple manner so as to be able easily to carry the motor chain saw, the outer leg of the profile is preferably longer than the inner leg which latter is advantageously offset.

According to a further development of the present invention, the front and/or rear handle members are by means of an intermediate member, such as a flange, connected to the supporting frame whereby a rigid connection is obtained between the handle members and the circumferential frame. Expediently the intermediate portion of the front handle protrudes at an incline in upward direction beyond the supporting frame.

According to a still further feature of the present invention, the rear handle member merges without any material steps gradually into the plane of the supporting frame so that the latter as well as the handle member can equally well be grasped, and a catching of branches and twigs on protruding portions of the saw will be avoided.

In order to maintain the vibration stroke of the motor unit at a minimum relative to the handle member unit, the vibration stroke of the frame is limited by an abutment.

Referring now to the drawings in detail and FIGS. 1 and 2 thereof in particular, the motor chain saw shown therein comprises a motor housing 1 which contains the driving unit formed by a two-cycle internal combustion engine or the like. The front side of the motor housing 1 has a guiding rail 5 connected thereto. Rail 5 is arranged in a plane which isperpendicular to the axis of rotation of the crankshaft of the driving engine and has guided thereon a saw chain (not shown) driven by the driving motor. At the front side'2 of the motor housing 1 there is provided a handle member 8 which extends around the housing portion 3 housing the guiding rail 5. The handle member 8 has at least one portion thereof connected to the housing 1 through the intervention ofa vibration damping bearing means 23, 23a in the form of a bonded rubber pad or a vibration dampening connector, as used for instance in the aviation industry. The rear side 4 of the housing 1 has connected thereto a further handle member 9 which forms a rearward extension of the housing 1; At the bottom side of the handle member 9 there is provided an adjusting means 5 for controlling the motor speed. The rear end 6 of the handle member 9 is through the intervention of a vibration damping bearing means 13 connected to an arm 7 which in its turn is connected to the bottom side of motor housing 1 by means of a flange 28. Arm 7 protrudes rearwardly beyond the motor housing 1 to an extent corresponding to said handle member 9. At the slightly upwardly extending end 12 of arm 7 there is provided a fork formed by two arms l5, 16 in which the bear-. ing 13 of vibration damping material is arranged. The bearing 13 comprises two coaxially arranged sleeves 13', 13" which flare in the direction toward each other. The sleeves 13', 13" are within the areas of those ends thereof which face away from each other held by means of a bolt 14 which is located in the arms l5, 16. Within the area in which the two

damping bodies

13, 13" meet each other, there is provided a clamp 17, said clamp 17 being located in an annular groove formed by the two damping sleeves 13', 13". By means of said clamp 17,

the handle member 9 is connected to the damping sleeves 13, 13''.

Between the front handle member 8 and the rear handle member 9 there is provided a circumferential frame 10 which has a contour approximately similar to the plan view of the motor housing. The circumferential frame 10 is located above the motor housing 1 and is approximately parallel to the top side 11 thereof. The circumferential frame 10 which is substantially trapezoidal has its rear end connected to the handle member 9 by means of a corresponding plate-shaped flange 18 while, within the range of its front side, said frame 10 is connected to the handle member 8 by means of an intermediate member 19. The intermediate member 19 is upwardly inclined and protrudes beyond the circumferential frame 10 while its cross section (FIG. 2) is substantially trapezoidal.

The circumferential frame 10 has a profile corresponding to a downwardly directed U, the outer leg 20 of said U-shaped profile being longer than the inner stepped leg 21.

Below the front transverse portion of the circumferential frame 10, the motor housing 1 has connected thereto bearing supports 22 for receiving the vibration damping bearing means 23 which comprises two damping

sleeves

23, 23" to which the circumferential frame 10 is connected by means of an inwardly directed clamp 24. The vibration damping bearing means 23 is, when viewing the motor chain saw from the top, located approximately completely below the front transverse portion 25 of the circumferential frame 10 so that it is covered up.

The

frame portions

25, 25', 25" of the circumferential frame protrude on all sides slightly beyond the motor housing 1, when seen in top view according to FIG. 2, so that the motor housing is laterally from the front and from the rear protected against shock. As shown in FIG. 1, the rear handle member 9 merges with its top surface approximately gradually, i.e., without major interruptions, with the surface of the circumferential frame 10 whereby a stable and roundedoff upper contour of the saw is obtained so that branches or twigs cannot catch on sharp corners or edges.

With the embodiment illustrated in FIGS. 3-5, the rear handle member 90 forms one piece with the circumferential frame 10a. The lower arm 70, the end of which has linked thereto the rear end of the handle member 9a through the vibration damping bearing means 13, forms one piece with the corresponding part of the motor housing 10. Such a structure results in a relatively simple design of the motor chain saw according to the invention.

As will be seen from FIGS. 3-5, a tank 26 is located within the circumferential frame 10a which may receive fuel or oil. The outer contour of said tank 26 extends substantially parallel to the corresponding contour of the circumferential frame 10. Only a closure member 27 for the tank 26 protrudes in upward direction beyond the circumferential frame 10a.

The bolts, as for instance the bolts 14 of the rear vibration damping bearing means 13, simultaneously serve as abutments for the maximum deformation of the vibration damping sleeves since said sleeves, in the course of their relative movement toward bolts 14, have their inner surface engage said bolts. The said bolts are located coaxially in said vibration damping sleeves. A design as just set forth will safely prevent an overloading of the vibration damping bearing means and

vibration damping sleeves

13, 23, 23a.

As will furthermore be evident from FIGS. 3-5, the lower end of the front handle member 8a is connected to the motor housing by means of the vibration damping bearing means 23a, while said vibration damping bearing means 23:: have the same axial direction as the other two vibration damping bearing means 23, 13. That end of the handle member 8a which is connected to said bearing means 23a extends coaxially with regard to the vibration damping bearing means 23a pertaining thereto. As will be seen from FIG. 4, the vibration damping bearing means 23a which holds the lower end of the front handle member 8a is located at one side of the motor housing la, whereas the vibration damping bearing means 23 directly supporting said circumferential frame 10a is located at the other side of the motor housing 1a. When viewed in the longitudinal direction of the guiding rail 5, the rear vibration damping bearing means 13 is located approximately between the two front vibration damping bearing means 23, 230 while the said rear vibration damping guiding means 13 is located in spaced relationship to and behind the motor housing la. Since the bearing means 23 which is directly connected to the circumferential frame 101: is arranged at least partially below the front frame portion and since furthermore the vibration damping bearing means 23a which carries the lower end of the front handle member 8a is provided on the front side of the motor housing 1a, the two front vibration damping bearing means 23, 23a are offset with regard to each other in the longitudinal direction of the guiding rail 5, one bearing means 23 being located on the top side of the motor housing 1a whereas the other bearing means 230 is located on the bottom side of the motor housing 1a. The upper front vibration damping bearing means 23 and the rear vibration damping bearing means 13 are of approximately the same design.

According to the embodiment shown in FIGS. 3-5, the cir cumferential frame 10a protrudes laterally and toward the rear beyond the motor housing la but not beyond the chain cover l'a provided on one side of the motor housing, nor does the circumferential frame 10a protrude beyond the cover I'a on the other side of the housing. The connection of the front handle member 8a to the intermediate member 19 is, when viewed from the top according to FIG. 4, located directly ahead of the upper vibration damping bearing means 23.

As shown in FIG. la, the lower end of the front handle member 8 pertaining to the motor chain saw of FIGS. 1 and 2 and formed by a bent pipe is connected to the motor housing by means of the vibration damping bearing means 230. The bearing means 23a has a cylindrical portion 30 of elastic material, such as rubber, respectively connected to two oppositely located end faces of said cylindrical portion 30 are

plates

31, 32. This connection may be effected for instance by vulcanization. The two

plates

31, 32 are respectively provided with threaded

bolts

33, 34 which are coaxially arranged with regard to the damping body 30. One threaded bolt 33 is threaded into a threaded sleeve 35 which is arranged in the lower end 29 of handle member 8 which end 29 is coaxial with regard to the damping body 30. The said sleeve 35 is positively held by means of an annular bead which engages a circumferential groove pressed out of the handle member 8. The threaded bolt 33 is tightened to such an extent that the plate 31 is braced in a play-free manner against the end face of the handle member 8. The bolt 34 of the other plate 32 is connected to a tubular member 37 which has a substantially circular cross section. The tubular member 37 in its turn is in a manner not shown connected to the bottom side of the motor housing, for instance by means of upwardly directed screws. The two

plates

31, 32 are parallel to the plane of the guiding rail 5 in such a way that the longitudinal axis of the damping body 30 is located perpendicular to the plane of the guiding rail 5 and thus is located parallel to the longitudinal axes of the remaining vibration damping bearing means 13, 23. The diameter of the damping body 30 corresponds to the diameter of the handle member 8. Between the damping body 30 and sleeve 35 there is provided a dish spring 38, and similarly a dish spring 39 is provided between member 30 and tubular member 37.

It is, of course, to be understood that the present invention is, by no means, limited to the particular embodiments referred to above but also comprises any modifications within the scope of the appended claims.

We claim:

1. A portable motor saw which comprises: a motor housing, front transversely extending hand graspable front handle means and longitudinally extending hand graspable rear handle means respectively associated with the front and rear portions of said housing, rigid frame means extending between said front and rear handle means and rigidly fixed thereto, said frame means when seen in plan view having a contour substantially corresponding to the contour of said housing, and comprising longitudinal side rail portions and transverse front and back rail portions arid being open between said portions, said frame means being spaced vertically upwardly from the top wall of said housing, elastic vibration damping means interposed between said housing and the ends of said handle means remote from said frame means, and a further elastic vibration damping means interposed between the front rail portion of said frame means and said housing.

2. A motor saw according to claim 1, in which at least the major portion of said frame means is substantially parallel to said top wall of said motor housing and protrudes beyond the outer contour of said housing.

3. A motor saw according to claim 11, which includes guiding rail means for a saw chain of said motor saw connected to and projecting forwardly from the front of said housing, and in which said elastic vibration damping means includes sleeve means having their axes extending substantially perpendicularly with regard to the longitudinal extension of said guiding rail means.

4. A motor saw according to claim 1, in which said elastic vibration damping means are each formed by a pair of coaxially arranged sleeves having their outer ends connected to said housing, and which includes connecting means arranged at those ends of each pair of coaxially arranged sleeves which face each other, said connecting means being connected to the respective adjacent handle means and to said front rail portion of said frame means.

5. A motor saw according to claim 3, in which each said rail portion of said frame means is an inverted U-shape in crosssection, the outwardly located leg of said cross-section being longer than the inwardly located leg thereof.

6. A motor saw according to claim 1, which includes an intermediate member interposed between and rigidly interconnecting said front handle means and the front rail portion of said frame means, said intermediate member protruding upwardly and forwardly from said frame means.

7. A motor saw according to claim l, in which said housing has a longitudinal arm fixed to the rear thereof at the bottom and projecting to the rear, said arm at its rear end being connected to the end of said rear handle means remote from said frame means, said elastic vibration damping means pertaining to said rear handle means being interposed between said rear handle means and said longitudinal arm.

8. A motor saw according to claim 3, which includes means for limiting the vibrationary movement of said frame means relative to said housing.

9. A motor saw according to claim 8, in which said means for limiting the movement of said frame means due to vibration includes bolt means coaxial with and extending through said sleeve means and supported by said handle means.

10. A motor saw according to claim 5, in which the said elastic vibration damping means pertaining to said frame means is located inwardly of the front rail portion of said frame means.

ll. A motor saw according to claim ll, in which said front handle means is curved in a substantially vertical plane so as to be concave toward said housing and the lower end of said front handle means is connected to said motor housing through the intervention of one of said vibration damping means.

12. A motor saw according to claim 3, in which said elastic vibration damping means includes: two vibration damping bearing means spaced from each other in transverse direction of said frame means and located near the front of said motor housing and which is adjacent to said guiding rail means, and one vibration damping bearing means located at the rear end of said housing and which is remote from said guiding rail means.

113. A motor saw according to claim 11, in which the one of said elastic bearing means which is associated with the lower end of said front handle means comprises two substantially parallel plate means spaced from each other and an elastic vibration absorbing cushioning member therebetween, one of said plate means being connected to the lower end of said front handle means, and the other one of said plate means being connected to said motor housing.

M. A motor saw according to claim 13, which includes a connecting member interposed between said other plate means and said housing.

115. A motor saw according to claim 13, which includes a cylindrical member inserted into said lower end of said front handle means and connected thereto, and threaded bolt means threadedly engaging said cylindrical member and connecting said one plate means thereto.

116. A motor saw according to claim 13, in which said cushioning member is a solid body.

17. A motor saw according to claim 113, in which said cushioning member has a diameter approximately equalling the diameter of the adjacent end of said front handle means.

18. A portable motor saw which comprises:

a motor housing, front transversely extending hand graspable front handle means and longitudinally extending hand graspable rear handle means located near the front and rear portions of said housing respectively, rigid frame means above said housing extending between said front and rear handle means and rigidly fixed thereto, said frame means-when seen in plan view having a contour substantially corresponding generally to the contour of said housing, and comprising longitudinal side portions and transverse front and back portions integral with said side portions,'said frame means being spaced vertically upwardly from the top wall of said housing, first elastic vibration damping means interposed between said housing and said handle means remote from the connection of said handle means with said frame means, and a second elastic vibration damping means interposed between the front portion of said frame means and said housing.

119. A motor saw according to claim 18, which includes tank means carried by said frame means within the lateral and longitudinal confines thereof.

20. A motor saw according to claim 18, in which said elastic vibration damping means comprise resilient rubber-like elements.

21. A motor saw according to claim 18, which includes blade-like saw chain guiding rail means connected to and projecting forwardly from the front of said housing and in which said first and second vibration damping means have a major degree of resilience in a direction substantially parallel to the plane of said guiding rail means and a substantially lesser degree'of resilience in a direction normal to said plane of said guiding rail means.

22. A motor saw according to claim 18, in which each said portion of said frame means includes an upstanding outer leg, said legs forming the outer contour of said frame.

23. A motor saw according to claim 18, in which said front handle means is disposed above said frame means and is connected to said frame means on one side of the vertical longitudinal central plane of said frame means so as to provide a hand graspable region in that portion of said front handle means which is intersected by said plane.

24 A motor saw according to claim 23, in which at least one lateral end region of said front handle means extends downwardly along said housing in spaced relation thereto and at the lower end forms that portion of said front handle means between which said housing and said first vibration damping means is interposed.

Claims

1. A portable motor saw which comprises: a motor housing, front transversely extending hand graspable front handle means and longitudinally extending hand graspable rear handle means respectively associated with the front and rear portions of said housing, rigid frame means extending between said front and rear handle means and rigidly fixed thereto, said frame means when seen in plan view having a contour substantially corresponding to the contour of said housing, and comprising longitudinal side rail portions and transverse front and back rail portions and being open between said portions, said frame means being spaced vertically upwardly from the top wall of said housing, elastic vibration damping means interposed between said housing and the ends of said handle means remote from said frame means, and a further elastic vibration damping means interposed between the front rail portion of said frame means and said housing.

3. A motor saw according to claim 1, which includes guiding rail means for a saw chain of said motor saw connected to and projecting forwardly from the front of said housing, and in which said elastic vibration damping means includes sleeve means having their axes extending substantially perpendicularly with regard to the longitudinal extension of said guiding rail means.

5. A motor saw according to claim 3, in which each said rail portion of said frame means is an inverted U-shape in cross-section, the outwardly located leg of said cross-section being longer than the inwardly located leg thereof.

7. A motor saw according to claim 1, in which said housing has a longitudinal arm fixed to the rear thereof at the bottom and projecting to the rear, said arm at its rear end being connected to the end of said rear handle means remote from said frame means, said elastic vibration damping means pertaining to said rear handle means being interposed between said rear handle means and said longitudinal arm.

11. A motor saw according to claim 1, in which said front handle means is curved in a substantially vertical plane so as to be concave toward said housing and the lower end of said front handle means is connected to said motor housing through the intervention of one of said vibration damping means.

13. A motor saw according to claim 11, in which the one of said elastic bearing means which is associated with the lower end of said front handle means comprises two substantially parallel plate means spaced from each other and an elastic vibration absorbing cushioning member therebetween, one of said plate means being connected to the lower end of said front handle means, and the other one of said plate means being connected to said motor housing.

14. A motor saw according to claim 13, which includes a connecting member interposed between said other plate means and said housing.

15. A motor saw according to claim 13, which includes a cylindrical member inserted into said lower end of said front handle means and connected thereto, and threaded bolt means threadedly engaging said cylindrical member and connecting said one plate means thereto.

16. A motor saw according to claim 13, in which said cushioning member is a solid body.

17. A motor saw according to claim 13, in which said cushioning member has a diameter approximately equalling the diameter of the adjacent end of said front handle means.

18. A portable motor saw which comprises: a motor housing, front transversely extending hand graspable front handle means and longitudinally extending hand graspable rear handle means located near the front and rear portions of said housing respectively, rigid frame means above said housing extending between said front and rear handle means and rigidly fixed thereto, said frame means when seen in plan view having a contour substantially corresponding generally to the contour of said housing, and comprising longitudinal side portions and transverse front and back portions integral with said side portions, said frame means being spaced vertically upwardly from the top wall of said housing, first elastic vibration damping means interposed between said housing and said handle means remote from the connection of said handle means with said frame means, and a second elastic vibration damping means interposed between the front portioN of said frame means and said housing.

19. A motor saw according to claim 18, which includes tank means carried by said frame means within the lateral and longitudinal confines thereof.

21. A motor saw according to claim 18, which includes blade-like saw chain guiding rail means connected to and projecting forwardly from the front of said housing and in which said first and second vibration damping means have a major degree of resilience in a direction substantially parallel to the plane of said guiding rail means and a substantially lesser degree of resilience in a direction normal to said plane of said guiding rail means.

24. A motor saw according to claim 23, in which at least one lateral end region of said front handle means extends downwardly along said housing in spaced relation thereto and at the lower end forms that portion of said front handle means between which said housing and said first vibration damping means is interposed.