US 3864830 A
A lumber sawing attachment for a chain saw includes a U-shaped clamp which is secured by set screws to the cutter bar. The clamp has a slot for receiving the cutter bar and an enlarged slot bottom to provide clearance for the cutting chain. The clamp is fixed to an axle which is rotatably supported on a guide bracket which is adapted for longitudinal movement along a guide member, such as a board fastened to the upper surface of a log. The axle can be tightened in selected adjusted positions and maintain the saw rigid with respect to the guide bracket and log to assist starting and sharpening of the saw, to control depth of cut and hold the cutter bar at an efficient sawing position.
Description (OCR text may contain errors)
O United States Patent 1 91 1111 3,864,830
Haddon Feb. 11, 1975 [541 LUMBER MAKING ATTACHMENT FOR A 3,695,316 10/1972 Pluckhahn 30/381 CHAIN SAW  Inventor: Jesse E. Haddon, Rt. 5, Burlington, 'f f' Lawrence Sm'th 53105 Assistant ExammerK. J. Ramsey Attorney, Agent, or Firm-Henry C. Fuller  Filed: Feb. 28, 1973  Appl. No.: 336,664 57] ABSTRACT A lumber sawing attachment for a chain saw includes  US. Cl 30/371, 30/377, 83/745 a U Shaped clamp which is Secured by Set screws to 1511. !P 1,V l-
the cutter bar. The clamp has a slot for receiving the  Field of Search- 83/574, 788, 794, 743, Cutter bar and an enlarged Slot bottom to provide 83/745, 6541 821; 30/3711 3721 clearance for the cutting chain. The clamp is fixed to 37413751 376137713811 383124/81 AE1 243 an axle which is rotatably supported on a guide G bracket which is adapted for longitudinal movement along a guide member, such as a board fastened to the 1561 References Cited upper surface of a log. The axle can be tightened in UNITED STATES PATENTS selected adjusted positions and maintain the saw rigid 371,408 8/1887 Becker 1.24/81 AE with respect to the guide bracket and log to assist 1,672,502 6/1928 Roth 24/243 S starting and sh rp ning 0f he saw, o n r l p h of 1,855,945 4/]932 Denyer 83/745 cut and hold the cutter bar at an efficient sawing posi- 2,779,359 1/1957 Koski 1 e 1 30/371 ti 2,942,633 6/l960 King 83/745 3,134,409 5/1964 Hayden 30/371 8 Claims, 3 Drawing Figures LUMBER MAKING ATTACHMENT FOR A CHAIN SAW BACKGROUND OF INVENTION Various types of attachments have been developed to facilitate guiding portable chain saws for cutting lumber from logs. The Hayden U.S. Pat. Nos. 3,05l,203 and 3,225,799 show two types of attachments which use rollers and wheels which cooperate with a guide for guiding movement of the chain saw. Attachments of this type are expensive because of the guide rollers and bearings required and have proved to be awkward and unsatisfactory in use. In addition, the use of rollers is undesirable because of the problem caused by chips which get between the rollers and the guiding surface which interfere with smooth, effective guiding action.
Also with the attachments shown in these patents, holes must be drilled in the cutter bar for fastening the attachment to the chain saw.
SUMMARY OF INVENTION The invention provides an attachment for making lumber or,boards from logs which eliminates some of the disadvantages of the prior art lumber attachments. The attachment is connected to the chain saw by a clamp which slips over the chain and clamps on the cutter bar at any convenient place on the cutter bar. An enlarged cavity at the bottom of the clamp slot provides clearance for the chain and chips.
The clamp is rotatably supported on a guide bracket by an axle which can be locked in any selected angular position to accommodate the height of the user, the height the log is off the ground, and the thickness of the log being cut. Thus the saw can be supported on a log at an appropriate angle for starting or sharpening of the chain. The guide bracket has downturned flanges in a close fit with a longitudinal guide member such as a 2 by 6 inch to eliminate the need for rollers.
In addition, the lumber making attachment of the invention is light weight and inexpensive compared with prior art devices and can be used for a variety of cutting operations in addition to cutting planks from logs such as felling trees and cutting firewood.
Further objects, advantages and features of the invention will become apparent from the following disclosure.
DRAWINGS FIG. 1 is a perspective view of a chain saw lumber making attachment in accordance with the invention.
FIG. 2 is a plan view of the guide bracket for the attachment shown in FIG. 1.
FIG. 3 is a sectional view along line 3--3 of FIG. 2.
DESCRIPTION OF PREFERRED EMBODIMENT Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. The scope of the invention is defined in the claims appended hereto.
In the drawings, FIG. 1 shows a chain saw attachment in accordance with the invention which is designated 10 and which includes a clamp 12 and a guide bracket 14 which is adapted to embrace a guide member 16. The clamp 12 includes a pair of opposed clamp body portions 18 and 20 which are spaced to define a cutter bar receiving slot 22. The slot is wide enough to receive various cutter bars. A width of one-half inch will accommodate most cutter bars. The slot extends from the upper surface 24 of the clamp to an enlarged recess or cavity 26 which provides clearance for the teeth of the cutter chain 28 and wood chips carried by the chain. The clamp is detachably secured to the cutter bar by two set screws 30 which are threadably received in apertures 32 in clamp body portion 18. The use of the clamp and bolts 30 eliminates the need to drill holes in the cutter bar as in prior art lumber making attachments.
In accordance with the invention, means are provided for pivotally connecting and supporting the clamp to the guide bracket 14. In the disclosed construction, the means includes a shaft or axle 36 which can be threaded at 38 and 40. The threaded end 38 is threadably received in a bore 42 in clamp body portion 20. Alternatively, the end 38 can be pinned in the bore 42. The means includes upstanding ears or tabs 44 and 46 which are struck from the bracket 14. The ears are provided with inturned annular flange portions 48 and 50 (FIG. 3) which define the apertures 51, 53 which receive the shaft. The flange portion 50 engages and is clamped against shoulder 54 of the axle 36 for purposes subsequently described.
The means for connecting the clamp to the guide bracket is also adapted to maintain the cutter bar and clamp in adjusted angular positions. As disclosed. the means includes a washer 60 and a nut 62 on shaft end 40. When the nut 62 is tightened, the washer will draw the shoulder 54 against the flange 50 and secure the axle against rotation. In use of the attachment for cut ting small logs such as that shown in FIG. 1, it is not necessary to have the axle clamped in a fixed position. Accordingly, the nut 62 can be loose and retained on the axle by a castillated nut 66 which has radial slots and is provided with a cotter key 68 which extends through an aperture 70 in the axle and retains the nut 66 on the axle.
The bracket 14 has downturned marginal flanges 70 and 72 which closely embrace the guide member 16 which can be a 2 X 6 inch. The top plate 76 of the bracket 14 can have several cutouts such as 78, 80 and 82 to minimize weight and release chips which may get between the plate and the guide member. The top plate can be provided with apertures 84 so that the top plate can be screwed or nailed to a short length of wood or filler strip such as a 2 X 2 inch. The apertures 84 or apertures 86 in both flanges 70, 72 can also be used with bolts or screws, etc. to rigidly secure the guide bracket 14 to the guide board 16 when sharpening the saw. Thus, the guide member can be smaller than a 2 X 6 inch, such as a 2 X 4 inch which will run the length of the log. In use, the guide members are temporarily tacked, clamped or otherwise fastened to the log. If a filler board is used, tapped apertures in the flange 70 or 72 on the side opposite the filler board can be used with bolts to secure the bracket and the saw to the log for sharpening, etc. Tapped apertures 86 in both the side flanges 70, 72 can also be used to secure the tiller board to the bracket 14. The side flanges can be made adjustable to accommodate any width guide board and- /or filler piece. For instance, a plate (not shown) located inside flange 72 and carried by bolts threaded in flange 72 can be adjusted to urge the filler board against guide boards of different widths.
in use of the chain saw attachment, particularly when cutting with the grain, the saw cuts best at a certain angle due to the character of the wood and the cutting chain teeth. The clamp and thus the cutter bar can be locked at the appropriate angle using the nut 62 to maintain the same angle for the entire length of cut. In addition to using the nut 62 to clamp the cutter bar at an appropriate angle and also rigidly secure the chain saw to the log, the nut 62 can be tightened to secure the guide bracket in a position which does not interfere with the use of the chain saw for other purposes such as cross cutting.
What is claimed is:
1. in combination, a chain saw with a cutter bar and a guide member, a lumber sawing attachment, said attachment comprising a clamp connectable to said cutter bar, a guide bracket adapted for sliding longitudinal movement on said guide member and means for pivotally connecting said clamp to said guide bracket to support said chain saw on said guide bracket for movement of said cutter bar in an are parallel to the direction of longitudinal movement of said guide bracket on said guide member and afford adjustment of the angular position of the clamp with respect to the guide bracket about an axis transverse to the direction of movement of said bracket and at right angles to said cutter bar and thereby afford control of the depth of cut of said cutter bar.
2. An attachment in accordance with claim 1 wherein said clamp includes means defining a slot extending from a clamp surface to a point intermediate the height of the clamp and terminating in an enlarged cavity sized to provide clearance with the cutter chain of a chain saw.
3. An attachment in accordance with claim 1 wherein said means for pivotally supporting said clamp on said guide bracket comprises upstanding ears on said bracket, coaxial apertures in said ears, a shaft rotatably supported on said apertures, said shaft having means to connect the shaft to said clamp and means on said shaft for adjusting the angular position of said clamp with respect to said guide bracket.
4. A lumber sawing attachment for a chain saw comprising a clamp connectable to the cutter bar ofa chain saw, a guide bracket adapted for longitudinal move ment on a guide member and pivot means for pivotally connecting said clamp to said guide bracket to support the chain saw on the guide bracket and afford adjustment of the angular position of the clamp with respect to the guide bracket, and wherein said pivot means for pivotally supporting said clamp on said guide bracket comprises upstanding ears on said bracket, coaxial apertures in said cars, a shaft rotatably supported on said apertures, said shaft having means to connect the shaft to said clamp means on said shaft for adjusting the angular position of said clamp with respect to said guide bracket, and wherein said shaft has two shoulders, each of said shoulders being spaced from one of said shaft ends, one of said shoulders being located between said ears, and said apertures in said ears being defined by inturned annular flanges, and wherein said means on said shaft for adjusting the position of said clamp comprises a threaded end on said shaft projecting through one of said ears, and a nut threadably received on said shaft to compress one of said flanges against one of said shoulders and secure said shaft against rotation.
5. An attachment in accordance with claim 4 including a lock nut on said shaft threaded end.
6. An attachment in accordance with claim 1 wherein said guide bracket has an upper plate portion and two depending flanges for embracing the top and sides of a rectangular guide board.
7. An attachment in accordance with claim 6 including apertures in said depending flanges and fasteners extending through said apertures and adapted to engage a guide member located between said flanges.
8. An attachment in accordance with claim 6 including apertures in said top plate and fasteners for securing said top plate to a guide member.