US 1132129 A
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Description (OCR text may contain errors)
F. M. STEVENS. SAFETY GRIP FOR CIRCULAR SAWS.
APPLIOATION FILED JUNE 15, 1914.
1,132,129. Patented Mar. 16, 1915.
-1HE NORRIS PETERS c0. PHOTCVLITHO WASHINGTON. D. c,
llldlTFdD FATFil lT @FFlQE FRED M. STEVENS, 0F CAMBRIDGE, MASSACHUSETTS.
SAFETY-GRIP FOR CIRCULAR SAWS.
Application filed June 15, 191 1.
To aw whom it may concern Be it known that 1, Fnno M. STEVENS, a citizen of the United States, and resident of Cambridge, in the county of Middlesex and State of Massachusetts, have invented new and useful improvements in Safety- Grips for Circular Saws, of which the following is a specification.
1n the operation of circular splitting saws there is constant danger that the piece of wood being sawed will bethrown back toward the operator by the swiftly rotating saw, especially if the piece is not held firmly and steadily while it is being advanced past the saw. when a piece is so thrown back it is projected with tremendous force and with serious and sometimes fatal consequences to the operator.
The object of the present invention is to provide an automatic safety grip for use in connection with circular splitting saws adapted to permit the free forward movement of the stick or piece being sawed but to prevent the possibility of its being thrown backward by the saw.
In the accompanying drawings which illustrate one embodiment of the invention,Figure 1 is a side elevation of the device applied to a circular splitting saw; Fig. 2 is a plan view of the parts shown in Fig. 1; Fig. 3 is a plan view of the safety grip folded and latched back in inoperative position; Fig. i is a rear elevation of said safety grip; Fig. 5 is a rear elevation of the grip folded and latched back in inoperative position; and Fig. 6 is a section on line 66 of Fig. 1.
Referring to the drawings, A represents the circular saw table made with a slot or through which projects the circular splitting saw S; B is the usual gage of cast iron or hard wood mounted on the saw table at the side of the saw to determine the width of the strip to be sawed; and M represents the piece of material, such as a stick of wood, being sawed.
The safety grip as herein illustrated is secured to the end of the gage B and consists of a plate divided into two sections 1 and 2, the plate section 1 having an 0&- set shoulder part 3 which is rigidly fastened by bolts 4: to the gage B so that the face of Patented Mar. 16, 1e15,.
Serial No. 845,990.
the plate section 1 and the face of the gage B lie in the same plane. The other plate section 2 is hinged to the plate section 1 by a pivoted rod 5 which passes through ears or lugs 6, 6, projecting from the rear sides of the plate sections 1 and 2. A coil spring 7 surrounds rod 5 and normally urges the swinging plate section 2 into operative or extended position as shown in Figs. 1, 2 and 4. Pivoted to the shoulder of the off set part 3 of plate section 1 is a latch 8, adapted to engage the catch 10 projecting from the rear side of plate section 2. When the plate section 2 is folded back upon plate section 1 the latch 8, which is normally pressed forward by spring 9, will automatically engage the catch 10, holding the swinging plate section 2 in folded or inoperative position. Thus, the grip may be thrown out of action if it is desired to use the saw without the grip, and without dismounting the fixed section 1 by removing bolt 4. The latch 8 is made with a nose 11 which limits the movement of the latch in its forward or downward direction.
On the front side of plate section 2 is supported the gripping dog 12, normally in the path of the material M, provided with a series of teeth or corrugations to grip the top surface of the material M. The gripping dog 12 is provided with an upwardly extending arm 13, and is carried and actuated by a pair of parallel arms 1% and 15, arranged one above the other, and each pivoted at one end to the swinging plate section 2 and at the other end to the upright arm 13. A spring 16 secured at one end to the upright arm 18 by pin 17 and at the other end of the swinging arm 15 by pin 18, normally tends to urge the gripping dog 12 downward in the direction of the material M. It will be seen that the gripping dog is adapted to operate in conjunction with sticks of various thickness and that in all positions of elevation within the range of its movement the angle of the gripping dog in relation to the surface of the material M will remain unchanged on account of the action of the parallel arms 14 and 15. It will also be observed that the bottom surface of the gripping dog is inclined to the direction of movement of the material M, as is also the bottom surface of the actuating arm. 15, so that as the material M is moved forward its leading end will first engage the bottom side of arm 15 thereby raising said arm and the gripping dog 12, and upon its continued movement the leading end of the material M will slip past the under surface of arm 15 and engage the inclined bottom surface of the dog 12, causing the same to ride up on top of the material, with its gripping edge in engagement with the top surface of the material as shown in Fig. 1. For convenience in elevating the dog 12 manually, should that be desired, the upper arm 14: is provided with a rearwardly projecting handle 19, which may be swung down into notch 20, in plate section 1, in order not to limit the upward movement of the dog.
The operation will be apparent from the foregoing description without further eX- planation. It will be seen that as soon as the forward end of the material being sawed passes underneath the gripping dog,v the latter will hold it against any possibility of flying back in the direction of rotation of the saw, and that the greater the tendency to fly back the greater will be the gripping action exerted by the dog 12. It will also be clear that the form of the dog is such as to permit the free forward movement of the material.
In case the safety grip is to be thrown out of action as above described, it will be observed by reference to Figs. 4: and 5 that the pivotal connection between the swinging plate section 2 and the fixed plate section 1 is upon an inclined axis so that as the swinging section 2 is folded backwardly upon section 1, it will rise clear of the saw table and thus pass over any sawdust or dirt which may accumulate upon the table.
Not only does my safety grip prevent the material from being thrown backward by the saw, but it enables the operator to push the stock through much faster than without the grip, since it is not necessary to finish and remove one piece of material before starting another, but each piece of stock may be pushed through by the piece following, and the gripping dog will hold and aid in guiding the material after it leaves the hand of the operator, and while it isbeing pushed forward by the next succeeding piece.
I claim: 1
1. In combination with a circular saw, a gage at the side of the saw, a gripping dog mounted at the end of the gage normally in the path of the material to be sawed, and pivotal connection between the dog and the gageadapted to permit the dog to be swung on the gage into inoperative position out of the path of the material.
2. In combination with a circular saw, a
gage at the side of the saw, a gripping dog, a support for said dog on which said dog is movably mounted, and hinged connec- 1 tion between said support and the gage adapted to permit the support and dog to be swung on the gage into inoperative position out of the path of the material.
3. In combination with'a circular saw, a
gage at the side of the saw, a gripping dog,
hinged to said gage for horizontal movement, means for engaging the support for urging the same in line with the material to be sawed, a gripping dog movable on the support and means engaging the dog to urge the same against the material when said support'is in line therewith.
5. In combination with a circular saw,
and a gage at one end thereof, of a support hinged to the gage, a dog on the support, a spring connected to the support for urging the same into line with the material to be sawed whereby to engage the dog with saidmaterial, the support being adapted to be swung out of line with the material and means for retaining the support in such'latter position. v v
6. A safety grip for circular saws adapted to be mounted on a circular saw table, comprising a gripping dog having an inclined bottom surface and an upright arm,
a vertical support for said dog, a pair of c arms working in parallelismeach pivoted at one end to the upright arm, and at the other to said support, whereby the relation of thegripping dog to the surface of the material to be sawed remains substantially unchanged in all the positions of the grip ping dog, said parallel arms normally extending downwardly toward the table whereby the end of the incoming piece of material to be sawed may successively engage the inclined surface of the 'lower parallel arm and the inclined surface of the gripping dogto lift the same and thereby admit the material to pass under the dog.
7. A safety grip for circular'saws adapted to be mounted on a circularsaw table, comprising a gripping dog having an inclined bottom surface and an upright arm, a vertical support for said dog,a pair of arms working in parallelism each pivoted at one end to the upright arm, and at the other to said support, whereby the relation .of the gripping dog to the surface of the material fed to the same for gradually raising the dog from the table.
Signed by me at Boston, Massachusetts, this 11th day of June, 1914:.
FRED M. STEVENS.
material to be sawed remains substantially unchanged in all the positions of the gripping dog, said parallel arms normally extending downwardly toward the table whereby the lower edge of the lower arm lies substantially in alinement with the beveled edge of the dog to provide a substantially uninterrupted cam surface for engagement with l/Vitnesses:
ROBERT CUSHMAN, FLORENCE A. COLLINS.
Copies of this patent may be obtained for five cents each, by addressing the Commissioner of latents,
Washington, D. G.