US3340611A - Bolt cutter having handles interlinked with cam means and gear means - Google Patents

Description

W. A. LAUCK Sept. 12, 1967 2 Sheets-Sheet 1 Filed July 18, 1966 R. M mm 7 9 mm M m, m N .m 1M a m a in M on v: N o B mm mm 1 9 0 m 0 mm a 7 2 a??? Sept. 12, 1967 w. A. LAUCIK BOLT CUTTER HAVING HANDLES INTERLINKED WITH CAM MEANS AND GEAR MEANS Filed July 18, 1966 2 Sheets-Sheet Fig. 8

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United States Patent 3,340,611 BOLT CUTTER HAVING HANDLES INTERLINKED WITH CAM MEANS AND GEAR MEANS William A. Lauck, Elyria, Ohio, assignor to Emerson Electric Co., St. Louis, Mo., a corporation of Missouri Filed July 18, 1966, Sr. No. 566,064 7 Claims. (Cl. 30124) This invention relates generally to cutting tools, and more particularly to cutters for bolts and cables.

Cutters for bolts and cables and the like, hereinafter referred to as bolt cutters, are designed to provide a very high mechanical advantage to effect very high cutting forces at the jaws. Conventional cam type cutters incorporate a pair of jaws which are pivoted to open and close and a pair of handles pivotally connected to the jaws and cammed in such a manner that when the handles are closed they will force the jaws to close with tremendous Accordingly, one of the main features of this invention is the provision of a bolt cutting tool or the like in which the reaction forces from cutting are carried by smooth cam surfaces on the handles, and the jaws and handles are synchronized by gear segments detachably secured to the handles. The gear segments carry a very minor portion of the load and are essentially non-load carrying members. However, they can be easily replaced if a tooth does break.

Another drawback to the prior art bolt cutters is that pins connecting the handles to the jaws are diflicult to replace when they break or are damaged, it usually being necessary to dismantle a substantial portion of the tool for such replacement.

Accordingly, another feature of this invention is a bolt cutter of the cam type in which the pins connecting the jaws and handles are held securely in position when the tool is in use, but which are easily accessible for replacement when a pin is worn, damaged, or broken.

Still other advantages of the invention, and the invention itself, will become more apparent from the follow ing description of several embodiments thereof, which I description is illustrated by the accompanying drawings and forms a part of this specification. In the drawings:

FIG. 1 is a plan view of one embodiment of a bolt cutter and embodying this invention;

FIG. 2 is a plan view of a portion of the bolt cutter on an enlarged scale from FIG. 1, showing the cover plates slid back for replacement of the pivot pins;

FIG. 3 is a sectional view taken substantially along the planedesignated by the line 33 of FIG. 2;

FIG. 4 is a plan view of a gear segment utilized in the bolt cutter;

FIG. 5 is a sectional view taken substantially on the plane designated by the line 5-5 of FIG. 1;

FIG. 6 is a plan view of the jaw end of another embodiment of a bolt cutter according to this invention incorporating a work piece retainer;

FIG. 7 is the device of FIG. 6 with the retainer pivoted into place and the jaws cutting through cabled material; and

FIG. 8 is a side elevation of the device of FIG. 7.

Patented Sept. 12, 1967 Briefly, the invention contemplates a pair of jaws pivotally connected to a pair of handles by pivot pins. Each of the jaws is pivotally connected to a cover plate by bolts, and bolts through the handles slidably engage the cover plate. When the bolts connecting the cover plate to the jaws are removed, the cover plate can be easily slid back to expose the pivot pins for facile replacement. The handles have smooth cooperating cam surfaces and the coaction of the pivots and the cam surfaces provides for a pivoting action of the jaws between an open position and a closed position. Non-load carrying gear segments are detachably secured to the handles to synchronize the motion of the handle and jaws. The device may also incorporate a work piece retainer connected to the jaws for pivotal movement into position to hold the piece being cut and prevent it from slipping out of the jaws.

More particularly, FIGS. 1 through 5 show one embodiment of a bolt cutter. According to this invention, the cutter includes a pair of handles 10 and a pair of jaws 12. The jaws have cutting edges or surfaces 14 and are pivotally connected to the handles by pivot pins 16. A pair of flat plates 18 and 20 are disposed on opposite sides of the jaws 12 and 14. The jaws 12 are pivotally connected to the plates 18 and 20 by bolts 22. Each bolt 22 passes through the plate 18 and one of the jaws 12, and is threaded into the other plate 20, as shown in FIG. 5. The bolt can be staked to provide a snug fit which will not loosen during use, but which can be loosened when it is desired to remove the bolts 22. Preferably, the bolts are locked by a lock plate 23 which comprises a flat plate, the ends of which are notched at 23a for engagement with the bolt heads, and is held in place by a screw 25 which is threaded into the plate 18.

Each of the plates 18 and 20 has a pair of elongated slots 24 and 26, the slots 24 of the opposite plates being aligned as are the slots 26. A bolt 28 extends through the slots 24 and one of the handles 10, and a bolt 30 ex-, tends through slots 26 and the other handle. Nuts 32 and 34 are secured to the ends of bolts 28 and 30, respectively. Each of the plates 18 and 20 also has a transverse reinforcing rib 35.

Each of the handles is bifurcated near the end to provide a pair of accurate cam surfaces 36 with a slot 38 therebetween. The cam surfaces 36 terminate in flat stop surface 39. Gear segments 40 are disposed in the slots 38, with their teeth in meshing engagement and their opposite ends engaging the bolts 28 and 30. Pins 42 secure the segments 40 inplace. Since the plates 18 overlie the pins 42, the pins can be loosely mounted in the jaws and segments forfacile removal when the plates are removed so that the segments 40 can be easily replaced. Thumb screws 44 are provided in the handles which will adjust the amount of closure of the handles in a conventional manner.

When the tool is in assembled relationship as shown in FIG. 1 and the handles are opened, the jaws will pivot to an open position with the cutting edges 14 spread. The stop surfaces 39 will engage each other to limit the jaw opening. The bolt or other object to be cut is inserted between the jaws, and the handles are squeezed together. As the handles are squeezed, the jaws pivot to the closed position about the bolts 22, connecting them to the cover plates 18 and 20. The handles and the jaws also pivot with respect to each other about the pivot pins 16, which pins move away from each other. As the pins 16 move away from each other, the bolts 28 and 30 move forward in the slots 24 and 26. The reaction forces from the cutting action -are carried by the cam surfaces 36 and the pivot pins 16. The gear segments 40 synchronize the movement of the handles and jaws, but carry only a minor portion of the load and are essentially non-load carrying members, the major portions of the load being carried on the smooth cam surfaces 36. This combination of smooth cam surfaces with non-load carrying gear segments in the handle provides all the advantages of gear synchronized movement, without the major disadvantages of the gears being load carrying members.

As can be seen in FIG. 1, the plates 18 and 20 cover the pivot pins 16 in both the open and closed positions. However, if one of the pins 16 should break or become bent during use, which can happen because of the great forces to which they are subjected, the bolts 22 can be removed, and the cover plates 18 and 20 slid back, as shown in FIG. 2, so that the pins 16 are exposed, or uncovered by recess portions formed in the plates 18 and 20. The slots 24 and 26 in the plates allow this movement, and the pins 16 can be removed and replaced by new pins. This also enables the jaws to be easily replaced when they become worn. This feature of easy access allows rapid replacement of broken or damaged pivot pins with a minimum disassembly of the tool and without disturbing the synchronizing gears.

Also, in the event that a gear tooth does break, the cover plates can be completely removed and the individual gear segment replaced. Since the segments used in each handle are identical, a stock of only a single type of segment need be maintained.

Referring now to FIGS. 6 through 8, another embodiment of a bolt cutter according to this invention is shown incorporating a retainer 50 for preventing a bolt or other object being cut from sliding out of the jaws during cutting. The retainer 50 incorporates a pair of L-shaped members 52. The L-shaped members 52 are mounted pivotally on a bolt 56 which has a nut 58 threaded on the end thereof, and passes through the plates 18 and the jaws 12. This replaces the staked bolts of the previously described embodiment. The head of the bolt 56 is provided with a stepped shoulder portion 60 which extends through one of the members 52. A spring washer 62 is located between the head of the bolt 56 and the member 52. The nut 58 has a similar stepped portion 64 extending through the other member 52 and a spring washer 66 is interposed between the nut 58 and members 52. The members 52 have work piece engaging surfaces 68 which are disposed to engage the object being cut, as shown in FIG. 7. The surfaces 68 are provided with a series of notches or grooves 70 to engage and retain the piece in cutting position between the jaws. Also in this embodiment the cutting edges of the jaws are serrated to better enable the jaws to cut a smooth object such as a bolt.

To utilize the device of this embodiment the retainer 50 is pivoted away from the opening of the jaws as shown in FIG. 6. The tension on the nut and bolt 56 and 58 is adjusted so that the retainer is loose enough to swing freely, but is tight enough so that it will stay in the position to which it is moved. When the retainer is in this retracted position, the jaws can be opened and the bolt or other object to be cut inserted between the jaws. The retainer is then pivoted until the surfaces 68 engage the work piece as shown in FIG. 7. The grooves 70 on the retainer are necessary to provide a firm non-slipping grip so that the object being cut will be held securely and positively in its cutting position and the jaws will not slip against a smooth surface. The cutting takes place exactly as in the previously described embodiment with the retainer 50 preventing the object being cut from slipping out from between the jaws.

Having thus described my invention in several embodiments thereof, I am aware that numerous and extensive departures may be made therefrom without departing from the spirit or scope of the invention as defined by the appended claims.

I claim:

1. In a bolt cutter having a pair of spaced plates with first and second cutter jaws disposed therebetween with pivot means pivotally mounting said jaws thereto, first and second handles connected to the first and second cutter jaws by first and second pivot pins, and means to slidably engage said handles with said plates, and wherein said jaws are operable by said handles for pivotal cutting movement, the improvement which comprises, mutually engaged smooth cam surface means on said handles, and gear means in meshing engagement detachably secured to said handles, whereby said gear segments synchronize the movement of the handles and jaws and said cam surfaces and pivot pins carry the major portion of the reaction forces.

2. The combination of claim 1, wherein said plates overlie and retain said pivot pins in the operative positions of said tool.

3. The combination of claim 2, further including recess portions formed in said plates, wherein when said pivot means mounting said jaws to the plates is removed, said plates are movable to a retracted position whereby said recess portions expose said pivot pins for removal.

4. The combination of claim 3, wherein said sliding contact between said plates and said handles is provided by slots in said plates and bolt means extending through said handles.

5. The combination of claim 1, wherein each of the handles has a slot providing bifurcated cam surfaces, and said gear means are disposed in said slots.

6. The combination of claim 1 further characterized by retainer means mounted for movement into and out of engagement of an object being cut, said retainer having grooved engaging surfaces.

7. The combination of claim 6, wherein said retainer member includes first and second generally L-shaped members pivotally mounted with respect to said jaws.

References Cited UNITED STATES PATENTS 672,869 4/1901 Bolsinger 30191 1,735,317 11/1929 Helwig et al. 30-124 1,836,967 12/1931 Helwig 30-192 X 1,901,739 3/1933 Engel 30124 X WILLIAM FELDMAN, Primary Examiner. G, WEIDENFELD, Assistant Examiner

Claims (1)

1. IN A BOLT CUTTER HAVING A PAIR OF SPACED PLATES WITH FIRST AND SECOND CUTTER JAWS DISPOSED THEREBETWEEN WITH PIVOT MEANS PIVOTALLY MOUNTING SAID JAWS THERETO, FIRST AND SECOND HANDLES CONNECTED TO THE FIRST AND SECOND CUTTER JAWS BY FIRST AND SECOND PIVOT PINS, AND MEANS TO SLIDABLY ENGAGE SAID HANDLES WITH SAID PLATES, AND WHEREIN SAID JAWS ARE OPERABLE BY SAID HANDLES FOR PIVOTAL CUTTING MOVEMENT, THE IMPROVEMENT WHICH COMPRISES, MUTUALLY ENGAGED SMOOTH CAM SURFACE MEANS ON SAID HANDLES, AND

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