US3902244A

US3902244A - Lever action nut cracker

Info

Publication number: US3902244A
Application number: US433488A
Authority: US
Inventors: Frederick R Mcfarland; Walter L Diffenderfer
Original assignee: KD Mfg CO
Current assignee: COMMONWEALTH NATIONAL BANK; HAMILTON BANK MORGAN GUARANTY TRUST Co OF NEW YORK; Easco Hand Tools Inc; KD Mfg CO
Priority date: 1974-01-15
Filing date: 1974-01-15
Publication date: 1975-09-02
Anticipated expiration: 1992-09-02

Abstract

A structural housing having parallel axes on either side includes downwardly depending flanges for sandwiching a pivotable lever arm between the axes. A screw adjustable chisel and a slidable plunger are mounted opposite to one another on the first axis. A screw on the second axis contacts the lever, which passes the screw force with mechanical advantage to the plunger, thereby providing force to crack a nut mounted between the plunger and the chisel.

Description

United States Patent [191 McFarland et al.

[ 1 Sept. 2, 1975 LEVER ACTION NUT CRACKER [75] Inventors: Frederick R. McFarland; Walter L.

Diffenderfer, both of Lancaster, Pa.

[73] Assignee: K-D Manufacturing Company,

Lancaster, Pa.

22 Filed: Jan. 15,1974

21 Appl.No.: 433,488

[ 52] US. Cl 30/272; 30/187 [51] Int. Cl. B26B 17/02 [58] Field of Search 225/93, 103; 30/272,

[56] References Cited UNITED STATES PATENTS 909,739 l/1909 Barrett 83/633 X 2,414,149 l/1947 Hall 30/189 2,482,025 9/1949 Persson 30/187 X 2,731,994 1/1956 Snell 30/1205 2,956,340 10/1960 Levenson 30/187 X Primary ExaminerDonald R. Schran Assistant Examiner-Leon Gilden Attorney, Agent, or FirmPaul & Paul 57 ABSTRACT A structural housing having parallel axes on either side includes downwardly depending flanges for sandwiching a pivotable lever arm between the axes. A screw adjustable chisel and a slidable plunger are mounted opposite to one another on the first axis. A screw on the second axis contacts the lever, which passes the screw force with mechanical advantage to the plunger, thereby providing force to crack a nut mounted between the plunger and the chisel.

7 ,Claims, 2 Drawing Figures LEVER ACTION NUT CRACKER BACKGROUND OF THE INVENTION This invention relates to tools, and more particularly to apparatus for breaking nuts from bolts or the like by compressive cutting.

A long standing mechanics problem has been the removal from bolts or the like of nuts which have become frozen thereon for one reason or another. This general problem is particularly recurrent in the field of automotive mechanics, due to the harsh and widely changing self generated and ambient temperature and weather conditions. Often, the only way the nut can be removed is actually to cut it from the bolt.

In response to this problem, there has been developed a class of compressive nut cutters in which a chisel and a plunger are pushed toward one another by direct application of force to sever a nut located therebetween. Generally, however, the requirements of the direct mode of application of force to the piston to push it toward the chisel have engendered'still further problems. Principally, these relate to the relatively large amount of force required to break a nut; thus, a direct force cutting tool generally requires use of additional wrenches or the like to hold the nut cutting tool during use. Furthermore, this proliferation of equipment needed makes it extremely difficult for the process to be conducted within the limited space often presented in an automotive environment.

It is accordingly an object of the present invention to provide a nut cutting tool which requires only light to moderate force to accomplish the nut cutting task.

It is a further object to provide a nut cutter which is compact in size and shape, thereby facilitating operation in limited space environment.

It is another object of the present invention to provide a nut cutter which may be held in position during use by hand, rather than by a proliferation of other tools.

SUMMARY OF THE INVENTION The present invention achieves the foregoing objects by providing a compact lever-drive nut cutting mechanism. By utilizing a lever to transfer force from a drive screw to a piston, which in turn forces the nut against a fixed chisel, a mechanical advantage is obtained which substantially lessens the difficulty of the cutting process. Moreover, the lever configuration facilitates an extremely compact design, thereby allowing for use in cramped quarters such as often are presented in automotive situations. In a preferred embodiment, an 80% reduction of force required is achieved, thereby permitting the tool to be hand stabilized during usage, rather than requiring use of additional wrenches or the like.

In an illustrative embodiment, the nut is positioned between a chisel member and a slidable piston, both of which are mounted substantially parallel to a screw member on a unitary structural housing. The housing includes downwardly depending flange portions sandwiching a lever arm which pivots between the screw and the plunger. Thus, application of turning force to the screw is transferred with mechanical advantage to the plunger by means of the lever. In turn, the plunger and the nut are driven toward the chisel, thereby providing the compressive force by which the chisel penetrates and eventually breaks the nut. For example, for

the largest sized nut normally encountered in an automobile, preferred embodiments of the present invention reduce the amount of torque required from 40ft.- lb. to 8 ft.-lbs. Clearly, while the former torque would require extensive force to stabilize the cutting tool, the later would not, and could be simply accomplished by hand.

DESCRIPTION OF THE DRAWINGS FIG. 1 shows a side view of an illustrative embodiment of the present invention; and

FIG. 2 shows a sectional view of the embodiment of FIG. 1.

DETAILED DESCRIPTION In the figures, a cutting tool is shown which utilizes lever action for the application of compressive cutting force in accordance with the principles of the present invention. A unitary structural housing 101 is configured with an upwardly depending arm 108 and two downwardly depending

flanges

102 and 103. The upward portion of the housing 101 is adapted to receive a screw adjustable chisel mechanism 104 having a pointed member 106 which actually accomplishes the nut cutting. Directly below the chisel portion 104, the housing 101 is penetrated to receive a slidable plunger member 107 including an upward platform portion and a shaft portion. Embedded in the shaft portion is a flexible insert 109, preferably rubber, which insures a secure fit of the plunger assembly in the housing 101. Between the chisel 104 and the plunger member 107, the housing 101 defines a void, generally designated 112, which is adapted to receive the nut to be broken. Thereupon, application of force to the piston member 107 forces the nut toward the chisel 104, thereby driving the chisel point 106 into the nut, first penetrating and eventually breaking it. On the side of the housing 101 opposite the chisel 104 and the plunger member 107, but on an axis substantially parallel to the axis thereof, is a screw 113 which penetrates into the housing 101.

At the bottom of the housing 101 and substantially sandwiched between the

flanges

102 and 103 is a pivotable lever 111. More particularly, the lever 111 pivots on a pin 110 which extends from flange 102 to flange 103. Thus, the lever 111 defines a longer arm portion which makes contact with the screw 113, and a shorter arm portion on the other side of pivot pin 110 which makes contact with the plunger 107. Accordingly, application of turning force to the screw 113 deflects the longer arm of lever 111 downwardly, and proportionally deflects the shorter arm upwardly against the plunger member 107. As is well known, the torque on either side of the lever must be equal, so that a smaller force applied to the longer arm of lever 111 produces a shorter deflection but a proportionally larger force to the plunger 107. Consequently, a rather limited application of force through the screw 113 will produce substantially more force as applied by the plunger to the nut against chisel 104. In preferred embodiments, the thread width of screw 113 and the arm lengths of lever 111 together produce an reduction in force required for the nut to be broken.

The structural compactness of embodiments of the present invention will be apparent from inspection of the drawings. Whereas much longer apparatus was required in the prior art, preferred embodiments of the present invention are fabricated with dimensions of approximately 4 inches high by 2 /2 inches wide by three quarters inches deep. Of course, such dimensions are completely variable, depending upon the type of cutting to be done.

The compact size of embodiments of the present invention together with the substantially reduced amount of force required to use them gives rise to yet another advantage, in that, while cutting, the device itself may be hand held. This is in marked contrast to the prior art, in which the cutting tool itself would have to be stabilized by means of a wrench or the like.

Another noteworthy feature of the present invention relates to the configuration shown for the lever 111. Not only does the curved, tapering shape enhance the compactness of the overall device, but furthermore the rounded ends which make limited contact with the screw 113 and the bottom of the plunger 107 substantially reduce the friction incurred, and therefore proportionally enhance efficiency of the cutting operation.

Briefly, a suggested procedure for using the tool shown in FIGS. 1 and 2 is as follows. The screw 113 is loosened to the maximum extent required for the platform portion of the plunger member 107 to be all the way down and flush with the housing 101. The tool is then placed, as desired, with the nut to be broken in the void portion 112, and the chisel 104 is screw adjusted until the pointed portion 106 just makes contact with the nut. Thereupon, the housing 101 may be hand held in position while the screw 113 is tightened, for example by means of a wrench. The tightening of screw 113 continues until the chisel point 106 penetrates and breaks the nut.

It is to be understood that the embodiments set forth herein are intended to be illustrative of the principles of the present invention. Many other alternatives will occur to those skilled in the art without departure from the spirit or the scope of the present invention. For example, alternate configurations for the lever 11] and the screw 113 may be utilized, perhaps with even greater mechanical advantage in the transfer of force by lever action to the piston.

We claim:

1. Apparatus for breaking metallic objects comprising: a screw adjustable fixed chisel means; slidably movable piston means for subjecting said objects to compression against said chisel means; screw means; and a lever means pivotable against said piston means to apply force from said screw means to urge said piston means toward said chisel means, said screw means being located on a first of two substantially parallel axes transverse to said lever means and said piston and chisel means being located on the second of said axes; unitary structural housing means for mounting said chisel means, piston means, screw means, and lever means; said housing means including a lower portion sandwiching said lever means and pivotally connected thereto, said screw means and said piston means penetrating said lower portion to contact said lever means on opposite sides of said pivotal connection; said housing means further including an upper portion depending from said lower portion and carrying said chisel means opposite said piston means, said upper and lower portions forming a void for receiving said objects between said chisel means and said piston means.

2. Apparatus as described in claim 1 wherein said piston means includes a platform portion for abutting said objects, a shaft portion depending from said platform portion into said housing means to contact said lever means, and a flexible pusher means embedded in said shaft portion to maintain a tight fit with said housing means.

3. Apparatus as described in claim 1 and further including a pin means penetrating said housing means to limit the pivoting travel of said lever means.

4. Apparatus as described in claim 1 wherein said lever means is generally tapered in shape, a wider portion being on the piston means contacting side of said pivotable connection, and a narrower portion being on the screw means contacting side of said pivotable connection.

5. Apparatus as described in claim 1 having a compact, generally rectangular overall configuration defined by the length of said screw means on a first side, by said screw means, said piston means, and the void between them on the side opposite said first side, by the topmost travel of said screw means and the top of said upper portion of said housing means on a third side, and by the bottom of said lever means on a fourth side.

6. Apparatus for breaking away nuts from bolts by application of compressive cutting comprising:

a chisel means having adjustable fixed mountings on a first axis; a piston means slidably mounted on said first axis opposite said chisel means, said piston means including a platform portion for contacting said nuts and a shaft portion depending from said platform portion away from said chisel means, nuts being located between said chisel means and said piston means and being broken by force applied to said piston means; a screw means movable on a second axis substantially parallel to said first axis; lever means pivotable about a point between said first and second axes and having a first arm contacting said pivot means and a second arm contacting said screw means, said lever means being of a generally tapered configuration from a wide part on said first arm to a narrow part on said second arm;

unitary structural housing means extending at least between said first and second axes, said housing means having flange portions which sandwich said lever means, said housing defining first and second channels on said first and second axes, respectively, for receiving said piston means and said screw means to make contact with associated arms of said lever means, said housing means further including a protuberance for holding said screw means and defining a void between said piston means and said screw means to receive nuts to be broken;

a pivot pin between the flanges of said housing means and through said lever means; and

a pin means penetrating said housing to limit the pivotable motion of said lever means.

7. Apparatus as described in claim 6 wherein said chisel means is screw mounted on said protuberance of said housing means, and wherein said piston means further includes a rubber insert on said shaft portion to secure a tight fit in said housing means.

Claims

6. Apparatus for breaking away nuts from bolts by application of compressive cutting comprising: a chisel means having adjustable fixed mountings on a first axis; a piston means slidably mounted on said first axis opposite said chisel means, said piston means including a platform portion for contacting said nuts and a shaft portion depending from said platform portion away from said chisel means, nuts being located between said chisel means and said piston means and being broken by force applied to said piston means; a screw means movable on a second axis substantially parallel to said first axis; lever means pivotable about a point between said first and second axes and having a first arm contacting said pivot means and a second arm contacting said screw means, said lever means being of a generally tapered configuration from a wide part on said first arm to a narrow part on said second arm; unitary structural housing means extending at least between said first and second axes, said housing means having flange portions which sandwich said lever means, said housing defining first and second channels on said first and second axes, respectively, for receiving said piston means and said screw means to make contact with associated arms of said lever means, said housing means further including a protuberance for holding said screw means and defining a void between said piston means and said screw means to receive nuts to be broken; a pivot pin between the flanges of said housing means and through said lever means; and a pin means penetrating said housing to limit the pivotable motion of said lever means.