US3648540A

US3648540A - Lever operated hand tool improvement

Info

Publication number: US3648540A
Authority: US
Inventors: Robert G King
Original assignee: Texaco Inc
Current assignee: Texaco Inc
Priority date: 1969-11-21
Filing date: 1969-11-21
Publication date: 1972-03-14
Anticipated expiration: 1989-03-14

Abstract

An adjustable lever arm extension for use on hand tools that employ an operating lever to apply force in operation of the tool. The extension is pivoted near the extremity of the operating lever, and has a grip that releases under predetermined force to permit the extension to pivot freely after that force has been reached. This limits the maximum amount of operating force applied by the tool.

Description

States Patent [151 3,648,540

King Mar. 14, 1972 [54] LEVER OPERATED HAND TOOL 1,099,079 6/1914 IMPROVEMENT 1,733,642 10/ 1,881,060 10/1932 [72] Inventor: Robert G. Klng, Stroud, Okla. 2 31 3 4/ 959 [73] Assignee: Texaco Inn, New York, NY. 3'060'763 10/1962 Filedi 1969 Primary Examiner-William F. ODea Assistant ExaminerF. D. Shoemaker [2U Appl' Attorney-Thomas H. Whaley and Carl G. Ries [52] US. Cl ..74/524, 74/525, 74/544, [57] ABSTRACT 51 Int. Cl. s 5 :50?) adjusable have hand um 58 Field ofSearch ..74/523 519 522 584 524 emPlY 1" apply PPemim the 74,525 254/l29 81752 tool. The extension IS pivoted near the extremlty of the operating lever, and has a grip that releases under predetermined force to permit the extension to pivot freely after that force [56] References cued has been reached. This limits the maximum amount of operat- UNITED STATES PATENTS s force pp y the tool- 2,594,89l /l 952 Embree ..74/524 2 Claims, 2 Drawing Figures LEVER OPERATED HAND TOOL IMPROVEMENT BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to hand tools generally and more particularly concerns an improvement for lever operated hand tools.

2. Description of the Prior Art While there are known arrangements for indicating torque in connection with hand tools having lever arm operation, they are not known to provide a release of actuation force when a predetermined maximum is reached. Nor is it known to provide an extension that is adjustable in lever arm length from the tool fulcrum with an arrangement for releasing the application of torque to the tool when a predetermined amount of force has been reached. It is the latter attributes which this invention specifically provide and which make practical a predetermined constant maximum application of torque, with respect to hand operated tools generally.

SUMMARY OF THE INVENTION The invention relates to a combination that is applicable to a hand tool of the type having an operating lever for applying force in operation of the tool. The combination comprises lever extension means carried by said operating lever, and means for holding said extension means in operative relation with said operating lever. The latter means comprises means for releasing said holding means when a predetermined amount of force is applied to said lever.

Also briefly, the invention concerns a hand tool of the type having an operating lever for applying force in operation of the tool. It comprises in combination, a handle for use in applying said operating force, and means for effectively releasing said handle from operative relationship with said tool when a predetermined maximum force is applied.

Again briefly, the invention concerns a hand tool of the type having an operating lever for applying force in operation of the tool. The invention concerns a combination which comprises an auxiliary lever arm that has a permanent magnet adjustably mounted near the inner end of said auxiliary arm, and a handle located near the extremity of said auxiliary arm. The combination also comprises a support collar for holding said auxiliary lever arm slidable longitudinally therein and pivot means for attaching said collar to said operating lever near the extremity thereof. The combination also comprises means for adjustably securing said auxiliary lever arm in said support collar, to permit variable setting of the spacing of said permanent magnet from said pivot along said operating lever.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects and benefits of the invention will be more fully set forth below in connection with the best mode contemplated by the inventor of carrying out the invention and in connection withwhich there are illustrations provided in the drawings, wherein:

FIG. I is an elevation of an assembly, illustrating the invention as applied to the operating lever arm of a banding tool that is shown in dashed lines; and

FIG. 2 is a fragmentary elevation showing the same as sembly view as FIG. 1 but with the parts in operating position for application of torque to the operating lever of the tool.

DESCRIPTION OF THE PREFERRED EMBODIMENT It is to be observed that the invention is applicable generally to any hand operated tool which is actuated by the application of torque, e.g., by means of an operating lever. While FIG. I of the drawings illustrates somewhat schematically a banding tool, it will be appreciated that many other hand operated tools might have this invention applied thereto.

With reference to the FIGS. I and 2 of the drawings, it will be noted that there is a hand operated tool 11 that is shown only in FIG. 1. Since it is not a material part of the invention, it is illustrated in dashed lines.

Thus, there is a tool II which might take other forms but is illustrated as a banding tool. It has an operating lever 12 which is actuated manually to apply torque in providing operating force for actuating the tool Ill. The lever I2 is pivoted about a pivot point (FIG. I) on the tool 11, and such pivotal action applies a torque to cause operation of the tool.

In order to have predetermined and adjustable maximum force that may be applied to the lever I2, there is an auxiliary lever arm 16. This and its related elements are shown somewhat exaggerated in relative size viz-a-viz the tool 11 and its handle or lever 12. However, it will be understood that such is a matter of design and therefore is a matter that is within the purview of one skilled in the art. I

The arm 16 is slidable longitudinally within a collar I7, which in its turn is pivotally mounted near the end of the lever 12 by means of a pivot pin 20. The pin 20 extends through both sides of a bifurcated portion of the collar 17, which portion straddles the lever arm 12. It will be noted that there is a set screw 2I in the top (as viewed in the drawings) of the collar I7. This acts of fix the slidable position of the auxiliary lever arm 16 relative to the collar 17.

At the outer extremity (relative to the tool II) of the auxiliary arm 16 there is a spherical handle 22 for being gripped manually as force is applied to the tool. At the other end of the arm I6, i.e., the end which when pivoted will lie substantially parallel with the lever arm 12 (see FIG. 2) there is a bracket 26 that is integrally attached to the end of the arm 16. While the bracket 26 might take various forms, it may be constructed of an angle shaped body which stands with one half at right angles to the end of the arm I6 where it is attached thereto. The other half lies parallel to the arm I6 so as to form a support for a permanent magnet 27. Magnet 27 is mounted in a housing 28 in any feasible manner, e.g., by being pinned therein as indicated by a pin 29. The housing 28 is mounted pivotally near the extremity of the bracket 26, and this may be accomplished in any feasible manner such as that illustrated. There is provided a lug 32 which is integral with and extends from the top of the housing 28, and a pivot pin 33 extends through the free end of the bracket 26 and through the lug 32 so as to provide the desired pivotal support for the housing and the magnet contained therein.

In order to hold the pivotal support for the magnet in position to provide an even gripping action against the lever arm I2 of the tool, there is an adjustment screw 36. The screw 36 extends througha tapped hole in the upstanding portion of bracket 26 and rests against the side of the housing 28. There is a nut 37 which may be tightened against the bracket 26 so as to maintain a desired pivotal position of the housing 28.

OPERATION It will be appreciated that the operation of this invention involves the ability to adjust the maximum amount of force that will be applied by a hand tool which employs a lever arm that is manually actuated. This entails the use of the pivotally attached auxiliary arm I6 which is mounted near the free end of the lever 12. The arm 16 may swing freely about its pivot 20 except when the magnet 27 is in contact with the lever I2. It will be appreciated that if the lever 12 is not constructed of a ferrous metal, there would be provided a strip (not shown) along the upper edge of the lever for having the magnet 27 make gripping contact therewith.

With reference to FIG. 2, it will be noted that this is the position the parts will take prior to the application of force in operation of the tool. Now, the maximum amount of force which may be applied to the tool depends upon the total amount of force, which includes the leverage from handle 22 to the tool operating pivot I5. However, this is only true so long as the magnet 27 remains in gripping contact with the lever I2. Consequently, whenever the amount of force being applied to the handle 22 exceeds that amount required to cause the magnet 27 to break free from the tool lever arm I2, the auxiliary arm I6 will pivot freely and application of force to the tool with cease. Thus, a predetermined maximum application of torque is transmitted to the tool, and this rriay be adprising justed for different desired forces by adjusting the position of an auxiliary lever arm with arm 16 in its supporting collar 17. It will be appreciated that a permanent magnet adjustably mounted near the inner the force on the magnet 27 tending to break it out of contact end of said auxiliary arm, and with the lever 12, changes as the setting of the auxiliary m 5 a handle located near the outer extremity of said auxiliary 16 is changed. arm,

As an example of the foregoing it will be noted th t if th a support collar for holding said auxiliary lever arm slidable auxiliary arm 16 is set with the handle 22 close to the end of longitudinally ther the lever arm 12, there will be greater force necessary to break l)wot means attaching Said collar to Said Operating level the magnet 27 free and greater maximum force may be apthe end thereof, f plied to the tool. The change (reduction) in the leverage of the meafls adlustably Securing fy lever tool input will have less effect than the change in the max- $ald PP? collar to Perm1t Varlable Setting f the p imum force that can be applied before the magnet breaks free. "8 of S ald penflanem magnet from Said P means While the foregoing specific embodiment of the invention along 531d operatmg l5 2. The invention according to claim 1 wherein said operating lever is constructed of ferrous metal, and

wherein said adjustable mounting for said permanent magnet is pivotal to permit even contact by the magnet with said operating lever. 4: a:

has been set forth in considerable detail in accordance with the applicable statutes, this is not to be taken as in any way limiting the invention but merely as being descriptive thereof.

lclaim: 1. In a hand tool of the type having an operating lever for applying force in operation of the tool, the combination com-

Claims

1. In a hand tool of the type having an operating lever for applying force in operation of the tool, the combination comprising an auxiliary lever arm with a permanent magnet adjustably mounted near the inner end of said auxiliary arm, and a handle located near the outer extremity of said auxiliary arm, a support collar for holding said auxiliary lever arm slidable longitudinally therein, pivot means for attaching said collar to said operating lever near the free end thereof, and means for adjustably securing said auxiliary lever arm in said support collar to permit variable setting of the spacing of said permanent magnet from said pivot means along said operating lever.

2. The invention according to claim 1 wherein said operating lever is constructed of ferrous metal, and wherein said adjustable mounting for said permanent magnet is pivotal to permit even contact by the magnet with said operating lever.