US3697060A

US3697060A - Adjustable height and variable force clamp

Info

Publication number: US3697060A
Application number: US145260A
Authority: US
Inventors: Walter A Kulson
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-05-20
Filing date: 1971-05-20
Publication date: 1972-10-10
Anticipated expiration: 1989-10-10

Abstract

A quick-acting, spring-pressed clamp adjustable for spring compression clamping force having a body with a lever fulcrummed on a pillar which is heightwise adjustable. A post on the body is also heightwise adjustable for compensating for the adjusted height of the pillar fulcrum point. Thus height adjustment of the post and pillar adjust the height of the lever. A clamp jaw is connected to the weight end of the lever with the jaw thereby being height opening adjustable relative to a workpiece. The post pivotally supports a toggle knee block which is connected by link to the power end of the lever. The knee block is actuated by a handle. A spring supported on the body surrounds the post and an adjustment nut on the body supports the post on the spring. An opposing nut on the post opposes the adjustment nut on the post so that the spring may be pre-compressed under load therebetween to adjust the clamping force as desired without changing the adjusted height of the jaw relative to a workpiece in its open position and without interference in its clamped position.

Description

United States Patent Kulson Oct. 10, 1972 [54] ADJUSTABLE HEIGHT AND [57] ABSTRACT VARIABLE FORCE CLAMP A quick-acting, spring-pressed clamp adjustable for [72] Inventor: Walter A. Kulson, 30034 Paul spring compression clamping force having a body with Court, Warren, Mich. 48091 a lever fulcrummed on a pillar which is heightwise ad- [22] Filed: May 20, 1971 justable. A post on the body is also heightwise adjusta- [211 App]. No.: 145,260

[52] US. Cl ..269/228, 269/236 [51] Int. Cl ..B25b l/14, B25b 5/12 [58] Field of Search ..269/196, 198, 201, 204, 221, 269/224, 228, 229, 236

[56] References Cited UNITED STATES PATENTS 2,439,483 4/ 1948 Merriman ..269/228 X 2,537,594 l/l95l Lehmann ..269/229 3,31 1,367 3/1967 Sendoykas ..269/228 X Primary Examiner-Robert L. Spruill Attorney-William T. Sevald ble for compensating for the adjusted height of the pi]- lar fulcrum point. Thus height adjustment of the post and pillar adjust the height of the lever. A clamp jaw is connected to the weight end of the lever with the jaw thereby being height opening adjustable relative to a workpiece. The post pivotally supports a toggle knee block which is connected by link to the power end of the lever. The knee block is actuated by a handle. A spring supported on the body surrounds the post and an adjustment nut on the body supports the post on the spring. An opposing nut on the post opposes the adjustment nut on the post so that the spring may be pre-compressed under load therebetween to adjust the clamping force as desired without changing the adjusted height of the jaw relative to a workpiece in its open position and without interference in its clamped position.

5 Claim, 3 Drawing Figures ADJUSTABLE HEIGHT AND VARIABLE FORCE CLAMP This invention relates to a quick-acting, springpressed clamp which is adjustable for spring clamping force and adjustable for opening height to accommodate various size workpieces.

A primary object of the invention is to provide a clamp which is simple in design and construction, easy to mount on a machine or fixture, and inexpensive to manufacture.

An object of the invention is to provide a clamp having a lever actuated by a toggle knee block to develop high mechanical clamping force.

An object of the invention is to apply the high clamping force of the clamp through a spring which is adjustable for spring load imposed so that the clamping force applied to a workpiece is adjustable by varying the compression of the spring.

An object of the invention is to provide a clamp jaw slidably mounted on the clamp body over a substantially long travel to accomodate various size workpieces.

An object of the invention is to provide a lever pivotally connected to the jaw for moving the jaw between its open and clamped positions.

An object of the invention is to provide an adjustable height fulcrum for the lever for positioning the jaw via the lever at the desired height.

An object of the invention is to provide a height-wise adjustable post supporting the actuating linkage connected to the lever for adjusting the height of the actuating linkage to compensate for the adjusted height of the lever and the jaw.

An object of the invention is to provide a spring based on the clamp body and surrounding the post and compression-wise adjustably connected to the post by an adjusting nut so that the post is based on the body via the spring with the spring adjustably compressable via the nut to vary the spring compression load applied through the clamp to a workpiece as desired.

These and other objects of the invention will become apparent by reference to the following description of a clamp embodying the invention taken in connection with the accompanying drawing, in which:

FIG. 1 is a side elevational view of a clamp embodying the invention in operational position on a machine or fixture in clamping condition on a workpiece shown in broken lines.

FIG. 2 is an end elevational view of the device seen in FIG. 1 from the right end thereof with the machine or fixture broken away; and

FIG. 3 is a vertical cross-sectional view of the device seen in FIGS. 1 and 2 taken on the line 3-3 of FIG. 2, in the open unclamped position with the showing of the workpiece deleted.

Referring now to the drawing wherein like numerals refer to like and corresponding parts throughout the several views, the clamp disclosed therein to illustrate the invention comprises, a body having transverse apertures for receiving

mounting screws

11, 12, and 13. The screws 11-13 are threaded in a machine or fixture 14 having an anvil or base 15 under the body 10. The body 10 has slide

ways

16 and 17 attached to the body by screws 18. The

ways

16 and 17 and the body 10 form a slide channel. A jaw 20 is slideably positioned in the slide channel against the body 10 behind the

ways

16 and 17 for movement toward and away from the base 15.

The body has a top 21, a bottom 22, and a channel 23 extending therebetween. A fulcrum pillar 24 lies in the channel 23 and projects above the top 21 and below the bottom 22. Jam nuts 25 and 26 are threaded on the pillar 24 and abut the top 21 and bottom 22 of the body 10 respectively and secure the pillar 24 relative to the body 10. The upper end of the pillar 24 has a top aperture. A fulcrum pin 27 lies in the top aperture of the pillar 24. The upper end of the jaw 20 has an aperture and a pin 28 lies therein.

A lever 30 is fulcrumed in its intermediate position on the pillar 24 via the pin 27 with its weight end pivotally connected to the jaw 20 via the pin 28. The power end of the lever 30 has an aperture receiving a pin 31. A push-pull link 32 has an end pivotally connected to the lever 30, by the pin 31. A toggle kneeblock 33'is pivotally connected to the other end of the link 32 by a pin 34.

The body 10 has a post bore 40. A threaded post 41 lies in the bore 40 and has an upper end equipped with an aperture receiving the pin 42. The pin 42 pivotally connects the knee-block 33 on the post 41. A spring 43 surrounds the post 41 in the bore 40. A heavy washer or plate 44 is welded on the body 10 at the bore 40. A spring 43 lies in the bore 40, surrounds the post 41, and has a bottom end based on the plate 44. An adjusting nut 45 is threaded on the post 41 and abuts the top end of the spring 43 in opposition to the plate 44. The post 41 is supportedon the body 10 via the plate 44, spring 43 and adjusting nut 45. An opposing nut 46 is threaded on the post 41 and abuts the plate 44. The opposing nut 46 prevents upward movement of the post 41. The opposing nut 46 also opposes the adjusting nut 45 relative to pre-load compression of the spring 43. An arm or handle 50 is attached to the knee-block 33 and moves the knee-block 33 to the pivot-point aligned and link 32 extended clamping position seen in FIGS. 1 and 2 and to the pivot-point cocked and link 32 retracted unclamping position seen in FIG. 3.

The pin 28 interconnecting the weight end of the lever 30 with the jaw 20 is undersize relative to the aperture in the lever 30 and/or the aperture in the jaw 20. As these apertures are oversize relative to the pin 28, relative movement is allowed between the lever 30 and the jaw 20 in their movement between the clamping position seen in FIG. 1 and the open position seen in FIG. 3.

In movement of the jaw 20 from the clamping position of FIG. 1 to the open position of FIG. 3, the pin 28 provides the connecting link between the parts. The pin 28 also initially provides the connecting link between the parts in their movement from the open position of FIG. 3 to the clamping position of FIG. 1 until the outer end of the lever 30 makes contact with the boss on the top of the jaw 20. This contact occurs about midway in the clamping direction of movement of the parts. Thus during the last portion of the clamping movement, the end of the lever 30 and the boss on the jaw 20 are in abutting engagement and transfer the entire heavy clamping force between the lever 30 and the jaw 20. Thus the pin 28 is subjected to only light forces in opening and the first portion of clamping and the lever 30 and jaw 20 directly engage during the imposition of the heavy clamping forces exerted by the mechanism.

The oversize apertures in the jaw 20 and/or lever 30 relative to the pin 28 thus allow for relative movement between the lever 30 and jaw 20 to eliminate any binding action therebetween both in the opening and closing of the jaw 20 and also allow force relief on the pin 28 after the lever 30 and jaw 20 directly engage one another in the last portion of movement in the clamping direction.

In use and operation, the linkage is moved to the unclamped position seen in FIG. 3 and a workpiece 51 positioned on the base 15. The operator then moves the handle 50 to the position seen in FIGS. 1 and 2 with the toggle knee 33 and link 32 raising the power end of the lever 30 and depressing the weight end of the lever 30 which moves the jaw 20 downwardly against the workpiece and clamps it against the base 15.

To adjust the clamp device for a different size workpiece than shown, such as a larger workpiece, the operator loosens the jam nut 26 on the pillar 24 and the opposition nut 46 on the post 41. The operator then tightens the jam nut 25 on the fulcrum pillar 24 which raises the lever 30 and the jaw 20 to accommodate the larger workpiece. As the opposition nut 46 is free, this also raises the actuating linkage and post 41 to compensate for the increased height of the lever 30 and the jaw 20. The operator then tightens the jam nut 26 on the pillar 24 to secure the pillar 24, lever 30, and jaw 20 at the adjusted height. The operator then tightens the adjusting nut 45 down on the spring 43 to compress the spring 43 against the plate 44 to provide the desired spring loading of the spring 43. The operator then tightens the opposition nut 46 to abut the plate 44 to prevent the post from moving upwardly when the device is in the unclamped condition. This provides a reaction point for raising the jaw 20 and prevents the spring 43 under pre-load compression exerting closing force on the linkage and lever 30 and this allows retraction on the jaw 20.

The device may be adjusted for desired spring compression load by tightening the adjusting nut 45 down on the spring 43 against the reaction point provided by the opposition nut 46 as both exert force on the post 41 in opposite directions which force is imposed on the spring 43. This provides the adjusted pre-load on the spring 43 prior to clamping. The clamping action of the device further compresses the spring 43 as the post 41 and opposition nut 46 are free to move downwardly whereas the spring 43 is blocked against further downward movement by the plate 44. Thus the clamping force exerted on the workpiece 51 by the jaw 20 is a combination of the mechanical advantage of the lever 30 and the toggle knee-block 33, the strength of the spring 43, and the adjusted pre-load imposed on the spring 43. Thus the operator may adjust the force imposed on the workpiece by selecting a spring of desired strength and adjusting the pre-load compression of the spring as stated.

In use the jaw is quickly resiliently spring-pressed against the workpiece with the desired force by moving the handle 50 to the clamping position and quickly released by movement of the handle in the opposite direction.

The appended claims define the scope of the invention.

I claim:

1. A quick acting combination toggle and lever clamp capable of adjustable spring compression to vary the clamping force as desired and adjustable for opening height to accommodate various size workpieces, comprising;

a body having a slide way, a fulcrum pillar channel,

and a post bore,

a clamp jaw in said body slide way,

a lever having weight and power ends and an intermediate fulcrum portion; said lever being pivotally mounted on said fulcrum pillar in its said intermediate fulcrum portion and pivotally connected to said clamp jaw at its said weight end;

a push-pull link having one end pivotally connected to said power end of said lever and an extending end,

a toggle knee block having two pivot points with one said pivot point pivotally connected to said extending end of said link,

a post having top and bottom ends lying in said post bore of said body with its top end pivotally connected to said other pivot point of said knee block; said bottom end of said post being freely slideable in said post bore;

a spring surrounding said post in said bore; said spring having top and bottom ends;

said body having spring supporting means abutting said bottom end of said spring;

said post being threaded for receiving a nut thereon;

an adjustment nut threaded on said post and engaging said top end of said spring; and

an actuator handle on said knee block;

movement of said handle in one direction cocking said knee block and moving said lever power end via said link toward said body to raise said weight end of said lever to retract said jaw away from a workpiece;

manual movement of said handle in the other direction moving said power end of said lever via said link away from said body to depress said weight end of said lever to advance said jaw toward a workpiece;

said post being supported on said spring via said adjustment nut;

said adjustment nut being adjustable on said post relative to said spring to increase and decrease the compression of said spring to increase and decrease the resulting weight force of said jaw against a workpiece in the advanced clamping position of said jaw.

2. In a device as set forth in claim 1, said post having a threaded end extending beyond said spring supporting abutment means on said body; and an opposing nut threaded on said threaded projecting end of said post; said opposing nut abutting said abutment means;

said opposing nut acting in opposition to said spring adjustment nut to permit said spring adjustment nut to exert spring compression force on said spring to pre-load said spring as desired without pre-load affect on the open head space, shut engagement, and travel of said jaw.

3. In a device as set forth in claim 1, said body having a top and a bottom; said pillar being threaded;

a base nut on said pillar engaging said top of said body thereby supporting said pillar against inward movement relative to said body, and

a jam nut on said pillar engaging said bottom of said body supporting said pillar against outward movement of said pillar relative to said body; said pillar being raisable and lowerable by said nuts to selectively raise and lower its fulcrum point to adjust the height of said lever and jaw relative to a workpiece;

said spring adjustment nut being adjustable relative to said post to also selectively raise and lower said post on said spring at said power end of said lever to compensate for height adjustment of said fulcrum point of said lever at said pillar and to compress said spring as desired at the adjusted height.

4. In a device as set forth in claim 1, said clamp jaw and said lever having aligned apertures and a pin lying in said apertures pivotally interconnecting said clamp jaw and said lever;

said pin being undersize relative to at least one aperture in said clamp jaw and said lever to allow relative movement therebetween to eliminate binding during clamping and opening movement;

said lever having an outer end and said clamp jaw having a top portion engaging one another in the clamping direction of movement to directly transfer force between said lever and said clamp jaw and to relieve heavy force imposition on said pm.

5. In a device as set forth in claim 1, said post having a threaded end extending beyond said spring supporting abutment means on said body; and an opposing nut threaded on said threaded projecting end of said post; said opposing nut abutting said abutment means;

said opposing nut acting in opposition to said spring adjustment nut to permit said spring adjustment nut to exert spring compression force on said spring to pre-load said spring as desired without pre-load affect on the open head space, shut engagement, and travel of said jaw;

a base nut on said pillar engaging said top of said body thereby supporting said pillar against inward movement relative to said body;

said spring adjustment nut being adjustable relative to said post to also selectively raise and lower said post on said spring at said power end of said lever to compensate for height adjustment of said fulcrum point of said lever at said pillar and to compress said spring as desired at the adjusted height;

said clamp jaw and said lever having aligned apertures and a pin lying in said apertures pivotally interconnecting said clamp jaw and said lever;

said lever having on outer end and said clamp jaw having a top portion engaging one another in the clamping direction of movement to directly transfer force between said lever and said clamp jaw to relieve heavy force imposition on said pin.

Claims

1. A quick acting combination toggle and lever clamp capable of adjustable spring compression to vary the clamping force as desired and adjustable for opening height to accommodate various size workpieces, comprising; a body having a slide way, a fulcrum pillar channel, and a post bore, a clamp jaw in said body slide way, a lever having weight and power ends and an intermediate fulcrum portion; said lever being pivotally mounted on said fulcrum pillar in its said intermediate fulcrum portion and pivotally connected to said clamp jaw at its said weight end; a push-pull link having one end pivotally connectEd to said power end of said lever and an extending end, a toggle knee block having two pivot points with one said pivot point pivotally connected to said extending end of said link, a post having top and bottom ends lying in said post bore of said body with its top end pivotally connected to said other pivot point of said knee block; said bottom end of said post being freely slideable in said post bore; a spring surrounding said post in said bore; said spring having top and bottom ends; said body having spring supporting means abutting said bottom end of said spring; said post being threaded for receiving a nut thereon; an adjustment nut threaded on said post and engaging said top end of said spring; and an actuator handle on said knee block; movement of said handle in one direction cocking said knee block and moving said lever power end via said link toward said body to raise said weight end of said lever to retract said jaw away from a workpiece; manual movement of said handle in the other direction moving said power end of said lever via said link away from said body to depress said weight end of said lever to advance said jaw toward a workpiece; said post being supported on said spring via said adjustment nut; said adjustment nut being adjustable on said post relative to said spring to increase and decrease the compression of said spring to increase and decrease the resulting weight force of said jaw against a workpiece in the advanced clamping position of said jaw.

2. In a device as set forth in claim 1, said post having a threaded end extending beyond said spring supporting abutment means on said body; and an opposing nut threaded on said threaded projecting end of said post; said opposing nut abutting said abutment means; said opposing nut acting in opposition to said spring adjustment nut to permit said spring adjustment nut to exert spring compression force on said spring to pre-load said spring as desired without pre-load affect on the open head space, shut engagement, and travel of said jaw.

3. In a device as set forth in claim 1, said body having a top and a bottom; said pillar being threaded; a base nut on said pillar engaging said top of said body thereby supporting said pillar against inward movement relative to said body, and a jam nut on said pillar engaging said bottom of said body supporting said pillar against outward movement of said pillar relative to said body; said pillar being raisable and lowerable by said nuts to selectively raise and lower its fulcrum point to adjust the height of said lever and jaw relative to a workpiece; said spring adjustment nut being adjustable relative to said post to also selectively raise and lower said post on said spring at said power end of said lever to compensate for height adjustment of said fulcrum point of said lever at said pillar and to compress said spring as desired at the adjusted height.

4. In a device as set forth in claim 1, said clamp jaw and said lever having aligned apertures and a pin lying in said apertures pivotally interconnecting said clamp jaw and said lever; said pin being undersize relative to at least one aperture in said clamp jaw and said lever to allow relative movement therebetween to eliminate binding during clamping and opening movement; said lever having an outer end and said clamp jaw having a top portion engaging one another in the clamping direction of movement to directly transfer force between said lever and said clamp jaw and to relieve heavy force imposition on said pin.

5. In a device as set forth in claim 1, said post having a threaded end extending beyond said spring supporting abutment means on said body; and an opposing nut threaded on said threaded projecting end of said post; said opposing nut abutting said abutment means; said opposing nut acting in opposition to said spring adjustment nut to permit said spring adjustment nut to exert spring compression force on said spring to pre-load said spring as desired without pre-load affect on the open head space, shut engagement, and travel of said jaw; a base nut on said pillar engaging said top of said body thereby supporting said pillar against inward movement relative to said body; a jam nut on said pillar engaging said bottom of said body supporting said pillar against outward movement of said pillar relative to said body; said pillar being raisable and lowerable by said nuts to selectively raise and lower its fulcrum point to adjust the height of said lever and jaw relative to a workpiece; said spring adjustment nut being adjustable relative to said post to also selectively raise and lower said post on said spring at said power end of said lever to compensate for height adjustment of said fulcrum point of said lever at said pillar and to compress said spring as desired at the adjusted height; said clamp jaw and said lever having aligned apertures and a pin lying in said apertures pivotally interconnecting said clamp jaw and said lever; said pin being undersize relative to at least one aperture in said clamp jaw and said lever to allow relative movement therebetween to eliminate binding during clamping and opening movement; said lever having on outer end and said clamp jaw having a top portion engaging one another in the clamping direction of movement to directly transfer force between said lever and said clamp jaw to relieve heavy force imposition on said pin.