US3926418A - Rotating detented push-pull plunger clamp - Google Patents

Abstract

A manually operated clamp has linkage-producing mechanical advantage and toggling to lock a plunger in the forward push position. If the handle is retracted approximately 180*, the link between said handle and plunger will cross over the handle pivot, allowing the toggle linkage to produce a mechanical advantage and lock in the rear or pull position. A set screw retainingly engages the plunger in either of these positions to create a prepressure on the linkage, maintaining it in the locked position. The complete clamping mechanism is rotatably positioned in a reversable base and is ball detented in both directions of the desired rotatable position. The plunger is drilled and tapped for application of clamping fingers and components. A key in the base extends into a groove in the body retaining the body against longitudinal movement and limiting rotary movements of said body.

Description

United States Patent 191 Blatt Dec. 16, 1975 1 ROTATING DETENTED PUSH-PULL PLUNGER CLAMP [76] Inventor: Leland F. Blatt, 31915 Groesbeck Highway, Fraser, Mich. 48026 [22] Filed: May 8, 1974 [21] Appl. No.: 468,019

[52] US. Cl. 269/13; 269/91; 269/228 [51] Int. Cl. B25B 1/14 [58] Field of Search 269/13, 32, 35, 38, 70,

269/91, 201, 228, 285, 321 R, 321 ME [56] References Cited UNITED STATES PATENTS 2,106,525 l/l938 Henry 269/70 2,869,597 l/1959 Lozon 269/38 X 3,237,463 3/1966 McPherson 269/228 X 3,628,783 12/1971 Blatt et a1. 269/91 3,672,660 6/1972 Jagob 269/203 Primary ExaminerRoy Lake Assistant ExaminerNeil Abrams Attorney, Agent, or Firm-Cullen, Settle, Sloman & Cantor ABSTRACT A manually operated clamp has linkage-producing mechanical advantage and toggling to lock 21 plunger in the forward push position. If the handle is retracted approximately 180, the link between said handle and plunger will cross over the handle pivot, allowing the toggle linkage to produce a mechanical advantage and lock in the rear or pull position. A set screw retainingly engages the plunger in either of these positions to create a pre-pressure on the linkage, maintaining it in the locked'position. The complete clamping mechanism is rotatably positioned in a reversable base and is ball detented in both directions of the desired rotatable position. The plunger is drilled and tapped for application of clamping fingers and components. A key in the base extends into a groove in the body retaining the body against longitudinal movement and limiting rotary movements of said body.

6 Claims, 4 Drawing Figures US. Patent Dec. 16, 1975 ROTATING DETENTED PUSH-PULL PLUNGER CLAMP BACKGROUND OF THE INVENTION I-Ieretofore, push-pull clamps have been provided with suitable toggle linkages for achieving a mechanical advantage for securing the plunger of the clamp in forward position or in fully retracted position. Examples of such constructions are shown in US. Pat. Nos. 3,735,972 and 3,628,783.

BRIEF DESCRIPTION OF THE INVENTION It is an object of the present invention to provide an improved push-pull toggle clamp wherein the clamp body with its associated plunger and handle are rotatively mounted within the longitudinal bore of a base and restrained against relative longitudinal movement.

It is another object to provide an improved push-pull clamp wherein, rotation of the clamp assembly relative to the base is limited between positions corresponding to work piece securing position and work piece clearance position.

It is another object to provide detent means for retainingly securing the clamp assembly in either of said positions.

It is another object to provide an adjustable set screw for providing a pre-pressure upon the plunger for the purpose of securing said plunger and related linkage in work piece securing position as well as in fully retracted work piece retaining position.

These and other objects will be seen from the following specification and claims in conjunction with the appended drawing in which:

THE DRAWING:

FIG. 1 is a side elevational view of the present pushpull clamp showing in dash lines the retracted position of the clamp handle, as mounted upon a support, fragmentarily shown.

FIG. 2 is an end elevational view thereof.

FIG. 3 is a plan view thereof.

FIG. 4 is a fragmentary view corresponding to FIG. 1, illustrating the plunger when used for clamping a work piece in the retracted pull position.

It will be understood that the above drawing illustrates merely a preferred embodiment of the invention, and that other embodiments are contempated within the scope of the claims hereafter set forth.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawing, the present push-pull clamp includes a reversable base 11 mountable upon support 13, fragmentarily shown, and retained in position by a series of cap screws 15, FIG. 3. In view of the symmetrical construction of the base 11 and the location and arrangement of the cap screw apertures, said base may be reversed 180 as desired and resecured to said support.

Within bore 17 of said base, there is rotatively positioned the elongated cylindrical body 19 which has a longitudinal bore 21 therethrough of circular shape. Within said bore is the square broached hole 23, FIG. 2, which provides the longitudinal support for the reciprocal plunger 25 of square cross section.

The rear portion of said body has a transverse slot 27 which guidably receives an end portion of handle 29 which is, thus, nested within body 19 and pivotally mounted thereon by the pivot pin 31. Said pin extends through a suitable bushing 35 within said handle. Spacers 33 are mounted on said pin on opposite edges of said handle for cooperative registry with the walls of the slot 27.

The spacer stop 37 projects transversely into a portion of said handle within said body and is adapted for stop registry with the link 41 when the handle has been retracted to the dash line position shown.

Said link at one end extends into slot 39 of said handle and is pivotally connected thereto by pivot pin 43. Its opposite end is nested within plunger slot 45 and pivotally connected thereto by pivot pin 47.

Said plunger has an outwardly opening threaded bore 49 adapted to receive fastener 53 for securing the work piece clamping finger 51 or other attachment. Said finger is adapted to engage fixture 55 with work piece W interposed, as fragmentarily shown in FIG. 1.

An annular recess 57 is formed around the forward portion of said body 19 within base 11. Retainer key 59 is projected through a radial bore in said base 11 and includes at its inner end a key 61 which is slidably registerable down within the recess 57 for restraining the body 19 against longitudinal movement with respect to base 11. Said retainer is anchored within said base by the removable retainer ring 63, FIG. 2.

Nested within the annular slot 57 are a pair of spaced stops 65 which are adapted to selectively register with opposite stop edges of key 59 for limiting the rotative position of the clamping mechanism to the upright work piece securing position of FIG. 2 or to a second rotated position with the plunger and its work piece engagingfinger in a work piece clearance position.

In the illustrative embodiment the stops 65, FIG. 2, are'spaced apart ,so that the clamping mechanism is adapted for rotation to a release or a work piece clearance position of approximately ,clockwise, as viewed in FIG. 2.

There is also provided a suitable ball detent means for retaining the clamping means mechanism in both of these positions. For this purpose, there are provided a pair of diametrically opposed recesses 69 of substantially hemispherical shape, which are nested down into the body 19 within said base and are adapted for selective cooperative registry with the ball detent 67 within said base and biased by spring 71 held in position by plug 73, FIG. 3.

Formed at a 45 angle along the top comer of the plunger as at 75, is an elongated bevel adapted for cooperative registry with the adjustable angular set screw 77. Said screw is threaded down through the body and adapted for operative retaining pressure along the length of said bevel.

This is for the purpose of retaining the plunger and the linkage connected thereto in a work piece securing position such as shown in FIG. 1. In this position, the pivot 43 between the handle and link has passed dead center with respect to pivot 47 and pivot 31 normally locking the push-pull clamp in the forward work piece securing position shown in FIG. I. Said set screw creates a holding pressure on the 45 angular bevel 75 for maintaining the clamp in a locked position.

By retracting the handle 29 in a clockwise direction from the position shown in FIG. 1, the plunger 25 is likewise retracted for releasing the work piece. Once it is released, the handle 29 and the associated clamping assembly may be rotated including body 19 through an arc of 180 to provide suitable clearance for removal of the work piece upon a fixture and for mounting a sec- 3 ond work piece for illustration. Before such rotation, one stop 65, FIG. 2, engages the key 59. Rotation to the second position is limited by engagement of the second stop 65 with said key. In both positions ball detent 67 is nested in one of the recesses 69, to retain the assembly in such position.

The present push-pull clamp can also function in a completely retracted pulling position wherein, the handle 29 is retracted clockwise through an arc of approximately 180 as shown in dash lines, FIG. I.

Here again, the pivotal connection 43 between the handle and link has dropped below dead center of the two pivot points 47 and 31, creating a toggle-locking condition with the plunger fully retracted. Clamp finger 79 is secured to said plunger by fastener 53, FIG. 4, and operatively engages work piece W with respect to fixture 81 or clamp plate. In this position, link 41 as shown schematically in dash lines, FIG. I, engages the spacer stop 37 of FIG. 3.

In the forward securing position shown in FIG. 1, link 41 at its pivotal connection with the handle engages the bottom of said body as at the stop 83.

Having described my invention, reference should now be had to the following claims.

I claim:

I. A push-pull clamp for anchoring a work piece against a fixture comprising:

a base mounted on a support and having a longitudinal bore;

an elongated cylindrical body projected through said bore and rotatively adjustable upon said base;

said body having a longitudinal bore therethrough of square cross section;

there being an outwardly opening radial slot through said body;

a plunger of square cross section slidably and guidably reciprocated within one end of said body and at one end projecting from the body adapted to retainingly engage a workpiece;

a handle at one end guidably nested in said slot and pivotally mounted upon said body.

a link at one end pivotally connected to said plunger and at its other end photally connected to said handle;

and cooperating means on said base and body retain ing said body against longitudinal movement relative to said base and detent means on said base and body for restraining said body against rotation when in extreme rotative positions, said body being at all times free to rotate with respect to said base between its detented positions when the plunger is in unclamped position, said cooperating means including an annular groove on said body, and a key nested in said base and extending into said groove.

2. In the push-pull clamp of claim 1, said base having a bore receiving said key, and a retainer ring on said base anchoring said key therein.

3. In the push-pull clamp of claim 1, a pair of spaced radial stops mounted on said body and extending into said groove alternatively engageable with said key for locating said body in workpiece securing position and in a rotated workpiece clearance position.

4. In the push-pull clamp of claim 3, said detent means including cooperating ball detent means on said base and body for locating and releasably holding said body and plunger in work piece securing position and in rotated work piece clearance position.

5. In the push-pull clamp of claim 4, said ball detent means including a pair of diametrically opposed recesses in said body, and a spring-biased ball detent in said base alternately registerable with said recesses.

6. In the push-pull clamp of claim 1, said detent means including cooperating ball detent means on said base and body for locating and holding said body and plunger in work piece securing position and in rotated work piece clearance position.

Claims (6)

1. A push-pull clamp for anchoring a work piece against a fixture comprising: a base mounted on a support and having a longitudinal bore; an elongated cylindrical body projected through said bore and rotatively adjustable upon said base; said body having a longitudinal bore therethrough of square cross section; there being an outwardly opening radial slot through said body; a plunger of square cross section slidably and guidably reciprocated within one end of said body and at one end projecting from the body adapted to retainingly engage a workpiece; a handle at one end guidably nested in said slot and pivotally mounted upon said body; a link at one end pivotally connected to said plunger and at its other end pivotally connected to said handle; and cooperating means on said base and body retaining said body against longitudinal movement relative to said base and detent means on said base and body for restraining said body against rotation when in extreme rotative positions, said body being at all times free to rotate with respect to said base between its detented positions when the plunger is in unclamped position, said cooperating means including an annular groove on said body, and a key nested in said base and extending into said groove.

2. In the push-pull clamp of claim 1, said base having a bore receiving said key, and a retainer ring on said base anchoring said key therein.

3. In the push-pull clamp of claim 1, a pair of spaced radial stops mounted on said body and extending into said groove alternatively engageable with said key for locating said body in workpiece securing position and in a rotated workpiece clearance position.

4. In the push-pull clamp of claim 3, said detent means including cooperating ball detent means on said base and body for locating and releasably holding said body and plunger in work piece securing position and in rotated work piece clearance position.

5. In the push-pull clamp of claim 4, said ball detent means including a pair of diametrically opposed recesses in said body, and a spring-biased ball detent in said base alternately registerable with said recesses.

6. In the push-pull clamp of claim 1, said detent means including cooperating ball detent means on said base and body for locating and holding said body and plunger in work piece securing position and in rotated work piece clearance position.

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