US3149832A - Toggle clamp with adjustable guide - Google Patents

Description

Sept. 22, 1964 A. W. M PHERSON TOGGLE CLAMP WITH ADJUSTABLE GUIDE Filed April 2, 1962 EEEE @i /fj@' ATTORNEYS United States Patent Office 3,l49,832 Patented Sept. 22, 1%64 This invention relates to an improvement in a toggle clamp construction of the general type disclosed in United States Letters Patent 2,054,572 and more particularly to the provision of an adjustable guide means for the clamp bar which results in rigid lateral stability.

In many toggle clamp applications it is necessary or highly desirable to have a lateral stability for the clamp bar which is inherently difiicult to provide with conventional construction due to clearances required for freedom of clamp bar travel and related tolerances. If the conventional elements connected by toggle pivots are held together in a sufliciently tight fit to provide a high degree of lateral stability to the clamp bar in its clampng position, the operation of the clamp in its releasing and engaging travel becomes unduly stiff; furthermore, the connecting elements normally available to laterally stabilize the clamping bar are usually so located as to have a high degree of mechanical disadvantage in retaining the clamping end of the bar against lateral displacement.

The present improved construction incorporates extensions to conventional clamp base elements adapted to provide a guide for the clamp bar engaged during its final closing travel advantageously located for lateral stabilizing purposes together with an adjustable take-up for the spacing between opposed guide surfaces in order to provide exactly the desired closeness of fit.

These and other objects of the present invention will be best understood by reference to the following description of a preferred embodiment illustrated in the drawings wherein:

FIG. 1 is a side elevation of the improved clamp assembly;

FIG. 2 is an end elevation thereof; and

FIG. 3 is a sectional view taken along the line 3--3 of FIG. 1.

Conventional elements of the toggle clamp include a central clamp bar pivotally connected at 11 to a pair of spaced base plates 12, having attachment holes 13 for connection to a fixture or like mounting. A pair of handle elements 14 welded together at the top are formed as a yoke at the bottom spanning the base plate 12 and pivotally connected thereto at 15 as well as at an intermediate point 16 to a link stop member 17 having side elements 18 pivotally connected at 19 within the yoke portion of the handle to the clamp bar 10.

The assembly is shown in clamping position with the stop member 17 registering against the clamp bar at 20 and the pivotal connections 15, 19 and 16 in substantial alignment. Unlocking and opening of the clamp is accomplished by moving the top of the handle to the left as seen in FIG. 1 thereby breaking the toggle linkage and causing the clamp bar 10 to raise as the handle is moved progressively back.

The base plate elements 12 are provided with forward guide extensions 21, beveled at their upper ends 22 as best shown in FIG. 3 to guidingly receive the clamp bar 10 as it moves downwardly into clamping position. An adjustment bolt 23 permits the base plate extensions 21 to be drawn together to a zero clearance relation with the clamp bar 10 and with precisely the right contact pressure to assure positive stabilizing against lateral play without undue interference with the release of the clamp. As soon as the guide bar 10 has cleared the guide extensions 21 in opening movement any frictional contact pressure with the guide extensions is eliminated and the assembly is free to move to a wide open position without any resistance from the guide elements.

It will be understood that the base could take other forms, for example as adapted for attachment to a horizontal surface, and that other modifications might be resorted to without departing from the scope of the invention as defined in the following claims.

I claim:

1. A toggle clamp comprising base, clamp bar, handle and link elements pivotally inter-engaged to cause said clamp bar to move to a toggle-actuated locked clamping position, characterized by rigid stationary laterally adjustable guide means for engaging the sides of said clamping bar element to provide lateral stability thereto in its clamping position relative to its plane of actuation.

2. A toggle clamp as set forth in claim 1 wherein said guide means comprise extensions of said base plate elements projecting outwardly of the inter-engaging toggle connections toward the clamping end of said clamping bar element.

3. A toggle clamp as set forth in claim 2 wherein said guide extensions are provided with beveled edges for leading said clamp bar element between said guide extensions as it approaches final clamping position.

4. A toggle clamp as set forth in claim 2 including adjusting means for drawing said extensions toward each other in a close fitting relationship with said clamping bar element.

5. A toggle clamp as set forth in claim 4 wherein said adjusting means comprises a bolt passing through said extensions at a position immediately adjacent the final clamping position of said clamping bar element.

6. A toggle clamp mechanism comprising a pair of spaced base plate elements, a central clamp bar extending between said base plate elements, a first pivotal connection between one end of said clamp bar and said base plate elements, a handle having a yoke spanning said clamp bar and base plate elements, a second pivotal connection between the ends of said yoke and said base plate elements, a pair of link elements extending within said yoke, a third pivotal connection between one end of said link elements and said clamp bar, a fourth pivotal connection between the other end of said link elements and said yoke, said third pivotal connection being intermediate and alignable with said second and fourth pivotal connections when said clamp arm is in clamping position, said base plate elements having guide extensions for receiving said clamp bar outboard of the respective pivotal connections, and an adjustable bolt for drawing said guide extensions together to a closely fitting relationship with said clamp bar when the latter is in clamping position.

References Cited in the file of this patent UNITED STATES PATENTS 2,054,572 McKenna Sept. 15, 1936 2,577,029 Moorehead Dec. 4, 1951 3,035,831 Blatt May 22, 1962

Claims (1)

1. 6. A TOGGLE CLAMP MECHANISM COMPRISING A PAIR OF SPACED BASE PLATE ELEMENTS, A CENTRAL CLAMP BAR EXTENDING BETWEEN SAID BASE PLATE ELEMENTS, A FIRST PIVOTAL CONNECTION BETWEEN ONE END OF SAID CLAMP BAR AND SAID BASE PLATE ELEMENTS, A HANDLE HAVING A YOKE SPANNING SAID CLAMP BAR AND BASE PLATE ELEMENTS, A SECOND PIVOTAL CONNECTION BETWEEN THE ENDS OF SAID YOKE AND SAID BASE PLATE ELEMENTS, A PAIR OF LINK ELEMENTS EXTENDING WITHIN SAID YOKE, A THIRD PIVOTAL CONNECTION BETWEEN ONE END OF SAID LINK ELEMENTS AND SAID CLAMP BAR, A FOURTH PIVOTAL CONNECTION BETWEEN THE OTHER END OF SAID LINK ELEMENTS AND SAID YOKE, SAID THIRD PIVOTAL CONNECTION BEING INTERMEDIATE AND ALIGNABLE WITH SAID SECOND AND FOURTH PIVOTAL CONNECTIONS WHEN SAID CLAMP ARM IS IN CLAMPING POSITION, SAID BASE PLATE ELEMENTS HAVING GUIDE EXTENSIONS FOR RECEIVING SAID CLAMP BAR OUTBOARD OF THE RESPECTIVE PIVOTAL CONNECTIONS, AND AN ADJUSTABLE BOLT FOR DRAWING SAID GUIDE EXTENSIONS TOGETHER TO A CLOSELY FITTING RELATIONSHIP WITH SAID CLAMP BAR WHEN THE LATTER IS IN CLAMPING POSITION.

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