Patent Publication Number: US-3874647-A

Title: Toggle clamp with positive latch and clamp actuating handle

Description:
United States Patent [191 Blatt [451 *Apr. 1, 1975 TOGGLE CLAMP WITH POSITIVE LATCH AND CLAMP ACTUATING HANDLE [76] Inventor: Leland F. Blatt, 31915 Groesbeck l-lwy., Grosse Point Shores, Mich. 48026 Notice: The portion of the term of this patent subsequent to Feb. 19, 1991, has been disclaimed.  
 [22] Filed: Nov. 28, 1973 [21] Appl. No.: 419,611  
 Related U.S. Application Data [63] Continuation-in-part of Ser. No. 326,899, Jan. 26, 1973, Pat. No. 3,792,853, which is a continuation-in-part of Ser. No. 292,877, Sept. 28, 1972, Pat. No. 3,782,712.  
 Primary Examiner-Roy Lake Assistant Examiner-Mark S. Bicks Attorney, Agent, or Firm-Cullen, Settle, Sloman &amp; Cantor [57] ABSTRACT A toggle clamp includes a pivot base mountable upon a support with a pair of side plates adjustably mounted upon said pivot base in a pre-selected angular position and guidably receiving therebetween a pivot arm pivotally mounted upon said plates and terminating in a work piece engaging clamp arm. A U-shaped handle link is pivotally mounted over and upon the guide plates and pivotally mounts interiorly a pair of arm links at their one ends, with the other ends of said arm links pivotally connected to the handle link. A yieldable latch is positioned between the arm links and pivotally connected thereto and adapted to interlock with a latch plate spanning said guide plates when the handle link has been moved to a release position.  
 The improvement comprises a latch handle secured to said latch. An operative handle is secured to the free end of the latch handle at any desired angle for disengaging said latch from the latch plate and for successive return movement of the clamp arm to workpiece securing position, and release position.  
 9 Claims, 2 Drawing Figures TOGGLE CLAMP WITH POSITIVE LATCH AND CLAMP ACTUATING HANDLE RELATED APPLICATIONS This application is a continuation-in-part of my copending application, Ser. No. 326,899 filed Jan. 26, 1973, now US. Pat. No. 3,792,853 dated Feb. 19, 1974. The latter application is a continuation-in-part of my copending patent application, Ser. No. 292,877 filed Sept. 28, 1972, now U.S. Pat. 3,782,712 dated Jan. 1, 1974 entitled TOGGLE CLAMP WITH DE- TENT OPEN GUIDED ARM.  
 BACKGROUND OF THE INVENTION Toggle clamps are known to include upon a base a pivotal clamp arm with a suitable handle link pivotally mounted upon a base with additional linkage which pivotally engages the clamp arm for moving the same from workpiece securing position to a retracted workpiece release position.  
  Examples of such toggle clamps are shown in my US. Pat. Nos.: 3,009,694 3,010,171 2,972,476 3,035,831.  
 BRIEF DESCRIPTION OF THE INVENTION The present invention is directed to an improved latch actuating handle for a toggle clamp which includes a yieldable latch mounted upon a handle link assembly adapted for interlock with a stationary latch plate for anchoring a clamp arm in clamp-release posi tion. A latch handle is secured to the latch and an operative handle is secured to the latch handle at any desired angle.  
  It is an object of the present invention to employ the operative handle to control pivotal movements of the latch and reciprocal opening and closing movements of the clamp arm.  
 IN THE DRAWING FIG. I is a fragmentary side elcvational view of the present toggle clamp with the release position of the latch handle and clamp arm shown in dash lines;  
 FIG. 2 is a left end elevational view thereof.  
  The above drawing illustrates a preferred embodiment of the invention. Other embodiments are contemplated within the scope of the claims hereafter set forth.  
 DETAILED DESCRIPTION Referring to the drawing, clamp 11 includes a pivot base 13 anchored by fasteners 15 to a suitable support F or fixture or mounting surface as fragmentarily shown, FIG. 1, and supporting work piece W. A pair of upright opposed and spaced guide plates I7 and 19 each having corresponding arcuate end faces 21 is pivotally mounted initially by pivot pin 4] or bolt upon opposite sides ofthe base 13 and affixed thereto in the desired position of angular adjustment by the welds 23.  
  Transversely arranged latch plate 25 is selectively positioned across plates 17 and 19 at the desired angle and secured in position by the welds 27. The latch plate has been located so as to yieldably retain the handle assembly when it has been moved to the retracted release position shown in dotted lines.  
  Pivot arm 29 is guidably and movably positioned between plates I7 and 19 and pivotally mounted thereon upon the pivot pin 33 with bushing 31 interposed and nested within an end portion of said pivot arm. The  
 pivot arm extends laterally outward from said guide shown in operative clamping position with respect to work piece W upon the support F.  
 The inverted U-shaped handle link 37 is guidably positioned over opposite outer surfaces of the plates 17 and 19 and at its lower ends pivotally mounted upon bolt 41 hereafter referred to as a first pivot point. The pivotal mounting of pivot arm 29 as at 33 is referred to as a second pivot point.  
  Bolt 41 is anchored upon the guide plates 17 and 19 with a suitable nut 43, FIG. 2. A pair of spaced arm links 45,47 are arranged upon the interior of the handle link coplaner with the respective guide plates 17 and I9 and pivotally connected to the handle link by transverse pin 49. Latch 51 is interposed between said arm links at their upper ends and pivotally mounted on the same pivot pin 49. This is the third pivot point.  
  The lower ends of the arm links engage opposite sides of the pivot arm 29 and are pivotally connected thereto by the transverse pin 53, referred to the fourth pivot point. Latch 51 upon one side has a lateral projection or stop 55 adapted to bear against a portion of the handle link 37 under the bias of the coil spring 57. The latter is nested within socket 59 in said latch and at its opposite end bears against a portion of the handle link, FIG. 1.  
  The transverse notch 61 formed in the outer surface of the latch has a rear angle face 63. Upon retraction of the handle link 37 to clamp arm release position, the latch slot 61 is adapted for selective registry with latch plate 25, as shown in dash lines, FIG. I. Said latch plate has a front angle face 65 adapted for cooperative registry with latch rear angle face 63, for a snap interlock therewith.  
  The latch plate may be selectively positioned along the arcuate edges of the guide plates and affixed thereto for stablizing the assembly and spacing between the plates 17 and 19, and for yieldably retaining the handle assembly when the clamp arm has been moved to a release position shown in dash lines in FIG. I. In the solid line work securing position, pivot point 3 at 49 has moved across dead center with respect to pivot points I and 4; namely, the pivots 41 and 53 of FIG. 1 when the clamp arm 36 is in its work piece securing position. The. angular movement of retraction of the clamp arm can be set at to depending upon the location of latch plate 25 and its securing to guide plates 17 and 19.  
  Since the latch notch 61 includes rear angle face 63 adapted for snug interlock with respect to front angle face 65 of the latch plate 25, there is a positive securing or snubbing action as the handle link 37 is moved from the solid line position in FIG. I to the dash line release position. Here the latch 51 is hooked onto latch plate 25, serving two purposes. It acts a snubbing action when the handle link has been moved to open position, and after latching, maintains zero play between rear angle face 63 of the latch and front angle face 65 of the latch plate to, thus, maintain a tight hooking contact.  
 DETAILED DESCRIPTION OF THE INVENTION In order to release the latch from the latch plate, there is provided latch handle 69. Said handle is a part of and extends outwardly of latch 51. Said latch handle has a free end 75 spherical in shape. Operative handle 77 at one end has a spherical socket 79 for registry with the free end 75. Said operative handle is set by the user to any desired angle relative to the latch handle and secured thereto by welds 81. One such angle is shown in FIG. 2. Said operating handle may be inclined laterally at an acute angle with respect to the plane of movement of the latch in the range of to 60 upon opposite sides thereof.  
  In view of the spring bias and pivotal mounting of latch 51, on full retracting movement of operating handle 77 to the dash line release position shown, there will be an automatic engagement of latch 51 with latch plate 25.  
  A pre-stop block 83, FIG. 2, interconnects plates 17 and 19 forwardly of the pivotal connection 33 of the pivot arm. Adjustable set screw 85 extends through said block and is adjusted to apply pressure to pivot arm 29. This removes all shake of tolerance in the mechanism, causing clamp arm 35 to be in a stable noshake or stationary position.  
 OPERATION The present latch 51 and the latch handle 69 are so constructed and arranged that upon normal movement of the operating handle 77 in a counterclockwise direction from the dash line position shown, FIG. 1, will first pivot the latch so as to disengage the latch from the latch bar 25. Continued successive movement in the same direction of the operative arm 77 will rotate the clamp arm 35 to the work piece securing position shown in FIG. I.  
  Thereafter successive retraction or rotation of the operative handle 77 in the opposite direction, i.e., clockwise, will in effect retract the pivot arm and connected clamp arm 35 to the dotted line release position shown. In this position, the latch 51 due to its spring bias 57 will again snap lock with respect to the latch plate 25 holding the assembly including the pivot arm in such retracted release position.  
  Accordingly, it appears that the operative handle 77, being the sole handle for manual application, is arranged at the desired angle normally laterally of the path of rotation of the latch handle 69 such as shown in FIG. 2. Additionally, the single operative handle 77 is adapted for effecting manual release or disengaging movements of the latch with respect to the latch plate 25 and, furthermore, is adapted to control swinging movements of the clamp arm to the operative position shown in FIG. I or to the retracted dotted line release position shown.  
  The latch handle 69 is so arranged with respect to the handle link that after initial rotation of the operative handle 71 in a counterclockwise direction, the latch handle will operatively engage the handle link so as to effect rotation thereof to the work piece securing position shown in FIG. 1.  
  Having described my invention, reference should now be had to the following claims.  
 I claim:  
  I. In a toggle clamp having a pivot base mountable upon a support; a pair of upright parallel spaced guide plates secured upon said pivot base in a pre-selected angular position; a pivot arm guidably positioned between said plates and at one end pivotally mounted upon said plates and terminating in a clamp arm adapted to retainingly engage a workpiece on said support; a U-shaped handle link overlying said guide plates and at its free ends pivotally mounted upon said side plates; a pair of spaced arm links at their one ends pivotally mounted upon said handle link coplaner with said guide plates, and at their lower ends engaging opposite sides of and pivotally connected to said pivot arm; a latch between said arm links at their upper ends and pivotally mounted upon said handle link; said latch having a transverse detent notch; a latch plate transversely spanning and connected to the outer side edges of said guide plates; said latch notch on retracting movement of said handle link yieldably receiving said latch plate anchoring the handle link in a retracted release position; the improvement comprising:  
 a latch handle on said latch; and an operating handle at one end secured at a preselected angle to the end of said latch handle, in a -plane transverse to the plane of movement of the latch, adapted to manually rotate said latch to disengage it from the latch plate; and further adapted on rotation in a counterclockwise direction to rotate said clamp arm into workpiece securing position, and successively in the opposite direction, to rotate said clamp arm and latch to a retracted release position.  
  2. In the toggle clamp of claim 1, resilient means biasing said latch against said handle link.  
  3. In the toggle clamp of claim 1, said guide plates being pivotally adjusted initially at a first pivot point upon said base; the mounting of said pivot arm being at a second pivot point said plates; the mounting of said arm links at their one ends being at a third pivot point upon said handle link, and the connection at their other ends to said pivot arm being at a fourth pivot point; the latch mounting being at said third pivot point.  
  4. In the toggle clamp of claim 3, said guide plate outer side edges being arcuate at a fixed radius to said first pivot point; said latch plate being selectively positioned along said outer side edges and secured thereto depending upon the desired arc of release retraction of said first handle.  
  5. In the toggle clamp of claim 3, said third pivot point passing dead center with respect to said first and fourth pivot points when said first handle has moved the clamp arm to work piece securing position.  
  6. In the toggle clamp of claim 1, said latch plate having an undercut front angle face; said latch notch including a rear angle face for cooperative interlock therewith.  
  7. In the toggle clamp of claim 1, said operating handle being inclined laterally at an acute angle with respect to the plane of movement of said latch handle in the range of 0 to 60 upon opposite sides thereof.  
  8. In the toggle clamp of claim 1. a pre-stop block interposed between and secured to said guide plates forwardly of the pivotal mounting of said pivotal arm; and an adjustable set screw threaded through said block adapted to apply a stabilizing pressure to said pivotarm, to remove all shake due to tolerance in the assembly.  
  9. In the toggle clamp of claim 7, one end of said latch handle being of spherical shape; the corresponding end of said operative handle having a spherically shaped socket cooperatively receiving said latch handle.