US2473764A - Clamp - Google Patents

Description

A. J. PARK June 21, 1949.

CLAMP Filed April 6, 1945 INVENTOR. Aug/v J I ARK BY f Patented June 21, 1949 UNITED STATES PATENT 0F FKIE CLAMP Allan. J, Park, Lakewood, Ohio.

Application April 6, 1945, Serial No. 586,975

4- Claims. 1.

The present invention relates generally to clamps, and particularly to. clamps for suspending metal, articles while they are being conveyed thru a furnace.

Many different types. of hanger clamps. have been proposed. heretofore for supporting. freshly painted sheet metal articles; while they arev being conveyed thru pain-t drying furnaces. None of these clamps, with which I am familiar, been entirely satisfactory. Certain of these prior clampsv relied on spring tension for; holding the. work pieces. Since it is-necessary thatthe clamps should retain the articles when a. certain specified Dull was exerted on the: articles, the; springs were; fairly stiff and required exertion of considerable force by the operator to open and close the clamps when work pieces were being placed in or removed from the clamps. The spring tension could not beadjuste'd; The rate and amount of production obtainable whenv such. clamps wereused, was limited by the strength and fatigue resistance of the operators.

Other prior clamps which relied on. mechanical action as contrasted with spring tensionwere awkward to operate. In opening or closing them the operators had touse both hands. This-meant.

slow operation for after the clamp was opened the work piece had to be placed. in position and held there while the clamp. was being closed.

The present invention aims to avoid the disadvantages of prior suspension clamps and. achieves this aim by providing a clamp whichcan be opened or closed bya light gripping action by one hand of the operator, which may be ad justed to exert a clamping force which can 'bevaried widely without material variation in the force required to. open and close the clamp and which leaves one hand of the operator free to handle the work piece during the opening and closing of the clamp.

The present invention will be understood by those skilled in the art from the following description and from thedrawingswhich accompany and form a part of this specification and in which Figure 1 is a side elevational; view of one em- The; embodiment of the present invention which is shown in the drawings comprises a main jaw i, a movable jaw 2:, a U-shaped. lever 3 and means t piw lly connecting; lever 3' and movable jaw 2.

Main jaw i, as, shown, consists of a piece of strap iron bent into U-shape with its upper free ends provided: with an opening 5 toreceive the heck of a conveyor. An abutment plate 6 is disposed on one side of the. jaw at its lower, looped end and is secured in place, as by weld metal '1'. Plate 6' afiordsla fiat surface, against which a work piece. may bec-lamped. Leg 8, which may consist. of a piece of strap iron bent into U-shape,, is attached to the outer sides of leg I-, as by weld metal 9 and projects laterally from the leg. past the top adjacent edge of plate 6'. Atits free end, leg 8 carries a pivot ID on which is pivotally mounted movable jaw 2.. This jaw carries an adjustable screw l2, a rod l3, welded or otherwise secured to the. head of screw I2, serves to. rotate'the screw while lock nut 14 serves to maintain the screw in axially adjusted position in jaw-2. At its innerend, screw l2 carries-a clamping head Hi. This head i5 is preferably composed of hardened steel; and has a shank 16 which may be pressed into place in. socket. H at the inner end of screw 12. The exposed surface of. head ti is preferablyconical, as is shown at l8, and terminates in point. I?! which is to engage one side. of a. work piece 20 (Fig. 1) and press it against the opposed surface of clamping plate B-of main jaw It. Whenv av larger contact area is required, as when heavier articles are to be held by the clamp, the head. ldmay be larger or heavier orhave a surface other than conical opposed to the article.

The lower portion of movable.- jaw 2, that is between. pivot H)v and its lower end, is preferably vertical and: parallel to main jaw I: when the. twojaws are in work holding position. Theupper portion. of jaw 2, thatis, the portion above pivot l0, extends upwardly and outwardly at an angle to main jaw l and a top free end: is pivotally connected to. a pair of links. 2-1., as by pivot pin The U-shaped lever 3 extends between. the sides of.- mainjaw I; and is secured in place by pivotpin 23: which extends thru: lever 3. between its ends. One arm of lever 3: is pivotally connected. asby pivot 24; to: links. 21.

. It willcbe noted from Fig. I that whenthe clamp in closed position. with. work piece 20. clamped between. laws 1 and 2; the center line of pivot 24 is in or just below the plane in which the centerlines of pivot pins 22 and 23 are located. Such positioning insures that the jaws will not he accidentally moved from clamped to unclamped position. It will also be noted from Figs. 1 and 3 that each arm of lever 3 is close enough to the upper portion of main jaw I for an operator to grasp both of these parts in one hand. When the clamp is closed, as shown in Fig. 1, an operator may open it by grasping jaw I and the right arm of lever 3 in one hand and pressing the arm toward the jaw. Movement of lever 3 about pivot 23 pivots jaw 2 about its pivot I0 thereby releasing a work piece between the screw l2 and plate 6. When the clamp is in opened position, as is shown in Fig. 2, the lefthand arm of lever 3 and main jaw I may be grasped by one hand of the operator and the arm pressed toward the jaw about pin 23 to actu ate the movable lever 2 into clamping position. As is shown in Fig. 1, the righthand arm of lever 3 may bear against the adjacent end of movable jaw 2 when the jaws are in clamping position and thus pivoted movement of the lever may be limited.

It will be understood that by axial adjustment of the screw 1 2 in jaw 2, work pieces 20 of various thicknesses may be clamped between the jaws of the device, or more or less clamping force may be exerted on work pieces of a given thickness. However, considerable variations in clamping pressure make comparatively little diiTerence in the force which must be exerted on the arms of :"s

lever 3 to open or close the clamp since all the force that is required for this purpose is to break the toggle comprising lever 3, jaw 2 and the connecting means 4.

While jaw I is shown as being straight, and

provided with an opening 5 for reception of a hook extending transversely of the conveyor, which would position the device of Fig. i with its lever 3 parallel to the direction of travel of the conveyor, it will be understood that when this device is to extend transversely to the direction of travel of the conveyor the upper end of jaw i may be turned thru 90 and will then receive a hook lying in the plane of travel of the conveyor instead. of transversely thereto as is the case with the device of Fig. 1.

Altho jaw 2 and lever 3 are shown as solid bars, it will be understood that they may be sheet metal stampings, or flat pieces of metal, depending on the service conditions which are to be satisfied. Similarly, jaw I and leg 8 may be made of solid bars or stampings if desired. Various other modifications of the specific embodiment shown and described herein, and not involving invention, may be made by those skilled in the art without departing from the spirit of the present invention.

Having thus described my invention so that others skilled in the art may be able to understand and practice the same, I state that what I desire to secure by Letters Patent is defined in what is claimed.

What is claimed is:

l. A clamp comprising main and movable jaws spaced apart and pivotally connected together between their ends, a lever pivoted to the main jaw on one side of said pivotal connection, means between and pivotally connected to the movable jaw and lever on the same side of said pivotail connection, the lever being movable about its 1 pivotal connection to the main jaw to move the parts of the jaws on the other side of their pivotal Lil connection into clamping position by moving the center of the pivotal connection of said means to the lever just beyond a plane joining the centers of the pivotal connections of the lever to the main jaw and said means to the movable jaw and to lock the jaws in clamping position by abutting against the movable jaw.

2. A clamp comprising main and movable jaws spaced apart and pivotally connected together between their ends, a lever pivoted to the main jaw, a [link pivoted to the adjacent end of the movable jaw and to the lever between the jaws, one jaw having near the clamping end thereof adjustable work engaging means projecting therefrom toward the other jaw, the lever being movable about its pivotal connection to the main jaw to move the opposite ends of said jaws into clamping position by moving the center of the pivotal connection of the link to the lever just beyond a plane joining the centers of the pivotal connec tions of the lever to the main jaw and the link to the movable jaw and to lock the jaws in clamping position by abutting against the movable jaw.

3. A clamp comprising main and movable jaws pivotally connected together between their ends, the portions of said jaws on one side of said pivotal connection being work engaging and parallel portions when in clamping position and the portions on the other side of said connection being diverging portions, a lever pivoted to the divergent portion of said main jaw. a link between -the divergent portions of said jaws and pivotally connected to the movable jaw and to the lever, the lever being movable about its pivoted connection to the main jaw to move the clamping portions of said jaws into clamping position by moving the center of the pivotal connection of the link to the lever just beyond a plane joining the centers of the pivotal connections of the lever to the main jaw and the link to the movable jaw and to lock the jaws in clamping position by abutting against the movable jaw.

4. A clamp comprising main and movable jaws spaced apart and pivotally connected together between their ends, a lever pivoted to the main jaw and having portions diverging from opposite sides of said jaw, a link pivoted to the movable jaw and to one diverging portion of the lever, the lever being movable about its pivoted connection to the main jaw to move the jaws into clamping position by moving the center of the pivotal connection of the link to the lever just beyond a plane joining the centers of the pivotal connections of the lever to the main jaw and the link to the movable jaw and to lock the jaws in clamping position by abutting against the movable jaw.

ALLAN J. PARK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 737,527 Teilborg Aug. 30, 1905 790,880 Boyer May 30, was

1,580,083 Boadle Apr. 6, 1926 1,580,578 Berry Apr. 13, 1926 2,197,128 Harrison Apr. 16, 1940 2,327,368 Olson Aug. 24, 1943

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