US2433640A - Tool for applying sheet clamps - Google Patents

Description

Dec. 30, 1947. J. c. WRIGHT I TOOL FOR APPLYING SHEE T CLAMPS Filed June 19, 1943 Inventor John C.- Wright Agent Patented Dec. 30, 1947 TOOL FOR APPLYING SHEET CLAMPS John C. Wright, Los Angeles, Calif, assignor, by mesne assignments, to Herman H. Helbush, Los

Angeles, Calif.

Application June 19, 1943, Serial No. 491,458

This invention relates to tools for installing or applying clamps to sheet parts and the like to temporarily hold such parts against movement preparatory to and during riveting, spot welding, and like operations.

Spring actuated sheet clamps or fasteners are in extensive use to temporarily hold sheet parts against relative movement during the riveting, welding and bolting together of the sheets. Clamps of the general character herein referred are disclosed in Patent Number 2.317.315 granted to F. C. Wallace April 20, 1943. Tools resembling pliers have been employed to compress the clamps and facilitate their insertion into the registering openings in the sheet parts, Frequently the partly compressed clamps escape from the plierlike tools. The clamps when thus accidentally released from the tools are projected by the force of their springs with sufficient velocit to injure the operator and adjacent workmen.

It is a general object of this invention to provide a practical and effective tool for applying sheet clamps that is safe and dependable in operation. The partially compressed clamps cannot escape from the tool of the invention to injure the operator or other workmen.

Another object of the invention is to provide a tool of the character referred to embodying chuck elements or cradles that are adapted to close about the shell or shank of the clamp to positively prevent the escape of the clamp when the latter is compressed.

Another object of this invention is to provide a tool of the character mentioned in which the cradles are automatically opened and closed simultaneously with the retraction and actuation of the clamp compressing plunger.

A further object of the invention is to provide a tool of the character referred to that is easy and convenient to operate and simple and inex-' pensive to manufacture.

The various objects and features of the invention will be fully understood from the follow-. ing detailed description of typical preferred forms of the invention throughout which description reference is made to the accompanying drawing in which:

Fig, 1 is a central longitudinal detailed sectional View of the tool of the invention.

' Fig. 2 is a front elevation of the tool.

Fig. 3 is a horizontal detailed sectional view taken as indicated by line 33 on Fig. 1.

Fi 4 is a fragmentary detailed sectional view taken as indicatedby line 4-4; on Fig. 1, and

1 Claim. (Cl. 29-270) Fig. 5 is a fragmentary vertical sectional view of another embodiment of the invention.

The form of the invention illustrated in Figures 1 to 4 inclusive may be said to comprise generally a body ID, a reciprocable plunger llin the body, means l2 for operating the plunger l I, one or more holding members or cradles l3 for holding the shank of a clamp in alignment with the plunger ll, and means M for operating the cradles.

The housing or body It] is preferably, though not necessarily, of pistol shape to make the tool convenient to operate. The construction of the body l0 may vary greatly. In the case illustrated the body l0 comprises two complementary sections l5 shaped or pressed to constitute .a hollow housing. The sections l5 have indented parts It spot welded together at 16a so that the two sections form a rigid unit. Two of these indented parts lfib are elongated horizontally and are spaced apart vertically to serve as guides for the plunger I! as will be later described. The body It constructed as just described has a handle grip H and a barrel 18. The barrel l8 houses the plunger I l and is open at its forward end to permit the plunger to act on the sheet clamps.

The plunger H is an elongated part operable to press against the head of the sheet clamp to compress the clamp. In practice the plunger ll may be square or rectangular in cross section and is guided for movement toward and away from the open forward end of the barrel I8. The above mentioned indented parts I61) may serve as guides for the rear portion of the plunger and the side walls of the barrel aid in guiding the plunger. A cylindrical portion 20 is provided on the forward end of the plunger II to engage the clamp and the forward end face of the plunger may have a recess or dimple for cooperating with the rounded end of the clamp.

The meansv l2 for operating the plunger II includes a handle or trigger 2|] to be operated by the workman to actuate the plunger H. The

V trigger 2| extends downwardly in front of the handle H and its upper portion enters an opening 22 in the forward edge of the body It). A horizontal pivot pin 23 supports the trigger 2! for pivotal movement. As illustrated, the trigger 2| may be a channel shaped part and the pivot pin 23 may pass through openings in the spaced side parts of the trigger and may have its ends supported in the side walls of the body, see Fig, 4. The trigger 2! is shaped and positioned to be conveniently operated by the fingers of the workmans hand which grips the handle IT. A notch 24 is provided in the lower edge of the plunger II and a finger 25 is provided on the upper end of the trigger 2| to engage in notch 24. It will be seen that upon rearward movement of the trigger 2| the finger 25 engaging in the notch 24 produces forward movement of the plunger I I.

The means I2 for operating the plunger I I further includes a: helical tensionspring 26 for retracting the plunger I I following operation. An ear 21 is provided on the trigger 2| within the body Ill and a similar car 28 is provided on the' interior of the handle II. The springZB-is connected under tension between the ears 2? and 28. It will be seen that the-tension spring 25 normally holds the plunger II in a retracted position and holds the trigger 2I in the forward position indicated by the broken lines in Fig. 11 The rear end of the plunger I I may contact the rear wall of the barrel I8 to limit rearward movement of the plunger.

The members I3 are provided to enclose and retain the shell or shank of the clamp when the clamp is compressed. In accordance with the invention there may be one or more members I3. In the particular embodiment of the invention being described there are two like and opposed members I3-entering the forward end of the barrel I8. The members I3 are-supported for pivotal movement by vertically spaced horizontal pivot pins 30. The members I3 project forwardly beyond the end of the barrel I 8 and the end portion ofthe'barrel has notches 3| to permit substantial outward swingingof the members, As best illustrated in Fig. 2, the forward portions of the members I3 are tubular and are generally square in transverse cross ection;

The opposing surfaces32 ofthe members I3 are designed to effectively engage and hold the clamp. These surfaces 32 are cylindrically curved and each has a curvature of slightly less than 180 so that when the members I3 are in theirclosed active. position the shank of the clamp is substantially entirely surrounded. The active concave surfaces 32 of. the members I3 are reduced in diameter adjacent the forward ends of the members to provide the members with abrupt rearwardly facing shoulders 33. The shoulders 33 are engageable with the usual flange on the rear end of the clamp shank. When the members. I3 are closed about the clamp, theclamp is securely and positively held against displacement.

The means I4: for operating the cradle members I3 serves to open or spread the members when the plunger is moved rearwardly and serves to swing the members inwardly about the clamp when the plunger is moved forwardly. The means I4 includes tail-pieces 34 on the cradle members I3. The tail-pieces 34 have rounded convex extremities. The means Iifurther includes projectionsor cams35 on the upper and lower sides of the plunger II for cooperating with tailpieces 34. When the plunger I I is movedforwardly the cams 35 simultaneously engage the rounded ends of the tail-pieces. to swing the members I3 inwardly or toward one another to engage about the clamp.

The operating means I4 further; includes springs 31 and 38. These springs are housed within. the barrel II and are in the form of leaf springs. The spring 31 is engaged or hooked behind the upper part I56 and bears downwardly against a pin 39 on the tail-piece 34 of the upper member I3 to urge the upper member outwardly or-upwardly. The" spring-38 is hooked around the pivot pin 23 and bears upwardly against a pin 40 on the tail-piece 34 of the lower member I3 to urge the lower member outwardly or downwardly. When the plunger II is restored to its normal or idle position the springs 31 and 38 automatically spread the members I3 to their open position so that the tool may readily receive the next clamp. In this connection it will be noted that in the locations at which the tailpieces join the cradles I3 arcuate enlargements are provided which cooperate with the upper and lower sides of the plunger II to guide the latter while being extended and retracted in the manner described, It will be noted further that the curved surfaces of the enlargements are coaxial with relation to the axes of the respective pins 30 and as a consequence the enlargements will cooperate with the plunger to guide the outer end of the latter in the desired relation with respect to the operating elements of the clamps while at the same time enabling rocking movements of the cradles in the manner and for the purpose described without impairing the gui'ding'action of the enlargements.

The embodiment of the invention illustrated in Fig. 5 includes a single pivoted guard or cradle member I311: The member I3a may be of the same construction as the members l3 and is pivotally' secured to the-forward portion of the barrel I8 by apivot pin 30a. The upper guard or cradle I3b may be-fiXed in thesaid portion of the barrel I8 as by welding or the like, or may be formed as an integral part of the body I0 as illustrated. The members I31: and I3b have opposing cylindrically curved. concave surfaces 32a shaped to conform to the body of the clamp and have abrupt inwardly facing shoulders 33a. for engaging with the flange of the clamp.

The pivoted guard or cradle member I3a has a tail-piece 5I extending rearwardly in the barrel I8 and the undersi'de'of the plunger I I has a downwardly projecting cam 52 for cooperating with therounded end of'the tail-piece 5|. Upon forward movement of the plunger II the cam 52 cooperates with the rounded end of the tailpiece 5| to swing the member I3a upwardly to its active position to engage about the shank of the clamp A spring 38a engages upwardly against a pin 40a on the tail-piece 5| to'normally urge the member I3a to its down or open position.

In this form of the invention a notch 53 is formed in the underside'of the plunger I I in front ofthe cam 52 to permit ample pivotal movement of the member I311. The broken lines in Fig. 5 illustrate the manner in which thetail-piece 5| enters the notch 53 when the member I3a is in its retracted position. The parts are formed and proportioned so that the sheet clamp may be readily entered between the fixed member I31) and the pivoted member I3o when themember I30; is in its open position.

It is believed that the operation of the tool will be readily understood from the foregoing detailed description. Referring now to the form of the invention illustrated in Figures 1 to 4 inclusive, it will be apparent that the sheet clamp may be easily engaged in the forward end of the tool when the members I3 are in the open positions illustrated by the broken lines in Fig, 1. When it is desired to compress the clamp the trigger 2| is pivoted rearwardly. This causes forward movement of the plunger II and as the plunger moves forwardly the cams 35 cooperate with th tail-pieces 34 to pivot the members I3 inwardly toward one another. Thus the guard members or cradle members l3 are actuated to engage about the shank of the clamp when the clamp is to be compressed. The members l3 engaging about the clamp positively preclude the possibility of the clamp springin or escaping from the tool and thus eliminate all hazard in the use of the tool. When the pressure is relieved from the trigger 2| the spring 26 restores the plunger II and the trigger 2! to their normal positions. Upon restoration of the plunger H the members 13 are swung to open or idle positions by the springs 31 and 38.

Having described only typical forms of the invention I do not wish to be limited to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claim.

I claim:

A tool for applying clamps of the kind having a shank and a, movable operating element, said tool including a body, a barrel on said body having an open end, a plunger in said barrel having an outer end which is engageable with the movable operating elements of said clamps, a lever for moving said plunger axially insaid barrel to ward the open end thereof, resilient means for restoring said plunger to, and for normally holding it in a retracted position, outwardly extending cam surfaces provided on opposite sides of said plunger a substantial distance inwardly from the outer end thereof, a pair of cooperating cra dles, said cradles being located at opposite sides of said plunger and having tail-pieces, pins connecting said cradles to said barrel and providing pivotal mountings for said cradles, the cam surfaces on said plunger being located inwardly with respect to said tail-pieces in the retracted position of said plunger, and resilient means acting on said tail-pieces to pivot said cradles on said pins and in so doing spread them apart so that a clamp may be arranged between them when the plunger is so retracted, said cams being operative when said lever is actuated and said plunger is extended, and prior to engagement of the latter with the movable operating element of said clamp, to engage said tail-pieces and pivot the cradles on said pins to cause them to embrace the shank of said clamp, whereby durin continued movement of said plunger the movable element of the clamp will be operated,

.and inwardly-extending, arcuate enlargement-s on said taiLpieces which engage and guide the outer end of said plunger, the centers of said arcuate enlargements bein coincident with the axes of said pins, whereby said enlargements are caused to maintain guiding contact with said plunger as said cradles are pivoted on said pins in the manner and for the purpose described.

JOHN C. WRIGHT.

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

UNITED STATES PATENTS Sorensen Apr. 22,

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