US2944581A - Dimpling tool - Google Patents

Description

A. A. SHYMANSKI 2,944,581

YDIMPLING TOOL July 12, 1960 Filed Sept. 4, 1956 2 Sheets-Sheet 1 INVENTOR ADOLPH A. SHYMANSKI p Patented July 12,, 1966 DIMPLING TOOL I Adolph A. Shymanski,- Los Angeles, Calif., assignor to Zephyr Manufacturing (10., Inglewood, Calih, a partnership Filed Sept. 4, 1956, Ser. No. 607,621 3 Claims. ((1153-41) This invention has to do with fluid-actuated tools for applying pressure in oppositedirections to a work piece, such as, for instance, a metal sheet, and while the" invention is adaptable for other uses, it finds its chief utility as a tool for embossing, countersinks or dimples in such work sheets around the holes provided therein for the reception of rivets and other fasteners,

One of the objects of my invention is to provide a device of this character which is so designed and constructed as to be capable of being made relatively small, self contained, of lightweight and portable to the extent that it is adaptable for use as a hand tool.

Another object of. the invention is to provide a dimpl'ing tool. which provides substantial leverage advantages capable of reducing to a minimum the ainount'of fluid pressure required to supply the necessary'operating pressures.

A more specific object is to provide a d'impling tool wherein a gun-type body member presents a metal fortning surface through which a fluid-actuated plunger projects and is reciprocable, the outer end of the plunger releasably carrying a second metal forming member, so that a work sheet may be placed between the forming members, the forming members then being moved towards each other by the fluid pressure against opposite surfaces of the sheet to emboss the sheet around a fastener-receiving perforation therein.

My invention additionally includes as objects other novel structural features which enable the attainment of the before-mentioned, and-includes other objects and advantages, all of which will become readily apparent from the ensuing description.

While 'I shall point out in the appended claims the features which I believe to be new, I shall now, for the purpose of rendering my invention clearly understandable to those skilled in this art, describe a presently preferred embodiment thereof for which purpose I shall. refer to the accompanying drawings wherein,

Fig. 1 is a side elevational view of the pneumatic gun; M Fig. 2 is an end elevational view taken on line' 2'--2' of Fig. 1;

Fig. 3 is an enlarged section taken on line 3--3 of Fig. 2, showing the parts in their idle position;

Fig. 4 is a fragmentary sectional view showing the parts in the position which they occupy at the end of the power stroke of the piston;

Figs. 5 and 6 are enlarged sectional views taken respectively on lines 5-5 and 6-6 of. Fig. 3; and

Fig. 7 is a view taken on line 77 of Fig; 4. Referring now to the drawings, I show an embodiment of my invention which preferably has a pistolshaped main body portion A having a handle portion casting 5 presenting a bore 7 having a liner. 8 defining an air inlet chamber 9. The liner 8 is merely to insure that air pressure will not rupture the handle casting. if

the casting should be faulty, and' may be eliminated if desired. The bottom end of this bore is enlarged and internally threaded to threadedly receive a nipple 10, a

seal ring 11 being provided between the nipple and the handle. The nipple has a threaded socket 15 for connecting the handle, as by a flexible hose not shown, to" a source of compressed, air, not shown. I

The upper part of the handle portion is provided with an internally threaded, forwardly opening socket 17 into which the inner end 18a of a cylinder 18 is threaded. A plug 20 has a reduced inner end portion 20a threaded into the internally threaded outer end portion of cylinder 18'. p

A guide member 25 has its hollow relatively large diameter inner end portion 25a threaded into an internally threaded socket 26 in the outer end of the plug, a lock nut 27 being employed to lock the guidemember to the plug in various positions of axialadjus'tment to accommodate work. sheets'S of different thickness. The lock nut has a radial opening. 27a to receive a tool for rotating the'nut.

A'piston 30', having a seal ring 3021, is mounted to reciprocate in the cylinder 18, the piston having an,

outwardly opening e-nd recess 31', and having, an axial opening. 32. to slidably pass a tube 34 which has a pcripheral flange 35 presenting an annular shoulder 36 against which the piston abuts when in its innermost position (Fig. 3) the flange being held against the inner end of the socket by a screw' 3411. Tube 34 has an air inlet passageway 38 which admits air to the interior of the tool ahead of the piston for cooling purposes and will be more'fully explained hereinafter and also for returning the piston inwardly after the power stroke; The air enters tube 34 from chamber'9 through a passageway 40 in the handle, which passageway is controlled by a valve 42 actuated by a finger-operated. trigger 43 which is urged outwardly by spring 44, the outward movement of the trigger being restricted by a pin 45 disposed in a longitudinal slot 46 in the trigger. A seal. ring 47 is disposed between the tube 34' and piston 30 to prevent air from the chamberSG, behind the piston, from passing around the tube. Chamber 50 is defined by' the inner end of socket 17, the inner end of piston 30' and the cylinder 18.

Air is admitted to chamber 50 from inlet chamber 9 through a passageway 52, which is controlled by the valve 42. The latter valve has an axial passageway 54', a radial passageway 53', a restricted radial bleed port 55, and has a' transverse passageway 57 spaced forwardly from passageway 53' and adapted to register with port 52' when the trigger 43 is pressed inwardly to actuate the piston. Inward movement of the valve closes the passageway 40. 7

Plug 20 has an axial bore 60' in which a plu'ngerdl is mounted to reciprocate. The reduced inner end portion of the plunger carries a cam disk or washer 62 secured thereon by. a nut 63. The opposite end portion of the plunger has an enlarged diameter threaded portion 65 which threads into an internally threaded head member .66. Said head member has a rearwardly facing. annular shoulder 67 against which one end of acoil spring; 68 bears, the opposite end of the spring bearing against the inner end of bore 26 in the plug. The hollow inner end portion of guide member 25 provides a socket 69 in which head member 56 reciproca'tes.

Guide member 25 has an axially outwardly extending, externally threaded, reduced diameter, tubular portion 25b .onto which is threaded a sleeve memberZS'c as well as a punch member 70 having a frusto-conical outer end metal forming surface 71.

In use, I prefer to mount, on the periphery of the punch member and the portion 250, a sleeve-like electric heater, denoted in Fig. 3 by broken line H. While there Letters Patent No. 2,740,035 to be well suited, the purpose of the heater being to heat the metal work sheet S being dimpled, by heat transfer through the punch mem ber 70. Sleeve member 25c has a heat insulating chamber C. a a

A combination pilot pin and pull member 75 (which may be considered as an extension of plunger 61) has a headed inner end 76 disposed within member 66 and keyed portion 65 of the plunger by a key 78 to prevent relative rotation between those two members. The outer end portion of the pilot pin then extends outwardly through a bore 79 in punch member 76 and axially through the forming surface 71, terminating in a project ing outer end portion for the reception of a die or second formingmember 80 whose inner end presents a frustoconical forming surface 82 conforming and opposed to the punch member 70.

Die member 80 comprises a housing 81 having an axial bore presenting a relatively large diameter portion 81a and a relatively small diameter portion 81b. Die portion 83 has a relatively large diameter end portion 83a in which metal forming surface 82 is provided, and a relatively small diameter portion 83b which fits in the open end of bore portion 811;, the annular shoulder 83c engaging the contiguous end of the housing. Portion 83b is retained in the housing by means of radial pins 84. Die member 83 has an axial bore 83d (see Fig. 6) which is coaxial with the housing and the left hand end surface 83:: of member 83 is beveled or flared whereby to provide an annular beveled cam surface.

A two-jawed collet 85 presents a beveled outer surface 8511 on the right hand end portion of each jaw, which surfaces conform to and carnmingly engage surface 832, the collet jaws being urged against surface 83a by a coil spring 86, a ring 87 being interposed between the spring and the annular shoulder 85b of the collet.

Pilot pin 75' has a flattened portion 75b (see Figs. 1, 3 and 6) adjacent its free end, the opposite sides of which flattened portion engage between the jaws of the collet. The rounded outer end of the pilot pin is first inserted through a hole S in the work sheet S and thence into the bore member 80 and thence between the jaws 85 of the collet, the rounded left hand end of the pilot pin functioning to spread the collet jaws apart enabling the pilot pin to slide between the jaws until the flattened portion reaches a position between the jaws, at which time the jaws will, by virtue of the spring 86 and the cooperating cam surfaces, snap into position against opposite surfaces of the flattened portion of the pilot pin, the opposed shoulders 75a (see Fig. 1) presented by the pilot pin at the ends of the flattened portion, engaging the ends of the collet jaws to prevent further axial movement of the pilot pin relative to the jaws in either direction. However, the pilot pin may be withdrawn from the member 80 by rotating the member 80 relative to the pilot pin until the collet jaws engage the maximum diameter portion of the pin, as shown in Fig. 6 at which time the pilot pin may be withdrawn axially from the die member or the die member may be removed axially from the pilot pin as may be desired. To prevent the collet from rotating relative to the housing, I provide, in the housing, radial pins 81c which extend inwardly to a limited extent between the collet jaws.

Plunger 61 slidably and rotatably carries a cam disk 90 which abuts against the inner race 92 of a ball hearing member 93 whose outer race 94 fits in an annular recess 95 in plug 20.

A plurality--preferably three in number, as best shown in Fig. 7of circumferentially spaced arms or levers 100 are pivotally connected to the left or outer end of piston 30 adjacent its periphery by pivot pins 101. While each of the arms may be generally described as being L-shaped, each has a straight medial portion 100a, a radially and rearwardly disposed top end portion 1100b, and a rearwardly disposed bottom end portion 100:: whose curved 4 free end portion 160d engages the outer face of the cam disk 62.

In the idle position of the parts, as shown in Fig. 3, the outer or left hand edge of each arm 100 bears against the recessed inner face of cam disk 90 approximately at the point of the curved intersection of arm portions 109a and 10%.

Each of the members 250 and has a radial socket 105 for the reception of a tool not shown, for the purpose of rotating said members relative to the threads 25b for the purpose of screwing said members onto and unscrewing them from the threads 25b.

Member 25 has circumferentially spaced radial air bleed ports 107 communicating with the socket 69, a

perforated sleeve 108 being mounted on the periphery of member 25 over the outlet ends of the perforations. Those perforations are for the purpose of discharging the cooling air which is introduced through the device through tube 34 during the idle position of the parts Operation of the device is as follows:

Commencing with the idle position illustrated in Fig. 3, the operator inserts the outer end portion of the pilot pin through a previously drilled rivet or screw-receiving hole S in the work sheet S, holding the handle 5 in one hand, the operator using his other hand to mount the die member on the outer end of the pilot pin at the opposite side of the sheet. The operator then presses trigger 43 inwardly placing ports 54 and 57 in communication with air passageway 52 leading from the inlet chamber 9 into the cylinder 18 behind the piston 30. The air pressure then moves the piston 30 outwardly or to the left, causing the arms or levers 10!) to engage cam disk and thus to swing inwardly or to the right to cause their ends d to engage and push the cam washer 62 to the right, as shown in Fig. 4, thus pulling plunger 61 and pilot pin 75 inwardly or to the right, causing the sheet to be embossed between the forming surface 82 of member 80 and the forming surface 71 of member 70. Ball bearing 92 allows carn disk 90 to rotate when engaged by arms 100, thus reducing the friction.

It will be observed that an annular flat surface 110,

perpendicular to the longitudinal axis of the tool, is pro.-

vided around the base of the frusto-conical forming portion 71, while a like flat annular surface 111 is provided around the forming surface 82 in the forming member 80, the two flat surfaces being opposed to each other. Thus, as the air pressure is applied to the chamber 50 in cylinder 18, the tool is operated first to preliminarily fold the dimple before the flat surfaces around the hole 5' in the work sheet become clamped between the annular surfaces 110 and 11 1, after which the sheet becomes clamped between those flat surfaces during the coining of the dimple between forming surfaces 71- and 82. When the trigger is released from its said inwardly pressed position, the air is restn'ctedly released through the restricted bleed port 55 in valve 42 while port 40 is opened to admit air through tube 34 to return the piston inwardly or to the right in cylinder 18. Y Inasmuch as the main body of the tool tends to becom heated by conduction from the heating element H, I pro vide for the constant passage of a stream of cooling air through port 40, tube 3 and bore 69 around the plunger, and thence outwardly through bleed ports 107 and per f-orated sleeve 108, so long as the valve is in the position of Fig. 3.

I claim: l. A pressure applying tool comprising a body providing a cylinder, a piston mounted to reciprocate in said cylinder, a pull plunger reciprocally carried :by said body and having its outer end portion projecting therefrom, said body having an outer end work engaging surface through which said outer end portion of said plunger extends, and means for moving said plunger inwardly of said body in response to movement of said piston in the opposite direction, comprising a cam member in said body surrounding the inner end portion of said plunger having thrust bearing against said body, acam disc carried by the inner end portion of said plunger in longitudinally spaced opposed relationship to said cam member,

levers pivotally secured at their inner ends to said piston in circumferentially spaced relationship to each other; each of said levers having an L-shaped outer end portion presenting portions engageable respectively with said cam member and said cam disc in response to movement of said piston in a direction outwardly of said body, and

' means for reciprocatingsaid piston; said piston, plunger,

cam member, cam disc, and said work engaging surface are coaxial with said body and wherein said levers are arranged symmetrical to said plunger.

2. The tool of claim 1 which additionally includes a 7 work forming member carried by the. outer end portion of said plunger in longitudinally spaced opposed relationship as said work engaging surface of said body.

3. The tool of claim 1 in which said cam member is rotatable relative to said body and relative to said plunger.

References Cited in the file of this patent UNITED STATES PATENTS

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