US2383082A - Rivet squeezer and the like - Google Patents

Description

Aug. 21, 1945. P. F. RossMANN 2,383,082

RIVET SQUEEZER AND THE LIKE Filed June 30, 1942 2 Sheets-Sheet 1 F'IC5-4.

ATTORNEY Aug. 2l, 1945. P. F. RossMANN RIVET SQUEEZER AND THE LIKE Filed June 30, 1942 2 Sheets-Sheet 2 F'IG.6.

INVENTOR.

, PlsToN TRAVEL.

F`| G. IO.

ATTO RN E Y Patented Aug. 21, 1945 l UNITED STATES PATENT OFFICE RIVET SQUEEZER AND THE LIKE Peter F. Rossmann, Snyder, N. Y.

Application June 30, 1942, Serial No. 449,191

(ci. '1s-42) l 4 claims The present invention relates generally to machines or devices of the type embodying relatively reciprocatingmembers for applying pressure to Work positioned between said members, more particularly to a rivet squeezer, but equally useful for punching, Dressing, forging and similar operations.

An object of the invention is to provide a rivet squeezer lor the like constructed and arranged applied to the work, thereby greatly increasing its flexibility in use and allowing of manual or direct hand operation.

A further object is to provide a rivet squeezer or the like capable of enabling ank accurate control of the extent of travel of its relatively movable or pressure applying member by the operator, in particular to stop the pressure application at any point of the working stroke of the device to existing requirements and operating condi- 1ons.

These and further objects of the invention will be in part discussed and inpart become apparent from the following detailed description of two practical embodiments thereof taken with reference to the accompanying drawings forming part of this specication and wherein:

Figure 1 is a longitudinal cross-sectional view of a rivet squeezer, in the normal or,nonuse position. embodying the principles of the invention; Figure 2 is a section taken on line 2-2 of Figure 1; Figure 3 is a section taken on line 3-3 of Figure 1; Figure 4 is a partial `top view of Figure 1; Figure 5 is a fragmental view of Figure 1 showing the position at an intermediate point during the working stroke; Figure 6 is a longitudinal cross sectional view of a rivetvsqueezer similar to Figure 1 and/embodying a modiiication of the invention; Figure 7 is `a view similar to Figure 6 being in part in elevation and showing the position at an intermediate point of the operating stroke; Figure 8 is a section taken on line 8-8 of Figure 6; Figure 9 is a section taken on line 9 9 of Figure 6; and Figure 10 is a plot showing .the Working pressure obtained during the operating stroke with a device according to the invention compared with known rivet squeezers at present in commercial use.

Like reference characters identify like parts throughout the different views of the drawings. Referring to the embodiment of the 'invention `shown in Figures 1 to 4, the numeral 10 indicates a cylindrical housing of my improved rivet squeezerhaving an integral` end wall II at its front and being provided with a screwed-on or otherwise' secured cover or cap I2 at its rear,

said cap havingy an integral cylindrical extension or sleeve I3 of lesser diameter than and coaxial with the housing I0.

The movable unit of the squeezer comprises a hollow shaft I4 carrying an anvil or rivet set I5 at its front end and serving to support a plurality--four beingshown in the drawingsof disc-shaped pistons I6 preferably equally spaced from each other and supported by the inner cas- `ing wall in such a manner that the entire assembly comprising. said shaft and pistons is free to move axially. In the example illustrated, the pistons I6 having an inner diameter to afford `an easy slip-lit over the shaft I4are secured Yto the latter by means of ring-shaped spacers I1 and a nut I8 engaging the threaded en d of the rearwall of the housing Ill by means of outer spacerA rings 24 similar to the spacers I1 and clamped between the outer edges of the discs 23 by the cap I2 gripping the rearward-most disc 23 with the forward-most spacer engaging the f rqpt wall II of the housing I0. The inner edgesof the discs are fitted with suitable packings 25 retained by packing rings 28 which are connected, by rivets 2l or otherwise secured to the discs to provide an airtight, slidable connection with the spacer rings I1 of the movable unit. Similarly, the outer edges of the pistons I6 are fitted with packings 28 retained by packing rings 30 which are connected by rivets 32 or otherwise securedto the pistons to provide an air-tight sliding engagement with the outer stationary spacer rings 24. There are thus provided a plurality of high and static pressure chambers to the right and left of each The static pressure cham-bers S are constantly connected with the outside atmosphere through chambers H passing through the wall of said shaft and the spacing rings I1. As more clearly shown l in Figures 2 and 3, the spacing rings I1 and 24 are provided with annular grooves 34' and 33', respectively, registering with an communicating with the adjacent portholes whereby the ingress and egress of compressed air or other medium is insured in any relative position of said rings with respect to the shaft I4 and housing I0, respectively.

There is further provided in Figure 1 a cooperating anvil or rivet set 35 disposed opposite to the anvil I5 and adjustably mounted in the free end of a removable yoke screwed on or other- Wise detachably secured to a threaded extension sleeve 31 of the housing I0, said `sleeve acting as a bearing for the anvil I5. Any other type of pressure applicator may be provided depending on the use and purpose for which the squeezer is designed as will be readily understood.

In order to move the entire piston assembly comprising parts I4, I5, I1, I8 and to apply pressure to the work such as a; rivet placed between the anvil I5 and the cooperating anvil or rivet set, 35, there is provided an adjustable valve structure for admitting compressed air, liquid or an equivalent medium into the high pressure chambers H, said valve being designed in such a manner as to synchronize the movement of the valve adjusting element controlled by the operator with the advance or travel of the pistons so as lto enable an accurate control of the speed and movement of anvil I5 and in turn of the degree and period of pressure application to ,the work being operated on within the operating range or working stroke of the squeezer.

presently. Valve member 45 is normally urged into its rearward-most or zero position by any suitable means consisting in the example shown,

, of a coiled compression spring 48 encircling the In order to normally maintain the squeezer in the zero or starting position shown in Figure 1, there is provided in .the example shown a coiled compression spring 38 arranged within shaft I4, the rear end of said spring engaging a plug 40 screwed into the end oi' the rear shaft portion 20 to form an air or liquid-tight closure and the front end of said spring bearing against the rear K end of a cylindrical plug 4I'placed inside the shaft I4 and having its front end engaging the inside of anvil I5. Plug 4I which snugly'flts within the shaft I4 is retained against rotation by means of a pin 42 mounted in press-fit ensagement within a bore .through the extension 31 of the housing. Shaft I4 is further provided with a slot 43 engaged by pin 42 to enable axial movement of the shaft within a given range or stroke for which .the device is designed. The plug4I is furthermore of sufiicientlength to act as a seal for and prevent compressed air within shaft I5 from entering the forward-most static pressure chamber.

The control ^nd valve mechanism comprises a cylindrical, suitably knurled or uted hand grip 44 rotatably mounted upon the extension sleeve I3 of .the housing I 5 and a cylindrical valve member 45 in snug fitting and rotating engagement with the inside oi' sleeve I3. Said valve member has an inner diameter somewhat larger than the diameter of the adjacent shaft portion 2li and is provided with an inwardly directed annular flange or rim 45 engaging the outer lsurface of shaft portion 20 and serving as a valve element cooperating with the 'inlet portholes 41 through said shaft in the manner to be described rearward-most spacing ring I1 with one end engaging the rearward-most separating disc 23 and with its other end bearing against a shoulder of the member`45.

Valve member 45 is connected with the hand grip'44 through a pin or set screw 5I) having an intermediate portion arranged to move within an oblique guide slot 5 I in the sleeve I3 (see Figvure 4), whereby rotation of hand grip 44 will result in an axial forward movement of the valve member 45. A flexible tube 52 'from a supply tank of compressed air or the like (not shown) is screwedinto the rear end of the sleeve I3, the arrow A in the drawings indicating the direction of entrance of the compressed air or other medium.

The function and operation of the rivet squeezer aforedescribed is as follows: In the zero or rest position shown in Figure 1, both the static and high pressure chambers S and H are connected to the outside atmosphere directhr through the pontholes 33 on Ithe one hand and through portholes 34 by way of the inside of shaft I4, valve portholes 41 and exhaust portholes 53 on the other hand, respectively. In this position, the compressed air supply as indicated by the arrow A is blocked by the valve element 46 which closely engages the outer surface of rear shaft portion 20. If now the hand grip 44 is rotated in the clockwise direction, .the valve member 45 will advance axially in the forward direction against the action of the spring 48 due to .the pin I5 sliding within the guide slot 5I in the manner described. As a result, the valve element 4B will at first cover the portholes 41 thereby shutting of! .the high pressure chambers H from the outside air. Further advance of the valve by continued rotation of the hand grip 44 will result in the uncovering of the valve ports 41 as shown in Figure 5 and admission of compressed air or other medium. Accordingly therefore the compressed air will enter the inside of shaft I4 and pass through ingress portholes 34 into the high pressure chambers H, the path of the air being indicated by the dotted arrows in Figure 5. All the pistons I6 will thus be simultaneously moved in the forward direction, resulting in a corresponding advance of the anvil or rivet set I5 and application of pressure to the work such as a rivet placed therebetween and the cooperating anvil 35. The position of anvil I5 at the end of the working stroke has been indicated in dashed lines in Figure l.

The'employment of a plurality of simultaneously operated pistons in tandem arrangement as shown has the eii'ect of a correspondingly increased total pressure applied by the anvil I5 and l results in a highly compact rivet squeezer of considerably reduced size and weight suitable for hand operation even for comparatively large size rivets or working pressures.

The initial movement of the piston I5 as a result of the rotation of the hand grip 44 to a certain extent in the manner described, in its turn will entail an axial forward movement oi' the shaft I4, 20 which forms a rigid unit together with the pistons, whereby after a certain advance of the pistons determined by the initial extent of rotation of the hand grip. the valve will be returned to its relative initialposition. wherein the 'valve element 45 will again register with lcoiled spring 38 of Figure 1.

the speed of travel during the complete power stroke, the length of the stroke and degree of pressure application may be controlled and individually adjusted to suit existing requirements and conditions. l A

Upon release of the-hand grip either at the end of the operating stroke or at any intermediate point thereof, the valve will be returned to its zero or starting position by the spring 48 as shown in Figure 1, whereby the inside of the shaft will be connected with the outside atmosphere, allowing the compressed air in the pressure chambers ,HH to escape through portholes 34, shaft I5, valve portholes 41 and exhaust portholes 53. At the same time, the spring 38 will return the entire movable unit to its rearwardmost or starting position as shown in Figure 1.

From the foregoing itwill be understood that the tandem arrangement of a plurality of pistons simultaneously operated by a`suitab1e compressed medium may be used in connection with e this manner, by-a follow up control of this type,

any other known type of valve and control device and vthat the .synchronized or follow-up control of the piston travel or pressure application is not limited to the use of more than one piston but may be employed in combination with any type of piston Without departing from the scope and spirit of the invention.

Referring to Figures 6 to 9, there is shown a modified power squeezer differing from the con-k struction of Figure 1 by the; elimination of the return spring 38 and provision 4of means to return to and maintain the movable unit in its zero position by pneumatic pressure. The housing Ill, separating discs 23, the movable unit comprising pistons IS and shaft I4 as well as the operating parts M, 45, and 50 of the valve structure are substantially similar to those according to Figures 1 to 5 with the exception that the outer portholes 33 are omitted and one or more pistons, in the example shown the rearward-most piston IS', are arranged for'operation by air -pressure in-either direction. Accordingly therefore the chambers Hs and SH on the opposite sides of piston I6' are .utilized both as high and static .pressure chambers to cause piston I6' to act simultaneousl'y withv the remaining pistons during' rearward-most or zero position. In other words, piston I6' serves bbthas an operating piston together with the remaining pistons I6 during the forward travel in the same manner as in the case of Figure 1 and is utilized additionally as a means to return and urge the movable unit into its z'ero position; that is, taking the place of the For the aforementioned purpose, there is provided in the embodiment according to Figures 6 td a modified valve structure designed in such aj-manner that normally, i. e., in the zero position ofthe squeezer shown in Figure 6, the high pressure chambers H aredisconnected from the com-l pressed airsupply with the exception of charnber Hs to the left of the return piston I6 insuch a manner that the movable unit will be urged to and maintained in the rearward-most or zero position. At the same time, the static pressure chambers Sand the chamber SH to the right of the return piston I6' are connected with the outside atmosphere. Upon rotation of the hand grip or other control element, the valve will assume a position so as to admit "compressed air into the high pressure chambers H in a manner similar to that according to Figures 1 to 5, while at the same time the relationship between chambers Hs and SH on both sides of the return piston I6 will be reversed, i. e., chamber Hs will become a static pressure chamber connected to the outside atmosphere similar tothe. chambers S, while chamber Sn will become a high pressure chamber connected to the compressed vair supply similar to the chambers H. The valve is advantageously so constructed thatat rst the change from static to high pressure and vice versa in the chambers SH and Hs will be eiected, whereupon the compressed air will ne admitted to all the high pressurechambers for initiating the power strokevand effecting the advance oi the anvil or other pressure applicator.

Upon release of the hand grip at a point within or at the end of the working stroke, the. valve to 9 by means of a modified valve structure com-` prising a rst tube 55 snugly fitting and slidable within the shaft I4, said tube containing two separate longitudianl chambers s and h such as. in the embodiment shown, by the provision of la further tube 56 of lesser diameter brazed to or otherwise secured to the inside of tube 55 as shown more clearly at 51 in Figures 8 and 9. Chamber h lis permanently under high pressure by direct connectionto the high pressure intake valve chamber Vn, and tubular chamber s having its opposite ends hermetically closed by means of plugs 60 and VG'I is connected to the outside or static pressure through. the exhaustv portholes 62 at the rear end of tubes 55 and 56 communil cating with the static pressure valve chamber Vs which in turn communicates with the outside atmosphere through the exhaust portholes 53.

` The high and static pressure valve chambers Vn and V. are separated by the inner flange or .rim 63 of valve member 45 rigidly secured in an airtight manner such as by shrinking or the like to the projecting right Lend of valve tube 55. As

- a result, rotation of the hand grip Il will cause groove in the members I1 and 55 andcooperating portholes through the members 55, Il, I1 and 55, 55, Il and Il, respectively, Ais such, that in the zero position as shown in Figure 6, all the chambers S as well as chamber SH are at static pressure being connected t chamber s, while chamber Hs is connected to the high pressure chamber h. thereby urging the entire movable unit into its rearward-most or zero position.

If the hand grip 44 is now rotated in a clockwise direction to a certain extent as shown in Figure 7, at rst the relationship between chambers Hs and Sn is reversed, i. e., chamber Hs is tion with Figure 1. If the hand grip is released,

the relative movement of the valve tubes 55 and 56 with respect to the shaft Il will be reversed by the return spring I8 urging the valve back into its zero or rearward-most position. During this return movement the chambers H are temporarily connected with the chamber s thereby allowing the air inithe high pressure chambers to escapeto the outside, whereupon at the end of the valve return movement chamber Hs will be connected to chamber h and chamber SH will be connected to chamber s, resulting in a return of the entire movable unit to its rearwardmost or zero position in the manner understood from the foregoing.

Due to the use of piston I6 as an operating element both during the forward travel and for eifecting the return of the pistons to the zero position, the chamber enclosed by the two rearward-most separating discs 23 and 23 has to be increased accordingly depending on the extent of the travel or operating stroke, and the piston I6 as well as disc 23' are fitted with suitable packings on either side thereof by reason of the fact that air pressure is applied to b'othsides of these members.

An advantage of a squeezer according to the invention, in addition to the accurate and gradual control of the travel or operating stroke in the manner described, is the fact that the desired pressure isdirectly applied from the pistons to the pressure-applying member or anvil by the use of a suitable number of pistons in tandem substantially without any intermediate linkage or like power transmission mechanisms as used in therprior art devices in order to obtain a desired working pressure. In addition, the pressure applied by the squeezer according to the invention is substantially constant throughout the entire working stroke compared with the gradual pressure application from an initial low value to the final pressure in case of devices employing linkage or other transmitting mechanism between the piston and anvil or other pressure applicator, as illustrated at a and b in Figure 10, respectively, representing the plots of the working pressure during the piston stroke obtained by the invention and with the known constructions, respectively.

While I have shown and described a few desix'able embodiments oi the invention, it isun- '/'Vderstood that this disclosure is for the purpose of illustration and that various changes in shape, proportion and arrangement of parts as well as the substitution of equivalent elements for those herein shown and described may be made without departing from the spirit and scope of the invention as dened in the appended claims.

I claim:

1. In a rivet squeezer, a housing forming a cylinder having a plurality of chambers, a plurality of pistons each movable within one of said chambers, a hollow piston rod extending into all the chambers andI projecting from both ends of said cylinder, said piston rod having inlet port means connecting the inside thereof with said chambers on one side of said pistons, a rivet set at one of the projecting ends of said rod, a yoke carrying a cooperating riveting tooland secured to said housing, control means for admitting compressed air or fluid through said rod to said chambers, said control means comprising an adjustable valve member carried by an extension of said housing and cooperating with an inlet opening of and arranged at the opposite vprojecting end of said rod, and means to resiliently urge both said piston rod and said valve Imember to a predetermined starting position, whereby to normally interrupt the supply of compressed air or fluid to said chambers and to synchronize in a continua1 follow-up action the advance and return of said pistons with the adjusting movement of said valve member.

2. In a rivet squeezer, a housing forming a cylinder, at least one piston movable within said cylinder, a hollow piston rod projecting from both ends of said cylinder, said rod having inlet port means connecting the inside thereof with said cylinder on one side of said piston, a rivet set at one of the projecting ends of said rod, a yoke carrying a cooperating riveting tool and secured to said housing, control means for admitting compressed air or uid through said rod to said cylinder, said control means comprising an adjustable valve member carrier by an extension of said housing and cooperating with an inlet opening of and arranged at the opposite end of said rod, and means to resiliently urge both said piston rod and said valve member to a predetermined starting position, whereby to normally interrupt the supply of compressed air or fluid to said cylinder and to synchronize in a continual follow-up action the advance and return of said piston with the adjusting movement of said valve member.

3. In a rivet squeezer, a housing forming a cylinder, at least one piston movable within said cylinder, a hollow piston rod projecting from both ends of said cylinder, said rod having inlet port means connecting the inside thereof with said vcylinder on one side of said piston, a rivet set at at the opposite projecting end 0f said rod, and.

means to resiliently urge both said piston rod and said valve member -to a predetermined starting position, whereby to normally interrupt the supply of compressed air or fluid to said cylinder and to synchronize in a continual follow-up action the advance and vreturn of said piston with the ad-

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