US2113161A - Riveting apparatus - Google Patents

Description

April 5, 1938. l R. s. osBORNE 2,113,161

RIVETlNG APPARATUS Y Filed July 19 1934 Y 2 sheets-Sheet 1 2 HYDRA UL IC PR ESSURE PNE UMAT/ C HQEJSURE 1N VENTOR.

WIT/VE E6 4 ATTORNEYJ.

RS QSBRNE RIVETlNG APPARATUS April 5, 1938.

Filed July '19 1934 2 Sheets-'Sheet HYDRAULIC PRESSURE 128 1&3

INVENTOR.

-lv ATToRNEYs.

KE MW mm 7 6 1 4 iff AA ff/AZ :Mr/wh- 24J -l i WMM o j W/TN $556 WMM Patented Apr. 5,' 1938 UNITED STATES PATENT l0.1-1-*1c1-z RIVETINGAPPARATUS Raymond S. Osborne, Sewlckley, Pa.

Application July 19, 1934, Serial No. 736,026

9 Claims.

This invention relates to compression riveters, and more particularly to riveters usedfor driving rivets cold.

It is desirable that riveters of thetype referred to herein operate at maximum speed whenever possible so as to save time, and also that they operate more slowly as the difficulty of the work increases in order that the work may be properly done. As it is usually not practicable to slow up the return stroke of the driving die as well as its driving stroke, it is desirable that the speed of the driving stroke be easily adjusted tothat desired independently of the speed of the return stroke. In some types of work it is likewise desirable that the driving die of the riveter approach the work slowly so as to allow proper alignment of the rivets with the dies, and then quickly drive the rivet and return to its original position. With compression riveters known heretofore such speed control has not been possible except to the extent made possible by careful manual operation of the control lever, commonly termed inching up on the rivet, and with the attendant loss of time and uncertainty of operation.

In certain types of work, such as when there are no obstructions to pass between the dies of the riveting apparatus, it has been found feasible to economize on time by diminishing the distance which the driving die can be moved away from the stationary die; in other words, to shorten its stroke. Here again, prior to the present invention, the strokes of each riveter have been uniform in length.

Again, it is desirable that riveters of this type be adapted for use with hydraulic 4as well as with pneumatic power, and that their operation may be controlled entirely by a trigger valve independently of the usual automatic control.

It is among the objects of this invention to provide a compression riveter in which the speed of operation can be varied at the will of the operator, in which the speed of operation during a single cycle can be varied, and in which the distance the driving die moves away from the stationary die can be varied as desired, all by positive automatic controls.

Other objects are to provide a riveter in which the driving die is driven by hydraulic pressure, in which the pressure applied to the rivets can be automatically controlled, and in which both the driving and return stroke of the driving diecan be initiated by a trigger valve.

A still further object is to provide such ariveter in which the control mechanism is simple. sturdy and easy to operate.

(Cl. '1S-42) `The invention is illustrated in'the accompany# ing drawings, i'n which Fig. 1 is a 4view' in section and somewhat diagrammatic of a compression riveter in which the riveting mechanism is operated by hydraulic' pressure; Fig. 2 aside view ofthe main valve and itsassoclated parts; and Fig. 3 a front view in section of a modified form of hy- 1 draulic riveter. I

Referring toFig. 1 of the drawings, there is shown a riveting mechanism comprising a riveter' i frame or yoke I supporting a stationary die 2 and carrying a vertically reciprocable and adjustable driving die 3 which is actuated through'a toggle connection [by a -driving pistoni connected to the toggle by a piston rod 1. 'I'he'pifston is provided with a cylindrical skirt l', and'is reciprocable in a driving cylinder 9 the opposite ends'of which communicate through passages II `and I2 with the central borev I3 of a main valve I4 mounted on the cylinder.` vBore I3 is connected by'a conduit I6f toa source of fluid under pressure, preferablyhydraulic pressure, and by an exhaust `passage I1 to the atmosphere. `Dis-posed in the valve bore is a valve member I8 which isk turned by 'a shaft I3 projecting through the wall of the valve, and which is so formed that when it is turnedto either end of its path of movement it connects either passage I I or passage I2 to exhaustpassageil and permitsthe pressure fluid fromconduit I6 to enter the driving cylinder through the remaining pas. sage. Thus, driving piston 6 is forced to one end or the other of the driving cylinder by hydraulic pressure, depending on which Way valve member I8 is turned.

This valve member is actuated by pressure fluid operated means comprising a cylinder 2 Iv in which is disposed a piston 22 having a piston rod 23 pivotally connected to a sleeve. which is slidable axially on a lever 26 rigidly mounted on the projecting end of shaft I9 at a right angle thereto (Fig. 2). The opposite ends of cylinder 2| are connected by conduits 21 and28 to ports 29 andf 3I, respectively, which lead through the wall of a trigger valve 32 into an axial bore 33 therein. Equidistant from ports 29 and 3| the trigger valve is provided with lan inlet port 34 which is connected by a conduit 36 to a source of fluid under pressure for moving piston 22 in cylinder 2| in order to operate the main valve. The fluid used for this purpose is preferably gaseous, vsuch as compressed air, 'because liquids do not ow fast enough to obtain the-almost instantaneous .response of the control mechanism which is highly desirable. f p

To restrict theftlow of ythepressure fluid to only one end of cylinder 2I at a time, trigger valve bore 33 is provided with a snugly tting axially movable plunger 31 having an annular recess 35 therein which is long enough to connect inlet port 34 Y to either one of ports 23 and 3|, depending on the position of the plunger. When this annular recess places port 34 in communication with port 3l, an annular groove 33, with which the plunger is also provided, registers with port 23 and vents it through a radial bore 4I and an axial plunger bore 42 to the atmosphere, wherebymovement of piston 22 is not restricted by compression in the piston rod end of cylinder 2I. Also, for the same reason, the portion of the plunger between the outer end of annular recess 33 and the adjacent end of the plunger is short enough to leave port 3| uncovered when the recess connects inlet port 34 to port 23.

One end of the plunger has a trigger 43 connected thereto for moving the plunger back and forth in the trigger valve.,V When this trigger is pressedinto contact with .the valve casing, fluid under vpressure flows fromconduit 35 into the head end of cylinder 2| and forces piston 22 to the opposite end of the cylinder. 'I'hismovement of the piston turns valve member I5 to permit hydraulic pressure to force driving piston 5 from the head end of the driving` cylinder to the opposite endthereof, thereby causing driving die 3 to drive a rivet 44. If trigger 43 is then `pulled its iull distance away from the trigger valve casing,

the movements ofallparts are reversed and the drivingk die is again raised to its upper position.

y However, as it is highly desirable that just the proper amount of pressurebe applied toarivet to avoid either incomplete driving or damage to the workjoutward movement of plunger 31 is not generally left to the variable human element, but is ordinarilyaccomplished automatically at the moment a predetermined pressure is applied totherivet.

Accordingly, the portion yoi' trigger `valve bore 33 adjacent trigger 43 is enlarged, .and a piston 45 is rigidly mounted on plunger 31 therein. The

.wall oi the valve is provided with a port 45 which connects the inner end ofthe enlarged bore to a conduit 41 leading through va pressurecontrol valve 45 to a conduit 43 preferably connected to the same source of compressed air or the like to which conduit 35 -is connected. Consequently, when pressure is applied to the inner face of piston 45, plunger 31 is moved to connect conduit 35 with the piston rod end of cylinder 2l, and driving die 3 is withdrawn from the work. Piston 45 also acts as a stop for limiting the movement of plunger 31 in either direction. It isthe purpose of pressure control valve 45 to admit pressure fluid to conduit 41 at the proper time as determined by the driving pressure in the head or driving end of cylinder 3.

In accordance with this invention, valve 43 is provided with an axial bore 5I enlarged near its upper end, as at 52, and closed at its lower end by an adjusting screw 53. The upper end of the bore is connectedby a conduit 54 to the driving end oi' cylinder 3, but pressure iluid is normally prevented from entering enlarged bore 52 yfrom the driving cylinder by a bali 55 disposed in the enlarged bore and seated across the opening in the upper wall `thereof by a plunger 51 and a coil spring 55 resting on the screw 53. Near the lower end of this plunger the valve casing is provided with a pair of unaligned ports 53 and 5I to winch conduits 41 and 43l are connected, respectively, and which open into axial bore 5I but Yencl of the driving cylinder.

rpressure'iluid to enter enlarged bore 52 where it passes the ball through grooves 53 and strikes piston 52, thereby quickly depressing plunger 51 and compressing the coil spring since the area oi' bore 52 is greater than that of ball seat 55. An outlet 54 in the lower end oi' valve 45 and an outlet 55 below piston 52 exhaust the spaces below the plunger and piston, respectively, when the latter are depressed.v It will be understood that adjustingscrew 53 is adjusted so as to hold ball 55 against its seat until the driving pressure in cylinder 5 produces the maximum pressure that is to be applied to rivet 44, at which instant the ball is unseated.

With the plunger in its lowest position. ports 53 and 5I are connected by an annular recess 51 in the plunger, and fluid under pressure flows from conduit 43 through the pressure control valve land conduit 41 into the trigger valve where it strikes piston 45 and moves plunger 31 outwardly. Tins causes main valve I4 to be reversed and the driving piston to be returned to the head When the main valve is reversed in this manner the head end of the driving cylinder is vented to the atmosphere through passages I2 and I1, and the pressure that depressed plunger 51 of the pressure control valve escapes. Thereupon, coil spring 55 again raises plunger 51 and forces bali 55 to its seat, whereby the ow of pressure fluid through valve 45 is shut oiill.

In the upper position 'of the plunger, conduit 41 is vented to the atmosphere through port 55 and outlet 54. This removes the pressure from piston 45 and permits plunger 31v to again be actuated manually for putting the riveting mechanism in operation. Also, when plunger 51 is in its upper position conduit 43 is connected by annular. recess 51 to a port 12 in the wall of the valve. This port is closed by a plug 13 which can be removed in case it is desired to connect a conduit to the port for automatic repetition of the cycle ofA driving.

If it is desired to operate the apparatus entirely manually'by means of the trigger valve, valve 14 in conduit 54 is closed to prevent the pressure in cylinder 3 from operating pressure control v valve 45.

As set forth at the outset, it is desirable to be able to operate riveting apparatus at different speeds. Therefore, as shown in Fig. 2, lever 25 of main valve I4 is provided with an extension 15 the movement of which is limited by adjustable set screw stops 11 threaded in lugs 15 projecting from the valve. By turning these stops, sin-` gly or together, toward or away from lever extension 15, the amount that the valve member I5 is turned, and, consequently, the amount that the upper ends of passages II and I2 are uncovered by valve member I5, can be varied. If the stops are set so that both passages can be only partially uncovered regardless ofthe direction in which valve member I5 is moved, the entrance of fluid under pressure into either end of cylinder 3 will be retarded and the rate of movement of piston 8 correspondingly diminished. rOn the other hand, if one stop is moved away from lever extension 'I6 and the other stop toward it, movement-of valve member I8 in one direction `will y fully uncover the passages, while its movement in theopposite direction will only partly uncover them, thereby givingeither a fast driving stroke and a slow return, or vice versa.

Where the work is diiilcult but it is necessary for the dics to be spread apartas ,faras possible to pass over obstructions, the driving die can be made to approach the work slowly while the rivet is being properlyaligned with the dies, and then moved rapidly during the rest of its driving stroke and return. This is made possible by the presence of a coil spring 8| in cylinder 2| where one end of it encircles an inwardly projectingstop 82. By moving trigger 43 of the trigger valve quickly toward the valve casing and back to a neutral position where annular recess 38 does not register with either port 29 or port 3|, sufllcient pressure fluid `is permitted to enter cylinder 2| to force piston 22 against coil spring 8| the resistance of which stops further movement of the piston. 'I'his initial movement of the piston turns valve member I8 only farenough to partially open passages II and I2, whereupon piston 8 moves the driving die slowly toward the work. When the work and rivet have. been properly adjusted, the trigger 43 is again pressed against the valve casing and allowed to remain there, and the pressure fluid then forces piston 22 the rest of the distance of its stroke until it strikes against stop 82, coil spring 8| being compressed during this second movement of the piston as shown in Fig. 1. The result is that passages and I2 are fully opened at this time, whereupon the driving die quickly drives a rivet and returns to its starting point. When` the work is easy to do and there are but few or minor obstructions to pass between the dies, the distancey which the driving die moves away from lower die 2 can be decreased to save power and time.v This is accomplished by limiting the return stroke of the driving piston by a piston stop 83 mounted on the inner end of a piston rod 84 reciprocable through the head of cylinder 9 and provided at its outer end with a piston 8B disposed in an auxiliary cylinder 81 mounted on cylinder 9. 'I'he length of piston rod 84 will depend on the amount the driving piston around skirt 8. While stop 83 is projecting into the driving cylinder, piston 6 can not move backward the full length of the cylinder and, therefore, the driving die is not withdrawn as far as otherwise possible from the stationary lower die. To make the use of the piston stop optional, conduit 88 is provided with a three-way valve 88 which, when turned to shut oil the flow of uid to the auxiliary cylinder, opens the latter to an exhaust line. Piston 6 can then push stop 83 back into the recess 9| provided for it in the cylinder head where it remains until valve 88 is again operated.

l VA:s -In Fig. 3 there is'illustrated a modlned formo! hydraulicriveter in which :a drivingplston |88A acts directly on-the driving die v.|88 `instead of through the medium of a tosle. 'A yoke or frame |8| carries the driving die and a cooperating vertically-adiustable lower die |82, andfsupports substantially all of the control mechanism. `'Ihe driving diels mounted on the lower end of a lpiston rod |81 to the upper'end'ofowhich piston |88 is rigidly connected, the piston vbeing .reciprocable vertically in a cylindery 88 securely Vmounted on the front of the riveter frame. Theopposite ends of this cylinder are connected by passages I|| and |I2 to acylindrical bore |I8.in a main valve I4 'attachedtoone side of the cylinder, the valve also being provided midway between vthese passages with an exhaust passage I I1. Fluid pressure, preferably hydraulic, is admitted to opposite ends of the cylindrical bore of the valve through a conduit I8 and branch conduits I Ila and. I |8b. f The end of driving cylinder |88 to which pressure fluid is admitted -is governed by a pistonl valvemember ||8 reciprocable in bore |I8, the central portion of the valve'lmember lbeing provided with an lannularrecess |I8a which connects either passage I II or passage I I2 to exhaust pas-V fluid under pressure to enter the remaining passage frorn conduit IIB'and the adjacent branch conduit. The lvertical position of Apiston valve member II8 in the main valve is controlled by a piston |22 disposed in a cylinder |2| and connected to the valve member by piston rods A|28 and I|8. The head end of this cylinder is connected by a conduit |28 to the axial bore |88 oi' a trigger valve |82 located in a position convenient for the operator of the riveting apparatus, and the opposite end of the cylinder is connected by a conduit I21to trigger valve bore |88 at a point below conduit |28. The trlgger'valve is also connected to a' source of fluid pressure, preferably pneumatic to insure quick response of the control mechanism, by a conduit |88 which opens into axial bore |38 midway between conduits |21 and For selecting'to which of these latter conduits the pressure fluid shall be admitted. a plunger |31 is disposed inthe trigger bore and is provided at its lower end with a trigger |48 for manipulating it. This plunger is alsoprovided with an annular recess'` |38 which connects conduit |88 with conduit |28 when the plunger is in its upper position, and with conduit |21 when the plunger is in its lower position. In the yfirst case conduit |21 is exhausted through an annular groove |28, a radial bore |4|, an axialv bore I42,"a radial bore |44, and an annular recessV |45, all in theplu'nger, and a port |48 in the wall of the trigger valve. When the plunger is lowered, r`conduit |28 is exhausted through the upper end of valve bore |88.

For automatically reversing main-valve |I4 to withdraw the driving die from a rivet when a predetermined pressure has been applledthereto, the trigger valve plunger is actuated by a pres,- sure control valve |48 which is operated by the pressure in the driving end of cylinder |09. The pressure control valve is provided with an axial borev |5I that isconnected at its upper end by aI conduit` |54 to the head end of cylinder |88. The

opening between conduit |54 and bore |5| is norwhich is constantly forced upwardly byl a coil spring |58 `resting on a. hollow adjustingscrew ing screw |63, and resting on the upper end of plunger |31.

When the pressure in the., driving -end 4of cylinder |88 reaches the amount for which the adjustingscrew has been. adjusted it unseats the ball-H6; and thev pressure fluid passes the ball through `grooves |63 formed in the` wall o! the valve and strikes piston |62 which is thereby quickly forceddown against the resistance of the coil spring. 'I'his movement is transmitted to the triggervalve plunger by piston rod |51, and conduits |36 and |28 are connected toconduit |21 and theexhaust, respectively, whereupon` the mainvalve is reversed and the driving die withdrawn from the work. y Y c The distancewhich piston valve member ||3 moves inbore ||3 can be regulated by adjustable stops |11 against which'abuts an arm |16 projecting laterally from piston rod I8. If the path of movement is shortened by the -.use of these stops, passagesjili and ||2 will be only partly uncovered and the speed of operation of the rivetingapparatus will be correspondingly reduced, the lower stop governingthe forward movement and the upper stop the return movement of piston |06. In short, stops |11 function in the same manner as stops 11 sho wn in `Fig. 2. Y

To facilitate varying the speed of die |03 during its driving stroke, a coil spring |8| is disposed in cylinder |2| where it encircles piston rod |23. This spring functions in the `same manner` as spring 8| in Fig. 1. l y Y.

In order to shorten the stroke of the driving die, a back stop |83 is disposed in a recess in the headof cylinder |09. This stopis projected into the cylinder by a piston |86 disposed ina superposed auxiliary cylinder |81, the piston being depressed by fluid pressure preferablyrobtained from hydraulic pressure line ||6 by a conduit |88 provided with a three-way valve 1|88. i

Riveting apparatus constructed in accordance with this invention is adapted particularly for the use of hydraulic pressure in'driving rivets, al-

though it is also possible to use pneumatic pressure throughout. The apparatus is also adapted to dohighly satisfactory work underall conditions because the speed atwhich it operates can be easilyand quickly set so as to be automatically controlled to that proper and safe for the work in hand, while the pressure'vapplied to the rivets can be automatically controlled to that proper for the work and size of rivets. By using a short driving stroke where feasible, the dies and rivet can be more easily and exactly aligned, and time canbe saved. The simplicity and'ruggedness of the apparatus insure lack of trouble, and thcV certainty of operation insures the high quality of the Work. l

According'to the provisionsv of the patent statutes. I have explained the principle and mode of operation of my invention. and have illustrated an'd described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise'thanas specifically illustrated and described.

Iclaim: v

l. Fluidactuating mechanism `for a riveting die, comprising a cylinder, a piston therein connected to the die, a conduit connecting a source of' hydraulic pressurev to Athe cyllnder'for recipro- 'catingthe piston to actuate the die, a'main valve insaid conduit for controlling the application of said-hydraulicpressure to said-piston, means forv operating said main valve, a conduit connecting a source of pneumatic pressure to said valve-operating means for actuation thereof, a trigger valve in said pneumatic pressure conduit for consure control valve for reversing said trigger valve,

said control valve being actuated by predeter' mined'hydraulic drlvingpressure in the driving end offsaid cylinder and being formed to keep said hydraulic pressure fluid from passing therethrough.

2. Fluid actuating-mechanism for a riveting die, comprising a cylinder, a piston therein connected to the die, a conduit connecting a source of hydraulic pressure to the cylinder for reciprocating the .piston to actuate the die, a main valve in said conduit for-controlling the application of said hydraulic pressure to said piston, means for operating said main valve, a conduit connecting va source of pneumatic pressure to Said valve-operating means for actuation thereof, a trigger valve insaid pneumatic pressure conduit for controlling the application of said pneumatic pressure to said valve-operating means, and a pressure control valve for reversing said trigger valve, said pressure control valve being actuated by predetermined hydraulic driving pressure in the driving end of said cylinder, actuation of. said pressure control valve placing said source of pneumatic pressure in communication with said trigger valve 'to reverse it, whereby the main valve is reversed. I

3. Fluid actuating mechanism forma riveting die, comprising a cylinder, a piston therein connected to the die, a conduit connecting a source of hydraulic pressure to the cylinder for reciprocating the piston to actuate the die, a main valve in said conduit for controlling the application of `said hydraulic pressure to s'aid piston, means for operating said main valve, a conduit connecting a source o'fy pneumatic pressure to said .valve-operating means for actuation thereof, a

trigger valve in said pneumatic pressure conduit pressure controlvalve for reversing said trigger valve, said pressure control valve being actuated by predetermined hydraulic driving pressure in the driving end ofk said cylinder, and a mechanical connection between the pressure control valve and the trigger valve for transmittal of movement from the former to the latter when the pressure control valve is actuated, whereby the trigger valvey is reversed. n'

4. Fluid actuating mechanism for a riveting die, comprising a cylinder, aipiston therein connected to the die, a conduit connectinga source of iiuidunder pressurcto the cylinder for reciprocating the piston to actuate the die, a. main valve in said'conduit for controlling the ilow of said fluid to the cylinder, means for operating said main valve, and adjustable stops associated with said valve-operating means for selectively limiting the movement thereof, whereby the 'size of the passage through the valve'is varied to vary therate at which said fluid is admitted to the cylinder. l

5. Fluid actuating mechanism for a riveting die, comprising a cylinder, a piston therein con-- nected to the die, a conduit connecting a source of fluid under pressure to the cylinder for reciprocating the piston to actuate the die, a main valve in said conduit for controlling the iloW of said fluid to the cylinder, pressure lluid operated means for operating said main valve, a trigger valve for admitting fluid under pressure to said means, means for selectively Varying the size of the passage through the main valve to thereby vary the rate at which said fluid is admitted to the cylinder, and a pressure control valve 0perated by predetermined driving pressure in the driving end of said cylinder for automatically reversing the trigger valve, whereby the main valve is reversed.

6. Fluid actuating mechanism for a riveting die, comprising a cylinder, a piston therein connected to said driving die, a conduit connecting a source of fluid under pressure to the cylinder for reciprocating the piston to reciprocate the driving die, a main valve in said conduit for controlling the flow of said uid to the cylinder, means for operating said main valve, and means for restricting the forward speed of the driving die at Will, said restricting means being adapted to be displaced at will to permit a subsequent fast driving speed of the driving die.

7. Fluid actuating mechanism for a riveting diea comprising a cylinder, a piston therein connected to the die,`a conduit connecting a source of fluid under pressure to the cylinder for recipro eating the piston to actuate the die, a main valve in said conduit for controlling the flow of said fluid to the cylinder, means for operating 'said main valve, and means for restricting movementr of the valve in one direction to thereby restrict the flow of iluid to the driving end of the cylinder, said restricting means being adapted to be dis'- placed by the application of additional pressure thereto. 1

8. Fluid actuating mechanism for a riveting die, comprising a cylinder, a piston therein connccted to the die, a conduit connecting a source of fluid under pressure to the cylinder for reciproeating the piston to actuate the die, a main valve in said lconduit for controlling the flow of said fluid to the cylinder, a pressure fluid operated piston connected to said valve for operation thereof, resilient means for restricting the movement of said piston inone direction to thereby restrict the flow of fluid to the driving end of said cylinder, said resilient means being adapted to be stressed by the application of additional pressure to said piston, whereby the main valve is opened wide. f

9. Fluid actuating mechanism for a riveting die, comprising a cylinder, a piston therein connected to the die, a conduit connecting a source of fluid under pressure to the cylinder for reciprocating the piston to actuate the die, a main valve in said conduit for controlling the flow of said fluid to the cylinder, means for operating said main valve, a back stop disposed in the driving end ol.' said cylinder, and pressure operated means for moving said back stop into operative position.

RAYMOND S. OSBORNE.

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