US2374737A - Portable riveting press - Google Patents

Description

y 1, 1945- c. DESOUTTER PORTABLE RIVETING PRESS Filed Feb. 26, 1940 3 Sheets -Sheet 1 fly/ 7.

y '1, 1945- c. DESOUTTER 2,374,737

PORTABLE RIVETING PRESS Filed Feb. 26, 1940 3 Sheets-Sheet 3 Patented May I, 1945 UNITED STATES PATENT '0 FFICE PORTABLE RIVETING PRESS Charles Desoutter, London NW. 3, England Application February 26, 1940, Serial No. 320,944

In Great BritainMarch 2 Claims.

This invention relates to self-contained poweroperated hydraulic riveting presses of the kind comprising a reservoir for the operating liquid (preferably oil), a pressure-applying piston within a cylinder, and a pump for transferring liquid under pressure from the reservoir to the pressure cylinder. g

The object of the present invention is to devise improvements in the construction and arrangesupply the oil from the reservoir to the pressure cylinder but a further feature of the invention,

liminary means of supply of'the oil from the reservoir to the pressure cylinder isprovided. This by the oil in the pressure cylinder being by-passed back to the reservoir.

According to another feature of the invention, and preferably operating in combinationwith such unloading means, handor automaticallycontrolled valve means are provided, preferably 'voir, the said piston control conduit;

having the form of a piston valve, associated with suitable supply andreturn conduits for the oil from the reservoir to the pressure cylinder and from the pressure cylinder to the reservoir. This piston control valve means may besuch that it is held in a rest positionby pneumatic pressure,

alone or assisted by spring means, or even by spring means alone leaving open, through'a oneway valve, the return conduitfrom'the pressure cylinder to the reservoir. When, however, oil under pressure is first suppliedfrom the reservalve immediately is moved (automatically or otherwise) to close the said return conduit; .in some cases the piston control valve'in its rest position closes the supply conduit and consequently when it is moved from the rest position it also opens the said, supply A still further feature of the invention consists in the main control means for the operation of the tool. This includes a manually-operated part such as a push-button, trigger or otherwise, which moves through a determined path, andby its movement controls a valve,,and which may include electrical switching means if an electric motor is used. In this Way, according to the degree of movement of the manually operable part, the operation can be effected by, stages.

In the case the following description.

described with reference riveting dies or the like.

view on the general line similar to a part of Figure but showing a modification.

Figures 7, 8 and 9 are diagrammaticviews of modifications of the arrangement of the actual Figures 10 and 11 show diagrammatic views illustrating modifications in the'pump drive.

Figure 12 shows a section of a modified detail hereafter referred to.

In carrying my invention into effect in one convenient manner I provide the press with a body III formed from a drop forging or otherwise and bored at one end to constitute a pressure cyl- I2 to an extension of U frame I3, .a lock-nut inder II having a cover which cover is attached a I4 securing the parts in position. At the other end the body [0 is bored totake one end of a casing I5 to accommodate a rubber sack I6 as shown, and in an intermediate position it is bored to I have attached thereto by screwing one end of a pneumatic motor H, the axis of which is parallel to or slightly inclined to that of the pressure cylinder II. In addition, the body In is fabricated to accommodate the various parts hereafter referred to and has numerous conduits and passages for air and liquid (oil). These conduits and passages generally are shown in convenient positions to render clear the. understanding of the drawings but it should be understood they comprise various bores and cross bores, many from the exterior, cases are plugged. nections as shown in the drawings.

In the pressure cylinder II is an associated pressure piston I8 having apiston rod I9 the outer extremity of which carries a riveting die and aspring-pressed clamping member 2I. During the preliminary portion of the stroke of the piston I8 the clamping member 2| is brought into clamping position with respect to the rivet and resiliently held in position by the spring act-, ing thereon. The hold-up or fixed die 22 is carried by the frame I3.

The cylinder II on the underside of the pressure piston I8 has opening, thereinto one end of a conduit 23 of the compressed air system, the other end of which terminates in a port 24 controlled by a valve 25 as hereafter explained, This valve which is of general hollow cylindrical form (Figures 1 and 2) works ina bore 25 in the body III and has two spaced flanges 21 and 28 between which is an annular space in said bore. The valve is kept pressed to its out-of-action position by a compression spring 29 and is operated by a trigger 30. 3I is a screwed bore for the connection of the supply of compressed air which bore is extended to open into the bore 25, so that in the position of rest of the valve 25, .it communicates with the annular space around the valve between the flanges 21 and 28, as'shown in 2. In this position also it will be realised that the port 24 communicates with this annular space. Thus, in the position of rest of the valve 25, when the compressed a'r is supplied through the bore (II, it immediately passes through the port 24 along the conduit 23 to the cylinder II the ends of which in some They however form the conportion on the underside of the piston I8, and ensures the piston being fully returned to the position shown in Figure 1.

To prevent air entering at the underside of the piston I8 upper part of the cylinder, where it would mix with the oil and affect the efliciency of the press, the central metal member I26 of the piston I8 has a circumferential groove I21 with one or more radial bores I28 passing to an axial bore I25 in the piston rod I9. The lower end of this axial bore I29 terminates in one or more radial apertures I30 in the lower part of the piston rod. Thus, any compressed air that-may find its way ast the lower part of the piston I8 is exhausted to atmosphere through the groove I30 and the socket in I21, bores I28, I29 and is mounted with which the clamping member 2| out fluid tight fit.

The bore in the body III which receives the end of the pneumatic motor I1v is extended to take ball bearings32 in which is mounted the shaft 33 of the pneumatic motor. Between the ball bearings 32 this shaft has an eccentrically formed portion 34 which is mounted in a strap 35 with the interposition of roller or needle bearings 36. v

When the parts are so mounted, an'annular space 31 is left at the end of the bore receiving the casing of the motor I1, which annular space 31 has opening thereinto one end of an air conduit 38, the other end of which terminates in a port 39 opening into the bore 25. An inlet conduit 40 establishes communication between the space 31 and the inlet of the 'motor I1, while II (Figure 1) are the exhaust openings from the motor. As the port 39 does not communicate with the bore 3| in the rest position of the valve 25, it will be understood that the compressed air cannot operate the motor in this position. Ac tually it is not until some substantialmovement is given to the v'alve 25 that the flange 28 passes over the port 39 to effect the necessary communication. v

The bore in the body III for the end of the casing l5 includes, as *will be seen from Figures 1 and 2, an annular space'42 whichcommu'nicates by 'a conduit 43.with another port 44 in the bore 2t. This port is also below the flange 28 in the rest position of the vahe 25, but upon the initial opening movement of the valve, the flange 28 passes thereover so that air can pass to the conduit 43.

The rubber sack tailed flange 44' which is carriedbetween two ring members 45 and 46. Theupper end of the ring 46 abuts against the end of a screw spigot and the ring is provided with apertures "ted in posiposition, 41 which, when the parts are mo tion, are adjacent the annular space 42. As will be seen also the exterior of the sack I8 is spaced from the inner surface of the casing I5. Consequently, after the preliminary opening movement of the valve 25, the pressure air can enter the space around the sack I6. The upper end of the sack has an inlet nozzle 48clampecl therewhich passes to the exterior of the casing I5 and is closed by a cap 48.

At the'lower end of the bore 26 is-an exhaust port 50.

tion .of the device thus far described is as follows.

the possibility of the compressed at its lower end has a clove of the casing I5 to hold the parts in exhaust through port leather which is kept thro'ughport 3|,.bore 26 the underside of the piston the fully returned position preciatemfrom' Figure 5, the to receipt of any compressed time, by the movement of the purpose hereafter explained.

Moreover, this supply of the compressed air to'the space around the In a bore in the body Hi having various diameters and at right angles to the axis of the shaft 33, there is arranged a flanged sleeve 5|, the flanged end of which supports a bucket pressed into position'by a sleeve-like extension of a closing plug 53. i This sleeve-like extension is apertured at 54 for the is mounted to reciprocate.

The plunger is formed from three connected parts, namely, two end parts 55 and 55', and an intermediate connecting part 55", which in the construction shown is a helicalcompression ends of the other parts. The part 55 has a bore extending partly therethrough to receive one end of a compression spring .58 the other end of which is located in a recess in the closing plug 53. The spring 56 is much weaker thanthe spring 55 'and serves to keep the plunger as a whole 'pressed into a groove on the surface of the strap 35. i

The spring 55 forming part of the plunger efiects what may be termed a spring loading of the reaction pressure a the pump, so that when in conduit '10; bore 58 and conduit 51 is slight, the pump plunger has its full stroke whilst when the reaction pressure is greater, the .eifective stroke of the plunger pression of spring 55 Modification constructions may be adopted, for example as shown in the diagram of Figures and 11.

In Figure, 10, H3 representsthe plunger (corresponding to the part 55 of the foregoing modie and ports 24 and 23 to is lessened due to com- 1 example as vulcanized 'fibre' flcation) and I it an eccentric mounted upon the driving shaft 33 of the motor. A Thisshaft passes through a guide block H8 mountedto, slide in a radialslot H1 in the eccentric ill. 1 Thereocentric is normally kept pressed 'to the. maxithe'eccentrlcity and therefore the stroke or the p mp. a a v Figure 11 illustrates a multiple-plunger'pump in'which H9 are the plungers and lnthe driving shaft. This latter has mounted thereon by a pivotal connection l2l a swash plate I22 forming thedriving means for the plungers. This swash plate normally is kept at the maximum angle by a compression spring I23 abutting a flange I24 but when the reaction pressure is sufficiently great, the spring is more or less compressed to vary the stroke of the plungers.

-The space into which the outer part 55 of the I plunger projects communicates'through the apertures 54 and a conduit 51 on a stepinthe bore to co-operate with the inletvalve while the other seat 65 in position .on a

holds a similar apertured step in the bore to co-operate' with the outlet valve. Each valve 59 or 60 preferably is formed from a synthetic resin such, for example, as that known under the registered trade-mark Bakelite reinforced by fabric. materials may be used for the valves, such for DQunds reinforced by fabric. circular disc-like form and is kept pressed on its seat by a'compression spring 6 6 located on the stem of a headed screw 61, screwing into the seat 64 or 65 as the case may be.

On the one hand, tion with the inlet valve'communicate. witht'a conduit orpassage 68 in the body liljwhich'opens into'the end of receives'the casing I5 and ring member 45: This latter carries a filter 69 so that before the-oil which is contained in the sack I6 passes to the conduit 68 it must pass through the filter." The 60' aperture 63 in association with the delivery or of the 'cylinderli. w w The, arrangement is such that when the motor I? is running, oil from the sack lfiisubject to the squeezing action of the compressed air there- I around) first of all passes the valve 59 because of the combined action of the said squeezing action on the sack and the suction oftheplunger 55, 55?, 55 and thenis forced past the valve 60 by the action of'the plunger in its pressure strokeand into theconduit lllandto the upper part-of the cylinder II. v I

Th ring member 45 has a centrally disposed apertured plug "H which communicates with a In some cases other i or cellulose'coma Each valve is of the apertures 63 in-associal the bore in the body ll-which j 16. valve is reduced piston 18 separate therefrom. This comprised of two parts which normally in the position of rest (where held in the pressed air from against the reduced portion 11 by compressed air i in the end of the bore 13 supplied by a conduit |25 in communication with 1 closed by plugs 14 and (Figures 3 and 4). In

this cross bore is mounted to move a cut-ofi valve At the end remote from the conduit 12 this in diameter at 11- and abuts a piston is the pressure piston i8 is fully returned position by the comthe'conduit 23) are kept pressed If desired a compression spring 19 can also be used in addition to 19 alone is used.

the conduit '23. (Figure l the compressed air for I increasing the pressure on the piston 18, although 5 this is not essential and in spring such as struction'is indicated in Figures 3 and 4 and in a further alternative a This last con- ,1

this last case the cap 15 against which the spring abuts is open to Just beyond the step of the piston valve18 is an annular space 8| which communicates by a conduit 82 with the upper end of the cylinder I. It

the device is operated at the end of the bore should be noted that when to effect riveting-the space 13 behind the piston 18 (as it communicates by the conduit I with the conduit 23)-is open to atmosphere through the port 24.

ment ofthe piston control valve.

The action of this cut-off valve is the following. When the oil from the sack It by the preliminary pressure of the compressed air coming on the exterior of the said sack passes through the apertured plug 1| to the conduit 12, it .first of all causes the cut-off valve 18 to move to the right'as shown of the spring 19 if this latter is provided). When the valve 18 is. so moved, the one-way valve 94 in the cut-off valve 18 is closed by the air pressure. The valve by its larger diametered portion shuts off the annulus 8| from the bore 13. At the same time, however, the pressure oil alsopasses through the conduit 68 and past the valves 59 and 69 (although the pump is not running) and then through the conduit 19 passes to the cylinder H to cause the preliminary portion of the'stroke of the piston l8, that is to say until the clamp 2| comes nto action and the movable die 29 comes against the end of the rivettobe squeezed over. When this positionis attained, then upon the still further movement of the trigger 30, the pump is brought into operation so that the pressure built up thereby in the upper end of the pressure cylinder completes the stroke of the piston I8 and thus efiects the squeezing over of the rivet'head.

An adjustable pressure relief valve device is provided in the body It! closed by a flanged plug 83 which is apertured for the stem of an adjustable screw 84 passing through a leather gasket 85 and abutting another plug 88, the inner endof which has a cross bore 81 with a passage 88 opening thereinto controlled by a conical valve 89 which is adjustably loaded the atmosphere by a vent 88.

Consequently the compressed air doesnot oppose the movein Figure 4- (against the actionthrough a compression spring 98 controlled by I the variable position of the adjustable screw 84.

reduced portion 11 of the piston valve. This piston valveis made hollow and provided with the conduit 99 to the a bore 92 therein having apertures 93 opening thereinto, in the reduced portion 1-1. Moreover, the bore 92 is controlled by a one-way valve 94 also located in cross bores 95inthe said piston valve. I y

In this manner when the pressure of the oil in the cylinder |'|v exceeds. a certain predetermined amount (after riveting) the oil pressurebuilds up in the conduit 82 and annular space 8| and the valve 89. is lifted, permitting the: oilfrom the pressure cylinder II to flow up the conduit 82, into theannular groove 8|, through thepassage 88; through the cross passage 81 and the conduit 9|, into the bore 13 through the apertures 93 past'the valve 94,-.into-the cross bores 95. At this stage this highxpressure oil presses against the shoulder formed between the large and small diameter portions of element, and moves element 16 to the left into the position shown in Figure 3 and thus uncovers conduit 82. This high pressure oil'thenflows up conduit 82, into annulus 8| and bore 13, through holes 93 and bores 92 and 95 and so to return through the conduit 12 and apertured plug 1| to thesackIB. 7., Ii

When the riveting operation is completed, the trigger 30 is released and thevalve 25 is brought by the spring 29 to its rest position so that the motor I1 is stopped and the pressure around the sack I6 isrelieved by "exhaustion of the compressed air through conduit 43, port 44, bore 26, and exhaustport 59and thev compressed air is admitted to the conduit v23 and consequently to the space at theend of the bore 13'. The compressed air supplied to the space therefore-operates on the piston 18 and effects its return tothe position shown in Figure 3.

It will of course be understood that prior to using the tool, the cap '49 .is' removed and the sack and passages inconnection therewith right through to the upperportion of the pressure cylinder H are filled with a suitable oil, forexample castor oil. Moreover, it should be remarked that .with the disposition of the parts shown in the drawings (Figure l), by holding the tool in this position with the cap removed, any trapped air will rise .to the top thus perfilled with the oil.

In the modified arrangement of cut-otivalve (substituted for the cut-off valve 18 hereinbefore described) shown in Figure 6, the valve '96 has a reduced end 91 which abuts. the end of its bore, and in the rest position closesthe communication from the conduit 12 to a conduit 98 leadin to the inletvalves 59 "andrlill. In this position also, a return passage 99 fromthe cylinder l| communicates across the bore of the cut-off valve 95 with an inlet N18 to' the sack |8,which is controlled by a one-way-valve |0|. Thus, in the positionshown in the drawings, the oil returning from the cylinder H has passed through inlet I99. past the valve Illl intothe sack |6.." The pressure relief valve 89 is located in another conduit |82. .To the rear of the cut-off valve, 95 is provided an eX- the rear of the piston control valve 96 and the piston device 18.

In operation, when the oil under pressure passes along the conduit 12, lit movesthe valve 96 to the right, the space behind the, piston 18 being open to exhaust, and places the conduit 98 in communication with the conduit I2, allowing the oil under pressure to pass through the valves 59 and B to the cylinder II. At the same time, however, it closes the communication of the return conduit 99 across its bore so that the only return conduit that communicates with the annular space behind the .piston control valve 96 is the conduit I02 from the pressure relief valve 89. I

Thus, in the operation of the tool with the cut-off valve in the right-hand position, upon the valve 8 9 rising fromits seating, the oil under pressure is released from the cylinder II and passes through the conduit I02 back to the annular space between the piston device 78 and the rear of the piston control valve. The

pressure of this oil moves the piston control valve 96 towards the rest position, which itattains, and opens ,up the'return conduit 99 to the sack I6 through the one-Way valve IOI, the

oil from the pressure cylinder returning to the sack I G'by the rise of the piston I8 under the action of compressed air supplied through the conduit 23.

As will be realised, the riveting dies may be arranged in any manner to suit the particular work to be performed. Figures 7, 8 and 9, somewhat diagrammatically, show some of these methods.

In Figure 7, the dies are carried by jaws I03 and I04, the former being attached to the body the latter being' in any suitable manner and pivoted at I05 to the jawI03. The jaw I04 has an arm I 06 connected by pin and slot or other mechanism with the piston rod or the like I01 in connection with the pressure piston.

A somewhat similar arrangement is shown in Figure 8. In this case no additional arm I06 is necessary. I

In Figure 9, the piston rod or the like I0I controls the closing of pivoted jaws I08 and I09, which are pivoted together at IIO on a part carried from the body, through cam and roller means III. I

Figure 12 shows a construction of piston control valve such as 96 and the piston-member 18 indicated diagrammatically in Figure 6. This latter in preferred forms where compressed air I is used in the bore I3 for effecting the return of the piston control valve 96, has a peripheral groove I3I with a radial bore or bores I32 communicating with an axial bore I33 in a, rod-like extension I34 sliding in a guidewaytl35 carried by the end cap. In this manner any compressed air that tends to leak past the piston 18 to the liquid ystem is trapped by the groove I3I and passes by the bores I32 and I33 to the atmosphere.

As will be realised, the invention is not limited to the particular examples thereof illustrated in the drawings but can be carried into effect in a. great variety of manners. I

For example, where a motor other than a pneumatic motor is utilised, the copious preliminary supply may take placethrough the action of a. pump which is either the pump connected to the motor, or .a, upplementary pump driven by the motor. 1

Insofar as details are concerned, in place of utilising, as illustrated, a control valve, which in: the example is a. piston control valve, in connection with, the supply. and return passages. and operating automatically, such control valve may be operated manually and suitably connected with the trigger,..p1 mger :or the: 1ike whichjoperates the other 1 parts of the apparatus. In. some cases even, a special manipulatable control maybe provide for setting this valve devlcein the required position according tothestage cfthe operation being performed.

'Althouah inpractice the sack deviceoper'ated upon by compressed air gives good service, in some cases it-m'ay be replaced by another contamer... For example, such container may consist of a cylinder having a piston, therein normally returned'to one end thereof, preferably assisted by sprin means. This pistonis adapted to 1 be'operate to effect an ejection of the oil from the container by-compressed air;- or other ,means. In a particular exemplification of such cylinder. and piston means, the cylinder may. be of transparent material (glass, synthetic resin orotherwiselenclosed within. an, outer casingohaving a window 'orwindows (for example a longitudinal slot), so that from, the exterior the-operator, can ascertain the amount of liquid (oil) in the said cylinder.

Although the invention has been particularly described and is particularly designed for" effecting riveting operations, it is obvious that with but slight modifications the riveting dies may be replaced by other'corresponding parts such as punches and cooperating dies or otherwise without any general changes of the other mechanism, and the invention must be regarded as embracing such mechanical variations. 3

In some cases the cylinder on the underside of the pressure piston may have the liquid therein and form part of the reservoir, or even the reservoir. In this case it is connected through suitable conduits or the like with the upper side of the pressure cylinder, with or without the inclusion in the said circuit of a supplementary reservoir. When such supplementary reservoir is provided, it may have spring i or cartridges. In

this manner when, through leakage or the like, I

the oil in the system partially is used up, by the removal of the old container or the like and replacement by a fresh cartridge or the like, the oil system would be replenished.

The invention is not limited to theprec se forms or details of construction described, as these may be varied to suit particular cases.

I claim:

1. A portable self-contained riveting press comprising a, closed reservoir for operating liquid, a cylinder, a pressure applying piston in said cylinder, separate parallel conduits con necting said reservoir with 'one end of said cylinder, a, pump connected with one of said conduits for transferring liquid from said reservoir to said cylinder to advance said-pistomaninlet for a fluid pressure medium, control means opoil), may be pro-y erable' in one position to connect said inlet with said reservoir for rendering the fluid medium effective totransferapreliminary supply'of said liquid from said reservoir through said one conduit to said cylinder and operable in another position to conduct said fluid pressure medium from the inlet to the-opposite end of said cylinder to retract said piston and returnsaid liquid from said'cylinder to said'reservoir through the other conduit, a cut-ofi valve in the second conduit maintained in closed position by the pressure of the liquid while the 'control means is maintained in the first position, and means operable' during the retraction of said piston to open said cut-off valve whereby the liquid may freely passfrom the cylinder to the reservoir through the second conduit, said cut-off valve being in the'form of a slide controlling communication through the second mentioned conduit and one end thereof being presented to the pressure of the fluid medium in the portion of thesecond mentioned conduit adjacent said reservoir. r v

' 2. A portable self-contained riveting press comprising a deformable reservoir for operating liquid, a cylinder,- a pressure applying piston in said cylinder, separate parallel conduits connecting said reservoir with one end of said cylinder, a pump connected with one-of said conduits for transferring liquid from said reser- 'voir-to said cylinder to advance said piston, control means operable in one position'to apply a fluid pressure medium to the exterior of said reservoir for transferring a preliminary supply of said liquid from saidreservoir through said one conduit to said cylinder and operable in another position'to supply fluid pressure medium to the opposite end'of said cylinder to retract said piston and return'said liquid from said cy1-' tw'ee'nthe cylinder and the cut-off'valve and op-- erable, when opened, to apply the pressure liquid from" said cylinder to s'aid'cut-off valve in a direction to'cause said cut-ofl valve to open; CHARLES DESOUTTER."

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