US2231963A - Press - Google Patents

Description

. Feb. 18, 1941. EJSTRATTYON PRESS Filed Sept, 16, 1937 3 Sheets-sheet 1 Patented Feb. 18, 194i PATENT OFFICE PRESS Frank, E. Straiton, Beverly, Mam, assignmto United Shoe Machinery Corporation, Borough of Flemington, N. 1., a corporation or New Jer- Application September 16, 1937, SerialNo. 164,205

7 Claims- This invention relates to presses and more particularly to fluid operated means which furnishes the power for operating presses. The invention is illustrated as embodied in a machine for moldi ing shoe parts, disclosed and claimed in a copending application tiled in the names of Frank Kennison and Frank E. Stratton, since issued as Patent No. 2,151,974. It is to be understood, however, that the invention and various important features thereof may have other applications and uses.

It is an object of the invention to provide an especially simple and compact hydraulic mechanism as the power means for presses. It is another object of the invention to provide a simple and efiective hydraulic means for operating the presses of a twin machine from a single manually controllable member. A further object of the invention is .to provide an improved hydraulic mechanism such that the extra pressure required in work compressing and molding operations will be automatically applied after the presser members contact the work.

To these ends and in accordance with an important feature of the invention, a large and a small piston are provided in communicating chambers in an hydraulic mechanism wherein a valve mechanism controlled by the small piston communicates pressure to the presser medium ,back of the large piston when a predetermined pressure has been built up back of the small piston. It is an advantage of this construction that the presser members are caused to contact opposite surfaces of a work piece through pressure applied upon the small piston which efiects relatively rapid movement of the presser members toward each other to engageopposite surfaces of the work piece, and that the building up of pressure back of the small piston causes opening of a valve structure to admit pressure back of thelarge piston to effect the desired treatment of the work piece.

In the illustrated construction, a valve is provided in the wall of the small piston chamber in which the small piston operates, so positioned that the valve is retracted by the pressure medium as pressure is built up after the presser members engage opposite surfaces of the work piece, the valve yielding against a spring to admit pressure medium back of the small piston into the chamber containing the large piston whereupon the desired treatment of the workpiece takes place. This construction provides a simple and compact mechanism in marked contrast to the relatively complex arrangements heretofore considered (c1. Gil-97) necessary to secure the same results. Conveniently, the movable valve is hollow so that the pressure medium may pass therethrough into the large piston chamber as the large piston moves under force supplied by the small piston, it being understood that the pressure medium at this time in the large piston chamber is not under pressure but simply fills the space back of the large piston during its movement under force supplied by the small piston, so that only a minimum amount of pressure medium must be introduced into the large chamber when the said valve opens to admit the pressure medium under high pressure from the small piston chamber, thereby assuring expeditious and eificient operation of the press in its work treating operation.

These and other, important features of the invention and novel combinations of parts will now be described in detail in the specification and thenpointed out more particularly in the appended claims.

In the drawings,

In Fig. 1 is a viewin front elevation of a twin press in which the various features of the invention are conveniently embodied;

Fig. 2 is an enlarged detail view, partly in section, of an hydraulic mechanism for operating the press;

Fig. 3 is a detail view of a valve member, shown in section in Fig. 2;

Fig. 4 is a detail view of a safety locking means for the manually operable lever by which operations of the press are initiated and terminated;

Fig. 5 is a side view of a valve which is hand operated to initiate and terminate operations of the press; and

Fig. 6 is a sectional view of said valve.

In the illustrated machine, which is designed as a twin machine particularly adapted to perform molding operations upon shoe parts, there is provided a lower presser member or mold I0 (Fig. 1) upon which a shoe part may be placed preliminary to a molding'operation. For co-operation with the mold Hi there is provided an upper mold or pad l2 arranged to be moved in a downward direction to perform the molding operation in co-operation with the mold I0. As shown, the mold I2 is at the upper end ofan arm [4 (Figs. 1 and 2) which is pivoted at IE to a block l8, in turn pinnedto a piston rod 20 near the upper end of the latter. Secured to'the piston rod 20 is a small piston 22 (Fig. 2) movable within a relatively small chamber 24. As indicated in Fig. 2, the piston rod 20 is provided with a shoulder at 26 for engagement with the lower surface of the small piston 22 so that as the small piston 22 is forced downwardly, it will carry the piston rod 28 along in the same direction. Below the small piston chamber 24 and communicating therewith, is a large piston chamber 28 within which a large piston 38 is arranged for vertical reciprocation. It will be understood that the piston 38 fits firmly upon the lower end of the piston rod 28 andthat it is provided with a shoulder at 32 for engagement with an upwardly facing surface on the piston rod 28 so that downward movement of the large piston'38, under pressure of the medium in the chamber 28, will cause a corresponding downward movement of the piston rod 28. Since the upper mold or pad I2 is connected to the piston rod 28 at [8, downward movement of the piston rod is accompanied by downward movement of the mold or pad.

To'secure relatively rapid downward movement of the pad l2, a pressure medium is introduced under pressure into the small chamber 24 above the small piston 22, an advantage of the small chamber being that it requires much less pressure medium to enter the small cylinder to effect the necessary movement of the piston rod 28 than would be the case with a larger piston in a larger chamber. Accompanying the downward movement of the small piston 22, the large piston 38 (Fig. 2) draws a pressure medium into the large chamber 28 through a pipe 38 extending downwardly into a tank 38 for the pressure medium, which may be a fluid, such as oil or water. At its upper end, the pipe 38 communicates with a small valve chamber 48 in which slides a hollow valve member 42, the arrangement being such that the pressure medium may pass through the chamber 48 and through the hollow valve member 42 to a passageway 44 into the upper end of the large piston chamber 28. Upon inspection of the valve member 42 (Figs. 2 and 3), it will be observed that it has a solid portion or head 48 which closes a port 58 in the wall of the small chamber 24. Back of the solid head 48 of the valve member 42 is a disk portion 52 which is receivable in 'piece on the lower mold ID, the said piston 22 has also moved downwardly far enough to uncover a portion of the head 48 of the valve member 42,

thereby subjecting such member to pressure applied by the pressure medium back of the small piston 22. In this connection, it is to be noted that the end face of the head 48 is set back from .the inner wall of the cylinder 24 about one thirtysecond of an inch so that pressure is applied to the head 48 of the valve member 42 the instant any part of the said end face of the head is uncovered to the high pressure medium in the chamber 24 during downward movement of the piston 22. With the upper mold or pad l2 in contact with the work piece onthe mold l8, pressure continues to be built up rapidly back of the small piston 22 (due to the continuous operation of a pump) until it forces the hollow valve member 42 backwardly against the spring 54 to a point where a passageway "is established between the pressure medium in the small chamber 24 through the port58 and the passageway 44 into the upper end of the large chamber 28. Since it takes only about a spoonful or two of the oil or other pressure medium to flll this port'and passageway, the increased pressure afforded by the upper surface of the large piston 38 is at once applied to the work piece between the molds. This pressure is built up by a constantly running pump to a maximum point which may be predetermined by the operator, a relief valve'of usual construction being also provided to put a limit to the pressure. This pressure of the press upon the work piece is applied for a time which depends upon the operator.

For supplying a pressure medium, such as oil, under pressure of the piston chambers 24 and 28, there is provided a pulley 18 arranged to be driven from any suitable source of power such as a belt II and a motor 13 (Fig. 1), the said pulley I8 being rigidly secured to a shaft 12 (Fig. 2), the other end of which is secured to one of the two gears of a gear pump (not shown) of a wellknown construction and contained in a pump chamber 14. The pressure medium is supplied to the chamber 14 by a pipe 16 which dips into the supply tank or reservoir 38. While the gear pump isrotating, oil under pressure is passed from the pump chamber 14 through a pipe 18 to a valve chamber 88 (Figs. 2 and 6). From this valve chamber 88, the pressure medium passes through a pipe 82 (Figs. 1, 2 and 6) to the upper end of the small chamber 24, upon proper manipulation of a rotary valve 84 (Figs. 2 and 6), in the'valve chamber 88, the result being that the presser or molding members l8 and I2 are caused to operate on the work piece in the manner already described.

The valve member 84 (Figs. and 6) is constructed to control the pressure applying opera-' tions of two presses or molding mechanisms. In the illustrated construction, the valve member 84 has a passageway which in one position of the valve (Fig. 6) connects the pipe 18 with the pipe 82 (Figs. 1 and 2) while a pipe 88 arrangedto supply, under control of the valve member 84, the other small cylinder 24 is shown connected to a return pipe 92 whereby pressure is relieved in such second small cylinder while pressure is being built up in the small cylinder 24 at the right in Fig. 1. If now the-valve member 84 be rotated in a clockwise direction (Fig. 6) by means of a hand lever 84 operatively connected to a valve shaft 85, having valve member 84 secured thereto, the said member 84 may be so positioned that pressure medium from the pipe 18 passes directly through a passageway 98 in the valve member84 to the pipe 88, thus initiating operation of the molding press at the left in Fig. 1. This movement of the valve member 84 serves to bring a passageway 98 in the rotary valve member 84 into alinement with the upper ends of both of the pipes 82 and 92, with the result that the pressure medium in the small cylinder 24 at the right in Fig. 1 is connected to the return pipe 92 and thus relieved of all pressure so that the molding press at the right in Fig. 1 may be returned to its initial work receiving position. It may be noted that the high pressurepipe 18 has an extension 9| (Fig. 1) to which is connected a pressure gage 83 and a relief valve 95 which discharges through a pipe 91 back to the tank or reservoir 38.

In the illustrated molding press, the upper mold or pad l2 must be lifted away from the mold I8 to release the molded article and to permit the introduction of a fresh piece of work. While lifting of the upper mold or pad might be accomplished through a suitable valve mechanism to introduce the pressure medium under pressure below the large piston 30 (Fig. 2), I have provided a simpler mechanism, as shown most clearly in Fig. 1 of the drawings. Pivoted at 99 on a post IOI, supported by the machine frame, is a. lever I03 having its opposite ends pivotally connected at I05 to the piston rods 20. It follows that as one piston rod 20 descends, in moving its associated pad (I2) to molding position, the other pistonrod 20 is lifted, whereby its associated pad I2 is elevated to permit the removal of the piece of work and its replacement by a fresh piece. Such upward movement, for instance, of the pad I2 at the left in Fig. 1 has taken place due to the movement of the pad at the right to molding position, it being recalled that movement of the hand lever 94 (Figs. 1 and 4) to either of its extreme positions will result in the application of pressure on the pistons below one set of molds I0 and I2 and the simultaneous release of the pressure in the piston chambers below the other set of molds. Hence, the lever I03 is rocked in one direction to effect lifting of one of the upper molds I2 while the other is moving to.molding position, and is then rocked in the opposite direction to effect lifting of the other upper mold.

In order that pressure on the valve member 84 may be balanced, the passageway 96 is forked to provide a passage I00, the end of which leads to a portion of the inner surface of the wall of the valve chamber 80. It follows that at any given consent, pressure in the passageway 96 is transmitted to the wall of the chamber 80 and not to the member 84 in a way to cause binding of the latter against the wall of the surrounding chamber. Similarly, the passageway 98, which is always utilized to relieve pressure in one small cylinder 24 or the other, has connected therewith a passageway I M which leads diametrically across to a space I02 so that pressure (or rather the lack of it) is also balanced in a direction at right angles to the passage 96 in the member 84. An advantage of the construction of this valve, with respect to the balancing of pressure in various surfaces thereof, is that the valve 84 may be rotated with the minimum of effort on the part of the operator.

As shown in Figs. 1, 2, and 6, the valve 84 is operated by a lever 94 adapted for manual operation, the said lever being rigidly secured to a shaft I40 mounted in a bearing I42 (Fig. 2) in the machine frame and having its other end fitted to receive the shaft 85 to which the valve 84 is secured. To facilitate assembling of the parts the end of the shaft I40 is slotted to receive a pin I46 secured in the end of the shaft 85. Movement of the lever 94 in the direction of the arrow in Fig. 6 will initiate operation of the hydraulic mechanism disclosed in Fig. 2 of the drawings. As a safety means the lever 94 is locked at each extreme of its rocking movements.

The locking means referred to above comprises, in the illustrated construction, latch members I50, I 52 (Fig.4) pivoted at I53, I54, respectively, on the frame of the machine and being held yieldingly toward each other by a. spring I56. The latch member I50 is shown engaged in a notch I58 similar to a notch I60 which'is adapted to be engaged by the latch member I52. Before the lever 94 can be moved in the direction of the arrow in Fig. 4, the latch member I50 must be removed from looking position, this being accomplished by movement of a lever I62 in the direction of the arrow in said figure. For this purpose there is pivotally connected to the lower end of the lever I62 at I64 a rod I66 which is pivotally connected at I68 to a similar hand lever I which is pivotally mounted in the frame of the machine. The rod I66 has secured thereto a latch engaging member I12 to move the latch member I50 to inoperative position and a corresponding member I14 to move the latch member I52 to its inoperative position. Conveniently stops I16, I16 are provided on the frame of the machine to limit the movement of the corresponding latches I50, I52. Before the valve controlling lever 94 can be moved to initiate an operation of the press by the described hydraulic means, the lever I62 must be moved in the direction of the arrow (Fig. 4) to withdraw the latch I50 from operative position and this lever I62 must be held in unlatching position in order to move the valve controlling lever 94, since the spring I56 constantly urges the latch I50 intoor toward operative position. This insures that both hands of the operator are in use in initiating an operation of the machine and hence that they are in safe positions and not subject to injury. It will be understood that the valve controlling member 94 must be moved far enough in the direction of the arrow (Fig. 4) in effecting the desired operation of the hydraulic mechanism to insure that the latch member I52 drops into the notch I60, whereby the lever 94 is again locked, this being clear from the showing of the valve 84 in Fig. 6.

In operating the twin machine shown in Fig. 1 of the drawings, the operator will place a shoe part, such as an insole, upon one of the lower molds I0. Assuming that this has just been done in the molding unit at the left in Fig. 1, the operator now swings the levers 94 and I62 toward each other, lever I62 being moved slightly in advance of lever 94 so as to unlock the latter. By this movement of the lever 94 the mold I2 is caused to descend to perform a molding operation upon the insole resting on the mold I0. At the same time the mold or pad I2 at the right in Fig. 1 is raised, due to the movement of the lever I03, as already described. The molding operation upon the insole at the left is then continued while the operator assembles and places another insole upon the mold I0 at the right in Fig. 1. When this has been done the levers 94 and I10 are moved toward each other to effect a molding operation by the right-hand unit in Fig. l the other molding unit being simultaneously conditioned, through the connecting lever I03, to receive a 'new piece of work after removal of the'piece which has just been molded.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a press, presser members relatively movable toward and from each other, a small piston to move one of said presser members rapidly toward the other, a large piston to exert heavy pressure on said one of the presser members to secure the desired treatment of the work piece, a small piston chamber and a large piston chamber for the small and the large pistons, respectively,

. said chambers being in line with each other with the small chamber arranged as an extension of the large chamber, a passageway having an opening into the side of the small piston chamber and adapted to connect, the small piston chamber with the large piston chamber, whereby a pressure medium under high pressure may pass from the former to the latter, and a spring controlled valve member yieldable at a predetermined pressure and normally closing said opening into the passageway, said small piston being arranged to uncover said opening and valve member to the pressure of the medium in the small piston chamber at a predetermined point in the operative stroke of the small piston, whereby the timing of the introduction of high pressure medium into the large piston chamber is determined by the small piston.

2. In a press, presser members relatively movable toward and from each other, a small piston to move one of said presser members rapidly toward the other, a large piston to exert heavy pressure on one of said presser members to secure the desired treatment of the work piece, a small piston chamber and a large piston chamber for the small and the large pistons, respectively, a passageway adapted to connect the small piston chamber with the large piston chamber, a valve member normally closing said passageway, and a spring backing said valve member and yieldable to open the passageway at a predetermined pressure of the pressure medium in the small piston chamber, the small piston being constructed and arranged to uncover in its operative movement the valve member to the pressure of the pressure medium in the small piston chamber, whereby opening of the passageway into the large piston chamber through retraction of the valve member is determined by the pressure of the medium in the small piston chamber.

3. In a press, presser members relatively mov able toward and from each other, a small piston to move one of said presser members rapidly toward the other, a large piston to complete the movement of said presser member under heavy pressure, a small piston chamber and a large piston chamber for the small and the large pistons, respectively, a passageway adapted to connect the small piston chamber with the large piston chamber, said passageway opening as a port into the small piston chamber, a valve member fitting in and normally closing the port and located in the passageway lengthwise thereof and movable in one direction to open said port, a spring to hold the valve member yieldingly in place against movement by the pressure medium in the small piston chamber until the pressure in said medium has been built up to a predetermined point, yielding of the valve member against said spring finally permitting pressure medium to pass from the small chamber through said port and passageway to the large piston chamber whereby heavy pressure is applied to the work piece between said presser members, a reservoir, and a passageway between the large piston chamber and the reservoir to supply pressure medium to the large piston chamber while the small piston is moving the large piston, said valve member being operative to close the second-mentioned passageway at the same time that it is moved to open the first-mentioned passageway and port.

4. In a press, presser members relatively movable toward and from each other, a small piston to move one of said presser members rapidly toward the other, a large piston to exert heavy pressure on one of said presser members to secure the desired treatment of the work piece, a small piston chamber and a large piston chamber for the small and large pistons respectively, said small piston chamber being mounted ons' said large piston chamber, a reservoir for pressure medium, a passageway having a port opening into a side wall of the small piston chamber and also a second port opening into an adjacent part of an end wall of the large chamber and adapted to connect the small piston chamber with the large piston chamber, a second passageway between the reservoir for the pressure medium and said port opening into the chamber of the large piston whereby, during movement of the large piston by force exerted against the small piston, pressure medium enters said large chamber through suction effect by the large piston, and a valve member fitting- .the second passageway leading from the large piston chamber to said reservoir, while the firstmentioned port is open, and said valve member having an opening therethrough to serve as part or the passageway connecting the reservoir with the large piston chamber while said valve member is in position to close the first-mentioned port.

5. In a press, presser members relatively movable toward and from each other, a piston rod connected to one of said presser members, a small and a large piston connected-t0 said piston rod, a small piston chamber and a large piston chamber for the small and the'large piston, respectively, a passageway opening as a port into the small piston chamber and adapted to connect the small piston chamber with the large piston chambenand a spring controlled valve member located in said passageway and arranged normally to be held in position to close said port but movable to open the port in response to pressure of fluid in the small chamber against it, said valve being so located as to be exposed to the pressure fluid in the small chamber only after the small piston has substantially completed its operative movement.

6. In a press, presser members relatively movable toward and from each other, a piston rod connected to one of said presser members, a small and a large piston connected to said piston rod in spaced relation to each other, a small piston chamber and a large piston chamber for the small and the large piston, respectively, the small chamber being an extension of the larger piston chamber, a passageway opening through the walls of the large and small chambers and adapted to connect the chambers with each other, saidpassageway opening as a port into the lower part of the small piston chamber so that it is uncovered by the small piston only after relative movement of the presser members has been initiated, a valve member located in the passageway normally to close said port, a spring to hold thevalve member yieldingly in placeagainst movement by the pressure medium in the small piston chamber until the pressure in said medium has been built up to a predetermined point, yielding of the valve member against said spring finally permitting pressure medium to pass from the small chamber to the large chamber whereby heavy pressure is applied to the work piece between said presser members.

7. In an hydraulic mechanism, the combination of a small high pressure piston chamber and a large piston chamber with small and large pistons movable respectively in said small and large pis- 1| ton chambers, a port opening through a side wall 'the high pressure medium in the small piston of the small piston chamber, a port opening into chamber whenthe small piston uncovers the port the large piston chamber, the port in the wall 0! in the small chamber wall, whereby the timing of the small chamber being normally covered by the the introduction of high pressure medium into the small piston except near the end of the operative large piston chamber from the small piston cham- 5 stroke of the small piston when it is uncovered her is determined, in part at least, by. the small by the latter, a passageway connecting said ports piston. and a valve member normally closing saidpas- FRANK ESTRA'ITON. sageway but movable to inoperative position by CERTIFICATE OF CORRECTION. Patent No. 2,251,965. February 18, 19m.-

' FRANK E. STRATTON.

lt is hereby certified that ez ror appears in the printed specification of the above numbez 'ed intent rquiring correction as follows: P8 .ge 5,.fi1fst column, line 55, for the word "consent" read. --instant and thhtfbhb said Le tt zers Ratent should be read with this correction therein thatthe same Ina 3 conform to the record of the case in the P'tent Office.

.si nea And gealed this 2 t day of March, A 1). 191 1.

' Henry Van Arsdale, (Seal) 9 Acting Commissioner of Patent s.

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