US2298337A - Press - Google Patents

Description

Get. 13, 1942.

M. H. BALLARD ETAL PRESS Filed June 30, 1941 4 Sheet s-She'et' 1 Oct. 13, 1942. BALLARD ET AL 2,298,337 I PRESS I Filed June 30, 4 s t t 2 Fig: 3

Oct: 13, 1942.

M. H. BALLARD T AL PRESS 4 Sheets-Shet 3 Filed June 30, 1941 Oct. 13, 1942.

M. H. BALLARD ETAL 2,298,337

PRESS Filed June 30, 1941 4 Sheets-Sheet 4 po Which f s ty s 50 des d nd SuP- to enable the operator to adjust the stop against Patented Oct. 13, 1942 onirso sTaTss earner orFicE PRESS Milton H. Ballard and Frank E.. Stratton, Beverly,

Mass., assignors to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application June 30, 1941, Serial No. 400,396 15 Claims. (Cl. 164-23) This invention relates to improvements in valve to its exhaust position the work support presses and is herein .illustrated as embodied in is quickly moved to its inoperative position so a clicking machine of the type disclosed in United that in the case of a stalled presser member the States Letters Patent No. 921,503, granted May sprung machine parts may quickly be released 11, .1909, on anvapplication filed .in the name of without any effort on the operators part and Arthur Bates. It is to be understood, however, without any danger of breaking the machine that in Various 110K161 d u l pects the inparts or any necessity of disconnecting them. i h vi5 no l i d to m s e pa Still another feature of the invention is a valve ticular type illustrated. arrangement according to which the valve may n the u f pr s f th ab ve-m n i n d he moved into two different exhaust positions. In type, each of which is commonly provided with one exhaust position the fiuid pressure means a member for pp y p e to a workpiece is immediately and fully released. This particumhuhted 011a Workfillpport, i O t e pp lar valve position will be selected when a quick that the press becomes stalled .because the pressmovement of t work Support t t inoperaver member is unable to Complete its p ve tive position is desired to release the presser S o e. W t i 0 01 5 t s, O s y member, if stalled. In the other exhaust position difiicul-t to release the parts without substantially of the valve the fluid pressure is only slowly and d s a h m c n y, the Work D- partially released, the release being just sufficient ported that it will readily sustain the heavy preswhich the work support is moved by the fluid sure applied to it, is immovable .in the heightwise pressure means.

direction of the machine so that a stalled presser In accordance t a further feature of th member cannot be l d y a l w n of the vention, the illustrated press is rovided with a work 1 1p;rt. tgn cases when? the supp r pump for supplying the pressure medium and an 15 provl 9 W1 mac amsm a 1115 mg 1 1n accumulate in which the ressure medium is the direction of pressure application, that mecha- Stored h2 r ss-operating mechanism is pronism frequently becemes P sprung and frozen vided with means which during each cycle of op- $1 22 2 Pg ghfii l s gi til tg sz ir g ig g eration of the press operates a pump actuating e e e r r mechanism so that the latter produces one comthe] work supgiirt ad usting mechanism is opractipression stroke of the pump during each cycle of ca lm-possl operation of the press.

It 18, therefore, .an obJect of this 1n" other objects of the invention and features of to fi i m s -g i construction will be apparent from the following ti gir g h alg gz fin s'ta gd gj a g1: description and will be pointed out in the claims.

' e In the drawings,

i i ggi i; 1x Support m Fig. 1 is a front view, partly in section, of the JaCCOIdgCe with 2 impor'mnt feature of lower portion of a press in which the present 1nvention is embodied' the 1nvent1on, the illustrated press 1s provided with fluid pressure means for moving the work 40 ifi g gg igig g g manually Operated support into its operative pressure sustaining Va L r Fig. .l is a left-hand side elevation of the map sition .and maintaining v1t in that p0s1t1on. u and ith certah arts This operative position of the work support is 0 i par m sec Ion W L p determined by an adjustable stop against which f w 1 d cal of the work support is moved and held by the fluid 1s detau n en aljge e pjcessure means a portion of the mechanism shown in F1g. 3 for In accordance with another feature of the inadjusting a Stop n ng the Operative posivention, the illustrated press is provided with a of h WOT}? Support the machmef manually operable valve for eontronin th flow ig. 5 1s a view partly 1n rear elevation and of a suitable pressure medium, s ch as pressure partly in section illustrating the pump, the acoil, toward and from fluid pressure mechanism. Gllmulfitor, and the mechanism for Opera/3mg the In the position of pressure application of the h valve the work support is effectively .held in its 6 15 a detall VleW 0f ducts In the mp operative pressure sustaining position by the fluid h pressure means, whereas on movement of th Fig. 7 1s a detail view of a casing containing a valve controlling the flow of pressure fluid toward and from the fluid pressure means;

Fig. 8 is a section taken on the line VIII-VIII of Fig. 7, showing the valve in its normal position of pressure application;

Fig. 9 is a view similar to Fig. 8, but showing the valve in its partial exhaust position;

Fig. 10 is a view similar to Fig. 8, but showing the valve in its full exhaust position;

Fig. 11 is a diagrammatic view illustrating the fluid pressure operating means and the valve for controlling its operation.

The illustrated press comprises a C-shaped frame member 26 (Fig. 3), containing bearings for the upper and lower ends of a vertical column or post 22 which is adapted to be rotated manually to bring a presser arm or beam 24, fixed to the post, into any desired position over a work support herein illustrated as a cutting block or bed 26.

The post 22 and presser arm 24 are reciprocated vertically by mechanism of the nature described in the aforementioned United States Patent for the purpose of causing the presser arm 24 to apply pressure to a die placed on a workpiece supported on the block 26. The mechanism for actuating the post 22 and presser arm 24 includes a driven pulley 28 (Fig. 3) and a clutch 29. The clutch is connected by a clutch tripping link and lever mechanism 36 and 3! to a handle 32 on the presser arm 24. The handle 32 which is grasped by the operator serves to rotate the presser arm 24 as well as to trip the clutch 29 to initiate an operative cycle. The clutch, when tripped, transmits the motion of the continuously rotating pulley 28 to a horizontal shaft 34 mounted in bearings in the frame member 26 and carrying at its inner end an eccentric 36 (Figs. 1, 3, and 5) surrounded by a strap 38 into which is threaded a rod 46. The rod 46 serves to impart up and down that end it is connected at its upper extremity to the upper end of the post 22 by a universal joint (Fig. 3) of well-known construction.

, For supporting the cutting block 26 and the fluid pressure means for moving the cutting block into its elevated operative position and for maintaining it in that position during the operation of the machine, the illustrated machine is provided with a casting 42 (Figs. 1 and 3) having at its rear face a projection or tongue 44 (Fig. 3) fitting into a groove 46 provided in a vertical front face of the frame member 26. The casting 42 and the entire movable assemblage of cutting block 26 and block elevating means are adapted to be rotated as a unit laterally of the machine about a, substantially vertical axis for the purpose of exposing the inner end of the shaft 34 and the eccentric 36 to facilitate the installment or the removal of the latter members. To that end, the casting is provided with a laterally extending portion 48 (Fig. 1) having bearing members 56 in which is received a substantially vertical shaft 52, the shaft being secured in the bearing members by screws or the like. Surrounding the shaft 52 and located intermediate the two bearing members 56 is a bearing 54 which is bolted to the frame member 28. The upper portion of the shaft 52 is seated in a bearing provided in the lower face of a carrier or table 56 on which the cutting block 261s mounted. In its normal operative position the casting 42 is held in place by suitable means such as bolts 55 (Fig. 3)

During the operation of the illustrated mamotions to the post 22, and to chine, the block 26 and carrier 56 are acted upon by a pressure medium, for example oil,

which causes these two members to be held in their operative position after they have been moved into that position under the force of the pressure medium. The operative position of both the block 25 and carrier 56 is adjustably determined. This arrangement of elevating the cutting block 26 into an adjustably determined position and holding it in that position during the normal operation of the machine has the advantage of permitting quick partial release of the work support from its operative position when an adjustment of that position becomes necessary or desirable and still further for a quick dropping of the cutting block to its lowermost position when the presser member 24 has become stalled on the block 26.

For the purpose in view, the carrier 56 is provided with a downwardly extending, hollow plunger 66 (Fig. 3) which is slidingly received in a cylindrically shaped portion 62 of the casting 42. A spring-pressed pin 58 (Fig. 1), carried by the laterally extending portion 48 of the casting 42, normally engages a socket provided in a portion of the carrier 56 to prevent relative rotary movement between the plunger 66 and the cylinder 62. The plunger 66 is provided at its upper portion with a peripheral shoulder 63 which in the lowermost position of the movable assemblage, composed of block 26, carrier 56, and plunger 66 is seated upon a rim at the upper end of the cylinder 62 (see Fig. 3). The lower portion 64 of the plunger 66 is of reduced diameter to provide between the plunger 66 and the inner wall of the cylinder 62 an annular chamber 66 into which fluid under pressure is admitted through a port 68 to elevate the plunger 66 relatively to the cylinder 62. The annular chamber 66 is sealed by gaskets 16 secured to shoulder portions of the plunger 66 and the cylinder 62, respectively, to prevent the pressure fluid contained in the annular chamber from leaking out along the inner wall of the cylinder 62. As illustrated, the reduced lower portion 64 of the plunger 66 extends through an opening in the bottom of the cylinder 62 and has a close fit therein.

For determining the elevated operative position of the movable assemblage there is provided an adjustable stop serving to limit the upward movement of the plunger 66, the plunger 66 being held against the stop by the fluid pressure after it has been elevated. To that end, there is provided a cap or lid 14 (Fig. 3) closing the upper end of the hollow plunger 66. Secured to the lower face of the lid by screws or the like is a downwardly extending cylindrical member 16 (Figs. 3 and 4) having its lower end open. Near its lower end, the cylindrical member 16 is provided with shoulders 18 carrying ball bearings 86 on which is rotatably supported a gear 82. The gear 82 has an elongated hub which has a sliding fit on a sleeve 84 provided with an internal thread. The sleeve 84 is threaded upon a long screw 86 extending downwardly through the entire length of the plungers 66 and the bottom thereof, the screw 86 being fixed, as will be explained, to the casting 42. To permit the gear 82 and the sleeve 84 to rotate together while at the same time permitting relative movements of the gear 82 and sleeve 84 along their axis of rotation, the gear 82 is provided with a key 88 engaging a keyway provided in the sleeve 64. The upper end of the sleeve 84 has a flange 96 and this flange acts as an adjustable stop for the movable assemblage when the pressure fluid is admitted through the port 68 to the annular chamber 66.. From-the inoperative positions of the parts illustrated in Figs. 3 and 4, the plunger 68 and with it the cylindrical member I6 and gear 82 are elevated upon admission of the pressure fluid to the chamber 56 until the upper end of the gear 82 abuts the flange 98 of the sleeve 84, thereby terminating the upward movement of these members and determining the upper elevated position of the cutting block 26. The sleeve 84 is normally held stationary because of its threaded engagement with the stationary long screw 86. In order to adjust the sleeve 84 and particularly the. flange 98 provided thereon heightwise so as to vary the operative position of the cutting block 26', the gear 82 is meshing with a vertical gear 92 secured to the inner end of a shaft 94 (Fig. 1) rotatably mounted in bearings provided at the lower face of the carrier 56 and having on its outwardly projecting end a hand wheel 96, by means of which the shaft 94 may be rotated to rotate the gear 62 and the sleeve 84 rotatably connected to the gear by the key 88, with the result that the sleeve 84 is lowered or raised on the upper extremity of the stationary screw 86. It is understood, of course, that this adjustment can take place only after at least a partial release of the pressure fluid from the chamber 65.

As previously mentioned, the screw 86 extends through the bottom of the hollow plunger 60. The lower end of the screw 86 is mounted in a bearing provided at the forward end of a bracket 98 bolted to the casting 82. The bearing in the bracket 98 is provided with a key engaging a keyway in the screw 86 to prevent the latters rotation. A nut 97, threaded upon the lower extremity of the screw 86 and abutting the bracket 98, serves to hold the parts in place.

In order to lend additional support to the fluid pressure means so far described, the lower end of the plunger 68 is connected by two telescopically adjustable braces 99 (Fig. 1) to lugs on the lower face of the carrier 56.

The means for supplying and controlling the pressure fluid in the illustrated machine will nOW be described. As previously mentioned, the mechanism for actuating the presser arm 24 includes an eccentric strap 38 (Fig. 5). This strap u is provided with a laterally extending projection I25 which upon up and down movement of the strap, as a result of a single revolution of the shaft 3 serves to actuate a pump for supplying the pressure fluid, preferably oil. There is also provided an accumulator in which the pressure fluid is stored, and mechanism for controlling the flow of the operating fluid from the accumulator to or from the pressure chamber 65', thereby causing the cutting block 28 to be moved upwardly to its operative position relatively to the presser member 26 or to be lowered out of operative position. n downward movement of the strap 33, the projection I90, which engages a laterally extending arm I02 on a pump actuating lever 5%, causes a swinging movement of this lever in a counter-clockwise direction (Fig. 5) about its supporting shaft Hi5 which is rotatably mounted in suitable bearings provided in the machine frame. The pump comprises a casing H36 integral with one wall of an oil reservoir [68 secured by bolts I 59 to the frame member 26, and a hollow plunger IIiJ arranged to be reciprocated in a horizontal, cylindrical bore in the casing I06. The bore is closed at its forward end by a cap provided with an openin through which the closed left-hand portion (Fig. 5) of the plunger II il extends. The lower end of the lever I54 engages the left-hand end of the plunger Hi1. A spring. N2, the left-hand end (Fig. 5) of which extends into the plunger and is seated therein, and the right-hand end of which bears against the right-hand end of the horizontal bore in the pump casing I535, tends to move the plunger III] outwardly, i. e., toward the left of Fig. 5. The hollow interior of the pump casing I56 is in communication with a substantially vertical duct I I4 provided in a block H5 integral with the pump casing and the bottom of the reservoir m8. There is provided a pressure relief valve II3 of well-known construction which automatically opens and permits oil to spill over into the reservoir H33 when a predetermined maximum pressure has been reached inside of the pump casing led and duct E I i. The lower end of the duct H4 is provided with a ball valve l and is connected by an intake port I 58 with the reservoir Hi8. Accordingly, upon outward movement of the plunger H5 toward the left of 5 underthe pressure of the spring M2, the plunger its is on its suction stroke, as a result of which the ball valve H3 is opened to admit oil from the reservoir I98 into the duct M and the pump casing i 56. Upon movement of the pump actuating lever EM in a counter-clockwise direction, as viewed in Fig. 5, during the downward movement of the eccentric strap 8% the plunger ill is moved inwardly against the pressure of the spring M2 to compress the oil contained in the casing H36 and duct i M thereby closing the ball valve I 56. The fluid under pressure is permitted to escape through a passage 529 in the block Iii-5 and spring-pressed check valve 522 into a passage E24 also provided in the-block I 55. The lowerend of the passage I 24- is the intake for the already mentioned accumulator, also shown in section in Fig. 5 of the drawings. The accumulator comprises cylindrical 425 open at its upper end and closed at i s lewer end and provided at its upper extremity a flange or rim bolted to the bottom of the reservoir H38. A two-part plunger l28, comprising two nested cup-shaped members, has a sliding fit in the cylinder I726. The plunger I28 is hollow, its upper end is closed and its bottom end is open. Seated in the interior of the plunger I28 is the upper end of a comparatively heavy spring I38, the lower end of which is seated upon the bottom of the cylinder I25. Threaded into the bottom of the cylinder IE6 is a rod i32 which extends part way through the spring I33 and serves to limit the downward movement of the plunger $28 under the pressure of the oil being pumped into the upper end of the accumulator. As illustrated in Fig. 3; the lower portion of the cylinder 1:25 is connected by a pipe 53 with th reservoir Its so that any oil, which may have leaked past the plunger I28 into the lower portion of the cylinder I26, may be forced back into the reservoir on downward movement of the plunger I28.

The upper end of the accumulator is in communication with a passage 536 (Figs. 3 and 5) provided in the bottom of the reservoir i558, the outer end of this passage being provided with a nipple 538 to which is fitted one end of a pressure resisting hose, the other end of Which is connected to an inlet passage iii; of a valve casing Md (Figs. 1, 7 to 16) securedby bolts M2 to the casting 42.

As already mentioned, the flow of pressure fluid l to and from the pressure chamber 66 of the cylinder 62 is specially controlled and for that purpose there is rotatably mounted in a bore provided in the valve casing I40 a cylindrical valve member I44 (Figs. 8 to which is provided in its surface with two recesses I46, I41 serving to establish communication between various oil passages leading into or out of the valve casing, as will be described. The position of the valve member I44, illustrated in Fig. 8, is its normal position in which communication is established between the accumulator through the inlet passage I48, recess I46, and an outlet passage I50, and the pressure chamber 66, the passage I50 being connected by a hose to the port 68 of the pressure chamber 66. In the upper portion of the valve casing I40 is provided a spill-over tank I52 into which oil under pressure is returned from the chamber 66 upon movement of the valve I44 into exhaust position. This chamber I52 is connected by a duct I 54 to the bore in the valve casing. Moreover, the valve casing is provided with a duct I55 communicating with a duct I58 through which ducts the oil is caused to flow back from the chamber I52 to the reservoir I08. The duct I58 is connected by means of a nipple and T-fitting I60 and hose to a nipple I6! (Fig. 3) communicating with the reservoir I08.

As illustrated in Figs. 9 and 10, the valve I44 may be rotated into two different pressure release or exhaust positions. In the position illustrated in Fig. 9, the duct I54 is opened partly to the duct I50 by the agency of the valve recess I46. Accordingly, the oil contained in the chamber 66 is forced under the heavy pressure of the machine parts, particularly the block 26, the carrier 56, and the plunger 60, back through the ducts I50 and I54 into the chamber I52. In view of the restricted passage of the oil through the only partially opened duct I54, the release of the pressure is very gradual and slow. As a matter of fact, only so much pressure is released as is necessary to facilitate a rotation of the gear 82 by a rotation of the hand wheel 96 to adjust the sleeve 84 and stop flange 90 in a heightwise direction. After this adjustment has been made, the valve is immediately returned into the position illustrated in Fig. 8 so that full pressure may quickly be restored in the chamber 66 and, consequently, very little time is wasted in making this adjustment.

If, however, it should become necessary to move the block 26 into its lowermost position, for example to release the presser arm 24 after it has become stalled on the block 26, the valve I44 is moved into its full pressure release position, illustrated in Fig. 10, in which the duct I54 is opened wide to the duct I50 so that the oil, contained in the chamber 66, may be immediately and quickly released from the chamber 66 and caused to flow into the chamber I52, thereby dropping the plunger 60 and block 26 into their lowermost positions, as determined by the engagement of the shoulder 63 with the rim at the upper end of the cylinder 62 (see Fig. 3). It is understood that after the presser arm 24 has been released by dropping the block 26, pressure is restored to the chamber 66 and the block 26 is elevated by turning the valve I44 back into the position illustrated in Fig. 8. As further shown in Fig. 8, in the normal position of pressure application of the valve I44 the duct I54 is in communication through the recess I41 of the valve I44 with the passages I56 and I58 so that the oil contained in the chamber I52 against the pressure of the body of air behind it, which has been somewhat compressed upon forcing the oil from the chamber 66 into the chamber I52, is now caused to flow out of the valve casing back into the reservoir I05.

To operate the valve member I44, as described, it has an outwardly extending stem portion I62 (Figs. 1 and '7) connected by a universal joint with one end of a rod I64, the other end of the rod being connected by a universal joint to a stub shaft I66 (Figs. 1 and 2) rotatably mounted in a bracket I68 which is bolted to the carrier 56. Secured to the outer end of the shaft I66 is an arm I10 (Fig. 2), the free end of which is connected by a link I12 to a hand lever I14. The hand lever I14 is mounted on a stub shaft I16 rotatable in the bracket I68. A second hand lever I18 is loosely mounted on the shaft I16. The hand lever I18 has a downwardly extending projection I00 which is adapted to engage a pin I82, by which pin the link I12 is connected to the first-mentioned hand lever I14. Secured in the bracket I60 is a stop pin I84 for arresting the hand lever I 18 after it has been moved downwardly from its position illustrated in Fig. 1. To terminate the downward movement of the hand lever I14, the bracket I68 is provided with a shelf I86 which is engaged by a stop pin I88 carried by the hand lever I14. Moreover, to determine the uppermost inoperative position of the hand lever I18, the shelf I86 carries a stop pin I90 which is adapted to engage a tail piece I92 provided on the hand lever I18. To move both hand levers I14 and I18 into their upper inoperative positions, there is mounted on the shaft I66 a torsion spring I94, one end of which abuts a. pin I96 which acts as a pivot connection between the arm I10 and the link I12, and the other end of which spring abuts a pin I98 which may be inserted into any one of several sockets 200 provided in the bracket for the purpose of adjusting the tension of the spring. The spring I 94 tends to move the link I12 upwardly, thereby moving the hand lever I14 upwardly which, by reason of the engagement of the pin I82 with the projection I on the hand lever I18, also elevates the latter hand lever I18 into its normal inoperative position.

If it is desired to move the valve member I44 from its normal position of pressure application, illustrated in Fig. 8, into its partial pressure release or exhaust position, illustrated in Fig. 9, for the purpose of making an adjustment of the stop flange and sleeve 84, the hand lever I18 is depressed until it engages the stop pin I84 secured to the bracket I68. In doing this, the valve I 44 is rotated into the position shown in Fig. 9 and this by reason of the fact that, due to the engagement of the projection I80 on the hand lever I18 with the pin I82 of hand lever I14, the latter hand lever has been partially depressed, thereby rotating, through the agency of the link I12 and arm I10, the shaft I66 and the valve I44. If, on the other hand, it is desired to move the valve member I44 from its normal position of pressure application, shown in Fig. 8, into is full pressure release position, shown in Fig. 10, only the hand lever I14 is depressed which, as illustrated in Fig. 1, is so mounted that it clears the fixed stop pin I84. Accordingly, the hand lever I14 may be further depressed until the pin I88, carried by it, engages the shelf I86. In this position of the hand lever I14 the valve I44 has been rotated into its full pressure release position, shown in Fig. 10.

For the sake of making a complete and somewhat simplified showing of the entire fluid pressure mechanism of the illustrated machine, including the valve mechanism, Fig. 11 of the drawings shows diagrammatically the various parts of the fluid pressure mechanism in their mutual relationship. The pump, indicated in Fig. 11 by -P, has an intake connected with the oil reservoir I118. The pressure side of the pump is connected with the accumulator identified by the cylinder I26 and piston I28. As previously explained, the accumulator is connected to the valve casing I40. In the normal position of the valve I44 shown in Figs. 8 and 11 the pressure fluid is caused to flow through the valve into the annular pressure chamber 66 where it is active to elevate the plunger 60, the carrier 55, and the cutting block 26, as previously described.

The fluid pressure is sufficiently strong effectively to maintain the block 26 in its pressure sustainingposition, particularly when the presser arm 24 is operative to apply pressure upon the work supported on the block '26. It is to be understood, however, that since an open connection is maintained between the accumulator and the chamber 65 in the position of pressure application of the valve I44, excessive pressure applied by the presser-arm 24 to the block 26 may be taken up by the accumulator, in which case the spring I31 may be caused to yield somewhat.

In the position of pressure application of the valve any oil contained in the chamber I 52 above the valve is returned through ducts I54, I58 and I58 to the reservoir I 58. Rotation of the valve into its partial or full exhaust positions, shown in Figs. 9 and 10, disconnects the cylinder 62 from the accumulator and establishes communication between the cylinder 62 and the chamber I52 with the result that the pressure fluid contained in the cylinder 62 spills over into the chamber I52, thus releasing the pressure in the chamber 66 and lowering the carrier 56 and cutting block 25.

It is possible that after the full or partial release of the hydraulic pressure in the chamber 8% for the purpose of lowering the cutting block 255, the pressure of the oil stored in the accumulator is insufficient to restore the cutting block to its elevated operative position with the result that the machine, due to the improper position of the cutting block, cannot be operated and, hence, the pump cannot be operated to replenish the supply of pressure oil in the accumulator and to load the spring I 30. To cope with this situation, the illustrated machine is provided with means for manually operating the pump, while the machine is at rest, to store pressure fluid in the accumulator in an amount sufficient to raise the cutting block so that the machine operation may be resumed. To this end, the above-described shaft I65 carrying the pump operating lever N34 has secured to it an arm 202 (Fig. 5), the lower surface of which is engaged by one arm of a bell-crank lever 2G4 pivotally mounted on a stud 265 secured in a bracket 208 bolted to the frame member 28. A spring 2H3, secured at one end to the frame member 29 and at the other end to the right-hand arm (Fig. 5) of the bell-crank lever 204, tends to rotate the bell-crank lever 294 in counter-clockwise direction, as viewed in Fig. 5, into inoperative position. For the purpose of swinging the bell-crank lever 204 in clockwise direction to impart a counter-clockwise movement to the arm 292 and lever I04 and thereby to operate the pump, the abovementioned right-hand arm of the bell-crank lever 204 is provided with a socket 2I2 in which is secured one end of a rod 2M. As will be seen by manually depressing the rod 2I4 repeatedly, the pump III] is operated to store up pressure fluid in the accumulator.

The operation of the machine and particularly of the fluid pressure mechanism is apparent from the foregoing description but may be briefly summarized here. Assuming that there is sufficient pressure fluid in the accumulator for the cutting block to be maintained in its elevated operative position, the clutch 29 is tripped by means of the handle 32 and an operative cycle is initiated during which the presser arm 24 descends and strikes upon a die previously placed in a selected position upon a piece of sheet material, such as a piece of shoe upper leather, supported on thecutting block 26. While this occurs, the eccentric strap 38, which is reciprocated once during each cycle, produces a single compression stroke of the pump, the presssure fluid supplied by the pump being stored in the accumulator.

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

1. In a press, the combination with a work support and means for applying pressure to a workpiece on said support, of fluid-operated means for moving the support into its operative position and an adjustable stop for determining the operative position of the support.

2. In a press, the combination with a work support and means for applying pressure to a workpiece on sad support, of fluid-operated means for moving the support into its pressure sustaining position, an adjustable stop for determining the pressure sustaining position of the support, and a valve for controlling the operation of said fluid-operated means.

3. In a press, the combination with a work sup port and means for applying pressure to a workpiece on said support, of fluid-operated means for moving the support against an adjustable stop determining its operative position, and a manually operable valve for controlling the flow of pressure fluid toward and from said fluid-operated means, the valve having three positions of adjustment, in one of which the pressure fluid is admitted to the fluid-operated means, in another the fluid pressure is gradually reduced to lower the support sufficiently to adjust the stop, and in a third the fluid pressure is immediately and fully released.

4. In a press, the combination with a work support and movable means for applying pressure to a workpiece on said support, of fluidoperated means for moving the work support into its operative position, and means responsive to movement of said pressure applying means for supplying pressure fluid to actuate said fluidoperated means.

5. In a press, the combination with an adjustable work support and movable means for applying pressure to a workpiece on said support, of fluid-operated means for maintaining the support in its operative position, an adjustable stop for determining the operative position of the support, a pump responsive to movement of said pressure applying means for actuating the fluidoperated means, and a valve for releasing pressure from the fluid-operated means to permit adjustment of the stop.

6. In a press for cutting out blanks from sheet material, the combination with a vertically adjustable cutting bed and a vertically movable presser arm adapted to apply pressure to a die placed on the sheet material supported on the cutting bed, of a fluid-operated mechanism for raising the cutting bed, the mechanism including a cylinder and a plunger of which the latter is connected to the cutting bed, a pump actuated upon movement of the presser arm, to force a pressure fluid into the cylinder to raise the plunger and the cutting bed, and a manually adjustable stop for limiting the upward movement of the piston.

7. In a press for cutting out blanks from sheet material, the combination with a vertically adjustable cutting bed and a vertically movable presser arm adapted to apply pressure to a die placed on sheet material supported on the cutting bed, of a fluid-operated mechanism for raising the cutting bed, the mechanism including a cylinder and a plunger of which the latter is connected to the cutting bed, a pump actuated upon movement of the presser arm to supply pressure fluid, a manually operable valve for determining the flow of said pressure fluid into the cylinder to raise the plunger and the cutting bed, and a manually adjustable stop for limiting the pressure movement of the plunger and thereby determining the operative position of the cutting bed.

8. In a press for cutting out blanks from sheet material, the combination with a vertically adjustable cutting bed and a vertically movable presser arm adapted to apply pressure to a die placed upon sheet material supported on the cutting bed, of a fluid-operated mechanism for raising the cutting bed into its operative position, the mechanism including a cylinder and a plunger of which the latter is connected to the cutting bed, a pump responsive to movement of the presser arm for supplying pressure fluid, a manually adjustable stop for limiting the pressure movement of the plunger and thereby determining the operative position of the cutting bed, and a manually operable valve which in one position admits said pressure fluid to the cylinder to raise the plunger and cutting bed and which in another position permits the expulsion of the pressure fluid from the cylinder to lower the cutting bed.

9. In a press, the combination with a work support and movable means for applying pressure to a workpiece on said support, of fluid-operated means for moving the work support into its operative position, a pump for supplying pressure fluid, means responsive to movement of said pressure applying means for operating the pump, and manual means for operating the pump.

10. In a press, the combination with a work support and movable means for applying pressure to a workpiece on said support, of fluid-operated means for moving the work support into its operative position, means responsive to movement of said pressure applying means for supplying pressure fluid, means for storing said pressure fluid, and a valve for controlling the flow of the pressure fluid from said storing means to said fluid-operated means to actuate the fluidoperated means.

11. In a press, the combination with an adjustable work support and movable means for applying pressure to a workpiece on said support, of fluid-operated means for moving the support into its operative position, an adjustable stop for determining the operative position of the support, a pump responsive to movement of said pressure applying means for supplying pressure fluid, an accumulator connected to the pump for receiving and storing the pressure fluid, and a valve for controlling the passage of the pressure fluid to and from said fluid-operated means.

12. In a press, the combination with a vertically adjustable work support and movable means for applying pressure to a workpiece on said support, of fluid-operated means for moving the work support into its operative position, means responsive to movement of said pressure applying means for supplying pressure fluid, means for receiving and storing the pressur fluid, and connections between said fluid-operated means and said storing means, the storing means acting to cushion the effect of the operative engagement of the pressure applying means with the work support.

13. In a press, the combination with a work support and movable means for applying pressure to a workpiece on said support, of fluid-operated means for raising the work support into its operative position, a valve mounted in a casing and controlling the flow of pressure fluid toward and from said fluid-operated means, a spillover chamber provided in the valve casing for receiving the pressure fluid expelled from the fluid-operated means in the exhaust position of the valve, a reservoir for the fluid, connections between the reservoir and the spill-over chamher, said connections being opened on movement of the valve into its position of pressure application to return the fluid contained in the spillover chamber to the reservoir.

14. In a press, the combination with a Work support and means movable toward an operative position to apply pressure to a workpiece on said support, a fluid-operated means for moving the support into its operative position and for sustaining it in that position against the impulse of the pressure applying means.

15. In a press, the combination with a work support and means movable toward an operative position to apply pressure to a workpiece on said support, of fluid-operated means for moving the support into its operative position and for sustaining it in that position against the impulse of the pressure applyin means, and a valve for controlling the operation of said fluid-operated means.

MILTON H. BALLARD. FRANK E. STRATTON.

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