US2720666A - Pressure applying apparatus - Google Patents

Description

Oct. 18, 1955 r. A. KESTELL PRESSURE APPLYING APPARATUS 3 Sheets-Sheet 1 Filed March 27, 1952 lnven for Thomas A/lesfefl 251440 I I I 45 42 5848 42 his Attorney Oct 1955 T. A. KESTELL PRESSURE APPLYING APPARATUS 3 Sheets-Sheet 2 Filed March 27, 1952 [rwen for 7770777475 /\./\esfe// By his Attorney W Oct. 18, 1955 Filed March 27, 1952 T. A. KESTELL PRESSURE APPLYING APPARATUS 5 Sheets-Sheet 3 Inventor United States Patent PRESSURE APPLYING APPARATUS Thoma's Aubrey Kestell, Leicester, England, assignor to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application March 27, 1952, Serial No. 278,8G1 Claims priority, application Great Britain April 13, 1951 18 Claims. (Cl. 12-36) This invention relates to pressure applying apparatus, and more particularly to machines for applying pressure to shoe bottoms. The invention is illustrated herein as embodied in a two-station sole laying machine of the type illustrated in Letters Patent of the United States 1,549,243 granted August 11, 1925 on an application filed in the name of E. E. Winkley. It will be understood that the invention is not limited in its application to machines of the type illustrated in that patent but may be embodied in machines for performing various operations on the bottoms of shoes such as sole attaching, sole leveling and lasted bottom ironing, or may be embodied in other machines such as machines for use in sole moldmg.

Machines of the type described above are commonly provided with a toggle mechanism for causing relative movement of a pair of pressing members to apply pressure to a work piece placed between the members. In order to compensate for variations in the heights of lasts or the thicknesses of soles, one of the toggle links is carried by a yieldable abutment, a long pressure spring being provided to resist movement of the abutment thus compensating for variations in the thickness or height of the work without afiecting to any considerable degree the amount of pressure applied to the work. Of necessity, however, the ultimate pressure applied to the work will increase to some extent with increases in the thickness of the sole or the height of the last.

It is sometimes desirable to apply a predetermined pressure to the work regardless of the variables mentioned above and also to insure that the toggle links will be approaching straightened position before any substantial amount of pressure is applied to the work in order to eliminate excessive torque in the drive mechanism, it being understood that the mechanical advantage of the toggle increases as it approaches straightened position. i

It is an object of the present invention to provide improved mechanism for applying pressure to bottoms of shoes whereby the same pressure is applied to successive shoe bottoms irrespective of the thickness of the sole and/or the height of the last.

A further object of the invention is to provide in a machine of the type described above, having a toggle mechanism for moving one press member toward another, improved means for preventing the application of any substantial amount of pressure to the work piece between the press members until the toggle links, in moving toward straightened positions, have attained a predetermined relationship to each other, at which time pressure is applied and increases to a predetermined amount irrespective of the thickness of the sole being acted upon or the height of the last carrying the shoe.

To these ends and in accordance with a feature of the invention, the toggle links act against an abutment which initially is yieldably mounted so that only a light pressure .is applied to the work until the toggle links are nearly in straightened positions, whereupon the abutment is held against further yielding movement until the pressure on the work reaches a predetermined amount which may be readily controlled by the operator after which the abutment is again permitted to yield. Thus pressure is applied to the work only during the latter part of the straightening movement of the toggle links, thereby minimizing the driving torque in the machine and the same pressure is always applied, if desired, regardless of the thickness of the sole or the height of the last located between the presser members.

As illustrated herein the abutment is initially held by a relatively light spring so that the abutment may yield upon application of a light pressure to the work and fluid pressure control mechanism is rendered operative when the toggle links attain a predetermined relationship at which time they are nearly straightened, to prevent further yielding of the abutment, the fluid pressure control mechanism remaining effective until the pressure on the work reaches a predetermined value. This fluid pressure control mechanism and the light spring acting on the abutment take the place of the long compression.

spring, as shown in the aforementioned Winkley patent, and minimize the driving torque required in the machine while insuring a more accurate control of the pressure applied to the work.

The above and other features of the invention, including various details of construction and novel combinations of parts will now be described by reference to the drawings and pointed out in the claims.

In the drawings,

Fig. 1 is a front elevation, partly in section, of one form of machine in which the invention is embodied;

Fig. 2 is a vertical section through mechanism by which the pressure applied to the work is controlled;

Fig. 3 is a section on a larger scale of a portion of the mechanism shown in Fig. 2;

Fig. 4 is a section on a still larger scale on the line IVIV of Fig. 2; and

Fig. 5 is a section on the line VV of Fig. 4.

The machine is illustrated as having a base 10 which supports pairs of posts 12 to the upper ends of which are attached vertically extending rods 14. Only the front posts and rods are illustrated herein but it will be understood that similar posts and rods are carried by the base 10 behind those shown. Each pair of rods 14 supports a jack 16 carrying heel and toe supports 18 and 20 for a lasted shoe S the bottom of which is to be subjected to pressure exerted through a pad 22 carried by a pad box 24. The jacks 16 are arranged to be vertically adjusted along the rods 14 by means of screws 26.

The pad boxes 24 are pivoted at 28 in frames 30 arranged to slide along the rods 14 to move the pads 22 toward and from shoes supported by the jacks 16. Each sliding frame 30 is moved along the rods 14 by a toggle mechanism comprising an upper toggle link 32 and a lower toggle link 34, these links being pivotally connected at 36. The upper link 32 is pivoted at 38 to the sliding frame 30 and the lower link 34 is pivoted at 40 to the end of a lever 42 mounted on a pin 44 supported by a plate 46 and a plate (not shown) at the rear of the machine. The plate 46 is carried by adjustable studs 48 at the front of the machine. The toggle mechanisms at opposite sides of the machine are arranged so that the pad boxes are lowered as the pivots 36 connecting the toggle links move toward the center of the machine and are lifted as the pivots move outwardly. The lower links 34 of the toggles are connected by a link 50 so that movement of the link in either direction will cause reverse operation of the two toggle mechanisms.

A drive pulley 52 is arranged to be connected to a drive gear 54 through a half revolution clutch (not shown) each time a treadle 56 is depressed. The gear 54 is connected through suitable mechanism to the link 50 St) thfit T125611 ill dPlfiSlGil 6f the ClllfCh pedal thfi link moves either to the right or to the left causing upward. movement of. one pad box 24 and downward move-- merit of the other.. Inasmuch as this particular mechanisrn forms no part of the present invention it is notdisclosed herein but is'i llust'rated and described clearly in the aforementioned Winkley patent.

The adjacent ends of the levers 42 overlap, asindicated at 58, and engage an' abutment 60 which acts with a varying force as will be explained to hold the ends 58.

down. Duringthe initialstraighteningof one of the pairs of toggle links 32, '34, the end 58 of'the associated lever '42, remainsin the position illustrated until the pad has moved upwardly into an engagement with the shoe carried by the jack 16; During further straightening movement of the toggle'links the abutment 60 yields upwardly due'toforee exerted on the lever 42, permitting the pivot 40 to move downwardly sothat no additional pressure is applied to the shoe during the period that the abutment 6 isfree to move upwardly. This upward movement of the abutment continues until the toggle links have moved nearly into straightened positions whereupon further up-.

'ward movement of the abutment 60 is resisted until a predetermined high pressure exerted on the abutment through the lever 42 is attained. Consequently at a predetermined point during the straightening movement of the toggles, high pressure is applied to the shoe and increases until-a predetermined pressure is reached. The mechanism by which this is controlled will now be explained.

The abutment is formed at the lower end of a cylinder 62, the c'ylinderconsistingof parts 64 and 66 threaded together. The cylinder is guided for vertical movement by a sleeve 68 which provides between its ends and annular'space70 between the sleeve and portion 66 of the cylinder Communication between the lower portion of the cylinder 62 and the interior of the sleeve 68 is controlled by a valve mechanism 72 carried by the lower wall of the sleeve 68. The valve mechanism includes -a cylindricalhousing 74 threaded into the bottom wall of the sleeve '68 and having a flange 76 at its lowerend. Formed in the bore of the housing 74 is an internal flange 78 (:Fig; providing a seat for a ball valve element80 which controls the flow of fluid through the housing 74 from the cylinder. 62 into the sleeve 68. Toprevent unintentional passage of fluid from the lower 'end'o'f the cylinder into the sleeve 68 aflat leather washer 82' and a cupped leather washer 84 are clamped between the'flange 76 and the lower endofi the sleeve 68 by a metallic 'washer 86. V

I Threaded into the lower end of the housing 74 is a plug '88 having an upwardly extending shank portion 90 spaced from the interior of thehousing 74 and terminating in'a reduced portion providing an abutment for the lower end of a spring 94 theupper end of which engages ball valve element 81] nermally holding the valve element upwardly off the seat 78. Ports 96 formed in the flange T6 of the housing 74 provide communication between the interior of the cylinder 62 and the valve housing 74 and other .por-ts'98 provide communication between 'the upper end of the valve housing '74 a nd the lower end of the sleeve 68. sothatf-reefiow of fluid tom the cylinder 62 to the sleeve 68 is permitted when the valve element 80 is held by the spring 94 oii the seat 78. A compression spring 109. acts between the flange 76 of the valve h'ous- -in g7 4 and the lower end of -the cylinder 62 to hold the cylinder-in itslowermost position until pressure greater than that required to lift zthe pad box-during thest-raightenin'g-movement of the toggles is applied; to the abutment 60 tormedat the lowerend' of, the cylinder. 7

The upper end of. the sleeve 68 is provided with di- .amet'rically opposed laterally projecting bosses I02 arranged to receive trunnions 104 (Fig. 1) carried by a supporting plate l 06 which is in turn supported by the posts 12. at opposite sides of the rnaclline; Consequently the sleeve 68 is held against upward movement during the operation of the machine. It will thus be understood that V 7 34 cannot move downwardly. At the beginning of the v straightening movement of theitoggle' links the ball valve element is permitted to be lifted from'its seat by the spring 94 so that the only force holding the cylinder 62 down is that exerted bythe spring 100. After a predetermined time in. the straightening movement of the toggle links the ball valve element 80 is forced against the action of the spring 94 into engagement with the seat 78 as will now be explained.

Carried by the upper end of the sleeve 68 is a cap in which is threaded a sleeve 112,forming a guide for the upper end of a rod 114 the lower'end 116 ofwhich is arranged, when the. rod is moved downwardly, to engage the ball valve element 80 and hold it in engagement with the valve seat 78. The lower end 116 is provided with spaced radial projections 118 (Fig. 5) arranged to engage the upper end of the valve housing 74 thereby assisting in guiding the rod 114'in its vertical movements.

Secured to the upper end of the sleeve 112 is a hand wheel 120 provided for turning the sleeve in the cap 110 to adjust its vertical position therein. The lower end of the sleeve 112 forms an adjustable, abutment for a spring 122 which is enclosed by a housing 124. This housing rests on a flange 126 on the rod 114 and to the bottom of the housing 124 is secured a cap 128 engageable with the underside of the flange 126 so that the housing 124 in effect forms a portion ofthe rod 114, vertical movement a of the housing being transmitted to the rod.

The rod 114 is arranged to be lifted at the beginning of a cycle of operations to permit the ball'valve element 80 to be lifted from its seatv 78 by the spring94. For this purpose a lever 130 is pivoted at 132 between a pair of lugs-134integr-al with the upper end of the sleeve 68. The inner end of the lever 130 engages the under-face of a flange 136 at the upper end of the housing 124 and the other end of the lever is connected to a downwardly extending rod 138', the lower end ofwhich isconnected to a lever 140 (Fig. l) which is in turn pivoted at 142 to a plate 144 secured to the front posts 1 2 of the machine. The. other end of the lever Mil-carries a camroll 146 arranged .for engagement'with the periphery of a earn 148 movable with the gear 54 so that-the rod 138. and consequently the rod 114 move in a predetermined timed re'la tion the operation of the machine.

With the .rod 114 lifted by the cam 148 thefluid in the lower portion 64 of the cylinder 624s free to pass by the ball valve element '80 upon upward movement of the cylinder during straightening of the toggle links 32;, 34 after the'pad 22 .has engaged the bottom of a shoe. When the rod 114 is moved downwardly by the lever 130 acting applied to the work depends upon the force exerted by this spring which' is in turn controlled by the heightwise position of the sleeve 112 which-forms the abutment for the upper end of the spring 122.

To facilitate adjustment of the machine for the application of a predetermined pressure to the work; indicating means .is provided to apprise the operator of the desired setting of the hand whee'l120. This indicating means comprises 'an indicating arm or pointer 152 carried by one end of a shait 154 joumaled'in a bracket 156'-car-.

ried by the upper end of the sleeve 68. To the other end of the shaft is secured an arm 158 engageable with a flange 160 on the vertically adjustable sleeve 112. Also secured to the shaft 154 is an arm 162 (Fig. 1) to which is attached one end of a spring 164 the other end of which is secured to a hook 166, secured to the upper end of the sleeve 68. Thus the arm 158 is urged in a counter clockwise direction, as viewed in Fig. 1, into engagement with the flange 160. The pointer 152 cooperates with a scale 168 calibrated in any suitable manner as pounds pressure. It will be understood that upon vertical movement of the sleeve 112 by the hand wheel 120 to adjust the spring 122, the pointer 152 will move over the scale 168 thus facilitating adjustment of the machine for any desired pressure to be applied to the work.

Provision is made to facilitate return of the pressure fluid into the lower portion 64 of the cylinder 62 between each cycle of operations of the machine or during downward movement of one pad box and the initial upward movement of the other pad box. For this purpose a sleeve 170 is secured to and surrounds the cylinder 62, this sleeve having a plurality of radially spaced vertically extending passageways 172 (Figs. 4 and Ports 174 provide communication between the upper ends of the passageways 172 and ports 176 in the wall of the upper portion 66 of the cylinder 62 so that the passageways 172 are always in communication with the upper portion of the cylinder. Between the passageways 172 are short passageways 178 connected by ports 189 to the lower portion 64 of the cylinder 62. To the lower end of the sleeve 170 is clamped a ring member 182 having an annular channel 184 therein, the ring memher being held against a sealing gasket 186 at the lower end of the sleeve 170 by a clamping nut 188 threaded onto the lower portion 64 of the cylinder. The channel 184 is connected by ports 190 with the short passage ways 178 in the sleeve 170. Balls 192 form check valves which prevent flow of fluid downwardly through the. passageways 178. The channel 184 communicates by ports 194 with the passageways 172. It will thus be understood that fluid can flow from the upper portion of the cylinder by way of ports 176, 174, passageways 172 and ports 194 into the channel 184 and thence by way of ports 190 past the balls 192, passageways 178 and ports 180 into the lower portion of the cylinder 62. it will of course be understood that fluid may also flow past the ball valve element 89 with the rod 114 in raised position but because of the limited capacity of the passageway most of the fluid will follow the course outlined above.

in the operation of the machine it will be assumed that the right hand pad box has been moved upwardly by straightening of the toggle links 32, 34 placing a shoe S under pressure. At this time the valve element 89 (Figs. 2 and 5) is held by the rod 114 in engagement with the seat 78, the rod 114 being in its down position by the spring 122. The pressure of the fluid in the lower portion 64 of the cylinder 62 will be determined by the setting of the hand wheel 120 thus determining the pressure applied to the bottom of the shoe. Assuming that the machine is being used for a sole laying operation, an assembled shoe and outsole are positioned in the left side of the machine, the shoe being carried by the heel and toe abutments 18 and 2t), and the treadle 56 depressed. The drive gear 54 now starts to rotate through a half revolution breaking the toggle links 32, 34 at the right side of the maclune and moving the toggle links at the left side of the machine toward straightened position. At the beginning of this movement of the gear 54, the lever 140 (Fig. l) is moved in a counterclockwise direction pulling the rod 138 downwardly and moving the rod 114 upwardly away from the ball valve element 80. The cylinder 62 moves downwardly under the force exerted by the spring 100, fluid being drawn into the lower portion of the cylinder through ports 176, 174 (Fig. 5), pasasgeways 172, port's 194 into the channel 184 past the check valves 192 and upwardly into passageways 178 and ports 180 into the lower portion of the cylinder.

The cylinder 62 remains in its lowermost position until the pad 22 has moved upwardly to apply light pres sure to the shoe bottom. The resistance encountered is sufiicient to overcome the force exerted by the spring before any substantial amount of pressure has been applied to the shoe bottom whereupon the lever 42 moves in a counterclockwise direction during further straightening movement of the toggle. This continues until the toggle links have been moved nearly into the straightened positions. At a predetermined time in the straightening of the toggle links, as for example, when they are within 20 of being straightened, the cam roll 146 (Fig. 1) drops off the high portion of the cam whereupon the spring 122 moves the rod 114 downwardly causing the ball valve element 80 to engage the seat 78 preventing upward flow of fluid from the lower portion of the cylinder 62 into the upper portion thereof. Hence the abutment 60 is locked in position so that upon further straightening of the toggle links the pad box is forced upwardly to apply heavy pressure to the bottom of the shoe, this pressure being limited by the setting of the spring 122 by the hand wheel 120. As soon as the pressure exceeds this value, the ball 80 will be forced from its seat to permit completion of the straightening movement of the toggle links without an excessive pressure being applied to the work.

It will thus be seen that irrespective of variations in thickness of outsole or variations in the height of the last the pressure will be determined by the setting of the hand wheel and will be unafiected by such variations. Also no substantial driving torque is required to straighten the toggle until the links are nearly in their straightened positions, and this again is unaffected by variations in the thickness of the outsole or the height of the last but is determined solely by the cam 148.

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

1. Pressure applying mechanism comprising a movable pressure applying member, a toggle connected to said member for applying pressure to a work piece, power operated mechanism for moving said toggle to straightened position in the pressure applying operation, a support for said toggle arranged to yield in response to the application of a light pressure to the work, and means independent of the toggle but operative at a predetermined time in the movement thereof toward straightened position for resisting movement of said support until a predetermined high pressure has been applied to the work, said means including means for limiting the ultimate pressure applied to the work.

2. Pressure applying mechanism comprising a movable pressure applying member, a toggle connected to said member for applying pressure to a work piece, power operated mechanism for moving said toggle to straightened position in the pressure applying operation, a support for said toggle arranged to yield in response to the application of a light pressure to the work, and means independent of the toggle but operative at a predetermined time in the movement thereof toward straightened position for resisting movement of said support until a predetermined high pressure has been applied to the work, said last named means including a fluid pressure'device and a valve in control of said device for limiting the pressure applied thereby.

3. Pressure applying mechanism comprising a movable pressure applying member, a toggle connected to said member for applying pressure to a work piece, power operated mechanism for moving said toggle to straightened position in the pressure applying operation, a support for said toggle arranged to yield in response to the application of pressure to the work, means opposing yielding of said support comprising a fluid pressure device and a spring, a valve in control of said device to control 7 pressure applying member, a toggle connected to said member for applying pressure to a work piece, power operated mechanism for moving said toggle to straightened position in thepressure applying operation, a support for said toggle arr-angedto yield in response to the application of pressure to the work, means opposing yielding of said support comprising a fluid pressure device and a .spring,;a' valve in control of said device to control the pressure applied thereby, means initially holding said valve in open position whereby movement of said support is restricted only by the spring, and means independ-' ent of the toggle but operative at a predetermined time in the 'movement thereof toward straightened position for closing said valve whereby movement of the support is restricted additionally by said fluid pressure device,

I said last named means including a spring arranged to permit opening of said valve in response to attainment of a predetermined pressure in the fluid pressure device thereby limiting the pressure applied to the work.

5. In a machine for applying pressure to shoe bottoms,

pressure mechanism comprising a jack and a pressing pad,

power operated mechanism for efiecting relative pressing movement between the jack and the pad comprising a toggle, an abutment for said toggle arranged to yield upon application of light pressure to the bottom of a-shoe carried by the jack, means operative upon movement of the links of the toggle into a predetermined relationship for holding the abutment against yielding movement, and means operative in response to the attainment of a predetermined high pressure on the shoe bottom for rendering the last named means ineffective.

6. In a machine for applying pressure to shoe bottoms, pressure mechanism comprising a jack and a pressing pad,

power operated mechanism for efiecting relative pressing movement between the jack and the pad comprising a toggle, an abutment for said toggle arranged to yield upon application of light pressure to the bottom of a shoe carried by ,the'jack, means operative upon movement of thelinks of the toggle into a predetermined relationship for holding the abutment'against yielding movement,

means operative in response to the attainment of a .pre-

determined high pressure on the shoe bottom for rendering said holding means ineflective. and means for adjusting .said last: named means to control the final pressure applied to the shoe bottom.

7. In a machine for applying-pressure .to shoe bottoms, pressure mechanism comprising a jack and a pressing pad, power operated vmechanism for efiecting relative pressing movement between the jack and the pad comprising a toggle, abutment for said toggle, a cylinder carrying said abutment and providing a chamber for a substantially noncompressible fluid, yielding means opposing movement of said cylinder, a sleeve over, which said cylinder :is; arranged to slide in response to pressure appliedto said abutmentysaid sleeve having an end wall in fluid-tightrelation to said cylinder forming a closed chamberrfor said'fluid, a valve in said wall arranged-to permit flow :of; fimd therethroug-h, means holding said valve open at the beginning of a cycle of operations to permit movement of said abutment against the action of said yielding means during the straightening ofthe toggle, and means operative ata predetermined in "the straightening of the toggle for closing said valve thus preventing vtnovernent of the abut-ment.

8-1a atmachine .for applying pressure to shoe bot-toms,

comprising a jack and a'pressing permit flow of fluid therethrough, means holding 'said valveropen at the beginning ,ofa cycle of operationsto permit movement of said abutment against the action of said'yielding means during the straightening of the toggle, and means operative at a predetermined time in the straightening of the toggle for closing said valve thus preventing movementrof the abutment, said last named means including a yieldable member permitting movement of said abutment upon the attainment ota predetermined pressure on the work.

9. In a machine for applying pressure to shoe bottoms, pressure mechanism comprising a jack and a pressing pad, power operated mechanism for effecting relative pressing movement between the jack and the pad comprising a toggle, an abutment for said toggle, a cylinder carrying said abutment and providing a chamber for a substantially noncompressible fluid, yielding means opposing movement of said cylinder, a sleeve over which said cylinderis arranged to slide in response to pressure applied ative at a predetermined time in the straightening of the a toggle 'foryclosing said valve thus preventing movement of the abutment, 'said last .named means including a, yieldable member permitting movement of said abutment upon the attainment of a predetermined pressure on the work, and means for varying the eifectiveness of said member tocontrol the ultimate pressure applied to the.

work.

19. In a machine'for applying pressure to-shoe bottoms, pressure mechanism comprising a jack and a pressing pad, power operated means for moving said pad vertically toward and away from said jack, said means comprising a toggle having a pair of linksone of which is connected to said pad, a drive member connected to the toggle for moving it in and out of straightened position, a lever supporting the other link of said toggle, means opposing movement of said lever during straightening of said toggle comprising an abutment, a spring acting to move said abutment in a direction'opposing straightening of said toggle but permitting movement thereof in the opposite direction in response to the application of a light pressure on the work, a yielding fluid pressure device assisting said spring in opposing movement of the abutment, and means rendering said device operative only after the toggle has been moved a predetermined amount toward straightened position. V

1.1. In amachine for applying pressure to shoe bottoms, pressure mechanism comprising a jack and a pressing pad, power operated means for moving said pad vertically toward and .awayfrom said jack, said means comprising a toggle having a pair of links one of which is connected to said pad, a drive member connected to the move said abutment in a direction opposing straighten- .ing of said toggle but permitting movement thereof it? p the opposite direction-in response to the application a light pressure on the work, a fluid pressure device assisting said spring in opposing movement of the abutment, means rendering said device operative only after the toggle has been moved a predetermined amount toward straightened position, and means controlling said fluid pressure device to limit the ultimate pressure applied to the work.

12. Pressure applying mechanism comprising a movable pressure applying member, a toggle connected to said member for applying pressure to a work piece, power operated mechanism for moving said toggle to straightened position in the pressure applying operation, a support for said toggle arranged to yield in response to the application of a light pressure to the work, and means operated by said power operated mechanism at a predetermined time in the movement of said toggle toward straightened position for resisting movement of said support until a predetermined high pressure has been applied to the work.

13. Pressure applying mechanism comprising a movable pressure applying member, a toggle connected to said member for applying pressure to a work piece, power operated mechanism for moving said toggle to straightened position in the pressure applying operation, a support for said toggle arranged to yield in response to the application of a light pressure to the work, said support including fluid pressure mechanism, a valve in control of said fluid pressure mechanism and operative upon movement into a predetermined position for resisting movement of the support, and cam operated mechanism controlled by said power operated mechanism for moving said valve into said predetermined position at a predetermined time in the movement of said toggle toward straightened position.

14. Pressure applying mechanism comprising a movable pressure applying member, a toggle connected to said member for applying pressure to a work piece, power operated mechanism for moving said toggle to straightened position in the pressure applying operation, a support for said toggle arranged to yield in response to the application of a light pressure to the work, said support including fluid pressure mechanism, a valve in control of said fluid pressure mechanism and operative upon movement into a predetermined position for resisting movement of the support, and cam operated mechanism controlled by said power operated mechanism for moving said valve into said predetermined position at a predetermined time in the movement of said toggle toward straightened position, said last named means including a yielding member permitting movement of said valve out of said position and yielding movement of said support in response to the application of a predetermined high pressure to the work.

15. In a pressure applying machine, twin mechanisms, each comprising a movable pressure applying member, a toggle connected to each member for applying pressure to a work piece, power operated mechanism for alternately moving said toggles to straightened positions in the pressure applying operation, a support for said toggles arranged to yield in response to the application of light pressure to the work, and means operative upon movement of either of said toggles a predetermined amount toward straightened position for restricting movement of said support until a predetermined high pressure has been applied to the work, said means including means for limiting the ultimate pressure applied to the work.

16. In a pressure applying machine, twin mechanisms each comprising a movable pressure applying member, a toggle connected to each member for applying pressure to a work piece, power operated mechanism for alternately moving said toggles to straightened positions in the pressure applying operation, a support for said toggles arranged to yield in response to the application of light pressure to the work, and means operative upon movement of either of said toggles a predetermined amount toward straightened position for restricting movement of said support until a predetermined high pressure has been applied to the work, said last named means including a fluid pressure device and a valve in control of said device for limiting the pressure applied thereby.

17. In a pressure applying machine, twin mechanisms, each comprising a movable pressure applying member, a toggle connected to each member for applying pressure to a work piece, power operated mechanism for moving said toggles to straightened positions in the pressure applying operation, a support for said toggles arranged to yield in response to the application of pressure to the work, means opposing yielding of said support comprising a fluid pressure device and a spring, a valve in control of said device to control the pressure applied thereby, means initially holding said valve in open position whereby movement of said support is restricted only by the spring, and means operative after either toggle has moved a predetermined amount toward straightened position for closing said valve whereby movement of the support is restricted additionally by said fluid pressure device.

18. In a pressure applying machine, twin mechanisms, each comprising a movable pressure applying member, a toggle connected to each member for applying pressure to a work piece, power operated mechanism for moving said toggles to straightened positions in the pressure applying operation, a support for said toggles arranged to yield in response to the application of pressure to the work, means opposing yielding of said support comprising a fluid pressure device and a spring, a valve in control of said device to control the pressure applied thereby, means initially holding said valve in open position whereby movement of said support is restricted only by the spring, and means operative after either toggle has moved a predetermined amount toward straightened position for closing said valve whereby movement of the support is restricted additionally by said fluid pressure device, said last named means including a spring arranged to permit opening of said valve in response to attainment of a predetermined pressure in the fluid pressure device thereby limiting the pressure applied to the work.

References Cited in the file of this patent UNITED STATES PATENTS 1,007,831 Whitney Nov. 7, 1911 1,180,626 Walker Apr. 25, 1916 1,301,898 Benjamin Apr. 29, 1919 1,549,243 Winkley Aug. 11, 1925 2,171,235 Gates et al Aug. 29, 1939 2,193,195 Gouldbourn et al Mar. 12, 1940 2,329,197 Hart Sept. 14, 1943 FOREIGN PATENTS 107,309 Australia Apr. 28, 1939 219,343 Germany Feb. 22, 1910

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