US3082725A

US3082725A - Press

Info

Publication number: US3082725A
Application number: US800576A
Authority: US
Inventors: Cannon Earl
Original assignee: FREEMAN CRAMPTON
Current assignee: FREEMAN CRAMPTON
Priority date: 1959-03-19
Filing date: 1959-03-19
Publication date: 1963-03-26
Anticipated expiration: 1980-03-26

Description

March 26, 1963 E. CANNON PRESS 2 Sheets-Sheet 1 INVENTOR.

Filed March 19, 1959 {Qa w AT TQRNEY March 26, 1963 E. CANNON 3,082,725

' PRESS Filed March 19, 1959 2 Sheets-Sheet 2 ATTORNEY 'blank to and from the machine.

United States Patent Ofihce 3,082,725 Patented Mar. 26, 1963 PRESS Earl Cannon, Birmingham, Mich., assignor of one-fourth to Freeman Crampton, Toledo, Ohio Filed Mar. 19, 1959, Ser. No. 800,576

16 Claims. (Cl. 11338) which the movable pressure exerting part is in constant motion are manifold. Among these advantages is that of eliminating operable connections, such as clutches and the like, between the driving source of power and the movable pressure exerting part. These connections are not only costly but in their function are subject to rapid wear and high maintenance cost. In addition, a pressure exerting part in constant motion takes full advantage of kinetic inertia of the masses involved and in movement to efiiciently utilize the power applied to and through the part to perform the pressing work. This, besides increasing efficiency, can also produce a more desirable continuity of movement in the movable pressure exerting part, a characteristic oft-times of importance in deep drawing of metal.

One great disadvantage of machines of the type mentioned having pressure producing parts in constant motion, however, resides in the limitation that such constant motion places upon feeding and withdrawing of a work If production speed is the desired goal, so that the machine must be operated at high speed, theopening and shutting time between the pressure exerting parts is usually insu'flicient to get successive work blanks to and from between the parts.

It is therefore essentially the purpose of my invention to propose a structure by which the advantages heretofore mentioned, as well as others, may be enjoyed by the art, without sacri fice to the disadvantage mentioned or to other disadvantages inherent in machines in earlier use.

My invention, in summary, so far as it concerns a pres sure exerting machine, resides in an arrangement of means and parts in a pressure exerting machine having a pair of pressure exerting parts of which, at least, one is movable and also having two operable means in tandem relation, operatively speaking, connected to and for moving the movable pressure exerting part relative to the other pressure exerting part and a source of power operatively connected to one of the operable means to produce continuous motion of that means and to the other operable means to produce intermittent motion of that means in synchrony with the continuous motion of the first mentioned means, the continuous motion of the first mentioned means being capable of accomplishing a power-pressing and work blank forming stroke of the movable pressure exerting part and the intermittent motion of the second mentioned means being capable of withdrawing the movable pressure exerting part relative to the other pressure exerting part adequately to allow work blank loading between the parts.

In so far as my invention concerns a drive for a pressure exerting machine of the kind mentioned, the invention resides, in summary, in an arrangement by which the two means for moving the movable pressure exerting part toward or away from the other pressure exerting part operate coincidentally to produce orderly advance and withdrawal of the movable pressure exerting part relative to the other pressure exerting part.

My invention has for one of its obects to eliminate the commonly provided clutch in the conventional crank or eccentric driven mechanical press, while using a press drive power means of conventional low cost power delivering capacity.

In the field of mechanically actuated pressure exerting machines, my invention teaches the construction of what may be called a clutchless press. A so called clutchless press is one in which the movable pressure exerting part is directly connected to a constantly'applied source of power, such as the driving motor. However, in order to load or remove work in the conventional clutchless press, it has been necessary to stop the motor when the pressure exerting parts were apart and then restart the motor to resume operations.

Another object of my invention is to provide a pressure exerting machine, such as a press, having a short power and work forming stroke of its movable pressure exerting part, permitting moving the movable pressure exerting member at a high speed, particularly in the power or work forming stroke.

Still another object of my invention is to provide a pressure exerting machine, such as a press, having a pair of pressure exerting parts of which one is movable relative to the other and in which the stroke of the movable toward the other pressure exerting part may be used entirely in producing pressure on the work. .When this objective is met in a mechanically driven press, a shorter crank may be used to secure a more rigid drive to obtain greater working pressure available at the mid-stroke phase of movement of the movable pressure exerting part toward the other.

A still further object of my invention is to provide a pressure exerting machine having a constantly moving movable pressure exerting part, allowing, notwithstanding, long periods of work blank feed.

A still further object of my invention is to provide, in

a pressure exerting machine having two pressure exerting parts of which at least one is a movable pressure exerting part, an independently operable plurality of operable means for moving the movable pressure exerting part relative to the other pressure exerting part, the compound operation of said means being determinative of the time and distance that the movable pressure exerting part moves toward and away from the other pressure exerting art. p One of the more specific objects of my invention is to provide a pressure exerting machine that, when adapted to the metal forming arts, may be used to good advantage not only in blanking and drawing but also to die forging. When so adapted to the last mentioned type operation, embodiments of my invention have the advantages of eliminating clutch difiiculties so prevalent in such apparatus and, because of the short power work-performing stroke possible, deliver a rapid series of strokes to the work from a much more rugged backing structure notwithstanding the greater potential ability to withdraw the hammer further to allow work removal and loading than is possible in machines of the prior art.

Another of the specific objects of my invention is to provide, in a pressure exerting machine having a pair of pressure exerting parts of which at least one is movable relative to the other, an arrangement of a pair of means for moving the movable pressure exerting part relative to the other of which means, one is intermittently operating under only nominal or no load and thus easily started and stopped and the other means is continuously operating and capable of exerting a high degree of work pressure and is rendered effective relative to the other pressure exerting part, however, only when positioned to do so by the intermittently operating means.

My invention has for further objects those of providing other advantageous structures and arrangements which will appear from the following description and from an examination of the accompanying drawings. Pressure exerting machines containing my invention may take various forms,

- one of which, now appearing to me to be the best mode of carrying out my invention, is described hereinafter and is shown in accompanying drawings. In making such description and referring to the drawings during the course thereof, I do not imply that I am unaware that there are variations from the structure described or shown which also embody my invention nor do I disclaim such vari ations as beyond the contemplation of my invention made manifest herein.

FIG. 1 of the accompanying drawings illustrates a view of a front elevation of a pressure exerting machine embodying my invention. The particular pressure exerting machine selected by me to illustrate the invention is a mechanical sheet metal press.

FIG, 2 of the drawings illustrates an end view of the pressure exerting machine shown in FIG. 1, shown partially cut away and showing certain parts of the machine after they have moved from the positions thereof shown in FIG. 1.

FIG. 3 of the drawings illustrates an enlarged view of one of a pair of timers shown in FIG. 1 that are adapted for initiating movement of the movable pressure exerting part moving means, first in one direction and subsequently in the other direction, relative to'the other pressure exerting part.

FIG. 4 of the drawings shows an enlarged perspective view of a second pair of timers, shown in FIG. 2, that are adapted for terminating movements initiated by the pair of timers mentioned in describing FIG. 3 of the accompanying drawings.

FIG. 5 of the accompanying drawing illustrates, diagrammatically, the circuits by which motors shown in FIGS. 1 and 2 of the drawings are driven and controlled by the timers shown in FIGS. 3 and 4 of the drawings.

FIG. 6 is a motion diagram showing the timed relations between individual and a composite of the movements induced by each of the two movable pressure part moving means.

The embodiment of my invention, selected for'purposes of illustration, comprises a mechanically driven sheet metal press 10 driven by suitable power means that are operatively connected to the source of power S and controlled by circuits by means of two pairs of structurally

similar timers

140 and 1400 and 170 and 1700.

The Sheet Metal Press 10 The pressure exerting machine, shown in the accompanying drawings, is of the type commonly referred to as a mechanically driven, eccentric operated, sheet metal press and is generally indicated at 10. This press has a base 11 from the opposite ends of which suitable uprights 12 extend vertically to support a crown 14. The base 11, crown 14 and uprights 12 are connected together by the usual tensioned tie rods 15, extending through the uprights 12.

The base 11 provides a suitable bed 16 on which a bolster 17 and metal forming dies and cushions (not shown) may be located, in the manner well known in the art. The bed 16, with its bolster 17, is designed to operate as a pressure exerting part, in conjunction with a movable pressure exerting part embodied in a plunger 13.

The plunger 18 extends between the uprights 12 and slidably engages ways 19. The ways 19 extend along the uprights so that plunger 18 is supported for reciprocable movement toward and away from the bed 16 and bolster 17. Like the bed supported bolster 17, the plunger 18 may mount metal forming dies (not shown) designed to cooperate with the bolster supported dies to shape work blanks (not shown) that may be placed between the rnov able pressure exerting plunger part 13 and the fixed pressure exerting bed and

bolster part

16 and 17.

In order to counterbalance the weight exerted by the plunger 18 tending to cause the plunger to fall, independent of being driven to a position of work with the bed supported bolster 17, a plurality of well known counterbalance air cylinders 21) are provided. The cylinders 20 are mounted on the crown 14 and by rods 21 are connected to the plunger 18. The movement of the plunger 18 toward the

bed

16 and 17 is thus made a consequence, in part, of the position of a slide 22 with reference to the bed 16 of the press.

The slide 22, like the plunger 18, extends between the uprights 12 in a position between the plunger 18 and the crown 14. The slide 22 slidably engages the ways 19 and is movable along such ways. To counterbalance the weight of the slide 22, a suitable air cushion means 23, well known in the art and mounted on the crown 14, is connected to the slide 22 by a rod 24. The slide 22, in order to effect movement of the plunger 18, relative to the bed 16 is connected to the plunger.

The means for connecting the plunger 18 to the slide 22, in the form shown, comprises a pair of links 25 which, by straps 26, are connected to eccentric shafts 27 journalled on the slide 22. It will be seen that rotation of the shafts 27 will cause the links 25 to reciprocate the plunger 18 relative to the slide 22 and the bed 15 and bolster 17.

To drive the shafts 27, I provide a constant operating electric motor 28. The motor 28 is suitably mounted on the slide 22 and by gear trains having gears 29 is operatively connected to each of the shafts 27. The motor 28 receives power from the source of power S through one of the circuits which will be described later herein.

The elfectiveness of the plunger 18 in its motion, due to the rotation of the shafts 27, in doing work on a work blank, depends upon the position of the slide 22 in relation to the bed 16 and bolster 17. Hence, I provide means for moving the slide 22 which I shall now describe. Preferably, the uprights 12 have openings 30 that extend vertically and lengthwise of the uprights. The slide 22 has extensions 31 at opposite ends of the slide that extend through the openings 30. The extensions 31 mount pins 32 that each pivotally engage one end of one of two links 33 extending vertically and exterior of the uprights 12, from a point on one side of the bed 16 to a point on the opposite side of the bed 16. The links 33 are pivotally connected by pins 34 to cranks 35 mounted on shafts 36. The shafts 36 are journalled, as at 37 on the base 11. Intermittently operated

electric motors

38 and 381, receiving power through the circuits to be hereinafter described and mounted on the base 11, serve to drive and rotate the shafts 36 through suitable gear trains having gears 39 mounted on the base 11.

Thus, when the shafts 36 are rotated the links 33, connected to the slide extensions 31, will be drawn in one direction relative to the base 11, such as toward the base and then moved in the opposite direction, such as away from the base 11. This will move the slide 22 from a position shown in FIG. 1 of the drawings first nearer the bed 16 and bolster 17, to a position shown in FIG. 2 of the drawings at which time rotation of the plunger driving shafts 27 will cause the plunger 18 to engage the bolster 17 and work on a blank therebetween. When, however, the movement of the links 33 move the slide away from the bed 16 and bolster 17 the rotation of the shafts 27 will be ineffectual to cause the plunger 18 to engage the bolster. This will enable a work blank to be removed from between the plunger 18 and bolster 17 and to be replaced by a yet unworked work blank.

To summarize, in reference to the potential operability of the structure so far described, the pressure exerting press 10 has, in the bed 16 or its supported bolster 17 and the movable plunger 18, a pair of pressure exerting parts in which the plunger 18 is movable relative to the bed 16 and bolster 17; and, in the links 25', the motor 28 and the slide 22 with its movable links 33, the cranks 25- and

motors

38 and 381, a pair of operable means, in tandem, connected to the plunger 18 for moving the same relative to the immovable bed supported bolster part 17; the motors being operatively c-onnectable through circuits to a source of power S to produce continuous motion of the motor 28 and, thus, of the plunger 18 rela tive to the slide 22 and intermittent motion of the

motors

38 and 381, and thus of the slide 22 and the plunger 18 so that the range of reciprocation of the plunger 18 is at one time, one in which the plunger at one point engages the bolster 17 to do work and, at another time, is one in which the plunger 18 does not engage the bolster but is rather retained so that the plunger :18 is spaced from the bolster 17.

The Circuits The circuits, by which the

motors

28 and 38 and 381 are caused to drive the gears in gear trains 29 and 39, proceed from the source of power S by way of main lines S-l, S-2 and S-3. The main lines S1, S-2 and S-3 are connected by suitable electric

motor starter controllers

51 and 52 well known in the art to

motors

28 and 38 and 381. The operations of the

starter controllers

51 and 52 to effect or break such connections of the motors with the source of power are controlled by pilot circuits having

principal lines

53 and 54 leading from main line S1 and main line S-3, respectively. The flow of current through the pilot circuits is made to depend on the position-on or oiiof a manually operated main switch 55. The switch 55, in its closed position, bridges two pairs of contacts 56 and 57. Contacts 56, when bridged, connect a line 58 leading from principal line 53 to a line 59 and to the motor starter-controller 51 which by line 60 is connected to the other principal line 54 to complete the circuit back to main line S-3. Contacts 57, when bridged, connect a line 61, leading from principal line 53 to a line 62 of the circuit that operated the motor starter-controller 52 in a desired synchrony with movements of the plunger 18 produced by the continuously operating motor 28 started by the starter-controller 51.

A manually operated switch 70 having two pairs of contacts 71 and 72 controls the flow of current to the circuit operating the starter-controller 52. Line 62 from the main switch 55 connects contacts 57, of that switch, with contacts 71 of the switch 70. When switches 55 and 70 are closed, a circuit through contacts 71 leading over a line 73, a line 74, through a master relay coil 75 to return along principal line 54 to main line S-3 is made. Energization of the master relay coil 75 causes closure and retention of normally open

master relay contact

751, 752, and 753. Relay contacts 751 by a line 76 and a normally closed safety stop switch 77 and a line 78 connect, when closed, principal line 53 to the line 74 through a line 79. Those skilled in the art will at once recognize that in the provision of the stop switch 77 there is a means by which any holding circuit through the master relay coil 75 may be interrupted, notwithstanding a closed position of switch 70 at that time.

Relay contacts 752, through a line 88, connect the line 79 to one side of the contacts 72 of switch 70 and, through now closed master relay contacts 751, the line 78, normally closed stop switch 77 and the line 76, communicate with the principal line 53. The remaining master relay contacts 753 connect, when closed, the return principal line 54 and a supplementary return line 541.

Thus contacts 72 of switch 70 are connected on one side to principal line 53 through line 76, normally closed stop switch 77, line 78 and the now closed but normally open master relay contacts 751, lines 79 and 80 and master relay contacts 752. On the other side, contacts 72 connect through a line 81, a line 8-2 with a relay coil 83- connected to supplementary return line 541 and through the now closed master relay contacts 753 to the return principal line 54. This causes the relay coil 83 to become energized to close the normally open relay con tacts 831 and 832 thereof and to open normally closed

contacts

833 and 834 thereof. The closure of relay contacts 831 establishes a relay hold circuit on one side through a line 84, the lines and 78, now closed master relay contacts 751, stop switch 77, line 76 to line 53 which circuit is made to depend on the stop switch 77 remaining closed and on the other line 82, coil 83, line 541, now closed relay contacts 753 and line 54. The opening of normally

closed relay contacts

833 and 834 locks out operation of other circuits which will be ex plained as this description progresses.

The closing, however, of the normally open relay contacts 832 prepares a circuit comprising principal line 53, line 76, stop switch 77, line 78, contacts 751, line 80, line 85, now closed contacts 832, a limit switch 86, a line 88 to a relay coil 87, line 541 and through contacts 7 53 to return principal line 54. Line 88 includes in circuit two pairs of normally closed relay contacts which will be identified later The excitation of the relay coil 87 causes closure of normally

open relay contacts

871, 872 and 873. Closure of relay contacts 871 establishes a relay holding circuit comprising line 53 and 7 6, stop switch 77, line 78, closed master relay contacts 751 lines 79 and 80 to a line 92, a line 93, line 88, relay coil 87, line 541, master relay contacts 753 to return principal line 54.

Closure of the

other relay contacts

872 and 873 completes a circuit through the motor starter-controller 52 which includes principal line 53, line 93, relay contacts 872, motor starter-controller 52, a line 94, relay contacts 873, line 541, master relay contacts 753 and return principal line 54. This last named circuit energizes the motor starter-controller 52 to connect

motors

38 and 381 to the source of power S. Thus, the starting of

motors

38 and 381 is made to depend on the closing of the normally open limit switch 86. The construction of the limit switch 86 which constitutes part of the timer will be described when the timer is later described. It will suffice the purpose of the moment to say that the limit switch 86 is operated in synchronous relation with the movement of the plunger 18 to move the slide 22 through a stroke relative to the bolster 17 and thus to bring the plunger 18 into a range of reciprocation relative thereto, such as a range in which the plunger 18 engages the bolster -l17 or dies thereon, at one point in the reciprocation of the plunger.

In order to disconnect the

motors

38 and 381 from the source of power S, such as when the slide 22 reaches a desired position to support the plunger 18 for reciprocation through a certain range, another circuit controlled by a limit switch 96 is provided. This circuit begins with a line 97 and extends from the line 80 that is connected to principal line 53 and extends through the stop switch 77 circuit previously described. Line 97 is connected by the limit switch 96, when closed, to a line 98 and to a relay coil -99 connected to the line 541 and by the closed master relay contacts 753 to the return principal line 54. Closure of this circuit excites the relay'coil 99 which has normally closed

contacts

991, 992 and normally

open contacts

993 and 994.

The normally closed

contacts

991 and 992 operated by the relay coil 99 are in

lines

82 and 88 and their opening by energization of the relay coil 99, opens the circuits to relay

coils

83 and 87. Opening of relay coil 83 circuit allows the closed but normally open relay contacts 831 and 832 to open and the open but normally

closed relay contacts

833 and 834 to close. The opening of relay contacts 832 breaks one of the circuits through relay coil 87 and allows the closed but normally

open relay contacts

871, 872 and 873 to open. Opening of relay contacts 87 2 and 873 breaks the flow of current to the motor starter-controller 53 which interrupts the flow of current from S to the

motors

38 and 381, allowing the slide 22 to come to rest.

In addition, energization of the relay coil 99 in closing the normally

open contacts

993 and 994 establishes circuit conditions by which the

motors

38 and 381 may be reconnected to the source of power S. The contacts 993 of the relay coil 99 connect line 97 through a line 100, a line 101 and a line 102 in a holding paralled circuit around the limit switch 96. The contacts 994, closed by energization of relay coil 99, set up a circuit from the line 100 to a line 103 of a circuit adapted to reconnect the

motors

38 and 381 to the source S. The establishment of this circuit becomes important as when it is desired to move the slide 22 automatically in synchrony with the momentary movement of the plunger 18 and so that the reciprocating plunger 18 will subsequently reciprocate through a range of reciprocation spaced from the bolster 17. This circuit is controlled by another limit switch 105 in line 103. Closure of the limit switch 105 establishes a circuit allowing current to flow from principal line 53, line 76, the stop switch 77, line 78, closed relay contacts 751,

lines

80, 97, 100 and 103, through closed relay contacts 994, to and through (when closed) switch 105, a line 106 and a relay coil 107, line 541, closed relay contacts 753 to the return principal line 54. The flow of current through the relay coil 107 closes normally

open relay contacts

1071, 1072 and 1073 thereof.

Contacts 1071 are in a holding circuit, paralled to the limit switch 105 that comprises a line 109 leading from the line 100 to

lines

110 and 106 and bridging the line 103, now closed normally open relay contacts 994 and the limit switch 105. Contacts 1072 form part of a bridging parallel circuit to the normally closed now open relay contacts 992. This circuit consists of a line 111 leading from the line 88 from a point therein between the limit switch 86 and contacts 992 to a line 112 connecting with a point on the line 88 on the other side of the contacts 992. Likewise, contacts 1073 control a circuit having a line 114 leading from the line 80 and a line 115 connecting with the line 93 and forming a circuit in paralled to the limit switch 86 and the normally open relay contacts 832.

The closure of the normally

open relay contacts

1072 and 1073 reestablishes a flow of current through the relay coil 87 causing closure of the

relay contacts

872 and 873. Thus, current again flows through motor starter-controller 52 which is then actuated to connect

motors

38 and 381 to the source of power S, as transmitted therefrom by the main lines S-l, S-2 and S-3. Activation of the

motors

38 and 381 causes the slide 22 to move and moves the plunger 18 toward a position supporting the latter for reciprocation through another range of reciprocation, such as one well spaced from the bolster 17 as to allow removal and replacement of work between the plunger and bolster.

The movement of the slide 22 continues as long as the

motors

38 and 381 remain connected to the source of power S. To disconnect the

motors

38 and 381 and thus allow the slide 22 to come to rest at some desired position, I provide a further limit switch 118 and a circuit including a line 119 leading from the line 80, the normally and now closed relay contacts 834, a line 120 and a relay coil 117 to the line 541. Relay coil 117 has normally closed relay contacts 1171 and 1172. Contacts 1172 are in the line 97 and form therewith a part of the circuit of relay coil 99. Opening of contacts 1172 opens the circuit of the coil 99 and through its contacts the circuits of coil 107 whose contacts 1073 control coil 87. Contacts 1171 also form a part of the circuit of the relay coil 87 so that, when the relay coil 117 is energized, the contacts 117 1 and 1172 are opened, opening the circuit through relay coil 87. This causes the then closed but normally

open relay contacts

872 and 873 to return to their normally open relation and thereby interrupt the How of current through the motor starter/ controller 52. Discontinuance of current through the motor starter/controller 52 deactivates the connection therethrough to the

motors

38 and 381 from the source of power S and the motors stop. The slide 22 also stops, pending the actuation of the limit switch 86 which actuation initiates a repeat of the cycle of operations described.

A discontinuance of a repeat in the cycle may be had by operation of the switch 70 to open the circuits that switch controls. However, if it becomes desirable to stop a cycle at some intermediate stage thereof, the stop button 77 may be actuated. If this should be done, after the cycle has passed through the stage at which the limit switch 96 has been operated, the further continuity of the described cycle depends on actuation of a supplementary switch 122. Switch 122 controls circuits, one of which comprises a line 123 leading from the principal line 53, a line 124, the line 74, main relay coil 75 and the return principal line 54. Energization of this circuit re-establishes the heretofore described circuits interrupted by opening of the stop switch 77.

Another circuit made by the switch 122 includes a line 125 leading from line 100 and a line 126 connecting through normally closed relay contacts 833 and the line 102 with the line 98 of relay coil 99. This circuit is parallel to the limit switch 96 circuit and enables the broken continuity of the cycle to be picked up and continued in the sequence and manner heretofore described.

The activations of the

various limit switches

86, 96, 105, and .1 18 are made to occur at times in synchrony with phases in the movement of the plunger 18 to produce desired dwell periods, operatively speaking, for loading and unloading work blanks between the plunger 18 and bolster 17, without interrupting the continued reciprocation of the plunger 18. The synchrony mentioned is obtained by timers and 1400 and and 1700.

The Timers In the embodiment shown in the accompanying drawing, the

timers

140 and 1400 which assure the synchrony of movement of the slide 22 in relation to the movement of the plunger 18 are operated by the movement of the shafts 27 which cause reciprocation of the plunger 18 relative to the slide 22. The

timers

170 and 1700 which allow the slide 22 to come to rest and dwell at appropriate times in the movement of the plunger 18 are operated by the movement of one of the crank shafts 36.

One timer 140 insures that the

motors

38 and 381 moving the slide 22 start at a time in the movement of the plunger 18 so that in the interim between their starting and the time it takes to move the side 22 a full stroke, such as one toward the bolster 17, the movement of the plunger 18 will, at the time the slide 22 reaches the end of such stroke, be moving in a substantially coinciding direction relative to the bolster 17 with the movement of the slide 22. This is illustrated in FIG. 6 of the accompanying drawings wherein a continous sine curve line 182 diagrammatically illustrates the continuous movement of the plunger 18 relative to the bed 16 and line 222 illustrates, diagrammatically, a periodic movement of the slide 22 relative to the bed 16.

In order to secure the composite movement of both plunger and slide toward the bed 16, which movement is indicated diagrammatically by line 602, shown in FIG. 6, the timer 140 starts the motors 38 and 381 (disregarding inertia) at a point 603 on line 182 in the movement of the plunger 18.

Then, the slide 22 will reach a point 604 on line 222, that is the nearest point it moves toward the bed 16, at a time just prior to the time the plunger 18 reaches point 605 on line 182. The composite movement thus produced causes the slide and plunger to elfect a plunger movement in the manner diagrammatically illustrated by line 602 shown in FIG. 6 between points 603 604 and 605 on line 602 and which are vertically aligned and are therefore coincident with the previously mentioned

points

603, 604 and 605, respectively.

The other timer, indicated at 1400, insures that the

motors

38 and 381 start to move the slide 22a full stroke, in the opposite direction from the direction of the stroke just described, only after the plunger 18 has completed its full stroke toward the bed 16 and bolster 17 and while the plunger is beginning its immediately subsequent retracting stroke. This also is illustrated in FIG. 6 of the accompanying drawings. There it is shown, diagrammatically, that in order to secure the return composite movement of plunger 18 and slide 22 as shown by line 602, the timer 1400 starts the motors 38 and 381 (disregarding inertia) at a point 606 on line 222 in the movement of the slide 22. Point 606 roughly coincides with or is just a shade subsequent to point 605 in the plan of operation of the described embodiment.

When so timed, the slide 22 reaches point 607 on line 222, which is furtherest point it moves away from the bed 16, at a time roughtly coincident to the time the plunger 18 reaches point 608 on line 182. The composite movement thus produced causes the slide and the plunger to produce the return movement illustrated by the portion of line 602 of FIG. 6 between

points

606 and 607 and 608 on line 602 which are vertically aligned duplicates of the heretofore mentioned

points

606, 607 and 608.

The timers 1-40 and 1400 may be structurally and, within each of their individual structures, functionally identical. The timer 140 is operated by one and the timer 1400 by the other of the shafts 27. A description of the parts of the timer 140 will serve to describe the parts of the timer 1400, like parts in the timer 1400 bearing four place legend numerals corresponding in ending to those used in describing the timer 140- parts of corresponding nature and structure; for example, a part in timer 1400 which is a counterpart to a part of timer 140 bearing legend 144 will, in the description which follows, bear legend numeral 1404 and so on. Where differences appear, specific reference will be made thereto. One end 271 of one shaft 27 extends beyond a face 221 of the slide 22. A bushing 143 surrounds the end 271 and supports a bracket 144 that has an annular bearing portion 145 an arm portion 146 and a worm gear sector portion 147. The arm and gear sector portions are disposed in approximate diametrically opposed relation to each other on the bearing portion 145.

The arm portion 146 supports a switch box 148 enclosing one of the

switches

86 and 105. Extending from and pivotally mounted on the switch box 148 is a switch operating lever 149 that has end roller 150. When the lever 149 is moved in one direction the switch within the switch box 148 will be closed, establishing circuits heretofore described. A means for moving the lever 149 embodied in a cam member 151 that is mounted, as by suitable bolts 152, on the end 271 of the shaft 27. The position of the cam member 151 is such that, as the shaft rotates, the cam member will rotate with the shaft and the roller 150 on the switch operating lever 149 will ride the cam surface of the cam member 151. When a high point 153 of the cam member 151 engages the roller 150, the lever 149 will be moved to close the switch in the switch box 148.

Assuming that the switch box 148 contains the switch 86 and that manually operated starting switches 55 and 70 have been closed, momentary closure of switch 86 within the switch box establishes circuits, causes current to flow through coil 87, closing normally

open contacts

872 and 873 to activate the motor starter/controller 52. This connects the

motors

38 and 381 to the source of power until switch 96 is operated. In order that the switch 86 may be operated to obtain desired synchrony between the movements of the plunger 18 and slide 22, the position of the arm portion 146 supporting the switch box 148 and its switch operating lever 149 may be varied arcuately about the axis of the shaft 27. T is variation may be effected by some suitable adjusting means, such as the hand operated worm 155 which meshes with the gear sector portion 147. The worm 155 is journ'alled in straps 156 on the face 221 of the slide 21. The worm 155 is keyed to a shaft 15-7 likewise keyed to a suitable hand wheel 158 or other shaft turning means. Hence, by turning the shaft 157 and worm 155, the bracket 144 may be caused to rotate on its bearing portion 145 about the shaft 27, one way or another, to locate the arm portion 146 and switch box 148 it supports in any desired adjusted position in an orbit whose axis coincides with that of the shaft 27. By thus adjusting the bracket 144, the switch operating arm 149 may be positioned to be actuated by the cam high point 153 at any desired point in the rotation of the shaft 27 and thus at any desired point in the lineal movement of the plunger 18 reciprocated by rotation of the shafts 27.

With suitable adjustment, the activation of the switch operating arm 149 and switch 86 to initiate the movement of the slide 22 may be synchronized with the movement of the plunger 18 to produce a compound of movements in a desired direction and order such as the one shown in FIG. 6 of the accompanying drawings. As contemplated in the presently described embodiment, the switch 86 is activated to begin the slide movement downward toward the bed 16 and so that in the interim of time it takes the slide 22 to reach the lowest point of its stroke, relative to the slide 22, the plunger 18 will be moving toward the bed 16.

In order to disconnect the

motors

38 and 381 from the source of power at a desired point in the movement of the slide 22 following initiation of its movement by switch 86, the switch 96 is operated in the structure shown herein by means on one of the shafts 36. The particular means shown is embodied in a timer 170 shown in FIG. 4 of the accompanying drawings. The timer 170 includes a cam 171 mounted on one of the shafts 36 so as to move through a path to engage a roller 172 on the end of a switch operating lever 173 pivotally mounted on a switch box 174 containing switch 96. The switch box 174 is adjustably mounted, as by suitable bolts 175 on the base 11 of the press. The cam 171 in consequence of the rotation of the shaft 36, engages the roller 172 and moves the switch operating lever 173 to close the switch 96 at a time which coincides with that time at which the cranks 35 have moved the slide 22 to one extreme of its movement, such as, in the structure shown, to that ex treme nearest to the bed 16. Operation of the switch 96 establishes circuits, previously described, which disconnect the

motors

38 and 381 from the source of power. Thus, the slide 22 begins on operation of switch 96, a dwell period. During the dwell period of the slide 22, the plunger 18 completes its movement in the direction toward the bed 16.

As the plunger 18 completes its movement aforesaid, the switch 105 is operated. The switch 105 is operated by the timer 1440. Timer 1400, like timer 140, has a bracket 1440 with a bearing portion 1450 and an arm portion 1460 supporting a switch box 1480 for housing the switch 105. The timer 1400 is preferably mounted on the end of the other crank shaft 27 that is a contemporary to the shaft 27 on which the timer 140 is mounted. As will be noted from FIG. 1 of the ac companying drawings, the arm 1460 supports the switch box 1480 containing the switch 105 in a position that a switch operating lever 1490 pivotally mounted on the box 1480 and supporting a roller 1500 may be engaged by a cam 1510 having a high point 1530- and being mounted, as by bolts 1520, on the end of the other shaft 27. The high point 1503 of cam 1501, it will be noted, is diametrically opposite extending from its shaft 27 to that in which the high point 153 of cam 151 extends from its shaft 27. Now, as the shafts 27 rotate to move the plunger 18 through the just described closing stages of its movement toward the bed 16', the cam high point 1503 engages the roller 1500 and through the switch operating lever 1409 causes switch to close.

Closure of the switch 105 establishes circuits heretofore described that actuate the motor controller/starter 52 to connect

motors

38 and 381 with the source of power. The slide 22 then begins to move, in the embodiment shown, away from the bed 16 moving the plunger 18, whose movement at that stage is also away from the bed.

Preferably, the movement of the slide 22 continues until, as in the form here described, the slide reaches its most remote position away from the bed 16. In this position, the plunger 18, even though continuing to reciprocate, will, in all of its extremes of movement, be sufficiently spaced from the bed 16 to allow work that may be on the bed to be removed and new work to be placed between the plunger and the bed for subsequent workmg.

The slide 22 is brought to a stop at this position to dwell until, for example, the switch 70 is again closed to initiate a new cycle. In order to bring the slide 22 to a stop, the switch 118 needs to be closed. This, as in the case of closing switch Q6, may be effected by the companion timer 1700. The timer 1700, like timer 170 includes a cam 1701 mounted on and rotating with the shaft 36 on which cam 171 is mounted. The cam 1701 is positioned so that rotation of the shaft 36 moves the cam 1701 in a path to engage and move a roller 1702 on the end of a switch operating lever 1703 pivotally mounted on a switch box 1704 containing the switch 118. The switch operating lever 1703 is operatively connected to the movable switch member of the switch 118 so that when the lever is moved in one direction the switch 118 will be closed.

The switch box 1704 is adjustably mounted, as by bolts 1705 on the press base 11. By adjusting the position of the switch box 1704 on the base 11, the moment of operation of the switch 118 may be timed to synchronize with that at which the cranks 35 moving the slide 22 to complete its movement to an extreme of the slide reciprocation, such as in the selected press, a position furtherest from the bed.

As was described in connection with the circuits, closure of the switch 118 establishes circuits that are operative to disconnect the

motors

38 and 381 from the source of power. The slide 22 begins a dwell and continues for such a time allowing unloading and reloading of the work and until switch 70 is again operated. Those skilled in the art recognize that switch 70 may be operatively connected to and be automatically operated after a prescribed interval by a conventional timer device or, if a work feeder be included in the assembly, by the work feeder apparatus itself, after completion of the work feed.

Operation Those skilled in the art will appreciate that, in use, the switch 55, when closed, connects the plunger operating motor 28 to the source of power through the medium of the starter/controller '51. This provides a constant flow of current to the motor 28 with the result that plunger 18 is driven in an uninterrupted series of reciprocations, such as are diagrammatically shown by line 182 in FIG. 6 of the drawings.

This reciprocation of the plunger 18 is always with reference to the slide 22, however, so that when it is desired to change the site of the range of reciprocation of the plunger 18, movement of the slide 22 is required. When the slide 22 is at the position shown in FIG. 1 of the drawings, the continuous reciprocation of the plunger 18 is through a range that is spaced from the bolster 17 and bed 16 sufficiently that the plunger 18 does not approach the bolster and bed closer than a space adequate to enable the operator to place a work blank for work on the bolster. This position is called the starting position and the following description of operation proceeds from that position.

Having placed the work blank on dies as may be supported on the bolster 17, the operator closes switch 70. Automatically at a proper time in synchrony with the continuous reciprocation of the plunger 18, switch 86 is closed by timer 140 resulting in a compound movement of slide and plunger represented by the portion of line 602 in FIG. 6 of the drawings extending from point 603 on line 602 to 605 on line 602.

At this point the slide 18 and plunger 22 will be in positions shown in FIG. 2 of the drawings. In these positions, a previously placed work blank is being engaged by the plunger 18 to be worked against bolster supported dies.

During the course of movement to these positions and at the point 604 on :line 602 of FIG. 6, the timer 170 actuates switch 96 causing the slide 22 to discontinue its movement and to dwell while the plunger 18 completes its movement indicated by the portion of line 602 between

points

604 and 605 As the plunger 18 completes such movement, timer 1400 actuates switch 105 causing slide 22 to discontinue its dwell and to begin to move upward and away from the bolster and bed. This movement of the slide and the coincident movement of the plunger 18 produces a compound movement of slide and plunger indicated diagrammatically by the portion of line 602 in FIG. 6 extending from point 605 /606 to point 607 /608 This compound movement causes the return of the slide and plunger to the mentioned starting position shown in FIG. 1 of the drawings. Now, the worked work blank may be removed from between the bolster and plunger and, if desired, an unworked work blank be placed in position ready for work. Ample time is allowed for this removal and reloading of work blanks because as the slide 22 moved upward, the timer 1700 operates switch 118 disconnecting the

motors

38 and 381 driving the slide 22. Thus, the slide 22 comes to rest and begins to dwell at point 607 on line 602 of FIG. 6 until the operator again closes switch 70 to initiate a new cycle.

Thus, it will be apparent that my invention teaches that by utilizing a pair of pressure producing parts of which, at least, one is movable and having two operable means in tandem for moving the movable pressure exerting part and means connecting to each said operable means for actuating one continuously and the other intermittently in synchrony, however, with the continuous movement of the continuously moving means, a press may be constructed that obviates the need for clutching or for stopping and starting and without sacrifice of the freedom in time in which to place a work blank for working or to remove a work blank following working.

I claim:

1. In a press or the like having a frame, a bed on the frame, a slide in sliding engagement with the frame for movement between two points spaced different distances from the bed, movable means in movable engagement with the slide and the frame and adapted in moving to reciprocate the slide between the mentioned points, a plunger in sliding engagement with the frame for movement toward and away from the bed, and a second movable means in movable engagement with the plunger and the slide and adapted in moving to reciprocate the plunger relative to the slide and when the slide is at the point of the mentioned points nearer the bed to support the plunger so that at one stage of the plungers reciprocation it engages the bed; the combination therewith of a source of power, a motor on the slide in operatively connecting engagement with the source of power and with the second movable means and adapted to continuously operate the second movable means to reciprocate the plunger relative to the slide, a second motor on the frame and in operatively connecting engagement with the first named movable means, and actuatable means in operatively connecting engagement with the second motor and the source of power and operative when actuated to connect the second motor to the source of power, and a movable element 13 in movable engagement with the frame for actuating the actuatable means and being in a position to be engaged and moved by the movement of the second movable means as the same moves the plunger and so that a connection of the second motor to the source of power to actuate the first named movable means to move the slide and plunger toward the bed occurs at a time in the plunger movement between the start and end of a stroke of the plunger toward the bed and so that immediately successive thereto the plunger in response to operation of the second movable means moves to complete its movement toward the bed at a time subsequent to the slide completing its movement toward the bed in response to operation of the first named movable means.

2. In a press or the like as described in claim 1 having in addition thereto, a second movable element in movable engagement with the frame at a position to be engaged and moved by the first named movable means at a time when the same has moved the slide to the point nearer the bed and adapted when so moved to disconnect the second motor from the source of power thereby allowing the slide to dwell.

3. In a press or the like as described in claim 2 having in addition thereto a third movable element in movable engagement with the frame at a position to be engaged and moved by the second movable means as the same in addition thereto, a fourth movable element in movable engagement with the frame at a position to be engaged and moved by the first named movable means at a time when the same has moved the slide to the point remote from the bed, the fourth movable element adapted when so moved to disconnect the second motor from the source of power thereby allowing the slide to dwell.

5. In a press or the like as described in claim 4 in which each of the severally named movable means includes a cam in engagement with and adapted to be moved by the movable means and each of the severally named movable elements comprises a movable switch part connected with the source of power and in a position to be engaged and moved by one of said cams and there being, in addition, means connected to each switch and to the second motor for rendering each switch operative in sequence when moved to connect and disconnect the second motor to and from the source of power.

6. In a press of the like as described in claim 5 having in addition thereto a manually operable part in operative connection with the source of power and the last named means operable to render the last named means operative.

7. A press or the like having a frame, a bed on the frame, a slide in sliding engagement with the frame, slide operating means operatively connected to the slide and to the frame and adapted on actuation to move the slide between two points on the frame spaced difierent distances from the bed, a plunger in sliding engagement with the frame, plunger operating means operatively connected to the plunger and to the slide and adapted when actuated to reciprocate the plunger relative to the slide and at one stage of the plunger reciprocation while the slide is at one of the points to support the plunger for engaging the bed and while the slide is at the other point to support the plunger for reciprocation at all stages thereof spaced from the bed, and motor means independent to and operatively connected to each of the slide and plunger operating means for actuating the same, the motor means operatively connected to the plunger operating means being continuously operating and capable of accomplishing power pressing strokes of the plunger, and

the motor means operatively connected to the slide operating means being intermittently operating in synchrony with the plunger pressing strokes to withdraw the slide and plunger from the bed after a pressing stroke of the plunger thus to allow work blank loading on the bed and to advance the slide and plunger toward the bed prior to a pressing stroke of the plunger to allow pressing on the work blank.

8. In a pressure exerting machine having a frame, a pressure withstanding part on the frame, a plunger in movable engagement with the frame, movable means in engagement with the plunger for moving the plunger, a source of power in operative connection with the movable means for continuously moving the same to cause reciprocation of the plunger, and a second movable means in engagement with the frame and the first named movable means for moving the same and the plunger relative to the pressure withstanding part and between a plurality of positions with respect thereto, one of the positions being such that movement of the first named movable means causes plunger reciprocation through a range in which the plunger moving therein engages the pressure withstanding part and the other of the positions being such that movement of the first named movable means causes plunger reciprocation through a range spaced from the first described range in a direction away from the pressure withstanding part; the combination therewith of a transmission means in operative engagement with the source of power and the second movable means and including a movable element in movable engagement with the frame at a position to be engaged and moved by the first named movable means upon movement of the plunger through a point in one range of reciprocation and adapted when thus moved to operatively connect the. second movable means and the source of power through the transmission means whereby the plunger first named movable means are moved from the position of the one range of reciprocation to the position of the other range of reciprocation in synchrony with the plunger movement through the mentioned point in the one range of reciprocation.

9. In a pressure exerting machine as described in claim 8 in which said transmission means includes a second movable element in movable engagement with the frame at a position to be engaged and moved by the second named movable means upon a predetermined movement of the plunger and first named movable means from the position of the one range of reciprocation to the position of the other range of reciprocation to disconnect the source of power from the second named movable means whereby the second movable means dwells in the position of the other range of reciprocation.

10. In a pressure exerting machine as described in claim 8 in which the movable element is in movable engagement with the frame at a position to be engaged and moved by the first named movable means upon move ment of the plunger through a point in the first describedt range of reciprocation to operatively connect the sec-v ond movable means and the source of power to move the plunger and first named movable means from a position in the first described range of reciprocation to a position in the second described range of reciprocation.

11. In a pressure exerting machine as described in; claim 8 in which the movable element is in movable engagement with the frame at a position to be engaged and moved by the first named movable means upon movement of the plunger through a point in the second described range of'reciprocation to operatively connect the second movable means and the source of power to move the plunger and first named movable means from a position in the second described range of reciprocation to a position in the first described range of reciprocation.

12. In a pressure exerting machine as described in claim 11 having in addition a second movable element in movable engagement with the frame at a position to be engaged and moved by the first named movable means upon movement of the plunger through a point in the first described rangeof reciprocation to operatively connect the second movable means and the source of power to move the plunger and the first named movable means from a position in the first described range of reciprocation to a position in the second described range of reciprocation.

13. In a pressure exerting machine having a frame, a pressure withstanding part on the frame, a slide in movable engagement with the frame, operable means in movable engagement with the frame and the slide and adapted when operated to reciprocate the slide toward and away from the pressure withstanding part, a plunger in movable engagement with the frame, a second operable means, connecting means separate from and independent of the first mentioned operable means and in engagement with the slide and the second operable means for operatively connecting the second operable means to the slide and moving the second operable means with the slide, a second connecting means separate from and independent of the first mentioned operable mean and in engagement with the plunger and the second operable means for operatively connecting the second operable means to the plunger whereby the plunger is adapted when the second operable means is operated to reciprocate relative to the slide and toward and away from the pressure withstanding part, a continuously acting source of power operatively connected to the mentioned second operable means to thereby uninterruptedly reciprocate the plunger, an intermittent acting source of power operatively connected to the first named operable means to thereby periodically reciprocate the slide and to alternately bring the plunger to a range of reciprocation to engage the pressure withstanding part and thereafter to a range of reciprocation spaced from the pressure withstanding part.

14. In a pressure exerting machine having a frame, a pressure withstanding part on the frame, a slide-in movable engagement with the frame, operable means in movable engagement with the frame and the slide and adapted when operated to reciprocate the slide toward and away from the pressure withstanding part, a plunger in movable engagement with the frame, a second operable means, connecting means separate from and independent of the first mentioned operable means and in engagement with the slide and the second operable means for operatively connecting the second operable means to the slide and moving the second operable mean with the slide, a second connecting means separate from and independent of the first named operable means and in engagement with the plunger and the second operable means for operatively connecting the second operable means to the plunger whereby the plunger is adapted when the second operable means is operated to reciprocate relative to the slide and toward and away from the pressure withstanding part, a continuously acting source of power operatively connected to the mentioned second operable means to thereby uninterruptediy reciprocate the plunger, an intermittent acting source of power operi6 atively connected to the first named operable means to thereby periodically reciprocate the slide and to alternately bring the plunger to a range of reciprocation to engage the pressure withstanding part and thereafter to a range of reciprocation spaced from the pressure withstanding part and in which the plunger is at all times and in every stage of its reciprocation on the slide side of the pressure withstanding part and the pressure withstanding part side of the slide.

15. A sheet metal press having a frame, a bed on the frame, a slide in slidable engagement with the frame and being reciprocably movable thereon relative to the bed, intermittently actuated power means on the frame including a part in engagement with the slide and operative when actuated to move the slide relative to the bed, a plunger in slidable engagement with the frame on the bed side of the slide and being reciprocably movable relative to the bed and slide, a continuously actuated power means on the slide including a movable part in engagement with the plunger connecting the plunger with the slide and producing continuous movement thereof relative to the slide, and timing means operatively connected to both power means and adapted to limit the actuation of the first named power means to move the slide and plunger in one direction relative to the bed to a time so that the movement of the slide in said direction and in response to said actuation of the first named power means is completed just prior to the close of the movement of the plunger in the same direction relative to the bed in response to the actuation of the second named power means.

16. A sheet metal press having a frame, a bed on the frame, a slide in slidable engagement with the frame and being reciprocably movable thereon relative to the bed, intermittently actuated power means on the frame including a part in engagement with the slide and operative when actuated to move the slide relative to the bed, a plunger in slidable engagement with the frame on the bed side of the slide and being reciprocably movable relative to the bed and slide, a continuously actuated power means on the slide including a movable part in engagement with the plunger connecting the plunger with the slide and producing continuous movement thereof relative to the slide, and a timing means in operative connection with each power means to energize the same in predetermined synchronism with each other and according to the relative movements of the slide and plunger, the timing means including actuating elements in adjustable engagement with the press frame and adapted when adjusted to actuate each timing means to energize each power means in any predetermined synchronism and according to any relative movements of the slide and plunger.

References (Iitcd in the file of this patent UNITED STATES PATENTS

Claims

13. IN A PRESSURE EXERTING MACHINE HAVING A FRAME, A PRESSURE WITHSTANDING PART ON THE FRAME, A SLIDE IN MOVABLE ENGAGEMENT WITH THE FRAME, OPERABLE MEANS IN MOVABLE ENGAGEMENT WITH THE FRAME AND THE SLIDE AND ADAPTED WHEN OPERATED TO RECIPROCATE THE SLIDE TOWARD AND AWAY FROM THE PRESSURE WITHSTANDING PART, A PLUNGER IN MOVABLE ENGAGEMENT WITH THE FRAME, A SECOND OPERABLE MEANS, CONNECTING MEANS SEPARATE FROM AND INDEPENDENT OF THE FIRST MENTIONED OPERABLE MEANS AND IN ENGAGEMENT WITH THE SLIDE AND THE SECOND OPERABLE MEANS FOR OPERATIVELY CONNECTING THE SECOND OPERABLE MEANS TO THE SLIDE AND MOVING THE SECOND OPERABLE MEANS WITH THE SLIDE, A SECOND CONNECTING MEANS SEPARATE FROM AND INDEPENDENT OF THE FIRST MENTIONED OPERABLE MEANS AND IN ENGAGEMENT WITH THE PLUNGER AND THE SECOND OPERABLE MEANS FOR OPERATIVELY CONNECTING THE SECOND OPERABLE MEANS TO THE PLUNGER WHEREBY THE PLUNGER IS ADAPTED WHEN THE SECOND OPERABLE MEANS IS OPERATED TO RECIPROCATE RELATIVE TO THE SLIDE AND TOWARD AND AWAY FROM THE PRESSURE WITHSTANDING PART, A CONTINUOUSLY ACTING SOURCE OF POWER OPERATIVELY CONNECTED TO THE MENTIONED SECOND OPERABLE MEANS TO THEREBY UNINTERRUPTEDLY RECIPROCATE THE PLUNGER, AN INTERMITTENT ACTING SOURCE OF POWER OPERATIVELY CONNECTED TO THE FIRST NAMED OPERABLE MEANS TO THEREBY PERIODICALLY RECIPROCATE THE SLIDE AND TO ALTERNATELY BRING THE PLUNGER TO A RANGE OF RECIPROCATION TO ENGAGE THE PRESSURE WITHSTANDING PART AND THEREAFTER TO A RANGE OF RECIPROCATION SPACED FROM THE PRESSURE WITHSTANDING PART.