US3791496A - Dual control adapter for press - Google Patents

Abstract

Safety actuating device for a press. In a press, as a punch press, having a one-way clutch and a rod responsive to actuating means for operating said clutch to control the press, there is provided means interposed between actuating means and said rod to insure that the press will operate only in response to a force occurring in a predetermined manner and place. The rod is connected to a pivotally mounted lever whose operation is first resisted and then effected by successive operation of two linkages responding to energizing of a pressure cylinder. One linkage first, and normally, provides support means under said lever for positively preventing it from effecting movement of said rod. A pair of hand switches are each connected to a valve for energizing the cylinder when both of the operator''s hands are on the respective switches. With the device of the invention in place and the actuating cylinder energized, the first operation is to pull the support means out of locking position and thereby to permit downward movement of said lever. This is followed immediately by engagement of said lever by said second linkage which draws the ever downward sufficiently to effect such movement of said pull rod as to energize the clutch and initiate one operation of the press.

Description

United States Patent [191 Emrick Feb. 12, 1974 1 1 DUAL CONTROL ADAPTER FOR PRESS Homer R. Emrick, Kalamazoo, Mich.

[75] Inventor:

[52 US. 01. .Q 192/22, 192/131 R [51] Int. Cl Fl6p 3/18 [58] Field of Search 192/22, 131 R, 24

[56] References Cited UNITED STATES PATENTS 2,411,543 11/1946 Kann 192/22 X 1,939,006 12/1933 Hawkins 192/24 X 1,851,171 3/1932 Goellner 192/22 X 2,340,416 2/1944 Eason 192/24 X 2,496,793 2/1950 Herbers 192/22 X 1,167,475 l/1916 Benjamin 192/131 Primary ExaminerAllan D. Herrmann Attorney, Agent, or Firm-Woodhams, Blanchard & Flynn [57 ABSTRACT Safety actuating device for a press. In a press, as a punch press, having a one-way clutch and a rod responsive to actuating means for operating said clutch to control the press, there is provided means interposed between actuating means and said rod to insure that the press will operate only in response to a force occurring in a predetermined manner and place. The rod is connected to a pivotally mounted lever whose operation is first resisted and then effected by succes sive operation of two linkages responding to energizing of a pressure cylinder. One linkage first, and normally, provides support meansunder said' lever for positively preventing it from effecting movement of said rod. A pair of hand switches are each connected 7 Claims, 2 Drawing Figures DUAL CONTROL ADAPTER FOR PRESS FIELD OF THE INVENTION The invention relates to safety actuators for presses and particularly to a type thereof which positively prevents actuation of the press starting mechanism until both of the operators hands are on actuating switches. When so energized the mechanism first withdraws a locking mechanism and then applies a suitable force to the operating rod.

BACKGROUND OF THE INVENTION IN the operation of punch, and similar, presses, it has long been customary to utilize a continuously operating, inertia storage, element such as a large flywheel which is then by suitable means, such as a singlerevolution clutch, connected to the crank or other mechanism by which the press is caused to operate. In connection therewith, it has long been customary to provide dual hand controls to insure that both of the op'erators hands are in a safe location prior to energization of the press to bring the dies thereof together. However, in spite of the long time during which this problem has been recognized and the many devices which have been offered to improve the level of safety encountered in connection withsuch presses, there has still remained the problem of positively insuring that the actuating mechanism of the press will not move unless anduntil it is appropriately energized. Particularly, in certain devices known in the past there is provided merely an adjustable hook which upon actuation moves to engage means connected to a pull rod for closing said clutch.

However, if in some manner this hook is accidentally caused to engage and operate the pull rod the machine will start. Thus, the press is subject to accidental starts and it is desirable to prevent this from happening.

Accordingly, the objects of the invention include: 1. To provide a safety press control which positively prevents actuation of the press until the actuation which will be highly versatileand readily adaptable to use on and with presses and press control means of a wide range of specific designs.

Other objects and purposes of the invention will be apparent to persons acquainted with apparatus of this general type upon reading the following specification and inspection of the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 is a somewhat schematic side view of atypical punch press showing the location and arrangement with respect to the press of the safety control device.

FIG. 2 is an elevation, partly schematic view, of a safety control device embodying the invention.

DETAILED DESCRIPTION Referring first to FIG. 1, there is shown in side elevation a conventional punch press of the type for which the apparatus of the invention is particularly, though not exclusively, adapted and to which reference is made to illustrate the details and application of the invention.

The press shown in FIG. 1 comprises an upright frame 1 mounted in any convenient manner on a pedestal 2 and supporting a work table 3. Said frame 1 carries bearing structure 4 for rotatably supporting a shaft 5 to be driven in any convenient manner from one, here the leftward, end thereof and crank means such as an eccentric 9 is carried on the other, here the rightward, end thereof for vertically'reciprocating the ram 11 by which in a conventional manner a suitable die, nOt shown, is caused to act on work held on the work table 3.

In the press shown, a shaft 6 is supported in a suitable bearing 7 and carries at one, here the leftward, end thereof an inertia device 8, as a conventional flywheel.

A one revolution clutch 12 connects the shafts 5 and 6 upon appropriate mechanical actuation thereof by suitable trip means, as by the trip rod 13. Power means such as an electric motor schematically indicated at 14 is provided in any convenient manner for driving the shaft 6 at a continuous and substantially uniform rate in any conventional manner.

A power means in the form of a pressure fluid cylinder 16 is provided to operate appropriate mechanism,

in a translating device 17 through which actuation of the pressure cylinder 16 effects vertical actuation of the rod 13 and connecting of the clutch 12. The cylinder 16 is energized by opening of the valve 18 which connects the cylinder 16 with a pressure line 19. The valve 18 is in many conventional embodiments, and here, operated by a solenoid 21 which is in turn energized by a pair of serially connected hand switches 22 and 23v through which the solenoid 21 is connected to a power source P.

Thus, actuation of both switches 22 and 23 will energize the solenoid 21 by which the valve 18 is opened and the cylinder 16 energized/Energizing of said cylinder acts through the translating device 17 to actuate the rod 13 by which the clutch 12 is closed and the I shaft 6 connected to the'shaft 5. Energy stored in the inertia device 8 drives the shaft 5 and thereby the eccentric 9 to operate the punch in the usual manner.

Release of one or both of the hand switches 22 and 23 de-energizes the solenoid 21 and, also in a conventional manner, reverses the valve 18 by which to depressurize the cylinder 16. Means are provided for returning the plunger 26 again upwardly when the air pressure has ceased to operate. In the present embodiment same is indicated by a coil spring 20 positioned between the cross head 27 and the cylinder 16 but other means may be provided-as desired such as the reversal of the air pressure on the cylinder 16 when the solenoid 21 is de-energized. The apparatus -is now returned to the beginning condition and is ready for an-. other cycle.

All of the foregoing is conventional and well known to the industry. Hence, further description thereof is believed unnecessary.

Turning now to the details of the present invention, same are illustrated in FIG.'2 and comprise the contents of the translating device 17. The cylinder 16 carries and actuates a rod 26 and said latter has rigidly mounted on its free end the connector or cross arm 27. At one end of said cross arm, near the leftward end, there extends upwardly and pivotally connected thereto a link 28. Immediately above said link and related thereto in a manner to be described hereinafter is a power transmittal member, here a lever 29, which is pivoted at one end 31 to frame means, as a plate 25, and connected at its other end to the above-mentioned rod 13. A pin 32 projects outwardly from said lever 29 and is positioned for engagement by a hook portion 33 which latter is located at the upper end of the link 28. In' the starting position shown, pin 32 is spaced a short distance below hook 33 to provide a lost motion relationship as further dealt with below. The lower part of said hook member is positioned substantially perpendicular to the longitudinal extent of the link 28. Thus, for reasons further appearIng hereinafter, the hook 33 will restrain upward movement of the pin 32 but the pin 32 Will not restrain clockwise movement of the link 28 around the pivot point 30. Suitable means, as a spring 35, are provided to constantly urge a clockwise rotation of the lever 29 around its pivot point 31, the force thereof, however, being little if any more than merely enough to balance the weight of said lever.

Midway between the ends of the link 28 there is provided a cam 34 for cooperation with a pin 36. Said pin 36 is mounted on a vertically adjustable plate 37. Said plate 37 is mounted in any convenient manner for vertical adjustment as desired, in this embodiment same being provided by the slot 38 in said plate receiving a screw and washer guide device 39 and vertically adjusted by means of a screw 41 threadedly mounted on a suitable lug 42 which is in turn mounted on the frame plate 25. Suitable means, as a spring 43, constantly urges the link 28 in a leftward direction around its pivot point 30 for reasons appearing hereinafter.

A downwardly projecting lug 46 is also provided on the lever 29 and has a generally flat surface 47, preferably provided in the form of a portion of a step 48 in the lower part of Said lug 46. A latch 49, here of bellcrank shape, is pivotally affixed at 51 to the frame plate 25 and has a notched portion 52 at its upper end shaped to mate with the step 48. Means are provided for normally urging said arm 49 counterclockwise around the pivot 51, in this case such means being the counterweight provided by the arm 53.

A latch release link 54 is pivotally affixed at a point 56 to the rightward end of the cross arm 27 and is provided with a hook 57 arranged for normally engaging a pin 58 positioned on the bell crank in such position as to limit the above-mentioned counterclockwise pivotal movement of the arm 49. The lower edge, however, of said hook 57 is of such contour that while it restrains upward movement of said pin 58 it will not restrain clockwise movement of the lever 54 around said pivot 56. There is further provided on said lever 54 a projection 60 defining a cam surface 61. A pin 59 is mounted on the frame plate 25 and projects therefrom in a position to engage the cam surface 61 upon downward movement of the link 54 which engagement will cause clockwise rotation of said lever 54 about its pivot point 56.

OPERATION At the beginning of a cycle of operation, the motor 14 is, of course, energized and the shaft 6 rotates. A

downward stroke of the rod 13 will close the clutch l2 and effect a single revolution of the shaft and consequently a single operation of the punch. The objective 5 of the mechanism of the invention is, therefore, to effect a downward movement of the rod 13 when and as desired to actuate the punch but to positively prevent such downward movement at any time other than during the operational cycle.

In this condition of the apparatus the upper end of the lever 49 and particularly its surface 52 is received into the step 48 and thus positively prevents the downward movement of the lever 29. This positively prevents downward movement of the rod 13 and hence prevents an accidental engagement of the clutch 12.

When the operator places both hands on the switches 22 and 23, which are, of course, placed on the machine at suitable points according to known practice, they energize the solenoid 21 to open the valve 18 and thereby supply pressure fluid to the upper end of the cylinder 16. This pulls the cylinder rod 26 downwardly against the spring and thereby moves downwardly the cross head 27. Since the hook 57 is in contact with the pin 58 and the hook 33 is spaced from the pin 32, the first operation will be to pull said pin 58 downwardly and thereby effect a clockwise rotation of the lever 49 which will remove the upper end of same'out from under the step 48. Immediately after this occurs, the hook 33 moves downwardly sufficiently to engage the pin 32 and pull same downwardly, thus pulling the rod 13 and closing the clutch 12. This effects an operation of the punch in the normal manner.

It will be apparent that the lost motion space between the pin 32 and the hook 33 is preferably as small as possible but it must be sufficient to insure full retraction of the latch 49 from under the transmittal lever 29 before the hook 33 engages the pin 32.

In the meantime, the pin 59 acts against the cam 61 to move the upper end of the link 54 rightwardly and thereby release the pin 58. This permits the latch 49 to response to the counterwieght 53 and rotate counterclockwise until it bears against the leftward side 46a of the lug 46.

As the downward stroke continues, the pin 36 will bear against the cam 34 to move the upper end of the link 28 rightwardly to release the pin 32 and thereby permit the spring 35 to return the lever 29 upwardly. This will open the clutch 12 and make same ready for the next cycle of operation.

When the piston rod 26 reaches the bottom of its stroke, the air in the cylinder 16 may be automatically exhausted if desired. but in the embodiment shown same will be exhausted only when the operator releases one or both of the switches 22 and 23 to de-energize the solenoid 21. In whatever manner this exhaust is effected, the air is exhausted at an appropriate point and the spring 20 returns the piston rod 26 and thereby the cross arm 27 upwardly. As this occurs, the cam 34 isreleased from the pin 36 and the lever 28 responds to the spring 43 to return to the position shown in FIG. 2 so as to be ready for the next cycle. At the same time, the cam 61 is released from the pin 59 and the lever 54 responds to the spring 55 to return to the position shown in FIG. 2. Virtually simultaneously with this movement the surface 52 at the upper end of the latch 49 clears the corner between the surface 47 of the step 48 and the surface 46a so as to permit the upper end of said latch to swing leftwardly to re-engage said surface 52 with the step 48 as shown.

The parts are now all back into the original condition and ready for the next 'cyclewhich may be repeated in the same manner as that above described. 5

It will be recognized that a number of changes may be made from the specific apparatus herein shown to illustrate the invention, which changes will all be well within the scope of the invention. As examples of some of such changes the lever 29 may be arranged for vertical sliding motion rather than pivotal motion as shown and the latch 49 may be caused to return to its latched position by the presence of a spring rather than by the counterweight shown. The entire latch structure including particularly the latch 49, link 54, and parts asl5 sociated therewith, may be placed on the opposite side of the pull link 28 from where it is shown in the drawing and the pin 58 may be spaced horizontally a greater distance than shown from the pivot point 51 if desired to provide a more positive withdrawal of the latch from under the lug 46. Further, the apparatus may be narrowedsomewhat by moving the lug 46, latch 49 and lever 54 all leftwardly closer to the pull link 28 eliminating the counterweight 53 and replacing its function by a compression spring acting leftwardly against the upper end of the latch lever 49.

Other modifications and variations will be apparent to persons acquainted with apparatus of this general type but will be within the scope of the hereinafter appended claims excepting as said claims by their own terms clearly require otherwise.

The embodiments of the invention in which exclusive property or privilege is claimed are defined as follows:

1. Operating means for a press utilizing a clutch operable by substantially rectilinear motion of a trip means, the combination comprising:

power means actuated by an operator for generating mechanical 'rectilinear motion, said power means including a head member movable in a direction parallel to said direction of movement of said trip means in response to actuation of said power means; translating means adapted to receive said rectilinear motion from said power means and apply same to said trip means, said translating means being normally held in a first position corresponding to the inoperative position of said clutch and movable by said power means to a second position corresponding to the operative position of said clutch; said translating means including a power transmitting member and means mounting same for movement with a substantial component thereof in a direction parallel to the direction of movement of said trip means as same moves to operate said clutch; first link means operatively responsive to movement of said head member and having a lost motion connection with said transmitting member; latch means engaging at least a portion of said translating means and normally in a blocking position to positively hold said translating means in said first position, said latch means including a latch and means normally holding same in position for blocking movement of said power transmitting member in a direction corresponding to closure of said clutch; and release means actuated by said power means and effective to withdraw said latch means from said blocking position immediately prior to application of force by said power means to said translating means;

said release means including second link means responsive to movement of said head member and connected for retracting said latch from said blocking position in response to movement in said direction by said head member, the lost motion relationship of said first link means being sufficient to permit said latch to be retracted prior to connection of said first link means to said transmitting member in power transmitting relationship;

whereby upon the appearance of a force output by said power means said latch means will be withdrawn from said blocking position and force applied by said power means to said translating means will be effectively applied to said trip means for actuation thereof.

2. The device of claim 1 wherein said power transmitting member comprises a power transmittal arm pivotally mounted with respect to the frame of said press and arranged for movement having a substantial component in a direction parallel to the direction of movement of ,said trip means as same moves to operate said clutch;

said head member comprising a cross head arranged in a position substantiallyperpendicular to said direction and arranged for movement in said direction in response to energization of said power means;

said first link meanS including a first link pivoted to oneportion of said cross head and having a lost motion relationship with a first portion of said power transmittal arm at a location spaced from the point of pivoting thereof; and

said second link means including lost motion means for connecting said cross head to said latch for moving same from said blocking position to a released position on movement of said cross head in the clutch closing direction.

3. The device of claim 2 wherein said second link means is connected by a hookand pin arrangement to said latch and including also cam means for disconnecting said hook and pin upon movement of said cross head through a selected distance in the clutch closing direction whereby said latch will be free to return to its blocking position immediately upon return by said power transmittal arm to its first position and regardless of whether said cross head has yet returned to the position occupied by same at the beginning of the cycle.

4. In a power translation device for imposing a rectilinear operating motion' onto trip means adapted to operate the clutch of a punch press in response to power means actuated by an operator and including a power transmitting member arranged for rectilinear movement with at least a substantial component thereof parallel to the direction of movement of said trip means, and drive meansresponsive to actuation by said power means for actuating said clutch in response to output by said power means, the improvement in safety means therefor comprising:

a latch means normally positioned for blocking movement of said power transmitting member from a first position corresponding to the open condition of said clutch to a second position corresponding to the closed condition of said clutch;

means constantly urging said latch means toward a blocking position;

link means responsive to movement of said power means for movement of said latch means out of said blocking position; and

said drive means including lost motion linkage means connecting same to said power transmitting member, whereby energization of said power means effects movement first of said latch means out of said blocking position followed by, upon run-out of said lost motion, movement of said power transmitting member for effecting motion of said ,trip means in the clutch closing direction.

5. The device of claim 4 wherein said latch means includes a pivoted bell crank latch member wherein one arm thereof constitutes a counter-weight normally urging the other arm thereof into said blocking position.

6. Operating means for a press utilizing a clutch operable by substantially rectilinear motion of a trip means, the combination comprising:

power means for generating mechanical rectilinear motion;

a pair of manually actuated switch means connected in series with one another and operably connected to said power means for permitting energization thereof only when both of said switch means are closed, said pair of switch means being sufficiently spaced apart so as to require an operator to utilize both hands so as to permit simultaneous manual actuation of both of said switch means;

translating means adapted to receive said rectilinear motion from said power means and apply same to said trip means, said translating means being normally held in a first position corresponding in the inoperative position of said clutch and movable by said power means to a second position corresponding to the operative position of said clutch;

linkage means operatively coacting between said power means and said translating means for transmitting the rectilinear motion of said power means to said translating means, said linkage means including a lost-motion connection for permitting a preselected amount of rectilinear movement of said power means without causing a corresponding movement of said translating means;

latch means engaging at least a portion of the translating means and normally maintained same in a blocking position to positively hold said translating means in said first position; and

release means coacting between said power means and said latch means and actuated during said selected amount of rectilinear motion for withdrawing said latch means from said blocking position as said power means moves through said preselected amount of rectilinear movement prior to movement of said translating means by said linkage means;

whereby upon the appearance of a force output by said power means, said latch means will be initially withdrawn from said blocking position prior to the application of force to said translating means by said power means, whereupon said power means will then apply force to said translating means for moving said trip means to thereby actuate said clutch.

7. Operating means according to claim 6, wherein said latch means includes a latch member mounted for pivotal movement and normally urged into blocking engagement with said translating means, and said release means including a release member connected to said power means and movable therewith, said release member being pivotal and having a portion thereof releasably engageable with said latch member.

Claims (7)

1. Operating means for a press utilizing a clutch operable by substantially rectilinear motion of a trip means, the combination comprising: power means actuated by an operator for generating mechanical rectilinear motion, said power means including a head member movable in a direction parallel to said direction of movement of said trip means in response to actuation of said power means; translating means adapted to receive said rectilinear motion from said power means and apply same to said trip means, said translating means being normally held in a first position corresponding to the inoperative position of said clutch and movable by said power means to a second position corresponding to the operative position of said clutch; said translating means including a power transmitting member and means mounting same for movement with a substantial component thereof in a direction parallel to the direction of movement of said trip means as same moves to operate said clutch; first link means operatively responsive to movement of said head member and having a lost motion connection with said transmitting member; latch means engaging at least a portion of said translating means and normally in a blocking position to positively hold said translating means in said first position, said latch means including a latch and means normally holding same in position for blocking movement of said power transmitting member in a direction corresponding to closure of said clutch; and release means actuated by said power means and effective to withdraw said latch means from said blocking position immediately prior to application of force by said power means to said translating means; said release means including second link means responsive to movement of said head member and connected for retracting said latch from said blocking position in response to movement in said direction by said head member, the lost motion relationship of said first link means being sufficient to permit said latch to be retracted prior to connection of said first link means to said transmitting member in power transmitting relationship; whereby upon the appearance of a force output by said power means said latch means will be withdrawn from said blocking position and force applied by said power means to said translating means will be effectively applied to said trip means for actuation thereof.

2. The device of claim 1 wherein said power transmitting member comprises a power transmittal arm pivotally mounted with respect to the frame of said press and arranged for movement having a substantial component in a direction parallel to the direction of movement of said trip means as same moves to operate said clutch; said head member comprising a cross head arranged in a position substantially perpendicular to said direction and arranged for movement in said direction in response to energization of said power means; said first link meanS including a first link pivoted to one portion of said cross head and having a lost motion relationship with a first portion of said power transmittal arm at a location spaced from the point of pivoting thereof; and said second link means including lost motion means for connecting said cross head to said latch for moving same from said blocking position to a released position on movement of said cross head in the clutch closing direction.

3. The device of claim 2 wherein said second link means is connected by a hook and pin arrangement to said latch and including also cam means for disconnecting said hook and pin upon movement of said cross head through a selected distance in the clutch closing direction whereby said latch will be free to return to its blocking position immediately upon return by said power transmittal arm to its first position and regardless of whether said cross head has yet returned to the position occupied by same at the beginning of the cycle.

4. In a power translation device for imposing a rectilinear operating motion onto trip means adapted to operate the clutch of a punch press in response to power means actuated by an operator and including a power transmitting member arranged for rectilinear movement with at least a substantial component thereof parallel to the direction of movement of said trip means, and drive means responsive to actuation by said power means for actuating said clutch in response to output by said power means, the improvement in safety means therefor comprising: a latch means normally positioned for blocking movement of said power transmitting member from a first position corresponding to the open condition of said clutch to a second position corresponding to the closed condition of said clutch; means constantly urging said latch means toward a blocking position; link means responsive to movement of said power means for movement of said latch means out of said blocking position; and said drive means including lost motion linkage means connecting same to said power transmitting member, whereby energization of said power means effects movement first of said latch means out of said blocking position followed by, upon run-out of said lost motion, movement of said power transmitting member for effecting motion of said trip means in the clutch closing direction.

5. The device of claim 4 wherein said latch means includes a pivoted bell crank latch member wherein one arm thereof constitutes a counter-weight normally urging the other arm thereof into said blocking position.

6. Operating means for a press utilizing a clutch operable by substantially rectilinear motion of a trip means, the combination comprising: power means for generating mechanical rectilinear motion; a pair of manually actuated switch means connected in series with one another and operably connected to said power means for permitting energization thereof only when both of said switch means are closed, said pair of switch means being sufficiently spaced apart so as to require an operator to utilize both hands so as to permit simultaneous manual actuation of both of said switch means; translating means adapted to receive said rectilinear motion from said power means and apply same to said trip means, said translating means being normally held in a first position corresponding in the inoperative position of said clutch and movable by said power means to a second position corresponding to the operative position of said clutch; linkage means operatively coacting between said power means and said translating means for transmitting the rectilinear motion of said power means to said translating means, said linkage means including a lost-motion connection for permitting a preselected amount of rectilinear movement of said power means without causing a corresponding movement of said translating means; latch means engaging at least a portion of the translating means and normally maintained same in a blocking position to positively hold said translating means in said first position; and release means coacting between said power mEans and said latch means and actuated during said selected amount of rectilinear motion for withdrawing said latch means from said blocking position as said power means moves through said preselected amount of rectilinear movement prior to movement of said translating means by said linkage means; whereby upon the appearance of a force output by said power means, said latch means will be initially withdrawn from said blocking position prior to the application of force to said translating means by said power means, whereupon said power means will then apply force to said translating means for moving said trip means to thereby actuate said clutch.

7. Operating means according to claim 6, wherein said latch means includes a latch member mounted for pivotal movement and normally urged into blocking engagement with said translating means, and said release means including a release member connected to said power means and movable therewith, said release member being pivotal and having a portion thereof releasably engageable with said latch member.

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