Control mechanism for pressing machines

Abstract

Claims

Sept. 5, 1939. G. w JOHNSON CONTROL MECHANISM FOR PRESSING MACHINES Original Filed Aug. 7, 1937 2 Sheets-Sheet 1 N 0; IT J mw mE ATTO p 5, 1939- Q G. w. JOHNSON 2,171,568 CONTROL MECHANISM FOR PRESSING MACHINES Original Filed Aug. 7, 1937 2 Sheets-Sheet 2 FIG.--3 - INVENTOR GEORGE W. JOHNSON Patented Sept. 5, 1939 UNITED STATES PATENT OFFICE CONTROL MECHANISM FOR PRESSING MACHINES Ohio Application August 7, 1937, Serial No. 157,825 Renewed November 26, 1938 9 Claims. This invention relates to improvements in control mechanism for pressing machines. While my improved control mechanism may be applied to any type of press having coacting platens, it is particularly applicable to a press of the type used for laundry and garment work. One of the features of the present invention is the provision of a safety two-hand control for keeping the operators hands occupied during the closing movement of the press and the arrangement of the two controls or manuals for a two-stage movement, the first stage corresponding to movement of the pressing members to a safe closed position and the second stage of 151 manual movement corresponding to the final closing of the press. My invention relates to a novel arrangement of a pair of control manuals wherein both manuals must be actuated coincidently to produce press closure. The two manuals 20 are connected by a whifiletree or equalizer bar in such a manner that actuation of both manuals is necessary to operate a press control member. This equalizer bar is of a resilient type and arranged in a novel manner so that during the first 25 stage of manual movement it is eiiective to return the manuals to unoperated position and during the second stage of manual movement it is effective to move the manuals into final operated position and to hold them there. 30 The novel features of my invention will be apparent from the accompanying drawings and specification and the essential features will be summarized in the claims. In the drawings, Fig. 1 is an end elevation of 35 a pressing machine embodying my invention with the press parts in open position; Fig. 2 is a diagrammatic layout of the control mechanism for the pressing machine with the parts in the position corresponding to the press of Fig. 1; Fig. 3 4.0 is a view of the pressing machine showing the position of the press parts in full lines in safe closed position and in dot-dash lines in fully closed position; while Fig. lis a diagram of the control mechanism similar to Fig. 2 but showing 45- in full lines the position of the control parts corresponding to the full line position of the press parts of Fig. 3 and .in dot-dash lines showing the position of the control parts corresponding to the dot-dash position of the press parts of Fig. 3. 50 My invention is applicable to various types of presses but I have illustrated a press having a frame It supporting a pressing bed H and a pivoted yoke l2 by means of which a pressing head 53 is oscillatableirom the open position of Fig. 1 55 to the closed position of Fig. 3. A spring M normally maintains the head in open position and toggle mechanism l5 actuated by motor it: moves the head into pressure engagement with the bed. The motor I 6 is of the cylinder and piston type through which fluid is supplied from supply line 5 il through valve l8 and line l9. Valve I8 has a normally closed inlet port I 8a and a normally open outlet port 18b and a stem E80 by which the valve is actuated. For valve actuation a diaphragm motor 20 is provided having a piston 20a 10 operable by diaphragm 23b to actuate the valve stem I80. The parts are normally biased to the position of Fig. 2 by the spring 238. Pressure fluid is supplied back of diaphragm 2th through the conduit 2|, supply for which is through conduit 22 and pilot valve 23. This pilot valve has an inlet port 2311 closed by the ball 231), an exhaust port 23c and a valve stem 2301. The pilot valve is actuated by means of pin 24 which is connected intermediate the ends of a whifiietree or equalizer bar 25, the opposite ends of which are connected by toggle mechanisms 26 and 27 with manuals 213 and 29. Stop pins 38 limit the movement of the manuals in the unoperated position of Fig. 2. A movable stop member 3! lies between the toggle mechanisms 26 and 21 when the press is open. The stop member 3i is a part of a bellcrank member 32 pivoted to the press frame at 33. The lower arm of the bellcrank is pivotally connected with rod 34 which carries rigid with it the collars 35 and 36. The rod as shown passes through a bracket 3'! on the toggle mechanism 15. A spring 38 biases the bellcrank 32 and the stop 3! to the position shown in Figs. 1 and 2 and in full lines in Fig. 3. 35 The equalizer bar 25 is resilient and preferably is a piece of spring metal convex toward the pilot valve as indicated in Fig. 2. The resilience of this equalizer bar is utilized to hold the manuals 28 and 29 in both the unoperated position of Fig. 2 40 and the fully operated position of Fig. 4, as will hereinafter appear. In the operation of the press, work is arranged on the bed l i and the operator actuates manuals 28 and 29 until the toggles 26 and 2? reach a limiting position against the stop member 3i as in dicated in full lines in Fig. 4. It will be noted that there is a lost motion between the pin 24 and the valve stem 23d'so arranged that actuation of either of the manuals alone will take up this lost motion but will not move ball 23b from the valve seat 23a. It is necessary to produce coincidental actuation of the two manuals to move the ball from its seat as indicated in Fig. 4. In this position of the parts the shoulder 23c on the valve stem has engaged the exhaust valve seat 230 and the resilient equalizer bar 25 has been flexed toward the left as viewed in Fig. 4. In this position of the parts if either or both of the manuals are released the energy stored in the flexed bar 25 will return the manuals to the unoperated position of Fig. 2. When the manuals have reached the full line position of Fig. 4, valve 23 is actuated, permitting a flow of pressure fluid through conduits I? and 22, valve 23 and conduit 2! to diaphragm motor 29. This motor makes a stroke toward the left as shown in Fig. i, actuating valve i8 and admitting pressure fluid through line ll, valve l8 and line I!) to motor It so as to actuate the press in closing direction, bringing the head down to the full line position of Fig. In this position of the parts it is no longer possible or likely that an operator will be able to place a hand between the pressing members with subsequent injury. When the press has reached this safe closed position the bracket 37 engages the collar 36 exerting a pull on rod 34 against the bias of spring 38, moving the bellcrank 32 from the full line to the dot-dash position of Fig. 3. This moves the stop member 3! downwardly from between the toggles 26 and 21, permitting further actuation of manuals 28 and 29 to the dot-dash position of Fig. 4. It will be noted that the toggles 26 and 27 thus pass from an over-center position where they tend to move outwardly to an over-center position where they tend to move inwardly. As the toggles move toward the dot-dash position of Fig. 4 and pass over their center line position, the energy stored in spring bar 25 is effective to continue the movement of the toggles 25 and 2? inwardly until they reach the limit stop 39 and thereafter the spring bar 25 holds the toggles and the manuals in fully actuated position. This maintains valve 23 open which in turn through motor 2i! holds valve l8 open, supplying fluid to motor l6 and holding the press closed. To release the press one or both of the manuals 28 or 293 is returned to the position of Fig. 2, whereupon all of the parts return to the position of Fig. 2, and the press is opened by the spring 64. A spring is shown for returning the ball valve 2% to its seat although the air pressure against it is sufiicient to perform this function if the valve is horizontal. As the press opens, spring 38 is efiective to return the stop 3! between the toggles 2t and 21, thus completing the breaking of these toggles outwardly and positioning the parts for another press operation. What I claim is: 1. In a pressing machine having a pair of coacting pressing members and power means for causing a pressing operation between them, control mechanism including a control member for said power means, a pair of manuals spaced to require a hand of the operator on each for their coincidental actuation, a resilient equalizer bar between said manuals adapted to return them to unactuated position, said bar having an operative connection with said control member requiring coincidental actuation of both of said manuals for efiective actuation of said control member, said manuals being arranged to stress said equalizer bar upon actuation of said control member, and an operative connection between said bar and manuals for holding said manuals in actuated position by said stress in said bar. 2. In a pressing machine having a pair of coacting pressing members and power means for causing a pressing operation between them, control mechanism including a control member for said power means, manual means requiring both hands of the operator for actuation thereof, operating connections between said manual means and said control member including a resilient bar and toggle means connected with said manual means, said toggle means being arranged for movement over-center when said control member is actuated, said bar being arranged for flexure when said control member is actuated, and said bar and toggle means being so constructed and arranged that said bar in flexed position holds said toggle means in over-center position. 3. In a pressing machine having a pair of coacting pressing members and power means for causing a pressing operation between them, control mechanism including a control member for said power means, a pair of manuals spaced to require a hand of the operator on each for their coincidental actuation, a resilient equalizer bar having an operative connection with said control member intermediate its ends, operative connections between the ends of said bar and said manuals, at least one of said last named connections comprising a toggle movable to opposite sides of its central fully-extended position by manual manipulation, and the parts being so arranged that said bar is flexed by movement of said toggle sufficient to move said control member to actuated position, whereby the resilience of said flexed bar is operative to hold said toggle in either of its ofi-center positions. 4. In a pressing machine having a pair of coacting pressing members and power means for causing a pressing operation between them, control mechanism including a control member for said power means, a pair of manuals spaced to require a hand of the operator on each for their coincidental actuation, a resilient equalizer bar having an operative connection with said control member intermediate its ends, operative connections between the ends of said bar and said manuals, at least one of said last named connections comprising a toggle movable to opposite sides of its central fully-extended position by manual manipulation, the parts being so arranged that said bar is flexed by movement of said toggle sufiicient to move said control member to actuated position, whereby the resilience of said flexed bar is operative to hold said toggle in either of its offcenter positions, said parts being arranged to lie normally with said control member in unactuated position, means normally preventing movement of said toggle over center, and means for removing said last named means responsive to movement Of the pressing machine to a safe-closed position. 5, In a pressing machine having a pair of coacting pressing members and power means for causing a pressing operation between them, control mechanism including a control member for said pow-er means, a pair of manuals spaced to require a hand of the operator on each for their coincidental actuation, a resilient equalizer bar having intermediate its ends an operative connection with said control member, toggles connecting the ends of said bar with said manuals, each toggle being movable to opposite sides of its central fully-extended position by manipulation of its associated manual, the parts including said toggles and equalizer bar and control member being arranged to require coincidental actuation of both of said manuals for effective actuation of said control member, and said parts being so arranged that said bar is flexed by movement of said toggles sufficient to move said control memher to actuated position, whereby the resilience of said flexed bar is operative to hold said toggles in either of their off-center positions. 6. In a pressing machine having a pair of coacting pressing members and power means for causing a pressing operation between them, control mechanism including a control member for said power means, a pair of manuals spaced to require a hand of the operator on each for their coincidental actuation, a resilient equalizer bar having intermediate its ends an operative connection with said control member, toggles connecting the ends of said bar with said manuals, each toggle being movable to opposite sides of its central fully-extended position by manipulation of its associated manual, the parts including said toggles and equalizer bar and control member being arranged to require coincidental actuation of both of said manuals for effective actuation of said control member, said parts being so arranged that said bar is flexed by movement of said toggles sufiicient to move said control member to actuated position, whereby the resilience of said flexed bar is operative to hold said toggles in either of their ofi-center positions, said parts being arranged to lie normally with said control member in unactuated position, means normally preventing movement of said toggles over center, means for removing said last named means responsive to movement of the pressing machine to a safe-closed position, and stop means holding said toggles in extended position after they have moved slightly over center, whereby said control member is held in actuated position. '7. In a pressing machine having a pair of coacting pressing members, power means for causing a pressing operation between them, means normally tending to return said members to open position, and a control member normally in unactuated position and when actuated adapted to cause press-closing operation of said power means, the combination of a pair of manuals spaced to require a hand of the operator on each of them for their coincidental actuation, a resilient equalizer bar having intermediate its ends an operative connection with said control member, a pair of toggles, one operatively connected between each manual and an end of said equalizer bar in such a manner that said bar normally holds said toggles on one side of central straightened position, the parts including said toggles and equalizer bar and control member being so arranged as to require coincidental movement of both of said toggles to semi-straightened position for eifective actuation of said control member, block means effective in all positions of said pressing members between open and safe-closed position to stop said toggles short of straightened position but sufliciently straightened to actuate said control member, whereby said equalizer bar is flexed and the energy stored therein is available to break said toggles if said manuals are released, means responsive to movement of the press parts to safe-closed position for removing said block means, whereupon continued actuation of the manuals by the operator is effective to move said toggles over-center, and stop means limiting said toggles to semi-straightened overcenter movement in which position they are held by the energy stored in the flexed equalizer bar. 8. In a pressing machine having a pair of coacting pressing members and power means for causing a pressing operation between them, a control member for said power means, a pair of manuals spaced to require a hand of the operator on each for their coincidental actuation, a train of mechanically connected motion transmitting parts between said manuals and said control member requiring coincidental actuation of both of said manuals for effective actuation of said control member, said motion transmitting parts including a flexible bar which is resilient and is positioned to be bent transversely by actuation of said control member and thereby becomes effective in said train for holding said control member in actuated position after it is manually moved thereto. 9. In a pressing machine having a pair of coacting pressing members and power means for causing a pressing operation between them, a control member for said power means, a pair of manuals spaced to require a hand of the operator on each for their coincidental actuation, a train of mechanically connected motion transmitting parts between said manuals and said control member requiring coincidental actuation of both of said manuals for effective actuation of said control member, said motion transmitting parts including a flexible bar which is resilient and is positioned to be stressed transversely by actuation of said control member, said train including toggle means between said manuals and said resilient part adapted to move to an overcenter position and to be there held by the stress in said resilient part when it is bent, and said resilient part together with said toggle means in over-center position being effective to hold said control member in actuated position. GEORGE W. JOHNSON.

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Cited By (2)

    Publication numberPublication dateAssigneeTitle
    US-2519311-AAugust 15, 1950Byers Machine CompanyFluid pressure operated trip actuating mechanism
    US-4252228-AFebruary 24, 1981Scovill Inc.Two-hand mechanical control device