US2067045A - Press control mechanism - Google Patents

Description

Jan. 5, 1937. J. P. DALY PRESS CONTROL MECHANISM Filed Sept. 12, 1934 i f/OJ l L R `l Nl i Y,

ATTORNEY j lNvENToR JOSEPH P. DALY Patented Jan. 5, 1937 UNITED STATES PRESS CONTRQL MECHANISM Joseph P. Daly, New York, N. Y., assigner to The American Laundry Machinery Company, Cincinnati, Ohio, a corporation of Ohio Application September 12, 1934, Serial No. 743,694

6 Claims.

'Ihis invention relates to control mechanism for fluid pressure actuated presses, particularly the type used in garment and laundry pressing Work.

My improved control is particularly applicable to presses in which the coacting pressing members have a preliminary closing movement and a nal pressure movement.

An object of the invention is to provide control mechanism for causing the preliminary closing of the press under a safe pressure, that is, a pressure which will not injure the operators hands if they are accidentally caught between the pressing members, together with means actuated by the preliminary closing movement to control the application oi final pressure.

Another object of the invention is to provide a two-hand control during the preliminary closing of the press.

A further object of the invention is to provide an automatic arrangement for controlling the pressure available to cause the preliminary closing movement.

In the drawing, Fig. 1 is a diagrammatic view of the control'applied to a pressing machine; while Fig. 2 is a partial sectional detail of an auX- iliary or shuttle valve and a portion of the operating cylinder.

` My invention comprises in general a fluid pres- :5o sure actuated motor for moving the pressing members toward each other, means for causing a preliminary closing of the press under a safe pressure, and means for supplying final pressure after the press is safely closed. The means illustrated for controlling the preliminary closing pressure comprises a reservoir or metering tank of a limited capacity and control means for conducting the fluid pressure from said reservoir toY the fluid motor. The capacity of said reservoir is adjustable so that charges of fluid pressure may be supplied sufcient to close the press under safe pressure, and even then to close it but once on a single charge, necessitating recharge of the reservoir for a second operation. The capacity may be arranged to close the press with zero pressure but somewhat greater capacity in the reservoir `vvill do no harm as the pressing members will then be brought together under a pressure so slight as to cause no harm if the operators hands should be caught between the coacting members. The control means for preliminary closing might be a single valve, but I prefer a two hand control with positions for alternatively connecting the reservoir with the inain supply line .or the operating motor.. A

control valve is provided for the control of the ilow and exhaust of nal pressure to and from the luid motor. As an additional safeguard for the operator, interlocking means is provided for this latter valve whereby nal pressure may not 5 be supplied to the fluid motor until the press has been safely closed. An auxiliary or shuttle valve is provided for alternatively conducting the preliminary or nal closing pressure to the fluid motor. 10 While my control mechanism is applicable to any press having coacting relatively movable pressing members, I have illustrated the control applied to a well known type of press comprising a stationary bedv l0 and a coacting head 15 H carried by a head lever` I 2 pivoted as at I3 to a frame M. The conventional toggle levers I5 are illustrated for actuating the pressing members in press closing di-rection and a spring 1 6 for returning the members to open position. 2b A uid motor is provided for actuating' the pressing members in press closing direction and comprises a cylinder l1 pivotally carried by the frame and having a piston I8 and piston rod I9 pivotally connected at 20 to one ofthe toggle '2'5 members. Fluid pressure is supplied to the cylinder through a port 2| communicating through port 22 with an auxiliary or shuttle valve chamber 23, which, as shown, may be mounted' on the forward end of the cylinder. This valve cham- 30 ber has a communicating conduit 24 through which fluid pressure is supplied for the preliminary closing movement of the press. The valve chamber 23 has second connection through 'conduit 25 with a control valve chamber 26 through 35 which nal pressure is supplied' to or exhausted from cylinder I1. A differential pressure actuated valve 21 is adapted to move in chamber 23 to alternatively close the connection withv conduit 24 or conduit 25. 'Ihis auxiliary or shut- 4,0 tle valve 21 is provided with sealing discs 2B so as to properly close the ports. The port 22 is arranged in intermediate position in the valve chamber so as to be alternatively in communication with conduit 2d or 25. Pressure is supplied to conduit 24 under limited pressure for causing preliminary movement of the pressing members. I have illustrated for this purpose a reservoir or metering tank 29, the capacity' of which is adjustable by means of a par- 50 tition 3i) in the nature of a piston adjustable by means of a screw 3l having a threaded connection with the cap 32 of the reservoir. The reservoir is preferably arranged to be connected alternatively by control members to a main supply line 33 or to the conduit 24. The control means preferably takes the form of a two hand control comprising valves 34 and 35, each of which has movable members 36 and 31 respectively controlled by handles 38 and 39 normally held in the position illustrated in Fig. 1 by springs 40. The valve 34 has a passage 4I adapted to connect conduits 42 and 43 and a second passage 44 adapted to connect conduits 45 and 46. Valve 35 has a passage 41 adapted to bridge the connection between conduit 24 and an exhaust opening 48 and in another position to connect conduits 24 and 43. A second passageway 49 in valve 35 is adapted to connect conduit 45 through conduit 50 to the main supply conduit.

In the normal position of the control handles 38 and 39 illustrated in Fig. 1, fluid pressure flows from the main supply conduit 33 through conduit 5I), passageway 49, conduit 45, passageway 44 and conduit 46, thus charging the reservoir 29. The pressure cannot escape from the reservoir as conduit 42 is closed by the position of valve 34. To actuate the press for its preliminary closing movement, handles 38 and 39 are both moved downwardly, thus breaking the connections between conduits 50 and 45 of valve 35 and between 45 and 46 as connected through valve 34. At the same time, passageway 4I moves in a position to connect conduits 42 and 43, while passage 41 of valve 35 laps the exhaust port 48 and connects conduit 43 with conduit 24. Thereupon fluid pressure flows from the reservoir 29 through conduit 42, passage 4I, conduit 43, passage 41, and conduit 24 to auxiliary valve member 23. At this time, the rear or left hand end of shuttle valve 21 is subjected to atmospheric pressure only, as will presently appear, and the pressure admittedfto conduit 24 moves valve 21 rearwardly to the broken line position of Fig. 2, thus sealing off conduit 25 which is open to the atmosphere and admitting preliminary closing pressure through ports 22 and 2l to cylinder I1 and moving piston I8 and its associated parts rearwardly to move the pressing members II and Il) toward each other. It will be apparent that both valves 34 and 35 must be actuated to connect the various conduits to cause the flow of fluid pressure from reservoir 29 to auxiliary valve chamber 23.

The valve chamber 26 for the control of the flow and exhaust of final pressure to cylinder I1 is illustrated as comprising an inlet valve 5 I, normally maintained in closed position by a spring 52 and an exhaust valve 53 normally maintained in open position by the same spring. Conduit 54 provides communication between the inlet valve 5I and the main pressure supply conduit 33, while conduit 55 connects exhaust valve 53 to the atmosphere. Conduit 25, as previously described, forms a common connection for either inlet or exhaust to the auxiliary valve chamber 23.

Interlocking means is provided between valves 5I and 53 and a member actuated by movement of the pressing members in the preliminary closing of the press. The connection illustrated comprises a cam 56 movable with the piston I8 and associated parts and a follower 51 mounted on a bell crank 58 pivoted at 59 and having an upstanding arm 60 adapted to contact stem 6I for actuating valves 5I and 53. The follower 51 is held in contact with its cam 56 by means of spring 62. A notch 63 in the cam is entered by the follower 51 when the pressing members have reached the end of their preliminary closing movement whereupon bell crank 58 moves counterclockwise, closing exhaust valve 53, opening inlet 5|, causing fluid pressure to flow through conduit 54, valve 5I, conduit 25 to auxiliary valve chamber 23. The valve 21 is then in its rearward position, as indicated in broken lines in Fig. I2, and the pressure from conduit 25 being greater than the preliminary closing pressure acting on the forward end of valve 21, the valve is moved forward or to the right in Figs. l and 2 and the nal pressure ows through ports 22 and 2I into cylinder I1.

For releasing the press, bell crank 58 is provided with a projecting arm 64 which lies in the path of a second bell crank 65 which may have a connection by means of rod 68 with a foot treadle 69, whereby pressure upon the foot treadle actuates bell cranks 65 and 58 in clockwise direction, so that spring 52 returns valve 5I to its closed position and opens valve 53, whereupon pressure is exhausted from cylinder I1, through chamber 23 and conduit 25 to the exhaust conduit 55.

I have thus provided a. press in the operation of which the operator has triple protection. First, both hands must remain on the control handles until the press is closed. Second, if the operator should tie down one control handle it would have to be untied during each cycle of operations to recharge the reservoir, in any case but a limited supply of fluid pressure is available to close the press and no harm would be caused to a hand caught between the pressing members. Third, the interlocking means prevents the ow of final pressure to the operating motor until the press actually reaches closed position.

What I claim is:

1. In a press of the class described, the combination of a pair of coacting relatively movable pressing members having a preliminary closing movement and a final pressure movement, a uid motor for causing said movements, a reservoir having a fluid pressure capacity just sufficient to close the press with zero pressure, two hand control means for alternatively charging said reservoir or admitting fluid pressure from said reservoir to said motor, differential pressure actuated means for controlling the application of nal pressure, and means actuated by the preliminary closing movement for eiecting actuation of the differential pressure actuated means.

2. In a press of the class described, the combination of a pair of coacting relatively movable pressing members having a preliminary closing movement and a nal pressure movement, a fluid motor for causing said movements, means for causing the preliminary closing movement with a pressure less than the nal pressure, and differential pressure actuated means for controlling the application of final pressure, said last named means comprising a shuttle valve operable in two directions by pressure difference on opposite sides thereof, a normally open exhaust valve for relieving pressure on the first side, means for applying preliminary pressure to the second side, a normally closed inlet valve for controlling the flow of fluid under nal pressure to said motor, a communicating conduit between said inlet valve and said first side of said shuttle valve, and means actuated by the preliminary closing movement for closing said exhaust valve and opening said inlet valve.

3. In a press of the class described, the combination of a pair of coacting relatively movable pressing members having a preliminary closing movement and a nal pressure movement, a uid motor for causing said movements, means for causing the preliminary closing movement with a pressure less than the nal pressure, differential pressure actuated means for controlling the application of final pressure, said last named means comprising an auxiliary valve chamber,

ports therein communicating respectively with the fluid motor, preliminary pressure, nal pressure and atmospheric exhaust, valve mechanism adapted to alternatively establish communication between preliminary pressure and the motor, or between the motor and nal pressure or exhaust, and means actuated by movement of the iluid motor for controlling the connection of the third port to nal pressure or exhaust.

4. In a press of the class described, the combination of a pair of Ycoacting relatively movable pressing members having a preliminary closing movement and a final pressure movement, a fluid motor for causing said movements, means for causing the preliminary closing movement with a pressure less than the final pressure, differential pressure actuated means for controlling the application of final pressure, said last named means comprising an auxiliary valve chamber, a shuttle valve movable therein, a comparatively low pressure conduit communicating with said chamber, a passageway from said chamber to said motor, a control Valve chamber for said motor, a valve therein controlling inlet and outlet ports, a common inlet and exhaust conduit from said control valve chamber to said auxiliary valve chamber, and said shuttle valve being movable by pressure differential to one position adapted to close said common conduit and connect the low pressure conduit with the passageway, and to another position adapted to close said low pressure conduit and connect the common conduit with the passageway.

5. In a press of the class described, the combination of a pair of coacting relatively movable pressing members having a preliminary closing movement and a nal pressure movement, fluid actuated motor means for causing relative movement of said members, motive uid supplies-of greater and less pressures respectively, means for utilizing said supply of less pressure in said motor means for causing said preliminary closing movement, means for utilizing said supply of greater pressure in said motor means for causing said final pressure movement, including diiTerential fluid pressure actuated means responsive to the difference in pressure between said motive iluid supplies for controlling the application of final pressure, and means actuated by said preliminary closing movement for supplying fluid from said supply of greater pressure to said differential fluid pressure actuated means.

6. In a press of the class described, the combination of a pair of coacting relatively movable pressing members having a preliminary closing movement and a nal pressure movement, fluid motor means for causing said movements, a reservoir having a fluid pressure capacity just suincient to operate said motor means to close the press with safe pressure, valve means for admitting fluid pressure from said reservoir to said motor means, a heavy pressure uid supply, differential uid pressure actuated means responsive to the diierence between said safe and said heavy pressure for controlling the admission of heavy pressure uid to said motor means, and means actuated by the preliminary closing movement for supplying said heavy pressure iluid to said differential fluid pressure actuated means.

JOSEPH P. DALY.

Images