US2171569A - Press control mechanism - Google Patents

Description

Sept. 5, 1939. w JQHNSQN 2,171,569

PRESS CONTROL MECHANISM Filed Aug. 25, 1957 3 Sheets-Sheet 1 FIG-I INVENTOR SEORGE W. JOHNSON ATTO p 1939- ca. w. JOHNSON 2,171,569

PRESS CONTROL MECHANI SM Filed Aug. 25, 1937 3 Sheets-Sheet 2 FIG-3 INVENTOR GEORGE W. JOHNSON Sept. 5, 1939. 3, w JOHNSON 2,171,569

PRES S CONTROL MECHANISM Filed Aug. 25, 1937 3 Sheets-Sheet 3 FIG-6 INVENTOR (QEORGE W. JOHNSON Patented Sept. 5, 1939 UNITED STATES PATENT OFFICE PRESS CONTROL MECHANISM Ohio Application August 25, 1937, Serial No. 160,873

3 Claims.

This invention relates to improvements in press control mechanism of the two-hand safety type. An object of the present invention is to provide a novel control mechanism for a power closed press having a control member operated by spaced safety manuals, one or both of which is arranged for two-stage operation, the first stage being effective to close the press but without any maintaining effect so that if the manuals are released the press will open and a second stage made possible only after the press is safe closed, by which a novel maintaining effect is produced. In the present instance this novel maintaining effect is the supply of pressure fluid to a small servo motor for holding the control means in operated position so that the manuals may be released and the press will remain closed.

Other novel features of my invention and advantages thereof will be apparent from the accompanying drawings and specification and the essential features thereof will be summarized in the claims.

In the drawings, Fig. 1 is an end elevation of a pressing machine embodying my invention with the press in open position; Fig. 2 is a diagrammatic view of the control mechanism for the pressing machine corresponding to the position of the parts in Fig. 1; Fig. 3 is a View of the pressing machine of Fig. 1 showing in full lines the safe closed position and in dot-dash lines the fully closed position; Fig. 4 is a diagrammatic view of the control mechanism showing the position of the parts just prior to the safe closed position of the press; Fig. 5 is a diagrammatic View of the controlling mechanism similar to Figs. 2 and 4 showing the position of the parts after the press has passed the safe closed position and the manuals have been moved through their second stage of operation; Fig. 6 is a similar view .of the control mechanism with the manuals released after the press is fully closed, while Fig. 7 is a view of a portion of the control mechanism of a modified form wherein but one manual is provided with a stop means.

I have illustrated my invention as applied to a pressing machine of the type used in laundry and garment work comprising a frame .II] supporting a bed II and a yoke I2 which carries a head I3 into and out of engagement with the bed II by actuation of the toggle I4 by means of fluid motor I5. A spring I6 biases the head toward open position.

The supply of pressure fluid for motor I5 is by way of conduit 11, valve casing I8 and conduit I9. In casing I8 is an inlet port [8a opened and closed by the ball valve I82) and an exhaust port I which is opened and closed by the shoulder I8d on the valve stem I8e which carries a pin I81. A spring 20 normally urges the inlet port closed and the outlet port open as in Fig. 2. This spring and its equivalent in casing 23 may be omitted if the valve casings are positioned to make the valves self-closing.

While the valves in casing I8 might be directly operated by the manuals to render operation easier, the valves in this casing are power operated by the diaphragm motor 2I and have a rod 2Ia which engages valve stem I8e. Ihe supply of pressure fluid for motor 21 is by way of conduit 22, valve casing 23 and conduits 24 and 25. The valves in casing 23 are similar to those in casing I8, namely, a normally closed inlet valve 23a. and a normally open outlet valve 23b on stem 230, which has a yieldable end 23d).

A two-hand operated device is provided for actuating the pilot valve 23, comprising a pin 26 on whiffletree 21 which is connected by links 28 with manuals 29 and 30 respectively. Springs 3I urge the manuals toward unoperated position.

The blocks 32 are held in the position of Fig. 2 when the pressing head is anywhere between open and safe closed position. These blocks are rigid with shaft 33 which has an arm 34 connected by rod 35 to a press part. As shown in the drawings, rod 35 passes through a slotted bracket 38 on toggle I4. Rod 35 has the collars 35a and 35b and is biased by spring 31 to hold the blocks 32 in the position of Fig. 2.

Means is provided operable by second stage operation of the manuals for maintaining the control means for motor I5 in actuated position so that the manuals may be released. The mechanism shown for this purpose comprises a diaphragm motor 38 having a pin 39 engaging one end of a lever 40, the other end of which is adapted to engage the pin I8 on valve stem I 86 to hold the valves in casing I 8 in actuated position when motor I5 is energized. The supply of fluid for motor 38 is by way of conduit 4|, valve casing 42 and conduits 43, 25 and I1. Valve casing 42 houses a normally closed inlet valve 42a operable by a stem 42b.

For opening the press, conduit 44 leads from conduit M to a normally closed exhaust valve 45. This valve has a stem 45a by which it may be operated.

The device just described is operable as follows: With the parts in the position of Fig. 1 the operator arranges the lay of work on the bed II and depresses manuals 29 and 30 from the position of Fig. 2 to the position of Fig. 4, where movement is limited by the stops 32. Depression of either manual alone is insuflicient to actuate the valves in casing 23 because of the gap between pin 26 and the valve stem 23d. However, upon coincidental actuation of both manuals the valve is opened as shown in Fig. 4, supplying pressure fluid through conduits I1, 25 and 24, casing 23 and conduit 22 to the diaphragm motor 2|. This actuates the valves in casing l8 to the position of Fig. 4, supplying motive fluid through conduit l1, casing 8 and conduit l9 to motor I5. This will cause closing of the press. If either of the manuals is released it will be returned to unactuated position by its spring 3|, thus returning the valves'in casing 23 totheir unactuated position and evacuating the diaphragm motor 2|, which will also return the valves in casing IE to their unactuated position, allowing the press to open. However, after the press is safe closed the engagement of collar 350. by bracket 36 moves the blocks 32 to the position of Fig. 5, permitting second stage operation of the manuals, compressing the yieldable end 23d of. the valve stem 23c and actuating valve 4211, by its stem 421) as shown in Fig. 5. This supplies a shot of pressure fluid through conduit 43, valve casing 42, and conduit 4| to the maintaining motor 38. This moves the lever 40 into engagement with the pin I81, thus holding the valves in casing E8 in actuated position, permitting the release of the manuals as shown in Fig, 6 with consequent return of the valves in casing 23 to their unoperated position and the evacuation of motor 2|. To-open the press valve 45 is momentarily opened by depressing its stem 45a, thus evacuating the holding motor 38, permitting the valves in casing l8 to return to their position as in Fig. 2, where upon the press will open. 7

In the modification of Fig. 7, only one of the manuals is provided with a stop member 32, but otherwise constructed as in Figs. 1 to 6. In this modification manual 30 may be moved through its complete cycle of operation immediately, but

, manual 29 can move only until it engages the stop 32 during the preliminary closing of the press. When the press is safe closed block 32 is removed, permitting the manual 29 to engage valve stem 42b to actuate the valve 42a in casing 42 as before, thus supplying a. maintaining pressure against the diaphragm of motor 38.

What I claim is: 7 a

1. In a pressing machine, a pair of relatively movable coacting pressing members, power means for causing a pressing operation between said members, normally unactuated control means for causing actuation of said power means, manual means for operating said control means and comprising two manuals spaced to require a hand of the operator on each of them for coincidental actuation thereof, said control means and manual means being so constructed and arranged as to require coincidental operation of both manuals for effective actuation of said control means, said manual means having two stages of operation, a first stage adapted to actuate said control means whereby the pressing machine may be closed and a second stage adapted to cause said control means to be maintained in actuated position after the press reaches safe closed position, means normally preventing effective second stage operation of said manual means, means responsive to movement of the machine to safe closed position and coacting with said last named means for enabling second stage operation of said manual means, power means for holding said control means in actuated position, a control member for energizing said last named power means, said control member being arranged for operation by second stage operation of said manual means, and means for causing control-means-releasing operation of said last name-d power means, whereby to cause opening of the machine.

2. In a pressing machine, a. pair of relatively movable coacting pressing members, power means for causing a pressing operation between said members, normally unactuated control means for causing actuation of said power means, manual means for operating said control means and comprising two manuals spaced to require a hand of the operator on each of them for coincidental actuation thereof, said control means and manual means being so constructed and arranged as to require coincidental operation of both manuals for efiective actuation of said control means, said manual means having two stages of operation, a first stage adapted to actuate said control means whereby the pressing machine may be closed and a second stage adapted to cause said control means to be maintained in actuated position after the press reaches safe closed position, means normally preventing effective second stage operation of said manual means, means responsive to movement of the machine to safe closed position and coacting with said last named means for enabling second stage operation of said manual means, a fluid actuated servo-motor for holding said control means in actuated position, fluid supply means for said servo-motor including a normally closed valve, means for opening said valve by second stage operation of said manual means, and means for releasing fluid from said servo-motor to permit said control means to return to unactuated position.

3. The combination of claim 2, in which said normally closed valve is a check valve for trapping pressure fluid in said servo-motor upon actuation of said manual means through said second stage when followed by manual release.

GEORGE W. JOHNSON.

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