US2934189A - Pressing machine with movable safety guard - Google Patents

Description

April 26, 1960 w. c. WILSON ET AL 2,934,189

PRESSING MACHINE WITH MOVABLE SAFETY GUARD Filed May 19, 1958 3 Sheets-Sheet 1 .1 for)? April 1960 w. c. WILSON ETAL 2,934,189

PRESSING MACHINE WITH MOVABLE SAFETY GUARD Filed May 19, 1958 3 Sheets-Sheet 2 April 26, 1960 w. c. WILSON ETAL 3 Sheets-Sheet 3 PRESSING MACHINE wrrrr MOVABLE SAFETY GUARD William Courtney Wilson and Robert H. Anderson, Chicago, Ill., assignors to Pyroxylin Products, Inc Chicago, Ill., a corporation of Illinois Application May 19, 1958, Serial No. 736,075

11 Claims. (Cl. 192-134) The present invention relates generally to electrically controlled presses having a pressing element movable to and from a pressing location, and particularly to such a press incorporating numerous safety devices and designed for thermosealing patches on garments, as in a laundry or cleaning establishment.

Presses in general are frequently operated by persons who become incautious and who are, therefore, subject to injury by being caught between the pressing element, or in case of a heated platen, of being burned by inadvertent contact with the platen.

The present invention relates to such a press which is operated by compressed air and which is provided with a safety device to protect the operator, and which is electrically controlled- Thermosealing of patches on garments is a well established practice, but it is commonly a hand operation resulting in many variations from uniform results. Not only the pressure applied by hand, but the temperature and time lead to non-uniformity. Additionally, the garment structure as to buttons, seams and the like, lead to lack of uniformity within a single patch. The present invention provides a machine which overcomes these numerous disadvantages and a machine which may be operated by unskilled help without danger of injury.

It is the general object of the invention to provide a pressing machine capable of repeating operation under predetermined conditions, such as time, pressure and temperature, when heating is involved.

It is a further object of the invention to permit operation of the press only when the safety device is in its protective position.

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It is a further object of the invention to provide an automatic timer for the pressing action and further to have the timer take over full control and ending of the pressing cycle from the operator after initiation thereof by the operator as well as resetting the press for the next operation.

It is a particular object of the invention to provide a thermosealing patching press which applies substantially uniform pressure over obstructed areas of a garment, such as at seams and buttons, as well as at unobstructed areas.

Various other and ancillary objects and advantages of the invention will become apparent from the following description and explanation of a press embodying the features of the present invention.

Although the present invention may be embodied in presses of various kinds for various kinds of pressing operations, the invention is illustrated by a machine which is designed particularly for applying heat-sealed patches to garments. Such a machine has utility particularly in laundries and cleaning establishments where garments being cleaned are found to be torn and are, therefore, mended before delivery. Garments, such as workmens clothing, are most commonly subject to such operations. ,Patches have long been known for various sizes and of various materials, provided with a thermosetting or thermoplastic adhesive so that a suitable patch maybe placed over-a garment to be mended and the patch sealed on by heat and appropriate pressure. Such patches have heretofore been applied by a hand iron. This method has not been satisfactory for garments, such as shop uniforms, because the time of pressing, the pressure, and the temperature of the iron all vary, not only as to different operators, but from one patch to another with the same operator. As a result, some patches stay in place during laundering and some come off the garment. Such a machine is shown in the drawings, in which:

Fig. 1 is a perspective View of the press as positioned for operation.

Fig. 2 is a view of the same press shown in Fig. 1 as positioned in pressing.

Fig. 3 is a diagrammatic representation of the parts coupled with the electrical connections therefor.

It is to be understood that the invention is not limited to or by the illustrative embodiment shown in the drawings, and that numerous changes and modifications are contemplated as falling within the scope of the invention as expressed in the appended claims.

The assembly shown consists of more than one pressing platform on which work is placed to be pressed, and a movable arm carrying the pressing plate, so that while the platen functions on one platform, the other or others may be cleared from a previous pressing operation and be readied for a pressing operation.

The pressing platen moves vertically with respect to the platform as well as horizontally from one to another. The preferred mounting of the platen for these move ments includes a generally horizontal arm swinging about a vertical axis, and a vertically movable, carrier for the platen proper fixed on the horizontal arm. Where the movable platform swings about a vertical axis, the several platforms radiate from that axis. The axial region may be employed for mounting certain controls for the press so that they remain in a fixed position.

The platen is raised and lowered by an air-operated piston electrically controlled. The electric control is such that once operation of the press is initiated by closing a circuit, the platen moves onto the work, remains for a set time, is withdrawn, and the circuit opened for a repeated operation.

Safety means is provided such that the space between the platen and the platform is closed against accidental entry by the o perators hands, while the platen moves onto the platform and remains there. This is effected by a movable cage, which is so mounted that the heated platen is always upwardly within the cage, again to prevent accidental contact with the platen. A feature of the cage is the regulation of its movements.

The cage is arranged to have alocked idle position and a normally stable protective position, to be unlocked manually from idle position to fall into the protective position, to be locked in protective position by the arrival of the platen, to be moved by the rising platen to locked idle position, and in idle position to be ready for a repeated operation. After leaving idle position, and prefably upon reaching protective position, the cage is employed automatically to close the controlling circuit.

The foregoing functions are satisfied by a machine having two radial base legs 10 and 11 forking from a central axial region 12. The legs have pressing platforms 13 and 14 preferably of molded resilient silicone foam blocks.

The axial region 12 has a fixed post 16 to which a hori zontally swinging arm 17 is mounted on a vertical axis. The free end 18 of the arm 17 carries an upwardly extending cylinder 19 in which is housed a vertically movable piston 20. Air pressure is used to raise and lower the piston in a conventional manner, and thus air pressure serves to provide and maintain the pressing pressure. The

lower end of the piston carries a working element, such as pressing platen 21, within which is an electrical heating element 22 thermostatically controlled so as to maintain apredetermined temperature. In Fig. 3 the numeral 23 designates diagrammatically a thermostat control.

The apparatus is arranged for complete safety in operation. When the pressing platen is in its uppermost position above a work piece on a platform, the pressing element 21 may not be lowered by action of the cylinder 19 until a safety device, preferably in the form of a cage 25, is in its protective position. The safety cage 25 is mounted on a vertically swinging arm 26 pivoted at 27 adjacent the inner end of the horizontal arm 17. The cage 25 is formed so that it completely surrounds the heated pressing platen in a manner to prevent an operator inserting a hand or arm into the path of the pressing platen zl, or in contact with the heated platen. When the safety cage 25 is in its raised position, the apparatus is electrically inoperative, and when the cage 25 rests in its protective position by' its own weight, it closes a switch 40 which initiates operation, as described hereinafter.

The cage 25 and the platen are associated by an automatic latching means. Pivoted to the cage at 31 (Fig. 3) is a vertical manual lever 32 projecting upwardly with a knob 33 to be grasped by the operator to be moved into dotted line position 34 (Fig. 3), against the tension of spring 35. The lower end 36 of the lever 32 normally rests on a ledge 37 carried by the platen 21, so that the platen holds the cage in its idle position. Manual movement of the lever releases the latch and lets the cage fall into the position shown in Fig. 2, in which position the spring 35 effects latching the cage to the platen for movement upwardly to the position of Fig. 1 by the platen 21. When the platen reaches protective position it closes a switch 40 as shown in Fig. 2. The closing of switch 40 energizes a solenoid valve 41, which then causes air pressure to move the piston 20 down.

The air pressure is provided from a main supply42 through a cleaner 43, through a reducing valve 44, and through an oiler 45 which introduces drops of oil into the passing air to lubricate the piston. The air then passes via conduit 46 to a T-fitting 47 which discharges via coupling 48 into solenoid valve 41 and via coupling 49 to a manifold 51 at the top of cylinder 19.

The manifold is associated with valve means which has two positions-one to introduce air to the top of the cylinder and vent air. from the bottom of the cylinder and the other, to introduce air to the bottom of the cylinder and vent air from the top of the cylinder. Any conventional valve mechanism for this purpose may be employed. Such a valve structure includes a sliding valve member 52, shown more or less diagrammatically in Fig. 3. In the position shown, the valve member 53 permits air to enter the bottom of the piston via conduit 53, but, when moved to the left in Fig. 3, it uncovers port 54 and lets air move the piston 16 downwardly. The valve is so moved to the left by a diaphragm S in a casing 56 which diaphragm is normally urged to the right by a spring 57. The numeral 58 indicates a connecting link from the slide valve 52 to the diaphragm 55. Numeral 59 represents a small hole in the casing 56 on the pressure side to vent air at a rate slower than air is supplied via tube 60 connecting the solenoid casing 41 with the casing 56. Solenoid valve 41, when energized, lets air pass from tube 48 into tube 60 to move the diaphragm 55 to the left. When the solenoid is not energized, the spring 57 moves the diaphragm to the right and hence the slide valve 52, thus causing the piston to rise. Suitable exhaust holes 62 and 63 from the cylinder are indicated but the connections thereto are conventionally involved in the slide valve.

For automatic operation following the closure of switch- 46. there is included a standard timing clock for opening the circuit to the solenoid valve 41 after a preset time.

The timer is represented generally by the dotted line block 65. It has a clock motor which runs when the switch 40 is closed. The clock operates to open a normally closed timed switch in series with the switch 40 and solenoid valve 41. The opening'action takes place after a preset running time for the clock to deenergize the solenoid valve 41, and then after a short interval of a fraction of a second the timed switch closes and the clock returns to starting position. During said short interval, the deenergization of solenoid valve will have caused the cage 25 to rise with the platen and thereby open switch 40. Thus, on return of the platen to idle position the press is ready for a repeating operation.

The timing clock above described is a standard one capable of numerous internal and external electrical connections for ditferent results. Those presently utilized are now described. Numeral 66 represents the clock and numeral 67 the pointer manually set for a chosen period of the pressing operation. Numeral 68 represents the normally closed switch opened by the timer, with leads 69 and 70 to'it.

The main power leads '72 and 73 supply outlet box 74 into which the cable 75 to the heating element 22 may be plugged. They then lead to a two-wire cut-ofi switch 76 mounted on post 16, from which the line 77 leads to the clock 67 and connection 70. Line 78 leads to the switch 40 from which line 79 leads to the clock and line 80 leads through the solenoid valve 41 to line 69.

In operation, when work is placed on one pad 12 or the other 13, the arm 17 is swung over the work, and knob 33 pushed inwardly. This unlatches the cage at the ledge 37, allowing the cage to drop into place. After this, and preferably at the bottom of its fall for reasons given later, it closes switch 40. This energizes solenoid valve 41 through the normally closed switch 68 in the timer, and air pressure forces the piston and platen down. When down the ledge 37 again latches onto the lever 32 at its end 36. The platen remains down so long as the solenoid remains energized and this time period is controlled by the set of pointer 67 on its dial. The clockwork then opens switch 68, which deenergizes solenoid valve 41 causing the platen to rise and lift the cage. The up stroke of the cage opens switch 40, which act must take place at a proper time relative to the time that switch 68 returns to its normally closed position. Because the responses are not instantaneous, depending upon pneumatic passages of air, the opening of switch 40 and the resetting of the timer switch 68 must be relatively timed with respect to the responses of the press. For this reason, the switch 40 is operated at the bottom point of fall of the cage;

However, it is to be understood that other but standard electrical equipment is available for by-passing switch 40 immediately after its closure, to take over control of the cycle and thereby destroy the controlling function of the cage. In the present instance where the platen moves between idle and pressing positions in about one-second, the location of switch 40 as disclosed gives adequate return time for the timer switch 68, which resets in about second. The disclosed arrangement is preferred to one in which the full pressing time is controlled wholly by the time clock. By compelling the energizing current during the entire operation to pass through the switch 40, the opera tor may always retract the platen merely by lifting the cage to open switch 40. So breaking the circuit to the timer 65 will cause it to return to normal starting position even though it has not completed its set advance.

This application is a continuation-in-part of applica' tion Serial No. 531,455, filed August 30, 1955.

We claim:

1. A press comprising a fixed horizontal platform, a platen vertically movable from idle position into pressing position over and toward said platform and away from said platform, a protective cage associated with said platen and vertically movable by gravity from idle position to withthe cage and the platen for holding the cage in idle position during the idle position of the platen and arranged for moving the'cage from protective to idle position by movement of theplaten from pressing to idle position, said latching means being releasable manually from latching position when the platen is out of pressing position, an electric circuit, an electric control switch in said circuit arranged to close the circuit by action of the cage when moving out of its idle position to protective position, a solenoid insaid circuit, platen-moving means normally urging-said platen into idle position and associated with said solenoid to move the platen out of idle position into pressing position and to hold it in pressing position only during energizing of said solenoid, a timing clock actuated to run for a preset time upon closing said switch, a timed switch in said circuit normally closed and arranged to be opened at said preset time by said clock and then automatically to-close after a preset interval of time, whereby said timed switch on opening deenergizes the solenoid, resulting in vertical movement to the idle positions of the platen and the cage latched therewith, and resulting in opening of the control switch prior to the expiration of said preset interval of time.

2..A press comprising a fixed horizontal platform, a platen vertically movable from idle positioninto pressing position over and toward said platform and away from said platform, a protective cage associated with'said platen and vertically movable by gravity from idle position to protective position to guard the space between the platform and the platen, automatic latching means associated with the cage and the platen for holding the cage in idle position during the idle position of the platen and arranged for moving the cage from protective to idle position by movement of the platen from pressing to idle position, said latching means being releasable manually from latching position when the platen is out of pressing position, an electric circuit, an electric-control switch in said circuit arranged to close the circuit by action of the cage when moving out of its idle position to protective position, a solenoid valve in said circuit, a pneumatically operated platen-carrying piston and a cylinder therefor arranged to move the piston in both directions by alternative connections of air pressure to the cylinder, means providing a supply of air under pressure, said solenoid valve when energized establishing air connection from said supply to one end of said cylinder to move the platen from idle to pressing position and to hold it in pressing position only during energizing of said solenoid valve, said solenoid valve being normally biased when deenergized to establish air-connection from said supply to the other end of said cylinder to move the piston to idle position, a timing clock actuated to run for a preset time upon closing said switch, a timed switch in said circuit normally closed and arranged to be opened at said preset time by said clock and then automatically to close after a preset interval of time, whereby said timed switch on opening deenergizes the solenoid valve, resulting in vertical movement to the idle positions of the platen and the cage latched therewith, and resulting in opening of the control switch prior to the expiration of said preset interval of time.

3. A press comprising a plurality of fixed horizontal platforms, a platen for movement to a position over each platform, a movable member carrying said platen for movement to each of said positions, said platen being vertically movable from idle position into pressing position over and toward a platform and away from said platform, a protective cage associated with said platen and vertically movable by gravity from idle position to protective position to guard the space between a platform and the platen, automatic latching means associated with the cage and the platen for holding the cage in idle posi- 6 tion during the idle position of the platen and arranged for moving the cage from protective to idle position by movement of the platen from pressing toidle position; said latching means being releasable manually from latching position when the platen is out of pressing position, an

electric circuit, an electric control switch in said circuit arranged to close the circuit by action of the cage when moving'out of its idle position to protective position, a solenoid in saidcircuit, platen-moving means normally urging said platen into idle position and associated with said solenoid to move the platen out of idle position into pressing position and to hold it in pressing position only during energizing of said solenoid, a timing clock actuated to run for a preset time upon closing said switch, a timed switch in said circuit normally. closed and arranged to be opened at said preset time by said clock and then automatically to close after a preset interval of time, whereby said timed switch on opening deenergizes the solenoid, resulting in vertical movement to the idle positions of the platen and the cage latched therewith, and resulting in opening of the control switch prior to the expiration of the said preset interval of time.

4. A press according to claim3 in which the plurality of platforms are radially located the same distance from a vertical axis, and in which the movable member carrying the platen swings about the axis.

5. A press comprising a fixed horizontal platform, a platen vertically movable from idle position into pressing position over and toward said platform and away from said platform, a protective cage associated with said platen and vertically movable by gravity from idle position to protective position to guardthe spacev between the platform and the platen, automatic latching means associated with the cage and the platen for holding the cage in idle position during the idle position of the platen and arranged for moving the cage from protective to idle position by movement of the platen from pressing to idle position, said latching means being releasable manually from latchingposition when the platen is out of pressing position, an electric circuit, an electric control switch in said circuit arranged to close the circuit by action of the cage when moving out of its idle position to protective position, a solenoid valve in said circuit, a pneumatically operated platen-carrying piston and a cylinder therefor arranged to move the piston in both directions by alternative connections of air pressure to the cylinder, said I solenoid valve when energized establishing air connection to move the platen from idle to pressing position and to hold it in pressing position only during energizing of said solenoid valve, a timing clock actuated to run for a preset time upon closing said switch, a timed switch in said circuit normally closed and arranged to be opened at said preset time by said clock and then automatically to close after a preset interval of time, whereby said timed switch on opening deenergizes the solenoid valve, resulting in vertical movement to the idle positions of the platen and the cage latched therewith, and resulting in opening of the control switch prior to the expiration of said preset interval of time.

6. A press according to claim 5 in which there are a plurality of horizontally spaced platforms radially located the same distance from a vertical axis, and in which there is a movable member carrying said platen, said movable member being mounted to swing about said axis.

7. A press according to claim 5 in which said platform is a silicone foam.

8. A press according to claim 5 in which there are a plurality of spaced platforms of silicone foam radially located the same distance from a vertical axis, and in which there is a movable member carrying said platen, said movable member being mounted to swing about said axis.

9. In a pressing machine a pair of coacting relatively moving pressing members normally biased into non-press? ing position, press-closing means including a fluid actuated motor and motion transmitting mechanism for moving one of, said members into pressing engagement with the other member, conduit means for the supply and exhaust'of motive fluid to and from said motor and including a normally closed inlet valve and a normally opened outlet valve, a solenoid arranged when energized to move said valve means to press-operating position with said inlet valve open and said outlet valve closed, and when deenergized to reverse the positions of said valve and thereby effect movement of the pressing members to their normally biased position, a protective cage normally biased to move into a protective position surrounding said pressing members and movable out of said position to an idle position corresponding to the normally biased positions of said pressing members, latching means be tween said cage and said pressingmembers operable to engage said cage in its normally biased position and to move it to and hold it in said idle position, said latching means being manually operable to release the cage for movement to its normally biased position, an electrical starting switch closed by movement of said cage to its normally biased position, an electrically operated timer containing a normally closed timed switch arranged to be opened only for a short interval of time following a preset time period beginning with energization of said timer, said solenoid being in series with said starting switch and said timed switch, and said timer being energized by closing said starting switch.

10. In a pressing machine having electrical means to be energized for actuating the machine, a safety cage and relatively movable normally separated pressing means movable together to press only during electrical energization of said electrical means, an electrically operated timer containing a normally closed timed switch arranged to be opened only for a short interval of time following a preset time period beginning with energization of said timer, a starting switch, said electricalmeans, said starting switch and said timed switch being in series for conconnected to be energized by said starting switch, said starting switch being arranged to be closed by movement of the cage into protective position from idle position and being movable to idle position by said pressing means in moving out of pressing position, and manually releasable latching means associated with said cage and pressing members and operable to move the cage out of protective position by movement of the pressing means out of pressing position.

11. In a pressing machine having electrical means to be energized for actuating the machine, a safety cage and relatively movable normally separated pressing means movable together to press only during electrical energization of said electrical means, a timer containing a normally closed timed switch arranged to be opened only for a short interval of time following a preset time period beginning with the timing action of said timer, a starting switch, said electrical means, said starting switch and said timed switch being in series for connection to a source of electric power, said cage being movable into protective position from idle position and being movable to idle position by said pressing means in moving out of pressing position, said timer being arranged for initiation of timing action by saidcage moving into protective position, and said starting switch being arranged to be closed by said cage moving to protective position, and manually releasable latching means associated with said cage and pressing members and operable to move the cage out of protective position by movement of the pressing means out of pressing position.

References Cited in the file of this patent UNITED STATES PATENTS 1,672,303 Carroll et al. June 5, 1928 2,315,151 Booth Mar. 30, 1943 2,324,660 Yanchenko July 20, 1943 2,341,689 Bryson Feb. 15, 1944 2,775,129 Peras Dec. 25, 1956

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