USRE22527E - Control op power actuated - Google Patents

Description

1944- H. H BROWNLEE Re. 22,527

CONTROL OF POWER ACTUATED MACHINERY Original Filed Jan.. 29, 1958 2 Sheets-Sheet 1 ATTORNEY TOR Aug. 15, 1944. H. H. BROWNLEE I CONTROL OF POWER ACTUATED MACHINERY 2 Sheets-Sheet 2 Original Filed Jan. 29, 1958 Y/M/ZM ATTORNEY ironing position.

affords no protection to others should they Reissued Aug. 15, 1944 CONTROL OF POWER ACTUATED MACHINERY I Henry Berbertson Brownlee, Washington, D. 0.

Original No. 2,313,917, dated March 16, 1943, S-

rlal No. 187,593, January 29 1938. Application for reissue December 14, 1943, Serial No.

14 Claims.

This invention relates to the art of controlling power actuated machinery. It is of special utility in association with machines that operate quickly, repeatedly and with great force as in power presses working on materials of various sorts. garment press in connection with which it has special advantages. Its objects are simplicity of operation, speed and efllciency of working and security against accidents.

In the laundry and tailoring business numerous types of machines are used for the purpose of ironing and pressing garments after the washing or dry cleaning operations. A common machine for this step is operated by pneumatic force applied to a heated ironing head, or buck, to bring it down. and hold it under pressure against a garment that the machine attendant had adjusted upon a padded, and sometimes also heated, lower buck.

To work such a machine it is necessary for the attendant to exercise control of compressed air for the energization of the pneumatic device. Hand operated air valves have been used for this purpose and, to protect the attendant from accidentally operating the press with one hand while adjusting the garment on the lower buck with the other, a dual control system requiring the joint l'se of two hands to close the press has been resorted to. Under that system the attendant must keep both hands on the air valve controls until the head has been locked in the This expedient, however,

thoughtlessly intrude the danger zone. As the space between the bucks when the press is open may be approached from all sides, the possibility of such intrusion is a hazard. especially in a busy laundry where numerous machines are in operation and many workers are moving about.

A machine equipped according to this invention is safe because it is rendered inoperative, or, if started, is immediately restored, by the mere presence near its working parts, or by the approach thereto from any direction, of the attendant or of any other person or body of like capacity. Simplicity of operation, speed and efliciency are secured because it is only necessary for the attendant to step away from the machine in order to'cause the power to be applied and whereby on the attendants return and, in the It is exemplified herein as applied to a its normal position in readiness for a subsequent tral area the attendant is free immediately after preparing one machine for operation to pass to the next in line and so on in rapid succession. The movements can be so timed that when the last machine has been attended to the work in the first is finished.

application of the invention to a garment press,-

on either such return or the drying of the garment in the press, whichever happens first, the power is disabled and the machine is restored to function normally.

These and other desirable characteristics of the invention are secured by the maintenance within a space surrounding the machine, or each machine or a group, or the danger zone thereof, of a field of energy sensitive to the movement intoand out of it of external bodies, and by suitable power applying and power disabling controlling apparatus responsive to the resulting energy effects. vided on failure of the controlling apparatus to In presses for ironing damp garments, the controlling apparatus is caused to be responsive to maintain and then to disable the power by and with the aid oi suitable devices sensitive to the moisture content of the garments themselves or to other eilective evidenceof the completion of the ironing operations.

In the drawings:

Fig. 1 is a side elevation of a garment pressing machine.

Fig. 2 is a vertical cross section of a magnetic air valve.

Fig. 3 is a. diagrammatic representation of a system of controlling circuits.

Flgi 4 is a diagrammatic plan view of a group of machines. 1

Fig. 5. is a plan view, in outline, of a typical ironing head showing an effective location of a plurality of auxiliary devices for determining the duration of the ironing period of damp garments, and 4 Fig. 6 is an end view .of an alternative ironing head, partly in section, equipped with a thermostatic device.

The press base or frame I supports a table-like top 2, on which is'mounted a goose neck support 3 for a lower or paddedbuck 4. An upwardly extending bracket 5 supports a rocker arm 6,

which carries at its forward end an upper or' ironing buck I, A rearward extension of this arm carries a counterweight 8 and is connected to the piston 9 of a pneumatic cylinder III by a system of levers working on the toggle principle. The

Power disablement is also pro- .2 V heating of the ironing buck is commonly provided for by a system of steam pipes, and channels within the buck, not shown. In Fig. l the movable parts are shown by full lines in the closed position of the press and by dotted line in the open or normal position.

A magnetic air valve i I Fig. 2 is mounted alongside the pneumatic device and serves when energized to open the cylinder above the piston to a compressed air source through a duct l2. When the air is thus let inthe piston descends pushing down on one arm of a bell crank l2 and, at

the end of its stroke, bringing the other arm almost into alignment with the link l4, thereby greatly adding to the force exerted on the garment. On the release'of the air the retractile springs It, IS aided by the counterweight I open the press. I

The valve provides for a short passage for the compressed air throughthe duct I to the cylinder Ill and, therefore, for quick action both in closing and opening the press. This valve has two plugs, better shown in Fig. 2, one; ll, normally closing the inlet it to the outlet l9 leading to the cylinder. The other 20, is normally in open position to an exhaust outlet 2l. -The plugs are joined by a spacer pin 22, A magnet 23 when energized by electric current in its coil 24 attracts thearmature 25 which depresses a plunger 26 against a spring 21 which in turn presses down a second plunger 28 to close the valve 20 and to open it at l1. The reverse action occurs when the magnet is deenergized. This structure may be supported by a bracket 29 to the base or frame i.

In the circuit diagram Fig. 3 the garment press is shown in general outline with the figure of an attendant 20a standing by. A protecting and controlling field of energy is indicated by the space III within the dotted line surrounding the press. This space by suitable adjustments is effective to adepth of several inches and may be limited, if desired, to a zone near the dangerous working parts. The press should be supported a few inches above the floor, as shown, or it may be otherwise insulated from ground or an insulated screen adjoining the press may be utilized to define the field of energy. in which latter case the press may be grounded.

A convenient way to generate this field of energy is to provide an oscillator of high frequency which may be several hundred kilocycles, and such oscillator may be of any known type. As shown it is of the three element vacuum tube type 3i having input and output coils 32, 22, inductively coupled. In'the input circuit the coil 32 and condenser 34, together with the condenser efiect of the insulated press itself, or its protecting screen, form a tuned circuit determining the normal frequency at which the tube will oscillate. In the output circuit of the oscillator are the primary coil 35 of a transformer, the usual B battery 28, or other equivalent source of current, and a protection relay I9 shunted by a condenser 40. In circuit with the secondary coil 26 of the transformer is a relay 4| in series with 'a rectifier 42, which may be the copper oxide type. This relay is shunted by a tuned circuit comprising an inductance 42 and condenser 44. Relay 4i controls a locking relay 45 and these two relays Jointly control the operation of the magnetic air valve ll. Also controlling the cirmoisture controlled switches 41. The oscillator and the other parts of this circuit arrangement. except the magnetic air valve Ii and the garment moisture controlled switches 41, may be assembled in a box or container 42 (see Figs. 1 and 3) mounted on the frame of the press beneath the front edge of its table. On the outsideof this honor container a switch handle 49 may be provided for manual control in placing the oscillator in and out of operation. The oscillator starting equipment is not detailed but may be arranged according to standard engineering practice. This entire circuit diagram typifies one of many controlling arrangements suitable cult of the magnetic air valve and the circuit of the locking relay 4! is a release relay 4B the coil of which is in series with one or more garment close,

for carrying out the invention.

Assuming the oscillator has been tarted and the field of energy around the press established, the operation is as follows: Normally, with the attendant Ilia, and all other external bodies of ample capacity, outside the energized space, the oscillations generated are adjusted to be such that in the output circuit the tuned shunt 42, 44 offers a low impedance to current flow and relay 4| receives insuflicient current for its energization. When, however, the attendant approaches the press for the purpose, say, of adjusting agarment therein the capacity of the input circuit of the oscillator is increased, in consequence of which the frequency of the oscillations is changed-in this case lowered. At such lowered frequency the tuned shunt 42, 44 offers a higher impedance to the current from the coil 36. Relay 4| thereupon attracts its armature, opens contacts III and BI and closes contact 52. As the protection relay 1!, at such times as the oscillator is working, is energized by the B battery 38 there is now a closed circuit from battery 53 through the back contact 54 of release relay 46, front contact 52 of relay 4| and the coil of relay 45 which relay-thereupon closes its contacts 55 and ID. This relay 4! is now locked in a circuit from battery I! through the contact of relay 39, back contact 54 of relay 4! and its own contact 58.

The attendant having adjusted the garment steps away from the press thereby removing her body from the energized field I0 whereupon the normal frequency of the oscillator is restored and the tuned circuit 42, 44 again efl'ectively shunts current from relay 4|. This relay 4| thereupon is deenergized and its normal contacts 50 and BI become again closed. Now the magnetic air valve is in a closed circuit from the battery I52 through contact of relay 29, back contact 54 of relay 46, back contact 50 of relay 4| and front contact 55 of relay 45. This causes compressed a to be applied to close the press. If during the descending movement of the press any external object such as the attendant or another person enters the field 20 the press will immediately be released by the opening of the circuit 'of the air valve at contact III of relay 4|. Without such outside influence, however, the press closes and the air valve comesv under control of the garment switches" (Fig. 5), or 41a (Fig. 6), which will effectively, by reason of current flow through the moisture of the garment, when placed flush with the ironing head as in Fig. 5, or, likewise, by reason of the cooling effect of the garment, if thermostatically sensitive and placed in a compartment just above the ironing surface as in Fig. 6. One or more of these garment switches now closes its contact, due to the moisture or cooling effect of the garment, and relay 48 is operating features of the energized in a circuit from battery 53, through contact of relay 3! one or more of the-closed switches 41 and back contact II of relay ll. The closure of contact 51 of relay 8 provides an independent path from the battery 53 to the coil of the magnetic air valve II. In this operation relay 48 also opens contact I releasing the loci:- ing relay ll. In a few seconds the reverse operation of the switches 41, or "a, takes place due to the drying, or heating of the garment, releasing relay 48 and opening the circuit of the air valve.

This causes the release of the press and the lifting of its ironing head. The garment is now properly dried and ironed and the press is ready for another operation.

The protection relay 3!, which, as stated, becomes energized when the oscillator is inoperation, will release, opening all circuits ted by the battery Bland thus disable the powerfor the press, on anyfailure of normal operation of the oscillator.

-A convenient arrangement for the control of a. I group 01' three presses GI, 82 and 63 is shown in Fig. 4. The attendant, 30a, having adjusted. a garment in press 8 I left it to automatically close,

adjusted another in press 82 and left it with like result, is here shown in the act of adjusting a third garment in press 03. On leaving the latter, it, too, will automatically close and, due to an appropriate time schedule of operations, press Ii will have opened or be about to open, whereupon the cycle of operations, as stated, may forthwith be repeated. At the left or the attendant is a table 64 for a supply of damp garments and a rack 65 for supporting garments that have been of said space and to open the press either upon the movement of such a body from the position outside to a position within said space or upon a certain reduction of the moisture content oi. said garment.

2. A press having coacting members for ironing garments and the like, power mechanism for closing the press, and a controlling system for said power mechanism including an electric generator adapted to ,maintain within a space surrounding the machine a field of energy and being sensitive in its energy output tothe movement of external bodies in said space, and including means in the vicinity of at least one said members to set up a condition sensitive to the moisture ,content of a garment in the press, apparatusassociated with said generator and responsiveto variations in the energy output thereof for controlling the application of power to close said press, and apparatus associated with said moisture sensitive means and responsive to variations in the condition thereof for controlling the disabling of power to open said press.

3. A textile press comprising a stationary buck member, a pivoted pressing head'member, fluid power motor means to actuate said head member,

a valve to control said fluid motor means, means vicinity of said 76 to produce an electric field in the members, a. balanced electrical circuit havin two conditions oi! balance, means to cause said circuit to change from one condition of balance to the other when a body of a predetermined nature passes into and out of said field, 'and means controlled by the condition of the circuit to actuate said valve to control the movement of thepress head'member.

4; A textile press comprising two pressing members, one of which is movable towards and away from the other, fiuid power motor means to "actuate said movable member, an electrically actuated valve to control said fluid motor means,

- an electric system including a thermionic device with a control grid and a conductor extending from said grid to the press, said system producing an electric field in the vicinity of said mem-- bers and having two conditions of operation, said thermionic. device being sensitive to said field and causing the system to change from one condition of operation to the other when a body of a predetermined nature passes into and out oi. said field, and a relay controlled by the condition of the system to cause the actuation of said valve to control the movement .01 the movable press member.

5. A textile press comprising a stationary buck member, .a pivoted head member, fluid power motor means for actuating said head, a valve for controlling said head member, an electromagnet for controlling said valve, an electrode insulatedly mounted on one 01' said members, a conductive path for said electrode subject to resistance vari ation when. said head member is actuated, said electromagnet being adapted when energized to actuate said valve to move said head member towards the buck member and when deenergized to actuate said valve to move the head member away from the buck member, means controlled at will to cause the initia1 energization of said electromagnet, and means controlled automatically in response to the variation of resistance in saidconductive path to temporarily maintain the energization of said electromagnet to hold the head member down on the buck member and finally to cause the deenergization thereof to movesaid head member .away' Irom the buck member.

6. A textile press comprising two pressing members, one of' which is movable towards and away from the other, fluid power motor means to actuate said movable member, a valve for controlling said motor means, an electrode insulatedlymounted on one oi! said members, a conductive path for said electrode subject to resistancevariation when said movable member is actuated, operator controlled means to actuate safd valve to move said movablemember toward the other member, an electric circuit having two conditions of operation, and means. responsive to the variation of resistance in said conductive path. to cause the said circuit to changeirom one condition of operation to the other to actuate said valve to move said movable member away from the other member.

'7. A textile press comprising two pressing members, one of which is movable towards and away from the other, fluid power motor means to actuate said movable member, a valve for controlling said motor means, an electrode insulatedly mounted on one of said members, a conductive path for said electrode subject to resistance variation when said movable member is actuated, a system of electric circuits having two in said system to render the; system responsive" to the variation of resistancesaid conductive path to close said valve. to..move .said movable member away from the other member."

8. A textile press comprising two pressing, members, one of which is movable towards andaway from the other, fluid. power motor means to actuate said movable member, an electrode insulatedly mounted on one of said members, a conductive path for said electrode subject to resistance variation when said. movable member is actuated, a system of electric circuits having two conditions of operation for controlling said valve, operator controlled means to cause said system to change from one condition of operation to another to open said valve to move said movable member towards the other member, and means in said system to render the system responsive to the variation of resistance in said conductive path temporarily to maintain said valve open to hold said movable member down upon the other member and finally to close said valve to move said movable member away from. the other member.

9'. A machine having two work of which is movable into and out of engagement with the other, motor means to actuate said movable member, an electrode insulatedly mounted on one ofsaid members, a conductive path for said electrode subject to resistance variation when said movable member has been moved into engagement with the other member, electroresponsive means adapted when energized to actuate said motor means to move said movable member into engagement with the other member and when deenergized to move said movable 10. A machine, power means for working said machine, an electric generator, electroresponsive means under the control 01 said generator and controlling in turn the application of said power means to said machine, and conducting means extending from said generator to said '.machine, said generator with the aid of said conducting means maintaining within a space surrounding said machine a field of electrostatic energy sensitiveto movements of external bodies in said members, one

controlling the application of said power means to said press. conducting means extending from said generator to said press, said generator with the aid of said conducting means maintaining within a space surrounding the press a field of electrostatic energy sensitive to movements of external bodies in said space, said generator being reactively sensitive to said field and responding upon a predetermined change in the energy thereof caused by such a movement to efiect an operation of said power means to close the press, and controlling means associated with a garment in the press and sensitive to the moisture content thereof, said controlling means being responsive upon a predetermined reduction of the moisture in the garment to effect an operation of said power means to open the press.

12. A machine, power means for working said machine, an electric generator, electroresponsive mechanism under the control of said generator and controlling in turn said power means, and conducting means extending from said generator to said machine, said generator with the aid of said conducting means maintaining within a space surrounding said machine a held of electrostatic energy sensitive to movements of extemal bodies into and out 01 said space, said generator being reactlvely sensitive to said fleld and control said actuating means, means to produce an electric fleld in the vicinity of said members, a balanced electrical circuit having two conditions of balance, means to cause said circuit to change from one condition oi balance to the other when a body of a predetermined nature passes into and out of said field, and means controlled by the condition of the circuit to actuate said device to control the movement of the press head member.

14. A textile press comprising two pressing members, one oi which is movable towards and away from the other, means to actuate said movable member, an electrically actuated device to space, and said generator being reactively sensitive to said held and responding upon a predetermined change in the energy thereof caused by such a movement to eflect an operation of said electroresponsive means to work the machine and upon another such predetermined change to efiect an operation of said electroresponsive means to stopthe working of the machine.

. 11. A garment press. power means for closing and opening said press, an electric generator for control said actuating means, an electric system including a thermionic device with a control grid and a conductor extending from said grid to the press, said sysem producing an electric field in the vicinity of said members and having two cpnditions of operation, said thermionic device being sensitive to said fleld and causing the system to change from one condition of operation to the other when a body of a predetermined nature passes into and out of said field, and a relay controlled by the condition oi the. system to cause the actuation of said electrically actuated device to control the movement of the movable press member.

HENRY HERBERTSON' BROWNLEE.

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