US2313917A - Control of power actuated machinery - Google Patents

Description

M.rh1e,194 s." H. H. BROWNLEE 2,313,911

CONTROL OF POWER ACTUA'IED MACHINERY Filed Jan. 29, 19:8 2 Sheets-Shut 1 3 INVENTOR M flaeatwrwaxv Bean M52 may W ATT'O R N EY March16,1943. H H; BRQWNLEE 2,313,917

CONTROL OF POWER ACTUATED MACHINERY Filed Jan. 29, 1938 2 Sheets-Sheet 2 ATTORNEY v Patented Mar. 16, 1943 CONTROL OF POWER ACTUATED MAC IIINERY Henry Herbertson Brownlee, New Yorka N. Application January 29, 1938, Serial No. 187,593

12 Claims.

This invention relates to the 'art of controllin power actuated machinery. It is of special utility in association with machines that operate quick- 1y, repeatedly and with great force as in power presses working on materials of various sorts. It is exemplified herein as applied to a garment pressin connection with which, it has special advantages. Its objects are simplicity of operation, speed and efficiency of working and security against accidents.

In the laundry and tailoring business numerous types of machines are used for the pur- I pose 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 thatthe machine attendant had adjusted upon'a padded, and sometimes also heated, lower .buck.

To work such a machine it is necessary 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 ac-v cidentally operating the press with one hand while adjusting the garment on the lower buck with the other, a dual control system requiring the joint use of two hands to close the press has been resorted to. Under that system the attendant must keep both hands on theair valve controls until the head has been locked in the ironing position; This expedient, however, affords no protection to others should they 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 emciency are secured because it is only necessary for the attendant to step away from the machine 50 .upwardly extending bracket 5 supports a rocker .in order to cause the power to be applied and whereby on the attendants' returnand, in the 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 for its normal position in readiness for a subsequent operation.

The invention serves with special advantage where the operation of a group of machines is 5 supervised by a single attendant. By placing the machines in line or arranging them about a central 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.

These and other desirable characteristics of the invention are secured by the maintenance within a space surrounding the machine, or each machine of a group, or the danger zone thereof, of a field of energy sensitive to the movement into and out of it of external bodies, and by suitable power applying and power disabling controlling apparatus responsive to theresulting' energy effects. Power disablement is also provided on failure of the controlling apparatus to function normally. In presses for ironing damp garments, the controlling apparatusis caused to be responsive to maintain and then to disable the power by and with the aid of suitable devices sensitive to the moisture content of the garments themselves or to other effective evidence of the completion of the ironing operations.

In the drawings:

Fig. 1 is a sideelevatlon 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 oi. controlling circuits. 7

Fig. 4 is a diagrammatic plan view of a group of machines.

Fig. 5 is a plan view, in outline, of a typical 40 ironing head showing an effective location of a plurality of auxiliary devices for determining the duration of the ironing period of damp garments, and

Fig. 6 is an end view of an alternative ironing head, partly in section, equipped with a thermostatic device. l

- The press base or frame i supports a tablelike top 2, on which is mounted a goose neck support 3 for a lower or padded buck 4. An

arm 6, which carries at its forward end an upper or ironing back I. A rearward extension 10 by a system of levers working on the toggle When the air is thus let in the piston descends pushing down on one arm of a bell crank II and, at the end of its stroke, bringing the other arm almost into alignment withthe link It, thereby greatly adding to the force exerted on the garment. On the release of the air the retractile springs i5, i6 aided by the counterweight 8 open the press.

ment moisturecontrolled 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 48 (see may be arranged according to standard engi- The valve provides for a short passage forthe compressed air through the duct l2a to the cylinder 10 and, therefore, for quick action both in closing andopening the press. This valve has two plugs, better shown in Fig. 2, one, i1, normally closing the inlet i8 to the outlet it leading to the cylinder. The other II, is normally open position to an exhaust outlet 2!. The plugs are joined by a spacer pin 22. A magnet 23 when energized by electric current in its coil 24 attractsthe armature 25 which depresses a plunger 2} against a spring 21 which in turn presses down a'second plunger 28 to close the valve 20 and to open it at 11. The re,- verse action occurs when the magnet is deenergized. This structure may be supported by a bracket 29 to thebase or frame I.

In the circuit diagram Fig. 3 the garment press is shown-in general outlinewith the figure of an attendant "a standing by. A protecting and controlling field' of energy is indicated by the space 30 within the dotted line surrounding the press. This space by suitable adjustments is .eifective to a depth of several inches and may neering practice. This entire circuit diagram typifies one of many controlling arrangements suitable for carrying out the operating features of the invention.

' Assuming the oscillator has been started and .the field of energy around the press established, the operation is as follows: Normally, with the attendant "a, 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 l3, oiiers a low impedance to current fiow and relay ll receives insuillcient current for its energization. when, however, the attendant approaches the press for the purpose, say, of adjusting a garment 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 43, ll oii'ers a higher impedance to the current from the coil 30. Relay 4! thereupon attracts its armature, opens contacts and Bi and closes contact it.

As the protection relay I9. at such times as the oscillator is working, is energized by the B batbe limited, if desired. to a zone near the dangerous working parts. The press should be supported a few inches above the fioor, as shown,

or it may be otherwise insulated from ground oran 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 cells 32, 38,

inductively coupled-:In-the input circuit the coil 32 and condenser 34, together with the concoil 38 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 l3 and condenser 44. Relay ll controls a locking relay 45 and these two relays jointly control theoperation' of the magnetic air valve l I. Also controlling the circuit of the magnetic air valve and the circuit of the locking relay 4! is a release relay' 4 the coil of which is in series with one or more gartery 38 there is now a closed circuit from battery 53 through the back contact 54 of release relay ll, front contact 52 of relay 4i and the coil of relay 4! which relay thereupon closes its contacts 55 and I6. This relay 45 is now locked in a circuit from battery 53 through the contact of relay 39, back contact 54 of relay 48 and its own contact I6.

The attendant having adjusted the garment steps away from the press thereby removing her body from the energized field 3O whereupon the normal frequency of the oscillator is restored and thetuned circuit 0, again eflectively shunts current from relayji. This relay 4i thereupon is deenergized and its normal contacts "and II become again closed. Now the magnetic air valve is in a closed circuit from the battery It through contact of relay 8|, back contact Q4 of relay 4', back-contact ll oi relay 4i and. front contact II of relay 4!. This causes compressed airto 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 30 the press will immediately be released by the opening'of the circuit of the air valve at contact 50 of relay ll. Without such outside influence, however, the press closes andv the air valve comes under control of the garment switches 41, (Fig. 5). or 41s,

. (Fig.6), which, will close, efiectiveiy. by reason of current fiow' through the moisture of the garment, whenplaced flush with the ironing head as in Fig. 5, or, likewise, by reason of the cooling eilect oi the garment, if thermostatically sensitive and placed in a compartment just above the ironingsurface as in Fig. 6. One or more of these. garment switches now closes its contact, due to the moisture or coollng'eiiect -age 13,91?

of the garment, and relay 46 is energized in a circuit from battery 53, through contact of relay 39 one or more of the closed switches 41 and back contact of relay 4i. The closure of contact 51 of relay 48 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 54 releasing the locking relay 4!. In a few seconds the reverse operation of the switches 41, or 41a, takes place due to the drying, or heating of the garment, releasing relay 46 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; v

The protection relay 39, which, as stated, becomes energized when the oscillator is in operation, will release, opening all circuits fed'by the battery 53 and thus disable the power for the press, on any failure of normal operation of the oscillator.

A convenient arrangement for the control 0 a group of three presses J2 and 83 is shown in Fig. 4. The attendantifla, having adjusted a garment in press 6|,leit it to automatically close, adjusted another in press 62 and left it with like result, is here shown in the act of adjusting a third garment in press 63.. On leaving the latter, it, too, will automatically close and, due to an appropriate time schedule of operations, pressil will have opened or be about to open, whereupon the cycle of operations, as stated, may forthwith be repeated. At the left of the attendant is a table 64 for a supply of damp garments and a rack 65 for supporting garments that have been ironed and dried,

I claim: v

'1. A power operated garment press, means for maintaining within a space adjoining the press a field of energy sensitive to movements relative thereto of external bodies, a device responsive to the moisture content of a garment in the press, and power applying and disabling means under the joint control of said energy maintaining means and said device and rendered effective to close the press only upon the movement of such a body from a position within to.

a position outside 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 of 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 to the movement of external bodies in said space, and in- A cluding means in the vicinity of at least one of said members to set up a condition sensitive to the moisture content of a garment in the press,

apparatus associated with said generator and responsive to 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. a,

3. A textile press comprising a stationary buck member, a, pivoted pressing head member, fluid power motor means to actuate saidhead mem- 10 movement of the press head member.

4. 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, 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 members 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 of said field, and a relay controlled by the ,condition of the system to cause the actuation of said valve to control the movement of the press head member.

5. A textile press comprising a stationary buck 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 of said members, a conductive .path for said electrode subject to resistance variation 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 initial ,energization oi said eiectromagnet, and means 'controlled automatically in response to the variation of resistance in saidconductive path to temporarily maintain the energization of said electromagnet to holdthe head member down I on the buck member and finally to cause the deenergization thereof to move said head member away from 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 insulatedly mounted on one of said members, a conductive path for said electrode subject to resistance variation when said movable member is actuated,

,operator controlled means to actuate said valve to move said movable member toward the other variation of resistance in said conductive path to cause the said circuit to change from one condition of operation to the other to actuate said valve to movesaid movable member away fro the other member. s

'7. A textile press comprising two pressing members, one of which is movable towards and away from the other, fiuld 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 member, a pivoted head member, fluid power member, an electric circuit having two conditions of operation, and means responsive to the 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 the other 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 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 and away 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 members, one of whichis movable into and out of engagement with the other, 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 has been moved into engagement with the other member, electro responsive 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 member out of such engagement, means controlled at will to cause the energization of said electro responsive means, and means controlled automatically in response to the variation of resistance in said conductive path to cause the deenergization of said electro responsive means.

10. A machine, power means iorworking said machine, an electric generator, electroresponsive means under the control of said generator and controlling in turn the application of said power means to said machine, and conducting means said generator with the aid of said conducti means maintaining within a space surrounding said machine a field of electrostatic energy sensitive' to movements of external bodies in said 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 effect an operation of said electroresponsive means to work the machine and upon another such predetermined change to effect an operation of said electro responsive means to stop the working of the machine.

11. A garment press, power meansfor closing and opening said press, an electric generator for controlling the application of said power means to said press, conducting means extending from saidgenerator 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 effect 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-oi said conducting means maintaining within a space surrounding said machine a field of electrostatic energy sensitive to movements of external bodies into and out of said space, said generator being reactively sensitive to said field and responding upon a predetermined change in the energy thereof caused by the movement of such a body out of said space to effect an operation of said mechanism to work the machine and responding upon another predetermined change in the energy thereof caused by the entrance of such a body to said space to eflect a second operation of said mechanism to stop the working thereof.

H. HERBERTSON BROWNLEE.

extending from said generator to said machine.

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