US2058668A

US2058668A - Photoelectric safety control

Info

Publication number: US2058668A
Application number: US477573A
Authority: US
Inventors: Davis Ernest
Original assignee: Prosperity Co Inc
Current assignee: Prosperity Co Inc
Priority date: 1930-08-25
Filing date: 1930-08-25
Publication date: 1936-10-27
Anticipated expiration: 1953-10-27

Description

Oct. 27, 1936. DAVls 2,058,668

PHOTOELECTR IC SAFETY CONTROL Original Filed Aug. 25, 1930 3 Sheets-Sheet l I NV ENTOR.

A TTORNE Y5:

0a. 27, 1936 DAWS 2,058,668

PHOTOELECTRIC SAFETY CONTROL Original Filed Aug. 25, 1930 5 Sheets-Sheet 2 INVENTOR.

132 5'0 I 5 137 BY- 134 ;gL-' M\*7" M Z F 4- ATTORNEYS.

Oct. 27, 1936. DAVls 2,058,668

PHOTOFLEGTRIC SAFETY CONTROL Original Filed Aug. 25,1950 5 Sheec-Sheet s I N VEN TOR viz M 1240? A TT ORNEYS'.

Patented Oct. 27, 1936 PHOTOELECTRIC SAFETY CONTROL Ernest Davis, Syracuse, N. Y., assignor to The Prosperity Company Inc Syracnse,N. 1., a

corporation of New York Application August 25, 1930, Serial No. 477,573 Renewed March 4, 1938 16 Claims. (01. 1121-38) -This invention relates to fabric pressing machines and particularly to control means for such machines as garment and ironing presses.

The pressing elements or press jaws of power 5 operated pressing machines come together with great pressure and many operators have been injured by having the press close before they remove their hands from between the pressing elements. Various means have been devised to 10 render pressing machines more safe and to prevent such injuries. The common safety means now employed is some form of two-hand control which requires the operator to use both hands to eflect a closing of the press and thus insures 15 against the operator closing the press while one hand is still between the pressing elements. Two-hand control devices have greatly lessened the danger from pressing machines, but with such safety means it is possible for a second per- 20 son standing near the operator be injured by the pressing machine. In many instances the twohand control mechanism is put out of order, either accidentally or maliciously, and it becomes possible for an operator to use one hand to close the 25 press, thus slightly increasing the speed at which work may be performed and greatly increasing the hazard of injury.

Theprincipal object of this invention is to.provide means for controlling the closing of a pressing machine and to operate these means through light sensitive control mechanism which will not permit the press to close so long as the opertaor, or any other person, is close enough to the pressing elements or press jaws to be injured thereby.

35 A further object of the invention is to provide control means, including light'sensitive means,

for closing a. pressing machine which will operate automatically to close the press when the operator steps out of reach of the pressing elements.

4 Other obiects and advantages will appear and will be pointed out as the description proceeds.

to the accompanying drawings. in which like characters designate corresponding parts in all the views.

Figure 1 is a fragmentary view in perspective,

'0'! a pressing machine to which my invention applied.

Figure 2 is a side elevation of a pressing machine such as illustrated in Figure l.

55 Figure 3 is a schematic showing, mostly in section, of the control mechanism of the pressing machine shown in Figures 1 and 2.

Figure 4 is a sectional view of a portion of the control mechanism of the press shown in Figures 1 and 2. 5

Figure 5 is a schematic showing; mostly in sectlon; of a modification of the control mechanism shown in Figure 3.

My invention is designed primarily for use with pressing machines having an opening and closing movement. A pressing jaw or head II is secured to a yoke H which is pivotally mounted at it on a pressing machine frame It. The pressing head I I is movable toward and from a fixed pressing element, Jaw or buck l5 which is supported by a neck l6 mounted on the pressing machine frame II. A fluid motor I8 is oscillatably mounted at IS on the pressing machine frame id and is provided with a piston rod which is pivotally connected at 2| with a bell crank 23. The bell crank 23is pivotally mounted at 2 3 on the pressing machine frame Ml. A connecting link 25 is pivotally connected at 26 to the yoke I2 and at 21 to the bell crank 23.

The link 23 and the upstanding arm of the bell crank 23 form a toggle which is broken when the press is open. Operation of the fluid motor l8 moves the piston rod 20 to rock the bell crank 23 and move the toggle intostraightened position to bring the pressing element II into contact with the buck IE to close the press. A spring 30 is connected at its upper end to the pressing ma chine frame M, and at its lower end to the bell crank 23. The spring 30 normally holds the press in open position. The mechanism thus far described is of the conventional type and the present invention can readily be used in connection with any type of fabric or garment press.

The motor It comprises a cylinder 32 having a piston 33 movable therein. The piston 33 is rlg- 4o idly connected to the piston rod 20. Working fluid passes to and from the cylinder 32 through a pipe 38 which connects with the cylinder 32 at one end and connects at the other end with a relief valve housed in a valve casing '36 (see Fig- 45 are 3).

The valve casing as contains a normally closed intake valve 40 and a normally open exhaust I valve 4| which are connected together by a spacer rod 02 so that they operate as a unit. A spring 43 holds the valves 40 and 4| in normal position. The exhaust valve 4| is formed with a valve stem N which projects through the end of the valve casing 38. A rocker arm 45 is pivoted at 46 to a bracket on the valve casing 38 and of the armature I2 as a result of the oblique pull J rocking movement of the rocker arm 45 in a clockwise direction, in Figure 3, about the pivotal connection 46 moves the valve stem 44 ,to operate the valves in the valve casing 36 to. open the" intake valve 40 and close the exhaust valve 4|. When the exhaust valve 4| is open, working fluid in the valve casing 36 will escape through the exhaust port 41., Working fluid is supplied to the valve casing 36 through a pipe 48.

The supply of working fluid to the pipe 48 is controlled by the valves in the valve casing 49. The valve casing 49 contains a normally closed intake valve 50 and a normally open exhaust valve 5| which are connected together by a spacer rod 52 so that they operate as a unit. A spring 53 holds the valves 50 and 5| in' normal position. The exhaust valve 5 IV is formed with a valve stem 54 which projects through the end of the valve casing 49. A rocker'arm 55 is pivoted at 56 to a bracket formed on the valve casing 49. Rocking movement of the rocker arm 55 in a counterclockwise direction, in Figure 3, moves the valve stem 54 to operate the valvesin the valve casing 49 to open the intake valve 50 and close the exhaust valve 5|. A handle 60 is connected with the rocker arm 55 to provide meansby which the operator may actuate the rocker arm 55. A diaphragm chamber 62 is formed in the upper part of the valve casing 48 and contains a diaphragm 63. A plunger 65 extends through the end of the diaphragm chamber 62 and when pressure is applied behind the diaphragm 63 the "plunger 65 will be moved into contact with the rocker arm 55 to hold the same in operated position. A pipe 61 connects thediaphragm chamber 62, at a point behind the diaphragm 63, with the pipe 35. p

Electro-magnetic means are provided to operate the valves in the valve casing 36. These 'electro-magnetic means include a solenoid I0 and an armature I2. The armature 12 may be connected to the rocker arm 45 by any suitablef means. As illustrated, the armature 12 passes through a hole 14 formed in the rocker arm 45. The armature I2 fits loosely in the hole 14 and the end of the armature I2 is enlarged so that it cannot pull through the hole 14. The sides of the hole 14 may be rounded to prevent binding of the armature 12.

The solenoid I0 is connectedby a conductor I6 with' the main power line and a conductor I8 connects the solenoid 10 with a 'contact'point of a normally open relay 82. When the relay 82 is operated, in a manner later to be described,

an armature 83 of the relay is drawn into contact with the contact point 80 to provide a ground connection for the solenoid 10 through the conductor I8, contact point 80, armature 83, and a conductor 85, which connects with the main power line.

The relay 82 is connected in series with light sensitive means such as photo-electric cells 90,

9| and 92. The photo-electric cell is connected to a conductor which leads from the main power line. A conductor 96 connects the photo-electric cells 9| and. 92 and a conductor 96 connects the photo-electric cells 90 and 9|. The photo-electric cell 92 is connected by a'conductor 91 with one terminal of the relay 82. The other terminal of the relay 82 is'grounded through aconductor 88 which leads to the main power line. I

Light sources are supplied to illuminate the photo-electric cells in order to render them con- .passes from the'incandescent light I00 to the photo-electric cell 92.

An openingv I06 permits a beam of light from the incandescent light I00 to pass to the photo-electric cell 90. A source of light comprising an incandescent light I08 is mounted in a box I09 which is provided with an opening 0 through which a beam of light is.

thrown to the photo-electric cell 9 I.

A shutter H2 is provided for cutting off the light supplied to the photo-electric cell 90. The

operation and purpose of this shutter will be described hereinafter; g

The photo-electric cells 90, 9| and 92 and the light sources including the boxes I02 and I09 are mounted on standards 5 which extend upwardly from a table ||8 secured to the pressing machine frame I4. .Referring'to Figure 1 it will The container I02 is provided with be noted that the beams of light between the light sources and the photo-electric cells form, in effect, a fence or barrier around three sides of the pressing elements and these beams of light are preferably spaced sufficient distance from the pressing elements so that it is'impossible for a person to come within reach of the pressing elements without intercepting one of the beams of light. The beams are so spaced from the pressing elements that an operator standing near the press to place work thereon, will intercept the beam of light which extends across the front of the pressing machine. across the back of the pressing machine since it is conventional practice to place a pressing machine close to a wallor other obstruction, and it is therefore impossible for a person to approach the press from such direction.

Presses of the kind shown herein have a table 8 under the buck I5 for supporting such parts of 'fabrics or garments as overhang the buck. This table will extend well out fromthe press and a recess MI is provided directly in front of the press. From this recess the operator can easily reach all parts of the buck, but at other positions the table makes it impossible or awkward and inconvenient to reach between the jaws. The operator, therefore, must stand in the recess MI in the'table I I8 in order to place on or remove from the buck material tobe pressed. The operator, therefore, cannot defeat the safety beam by attempting to operate the machine at a point nottraversed by the beam.

From the description thus far it will be apparent that if no shadow is cast on the photoelectric cells the solenoid 10 will hold the intake valve 40 open and the exhaust valve 4| closed. With the valves in the valve casing 36 thus held in operated position by the solenoid I0 the press may be closed by actuating the handle 60 to open the intake valve 50 and close the exhaust valve 5 I in the valve casing 49. When the

intake valves

50 and 40 are both open, working fluid from the fluid supply line I40 will pass through the valve casing 40, pipe 48, valve casing 36, and pipe 35 to the fluid motor I8 to operate the same to close the press.

The shutter H2 is carried by an arm' 4 which is pivotally supported at 6 on a bracket. A spring III normally holds the arm H4 and shutter I I2 down and out of the pathof the beam of light which illuminates the photo-electric cell 90. The arm 4 is operated, to move the shutter m, by a plunger m which extends through the top of a diaphragm chamber I22 which contains a diaphragm I24. Working fluid is supplied through a. pipe I25 to the diaphragm chamber I22 and the pressure of such working 'fluid behind the diaphragm I24 operates the normally open exhaust valve I3I which are connected together by a spacer rod I32 so that they operate as a unit. A spring 433 holds the valves I and I3I in-normal position( The exhaust valve BI is formed with a valve stem I34 against which a handle I 35 operates to move the valves in the valve casing I20 into operated position to open the intake valve I30 and close the exhaust valve I3I. Working fluid is supplied to the valve casing I28 through a fluid supply line I37.

No means are provided to lock the valves in the valve casing I28 in operated position and as soon as the operator releases the handle i35 the intake valve I30 will close and the exhaust valve I 3| will open thus releasing the pressure under the diaphragm I24 and permitting the shutter II2 to return to normal position. Although the shutter H2 does not remain in position to shut oh the light from the photo-electric cell 90, the momentary shadow on this photoelectric cell 90 is sufllcient to cause the press to open and remain in open position. Any passing shadow on the photo-electric cell 30 will cause an interruption in the power supplied to the relay 82 and the armature 33 will move away from the contact .80 to break the circuit to the solenoid I0. With the solenoid 70 no longer energized, the spring 43 will close the intake valve and open the exhaust valve M. Working fluid in the diaphragm chamber 52,will escape through the

pipes

51 and 35, past the open exhaust valve 4|, and through the exhaust port 41. When the pressure behind the diaphragm 63 is thus reduced the spring 53 will close the intake valve and open the exhaust valve 5|. So long as the shadow remains on the photoelectric cell 90, working fluid in the cylinder 32 will exhaust through the pipe 35, valve casing 36,-past the open exhaust valve M and through the exhaust port I]. When light again falls on the photo-electric cell 30, as for example when the shutter II 2 returns to normal position, the solenoid I0 willagain beenergized and the valves in the valve casing 36 operated to open the intake valve 40 and close the exhaust valve H. The opening movement of the press will not be efiected by this renewal of the power supply to the solenoid 10 since the working fluid in the cylinder 32 may exhaust through the pipe 35, valve casing 36, around the open intake valve 40, through the pipe40, and valve casing", past the. open exhaust v' alve "5|. v

When thepress is closed and the operator approaches the pressing elements, he will intercept the beam of light which illuminates the photoelectric cell 30 and the valves in the valve casing 36 will-be operated, in a manner to be described in detail hereinafter, to cause the press to open. When the operator works on two or more machines some saving initime may be eifected by mounting the valve casing I20 and the control handle I35 on another machine so that as the operator leaves such machine to walk over to the machine shown in the drawings, the

shutter 2 will be operated to cast a shadow on the photo-electric cell 30 to cause the press I to open before the operator reachesit. V

Figure 5 shows a modified form of control mechanism in which the opening and closing of the press operates automatically without the necessity of any manual control by the operator. For example, the press will automatically close whenever the operator steps out of the beam of light which illuminates the photo-electric cell 90 and the press will again open when the photoelectric cell is in shadow, as for example when the operator returns to position intercepting the beam of light which illuminates the photo-electric cell 90. The electrical control mechanism shown in Figure 5 is identical with that shown in Figure 3 and is indicated by the same reference characters. The control valves in the valve casing 36 are also identical with those shown in Figure 3 but some change is made in the piping which connects with the valve casing 36. A pipe I50 connects the valve casing 38, at a point midway between the valves to and M, with the cylinder 320i the fluid motor 63. Working fluid is supplied to the valve casing 36 through a fluid supply line I52 and a rotary valve I54 is inserted in the fluid supply line lbii and may be operated by a handle I55 to cut of! the supply of working fluid through the fluid supply line I52. The rotary valve I54 is used only when it is desirable to render the electrical control mechanism inoperative. In the ordinary routine operation of the press, bythe modified control mechanism shown in Figure 5, the operator will never use the valve I54 but will leave it in open position. There may be times when the operator will leave the press but will want the press to remain open. If the operator steps away from the press to get new work he may prevent the press from closing by moving the handle I55 to close the rotary valve I53 and the electrical control mechanism will be rendered inoperative to close the press since the supply or working fluid to the valve casing 36 is cut oft The operation of the machine is as follows (Figure 3) Before starting the operation of the machine the operator will light the incandescent lamps I00 'and I00 to throw beams of light on the photo-electric cells 90,-3I and 92, as previously described. The valves in the valve casing 49 will be in normal position with the intake valve 50 closed and the exhaust valve 5i open. After the operator has stepped into position to place the work on the press, the beam of light which fore be broken and the spring 43 will hold the valves 40 and ll, and the rocker arm 45 and armature I2, in inoperative position, as shown in Figure 3.

- After the operator has arranged the work on the buck he will step back from the pressing machine and his shadow will no longer cut oil the beam of light which illuminates the photo-electric cell 00. As soon as the beam of light from the incandescent lights I00 and I00 falls on the photo-electric cells, current will now through the from the fluid supp y break the circuit through the solenoid II. An?

photo-electric cells 88, II and 82 and the relay 82 to energize the relay and draw the armature 83' into contact with the contact point 88. As soon as the armature 88 makes contact with the contact point 88, current will flow through the solenoid I8, through the circuits previously described, to energize the solenoid-I8 and drawthe armature 12 into the solenoid II to move the rocker arm and operate thevalves in the valve casing 38. When the valves in the valve casing 36 are thus operated, the intake valve 48 will be moved into open position and the exhaust valve 4I into closed position. The operator may now actuate the 58 and close the exhaust valve 5I. Working fluid line I48, will flow around the open intake valve 58, through the valve casing 48, pipe 48, around the open intake valve 48, through the valve casing cylinder 82 01 the fluid motor l8 to operate the piston 88 and piston rod 28 to close the press. Working fluid from the pipe "will flow through the pipe 81 to the diaphragm chamber 82 and the pressure thus exerted behind the diaphragm 88 will-move the plunger 85 into contact with therocker arm and lock the\valves 58 and 5| in operated position so that it i s not necessary for the operator to hold the handle 88.

The beam oilight from the incandescent light I88 to the photo-electric cell 88 is so spaced from the front of the pressing machine that the operator cannot reach the pressingelements after he has stepped out of the beam of light. It the operator. approaches the press, during the closing movement, as for example tosmooth out a wrinkle in the work, his shadow will again be thrown on the photo-electric cell 88 and the current through the photo-electric cells 88, 8| and 82 and the relay 82 will drop so that the armature 88 will move away from the contact point 88 and time that the circuit through the solenoid I8 is broken, the spring 48 will return the valves 48 and H to normal position with the intake valve 48 closed and exhaust valve 4I open, thus cutting off the supply of working fluid to the motor I8 and permitting the working fluid inthe motor I8 to exhaust through the pipe 85, valvev casing 88, and past the open exhaust valve 4|, through the exhaust port 41. At the same time working fluid in the diaphragm chamber 82 will e ust through the pipes 81 and 85, valve casing 88, past the open exhaust valve 4I, and through'the exhaust port 41: When the pressure behind the diaphragm 88 is thus reduced, the spring '58 will close the intake valve 58 and open the exhaust valve 5|; From the above description it is apparent that the press cannot be closed so long as any one is standing within the danger zone, that is, close enough to the press to place a hand between the pressing elements. It will he further apparent that the press may be closed by actuating the handle 88 after the operator steps outside of the danger zone, but that such closing movement will immediately stop and the X again open it any one steps within e danger zone. I

While thepress is closed, it is conventional practice for the operator to work at another machine. When the operator returns from the other press and intercepts the light which illuminates the photo-electric cell 88, the pres will immediately open. as previously described. Even though this opening is at a rapid rate somelittle timewillbelostwaivngtorthepresstoopenand handle 88 to open the intake valve 88, and pipe to the this time may be saved it the operator can, actuate remote control means on another press, which will cause the flrst press to open while he is returning to it. The valves in the valve casinfl I28.provide such remote control means and before leaving the other machine the operator will actuate the handle I85 to operate the valves in the valve casing I28 to open the intake valve I88 and close the exhaust valve I8I. Working fluid from the fluid supply line I8I will flow around the open intake valve I88, through the valve cas ing I28, and pipe I25, to the diaphragm chamber I22 to operate the diaphragm I24 which will move the plunger I28 to raise the arm H4 and shutter II2 into position to intercept the beam of light which illuminates the photo-electric cell 88. The shadow of the shutter II2 on the photo-electric cell 88 will cause the press operating mechanism valve I88 andopen the exhaust valve I8I. The

working fluid in the diaphragm chamber I22 will escape through the pipe I25, valve casing I28, and past the open exhaust valve I8I. When the pressure behind the diaphragm I24 is thus reduced the spring ill will move the shutter I I2 back into normal position "outside of the beam of light which illuminates the photo-electric cell 88. -While the shadow cast on the photo-electric cell 88 by the shutter II 2 is of short duration, it is suflicient to cause the .press 'to open, as previously described.

The operation of the control mechanism shown in Figure 5 is as follows: When the operator wishes to render the electrical control mechanism operative, he will open the valve I54 to supply working fluid through the pipe I28 to the valve casing 88. While the operator is standing in front of the press arranging work, his shadow will be cast on the photoelectric cell 88 and the current flowing through the relay 82 will not be sufllcient to attract the armature 88 into engagement with the contact point 88. The circuit of the solenoid 18 will therefore be incomplete and no current will flow through the solenoid II. The spring 48 will hold the valves in the valve casing 88 in their normal position with the intake valve 48 closed and the exhaust valve 4I open.

When the operator has arranged the work on the buck he will step back out of the beam of cells and relay 82 will increase so that the relay will attract the armature-88 into. engagement with the contact point 88 and close the circuit through the solenoid 18. When the solenoid 18 is thus energized the armature I2 will be operated to move the rocker arm 45 and open the intake valve 48 and close the exhaust valve 4| Working fluid from the fluid supply line I52 will flow around the open intake valve 48, through the valve casing 88, and pipe I58 to the cylinder 82 of the fluid motor I8 to operate the same to close the press.

It the operator steps within the beam of light which illuminates the photo-electric cell 88, either during the closing movement of the press or aiterthepresshasclosed,thepresswlllimmediately open since the current through the relay 82 will be reduced and the armature 88 will move away from the contactpoint 88 thus breaking the circuit throughthe-solenoid I8 and permitting the spring 43 to close the intake valve 40 and open the exhaust valve M. The closing'of the intake valve 40 cuts off the supply of working fluid to the motor l8 and the opening of the exhaust valve 4| permits working fluid to escape from the cylinder 32 through the pipe I50, valve casing 36, past the open exhaust valve 4|, and through the exhaust port 471..

From the foregoing description it will be apparent that I have devised a novel safetycontrol means for a pressing machine which will prevent the closing of the press so long as the operator, or any other person, is standing within the danger zone of the press. Itwill be further apparent that I have devised modified control ,means by which the press will be automatically closed and opened when the operator steps away from the press or returns to the press, respectively.

The invention is illustrated in its preferred embodiment but changes and modifications may be made without departing from the spirit of the invention, as set forth in the appended claims.

What I claim is:

1. In a pressing machine comprising, in combination, cooperative pressing elements adapted to open and close on the work; operating mechanism for opening and closing the press; con trol means for the operating mechanism including, a light sensitive means mounted adjacent the pressing machine, and means projecting a beam of light upon the light sensitive .means in a direction to be obstructed by an operator when placing work in position; and a shutter adjacent the light sensitive means for obstructing the beam of light and casting a shadow on. said light sensitive means thereby causing the press to open.

2. In a pressing machine in combination, cooperative pressing elements adapted to open and close on the work operating mechanism to open and close the pressing machine; control means for the operating mechanism including light sensitive means mounted adjacent the pressing elements; a shutter for casting a shadow on the light sensitive means; and remote control means for operating the shutter to move the same.

3. A pressing machine comprising in combination, cooperative pressing elements adapted to open and close on the work; operating mechanism to open and close the pressing machine; control means for the operating mechanism including light sensitive means mounted adjacent the pressing elements; a shutter; remote control means for controlling the operation of said shutter to move the same into position to cast a shadow on the light sensitive means; and con-' trol means adjacent the pressing elements to restore the shutter to its original position out of the path of the light illuminating the light sensitive means. V p

4. In a garment pressing machine in combination, cooperative pressing elements adapted to open and close on the work; operating mechanism for opening and closing the pressing machine; light sensitive means adjacent the pressing elements and located in position so that an operator standing close to the press will cast a shadow on the light sensitive means; means, controlled bythe light sensitive means, for controlling the operating mechanism to open the press when a shadow is cast on the light sensitive means; and remote control means for cutting off the light to said light sensitive means.

5. A pressing machine having press jaws and a safety device, comprising in combination, a fluid motor to open and close the pressing machine,-a conduit to supply fluid pressure to said 1 motor, a relief valve in said conduit which relief including in series therewith, a photo-electric cell, and means for opening and closing said relief valve, said means being actuated to close the relief valve by illumination of the photo-- electriccell and to open the valve 'when said illumination is intercepted; and means to cast a beam of light on said photo-electric cell to 11- luminate it, said beam having such spaced relation to the press jaws that an operator cannot reach between said jaws without intercepting the beam of light and thereby operating the relief valve and rendering the fluid motor inoperative. 1

6. A pressing machine having 'closable pressing jaws incombination with an electriccircuit providing a safety control for the pressing machine, the jaws of said pressing machine being closable only when said electric circuit is closed and automatically opened upon 'the opening of said electric circuit, a photo-electric cell in series with said electric circuit, and means to cast a beam of light upon the cell which when illuminated renders the circuit substantially closed, said circuit being substantially open upon interception of the beam of light, the beam of light having such spaced relation to the jaws of the pressing machine that an operator cannot reach said jaws without intercepting said beam and thereby causing said electric circuit to open.

7. A,machineand safety device therefor comprising an electric circuit which"when closed renders the machine operable, and when open renders the machine inoperable, said circuit comprising alight sensitive electric cell which upon iilumination by a beam of light closes said' circuit and permits sufllcient current to flow through said circuit to render said machine operable and upon interception of said beam substantially opens said circuit and renders said machine inoperable, illuminating means to cast a beam of light upon said light sensitive element, the geometrical relation between the machine, the light sensitive element, and the said illuminating means being such that the saidbeam of light acts in efiect as a guard for the machine, the interception of said beam of light by the operator of the machine substantially opening the said electric circuit andrendering the machine inoperable.

8. A pressing machine and safety device therefor, comprising, in combination, cooperative pressing elements and a fluid motor, the said elements being arranged to be closed by the application of fluid to said motor and to be opened 'upon the release of fluid from said motor, a"concluit to supply fluid to said motor, a first valve in said conduit which when open delivers .fluid to said motor to close the pressing elements and when closed prevents access of fluid to said motor and releases fluid therefrom to open said pressing elements, a second valve in said conduit to control the supply of fluid to said first valve, an electric relay circuit which circuit when closed opens said first valve and when open closes said valve, said circuit comprising a light sensitive element whichupon illumination by a. beam of light permits sufiicient current to flow through said circuit to substantially close the same and upon interception of said beam substantially opens said circuit, illuminating means to cast a beam of light upon said light sensitive element, the geometrical relation between the ated position controls the actuation of the motor to close the press jaws, an electric circuit, including in series a photo-electric cell, and means for nioving said relief valve to operative and inoperative positions, said means being actuated to operate the relief valve into operative position to open the jaws by illumination of the photo-electric cell and to move the valve to inoperatie position when said illumination is intercepted, and means to cast a beam of iigiit on said photo-electric cell to illuminate it, said beam haing such spaced rela-- tion to the press jaws that an operator cannot reach between said jawswithout intercepting the beam of .light and thereby rendering the fluid motor inoperative.

10. A garment or ironing press having press jaws and a safety device comprising, in combination, motor means to open and close the press, a conduit to supply working fluid to said motor means, an operator actuated valve in said conduit,

' and a relief valve in said conduit which relief valve in operated position controls the actuation of the motor means to close the press jaws, an electric circuit, including in series a photo-electric cell, and means for moving said relief valve to operative and inoperative positions, said means being actuated to operate the relief valve into operative position to open the jaws by illumination of the photo-electric cell and to move the valve to inoperative position when said illumination is intercepted, and means to cast a beam of light on said photo-electric cell to illuminate it, said beam having such spaced relation to the press jaws that an operator cannot reach between said jaws without intercepting the beam or light and thereby rendering the fluid motor inoperative.

11. A pressing machine having press Jaws and a safety device comprising, in combination; a fluid motor to open and close the press; a conduit to supply fluid pressure to said motor; a relief valve in said conduit including a combined intake and exhaust valve, the relief valve inoperated position closing the exhaust valve and opening the intake valve to control the actuation of the motor and in inoperative position controllinz the exhausting of the motor and the opening of the press jaws; an electric circuit including in 1 series a photo-electric cell,- and means for opening and closing said relief valve, said means being actuated to operate the relief valve into operative position by illumination of the photo-electric cell and into inoperative position when said illuminaa safety device comprising, in combination; a

fluid motor to open and close the press; a conduit to supply fluid pressure to said motor; a relief valve in said conduit including a combined intake and exhaust valve, the relief valve in operated position closing the exhaust valve and opening the 5 intake valve to control the actuation of "the motor pand in inoperative position controlling the exhausting of the motor and the opening of the press jaws; an electric circuit including in series u a photo-electric cell, and means for opening and 10 closing said relief valve, said means being actuated to operate the relief valve into operative position by illumination of the photo-electric cell and into inoperative position when said illumination is intercepted; means to cast a beam of.l5

illumination on said photo-electric cell, said beam having such spaced relation to the press laws that an operator cannot reach between said jaws without intercepting the beam and thereby opening the exhaust vaive and exhausting the fluid 20 pressure from the fluid motor; an operator actuated intake valve connected in series with the combined valve; pressure operated holding means for retaining the latter intake valve open; and a connection from the motor to the holding means. 25

controlling the actuation of the fluid motor in- 30 cluding an operator actuated valve, safety means preventing a flow of fluid to the fluid motor. an electric circuit including in series a photo-electrio cell, means for moving said safety means to operative and inoperative positions, said means 35 being actuated to move the safety means into operative position to cause closing of the jaws by illumination of the photo-electric cell and to move the safety means to inoperative position when said illumination is intercepted, means to 40 cast a beam of light on said photo-electric cell to illuminate it, said beam having such spaced relation to the press jaws that an operator cannot reach between said jaws without intercepting the beam of light and thereby returning the 45 14. A garment or ironing press comprising, in 50 combination, cooperating pressing jaws adaptedto open and close on the work; a fluid motor to open and close the press; control valve means controlling the actuation of the fluid motor including an operator actuated valve, 9. second valve be- 55 tweenthe operator actuated valve and the fluid motor, an electric circuit including in series a photo-electric cell, means for moving said second valve to operative and inoperative positions, said means being actuated to move the second valve so into operative position to close the jaws by illumination of the photo-electric cell and to move the second valve to inoperative position when said illuminationis intercepted, means to cast a. beam of light on said photo-electric cell to illuminate it, 55

position, and means operated to hold the press in 70 closed position upon movement of the second valve into operative position.

15. A garment or ironing press comprising, in combination, cooperating pressing jaws adapted to open and close on the work; a fluid motor to 75 accuses open and close the press; control valve means controlling the actuation oi the fluid motor including an operator actuated valve, a second valve between the operator actuated valve and the fluid motor, an electric circuit including in series a photo-electric cell, means for moving said second valve to operative and inoperative positions, said means being actuated to move the second valve into operative'position to close the jaws by illumination of the photo-electric cell and to move the second valve to inoperative position when said illumination is intercepted, means to cast a beam of light on said photo-electric cell to illuminate it, said beam having such spaced relation to the press Jaws that an operator cannot reach between said jaws without intercepting the beam of light and thereby returning the second valve to inoperative position, and holding means retaining the operator actuated valve in operated position and operated upon movement of the second valve into operative position. I 16. A garment or ironing press comprising, in combination, cooperating pressing jaws adapted fun.

to open and close on the work; a fluid motor to open and close the press: control means controlling the actuation ot the fluid motor including an operator actuated intake valve, a second intake valve between the operator actuated valve and the fluid motor, an electric circuit including in series a photo-electric cell, means for moving said second valve to openand closed positions, said means being actuated to move the second valve into open position to close the laws by illumination of the photo-electric cell and to move the valve to closed position when said illumination is intercepted, means to cast a beam of light on said photo-electric cell to illuminate it, said beam having such spaced relation to the press jaws that an operator cannot reach between said jaws without intercepting the beam 01' light and thereby returning the second valve to closed position, and air pressure means retaining the operator actuated intake valve in open position and connected between the second valve and the motor.

ERNEST DAVIS.