US2491981A - Film developing machine - Google Patents

Description

1949 M. N. JANA'PoL ET AL 2,491,931

FILM DEVELOPING MACHINE Filed April 27, 1948 3 Sheets-Sheet 1 MEZV/A/ A4 JA/V/IPOL M54 1 A' 3. @0040 ATTORNEY Dec. 20, 1949 NAP ET AL 2,491,981

FILM DEVELOPING MACHINE Filed A ril 27, 1948 :5 Sheets-Shet 2 Maw/v /V. JANA/ 0A MERZE s. @0040 Patented Dec. 20, .1949

FILM DEVELOPING MACHINE Melvin N. Janapol and Merle S. Gould, Los

Angeles, Calif., assignors to Automatic Developer, Los Angeles, Calif., a corporation of California Application April27, 1948, Serial No. 23,428

12 Claims.

This invention is concerned with a film or photogenic paper developing machine and it is a general object of the invention to provide a machine which is coin controlled and of such character as to be of use to the general public for the development of film or sensitized paper after exposure.

Photographic film is commonl exposed in cameras in the hands of the general public, the public having sufiicient knowledge of photography to be able to satisfactorily expose film such as is commercially available. The development of exposed films has heretofore been confined to amateur photographers who have developed special skill or who are hobbyists, or to commercial laboratories where quantities of film are developed and where prints are made therefrom.

It is a general object of this invention to provide a simple, compact, effective machine or apparatus, preferably coin controlled and of such character that it may be located accessible to the general public so that any one desiring to develop a film may apply the film to the machine and then operate the machine to receive a developed film in a matter of a few minutes, I i

It is a further object of the present invention to provide a machine of the general character referred to involving a simple film carrier to which the film to be developed is applied, which carrier serves to successfully pass the film through baths which effect the desired development of the film.

It is another object of the present invention to provide a machine of the general character referred to wherein there is a body having a loading chamber under control of a closure and wherein there is a control system such that the machine cannot operate unless the closure is in the closed or sealed position.

A further object of the present invention is to provide a machine of the general character referred to involving a few simple parts arranged in a very convenient and practical manner so that the trays provided to carry the liquids to which the film is applied may be individually handled and are normally supported in a series so that the carrier operates to successively pass the film through the trays.

The various objects and features of our invention will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is a perspective view of a machine embodying the present invention with parts broken away to show the internal construction and showing the closure at the loading chamber in a proper position. Fig. 2 is an enlarged vertical longitudinal sectional view of the machine showing a film engaged with the carrier and partially operated through the machine. Fig. 3 is an enlarged detailed sectional view taken as indicated by line 3-3 on Fig. 2. Fig. 4 is a side elevational view taken on line 44 on Fig. 2. Fig. 5 is an enlarged detailed view taken as indicated by line 55 on Fig. 2. Fig. 6 is a transvers sectional view taken as indicated by line 6-6 on Fig. 5. Fig. '7 is an enlarged transverse sectional view taken as indicated by line 'll on Fig. 6. Fig. 81s a View similar to a portion of Fig. 2 showing the closure released and partially opened, and showing the film advanced in the machine to the point where it is ready to be withdrawn therefrom. Fig. 9 is an enlarged detailed sectional view taken as indicated by line 99 on Fig. 8, and Fig. 10 is a diagrammatic view of the control system included in the machine.

Throughout this application when we refer to film We mean to include various light sensitive webs, papers, elements or membranes, the base or body of the film may be transparent, translucent or opaque and such base or body may carry an emulsion or light sensitive coating.

The structure embodying the present invention involves, generally, a case or housing A, a, frame B within the housing, a plurality of liquid carrying trays 0 supported by the frame Within the housing, a film carrier D, mounting means E for the film carrier, drive means F for the film carrier, agitating means G for liquid in the trays, a fastener H for releasably securing a film to the carrier, and a control system J involving an electrical system under control of a coin mechanism ID.

The case or housing A is preferably an elongate horizontally disposed box-like structure so constructed as to be substantially air tight. The particular case illustrated in the drawings is of a form or type suitable for location in a store or like place, accessible to the public. The case may, in practice, be supported or mounted in any suitable manner, the case shown in the drawings being provided with supporting standards or legs 12, one located at each corner of the case.

The case shown in the drawings involves, generally, a fiat horizontally disposed bottom 13, a top I4, sides I5, a back end 16 and a front end 11. The principal elements of the case are preferably joined or secured together to form a permanent secure case or housing for the various working parts of the machine and one or more portions of the case is provided with an access opening I9 normally covered by a hinged closure 20, or the like, which may normally be locked in the closed position, and which serves as a means by which a person servicing the machine may have convenient access to the parts located within the case. In the machine illustrated in the drawings one of the sides i is provided with an opening [9 which opening is normally closed or covered by a closure 26 carried by hinges 2!.

In accordance with the present invention a partition 22 is provided in the front or forward end portion of the case and serves to define a loading chamber 23 in the upper forward portion of the front end of the case. The said portion of the case is provided with an opening 24 providing access to the loading chamber 23, and a cover or closure 25 is provided to normally cover or close the opening 24. The closure 25 is preferably a hinged closure carried by suitable hinges 26 and it is preferably normally releasably held closed by a suitable latch 21. The particular latch 2'3 shown in the drawings is carried on a pivot pin 28 and a spring 29 is provided to normally yieldingly hold the latch in position Where it engages a dog 39 on the closure 25 in such manner as to hold the closure in the closed position shown in Fig. 2 of the drawings.

In practice the closure 25 may be so designed, shaped and mounted as to be movable to a position where it will remain open while a person loads film in the machine. In the drawings the closure is shown equipped with a suitable frictional brace 3| which offers resistance to movement of the closure and normally serves to hold it in an open position such as is shown in Fig. 1,

upon the closure being moved to such position.

In practice a convenient handle 32 is provided on the exterior of the closure to facilitate operation of the closure between the positions shown in Figs. 1 and 2.

The particular machine illustrated in the drawings involves a frame B mounted or located within the case A and the frame illustrated involves spaced parallel longitudinally disposed 1 beams or rails 33 that extend between the front and rear ends it and ll of the case. are perfectly located at a suitable point between the top and bottom of the case and are located somewhat inward from the sides I5 of the case.

The liquid carrying trays C provided in the machine carry liquids necessary or incidental to the development of film to be handled in the machine. For instance, the trays may be such as to carry suitable quantities of developers, washes, fixers, etc. In the particular case illustrated the trays C are like open-topped box-like structures arranged side by side to form a series of trays extending longitudinally in the case. It is preferred that each tray C be independently suspended or mounted from the beams 33 of the frame through suitable mounting brackets 34 or the like. In practice it is desirable that the mounting construction carrying the trays be such as to enable the trays to be separately or individually removed, as circumstances may require.

The film carrier D of the present invention is an elongate, flexible element, for instance, a beltlike member formed of a rubber-like composition, or the like, not affected by the liquids carried in the trays and necessary for the desired de velopment of the film handled by the machine. The carrier is shown as an endless belt or loop wide enough to carry the maximum width of film desired to be handled by the machine and long The rails v the mounting means E.

4 enough to properly accommodate the maximum length of film to be handled by the machine as hereinafter described.

The mounting means E for the film carrier D supports the carrier for operation successively through the trays C and with a part accessible at the loading chamber 23. The mounting means E supports the carrier to have a lower portion to move generally rearward in the machine from the loading chamber 23 to the rear end portion of the machine and to dip into the several trays C in the course of such rearward motion and to have an upper portion which may extend substantially straight forward or in a horizontal direction from the rear of the machine to the front of the machine at or adjacent the loading chamber.

In accordance with the preferred form of the invention the mounting means E involves rollers rollers 43 and in such manner as to carry or dip.

the carrier into the trays C. As illustrated in the drawings there may be one or more tray rollers 42 at or in each tray C while the guide rollers 43 are located above and between the trays, all with the result that the lower portion of the carrier passing rearward through the machine follows a zig-zag course and successively dips into the trays and finally leaves the rearmost tray to pass over the rear roller 41.

In practice the several rollersof the means E may be mounted or supported in any suitable manner. In the case illustrated the rollers are supported from or through suitable brackets 45 carried by the rails 33 of frame B there being brackets depending from the rails to carry the tray rollers so that they are within the trays, as clearly illustrated in Fig. 2 of the drawings.

The front roller 40 of the means E is located at or immediately adjacent an access opening 46 provided inpartition 22 and the carrier D operates over the front roller 40 so that a portion of the carrier is at or accessible through the opening 46.

The drive meansF provided for operating the carrier preferably operates the carrier through In the case illustrated the drive means F operates the carrier by driving one of the rollers on or around which the carrier is engaged. In the case shown the drive means Finvolves a prime mover or motor M driving the rear roller 4| through a suitable speed reducing mechanism 47. It is desirable in practice that the shaft 58 of roller 4i be extended from its sup-.

porting bracket 45 into a compartment 5! formed in the case to carry the motor and speed reducing mechanism 4? and the extension of the shaft is,

preferably sealed by a suitable seal or packing means 52 where it enters the compartment 5|. Through this construction the motor M and mechanism 41 are sealed away from the interior of the case Where there may be fumes or vapors from the liquids in the trays C.

The agitating means G provided by the present invention operates to keep the liquids in the several trays suitably mixed or agitated .in a manner desirable in the case of most liquids employed inphotographic processes. The agitating means G may be applied to all of the trays in the machine or only to those requiring agitation. Where agitation is required or desired the agitating means G involves one or more paddles 55 on the shaft 56 of a tray roller. In the drawings paddles are shown located at the ends of the tray rollers, as shown in Fig. 4.

The fastener H serves to releasably secure a film 68 to the carrier so that as the carrier is advanced or operated the film is drawn or carried with it in a manner to be successively immersed in the trays C. In the preferred form of the invention the means H is in the form of a clamp or clip mechanism fixed on the carrier D and is such as to effectively receive and hold one end of the film strip. It will be apparent that the means H may, in practice, vary widely in form or construction. The particular clamp of means I-I shown in the drawings involves a base 6|, fixed to the carrier D, flanges 62 projecting upwardly from the base, a pivot pin 63 carried by the flanges and pivotally supporting a clamp jaw 64 which has a projecting handle portion 65 between the flanges, and a spring 66 normally yieldingly urging the jaw 64 toward the base so that the end of a film arranged between the jaw and the base is effectively gripped, as shown in Figs. 5 and 7 of the drawings. It is to be noted that the flanges 62 of the structure just described project above the jaw and handle 65 so that the clamp may be passed over or around rollers of the means E without releasing the jaw from the clamped or operating position.

The machine may also include a film holder J serving to mount or support a film carrying spool in position in the loading chamber 23 so that film can be conveniently withdrawn therefrom as the machine operates. The particular holder J illustrated in the drawings involves opposed conical centers 10 one of which is mounted on a shiftable spindle H and is normally urged toward the other by a spring 12. The construction is such that a film spool 13 can be conveniently arranged between the centers and when it is arranged between or is engaged by the centers, as shown in the drawings, it is located in line with the access opening 46 making it convenient to unroll the end portion of the film 68 and fasten it to the carrier D by means of the clamp, the clamp being located at the access opening 46.

As the machine operates the film may pass from the spool 13 over a guide roller 15 so that it is carried along by the lower portion of the carrier to successively dip into the trays C and finally pass from the rearmost tray onto the upper horizontal portion of the carrier. When the cycle of the machine has been completed the clamp has returned to the access opening 46 so that the end of the film clamped to the carrier can be released so that it is free as shown in Fig. 8, from which position the film can be readily withdrawn from the machine by merely pulling it forward.

The control system provided by the present invention involves, generally, a coin control mechanism I8 and a suitable electric circuit. The particular control mechanism shown in the drawings also includes an operator 88 controlling the latch 21.

The coin control mechanism l8 may be of any suitable form, type or construction. In the drawings we have shown a mechanism I8 of the type common to machines. of this general character and have shown the coin receiving chute 8| of the mechanism W at the forward end of the case where it is convenient to the operator.

The actuator 88 for the latch 21 is shown as a lever mounted on a pivot pin 83 and coupled to the latch 21 by a suitable link 84. The structure is such that when the lever is swung from the position shown in Fig. 2'to that shown in Fig. 8 the latch 21 is released freeing the closure 25 so that it can be opened. A lugv 86 is carried by or located on the carrier D and cooperates with or engages one arm of the lever so that when the carrier reaches the position where the film clamp H is at the access opening 46, the latch 21 is released.

The electrical system involves, generally, a starter switch 85 under control of the coin controlled mechanism H], a safety switch 86 under control of the closure 25, and a stop switch 81 under control of the carrier D.

It is important, in practice, that the closure 25 be maintained in closed position during operation of the machine so that light does not enter the case to strike the film. To prevent opening of the closure during operation of the machine the starter switch 85 controlled by mechanism In and the safety switch 86 are in series to the circult to the operating motor M. The safety switch 86 is so located in the case adjacent the access opening 24 as to be closed only when the closure- 25 is closed. From Figs. 2 and 8 of the drawings it will be apparent how the operator 88 of the switch 86 is so located as to be engaged and actuated by the closure 25 when the closure 25 is closed.

The stop switch 81 is such as to open the circuit to the motor when the cycle of the machine has been completed. In the particular case illustrated the stop switch is actuated from the carrier D through the lug 86 and the actuator 88. The switch 81 is so located in the case as to be opened by the actuator 88 when the actuator has been moved by the lug to the position where the latch 21 is released. Through this mechanism or arrangement of parts the machine operates through its cycle when switches 85 and 86 are closed and when it has completed its cycle the stop switch 81 operates and the latch 21 is opened. In the particular circuit illustrated in the diagram, Fig. 10, the switches 85, 86 and 81 control the power circuit to the motor M through a suitable relay R. The relay R is such that when the switches 85 and 86 are closed the relay is energized and the motor circuit held closed, whereas when the stop switch 81 is closed or operated the. relay is dropped, opening the circuit to the motor.

In the preferred form of our invention we provide heating means P to temper the interior of the housing so that the liquids in the trays C are maintained at the desired temperature. In practice the heating means may involve one or more electric heating elements I located within the case A, carried by suitable insulators is], or the like. As shown in the diagram Fig. 10 the elements I88 may be governed by a thermostat control I82 which may be set to control the elements so that the desired temperature prevails within the case A.

From the foregoing description it will be apparent that the present invention provides a machine that is simple and which involves few dependable parts. In practice it is desirable to construct the various working parts of materialsthat will resist the fumes or vapors that come If; from the liquids carried in the trays C. It. has

'7v beenfound, in practice, that suitable plastics are preferred in the construction of the machine, rather than metals. a

To operate the machine a film spool is applied to the holder J-and the end of the film is attached to the clamp H. When a coin has been inserted in the mechanism I 0 and the mechanism operated and when the closure 25 is closed, the machine starts operation and the carrier operates the film 60 so that it is successively dipped into the trays C and is finally deposited on the upper portion of the carrier. When the machine has completed its cycle of operation it stops and the closure 25 is released, enabling the operator to release the film from the clamp and withdraw it from the machine.

In practice the film is preferably formed of a stock or web of water resistant material, for instance, paper that is non-absorbent, and ordinarily it is preferred that the liquids in the trays C be such as to develop the emulsion on the film so that a positive image results. Further, in practice it is desirable that the liquid in the last or rearmost tray C be a water repellant so that the film sheds water and is consequently dry when withdrawn following completion of operation of the machine.

Having described only a typical preferred form and application of our invention, we do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to ourselves any variations or modifications that may appear to those skilled in the art and fall within the scope of the following claims.

Having described our invention, we claim:

1. Film developing apparatus including, a boxlike body providing an enclosed light-tight chamber, said body having a loading chamber with an opening controlled by a closure, a plurality of liquid carrying trays within the body, an elongate film carrier having portions dipping into the trays and a portion accessible at the chamber, means fixed on said carrier releasably securing a film to the carrier, said film being inserted into said body through said opening to secure the same to said carrier at the loading chamber, and means operating the carrier lengthwise to carry the film from the loading chamber successively through the trays and back to the loading chamber where it is removed from the carmen 2. Film developing apparatus including, a boxlike body providing an enclosed light-tight chamber, said body having a loading chamber with an opening controlled by a closure, a plurality of liquid carrying trays within the body, an elongate film carrier, mounting means supporting the carrier in the body with portions dipping into the trays and a portion accessible at the chamber, a clamp fixed on said carrier releasably securing a film to the carrier, said film being inserted into said body through said opening to secure the same to said carrier at the loading chamber, and means operating the carrier lengthwise to carry the film from the loading chamber successively through the trays and back to the loading chamber'where it is removed from the carrier.

3. Film developing apparatus including, an elongate horizontally disposed box-like body providing an enclosed light-tight chamber, said body having a loading chamber with an opening controlled by a closure, a plurality of liquid carrying trays in a longitudinal series'within the body, an elongate film carrier having portions dipping 8 into the trays and a portion accessible at the chamber, a clamp fixed on said carrier releasably securing a film to the carrier, said film being inserted into said body through said opening to secure the same to said carrier at the loading chamber; said clamp comprising flanges and a clamp jaw pivotally supported by said flanges; and means operating the carrier lengthwise to carry the film from the loading chamber successively through the trays and back to the loading chamber where it is removed from the carrier.

4. Film developing apparatus including, a boxlike body providing an enclosed light-tight chamber, said body having a loading chamber with an opening controlled by a closure, a plurality of liquid carrying trays within the body, an elongate film carrier having portions dipping into the trays and a portion accessible at the chamber, a clamp fixed on said carrier releasably securing a film to the carrier, said film being inserted into said body through said opening to secure the same to said carrier at the loading chamber; said clamp comprising flanges and a clamp jaw including a handle pivotally supported by said flanges projecting above said clamp jaw and handle; and means operating the carrier lengthwise to carry the film from the loading chamber successively through the trays and back to the loading chamber where it is removed from the carrier, said means including a plurality of rollers supported in the body on parallel axes, the carrier being a flexible element engaged over the rollers.

5. Film developing apparatus including, a boxlike body providing an enclosed light-tight chamber, said body having a loading chamber with an opening controlled by a closure, a plurality of liquid carrying trays within the body, an elongate film carrier having portions dipping into the trays and a portion accessible at the chamber, means releasably securing a film to the car rier, said film being inserted into said body through said opening to secure the same to said carrier at the loading chamber, means operating the carrier lengthwise to carry the film from the loading chamber successively through the trays and back to the loading chamber Where it is removed from the carrier, said last recited means including a motor, and a control for the motor -including a coin controlled mechanism.

6. Film developing apparatus including, a boxlike body providing an enclosed light-tight chamber, said body having a loading chamber with an opening controlled by a closure, a pluralityof liquid carrying trays within the body, an elongate film carrier having portions dipping into the trays and a portion accessible at the chamber, means releasably securing a film to the carrier, said film being inserted into said body through said opening to secure the same to said carrier at the loading chamber, means operating the carrier lengthwise to carry the film from the loading chamber successively through the trays and back to the loading chamber where it is removed from the carrier, said last recited means including a motor driving the carrier, and a control for the motor including a coin controlled mechanism, a starter switch controlled by said mechanism, and a stop switch operated by the carrier.

'7. Fihn developing apparatus including, a box- 9 gate film carrier having portions dipping into the trays and a portion accessible at the chamber, means releasably securing a film to the carrier, said film being inserted into said body through said opening to secure the same to said carrier at the loading chamber, means operating the carrier lengthwise to carry the film from the loading chamber successively through the trays and back to the loading chamber where it is removed from the carrier, said last recited means including a motor drivingthe carrier, and a control for the motor including a coin controlled mechanism, a starter switch. controlled;bysaid mechanism, a safety switch in series fwiththe starter switch and controlled-by the closure," and 1 a stop switch operated by the carrier.

8. Film developing apparatus including, an elongate horizontally disposed box-like body providing an enclosed light-tight chamber, said body having a partition at its forward end defining a loading chamber and a hinged closure for an opening into the chamber, a plurality of open topped liquid carrying trays in the body in a series longitudinally of the body, an elongate flexible carrier in the form of a loop, a rear roller in the rear end portion of the body, a front roller in the forward end portion of the body adjacent the chamber, tray rollers in the trays, and guide rollers above and between the tray rollers, the carrier being carried by the rollers with portions dipping into the trays and a portion adjacent the chamber, a releasable fastener carried by the carrier to hold a film, said film being inserted into said body through the opening to secure the same to said carrier at the loading chamber, operating means including a motor driving one of the rollers, said operating means operating the carrier to carry the film from the loading chamber successively through the trays and back to the loading chamber where it is removed from the carrier, and a control including a starter switch for the motor, a safety switch in series with the starter switch and operated by the closure, and a stop switch operated by the carrier.

9. Film developing apparatus including, an elongate horizontally disposed box-like body providing an enclosed light-tight chamber, said body having a partition at its forward end defining a loading chamber and a hinged closure for an opening into the chamber, a plurality of open topped liquid carrying trays in the body in a series longitudinally of the body, an elongate flexible carrier in the form of a loop, a rear roller in the rear end portion of the body, a front roller in the forward end portion of the body adjacent the chamber, tray rollers in the trays, and guide rollers above and between the tray rollers, the carrier being carried by the rollers with portions dipping into the trays and a portion adjacent the chamber, a releasable fastener carried by the carrier to hold a film, said film being inserted into said body through the opening to secure the same to said carrier at the loading chamber, operating means including a motor driving one of the rollers, said operating means operating the carrier to carry the film from the loading chamber successively through the trays and back to the loading chamber where it is removed from the carrier, a latch releasably holding the closure in closed position, an operator for the latch actuated by the carrier, and a control including a starter switch for the motor, a safety switch in series with the starter switch and operated by aibipsi 10 l the operator, and a stop switch operated by the carrier.

10. Film developing apparatus including, an elongate horizontally disposed box-like body providing an enclosed light-tight chamber, said body having a partition at its forward end defining a loading chamber and a hinged closure for an opening into the chamber, a frame in the body, a plurality of open topped liquid carrying trays in the body carried by the frame in a series longi tudinally of the body, an elongate flexible carrierv inthe form of a loop, a rear roller in the rear. end'portion of the body, a front roller in the. forward .end portion of the body adjacent the chamber, tray rollers in the trays, and guide rollersabove and'between the tray rollers, the carrier being carried-bythe rollers with portions dipping into the trays and a portion adjacent the chamber, the rollers being carried by the frame, a releasable fastener carried by the carrier to hold a film, said film being inserted into said body through the opening to secure the same to said carrier at the loading chamber, operating means including a motor driving one of the rollers, said operating means operating the carrier to carry the film from the loading chamber successively through the trays and back to the loading chamber where it is removed from the carrier, and a control including a starter switch for the motor, a safety switch in series with the starter switch and operated by the closure, and a stop switch operated by the carrier.

11. Film developing apparatus including, an elongate horizontally disposed box-like body providing an enclosed light-tight chamber, said body having a partition at its forward end defining a loading chamber and a hinged closure for an opening into the chamber, a plurality of open topped liquid carrying trays in the body in a series longitudinally of the body, an elongate flexible carrier in the form of a loop, a rear roller in the rear end portion of the body, a front roller in the forward end portion of the body adjacent the chamber, tray rollers in the trays, and guide rollers above and between the tray rollers, the carrier being carried by the rollers with portions dipping into the trays and a portion adjacent the chamber, a releasable fastener carried by the carrier to hold a film, said film being inserted into said body through the opening to secure the same to said carrier at the loading chamber, operating means including a motor driving one of the rollers, said operating means operating the carrier to carry the film from the loading chamber successively through the trays and back to the loading chamber where it is removed from the carrier, and a control including a starter switch for the motor, a safety switch in series with the starter switch and operated by the closure, and a stop switch operated by the carrier.

12. Film developing apparatus including, an elongate horizontally disposed box-like body providing an enclosed light-tight chamber, said body having a partition at its forward end defining a loading chamber and a hinged closure for an opening into the chamber, a plurality of open topped liquid carrying trays in the body in a series longitudinally of the body, a thermostatically controlled heater in the body for maintaining the liquids in the trays at the desired temperature, an elongate flexible carrier in the form of a loop, a rear roller in the rear end portion of the body, a front roller in the forward end portion of the body adjacent the chamber, tray rollers in the trays, and guide rollers above and between the tray rollers, the carrier being carried by the rollers with portions dipping into the trays and a portion adjacent the chamber, a releasable fastener carried by the carrier to hold a film, said film being inserted into said body through the opening to secure the same to said carrier at the loading chamber, operating means including a motor driving one of the rollers, said operating means operating the carrier to carry the film from the loading chamber successively through the trays and back to the loading chamber where it is removed from the carrier, and a control including a starter switch for the motor, a safety switch in series with the starter switch and operated by the closure, and a stop 15 switch operated by the carrier.

MELVIN N. JANAPOL. MERLE S. GOULD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 688,115 Pollak et a1. Dec. 3, 1901 1,967,889 Kitroser July 24, 1934 10 2,386,781 Daly Oct. 16, 1945 FOREIGN PATENTS Number Country Date 527,825 France Aug. 3, 1921 343,080 Great Britain Feb. 13, 1931 206,968 Switzerland Dec. 1, 1939

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