US1925657A

US1925657A - Fire shutter for motion picture projection machines

Info

Publication number: US1925657A
Application number: US321118A
Authority: US
Inventors: Frappier Louis Simon; Boecking Ewald
Original assignee: INTERNAT PROJECTER CORP
Current assignee: INTERNAT PROJECTER CORP; INTERNATIONAL PROJECTER Corp
Priority date: 1928-08-31
Filing date: 1928-11-22
Publication date: 1933-09-05
Anticipated expiration: 1950-09-05

Description

| s. FRAPPIER ET.AL 1 1,925,657

Sept. 5, 1933.

FIRE SHUTTER FOR MOTION PICTURE PROJECTION MACHINES 4 Sheets-Sheet 1 Filed Nov. 22, 1928 p 3 L. s. FRAPPIER ET AL 1,925,657

FIRE SHUTTER FOR MOTION PICTURE PROJECTION UGHINES Filed Nov. 22, 1928 4 Sheets-Sheet .2

Sept. 5, 1933.

L..S. FRAPPIER ET AL FiRE SHUTTER'FOR MOTION PICTURE PROJECTION MACHINES Filed Nov. 22, 1928 4 Sheets-Sheet 3 Sept- 1933- L. s. FRAPPIER ET AL 1,925,657

FIRE SHU'ITEiR FOR MOTION PICTURE PROJECTION MACHINES Filed Nov. 22, 1928 4 Sheets-Sheet 4 Patented Sept. 5, 1933 UNITED STATES FIRE SHUTTER FOR MOTION PICTURE PROJECTION MACHINES Louis Simon Frappier and Ewald Boecking,

Brooklyn, N. Y

., assignors to International Projecter Corporation, New York, N. Y., a corporation of Delaware Original application August 31, 1928, Serial No.

303,162. Divided and this application November 22, 1928. Serial No. 321,118

6 Claims.

This invention relates to projection machines, and more particularly, to a fire shutter for preventing the projection light from being applied to the motion picture film when the film becomes stationary. The invention is particularly applicable to a motion picture projection machine having a wide film which is capable of absorbing a considerable amount of heat from the rays of the projection light, and provides for cutting off said rays when the speed of the film has decreased to such a low value that the continued application of the light rays would constitute a fire hazard.

An object of the present invention is to provide mechanism for automatically controlling the .light rays which are appliedto the projection film in accordance with the speed of the machine.

Another object is to provide for the control or said light raysinaccordance'with the instantaneous condition of the film.

A further object is to shield the film from the light rays when the film becomes stationary due to breakage.

The above objects and others, which will be apparent as the nature of the invention is disclosed, are accomplished by providing a fire shutter which may be automatically controlled by a centrifugal governor for cutting off the light rays when the speed of the machine falls below a predetermined. value. Mechanism is also included for operating the shutter when breakage of the film occurs, and means is provided whereby the centrifugal governor raises the fire shutter out of the path of the light rays when the machine reaches normal running speed, regardless of whether the shutter becomes closed as the result ofnormal operation or because of a break in the film.

This application is a division of our copending application, Serial No. 303,162, filed August 31, 1928, for-Improvements in projection machine.

Although the novel featureswhich are believed to be characteristic of this invention will be particuluarly pointed out in'the claims appended hereto, the invention itself, as to its I objects and advantages, the mode of its opera- 5 fire shutter with respect to the motion picture film;

Fig. 2 is a section taken on .the line 2-2 of Fig. 1 showing the fire shutter and centrifugal control mechanism;

Fig. 3 is a section taken on the line 3-3 of Fig. 2;

F1Fig. 4 is a section taken on the line 4-4 of Fig. 5 is an enlarged detail view of the fire shutter showing its relationship to the aperture plate;

Fig. 6 is an enlarged detail View of the supporting means for the fire shutter;

Fig. 7 is a horizontal section showing the film operated control mechanism for the fire shutter;

Fig. 8 is a side elevation of the centrifugal control in operative position;

Fig. 9 is a section taken on the line 9-9 of Fig. 8;

Fig. 10 is a side elevation of the centrifugal control in inoperative position; and

Fig. 11 is a section taken on the line 11 -11 of' Fig. 10.

Like reference characters denote like parts in the several figures of the drawings.

In the following description and in the claims parts will be identified by specific names for convenience, but they are intended to be as generic in their application to similar parts as the art will permit.

Referring to the drawings more in detail, the invention is shown as applied to the projection head of a motion picture projection machineineluding a continuous sprocket 20 (Fig. 1) for withdrawing the film- 21 from the upper film magazine (not shown). Said fihn is. passed around sprocket 20, formed into upper loop 22, is passed over film gate 23, around intermittent sprocket 24, is formed into a second loop 25 and withdrawn from the machine or applied to associated sound reproducing mechanism. The projection light is passed through aperture 26 in the casing 27 of the projection head through a light cone 28, then through aperture plate 29, film 21, film gate 23 and lens tube 30, by means of which said light is focused on a distant screen.

Fire gate 35 is formed of a pair of face plates 36 (Figs. 5 and 7 which are supported in spaced 05 relationship by means of rivets 3'7. Said fire gate is supported from link 38 and adapted to slide vertically across aperture 26 in channel plate 39, which is secured to said frame 27 by suitable means, such as screw 40.

vents pin 45 from being withdrawn from fire shutter 35 in response to the pressure of said spring. Said pin is normally held in such "position that head 44 enters aperture 43 of,link 38 and suspends fire shutter 35 therefrom. The

shank of pin 45, however, is ofsuch diameterthat when said pin is moved inwardly against the tension of spring 47, said pin will .be' free to slide in slot 42, thereby allowing fire shutter 35 to drop with respect to link 36 and assume a position in front of aperture 26.

For operating pin 45 a lever 50 is provided (Figs. 1 and 4) which is pivotalLv supported as by pin 51 from a convenient portion of the pro- 1 jection head. Said lever is provided with. a 2 curved portion 52 which is positioned adjacent upper loop 22 of film 21.

when a break in the film occurs during the operation of the machine, the continued feeding of film 21 by sprocket 20 will cause an enlargemerit of loop 22 which contacts with curved portion 52 of lever 50 and causes said lever to pivot about pin 51 and to exert pressure against pin 45. The pressure thus applied compresses spring 4'7 and withdraws head 44 from aperture 43 and permits the fire shutter to drop in front of aperture 26, thereby cutting of! the light rays from film 21. For operating said fire shutter in accordance with the speed of the projection machine, a centrifugal control device is provided which includes a housingdo' to which lever 61is connectedns by pin and slot connection 62. Lever 61 is pivotally secured as by bolt 63 to stationary sul port 64 which is attached to the framework of the machine as by bolts 65. Lever 61 is pivotally connected to link 38 by bolt 69 and controls the vertical position of fire shutter 35.

. Housing 6i) is journalledon shaft '10 which is supported in suitable bearings '11 and '12 in supporting member 64. Said housing is also provided with a counterweight '73 for normally maintaining. said shutter in closed position.

The centrifugal control mechanism comprises a pair of weights '15 and 76, which are pivotally mounted on disc 77 by means of

pins

78 and 79 respectively. The free ends of said weights 75 and '16 are resiliently secured by

springs

80 and 81 t0 pins 79 and "I8 respqrtively. Said weights are positioned inside of housing and are provided with friction elements 82 which may be formed of any suitable friction material, such as soft metal or fibre. Said friction elements are brought into engagement with the inner surface of housing 60 when

weights

75 and 76 are pivgted about pins 7s and '19 due to centrifugal orce. Y

Disc'l'lissecuredtosbaft'li) andisadapted .to rotate in accordance with said shaft. Shaft is driven from the main driving shaft 85 by cooperating gears so and a7. Said driving shaft may be utilised for driving the various sprockets of theproiectlon head and may be driven from any suitable source (not shown).

when the projection machine is at rest, disc '1': will be stationary and weights and 76 will be held by

springs

30 and 81 in the position shown in Fig. 10. Friction members 82 are thus out of engagement with housing 60, whereby said housing is allowed to rotate due to counterweight 73, thereby permitting lever 61 to rotate so about pin 63 whereby link 38 and fire shutter 35 are brought into their lower position (Figs.

1 and 3). Fire gate 35 is thus brought opposite aperture 26 and cuts of! the light from the projection film.

When the machine is operating normally, disc '77 is rotated at a speed proportional to that of main shaft 85 and causes a similar rotation of

weights

75 and 76. These weights are then moved by centrifugal force into the position 00 shown in Fig. 8, whereupon friction members 82 contact with'the inner surface of housing 60 and cause said housing to rotate a sufiicient amount to operate lever 61 and raise fire shutter 35 from the path of the projection rays.

When a break in the film occurs, pin 45 will be operated thereby allowing the fire shutter 60 fall to its lower position and after the machine has been stopped to permit the film to be repaired, the centrifugal control mechanism operates to bring link 38 into its lower position. When opening 43 of said link falls opposite head 44 of pin 45, said pin will be moved in response to spring 47 into engaging position, and when the machine is again started, link 38 will be raised in response to the centrifugal control mechanism, above described, thereby raising fire shutter 35 out of the path'of the projection rays. It is noted, therefore, that the fire shutter is operated either by slowing down or stop- 1 ping of the machine, which 'decreases the friction of members 62 on housing 60, or by breakage of the film which operates pin 45. In either case when the machine is again started, the fire shutter is raised by the centrifugal control mechanism thereby permitting the projection rays to be again applied to the film.

While certain novel features of the invention have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. In a motion picture machine a fire shutter, a supporting link therefor having a slot terminating in an enlarged aperture, a pin having an enlarged head adapted to cooperate with In said aperture and a reduced shank adapted to slid in said slot, means for slidably securing said pin in said shutter, a spring for normally maintaining said head in engagement with said aperture whereby said shutter is supported from said link, and film operated means for releasing said head and permitting the shank of said pin to traverse the slot in said link thereby 'permitting said shutter to assume a closed position.

2. In a motion picture machine a fire shutter, a supporting link therefor having a slot terminating in an enlarged aperture, a pin having an enlarged head adapted to cooperate with said aperture and a reduced shank adapted'to slide 5 in said slot, means for slidably securing said pin in said shutter, a spring for normally maintaining said enlargedhead in engagement with said aperture whereby said shutter is supported from said link, a lever pivotally secured to the projection head and adapted to bear against said pin,said lever having a portion located loop causes said lever to release said pin whereby the shank portion thereof traverses said slot and the fire shutter assumes a closed position.

3. In a motion picture machine, a fire shutter, a supporting link therefor having an elongated slot and an enlarged aperture, a spring pressed detent normally cooperating with said aperture for securing said shutter to said link, a lever for operating said detent, a portion of said lever being positioned adjacent the upper film loop whereby pressure of said film releases said detent and allows said fire shutter to close, a pivoted lever supporting said link, a housing .for controlling the position of said lever, centrifugal mechanism comprising a pair of weights associated with said housing, means for driving said centrifugal mechanism in accordance with the speed of said motion picture machine, and means associated with said weights for cooperating with said housing for raising said fire shutter when said machine is operating at normal speed.

4. In a motion picture machine, a fire shutter, a supporting link therefor, a releasable detent for securing said shutter to said link, centrifugal means controlled in accordance with the speed of said machine for controlling the position of said link whereby said shutter is closed when a the speed of said machine falls below a predetermined value and is opened when said speed is raised above a predetermined value, film operated means for releasing said detent and causing said shutter to close independently of said link, and automatic means for causing said detent to re-engage said link when said centrifugal means is operated to close said shutter.

5. In a machinehaving a travelling film, a slidable shutter, means for normally maintaining said shutter in elevated position during operation of said machine, a releasable link having an elongated slot, a pin slidable therein and normally connecting said shutter to said means, and film operated means for releasing said pin and allowing said pin to slide in said slot whereby to cause said shutter to fall into a second position in response to breakage of said film.

6. In a motion picture machine, a fire shutter, centrifugal means controlled in accordancewith the speed of operation of said machine for normally controlling the position of said shutter, a releasable pin connecting said-shutter to said centrifugal means, film operated means for releasing said pin and thereby causing said shutter to close independently of said centrifugal means, and means associated with said centrifugal means for automatically reengaging said pin when said centrifugal means is brought into position to close said shutter whereby said shutter is again automatically connected to said 1 centrifugal means.

LOUIS SIMON FRAPPIER. EWALD BOECKING.