US2444370A - Firetrap for projection machines - Google Patents

Description

June 29, 1948. REYNOLDS 2,444,370

FIRETRAP FOR PROJECTION MACHINES Filed July 8, 1946 2 Sheets-Sheet 1 IN VEN TOR.

fl/Air/ 26,004.4- B J J M M June 29, 1948. A. H. REYNOLDS ,3

FIRETRAP FOR PROJECTION MACHINES Filed July 8, 1946 2 Sheets-Sheet 2 Patented June 29, 1948 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to fire traps for motion picture projection machines, and more particularly to a device for cutting the film and sealing the openings between the projector and the film magazines.

It is an object of this invention to provide a device for severing the film and sealing oil the openings between the projector and the film magazines, upper and lower, when a fire develops in the projection or sound head.

Another object of this invention is to provide a device which releases a. knife to cut the film between the film magazine and the projector when the temperature in the projector reaches a predetermined degree, and it has been found that a temperature of 110 degrees Fahrenheit should not be exceeded in the projector.

Another object of this invention is to provide a device for trapping a fire in the projection head which may be readily adapted to various sized projectors and film magazines and which may be readily installed on or incorporated in any or all present existing machines and need not be a device necessarily installed only at the time of manufacture of the projector or magazine.

Still another object of this invention is to provide a fire trap of the kind to be hereinafter described which may be readily manufactured and sold at an economical price, and in which the installation costs are practically negligible.

With the above and other objects in view, my invention consists in the arrangement, combination and details of construction disclosed in the drawings and specification, and then more particularly pointed out in the appended claims.

In the drawings,

Wherein similar reference characters designate similar parts throughout the respective views,

Figure l is a side elevation, partly broken away and partly in section, of a projector equipped with a fire trap constructed according to an embodiment of my invention,

Figure 2 is a side elevation, partly broken away and partly in section, of my fire trap installed in an upper magazine,

Figure 3 is a side elevation, partly broken away and partly in section, of my fire trap installed in a lower film magazine,

Figure 4 is a section taken on the line 44 of Figure 5,

Figure 5 is a top plan view, partly broken away, with the top cover removed,

Figure 6 is a vertical section taken on the line 6-6 of Figure 5.

Referring to the drawings, the numeral Ill designates generally a motion picture projection machine having a sound head ll fastened to or formed on the lower end thereof, and is equipped with the conventional type of upper and lower film magazines I2 and I 4 respectively.

(ill

The numeral I5 designates generally a fire trap constructed according to an embodiment of this invention and is so constructed and designed that it may be secured on a motion picture projector l0 between the projector Ill or sound head I l and the magazines I 2 and M as shown in Figure 1, or may be installed or incorporated within the magazines [2 and [4 as shown in Figures 2 and 3. The type of installation is optional for a user, depending on his particular desires or upon the particular equipment on which this fire trap I5 is to be installed. The only difference in the installations is the location and means of attachment which may be varied to any circumstances and do not form a part of this invention inasmuch as the same fire trap l5 may be used irrespective of the installation. No particular means of securing this fire trap i5 are shown in the drawings as it is considered that this fire trap 15 may be frictionally held in position between the magazine and projector body by the magazine attaching clamps in Figure 1 not shown, or may be fixed by bolts or rivets or any other suitable attaching means not shown, in Figures 2 and 3.

The fire trap l5 comprises a relatively thick metal segmental arcuate body plate iii, an upper cover plate I l, a lower cover plate l8, and a. knife blade I9 slidably carried between the body plate i6 and upper cover plate IT.

The body plate I6 is formed of a rectangular segmental arcuate strip of relatively thick metal and is formed on the upper concave side with a large rectangular recess 20 near one end thereof in which the knife I9 is adapted to be slidably engaged. A pair of parallel longitudinally extending slots 2| are formed in the plate l6 and extend from one end well into the recess 20. The plate i6 is further formed with a rectangular opening 22 which opens vertically from the recess 2! and a side opening or cut out 24 communicating with the opening 22 and recess 2| whereby the film may pass through the opening 22 when the projector is in operation and through the opening 24 when the fire trap I5 is being installed or removed.

The knife I9 is formed of a substantially rectangular body having a beveled knife edge 25 on one end thereof and a pair of rearwardly extending lugs 26 on the opposite end. The blade i9 is slightly shorter in width than the recess '20 and considerably shorter in length whereby it may be slidable therein. A pair of coiled springs 21 are carried in the slots 2| and engage the end of the plate l6 at one end and engage the blade I9 at the other end byengaging over the rearwardly projecting lugs 26.

The upper cover plate I1 is formed of an elongated sheet of metal of substantially the same dimensions as the platee l6 and is formed with 3 openings 28 and 29 which register with openings 22 and 24 of plate |6 for admitting the film 30.

The lower cover plate |8 is formed of an elongated sheet of metal of the same Width as the plates l5, H and is formed with upstanding flanges 3| on each end thereof which are adapted to be attached to the ends of plate by screws 32 or other suitable attaching means, while the upper cover plate I! is secured to plate l5 by flush screws 34 through the upper surface of the plate IT.

The knife is is further formed with a detent on the lower convex surface in which the upper end of a trigger or belt 35 is adapted to be engaged.

For holding the knife IS in retracted position for normal operation of the projector I5, there is provided a renewable fuse 4|! which is secured to the plate Hi and extends through the walls of t projector and through the magazine supporting well 3i. The {use 40 consists of a tubular body l! threaded externally along its length as at and is provided at its inner end with an an nular flange M- which is adapted to engage inner recessed surface of the recess 20 for support ing the fuse All therefrom. The fuse body H extends outwardly from the plates H5 and I8 and a nut 45 about the body 4| clamp the fuse Ml onto the plates |5 and It.

Enclosed and slidable within the body 4| is a cylindrical trigger member 36 having a rounded knife engaging end and a reduced diameter outer and 45. Also slidable in the body 4| at the opposite end is a cylindrical plug engaging member ti having a reduced diameter tubular inner end portion fi' The reduced end 46 of the trigger 35 siidably engages in the reduced tube &8 and a spring lt therein constantly urges the trigger 3E3 upwardly into engagement with the blade IS. A second spring 50 about the trigger 3E and reduced tube 48 engages the inner end wall of the body ill at its inner end and the rear side of the memoer ll at its outer end for constantly urging the member 4i outwardly thereby releasing the trigger 36.

For holding the trigger in engagement with the knife I9, I have provided a plug 5| which is threadable on the outer end of the body ll. The wall of the plug 5| is formed with an annular opening 52 through which the reduced outer end 5 3 of member 41 may be slidably engaged.

A pair of oppositely disposed substantially U- shaped levers 55 are pivotally connected to the outer side of the plug 5| in such a manner that one arm of each lever 55 extends over the opening 52 and the end 54 of the member 41 engages these arms which arms retain the member 4'! in retracted position. The other arms of the levers 55 are connected to each other by a fusible elemen't 53 for holding the levers 55 in operative position. When an excessive temperature is reached the fusible element 56 separates and the levers 55 are pivoted permitting the member 41 to be urged to the outer end of the body 4|, thus reducing the spring tension on the trigger 35 and permitting the knife IE to separate the film 30 and seal the opening 22. In this condition the reduced portion 54 protrudes through the plug 5|. To restore the projector to operative condition a new plug 5| must be installed and the knife I9 moved to retracted position.

In all types of installations it is desirable that the body 4| be of considerable length in order to support the fusible plug 5| within the projector body Ill or within the sound head I where the fire is usually originated. r r

I do not mean to confine myself to the exact details of construction herein disclosed, but claim all variations falling within the purview of the appended claims.

Having thus described desire to claim is:

1. A fire trap for attachment to a motion picture projector and magazine comprising a recessed guide plate for attachment between the projector and magazine, a spring-pressed knife slidable in said plate for severing the film and closing the opening between the projector and magazine, a tubular body carried by said plate, a trigger supporting tube slidable in said body, a spring-pressed trigger slidable in said trigger supporting tube engaging said knife for normally holding said knife in retracted position, an apertured plug removably carried by an end of said body opposite from said trigger, a portion of said supporting tube extensible through said plug for releasing the sbring tension of said trigger, a pair of levers rockabiy carried by said plug, and fusible means connecting aid levers together for restraining said trigger supporting tube in said body.

2. A fire trap for a motion. p..ot'=:.re projector and com rising rec guide plate be- Jcctcr magazine, a spring bie in p invention, what I be proector and magazine, a tubular trigger and fuse supporting body on said plate extenc lg into said projector, a trigger, a trigger supporting mem ber slidable in said body, spring means between said trigger and trigger supporting member biasing trigger into restraining engagement with said .ife, sp ing means urging trigger supporting member into trigger spring tension releasing position, a plug on body, and fusible means carried by said plug restre 1g said trigger supporting member in trigger 5 ng tensioning position.

3. In a fire trap for a motion. picture projector and magazine having a spring-pressed knife slidab-ly supported between said magazine and pro-- jector for evering the film and closing the opening between the projector and magazine, a recessed knife guide member, a tubular trigger housing carried by said guide member and extending into said projector, a pring ressed trigger supporting member slidabie in said housing, and biased downwardly therein, a spring-pressed trigger carried by said supporting member and extending from one end of said housing for engagement with said knife, an. apertured plug threadably carried by the other end of said housing, said trigger supporting member extensible through aid apertured plug for releasing the tension of said spring ressed trigger, a pair of rock levers carried by said plug restraining said supporting member in trigger tensioning position and fusible means holding said rock levers in engagement with said trigger supporting member.

ALBERT I-I. REYNOLDS.

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

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