US2468598A - Alarm device - Google Patents

Description

Patented Apr. 26, 1949 UNITED STATES PATENT OFFICE Claims.

This invention relates to alarm devices. More particularly the invention relates to a film feed reel alarm.

It is customary to make up most motion pictures in several reels of film. In order that the projection of the picture may be uninterrupted, due to the changing of the film reel, it is common practice to use two projectors alternately to show a complete picture. The object of this invention is to provide an alarm which will apprise the operator of the machine when a film reel is about to be exhausted of its film, so that he can adjust the operation of the projectors alternately without any break in the projected picture.

Heretofore, devices for this purpose have been provided. Such devices, however, have not met with any great degree of commercial adaptation because they either required an electrical connection to effect operation of the alarm mechanism at the proper time or their employment resulted in undue noise much to the displeasure of the operator and to those viewing the projected picture.

Therefore, it is an object of this present invention, in addition to that of providing a simple and expeditious alarm for apprising the operator just prior to the exhaustion of the film from the film feed reel, to provide the mechanism in a manner such that it will operate substantially noiselessly and with accuracy and the greatest degree of efficiency.

Yet another and equally important object of the invention is the provision of an alarm system for the purpose herein set forth, which may be incorporated in the standard projecting machine without any material changes or alterations.

Other objects will appear hereinafter.

T he invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawings showing the preferred form of construction, and in which:

Fig. l is a fragmentary side elevational View of a film reel and magazine therefor, showing my improved film feed reel alarm associated therewith;

Fig. 2 is a fragmentary top plan view of the same;

Fig. 3 is a view similar to Fig. 1 showing the reverse side thereof and with the gong striker in striking position.

It is desirable that the several objects of my invention be accomplished by mechanism shown in its preferred form of construction in the accompanying drawings and which mechanism will now be described.

In these drawings a magazine chamber is fragmentarily illustrated at l6. This chamber provides a suitable bearing l I through which is journaled a shaft 12. On this shaft I2 is arranged a feed reel i3 from which the film strip 14 is fed to a take-up reel (not shown). The shaft I2 carries at one end portion a gear l5.

On the bearing l l is 2. depending bracket arm I6 carrying a plate H, the bracket arm l6 being secured to the bearing by set screws 16' or by any other suitable means. This plate at opposite end portions provides bearing plates 18 between which is rotatably supported a shaft l9. This shaft [9 is operatively connected to the gear l5 and is driven thereby through the medium of a worm gear 2! On this shaft I9 is a governor 2| including arms 22 having weights 23 thereon. This governor 2| includes a flanged collar 24 movable longitudinally of the shaft 59 according to the centrifugal action of the governor 2|.

On this plate [1 is a latch arm 25. This latch arm 25 is pivotally connected to the plate I! as at 25. The arm 25 has an angled end portion 21 provided with a friction stud 28 adapted to engage the face 29 of the flanged collar 24.

The opposite end portion 30 of the latch arm 25 includes an adjustable latch p-in 3| adapted to engage an arm 32 pivotally connected as at 33 to the plate I? to maintain this arm 32 in a substantially vertical position as shown in Fig. 1. To this arm 32 there is connected a hammer 34. Extending from the plate I? is a supporting arm and carried at the upper end of this arm 35 is a bell or gong 35 so related with respect to the hammer 3? as to be struck thereby when the hammer 34 is pivoted in a clockwise direction as viewed in Fig. 1, under the action of a spring 37.

The latch arm 25 is normally urged into latchposition with respect to the arm by means of a spring 33 (Fig. 3)

As the motion picture projector is operated in the customary manner, the film strip I4 is fed from the reel #3 to a take-up reel (not shown). It is a known fact that with the film traveling at a constant speed through the projector the speed of rotation of the film reel [3 and shaft IE will increase as the film strip it is unwound therefrom. This increased speed of rotation of the shaft 12 obviously increases the rotation of the shaft [9 and by reason of this increase in the speed of rotation of the shaft I9, the governor weights 23 will be thrust outwardly, moving the flanged collar 24 relative to the fixed bearing 24' of the governor. This movement of the flanged collar 24 will pivot the latch arm 25 by virtue of its engagement with the friction stud 28. This pivotal movement of the latch arm 25 is against action of the spring 38, and when the latch arm 25 is thus pivoted the arm 32 will be pivoted to the right as viewed in Fig. 1 under the action of the sprin 31, bringing the hammer 34 into striking contact with the gong or bell 36, thereby apprising the operator of the motion picture projector machine of the fact that the film strip is about to be dispensed completely from the reel l3. Upon hearing the gong or bell 36, the operator then may prepare for operation the other moving picture projector machine or prepare to discontinue the operation of the projector machine having the thus nearly spent film strip.

After the latch arm 25 has been pivoted in the foregoing manner to release the hammer 34, the operator then resets the alarm by pivoting the hammer 34 in a clockwise direction as viewed in Fig. 3, against the action of the spring 31. This will dispose the lower end portion of the arm 32 in a position to allow the resetting of the latch arm by action of the spring 38, that is, with the latch finger or pin 3| disposed in latched engagement with respect to the lower end portion of the arm 32, thereby retaining this arm and the hammer in non-striking position until the speed of the shaft I9 causes the outward thrust of the weights 23, at which time the hammer 34 will then be released in a manner hereinbefore set forth.

From the foregoing description, it is manifest that the releasing of the hammer 34 is by mechanism which is substantially silent in operation, thereby avoiding any disturbance until the hammer has actually engaged or struck the gong or bell.

The mechanism is effective and positive in operation and can be manufactured at an economical cost. The device may be attached to any standard motion picture projecting machine without any material changes or alterations therein.

In the drawings I have illustrated the spring 31 attached to the wall Ill of the film reel housing. If desired, this spring 31 may be attached to the usual door of the film reel housing so that when the door is open spring 31 will be expanded and the striker or hammer 34 will return automatically to its upright position as shown in Fig. 1.

While I have illustrated and describied the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. In combination, a mounting bracket, a variable speed shaft, a driven shaft rotatably carried by the bracket and arranged substantially at right angles with respect to said speed shaft, 2. governor carried by and rotatable with the driven shaft and having a collar movable longitudinally of said driven shaft, a worm gear connection between said speed shaft and said driven shaft, a bell supported by said bracket, a hammer adapted to strike said bell, means providing a pivotal connection between said hammer and said bracket, latch means carried by said bracket and adapted to releasably latch said hammer in a non-striking position with respect to said bell and including a member operatively related to said collar whereby when said collar is moved in one direction by said governor relative to said driven shaft said latch means will release said hammer for pivotal movement in a direction to strike said bell, and means for moving said hammer into contact with said bell upon release of said hammer from said latch means.

2. In combination, a mounting bracket, a variable speed shaft, a driven shaft carried by said bracket, driving connection between said speed shaft and said driven shaft, a governor carried by and rotatable with said driven shaft and having a collar mounted on said driven shaft for movement longitudinally with respect to said driven shaft by said governor, a bell carried by said bracket, a hammer adapted to strike said bell, means providing a pivotal connection between said hammer and said bracket, latch means for releasably latching said hammer in non-striking position and having means operatively related to said collar whereby when said collar is moved in one direction longitudinally of said driven shaft by said governor, said latch means will release said hammer for pivotal movement in a direction to strike said bell, and means for moving said hammer into contact with said bell upon release of said hammer from said latch means.

3. A film feed reel alarm including a shaft on which a film feed reel is mounted, a mounting bracket, a driven shaft rotatably carried by the mounting bracket, means providing connection between the driven shaft and the film reel supporting shaft, a bell striker, means pivotally supporting said striker from said bracket, a bell supported by said bracket and adapted to be struck by said striker, latch means carried by said bracket for releasably latching the striker in nonstriking position, means controlled by the speed of said driven shaft for actuating said latch means to release said striker for movement into bell striking position, and means for moving said striker into contact with said bell upon release of said striker from said latch means.

4. A film feed reel alarm including a shaft on which a film feed reel is mounted, a mounting bracket, a driven shaft rotatably carried by the mounting bracket, means providing connection between the driven shaft and the film reel supporting shaft, a bell striker, means pivotally supporting said striker from said bracket, a bell supported by said bracket and adapted to be struck by said striker, latch means carried by said bracket for releasably latching the striker in nonstriking position, means controlled by the speed of said driven shaft for actuating said latch means to release said striker for movement into bell striking position, said last-named means including a centrifugally actuated device carried by said driven shaft and movable longitudinally with respect thereto and operatively related to said latch means to actuate said latch means to release said striker when said device is moved in one direction relative to said driven shaft, and means for moving said striker into contact with said bell upon release of said striker from said latch means.

5. In combination, a film reel supporting shaft, a driven shaft arranged substantially at right angles with respect tosaid' reel supporting shaft, means providing connection between said reel 5 supporting shaft and said driven shaft, a governor REFERENCES CITED on said driven shaft and including a slidable collar, alarm means including a pivotally supported g igiig ggi ff are of record in the member, and latch means adapted to latch said member in a predetermined position and opera- 5 UNITED STATES PATENTS tively related to said collar whereby when said Number Name Date collar is moved longitiudinally of said shaft, said 3 9 750 Edwards APR 3 13 latch means wil be operative to release said mem- 2,123,084 Tanson July 5 193 her for pivotal movement, and means for moving said member into contact with said bell upon re- 10 FOREIGN PATENTS lease of said member from said latch means. Number Country Date WILLIAM C. HEINTZ. 21,762 Great Britain Sept. 22, 1910

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