US1875707A

US1875707A - Circuit controlling device

Info

Publication number: US1875707A
Application number: US403052A
Authority: US
Inventors: William E Cox
Original assignee: Individual
Current assignee: Individual
Priority date: 1929-10-28
Filing date: 1929-10-28
Publication date: 1932-09-06
Anticipated expiration: 1949-09-06

Description

P 6, 1932- w. E. cox 1,875,707

CIRCUIT CONTROLLING DEVIC E Filed 001. 28, 1929 2 Sheets-Sheet 1 J7 Mm Y I '27 I Inventor 1 4 mum/"65K Attorney Sept. .6, 1932. w. E. cox

CIRCUIT CONTROLLING DEVICE Filed Oct. 28. 1929 2 Sheets-Sheet 7 VV/LL/AMECOX.

' Attorney Patented Sept. 6, s 1932 .WILIJAM a 001:, or New roar, N. Y.

cracurr conraonnmq Dav-r01:

Application filed October 28, 1929. Serial 1T0. 403,052.

This invention relatesto a circuit controlling device which is mainly designed for use in a motion picture projecting machine.

The primary object of the invention resides in a switch device for installation in the casing of a motion picture projecting machine and which is automatically controlled by the film strip passing through the machine for closing an electric signal circuit for visually or audibly warning the machine operator that the lm is nearing the end and to be ready to throw the other machine in operation to prevent any lapse in the continuity of the motion picture being shown.

Another object ofthe invention is to provide a switch device which includes a switch arm normally disposed under tension for closing an electric signalling circuit in which it is arranged but which is held out of closing position against its tension by engagement of the switch arm with one edge of the film strip as it passes from the take ofi' reel into the casing of the projecting machine, the said film strip bein suitably notched along the said edge near t e end of the strip to release the switch arm to' allow the same to moveunder tension to circuit closing position.

A further object of the invention is the provision of a means for holding the switch arm in a neutral out of the way position against the action of the spring tension for facilitating the convenient threading of the'film strip into the machine when inserting a new reel of film therein.

A still further object is to provide a switch device of the kind mentioned which may be quickly installed in a motion picture projecting machine of thetype now in use without requirin alterations thereto and which is simple 0 construction and positive of operation.

With these and other objects in view, the invention resides in the certain novel construction, combination, and arrangement of parts, the essential features of which are hereinafter fully described in the foregoing specification, are particularly pointed out in the appended claims, and are illustrated in theaccompanying drawings, in which:

, Figure 1' is a fragmentary side elevational viewof a motion picture projecting machine showing the casing door in an open position with my'invention installed therein, 1 Figure 2 is an view of my invention mounted in operative position. 7 I I Figure 3' is a side elevational view of my invention per se looking in the opposite to that shown in Figure 2.

Figure 4 is a vertical longitudinal sectional view. 7, j j p F igure 5 is a top plan view with parts shown in section. g

Figure 6 is a vertical transverse sectional view on the line 66 of Figure 5, looking in the direction of the arrow I Figure 7 is an enlarged detail sectional view through the outer end of the switch arm.

Figure 8 is a front eleational view of a portion of a film strip illustrating the manner in which the notch in the said strip releases the switch arm to closing position. 1

Figure 9 is a detail-sectional elevational view of the springtensionmeans, and the coacting angular cam.

Referring to the drawings by reference characters, the numeral 10 designates a portion of a moving picture projecting machine which includes the usual upper magazine 11 for supporting the take ofl reel 12, a lower magazine 13 for housing the take up reel 14, while interposed between the upper and lower magazines is the casing or housing 15, access to which is gained through a hinged door 16 provided on one sidethereof. The film strip 17 passes from the pay-off reel 12 to the take-up reel 14' and is threaded through the casing in the usual well known manner.

, My improved switch or cueing device is shown in its entirety as at 18 and is mounted in the upper right hand corner of the casing '15 at a point adjacent the entrance of the film strip into the casing for a purpose which will be hereinafter appreciated.

The switch device 18 includes a base of rectangular shape 19 which fits against the front wall of the casing 15 and is secured thereto by screws or like fastening elements enlarged side, elevational direction 20. The under face of the base19 isrecessed as at 21, while the opposed parallel top and bottom walls are beveled inwardly as at 22 to receive the dove tailed portions 23 of a supporting bracket 24. Journaled in the end walls of the recess 21 is a screw shaft 25 which has threaded connection with a bore 26 extending through the bracket 24, while fixedly mounted to the screw shaft and disposed within the recess is a knurled manipulatin knob 27 whereby rotation of the knob wil cause the supporting bracket 24 to move laterally on a horizontal plane for a purpose to be presently explained.

The outer end of the supporting bracket 24 is bifurcated and journaled in the forked ends thereof is a transversely disposed shaft 28, one end of the shaft extending beyond one side of the bracket to receive a conductor collar 29 insulated from the shaft by a bushing 30. Fixed to the adjacent side of the bracket 24 is a block of insulating material 31 having a socket 32 therein for the reception of an expansion spring 33, one end of which bears against a contact pin 34 which constantly engages the collar 29, while the other end of the spring is fixedly connected to a terminal screw 35 with which an electric wire 36 connects and which leads to a source of electric energy as will be hereinafter explained. It will be appreciated that current will flow from the wire 36 through pins 35, spring 33, pin 34, collar 29 and the several other parts which will now be explained.

Fixed to the shaft 28 and disposed for movement within the slot provided by the bifurcation is a switch arm 37, the outer end of which is provided with an opening 38 for the reception of the stud 39 extending from the head 40, the latter being provided with a kerf or slot 41 for engagement with one edge of the film strip 17, as shown in Figures 5 and 8 of the drawings. The inner end of the switch arm 3'7 supports a block of insulation 5 42 which overlies a portion of one side of the switch arm, and which block carries a contact terminal 43, which is electrically connected to the collar 29 by an angular shaped contact strip 44 which overlies the block of insulation 42 so as to prevent short circuiting of the device. It might be mentioned that the head is secured in position upon the outer end of the arm 37 by a screw 45 which threads into the stud 39 as clearly shown in Figure 7 of the drawings.

Mounted in the supporting bracket 24 at the closed end of the slot formed by the bifurcation therein is a cup 46 of insulating material, the bottom of which supports a stationary contact terminal 47 from which a fiat strip 48 extends, and to which a wire 49 is connected and whichserves as part of an electric circuit to be presently described. The contact terminal 43 carried by the switch arm 37 is movable into the cup 46 for contacting engagement with the stationary contact 47 for the purpose of closing an electric circuit.

Fixed to the shaft 28 to one side of the switch arm 37 is a cam member 50 provided with right

angular faces

51 and 52 for con tacting engagement by the outer flat face of a pin 53 extending into a socket or bore 54 provided in the supporting bracket 24 and which pin is under the action of an expension spring 55, one end of which abuts the inner end of the pin 53 and the opposite end abutting the closed end wall of the socket 54. When the angular face 52 of the cam is in flat bearing engagement with the end of the pin 53 as shown in full lines in Figure 9 o the drawings, the switch arm 37 is in such position that'the movable contact 43 carried thereby is in contacting engagement with the stationary contact 47, while the dotted position of the cam in Figure 9 and the full line position of the said cam in Figure 5 illustrates the position thereof when the head 40 of the switch arm is in bearing engagement with the side edge of the film strip 17 during the showing of a film. However, the said edge of the said film strip 17 is notched adjacent its end as at 56 as shown in Figure 8 of the drawing, and as the said notched portion of the film strip reaches the head 40, the switch arm 37 will be released and will be moved by the action of the spring to a position to cause the stationary contact 47 to be engaged by the contact 43 on the switch arm.

The circuit hereinbefore referred to is shown in Figure 1 of the drawings and includes the

wires

36 and 49 together with a source of electric energy such as a battery 57 and either an audible or visual electric signalling device such as a bell, buzzer or electric lamp 58.

When threading the film strip of a. motion picture film into the projecting machine, one edge of the strip is inserted in the kerf 41 of the head 40, and the manipulating knob 27 is turned to adjust the supporting bracket 24 to a position whereby when the edge of the strip is seated in the kerf 41., the switch arm 37 is depressed against the action of the spring 55 to cause the contact 43 to move out of engagement with contact 47, thus normally holding the circuit in an open condition. Assume that the film strip 17 is nearing its end, and as the notch 56 in the edge of the film reaches the head 40, it releases the switch arm 37 whereupon the action of the spring 55 causes the switch arm to be moved to a closed position whereupon the

contacts

43 and 47 engage, thus closing the circuitand operating the visual or audible signal 58 which gives warning to the machine operator that he must be ready to throw the next machine into op eration in order to avoid any lapse in the continuity of a moving picture. In other words, the device serves as a cue for moving picture operators in the showing of moving pictures involving a number of separate reels.

In threading the film strip 17 into the machine, the switch arm 37 may be moved to an out of the way position as shown in dotted lines in Figure 5 of the drawings, whereupon the said switch arm is moved one quarter turn so that the fiat face 51 engages the outer flat face of the pin 53 at which time the said switch arm is held against swinging movement. The cam 50 is provided. with stop shoulders 59 for engagement with opposite sides of the pin for limiting turning movement of the cam and the other parts carried by the shaft 28.

While I have shown and described what I deem to be the most desirable embodiment of my invention,I wish it tobe understood that many of the details may be varied if desired without in any Way departing from the spirit of my invention, and I therefore do not limit myself to anything less than the whole of the invention limited only by the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is 1. An electric switch for motion picture projecting machines comprising a base, a bracket slidably mounted on said base, manipulative screw means for imparting sliding movement to said bracket and for securing the same in an adjusted position, a stationary contact mounted on said bracket, a switch arm pivoted on said bracket, a contact on one end of said switch arm, a kerfed head on the other end of said switch arm adapted for hearing engagement with the edge of a film strip, and spring means tending to urge said switch arm in a direction to cause the contact thereon to engage the stationary contact, both of said contacts adapted to be arranged in an electric circuit, substantially as and for the purpose. specified.

2. An electric switch for motion picture projecting machines comprising a base, a bracket slidably mounted on said base, manipulative screw means for imparting sliding movement to said bracket and for securing the same in an adjusted position, a stationary contact mounted on said bracket, a switch arm pivoted on said bracket, a'contact on one end of said switch arm, a kerfed head on the other end of said switch arm adapted for hearing engagement with the edge of a film strip, and spring means tendingto urge said switch arm in a direction to cause the contact thereon to engage the stationary contact, both of said contacts adapted to be arranged in an electric circuit, said spring means including an angular shaped cam fixed to said switch arm, and a spring actuated pin in bearing engagement with said angular shaped cam, substantially as and for the purpose specified.

said stationary contact against the action of said spring means, a bracket for said support, and screw actuated means for adjusting said support relative to said bracket substantially as and for the purpose specified.

4. An electrical switch device comprising a base, a bracket slidably mounted on said base, a screw shaft journaled for rotation in said base, and to which said bracket is threadedly connected, a manipulating head on said screw shaft by which it may be manually turned, a sationary contact provided on said bracket, a switch arm pivoted to said bracket, a contact on one end of said switch arm for contacting engagement with said stationary contact, and spring means acting upon said switch arm to move the contact thereon into contacting engagementwith said stationary contact, substantially as and for the purpose specified.

5. An electric switch of the class described comprising a base having a clove tailed channel provided therein, a bracket provided with a dove tailed portion slidable in said dove tailed channel, a screw j ournaled in said base and extending within said dove tailed channel, said bracket being threaded to said screw, a manipulating element carried by said screw by which the same may be manually turned, a stationary contact mounted on said bracket, a switch arm pivoted on said bracket, a contact on one end of said switch arm for coacting engagement with said stationary contact,

a bearing head on the other end of said switch arm adapted to bear against an element by which the actuation of the switch is controlled to hold the contact on said arm from engagement with the stationary contact on said bracket, and spring means acting upon said switch arm to cause the contact thereon to engage said stationary contact.

In testimony whereof I afiix my signature.

WILLIAM E. COX.