Microfilm projector with reel selection mechanism

Claim 1

A microfilm projector with selection mechAnism, made up of a base, upon which is mounted side panels to support a central stationary tube which in turn serves as the axle of a revolving drum, said revolving drum having flanges on which are mounted a number of reels, one serving as driven reel, the other serving as a payout reel, having a film so mounted on and between them as to permit movement across a projecting light beam, said light beam originating in the central stationary tube, through an opening in said tube, thence through an opening in the revolving drum, thence through the film stretched from the driven reel to the payout reel, into a projecting lens mounted on a pedestal supported by aforementioned base, thence to a rear projection screen where image on film is reproduced; and mounted on aforementioned base, two electric motors, rotating in opposite directions, having each an electric solenoid to effect engagement of driving pinion, mounted on the motor, with the rim of driven reel, said solenoid having an armature mechanically connected to said motor in such manner as to move motor on a pivotal mount to engage and disengage said driving pinion on motor, said solenoid being controlled by means of a switch, single-pole, double-throw, with speed control incorporated in said switch to effect fast or slow motion of film across projection beam; and mounted on the aforementioned base, a series of electrical contacts, equal in number to the number of pairs of reels, each contact with a numbered or lettered button to close said contact by pressing, and open by releasing, causing the closing of an electric circuit to actuate a magnetic relay, mounted on the aforementioned base, the magnetic relay in turn controlling the circuitry to start and stop an electric motor, mounted on aforementioned, base, said motor driving a belt which in turn drives rotation of aforementioned drum, and the flange of said drum having mounted on it and so placed as to revolve with the drum, a permanent magnet actuating spring contacts, equal in number to the number of reels on said flange, mounted on a subpanel of supporting panel, arranged in a circle, whose radius is equal to the radius of the circle described by said permanent magnet rotating with the flange of said drum, said spring contacts being of sufficient length to cause said drum to lose part of its momentum to allow engagement of solenoid actuated plunger, mounted on aforementioned base, in specially formed slots cut in periphery of drum flange, such slots being so formed as to secure drum in precise alignment with projection light beam, opening in body of drum, and opening in central stationary tube, and with selected reel of film, actuation of said spring contacts by permanent magnet opens contacts, thus cutting off electric power to motor rotating drum, when permanent magnet passes before contacts corresponding to selected position of drum, all other contacts remaining closed thus enabling further selection by pressing another button of series of electrical contacts, all of which are normally open when no selection is being made.