Patent GB-221303-A (GB)
Title: Improvements in or relating to photographic apparatus
IPC: G03B1/54
Filed: 1923-06-27
Abstract: 221,303. Stringer, H. B., and Stratton, A. June 27, 1923. Teaching gunnery.-In a camera gun constructed in the form of a machine gun, the film winding mechanism is driven by a motor in the breech casing so arranged that the operation equivalent to commencing fire releases a brake acting on the motor and then closes the circuit or opens the power supply of the motor, whilst the operation equivalent to ceasing fire opens the circuit or shuts off the power supply and then applies the brake. The film driving mechanism is arranged in a casing as a separate unit or magazine removable from and replaceable in the breech casing. The camera gun comprises a breech casing 1 and barrel casing 2, the breech casing being divided by a partition 3, the rearward portion of the casing containing the driving motor &c., while the film magazine is inserted into the forward portion. The electric motor 9 is connected by gearing 14 - - 20 to a shalt 12 mounted within a casing 74 and having at its forward end a bevel wheel 21 gearing with a bevel wheel 22 to rotate a crank pin 24 which drives the film-feeding means. The brake applied to the motor consists of a disc 25, Fig. 5, secured to the armature shaft and co-operating with two semicircular brake shoes 26 mounted on a pivot 27 and connected together by a tension spring 28 Extending between the shoes 26 is a flattened pin 30 carried by an arm 31 which can be rotated to separate the shoes by the longitudinal movement of a wedge-shaped member 32 the inclined face of which bears on the arm 31. The member 32 is carried by a rod 33 passing through a sleeve 34, and can be displaced by pushing in a thumb-piece 8 against the action of a spring 35. Alternatively, the rod 33 may be operated by a Bowden wire attached to a bell crank 36, the arm 37 of which passes through slots in the sleeve 34 and rod 33. The forward movement of the member 32 also operates contacts 40, 41, 42, Fig. 16, for closing the circuit of the motor 9 and for illuminating a time indicating device described below. At its rearward end, the shaft 12 carries a worm 43 operating a worm wheel 44 on an inclined shaft 45, the upper end of which carries a worm 46 gearing with a worm wheel 47 rotatably mounted on a sleeve 48 to which is secured a graduated disc 49 visible through an aperture in the end of the casing and indicating the length of film exposed. The wheel 47 is caused to drive the sleeve 48 frictionally by a spring plate 53 pressing it against a flange 52 on the sleeve, so that the disc 49 can be set to zero by means of a hand-wheel 51. At its forward end the shaft 12 is geared to a countershaft 62 which is geared to a pinion 68 attached to a shutter 69 rotatable around a pivot 70 mounted in the partition 1<2>. The barrel casing 2 contains the camera objective, and baffle plates 81, 81<1>, and is connected to the breech casing 1 by bayonet fastenings and a spring plunger locking-device. The film magazine is adapted to be inserted in the space 5 of the breech casing, and comprises a box 100, Figs. 7 and 10, the side 102 of which is hinged while the end 106 is formed as a mask plate, which is also hinged. This plate has a turned-over edge 106<1> engaging the side 102 so that the plate must be opened first. Within the box is a feed spool 113 from which the film passes over rollers 114, 115, under a roller 116 and around a feed sprocket 117, then through the gate, under a beater roller 120 and over rollers 121, 122 to a take-up spool 123. The beater 120 is eccentrically mounted on a spindle 126 provided with an arm 125 engaged by the crank pin 24. The spindle 126 is connected by gearing 128, 129 to sprocket 117 and spool 123. The feed spool 113 is loosely mounted on a rotatable sleeve 130 but is loosely clamped by a disc spring 131 having a leather ring 132 engaging the spool flange. A similar spring is provided for the spool 123 which is arranged to be driven frictionally, the spool being mounted on the outer of the two tubes 134, 135 provided with flanges between which the wheel 129 is loosely mounted on the tube 135; the flanges are urged toegther by a spring 137. Relative rotation of the tubes 135, 134 is prevented by a key, and the spool is positively driven by the tube 134. The rollers 116, 121 and 122 are mounted on pivoted frames so that they can be moved to the positions shown in chain lines in Fig. 7 for threading the film. The frames carry pivoted levers 147 having pressure plates 148 at one end and at their other ends entering recesses in the supporting lugs 149, so that the side 102 cannot be closed unless the rollers are in the fullline positions. The mask plate 106 is provided with a circular aperture 160, Fig. 12, through which the image of a watch &c., 171, Fig. 1<b>, is projected and a graticuled rectangular aperture 161 through which the image of the target is projected. The watch is mounted in a conical container 172 provided with a lens 173 and with tubes 174 containing lamps 175, which are controlled by the member 32 and also by contacts 180, 181 engaging together when the casing 2 is in position. The gearing of the shutter is such that between successive exposures the beater operates the film twice so that both the target and the watch are photographed. The top and right-hand side of the breech casing 1 are hinged to the body so that they can be opened for inspection of the motor mechanism and for insertion and removal of the film magazine.