Patent GB-222548-A (GB)
Title: Improvements in and relating to camera apparatus
IPC: G03B15/00
Filed: 1923-06-27
Abstract: 222,548. Laws, F. C. V., and Stringer, H. B. June 27, 1923. Aeronautical photography and apparatus ; lens fittings ; roller slides and roll spools; shutters.- Camera apparatus, more particularly for use on aircraft, having the film or plate changing and shutter-setting mechanism operated automatically by a windmill or other motor drive or by hand, comprises as separate units a film box or film or plate magazine 1, Figs. 1 and 2, a shutter-box or shutter-unit 5, and a driving-gear box 7, each of which is independently attached directly to the camera body 2. The timing and sequence of all operations except the shutter release are effected by the gear-box mechanism. An instrument-box 6, Fig. 25, and a clockwork remote control box 14 may also be provided and be electrically connected to the camera body, to which also the instrument-box 6 also is connected directly. The remote control-box effects operation of the gearbox to secure single exposures, or repeated exposures the timing of which it can vary. Exposures may also be effected by a Bowden or other control 13. The film-box 1 is attached at the top of the camera body 2, preferably bv hinged clips 3 engaging clips 4 on the body 2. The gear-box 7 is attached at the side of the bodv and has a handle 9 for hand drive and a. shaft 152 and flexible coupling 10 for windmill 8 or other motor drive. In one construction of camera, the film-box 1, Fig. 5, has an open side 18 and bottom 20. A wooden roller-blind 21, which can be slid back over the plate 19, which closes the top of the box, closes the bottom 20. Catches 22 on a flat spring 23 on the blind engage sockets 25, 26 on the top in the open and closed positions. The film-spool carrier, which is inserted in the box 1 through its open side 18, consists of a framework 32, Fig, 9, carrying the two spools 28, 29, a spiked feed-roller 57, and a pressure plate 35 which is pivoted at its centre to a horizontal lever 44 hinged at one end 45, Fig. 11, to the framework. The lever 44 has at its other end a pin 47 engaging a cam surface 48 in a mutilated tooth wheel 38 by means of which the plate is raised at the correct time to permit feed of the film 27. The plate 35 is normally pressed forward by a pivoted bell-crank lever 51 controlled by a spring 52 to engage the film 27 against a front glass 41 hinged t'o the frame. The film-feeding means is actuated by a radial arm 60 mounted on the spindle 59 carrying the wheel 38 and adapted to be engaged by a coupling disc in the main driving-gear box 7. The mutilated toothed wheel 38 drives the spindle 58 carrying the spiked feed-rollar 57 through gear wheel 63, Fig. 14, gear wheel 64 integral with wheel 63, and gear wheel 65. The spindle 31 carrying the take-up spool 29 has a slipping friction drive, the wheel 64 being pressed by a spring 73, which is adjusted by a nut 74 against a flange. 71 on the spindle, a fibre washer 72 being interposed. A spring-pressed pawl engages the wheel 64 and prevents it over-running when the wheel 63 is not in mesh with the wheel 38. The spindle 30 for the film spool 28 has an adjustable friction brake comprising a bearing-bush 75, a flange 76, and fibre washer 77 against which a cam disc 80 slidable on the spindle 30 is pressed by a spring 78. An oscillating plaque 88, Figs. 13 and 13<a>, having alternate black and white bands, attached to a spring-controlled lever 86, driven bv the cam disc 80, indicates when the film feed is operating. The number of photographs taken is indicated by a counter-wheel 81 driven by engagement of teeth 85<x> thereon with one end of a pivoted lever 82, the other end of which is engaged by a pin 85 on the wheel 38. The plaque 88 and counter-wheel 81 are observed through windows 89, 90 in the cover. The film spools 28, 29 are removably mounted, the pivots engaging their outer ends being carried by hinged flaps held in position by a turn-button 97, Fig. 11, controlled by a spring 98. The focal-plane shutter-box comprises a frame 5, Figs. 17 and 21, slidable into the camera body and carries an exposure blind 103 and a capping blind 105 wound on rollers 109, 107 rotated by spur-wheels 110, 108 driven from the gear-box 7. The exposure blind consists of two portions 103, 103<x> connected by tapes 111, secured to the portion 103<x> and passing through a wire loop 112 on the portion 103, over a spring roller 114, on which the portion 103<x> is wound, over pulleys loose on a spindle 116 and back to the roller 114 where they are fastened under the blind. The blind aperture 106 is varied by adjustment of the spindle 116 which is carried by arms 118 secured to a shaft 119 rotated by the engagement, with a sector wheel 120 thereon, of a spur wheel 121 which is rotated by turning a milled head 122. The capping blind 105 is connected to the roller 107 by tapes 129 and at its other end is wound on a spring roller 117 on the spindle 116. Release of the shutter is effected by a tripping arm 136, operated from the gear box 7, having on its pivotpin 134 a pawl 133 normally held in engagement by a spring 135 with a ratchet-wheel 132 secured to the shaft of the roller 109. Five instrument lenses 99 are carried on a plate 102 on the underside of the frame 5. The camera body 2, Fig. 25, has rails 137, on which the frame 5 slides, and vertically arranged plates 138 leaving a space at one side for the instrument-box 6 which is inserted through a hinged door 151. Horizontal apertured baffle plates 139 are also provided. The recording instrument-box 6, Figs. 26 and 27, has a hinged side 140<x> and cover 140, and contains a watch 142, an identification tablet 143, a cross level 144, a counter 145, and an aneroid barometer 146 opposite openings in the lid. During exposure electric lamps in the box illuminate the devices, which are then photographed on t'he film through the lenses 99. The counter 145 is operated by an electromagnet 147 through a freewheel arrangement and against a return spring 148. Connections for the lamps and magnet 147 are made by plug contacts 150 entering sockets in the body 2. The main gear-box 7 containing the gearing for operating the main and capping shutter blinds 103, 105, winding the film 27, and operating the pressure-plate 35, is motor-driven through shaft 152, Fig. 30, worm 153 and wormwheel 154 on shaft 155 which also carries toothed wheel 156, Fig. 33, and handle 9 for the hand drive. The worm-wheel 154 and handle 9 can be independently engaged by means of ratchet clutches 189, 190 with the toothed wheel 156, to provide alternative drives. Wheels 154, 156 are mounted on ball bearings 187, 188. The spurwheels 108, 110 for winding the shutter blinds are operated from wheel 156 through toothed wheel 157, mutilated toothed wheel 158 secured to toothed wheel 159 which engages with toothed wheel 160 secured to mutilated toothed wheel 161 meshing with spur-wheels 108, 110. A coupling disc 62 engaging with the driving arm 60, Fig. 14, of the film carrier is rotated with wheels 158, 159. A spring-controlled cam lever 180 engages with a pin 182 on wheel 158 to re-engage the wheel at its mutilated part with the wheel 157. Operation of the gear-box is begun by depression of a spring-controlled pivoted bellcrank lever 165, either by an electromagnet 163 and plunger 164 operated from the remote control-box 14, Fig. 1. or by a slide-block 184 depressed by the Bowden mechanism 13 against tension of a spring 185. The depending arm 166 of the lever 165 reciprocates a rod 167 which at one end allows a spring contact' 168 to close the circuit of the instrument-box lamps, and at the other end operates the shutter tripping arm 136. Further movement of the lever 165 trips, by means of link 171 and lever 172, a catch 170 pivotally mounted' with and engaging a spring- controlled lever 173 on the wheel 159. Release of the lever 173 frees a catch 178 thereon from a stop 179 on the gear-box and allows movement of the wheels 158, 159. The camera may be operated continuously by keeping the lever 165 depressed. A block 191 of insulating material on the wheel 160 operates successively spring contacts 192, 193, 194. Contact 192 is first closed by rotation of the toothed wheel 158 by lever 180, and closes the circuit of an electric motor 260, Fig. 54, which can be used to operate the gear-box 7 through reduction gear, in place of the windmill drive 8, Fig. Contact 193 closes the circuit of a counter 195 in the remote controlbox 14 and the counter 145, Fig. 26, in the instrument-box 6. Contact 194 opens the circuit' of a device 196 in the control-box 14 indicating completion of the shutter rewinding. The speed of the windmill 8 is varied by varying its inclination by means of a handle 206, a spring catch on which engages a toothed cuadrant' 207 secured to the support 203. The remote control-box 14 controls the gear-box electromagnet 163 to obtain separate exposures by depression of a push-button 216, or successive exposures automatically at definite intervals, in which the images may overlap, by operation of a switch 219. The clockwork mechanism for obtaining the required interval is set by a pointer 217, and consists of a rack 223, Figs. 46 and 47, connected at one end to a pulley 225 on a clock-spring barrel 226 and at its other end to the plunger 222 of an electromagnet 221, energization of which draws down the rack 223 and winds the clock-spring. The interval between exposures is varied through the rack 223, an insulated pin 27 on which closes a spring-contact 228 in the circuit of the magnet 163, and effects an exposure. A balance-wheel 229, Fig. 50, and escapement 230 control the return speed of the rack through a pin wheel 231 and a toothed wheel 232 mounted, through a ratchet clutch to allow return of the rack, on the spindle 233 of a pinion 234 gearing with the rack. The setting of the pointer 217 determines the timing of energization of the magnet 221 by varying, through gear-wheels 252, 23