Patent GB-975396-A (GB)
Title: Improvements in and relating to photographic copying apparatus
Inventor: WOODCOCK EDWARD CECIL
IPC: G03B27/62
Filed: 1959-11-18
Abstract: 975,396. Photographic projection copying apparatus. WILLIAMSON MANUFACTURING CO. Ltd. Feb. 20, 1961 [Nov. 18, 1959], No. 39149/59. Heading G2A. In photographic projection copying apparatus, particularly for compiling unbroken columns of information from a number of shorter entries of standard width but varying length, originals placed on a support 11 (Fig. 2) and illuminated by lamps 19 may be copied into sensitive material 17 at an exposure gate 22 by means of a lens 16. The apparatus also includes a lamp 13, a lens 14, an adjustable mask at 24 coupled to the gate 22 and a mirror 18 for projecting by way of the lens 16 a patch of light on to the support 11 of such area as to delimit the area which will subsequently be copied. A single hand control 25 adjusts (as described below) both the coupled mask and gate and also a variable stroke feed mechanism for the sensitive material. For the purpose above mentioned, a control addition to the knob 25 (see below) enables the exposure gate to be adjusted in the feed direction independently of the mask so as optionally to obtain a varying overlap of successive exposures on the on the material 17 (the stroke of the feed mechanism also being adjusted by said control addition), As shown in Figs. 3 and 5, adjustable plates 23, 24 of the gate and mask respectively carry racks 45, 32 engaged by pinions 44, 31 mounted on concentrically arranged shafts 37, 29. The control knob 25 is coupled by way of a flexible cable 26 to a worm 27 engaged by a wormwheel 28 coupled to shaft 29 either rigidly or through a friction-clutch. On adjustment of the knob 25, plate 24 is adjusted by drive transmitted through members 26-29, 31 and 32 whereas plate 23 is adjusted by an equal amount by drive transmitted through members 26-28, pinion 33 rigid with 28, pinions 34 and 35 mounted on fixed axles, a pinion 36 freely rotatable about shaft 37, planet wheels 38, 39 fixedly coupled together and mounted by a pin 42 on a normally stationary drum 43, a pinion 41 rigidly mounted on shaft 37, and members 44 and 45. A further knob 51 (Fig. 8)-the control addition-is provided coupled to a drum 47 normally engaging a stationary friction cone 49 under pressure of a spring 48. Drum 47 is coupled to drum 43 by a cable 46 and on pulling knob 57 axially outwards the plate 23 may be adjusted alone by way of drive transmitted through members 47, 46, 43, 42, 39, 41, 37, 44 and 45 the worm gearing 27, 28 being of such low gearing as to hold pinion 36 in a fixed position during the adjustment. Knob 51 is calibrated to indicate overlap. The material is fed from a supply spool 78, through the exposure gate 22, over an advancing and metering roller 68 and on to a spool 81 housed in a cassette 95 (cf. also Figs. 5 and 9). On fitting the cassette into the apparatus, the spool is automatically coupled through a dog clutch 96 and a friction clutch 83 to a drive pinion 82 coupled to the roller 68. A manual handle 98 is provided which may be coupled with the spool on depressing said handle against a spring 99. The cassette includes a rotatable inner portion 101 having a guillotine edge 103 for severing unwanted ends of material 17 and for forming a light tight closure with the outer portion of the cassette 95. The apparatus includes automatic control mechanism for controlling the sequence of events during exposure, said mechanism going through a single cycle at each exposure. This automatic control mechanism is set into operation by actuation of a remotely situated-for example foot operated-switch and includes cam elements on rotatable members (Figs. 6 and 7 not shown) for sequentially moving mirror 18 out of the path of the exposure beam, possible fading lamp 13, clamping material 17 by its edges in the exposure gate 22, operating pneumatic means for holding material 17 flat in the exposure gate, effecting exposure by means of lamps 19 (time of exposure is consfant but a knob 94 is provided for adjusting the intensity of illumination of lamp 19) and finally for effecting advance of the material 17 by an amount corresponding to the adjustment of the plate 23. Said advance is effected in that a crank-operated rack element rotates a pinion wheel which is coupled to roller 68 through a one-way clutch and a variable lost-motion coupling-the amount of lost motion being automatically set in correspondence with the setting of the plate 23. The apparatus also includes indicators of the number of exposures made in a column length of space left in a column (both of which may be zeroed) and supply of material 17 left on spool 78. Warning devices may be included which operate when the end of a column and/or when the end of the supply of material 17 are approached. A member 90 is pivotable into a lower position wherein ditto or dash marks may obscure parts of originals not required to be repetitively reproduced.