Patent GB-191204164-A (GB)
Title: Improvements in and relating to Enlarging, Copying and Reducing Apparatus.
Inventor: HOLST LODEWYK JAN RUTGER
IPC: G03B27/36
Filed: 1912-02-19
Granted: 1913-02-19
Abstract: 4164. Holst, L. J. R. Feb. 19. Enlarging, copying, and reducing.-In apparatus for copying, enlarging, and reducing wherein the focus is automatically maintained in adjusting the apparatus for different ratios of reproduction, the lens and object or plate holder 23, 22, Fig. 1, are connected to sleeves 8, 7 respectively, which slide on mutually perpendicular guides 6, 5 fixed to a block 11 which moves with the lens. The sleeves and frames are adjusted by means of two parallel rods 1 which slide through an oscillating guide 10 equidistant from the guides 6, 5. Each sleeve carries the pivot for one slide-rod and a bearing for the other rod. Provision is made for adjusting the apparatus by applying force to either of the sleeves 7 or 8 according to the angular position of the rods. In one construction of apparatus, means are provided to automatically transfer the driving force from one sleeve to another as the rods 1 pass through the position of a 45 degrees inclination to the guides of the sleeves. In order that the vertical motion of the sleeve 8 shall be equal to the horizontal motion of the lens frame and block 11, the sleeve is connected to a taut band 32<a> stretched between fixed blocks 32, 33 and over rollers 17, 34, 18 on the block 11. In adjusting the apparatus by turning the hand-wheel 12, the sleeve 7 is moved by a rack and pinion along the guides 5, and through the rod 1, sleeve 8, and block 11 the lens is automatically adjusted. In adjusting from the handle 14, the sleeve 8 is moved by the endless chain 16<a> to which it is attached, thereby also moving the lens, and the sleeve 7 and frame 22 are moved through the rod pivoted on the sleeve 8. The required amount of displacement for any given enlargement is directly proportional to the equivalent focal length of the lens; and for lenses of long focal length, provision is made for adjusting the oscillating guide 10 at a distance from the guides 5, 6 equal to a fraction of the focal length and also connecting the plate and lens frames 22, 23 with the sleeve 7, 8 through gearing having the inverse ratio. In one method, the lens frame 23, Fig. 5, is moved by the block 11 through gearing comprising an endless chain 53 attached to the block 11, two sprocket-wheels 40, 42 of different sizes on the shaft 31, and a second endless chain 53<a> connected to the lens frame 23. The chains 53, 53<a> pass round loose sprockets 41, 43. The plate frame 22 is similarly moved through gearing comprising an endless chain 52 driving the sprocket 46, and two larger sprockets 48, 48<a> on the same shaft 29 that drives the chains 75 and 75<a> to which the plate frame 22 is attached. The chains also pass over loose sprockets 47, 49, 49<a>. In a modified construction, more particularly for use with the apparatus shown in Fig. 1, the chains 74, 74b, Fig. 4, are attached to the lens frame 23 and the chains 73 and 73<b> to the plate frame 22. The chain 50 carries a rack and is moved by gearing mounted on the block 11, Fig. 1, which includes a pinion meshing with a stationary rack 21 and operated by the handle 14. The motion of the chain 50 and of the lens is thus determined by this gearing. The chain 73 carries a rack 51 and is moved by a similar gearing operated by the hand-wheel 12. In a further modified apparatus to which the multiple gearing shown in Fig. 5 is applicable, the guide 6, Fig. 3, extends in an upward direction. The sleeve 8 is moved by gearing the shaft 19 carrying the chain 16<a> to which the sleeve 8 is attached, with the stationary rack 21, so that the horizontal motion of the frame 11 is equal to the vertical motion of the sleeve 8. The sleeve 7 is attached to a short endless chain 12<b> and moved by turning the handle 12<a> on the frame 11. The fulcrumed guides 10 are adjusted in the slotted part 9<a> of the frame 11 and set by screws 9<b>. In the further modification shown in Fig. 6, provision is made for moving the frame 11 by a shaft 61 operated by the operator who is standing behind the focusing-screen, and for automatically transferring the driving force from one sleeve to another. A double-faced clutch 56 is slidable on the shaft 61, and can be coupled with a worm shaft 57 to move the sleeve 8 and lens frame, or with a second worm shaft 59 to move the sleeve 7. The clutch is changed as the slide 10 oscillates through its central position. The slide 10 carries a pin 71 which rocks a lever 52<a>, Fig. 6<a>, having a circular edge with a notch 52b in the middle. As soon as the slide 10 is in its middle position, a pin 66 on the lever 66<a> springs from a notch 54<b> in a slide 54 into the notch 52b. The slide 54 is connected to an arm 55 which carries a toothed segment. The weight of the lever 55 brings the toothed segment into gear with a short worm 56 of the clutch, and acts as a rack for the clutch, which travels along the shaft 61 and is first disengaged from the worm 59 and then coupled with the worm 57. The pin 66 in this position comes just over the edge of a second notch 54<c> in the slide 54 and in slipping into this notch 54<c> moves the slide to completely disengage the lever 55 from the worm 56.