GB1074583A - Sheet-handling apparatus - Google Patents

Abstract

1,74,583. Photographic copying apparatus. EASTMAN KODAK CO. Feb. 19, 1964 [Jan. 23, 1963], No.2814/63. Heading G2A. In a document-copying apparatus in which a photographic sheet is transported through a treatment zone, an adjustable member sets the degree of exposure to said treatment, and a reset mechanism automatically returns the adjustable member to a predetermined position after the sheet has left the treatment zone. The invention is shown as applied to a contact printing apparatus, Fig. 2, in which the photographic sheets are conveyed between an endless band 36 and a transparent drum 35, within which is a lamp-bank 1. The lamp-bank is rotatable, between the positions shown in full and dotted lines, so as to vary the degree of exposure, in co-operation with a fixed opaque shield 39 close to the inner surface of the drum. The bank is rotated by a handle 3, through an endless chain 6 passing over a sprocket 5 and another sprocket 2 on the shaft of the bank. The degree of rotation is measured by a helical scale 10 on a roller 9, also actuated by chain 6. The reset mechanism comprises a roller 21 connected through a clutch 22 with a cylinder 20. At the other end of roller 21 is a worm 33. When a sheet P is pushed into the apparatus, it engages against a cranked section of a shaft 30, displacing the shaft angularly, and so disengaging its hooked end 32 from worm 33. The shaft can now move in direction B under the action of spring 31, so switching on the driving means for a roller 21, and also allowing a catch 23, pivoted at 25, to turn under spring 26. A pin 24 on cylinder 20, previously resting against surface 27 of the catch, now rests against an indented surface 28. When the sheet P has passed completely over shaft 30, it is spring-urged back to its original position, so that hook 32 re-engages worm 33, and so shaft 30 is gradually moved back (opposite direction to B). As catch 23 is pushed round, pin 24 is released for a sufficient time for cylinder 20 to continue rotating for one complete revolution. A pin 16, mounted eccentrically at the end of cylinder 20, engages in a slot 17 in a lever 14 pivoted at 15, and can thus impart a reciprocating movement to the lever. This causes an arm 12 of the lever to engage against one or the other end of a crescent-shaped lobe 13 fixed to sprocket 2, till a final position is reached in which it is in contact with both lobes at once, so that the lamp bank is automatically returned to its original position.