Patent GB-662407-A (GB)
Title: Improvements in or relating to photographic film casettes
IPC: G03B17/30
Filed: 1949-11-01
Abstract: 662,407. Photographic roll-film casettes. DYE, W. C., BENNETT, G. H. P., and QUEMBY, J. C., (trading as SHIRLEYWELLARD INSTRUMENT CO.), and BUCK, W. J. H. March 7, 1950 [Nov. 1, 1949], No. 28004/49. Class 98 (i). In a roll-film casette of the kind in which a cylindrical casing housing the film spool has a shutter for opening and closing a window in the casing through which the film can be drawn, the shutter is rotatable about the axis of the casing to cover and uncover the window, means are provided for supporting the spool for rotative winding movement and for limited axial movement in the casing, and clutch means are provided for coupling the spool to the shutter to effect the covering and uncovering of the window, the clutch means being arranged for engagement and disengagement by the axial movement of the spool. The clutch connection may be by pin-and-slot, teeth, or friction. As shown, the casette comprises an outer cylindrical shell 10 having a longitudinal slot 11 forming a window and a flanged cap 13 having a central hollow neck 14 slit to grip resiliently a screw-plug 16 and an inner cylindrical shell 20 having a longitudinal slit 21 and an inturned flange 22 having a series of holes 38. Between the flange 22 and cap 13 is a washer 23 having a shallow sleeve 24, a spring 25 normally holding the washer against the flange 22, and the sleeve 24 engaging in an annular clearance between the neck 14 and flange 22. On the ends of the sleeve 20 are bearing-rings 28, 29 having a close sliding fit in the shell 10, and round the ring 29 is provided a slot 30 terminated by short lateral slots 31. The slot 30. is engaged by a grub-screw 32 forming a locking-pin threaded into a lug 33 carried by the cap 13. The lower end of the spool hub projecting beyond the lower flange 36 engages over the neck 14 and bears against the sleeve 24, and on the outer face of the spool flange are four pins 37, the spool 12 being normally held by the sleeve 24 and spring 25 in such position that the pins 37 are disengaged from the holes 38. The top end of the casette is provided with a detachable cap 40 having a tight press fit in the end of the shell 20 and formed with a serrated flange 41 forming a finger grip. The top end of the spool hub has a dog 44 engageable by the camera winding mechanism. After insertion of the closed casette into the camera the camera winding mechanism is coupled with the dog 44 and the winding knob is pushed inwardly to engage the pins 37 with the holes 38 and withdraw the locking-pin 32 from one lateral slot 31. Rotation of the knob rotates the shell 20 to open the window 11 and permit passage of the film. On release of the axial pressure on the knob, the clutch device is disengaged and the pin 32 engages in the other lateral slot 31. When the shell 20 has to be opened or closed with the casette removed from the camera, the necessary movements are effected by the cap 40. The alignment of the film in the camera may be adjusted by rotation of the screw-plug 16. The casette may be wholly of metal, or the outer shell of moulded plastic and the inner shell of die-cast metal.