Patent GB-934855-A (GB)
Title: Improvements in or relating to twin-lens photographic cameras
IPC: G03B13/20
Filed: 1960-10-17
Abstract: 934,855. Twin-lens photographic cameras. FRANKE & HEIDECKE G.m.b.H., [trading as ROLLEI-WERKE FRANKE & HEIDECKE]. Oct. 17, 1960 [Jan. 16, 1960], No. 35484/60. Class 98 (1). In a twin-lens photographic camera of the kind having a mirror reflex focusing view-finder chamber arranged above the exposure chamber in a common rigid housing, the exposure and view-finder objectives being mounted on a common support for displacement on the camera housing in the direction of the optical axes during focusing and the between-lens shutter and the film wind mechanism being coupled together so that the shutter is set while the film is being advanced and also being fitted with an interlock by which, in known manner, the shutter release is locked until the film has been wound on and conversely the film wind is locked until the shutter has been released, the objective support comprises a plate guided on the camera housing and on guide means on a front plate for movement in the direction of the objective axes, said front plate also being guided for similar movement on the camera housing and being coupled to the camera focusing means for adjustment therewith and the said plates are mutually supported and latched together by means operative parallel to said optical axes. As shown (Fig. 2), a front plate 3, to which an objective support plate 8 is releasably attachable is mounted on the front 1a of a camera housing 1 and is coupled through bushes 4 sliding on fixed guide pins 5 in the manner disclosed in Specification 735,679 to a focusing knob 2 (Fig. 1, not shown) on the camera side. The plate 8 is guided in the direction of the axes by means of pins 5 sliding in holes 9 and further pins 11 on the plate 3 sliding in holes 10. The plate 8 is releasably secured to the plate 3 by means of three latches of a type shown in Fig. 3, pins 22 of which, when depressed against loading of a spring 25, pass through holes 12-14 in plate 3 and have their annular recesses 23 engaged by edges 20 or 21 or by a spring-urged latch lever 28. Edges 20 and 21 are formed by a spring-urged plate 15 which is secured by screws 17 passing through slots 16 to the plate 3 so as to be slidable parallel thereto. Pins 45 on the plate 3 and possibly also on the plate 8 ensure correct positioning of the plate 8 relative to the film plane. The plate 8 may be uncoupled from the camera by depression of a knob 33 of a lever pivoted on the plate 8, which lever by means of a lug 32 engaging under a lug 31 fixed to the plate 15, lifts the plate 15 and disengages the latching surfaces 20, 21 from the recesses 23. Simultaneous unlatching by the lever 28 is obtained through a connecting slide 18. To prevent fogging of film contained in the camera when the objective plate 8 with its between lens shutter 34 is changed, two cover flaps 35, 36 are provided respectively pivotable about shafts 37, 38, and coupled for movement together by links 39, 40. A spring- urged lever 41 couples said links 39, 40 with a projection 42 on the slide 18 so that the flaps are automatically closed on depression of the knob 33. The flaps may be returned to their open positions after fitting a new plate 8 by operation of a lever 44 (Fig. 1, not shown) connected to the shaft 38. A nose 42a on the slide 18 prevents operation of the lever 44 when the plate 8 is removed. The coupling between the shutter 34 and the film wind is established in known manner through an arm 47 (Fig. 1, not shown).