Patent GB-191114855-A (GB)
Title: Improvements in Camera Shutters.
Inventor: BRUECK THEODOR
IPC: G03B9/22
Filed: 1911-06-26
Granted: 1912-06-26
Abstract: 14,855. Brueck, F., and Klein, R. June 25, 1910, [Convention date]. Shutters with pivoting blades.-The case of the shutter comprises a ring 1, Fig. 16, divided by an apertured partition into two chambers 3, 4, one serving for housing the blades and their connecting-levers, and the other for housing the shutter-operating mechanism, with removable covers 5, 6 for the chambers. The shutter blades 7, Fig. 3, are reciprocated about their pivots 8 by a pair of limbs 9, 10, which are pivoted at their middle points 11, 12 to the partition 2 and at their ends 13 to the shutter blades. The levers 10 are connected for simultaneous action by a link 14. One of the limbs 10 carries a finger 15 which projects through a slot 16 in the partition 2 and is actuated by the operating-mechanism. The operating - mechanism includes a swinging arm 21, Fig. 15, moved by the master-lever 17 to carry the pivot 20 of a latch 19 acting on the shutter finger 15, through a greater angle than that simultaneously moved through by the said master-lever 17. The operating finger-lever 35 of the shutter is pivoted to a link 37 which engages one of the pins 32 on the ratchet-wheel 28, one of the adjacent pins acting on the end of the master-lever 17. When the pin escapes past the end of the lever 17, the lever is returned by the spring 26 and on this return movement actuates the shutter. The latch 19 is formed with shaped shoulders 24, 25 for engaging the finger 15. On the first throw of the masterlever 17, the latch 19 first slides over the back of the finger 15, then slides back, and the edge 25 engages over the finger 15. On the return movement of the master member, the edge carries the finger along the slot 16 opening the blades and in the reverse movement the edge 24 returns the finger 15 and closes the blades. For time and bulb exposures, a stop 44, Fig. 5, is adjustable in two positions by a rotating cam 54 and controls the master-lever 17. The stop is thrown out of action for instantaneous exposures, and the cam 54 is further adjustable for different exposures by controlling the end 67, Fig. 12, of a lever 65, the other end of which controls the position of the lever 58, Fig. 5, of the retarding-mechanism 59, 60, 61. When the cam 54 is set for time or bulb exposures or for the quickest instantaneous exposures, the lever 65 holds the lever 58 out of the path of the master-lever 17. The bulb exposure lever 30 can be operated pneumatically and is connected to the finger lever 35 by pin- and-slot 43 and carries stops coacting with the time and bulb stop 44. For time exposure the cam 54 is set, and before exposure the projection 47 on the master-lever 17 normally rests in the slot 49 of the stop 44. On actuating the shutter, the projection 47 slides out of the slot and the stop 44 springs up under the action of a spring, so that the projection 46 is in the return path of the projection 47. On releasing the shutter, the master-lever returns until arrested by the projection 46 at open aperture and a shoulder 52 on the stop 44 arrests a stop 51 of the lever 30, thus preventing the link 37 and finger lever 35 from completely returning to their original position. The link 37, however, engages behind a pin 53 on the stop 44, and on re-actuating the shutter the stop 44 is rotated by the link 37 and releases the projection 47, thereby closing the shutter; it also releases the stop 51, thereby permitting the parts to return fully to their original position. For bulb exposures the cam 54 is adjusted in a position indicated and so that on actuating the shutter the stop 44 springs behind the projection 47, but the cam 54 arrests the projection 56 before the stop has moved far enough for the shoulder 52 to be in the return path of the stop 51. The projection 46 retains the master-lever in the position of open aperture on its return movement as long as the finger lever 35 or the bulb, but on releasing the lever or bulb the lever 30 acts on a projection 50 of the stop 44 and releases the projection 47 of the master-lever to close the exposure. In other positions of the cam 54, the cam engages the projection 56 of the stop 44 and holds it in inoperative position so that the projection 47 moves freely in the slot 49. The retarding-mechanism includes a clutch 62 interposed between the retarding-mechanism 59 and the master-lever 17 so that the latter can swing on actuating the shutter and is checked on the return movement, during which the shutter is operated. The clutch 62 is pivoted on one wheel 61 of a series which couples with a brake wheel or fan 59. The clutch 62 is actuated by a spring 63 in the direction of its free movement, so that its end engages the pivoted lever 58. The other end of the lever 58 engages a pin on the master-lever. On actuating the shutter, the end of the master-lever swings freely away from the lever 58, but on the return movement it engages the lever 58 at a point determined by the position of the lever 65 and corresponding to the adjustment of the cam 54, which thus controls the period and extent, of the action of the retarding-mechanism.