GB660539A - Improvements in or relating to dynamo-electric hand lamps - Google Patents

Abstract

660,539. Driving dynamos. BARON, R. M. A. Nov. 9, 1949 [Dec. 22, 1948], No. 28765/49. Class 35. [Also in Group XI] In a dynamo hand lamp of the kind wherein a reciprocating pusher member is pressed inwardly in opposition to a compressed returning- spring and actuates a gear train which drives the rotor of a generator, the gear train is driven by a ratchet system arranged so that a drive in a constant direction is imparted to it on both the forward and return strokes of the pusher member. The pusher member 4, shown in its innermost position in Fig. 1, is slidable within guides 5 in a two-part casing 1, 2, and has an integral cylindrical sheath or stem 33 which receives a guiding-rod 32 mounted rigidly inside the casing opposite to the base of the sheath, a helical spring 31 being located between the said base and the shouldered end of the rod 32. The upper and lower portions of the pusher 4 provide housings for connecting-rods 23, 25 pivoted therein on pins 24, 26 respectively at one end and provided at their other ends with laterally projecting pins 27, 28 arranged to engage between the teeth 7 of an internal ratchet-wheel formed within the periphery of a gear-wheel 6. During inward movement of the pusher 4 the pin 27 of the connecting-rod 23 is operative and drives the wheel 6 anti-clockwise, whereas the pin 28 of connecting- rod 25 is operative during the return movement when the pressure on the pusher is released. Springs 29, 30 located within recesses in the connecting-rods tend to hold the pins 27, 28 of the respective rods in contact with the teeth of the ratchet-wheel, both when driving and slipping. To maintain substantially constant angular velocity of the rotor 15 the spring 31 is made so long as possible, the connecting-rods 23, 25 are as long as possible to reduce their obliquity, and the spring 31 is located closer to rod 25 than to rod 23.