GB1351155A - Electric shavers - Google Patents

Abstract

1351155 Dry shavers GILLETTE CO 6 July 1972 [27 July 1971 (4) 8 Dec 1971] 35174/71 35178/71 35179/71 35180/71 and 56910/71 Heading B4B A battery powered electric shaver comprises two members arranged to be reciprocated or oscillated parallel and in antiphase, at least one member being a movable cutter and the members being each supported by a mounting ineluding a spring, the springs having constants K 1 , K 2 and the members having masses M 1 , M 2 so related that #K 1 /M 1 and #K 2 /M 2 are substantially equal. A motor reciprocates or oscillates the members substantially at a common natural frequency. The members may be an inner cutter member 1 and a pair of counterweights 9, the member 1 being borne by a block 2 on a bridge member 3 supported by outer spring arms 4, 5, Fig. 3, of a resilient member 6, a central arm 7 being fixed to a part 8 of the shaver body, while a lower part 11 is supported between resilient blocks 12. The weights 9 are borne similarly by a second bridge 3a attached to a resilient member 6a, supported between the part 8 and further resilient blocks 12a. Eccentric cams 23, 23a on a shaft 21 of the motor 19 are located in apertures 22, 22a of the bridges 3, 3a for effecting reciprocation of the members 1, 9, and flanges 17, 18, along with the general shape and elasticity of the members 1, 9, achieve the required reciprocation. Alternatively, Figs. 7 and 9, the inner cutter 1b may be supported by lugs 12b on bridges 10b between outer arms 9b of resilient members 6b attached to fixed parts 8b, the counterweight being borne on a bridge 16b between inner arms 9b of the members 6b. Respective pins 19b, 21b attached to the members 16b, 10b may be driven through connecting rods 20b, 22b by a crankshaft 18b of the motor 17b. The shaft 18b may also oscillate a rod (24b), Fig. 8 (not shown), for driving a long hair cutter. Further, Figs. 10, 11, two parallel inner cutter blocks 4c, spring urged apart by springs 10c, may be oppositely reciprocated by means of peg connections 18c to a disc 16c arranged to be oscillated under the control of springs 20c by an eccentric pin 14c of a motor-driven disc 13c, the blocks 4c sliding on rods 7c. Also, Fig. 14, two cutter sections lbd, lad may be supported on bridge members 10d for opposite reciprocation (c.f. Fig. 7), or parallel inner cutter blocks (4e), Fig. 16 (not shown), may be attached respectively to a coaxial coil (12e) and permanent magnet (15e) of a linear electric motor for opposed reciprocation. The invention is applicable to a razor in which two co-operating cutter heads are driven in antiphase to provide a shearing action. Again, an angularly oscillating foil may be split into two portions operating in antiphase and cooperate with an arcuate foil. A single cutter and counterweight may so oscillate.