| 摘要 |
1486283 Vacuum cleaners HOOVER Ltd 12 Sept 1974 [13 Sept 1973] 39895/74 Heading A4F [Also in Divisions F1, F2 and H1] A floor care appliance such as the canister-type suction cleaner shown comprises an electric on/off control switch 214, Fig. 10 or 245, Fig. 19, mounted on the body 11 and which can be operated by means at a remote location, e.g. the handle 76 of wand 68, for generating a pressure wave in conduits 64, 70 linking the generating means and a fluid-pressure operated actuator which, in response to a pressure wave, urges a switch operating member in one direction, the switch 214 or 245 being switched on when the operating member is urged in the one direction in response to a pressure wave and then released, and being switched off when the operating member is urged in the one direction by a subsequent pressure wave and then released. As shown in Fig. 8 the generating means comprises a piston/cylinder device 72 operated by pressure on a manual button 113. Alternatively, as in Fig. 18, (not shown) a squeeze bulb (230) may be used. The generated pressure wave is conveyed through a conduit 64 enveloped with suction hose 66 in a common coating 134 and linked at housing coupling fitting 28 with a conduit 70 connected either to a piston/cylinder device 182, 184, Figs. 10 and 11, or a bellows 232, Fig. 19. In the arrangement shown in Figs. 10 and 11, a pressure wave in conduits 64, 70 causes a pistonrod 196 to move to the right against the bias of a spring 194 and surfaces 210, 212 of a cam plate 208 secured to the piston-rod depress a button 216 of the switch 214. Rightward movement of the piston-rod 196 also causes a camming member 204 projecting from the rod to turn a pawl 218, rotatably mounted on a housing 190, into a position in which it blocks complete leftwards return movement of the piston-rod 196 by engaging a corner 226 of a latch cam 224 mounted on the rod 196. The button 216 is held depressed until the next pressure wave urges the piston-rod to the left whereupon the member 204 turns the pawl 218 further into a position in which, upon subsequent return of the piston-rod, the latch cam 224 is not blocked. The button 216 is then released. In the arrangement shown in Fig. 19 a pressure wave expands the bellows 232 and moves rods 234, 238 to the right, the rod 238 engaging a cam 262 on a pivotally-mounted switch blade 246 in order to turn the blade and close the switch. A spring 268 provides an over-centre action. A subsequent expansion of the bellows causes the rod 238 to move rightwards again, but this time the rod engages a cam 264 on the switch blade 246 which is thereby turned to open the switch. In either arrangement the switch 214 or 235 may be operated by a manual button 74 or 74' on the cleaner body as an alternative to being remotely operated. Specifications Nos. 1486281, 1486282 and 1486015 relate to other aspects of the appliance disclosed in this Specification.
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