| 摘要 |
<p>951,235. Electric timer switches. HOOVER Ltd. Jan. 17, 1961 [Jan. 19, 1960], No. 1948/60. Heading H2B. A cam-operated programme switch bank is driven step-by-step by a pawl-and-ratchet arrangement 72, 77 powered by an electric motor 51 acting through a mechanical changespeed gearing having at least two speeds, the higher or highest one being an overdrive which is brought into operation to step the programme switch rapidly to omit part of the sequence. The speed changes are made by dog clutches 58, 61 actuated by a face cam 81 coupled to the programme cam and the overdrive is brought in by a solenoid 89 operating a selector arm 85; at the same time the excitation of the driving motor is increased to develop a greater torque. As disclosed, the timer controls a washing machine and operates a bank of switches 78, each in series with a manually operated switch so that when one or more are selected by closing the appropriate manual switch they will switch in the overdrive and rapidly step the machine through that part of the cycle to which they relate. Some of the programme switches are monitored by conditions in the machine) temperature of water, level of water), the gear selectors having gone into neutral and the cycle thus being halted until the appropriate filling, emptying or heating action terminates, when the switches close to stop the programme cam to the next operation.</p> |
