| 摘要 |
606,537. Power take-off devices. EATON MANUFACTURING CO. Dec. 10, 1945, No. 33331. Convention date, July 10, 1944. [Class 79 (ii)] A windscreen wiper mechanism for an automobile is driven from the engine through a, substantially constant speed eddy current coupling operable .with continuous slippage, whereby the wiper is operated at a speed which remains nearly constant during the entire engine speed range. The coupling may also drive the fan of a blower for heating and ventilating the car interior. As shown, the coupling 36, which is mounted within the ducting of a ventilating system, comprises a housing 45 of magnetic material adapted to be driven by a belt 51 off the engine shaft by a pulley 52. Within the housing is located a rotor 46 also made of magnetic material and has integral with it an energizing coil 47 whose ends are connected to slip rings 65, 66 from which it derives it current. The rotor and slip rings are mounted on a shaft 49 about which the housing 45 rotates. The shaft 49 may be clutched to a flexible drive 34 for operating the wipers or remain unclutched for operating the blower only for the ventilating system such blower being driven off the coupling 36. The coil 47 is energized from the vehicle battery through a variable resistance 78 which controls the wiper speed. In operation a control arm 80 is moved across the resistance 78 and an arcuate contact 79. Current passing through the resistance energizes the coil 47 of the coupling and the contact 79 energizes a magnetic clutch 55 which connects the coupling to the wipers. When the contact 80 is returned to its off position the wipers will continue to operate until the crank 29 on the wiper mechanism opens the contacts 63a, 63b of a parking switch, which when closed maintains engagement of the clutch 55, whereby the wiper arms are correctly parked. The blower mechanism may be operated independently of the wiper mechanism by a control 7, which on actuation opens a valve 41 to admit air through the filler 40, fan 38 and duct 43 into the car interior. With the circuit shown, independent control of the blower speed by means of the control 71 is obtained only when the windscreen wiper control 80 is in the " off " position and arm 80 engages contact 81. When the wiper is in use the speed of the blower is dependent on the speed of the wiper as determined by the position of the control arm 80. In modifications the blower mechanism may be omitted and the coupling housing driven (a) as described above without the magnetic clutch or (b) off the generator shaft, also without the magnetic clutch.
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