| 摘要 |
<p>A vehicle washing system in which a rear wash brush is mounted on the free end of a normally rearwardly extending pivotable rear brush arm powered by a double acting piston and cylinder. A control system applies a low pressure to the cylinder when the rear brush washes the side of the vehicle, to avoid damage to mirrors and antennae. When the rear brush reaches the rear of the vehicle and the rear brush arm begins to pivot more forwardly, this actuates a valve in the control system which causes a substantially higher pressure to be applied to the cylinder, to wash the rear of the vehicle adequately. After the rear wash is completed, the control system reverses the fluid connections to the cylinder to return the rear brush arm to its original position. In addition, a pivotable front brush arm carrying a front brush normally extends across the vehicle path and is pushed forwardly by the vehicle to wash the front of the vehicle. The front brush arm is normally biased to extended position to maintain firm contact with the vehicle front, but when the front brush reaches the corner of the vehicle, the control system retracts the front brush to a parked position in which it contacts the side of the vehicle only lightly, to avoid damage to protecting mirrors and antennae.</p> |
