Abstract: A refrigeration system service coupling having a valved service adapter employing a spring biased sleeve valve to maintain the adapter valve in a closed no flow condition except when the service adapter is properly connected to a charging port of predetermined configuration and capable of retaining the service adapter sleeve valve to permit opening of the service adapter valve upon the service adapter being properly connected to the charging port.

Abstract: A control mechanism for adjusting the speed of a treadmill belt is disclosed. The mechanism includes a disk mounted on a drum of the treadmill. A drive head which defines a plurality of dimensionally distinct cross-sectional circumferences is biased against the disk. The drive head is mounted on the drive shaft of a motor, the motor is mounted for displacement vis-a-vis the disk responsive to the displacement of a cable-fitted control lever which is connected thereto. A displacement of the motor adjusts the drive head positioning whereby the length of a path of the disk over the drive head's exterior surface may be modified, thereby causing a change in the angular velocity of the disk.