Abstract: This knob assembly comprises a knob housing slidable on a body contained therein, and fixed to a centrally located control shaft. The body has means controlled by springs, to frictionally engage a disc non-rotatably keyed to a panel for said control shaft. Normally the knob housing can be freely spun, but when it is pushed in, it is lockingly engaged with the body whereby rotation of the pushed in knob housing will rotate the shaft with friction drag imposed on rotation of the shaft to thereby prevent inadvertent rotation of the shaft after setting of the angular position of the shaft. A spring causes the knob housing to pull out to disengage the knob housing from the body, to allow the knob housing to substantially spin freely again. The springs which cause friction between the body and the keyed disc, are stronger than the spring which pulls the knob housing out or returns it to normal when the knob housing is released.

Abstract: The knob comprises a body which cannot turn the control shaft unless the body is first pushed in. A brake prevents turning of the knob body when the body is in normal condition. Upon pushing the body rearwardly, the brake is disengaged to allow turning of the knob. Upon releasing the body, spring means projects the body forwardly back to normal condition in which the brake prevents the body from turning. Spring pressed balls allow the body to turn without turning the control shaft upon exerting excessive torque on the body to thereby prevent damage to the controls. Means is provided to limit turning of the control shaft to a predetermined angle.