Friction gear

Abstract

Abstract The present invention provides a friction gear comprising a drive pulley operated by a motor, a driven ring disposed around the drive pulley and forming a friction zone between the inside surface of the ring and the pulley. A flexible tractive member, such as a rope, cable, chain or belt, extends around the outside periphery of the ring and is in frictional connection therewith, suitably in a groove, the member producing a pressure in the friction zone proportional to the tension in the tractive member. The gear operates in an analogous manner in both directions of rotation of the ring and may be used for example as an extremely simple garage door operator installed on the inside of the door per se. Disengagement between the drive pulley and the driven ring is possible in a simple manner by actuating from the outside of the gear an opposite movement to the pivoting ring. The ring can also be raised to come into contact with both of a pair of counter pulleys one of which counter pulleys being normally in contact with the outside of the ring during operation under load to produce a lever effect for creating the pressure in the friction zone. Such elevation brings the gear into a free-wheeling condition. The rings and pulleys may be provided with electric means to increase the extent of pivoting of the ring in either direction which extra pivoting may be used to actuate additional devices or electrical contacts to control the door in certain conditions of the gear such as in the final stages of movement of the door or in an overload condition of the gear.

Inventors

• 👤 Wilhelm E. Altrogge

Bibliographic Details