Abstract: An automatic derailleur shifter system for example for a bicycle includes a hub to which is attached a chain wheel set and a derailleur system for moving the chain associated therewith from chain wheel to chain wheel for a gear changing system. Within the hub associated with the chain wheels is provided an automatic changing system including a member coupled to the chain wheel set which carries a helical screw cooperating with a sleeve slidable axially within the hub and cooperating with the screw so that rotation of the screw relative to the sleeve causes the sleeve to move axially. Axial movement of the sleeve is inhibited by a spring and rotational movement of the sleeve is prevented by engagement with the hub. Thus variations in the torque applied from the chain set to the hub through the screw in the sleeve cause axial movement of the sleeve which actuates change of the gears by moving to the derailleur set. The spring can be internal to the hub or can be provided outside of the hub.

Abstract: A large loop or ring of spring steel, which is rectangular in cross section, has two separable ends, one of which is releasably securable in a recess in the other by means of a removable shackle or wire snap. A plurality of key blocks are removably mounted on the ring for sliding movement thereabout coaxially of the ring. In one embodiment the ring is solid and projects slidably through a corresponding rectangular recess which extends centrally through each key block; and in a second embodiment the ring is hollow and the blocks are slidably mounted in the rectangular bore of the block. Numeral-bearing tags are secured to the faces of the blocks in each embodiment; and in the second embodiment an arcuate opening is formed in the front wall of the ring so that the tags on the blocks will be viewable through the opening. A small swivel ring projects from the underside of each key block to have a key secured thereto by a wire snap.