Abstract: A derailer for derailing a drive chain from one sprocket to an adjacent sprocket of a multi-stage sprocket assembly wherein operation of the derailer thereof is automatically controlled by centrifugal force so that the driving chain is automatically shifted to higher gears as the speed of the bicycle increases.

Abstract: A drive mechanism for a bicycle comprising a pump unit driven by the rotation of the bicycle pedals, a hydraulic motor driven by the pump unit, a conduit system creating a closed hydraulic system for circulating hydraulic fluid between the pump unit and the hydraulic motor, and a pressure regulator for controlling the flow of hydraulic fluid from the pump unit to the hydraulic motor and thereby controlling the speed at which the bicycle is propelled. The pump unit has a first gear assembly having teeth with a face width w.sub.1 and a whole depth d.sub.1 and the hydraulic motor has a second gear assembly having teeth with a face width w.sub.2 and a whole depth d.sub.2. The teeth upon the respective gear assemblies mesh together to form inter-tooth pockets which facilitates hydraulic fluid transfer about the closed hydraulic system. The rotary motion relationship between the first and second gear assemblies of the present invention, as defined by their respective teeth, may vary from approximately 2.

Abstract: A bowstring apparatus for use with an archer's bow comprising a pair of ring members each rotatably mounted on an axle pin with a tip interconnector attachably securing each limb tip to each axle pin and further interconnecting each axle pin to each other to enable each ring member to rotate about a parallel axle pin axis relative each other and with an arc member axially spaced on the axle pin and securely attached to the ring member so as to permit simultaneous rotation about the axle pin when the ring member rotates. A flexible cord member secures together each distal end of the arc member to enable simultaneous tensioning when the ring members are tensioned.

Abstract: A cable guard for use with a compound bow having a handle portion, a pair of bow limbs together with a first cable, a second cable and a bowstring comprises a rod with a first end and a second end. A mounting device attaches in use the first end of the rod to the handle portion of the compound bow to enable the rod to extend rearwardly from the handle portion of the compound bow. A single arm member includes a first end and a second end, with the second end of the single arm member attached to the second end of the rod. The single arm member extends outwardly from the rod and in a plane which includes the bow limbs. A first cable guide slidably receives and separates the first and second cable. The single arm member enables in use simultaneous vertical movement of the first cable guide with the first and second cable during the drawing and return of the bowstring.

Abstract: An apparatus for changing the leverage of an existing pedal assembly by telescoping the pedal of the pedal assembly during rotation of the pedal about the pedal assembly axle comprising a housing having an axle shaft rotatably disposed therein, a cam plate operatively mounted on the axle shaft being stationary with respect to the housing, a cam ring radially spaced from the cam plate by a ring bearing disposed therebetween, a pedal arm attached to the axle shaft, a telescoping pedal guide movably mounted on the pedal arm wherein the pedal guide includes a lead bolt attached thereto and a sprocket operatively interconnected to the pedal to rotate therewith in relationship to the axle shaft the lead bolt being slidably disposed on the periphery of the cam plate wherein the cam plate and cam ring control the movement of the lead bolt thus controlling the telescoping motion of the pedal guide as the pedal arm and pedal guide rotate with the axle shaft.