Abstract: A compensation system for a spiral spring hysteresis selectively provides a reactive compressive force to the spring after retractive movement of the outermost spring end relative to a fixed axial center of the spring. Such reactive compressive force reflects what, otherwise, would be the difference between the reactive forces of extension and retraction of the spring and along an axis of greatest transmissibility of force to the spring. The spring constants of extension and retraction of the spring are resultingly compensated.

Abstract: A system for measuring coordinates of a vector in x,y,z Cartesian space includes a flexible non-elastic string spirally mounted upon a selectably positively and negatively rotatably tensioned drum, the drum having an axle of rotation and being positively rotatable as a function of positive increments of length of the string. Mounted co-integrally with the drum axle is a translational measurement encoder for converting rotation of the drum axle into a signal output corresponding to positive increments of extension of length of the string. Further provided is an assembly for defining an origin of the vector to be measured, the assembly including an origin member having an aperture therein for slidable accommodation of the string.

Abstract: An improvement in a pedal-operated polycycle including a hydraulic cylinder in fluid and pressure integral communication with piston means depending from such pedals. Further included is a hydraulic line in substantial co-alignment with the mainframe of the polycycle, an input of the hydraulic line being in communication with the hydraulic cylinder. Further provided is a rear wheel drive secured in rotational relationship with both an output of the hydraulic line and a tangent surface of the rear wheel of the polycycle. Upon reciprocation of a hydraulic piston, hydraulic amplification of the pressure of the pedaling action is transmitted through the hydraulic line to the rear wheel drive means thereby applying a rotational force to the tangent surface of the rear wheel causing the resultant rotation of the wheel and a consequential translational movement of the polycycle.

Abstract: There is disclosed herein a gauge for aligning opposite points within opposite surfaces of a normally symmetric body. The gauge comprises an elongated guidebar disposed above and upon the symmetric body. The guidebar is also perpendicularly transverse to the plane of symmetry of the symmetric body. Also included are left and right calibration assemblies which are slideably disposed upon and within opposite halves of the guidebar, each of the calibration assemblies themselves include an X- and Y-axis joystick connected, in each axis, to respective means for converting linear physical displacement of the joystick to corresponding electrical output signals.