423,031. Cam mechanism; frictiongearing; positive clutches; shaft couplings. ZARUBA; A. J., 125, Gudrunstrasse, Vienna. April 18, 1933, No. 11338. Convention date, April 20, 1932. [Classes 80 (i), 80 (ii), and 80 (iii)] [See also Groups XXXI and XXXIV] A system of mechanical parts for use in transmitting rotary movement, or for converting rotary into reciprocatory or translatory movement or vice versa, comprises a hoop 1, of metal or other material which offers a resilient resistance to bending, and engaging a framework 2, through two or more antifriction rollers 3, so that movement of the framework relatively to a driven part or external body engaging the hoop, bends the hoop and transmits a variable force to the driven part or body. The framework 2 may itself be resilient. As applied to transmitting rotary motion, Fig. 3, the resilient hoop 1 is engaged externally by rollers 3 on a driving framework 2a and internally by rollers 31 on a coaxial driven framework 2<1a>. In Fig. 5, the reciprocatory movement of pistons 5, secured to the resilient non-rotary hoop 1, is converted into rotary movement of a framework 2 having rollers 3 engaging the hoop externally and internally on diameters at right angles to each other. As applied in Fig. 9 to an endless-track vehicle, the resilient hoops 1 support the vehicle and are driven around frameworks 2 by means of rollers 3, which can be used for steering by varying their relative speeds. As shown in Fig. 8<b>, a reversed or reduced drive may be imparted to the hoop 1 by tilting the members 2 of the framework, so as to bring different rollers II or III into contact therewith, these rollers being driven frictionally or otherwise from the main roller 3, through suitable idlers IV. The roller II may be an idle roller to provide a neutral. For an aircraft landing- wheel, the lower stay of the triangular framework is in two hinged parts resiliently pulled together and an additional upper external roller is used. The Specification as open to inspection under Sect. 91 states that the resilient hoop may be of steel or rubber, solid or formed as a rope or spiral, or be made up of different combinations of elastic materials, of circular polygonal or flat cross-section and either smooth or formed with flutings, or provided with coating layers of other materials. The system of parts may be applied to packing, mixing and kneading machines, flying machines with flapping wings, ships' screws, motor skates and skis. The framework of the vehicle shown in Fig. 9 may fold for storage purposes and the planes of the resilient hoops 1 may be adjustable and may contact at their apices. The hoops may be driven through differential gears, the main shafts being braked for steering purposes and transmission of power to the hoops may be effected through bevel or helical toothed gears, clutches, chains, cams or eccentrics. The changing of the rollers in Fig. 8<b> may be effected manually or automatically. The supporting frame 2 may rotate about an axis other than its centre, for instance about the focus of an ellipse formed by the hoop, and such axis may be arranged other than perpendicular to the hoop. The ends of the framework may also move in elliptical or straight paths. Fig. 10 (Cancelled) shows a construction which may be used either as a resilient driving-gear or a roller bearing and comprises three elements A, B, C, any one of which may be a driving, a driven or a fixed element. The element B comprises the resilient deformable hoops 1, which roll on the inner member A and in the outer one C. The hoops are supported on rollers 3 and tend to maintain their shape by means of any of the resilient or hinged inner frames 2, carrying the rollers 3. Fig. 11 (Cancelled) shows an arrangement in which a resilient hoop 1 is used for frictionally coupling together various combinations of driving wheels A, B, C, D with driven wheels a, b, c, d. The hoop can be distorted by means of its inner frame, moved bodily or turned into contact with the combinations of wheels to be coupled. The wheels may be arranged inside the hoop. Fig. 12 (Cancelled) shows a clutch for driving a shaft M, carrying the platen of a typewriter from a toothed wheel N, forming part of the line-spacing mechanism. The clutch comprises an outer resilient hoop 1<b>, rotating with the wheel N and rotationally connected to it by pins 3b which can move freely in radial slots 4. An inner hoop 1a is carried on rollers 3<a> on, or is fixed to, an expansible frame 2<a>, comprising a pair of links 2<a>, pivoted to an axially-movable collar, rotating with the shaft M. Expansion of the frame 2<a> distorts the hoops 1<a> and 1<b> from a circular, or non-driving position, shown dotted, into an elliptical form, in which the parts are clutched together. The inner hoop may have flanges guiding the outer one, and may, if desired, be dispensed with entirely. This subject-matter does not appear in the Specification as accepted. Reference has been directed by the Comptroller to Specifications 21460/93, 14516 /98, [both in Class 136] and 2421 /11, [Class 144 (i)].