Abstract: This application describes a peripheral cell structure for VLSI chips that requires the use of standard cells having both input and output capability connected to nearly all of the signal carrying pins. The cells function is alterable (to input or output and to where the data input signals originate) by control signals which may originate with a control register. The clock input signal is split into two independent signals to selectively disable the input or output registers, thus allowing the control register to be changed without affecting the contents of the other two registers. An early signal is also provided to prepare for mode changes.

Abstract: An improved ring oscillator for VLSI chips is shown, formed at the chip periphery. It may have specific initiation gates and have additional parasitic capacitance added to the ring to enhance accuracy. The circuit elements used for the ring are the same as those used for more centralized circuits.

Abstract: A rack and pinion assembly in which a rack bar (1) is longitudinally displaceable through a housing (2) by rotation of a pinion (4) engaging with the rack (3). The rack bar (1) is supported in engagement with the pinion (4) by a plastics moulded bearing member (7) having a saddle-shaped bearing part (9) and a tubular retaining part (8) which is displaced longitudinally from the part (9). The bearing part (9) is of saddle-shape to straddle the rack bar (1) opposite to the region of engagement between the rack and pinion teeth and has a resilient bearing surface which biases the rack bar laterally into engagement with the pinion. The straddling portions of the saddle-shape restrain the rack bar from displacement in the direction of the pinion axis (4a). The retaining part (8) locates the bearing member (7) in the housing (2) and restrains that member from rotation (by keying engagement between rib (11) and channel (12)) and from longitudinal displacement by its co-operation in an annular recess (15).

Abstract: A rack and pinion gear assembly 10 (FIG. 1) includes a resilient bushing which urges the rack into meshing engagement with the pinion. An arcuate inside bearing surface 54 (FIG. 4) of the bushing 18 has a larger radius of curvature than the curved outside surface 52 of the rack 12 against which it bears. The rack thus makes tangent contact with the bushing 18. When one portion of the bushing 18 is worn and therefore excessive play appears in the steering gear assembly 10, the bushing may be removed from the housing 16 of the assembly and rotated 180.degree. and then reinserted into the housing to thereby provide an unworn bearing surface which slidably engages the rack 12. The bushing 18 includes a plurality of axially extending grooves 70, 72, 74, and 76 through which lubricant is supplied to the bearing surfaces 52 and 54. In a second embodiment (FIG.