Abstract: An improved rotory positive displacement blower (10) of the Roots-type with reduced airborne noise and superior efficiency. The blower includes a housing (12) defining generally cylindrical chambers (32, 34) having cylindrical wall surfaces (20a, 20b) and containing meshed lobed rotors (14, 16) having the lobes (14a, 14b, 14c, 16a, 16b, 16c) thereon formed with an end-to-end helical twist according to the relation 360.degree./2n, where n equals the number of lobes per rotor. Preferably, n equals three. The blower housing (12) also defines inlet and outlet ports (36, 38) and the intersections of wall surfaces (20a, 20b) define a cusp (20d) associated with the inlet port (36) and a cusp (20e) associated with outlet port (38). The inlet and outlet port openings are skewed in opposite directions to increase the time the top lands of the lobes are in sealing relation with cylindrical walls (20a, 20b) of chambers ( 32, 34).

Abstract: A guide (28) is provided for retrofitting an existing internal combustion engine block (10) with roller cam followers (24 and 26) in place of conventional barrel-type lifters, without modification of the block itself. The guide includes a guide bar (64), keyed to the upper body (38) of each follower to allow limited rotational freedom thereof and a resilient C-shaped spring clip (70) which simultaneously bears downwardly on the upper surface of the guide bar and upwardly on the lower surface (40) of an engine block boss (18) defining follower receiving bores (20 and 22). Annular spacers (72) are provided, if required, to displace the guide bar upwardly from the upper surface (52) of the boss. An upper leg (76) of the spring clip wraps around the guide bar for retention therewith and a lower leg (78) of the spring clip is necked at a point (86) intermediate adjacent cylindrical portions (30 and 32) of the follower boss for retention therebetween.

Abstract: An improved Roots-type blower (10) and fixture (200) for timing rotors (20, 22) and timing gears (36, 38) of the blower during assembly. The blower includes a housing (12) defining generally cylindrical chambers containing the rotors having meshed, helical lobes (20c, 22c). The rotors are fixed to stepped diameter shafts (24, 26) pressed into stepped bores (20d, 22d) in the rotors. Straight splines on the shafts respectively form mating splines in the rotor bores and in the hub bore of timing gear (36). In a modified form of the blower, the straight splines form matting splines in both timing gears. The shafts are supported in the housing by fixed ball bearings (28, 30) at one end of the rotors and at the other end by ball bearing (32, 34) resiliently biased by springs which preload all four bearings. The fixture includes a base (202) having two surfaces (202f, 240a) for supporting ends (20b, 22b) of the rotors.

Abstract: An improved supercharger (10) of the Roots-type. The supercharger includes a three-piece housing assembly (14, 16, 18) defining generally cylindrical chambers containing two rotors (20, 22) having meshed lobes (20c, 22c) of modified involute profile which pump air from an unshown inlet to an outlet (56). The rotors are fixed to stepped diameter shafts (24, 26) pressed into centrally located through bores in the rotors. Straight splines (24e, 26e) on the shafts form mating splines in the rotor bores to prevent rotation of the shafts in the bores. Bearing assembly (28, 30) disposed at adjacent ends (20a, 22a) of the rotors support one end of the rotors in the housing and fix the axial position of that end of rotors relative to the housing. Bearing assemblies (32, 34) at the outer adjacent ends (20b, 22b) of the rotors support the other end of the rotors in the housing.

Abstract: An improved supercharger or blower (10) of the Roots-type with reduced airborne noise and improved efficiency. The blower includes a housing (12) defining generally cylindrical chambers (32, 34) containing meshed lobed rotors (14, 16) having the lobes (14a, 14b, 14c, 16a, 16b, 16c) thereon formed with an end-to-end helical twist according to the relation 360.degree./2n, where n equals the number of lobes per rotor. The chambers include cylindrical wall surfaces 20a, 20b and end wall surfaces 20c, 24a which sealing cooperate with the rotor lobes and ends. Blower housing (12) also defines inlet and outlet ports (36, 38). The inlet port includes a longitudinal extent defined by housing wall surfaces (20f, 20f) and a transverse extent defined by housing wall surfaces 20g, 20i. Transverse wall surfaces (20g, 20i) are disposed substantially parallel to the associated rotor lobes.

Abstract: An improved supercharger or blower (10) of the Roots-type with reduced airborne noise and improved efficiency. The blower includes a housing (12) defining generally cylindrical chambers (32, 34) containing meshed lobed rotors (14, 16) having the lobes (14a, 14b, 14c, 16a, 16b, 16c) thereon formed with an end-to-end helical twist according to the relation 360.degree./2n, where n equals the number of lobes per rotor. The chambers include cylindrical wall surfaces 20a, 20b and end wall surfaces 20c, 24a which sealing cooperate with top lands (14d, 14e, 14f, 16d, 16c, 16f) of the rotor lobes and end surface (14g, 14h, 16g, 16h) of the rotor ends. Spaces (32a, 34a) between adjacent lobes of each rotor transfer volumes of low-pressure air from an inlet port (36) defined by the housing (12) to relatively high-pressure air at an outlet port (38) defined by the housing.

Abstract: An improved valve disabler control for a multi-cylinder engine having individually pivoted rocker arms and an intake and exhaust valve pair for each cylinder. Half of the valve pairs are provided with valve disablers having rotatable sleeves. Rotation of the sleeves counterclockwise (ccw) allows sliding movement of the rocker arm fulcrums, thereby disabling the valves; clockwise (cw) rotation of the sleeves prevents sliding movement of the fulcrums, thereby enabling the valves. The improved control includes a link and a spring interconnecting the disabler sleeves for each valve pair. Each link rotates the intake valve disabler sleeve ccw in response to ccw rotation of the exhaust valve disabling sleeve. A slot connecting each link to the intake valve disabler sleeve allows cw rotation of the exhaust valve disabler sleeve before cw rotation of the intake valve disabler sleeve. Each spring provides a cw biasing force to the sleeves. The biasing force increases in response to ccw rotation of the sleeves.

Abstract: An improved valve selector assembly for selectively enabling and disabling the intake and exhaust valves of one cylinder of an internal combustion engine of the type having individually pivoted rocker arms for opening and closing the valves. Each selector assembly includes two valve disablers (one associated with the intake valve rocker arm and one associated with the exhaust valve rocker arm), and control means for orienting and switching the disablers between valve enabling and valve disabling. Each valve disabler is a spring capsule subassembly of the selector assembly and includes a slideable sleeve defining a fulcrum at one end, a cap slideably connected to the other end of the sleeve, and a spring reacting against the cap and biasing the fulcrum into engagement with its respective rocker arm.

Abstract: An engine valve control mechanism for varying the amount of opening and/or timing of a cylinder valve in a valve gear train of a multi-cylinder, internal combustion engine having an overhead camshaft which actuates the valve via a rocker arm pivotally bridged between the valve stem and a hydraulic lash adjuster. In one engine embodiment of the invention, the valve gear train portion for each intake valve is provided with a valve control mechanism of the invention by providing a camshaft having a high lift lobe and two low lift lobes for actuating the valve and by providing a valve rocker arm including a rigid link defining a first cam follower for following the low lift lobes and a second cam follower pivotally connected to the rigid link for following the high lift lobe.