GB403666A - Improvements in and relating to valve mechanisms for internal combustion motors and compressors - Google Patents

Abstract

403,666. Valve gear; cylinders. GIANNOTTI, M., 2, Via Saffi, Bologna, Italy, June 27, 1932, No. 18076. [Classes 7 (ii) and 7 (vi).] In valve gear for internal-combustion engines or compressors wherein inclined overhead inlet and exhaust valves are actuated by rockers, the pivots of which form a quadrilateral figure, the push-rods which actuate the rockers by means of cams in the crank case are arranged within the quadrilateral figure. Fig. 3 shows inlet valves 2, 2a actuated by arms 17, 19 of rockers 9, 9a, which are mounted on pivots 13 and formed with other arms 16, 18 connected together for operation by a single push-rod 20, Fig. 4. Exhaust valves 3, 3a are similarly actuated by rockers 10, 10a having arms 21, 23 connected to a second pushrod actuated by a separate cam shaft at the other side of the crank case. The rocker arm 16, Fig. 4, is formed with a hemispherical projection 16a engaging a socket 18a on the arm 18, or vice versa, and the arm 18 also bears on a ball head 20a on the push-rod. In modifications, the arms 16, 18 may engage the top of a hollow plunger resting on the top of the pushrod, or the push-rod may itself be widened to provide seating surface for both arms 16 and 18. A similar widened surface at the base of the push-rod may engage the cam directly, an interposing rocker being omitted. Again, two push-rods may be used for the two rocker arms, the lower ends of these rods being seated in a single rocker which engages the cam. The push-rods are mounted in casings, preferably cast integral with the cylinder, and provided at the top with caps 41, 42 pivoted on pins 40, 43. In another form, the push-rods for the inlet and exhaust valves are inclined so that their lower ends engage separate cams on a transverse shaft at one side of the crank case. Fig. 10 shows another arrangement, wherein the rockers 9, 10 are each formed with three arms, one 16 or 21 of which engages the top of the respective push-rod, a second 17 or 22 engages the inlet or exhaust valve 2 or 3, and a third 17<1> or 22<1> engages one of the arms 18 or 23 of the rocker 9a or 10a of the other inlet or exhaust valve 2a or 3a.