Control device of non-stage transmission

Claim 1

A control device of a stepless transmission, comprising: a stepless transmission comprising a primary and a secondary pulley having an endless belt circumscribed therearound, each of said pulleys having two flanges defining a V-shaped groove therebetween and cylinder disposed adjacent one of said flanges, said one flange being axially adjustable by applying hydraulic pressure to said cylinder such that the groove width and attendantly the effective diameter of each of said pulleys is variable; an electronic control device which receives information and generates duty control information; a pair of duty valves for independently generating respective reference pressures in response to the duty control information; a pair of pressure control valves comprising a cylindrical sleeve and a spool slidably disposed therein so as to define a reference pressure space communicating with an associated duty valve and a feedback pressure space communicating with an associated cylinder, said spaces being disposed on opposite ends of said spool, said spool having a control chamber intermediate of said reference pressure space and said feedback pressure space, said chamber communicating with said feedback pressure space and a high pressure line wherein axial movement of said spool causes said high pressure line to communicate with said feedback pressure space.