Transmission for self-propelled walking mowers

Claim 1

A transmission for self-propelled walking mowers comprising: an engine (1); a main clutch (2); a transmission casing (3); a drive shaft (4) journalled in said transmission casing and drivenly connected to said engine through said main clutch; a hollow speed-change shaft (5) journalled in said transmission casing and extending parallel with said drive shaft, one end of said speed-change shaft being spaced axially from an inner wall surface of said transmission casing by an interval (D); an axle (6) extending through said speed-change shaft and through said transmission casing and drivingly connected to left and right drive wheels (7); a key-shift transmission mechanism (8) disposed within said transmission casing and having a plurality of drive gears (9I, 9II, 9III, 9IV, 9V) fixedly mounted on said drive shaft, a plurality of speed-change gears (10I, 10II, 10III, 10IV, 10V) mounted rotatably on said speed-change shaft and meshed respectively with said drive gears, and a shift key (12) disposed slidably within an elongated axial groove (11) in the outer surface of said speed-change shaft and including a gear-engaging lug (12a) for coupling said speed-change gears one at a time to said speed-change shaft; an auxiliary clutch (13) disposed within said interval and operable to connect and disconnect between said speed-change shaft and said axle; and a clutch lever (14) connected to both of said main clutch and said auxiliary clutch and operable to engage and disengage said main and auxiliary clutches together.