Power take-off

Claim 1

A power take-off, comprising: a housing; a power transmission speed-changing gear train rotatably journaled at least partially in said housing, said train including an output shaft; drive means including a drive shaft rotatably connected to an engine for supplying rotary power to said train to rotate said drive shaft; coupling means at least partially in said housing for drivingly connecting said drive means to said train, said coupling means including a first friction disk drivingly connected to said drive means and a second friction disk laterally juxtaposed to said first disk and drivingly connected to said train, said coupling means further including a pressure plate juxtaposed to said disks and first spring means engaging said plate for forcing same away from said disks to uncouple said train from said drive means; braking means in said housing for arresting rotary motion of said output shaft upon uncoupling of said drive means and said train, said braking means including a piston shiftable parallel to the movement of said plate upon hydraulic actuation of said piston to arrest said rotary motion of said output shaft, and a second spring means biasing said piston to permit said rotary motion of said output shaft; and hydraulic circuit means including a first pressure space adjacent to said plate opposite said disks, a second pressure space adjacent said piston and a pressure source energized by said engine and effective only during operation of said engine for pressurizing said first space to urge in opposition to said first spring means said plate against said disks to force same to clutchingly engage one another, whereby said drive means is drivingly connected to said train, and to relieve said second space whereby said second spring means releases the braking means, said second space being relieved upon inactivation of said engine.