Dispenser for dispensing liquids in controlled quantities from a bottle

Claim 1

A dispenser for dispensing liquids in controlled quantities, said dispenser comprising; a cylinder adapted to be secured to a valve block, a piston adjustably guided in said cylinder for sucking and discharging an adjustable quantity of liquid, a handle means for moving said piston, said piston being secured at one end to said handle means, a cylindrical sleeve surrounding said cylinder and connected to said valve block at one end, an annular clearance defined between said cylindrical sleeve and said cylinder, an adjusting ring rotatably mounted on the other end of said cylindrical sleeve, said adjusting ring including two portions, a first portion located in said annular clearance and a second portion surrounding said cylindrical sleeve, an adjustable stop secured to said first portion of said adjusting ring for changing the length of a stroke of the piston and said quantity of liquid to be sucked and dispensed, said quantity of liquid depending on the length of said stroke, said adjustable stop defining a stepped configuration and being rotatable about the peripheral circumference of said cylinder, said adjustable stop being axially fixed relative to said cylindrical sleeve, a fixed stop located in said annular clearance and defining a detent shaped complementary to the stepped configuration of said adjustable stop, said fixed stop being secured at one end to said handle means and being slidably mounted in said cylindrical sleeve along the longitudinal axis of said cylindrical sleeve, the stepped configuration of said fixed stop spirally surrounding said cylinder in a single revolution, an undulating surface defined by said cylindrical sleeve located around its periphery and located between said first portion and said second portion of said adjusting ring, and detent means secured to said second portion of said adjusting ring and engaging said undulating surface of said cylindrical sleeve for fixing the position of said adjusting ring, said detent means being resiliently biased towards said undulating surface for locking said adjusting ring relative to said cylindrical sleeve, said cylindrical sleeve, said adjusting ring and said adjustable stop being rigidly locked to each other by said detent means and upon withdrawal of said piston from said cylinder by said handle means, said fixed stop engages said adjustable stop and said piston is fixed relative to said cylinder at a position determined by adjustment of said adjusting ring, said adjusting ring regulating the length of said stroke of said piston and thereby regulating the quantity of liquid to be sucked and dispensed.