Liquid dispenser of the metering type

Claim 2

A liquid dispenser of the metering type for manual support and manipulation comprising: a handpiece including a rigid body having a cylindrical liquid reservoir therein providing a pump chamber, piston means in said chamber movable between minimum and maximum volume positions, a compression spring for urging said piston means toward its minimum volume position, means including an adjustable seat for said spring mounted on said body in said chamber adjacent the end thereof remote from said piston means and movable to positions within a predetermined range for adjusting the effective maximum volume of said chamber, said spring being compressed between said piston means and said seat, stop means for determining the minimum distance between said seat and said piston means, inlet and outlet ports communicating with said chamber, valve means for opening one of said ports and closing the other of said ports and vice versa, means for supplying liquid under pressure to said chamber through said inlet port whereby said piston means is moved under pressure to its effective maximum volume position determined by the position of said seat, said spring being compressed to the same maximum compression condition between said seat and said piston means regardless of the position of said seat in said chamber whereby the pressure of discharge of liquid on opening said outlet valve is the same for all positions of said seat, said seat engaging the end of the spring and including a center portion, a rod threaded in the end of said chamber for axial movement with respect thereto and having an end engaging said center portion and rotatable with respect thereto for moving said seat forward and back in said chamber upon rotation of said rod, and a cylindrical cover telescoping over the end of said chamber and attached to said rod for rotational and longitudinal movement therewith for facilitating the rotation of said rod and for indicating the position of said seat in said chamber.

Claim 3

A liquid dispenser of the metering type for manual support and manipulation comprising: a hand piece including a rigid body having a cylindrical liquid reservoir therein providing a pump chamber, piston means in said reservoir and constituting a movable end of said pump chamber and movable between minimum and maximum pump chamber volume positions, a compression spring engaging the side of said piston outside said chamber for urging said piston means toward its minimum pump chamber volume position, means including an adjustable seat for said spring mounted on said body in said reservoir outside said chamber adjacent the end of said reservoir remote from said piston means and movable to positions within a predetermined range for adjusting the effective maximum volume of said chamber, said spring being compressed between said piston means and said seat, stop means for determining the minimum distance between said seat and said piston means and thereby determining the maximum compression of said spring, inlet and outlet ports communicating with said chamber, valve means for opening one of said ports after closing the other of said ports and vice versa, means for supplying liquid under pressure to said chamber through said inlet port whereby said piston means is moved under pressure to its effective maximum volume position determined by the position of said seat, said spring being compressed to the same maximum compression condition between said seat and said piston as determined by said stop means regardless of the position of said seat in said chamber whereby the pressure of discharge of liquid on opening said outlet valve is the same for all positions of said seat, and said body having an upper portion of flattened cross section providing a shouldered configuration constituting a stop limiting the movement of said piston to a fixed minimum volume position.

Claim 4

A liquid dispenser of the metering type for manual support and manipulation comprising: a hand piece including a rigid body having a cylindrical liquid reservoir therein providing a pump chamber, piston means in said reservoir and constituting a movable end of said pump chamber and movable between minimum and maximum pump chamber volume positions, a compression spring engaging the side of said piston outside said chamber for urging said piston means toward its minimum pump chamber volume position, means including an adjustable seat for said spring mounted on said body in said reservoir outside said chamber adjacent the end of said reservoir remote from said piston means and movable to positions within a predetermined range for adjusting the effective maximum volume of said chamber, said spring being compressed between said piston means and said seat, stop means for determining the minimum distance between said seat and said piston means and thereby determining the maximum compression of said spring, inlet and outlet ports communicating with said chamber, valve means for opening one of said ports after closing the other of said ports and vice versa, means for supplying liquid under pressure to said chamber through said inlet port whereby said piston means is moved under pressure to its effective maximum volume position determined by the position of said seat, said spring being compressed to the same maximum compression condition between said seat and said piston as determined by said stop means regardless of the position of said seat in said chamber whereby the pressure of discharge of liquid on opening said outlet valve is the same for all positions of said seat, and said body having an upper portion of flattened cross section providing a shouldered configuration constituting a stop limiting the movement of said piston to a fixed minimum volume position.

Claim 5

A liquid dispenser of the metering type for manual support and manipulation comprising: a hand piece including a rigid body having a cylindrical liquid reservoir therein providing a pump chamber, piston means in said reservoir and constituting a movable end of said pump chamber and movable between minimum and maximum pump chamber volume positions, a compression spring engaging the side of said piston outside said chamber for urging said piston means toward its minimum pump chamber volume position, means including an adjustable seat for said spring mounted on said body in said reservoir outside said chamber adjacent the end of said reservoir remote from said piston means and movable to positions within a predetermined range for adjusting the effective maximum volume of said chamber, said spring being compressed between said piston means and said seat, stop means for determining the minimum distance between said seat and said piston means and thereby determining the maximum compression of said spring, inlet and outlet ports communicating with said chamber, valve means for opening one of said ports after closing the other of said ports and vice versa, means for supplying liquid under pressure to said chamber through said inlet port whereby said piston means is moved under pressure to its effective maximum volume position determined by the position of said seat, said spring being compressed to the same maximum compression condition between said seat and said piston as determined by said stop means regardless of the position of said seat in said chamber whereby the pressure of discharge of liquid on opening said outlet valve is the same for all positions of said seat, said valve means comprising cylindrical wall portions adjacent said inlet and outlet ports and rod means carrying seals mounted thereon adjacent the respective ones of said ports, the seal adjacent said inlet port being positioned to enter the cylindrical wall portion adjacent the inlet before the seal adjacent said outlet port moves away from the respective cylindrical wall portion to open said outlet port whereby the inlet pressure is cut off from said chamber before said outlet port is opened and the discharge from said outlet port is independent of the pressure of the liquid in said supply means, a barrel mounted on said body and extending transversely of said cylindrical reservoir and having a passage connecting said ports and an opening providing communication between said passage and said chamber, said barrel having an external opening providing communication with said passage between said inlet and outlet ports and located opposite the opening between said passage and said chamber, a removable plug in said external opening, and said plug being interchangeable with said liquid supplying means whereby liquid under pressure may be supplied directly to said chamber for continuous discharge through said outlet port upon opening of said valve means for said outlet port.

Claim 6

A liquid dispenser of the metering type for manual support and manipulation comprising: a hand piece including a rigid body having a cylindrical liquid reservoir therein providing a pump chamber, piston means in said reservoir and constituting a movable end of said pump chamber and movable between minimum and maximum pump chamber volume positions, a compression spring engaging the side of said piston outside said chamber for urging said piston means toward its minimum pump chamber volume position, means including an adjustable seat for said spring mounted on said body in said reservoir outside said chamber adjacent the end of said reservoir remote from said piston means and movable to positions within a predetermined range for adjusting the effective maximum volume of said chamber, said spring being compressed between said piston means and said seat, stop means for determining the minimum distance between said seat and said piston means and thereby determining the maximum compression of said spring, inlet and outlet ports communicating with said chamber, valve means for opening one of said ports after closing the other of said ports and vice versa, means for supplying liquid under pressure to said chamber through said inlet port whereby said piston means is moved under pressure to its effective maximum volume position determined by the position of said seat, said spring being compressed to the same maximum compression condition between said seat and said piston as determined by said stop means regardless of the position of said seat in said chamber whereby the pressure of discharge of liquid on opening said outlet valve is the same for all positions of said seat, said valve means comprising cylindrical wall portions adjacent said inlet and outlet ports and rod means carrying seals mounted thereon adjacent the respective ones of said ports, the seal adjacent said inlet port being positioned to enter the cylindrical wall portion adjacent the inlet before the seal adjacent said outlet port moves away from the respective cylindrical wall portion to open said outlet port whereby the inlet pressure is cut off from said chamber before said outlet port is opened and the discharge from said outlet port is independent of the pressure of the liquid in said supply means, a barrel mounted on said body and extending transversely of said cylindrical reservoir and having a passage connecting said ports and an opening providing communication between said passage and said chamber, said barrel having an external opening providing communication with said passage between said inlet and outlet ports and located opposite the opening between said passage and said chamber, a removable plug in said external opening, and said plug being interchangeable with said liquid supplying means whereby liquid under pressure may be supplied directly to said chamber for continuous discharge through said outlet port upon opening of said valve means for said outlet port.