Liquid material dispenser and valve
First Claim
1. A liquid material dispenser, comprising:
- (a) a housing including a reservoir for storing liquid to be dispensed, an outlet through which the liquid is dispensed, and a connecting passageway between said reservoir and said outlet;
(b) a reciprocatable pumping member located in said passageway, one side of said pumping member defining a pumping chamber with said passageway, and the other side of said pumping member defining a pressure control chamber, said pumping member being cyclically displaceable through a pumping stroke for pumping liquid through said outlet and a drawing stroke for drawing liquid from said reservoir;
(c) valve means in said passageway effective, during said drawing stroke, to cause the pumping member to draw liquid from said reservoir into said pumping chamber, and during said pumping stroke, to cause the pumping member to pump liquid from said pumping chamber through said outlet;
(d) feeding means for feeding a gas at a preselected time and rate to said pressure control chamber to drive the pumping member through said pumping stroke; and
(e) a vent mechanism for venting said gas from said pressure control chamber to the atmosphere to drive the pumping member through said drawing stroke, said vent mechanism including;
an inlet vent opening providing communication between the pressure control chamber and the atmosphere;
said opening being caused to open to end said pumping stroke and to close after a portion of said gas has vented, wherein said vent mechanism includes a displaceable member connected to said pumping member, such that the opening and sealing of the vent opening occurs as a result of the movement of the displaceable member under the action of the pumping member.
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0 Petitions
Accused Products
Abstract
A liquid material dispenser, for use, for example, in dispensing liquid medicine over an extended period of time, which includes a housing (10) enclosing a reservoir (12) for storing the liquid to be dispensed and having an outlet (14) through which the liquid is dispensed, and a connecting passageway (16) between the reservoir and the outlet. Located in the passageway is a diaphragm (18), one side of which defines a pumping chamber (20) and the other side of which defines a pressure control chamber (22). The diaphragm (18) is cyclically displaceable through a pumping stroke for pumping liquid through the outlet (14) and a drawing stroke for drawing liquid from the reservoir (12). Also located in the passageway (16) are a pair of valves (30, 33) which serve, during the drawing stroke, to cause the diaphragm (18) to draw liquid from the reservoir (12) into the pumping chamber (20), and during the pumping stroke, to cause the diaphragm (18) to pump liquid from the pumping chamber (20) through the outlet (14). An electrolytic cell (24) generates gas at suitable times for suitable durations and rates which is supplied to the pressure control chamber (22) to drive the pumping member (18) through the pumping stroke. A vent is used for venting the gas from the pressure control chamber (22) to the atmosphere to drive the pumping member (18) through the drawing stroke. The vent has an inlet vent opening (40) inside the pressure control chamber (22), with the opening (40) being caused to open to end the pumping stroke and to close after a portion of the gas has vented.
357 Citations
19 Claims
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1. A liquid material dispenser, comprising:
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(a) a housing including a reservoir for storing liquid to be dispensed, an outlet through which the liquid is dispensed, and a connecting passageway between said reservoir and said outlet; (b) a reciprocatable pumping member located in said passageway, one side of said pumping member defining a pumping chamber with said passageway, and the other side of said pumping member defining a pressure control chamber, said pumping member being cyclically displaceable through a pumping stroke for pumping liquid through said outlet and a drawing stroke for drawing liquid from said reservoir; (c) valve means in said passageway effective, during said drawing stroke, to cause the pumping member to draw liquid from said reservoir into said pumping chamber, and during said pumping stroke, to cause the pumping member to pump liquid from said pumping chamber through said outlet; (d) feeding means for feeding a gas at a preselected time and rate to said pressure control chamber to drive the pumping member through said pumping stroke; and (e) a vent mechanism for venting said gas from said pressure control chamber to the atmosphere to drive the pumping member through said drawing stroke, said vent mechanism including;
an inlet vent opening providing communication between the pressure control chamber and the atmosphere;
said opening being caused to open to end said pumping stroke and to close after a portion of said gas has vented, wherein said vent mechanism includes a displaceable member connected to said pumping member, such that the opening and sealing of the vent opening occurs as a result of the movement of the displaceable member under the action of the pumping member. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification