US3885709A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid toner concentrate dispenser having a valve responsive to hydrostatic pressure
Assignee: Varian Medical Systems Inc
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Filing: 1974-02-01
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Granted: 1975-05-27
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Expires: 1994-02-01
Abstract
Abstract A pumping chamber is mounted along the bottom of a liquid concentrate reservoir. The pumping chamber has a reciprocating piston which has a downward pumping stroke and an upward return or priming stroke. A one-way normally closed valve is formed in the bottom of the pumping chamber. During the downward pumping stroke the hydrostatic pressure of the pumped toner concentrate forces the valve open, permitting a quantity of the toner concentrate to flow therethrough into a discharge region which is continuously flushed with developing fluid. The toner concentrate is absorbed into the developing fluid stream and carried therewith to the developer tank of an electrophotographic recorder. The upward priming stroke is slow, causing a gradual refilling of the pumping chamber through the clearance between the piston and the pumping chamber walls. The pumping stroke is fast and the piston moves downward rapidly creating a squirting action of toner concentrate through the valve opening and in the reverse direction through the piston clearance. This squirting action agitates the concentrate particles and prevents the settling of particles which would eventually clog the mechanism.
Inventors
- 👤 Raymond L Levy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:14
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/10; G03G15/104; D; D06; D06C; D06C15/00; D06C15/04; Y; Y10; Y10S; Y10S222/00; Y10S222/01
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
217 words
A self cleaning dispenser for dispensing toner concentrate into a developing tank through a flow of toner fluid, comprising the following combination: a reservoir for containing a quantity of the toner concentrate; a variable volume chamber in liquid communication with the reservoir formed by a wall member and an end member moveable relative to one another to vary the volume of the chamber; means for activating changes in volume of said chamber comprising means for reciprocating one of said members causing a decreasing volume stroke in which the chamber members are moved rapidly together causing a temporarily elevated hydrostatic pressure within the chamber, and an increasing volume stroke in which the chamber members are moved slowly apart; a valve formed in the wall member of the chamber and which opens in response to the temporarily elevated hydrostatic pressure within the chamber during the rapid decreasing volume stroke; and a discharge chamber formed about the valve for receiving the displaced toner concentrate from the variable volume chamber, the discharge chamber having an input port which receives a flow of toner fluid from the developing tank for diluting and agitating the displaced toner concentrate and having an outlet port through which the flow of toning fluid is returned to the developing tank along with the toner concentrate dispensed therein.
Claim 2
Dependent Claim
217 words
A self cleaning dispenser for dispensing toner concentrate into a developing tank through a flow of toner fluid, comprising the following combination: a reservoir for containing a quantity of the toner concentrate; a variable volume chamber in liquid communication with the reservoir formed by a wall member and an end member moveable relative to one another to vary the volume of the chamber; means for activating changes in volume of said chamber comprising means for reciprocating one of said members causing a decreasing volume stroke in which the chamber members are moved rapidly together causing a temporarily elevated hydrostatic pressure within the chamber, and an increasing volume stroke in which the chamber members are moved slowly apart; a valve formed in the wall member of the chamber and which opens in response to the temporarily elevated hydrostatic pressure within the chamber during the rapid decreasing volume stroke; and a discharge chamber formed about the valve for receiving the displaced toner concentrate from the variable volume chamber, the discharge chamber having an input port which receives a flow of toner fluid from the developing tank for diluting and agitating the displaced toner concentrate and having an outlet port through which the flow of toning fluid is returned to the developing tank along with the toner concentrate dispensed therein.
Claim 3
Dependent Claim
21 words
The dispenser of claim 1, wherein the wall member of the chamber is fixed and the end member moves relative thereto.
Claim 4
Dependent Claim
25 words
The dispenser of claim 2 wherein the end member is a piston which reciprocates periodically within the wall members in response to the activating means.
Claim 5
Dependent Claim
38 words
The dispenser of claim 3 wherein a controlled clearance is present between the side surface of the piston and the wall member adjacent thereto for providing a jet of toner concentrate therethrough during the rapid decreasing volume stroke.
Claim 6
Dependent Claim
65 words
The dispenser of claim 4, wherein the piston is provided with transverse port means on the side surface thereof and an interior channel which establish fluid communication between the variable volUme chamber and the reservoir at the beginning of the decreasing volume stroke for providing a jet of toner concentrate therethrough until the piston extends into the wall member sufficiently to block the transverse ports.
Claim 7
Dependent Claim
15 words
The dispenser of claim 5, further comprising resilient means for urging the valve means closed.
Claim 8
Dependent Claim
37 words
The dispenser of claim 6, further comprising sealing means between the valve means and the wall member of the variable volume chamber for preventing leakage of toner concentrate into the discharge chamber when the valve is closed.
Claim 9
Dependent Claim
12 words
The dispenser of claim 7, wherein the sealing means is an O-ring.
Claim 10
Dependent Claim
33 words
The dispenser of claim 4 wherein the means for reciprocating comprises a rotatable cam and a connecting rod secured to the piston which reciprocates up and down in response to the cam rotating.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |