Patent US3793934A successfully refreshed from Google Patents.
US3793934A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic coffee maker with liquid level sensor and siphon control
Assignee: Bunn O Matic Corp
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Filing: 1972-12-15
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Granted: 1974-02-26
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Expires: 1992-12-15
Abstract
Abstract Cold water is supplied to a basin until it reaches a liquid level sensor and then is siphoned from the basin into a hot water tank from which hot water is siphoned for coffee brewing purposes. Various cold water siphon arrangements are provided together with various means for varying the volume of cold water supplied to the basin.
Inventors
- 👤 J Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:55
CPC Classifications
A; A47; A47J; A47J31/00; A47J31/04; A47J31/057; A47J31/44; A47J31/54; A47J31/56
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
184 words
Coffee brewing apparatus comprising a hot water tank, means for heating water in said tank, a siphon tube for withdrawing hot water from said tank to brew coffee extract, means for placing said tank in communication with the atmosphere, a cold water basin above said tank, a cold water inlet pipe extending upwardly through said tank into said basin including an inverted U-shaped upper end portion having its opening near the bottom of said basin, an inlet water line for supplying cold water to said basin from a source under pressure, a valve in said inlet water line, means for opening said valve to cause cold water to flow into said basin, and means for closing said valve when said cold water reaches a predetermined level in said basin above said inverted U-shaped upper end portion whereupon said cold water is siphoned from said basin into said tank until the level of said cold water in said basin is lowered to said downwardly facing opening of said inverted U-shaped upper end portion and hot water is siphoned from said tank through said siphon tube.
Claim 2
Dependent Claim
184 words
Coffee brewing apparatus comprising a hot water tank, means for heating water in said tank, a siphon tube for withdrawing hot water from said tank to brew coffee extract, means for placing said tank in communication with the atmosphere, a cold water basin above said tank, a cold water inlet pipe extending upwardly through said tank into said basin including an inverted U-shaped upper end portion having its opening near the bottom of said basin, an inlet water line for supplying cold water to said basin from a source under pressure, a valve in said inlet water line, means for opening said valve to cause cold water to flow into said basin, and means for closing said valve when said cold water reaches a predetermined level in said basin above said inverted U-shaped upper end portion whereupon said cold water is siphoned from said basin into said tank until the level of said cold water in said basin is lowered to said downwardly facing opening of said inverted U-shaped upper end portion and hot water is siphoned from said tank through said siphon tube.
Claim 3
Dependent Claim
30 words
Coffee brewing apparatus according to claim 1 wherein said basin has a sump in the bottom and said opening to said U-shaped upper end portion faces downwardly in said sump.
Claim 4
Dependent Claim
31 words
Coffee brewing apparatus according to claim 1 wherein said inlet water line opens into the leg of said inverted U-shaped end portion above said opening near the bottom of said basin.
Claim 5
Dependent Claim
21 words
Coffee brewing apparatus according to claim 3 wherein T-shaped means interconnects said inlet water line and said inverted U-shaped end portion.
Claim 6
Dependent Claim
21 words
Coffee brewing apparatus according to claim 3 wherein Y-shaped means interconnects said inlet water line and said inverted U-shaped end portion.
Claim 7
Dependent Claim
31 words
Coffee brewing apparatus according to claim 1 wherein the bight of said inverted U-shaped upper end portion is positioned below and adjacent said predetermined level of cold water in said basin.
Claim 8
Dependent Claim
19 words
Coffee brewing apparatus according to claim 1 wherein said means for closing said valve includes a liquid level sensor.
Claim 9
Dependent Claim
54 words
Coffee brewing apparatus according to claim 7 wherein said liquid level sensor includes normally closed switch means controlled by a light responsive device, a light source and a prism for directing rays from said light source to said light responsive device as long as said prism is not contacted by water in said basin.
Claim 10
Dependent Claim
28 words
Coffee brewing apparatus according to claim 1 wherein an air vent line opens into said cold water inlet pipe at the upper end of said hot water tank.
Claim 11
Dependent Claim
34 words
Coffee brewing apparatus according to claim 1 wherein means are provided for varying the volume of cold water in said cold water basin required to reach said predetermined level therein for closing said valve.
Claim 12
Dependent Claim
46 words
Coffee brewing apparatus according to claim 10 wherein said volume varying means comprises a member having different volume varying sections on opposite sides, and means for securing said member in fixed position in said basin at said predetermined level with one side or the other uppermost.
Claim 13
Dependent Claim
23 words
Coffee brewing apparatus according to claim 11 wherein a cover overlies saId basin, a said member is detachably mounted in depending relation thereon.
Claim 14
Dependent Claim
33 words
Coffee brewing apparatus according to claim 10 wherein said volume varying means comprises a liquid displacing member, and means for variably vertically positioning the same relative to said predetermined level in said basin.
Claim 15
Dependent Claim
35 words
Coffee brewing apparatus according to claim 10 wherein a cover overlies said basin, and said volume varying means comprises a liquid displacing member, and a screw depending from said cover and threaded into said member.
Claim 16
Dependent Claim
57 words
Coffee brewing apparatus according to claim 10 wherein said means for closing said valve when said cold water reaches a predetermined level in said basin includes a liquid level sensor, and said means for varying the volume of cold water required to reach said level includes means for adjusting the vertical position of said liquid level sensor.
Claim 17
Dependent Claim
137 words
Coffee brewing apparatus comprising a hot water tank, means for heating water in said tank, a siphon tube for withdrawing hot water from said tank to brew coffee extract, means for placing said tank in communication with the atmosphere, a cold water basin above said tank, a cold water inlet pipe extending upwardly through said tank into said basin including an inverted U-shaped upper end portion having its opening near the bottom of said basin, means for supplying cold water to said basin until it reaches a predetermined level therein whereupon said cold water is siphoned from said basin into said tank until the level of said cold water in said basin is lowered to said downwardly facing opening in said U-shaped upper end portion and hot water is siphoned from said tank through said siphon tube.
Claim 18
Dependent Claim
137 words
Coffee brewing apparatus comprising a hot water tank, means for heating water in said tank, a siphon tube for withdrawing hot water from said tank to brew coffee extract, means for placing said tank in communication with the atmosphere, a cold water basin above said tank, a cold water inlet pipe extending upwardly through said tank into said basin including an inverted U-shaped upper end portion having its opening near the bottom of said basin, means for supplying cold water to said basin until it reaches a predetermined level therein whereupon said cold water is siphoned from said basin into said tank until the level of said cold water in said basin is lowered to said downwardly facing opening in said U-shaped upper end portion and hot water is siphoned from said tank through said siphon tube.
Claim 19
Dependent Claim
30 words
Coffee brewing apparatus according to claim 16 wherein said basin has a sump in the bottom and said opening in said U-shaped upper end portion faces downwardly in said sump.
Claim 20
Dependent Claim
27 words
Coffee brewing apparatus according to claim 16 an air vent line opens into said cold water inlet pipe at the upper end of said hot water tank.
Claim 21
Dependent Claim
51 words
Coffee brewing apparatus according to claim 16 wherein an air vent is located at the upper end of the cold water inlet pipe to place the upper end of said hot water tank in communication with the atmosphere and prevent siphoning of the hot water from said tank into said basin.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |