Patent US3921820A successfully refreshed from Google Patents.
US3922657A
Expired / Lapsed
US
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Low liquid level warning device
Assignee: Tokico Ltd
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Filing: 1974-12-18
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Granted: 1975-11-25
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Expires: 1994-12-18
Abstract
Abstract In a low liquid level warning device for use in a brake liquid reservoir supplying a tandem master cylinder in a vehicle hydraulic braking system, the improvement comprising: a partition wall dividing the interior of the reservoir into two chambers; a guide disposed in each of the two chambers for guiding a float, at least a portion of each guide extends from the bottom portion of the partition wall upwardly towards the center portion of each chamber in a declined manner; a lead switch disposed in the bottom portion of the partition wall; and a magnet for actuating the lead switch secured on each of the float.
Inventors
- 👤 Yoshihiro Hayashida
- 👤 Hiroyuki Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:02
CPC Classifications
B; B60; B60T; B60T11/00; B60T11/10; B60T11/16; B60T11/22; B60T17/00; B60T17/18; B60T17/22; G; G01; G01F; G01F23/00; G01F23/30; G01F23/64; G01F23/72; G01F23/74
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
119 words
A low liquid level warning device for use in a brake liquid reservoir supplying a tandem master cylinder or the like in a vehicle hydraulic braking system, said device comprises a lead switch disposed in the bottom portion of a partition wall dividing the interior of the reservoir into two chambers, a float disposed in each of said chambers and having a magnet thereon for actuating said lead switch, a guide disposed in each of the chambers for guiding the coRresponding float, at least a portion of each guide extends from the bottom portion of the partition wall upwardly towards the center portion of each chamber in a declined manner, and a warning circuit connected to said lead switch.
Claim 2
Dependent Claim
119 words
A low liquid level warning device for use in a brake liquid reservoir supplying a tandem master cylinder or the like in a vehicle hydraulic braking system, said device comprises a lead switch disposed in the bottom portion of a partition wall dividing the interior of the reservoir into two chambers, a float disposed in each of said chambers and having a magnet thereon for actuating said lead switch, a guide disposed in each of the chambers for guiding the coRresponding float, at least a portion of each guide extends from the bottom portion of the partition wall upwardly towards the center portion of each chamber in a declined manner, and a warning circuit connected to said lead switch.
Claim 3
Dependent Claim
25 words
A low liquid level warning device according to claim 1, in which said guide has a generally rectangular cross-section for receiving the float slidingly therein.
Claim 4
Dependent Claim
48 words
A low liquid level warning device according to claim 1, in which each of said guides is adapted to receive the float slidingly therein, and means (19a, 21a) for locating the direction of the float received in the guide are disposed on said guide and on the float.
Claim 5
Dependent Claim
31 words
A low liquid level warning device according to claim 3, in which said locating means on the guide is a groove (19a) for receiving a projecting portion (21a) of the float.
Claim 6
Dependent Claim
56 words
A low liquid level warning device according to claim 1, in which each of said guides has a portion extending from the bottom portion of the partition wall upwardly towards the center portion of the chamber, a portion extending generally vertically at the center portion of the chamber and a curved portion connecting aforesaid two portions.
Claim 7
Dependent Claim
35 words
A low liquid level warning device according to claim 1, in which each of said guides has generally parallel straight walls extending from the bottom portion of the partition wall upwardly in a declined manner.
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) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |