Hydraulic reservoir with fluid level detector

• US 4,626,700 A
• Filed: 07/01/1985
• Issued: 12/02/1986
• Est. Priority Date: 07/05/1984
• Status: Expired due to Fees

• Current Assignee: Nippon Air Brake Co., Ltd. (Nabtesco Corporation)
• Original Assignee: Nippon Air Brake Co., Ltd. (Nabtesco Corporation)
• Inventors: Tanaka, Akira, Tanaka, Ryuichi
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): Ip, Shik Luen Paul
• Application Number:
  US06/750,907
• Time in Patent Office: 519 Days
• Field of Search: 307/118, 340/618, 340/52 C, 340/679, 116/110, 73/290 R, 73/307, 73/308, 73/309, 73/314, 73/DIG. 5, 200/84 C, 200/84 R
• US Class Current: 307/118
• CPC Class Codes: B60T 11/26 Reservoirs integral with master controls B60T11/22
• CPC Class Codes: B60T 17/225 brake fluid level indicators level indication in general G01F; H01H
• CPC Class Codes: G01F 23/74 for sensing changes in level only at discrete points
• CPC Class Codes: H01H 36/02 actuated by movement of a float carrying a magnet

Abstract

A hydraulic reservoir with fluid level detector includes a main body having an internal space for containing brake oil; a cap attached to the main body for covering a top opening of the main body; a diaphragm arranged across the top opening of the main body, the outer circumference of the diaphragm being held between the main body and the cap, and the space between the cap and the diaphragm communicating with the atmosphere; a reed switch fixed to the main body, a float provided with permanent magnet, so arranged as to be vertically movable in the internal space of the main body, the reed switch and the float with permanent magnet constituting a fluid level detector, and when the float with permanent magnet is positioned under a predetermined level, the reed switch being closed by magnetic force of the permanent magnet; an operating rod for pushing down the float, being vertically movable and able to be pushed down from the external against buoyancy of the float; and a cylindrical portion integrally formed with the diaphragm, being closed at the lower end, the operating rod being inserted into the cylindrical portion and the float being pushed down through the closed end of the cylindrical portion by the operating rod.

Claims

1. A hydraulic reservoir with fluid level detector comprising:

(A) a main body having an internal space for containing

(B) a cap attached to said main body for covering a top opening of said main body;

(C) a diaphragm arranged across said top opening of the main body, the outer circumference of said diaphragm being held between said main body and said cap, and the space between said cap and said diaphragm communicating with the atmosphere;

(D) a reed switch fixed to said main body;

(E) a float provided with permanent magnet, so arranged as to be vertically movable in said internal space of the main body, said reed switch and said float with permanent magnet constituting a fluid level detector, and when said float with permanent magnet is positioned under a predetermined level, said reed switch being closed by magnetic force of said permanent magnet;

(F) operating means for pushing down said float, being vertically movable and able to be pushed down from the external against buoyancy of said float; and

(G) a cylindrical portion integrally formed with said diaphragm, being closed at the lower end, said operating means being inserted into said cylindrical portion and said float being pushed down through the closed end of said cylindrical portion by said operating means.

2. A hydraulic reservoir according to claim 1, in which the lower end portion of said operating means and that of said cylindrical portion of the diaphragm are firmly combined by a cup-shaped combining member which is elastically fitted to the lower end portion of said cylindrical portion of the diaphragm.

3. A hydraulic reservoir according to claim 2, in which said operating means is rod-like, and its lower end is shaped in horizontal vortex.

4. A hydraulic reservoir according to claim 1, in which an opening is formed in the upper wall of said cap, and a generally cup-shaped cylindrical body having a bottom wall is fixed to said opening of the cap, said cylindrical body defining a recess extending toward the inside of said main body from said cap, and said operating means being slidably guided in the vertical direction by a cylindrical guide portion integrally formed with the bottom wall of said cylindrical body.

5. A hydraulic reservoir according to claim 4, in which said operating means is urged by a spring arranged between the bottom wall of said cylindrical body and the top end of said operating means.

6. A hydraulic reservoir according to claim 5, in which cover means covers the top opening of said cylindrical body and the top end of said operating means.

7. A hydraulic reservoir according to claim 6, in which a push botton is fixed to the top end of said operating means.

8. A hydraylic reservoir according to claim 5, in which a stopper portion is formed in said operating means, contacting normally with the lower end of the cylindrical guide portion of said cylindrical body.

9. A hydraulic reservoir according to claim 8, in which said stopper portion contacts with the lower end of the cylindrical guide portion through a ring member fitted to said operating means.

10. A hydraulic reservoir according to claim 1, in which the lower part of said internal space of the main body is partitioned to two chambers by a generally crank-shaped wall which is integrally formed with the bottom wall of said main body, extending upwardly from the bottom wall.

11. A hydraulic reservoir according to claim 10, in which lateral projections are formed integrally with said crank-shaped wall, and vertical guide grooves are made in the opposite sides of said float, said lateral projections being slidably fitted to said grooves for vertically guiding said float.

12. A hydraulic reservoir according to claim 11, in which a lateral projection is formed integrally formed with said float, and a post having a stopper portion is vertically and integrally formed with the bottom wall of said main body, said lateral projection being engaged with said post and the upper position of said float being determined by said stopper portion.

13. A hydraulic reservoir according to claim 11, in which said permanent magnet is fixed to the lower end of said float, and said reed switch is arranged in a hole of a lateral and horizontal projection which is integrally formed with the outside of the bottom wall of said main body.

14. A hydraulic reservoir according to claim 1, in which a downward projection is formed in the lower end of said cylindrical portion of the diaphragm, said downward projection facing to the upper surface of said float.

15. A hydraulic reservoir acording to claim 14, in which the lower end portion of said operating means and that of said cylindrical portion of the diaphragm are firmly combined by a cup-shaped combining member which is elastically fitted to the lower end portion of said cylindrical portion of the diaphragm.

16. A hydraulic reservoir according to claim 15, in which said operating means is rod-like, and its lower end is shaped in horizontal vortex.

17. A hydraulic reservoir according to claim 16, in which vertical slits are formed in said combining member

18. A hydraulic reservoir according to claim 17, in which internal flanges are made in the upper end of said combining member.

19. A hydraulic reservoir according to claim 16, in which a hole is made in the bottom wall of said combining member, and said downward projection of the cylindrical portion of the diaphragm is inserted through said hole.

20. A hydraulic reservoir according to claim 1, in which the outer circumference of said diaphragm is pinched through a fixing ring between said cap and said main body.

21. A hydraulic reservoir according to claim 20, in which a cutout is made in said fixing ring, and the space between said cap and said diaphragm communicates through said cutout with the atmosphere.

22. A hydraulic reservoir according to claim 21, in which said cap and said main body are engaged with each other by threads.