FLUID ACTUATED BRAKE LOCKING MECHANISM

• US 3,874,747 A
• Filed: 10/03/1973
• Issued: 04/01/1975
• Est. Priority Date: 10/03/1973
• Status: Expired due to Term

• Current Assignee: International Transquip Industries
• Original Assignee: Walter Case, William F. Benefield
• Inventors: Case, Walter, Benefield, William F.
• Primary Examiner(s): Blix, Trygve M.
• Assistant Examiner(s): Butler, D. C.
• Application Number:
  US05/402,891
• Time in Patent Office: 545 Days
• Field of Search: 303/89 188/265,170 92/27,28,24X,24 137/598 192/3H
• US Class Current: 303/89
• CPC Class Codes: B60T 17/16 Locking of brake cylinders
• CPC Class Codes: F16D 2127/06 Locking mechanisms, e.g. acting on actuators, on release mechanisms or on force transmission mechanisms
• CPC Class Codes: F16D 65/14 Actuating mechanisms for brakes; Means for initiating operation at a predetermined position brake control systems, parts thereof B60T
• CPC Class Codes: Y10T 74/2133 Pawls and ratchets

Abstract

A brake locking mechanism for heavy vehicles, adapted to be installed in existing braking systems without altering the normal operation thereof, functions to prevent involuntary movement of the vehicle, due to system failure such as air or hydraulic fluid leakage, while standing. The mechanism includes a spring biased pawl engageable with rack teeth formed on the diaphragm actuated brake rod, the pawl being operated by an air or hydraulically actuated piston associated therewith and connected into the vehicle air or hydraulic system.

Claims

1. In a fluid operated brake setting system for heavy vehicles including, for each wheel unit, a brake, a brake actuator chamber and a brake actuator rod reciprocated by said actuator chamber and operatively connected to the wheel unit brake;

a brake locking mechanism comprising;

a casing adapted to be mounted in association with said actuator chamber;

said casing having a first passage therethrough, for accommodating the brake actuator rod for reciprocating movement, and a second passage transverse to and communicating with said first pAssage;

said brake actuating rod being provided with longitudinally spaced transverse rack teeth;

a pawl rod supported and guided for reciprocating movement in said second passage, having pawl means at one end for engagement with said rack teeth;

means in said casing defining a cylinder chamber;

piston means disposed in said cylinder chamber for reciprocating movement;

means coupling said piston means to said pawl rod;

spring means coupled to said pawl rod, normally urging said pawl rod in a first direction relative to said first passage to engage said pawl means with said rack teeth;

conduit means communicating said cylinder chamber with a source of pressurized fluid acting on said piston and urging said pawl rod in a second direction relative to said first passage to disengage said pawl means from said rack teeth.

2. A brake locking mechanism as set forth in claim 1 said coupling means comprising a crank arm pivoted within said casing;

one end of said crank arm being coupled to said pawl rod to provide for reciprocation of said pawl rod in response to oscillation of said crank arm;

said piston means acting on the other end of said crank arm.

3. A brake locking mechanism as set forth in claim 2 said piston means being moved, upon the introduction of fluid into said cylinder chamber, from a first position to a second position to disengage said pawl means from said actuator rod;

a threaded hole in the casing wall confronting the head of said piston; and

an adjusting screw disposed in said hole for maintaining said piston in said second position to disengage said pawl means from said actuator rod.

4. A brake locking mechanism as set forth in claim 2 said spring means acting on said other end of said crank arm, in opposition to said piston means, to normally engage said pawl means with said actuator rod.

5. A brake locking mechanism as set forth in claim 1 restricted passage means in said casing communicating said cylinder chamber with a fluid inlet chamber to restrict the rate of fluid flow into and out of said chamber.