Releasable lock for brakes

• US 4,007,815 A
• Filed: 12/12/1975
• Issued: 02/15/1977
• Est. Priority Date: 12/12/1975
• Status: Expired due to Term

• Current Assignee: Midbrake Corporation
• Original Assignee: Midland-Ross Corporation (Honeywell International Inc.)
• Inventors: Acre, Leon R.
• Primary Examiner(s): Blix, Trygve M.
• Assistant Examiner(s): Kazenske, Edward R.
• Application Number:
  US05/640,175
• Time in Patent Office: 431 Days
• Field of Search: 188/67, 188/69, 188/82.3, 188/82.7, 188/170, 188/265, 303/89, 92/24, 92/25, 92/27, 92/28
• US Class Current: 188/265
• CPC Class Codes: B60T 13/268 using accumulators or reservoirs
• CPC Class Codes: B60T 17/16 Locking of brake cylinders

Abstract

A locking device for a reciprocating rod brake actuator movable between brake applying and brake releasing positions includes a pivoted pawl movable between locking and releasing positions for releasably locking the rod in its brake applying position. A spring normally biases the pawl to its locking position, and a fluid cylinder is operative when pressurized for moving the locking device to its releasing position. The rod is movable toward and away from the pawl, and is normally supported against movement away from the pawl by a releasable support. Release of the support frees the rod for free movement between its brake applying and releasing positions even though the pawl is in its locking position.

Claims

1. A locking device for a reciprocating rod brake actuator movable between brake applying and brake releasing positions, said locking device including a pivoted pawl having a pawl surface engageable with said rod by moving in an arcuate path toward and away from said rod between rod locking and releasing positions, said pawl in said locking position thereof being in engagement with said rod for releasably locking same against movement in a direction from said brake applying position toward said brake releasing position while providing free movement thereof in a direction from said brake releasing position to said brake applying position, yieldable biasing means for normally biasing said pawl to said locking position, fluid pressure means operative when pressurized for moving said pawl to said releasing position against the force of said biasing means, pressure relief means for selectively relieving pressure in said fluid pressure means, and selectively operable releasing means separate from said fluid pressure means and located generally on the opposite side of said rod from said pawl for releasing said rod for movement from said brake applying position to said brake releasing position when said pawl is in said locking position by moving said rod away from and out of engagement with said pawl.

2. The device of claim 1 wherein said locking device includes a linearly movable shaft connected with said pawl and with a piston in a cylinder defining said fluid pressure means, said biasing means comprising a spring in said cylinder biasing against said piston for moving same in a direction for acting through said shaft to pivot said pawl to said locking position, and a fluid pressure conduit communicating with said cylinder on the opposite side of said piston from said spring.

3. The device of claim 2 wherein said releasing means includes a rotatable cam releasably locked in a first position supporting said rod against movement away from said pawl, and said cam being rotatable to a second position for providing movement of said rod away from said pawl.

4. A locking device for a reciprocating rod brake actuator extending through a housing and being movable between brake applying and brake releasing positions, said locking device including locking means movable to a locking position for locking said rod in said brake applying position, yieldable biasing means for normally biasing said locking means to said locking position, fluid pressure means operative when pressurized to move said locking means out of said locking position, said rod being movable toward and away from said locking means, a cam shaft rotatably mounted on said housing on a cam axis extending perpendicular to the longitudinal axis of said rod, said cam shaft being on the opposite side of said rod from said locking means, said cam shaft having a central portion receiving said rod and including an arcuate portion and a flat portion, said flat portion being located substantially closer to said cam axis than said arcuate portion, said cam shaft being rotatable between a position wherein said arcuate portion faces said rod for supporting same against movement away from said locking means and a position wherein said flat portion faces said rod for providing movement of said rod away from said locking means to free said rod for free movement between said brake applying and releasing positions when said locking means is in said locking position.