RAILWAY TRUCK BRAKE TESTING DEVICE

• US 3,782,185 A
• Filed: 08/21/1972
• Issued: 01/01/1974
• Est. Priority Date: 08/21/1972
• Status: Expired due to Term

• Current Assignee: George E. Novak, Robert L. Hassenauer, Thomas J. Wolak
• Original Assignee: George E. Novak, Robert L. Hassenauer, Thomas J. Wolak
• Inventors: Hassenauer, Robert L., Wolak, Thomas J., Novak, George E.
• Primary Examiner(s): Gill, James J.
• Application Number:
  US05/282,477
• Time in Patent Office: 498 Days
• Field of Search: 73/121,129,94,88.5,398AN
• US Class Current: 73/121
• CPC Class Codes: G01L 1/2206 Special supports with preselected places to mount the resistance strain gauges; Mounting of supports
• CPC Class Codes: G01L 5/28 for testing brakes

Abstract

A transducer device for converting a compression force, applied perpendicularly between two relatively sliding objects, into a tension force to be measured by a strain gauge rosette and, more particularly, for measuring a braking force when applied by a railway brake beam to a brake head and shoe unit in a direction normal to the periphery of a rotating vehicle wheel irrespective and independently of a tangential force due to friction between the wheel and the brake shoe unit. There exist devices for measuring a similar force applied normal to a railway wheel when stationary but they do not accurately measure such normal force under dynamic operating conditions because of the ancillary frictional force between the brake shoe and the rotating wheel. The present invention utilizes one or more bell cranks fulcrumed on a force-transmitting member so as to actuate a strain gauge rosette which can measure a tension force but cannot measure a compression force.

Claims

1. A device for measuring a compressive force applied in one direction between a railway truck brake shoe and wheel tread members, independently of a force applied in a transverse direction between said members, comprising a bell crank having a fulcrum on one of said members, anchorage means between one arm of said bell crank and the other of said members, an elongated tension element having a connection between one of its ends and the other arm of said bell crank, and a connection between the other end of said element and said first-mentioned member, respectively, and a strain sensitive gauge rosette mounted on said element intermediate said connections.

2. A device as described in claim 1 in which the anchorage means comprises a second bell crank having a fulcrum on the first-mentioned member spaced from the first-mentioned fulcrum, said bell cranks having two of their arms extending toward each other and interconnected and having their other two arms extending parallel to each other and interconnected by said tension element.

3. A railway truck brake testing device comprising a brake beam, a bell crank having a fulcrum on said beam with an axis parallel to the length of the beam, a brake block unit mounted on one arm of said bell crank, a link having one end connected to the other arm of said bell crank and its other end anchored to said beam, and a strain sensitive gauge mounted on said link intermediate the ends of the latter and registering tension strains.

4. In a railway truck brake testing device, an elongated brake beam, a bell crank frulcrumed on each end of said beam, a brake block unit mounted on one arm of each bell crank, a link secured at one end to the other arm of each bell crank and having its other end anchored to the beam, a strain sensitive gauge mounted on each link intermediate its ends, and a brake lever fulcrumed on the brake beam intermediate its ends.

5. In combination in a railway truck, a wheeled axle, a truck frame mounted thereon, an elongated brake beam supported by the frame, an upright box-like casing at each end of the beam having an open side facing the adjacent wheel, spaced upright bell cranks housed within each casing disposed one above the other and having individual fulcrums on side walls of the casing with their axes parallel to the open side of the casing, each of said bell cranks having an arm extending toward and connected to a corresponding arm of the other bell crank, each of said bell cranks having an arm extending angularly to said first-mentioned arm and away from the open side of the casing, a tension link extending between the outer ends of the latter-mentioned arms, strain sensitive gauge elements mounted on said link, and a brake head and shoe unit adjacent the open side of each casing with upper and lower lugs extending into the casing and pivoted to the adjacent ends of said first-mentioned bell crank arms.