Integrated Railmotive Systems Inc.

Excellence in Engineering

UNITIZED AIR & ELECTRIC CONNECTOR

    Early in the development of the recent AAR Electronically Controlled Pneumatic braking Development, Railmotive Systems noted that the weakest point in the systems initially demonstrated was the connection of the electric control cables between cars.  Electric cables on each car all had to be connected to one another after the air hoses were coupled, which more or less doubled the work of coupling cars to make up a train. Further the arrangement then (and still) used by the few users of this equipment posed a longer term problem in that the electric cable connection crosses over the pneumatic one as the air hoses are on the right, as one looks at the end of the car, while the electric cables are on the left.  So as shown in exhibit 15-1, both conduits cross the car centerline under the coupler and the electric connection is directly on top of the pneumatic one. This sets up a situation where normal action of the air couplings might combine with the extreme vertical displacement of “E” type car couplings and bring the coupler head into contact with the electric connectors from time to time. It is, at least, a situation to be guarded against.

    Experience with the air only system has shown that the air couplings come apart unintentionally from time to time as a result of either tortuous hose connections ((a particular problem with long cars) or simple wearing out of parts. With the electric connection directly beneath the pneumatic one, there is a good possibility that such an uncoupling with the hoses fully charged could result in the electrical coupling receiving a damaging blow from the accidentally disconnected hose couplings (or gladhands as they are colloquially known).

Finally, Experience with the deterioration of electric connectors on cables carried on a fleet of cars which were equipped with the ECP system but only used in standard all pneumatic service, convinced us that the loose hanging unused electrical connector was an invitation to damage, while a single connector which would simultaneously couple both air and electricity would prove very advantageous. We submitted designs to WABTEC and made up the prototypes shown in the photos of exhibit 15-2.  A patent on the configuration was issued in the name of Tom Engle, and the rights assigned to WABTEC.


The advantages of the combined brake system connector would be: 1) to simplify the situation shown above; 2) to assure that both systems would always be connected if either was, thus simplifying the yard man’s duties; 3) to reduce both the labor and time necessary to make the brake system connections, and; 4) to improve electrical reliability by using a self cleaning wiping contact on makeup of the trainline electrical connection.
The prototype connector shown above was tested at WABTECs plant, but no further development was undertaken. As shown above, the prototype was produced by modifying a par of standard Hose Coupling castings, to include a blade carried under the mating surface and a matching fork carried within a housing on the top of the coupling. A gate was provided over the blade, which completely prevented a trainman from touching any part of the contact, and this gate could only be opened by making up the coupling. The fork was actually composed of eight individually sprung contacts (4 above and 4 below) so arranged that at least three pairs of them would be grasping the blade at any point in its travel, eliminating the need for forcing the hose to a particular point when making up a connection. In other words, the trainman’s necessary actions in coupling hose would be identical to those now used.