摘要 |
An upgraded railway freight car brake control valve device comprises a novel emergency valve portion that embodies therein a plurality of simple and inexpensive poppet valves that replace yet perform the same functions heretofore performed by more expensive slide type valves which slide valves, and the flat seats upon which they slide as they are shifted from one position to another, in their manufacture require a considerable amount of accurate machining thus increasing the cost of the valve device of which they are an important part. |