| 摘要 |
Brake apparatus for a railway vehicle including a brake cylinder device of the type having a pair of interconnected pistons of unequal size to which the vehicle braking rigging is connected, the larger piston having first and second chambers formed on its opposite sides in which air is stored for use in controlling the vehicle brakes, and a control valve device that is operative responsive to a reduction of brake pipe pressure to transfer air from the first chamber to a third chamber formed on the side of the smaller piston corresponding to the side of the larger piston having the second chamber, to effect movement of the interconnected pistons to a brake application position. As piston displacement occurs, pressure in the second chamber is equalized with the pressure in the third chamber so that no pressure differential is developed across the larger piston, until a predetermined pressure is established in the third chamber consistent with a desired minimum brake application force. When this occurs, the control valve exhausts air from the first chamber, the volume of which is minimal in brake application position of the larger pistons, so that with but a small loss of air from the first chamber, a large pressure differential may be established across the larger piston by reason of the pressure in the second chamber being trapped at a substantially constant value, thus providing higher brake application forces with but a minimum of air consumption.
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