Automatic slack adjuster for cam brakes
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THE standard manually operated slack adjuster used in conjunction with diaphragm-type brake chambers and S-cam brakes has been replaced by an automatic slack adjuster made by Clayton Dewandre Co. Ltd. Although basically similar to the standard unit it has an additional ratchet mechanism as used in automatic adjusters which Clayton have been manufacturing for many years.
It works on the principle that when the brakes are applied the cam lever rotates, while the adjuster lever, connected by linkage to the axle, moves through a similar angle but in the opposite direction relative to the slack adjuster lever,
A pawl carried in the adjuster housing rides up a tooth of a ratchet wheel and it only engages with the next tooth when the movement corresponds to the lever setting required to retain the necessary shoe centre The automatic slack adjuster is available to suit brake camshafts with diameters of 1.125 in., 1.25 in. and 1.5 in. and the standard ten splines.
Available in varying lengths, the arms are drilled to take one or two bushes: one attachment point is for the brake chamber rod and the other for handbrake linkage.