An Ingenious Brake-shoe Mechanism
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Self-locating Shoes Expanded by Balanced Action
IN our issue dated September 23 we announced, in an article entitled "Brakes Hold a Lead," the introduction, by Benclix, Ltd., Tyscley, Birmingham, of its new Two Leading Shoe brake. We have now received a copy of this company's excellent brochure on this brake, and suggest that it is well worth the while of all interested in this novel and ingenious device to obtain a copy from the address given above.
The brochure is excellently produced and fully informative, explaining, by text and picture, how the brake functions and in what manner it fulfils efficiently scientific braking requirements.
Ingenious in design, the mechanism of the Two Leading Shoe brake (if it can be so called when there is no following shoe) is simple. On each end of each shoe is a pivoted triangular plate functioning as a bell crank.
534 Between the two vertical .edges of the upper pair is the Bendix floating wedge expander, and between those of the lower pair is the adjuster, whilst two push rods connect the horizontal edges —or, in effect, bell-crank arms. For symmetry, the plates and rods are duplicated, a set being mounted on each side of the shoe webs.
By this arrangement equal shoeexpanding force is applied to all four
pivots. Thus, the first action on applying the brake is -to bring both shoes into full contact with the drum. Then the shoes will locate themselves with their heels against the top and
bottom stops. After this, each shoe has a leading end and a point of anchorage, and each behaves in identical manner to the other, In this way they are both equally influenced by automatic servo action, whilst the whole area is in contact and wear is evenly shared.