Motor Truck Manual (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1921 Excerpt: ...of brake application is not commercially possible; but it is effectively a c c o m, ., -'.. Fig. 46.--Timken duplex internal pllShed by SeCUr-expanding brakes. ing to the wheels a metal drum, on which the friction members act. Brakes vary greatly in details of construction; however, there are practically two types, the internal expanding and the external contracting types. In some cases one set of each is used, while in others two sets of the internal expanding type are used. The external is usually of the band type, incorporating a steel band to which a frictional material is riveted. The expanding type usually consists of cast shoes having a friction material Fig. 47.--Stan-Par axle with internal brakes side by side. riveted to them. Fig. 46 illustrates the Timken brakes, which are termed a duplex brake, and consist of four friction fabric-lined shoes, so located that the pair of brakes takes up no more room than the ordinary singJe-shoe type. These four shoes are equally spaced on the inner circumference of the brake drum, on each pair located diametrically opposite are expanded by cams and supported by the brake spider, which is rigidly secured to the axle housing. Fig. 47 illustrates the internal expanding brakes of the Stan-Par axle. In this case they are located side by side, each pair operating on a single brake drum of considerable width. This illustration clearly depicts the type of cam usually employed to expand this type of brake. Fig. 48 illustrates the external type, and' also shows how this can be combined with an expanding type to operate on a single drum. The contraction of the band is usually accomplished by means of a toggle mechanism and lever located near the opening of the band. It permits providing a simple adjustment, in the form of a ...