614,241. Wool-combing machines. HARDY, E. E. March 27, 1946. No. 9495. Convention date, March 18, 1942. [Class 120(i)] [Also in Group XXIII] A dabbing brush for wool combs comprises a brush back and a bristle-clad face, the latter consisting of a toe portion having a fixed brush block and a heel portion composed of reversible and interchangeable brush blocks constrained to slide transversely on the brush back and with respect to the fixed brush block of the toe portion, the brush having means for maintaining the slidable blocks in operatively fixed relation to the brush back. The brush back 1, preferably of aluminium has a slot 3 for receiving the bolt which attaches the brush to the foot of the dabbing motion, the slot being located so that the zone of most rapid wear of the brush is located substantially wholly within the width of one of the two detachable and renewable brush sections 5 and 7. A brush section 9 covering the full width and substantially half the length of the brush is secured by bolts at the toe end of the brush. The section 9 comprises a plate 15, e.g. of fibre or metal, having holes in which the tufts of bristles are inserted and secured by staples driven into a second plate 21 of wood which may be held to plate 15 by the staples. At the heel end a fixed abutment 23 of quadrangular section is provided across the width of the brush and having one of its faces oblique to conform to the undercut slope of the heel end of back 1 and its face which is toward brush section 9 disposed perpendicularly to a reinforcing plate 13 of sheet metal which is applied to the inner face of the back 1. The abutment is bolted to the under face of the plate 13. Between the abutment and the brush section 9 a spline 27 of dove-tail or trapeziform section is located having the narrower of its parallel faces secured by bolting against the under side of plate 13. The brush sections 5, 7 comprise tufts of bristles set in holes in one-piece wooden blocks and have a dove-tail rabbet or recess 31 fitting closely over a spline 27 so that each section is held between the abutment 23 and brush section 9 and against the under surface of plate 13 with capacity for movement only lengthwise of spline 27. Each brush section 5, 7 has a hole 33 in each of its ends into which enters a cap screw 35 put through the oblique outward face. of abutment 23 so as to hold the sections in operatively fixed relation. When the bristles comprising the inward half of the face of removable section 5 become sufficiently worn down the screw 35 is backed out to clear the hole 33 in section 5 which is then removed by sliding along spline 27, then turned end for end and replaced on spline 27 to bear against the section 7, and the screw 35 tightened. When the bristles on the other half of section 5 have also been worn down the screw 35 is backed out and the section 7 is shifted along spline 27 to occupy the position of section 5, expelling the latter from the brush. A fresh replacement section is then inserted from the opposite side of the brush and the screw 35 again tightened. As shown in Fig. 2 the bristles 17 at the toe portion are longer than the bristles 18 of the heel sections which have correspondingly thicker bristle blocks to bring the ends of both sets of tufts to the same level. When the bristles 17 are worn the brush is removed from the dabbing motion the sections 5, 7 removed and the bristles 17 trimmed level so as to leave a definitely known length of bristle. Replacement sections are then installed in the heel portion having blocks of such thickness as to bring the ends of the bristles at the heel portion level with the ends of those at the toe portion, thus attaining the desired flat face of the brush without the need for retrimming its entire area. It is found convenient to remove a definite fraction, e.g. # in. by trimming of the bristles at the toe end so that a stock of replacement sections 5, 7 having blocks varying in thickness by # in. are kept for insertion in the brush after the retrimming operation. The bristles at the toe end may be made of horsehair while the remainder may be composed wholly of Chinese hog bristles.