GB976255A - Improvements relating to the manufacture of brushes - Google Patents

Abstract

976,255. Moulding brushes, combs &c. E. DENT, and J. VALLIS, [trading as VALDEN CO.]. May 28, 1962 [April 17, 1962], No. 20463/62. Heading B5A. Brushes, combs &c. are injection moulded in a mould having a series of grooved die plates which co-operate during the moulding operation to define closed bristle forming cavities, but which may be subsequently separated to facilitate easy removal of the moulded bristles therefrom. In an embodiment shown in Fig. 1 the mould comprises a base member 19, side walls 18 and a stack of die plates 10 each having a uniformly thick portion, a tapered portion, and bristle forming grooves 11. Prior to moulding the untapered ends of the die plates are clamped together by bolts 13, 13a passing through holes 10d, whilst the upper ends of the plates are separated by a gap 12 by virtue of their taper. During the moulding a member 22 is lowered so as to deform the plates in the direction indicated by the arrows 23, this forcing the plates together to form closed mould cavities. Upon removal of the member 22 the plates elastically reassume their original open position thus facilitating easy removal of the brush from the mould. In a modification, Fig. 6 (not shown), the die plates may be deformed by the side walls of the mould which are adapted to be movable. In a further modification as in Fig. 7 the die plates 410 are unstrained during the moulding operation and are subsequently strained to an open position by pressure from the curved member 423.