and has for its object to improve the construction of such class of brush SO as to cheapen the cost of production.
"According to this invention, a sweeping broom or brush having long bristles, comprises a wood stock or head, a recess formed in the face of the stock SO as to provide a wall or flange integral with the stock or head around the edge of the stock, arranging the bristles, hairs, fibres or mixture with their roots or thick ends at one end, and securing the roots or thick ends of the bristles, hairs, fibres or mixture within the recess by cement, rubber or like filling the recess. The bristles, hairs, fibres, or mixtures may be formed in separate tufts or not as desired, and a perforated plate or gauze may be provided to cover the cement through which the bristles, hairs or fibres or mixture project ".
S.A. Brush Co. Ltd., having been threatened by Samuel Taylor Pty. Ltd. with legal proceedings in respect of an alleged infringement by it of patent No. 106694 by the manufacture and distribution of
"pure bristle plastic set broom ", commenced an action in the Supreme Court of South Australia against Samuel Taylor Pty. Ltd., in which it alleged groundless threats of legal proceedings within the meaning of S, 91A of the Patents Act 1903-1946. The defendant counterclaimed, alleging infringement of the patent by the plaintiff. The plaintiff, in reply, alleged that the patent was invalid on the following grounds: (1) that the alleged invention was not a manner of new manufacture, (2) that the alleged invention was not new at the date of the letters patent, (3) that the alleged invention was not useful or, alternatively, not any improvement on prior methods, (4) that the alleged invention was obvious and did not involve any inventive step, and (5) that the specification was insufficient to enable the alleged invention properly to be carried into effect.
The evidence accepted by the trial judge established that long bristles had always been used for sweeping brooms, that brooms had for many years been made with wood stocks, that in the case of toilet brushes and clothes brushes the practice of forming a recess in the wooden body of the brush was well known, that long bristles were always supplied to broom manufacturers with their roots or thick ends together, and that for some years before the grant of the patent hair brushes and clothes brushes had been made with the bristles or hairs held in position by cement in a recess formed in the body of the brush. But, until the defendant in Australia, and its assignor in England, produced a broom known in Australia as the "Dustmaster", no one had made a long- bristled broom with the bristles held in position in a recess by cement, either in tufts (as in the Dustmaster ") or in lines. The