Brake Squeal i n Buses Cured
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A CURE for brake-drum squeal has .1-1 been devised after thorough experiments by Manchester Transport Department. Mr. T. Lees. chief mechanical engineer, has applied for patent rights. Mr. A. F. Neal. general manager, has taken a peat interest in the project.
The mechanism was demonstrated 'in Manchester, last week. and the results were completely convincing. Members of a party were taken out in a doubledecker which was used in the normal Manner, making halts at all the service stops, after which a series of emergency brake applications was carried out. :Throughout this demonstration there was not a' suspicion of squeal, whistle, or any similar noise emanating from the drums. The party then returned to the garage, where the anti-squeal devices were removed and it was shown how severely the brakes on this particular vehicle squealed in their normal state-,
As atmospheric conditions have ah undoubted effect on brake squeal, the device has been tested on the vehiclet of other corporations, including those of a south coast undertaking which has experienced particularly severe trouble of this kind.
Alongside the experiments by the corporation, and in conjunction with them. a scientific investigation on the same subject was being carried out by Small and Parkes, Ltd., under the guidance of the company's technical manager, Mr. Ivan Waller.
The best approach to the problem, concluded the scientists, was to damp of de-tune the resonator, rather than to attempt to deal with the sliding surface the volume of noise is traced to vibrit tion on the brake drum.
In Mr. Lees's device this movernent is prevented by eight steel springs, which are attached to the drum by a clamping band and bear against the rim of the road wheel. Whilst not of sufficient strength to cause distortion in the drum. the springs are stiff enough to damp out the vibration which is the cause of the trouble. About 50 buses have been thus equipped in Manchester and work is proceeding with others.
Sale of the anti-squeal fitting will be controlled by Transport Improvements. Ltd., IA-1B, Church Street. Didsbury. Manchester, 20, one of the directors of which is Mr. Eric Loram, who is also transport sales manager of Small and Parkes, Ltd.