MOTORING NOTES

Nelson Evening Mail, Volume LXVI, 18 June 1932, Page 3

MOTORING NOTES

REVOLVING WINDSCREEN “WIZARD” SMITH’S DEVICE DETAILS OF CONSTRUCTION The details of and the experiments carried out in perfecting the revolving windscreen invented by Messrs 11. Nattrass and W. Dailey, and fitted to the Fred H. Stewart Enterprise, were explained by Mr Nattrass during tlie week-end.

The screen is made, of triplex glass, and is 10in in diameter, being contained in a specially constructed ring gear, which, in turn, is mounted on ball bearings running in a stationary hardened steel housing, which is attached to the cowling. It thus protects tlie driver and follows the stream line. In this way it was possible to eliminate some of tho resistance which the square screen caused.

The drive is through a flexible shaft similar to that used for driving a portable grinder. One end is connected to the electric motor, mounted in the chassis, and the other lias attached to it a suitably geared driving wheel, mounted on ball hearings and also geared to tho main largo geared wheel. Tho glass is cemented to the inner circle of tlie ring gear, and in addition is held by a flange and screws. The glass revolves at a slant of about 80 degrees. Before the Enterprise left Mr Nat trass’ workshop in Auckland, duration tests were carried out, a special battery being used for 30 minutes on end. The battery developed half a horsepower, and drove the screen at 500 revolutions per minute. After half an hour’s running the windscreen revolutions were still the same, and the battery efficiency was only down 20 amps of its total capacity. An extra battery was fitted to the racing ear, however, so that the driver could increase the voltage and raise the revolutions, should the need arise from wind resistance, which might cause tlie screen to run slower. A pressure weight of 2001 b per square inch, calculated to equal the wind pressure when running at 300 miles an hour* was fried, and, despite tlie pressure, tho motor continued to drive the screen at 500 revolutions. That tlie device is a success was demonstrated at the beach, when, although running in very wet sand, Mr Smith had perfect vision on his short run.