From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
News release from International Technical Developments Ltd. about the H-C Vapour-Proof Switch.
| Identifier | ExFiles\Box 168a\2\ img360 | |
| Date | 1st October 1937 | |
| INTERNATIONAL TECHNICAL DEVELOPMENTS LTD. "I. T. D.{John DeLooze - Company Secretary}" TELEPHONE: VICTORIA 4640. TELEGRAMS: INTRATEC, SOWEST, LONDON. CABLES: INTRATEC. CODE: ABC & BENTLEYS. RESEARCH LABORATORIES: WRAYSBURY, BUCKS. THAMES HOUSE, MILLBANK LONDON S.W.1 CHAIRMAN: NORMAN S. HUNT, F.C.A. TECHNICAL DIRECTOR: H.{Arthur M. Hanbury - Head Complaints} DE LASZLO, M.A., PH.D. MANAGING DIRECTOR: R.{Sir Henry Royce} A.{Mr Adams} SAVILLE SNEATH. Handwritten: Switches Gear 6139 ATTENTION OF THE TECHNICAL DIRECTOR Rolls-Royce Limited Nightingale Road, DERBY. OCTOBER 1937 NEWS RELEASE NO. H.1 THE H-C VAPOUR-PROOF SWITCH IF ADDITIONAL COPIES ARE REQUIRED PLEASE RETURN TEAR OFF SLIP. AN IMPORTANT IMPROVEMENT IN SNAP-ACTION PRECISION SWITCHES The H-C Vapour-proof Switch is an interesting little device which will be welcomed by designers of electrical equipment and control gear. It should find valuable applications in almost every industry, for example - limiting and safety switches; gauging and counting devices; pressure, thermostatic and liquid level controls. It is equally useful for relays, governors, time-lag mechanisms and other industrial and laboratory equipment. It consists of a thin beryllium bronze diaphragm cemented and sandwiched between two hollow bakelite mouldings, the bottom part of which has no exit and is therefore gas tight and contains the actual electrical contacts. The overall size is 1 5/8" by 1" by 1". A bakelite plunger projects out of the top half and displaces the diaphragm from one equilibrium condition to another by a movement of 2/1000" with a clean snap-action, on the oil-can principle, causing contact to be made through the large silver-faced copper surfaces in the sealed off lower chamber. Oil, moisture and dust cannot reach the contacts which are consequently preserved from corrosion and deterioration. Other valuable features are the light operating load and small precision movement required. The H-C Switch is unaffected by vibration, can be mounted at any angle and may be operated above the boiling point of water without damage. OPERATING CHARACTERISTICS A net load of 2 ounces and a movement of only 2/1000" is required to make or break the contacts after a starting load of 10 ounces has been applied. The usual method of mounting the switch is to fix it in a metal clamp, pivoted at one end and placed against a spring at the other so that its position may be varied by an adjusting screw with respect to the movement applied to it. Switches adjusted for loads and movements other than those mentioned can be supplied for special operating conditions. | ||