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).
Article from 'The Autocar' reviewing various permanently fitted and detachable jacking systems for motor cars.
| Identifier | ExFiles\Box 139\2\ scan0063 | |
| Date | 9th March 1934 | |
| March 9th, 1934. The Autocar. 385 Jacking Made Easy popular makes. The Stevenson system is used to quite an extent on the Continent, not necessarily in its exact English form, and is standard equipment on certain models of Humber, Triumph, Mercédès - Benz, Steyr, B.M.W., D.K.W., Adler, Horch and Wanderer. A jacking system which has been on the market for some years is the Guna, which is of German manufacture and handled in this country by Edward G.{Mr Griffiths - Chief Accountant / Mr Gnapp} Annely and Co., Ltd., 4 and 5, Silk Street, Milton Street, London, E.C.2. Four jacks are used and are operated on much the same principle as the D.W.S., except that in the case of the Guna the extensions from the jack involve universal joints and are fixed to the end of the springs. Then, instead of a handle to wind the jacks down, a wheel brace is used. A complete set costs 5 guineas, and a large and a small size are made. The Marchal system does not actually use a permanently fitted jack, but deserves mention here in that it is specially designed to aid in jacking up low-built cars. Slides are carried permanently below the springs, and a special type of jack is inserted into them. A wheel brace is used to wind down the jack. The English concessionaire for the Marchal jack is C. Desiderio, of 143, Whitfield Street, London, W.1, and the price of the fittings is £4 4s. As a matter of fact, taking the matter strictly, the only "permanently fitted jacks" are the D.W.S., the Jackall, and the Guna, because the Oto, the Stevenson, and the Marchal all use jacks which are detachable and are carried separately with the tools. The half-dozen systems I have just described can all be purchased for fitting to your car, but there remain other jacking systems for which manufacturing negotiations are not complete. For instance, there is the Autojack, an interesting hydraulically operated system, also the A.R. system, which utilises cam-shaped legs on to which the car is reversed, and the Lake and Elliot, a design which has only just been evolved. The Autojack has four telescopic jacks connected by pipes to a distributor valve behind the instrument board. Water, containing a small percentage of oil, is forced under pressure to the distributor and thence to whichever jacks are to be used. Water was found to be the most suitable fluid, and is easily replaced. The pump used is of a special reciprocating type driven off the starter motor. Only sufficient current to run the pump at a correct speed is used, so that the Bendix pinion does not engage with the flywheel. The Autojack is thus entirely automatic and is operated without moving from the car. The designer claims that it takes only nine seconds to jack up the whole car, and I understand that the price of the Autojack will be in the neighbourhood of six guineas when it is placed on the market. The A.R. is a most ingenious system, and quite different from any of those previously described. Four cam-shaped legs are fitted to the axles near each wheel, and these are hinged so that on releasing the cable which holds them up they drop into contact with the road. By reversing the car a few inches the wheel is raised from the ground by reason of the self-energising effect of the cams. This system possesses the advantage of extreme lightness (it weighs only 8 lb. complete), and also simplicity. Obviously it would cost very little to fit, and it is, of course, easily operated without moving from the car. Lastly, there is the Lake and Elliot jack, which has only just been produced by Lake and Elliot, Ltd., of Braintree. Four jacks are used, fitted to the springs, and they are wound down by a wheel brace, although a special handle as also been developed so that, if necessary, the jack can be operated from the side, near the wheel. A wheel can be raised in-thirty seconds. Another point is that the jack closes automatically without depending on springs, and vibration, rather than shaking it down, will tend to make it climb and close tightly. I do not claim that the systems which are described here are the only ones which are marketed at present, as there are certain to be others in existence abroad. One fact emerges, however, and that is that jacking systems have received very little attention as yet in America. Image Captions: Top Left Image: A new design, the Lake and Elliot. Middle Left Image: ANGLE ATTACHMENT, UNIVERSAL JOINT. Bottom Left Image: LOCK, The Guna system has a jack per wheel, each operated by a brace and supplied with a lock. Bottom Right Image: HAND CONTROL, CABLE, RUBBER TREAD, Unorthodox is the cable-operated A.R. with cam-shaped jacks. | ||