Rolls-Royce Archives
         « Prev  Box Series  Next »        

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).
Comparison of Skyhi Jack models No.155 and No.156 for suitability on a 40/50 car.

Identifier  ExFiles\Box 26\3\  Scan040
Date  27th October 1927 guessed
  
contd :-

-2-

The Skyhi Jack, Model No.155 is .2" too high when fully closed and .10" too short when fully extended for use on a 40/50 car with rear axle jacking pads. The conditions under which it fails will probably never be encountered owing to the 1.5" we have added for safety. (Apart from this the figures given represent the lifting of a car from the bare rim to a fully inflated tyre height, a condition which is very rare). This jack then, is suitable for a 40/50 car with rear axle jack pads except under very extreme conditions.

Model No.156 is unsuitable for use under the front axle, its maximum height is too great by 1.35". It can be used however if the car is jacked from under the front springs. Its max. height is greater than model No.155 and it is therefore more suitable for use on a 40/50 chassis with no jacking pads under the rear axle, only falling short of the maximum height required by .250".

The deductions are that model No.156 is the more useful of the two in that it fulfils our requirements (with the exception of the .250" of max. height) both for chassis with and without the jacking pads, the only objection being that it is necessary to jack the front from the front springs.

Both these jacks leak slightly from the glands.

Hs{Lord Ernest Hives - Chair}/A.J.Lidsey.
  
  


Copyright Sustain 2025, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙