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 two suggested braking systems from Lockheeds, detailing specifications and pricing against a Girling system.

Identifier  ExFiles\Box 121\1\  scan0296
Date  24th June 1940 guessed
  
-2-

Lockheeds suggest 2 systems.

1. Twin 3/4" dia. master cylinders. This was suggested owing to the fact that they said they had no Tandem Cylinder large enough. Details were as follows:

Pedal leverage - 8.5
Pedal ratios - Front 34 ) P/R = 1.37
Rear 24.9
Total 58.9

Self-wrapping Coeff: 2.66 for - = 0.4
Giving total ratio : 156.5

This scheme is inconvenient due to the lack of chassis space on the Ripplette, and so Lockheeds supplied details of a layout as used on Vauxhalls, using a:

2. 1" dia. Tandem master cylinder. The layout gave the same line pressure for a slightly lower overall pedal ratio. Particulars are:

Pedal leverage - 5.8
Pedal ratios - Front 32.3) 1.37
Rear 28.9)
Total 61.2

Self-Wrapping Coeff. 2.66 for - = 0.4
Giving total ratio: 163.

The self-wrapping coefficient of 2.66 is very high and somewhere near the limit. Care would have to be taken with the linings.

The fronts have two 3/4" dia. wheel cylinders, while the rears have one 3/4" dia. cylinder with a special unit for the hand-brake, adjustment of the near brakes being thus made on the handbrake mechanism.

With regard to prices, the Girling system would be cheaper than the present R.R. system by the price of the servo motor only, while the Lockheed layout would allow a very large saving due to the elimination not only of the servo, but also of all the rods and levers, the removal of which would allow an appreciable saving in weight.

Continued.
  
  


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