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).
Patent situation and design considerations for shock dampers.
Identifier | ExFiles\Box 28\1\ Scan186 | |
Date | 6th January 1931 | |
X832 DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer}) FROM R.{Sir Henry Royce} HS.{Lord Ernest Hives - Chair} } (At Le CanadelHenry Royce's French residence.) R1/M6.1.31. X.235. X.832. SHOCK DAMPERS. THE PATENT SITUATION. ETC. C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} C. to Mr. CLAREMONT. (1) It would seem that we ought to have been able to control the patents for the double acting type of damper by covering the idea of forced transfer of the oil to the other chamber through the spring controlled release valve, and the combination of replacement valves combined with the spring loaded (transfer) valves - i.e. double acting. (2) When we took this work up again after about 20 yrs. there was nothing being done as far as I know except the type (Houdaille) depending upon restriction transfer passages - i.e. depending on viscosity and dynamic resistance of the passage, and the single acting hydraulic with relief valve into reservoir. (3) Our early attempts were not successful because we discharged through our spring loaded valves into a common reservoir, but I am not sure about my memory. I believe this was the chief cause of failure to retain the oil, and if so, the change equivalent to passing through the piston was important. (4) Anyway Mr. Bailey will see now we stand with reference to the Lovejoy patent as they seem to have taken up some of the valuable ground, because from HS{Lord Ernest Hives - Chair}'s report they have cut the piston in to two and pulled the two halves together by spring loaded bolts, exactly as what we were designing at WW. in December last. (5) So that as far as I can see we are driven away from this type to the double vertical which has two other advantages: (a) Central bearing is always loaded upwards. (b) The vertical pistons naturally allow the air to escape first - i.e. any leakage past these pistons acts as air release. We saw this on the single vertical Phantom 2. front ones, but did not think it was so valuable until HS{Lord Ernest Hives - Chair}/RM.{William Robotham - Chief Engineer} tested and found it made the most efficient type. (6) The design sent to Derby at Xmas is of this type, and has two or three features which we think are patentable. They are: (A) The single valve which acts both ways and can be designed for any ratio of pressure, therefore saving a second valve, passages, spring, etc. (B) The method of controlling the spring pressure on this valve and so controlling the damping from the driver's seat. This is made much more possible because of (A) only one by-pass valve. It will be noted that as the piston leakages allow the air to escape we conclude that no valve controlled | ||