ew Principle in Telescopic Damper I N a conventional telescopic
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damper. there is a compressible medium in the system to allow for the extra volume of the piston rod as it enters the working chamber on the down-stroke of the piston.
In a new design of damper known as the Telaflo, air is employed to provide this medium, but a new method of controlling the air has been devised. At the lower end of the working chamber there is a synthetic-rubber ball filled with air at a predetermined pressure. Thus the air is never in contact with the damping medium, which is a solution of synthetic uncured rubber in mineral oil.
Each of the two faces of the damper piston is provided with a spring flap valve covering bleed holes formed in the piston, the degree of damping being governed by the area of these bleed holes. The function of the syntheticrubber ball is to compensate for the extra volume represented by the piston rod as it descends into the damper cylinder.
When the rod descends its extra volume forces an equal amount of resistance medium from the working chamber of the damper into the spherical chamber containing the synthetic-rubber ball which compresses under the extra pressure. On the up-stroke of the piston, the ball re-asserts itself and the resistance medium passes back into the working chamber.
The wall thickness of the ball is
about in. and the air pressure inside it is from 7 lb. to 15 lb per sq. in. above atmospheric. Gas can be used
as an alternative to air. It is intended to make the damper in sizes with strokes varying from 3 ins. to 9 ins., buI the bore of the main body wilt probably remain constant at I ins, for all sizes of damper.
An important feature of this type of damper lies in the means provided for making an effective seal between the piston rod and its gland. This has been given special attention, the ingenious seal employed improving in efficiency as the demands made upon it increase.
The present design of Telaflo damper is intended for use an private ears, but the principle is. equally applicable to heavier units, Which will, irr•due dourse, he put into production.-"The, maker-is Universal Dampers, Ltd., -Cranmore Boulevard, Shirley, Birmingham.