Shock Absorber Designed for Ease of Maintenance
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Ease of Replenishment a Prominent Feature of a Well designed instrument
TT is probably correct to say that the 'average hydraulic shock absorber is, generally speaking, a neglected piece of equipment, This may be due to its being inaccessible or, when this does not apply, it is not always an easy job to replenish it with fluid.
Looked upon as accessories, shock absorbers, as a rule, are treated as such, whereas, if it were more fully appreciated that they form a vital part of the suspension system, more importance might be attached to their regular and correct servicing. As shock-absorber specialists, Newton and Bennett, Ltd., Valetta Road, Acton, London, W.3, has devoted considerable attention to those features in shock-absorber design which, from experience, it has found to be the main reasons for their not receiving correct servicing which, in turn, leads to excessive wear and ultimate failure.
Such points as protection from the ingress of foreign matter, easy refilling and adjustment and the sealing of the absorber against leakage of the fluid have been carefully studied and are embodied in the new C2 type absorber, a sectional drawing of which is reproduced herewith.
Its principle of functioning is that of the displacement of a fluid in a cylinder, such displacement being unobstructed in one direction, with a predetermined degree of restriction on spring rebound. Reference to the drawing will show that considerable attention has been paid to the sealing of the piston rod, and that double "
dust" covers provide a maximum of protection against the ingress of foreign matter.
Whilst no running adjustment is necessary, or desirable, the instrument can be regulated, instantly, by compressing the main inner and outer components until the adjusting tongues, shown in the drawing, register with slots in the adjustment screw. The top portion of the absorber is then turned in the desired direction to make the adjustment. Although this is intended for only works use, its ingenuity and simplicity warrant this reference.
Perhaps the most important feature, from. the maintenance viewpoint, lies in the means provided for replenishing with fluid. This is accomplished via a nipple arranged at the top of the absorber, in conjunction with a special pressure gun, the fluid being purchased in refill cans into which the gun, proper, screws direct. By this system, there is no chance of the fluid becoming cOntaminated, or, what is, perhaps, worse, of an incorrect medium being introduced.
When the fluid chamber is full, any excess passes a spring-loaded valve and overflows from a hole in the top of the absorber.