Abstract: A damping device operable to change a suspension characteristic of a vehicle in response to changes in a relative relationship between the piston and the cylinder of the damping device. The damping device comprising a pressure cylinder forming a working chamber operable to store damping fluid. A piston is disposed within the pressure cylinder defining an upper and lower portion of the working chamber. The damping device further comprises a transducer for emitting and receiving sound waves within the lower portion of the working chamber. The sound waves emitted by said transducer are reflected by the end surface of the cylinder or a base valve mounted at the end of the cylinder and are received by said transducer. A timing circuit determines the difference in time between the emitted and reflected sound waves and generates an output in response thereto.

Abstract: A hydraulic shock absorber is formed as a sealed assembly and subsequently, at a desired time, an opening is non-contaminantly pierced in the outer shell and the shock absorber is pressurized by passing a pressurized fluid through the opening and the opening is then non-contaminantly sealed with a metal ball by welding to make the hydraulic shock absorber permanently gas pressurized. The shock absorber assembly, the method of making it and the apparatus for making it are disclosed in this specification.

Abstract: A hydraulic shock absorber is formed as a sealed assembly and subsequently, at a desired time, an opening is non-contaminantly pierced in the outer shell and the shock absorber is pressurized by passing a pressurized fluid through the opening and the opening is then non-contaminantly sealed with a metal ball by welding to make the hydraulic shock absorber permanently gas pressurized. The shock absorber assembly, the method of making it and the apparatus for making it are disclosed in this specification.

Abstract: A snow vehicle suspension system including a pair of suspension struts associated one with each of the two steerable skis of the vehicle; each of the struts including a first generally tubular shaped housing fixably secured to the underside of the vehicle above the associated of the skis, a second generally tubular housing telescopically disposed within the first housing and connected at the lower end thereof to the associated ski, shock absorbing means within the second housing and including a reciprocable piston mounted on one end of a piston rod extending axially outwardly from the upper end of the first housing, the upper end of the piston rod being secured to a portion of the vehicle above the strut and having a helical coil spring extending coaxially thereof between the upper end of the strut and the aforesaid vehicle portion, a steering arm having a first portion operatively connected to the vehicle steering mechanism and a second portion rotatable about the longitudinal axis of the strut, with a secon

Abstract: An oil filter is disclosed as having a filter enclosure provided with oil inlet and outlet ports adapted for communication with the oil circulating system of an associated oil lubricated engine. Disposed within the enclosure is a filter element fabricated of any suitable filtering media. In addition to the filter element, a body of an oil soluble, relatively solid polymer having oil additives compounded therein is disposed within the enclosure. The polymer body is located within the enclosure so as to be in an area where minimum oil flow occurs, i.e. in a relatively non-turbulent oil flow area, which results in the polymer dissolving at a relatively uniform or linear rate so as to prevent undesirable concentrations of the additives during the effective service life of the filter.

Abstract: A snow vehicle suspension system including a pair of suspension struts associated one with each of the two steerable skis of the vehicle; each of the struts including a first generally tubular shaped housing fixably secured to the underside of the vehicle above the associated of the skis, a second generally tubular housing telescopically disposed within the first housing and connected at the lower end thereof to the associated ski, shock absorbing means within the second housing and including a reciprocable piston mounted on one end of a piston rod extending axially outwardly from the upper end of the first housing, the upper end of the piston rod being secured to a portion of the vehicle above the strut and having a helical coil spring extending coaxially thereof between the upper end of the strut and the aforesaid vehicle portion, a steering arm having a first portion operatively connected to the vehicle steering mechanism and a second portion rotatable about the longitudinal axis of the strut, with a secon