Abstract: A structural panel such as a door for a railway freight car has a lightweight core formed by two sheets of low density material e.g. balsa wood. Each sheet has bonded to one side a series of layers of glass fibre, and the sheets are bonded together in confronting relationship to form the panel. The glass fibre layers extend around the edges of the panel which edges are further reinforced by a channel-shaped plastics edging member.

Abstract: An adjustable flooring structure for swimming pools is formed by a series of large, flat, panel-like modules interconnected to form a floor. The structure includes ballasting means formed by serially connected pipes in the modules which pipes can be filled with water or air to alter the buoyancy of the structure as desired. The structure is supported from the pool floor on adjustable legs and without the legs has a low overall height so that it can be settled to the bottom of the pool when not required for use.

Abstract: A safety control system for a snowmobile engine provides a switch which senses the position of the carburetor control element, and a second switch which responds to the presence of the operator's hand on the throttle lever. The switches operate to short-circuit the ignition coil of the engine in the event of a malfunction so that, if the carburetor throttle remains stuck open after the pressure on the throttle lever has been momentarily released, the engine will be killed.

Abstract: In snowmobiles operating under wet snow conditions, compaction of the snow between the upper and lower runs of the snowmobile track may cause undue friction eventually resulting in stalling of the snowmobile. This invention provides a series of projecting ribs on the internal surface of the snowmobile track, the ribs being constructed and arranged to sweep the region between the suspension elements of the snowmobile thereby inhibiting the build up of snow.

Abstract: A vehicle windshield, for example for a snowmobile, comprises a contoured sheet of transparent plastics material having upper and lateral edges strengthened by the marginal areas thereof being sharply curved in the forward direction. Thus the edge of the windshield presented toward the vehicle operator is smoothly rounded and is less likely to cause injury.

Abstract: A light weight trail groomer is supported at its rear end on each side by a pair of longitudinally aligned skis connected to respective arms of a bracket pivotally mounted on a main frame element. The frame structure is arranged for connection at its forward end to a towing vehicle and includes a scraper blade structure the height of which can be adjusted by independent adjuster means connected between an auxiliary frame structure and each one of the main frame elements.

Abstract: In snowmobile tracks of the endless, internally driven type, high friction because of direct contact between the track and the slide elements of the slide suspension system caused deterioration and subsequent failure of the track. This invention provides a staple cleat installed in the track and positioned so as to provide a sliding interface between the track and the slide element whereby the otherwise destructive friction build-up is considerably reduced.

Abstract: A snowmobile windshield comprises a moulded sheet of transparent polycarbonate material having a series of mounting tabs spaced along its lower edge. The mounting tabs are of resilient form, being integral with the windshield and generally flat, but having laterally extending parts which can be compressed together to allow the tab to pass into engagement with a narrow mounting slot in the cab of the snowmobile. The windshield can be installed without requiring access to the underside of the snowmobile cab, and in accident conditions can yield by releasing the tabs from their mounting slots, thereby reducing the likelihood of facial injuries to the snowmobile driver.

Abstract: A disc brake suitable for use in a snowmobile has a pair of friction pads associated with respective limbs of a U-shaped caliper. One of the friction pads is actuated through a mechanical linkage, and includes a ratchet-and-pawl operated automatic adjuster. The brake caliper is floatingly attached to a mounting plate to permit accomodation of the positions of the friction pads with respect to the disc.

Abstract: An air intake silencer for an internal combustion engine of the two-stroke cycle type, for example a snowmobile engine, comprising a housing for connection to the intake side of the engine carburetor, and a filter chamber and resonance chamber defined within the housing to filter out engine noise in high and low frequency ranges. An intake duct of smooth uninterrupted tubular configuration extends in an axial direction through the housing and has a perforate tube section through which the incoming air is smoothly distributed to the filter chamber. The resonance chamber is separated from the filter chamber by means of a perforated baffle plate, the dimensions and volume of the chambers being selected to correspond to the frequency ranges of the noises to be eliminated.

Abstract: In a snowmobile suspension system, it is known to provide suspension system adjustment with an eye bolt-nut combination which provides an increase or decrease in tension in a torsion spring which acts on a suspension arm of the suspension system. This invention replaces the eye bolt-nut combination with a rotatably mounted cam having surface portions in the form of channels arranged at different distances from its axis. A lateral arm of the torsion spring is accommodated within these channels and upon rotation of the cam, torsion spring tension is increased or decreased which provides the necessary stiffness to the suspension system.

Abstract: In a rotary clutch for a snowmobile comprising a movable pulley flange which carries pivotally mounted flyweights operable on rotation of the clutch to effect axial displacement of the movable flange towards a fixed pulley flange, the pivot shafts for the flyweights have previously been retained in mounting lugs on the movable flange by cotter pins or the like. Improper maintenance of such clutches has on occasion led to unorthodox methods of retaining the pivot shafts, such as the use of wire instead of cotter pins, or the replacement of the pivot shaft by a nut and bolt thereby causing severe unbalance in the clutch. To obviate this problem, the pivot shafts are now designed to be retained solely by abutment means formed integrally with the bell housing which attaches to the rear side of the movable flange.