Snowmobile frame

Claim 2

In a snowmobile having a forward portion substantially supported by steerable ski means attached to said forward portion, a rear portion having a seat and being supported by a suspension system including a ground-engaging endless drive tread and a forwardly located engine compartment, an improvement in a body frame comprising: a pair of spaced-apart elongated side panels, each side panel extending longitudinally in a single plane along the rear portion of said snowmobile and along the forward portion thereof to a point approximately in line with the attachment of said ski means to said forward portion, each of said side panels including a stiffening member arounD the periphery thereof, a transverse panel extending laterally between said side panels, said transverse panel having a rearward portion disposed between rear portions of said side panels for supporting said seat and having a forward portion for separating said engine compartment from said drive tread area while forming the bottom of said engine compartment, and a drive clutch assembly operatively mounted directly on one of said side panels.

Claim 3

The apparatus of claim 1 wherein each of said stiffening members is tubular.

Claim 4

The apparatus of claim 1 wherein the planes defined by the side panels are in parallel relationship to each other.

Claim 5

The apparatus of claim 1 including a transverse front support extending laterally between the front ends of said side panels and laterally outwardly beyond said side panels to accommodate means for securing said ski means to said frame.

Claim 6

In a snowmobile having a forward portion substantially supported by steerable ski means attached to said forward portion, a rear portion having a seat and being supported by a suspension system including a groundengaging endless drive tread and an engine mounted within a forwardly located engine compartment, an improvement in a body frame comprising: a pair of spaced-apart elongated side panels, each side panel extending longitudinally in a single plane along the rear portion of said snowmobile and along the forward portion thereof to a point approximately in line with the attachment of said ski means to said forward portion and a transverse panel extending laterally between said side panels, said transverse panel having a rearward portion disposed between rear portions of said side panels and supporting said seat and a forward portion separating said engine compartment from said drive tread area and forming the bottom of said engine compartment; a transverse front support extending laterally between and beyond the front ends of said side panels; and an engine having a drive shaft mounted within said engine compartment, said drive shaft being journaled in bearing means directly on said side panels, thereby allowing said side panels to act as a heat sink for engine heat.

Claim 7

In a snowmobile having a forward portion substantially supported by steerable ski means attached to said forward portion, a rear portion having a seat and being supported by a suspension system including a groundengaging endless drive tread and an engine mounted within a forwardly located engine compartment, an improvement in a body frame comprising: a pair of spaced-apart elongated side panels, each side panel extending longitudinally in a single plane along the rear portion of said snowmobile and along the forward portion thereof to a point approximately in line with the attachment of said ski means to said forward portion and a transverse panel extending laterally between said side panels, said transverse panel having a rearward portion disposed between rear portions of said side panels and supporting said seat and a forward portion separating said engine compartment from said drive tread area and forming the bottom of said engine compartment; a transverse front support extending laterally between and beyond the front ends of said side panels; and an engine having a drive shaft mounted within said engine compartment, said drive shaft being journaled in bearing means directly on said side panels, thereby allowing said side panels to act as a heat sink for engine heat.

Claim 8

The apparatus of claim 1 wherein said drive clutch assembly includes a drive clutch, a driven clutch and a chain case, each of which is mounted through bearing means directly on said one of said side panels.

Claim 9

In a snowmobile having a forward portion substantially supported by steerable ski means attached to said forward portion, a rear portion having a seat and being supported by a suspension system including a ground-engaging endless drive tread and a forwardly located engine compartment, an improvement in a body frame comprising: a pair of spaced-apart elongated side panels, each side panel extending longitudinally in a single plane along the rear portion of said snowmobile and along the forward portion thereof to a point approximately in line with the attachment of said ski means to said forward portion, each of said side panels including a stiffening member around the periphery thereof, and a drive clutch, a driven clutch, and a chain case, each of which is mounted through bearing members directly on one of said side panels.

Claim 10

In a snowmobile having a forward portion substantially supported by steerable ski means attached to said forward portion, a rear portion having a seat and being supported by a suspension system including a ground-engaging endless drive tread and a forwardly located engine compartment, an improvement in a body frame comprising: a pair of spaced-apart elongated side panels, each side panel extending longitudinally in a single plane along the rear portion of said snowmobile and along the forward portion thereof to a point approximately in line with the attachment of said ski means to said forward portion, each of said side panels including a stiffening member around the periphery thereof, and a drive clutch, a driven clutch, and a chain case, each of which is mounted through bearing members directly on one of said side panels.