Motorcycle shock absorbing rear fork suspension

Claim 2

A motorcycle comprising: a. a main frame having a steering head and a tank rail extending rearward from said steering head; b. a rear fork having a forward end portion pivoted to the rear lower portion of said main frame; c. a fuel tank having an inverted generally U-shaped crosssection and straddling said tank rail; d. a pair of triangular subframes; e. supporting means mounted on said rear fork and connected to the base sides of said pair of triangular subframes; and f. hydraulic shock absorbing means extending along said tank rail so as to be mostly covered with said fuel tank, said shock absorbing means comprising: i. a oil damper comprising a cylinder filled with damping oil and a piston rod telescopically projecting from one end of said cylinder, one of said cylinder and said piston rod being connected to said main frame at a portion a little rearward of said steering head and the other of said cylinder and piston rod being pivotally mounted to the upper portions of said pair of triangular subframes; and ii. a gas tight container, the interior of which is divided by a movable member into two chambers, one of said chambers communicating with the interior of said cylinder and the other chamber being filled with compressed gas exerting pressure on the damping oil, thereby causing said compressed gas to urge said rear fork downward.

Claim 3

A motorcycle as claimed in claim 1 wherein said movable member comprIses a flexible membrane.

Claim 4

A motorcycle as claimed in claim 2 wherein said gas tight container is mounted on the other end of said cylinder.

Claim 5

A motorcycle as claimed in claim 3 wherein said gas tight container is fixed to said cylinder, said one of said cylinder and piston rod comprises said piston rod and said other of said cylinder and piston rod comprises said cylinder.

Claim 6

A motorcycle as claimed in claim 2 wherein said gas tight container is fixed to said cylinder.

Claim 7

A motorcycle as claimed in claim 1 wherein said gas tight container is mounted on the other end of said cylinder.

Claim 8

A motorcycle as claimed in claim 6 wherein said gas tight container is fixed to said cylinder.

Claim 9

A motorcycle as claimed in claim 1 wherein said gas tight container is fixed to said cylinder.

Claim 10

A motorcycle as claimed in claim 1 further including a helical coil spring having ends secured to said main frame and said rear fork respectively, whereby said helical coil spring and compressed gas cooperate to urge said rear fork downward.

Claim 11

A motorcycle as claimed in claim 9 wherein said movable member comprises a flexible membrane.

Claim 12

A motorcycle as claimed in claim 10 wherein said gas tight container is mounted on the other end of said cylinder.

Claim 13

A motorcycle as claimed in claim 11 wherein said gas tight container is fixed to said cylinder, said one of said cylinder and piston rod comprises said piston rod and said other of said cylinder and piston rod comprises said cylinder.

Claim 14

A motorcycle as claimed in claim 9 wherein said gas tight container is mounted on the other end of said cylinder.

Claim 15

A motorcycle as claimed in claim 13 wherein said gas tight container is fixed to said cylinder.

Claim 16

A motorcycle as claimed in claim 9 wherein said helical coil spring is wound around said telescopic oil damper, the ends of said helical coil spring being secured to said cylinder and said piston rod respectively.

Claim 17

A motorcycle as claimed in claim 15 wherein said movable member comprises a flexible membrane.

Claim 18

A motorcycle as claimed in claim 16 wherein said gas tight container is mounted on the other end of said cylinder.

Claim 19

A motorcycle as claimed in claim 17 wherein said gas tight container is fixed to said cylinder, said one of said cylinder and piston rod comprises said piston rod and said other of said cylinder and piston rod comprises said cylinder.

Claim 20

A motorcycle as claimed in claim 15 wherein said gas tight container is mounted on the other end of said cylinder.

Claim 21

A motorcycle as claimed in claim 19 wherein said gas tight container is fixed to said cylinder.

Claim 22

A motorcycle comprising: a. a main frame having a steering head and a tank rail extending rearward from said steering head; b. a rear fork having the forward end portion pivoted to the rear lower portion of said main frame; c. a fuel tank having an inverted generally U-shaped cross-section and straddling said tank rail; d. supporting means mounted on said rear fork including a pair of triangular subframes, the base sides of which are connected to said rear fork and the upper portions of which are joined together by means of a shaft; e. a lug rigidly fixed to said tank rail at a portion a little rearward of said steering head; f. hydraulic shock absorbing means extending along said tank rail so as to be mostly covered with said fuel tank, said shock absorbing means comprising: i. a telescopic oil damper comprising a cylinder filled with damping oil and a piston rod telescopically projecting from one end of said cylinder, one of said cylinder and piston rod being elastically connected to said lug by means of a pair of buffer rubber members disposed on both sides of said lug, and the other of said cylinder and piston rod being pivoted to said shaft of said supporting means; ii. a helical coil spring wound around said telescopic oil damper, the ends of said helical coil spring being secured to said cylinder and piston rod respectively; and iii. a gas tight container mounted on an extreme end of said cylinder, the interior of said container being divided by a flexible membrane into two chambers, one of which communicates with the interior of said cylinder and the other of which is filled with compressed gas exerting pressure on the damping oil in said cylinder, whereby said helical coil spring and compressed gas cooperate to urge said rear fork downward.

Claim 23

A motorcycle comprising: a. a main frame having a steering head and a tank rail extending rearward from said steering head; b. a rear fork having the forward end portion pivoted to the rear lower portion of said main frame; c. a fuel tank having an inverted generally U-shaped cross-section and straddling said tank rail; d. supporting means mounted on said rear fork including a pair of triangular subframes, the base sides of which are connected to said rear fork and the upper portions of which are joined together by means of a shaft; e. a lug rigidly fixed to said tank rail at a portion a little rearward of said steering head; f. hydraulic shock absorbing means extending along said tank rail so as to be mostly covered with said fuel tank, said shock absorbing means comprising: i. a telescopic oil damper comprising a cylinder filled with damping oil and a piston rod telescopically projecting from one end of said cylinder, one of said cylinder and piston rod being elastically connected to said lug by means of a pair of buffer rubber members disposed on both sides of said lug, and the other of said cylinder and piston rod being pivoted to said shaft of said supporting means; ii. a helical coil spring wound around said telescopic oil damper, the ends of said helical coil spring being secured to said cylinder and piston rod respectively; and iii. a gas tight container mounted on an extreme end of said cylinder, the interior of said container being divided by a flexible membrane into two chambers, one of which communicates with the interior of said cylinder and the other of which is filled with compressed gas exerting pressure on the damping oil in said cylinder, whereby said helical coil spring and compressed gas cooperate to urge said rear fork downward.

Claim 24

A motorcycle comprising: a. a main frame having a steering head and a tank rail extending rearward from said steering head; b. a rear fork having the forward end portion pivoted to the rear lower portion of said main frame; c. a fuel tank having an inverted generally U-shaped cross-section and straddling said tank rail; d. supporting means mounted on said rear fork including a pair of triangular subframes, the base sides of which are connected to said rear fork and the upper portions of which are joined together by means of a shaft; e. a lug rigidly fixed to said tank rail at a portion a little rearward of said steering head; and f. rod-shaped telescopic hydraulic shock absorber means extending along said tank rail so as to be mostly covered with said fuel tank, said shock absorbing means comprising: i. a telescopic oil damper having a cylinder filled with damping oil and a piston rod projecting from one end of said cylinder, the forward end of said piston rod being elastically connected to said lug by means of a pair of buffer rubber members disposed on both sides of said lug, and the rear end of said cylinder being pivoted to said shaft of said supporting means; ii. a helical coil spring wound around said telescopic oil damper, the ends of said helical coil spring being secured to said cylinder and piston rod respectively; and iii. a gas tight container mounted on the rear end of said cylinder, the interior of said container being divided by a flexible membrane into two chambers, one of which communicates with the interior of said cylinder and the other of which is filled with compressed gas exerting pressure to the damping oil in said cylinder, whereby said helical coil spring and compressed gas cooperate to urge said rear fork downward.

Claim 25

A motorcycle comprising: a. a main frame having a steering head and a tank rail extending rearward from said steering head; b. a rear fork having the forward end portion pivoted to the rear lower portion of said main frame; c. a fuel tank having an inverted generally U-shaped cross-section and straddling said tank rail; d. supporting means mounted on said rear fork including a pair of triangular subframes, the base sides of which are connected to said rear fork and the upper portions of which are joined together by means of a shaft; e. a lug rigidly fixed to said tank rail at a portion a little rearward of said steering head; and f. rod-shaped telescopic hydraulic shock absorber means extending along said tank rail so as to be mostly covered with said fuel tank, said shock absorbing means comprising: i. a telescopic oil damper having a cylinder filled with damping oil and a piston rod projecting from one end of said cylinder, the forward end of said piston rod being elastically connected to said lug by means of a pair of buffer rubber members disposed on both sides of said lug, and the rear end of said cylinder being pivoted to said shaft of said supporting means; ii. a helical coil spring wound around said telescopic oil damper, the ends of said helical coil spring being secured to said cylinder and piston rod respectively; and iii. a gas tight container mounted on the rear end of said cylinder, the interior of said container being divided by a flexible membrane into two chambers, one of which communicates with the interior of said cylinder and the other of which is filled with compressed gas exerting pressure to the damping oil in said cylinder, whereby said helical coil spring and compressed gas cooperate to urge said rear fork downward.