| US 7,540,480 B2 | ||
| Hydraulic shock absorber | ||
| Seiji Sawai, Shizuoka (Japan); and Yutaka Yamazaki, Shizuoka (Japan) | ||
| Assigned to Yamaha Hatsudoki Kabushiki Kaisha, Shizuoka (Japan) | ||
| Filed on Mar. 11, 2008, as Appl. No. 12/45,817. | ||
| Claims priority of application No. 2007-061559 (JP), filed on Mar. 12, 2007. | ||
| Prior Publication US 2008/0223673 A1, Sep. 18, 2008 | ||
| Int. Cl. F16F 9/06 (2006.01) | ||
| U.S. Cl. 267—221 [267/34] | 4 Claims |
| 1. A hydraulic shock absorber comprising:
a cylinder tube arranged to be connected to a first portion of a shock absorbing body;
a piston slidably fitted in the cylinder tube in an axial direction thereof to divide the cylinder tube into first and second
oil chambers;
a main piston rod extending from the piston to the outside of the first oil chamber through the first oil chamber, the main
piston rod having an extension end arranged to be connected to a second portion of the shock absorbing body;
a sub piston rod extending from the piston, the sub piston rod including an extension end extending to the outside of the
second oil chamber through the second oil chamber;
an oil chamber pressurizing device arranged to pressurize a hydraulic oil in the first and second oil chambers; and
a damping force generator arranged to generate a damping force by allowing the hydraulic oil to flow between the first and
second oil chambers; wherein
a sealed space containing the extension end of the sub piston rod includes a gas within the sealed space having a pressure
larger than atmospheric pressure and smaller than a pressure applied on the hydraulic oil by the oil chamber pressurizing
device.
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