Free piston type auto-tensioner
AssigneeAisin Seiki Kabushiki Kaisha
InventorsYoshio Okabe, Yukimori Kobayashi, Eiji Shirai
Life of this patent
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Abstract
A free piston type auto-tensioner adjusts a tension of an engine timing belt for automobiles. The auto-tensioner includes a body, a plunger slidably disposed in the body to form a first oil chamber, a free piston slidably disposed in the body to form a second oil chamber, a first seal member disposed between the body and the piston, a second seal member disposed between the piston and a rod of the plunger, an oil passage formed in the plunger to establish an oil communication between the first and second oil chambers, a check valve disposed in the oil passage, a first spring biasing the plunger, and a second spring biasing the piston.
Claims7
A free piston type auto-tensioner comprising:
- a body;
- a plunger having a rod and being slidably disposed in said body, said plunger cooperating with said body to form a first oil chamber in said body;
- a free piston slidably disposed in said body and cooperating with said body and said plunger to form a second oil chamber in said body;
- a first seal member disposed between said body and said piston;
- a second seal member disposed for sealing between said piston and said rod of said plunger;
- an oil passage formed in said plunger and comprising means for establishing oil communication between said first and second oil chambers;
- a check valve disposed in said oil passage and comprising means for permitting oil flow only in a direction from said second chamber to said first chamber;
- a first spring comprising means for biasing said plunger in the direction of said second oil chamber;
- and
- a second spring comprising means for biasing said piston in the direction of said second oil chamber.
Dependencies are inferred from the claim text.