Patent ID: 9046153
Filing Date: 2015-06-02
Classification: F16H

Abstract:
1. A ratchet-type tensioner, comprising: a housing body provided with an oil supplying passage of external pressure oil; a plunger accommodating hole formed in the housing body; a plunger that projects slidably out of the plunger accommodating hole in a projecting direction; a high-pressure oil chamber formed between the plunger accommodating hole of the housing body and a hollow portion of the plunger; a plunger biasing spring accommodated within the high-pressure oil chamber and biasing the plunger in said projecting direction; a columnar ratchet element fittingly inserted in a cylindrical ratchet accommodating hole formed in the housing body and sliding in a direction orthogonal to an advance/retract direction of the plunger; a ratchet biasing spring that biases the ratchet element such that ratchet teeth provided in a plunger-side edge region of the ratchet element engage with rack teeth engraved on a side surface of the plunger; and a spring anchoring plug fitted in the vicinity of a rear end of the ratchet accommodating hole and seating the ratchet biasing spring, wherein a ratchet releasing mechanism configured to disengage the ratchet teeth of the ratchet element from the rack teeth of the plunger by means of a tool pin includes a ratchet releasing pin guide hole formed through the housing body to insert a pin edge portion of the tool pin toward a plunger-side edge region of the ratchet element and a ratchet releasing pin engaging hole formed in the plunger-side edge region of the ratchet element to guide and engage with the pin edge portion of the tool pin inserted through the ratchet releasing pin guide hole.