Nhk Spring Co., Ltd.

Takahiro Ito

Takao Kobayashi

Tanehira Amano

Ikuomi Takahashi

Kazuhito Hiraoka

Yoshiyuki Takahashi

A load-applying device is provided that includes a spiral spring that is formed from a thin strip that is wound multiple times in a spiral shape; a movable body; and a fixing member. The spiral spring is disposed between the movable body and the fixing member, in a manner capable of performing a diameter reduction operation and a diameter expansion operation, and an outer-circumference part of the spiral spring contacting the movable body and the fixing member directly, or indirectly.

Load application device

A tensioner having a simplified structure, using engaging teeth having increased strength and reduced backlash, constructed from a reduced number of parts, reduced in cost, and having increased design freedom. A tensioner comprises: a tubular member () having engaging teeth () formed thereon; one or more engaging elements () having formed thereon engaging teeth () engaging with the engaging teeth (); and a shaft member () provided inside the tubular member () and having an engaging-element receiving section () or an engaging-element supporting section which receives the engaging elements () of the tubular member (). Either the tubular member () or the shaft member () functions as an advancing member which is moved by urging force in an advancing and retracting manner. The tensioner is provided with a ratchet mechanism which, when the engaging elements () move in a diameter reducing direction and move over the engaging teeth of the tubular member (), allows the advancing member to advance forward, and when the engaging elements () move in a diameter expanding direction and engage with the engaging teeth of the tubular member (), prevents the advancing member to retract.

Tensioner

A tensioner has a cylindrical member having multiple locking teeth, one or multiple locking pieces having locking teeth to be engaged with the locking teeth, and a locking piece receiving part to receive the aforementioned locking pieces. A shaft member is disposed inside the cylindrical member, and either the cylindrical member or the shaft member constitutes a thrust member that can be driven forward and backward by a biasing force. A ratchet mechanism allows the thrust member to move forward by the locking pieces riding over the locking teeth of the cylindrical member as they move in a reduced-diameter direction and constrains retraction of the thrust member by the locking pieces engaging with the locking teeth of the cylindrical member as they move in an increased-diameter direction. The locking teeth are all thread-like teeth having a lead angle.

Growing community of inventors

Nagano, Japan

Takahiro Ito