Tensioner device for belt or chain drives

• US 4,934,984 A
• Filed: 08/24/1989
• Issued: 06/19/1990
• Est. Priority Date: 08/31/1988
• Status: Expired due to Term

• Current Assignee: NHK Spring Company Limited
• Original Assignee: NHK Spring Company Limited
• Inventors: Ojima, Juji
• Primary Examiner(s): Bui, Thuy M.
• Application Number:
  US07/399,570
• Time in Patent Office: 299 Days
• Field of Search: 474/101, 474/109-111, 474/113-117, 474/133, 474/135, 474/136, 474/138
• US Class Current: 474/111
• CPC Class Codes: F16H 2007/081 Torsion springs
• CPC Class Codes: F16H 2007/0891 Linear path
• CPC Class Codes: F16H 7/08 Means for varying tension of belts, ropes, or chains pulleys of adjustable construction F16H55/52 ; gearings with endless belts F16H7/02; tensioning for chains or belts specially adapted for cycles B62M9/16; belt or chain tensioning arrangements for endless conveyors B65G23/44

Abstract

A tensioner device is provided with a rotary body energized the rotation by a spring and an urged body restricted the rotation by a bearing are inserted into a casing in a screwed state.

The inner part of the casing is tightly closed by being covered with a bellows between the above casing and the urged body, and the torque of the rotary body is converted into a propelling force in a rod direction.

In this case, an excess in pressurized air which compensates the change of an inner pressure caused by propelling of the urged body, is sealed within the casing.

Claims

1. A tensioner device wherein a rotary body energized the rotation with a spring and an urged body restricted the rotation by a bearing inserted into a casing in a screwed state, an inner part of the casing is tightly closed by being covered with a bellows between the casing and the urged body, and the torque of the rotary body is converted into a propelling force in a rod direction:

said tensioner device containing an excess of pressurized air which compensates the change of an inner pressure caused by propelling of the urged body is sealed within the casing.

2. A tensioner device according to claim 1 wherein a hole for pouring the excess of pressurized air sealed with an elastic sealing plug is boared in the casing.

3. A tensioner device according to claim 1 wherein a mechanism portion is a triple construction consisting of a spring, an urged body and a rotary body, said rotary body and the spring being arranged respectively at the inside and the outside thereof in a same rod state, and said urged body being screwed with the rotary body so as to position between the rotary body and the spring.

4. A tensioner device according to claim 1 wherein the spacer is interposed at an oppositely contacted portion of the bearing and the casing.

5. A tensioner device according to claim 4 wherein a circulating circuit of the lubricating oil is formed to the urged body, the bearing and the spacer.