# US 4,534,520 A · Webbing take-up amount limiting device of a retractor

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- Number: US 4,534,520 A
- Document ID: US4534520A
- Status: Granted
- Kind: A
- Application number: 06/563,218
- Filed: 1983-12-19
- Granted: 1985-08-13
- Earliest claimed: 1982-12-28
- Assignees: NSK-Warner K.K.
- Inventors: Hideo Yanagihara
- Web page: https://patentgrep.com/patent/US4534520A

## CPC

- B60R 22/44: with means for reducing belt tension during use under normal conditions {(not included in the retractor B60R22/19; B60R22/3405 takes precedence)}
- B60R 22/34: Belt retractors, e.g. reels (anchoring devices {, e.g. guide loops} , with means to tension the belt in an emergency B60R22/195)
- B60R 2022/4406: {Spring shapes; Spring characteristic; Springs with adjustable anchoring means}
- B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR

## Abstract

In a retractor having a base, a webbing take-up shaft rotatably supported by the base, and a biasing member for biasing the shaft in a webbing take-up direction, a webbing take-up amount limiting device is characterized in that between a portion movable in association with the take-up shaft and a portion integral with the base, a connecting member for connecting the two portions is provided so that in a condition in which a predetermined amount of webbing has been taken up around the take-up shaft, the connecting member assumes its tensioned state between the two portions and prevents the rotation of the take-up shaft in the webbing take-up direction to thereby limit any further take-up of the webbing.

## Claims

### Claim 1

In a webbing retractor having a webbing take-up shaft rotatably supported on a base and biasing means for biasing said shaft in the webbing take-up direction to take up said webbing around said shaft, a device for limiting the amount of webbing take-up, said device comprising means for preventing webbing take-up rotation of said shaft, said preventing means including an elongated flexible member connected between said base and said shaft and having means for tensioning said member in opposition to the force of said biasing means as said shaft rotates in the webbing take-up direction and thereby to prevent further rotation of the shaft in the webbing take-up direction when a predetermined amount of the webbing has been taken up.

### Claim 2 (depends on 1)

A device according to claim 1, wherein said elongated flexible member is a ribbon.

### Claim 3 (depends on 2)

A device according to claim 2, wherein said ribbon is spiral shaped.

### Claim 4 (depends on 2)

A device according to claim 2, further including a ribbon hook fixed to said shaft and an adjuster adjustable mounted on said base, one end of said flexible member being connected to the ribbon hook and the other end to said adjuster.

### Claim 5 (depends on 3)

A device according to claim 3, wherein said adjuster comprises means adapted to be fixed on said base at different positions spaced circumferentially about said shaft.

### Claim 6

In a webbing retractor having a webbing take-up shaft rotatably supported on a base and biasing means for biasing said shaft in a webbing take-up direction to take up said webbing around said shaft, a device for limiting the amount of webbing take-up, comprising means for preventing webbing take-up rotation of said shaft, said preventing means including an elongated flexible spiral member connected between said shaft and said base and wound about said shaft in a first direction when said webbing has been taken up on said shaft, and means for causing said spiral member to be unwound from said shaft as said webbing is drawn out and thereafter wound about said shaft in a direction opposite to said first direction when said webbing is further drawn out and for causing said spiral member to be unwound from said shaft and then to be re-wound on said shaft in said first direction when said webbing is taken up on said shaft and to be tensioned in opposition to the force of said biasing means to prevent further rotation of said shaft in the webbing take-up direction when a predetermined amount of said webbing has been taken up.