Friction clutch operated reduced tension safety retraction means

• US 4,303,208 A
• Filed: 10/18/1976
• Issued: 12/01/1981
• Est. Priority Date: 04/26/1976
• Status: Expired due to Term

• Current Assignee: American Safety Equipment Corporation of Michigan
• Original Assignee: American Safety Equipment Corporation of Michigan
• Inventors: Tanaka, Akira
• Primary Examiner(s): Jillions, John M.
• Application Number:
  US05/733,356
• Time in Patent Office: 1,870 Days
• Field of Search: 242/107-107.7, 297/474-479, 280/801-808, 180/268-270, 185/39
• US Class Current: 242/372
• CPC Class Codes: B60R 2022/4426 the additional retraction device being a second spring
• CPC Class Codes: B60R 2022/4453 the additional retraction device being a second spring
• CPC Class Codes: 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

Abstract

A safety belt retractor of the emergency locking type having a safety belt wound upon a spool rotatably journaled in a retractor frame is provided with a friction clutch operated dual tension belt retraction means wherein a first biasing means is provided for biasing the spool in a belt rewind direction, friction clutch means are interconnected between a second biasing means and the first biasing means and actuator means are provided for operating the friction clutch means to selectively apply and prevent operation of the second biasing means upon the first biasing means.

Claims

1. A safety belt retractor having a safety belt wound upon a spool rotatably journaled in a retractor frame comprising:

first biasing means for biasing said spool in a belt rewind direction and second biasing means for biasing said first biasing means in a manner to cause said first biasing means to maintain its bias on said spool during full belt retraction;

friction clutch means interconnected between said second biasing means and said frame for selectively blocking out the bias of said second biasing means; and

actuator means connected to said spool and engageable with said friction clutch means for operating said clutch means to selectively block and unblock the bias of said second biasing means upon said first biasing means in response to rotation of said spool in a predetermined manner.

2. The retractor of claim 1 wherein said friction clutch means comprises:

an interconnecting member interconnected between said second biasing means and said frame, said member having an arm portion;

a cylindrical member provided on said frame; and

a confining torsion spring seated about said cylindrical member on said retractor frame with opposite free ends thereof lying in generally adjacent relation about said arm portion of said interconnecting member and on engagement by said actuator means, said torsion spring expands and loosens about said cylindrical member to free said interconnecting member from said cylindrical member.

3. The retractor of claim 1 wherein said friction clutch means comprises:

an interconnecting member interconnecting said second biasing means and said frame, said member having an arm portion;

a cylindrical housing on said retractor frame; and

an expanding torsion spring seated within said cylindrical housing on said retractor frame with opposite free ends thereof lying in adjacent relation about said arm portion of said interconnecting member whereby said spring ends block movement of said interconnecting member and on engagement by said actuator means said torsion spring contracts and loosens within said cylindrical housing and frees said interconnecting member from said housing.

4. A safety belt retractor having a safety belt wound upon a spool rotatably journaled in a retractor frame comprising:

first biasing means for biasing said spool in a belt rewind direction and a second biasing means for biasing said first biasing means and being wound by said belt unwinding rotation of said spool, said second biasing means being provided to act on said first biasing means during belt winding rotation of said spool; and

means for selectively blocking out the bias of said second biasing means,

wherein said means for selectively blocking out the bias of said second biasing means includes means operable in response to a slight retraction movement of said spool following unwinding of said belt to a position of use for blocking out the bias of said second biasing means.

5. A safety belt retractor having a frame, a safety belt storage spool mounted on said frame and biased toward a belt stored condition under a bias applied by a first spring means and a safety belt connected to said spool comprising:

a second spring means for biasing said first spring means and being wound by said belt unwinding rotation of said spool, said second spring means being provided to act on said first spring means during belt winding rotation of said spool;

means for relieving the first spring means of the bias applied thereto by said second spring means; and

means for reapplying the bias of said second means on said first spring means in response to movement of said spool beyond a predetermined amount under the influence of the bias of said first spring means for rewinding said belt.

6. In a safety belt retractor having a frame, a spool rotatably journaled on said frame and a safety belt wound on said spool, the improvement comprising the provision of:

biasing means connected between said frame and said spool and including a first spring having one end connected to said spool and a second spring having one end connected to said frame, ends of said springs opposite said one ends, respectively, being connected to each other, whereby said second spring biases said first spring toward a wound up state; and

means for controlling the application of the bias of said second spring on said first spring in response to unwinding and winding movement of said spool in a predetermined manner unrelated to the amount of belt unwound from said spool as said belt is placed in use.

7. The improvement in safety belt retractor of claim 6 wherein said biasing means further comprises:

means responsive to movement of said spool under the biase of the first spring for applying the bias of said second spring on said first spring for fully rewinding the belt when said spool movement exceeds a predetermined amount.

8. In a safety belt retractor having a frame, a spool rotatably journaled on said frame and a safety belt wound on said spool the improvement comprising the provision of:

spool biasing means mounted on said frame for applying a bias on said spool and additional biasing means for biasing said spool biasing means in a manner to cause said spool biasing means to maintain its bias on said spool during full belt retraction, said additional biasing means being operable in response to unwinding and winding movement of said spool as said belt is placed in use, wherein said additional biasing means includes

means operable during spool retraction rotation for selectively blocking the bias of said additional biasing means.

9. The improvement in safety belt retractor of claim 8 which further comprises:

means responsive to movement of said spool under the bias of said spool biasing means for reapplying the bias of said additional biasing means on said spool biasing means for rewinding the belt when said movement exceeds a predetermined amount.

10. In a safety belt retractor having a frame, a spool rotatably journaled on said frame and a safety belt wound on said spool, the improvement comprising the provision of;

biasing means mounted on said frame for applying a spool rewind bias on said spool to be applied on unwinding of the belt and additional biasing means for biasing said spool biasing means in a manner to cause said spool biasing means to maintain its bias on said spool during a full belt retraction, the bias of said additional biasing means to be applied to said spool biasing means on rewinding the belt, the additional biasing means being operated in response to unwinding and winding movement of said spool in a predetermined manner unrelated to the amount of belt unwound from said spool as said belt is placed in use, and wherein said additional biasing means includes

means responsive to movements of said spool under the bias of the spool biasing means for selecting the application of the additional biasing means when said movement exceeds a predetermined amount.

11. In a safety belt retractor having a frame a belt storage spool rotatably mounted to said frame and a safety belt connected to and having belt portions stored on said storage spools for protraction and retraction relative to said frame, the improvement comprising the provision of:

first biasing means mounted on said frame for applying a first bias on said spool in a direction resisting unwinding of said belt from said spool to a position of use;

second biasing means mounted on said frame for applying a second bias on said first biasing means, said second bias being of a greater amount than said first bias;

means for selectively blocking out the bias of said second biasing means during retraction movement of said spool; and

means operable in response to a movement of said spool beyond a predetermined amount under the influence of said first biasing means for unblocking the bias of said second biasing means to act on said first biasing means during rewinding of said belt.

12. A seat belt retracting and winding device having a frame, a winding reel rotatably supported by said frame and a seat belt wound on said reel, comprising:

spring means connected between said frame and said winding reel and including a first spring connected to said reel at one end and a second spring connected to said frame at one end, opposite ends, respectively, of said first and second springs being connected to each other;

said winding reel being adapted to wind thereon a seat belt with a spring force of said first spring; and

means for controlling the application of spring force of said second spring on said first spring and operable in response to the rotation of said winding reel to apply only the force of said first spring during use of said seat belt said second spring acting to maintain said first spring wound up during full retraction of the seat belt onto said reel.

13. A seat belt retracting and winding device as defined in claim 12, wherein said controlling means includes clutch means for controlling the application of spring forces of said second spring to effect selectively said first and second conditions, and clutch control means operatively connected to said winding reel to operate said clutch means in accordance with the rotation of said winding reel due to paying out and winding of said seat belt.