Strop restraining means

• US 4,351,545 A
• Filed: 04/02/1980
• Issued: 09/28/1982
• Est. Priority Date: 04/03/1979
• Status: Expired due to Term

• Current Assignee: Minister of Transport In Her Britannic Majesty's Government of The United Kingdom of Great Britain and Northern Ireland
• Original Assignee: Minister of Transport In Her Britannic Majesty's Government of The United Kingdom of Great Britain and Northern Ireland
• Inventors: Cardew, Kenneth H. F.
• Primary Examiner(s): SONG, ROBERT
• Application Number:
  US06/136,709
• Time in Patent Office: 909 Days
• Field of Search: 280/806, 280/802, 280/804, 280/803, 280/808, 24/136 K, 24/196, 24/171, 24/194, 188/65.1, 188/65.2, 188/134, 242/107.2, 297/480, 297/483, 180/268
• US Class Current: 280/806
• CPC Class Codes: B60R 22/185 with stopping means for acting directly upon the belt in an emergency, e.g. by clamping or friction B60R22/195 takes precedence; combined with the retractor B60R22/42
• CPC Class Codes: B60R 22/1855 the means being sensitive to belt tension

Abstract

A device to prevent undesirable paying out under excess loading of a strop forming part of a load restraining means (including vehicle seat belts or safety harness) comprises a housing for receiving an intermediate part of a strop and including a roller around which the strop is guided. The roller is mounted so that it becomes dislodged when tension in the strop exceeds a predetermined value and the strop becomes trapped between the roller and a part of the guidance means which is curved in the opposite sense to the roller in order to produce a gradual stress gradient in the strop to reduce risk of parting. The roller is supported on bushes engaging chamfered apertures in flat washers and which will disengage under excessive resultant force on the roller. Slots cut into the ends of the rollers define teeth which serve to support the roller on cam members formed integrally with the housing with lobes which enter the slots on roller displacement.

Claims

1. Strop securing means comprising a housing containing a roller having a normal pivotal axis concentrically disposed in said roller, said normal pivotal axis having a fixed position relative to said housing, and means for eccentrically displacing said roller relative to said normal pivotal axis so that said normal pivotal axis is eccentrically disposed in said roller upon displacement, thereby pressing a strop passing around the periphery of said roller between said roller and a portion of said housing.

2. Strop securing means as in claim 1 further comprising means for retaining said roller in a displaced position.

3. Strop securing means according to claim 2 wherein said retaining means comprises cam means associated with said housing for supporting said roller in a displaced position, and engaging means associated with said roller for engaging said cam means when said roller is in a displaced position.

4. Strop securing means as in claim 3 wherein said engaging means comprises means defining openings at the periphery of said roller thereby defining projections arranged to engage said cam means and to support said roller thereon in the displaced position.

5. Strop securing means as in claim 4 wherein said cam means includes means defining a lobe for entering at least one opening in the periphery of said roller to facilitate engagement of said cam means by adjacent projections.

6. Strop securing means as in claim 1 or 2 further comprising means for guiding a strop around said roller so that predetermined tension in opposite end portions of the strop will responsively displace said roller relative to said normal pivotal axis.

7. Strop securing means as in claim 3 wherein the strop extends around at least 50% of the periphery of said roller.

8. Load restraining means comprising strop securing means according to claim 1, or 4.

9. Strop securing means as in claim 1 wherein said displacing means includes means defining cooperating chamfered surfaces for supporting said roller in an undisplaced position, and biasing means for maintaining said cooperating chamfered surfaces in said undisplaced position.

10. Strop securing means comprising a housing containing a displaceable roller having a normal pivotal axis which is coincident with the axis of symmetry of the roller when the roller is in an undisplaced position and a pivotal axis which does not coincide the axis of symmetry when the roller is in a displaced position, said normal pivotal axis having a fixed position relative to said housing, said roller being displaceable about said normal pivotal axis, means for displacing the roller so that said normal pivotal axis is eccentrically disposed in said roller upon displacement thereby pressing a strop passing around the periphery of the roller between the roller and a portion of the housing, and means for retaining the roller in a displaced position, said retaining means comprising cam means associated with said housing for supporting the roller in a displaced position and engaging means associated with the roller for engaging the cam means when the roller is in a displaced position.

11. Strop securing means as in claim 10 further comprising means for guiding a strop around the roller so that predetermined tension in opposite end portions of the strop responsively displace the roller relative to said normal pivotal axis.

12. Strop securing means as in claim 10 or 11 wherein the strop extends around at least 50% of the roller.

13. Strop securing means as in claim 11 wherein said roller is supported within said housing on co-operating chamfered surfaces maintained in normal engagement by spring loading.

14. Strop securing means as in claim 11 wherein said engaging means comprises means defining openings at the periphery of said roller thereby defining projections arranged to engage said cam means and to support said roller thereon in said displaced position.

15. Strop securing means as in claim 14 wherein said cam means includes a lobe shaped to enter at least one of said openings defined in the periphery of the roller to facilitate engagement of said cam means by adjacent projections.