SEAT BELT WEBBING TENSION MEASURING DEVICE

• US 3,817,093 A
• Filed: 10/05/1972
• Issued: 06/18/1974
• Est. Priority Date: 10/05/1972
• Status: Expired due to Term

• Current Assignee: Charles E. Williams
• Original Assignee: Charles E. Williams
• Inventors: Williams, Charles E.
• Primary Examiner(s): Myracle, Jerry W.
• Application Number:
  US05/295,376
• Time in Patent Office: 621 Days
• Field of Search: 73/144,99,100,143
• US Class Current: 73/862.474
• CPC Class Codes: G01L 5/102 using sensors located at a non-interrupted part of the flexible member
• CPC Class Codes: G01L 5/107 for measuring a reaction force applied on an element disposed between two supports, e.g. on a plurality of rollers or gliders

Abstract

A transducer for measuring seat belt loads comprising a yoke having a pair of spaced arms commonly connected at a crotch portion: a fence element adapted to nest within and between the arms of the yoke for guiding the seat belt against the interior surfaces of the arms and crotch of said yoke. The yoke is floatingly restrained against one side of the seat belt and tension loads applied to the belt are effective in applying force at the outer extremites of the yoke arms so as to move them apart applying compression at a central region of the yoke. Strain gauges are embedded within the central region of the yoke to sense compression as well as '"'"''"'"''"'"''"'"'poisson'"'"''"'"''"'"''"'"' tension; means are provided for converting the strain gauge signal to an indication proportional to the amount of load on said seat belt.

Claims

1. A transducer assembly for measuring loads imposed upon a seat belt having an extended disposition and having a flat web, comprising:

a. a yoke substantially disposed on one side of said belt web having a crotch and a pair of spaced arms extending therefrom, b. means connected to said yoke and disposed on the other side of said belt web effective to guide a portion of said belt web between said arms so that tension in said belt will result in stress of said yoke, and c. means responsive to stress in said yoke to render a signal proportional thereto indicative of the load on said belt.

2. A transducer assembly as in claim 1, in which said arms and crotch define interior surfaces for said yoke Against which said belt is urged by said guide means, a major proportion of said surfaces being arranged transverse to the general extent of the belt.

3. A transducer assembly as in claim 1, in which the ratio of the length of each of the lever arms to the interior spacing between said arms is greater than 10 to 1.

4. A transducer assembly as in claim 1, in which said yoke is pivotally connected to the crotch of said yoke for being floatingly carried against said seat belt to yield to extraneous contact with any portion of the yoke and thereby protect the accuracy of said signal.

5. A transducer assembly as in claim 1, in which said seat belt has a flat configuration, and the yoke has an outer curved wall having a width greater than the length of each of said lever arms, said yoke has interior sidewalls disposed normal to the plane of extension of the flat belt, and the intersection between said sidewalls and the outer curved wall being relieved.

6. A transducer as in claim 1, in which said signal means comprises a plurality of strain gauges carried on said yoke effective to sense predominantly compression in said yoke upon stress of said lever arms.

7. A transducer assembly for measuring loads imposed upon a seat belt having an extended disposition and having a flat web, comprising:

a. a yoke substantially disposed on one side of said belt web having a crotch and a pair of spaced arms extending therefrom, b. means connected to said yoke and disposed on the other side of said belt web effective to guide a portion of said belt web between said arms so that tension in said belt will result in stress of said yoke, said guide means extending into and between the arms of said yoke and being dimensioned to provide a space between said guide means and any of said arms no greater than twice the thickness of the belt web interposed therebetween, and c. means responsive to stress in said yoke to render a signal porportional thereto indicative of the load on said belt.

8. A transducer assembly as in claim 7, in which the ratio of the length of each of said arms to said space less the thickness of the belt is greater than 100 to 1.

9. A transducer for measuring stress in an extended strand, comprising:

a. a yoke floatingly carried against one side of said strand, said yoke having yoke arms, b. a fence element being pivotally connected to said yoke to permit said floating relationship of said yoke with said strand, said element being nestable within said yoke and adapted to engage the other side of said strand to urge the strand into engagement with the interior of said yoke, whereby tension in said strand exerts a force at the extremity of at least one of said arms tending to move said arm away from the other arm and thereby cause compression to occur in the exterior central region of said yoke, and c. strain gauge means embedded in said yoke exterior central region effective to sense said compression and transmit a signal proportional to the stress therein indicative of a tension load on said strand.

10. A transducer as in claim 9, in which the residual space between said arms, not occupied by said fence element and strand thickness, is no greater than the thickness of the strand.

11. A transducer as in claim 9, in which the yoke and fence element define a strand path having parallel and normal portions taken relative to the strand extension, the parallel dimension of the strand path through said transducer being no greater than the normal dimension of said strand path.