Force sensor

• US 6,865,961 B2
• Filed: 05/22/2003
• Issued: 03/15/2005
• Est. Priority Date: 06/28/2002
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Wolf, Konrad, Dukart, Anton
• Primary Examiner(s): NOORI, MAX H
• Application Number:
  US10/443,708
• Publication Number:
  US 20040000198A1
• Time in Patent Office: 663 Days
• Field of Search: 738/623.91, 738/626.32, 738/626.9, 738/624.51
• US Class Current: 73/862.69
• CPC Class Codes: G01G 19/4142 for controlling activation of safety devices, e.g. airbag systems electrical circuits for triggering safety arrangements in case of vehicle accidents B60R21/015
• CPC Class Codes: G01G 3/15 measuring variations of magnetic properties
• CPC Class Codes: G01L 1/122 by using permanent magnets

Abstract

A force sensor for determination of forces on a vehicle seat has a support element arranged between an upper frame and a lower frame, a force measuring cell arranged in the support element, the upper frame is a stationary part of a rail for a longitudinal or vertical adjustment, and the measuring cell is located inside the rail or on the rail.

Claims

1. A force sensor for determination of forces on a vehicle seat, comprising a support element arranged between an upper frame and a lower frame;

a force measuring cell arranged in said support element, said upper frame being a stationary part of a rail for a longitudinal or vertical adjustment, said measuring cell being located at a location selected from the group consisting of inside said rail and on said rail, said measuring cell having at least two bending beams which, in response to a force action to be determined influence a magnetic field in a region of a magnetic-field-sensitive sensor element of said measuring cell, at least one of said bending beams having one end which is held in a pot and another end mounted on a member selected from the group consisting of said rail and said lower frame, and said pot being mounted through a swivel nut and a mounted angle on said lower frame while the other end of the bending beams is mounted by a further mounting angle on a lower side or a side wall of said rail.

2. A force sensor as defined in claim 1, wherein said pot is mounted on a member selected from a group consisting of said lower frame or said rail.

4. A force sensor as defined in claim 1, wherein said measuring cell has a sensor element and bending beams, said sensor element being composed of a Hall element which is held on at least one of said bending beams and is deflectable under the action of a force which acts on said bending beams in a field of a relatively stationarily arranged permanent magnet.

3. A force sensor determination of forces on a vehicle seat, comprising a support element arranged between an upper frame and a lower frame;

a force measuring cell arranged in said support element, said upper frame being stationary part of a rail for a longitudinal or vertical adjustment, said measuring cell being located at a location selected from the group consisting of inside said rail and on said rail, said measuring cell having at least two bending beams which, in response to a force action to be determined, influence a magnetic field in a region of a magnetic-field-sensitive sensor element of said measuring cell, at least one of said bending beams having one end which is held in a pot and another end mounted on a member selected from the group consisting of said rail and said lower frame, said pot being mounted through a swivel nut and a further mounting angle on a lower side or a side wall of said rail, while another end of said bending beams is mounted through a mounting angle on said lower frame.

5. A force sensor as defined in claim 3, wherein said Hall element is provided with a closed integrated switching circuit which supplies an electrical output signal which is dependent on a deviation of said bending beams.