Force Transducer for a Motor Vehicle Seat

• US 20040007397A1
• Filed: 06/16/2003
• Published: 01/15/2004
• Est. Priority Date: 07/21/2000
• Status: Active Grant

• Current Assignee: Sartorius Lab Instruments GmbH & Co. KG (Sartorius AG)
• Original Assignee: Sartorius Hamburg GmbH (Sartorius AG)
• Inventors: Golla, Lothar
• Granted Patent: US 6,797,892 B2
• Time in Patent Office: Days
• US Class Current: 177/243
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: B60R 21/0152 using strain gauges
• 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

Abstract

A force transducer (2) for sensing the weight introduced into the mounting of a motor vehicle seat and comprises a force introduction element (4) that is connected to the motor vehicle seat, a force transfer element (7) that is connected to the mounting, and an extension member (5) that is arranged between the force introduction element (4) and the force transfer element (7) is disclosed which makes it possible to accurately determine the weight introduced into the mounting of the motor vehicle seat independently of other influencing forces by the fact that the force transfer element (4) or the force transfer element (7) surrounds the extension member (5) in a plane that extends parallel to the effective direction of the weight, and that at least one wire strain gauge (9) for sensing a shearing force parallel to the weight is arranged on the extension member (5).

Claims

1. A force transducer (2) for sensing the weight introduced into the mounting of a motor vehicle seat (F), comprising a force introduction element (4) that is connected to the motor vehicle seat (F), a force transfer element (7) that is connected to the mounting, and an extension member (5) that is arranged between the force introduction element (4) and the force transfer element (7), characterized in that the force introduction element (4) or the force transfer element (7) surrounds the extension member (5) in a plane that extends parallel to the effective direction of the weight, and that at least one wire strain gauge (9) for sensing a shearing force parallel to the weight is arranged on the extension member (5).

2. The force transducer according to claim 1, characterized in that the force introduction element (4) or the force transfer element (7) is realized in the form of a housing that surrounds the extension member (5) whereby the housing is connected to one end of the extension member (5) with one end (6).

3. The force transducer according to claim 2, characterized in that the housing surrounds the extension member (5) such that a thin peripheral gap (10) is formed in at least one location.

4. The force transducer according to claim 3, characterized in that the thin peripheral gap (10) is covered by a membrane.

5. The force transducer according to one of claims 1-4, characterized in that two wire strain gauges (9) are respectively arranged oppositely at the same angle referred to the longitudinal axis of the extension member (5) on a surface (8) of the extension member (5) which extends parallel to the effective direction of the weight.

6. The force transducer according to one of claims 1-5, characterized in that the extension member (5) has a reduced cross section at the location at which the wire strain gauge (9) is arranged.

7. The force transducer according to claim 6, characterized in that the extension member (5) contains a first recess in the region of the wire strain gauges (9), and that the axis of the first recess essentially extends parallel to the effective direction of the weight.

8. The force transducer according to claim 7, characterized in that the extension member (5) contains a second recess, the axis of which essentially extends in the longitudinal direction of the extension member (5) perpendicular to the axis of the first recess, and by the fact that the second recess penetrates the first recess within the extension member (5).

9. The force transducer according to one of claims 1-8, characterized in that the extension member (5) has an at least partially angular cross section.

10. The force transducer according to one of claims 1-9, characterized in that the extension member (5) has a plane surface which protrudes over the other contours and serves for attaching the wire strain gauges (9).