(Seat) force measuring device with a spring housing, inductive sensor and stops

• US 7,367,228 B2
• Filed: 09/07/2004
• Issued: 05/06/2008
• Est. Priority Date: 09/08/2003
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Christoph, Markus, Offereins, Henderikus-L
• Primary Examiner(s): NOORI, MAX H
• Application Number:
  US10/571,019
• Publication Number:
  US 20070028703A1
• Time in Patent Office: 1,337 Days
• Field of Search: 731/61
• US Class Current: 73/161
• 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: 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: G01L 1/04 by measuring elastic deformation of gauges, e.g. of springs
• CPC Class Codes: G01L 1/14 by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators
• CPC Class Codes: G01L 1/26 Auxiliary measures taken, or devices used, in connection with the measurement of force, e.g. for preventing influence of transverse components of force, for preventing overload

Abstract

The two housing parts are used as springing means which are mounted behind each other, thereby extending the full spring path. Despite the soft springs obtained by the housing, the individual housing parts can be manufactured from a stable material so that they remain dimensionally stable over a long-term period even when subjected to heavy stress by virtue of the fact that they are arranged between a vehicle seat and the chassis of the vehicle, thereby meeting the high quality standards required by the vehicle industry. Complex successive positioning of the springs inside the housing is avoided. As a result, it is possible to produce a force measuring device which is particularly compact, stable and economical. A coil with a core is used as an inductive deflection sensor.

Claims

1. A force measuring device, comprising:

a housing formed of a resiliently flexible first housing part and a resiliently flexible second housing part connected to said first housing part;

a first force introduction means associated with said first housing part, and a second force introduction means associated with said second housing part;

wherein said first and second force introduction means are disposed to introduce mutually opposite force components into said first and second housing parts, respectively, and to resiliently move along a common movement axis upon being subjected to the respectively opposite force components directed in mutually opposite directions; and

a deflection sensor for registering a movement of said first and second housing parts relative to one another.

2. The force measuring device according to claim 1, wherein said first and second housing parts are defined as spring means with spring constants having values that are different from one another by no more than a maximum of 75%.

3. The force measuring device according to claim 1, wherein said first and second housing parts are defined as spring means with spring constants of substantially equal value.

4. The force measuring device according to claim 1, wherein said first housing part includes a first spring lever forming said first spring means and said second housing part includes a second spring lever forming said second spring means, and said first and second spring levers are disposed in each case outside said movement axis.

5. The force measuring device according to claim 4, wherein said first and second spring levers extend substantially vertically with respect to said movement axis.

6. The force measuring device according to claim 1, wherein said deflection sensor is disposed along said movement axis.

7. The force measuring device according to claim 1, wherein said movement axis for said first and second housing parts and/or for said first and second force introduction means and/or for said deflection sensor defines a substantially rotationally symmetrical axis.

8. The force measuring device according to claim 1, wherein said first housing part is integrally formed in a single piece with said first force introduction means.

9. The force measuring device according to claim 8, wherein said second housing part is integrally formed in a single piece with said second force introduction means.

10. The force measuring device according to claim 1, which further comprises stop elements mounted to said housing and configured to limit a maximum possible deflection of said first and the second housing parts in each direction along said movement axis.

11. The force measuring device according to claim 8, wherein said stop elements include at least one internal stop element disposed inside said housing.

12. The force measuring device according to claim 11, wherein said internal stop element integrally formed in a single piece with one of said first and second housing parts.

13. The force measuring device according to claim 1, wherein said deflection sensor includes a first deflection sensor half rigidly connected, directly or indirectly, to said first force introduction means, and a second deflection sensor half rigidly connected, directly or indirectly, to said second force introduction means.

14. The force measuring device according to claim 13, wherein said deflection sensor is an inductive sensor.

15. The force measuring device according to claim 14, wherein said inductive sensor includes an induction coil with a core and a coil winding, and said first deflection sensor half comprises said core of said induction coil and said second deflection sensor half comprises said coil winding.