MIM force measuring device

• US 7,402,763 B2
• Filed: 01/24/2005
• Issued: 07/22/2008
• Est. Priority Date: 03/03/2004
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Menke, Oliver, Stadler, Franz
• Primary Examiner(s): Gibson; Randy W
• Application Number:
  US10/591,488
• Publication Number:
  US 20070180930A1
• Time in Patent Office: 1,275 Days
• Field of Search: 177/144, 177/211, 177/229, 738/626.36, 738/626.37
• US Class Current: 177/144
• 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 sensing device has a single-component metal housing. The housing has an upper rigid housing part and a lower rigid housing part that are interconnected by way of U-shaped spring elements and can be elastically displaced along a displacement axis in relation to each other by the action of a force. The spring elements are symmetrically arranged in relation to a section that is parallel to the displacement axis. A deflection sensor is disposed between the upper and lower rigid housing parts, for detecting the relative displacement of the two rigid housing parts in relation to each other. The housing is produced using metal injection molding technology.

Claims

1. A force measuring device, comprising:

a metal-injection-molded, single-piece metal housing;

said single-piece metal housing having a rigid upper housing part, a rigid lower housing part, and a plurality of U-shaped spring elements connecting said upper and lower housing parts to one another;

said spring elements enabling said upper and lower housing parts to be moved elastically relative to one another along a movement axis upon application of a force, and said spring elements being disposed symmetrically to one another parallel to said movement axis and relative to a sectional plane; and

a deflection sensor mounted between said u the upper and lower rigid housing parts to detect their relative movement in relation to each other;

said housing including at least four U-shaped spring elements, with a pair of two spring elements respectively pointing in a common direction from said sectional plane; and

said lower housing part including a securing lug between each said pair of two spring elements, said lugs enabling the force measuring device to be rigidly connected to a motor vehicle chassis.

2. The force measuring device according to claim 1, wherein each one of said U-shaped spring elements has two arms enclosing an acute angle.

3. The force measuring device according to claim 1, wherein each spring element has a wall thickness decreasing from said upper housing part and once more increasing towards a vertex thereof.

4. The force measuring device according to claim 1, wherein said spring elements are curved springs extending from said upper housing part to said lower housing part, and each said spring element has a wall thickness decreasing from said upper housing part and once more increasing towards a vertex of the respective said curved spring.

5. The force measuring device according to claim 1, which further comprises screw bolts adapted to said lugs and configured to attach the force measuring device to the motor vehicle chassis.

6. The force measuring device according to claim 1, wherein said metal-injection-molded, single-piece metal housing is an integral metal part formed in a metal injection molding process by molding a metal powder and subsequently sintering the molded body.