Force sensor with multiple piece actuation system

• US 5,760,313 A
• Filed: 03/05/1997
• Issued: 06/02/1998
• Est. Priority Date: 03/05/1997
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Guentner, Ronald E., Maurer, D. Joseph, Sheriff, Alan V.
• Primary Examiner(s): Dougherty, Elizabeth L.
• Application Number:
  US08/810,795
• Time in Patent Office: 454 Days
• Field of Search: 73/727, 73/862.584, 73/862.625, 73/862.631, 73/862.635, 73/862.636, 73/862.637, 73/862.639, 73/862.642, 73/DIG. 4, 338/47, 338/42
• US Class Current: 73/862.584
• CPC Class Codes: G01L 1/18 using properties of piezo-resistive materials, i.e. materials of which the ohmic resistance varies according to changes in magnitude or direction of force applied to the material
• CPC Class Codes: G01L 1/2237 the direction being perpendicular to the central axis
• 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

A force sensor is provided with a two piece actuation system. A first actuator is disposed in contact with the pressure sensitive component and a second actuator is disposed in contact with the first actuator. When an external force is exerted against a distal end of the second actuator, for force is transmitted through the second actuator to the first actuator. The force is then transmitted through the first actuator to the pressure sensitive component. By using a two piece actuation system, the first actuator can be maintained at a constant location in contact with a position on the pressure sensitive component. This position will not vary even when the second actuator is moved or tilted. An elastomeric plate can be used to retain the first actuator in a constant position relative to the pressure sensitive component.

Claims

1. A force sensor, comprising:

a housing structure, said housing structure having an opening formed therein;

a pressure sensitive component disposed within said housing structure;

a singular first actuator disposed in substantially single point contact with said pressure sensitive component;

a second actuator disposed in contact with said first actuator, said second actuator being disposed within said opening to transmit a force from an external source to said first actuator, said first actuator being disposed between said second actuator and said pressure sensitive component to transmit said force from said second actuator to said pressure sensitive component; and

a plate, separate from said pressure sensitive component and said actuators located within said opening, shaped to retain said first actuator in contact with said pressure sensitive component, said plate having a through-hole formed therein, said first actuator being disposed within said through-hole.

2. The sensor of claim 1, wherein:

said plate is made of an elastomeric material.

3. The sensor of claim 1, wherein:

said first actuator is a ball.

4. The sensor of claim 1, wherein:

said pressure sensitive component comprises a silicon die having at least one piezoresistive element disposed thereon.

5. A force sensor, comprising:

a housing structure, said housing structure having an opening formed therein;

a pressure sensitive component disposed within said housing structure;

a first actuator disposed in contact with said pressure sensitive component;

a second actuator disposed in contact with said first actuator, said second actuator being disposed within said opening to transmit a force from an external source to said first actuator, said first actuator being disposed inline between said second actuator and said pressure sensitive component to transmit said force from said second actuator to said pressure sensitive component; and

a plate, separate from said pressure sensitive component and said actuators shaped to retain said first actuator in contact with said pressure sensitive component, said plate having an opening formed therethrough, said first actuator being disposed within said opening formed through said plate, said plate being made of an elastomeric material, said first actuator being spherical, and said pressure sensitive component comprising a silicon die having at least one piezoresistive element disposed thereon.