Force and torque converter

• US 5,452,615 A
• Filed: 07/22/1993
• Issued: 09/26/1995
• Est. Priority Date: 10/25/1989
• Status: Expired due to Fees

• Current Assignee: Labtec, Inc. (Logitech International SA)
• Original Assignee: Spacetec IMC Corporation
• Inventors: Hilton, John A.
• Primary Examiner(s): Chilcot, Jr., Richard E.
• Assistant Examiner(s): Dougherty, Elizabeth L.
• Application Number:
  US08/095,904
• Time in Patent Office: 796 Days
• Field of Search: 73/862.041, 73/862.042, 73/862.043, 73/862.05, 74/471 XY, 250/211
• US Class Current: 73/862.043
• CPC Class Codes: G01D 5/34 the beams of light being detected by photocells
• CPC Class Codes: G01L 1/248 using infrared G01L1/241, G01L1/242 take precedence
• CPC Class Codes: G01L 5/1627 of strain gauges using piezoresistors G01L5/162
• CPC Class Codes: G01L 5/166 using photoelectric means
• CPC Class Codes: G01L 5/223 to joystick controls
• CPC Class Codes: G06F 3/03543 Mice or pucks G06F3/03541 takes precedence
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: Y10T 74/20201 Control moves in two planes

Abstract

A force and torque converter is provided that senses force and torque applied to the device. The converter includes a base, a grip, resilient connection members that extend radially and coplanarly from a central hub, located within the grip, and that connect to the grip, and sensing mechanisms to sense the displacement of the connection members. The displacements are resolved to determine the force and torque that is applied to the device, with respect to a Cartesian coordinate system.

Claims

1. An apparatus for providing an electronic representation in response to force being applied along and torque being applied about any of up to three mutually orthogonal axes originating in said apparatus, the apparatus comprising:

a support member;

a grip for receiving said applied force and torque;

three connection members fixed to and radially extending from said support member and engaging said grip, said connection members having a resiliency such that the grip is displaceable to a limited extent in response to the application of said applied force and torque; and

optical sensing means for detecting displacement of each of the connection members and for providing said electronic representation, the electronic representation being representative of the applied force and the applied torque.

2. The apparatus of claim 1 wherein the optical sensing means includes, for each connection member, a first and a second photo-emitter and photo-detector pair, the photo-emitter of each said pair being arranged to be in optical communication with the photo-detector of said pair such that the corresponding connection member, in response to applied force or torque, masks a portion of the optical energy being communicated between the photo-emitter and photo-detector of at least one pair.

3. The apparatus of claim 2 wherein the optical sensing means includes means for energizing the photo-emitters of the first and second pair in a time-division multiplexed manner.

4. The apparatus of claim 1 wherein the optical sensing means includes a first and a second photo-emitter and includes, for each connection member, first and second reflective members for receiving and reflecting optical energy from a corresponding photo-emitter, the first and second photo-emitter and corresponding first and second reflective members being arranged about a corresponding connection member such that the corresponding connection member masks a portion of the optical energy being communicated by the first and second optical-emitters, when an applied force or torque displaces the connection members, the optical sensing means further including a single photo-detector for each connection member, the single photo-detector being arranged to receive reflected optical energy from both the first and the second reflective members.

5. The apparatus of claim 4 wherein the optical sensing means includes means for energizing the first and second photo-emitters in a time-division multiplexed manner.

6. The apparatus of claim 1 wherein the optical sensing means includes, for each connection member, a first and a second photo-emitter respectively arranged in optical communication with a first and a second light pipe, and includes a corresponding connection member disposed relative to the photo-emitters and light pipes so as to mask a portion of the optical energy being communicated by the first and/or second photo-emitter, when a force and/or torque displaces the connection members, the optical sensing means further including a single photo-detector arranged in optical communication with both The first and second light pipes.

7. The apparatus of claim 6 wherein the optical sensing means further includes means for energizing the first and second photo-emitter for each connection member in a time-division multiplexed manner.

9. The apparatus of claim 1, wherein the first end of each connection member is fixed to the support member and a second end of the connection member engages the grip.

10. The apparatus of claim 9, wherein the second end of each connection member includes a ball section that engages a corresponding cylindrical hole.

11. The apparatus of claim 1, wherein there are three connection members only and the three connection members extend radially and coplanarly from the support member.

8. An apparatus for providing an electronic representation in response to force being applied along and torque being applied about any of up to three mutually orthogonal axes originating in said apparatus, the apparatus comprising:

a support member;

a grip for receiving said applied force and torque;

three connection members fixed to and radially extending from said support member and engaging said grip, said three connection members having a resiliency such that the grip is displaceable in response to the application of an applied force and/or torque;

optical sensing means for detecting displacement of each of the three connection members and for providing an output, representative of said displacement; and

a microcontroller, receiving the output from the optical sensing means and providing the electronic representation therefrom in accordance with a predetermined sensitivity curve, the electronic representation being representative of the applied force and the applied torque.

12. An apparatus for converting an applied force and/or torque into an electronic representation indicative of the applied force and/or torque, comprising:

a support member;

a grip for receiving the applied force and/or torque;

three connection members only, the connection members fixed to and radially and coplanarly extending from the support member, each said connection member engaging the grip at a distal end and each connection member having a resiliency such that, when the force and/or torque is applied to the grip, the grip is displaced in monotonic relation to the applied force and/or torque;

optical sensing means, arranged about each connection member, for detecting the displacement of each of the three connection members and for providing an electronic signal indicative of the displacement; and

a control circuit including an A/D converter that receives the electronic signal and provides a digital representation thereof and including a microcontroller that receives the digital representation and has means for providing the electronic representation indicative of the applied force and the applied torque according to a predetermined sensitivity curve.

13. An apparatus for providing an electronic representation in response to force being applied along and torque being applied about any of up to three mutually orthogonal axes originating in said apparatus, the apparatus comprising:

a support member;

a grip for receiving said applied force and torque;

three connection members fixed to and radially extending from said support member and engaging said grip, said connection members having a resiliency such that the grip is displaceable to a limited extent in response to the application of an applied force and/or torque; and

a photo-emitter and photo-detecter network arranged within the grip to detect the displacement of any of the connection members and to provide the electronic representation therefrom the electronic representation being representative of the applied force and the applied torque.

14. An apparatus for providing an electronic representation in response to force being applied along and torque being applied about any of up to three mutually orthogonal axes originating in the apparatus, the apparatus comprising:

a support member having a connection end and a base end;

a grip for receiving the applied force and the applied torque, the grip being adjacent the connection end of the support member;

a plurality of connection members, each connection member having a first end connected to the connection end of the support member, and a second end that engages the grip, each connection member radially extending from the connection end of the support member towards the grip; and

optical sensing means for measuring displacement of each of the connection members, and for providing the electronic representation representative of the applied force and the applied torque.

15. The apparatus of claim 14, wherein the optical sensing means is disposed within the grip.

16. The apparatus of claim 15, wherein the optical sensing means includes a light source and a light receiver, both the light source and the light receiver being disposed externally from the support member.

17. The apparatus of claim 16, further including circuitry that filters out electronic representations representative of at least one of the applied force and the applied torque less than a predetermined threshold.

18. The apparatus of claim 14, wherein the optical sensing means includes a light source and a light receiver, both the light source and the light receiver being disposed externally from the support member.

19. The apparatus of claim 18, further including circuitry that filters out electronic representations representative of at least one of the applied force and the applied torque less than a predetermined threshold.

20. The apparatus of claim 14, further including circuitry that filters out electronic representations representative of at least one of the applied force and the applied torque less than a predetermined threshold.