Force transducer

• US 4,493,219 A
• Filed: 08/02/1982
• Issued: 01/15/1985
• Est. Priority Date: 08/02/1982
• Status: Expired due to Term

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Sharp, Larry L., Klosinski, Mark
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/404,266
• Time in Patent Office: 897 Days
• Field of Search: 73/862.04, 73/862.05, 73/862.64, 73/718, 73/724, 338/47, 338/99, 338/114, 338/96, 340/365 A, 361/288, 361/280, 361/283, 361/278, 200/DIG. 1
• US Class Current: 73/862.05
• 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 1/142 using capacitors
• CPC Class Codes: G01L 1/20 by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids of piezo-resistive materials G01L1/18; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
• CPC Class Codes: G05G 2009/0474 characterised by means converting mechanical movement into electric signals
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 13/703 characterised by spacers between contact carrying layers
• CPC Class Codes: H01H 13/785 characterised by the material of the contacts, e.g. conductive polymers
• CPC Class Codes: H01H 2201/036 Variable resistance
• CPC Class Codes: H01H 2211/028 Contacts in depressions of layers
• CPC Class Codes: H01H 2215/046 Inflatable bubble or cell
• CPC Class Codes: H01H 2221/012 Joy stick type
• CPC Class Codes: H01H 2221/084 made at least partly of elastic foam
• CPC Class Codes: H01H 2239/006 Containing a capacitive switch or usable as such
• CPC Class Codes: H01H 2239/024 with inductive switch

Abstract

An energy conversion and transmission device is disclosed which, in its preferred embodiment, has a rigid substrate with a resistive area printed on its top surface, a spacer of non-conductive material with an aperture therethrough positioned in register with the rigid substrate resistive area, and a flexible substrate with a resistive area printed on its bottom surface in register with the aperture and the rigid substrate resistive area so that application of a force to the flexible substrate with an elastomeric actuator will move the flexible substrate resistive area to establish an electrical contact area with the rigid substrate resistive area, which electrical contact area increases and, thus, the resistivity of that area decreases as the applied force increases. Thus, when an electrical potential is applied across the two resistive areas, current flow through the two resistive areas increases as the applied force increases. Capacitive, inductive and other embodiments of the device are also disclosed.

Claims

1. An energy conversion and transmission device comprising a first non-conductive substrate, a second non-conducting substrate, an actuator means and a spacer means;

said first substrate being substantially flexibly resilient and having a first plurality of electrically resistive lands affixed thereto;

said second substrate being substantially rigid and having a second plurality of electrically resistive lands affixed thereto;

said spacer means being intermediate said first substrate and said second substrate and maintaining said substrates in spaced, substantially parallel relation;

each of said first plurality of resistive lands being in facing relation with and in register with one of said second plurality of resistive lands, said spacer means having a plurality of apertures therethrough, each of said plurality of apertures being in register with one of said first plurality of resistive lands;

said actuator means comprising a plurality of elastomeric actuators, each of said plurality of actuators being in register with one of said first plurality of resistive lands;

said actuator means further comprising a common actuator carrier, each of said actuators being connected to said common actuator carrier;

said actuator means further comprising a common control means, said common actuator carrier being connected to and responsive to said common control means.

2. An energy conversion and transmission device as recited in claim 1 wherein said actuator means further comprises a Z-control means and a Z-actuator;

said plurality of apertures, said first plurality of resistive lands, and said second plurality of resistive lands each being equal in number to and respectively in register with said plurality of actuators plus said Z-actuator;

said Z-control means being connected to said Z-actuator and operable independently from said common control means.

3. An energy conversion and transmission device comprising a first electrically propertied means and a second electrically propertied means, said first means being disposed in proximate relationship with said second means and responsive to a force moving said first means with respect to said second means to vary said electrical property proportionally to said force;

said second means being a substantially rigid non-conductive substrate with electrically propertied lands affixed thereto, and said first means being a substantially flexible non-conductive substrate with electrically propertied lands affixed thereto;

said device further comprising spacer means disposed intermediate said first means and said second means to maintain said first means in spaced, substantially parallel relation with said second means, said spacer means being non-conductive and having a plurality of apertures therethrough, at least a portion of said electrically propertied lands of said first means, at least a portion of said electrically propertied lands of said second means, and said apertures being in register with respect to each other;

said apertures allowing electrical communication therethrough between said electrically propertied lands of said first means and said electrically propertied lands of said second means; and

said device further comprising means for applying said force to said first means, said means for applying said force comprising a plurality of actuators carried upon a common actuator assembly, said plurality of actuators being capable of selectively impinging upon various areas of said first means.

4. An energy conversion and transmission device as recited in claim 3 wherein said plurality of actuators equals said plurality of apertures.

5. An energy conversion and transmission device as recited in claim 4 wherein each of said plurality of actuators is in register with one of said plurality of apertures.

6. An energy conversion and transmission device as recited in claim 5 wherein more than one of said plurality of actuators is capable of impinging upon more than one area of said first means simultaneously.