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US3830991A - Pressure sensitive mat switch construction - Google Patents

Pressure sensitive mat switch construction Download PDF

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Publication number
US3830991A
US3830991A US38213873A US3830991A US 3830991 A US3830991 A US 3830991A US 38213873 A US38213873 A US 38213873A US 3830991 A US3830991 A US 3830991A
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Prior art keywords
conductive
assembly
member
switch
bridging
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G Durocher
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Lear Corporation EEDS and Interiors
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Essex International Inc
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    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H3/00Mechanisms for operating contacts
    • H01H3/02Operating parts, i.e. for operating driving mechanism by a mechanical force external to the switch
    • H01H3/14Operating parts, i.e. for operating driving mechanism by a mechanical force external to the switch adapted for operation by a part of the human body other than the hand, e.g. by foot
    • H01H3/141Cushion or mat switches
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00Contacts
    • H01H1/02Contacts characterised by the material thereof
    • H01H1/021Composite materials
    • H01H1/029Composite materials comprising conducting material dispersed in an elastic support or binding material

Abstract

A pressure sensitive switch useful in a mat of the kind adapted to operate a door in response to a person''s stepping on the mat comprises a switch assembly composed of a pair of sheet-like electrical conductors between which is interposed a sheet of resiliently compressible and expansible non-conductive material such as foamed rubber or plastic having a plurality of openings therethrough in each of which is accommodated a bridging member operable to establish a conductive path between the two conductors when the latter are moved relatively toward one another in response to the application to the mat of a compressive force. The switch assembly is enclosed within a nonconductive rubber or plastic sheath. Conductive wires connected to the two conductors of the switch assembly extend through the sheath for connection to a source of energy and to the actuating mechanism for the door to be operated. Means are provided for limiting the compressive force to which said bridging member may be subjected.

Description

United States Patent [1 1 Durocher [451 Aug. 20, 1974 PRESSURE SENSITIVE MAT SWITCH CONSTRUCTION Gideon A. Durocher, Mt. Clemens, Mich.

[73] Assignee: Essex International Inc., Fort Wayne, Ind.

[22] Filed: July 24, 1973 [2l] Appl. No.: 382,138

[75] Inventor:

3,648,002 3/1972 Durocher 200/86 R Primary ExaminerDavid Smith, Jr.

Attorney, Agent, or Firm-Learman & McCulloch gggg gwngi i3 Yawn-summon, UL'JAVAUA mwnm v [57] ABSTRACT A pressure sensitive switch useful in a mat of the kind adapted to operate a door in response to a persons stepping on the mat-comprises a switch assembly composed of a pair of sheet-like electrical conductors between which is interposed a sheet of resiliently compressible and expansible non-conductive material such as foamed rubber or plastic having a plurality of openings therethrough in each of which is accommodated a bridging member operable to establish a conductive path between the two conductors when the latter are moved relatively toward one another in response to the application to the mat of a compressive force. The switch assembly is enclosed within a non-conductive rubber or plastic sheath. Conductive wires connected to thetwo conductors of the switch assembly extend through the sheath for connection to a source of energy and to the actuating mechanism for the door to be operated.

Means are provided for limiting the compressive force to which said bridging member may be subjected.

17 Claims, 4 Drawing Figures PRESSURE SENSITIVE MAT SWITCH CONSTRUCTION rated in a that which, when stepped upon by a person,

will effect operation of mechanism for opening a normally closed door or the like. Mat switches of the kind referred to conventionally are located adjacent doors leading into and out of supermarkets, airports, and other public places so as to lie in the path of pedestrians approaching such doors. As a pedestrian approaches such a door he steps upon the mat, thereby compressing the latter and closing a normally open switch con tained in the mat so as to actuate a mechanism for opening the door automatically.

Conventional mat switches have many problems associated therewith. For example, most of the mat switches currently in use-employ a switch mechanism comprising a pair of conductive, metal plates held in spaced apart relation by a plurality of insulators. When a compressive force is applied to the upper plate it is deformed to engage the lower plate, thereby closing a circuit. If the compressive force is applied directly over one of the insulators, however, the insulator prevents engagement of the plates. Moreover, the force required to effect closing of the switch varies in accordance with the distance from an insulator that the force is applied. Other problems are created by this construction upon the installation of a mat switch on an uneven surface, by the entrapment of stones between the mat and its foundation, and the bending or warping of one or both of the steel plates.

Additional problems associated with metal plate mat switches of the kind referred to are those resulting from the sheer weight of the plates themselves and from the necessity of degreasing and cleaning the plates. Once the plates have been cleaned, they must be incorporated rather quickly in the switch assembly so as to prevent corrosion of the surfaces of the plates with consequent adverse effects on the electrical integrity of the switch assembly.

An object of this invention is to provide a mat switch construction which overcomes the disadvantages referred to above of previously known mat switches.

Another object of the invention is to provide a mat switch construction which enables operation of the switch at any part of the mat under a uniform force.

A further object of the invention'is to provide a mat switch of the character described and in which the switch assembly incorporates means for automatically protecting the switch assembly against damage due to the application of excessive forces.

Other objects and advantages of the invention will be pointed out specifically or will become apparent from the following description when it is considered'in conjunction with the appended claims and the accompanying drawings in which:

FIG. 1 is a plan view of a mat switch constructed in accordance with the invention with parts being broken away;

FIG. 2 is a sectional view taken on the line 2-2 of FIG. 1 and illustrating the switch in its open or nonconductive condition;

FIG. 3 is a view similar to FIG. 2, but illustrating the mat switch in its conductive condition; and

FIG. 4 is a vertical section view taken on the line 4-4 of FIG. I and illustrating the means for connecting the mat switch to a source of energy and to apparatus to be operated by the switch.

A switch assembly constructed in accordance with the invention comprises a flat sheet I of resiliently compressible and expansible, non-conductive material such as foamed rubber, polyurethane, or the like having a plurality of rows of spaced openings 2 extending therethrough. The openings in each row are uniformly spaced apart at about 2-inch intervals and adjacent rows are spaced about one inch apart, with the openings in adjacent rows staggered. Adhesively secured to the lower surface of the sheet I is a plurality of washers 3, each of which has a bore 4. The washers may be formed of any suitable phenolic or other nonconductive, rigid, relatively incompressible material. The washers 3 are so arranged that one washer is associated with one of the openings 2 and is so oriented with respect to its associated opening that the opening 2 and the bore 4 are coaxial. The washers constitute force limiting means as will be explained more fully hereinafter.

On opposite sides of the non-conductive sheet 1 are flexible, electrically conductive sheets 5 and 6 which preferably comprise copper screens. The screen 5 may be adhered to the sheet 1 by an adhesive 7, if desired. The adhesive 7 preferably is electrically conductive, of which there are many known kinds, but if the adhesive 7 is not conductive, then such adhesive will be omitted at the openings 2. The conductive screen 6 may have applied thereto a layer of adhesive 8 similar to the adhesive 7. Again, the adhesive maybe electrically conductive or non-conductive. In the latter case, the adhesive will be omitted at the openings 2.

Accommodated in each opening 2 and in the bore of the companion washer 3 is a resiliently compressible and expansible switching or bridging member 9, each of which preferably comprises a cylindrical module composed of an elastomeric, non-conductive material, such as silicone rubber, throughout which is dispersed a large quantity of electrically conductive, preferably spherical particles. Each bridging member may be electrically conductive in the absence of an external compressive force or, if desired, each bridging member may be non-conductive until it is subjected to a compressive force of predetermined magnitude. In either case, any one of the bridging members is capable of establishing an electrically conductive path between the conductive screens 5 and 6.

The initial condition of conductivity of the bridging members 9 is determined in general by the concentration of the conductive particles and by the state of the elastomer. If the elastomer resin contains a relatively large number of particles and is molded under pressure, the bridging member may be normally conductive. If the number of particles contained in the resin is less, or if the resin is molded in the absence of pressure, the bridging member may be normally non-conductive. In this case, the application of a compressive force on the bridging member effects relative movement of the particles so that a sufficient number thereof move into engagement and establish a conductive path through the elastomer. Upon removal of the compressive force the elastomer expands, thereby enabling the engaged particles to move out of engagement and break the conductive path.

I member must be subjected to render it conductive depends upon several factors, such as the size and concentration of the particles, the hardness of the elastomer, and the dimensions of the bridging member. These factors are described in detail in pending application Ser. No. 857,941 filed Sept. 15, 1969, and to which reference may be had for a more detailed disclosure. Such factors also may be determined empirically.

Following assembly of the members 1, 3, 5, 6, and 9 in the manner illustrated in FIG. 2, the assembly may be enclosed in a molded, non-conductive sheath 10 composed of two mating halves 11 and 12 of a resiliently compressible plastisol such as polyvinylchloride. The two halves of the sheath then may be secured to one another by ultrasonic welding or the like so as to provide an airand moisture-tight enclosure for the switch assembly.

When the switch assembly is enclosed within the sheath 10 the sheet 1 will be compressed adjacent each washer 3, as is shown clearly in FIG. 2, due to the presence of such washer. The height of each bridging member 9, however, is less than the spacing between the conductive screens 5 and 6 so as to preclude any possibility of establishing a current path between the screens. The relative diameters of the openings 2, the bore 4, and the members 9 are such that clearance exists around each member 9 when the latter is in its normal, uncompressed condition.

Any suitable means may be utilized to connect the conductors 5 and 6 to a source of energy and to apparatus to be operated. FIG. 4 discloses suitable connection means comprising an annular, resiliently compressible and expansible contact member 13, similar to the bridging members 9 except for its annular configuration, in engagement with the conductor 5 and in engagement with a conductive terminal 14 which extends through the sheath 10 for connection to a mechanism 15 to be operated electrically. A contact member 16 like the contact 13 engages the conductor 6 and a terminal 17 which is adapted for connection to a source of electrical energy. Between the terminals 14 and 17 is an annular insulator l8. Insulating grommets 19 and 20 overlie the screens 5 and 6, respectively. A rivet 21 maintains the grommets in axial alignment so as to subject the members 13 and 16 to sufficient compressive force to maintain them conductive. The terminals 14 and 15 are enclosed within an insulating sheath 22.

To condition a mat switch constructed according to the invention for operation, the sheath-enclosed switch assembly may, be positioned on a suitable foundation adjacent a door (not shown) with the terminal 14 connected to the door actuating mechanism 15 and the terminal 17 connected to an energy source. When a person steps on the upper surface of the sheath 10 a compressive force F is applied on the upper half 11 of the sheath so as to deform the latter and effect downward movement of the conductive screen 6 toward the conductive screen 5; Downward movement of the conductor 6 is accompanied by compression of the insulating sheet 1 so as to enable the conductor 6 to bear against the upper surface of at least one of the bridging members 9 and axially compress the latter between the conductors 5 and 6, thereby establishing a conductive path from the energy source through the conductor 6, through the bridging member 9, and through the conductor 6 to the mechanism 15. The larger diameters of the opening 2 and the washer bore 4 enable the member 9 to be expanded radially as it is compressed axially. Upon removal of the compressive force F, the resilience of the sheet 1 and the bridging members will restore the parts to the positions shown in FIG. 2.

A switch assembly adapted to be actuated by pedestrians must be capable of functioning under greatly varying forces. For example, such a switch should be operable by the weight of a child, as well as by the weight of a much heavier adult. Further, such a switch must be capable of accommodating an extermely high concentration of force, such as that imposed by the relatively small area of a womans shoe heel. A switch assembly according to the invention is capable of functioning under the greatly differing load factors referred to inasmuch as the sheath 10, the member 7, and the bridging members 9 are all resiliently compressible and the conductors 5 and 6 are flexible.

The switch assembly can withstand greatly excessive compressive forces inasmuch as the washers 3 protect the bridging members 9 against excessive compression due to the incompressibility of the washers themselves. Thus, when the switch assembly is in the condition shown in FIG. 3, an increase in the force F does not cause a corresponding increase in the compressive force applied to the adjacent bridging member 9 inasmuch as the latter cannot be compressed to a thickness less than that of the force limiting washer 3. The bridging members, therefore, are protected by the washers against destruction or deterioration due to excessive compression, irrespective of the force applied on the switch assembly.

The disclosed embodiment is representative of a presently preferred form of the invention, but is intended to be illustrative rather than definitive thereof. The invention is defined in the claims.

I claim:

1. A pressure sensitive switch assembly comprising a resilient, compressible, non-conductive member having an opening therethrough; electrical conductors spaced apart by said non-conductive member, the compressibility of said non-conductive member enabling relative movement of said conductors toward one another; bridging means accommodated in said opening and operable in response to relative movement of said conductors toward one another to establish a conductive path between said conductors; and means for limiting the compressive force to which said bridging means may be subjected irrespective of the extent to which said non-conductive member may be compressed.

2. An assembly according to claim 1 wherein said bridging means normally is non-conductive and is rendered conductive in response to compression thereof.

3. An assembly according to claim 1 wherein said bridging means normally is conductive and has a height less than the spacing between said conductors when said non-conductive member is in its uncompressed condition.

4. An assembly according to claim 1 wherein said limiting means comprises a relatively. incompressible member encircling said bridging member.

5. An assembly according to claim 4.wherein said relatively incompressible member is interposed between said non-conductive member and one of said conductors.

6. An assembly according to claim 1 including a nonconductive sheath enclosing said assembly.

7. An assembly according to claim6 wherein said sheath is composed of resilient material.

8. An assembly according to claim 1 including means for connecting at least one of said conductors to a source of electrical energy. I

9. An assembly according to claim 1 wherein at least one of said conductors comprises a metallic screen.

10. An assembly according to claim 9 wherein said screenis adhesively secured to said non-conductive member.

11. An assembly according to claim 1 wherein said bridging member comprises an elastomer throughout which is dispersed a plurality of electrically conductive particles.

12. An assembly according to claim 11 wherein the quantity of said particles is such that a sufficient number thereof are in engagement to establish a conductive path through said elastomer without the application of external compressive force to said elastomer.

13. An assembly according to claim 11 wherein the quantity of said particles is such that a conductive path may be established through said elastomer only upon the application of an external compressive force to said elastomer.

14. A pressure sensitive switch assembly comprising a pair of spaced apart sheet-like conductors; a sheetlike, non-conductive, resilient, relatively compressible and expansible member interposed between said conductors and having a plurality of spaced apart openings therethrough, the compressibility of said nonconductive member enabling relative movement of said conductors toward one another; a bridging member accommodated in each of said openings and operable in response to relative movement of said conductors toward one another to establish an electrically conductive path between said conductors; and relatively incompressible limit means interposed between said conductors adjacent each of said bridging members for limiting the extent of movement of said conductors toward one another and consequently limiting the compressive force to which said bridging members may be subjected.

15. An assembly according to claim 14 wherein each of said limit means comprises an annulus encircling a bridging member.

16. An assembly according to claim 15 wherein each of said annuli is interposed between said nonconductive member and one of said conductors.

17. An assembly according to claim 14 including a resilient, non-conductive sheath enclosing said assembly.

Claims (17)

1. A pressure sensitive switch assembly comprising a resilient, compressible, non-conductive member having an opening therethrough; electrical conductors spaced apart by said nonconductive member, the compressibility of said non-conductive member enabling relative movement of said conductors toward one another; bridging means accommodated in said opening and operable in response to relative movement of said conductors toward one another to establish a conductive path between said conductors; and means for limiting the compressive force to which said bridging means may be subjected irrespective of the extent to which said non-conductive member may be compressed.
2. An assembly according to claim 1 wherein said bridging means normally is non-conductive and is rendered conductive in response to compression thereof.
3. An assembly according to claim 1 wherein said bridging means normally is conductive and has a height less than the spacing between said conductors when said non-conductive member is in its uncompressed condition.
4. An assembly according to claim 1 wherein said limiting means comprises a relatively incompressible member encircling said bridging member.
5. An assembly according to claim 4 wherein said relatively incompressible member is interposed between said non-conductive member and one of said conductors.
6. An assembly according to claim 1 including a non-conductive sheath enclosing said assembly.
7. An assembly according to claim 6 wherein said sheath is composed of resilient material.
8. An assembly according to claim 1 including means for connecting at least one of said conductors to a source of electrical energy.
9. An assembly according to claim 1 wherein at least one of said conductors comprises a metallic screen.
10. An assembly according to claim 9 wherein said screen is adhesively secured to said non-conductive member.
11. An assembly according to claim 1 whereiN said bridging member comprises an elastomer throughout which is dispersed a plurality of electrically conductive particles.
12. An assembly according to claim 11 wherein the quantity of said particles is such that a sufficient number thereof are in engagement to establish a conductive path through said elastomer without the application of external compressive force to said elastomer.
13. An assembly according to claim 11 wherein the quantity of said particles is such that a conductive path may be established through said elastomer only upon the application of an external compressive force to said elastomer.
14. A pressure sensitive switch assembly comprising a pair of spaced apart sheet-like conductors; a sheet-like, non-conductive, resilient, relatively compressible and expansible member interposed between said conductors and having a plurality of spaced apart openings therethrough, the compressibility of said non-conductive member enabling relative movement of said conductors toward one another; a bridging member accommodated in each of said openings and operable in response to relative movement of said conductors toward one another to establish an electrically conductive path between said conductors; and relatively incompressible limit means interposed between said conductors adjacent each of said bridging members for limiting the extent of movement of said conductors toward one another and consequently limiting the compressive force to which said bridging members may be subjected.
15. An assembly according to claim 14 wherein each of said limit means comprises an annulus encircling a bridging member.
16. An assembly according to claim 15 wherein each of said annuli is interposed between said non-conductive member and one of said conductors.
17. An assembly according to claim 14 including a resilient, non-conductive sheath enclosing said assembly.
US3830991A 1973-07-24 1973-07-24 Pressure sensitive mat switch construction Expired - Lifetime US3830991A (en)

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US3830991A US3830991A (en) 1973-07-24 1973-07-24 Pressure sensitive mat switch construction
CA 204301 CA1045696A (en) 1973-07-24 1974-07-08 Pressure sensitive mat switch construction
DE19742432844 DE2432844A1 (en) 1973-07-24 1974-07-09 Pressure-sensitive switch arrangement
GB3051374A GB1454805A (en) 1973-07-24 1974-07-10 Pressure sensitive switch construction
JP8427374A JPS5042385A (en) 1973-07-24 1974-07-24

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Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3873795A (en) * 1973-04-28 1975-03-25 Lucas Electrical Co Ltd Electrical switch with reciprocating cam
US4137116A (en) * 1977-04-22 1979-01-30 Miller Brothers Method of making a pressure switch
US4164634A (en) * 1977-06-10 1979-08-14 Telaris Telecommunications, Inc. Keyboard switch assembly with multiple isolated electrical engagement regions
US4172216A (en) * 1978-05-19 1979-10-23 Sprague Electric Company Pressure sensitive switch
US4200777A (en) * 1977-04-22 1980-04-29 Miller Norman K Pressure switch
US4233523A (en) * 1978-01-31 1980-11-11 Lars Jarder Pressure sensitive device
US4308439A (en) * 1978-06-08 1981-12-29 Nissan Motor Company, Limited Switching device
EP0068133A2 (en) * 1981-06-12 1983-01-05 Wilhelm Ruf KG Switch disposition with an elastic switch element
US4401896A (en) * 1981-05-26 1983-08-30 Fowler Eugene W Weight or ambient pressure-responsive mechanical pressure switch
US4439647A (en) * 1982-07-14 1984-03-27 Nick Calandrello Touchpad keyboard
FR2543764A1 (en) * 1983-03-31 1984-10-05 Canon Kk Element of entry such as a table switch
US4570521A (en) * 1984-03-30 1986-02-18 Jeffrey Fox Electronic musical instrument with string-simulating switches
US4617433A (en) * 1984-06-25 1986-10-14 Bridgestone Corporation Pressure-sensitive conductive strip switch assembly and a method of manufacturing the same
EP0210002A1 (en) * 1985-07-04 1987-01-28 Uniroyal Limited Pressure responsive electrically conductive materials
US4701629A (en) * 1985-04-10 1987-10-20 Citroen Maxime H Switch control unit for motor vehicle
EP0293734A1 (en) * 1987-06-02 1988-12-07 LEDA Logarithmic Electrical Devices for Automation S.r.l. Two-dimensional electric conductor designed to function as an electric switch
US5239148A (en) * 1991-05-15 1993-08-24 Progressive Engineering Technologies Corp. Lane discriminating traffic counting device
US5322086A (en) * 1992-11-12 1994-06-21 Sullivan Robert A Hands-free, leg-operated, faucet-control device
US5602428A (en) * 1995-06-07 1997-02-11 Acrometal Companies, Inc. Switch mat with active threshold
US6611783B2 (en) 2000-01-07 2003-08-26 Nocwatch, Inc. Attitude indicator and activity monitoring device
US6748869B1 (en) * 1998-12-16 2004-06-15 Delegation Generale Pour L'armement Batiment La Rotonde Device for firing a primer
US20070163365A1 (en) * 2006-01-19 2007-07-19 Progressive Engineering Technologies Corp. Sensor apparatus and method
US20090236207A1 (en) * 2008-03-21 2009-09-24 Shenzhen Futaihong Precision Industry Co., Ltd. Key button structure for electronic device
US20090241621A1 (en) * 2008-03-26 2009-10-01 Shenzhen Futaihong Precision Industry Co., Ltd. Key assembly
US20150114814A1 (en) * 2013-10-30 2015-04-30 Panasonic Intellectual Property Management Co., Ltd. Pressure-sensitive switch, manufacturing method for same, touch panel including pressure-sensitive switch, and manufacturing method for touch panel
US20150116073A1 (en) * 2013-10-30 2015-04-30 Panasonic Intellectual Property Management Co., Ltd. Pressure-sensitive switch, manufacturing method for same, touch panel including pressure-sensitive switch, and manufacturing method for touch panel
US9799183B2 (en) 2013-12-06 2017-10-24 SkyBell Technologies, Inc. Doorbell package detection systems and methods

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2854459A1 (en) * 1978-12-16 1980-08-28 Fraunhofer Ges Forschung share safety device for systems with moving in the room
DE2901704C3 (en) * 1979-01-17 1981-10-08 Hans Dipl.-Ing. 5928 Laasphe De Osterrath
US4367385A (en) * 1981-01-26 1983-01-04 W. H. Brady Co. Capacitance switch
US4373122A (en) * 1981-01-26 1983-02-08 W. H. Brady Co. Capacitance switch
US4373124A (en) * 1981-01-26 1983-02-08 W. H. Brady Co. Capacitance switch
GB8314801D0 (en) * 1983-05-27 1983-07-06 Minnesota Mining & Mfg Electrical switch
DE3507922C2 (en) * 1985-03-06 1987-10-08 Mayser-Gmbh & Co, 7900 Ulm, De
GB9222643D0 (en) * 1991-10-29 1992-12-09 Eja Eng Plc A pressure sensitive mat
US5695859A (en) * 1995-04-27 1997-12-09 Burgess; Lester E. Pressure activated switching device
GB2304458B (en) * 1995-08-19 1999-02-24 Rover Group A detection system
GB9625181D0 (en) * 1996-12-04 1997-01-22 Hodgkinson & Corby Limited Inflatable cellular support cushion or mattress detector
GB2326283B (en) * 1997-06-13 1999-05-05 Brite Power International Limi Pressure pad,switch and alarm apparatus

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1775755A (en) * 1928-11-26 1930-09-16 Nat Pneumatic Co Treadle switch structure
US2625621A (en) * 1950-02-11 1953-01-13 Stanley Works Electric mat switch
US3648002A (en) * 1970-05-04 1972-03-07 Essex International Inc Current control apparatus and methods of manufacture

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2044080A (en) * 1935-07-31 1936-06-16 Charles R Kemper Circuit controlling device
JPS429734Y1 (en) * 1965-01-27 1967-05-26
JPS441744Y1 (en) * 1966-06-07 1969-01-23

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1775755A (en) * 1928-11-26 1930-09-16 Nat Pneumatic Co Treadle switch structure
US2625621A (en) * 1950-02-11 1953-01-13 Stanley Works Electric mat switch
US3648002A (en) * 1970-05-04 1972-03-07 Essex International Inc Current control apparatus and methods of manufacture

Cited By (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3873795A (en) * 1973-04-28 1975-03-25 Lucas Electrical Co Ltd Electrical switch with reciprocating cam
US4137116A (en) * 1977-04-22 1979-01-30 Miller Brothers Method of making a pressure switch
US4200777A (en) * 1977-04-22 1980-04-29 Miller Norman K Pressure switch
US4164634A (en) * 1977-06-10 1979-08-14 Telaris Telecommunications, Inc. Keyboard switch assembly with multiple isolated electrical engagement regions
US4233523A (en) * 1978-01-31 1980-11-11 Lars Jarder Pressure sensitive device
US4172216A (en) * 1978-05-19 1979-10-23 Sprague Electric Company Pressure sensitive switch
US4308439A (en) * 1978-06-08 1981-12-29 Nissan Motor Company, Limited Switching device
US4401896A (en) * 1981-05-26 1983-08-30 Fowler Eugene W Weight or ambient pressure-responsive mechanical pressure switch
EP0068133A2 (en) * 1981-06-12 1983-01-05 Wilhelm Ruf KG Switch disposition with an elastic switch element
EP0068133A3 (en) * 1981-06-12 1983-03-30 Wilhelm Ruf Kg Switch disposition with an elastic switch element
US4439647A (en) * 1982-07-14 1984-03-27 Nick Calandrello Touchpad keyboard
FR2543764A1 (en) * 1983-03-31 1984-10-05 Canon Kk Element of entry such as a table switch
US4570521A (en) * 1984-03-30 1986-02-18 Jeffrey Fox Electronic musical instrument with string-simulating switches
US4617433A (en) * 1984-06-25 1986-10-14 Bridgestone Corporation Pressure-sensitive conductive strip switch assembly and a method of manufacturing the same
US4701629A (en) * 1985-04-10 1987-10-20 Citroen Maxime H Switch control unit for motor vehicle
EP0210002A1 (en) * 1985-07-04 1987-01-28 Uniroyal Limited Pressure responsive electrically conductive materials
EP0293734A1 (en) * 1987-06-02 1988-12-07 LEDA Logarithmic Electrical Devices for Automation S.r.l. Two-dimensional electric conductor designed to function as an electric switch
US4876419A (en) * 1987-06-02 1989-10-24 Leda Logarithmic Electrical Devices For Automation S.R.L. Two-dimensional electric conductor designed to function as an electric switch
US5360953A (en) * 1991-05-15 1994-11-01 Progressive Engineering Technologies Corp. Lane discriminating traffic counting device
US5239148A (en) * 1991-05-15 1993-08-24 Progressive Engineering Technologies Corp. Lane discriminating traffic counting device
US5322086A (en) * 1992-11-12 1994-06-21 Sullivan Robert A Hands-free, leg-operated, faucet-control device
US5602428A (en) * 1995-06-07 1997-02-11 Acrometal Companies, Inc. Switch mat with active threshold
US6748869B1 (en) * 1998-12-16 2004-06-15 Delegation Generale Pour L'armement Batiment La Rotonde Device for firing a primer
US6611783B2 (en) 2000-01-07 2003-08-26 Nocwatch, Inc. Attitude indicator and activity monitoring device
US20070163365A1 (en) * 2006-01-19 2007-07-19 Progressive Engineering Technologies Corp. Sensor apparatus and method
US7460027B2 (en) * 2006-01-19 2008-12-02 Progressive Engineering Technologies Corp. Sensor cord array and method with conductive sensors for detecting activity on or around an object
US8008591B2 (en) * 2008-03-21 2011-08-30 Shenzhen Futaihong Precision Industry Co., Ltd. Key button structure for electronic device
US20090236207A1 (en) * 2008-03-21 2009-09-24 Shenzhen Futaihong Precision Industry Co., Ltd. Key button structure for electronic device
US20090241621A1 (en) * 2008-03-26 2009-10-01 Shenzhen Futaihong Precision Industry Co., Ltd. Key assembly
US20150114814A1 (en) * 2013-10-30 2015-04-30 Panasonic Intellectual Property Management Co., Ltd. Pressure-sensitive switch, manufacturing method for same, touch panel including pressure-sensitive switch, and manufacturing method for touch panel
US20150116073A1 (en) * 2013-10-30 2015-04-30 Panasonic Intellectual Property Management Co., Ltd. Pressure-sensitive switch, manufacturing method for same, touch panel including pressure-sensitive switch, and manufacturing method for touch panel
US9509303B2 (en) * 2013-10-30 2016-11-29 Panasonic Intellectual Property Management Co., Ltd. Pressure-sensitive switch, manufacturing method for same, touch panel including pressure-sensitive switch, and manufacturing method for touch panel
US9508504B2 (en) * 2013-10-30 2016-11-29 Panasonic Intellectual Property Management Co., Ltd. Pressure-sensitive switch, manufacturing method for same, touch panel including pressure-sensitive switch, and manufacturing method for touch panel
US9799183B2 (en) 2013-12-06 2017-10-24 SkyBell Technologies, Inc. Doorbell package detection systems and methods

Also Published As

Publication number Publication date Type
DE2432844A1 (en) 1975-02-13 application
JPS5042385A (en) 1975-04-17 application
CA1045696A (en) 1979-01-02 grant
CA1045696A1 (en) grant
GB1454805A (en) 1976-11-03 application

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