O Umted States Patent [19]
`Van Zeeland et a].
`
`USOO5747757A
`[11] Patent Number:
`[45] Date of Patent:
`
`5,747,757
`May 5, 1998
`
`[54] TAMPER RESISTANT MEMBRANE SWITCH
`
`4,901,074
`
`211990 Sinn et a1. ............................ .. 200/5 A
`
`[75] Inventors: Anthony J. Van Zeeland, Mesa. Ariz.;
`Robe" 5- Bidik waukcsha» Wis-
`_
`‘
`[73] Asslgnw MQmPaPel Tedlm’logles’ Inc“ WC“
`Alhs- Wls-
`
`[21] Appl. No.: 711,507
`_
`[221 F11¢d=
`Sep- 10, 1996
`[51] Int. CL° ........................... .. H01H 13/10; HOlH 1/10
`[52] US. Cl. ............ ..
`200/5 A; 200/512; 200/517
`[58] Field of Search ................................... .. 200/5 A. 159.
`200/292_ 516‘ 512_ 517
`
`[56]
`
`nefermces Cited
`
`OTHER PUBLICATIONS
`PiezoPanelTM Product Brochure.
`Technigraphics of Maryland. Inc., Baltimore. MD. Electron
`ics Products. (Nov. 1994). Piezoelectric Switch Panels.
`Interlink Electronics. Carpinteria. CA. Interlink Electronics.
`FSRTM Rugged Keypad.
`
`Primary Examiner-Peter S. Wong
`Assistant Examiner-Rajnikant B. Patel
`Mame)‘, Agent, 0' Fi""—RYa"~ M11“? Man" & Hmnfdd‘
`[57]
`ABSTRACT
`
`A tamper resistant membrane switch includes a backer plate
`and an overlying metal panel. Sandwiched between the
`backer plate and metal panel is a membrane switch subas
`sembly. A plurality of spacers between the backer plate and
`metal panel separate the two but allow the metal panel to
`115- Pm DOCUMENTS
`7/1972 Kidd, Jr. et a1. ................... .. 40/130 M dc?w ‘Wald the back" Plat‘? when external ?nger Pressum
`3,676,943
`4,065,649 1211977 Carter et a1. .......................... .. 20015 A is applied- Such de?ection 910898 Kh? underlying P01cs 0f the
`4,228,330 10/1980 Larson .
`membrane switch subassembly to actuate the switch. The
`4,303,811 1211981 Parkinson .............................. .. 200/5 A
`positioning and size of the spacers determines where de?ec
`4,317,013
`2/1932 Larson -
`tion can occur and how much force is needed to actuate the
`2005 A
`_
`I};
`:23" -
`switches. The overlying panel. being formed of solid metal
`4/1986 Yoshihara ............................. .. 20015 A
`elrsagzttant to damage from
`l/1987 Taguchi .
`9/1988 DeSmet .
`4/1989 Ipcinski et a1. .
`
`4,580,018
`4,639,559
`4,771,139
`4,818,827
`
`eWlCZ m
`
`............... -.
`
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`
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`‘
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`20 Claims, 3 Drawing Sheets
`
`Apple Inc., et al.
`Exhibit 1013
`Apple Inc., et al. v. Global Touch Solutions, Inc.
`IPR2015-01175
`
`Exhibit 1013, Page 001
`
`

`
`US. Patent
`
`May s, 1998
`
`Sheet 1 0f 3
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`5,747,757
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`Exhibit 1013, Page 002
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`

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`US. Patent
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`May s, 1998
`
`Sheet 2 of 3
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`5,747,757
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`Exhibit 1013, Page 003
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`

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`US. Patent
`
`May s, 1998
`
`Sheet 3 of 3
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`5,747,757
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`Exhibit 1013, Page 004
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`

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`5,747,757
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`2
`It is an object of the present invention to provide a new
`and improved membrane switch assembly.
`It is a further object of the invention to provide a new and
`improved membrane switch assembly that is durable and
`free of knobs. buttons or exposed. physically delicate struc
`tures.
`It is a further object of the invention to provide a new and
`improved membrane switch assembly that is suited for use
`in unattended. publicly accessible machines that are often
`the targets of vandalous attack.
`It is a further object of the invention to provide a tamper
`resistant membrane switch assembly that is effective in use.
`that is relatively immune to false actuation and that is
`economical in manufacture.
`
`1
`TAMPER RESISTANT MEMBRANE SWITCH
`BACKGROUND OF THE INVENTION
`This invention relates generally to membrane switches
`and. more particularly. to membrane switch assemblies that
`are used. for example. on vending machines. washing
`machines or other devices made available for use by mem
`bers of the public in a commercial or business setting.
`Membrane switches are well-known in the electrical
`switch art. Such switches are frequently used in ?ush panel
`controls and typically include a membrane supported over
`and spaced from a substrate. Finger pressure applied to the
`switch pushes a conductive pad on the membrane into
`contact with a similar pad on the substrate. Contact between
`the pads closes the switch and completes the electrical
`circuit. Membrane switches are particularly well-suited for
`use in certain environments wherein it is desired to seal an
`electronic system against moisture. dust etc.
`One application in which membrane switches have par
`ticular utility is in commercial vending machines. laundro
`mat washing machines and the like. Such machines. which
`are typically left unattended in publicly accessible areas. are
`the frequent targets of thieves and vandals. One approach to
`combating thievery and vandalism centers on improving the
`physical integrity of the machine itself. thereby making it
`harder for lawbreakers to break into or otherwise physically
`damage the machine. Electrical switches and controls,
`which. necessarily. must remain responsive to relatively
`light input forces applied by legitimate users. are particu
`larly vulnerable to damage by thieves and vandals. Although
`membrane switches are advantageous in that they eliminate
`protruding knobs, buttons and levers that are easily broken.
`such membrane switches have. until now. employed exposed
`plastic ?lms and overlays that were susceptible to physical
`or cosmetic damage when subjected to vandalous attack. For
`commercial operators who lose money when machines are
`not in operating condition. “down time” due to vandalism or
`even ordinary wear and tear is a signi?cant concern.
`SUMMARY OF THE INVENTION
`The invention provides a membrane switch assembly
`having a backer plate. a membrane switch subassembly
`disposed over the hacker plate and a metallic overlay
`disposed over the membrane switch subassembly.
`The invention also provides a membrane switch assembly
`including a backer plate. a membrane switch subassembly
`disposed over the backer plate and a protective. tamper
`resistant overlay disposed over the membrane switch sub
`assembly.
`The invention also provides a tamper resistant membrane
`switch assembly including a substantially rigid backer plate
`de?ning a substantially planar upper surface and a plurality
`of stando?s adjacent the upper surface of the backer plate
`arranged so as to divide the upper surface of the backer plate
`into a plurality of switch-element receiving cells. The
`assembly further includes a plurality of membrane switch
`elements disposed over the upper surface of the hacker plate
`and received in the switch-element receiving cells. A sub
`stantially rigid. substantially planar protective panel overlies
`the backer plate and the membrane switch elements. The
`protective panel is supported by the standoifs in the regions
`between the switch-element receiving cells and is unsup
`ported in the regions over the switch-element receiving cells
`so as to be deformable toward the hacker plate and into
`contact with individual ones of the membrane switch ele
`ments substantially in the regions over the switch-element
`receiving cells.
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`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The features of the invention which are believed to be
`novel are set forth with particularity in the appended claims.
`The invention. together with the further objects and advan
`tages thereof. may best be understood by reference to the
`following description taken in conjunction with the accom
`panying drawings. wherein like reference numerals identify
`like elements. and wherein:
`FIG. 1 is a perspective view of a coin-operated.
`commercial-duty washing machine having a tamper resis
`tant membrane switch assembly embodying various features
`of the invention.
`FIG. 2 is an exploded perspective view of the tamper
`resistant membrane switch assembly shown in FIG. 1.
`FIG. 3 is a sectional view of a typical membrane switch
`element used at various locations in the tamper resistant
`membrane switch. useful in understanding the operation
`thereof.
`FIG. 4 is a sedrional view of the tamper resistant mem
`brane switch shown in FIG. 1 taken along line 4-—4 thereof.
`FIG. Sis a sectional view. similar to FIG. 4. showing the
`switch in an actuated condition.
`FIG. 6 is a sectional view of another embodiment of a
`tamper resistant membrane switch embodying various fea
`tures of the invention.
`FIG. 7 is a sectional view of still another embodiment of
`a tamper resistant membrane switch embodying various
`features of the invention.
`FIG. 8 is a sectional view of still another embodiment of
`a tamper resistant membrane switch embodying various
`features of the invention.
`FIG. 9 is a plan view of an alternate embodiment of a
`metal front plate or overlay used in a tamper resistant
`membrane switch embodying various features of the inven
`tion.
`FIG. 10 is a sectional view of the metal front plate shown
`in FIG. 9 taken along line 10—l0 thereof.
`FIG. 11 is a plan view of another alternate embodiment of
`a metal front plate or overlay used in a tamper resistant
`membrane switch embodying various features of the inven
`tion.
`FIG. 12 is a sectional view of the metal front plate shown
`in FIG. 11 taken along line 12-42 thereof.
`FIG. 13 is a plan view of still another alternate embodi
`ment of a metal front plate or overlay used in a tamper
`resistant membrane switch embodying various features of
`the invention.
`FIG. 14 is a sectional view of the metal front plate shown
`in FIG. 13 taken along line l4—14 thereof.
`
`65
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`Exhibit 1013, Page 005
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`

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`3
`DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`Referring to the drawings. and. in particular. to FIG. 1. a
`tamper resistant membrane switch assembly 10 embodying
`various features of the invention is shown. As illustrated. the
`switch assembly 10 is shown in the context of a commercial.
`coin-operated washing machine 12 of the type commonly
`found in Laundromats. Such machines are often left unat
`tended in publicly accessible area where they are frequently
`the targets of vandalism or attempted thievery. Other types
`of machines. such as coin-operated vending machines. tele
`phones etc.. are also subject to similar attack. Accordingly.
`it will be understood that the washing machine 12 is only
`one example of the type of device in which the switch
`assembly 10 can be used to advantage. It will be appreciated
`that the switch assembly 10 can be effectively used in a
`variety of other applications as well.
`The tamper resistant membrane switch assembly 10 pro
`vides a generally planar. uniform and continuous outer
`surface 16 that is substantially impervious to physical attack.
`At the same time. the switch assembly permits convenient
`user-control over machine operation through a plurality of
`manually actuable individual switches 18. The individual
`switches are not separate elements mounted on the outer
`surface 16. but. rather. comprise particular regions on the
`surface. When a pre-designated region on the outer surface
`is pushed or pressed. a desired control e?’ect is achieved. In
`accordance with one aspect of the invention. the desired
`control effects are not actuated if the surface 16 is pushed or
`pressed in areas other than the pre-designated regions com
`prising the individual switches 18.
`Refen'ing to the exploded view of FIG. 2. the tamper
`resistant membrane ,gvwitch 10 includes a hacker plate 20. a
`membrane switch subassembly 22 disposed over the backer
`plate 20 and a protective. durable. substantially continuous
`and substantially planar overlay 24 disposed over the mem
`brane switch subassembly 22. In the illustrated embodiment.
`the overlay comprises a rigid. durable. yet partially deform
`able metal sheet or panel. formed. for example. from
`approximately 0.030 inch stainless steel or aluminum. It will
`be appreciated that other durable materials. such as Lucite.
`Kevlar or tempm'ed glass. can also be advantageously used
`as the overlay 24.
`The membrane switch subassembly 22 includes a mem
`brane 26 disposed over a substrate 28. Conductive pads 30
`are deposited onto the membrane 26 and the substrate 28
`using known techniques. as are conductive runners 32. The
`conductive pads 30 are arranged so that they overlap or
`overlie each other in pairs. Conductive pads that overlie each
`other form a switch element 34 (FIG. 3) that can be actuated
`independently of the switch elements formed by the remain
`ing pads. The runners 32 interconnect the switch elements
`34 with the outside world.
`In accordance with known membrane switch techniques.
`and as illustrated in FIG. 3. the opposed conductive pads 30
`of the membrane 26 and substrate 28 are ordinarily held out
`of contact with each other by means of a spacer layer 36. The
`pads 30. however. are brought into contact to complete a
`circuit when they are pressed together. The particular type of
`membrane switch technology employed is not critical to the
`invention. and a variety of membrane switch subassemblies
`22 can be used.
`In further accordance with the invention. and referring
`further to FIGS. 2 and 4. a plurality of standoffs 38 are
`disposed between the backer plate 20 and the overlay 24.
`These standoffs 38. which in the ?gures are shown exag
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`gerated in size for clarity. ordinarily keep the overlay spaced
`su?iciently from the backer plate 20 to avoid actuating the
`individual switch elements 34 of the membrane switch
`subassembly 22. Preferably. the standolfs 38 are located so
`as to de?ne areas or cells for receiving the switch elements.
`Preferably the stando?’s 38 are located between the cells so
`that the overlay 24 is supported in the areas between the cells
`but is unsupported in the areas over the cells.
`As best seen in FIGS. 4 and 5. the standoffs 38 hold the
`overlay 24 away from the backer plate 20 and the switch
`element 34 when no external forces are applied (FIG. 4). but
`permit the overlay to ?ex inwardly when pressed (FIG. 5)
`and thereby actuate the switch element 34. The standotfs 38.
`being located between the various switch receiving cells.
`substantially keep the overlay from ?exing between the
`cells. This helps ensure that the various switch elements 34
`are actuated only when an external force is applied directly
`over the switch element and not when an o?i-center force is
`applied.
`As further illustrated in FIGS. 4 and 5. the stando?s 38
`can be integrally formed on the backer plate 20 by emboss
`ing them from the rear. The stando?s 38 project through
`appropriately sized and located holes 40 formed in the
`membrane 26 and substrate 28. Although round. post-like
`standotfs 38 arranged in a rectangular or square pattern are
`shown for illustrative purposes. it will be appreciated that
`the standoifs 38 can be formed into other con?gurations
`ranging. for example. from simple posts at the edges of the
`active switch area to full scale ridges around the perimeter
`of the switch.
`Various alternatives to the con?guration shown in FIGS.
`1—5 can be used. An alternative to forming the standoffs 38
`on the hacker plate 20 is to provide them. for example. on
`the front surface of the membrane 26 and over the spacer
`layer 36 as shown in FIG. 6.
`The actuation model of the tamper resistant membrane
`switch 20 closely approximates that of a ?exing beam. at
`least in cross-section. In some cases. it is desirable that the
`contact point between the overlay 24 and the membrane 26
`be concentrated at the center of the switch element 34. To
`achieve this. a thin additional. or actuator. stando? 42 can be
`adhesively bonded to the top surface of the membrane 26 as
`shown in FIG. 7. Similar results can be achieved by emboss
`ing a center post 44 into the backer plate 20 at the center of
`the switch element 34 as shown in FIG. 8. Similar results can
`also be achieved by embossing the overlay 24. To this end.
`the overlay 24 can. for example. be provided with ring
`embossing 46 as shown in FIGS. 9 and 10. pillow embossing
`48 as shown in FIGS. 11 and 12 or Braille embossing 50 as
`shown in FIGS. 13 and 14. Generally speaking. a standoff of
`some sort could also be applied as a discrete component or
`screened to the backer plate 20 or overlay 2A in place of the
`integrally formed actuator standotfs shown in the ?gures.
`Either concept will provide the effect of concentrating the
`force in the center of the switch.
`Preferably. the membrane switch elements 34 have rela
`tively large active areas. This provides a large target area for
`switching and further provides relatively low intrinsic
`switch actuation forces. Low intrinsic switch actuation
`forces are desirable in that these are added to the forces
`needed to de?ect the overlay. Thus. reasonable overall
`switch actuation forces are best achieved if intrinsic switch
`actuation forces are kept low.
`Preferably. the overlay 24 is “?oated” to allow the switch
`actuation mechanism to be one of de?ection rather than
`tensile stress. Similarly. the membrane switch subassembly
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`65
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`Exhibit 1013, Page 006
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`

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`5
`22 is not bonded to the backer plate 20 in order to avoid
`spontaneous actuation or buckling of the switch layers 26.
`28 resulting from differential expansion effects due to tem
`perature or moisture. For positioning. the membrane switch
`subassembly may be tacked.
`Preferably. functional indicia. graphics or other labeling
`52 are screened onto the front or back of the overlay 24
`depending upon whether the overlay is transparent or
`opaque. The graphics can also be applied to a ?lm layer that
`is bonded to the front surface of the overlay.
`_
`It will be appreciated that the tamper resistant membrane
`switch 10 disclosed herein provides a continuous. durable
`outer operating surface that is free of knobs. buttons or other
`projections that are vulnerable to vandalous attack.
`Accordingly. the tamper resistant membrane switch 10 is
`well suited for applications in which the potential for
`physical abuse exists. It will also be appreciated that.
`although the invention is well suited for use in applications
`where tamper resistance is desired. the invention is also well
`suited for use wherein tamper resistance is not of concern
`and where the primary desire is the esthetic effect provided
`by the brushed aluminum or stainless steel look provided by
`the invention.
`While a particular embodiment of the invention has been
`shown and described. it will be obvious to those skilled in
`the art that changes and modi?cations can be made without
`departing from the invention in its broader aspects. and.
`therefore. the aim in the appended claims is to cover all such
`changes and modi?cations as fall within the true spirit and
`scope of the invention.
`I claim:
`1. A membrane switch assembly comprising:
`a backer plate;
`a membrane switch subassembly disposed over the backer
`plate. the membrane switch subassembly including a
`plurality of individual switch elements;
`a metallic overlay disposed over the membrane switch
`subassembly and de?ectable toward the hacker plate in
`response to an applied actuating force. and
`structure between the backer plate and the metallic over
`lay for con?ning de?ection of the metallic overlay to
`areas substantially adjacent the applied actuating force
`so that substantially only single ones of the individual
`switch elements are actuated in response to application
`of the actuating force.
`2. A membrane switch assembly as de?ned in claim 1
`wherein the structure comprises a plurality of standolfs
`between the backer plate and the metallic overlay for spac
`ing the metallic overlay from the backer plate with the
`membrane switch subassembly between the backer plate and
`the metallic overlay.
`3. A membrane switch assembly as de?ned in claim 2
`wherein the stando?'s are integrally formed on the hacker
`plate.
`4. A membrane switch assembly as de?ned in claim 2
`wherein the standoffs are bonded to the backer plate.
`5. A membrane switch assembly as de?ned in claim 2
`wherein the standoifs are disposed on the metallic overlay.
`6. A membrane switch assembly as de?ned in claim 2
`wherein the standoffs are disposed on the membrane switch
`subassembly.
`7. A membrane switch assembly as de?ned in claim 1
`further comprising an actuating stando? interposed between
`the hacker plate and the metallic overlay and engageable
`with the membrane switch subassembly.
`8. A membrane switch assembly as de?ned in claim 7
`wherein the actuating stando?‘s are disposed substantially
`adjacent the center of each of the individual switch elements.
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`9. A membrane switch assembly as de?ned in claim 8
`wherein the actuating stando?’s are carried on the hacker
`plate.
`10. A membrane switch assembly as de?ned in claim 7
`wherein the actuating standoifs are carried on the metallic
`overlay.
`11. A membrane switch assembly as de?ned in claim 7
`wherein the actuating standoffs are carried on the membrane
`switch subassembly.
`12. A membrane switch assembly comprising:
`a hacker plate;
`a membrane switch subassembly disposed over the backer
`plate. the membrane switch subassembly including a
`plurality of individual switch elements;
`a protective. tamper-resistant overlay disposed over the
`membrane switch subassembly and de?ectable toward
`the hacker plate in response to an applied actuating
`force. and
`structure between the hacker plate and the overlay for
`con?ning de?ection of the overlay to areas substan
`tially adjacent the applied actuating force so that sub
`stantially only single ones of the individual switch
`elements are actuated in response to application of the
`actuating force.
`13. A membrane switch assembly as de?ned in claim 12
`wherein the tamper-resistant overlay is formed of stainless
`steel.
`14. A membrane switch assembly as de?ned in claim 12
`wherein the tamper-resistant overlay is formed of aluminum.
`15. A membrane switch assembly as defined in claim 13
`wherein the tamper-resistant overlay is formed of a rigid
`durable plastic.
`16. A membrane switch assembly as de?ned in claim 12
`wherein the tamper-resistant overlay is formed of tempered
`glass.
`17. A tamper resistant membrane switch assembly com
`prising:
`a substantially rigid backer plate de?ning a substantially
`planar upper surface;
`a plurality of standoffs adjacent the upper surface of the
`hacker plate and arranged so as to divide the upper
`surface of the backer plate into a plurality of switch
`element receiving cells;
`a plurality of membrane switch elements disposed over
`the upper surface of the backer plate and received in the
`switch-element receiving cells; and
`a substantially rigid. substantially planar protective panel
`overlying the hacker plate and the membrane switch
`elements. the protective panel being supported by the
`stando?‘s in the regions between the switch-element
`receiving cells and unsupported in the regions over the
`switch-element receiving cells so as to be deformable
`toward the backer plate and into contact with individual
`ones of the membrane switch elements substantially in
`the regions over the switch-element receiving cells.
`18. A tamper resistant membrane switch assembly as
`de?ned in claim 17 wherein the standoffs comprise posts.
`19. A tamper resistant membrane switch assembly as
`de?ned in claim 17 wherein the standoifs comprise ridges
`around the switch-element receiving cells.
`20. A tamper resistant membrane switch assembly as
`de?ned in claim 17 wherein the protective panel is embossed
`in the regions overlying the switch-element receiving cells.
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`5.747.757
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`Exhibit 1013, Page 007