US3594522A - Elastic diaphragm switch - Google Patents

Elastic diaphragm switch Download PDF

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Publication number
US3594522A
US3594522A US844349A US3594522DA US3594522A US 3594522 A US3594522 A US 3594522A US 844349 A US844349 A US 844349A US 3594522D A US3594522D A US 3594522DA US 3594522 A US3594522 A US 3594522A
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US
United States
Prior art keywords
diaphragm
contact
switch assembly
board
adhered
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US844349A
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English (en)
Inventor
Donald F Colglazier
Myron E Snesrud
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Application granted granted Critical
Publication of US3594522A publication Critical patent/US3594522A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/70—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard
    • H01H13/78—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard characterised by the contacts or the contact sites
    • H01H13/785—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard characterised by the contacts or the contact sites characterised by the material of the contacts, e.g. conductive polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/70—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard
    • H01H13/702—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2201/00—Contacts
    • H01H2201/022—Material
    • H01H2201/03—Composite
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2203/00—Form of contacts
    • H01H2203/022—Helical networks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2203/00—Form of contacts
    • H01H2203/036—Form of contacts to solve particular problems
    • H01H2203/05—Form of contacts to solve particular problems to avoid damage by deformation of layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2207/00—Connections
    • H01H2207/012—Connections via underside of substrate
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2209/00—Layers
    • H01H2209/006—Force isolators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2213/00—Venting
    • H01H2213/002—Venting with external pressure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2221/00—Actuators
    • H01H2221/008—Actuators other then push button
    • H01H2221/02—Actuators other then push button pneumatic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2229/00—Manufacturing
    • H01H2229/044—Injection moulding

Definitions

  • Elastic diaphragm switches have commonly been made by adhering a layer of conductive material to a flexible substrate such as polyester film with an overlying coversheet of elastic material to further resist abrasion or permanent deformation.
  • a layer of conductive material to a flexible substrate such as polyester film with an overlying coversheet of elastic material to further resist abrasion or permanent deformation.
  • Multiple layers of deformable materials and the impairment of the flexibility caused by the presence of conductors increases the necessary operating pressures required and limits the density of switches that may be placed in a given space. Further the fatigue of conductors induced by the flexing action limited the effective life of the individual switches.
  • This invention is directed to an elastic diaphragm switch utilizing a thin film of highly flexible material formed as an airtight diaphragm.
  • the diaphragm is deflected through such distances as 0.012 inch rather than the more typical 0.002 inch using the less flexible substrate materials such as previously utilized.
  • the copper conductive pattern extending from the diaphragm carriedcontact to a stationary lead extends in a helical'pattern to thereby approach a disposition perpendicular to the radial elongation of the diaphragm material and reduce the conductor flcxure per unit length to minimize the fatigue load to which the conductor is subjected. This simultaneously reduces the impairment of diaphragm flexibility caused by the adhered conductive material.
  • the diaphragm switch made in accordance with the present invention is high speed and economical. Using thin film polymer plastics, it has been possible to achieve response rates of 2,000 cycles per second using a 0.005 inch gap. Further, with diaphragm assembly packaging densities such as 16 per square inch, the structure can be readily fabricated at low cost by automated paging or sheeting techniques. Also, the low masses involved in the structure cause the device to be virtually shockproof.
  • FIG. 1 is an enlarged elevation view of a document punching and verification device utilizing the elastic diaphragm switch construction of this invention.
  • FIG. 2 is a section viewv taken along line 2--2 of FIG. 1.
  • FIG. 3 is an isometric view of the elastic diaphragm switch housing including the stationary contact circuit board which is an insert in the molded housing.
  • FIG. 4 is an isometric view of the stationary contact circuit board showing the major surface opposite that visible in FIG. 3.
  • FIG. 5 is an exploded view of the diaphragm and substrate assembly.
  • FIG. 6 is a fragmentary view of the elastic diaphragm material showing the conductor pattern extending from the stationary diaphragm portion to the movable contact.
  • FIG. 7 is an enlarged partial section of the diaphragm assembly including the rigid substrate and flexible membrane.
  • the elastic diaphragm switch assembly '10 is shown as a punch checking or verifying device fora parallel punch where a card passing in parallel, row by row through the punch station along the card guide surface 12 has rows of information punched therein. Two rows subsequent to the punching operation, the card is read to verify the information entered. For each punch element 13 there is a corresponding read position where a jet of air supplied through an orifice 14 is received by a passageway 15 whenever an unpunched card surface is not present to act as a valve.
  • the aligned orifice l4 delivers air to the passageway 15
  • the elevated pressure applied at the terminal end of such passage causes the diaphragm 18 extending over a fluidtight circular interface with the board 19 to be flexed outward therefrom bringing into engagement the aligned contacts carried by the diaphragm 18 and the stationary circuit board 20.
  • the switch assembly 10 in the environment shown has normally closed contacts as the passages 15 are subjected to airflow from the respectively aligned orifices 14.
  • a punched card guided along surface 12 and passing through the read-verify station serves as a valve intermediate the orifices and aligned passageways.
  • the logic circuits as sociated with the device which are activated when a card is present would find the matrix to consist of normally open switches and through the read timing circuit sense when a punched hole has permitted the associated diaphragm switch contacts to be closed.
  • the elastic diaphragm switch assembly 10 includes a molded housing 21 which has a circuit board 20 held captive as an insert and a diaphragm assembly 23 which is received by the housing in abuttingrelation with shoulder 25 and is aligned by the surrounding wall surface 26.
  • the circuit board 20 is also shown in FIGS. 3 and 4. As seen in FIG. 4 the epoxy circuit board has a series of terminals 28 individually connected to contacts 29 which are plated through apertures 30 (shown in FIG. 2) in the circuit board to the enlarged contact surfaces 31 on the opposite surface that l are disposed within the housing as seen in FIG. 3.
  • the extended surface contacts 31 provide the stationary contacts of the elastic diaphragm switch assembly.
  • the diaphragm assembly 23, as shown exploded in FIG. 5, is fabricated starting with epoxy board 19 which is provided with a series of apertures 35. Surrounding each of the apertures is a coating 36 of nonstick material, such as a flurocarbon in a carrier which does not adhere to the diaphragm material, applied in a circular pattern radially outward from each of the apertures. This nonstick material is selected to prevent adhesion between the circuit board and the subsequently applied overlying elastic film. The remaining surface 37 is coated with an adhesive. Over the surface which has thus been selectively coated with nonstick material and adhesive, a film 38 of highly flexible material is applied which carries a conductive layer on the exposed surface.
  • nonstick material such as a flurocarbon in a carrier which does not adhere to the diaphragm material
  • the conductive material is thereafter etched to form an extended helical conductor path 40 from the stationary conductor portion 41 disposed on the film portion adhered to the board and across the boundary 43 between adhered and nonadhered interfaces to the central contact 42 overlying the nonadhered interface.
  • the common circuit 40 printed on the diaphragm 38 is connected to a terminal on circuit board 20 by a conductor 39 which extends along the interface between gasket 48 and diaphragm assembly 23 and between mounting plate 45 and housing 21.
  • Diaphragm assembly 23 is shown in enlarged form.
  • the major dimensions of the diaphragm assembly are 1 inch by one-half inch which yields a packaging density within the matrix of 16 switches per square inch.
  • the diaphragm 38 is a 0.001 inch polymer film carrying a circuit of 9% ounce copper which is gold plated.
  • the switches are actuated by air delivered from the aligned orifice 14 at a pressure of 1 pound per square inch.
  • the elastic diaphragm is shown in an assembled section view in FIG. 2 with passageways leading to the diaphragm chambers formed in mounting plate 45 and completed by a closure member 46. Continuity of the passageway between mounting plate and board apertures and the separation of individual passages therebetween is maintained by the flexible gasket 48 having a series of aligned openings 49.
  • the individual elastic diaphragm switch assemblies are secured to the mounting plate by straps 50 which margin each transverse side. Conductors 52 leading from the circuit board terminals are clamped between housing flange 53 and a pressure block 54 to afford strain relief.
  • a diaphragm switch assembly comprising:
  • a first contact carried by a substantially rigid insulating support element
  • a diaphragm assembly including a flexible, electrically insulating diaphragm, supported in spaced relation to said support element;
  • diaphragm switch assembly of claim 1 wherein said diaphragm comprises an elastic film and said conductive lead comprises a metal surface portion plated on said elastic film.
  • said lead extending in a generally spiral path from said contact across the boundary between said adhesively bonded and nonadhesively bonded interfaces.
  • the diaphragm switch assembly of claim 2 further comprising: 1
  • said diaphragm material overlying said one major surface of said board and selectively adhered to said board at least in area portions margining. said discrete area to form a fluidtight interface between said board and diaphragm material;
  • passage means formed in said board member communicating with each of said fluidtight interfaces.
  • a diaphragm switch assembly comprising:

Landscapes

  • Push-Button Switches (AREA)
  • Switches Operated By Changes In Physical Conditions (AREA)
  • Manufacture Of Switches (AREA)
US844349A 1969-07-24 1969-07-24 Elastic diaphragm switch Expired - Lifetime US3594522A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US84434969A 1969-07-24 1969-07-24

Publications (1)

Publication Number Publication Date
US3594522A true US3594522A (en) 1971-07-20

Family

ID=25292475

Family Applications (1)

Application Number Title Priority Date Filing Date
US844349A Expired - Lifetime US3594522A (en) 1969-07-24 1969-07-24 Elastic diaphragm switch

Country Status (5)

Country Link
US (1) US3594522A (enrdf_load_stackoverflow)
JP (1) JPS4812707B1 (enrdf_load_stackoverflow)
DE (1) DE2036453C3 (enrdf_load_stackoverflow)
FR (1) FR2056198A5 (enrdf_load_stackoverflow)
GB (1) GB1251639A (enrdf_load_stackoverflow)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3783243A (en) * 1971-06-25 1974-01-01 Ibm Pneumatic reading system for document cards
US3814877A (en) * 1972-10-17 1974-06-04 Jonathan Mfg Co Pressure switch with diaphragm and adjustable contact
US3860772A (en) * 1973-04-30 1975-01-14 Carter Precision Electric Co Air pressure responsive switch for vehicle tire and the like with hinged contact and diaphragm
US3968336A (en) * 1974-09-23 1976-07-06 Xerox Corporation Keyboard switch assembly having movable contact, and supporting helicline type legs disposed co-planar to common conductive sheet
US5728986A (en) * 1996-12-20 1998-03-17 Eaton Corporation Block mounting of pressure switch cartridge
US5998745A (en) * 1998-03-31 1999-12-07 Agfa Corporation Vacuum detection switch

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6050590B2 (ja) * 1977-08-18 1985-11-09 第一電子工業株式会社 印刷回路板用フレキシブル積層板

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US541243A (en) * 1895-06-18 manger
US2798130A (en) * 1953-05-22 1957-07-02 Cutler Hammer Inc Electric switch devices
US2811599A (en) * 1953-10-15 1957-10-29 Statham Lab Inc Liquid pressure operated electrical switch
US3009032A (en) * 1959-05-26 1961-11-14 Bendix Corp Sealed pressure switch
US3240885A (en) * 1963-05-07 1966-03-15 Western Electric Co Multiple switching apparatus
US3267233A (en) * 1964-01-31 1966-08-16 Sperry Rand Corp Pneumatic transducer
US3308253A (en) * 1965-03-25 1967-03-07 Ibm Diaphragm switch having a diaphragm supported on an incompressible layer and an elastomer overlaying the diaphragm
US3331040A (en) * 1963-05-13 1967-07-11 Int Standard Electric Corp Miniature diaphragm relay
GB1108593A (en) * 1964-02-13 1968-04-03 Oasis Technical Invest Ltd Window and the combination thereof with alarm means
US3492420A (en) * 1967-05-29 1970-01-27 Telautograph Corp Platen switch
US3515828A (en) * 1968-03-01 1970-06-02 Singer General Precision Fluidic to electronic converter

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US541243A (en) * 1895-06-18 manger
US2798130A (en) * 1953-05-22 1957-07-02 Cutler Hammer Inc Electric switch devices
US2811599A (en) * 1953-10-15 1957-10-29 Statham Lab Inc Liquid pressure operated electrical switch
US3009032A (en) * 1959-05-26 1961-11-14 Bendix Corp Sealed pressure switch
US3240885A (en) * 1963-05-07 1966-03-15 Western Electric Co Multiple switching apparatus
US3331040A (en) * 1963-05-13 1967-07-11 Int Standard Electric Corp Miniature diaphragm relay
US3267233A (en) * 1964-01-31 1966-08-16 Sperry Rand Corp Pneumatic transducer
GB1108593A (en) * 1964-02-13 1968-04-03 Oasis Technical Invest Ltd Window and the combination thereof with alarm means
US3308253A (en) * 1965-03-25 1967-03-07 Ibm Diaphragm switch having a diaphragm supported on an incompressible layer and an elastomer overlaying the diaphragm
US3492420A (en) * 1967-05-29 1970-01-27 Telautograph Corp Platen switch
US3515828A (en) * 1968-03-01 1970-06-02 Singer General Precision Fluidic to electronic converter

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3783243A (en) * 1971-06-25 1974-01-01 Ibm Pneumatic reading system for document cards
US3814877A (en) * 1972-10-17 1974-06-04 Jonathan Mfg Co Pressure switch with diaphragm and adjustable contact
US3860772A (en) * 1973-04-30 1975-01-14 Carter Precision Electric Co Air pressure responsive switch for vehicle tire and the like with hinged contact and diaphragm
US3968336A (en) * 1974-09-23 1976-07-06 Xerox Corporation Keyboard switch assembly having movable contact, and supporting helicline type legs disposed co-planar to common conductive sheet
US5728986A (en) * 1996-12-20 1998-03-17 Eaton Corporation Block mounting of pressure switch cartridge
US5998745A (en) * 1998-03-31 1999-12-07 Agfa Corporation Vacuum detection switch

Also Published As

Publication number Publication date
JPS4812707B1 (enrdf_load_stackoverflow) 1973-04-23
DE2036453B2 (de) 1978-02-16
DE2036453C3 (de) 1978-10-12
FR2056198A5 (enrdf_load_stackoverflow) 1971-05-14
DE2036453A1 (de) 1971-02-04
GB1251639A (enrdf_load_stackoverflow) 1971-10-27

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