US3246086A - Switch assembly and circuit for electrically heated bedcovers - Google Patents

Switch assembly and circuit for electrically heated bedcovers Download PDF

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Publication number
US3246086A
US3246086A US276929A US27692963A US3246086A US 3246086 A US3246086 A US 3246086A US 276929 A US276929 A US 276929A US 27692963 A US27692963 A US 27692963A US 3246086 A US3246086 A US 3246086A
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US
United States
Prior art keywords
switch
push button
circuit
contact
push buttons
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
US276929A
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English (en)
Inventor
Chester F Jacobson
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.)
General Electric Co
Original Assignee
General Electric Co
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 General Electric Co filed Critical General Electric Co
Priority to US276929A priority Critical patent/US3246086A/en
Priority to GB14433/64A priority patent/GB1043576A/en
Priority to CH523564A priority patent/CH409170A/de
Priority to ES0299261A priority patent/ES299261A1/es
Priority to JP2409364A priority patent/JPS418097B1/ja
Priority to NL646404734A priority patent/NL144118B/xx
Priority to AT388664A priority patent/AT263968B/de
Application granted granted Critical
Publication of US3246086A publication Critical patent/US3246086A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B1/00—Details of electric heating devices
    • H05B1/02—Automatic switching arrangements specially adapted to apparatus ; Control of heating devices
    • H05B1/0227—Applications
    • H05B1/0252—Domestic applications
    • H05B1/0272—For heating of fabrics
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D23/00—Control of temperature
    • G05D23/19—Control of temperature characterised by the use of electric means
    • G05D23/1906—Control of temperature characterised by the use of electric means using an analogue comparing device
    • G05D23/1909—Control of temperature characterised by the use of electric means using an analogue comparing device whose output amplitude can only take two discrete values
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D23/00—Control of temperature
    • G05D23/19—Control of temperature characterised by the use of electric means
    • G05D23/1906—Control of temperature characterised by the use of electric means using an analogue comparing device
    • G05D23/1913—Control of temperature characterised by the use of electric means using an analogue comparing device delivering a series of pulses
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D23/00—Control of temperature
    • G05D23/19—Control of temperature characterised by the use of electric means
    • G05D23/20—Control of temperature characterised by the use of electric means with sensing elements having variation of electric or magnetic properties with change of temperature
    • G05D23/24—Control of temperature characterised by the use of electric means with sensing elements having variation of electric or magnetic properties with change of temperature the sensing element having a resistance varying with temperature, e.g. a thermistor
    • 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
    • H01H13/68—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having two operating members, one for opening and one for closing the same set of contacts
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/20—Heating elements having extended surface area substantially in a two-dimensional [2D] plane, e.g. plate-heater
    • H05B3/34—Heating elements having extended surface area substantially in a two-dimensional [2D] plane, e.g. plate-heater flexible, e.g. heating nets or webs
    • H05B3/342—Heating elements having extended surface area substantially in a two-dimensional [2D] plane, e.g. plate-heater flexible, e.g. heating nets or webs heaters used in textiles

Definitions

  • This invention relates to integrated multiple switch constructions, and in particular to an electrical control switch assembly to energize an electrically heated device, such as a bedcover, and a safety control circuit therefor.
  • an overtemperature protective circuit is a highly desirable safety feature for its operation to deenergize the electrical heater upon any over-temperature condition.
  • a protective circuit includes an electromagnetically operated switch to maintain the circuit closed for normal operating conditions, but which releases and opens the electric heater circuit upon any abnormally high operating temperature.
  • the manual actuator used to energize initially the electromagnetic means, for complete protection, must be arranged so that the heating device can be operated only when the protective circuit is fully operative. Even intentional jamming of the manual actuator must not be effective to defeat the safety control.
  • an electrically heated bedcover switch assembly utilizing a pair of manual actuators for respective, normally open, on and off switches in an assembly housing.
  • a normally closed safety switch is provided having a movable contact arm positioned between the movable elements of the on and off switches to open the heater or load circuit upon initial movement of either or both of the manual actuators.
  • the load circuit remains open upon any attempt to hold or jam either of the manual controls in an actuated or closed position.
  • Means are provided on the terminal board to which the fixed contacts of the on and off switches are secured so that the operating force of the push button or manual actuator is transmitted through the terminal board to the assembly housing.
  • each push button, the terminal board and portions of the assembly housing cooperate to insure substantially axial reciprocal motion of the push buttons in the housing.
  • FIG. 1 is a perspective view of the control switch assembly
  • FIG. 2 is a partial sectional view of the control switch assembly taken on line 22 of FIG. 1;
  • FIG. 3 is a partial sectional view of the control switch assembly taken on line 3-3 of FIG. 1;
  • FIG. 4 is a perspective view of certain elements of the control switch assembly showing all switch elements in their normal position
  • FIG. 5 is similar to FIG. 4 except that the switch elements are shown in their position upon depression of one push button and a typical electric bedcover heating circuit in which the switches may be used is shown.
  • FIG. 1 shows a control housing 10 of plastic or other suitable rigid, insulated, material.
  • the device shown by FIG. 1 is, typically, the bedside control unit for an electric bedcover having a rotatable knob 9 for temperature selection.
  • Housing 10 also includes a pair of apertures 11 and 12 which respectively accommodate actuators or push buttons 13 and 14 of on and off switches to be described.
  • FIGS. 25 reveal the structure and operation of the elements of the control switch assembly within housing 10.
  • Push button 13 is positioned so that the manual depression thereof through aperture 11 closes an on switch comprising a resilient conductive switch arm 15 and a fixed contact 16.
  • the depression of push button 14 closes an off switch comprising a resilient conductive switch arm 17 and a fixed contact 18.
  • a safety switch including a generally U-shaped conductive contact member 19 and a fixed contact 20 is operable to an open position, upon depression of either push button 13 or 14.
  • Terminal board 21 is secured to housing 10 by a single suitable fastener 22.
  • safety switch member 19 is generally U-shaped and provides one arm 19a secured at 23 to the terminal board and a second arm 19b which may carry a current contact at its free end or contact portion for normal engagement with fixed contact 20. Arms 19a and 1% are joined by a base 19c.
  • a reinforcing rib 25 is provided along base 19c and arm 19b of switch member 19. It is to be understood that fulcrum 24 is utilized in cooperation with reinforcing rib 25 to increase reliability of switch operation. Fulcrum 24 may be omitted when the reinforcing rib is used, as arm 19b will still pivot about a fulcrum in space upon depression of base 190.
  • base of the safety switch member lie adjacent the free ends of switch arms 15 and 17 and are engaged by radial flanges 26 and 27 of their respective push buttons. It is therefore clear that flanges 26 and 27 provide means for respectively linking or interconnecting actuators 13 and 14 to the base 190 of the safety switch so that inward movement of either of the actuators pivots the arm 19b to separate the contacts of the safety switch.
  • the corners of base 190 may normally assist switch arms 15 and 17 in biasing the push buttons to their outer inoperative positions.
  • each push button, the terminal board 21 and the assembly housing 10 provide vinterfitting elements. As the structure relating to each push button is exactly the same, only the features of one push button will be described.
  • Push button 13 is cylindrical and provides an eccentrically located axial projection 28 as well as radial flange 26.
  • projection 28 and flange 26 are integrally molded with the cylindrical portion of push button 13.
  • Housing It provides a semi-cylindrical guide 29 which extends coaxially with push button 13 to partially encompass the push button.
  • the internal end of guide 29 incorporates a radial flange or support surface 30 which defines a groove 31.
  • terminal board 21 provides an ear 32, having a recess 33, for each push button.
  • Terminal board 21 is secured to housing so that ear 32 lies within guide 29, in juxtaposition with radial flange 30 so that recess 33 is axially aligned with groove 31 to form an aperture therewith.
  • FIGS. 5 shows schematically a typical electrically heated bedcover circuit for which this switch assembly is particularly adapted.
  • Power is supplied for operation through terminals 34 and 35 arranged to be connected in the usual manner to an electrical power source.
  • the control circuit includes a relay having coil 36 for operating a switch 37 when the relay coil is energized.
  • a suitable resistance heating element 38 is distributed in a well-known manner over the heating area.
  • the load circuit for supplying power to electric heater 38 may be traced from line terminal 34, through the heater, a terminal of the safety switch, U-shaped conducting arm 19, through safety switch contact 20, conductor 41, relay switch 37, and conductor 42 to the other terminal 35 of the power source. It may be noted from this circuit that both the safety switch, comprising U-shaped member 19 and contact 20, and the relay switch 37 must be closed for power to be supplied to heater 38.
  • a temperature sensor arrangement including distributed conductors 43 and 44, which extend in proximity to one another, separated however, by a layer of material 45 which is an insulator at normal operating temperatures and a conductor of electric current of control magnitude upon occurrence of any abnormally high temperature.
  • relay coil 36 is energized through a control circuit commencing with power terminal 34, sensor conductor 43, a connecting lead 46, relay coil 36, conductor 47 to a resistor 48. From the other terminal of resistor 48, a connection is made through lead 49 to the other conductor 44 of the temperature sensor assembly, then through conductor 50 to a voltage dropping resistor 51 and through relay contacts 37 to the other side of the power source.
  • the relay may remain closed even though on switch 16 is in its normally open condition.
  • conduction takes place through the temperature sensing layer 45, which results in a drop in the voltage applied to relay coil 36, and the relay coil, therefore, releases its armature, and switch 37 opens the circuit to both heater 38 and the blanket control system.
  • On switch 1516 provides a means for initially energizing relay coil 36 through a circuit commencing with power line 34, conductor 43 of the temperature sensor assembly, connecting line 46, relay coil 36, and conductor 47, to on switch contact 16.
  • the circuit is completed through spring arm 15 of the on switch, a conductor 52, a current limiting resiStOr 53 to the other terminal of the power source 35.
  • T e size of the resistor 53 is, of course, selected to apply adequate voltage to the relay coil, so that it will close the relay switch 37. Thereafter, the relay remains closed under normal operating conditions through the circuit previously described. It should be noted particularly, however, that the heater 38 is ineffective as long as the on switch is even partially depressed, since the initial movement of the on push button opens the safety switch at contact 20.
  • the user occasionally desires to deenergize the heater and control circuit manually by means of push button 14. While the off button could operate in several different ways, as shown in FIG. 5 the closing of the off switch provides a shunt circuit around relay coil 36, conductor 47 and resistor 48. The shunt circuit is through conductor 54, off switch contacts 18 and 17 and conductor 55. Hence, when the off switch is closed, there can be essentially no voltage on the relay coil, upon which the relay switch opens.
  • axial projections 28 are accommodated in the aperture provided by the relationship of groove 31 and recess 33. This controls the path of the push buttons thereby insuring substantially axial motion thereof to prevent accidental jamming of the push buttons, which might otherwise result from application of an off-center force to a push button.
  • a switch assembly comprising:
  • an on switch including an electrically conducting member cooperating with said first push button for movement therewith and an electrical contact, said electrically conducting member and said contact being engaged with each other when said first push button is moved to an inner position, and disengaged when said first push button is moved to an outer position;
  • an off switch including an electrically conducting member cooperating with said second push button for movement therewith and an electrical contact, said electrically conducting member and said contact being engaged with each other when said second push button is moved to an inner position, and disengaged when said second push button is moved to an outer position;
  • a safety switch including a pair of contacts which are engaged with each other when said push buttons are in an outer position, and further including a movable arm carrying one of said safety switch contacts;
  • (f) means linking each of said push buttons to said movable arm of said safety switch for separating said safety switch contacts prior to engagement of the electricaly conducting members and their respective contacts when either one of said push buttons is moved from an outer to an inner position.
  • said safety switch comprises a resilient U-shaped contact member including a first arm connected to the housing, a second arm pivotally mounted about a fulcrum, and a base portion connecting said arms, said second arm providing a contact carrying portion on one side of the fulcrum and said base portion being on the other side of the fulcrum for said linking means to engage said base portion and pivot said arm about said fulcrum upon inward movement of either of said push buttons.
  • a switch assembly comprising:
  • a first switch including an electrical conducting member and a contact separated from each other when said push button is in an outer position, said electrically conducting member cooperating with saidpush button to engage the contact when said push button has been moved to an inner position;
  • a second switch including a pair of contacts engaged with each other when said push button is in an outer position, said second switch comprising a resilient U-shaped contact member including a first arm connected to the housing, a second arm pivotally mounted about a fulcrum, and a base portion connecting said arms, said second arm carrying one of said contacts on one side of said fulcrum, and said base portion being located on the other side of said fulcrum;
  • linking means for linking said push button to said base portion of the U-shaped contact member for pivoting said second arm to disengage said second switch contacts when said push button is moved from an outer to an inner position.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Textile Engineering (AREA)
  • Control Of Resistance Heating (AREA)
  • Push-Button Switches (AREA)
US276929A 1963-04-30 1963-04-30 Switch assembly and circuit for electrically heated bedcovers Expired - Lifetime US3246086A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US276929A US3246086A (en) 1963-04-30 1963-04-30 Switch assembly and circuit for electrically heated bedcovers
GB14433/64A GB1043576A (en) 1963-04-30 1964-04-08 Improvements in electrical control switch assemblies for electrically heated devicessuch as bedcovers
CH523564A CH409170A (de) 1963-04-30 1964-04-22 Steuereinrichtung für elektrisch heizbare Vorrichtungen, insbesondere Bettdecken
ES0299261A ES299261A1 (es) 1963-04-30 1964-04-28 Una disposiciën de control para una manta electrica
JP2409364A JPS418097B1 (de) 1963-04-30 1964-04-28
NL646404734A NL144118B (nl) 1963-04-30 1964-04-29 Stelsel van drukknoppen voor een elektrisch te verwarmen beddedeken.
AT388664A AT263968B (de) 1963-04-30 1964-04-30 Schalteinrichtung für elektrische Verbraucher, insbesondere Heizdecken

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US276929A US3246086A (en) 1963-04-30 1963-04-30 Switch assembly and circuit for electrically heated bedcovers

Publications (1)

Publication Number Publication Date
US3246086A true US3246086A (en) 1966-04-12

Family

ID=23058680

Family Applications (1)

Application Number Title Priority Date Filing Date
US276929A Expired - Lifetime US3246086A (en) 1963-04-30 1963-04-30 Switch assembly and circuit for electrically heated bedcovers

Country Status (7)

Country Link
US (1) US3246086A (de)
JP (1) JPS418097B1 (de)
AT (1) AT263968B (de)
CH (1) CH409170A (de)
ES (1) ES299261A1 (de)
GB (1) GB1043576A (de)
NL (1) NL144118B (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USD259721S (en) 1978-05-15 1981-06-30 Electrofilm, Inc. Control module
US11195399B2 (en) 2017-09-06 2021-12-07 Carrier Corporation Heat alarm unit

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2806907A (en) * 1953-10-30 1957-09-17 Mazzola Ambrose Electrical control switch
US2879345A (en) * 1956-02-01 1959-03-24 Jr Donald P Mossman Selective switching apparatus
US2935590A (en) * 1958-01-23 1960-05-03 Standard Oil Co Temperature control device
US2987602A (en) * 1959-01-26 1961-06-06 Eastman Kodak Co Temperature control system for a photographic copying apparatus
US3137773A (en) * 1961-10-30 1964-06-16 American Seating Co Manual control for a motorized hospital bed

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2806907A (en) * 1953-10-30 1957-09-17 Mazzola Ambrose Electrical control switch
US2879345A (en) * 1956-02-01 1959-03-24 Jr Donald P Mossman Selective switching apparatus
US2935590A (en) * 1958-01-23 1960-05-03 Standard Oil Co Temperature control device
US2987602A (en) * 1959-01-26 1961-06-06 Eastman Kodak Co Temperature control system for a photographic copying apparatus
US3137773A (en) * 1961-10-30 1964-06-16 American Seating Co Manual control for a motorized hospital bed

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USD259721S (en) 1978-05-15 1981-06-30 Electrofilm, Inc. Control module
US11195399B2 (en) 2017-09-06 2021-12-07 Carrier Corporation Heat alarm unit

Also Published As

Publication number Publication date
JPS418097B1 (de) 1966-04-27
AT263968B (de) 1968-08-12
ES299261A1 (es) 1964-06-16
NL6404734A (de) 1964-11-02
NL144118B (nl) 1974-11-15
GB1043576A (en) 1966-09-21
CH409170A (de) 1966-03-15

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