US3707633A - Thermoelectric pulse generator for motor vehicles - Google Patents

Thermoelectric pulse generator for motor vehicles Download PDF

Info

Publication number
US3707633A
US3707633A US3707633DA US3707633A US 3707633 A US3707633 A US 3707633A US 3707633D A US3707633D A US 3707633DA US 3707633 A US3707633 A US 3707633A
Authority
US
United States
Prior art keywords
pulse generator
circuit
circuit means
current
heating
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
Other languages
English (en)
Inventor
Eckhard Ursel
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.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
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 Robert Bosch GmbH filed Critical Robert Bosch GmbH
Application granted granted Critical
Publication of US3707633A publication Critical patent/US3707633A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H61/00—Electrothermal relays
    • H01H61/06—Self-interrupters, i.e. with periodic or other repetitive opening and closing of contacts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
    • B60S1/00—Cleaning of vehicles
    • B60S1/02—Cleaning windscreens, windows or optical devices
    • B60S1/04—Wipers or the like, e.g. scrapers
    • B60S1/06—Wipers or the like, e.g. scrapers characterised by the drive
    • B60S1/08—Wipers or the like, e.g. scrapers characterised by the drive electrically driven
    • B60S1/0803—Intermittent control circuits

Definitions

  • thermoelectric pulse generator used in particular for intermittent operation of windshield wipers in motor vehicles.
  • An adjustable resistor determines the heating effect of a thermal-sensitive adjusting element, and thereby the pulse frequency of the pulse generator.
  • the pulse duration is regulated by varying the magnitude of the heating current of the thermal-dependent adjusting element, when in the initial position.
  • This arrangement has the disadvantage that the pulse frequency can be regulated or varied only in relatively narrow limits.
  • an essential part of the pulse'duration, the cooling interval of the positioning element becomes only little influenced by the current which gives rise to the heating effect, and thereby the cooling interval remains substantially constant.
  • the temperature of the environment in the conventional pulse generators can have a significant effect upon the pulse frequency, and this is undesirable in many situations.
  • thermoelectric'pulse generator in which the pulse frequency may be regulated within wide limits, and which is independent of the surrounding temperature.
  • Anotherobject of the present invention is to provide an arrangement of the foregoing character which may be readily fabricated and easily assembled.
  • a still further object of the present invention is to provide an arrangement, as described, which may be economically constructed and maintained.
  • the heat-sensitive positioning element closes a first circuit when in its initial position. In this latter position, heating current flows through the element until it becomes actuated. Upon such actuation of the element a second circuit is closed through an adjustable resistor, whereby current also flows to result in a heating effect on the positioning element. The magnitude of this latter current is less than the heating current before-hand. As a result of this lesser current, the positioning element cools off upon the required temperature difference, to permit the element to return to its initial position.
  • the positioning element can be advantageously in the form of a bimetallic snap disc which closes a first pair of contacts for one current circuit, and a second pair of contacts for the other circuit.
  • the pulse generator is used for intermittent operation of windshield wipers in motor vehicles.
  • the required current pulse flows through the thermal positioning element, when in the initial position for the purpose of operating the wiper motor.
  • the motor thereby, has current applied to it, through conventional limit switch, until the wipers have executed a full to-from cycle.
  • the wiping intervals lying between .the individual pulses can be set to any desired value in view of the current which may be finely regulated in passage through the positioning element during the cooling phase. Such regulation of the current may be made over wide limits.
  • FIG. 1 is an electrical circuit diagram of the pulse generator arrangement, in accordance with the present invention.
  • FIG. 2 is a graphicalrepresentation of the function of parameters associated with the arrangement of FIG. 1.
  • the cleaning arrengement in accordance with the present invention has a DC motor 10 with permanent magnet excitation.
  • This motor 10 is switched on and off, in the conventional manner through a manually operated switch 11.
  • the motor 10 drives two windshield wipers, not shown, in a to-from manner.
  • the motor 10 receives current until the wipers have arrived to their initial or parking positions, by way of the circuit path from the positive terminal of a current source, the line 12, a limit switch 13, and the line 14.
  • the limit switch 13 When in the position a of the switch 11, the limit switch 13 becomes actuated by the motor 10 so that this limit switch assumes the position shown in the drawing. In this shown position of the limit switch 13, the current path to the motor is interrupted, and ground potential is applied to the switched motor terminal, through the line 15, line 14, switch 11. By applying ground potential to both terminals of the motor in this manner, braking action of the motor is obtained.
  • a switching contact 16 Connected in series with the line 14, is a switching contact 16 which is actuated by a relay coil 17.
  • This switching contact 16 is in the line 14 which leads from the limit switch 13 to the manually operated switch 11. In the initial position, this switching contact 16 interrupts the circuit path between the limit switch 13 and the manually operated switch 11, whereby the line 14 becomes directly connected to the line 12 leading to the voltage source.
  • the relay coil 17 lies within a current path leading from the positive terminal of the current source, to a second manually operated switch 18. The latter serves for intermittent operation of the wipers. From there the circuit leads to a first contact pair 19,19 of a thermoelectric pulse generator 20. The other terminal of the relay coil 17 is connected to ground potential.
  • the pulse generator 20 has a thermal-dependent positioning element in the form of a bimetallic snap disc 21 which serves directly as a contact element. This contact element becomes heated as a result of current flowing through it.
  • the bimetallic disc 21 is held at its center, and when not heated, the disc 21 lies on the first contact pair 19,19.
  • the pulse generator has a second pair of contacts 22,22 against which the bimetallic disc 21 becomes located upon being heated and actuated thereby.
  • the pair of. contacts 22,22 lie within a line 23 which includes a series-connected adjustable resistor 24. One terminal of this resistor 24 is connected to ground potential.
  • the movable contact of the adjustable resistor 24 is coupled to the switching shaft of the manually operated switch 18. As a result of this coupling, this switch-18 is turned on and off, as well as the value of the resistor 25 becomes set, simultaneously.
  • a resistor 25 which serves, furthermore to determine the heating current through the bimetallic disc 21, when in the position shown in the drawing.
  • the manually operated switch 11 is brought into the position b, whereby the motor 10 has current applied to it.
  • the switch 18 remains open so that all circuit elements connected in series with this switch remain without current, and the switching contact 16 is, thereby, in the position shown in the drawing.
  • the motor 10 Upon turning off the switch 11, the motor 10 still receives current until the wipers have attained their initial or parking positions, through the circuit path including the line 12, limit switch 13, contact 16, line 14, and the manually operated switch 11.
  • the manually operated switch 18 is to be closed, so as to close the circuit from the positive terminal of the current source to the relay 17, through the bimetallic disc 21 of the pulse generator 20.
  • the switching contact 16 is transferred to the actuated position.
  • the contact 16 interrupts the braking circuit through the limit switch 13, and establishes a circuit from the positive terminal of the current source to the motor.
  • the motor operates or turns and the limit switch 13 becomes thereby also actuated.
  • a relatively large current flows to the bimetallic disc 21, so that the pulse generator becomes actuated within approximately half a second.
  • the pulse generator thereby disconnects the current path to the relay 17, so that the switching contact 16 is returned to the position shown in the drawing, and the limit switch 13 is returned to its operative state.
  • the motor 10 now line 23 and the bimetallic disc 21.
  • the magnitude of the current is determined through the setting of the resistor 24, and is thereby pre-selectable.
  • the adjustable range of the resistor 24 is to be established so that even upon the smallest resistance setting of this resistor, the current flowing through the line 23 is to be still smaller than the heatingcurrent flowing through the pair of contacts 19,19.
  • This condition is imposed so that the bimetallic disc 21 experiences cooling in every case inspite of the heating effect.
  • the cooling leads to the condition after a predetermined time interval, where the bimetallic disc 21 snaps back to its initial position, and the motor pass current again applied to it for a brief period of time through the relay 17.
  • FIG. 2 indicates the dependency of the time t on the current I which flows through the second pair of contacts 22,22.
  • the time parameter is determined by the setting of resistor 24, and the diagram of FIG. 2 corresponds to a predetermined pulse generator type. From this diagram of FIG. 2, it is evident that the time interval t can be adjusted between 1.5 and 8 seconds which is sufficient for many applications.
  • thermoelectric pulse generators for motor vehicles differing from the types described above.
  • thermoelectric pulse generator for motor vehicles, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
  • a pulse generator comprising, in combination, a heat-sensitive movable element having a first position when in a substantially low-heated state and having a second position when in a relatively high-heated state; first circuit means connected to said heat-sensitive movable element and closed when said element is in said first position, the current in said first circuit means passing through said element when in said first position and heating said element; second circuit means closed when said element is in said second position, said element moving from said first position to said second position after predetermined heating by said first circuit means, said second circuit means heating said element in said second position with current having a smaller magnitude than the current of said first circuit means, said element cooling under the passage of said smaller current to a predetermined temperature for returning said element to said first position; and means for regulating the magnitude of the current in said second circuit means for regulating the pulse frequency of said pulse generator.
  • said first circuit means comprises electrical contact means closed when said element is in said first position, said contact means being opened when said element moves from said first position to said second position.
  • circuit means including first contact means closed by said bimetallic snap disc when in said first position, said second circuit means including second contact means closed when said bimetallic snap disc is in said second position.
  • the pulse generator as defined in claim 1 including motor means; and control circuit means connected to said first circuit means and said second circuit means for controlling the operation of said motor in relation to the position of said element.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Direct Current Motors (AREA)
  • Stopping Of Electric Motors (AREA)
  • Control Of Position Or Direction (AREA)
US3707633D 1971-03-10 1972-03-01 Thermoelectric pulse generator for motor vehicles Expired - Lifetime US3707633A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19712111447 DE2111447A1 (de) 1971-03-10 1971-03-10 Thermoelektrischer Impulsgeber,insbesondere fuer den intermittierenden Betrieb von Fahrzeugscheibenwischern

Publications (1)

Publication Number Publication Date
US3707633A true US3707633A (en) 1972-12-26

Family

ID=5801078

Family Applications (1)

Application Number Title Priority Date Filing Date
US3707633D Expired - Lifetime US3707633A (en) 1971-03-10 1972-03-01 Thermoelectric pulse generator for motor vehicles

Country Status (5)

Country Link
US (1) US3707633A (enrdf_load_html_response)
JP (1) JPS4731344A (enrdf_load_html_response)
DE (1) DE2111447A1 (enrdf_load_html_response)
FR (1) FR2129366A5 (enrdf_load_html_response)
IT (1) IT949929B (enrdf_load_html_response)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5318867A (en) * 1976-08-06 1978-02-21 Mitsubishi Heavy Ind Ltd Filter frame pressing plate for diaphragm-type compressed filter compressor
JPS5418782U (enrdf_load_html_response) * 1977-07-08 1979-02-06
JPS5647336A (en) * 1979-09-21 1981-04-30 Nissan Motor Co Ltd Intermittent drive control device for wiper
JPS5836747A (ja) * 1981-08-28 1983-03-03 Toyota Motor Corp ワイパ装置

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2428525A (en) * 1944-09-20 1947-10-07 Mcgraw Electric Co Thermal retarder
US2838645A (en) * 1956-11-14 1958-06-10 Gen Electric Surface heating unit control system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2428525A (en) * 1944-09-20 1947-10-07 Mcgraw Electric Co Thermal retarder
US2838645A (en) * 1956-11-14 1958-06-10 Gen Electric Surface heating unit control system

Also Published As

Publication number Publication date
IT949929B (it) 1973-06-11
JPS4731344A (enrdf_load_html_response) 1972-11-11
FR2129366A5 (enrdf_load_html_response) 1972-10-27
DE2111447A1 (de) 1972-09-14

Similar Documents

Publication Publication Date Title
GB1192089A (en) Electric Heating Systems for Vehicles
US3566225A (en) Magnetic circuit opening and closing motor starting switch in response to heat varying macnetic permeance
US2539206A (en) Electric switching apparatus
US2727973A (en) Temperature controllers
US3707633A (en) Thermoelectric pulse generator for motor vehicles
US2175032A (en) Single phase motor control
US2573404A (en) Thermal control means for induction motors
US4724504A (en) Rapid turn-on, slow drop-out control arrangement
US3057978A (en) Thermo-magnetic contact device
US2622677A (en) Electrical interval timer
US1774966A (en) Time-element device
US4215383A (en) Current regulator for DC motors including sensitivity control means therefor
US3588471A (en) Sequential loading temperature control system
US2394294A (en) Time delay relay circuit
GB1089875A (en) Control circuit of an electric hotplate
CA2022282C (en) Arrangement of automatically restoring normal operation of latch-in-relay
US3171019A (en) Temperature control system
US2437756A (en) Electromagnetic timing relay
JPS62223916A (ja) ラツチングスイツチ組立体
US3919612A (en) Interval windshield wiper arrangement
US3959662A (en) Engine starting systems
US3611217A (en) Voltage and load compensated flasher
US2810055A (en) Windshield heater control device and system
US2355041A (en) Heat motor
JPS57183281A (en) Controlling circuit for number of revolution