DE2147193A1 - Thermal switching device - Google Patents

Description

PATENTANWÄLTE a? 02 aucsbupg-göggingen, ²¹ · 9 · 1971

v. Eichender "-stroß" "10 21 ^ 7193

DR. ING. E. LIEBAU Our mark R 8556

_ (Please specify when replying)

DIPL.ING. G. LIEBAU

Your sign

Your message from

DIRECTED BY NATIONALE DES USINES RENAULT 8/10 Avenue Emile Zola
Billancourt (Seine) France

and

AUTOMOBILE PEUGEOT

75, Avenue de la Grande Arme * e Paris / France

Thermal switching device

The invention relates to a thermal switching device for switching an electrical circuit with different closing and opening times.

Such a device can particularly, but not exclusively, be used in combined circuits of windscreen washer and wiper systems of motor vehicles use.

2098U / 0993

As is well known, when cleaning a vehicle window it is advantageous to first use the windscreen washer system or Switch on the flushing system and shortly afterwards the windscreen wiper, but the latter after switching off keep the windscreen washer system running for a short time. A quiet operation, with different ones Delays in closing and opening the safety contacts are already encountered with certain devices achieved, in particular with a device as described in the earlier French patent no. 69 / 26.857. In the device according to this patent, a heating wire, an electromagnet act and a bimetal strip with a heating resistor together.

However, the known devices have the disadvantage that the windshield wiper is in its rest position must have returned before the windshield washer is actuated again and a new work cycle is initiated can be.

The aim of the invention is therefore to create a thermal switching device which avoids this disadvantage does not have, so that the duty cycle can be repeated at any time without waiting for the controlled Circuit has returned to its rest position.

The device according to the invention is characterized by an electrically conductive wire with a considerable coefficient of thermal expansion, on the one hand with a switch and on the other hand is connected to one end of a leaf spring which at this end has a Contact carries that come into contact with another contact, which is connected to ground via a resistor

BATH

2098U / 0993 ^B

2U7193

can, while the other end of the leaf spring has a second resistance that is much stronger than the first-mentioned resistor is connected to ground, wherein the leaf spring further carries an arm that on a movable lever acts, which closes and opens the circuit to be controlled via a switch causes.

The device according to the invention, as well as its application in a combined circuit of a windshield washer and wiper system are described in more detail below, reference being made to the accompanying drawings will.

Show it:

Fig. 1 is a schematic representation of the device according to the invention;

FIG. 2 shows an embodiment of the device according to FIG. in Schnxttansicht and

Fig. 3 shows an electrical circuit in which the device is installed according to the invention in a windscreen washer and wiper system.

From the schematic representation of FIG. 1 it can be seen that the device according to the invention has a resistance wire 1 designated as a "heating wire", one end of which is connected to a fixed point of a circuit I, while its other end is connected to a leaf spring 5 is attached, the iceres end over a strong Vi id he stood 2 at ground ■ öit. The '■: i ^{h connected to} the Ho 1 "' wire? Cnöe the leaf-

^{liM!; U``i | rJl>} BAD ONQINM.

2H7193

spring carries a contact 3, which is connected to a contact 4 cooperates, which via a resistor 12, the is weaker than the resistor 2, is connected to ground. The leaf spring 5 also has an arm 6 on, which is also visible in Fig. 2 and consists of non-conductive material. This arm 6 forms a mechanical connection between the leaf spring 5 and a lever 7, the lever 7 has at one end a fixed point, while its other end is supported on a scroll spring 8, the two end positions can take. This spring takes a contact lever 9 between the contacts 10 and 11 of a switch is pivotable in a circuit II.

When wire 1 does not have current flowing through it, it is located the device is in the rest position, the forces being directed in the direction of the arrows "a" and the contact lever 9 rests on the contact 10. If the wire 1 has a current flowing through it, it heats up and expands; the lever 7 and the leaf spring 5 connected by the arm 6 move move in the direction of arrows "b", causing the contact lever 9 comes to rest against contact 11.

Figure 2 is a sectional view of one embodiment of the device shown schematically in FIG. I, the reference numerals corresponding to those of FIG.

From FIG. 2 it can be seen particularly clearly that the leaf spring 5, which is pulled upward by the wire 1 relaxes as the wire expands so that arm 6 moves down and onto lever 7 presses, which raises the contact lever 9 via the tiltable spring 8 and brings it against the contact 11 to the plant.

2098 U / 099 3 _BATH

2,7193

Fig. 3, in which the same reference numerals denote the same parts as in Fig. 1, shows in Schematic representation of the electrical circuit a system that has a windshield wiper A with an electric motor with permanent magnet and with automatic filing of the leaves, a windshield wiper switch B, a windshield washer pump C and a delay relay D, the latter after use of the windshield washer pump increases the operating time of the windscreen wiper.

Fig. 3 shows that the wiper motor 15 has three terminals, namely:

- the terminal 16, which is connected to ground and to the terminal 17, which in turn is connected to the contact 18 of the the automatic storage of the wiper blades causing the limit switch is connected, the other terminal 20 is connected to the positive terminal 21 of the power source and to the contact 11, which is connected to the contact lever 9 cooperates;

- The terminals 22 and 23, which are connected to the contacts 24 and 25 of the wiper switch B, which correspond to the high or low speed of the windshield wiper.

In addition to the contacts 24 and 25, the switch B also has a contact 26 connected to the positive terminal of the power source and one to the lever 7 connected contact 27. By means of a sliding contact 2, the contacts 24 and 2 6 (high speed), 2 5 and 26 (low speed) and 25 and 27 (rest position) are connected to one another.

BAD ORIGINAL 2098U / 0993

2U7193

The delay relay D comprises the parts already described above: heating wire 1, leaf spring 5, resistors 2 and 12, arm 6, lever 7, toggle spring 8 and contact lever 9.

The windshield washer system C finally comprises a motor pump 29, a push button switch 30 and a connecting conductor 31, which connects terminal 32 of the motor pump to heating wire 1.

The armature of the windshield wiper motor is in the rest position 15 via the sliding contact 28 in the switching position 25-2 7, the lever 7, the contact 10, the Limit switch contact 18 and the ground terminal 16 short-circuited.

When the windscreen washer system C is started should, you press the push button switch 30, whereby the windshield washer pump 29 begins to run and at the same time the wire 1 heats up quickly. A stream that is regulated to a "high" value by the resistor 12, the wire 1 flows through; this one lengthens, the leaf spring 5 relaxes, the contacts 3 and 4 open, the current flowing through the leaf spring 5 is diverted to ground via the resistor 2, whereby the current strength assumes a "low" value, which however sufficient to keep the wire 1 in its state. While the leaf spring 5 relaxes, it pushes over the arm 6 on the lever 7. When the tipping point of the scroll spring 8 is reached, the contact lever 9 pivots away Contact 10 to contact 11, so that the armature of the windshield wiper motor 15 is no longer short-circuited, but is connected to voltage. As soon as you press the button 30 presses, the circuit is closed, the windshield wiper pump starts to run, the leaf spring 5 of the delay relay remains relaxed and the disc

2098U / 0993

2H7193

wiper motor continues to run. If you press the button 30 free, the motor of the windscreen washer pump stops, the heating wire 1, which is no longer energized cools down under the influence of the ambient air and therefore contracts slowly in a predetermined time When this time has expired, the leaf spring 5 assumes its starting position, the contacts 3 and 4 close, the lever 7 is followed by the arm 6 pulled up. As soon as the tipping point of the scroll spring 8 is reached, the contact lever 9 pivots back to the contact 10. As long as the limit switch contact 18 is in connection with the contact 17, the windshield wiper motor runs Further. When the limit switch, which causes the automatic final storage of the wiper blades, the circuit interrupted, the braked motor returns to its rest position.

The system is ready for operation again and a new work cycle begins when button 30 is pressed again becomes what can be done without waiting for the wiper motor to return to its rest position.

Patent to claims:

2098U / 0993

Claims (1)

Claims _# \ Thermal switching device for switching a circuit with different opening and closing times, characterized by an electrically conductive wire 1 with a considerable coefficient of thermal expansion, which is connected on the one hand to a switch and on the other hand to one end of a leaf spring (5) which has a contact at this end (3), which can come into contact with another contact (4 ·) connected to ground via a resistor (12), while the other end of the leaf spring (5) via a second resistor (2) which is much stronger is connected to ground as the first-mentioned resistor (12), the leaf spring (5) also carrying an arm (6) which acts on a movable lever (7) which, via a switch (9), closes and opens the to be controlled circuit causes. Thermal switching device according to claim 1, in a combined circuit of a windshield washer and -wiper system, characterized in that the wire (1) is connected to the circuit of the motor (29) of the windshield washer system (C) is connected that it is applied simultaneously with this voltage, during the The wiper circuit (A) is controlled by the lever (7), which is activated by the expansion of the Wire (1) is actuated, the first resistor (12) a rapid heating of the wire (1) and a 2098U / 0993 fast switching on of the windshield wiper ensures, while the second resistor (2) the .Wire (1) holds in its expanded state, and the cooling of the wire (1) by the surrounding it Air causes the windshield wiper to return to its rest position after a longer period of time. 2098U / 099 3