US3688078A

US3688078A - Constant-current heating devices for fixed window seals

Info

Publication number: US3688078A
Application number: US129822A
Authority: US
Inventors: Andre Ferrand; Michel Bonnefont
Original assignee: Automobiles Peugeot SA; Renault SAS
Current assignee: Automobiles Peugeot SA; Renault SAS; Regie Nationale des Usines Renault
Priority date: 1970-04-10
Filing date: 1971-03-31
Publication date: 1972-08-29
Anticipated expiration: 1989-08-29
Also published as: BE764132A; DE2117242B2; DE2117242C3; CA930402A; DE2117242A1; GB1325265A; FR2086842A5

Abstract

This device for electrically heating a wire embedded in the molding strip of a fixed window, such as a windshield or the like, for sealing same to the surrounding frame, comprises a movable supply cabinet, a voltage regulator for maintaining a constant current value in said wire, a data processing unit comprising members adapted to deliver orders of an instantaneous or delayed-action nature for controlling in succession preheating and heating control circuits for energizing said wire during two different time periods, and safety members controlling the current value in said wire and the voltage across the terminals through which said wire is connected to the device. This device is applicable to automotive construction and also to building construction.

Description

[22] Filed:

States Patent Ferrand et al.

[ 1 Aug. 29, 1972 [54] CONSTANT-CURRENT HEATING DEVICES FOR FIXED WINDOW SEALS [72] Inventors: Andre Ferrand; Michel Bonnefont,

both of Billancourt, France [73] Assignees: Regie Nationale des Usines Renault, Billancourt; Automobiles Peugeot, Paris, France March 31,1971 [2i] Appl. No.: 129,822

30 Foreign Application Priority Data April 10, 1970 France ..-.70/130os 52 U.S.Cl. ..219/482,2l9/498,2l9/501 51 Int. Cl. ..H05b 3/02 [58] Field of Search ..219/482, 203, 483, 501, 498, 219/485, 486, 490, 509, 522; 263/3 [56] References Cited UNITED STATES PATENTS 3,560,712 2/ 1971 Toohill ..219/483 3,465,126 9/1969 Blumenkranz ..219/482 Primary ExamineF-Bemard A. Gilheany Assistant Examiner-F. E. Bell Attorney-Stevens, Davis, Miller & Mosher [57 ABSTRACT This device for electrically heating a wire embedded ous or delayed-action nature for controlling in succession preheating and heating control circuits for energizing said wire during two different time periods, and safety members controlling the current value in said wire and the voltage across the terminals through which said wire is connected to the device.

This device is applicable to automotive construction and also to building construction.

7Claims,4DrawingFigures P'A'TENTED I912 3.688.078 SHEET 2 [IF 3 FIXED WINDOW SEALS This invention relatesto a device for heating the sealing or moulding strips, incorporating a heating wire element, of fixed windows.

This invention is concerned more particularly with a device adapted to heat by Joule effect and giving a constant amount of heat per unit length of the seal (for a given constant cross-section of the resistance wire) while taking due account of any defects or failures likely to occur during the heating operation.

This invention further relates to the application of this device to the sealing of windscreens of motor vehicles by resorting to the known method consisting in applying a voltage to a metal wire covered with, or embedded in, a tube of rubber or thermosetting plastic material, in order to heat this tube so that the curing thereof will seal the windscreento its frame.

It is thus clear that the heating effect is obtained by using an electric resistance embedded in the seal or moulding as it is extruded or otherwise produced.

A method is already known wherein the seal or moulding is heated in two different time periods, i.e. a first, relatively short preheating period and a second, relatively longer heating period, a transfonner being used for adapting the mains voltage to a specific value for a well-defined seal or wire length. This transformer can deliver a plurality of secondary voltages to permit the heating of seals of different lengths, but in this case some means must be provided for displaying the type of vehicle or the seal length.

The main inconveniences characterizing this known method may be listed as follows: X

a. it applies to a specific seal length, so that it is not possible to admit different types of vehicles on the same production line without any preliminary display, thus implying additional operations and an increased possibility of error;

b. it is a source of poor electric contacts, and the variations in length of the seal or moulding have a direct bearing on the degree or quality of the curing;

c. since the maximum current is preset, the maximum permissible current must be reduced so that the current as a function of the various parameters cannot exceed the permissible value, and therefore the length of the production line must be increased, since the quantity of heat is constant and the current is lower, so that a longer heating time is required and the length to be attributed to the application unit associated with the production line must also be lower;

(1. in case of short-circuit during the operation, which causes the fuse to melt, the intervention of an electrician is necessary.

It is the essential object of the present invention to provide a heating device adapted to eliminate the various inconveniences set forth hereinabove, this device being furthermore characterized by the following advantageous features:

i. it permits defining and reproducing with maximum fidelity a given quality of seal vulcanization, irrespective of the variations in the supply voltage, the value of the contacts connecting the moulding to the source of current, etc...

. ii. the windscreens of different vehicles can be sealed in their frames without modifying the adjustment iii. no restraint arises in case of shorts or grounding of the connecting clamps iv. any possible failures are signaled positively by telltale or pilot lamps, and in this case the vehicle is directed to a retouch line 7 I v. the length of the assembly line may be calculated within very close limits.

Of course, the device of this invention is also applicable to the sealing of fixed windows in buildings, prefabricated wall panels, etc... in this case the method is highly advantageous due to the great variations in the lengths of the sealing mouldings and considering the impossibility of previously displaying the necessary voltage. I

The device according to this invention for heating a seal or moulding strip having a metal resistance wire embedded therein and submitted to successive preheating and heating periods, is characterized essentially in that it comprises in a movable supply cabinet or like unit a voltage regulating member adapted to maintain a constant current value in the seal wire irrespective of its length, a data processing unit for controlling the heating phase and comprising members adapted to deliver instantaneous orders and delayed orders for controlling in succession the preheating control circuit and the heating control circuit, respectively, so as to energize the resistance wire during two different time periods, and first and second safety members controlling the value of the current delivered to said wire and the voltage across the connecting terminals of said wire.

Other features and advantages of this invention will appear as the following description proceeds with reference to a typical form of embodiment of the heating device constituting the subjectmatter thereof, given by way example with reference to the attached drawings, in which FIG. 1 is a diagrammatic elevational and cross-sectional view showing an assembly line in an automobile factory, where windscreens are fitted to the vehicles, the section being taken along the line I-[ of FIG. 2

FIG. 2 is a plan view of one section of the assembly line of FIG. 1

FIG. 3 is a diagrammatic illustration, on a larger scale, of the supply cabinet, and

FIG. 4 is the wiring diagram of a data processing unit.

Referring to FIGS. 1 and 2 of the drawings it will be seen that an assembly line for the windscreens of motor vehicles carries vehicles V1, V2, V3, V, the resistance wire embedded in the moulding of the windscreen of each vehicle is adapted to be energized through a heating device D accompanying the vehicle. Each device D comprises, as shown in FIGS. 1 to 3, a movable cabinet C travelling on feed trolleys M of a closed loop feed rail system G having an operating branch G and a return branch G This cabinet is connected to a supply cable A to which a control box B provided with a push-button 11 is attached. The cable A emerging from the box B is connected to a pair of clamps P adapted to be connected to the ends of the heating or resistance wire (not shown) of the seal or moulding J.

The assembly line may comprise any desired and suitable number of devices D and associated movable cabinets C. By way of example, three such devices are illustrated in the drawings, one device C being in operation while the other two C and C travel on the return rail section G The supply cabinet C connected to the closed-circuit rail system G through the medium of a travelling tap M comprises, as illustrated in FIG. 3, firstly a voltage regulator R for setting the intensity of the current flowing through the wire resistance at a predetermined constant value, irrespective of the length of said wire and therefore of its resistance. The cabinet C further comprises a data processing unit T and, connected to this unit,

safety members

15 and 16 adapted to interpret the passage of current through the wire of seal J and the voltage across the terminals of said wire, respectively, and a front contact 1 interposed in the energizing circuit of said wire.

The data processing unit T comprises the following circuits (FIG. 4-) 8 Circuit 101 this circuit comprises in series, between the phase Ph and neutral N, for example, an electromagnet coil 1 adapted to actuate the front contact 1 of the wire supply circuit, a delayed-action back contact 8 and a front contact 9 actuated by

electromagnet coils

8 and 9/10, respectively.

Circuit 102 this circuit comprises an electromechanical timer adapted to count or calculate the wire preheating time. This timer comprises a motor 2 driving cam means for actuating correspondingtimelag contacts and an electric clutch 3 actuating instantaneous contacts the motor 2 is connected in series with its delayed-action back contact 2 and the clutch is connected in parallel with this assembly these elements are followed in series by a front contact 16 actuated by a variable-threshold, minimum-voltage relay 16, by a delayed-action front contact 14 actuated by an auxiliary contact 14, and by a front contact 3 actuated instantaneously by said clutch 3, this contact 3 being also connected in parallel with contact 9 of circuit 101 Circuit 103 it comprises the motor 4 of an electromechanical timer exactly similar to the preceding

timer

2, 3 but providing a higher time-lag than motor 2. This motor 4 is mounted in series with its delayed-action back contact 4, and a front contact 3 this assembly being connected in parallel with clutch 3 and a tell-tale or pilot lamp 6, and clutch 5 is connected between the neutral and the common point of

contacts

4 and 3 When lighted the pilot lamp 6 indicates that the heating is on.

Circuit 104 it comprises, connected in series between the phase and the neutral, a delayed-action front contact 2 actuated by the motor 2 and a pilot lamp 7 signalling the end of the preheating period.

Circuit 105 this circuit includes, connected in series between the neutral and the phase, an electromagnet coil (already mentionned hereinabove in connection with circuit 101) and a delayed-action front contact 4 actuated by said motor 4 and having connected across its terminals the holding front contact 8 of coil 8.

Circuit 106 it comprises, connected in series between the neutral and the phase, the coil 9 controlling the closing of the contacts of an auxiliary contact unit comprising mechanical locking means, a front contact 8 responsive to coil 8 and a back contact actuated by clutch 5, a manually operated push-button 11 neutral and phase a coil 10 for controlling the opening of the contacts of the auxiliary contact unit of circuit 106, and a front contact 5 responsive to clutch 5.

Circuit 108, 'it comprises, connected in series between-neutral and phase, a pilot light 12 and a front contact 9 responsive to coil 9 the pilot light 12 signals that the preceding cycle took place without any incident.

Circuit 109 this circuit comprises in series between neutral and phase a pilot light 13 showing that the voltage value is normal, and a front contact 16 actuated by the minimum-voltage relay 16.

Circuit it comprises in series between neutral and phase an auxiliary contact unit 14 actuating the front contact 14 of circuit 102, and a front contact 15, responsive to a minimum-current relay 15 a pilot light 17 showing that the current intensity in the resistance wire is normal this pilot light 17 is connected across the terminals of the coil of contact unit 14.

The variable-threshold minimum-current relay 15 connected across the terminals of a shunt S inserted in the heating circuit of wire J is responsive to the current flowing through the wire.

In case of faulty contact or of excessive wire length in comparison with the characteristics of the current supply available, which would cause a reduction in the current value, relay 15 is energized to open its contact 15 put out pilot light 17 and de-energize the relay 14 to discontinue the heating.

7 In case of short-circuit or stray resistance in parallel to the wire J, causing a reduction in the voltage across the wire terminals, relay 16 opens its

contacts

16, and 16 thus putting out pilot light 13 and discontinuing the heating.

Whatever the failure occuring during the heating cycle, relays 15 and/or 16 are de-energized.

The function of the data processing unit T is to permit an automatic cycle operation while providing the necessary safety measures for properly causing the moulding strip J to adhere to its surrounding frame.

This apparatus operates as follows When the operator has connected the clamps P to the terminals of the wire embedded in moulding strip J, current is caused to flow through this wire. Contact 9 (circuit 101) was closed at the end of the preceding cycle and contact 8, controlling the end of the heating cycle proper is still inoperative thus, relay 1 is energized and contact 1 is closed.

If the complete system operates normally the contact 16 is closed instantaneously contact 14, also closes but with a certain time lag due to the fact that the operator cannot obtain a perfect contact within a zero time. Timer 2-3 begins its counting period the circuit is through 9,, 14 and 16 The clutch 3 of timer 2-3 releases the other timer 4-5 by closing contact 3 A contact 5 causes the contact 9 to drop by an impulse delivered to coil 10 (circuit 107) the continuity of the circuit for holding the assembly 2-3, 3-4, 6 is obtained via contact 3 At the end of the count of timer 2-3 the pilot light 7 is energized via contact 2 (circuit 104) and the operacontact 8 The circuit 101 of relay 1 (energization of p the wire in mouldingstripl) is subsequently de-energized by the opening of contact 8 At the same time the closing of contact 8 re-closes the contacts of relay 9, which indicates the triggering thereof without any incident, so that 'l. the operator is informed through pilot light 12 (closing of contact 9 in circuit 108) .that the cycle took place without any incident or failure I H. the next cycle can be authorized by closing contact 9 (circuit 101).

However, the operator has not, disconnected the wire in seal J, so that all the necessary requirements would be met for starting another heating cycle, were it not for the contact unit 8 being held in its energized condition (circuit 105) and thus preventing this next cycle.

Relay 8 is not released until the supply circuits are cutoff on the return circuit G therefore necessarily at a time whenno heating wire is connected to the ap paratus.

If a failure or other defect occurs during the heating period contacts 14 or 16 (circuit 102), are opened automatically. Y

Contact 3 (circuit 102) then drops and since contact 9 (circuit 101) was not returned to its open position, the cycle cannot be resumed unless a manual operation takes place, and if the operator normally disconnecting the wire in moulding strip J at the end of the heating cycle fails to see the pilot light No incident 12 (Circuit 108) he will deliver or switch the vehicle to a retouch line and restore the apparatus to its normal operating condition by re-energizing relay 9 by depressing push-button 11 (circuit 106).

Pilot lights 13 (circuit 109 normal voltage) and 17 (circuit 110 normalcurrent) are tell-tale devices to be used only for emergency purposes.

Although the present invention has been described with reference to a preferred form of embodiment it will readily occur to those skilled in the art that various modifications, variations and applications may be contemplated and embodied without departing from the basic principle of the invention as set forth in the appended claims.

What is claimed as new is 1 Device for heating the seal or moulding strip of fixed windows, said strip having embedded therein a metal wire adapted to act as an electric resistor and being firstly preheated and then heated, for causing the window to adhere to its surrounding frame, characterized in that it comprises in a movable cabinet connected to travelling supply means a voltage regulating member adapted to maintain a constant current intensity in said wire, irrespective of the wire length, a data processing unit controlling the heating operation and comprising members issuing instantaneous orders and delayed-action orders for controlling in succession preheating control circuits and heating circuits to ensure the energization of said wire during two difierent time eriods, andfi and second safet me be s s 'd firs ember contro img the current vzi lue iii said w i re and said second member controlling the voltage. drop across the connecting terminals of said wire.

'2. Device according to claim 1, characterized in that the member controlling the current value in said wire is a minimum-current relay'inserted in the supply circuit of said wire and adapted to actuate through a front contact a first auxiliary contact unit comprising a delayedaction contact controlling in turn all the heating control circuits.

3. Device according to claims 2, characterized in that the member controlling the voltage drop acrossthe terminals of said wire comprises a minimum-voltage relay having a front contact adapted to controlin series with said delayed-action contact all the heating control circuits.

4. Device according to claim 1, characterized in that the preheating control circuit comprises a first circuit including a motor in series with a delayed-action back contact responsive thereto, and a second circuit in parallel with the first circuit and comprising a clutch for actuating a pair of instantaneous contacts.

5. Device according to claim 4, characterized in that the heating control circuit comprises a first circuit incorporating a motor in series with a delayed-action back contact responsive thereto and a second circuit parallel to said first circuit and comprising a clutch for actuating another back contact and a front contact, the assembly of said last-named motor and clutch being connected in series with a from contact responsive to said preheating control circuit clutch; and, a rninimumvoltage relay having a front contact, the two heating circuits being connected in parallel and inserted in the supply mains in series with the front contact on said minimum-voltage relay and also with a front contact responsive to the preheating clutch.

6. Device according to claim 5, characterized in that the contact responsive to said clutch of said heating control circuit are adapted to control the energization of the coil of another auxiliary contact unit having a front contact adapted to control in turn the energization of a control relay inserted in the circuit connected to said wire, in series with a delayed-action back contact actuated by a third auxiliary contact unit responsive to a delayed-action front contact actuated by the motor of said heating control circuit.

7. Device according to claim 6, characterized in that a push-button is adapted to energize the coil controlling the actuation of said second auxiliary contact unit.

Claims

1. Device for heating the seal or moulding strip of fixed windows, said strip having embedded therein a metal wire adapted to act as an electric resistor and being firstly preheated and then heated, for causing the window to adhere to its surrounding frame, characterized in that it comprises in a movable cabinet connected to travelling supply means a voltage regulating member adapted to maintain a constant current intensity in said wire, irrespective of the wire length, a data processing unit controlling the heating operation and comprising members issuing instantaneous orders and delayed-action orders for controlling in succession preheating control circuits and heating circuits to ensure the energization of said wire during two different time periods, and first and second safety members, said first member controlling the current value in said wire and said second member controlling the voltage drop across the connecting terminals of said wire.

2. Device according to claim 1, characterized in that the member controlling the current value in said wire is a minimum-current relay inserted in the supply circuit of said wire and adapted to actuate through a front contact a first auxiliary contact unit comprising a delayed-action contact controlling in turn all the heating control circuits.

3. Device according to claims 2, characterized in that the member controlling the voltage drop across the terminals of said wire comprises a minimum-voltage relay having a front contact adapted to control in series with said delayed-action contact all the heating control circuits.

5. Device according to claim 4, characterized in that the heating control circuit comprises a first circuit incorporating a motor in series with a delayed-action back contact responsive thereto, and a second circuit parallel to said first circuit and comprising a clutch for actuating another back contact and a front contact, the assembly of said last-named motor and clutch being connected in series with a front contact responsive to said preheating control circuit clutch; and, a minimum-voltage relay having a front contact, the two heating circuits being connected in parallel and inserted in the supply mains in series with the front contact on said minimum-voltage relay and also with a front contact responsive to the preheating clutch.