|Title of Invention||
A DEVICE FOR RAISING AND LOWERING THE WINDOW PANES OF AUTOMOBILES
|Abstract||(57) Abstract: automobiles comprising a reversable motor provided for drive means coupled to one window pane. At least two manually operable switches and at least one microswitch are operable by the drive means. A microcontroller is activated on operation of one or more of the said switches. An amplifier and comparator are provided in the motor circuit for amplifying the motor current and comparator activates the microcontrol for whenever the motor current exceeds the preset voltage reference. The microcontroller in its activated state is programmed to energise, de-energise, reverse or disable tales, lower, reverse or arrest the movement of, he reversal of, the motor to cause the drive means to the said pane or panes. PRICE: THIRTY RUPEES|
This invention relates to a device for raising and lowering the window panes of automobiles.
The device is an electronic control system -for control ling power window systems in automobiles. It makes power window operation fully automatic and inc lodes safety -features for avoiding injury to passengers.
The device proposed enables a window pane to be raised or lowered by momentarily touching the "up" switch or "down" switch.
After momentarily touching the "up" or "down" switch, the motion of the window pane is automat¬ic . The window pane continues to move up or down. as the case may be, to the end of its travel at which point the motor is de-energized by a micro-controller.
During the upward travel of the window pane if an obstacle„ such as the hand of a passenger, ob¬structs the motion (this is sensed by the micro-
controller as a -force exerted on the pane) the pane stops and reverses motion, thus allowing the passenger to withdraw his hand and avoid injury.
Various other features of this invention will be apparent from the following further description thereof.
The device for raising and lowering the window panes of automobiles, according to this invention, comprises a reversible motor provided for drive means coupled to one window pane; at least two manually operable switches and at least one raicroswitch operable Uv the drive means; a micro-control leer activatable on operation of one or more of the said switches s an amplifier and comparator provided in the motor circuit for amplifying the motor current and comparing it with
a preset voltage reference, the comparator acti¬vating the microcontraller whenever the motor current exceeds the preset voltage reference, said microcontraller, in its activated state,
Energising, de-penergising, reversing or dishing the reversal of, the motor to rat* the drive means to rise, lower, reverie or arrest the movciBpnt of, the said pant* or panting.
This invention will now be described with preference to the accompanying drawings which illustrate, by may of example, one of various* possible pmbodiwBnta of the device proponed here¬in, wherein
Fig- 1 illustrates the circuitry of the embodiment Fig. 1 illustrates the. layout of the major compo¬nent« of the embodiment and
Figs. 3 to 7 illustrate operational flow charts of the embodiment.
In the embodiment lustrated, the electronic module ironsmiths; of a microcontroller simultaneous-ly control 1 ing two windows. This two microtone stroller modules are required to control all four
doors in a car. This arrangement is dictated by convenience since a microcontroller
module can also be made to control one or more windows, if necessary.
The microcontroller is compatible with the central locking system. A one touch button can be used to raise al1 the window panes in the car. This feature is useful while parking and locking the vehicle.
The device is protected against electrostatic discharge at the input terminals and also against surges and transients in power supply.
In the drawings UP1 and DN1 indicate the "up" and
"down" switches which are manually operable, that
is, operable by the passenger. for raising and
lowering the window panes on the le-ft side o-f the
vehicle. Similarly, UP 2 and DN2 srs the "up" and
"down" switches for the right side door of the
A third manually operable switch is CLS. This is
operable by the driver for raising all the window
panes (on the left as wel1 as on the right side of
the vehicle)- This input can also be coupled
directly to the central locking system.
The manually operable switches wi11 preferably be of the pushbutton type.
USl and US2 are micraswitches which are operable by the drive mechanisms coupled to the window panes on the left side and on the right Bide of the vehicle, respectively.
The embodiment illustrated will now be described in further detai1 mainly with regard to the left side of the vehicle. The same description wil1 be applicable to the right side of the vehicle also.
A reversible motor Ml such as a dc motor is pro¬vided for the drive means coupled to window panes on the left side of the vehicle for raising and lowering the panes depending upon the direction of rotation of the motor.
Two manual 1v operable by the drive means connected to a microcon--stroller MC. The microcontroller is activatable on operation of one or more of the said switches,
An amplifier and comparator Al provided in the motor circuit amplifies the motor current carried by the cupro-nickel alloy wire shunt SI and com¬pares it with a preset voltage reference, the comparator activating the microcontroller whenever the motor current exceeds the preset voltage reference.
It is noteworthy that the device is current, sensi¬tive. The motor current is a direct indication of the force against which the window panes move. Thus any load on the motor Ml larger than what is normal ly encountered -for moving the window panes up and down (e.g. when the hand of a passenger obstructs the upward movement of a window pane) draws a correspondingly larger motor current than
normal and if this current exceeds the preset reference, the comparator output is a signal 1 activating the microcontroller, in the manner hereinafter described.
The said microcontroller, in its activated state, is programmed to energise, de-energise, reverse or disable the revereal of„ the motor to cause the drive means to raise, lower. reverse or arrest the movement of, the ©aid pane or panes. This is explained hereunder with reference to the embodi¬ment i1 lustrated -
The motor circuit includes a dual relay system comprising the relay driver Dl and the relays Rl with energising coils RC11 RC12. By energising coi1 RC11 the motor rotates in one direction j by energising coil RC12, the motor rotates in the other direction. If neither coil is energised, the motor is off. The microcontroller MC is thus enabled to run the motor Ml in either direction or to switch it off depending upon its activation.
The microswitches US1 and UB2 are switched on whenever the window panes reach a predetermined point in their upward travel, say, 1/4 to 1 inch ■from the end of upward travel of each pane. When the microswitch US1 or US2 is switched on, it activates the microcontroller which disables the reversing -function of the microcontroller beyond this point.
The flow charts illustrated in Figs.3 to 7 indi¬cate the sequence of operations and &re self-explanatory.
As soon as the device is switched on, it enters the "start" state. The microcontroller then performs a power -on -se 1 f test If the UP1 switch is now operated
window panes upwards on the left side of the vehicle. After a delay of 600 ms the microcontroller checks for a DN1 switch press (operation ) and if this switch is operated, the motor direction is reversed by the microcon trol1er and the window pane is lowered.
If the USI switch is operated by the window pane drive means and at the same time if the motor current is higher than the preset reference, motor Ml is de-energised, hence stopping the window pane at the end of its travel.
If the window pane* on the left side are* moving up and the switch US1 is not depressed (not operated) and the motor current is higher than the preset reference, the microcontroller reverses the motor direction for a period of 620 ms and then de-energizes the motor.
If the window panes on the left side are moving up and the UP1 switch is pressed (operated) for the
second time, the microcontroller de-energises the motor. Similarly, if the DN1 switch is pressed for the second time after the window panes start moving downwards, the motor is de-energised.
As already stated above, what has been stated with respect to the left side door of the vehicle is applicable at the right side door of the vehicle.
At the end of the loop see flow charts) the microcontroller checks if the Cuts key is pressed (operated). If this is so, the microcontroller energises both left side and right side motors Ml and M2 to raise al1 windows. The control is passed back the beginning of the lap as shown in the flow charts and the entire process is repeated again.
The circuit incorporates an input buffer stage to isolate the microcontroller for protection against electrostatic discharge. The circuit is also protected against over voltage conditions, high voltage transients and battery reversal.
The terms and expressions in this specification &r& of description and not of limitation, there being no intention in the use of such terms and expressions of excluding any equivalents of the features i 1 lust rated and described, but it. is understood that various other embodiments of the device proposed herein BTB possible without departing from the scope and ambit of this inven¬tion .
1. A device for raising and lowering the window panes of automobiles comprising a reversible motor provided -far drive moans coupled to one window panel at least two manually operable switches and at least one microswitch operable by the drive means; a microcontroller activatable on operation of one or more of the said switches ; an amplifier and comparator provided in the motor circuit for amplifying the motor current and comparing it with a preset voltage reference, the comparator acti¬vating the microcontroller whenever the motor current exceeds the preset voltage reference, said microcontroller, in its activated state, energis¬ing, de—energising, reversing or disabling the reversal of, the motor to cause the drive means to raise, lower, reverse or arrest the movement of, the said pane or panes.
2. A device as claimed in Claim 1 wherein a dual relay with
driver and current shunt is provided in the motor circuit for
rendering the motor reversible.
3. A device as claimed in Claim; 1 or 2 wherein, when the drive
means are coupled to two or more window panes, two or more
manually operable switches are provided, the microcontroller
being activatable on operation of the said switches and in its
activated state, energising, de-energising, reversing or
disabling the reversal of the motor, to cause the drive means to
raise, lower, reverse or arrest the movement of the said panes.
4. A device as claimed in any one of the preceding claims
wherein the microcontroller has means to perform a power-on-self
test in its "start" state.
5. A device for raising *nd lowering the window panes of
automobiles substantially as herein described with reference to,
and as illustrated in, the accompanying drawings.
Dated this the 15th day of April 1996.
|Indian Patent Application Number||622/MAS/1996|
|PG Journal Number||02/2006|
|Date of Filing||15-Apr-1996|
|Name of Patentee||LUCAS-TVS LIMITED,|
|Applicant Address||PADI, CHENNAI-600 050|
|PCT International Classification Number||B60J5/04|
|PCT International Application Number||N/A|
|PCT International Filing date|