GB2322409A

GB2322409A - Vehicle door:unlocking:opening

Info

Publication number: GB2322409A
Application number: GB9626098A
Authority: GB
Inventors: John Phillip Chevalier
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-12-16
Filing date: 1996-12-16
Publication date: 1998-08-26
Anticipated expiration: 2016-12-16
Also published as: EP0968348A2; GB9626098D0; JP2009007927A; GB2320943A; WO1998027301A3; EP0968348B1; AU7739098A; WO1998027301A2; GB9726341D0; GB2322409B; KR100567973B1; DE69739518D1; KR20000071023A

Abstract

To unlock, and start the opening of, a vehicle door, motor 70 lifts pawl 24 and rotates latch 11 in direction 18 to be unlatched from frame bolt 18, the latch reacting with the bolt to push the door open (to the right). The motor oppositely rotates the latch to lock the door. The motor rotates a cam (Figs. 4 to 7, not shown), which is also moved axially by a spring, to actuate microswitches to reverse the motors' polarity, and thus its rotation.

Description

1 M&C Folio: 230P76255 Control System for Opening a Doo 2322409 This

invention relates to a control system for opening a door, and also to a control system for either opening or closing a door; it is particularly useful in a motor vehicle, and can be integrated in a central locking system for vehicle doors.

The invention also relates to a control system for supplying electric power with alternating polarity to a motor, which is particularly useful in the power-assisted vehicle door latch control.

It is already known to provide motorised movement for effecting complete closure of a vehicle door, once the door has been partially closed manually. There is a demand for further labour-saving luxury features in passenger cars, and the present invention is intended to provide for the power-assisted opening of vehicle doors. The invention also aims at minimising the size and number of components in a door control system, so as to keep to a minimum the cost of manufacture.

Accordingly, the invention provides a control system for a door or other closure mounted on a frame, the door being latchable to the frame by a latch engaging a striker, the latch being moveable between latching and unlatching positions such that movement from its latching to its unlatching position causes a reaction force from the striker onto the latch intending to open the door, comprising a motor coupled selectively to drive the latch from its latching to its unlatching position and thereby to unlatch and at least partially to open the door.

The invention also provides a control system for a door or other closure mounted on a frame, the door being latchable to the frame by a latch engaging a striker, the latch being moveable between latching and unlatching positions, comprising a motor coupled selectively (a) to drive the latch from its latching to its unlatching position and (b) vice versa whereby respectively (a) to unlatch and at least partially open the door and (b) to complete closure of the door and to latch it.

The invention also provides a motor control system comprising a motor coupled to drive a body in either of two opposite directions, between extreme positions of the 2 body, dependent on the polarity of electric power supplied by a power supply circuit to the motor, and a pair of microswitches, arranged in the power supply circuit such that closure of one of the microswitches, supplies the electric power at one polarity and closure of the other microswitch supplies the electric power at the opposite polarity to the motor, the microswitches being responsive mechanically to the position and to the direction of movement of the body between its extreme positions.

In order that the inventions may be better understood, preferred embodiments of the present inventions will now be described, by way of example only, with reference to the accompanying schematic drawings, in which:

Figure I shows diagrammatically part of the internal latch mechanism for controlling a motor vehicle door; Figure 2 is a partial view of two of the components in Figure 1, separated for clarity, Figure 3 is a simplified view of two of the components of Figure 1, but in which the motor gearing is modified; Figure 4 is an enlarged view from one side of a mechanically-driven switch arrangement forming part of the mechanism shown in Figure 1; Figure 5 is a diagrammatic plan view of a cam assembly forming part of the arrangement shown in Figure 4.

Figure 6 is a schematic circuit diagram of the motor control circuit including the switches shown in Figure 4; and Figure 7 is a circuit diagram corresponding to Figure 6, but additionally including a relay switch for door opening control.

With reference first to Figures I to 3 of the drawings, a vehicle door closure arrangement comprises a striker 10 connected to the door frame of a vehicle, and a latch bolt I I forming part of a latch arrangement supported on the edge of the vehicle door. Whilst the shape of the latch bolt I I in Figure I is special to the present invention, its general function is conventional and need not be described in detail here. The latch bolt I I is mounted pivotally at 15 for rotary motion as shown by arrow 18, driven by the relative motion 17 of the striker 10 in a Ushaped notch 12 formed in the latch bolt 11. The latch bolt I I has two further notches 13, 14 formed in its periphery, for 3 engagement with a locking pawl 20. Notch 13 is for locking the latch bolt at a latching rotary position, which retains the striker 10 and maintains closed the vehicle door. The door is capable of being opened, towards the right in Figure 1, by releasing the pawl 20 from its locking position in notch 13, allowing the striker 10 to drive the latch bolt I I clockwise 18 under the camming action of the indentation 12, until it is no longer detained by the striker 10. However, if the locking pawl 20 is allowed to engage the further notch 14, at a so-called half latch position, then the door can be half latched, partially open.

The locking pawl 20 is mounted pivotally at 21, and pivot points 15 and 21 are both fixed to a latch housing (not shown). The pawl 20 has an end tooth 24 for locking engagement in notches 13, 14. At the same end, it is formed with a pin 23 on which there is pivotally mounted a link arm 25 which is coupled to a door handle for actuating the pawl. Lifting the door handle causes the link arm 25 to move in the direction shown by arrow 26, pulling the pawl 20 anticlockwise as shown by arrow 22, and moving the pawl to its unlocking position (not shown).

In accordance with the present invention, the latch bolt I I is coupled drivingly to an electric drive motor 70, of the type commonly used for the central locking of vehicle doors. This coupling arrangement, to be described in greater details below, also incorporates an arrangement for releasing the pawl.

The motor 70 is coupled to the latch bolt I I through gears 40, 50, 60. Gear 40, shown in isolation in Figure 2, meshes at 45 with teeth 16 on the latch bolt 11. It is mounted for rotation about axis 42, which is shared by the larger-diameter gear 50, shown in isolation in Figure 3. Gear 50 is drivingly coupled to gear 40, with 60 degrees of rotary free play, by means of a pair of slots 52, 53 in one of the plates of gear 50, through which slots project a pair of driving pins 44, 43 connected to gear 40. This 60 free play is important, in this embodiment, to allow for proper sequencing of the pawl release and latch bolt drive.

Rotary motion of gear 50 in the direction shown by arrow 41 is controlled by its direct meshing engagement with the spindle of the motor 70. In the embodiments shown in Figure 1, this coupling is through the meshing of gear 71 on the motor spindle and teeth 62 on crown gear 60, gear 60 being connected to a smaller-diameter gear 61 4 which drives teeth 54 on gear 60. In the alternative embodiment shown in Figure 3, worm gear 72 is driven directly by the motor spindle, and drives gear 50 directly.

One section of gear 50 has a U-shaped indentation 51 which cams against a limb 33 projecting from a hook 32 at the end of a pawl actuator 30. The actuator 30 is constrained by formations on the latch housing (not shown) to reciprocate generally in the direction shown by arrow 34 in Figure 1, so as to link mechanically with pin 23 of the pawl 20. The upper end of the pawl actuator 30 is shaped as a dog leg with an extension formed with a slot 31 which surrounds the pin 23. This arrangement provides free play in the driving connection between the pawl actuator 30 and the pawl 20.

The operation of the power-assisted door latch will now be described. It will be appreciated that the door latch can be operated either mechanically, without motor power, or else under motor power. This of course is an important safety feature.

Powered operation will be described first. With the door in its closed position, as shown in Figure 1, the latch bolt 11 is at its latching position, and the locking pawl 20 at its locking position. Pawl actuator 30 is engaged by the gear 50. Upon receipt of a command to open the door, from a central electronic control circuit 90 (Figures 6 and 7, to be described below), the motor 70 drives the gear 50 anticlockwise as shown at 41. For the first 60 of rotation, the gear 40 will remain stationary, and no attempt is made to rotate the latch bolt 11. Otherwise, the latch and pawl would jam. The indentation 5 1 pushes the pawl actuator 30 in the direction of arrow 34, and this immediately pushes against pin 23 and drives the pawl anticlockwise as shown by arrow 22, to move it to its unlocking position. Continued rotation of gear 50 earns out the extension 33 of the pawl actuator 30, so that it rests on the outer periphery of gear 50, and is temporary prevented from re-entering. Continued rotation past the first 60 causes the walls of slots 52, 53 to engage the pins 44, 43 of the smaller gear 40, which drives the latch bolt 11 in the direction shown by arrow 18. With powered operation in this way, half latching is deliberately prevented. Thus the latch bolt is rotated so that notch 14 passes tooth 24, and until the outer surface of latch bolt 11 engages tooth 24 the pawl 20, preventing re-entry of the pawl.

Electronic position sensors, to be described below, cause the motor drive to switch off at the point that the vehicle door is partially open, and has passed its C1 unlatched position. The door can then conveniently be opened fully by the passenger or driver.

Driving the latch bolt 11 clockwise has the desirable effect of pushing the door open, by reacting against the striker 10. This accelerates opening movement of the door, and such opening movement will continue until it is decelerated by friction in the door hinges, by an amount dependent on the inclination of the vehicle.

When the door is closed, it will reach the same position, just beyond the half latch position, and will then cause the electric motor to be switched on again, with reverse polarity (to be described below). The motor then provides power-assisted door closing, to ensure that the door is probably closed and latched. Again, the half latch position is not possible, with power assisted closing. As the door commences full closure, clockwise rotation of the latch bolt 11 accompanies clockwise rotation of the smaller gear 40 together with the larger gear 50. After the first phase of such rotation, the extension 33 of the pawl actuator 30 drops into the indentation 51 in gear 50, and for the final phase of rotation the pawl actuator 30 translates back downwards. The free play between the pawl actuator and the pawl 20 allows the pawl 20 to ride over the slot 14 and into the slot 13, under a clockwise spring bias (not shown), without jamming. As the tooth 24 lodges in the slot 13, the arrangement returns to the position shown in Figure 1.

Without power assist, the latch can be controlled by the door handle through the link arm 25. The mechanical interactions remain, and opening and closing the door causes rotation of the motor spindle, but this simply provides a small amount of mechanical resistance. Lifting the link arm 25 releases the pawl, allowing the door to be opened, whereby the latch bolt 11 is turned clockwise by the striker 10. Again, the pawl actuator 30 is released from engagement with the gear 50 until the door is reclosed. It will also be appreciated that since the mechanical sequence is the same, power assisted closing can follow non power assisted opening, and vice versa. When the latch is operated purely mechanically, it is capable of lodging in the half latch position, with tooth 24 of pawl 20 in notch 14. This is an additional convenience and safety feature.

11" 6 The electrical control system will now be described with reference to Figures 4 to 7. In accordance with the invention, there is mechanical position-sensing using microswitches, which alternates the polarity of the electricity supply to the motor, corresponding to the reciprocating motion of the body being driven by the motor, in this case the latch bolt 11. This mechanical ly-responsive power supply can also be operated together with electronic control through a relay switch, for initiating door opening, as will be described below with reference to Figure 7.

As shown in Figure 4, a camming member 10 1 is arranged for pivotal motion about the same axis 15 as the latch bolt 11, and it is driven by means of a projection 140 engaging in a recess 141 in the latch bolt 11. As also shown in Figure 4, the latch housing 100 has three parallel layers, and these three layers are rigidly interconnected by means of a hinge on the axis 15, serving both the camming member 101 and the latch bolt 11. The camming member 101 is capable of sliding upwards and downwards on its pivot axis, to allow cam-following microswitch actuators 111, 121 and 131 to follow rectangular cam tracks C, B, A respectively shown in Figure 5. The camming member 101 is biased by a spiral spring 19, upwards in Figure 4, and downwards, shown by arrow 191, in Figure 5. A bank of three microswitches 110, 120, 130 is connected rigidly to the latch housing 100, so that the corresponding microswitch actuators ride along their respective rectangular cam tracks.

The face of the camming member 101 which faces the bank of microswitches is shown, to an enlarged scale, in Figure 5. Unshaded portions of each cam track are the deepest, as represented by line 102 in Figure 4; heavily shaded areas in Figure 5 represent a shallow floor to the cam track, as represented by line 103 in Figure 4. Ramps from the deeper to the shallower areas are shown by shading of an intermediate density in Figure 5. The respective rectangular cam tracks are defined by rectangular walls as shown, and by central walls 104, 105 and 106. The pin-shaped microswitch actuators I 11, 12 1, and 13 1 are represented as circles in Figure 5, at positions indicative of their motion along the respective cam tracks. When the door is open, the microswitch actuators are at the top right hand comers of the cam tracks shown in Figure 5. As the door begins to close, their relative positions move in the direction 1 7 shown by letter L, to the positions shown as A, B, C in Figure 5. At this point, the door is fully closed.

A step formation R extending diagonally across the middle cam track B, and continuous with the end face of the middle wall 105, cams the entire cam assembly 101 upwards in Figure 5, against the spring bias, in the direction M, as the latch bolt 11 moves towards the door open position. This is because of the sliding camming action of pin 121 on step H. Continued motion in the direction K brings the microswitch actuators back to position F, at which point the spring force 191 returns them to the top right hand corner as shown in Figure 5, with the cam assembly moving in direction N. The ramps E cause the cam actuators to be depressed into the respective microswitches, to change the microswitches from "off'to "on". Abrupt steps H allow the microswitch actuators to spring out again, turning the microswitches off.

The motor control will now be described with reference to Figures 6 and 7, which show alternative arrangements of the circuitry. In a motor vehicle, each door is controlled by its own motor 70, and each door has a red hazard light 80 to warn motorists that the door is open. The vehicle has a central electronic control circuit 90, with integrated stall current sensor circuitry 9 1, of a conventional type. First microswitch 110 controls the switching of the door hazard light 80. Second microswitch 120 provides power of one polarity to the motor, appropriate for door closing control. Third microswitch 130 supplies power at the opposite polarity to the motor, appropriate for door opening control. The mechanical arrangement of Figures 4 and 5 ensures correct sequencing of these microswitches. Using conventional notation, NO represents the normally open terminal, NC represents the normally closed terminal, and, C represents the common terminal. With the door closed, the microswitch actuators are at positions A, B and C in Figure 5, and all microswitches are off. Movement towards the opening position causes motion of the microswitch actuators in the arrow K of Figure 5, and after a small neutral movement, microswitch 130 is switched on, as actuator 131 rides up the ramp E. This provides power assisted door opening. Whilst the door is being opened, the door hazard light control microswitch comes on, as actuator 111 rides up its own ramp. When the door has reached the end of the power assisted motion, the door opening microswitch 130 is switched off, and only 1 i 8 the door han d light remains on. As the door is reclosed, the door closing control microswitch is immediately switched on, as the actuator 121 rides up its ramp from line F of Figure 5. During door closure, the hazard light is switched off.

When fully closed, the door closing control microswitch 120 switches off, as actuator 121 drops down the step at line G in Figure 5.

It is preferred that door opening be initiated under central electronic control, and this is provided by the relay switch 140 of Figure 7. A signal from the central electronic control circuitry 90, along lines 150, switches on the relay 140 to power the motor, and remains on for a sufficient period to move the mechanical arrangement to the point at which the third microswitch 130 switches on. The relay switch will then switch off, or time out.

The stall current sensor circuitry 91 need not be described in detail. In this example, it is a circuit breaker which provides over current protection, and is manually re-settable when tripped. Current sensing of the drive motor current takes place in its ground return path, and current sensing is effected by means of a resistor, whose voltage is amplified by an appropriate integrated differential amplifier. A second amplifier determines the voltage difference between the resistance value and the value of a reference voltage, provided by a temperature stable diode. The second differential amplifier acts as a comparator, providing logic level conversion, and outputting a stall signal.

Remote control transmitters are conventionally provided to control the central locking system, for example to unlock or lock the car from outside. The same command can be used by the central control system to open the doors, or specific doors, by remote control.

The central electronic control circuitry preferably receives inputs from sensors, some of which are placed inside the latch to determine the positions of pawl, the latch bolt, and pawl actuator, or any other part of the latch mechanism. Some other sensors are preferably placed elsewhere in the vehicle, for example to monitor the state of the car engine. For example, the current energising the drive motor can be cut off by the central electronic control circuitry 90, when the engine has been started and the car is in motion. This safe guards against accidental electrical door opening. As a further 7 9 example, if the door is jammed and the motor drive is stalled, the current sensor circuitry 91 sends a message to the central electronic control circuitry 90 which cuts the current energising the motor until it detects certain predetermined favourable conditions, for example the release of the door handle and the moving of the door to a certain position manually.

It will be appreciated that many alternative arrangements are possible, and that the various inventions are applicable very broadly, within the scope of the respective claims. The mechanical link between the motor and the locking pawl 20 can take many different forms, and in particular the link actuator 30 can take any geometrical form, and can be stamped or moulded. It could be coupled with the pawl 20 by means of a rivet pin for free rotation, or it could mesh or be coupled freely with the pawl. It could be constrained to move linearly, as described, or else to pivot so as to function as a lever. The connection between gear 50 and the link arm 30 could be replaced by an arrangement for kicking the link arm, for example by providing a radial projection from gear 50; alternatively, there could be gear meshing between the gear 50 and the link arm 30, for example using a segmented gear. The link arm could then function as a rack suitably toothed or partly toothed.

Whilst the description relates to a vehicle door, the inventions are more broadly applicable. The latch arrangement could be used for any closure which is opened or closed relative to a frame. The mechanical lyresponsive polarity switching arrangement, exemplified in figures 5 to 7, for supplying power to a motor, is equally applicable to any motor drive arrangement, with the driven body providing mechanical feedback to the switches.

The specific arrangements described above in the context of a motor vehicle provide significant cost benefits. By incorporating the switches in the latched housing, this minimises the length of wiring, and in fact it is possible to reduce the necessary wiring to just the two wires shown in Figure 6, or the four wires 150, 151 and 152 shown in Figure 7, linking the door latch with the central control. By integrating the door hazard light with the door latch, for example by having a simple plug-in lamp, this minimises wiring and assembly costs. The integrated arrangement of the door opening and door closing microswitches, arranged in the same bank, is the most efficient arrangement, and minimises wiring. The mechanical arrangement for the latch reduces to a minimum the number of component parts, yet provides a mechanically rigid structure, and structurally strong components, particularly the latch bolt 11 and pawl 20 which distribute the mechanical shock and strain from the interaction with the latch striker 10.

C.7' 11

Claims

CLAIMS:

1. A control system for a door or other closure mounted on a frame, the door being latchable to the frame by a latch engaging a striker, the latch being moveable between latching and unlatching positions such that movement from its latching to its unlatching position causes a reaction force from the striker onto the latch tending to open the door, comprising a motor coupled selectively to drive the latch from its latching to its unlatching position and thereby to unlatch and at least partially to open the door.

2. A control system for a door or other closure mounted on a frame, the door being latchable to the frame by a latch engaging a striker, the latch being moveable between latching and unlatching positions, comprising a motor coupled selectively (a) to drive the latch from its latching to its unlatching position and (b) vice versa whereby respectively (a) to unlatch and at least partially open the door and (b) to complete closure of the door and to latch it.

3. A control system according to claim 1, in which the door is a vehicle door, and in which the vehicle has a central locking system for the vehicle doors, in which the central locking system comprises control means for selectively opening the door or doors.

4. A control system according to claim 2, in which the door is a vehicle door, and comprising a vehicle central locking system comprising control means for selectively energising the motor to open or to close the door or doors.

5. A control system according to any preceding claim, comprising a portable remote control electronic unit capable of communicating with a motor control means for selectively opening the door.

1 12

6. A control system according to any preceding claim, comprising means for locking the latch at its latching position, and comprising a mechanical actuator coupled to the locking means for disengaging the locking means from the latch.

7. A control system according to claim 6, comprising a linking means for coupling the motor to the locking means, the arrangement being such that, with the door closed and the latch at its latching position, initial movement of the motor causes the locking means to move from its locking position to its unlocking position to free the latch, and further movement of the motor then causes movement of the latch from its latching position towards it unlatching position.

8. A control system according to claim 6 or 7, in which the latch comprises a pivotal ly-mounted latch bolt rotatable between its latching and unlatching positions, and in which the locking means is a pawl arranged to lock the latch bolt, the mechanical actuator being coupled to the pawl for releasing the pawl and thereby unlocking the latch bolt.

9. A control system according to claim 2, comprising a motor control circuit for supplying power to the motor, and a pair of microswitches arranged in the motor control circuit such that closure of one microswitch causes motor drive in a direction such as to drive the latch to open the door, and closure of the other microswitch causes motor drive in a direction such as to drive the latch to close the door.

10. A control system according to claim 9, comprising a camming member moveable with the latch and arranged to cam the switch actuators of the pair of microswitches so as to sequence the switching of the motor in its alternating polarities for opening and closing the door.

11. A control system according to claim 10, in which the camming member comprises a cam track for each microswitch actuator, the cam tracks being generally C - t i i r 13 rectangular and mutually parallel, and further comprising means for causing the microswitch actuators to follow their respective tracks in only one direction of motion.

12. A control system according to claim 11, in which the means for causing the microswitch actuators to follow their respective tracks comprises a spring biasing the camming member, relative to the pair of microswitches, in a direction in the plane of the tracks, and in which the camming member comprises a cam surface across one of the tracks which converts relative motion of the camming member and the pair of microswitches, corresponding to the opening or closing of the door, into a transverse relative motion so as to guide both microswitch actuators, as cam followers, to the next section of track in the said one direction of motion.

13. A control system according to any of claims 9 to 12, comprising a third microswitch arranged adjacent the pair of microswitches, and connected electrically to a hazard light circuit, the third microswitch actuator acting as a cam follower in a third cam track in the camming member, so as to switch the hazard light on and off when the door is respectively open and closed.

14. A control system according to any preceding claim, comprising a relay switch for electronically switching on a motor, when the door is closed, to unlatch and partially open the door.

15. A control system according to claim 9, in which the microswitch for opening the door is positioned such that it is actuated once the door has been partially opened; and a relay switch for electronically switching on the motor, when the door is closed, to unlatch and partially open the door, the relay switch being capable of being closed for a sufficient period to cause the motor to move the door to the point at which the dooropening microswitch is actuated.

14

16. A control system according to any preceding claim, comprising stall current sensor circuitry associated with the supply of current to the motor, for temporarily disconnecting the power supply to the motor in the event that a stall current is detected.

17. An electrically-controlled door opening system for motor vehicles, substantially as described herein with reference to the accompanying dra-, hings.

18. A central locking system for a vehicle, comprising for each of at least two doors, a control system according to any preceding claim, controlled by a central control circuit.

19. A motor control system comprising a motor coupled to drive a body in either of two opposite directions, between extreme positions of the body, dependent on the polarity of electric power supplied by a power supply circuit to the motor, and a pair of microswitches arranged in the power supply circuit such that closure of one of the microswitches supplies the electric power at one polarity and closure of the other microswitch supplies the electric power at the opposite polarity to the motor, the microswitches being responsive mechanically to the position and to the direction of movement of the body between its extreme positions.

20. A motor control system according to claim 19, comprising a camming member moveable with the body and arranged to cam the switch actuators of the pair of microswitches so as to sequence the switching of the motor in its alternating polarities.

21. A motor control system according to claim 20, in which the camming member comprises a cam track for each microswitch actuator, the cam tracks being generally rectangular and mutually parallel, and further comprising means for causing the microswitch actuators to follow their respective tracks in only one direction of motion.

22. A motor control system according to claim 21, in which the means for causing the microswitch actuators to follow their respective tracks comprises a spring biasing the camming member, relative to the pair of microswitches, in a direction in the plane of the tracks, and in which the camming member comprises a cam surface across one of the tracks which converts relative motion of the camming member and the pair of microswitches, into a transverse relative motion so as to guide both microswitch actuators, as cam followers, to the next section of track in the said one direction of motion.

23. A motor control system substantially as described herein with reference to Figures 4 and 5 of the accompanying drawings.

C,