EP1234937B1 - Electrical latch with an emergency actuation - Google Patents

Description

The present invention relates to an electric lock for opening of a motor vehicle, in particular for a tailgate, according to the preamble of claim 1. Such a lock is known from the document EP 812 972 A2.

EP 812 972 A2 discloses an electric lock for opening of a motor vehicle, which comprises a rotary bolt in the form fork, movable between an open position and a position of closure, in which the bolt is capable of retaining a keeper, a pawl pivoting subjected to an elastic return which pushes it towards a position of retainer, in which the pawl is able to cooperate with at least one latch notch to hold the latch in the closed position, and a chain motorized kinematics comprising an electric actuator, a wheel rotated by said actuator and at least one pin carried fixedly by the wheel, the crank pin projecting from the wheel. During the rotation stroke of the wheel, said crankpin acts by through a coach on said pawl so as to move it away from the restraining position and cause the lock to open.

Also in known manner, a lock of this type can include a manual control means able to cooperate directly or indirectly with the ratchet to open the lock.

These locks have drawbacks: in the event of unexpected blocking of the motorized drive train, for example by electric actuator failure, by power supply failure actuator or by failure of a mechanical part of the motorized kinematic chain, the crankpins can be blocked in a position in which they hinder the movements of the pawl in the direction of opening or closing, or in both directions, so that the lock can no longer be opened or closed respectively. This results in a lack of security of these locks in the event of failure motorized drive train, the opening of the vehicle carrying the faulty lock which can no longer be opened or closed.

The object of the invention is to propose an electric lock not having the aforementioned drawbacks.

For this, the invention provides an electric lock for opening of a motor vehicle, said lock comprising a rotary bolt fork-shaped, movable between an open position and a closed position, in which said bolt is capable of retaining a keeper, a pivoting pawl subjected to an elastic return which pushes it towards a retaining position, in which said pawl is able to cooperate with at least one notch of said bolt to retain said bolt in the position of closing; said lock comprising a motorized kinematic chain comprising an electric actuator, a wheel driven in rotation by said actuator and at least one pin carried by said wheel, said crank pin projecting from said wheel for at least one active part of a rotation stroke of said wheel, during which active part said pin acts directly or indirectly on said ratchet so as to move it away from said retaining position for cause the opening of said lock, characterized in that said lock has means manual control able to cooperate directly or indirectly with said ratchet to open said lock and the fact that said crankpin is mounted movable in translation relative to said wheel, said crank pin being able to retract into said wheel during an opening manual operation of said lock to disengage said kinematic chain motorized with respect to said pawl, so that said lock remains suitable to be opened and closed manually in case of blockage of said chain motorized kinematics.

Advantageously, the lock according to the invention comprises a ramp to cause a translation of said crankpin during the rotation stroke of said wheel.

Advantageously, said crank pin has an engaged body through said wheel, a lower end of said body being able to take support on said ramp.

Advantageously, said pin carries a tip on said lower body end to limit friction of said body on said ramp.

Preferably, an elastic return means recalls said crankpin towards said ramp.

Preferably, the underside of said wheel has a housing in a ring around its axis to receive said ramp.

According to a particular characteristic of the invention, said translation takes place substantially parallel to the axis of said wheel, said ramp being helical, or else said translation takes place substantially radially with respect to said wheel, the ramp ramp being in spiral.

Advantageously, said ramp has a section inclined traversed by said lower body end from a low end towards a high end before said active part of rotation stroke, so as to bring out said protruding mancton by relative to said wheel.

Advantageously, said ramp has a low section located in the continuity of said lower end of inclined section and connected to said upper end by a step.

Preferably, said step is arranged substantially at start of said active part of the crankpin stroke, said bottom section being arranged substantially in line with said active stroke part of the pin.

According to another characteristic of the invention, the lock comprises an intermediate drive member arranged so as to connecting said motorized kinematic chain to said pawl, said member drive intermediate being movable between a rest position, wherein an arm of said intermediate drive member cuts the stroke of said crankpin and an active position, in which said member intermediate drive away said pawl from said position retained so as to open said lock, said crank pin pushing said arm during said active stroke portion so as to move said intermediate member for driving from said rest position to said active position.

Advantageously, said crank pin comprises a head capable of take support on said arm to retain said protruding pin by relative to said wheel during said active part of the crankpin stroke.

Preferably, said manual control means is capable of cooperate with said intermediate drive member to move it at said active position, so that if said actuator stops electric, manual movement of said intermediate member drive is able to remove said arm from below said head for retract said pin in said wheel.

Advantageously, said crank pin comes into contact with said arm substantially at the time of crossing said step, said crankpin being retained by its head resting on said arm and not being in contact with said ramp after crossing said step.

Preferably, at the end of said active part of travel of said crankpin, said arm escapes from said crankpin, said crankpin falling on said ramp substantially at the lower end of said inclined section.

Advantageously, the course of said inclined section corresponds to an inactive part of the crankpin rotation stroke in which said pin does not cooperate with said member training intermediary.

• la figure 1 est une vue partielle en perspective d'une serrure selon l'invention en position fermée, la chaíne cinématique motorisée étant au début de sa course d'ouverture,
• la figure 2 est une vue en perspective éclatée montrant une roue dentée, un maneton, un ressort de rappel et une rampe de la serrure de la figure 1,
• la figure 3 est une vue analogue à la figure 1 à une étape intermédiaire de la course d'ouverture de la chaíne cinématique motorisée,
• la figure 4 est une vue plane des organes de cinématique de la serrure selon la flèche IV de la figure 3,
• la figure 5 est une vue analogue à la figure 3 à une étape d'ouverture de secours de la serrure,
• la figure 6 est une vue plane des organes de cinématique de la serrure selon la flèche VI de la figure 5.

The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly during the following description of a particular embodiment of the invention, given solely by way of illustration and not limiting, with reference to the accompanying drawing. On this drawing :

• FIG. 1 is a partial perspective view of a lock according to the invention in the closed position, the motorized kinematic chain being at the start of its opening stroke,
• FIG. 2 is an exploded perspective view showing a toothed wheel, a crank pin, a return spring and a ramp of the lock of FIG. 1,
• FIG. 3 is a view similar to FIG. 1 at an intermediate stage of the opening stroke of the motorized kinematic chain,
• FIG. 4 is a plan view of the kinematics members of the lock according to arrow IV of FIG. 3,
• FIG. 5 is a view similar to FIG. 3 at a stage of emergency opening of the lock,
• FIG. 6 is a plan view of the kinematics members of the lock according to arrow VI of FIG. 5.

Referring to Figure 1, the lock has a housing monoblock not shown, for example of molded plastic, having two wings arranged perpendicularly in the shape of an L. A wing of base forms a wall of a lock retention compartment which contains the retention elements, namely the bolt 7 and the pawl 8 movable in rotation about their respective axes 13a and 13b.

A return spring not shown recalls the bolt 7 towards its open position. Another return spring 14 recalls the pawl 8 towards its bolt retaining position 7. The bolt 7 is of the fork type and molded with plastic. On a branch of the bolt fork 7, two notches 7a and 7b are stripped to avoid bursting of the overmolding during contact of these notches 7a and 7b with the pawl 8, such a burst can cause friction of the bolt 7 on the housing. At the position for closing the lock, the notch 7a comes into contact with a tooth 8a of the pawl 8 to retain the bolt 7 in the closed position. Notch 7b comes in contact with said tooth 8a when the lock is semi-open.

A second wing of the housing (not shown) carries the kinematics of the lock, namely an intermediate lever opening 21 mounted in rotation about an axis perpendicular to said wing, an external opening lever 22 rotatably mounted around the same axis, and the motorized kinematic chain of the lock comprising an electric motor 23 whose shaft 33 parallel to the second wing carries an endless screw 34 meshing on the toothed edge 35 of a wheel 31.

The intermediate opening lever 21 has four arms 21a, 21b, 21c and 21d each extending substantially radially from the axis of rotation 20 of the lever 21. The arm 21a has one end angled toward the end portion 26 of the arm 16. When the lever opening intermediate 21 is rotated from its rest position, visible in Figure 1, in the direction of the opening of the lock, shown by arrow G1, the arm 21a pushes the end part 26 of the arm 16 and rotates the pawl 8 to its open position. A spring of return 24 mounted around the axis 20 return lever 21 to its position rest.

The arm 21b arranged substantially at 90 ° to the arm 21a in the opening direction has a curved 21st end tab perpendicularly along a lateral edge of the arm 21b. At the position of rest, the arm 21b is substantially superimposed on the opening lever outside 22. The end of the outside opening lever 22 has a leg 28 curved perpendicularly intended to be connected to a system manual operation, for example a rod, to cause manually opening the lock. When activated manually in the opening direction, according to arrow G1, the lever opening 22 abuts laterally on the end tab 21st so as to drive the intermediate opening lever 21 towards its active position.

The arm 21c is substantially diametrically opposite the arm 21b. As best seen in Figure 4, the arm 21c has a first part 29 bent substantially parallel to the axis 20 towards the high relative to the support of the lever 21 and a second part 30 angled perpendicular to the first part 29 for extend parallel to the lever support 21 above the wheel toothed 31 rotatably mounted about an axis 32 parallel to the axis 20.

The motor 23 has a single direction of rotation so as to drive the gear 31 in the direction of the arrow G2, opposite to the direction lever G1 opening 21.

With reference to FIG. 2, the toothed wheel 31 includes a disc-shaped body 36 carrying the toothed edge 35 at its periphery skirt shape. Under the body 36, a housing 37 in the form of a crown is defined between the axis of rotation 32 and the skirt 35. The support (not shown) of the toothed wheel 31 carries directly above the housing 37 a helical ramp 38 which is housed in the housing 37 when the wheel 31 is placed on said support.

The ramp 38 has the shape of a section torus rectangular, the height of which varies along its periphery. traveled in the direction of rotation G2 of the wheel 31, the ramp 38 has successively a low section 39 of substantially constant height extending over an angular sector a, for example of substantially 90 °, corresponding to the lower height portion of the ramp 38. The lower section 39 is extended by an inclined section 40 extending over a angular sector which completes the angular sector a in turn, by example of substantially 270 °. The height of the inclined section 40 increases continuously from the height of the lower section 39 to a height maximum, for example substantially double the height of the section low 39. The top 41 of the inclined section 40 is connected to the section low 39 by a vertical step 42.

The toothed wheel 31 comprises, molded onto the body 36, a protruding block 46 having a first circular rib 47 surrounding the axis 32 and a second circular rib 48 surrounding a bore 49 formed in the body 36 and intended to receive the cylindrical body 45 a crank pin 43 to guide it in translation parallel to the axis 32. The crank pin 43 has a head 44 substantially in the form of a disc with the upper end of the rod 45. The head 44 has a diameter greater than that of bore 49.

The rod 45 of the crank pin 43 passes through the body 36 of the wheel 31. Its lower end protruding into the housing 37 carries a tip 50 fixedly fitted on the rod 45 and having an end face 51 intended to come into sliding contact with the ramp 38. A spring of reminder 52 is engaged on the rod 45 of the crankpin in the housing 37 with one end resting on the underside of the body 36 and the other end on the end piece 50, so as to exert a restoring force on the crankpin 43 towards the ramp 38.

The operation of the electric lock will now be explained. The lock being initially closed, as visible on the Figure 1, the bolt 7 is retained by the pawl 8, the pawl 8 is maintained closed by its return spring, the intermediate lever 21 is held in the rest position by the spring 24 so that the arm 21a does not not touch the pawl and the arm 21c extends over the wheel 31 to near the crank pin 43, so that the head 44 overlaps the part 30. In its initial position, the crank pin 43 is substantially at the right of the top 41 of the ramp 38 with the lower end of the rod 45 resting on the vertex 41. The maximum height of the ramp is chosen so that the rod 45 protrudes above the wheel 31, the head 44 being above of the second part 30 of the arm 21c. The motor 43 is able to be controlled in a manner known per se for making a turn complete with toothed wheel 31 in direction G2 in order to open the lock.

Referring to Figure 3, the motor 23 is omitted. In the beginning of the rotation stroke of the wheel 31, the rod 45 comes into contact laterally with the edge 53 of the second part 30 of the arm 21c, which marks the start of the active part of the crankpin stroke. Substantially at the same time, the crank pin 43 crosses the step 42 of the ramp. By turning, the crank pin rotates the intermediate lever 21 in direction G1 by sliding against the lateral edge 53. The lever intermediate 21 turns the pawl 8 in the opening direction G3 by contact between the branch 21a and the end portion 26. From the crossing step 42, rod 45 is no longer held by its lower end and begins to retract towards the lower section of the ramp 38 under the effect of the spring 52. The head 44 overlapping the arm 21c, it takes support on it and stops the downward movement of the crankpin 43.

As the gear wheel continues to rotate, the crankpin pushes the intermediate lever 21 which pushes the pawl 8 until the bolt is released 7, which pivots in the open position under the effect of its spring recall or movement of the door on which the lock is mounted relative to the keeper (not shown), so that the lock opens. After opening the lock, the crank pin reaches the end 54 of the arm 21c, the intermediate lever 21 is in the maximum pivoting position in the direction G1. When the crankpin has crossed the end 54, the head 44 escapes from the arm 21c so that the crank pin 43 falls back onto the ramp 38 under the effect of the spring 52, substantially at the lower end of the inclined section 40. The intermediate lever 21 is no longer in contact with the crank pin 43, it returns to its rest position under the effect of spring 24. The fallout of the crank pin 43 marks the end of the active part of its course. Thus, the lower section 39 of the ramp 38 is arranged substantially in line with the entire active stroke of the crankpin 43.

The rotational stroke of the toothed wheel 31 continues until completion of the complete turn, the crankpin being pushed gradually upwards by its lower end in abutment on the inclined section 40 of the ramp 38. On this part of the race, the crankpin is inactive. At the end of the turn, the crank pin 43 and the lever 21 returned in their respective initial positions.

As a variant, the initial position of the crank pin 43 is not necessarily to the right of the summit 41 of the ramp 38 and may be at a any level of the inclined section 40.

In a manner known per se, a stop lever not shown is mounted coaxially with the intermediate lever 21 to stop the engine 23 after a complete revolution of the wheel 31.

An emergency actuation mode of the lock will now be described with reference to Figures 5 and 6.

Referring to Figure 5, the gear wheel has started to opening cycle under the action of the motor 23, omitted in FIG. 5, and has stopped during the active stroke of the crank pin 43. The crank pin 43 having crossed the step 42 is retained by the head 44 on the arm 21c. The lever intermediate 21 turned and pushed the pawl 8, but not enough to release the bolt 7, the notch of which 7a abuts on tooth 8a of the pawl 8. The wheel tooth 31 is blocked in this position due to a failure of the electric motor, power supply failure, or from another accidental cause.

By manually pulling, indicated by the arrow T, on the external opening lever 22, it is possible to make rotate the intermediate lever 21 in direction G1 until causing opening the lock. During this pivoting of the intermediate lever 21, the arm 21c escapes from below the head 44 of the crank pin 43, the said crank pin being immobilized with the wheel 31. The crank pin 43 retracts under the effect of the spring 52. The crank pin 43 is in line with the lower section 39 of the ramp 38. The height of the lower section 39 is chosen fairly weak so that the rod 45 retracts completely into the wheel 31 without come into contact with the ramp 38 until the head 44 comes in support on the rib 48, as visible in FIG. 6. Thus, the crankpin in the retracted position no longer cooperates with the intermediate lever 21, which can pivot freely above the head 44. The lever intermediate 21 is completely disengaged from the kinematic chain motorized so that the lock remains functional and able to be opened and closed manually.

The width of the head 44 can be chosen from a fairly large size. small to allow the crankpin 43 to be retracted as soon as a rotation of a few degrees of the intermediate lever 21 in the direction G1, for example 10 °. Thus, the amplitude of the tensile movement T necessary for release the head of the crank pin 43, and therefore disengage the intermediate lever 21 motor 23, can be chosen less than the range of motion necessary to cause the pawl 8 to open. The lock has therefore not necessarily need to be open to become manually again functional.

Although the invention has been described in connection with a mode of particular achievement, it is obvious that it is by no means limited and that it includes all the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention as claimed. In particular, the translational movement of the crankpin can be oriented in any direction. This translational movement crankpin is not necessarily straight and may, for example, be combine with a circular translational movement or a movement of rotation.

Claims (17)

1. Electric latch for a car door, said latch comprising a rotary bolt (7) in the form of a fork, able to move between an open position and a closed position, in which the said bolt (7) is able to hold a keeper, and a pivoting catch (8) subjected to an elastic return which pushes it towards a holding position, in which the said catch (8) is able to cooperate with at least one notch (7a) of said bolt (7) in order to hold said bolt (7) in the closed position; said latch comprising a motorised kinematic chain comprising an electrical actuator (23), a wheel (31) driven in rotation by said actuator (23) and at least one crank (43) carried by said wheel (31), said crank (43) projecting with respect to said wheel (31) for at least an active part of a rotation travel of said wheel (31), during which active part said crank (43) acts directly or indirectly on said catch (8) so as to move it away from said holding position in order to cause the opening of said latch, characterised in that said latch comprises a manual control means (22) able to cooperate directly or indirectly with said catch (8) in order to open said latch and by the fact that said crank (43) is mounted so as to be able to move in translation with respect to said wheel (31), said crank (43) being able to retract into said wheel (31) when said latch is opened manually in order to disengage said motorised kinematic chain (23, 31, 43) with respect to said catch (8), so that said latch remains able to be opened and closed manually in the event of locking of said motorised kinematic chain (23, 31, 43).
2. Latch according to Claim 1, characterised by the fact that it comprises a ramp (34) for causing a translation of the said crank during the rotation travel of the said wheel.
3. Latch according to Claim 2, characterised by the fact that the said crank (43) comprises a body (45) engaged through the said wheel, a bottom end of the said body being able to bear on the said ramp (38).
4. Latch according to Claim 3, characterised by the fact that the said crank (43) carries an end piece (50) on the said bottom end of the body in order to limit friction of the said body on the said ramp.
5. Latch according to one of Claims 2 to 4, characterised by the fact that an elastic return means (52) returns the said crank towards the said ramp.
6. Latch according to one of Claims 2 to 5, characterised by the fact that the bottom face of the said wheel has a ring-shaped housing (37) around its axis (32) in order to receive the said ramp (38).
7. Latch according to one of Claims 2 to 6, characterised by the fact that the said translation takes place substantially parallel to the axis (32) of the said wheel, the said ramp (38) being helical.
8. Latch according to one of Claims 2 to 6, characterised by the fact that the said translation is effected substantially radially with respect to the said wheel, the said ramp being in a spiral.
9. Latch according to Claims 3 and 7 taken in combination, characterised by the fact that the said ramp (38) has an inclined section (40) travelled over by the said bottom end of the body (50) from a bottom end towards a top end (41) before the said active rotation travel part, so as to make the said projecting crank emerge with respect to the said wheel (51).
10. Latch according to Claim 9, characterised by the fact that the said ramp (38) has a bottom section (39) situated in line with the said bottom inclined-section end and connected to the said top end by a step (42).
11. Latch according to Claim 10, characterised by the fact that the said step (42) is arranged substantially at the start of the said active crank travel part, the said bottom section (39) being arranged substantially in line with the said active crank travel part.
12. Latch according to one of Claims 1 to 11, characterised by the fact that it comprises an intermediate drive member (21) arranged so as to connect the said motorised kinematic chain (23, 31, 43) to the said catch (8), the said intermediate drive member being able to move between an idle position in which an arm (21c, 30) of the said intermediate drive member intersects the travel of the said crank (43) and an active position in which the said intermediate drive member moves the said catch (8) away from the said holding position so as to open the said latch, the said crank pushing the said arm (21c, 30) during the said active travel part so as to move the said intermediate drive member (21) from the said idle position to the said active position.
13. Latch according to Claim 12, characterised by the fact that the said crank comprises a head (44) able to bear on the said arm (21c, 30) in order to hold the said crank (43) projecting with respect to the said wheel (31) during the said active travel part of the crank.
14. Latch according to Claim 13, characterised by the fact that the said manual control means (22) is able to cooperate with the said intermediate drive member (21) in order to move it to the said active position, so that, in the event of stoppage of the said electrical actuator (23), a manual movement of the said intermediate drive member is able to withdraw the said arm (21c, 30) from below the said head (44) in order to retract the said crank (43) into the said wheel (31).
15. Latch according to Claims 11 and 14 taken in combination, characterised by the fact that the said crank (43) comes into contact with the said arm (30) substantially at the time of crossing the said step (42), the said crank being held by its head (44) in abutment on the said arm (30) and not being in contact with the said ramp (38) after the said step (42) is crossed.
16. Latch according to Claim 15, characterised by the fact that, at the end of the said active travel part of the said crank (43), the said arm (21c) escapes from the said crank, the said crank falling back onto the said ramp (38) substantially at the bottom end of the said inclined section (40).
17. Latch according to Claim 16, characterised by the fact that the travel of the said inclined section (40) corresponds to an inactive part of the rotation travel of the crank (43) in which the said crank does not cooperate with the said intermediate drive member (21).

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