Door latch actuator

A door latch actuator comprises a reversible motor, a rotating object, a drive portion and an actuating member. The drive portion comprises two locking/unlocking drive projections and stopping projections. The actuating member comprises a pair of driven portions. When the drive portion is rotated in one direction, one of the locking/unlocking drive projections comes in contact with one of the driven portions to move the actuating member to a lock position. When the actuating member is moved to the lock position, the locking/unlocking drive projection leaves a recess, and the stopping projection comes in contact with the actuating member to stop rotation of the drive portion. When the drive portion rotates in an opposite direction, the other locking/unlocking drive projection comes in contact with the other driven portion, so that the actuating member is moved toward an unlock position. When the actuating member is moved to the unlock position, the other locking/unlocking drive projection leaves the recess, and the stopping projection comes in contact with the actuating member thereby stopping rotation of the drive portion.

BACKGROUND OF THE INVENTION

The present invention relates to a door latch actuator disposed in a door latch device of a vehicle to switch a locking mechanism in a door latch device to a lock state and an unlock state.

As described in JP2007-211506A, a conventional door latch actuator comprises a reversible motor; a worm wheel rotated by the motor; a pinion fixed to a rotary shaft of the worm wheel; and an actuating member that actuates a locking mechanism of the door latch device to a lock position for a lock state and an unlock state for an unlock state.

JP2013-217050A discloses an actuator that comprises a reversible motor; a worm wheel rotated by the motor; three teeth equally spaced on a rotary surface of the worm wheel; and a lock lever that comes in contact with any one of the three teeth based on rotation of the worm wheel, wherein the teeth is rotated together with the worm wheel by the motor to rotate the lock lever to a lock position and an unlock position to switch the door latch device to a lock state and an unlock state.

In order to make the actuator in JP2007-211506A smaller and lighter, a drive torque has to become greater and a diameter of the pinion has to be made as small as possible, which increases operation time of the motor for moving the actuating member with the pinion from an unlock position to a lock position and vice versa and increases a rotation angle of the worm wheel driven by the motor and of the pinion. Thus, there is a problem that operation time of the actuator with the motor is long until the door latch device is switched to the lock state and the unlock state.

The actuating member is moved to the lock position and the unlock position by manually operating means such as a knob lever and a key cylinder. Because the pinion always meshes with the actuating member, the worm wheel and the motor rotate together to make a motion of the manually operating means leaden when the actuating member is moved by the manually operating means.

In the actuator in JP2013-217050A, the three teeth are spaced circumferentially by nearly 120 degrees, and each of the teeth is in contact with the lock lever, increasing a rotation angle of the worm wheel for rotating the lock lever to the lock position and the unlock position and thus increasing operation time of the actuator for switching the door latch device to the lock state and the unlock state.

SUMMARY OF THE INVENTION

In view of the disadvantages, it is an object of the present invention to provide a door latch actuator that reduces operation time for switching a door latch device to a lock state and an unlock state, wherein manually operating means can be operated by a small force.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

One embodiment of the present invention will be described with respect to the drawings as below.

InFIGS. 1 to 7, a door latch device1comprises an engagement unit2fixed to the rear end of an inner panel D1of a door D; an operation unit3integrally connected to the engagement unit2; and an actuator4according to the present invention in the operation unit3.

InFIGS. 1 and 3, the engagement unit2comprises a synthetic-resin box-like body5; and a metal cover member7fixed with a body5to a rear part of the inner panel D1in the door. Within a space between the body5and the cover plate7, there is housed an engagement mechanism9for holding the door closed. In the body5and the cover plate7, there is formed a striker-entering groove10into which a striker8comes.

The engagement mechanism9is pivotally mounted in the body5via a pivot shaft11, and comprises a latch12that engages with the striker8of a vehicle body, and a locking portion14pivotally mounted in the body5via a pivot shaft13to engage with an outer circumference of the latch12thereby preventing the latch12from turning in an opening direction or counterclockwise inFIG. 3. The latch12is forced in an opening direction by a spring16wound around the pivot shaft11.

When the latch12turns from an open position to a closed position, the locking portion14turns from an engagement position where it engages with the striker8against a force of a spring15for urging the locking portion14in an engagement direction, and engages with an outer circumference of the latch12to prevent the latch12from turning in an opening direction. With a door-opening outside handle on the door outside the vehicle or an inside handle (not shown) on the door inside the vehicle, an opening lever18later described is released, so that the locking portion14turns from the engagement position where it engages with the outer circumference of the latch12in a releasing direction to enable the door to open.

Over a front surface of the body5, an L-shaped metal base member17fixed to a housing23later described is mounted, and an opening lever18fixed to the pivot shaft13to rotate with the locking portion14, an outside lever21pivotally mounted via a pivot shaft20and connected to the outside handle via a motion-transmitting member S, and a subsidiary lever22that comprises a first lever22aand a second lever22bas part of a locking mechanism between a locking lever19and the outside lever21are connected to the front surface of the body5. The lower end of the first lever22ais pivotally mounted to a free end of the outside lever21, and a vertical elongate hole22cat the upper part is slidably connected to a projection19bat the lower end of the locking lever19.

The locking lever19can be switched between a lock state and an unlock state with a locking/unlocking knob (not shown) on the door inside the vehicle and a key cylinder (not shown) on the door outside the vehicle. The second lever22bis pivotally coupled at its lower end to a lower end of the first lever22a.

When the engagement unit2is connected to the operation unit3, the locking lever19can be switched between the lock state and the unlock state with an actuating member52by connecting a forward connecting portion19ato the actuating member52(later described of the actuator4.

The operation unit3comprises an approximately L-shaped synthetic resin housing23. The housing23comprises a first case25disposed in the door D close to the side of an inner panel D1, and having an operation-mechanism holding portion24which is open toward the inside of the vehicle; a second case26that extends approximately at right angles toward the outside of the vehicle from the rear end of the vertically middle portion of the first case25as a body-holding portion in which the engagement unit3is fixed over the rear surface and a synthetic-resin cover27that covers an opening of the operation-mechanism holding portion24of the first case25except the striker-entering groove10of the body5of the engagement unit3. Electrical components, such as an operation mechanism28including the actuator4, a switch plate46and switches60,61, are disposed in the operation-mechanism holding portion24of the first case25.

An outer peripheral wall251which projects toward the outside of the vehicle is formed over an upper part of the operation-mechanism holding portion24of the first case25, and a plurality of projections252is formed on the outer surface of the outer peripheral wall251. A plurality of engagement portions272which can engage with the projections252is provided on an outer peripheral wall271which faces the outer peripheral wall251of the first case25of the cover27. After the operation mechanism28is disposed in the operation-mechanism holding portion24, the engagement portions272engage with the projections252of the operation-mechanism holding portion24, and the outer peripheral wall251is made close to the outer peripheral wall271. The cover27covers the operation mechanism28in the operation-mechanism holding portion24, so that the cover27is fixed to the first25.

InFIGS. 1 and 7, at a lower front part of the operation-mechanism holding portion24of the first case25, there are provided two upper and lower U-shaped conduit fixing portions29,30that are open toward the inside of the vehicle. Front ends of the conduit fixing portions29,30project forward from the front surface of a watertight top cover42later described. Elastically-deformable claws29a,29a,30a,30aproject perpendicular to the conduits32,34(later described) on the inner wall surfaces of the conduit fixing portions29,30.

A larger-diameter end32aof the conduit32fits in the upper conduit fixing portion29and is fixed with the elastic claws29a,29a. One end of the conduit32is coupled to a locking knob (not shown) on the door inside the vehicle, and the other end has a cable31coupled to a knob lever55later described. A larger-diameter end34aof the conduit34fits in the lower conduit fixing portion30and is fixed with the elastic claws30a,30a. One end of the conduit34is coupled to an inside handle (not shown) on the door inside the vehicle, and a cable33coupled to the inside lever57passes through the other end.

InFIGS. 1 and 8, there are formed openings35,35that are opens outward and forward in the cover27at a part facing the conduit fixing portions29,30of the first case25. Through the openings35,35, the larger-diameter ends32a,34aof the conduits32,34fits in the conduit fixing portions29,30. Between the upper and lower openings35and35, the cover27projects a little between the upper openings35and35.

InFIGS. 1, 4 and 13, on a lower surface of the lower-conduit fixing portion30, there are formed a U-shaped holding portion36that is open along a width of the vehicle, and an engagement portion37is gradually inclined downward toward outside of the vehicle. At the front lower part of the cover27facing the holding portion36, an elastic engagement projection38with an engagement hole38aprojects toward the outside of the vehicle along the width of the vehicle. When the cover27is mounted to the first case25, the elastic engagement portion38fits in the holding portion36, and the engagement hole38aelastically engages with the engagement projection38, so that a lower part of the cover27is fixed to the first case25. Slightly under the elastic engagement portion38of the cover27, a slit39that can engage with an insert portion406of an auxiliary cover40is formed to face an inner space of the holding portion36.

InFIGS. 1 and 8, there are formed a first rain-water guide projection273, a second rain-water guide projection274, and a third rain-water guide projection275for preventing rain water from flowing down toward the upper and lower openings35by guiding rain water that flows down along the side of the cover27that faces the interior of the vehicle. The first rain-water guide projection273is spaced from a rear part of the upper opening35and tilted downward and backward. The second rain-water guide projection274is slightly spaced below the first rain-water guide projection27and tilted backward and downward along an upper edge of the upper opening35. The third rain-water guide projection275is tilted above a rear part of the lower opening35and below a rear part of the second rain-water guide projection274. A lower half of the third rain-water guide projection275extends downward vertically close to the lower opening35.

Rain water that flows down along the side of the cover27facing the inside of the vehicle is received by the first and second rain-water projections273,274and guided backward and downward. Thus, rain water in the door is prevented from flowing into the housing23through the upper and lower openings35along the side of the cover27. Between the first rain-water guide projection273and the second rain-water guide projection274, an outer peripheral wall402of the auxiliary cover40later described is inserted, and a labylinth seal formed by the first and second rain-water guide projections273,274and the outer peripheral wall402of the auxiliary cover40prevents rain water from flowing into the opening35inFIG. 14.

The synthetic-resin auxiliary cover40for closing the upper and lower openings35to prevent rain water from flowing in is mounted at the side of the cover27facing the inside of the vehicle as below.

InFIGS. 5 and 8-10, the auxiliary cover40is a trapezoid enough to close the upper and lower openings1and the upper and lower conduit fixing portions29,30. At upper and lower parts of the front end of the auxiliary cover40, there are formed pressing portions401,401which can press an outer peripheral surface of the larger-diameter ends32a,34aof the conduits32,34which fits in the conduit fixing portions29,30. The upper and lower pressing portions401at the front end also act as a cover for covering front openings of the conduit fixing portions29,30except the conduits32,34from front.

InFIG. 10or a back view, at an upper part of the auxiliary cover40, there is formed the outer peripheral wall402disposed between the first rain-water guide projection273and the second rain-water guide projection274, and at a lower part of a rear edge, there is formed an outer peripheral wall403that can contact the side of the cover27close to the third rain-water guide projection275. At an upper end continuous with the outer peripheral wall402, there is an upward projection404covered with a vehicle-inside watertight wall426of the watertight top cover42later described.

Between the upper pressing portions401and401at the back surface of the auxiliary cover40, a pair of elastic engagement portions405,405that have engagement claws405athat are directed oppositely at ends projects. When the auxiliary cover40is mounted to the cover27inFIG. 8, the elastic engagement portions405fits in a rectangular opening253formed between the upper and lower conduit fixing portions29and30of the first case25, and the engagement claw405aelastically engages with an end face of a pair of engagement portions254,254that projects from the opening253inFIG. 12.

At the lower end of the back surface of the auxiliary cover40, the inserting portion406projects. When the auxiliary cover40is mounted to the cover27, the inserting portion406passes through a fitting hole39of the cover27and fits on the U-shaped holding portion of the first case25inFIG. 13.

An engagement claw403aprojects from the back surface of the outer peripheral wall403of the auxiliary cover40. When the auxiliary cover40is mounted to the cover27inFIGS. 5, 8 and 9, the engagement claw403aengages with an L-sectioned engagement projection276of the cover27inFIG. 15.

InFIGS. 8 and 10, an elongate engagement hole407is formed at an upper part of the auxiliary cover40, and an engagement projection408which is smaller than a vertical distance of the engagement hole407is formed in the middle of an upper surface of the engagement hole407. A projection277projects from the surface of the cover27opposite the engagement hole407and can fit into the engagement hole407. In a sectional view ofFIG. 14, under the engagement projection277, there is formed an engagement hole277ainto which the engagement projection408comes. Through the cover27and the auxiliary cover40, there are formed axial holes41,41into which the end of a support shaft56of the inside lever57(later described) of the first case25fits inFIG. 1.

In order to connect the auxiliary cover40to the cover27, a pair of elastic engagement portions405of the auxiliary cover40is fitted into the opening253of the first case25, and the engagement claw405aof the elastic engagement portion405is elastically fitted with the engagement portion254of the first case25inFIG. 12. The engagement claw403aof the auxiliary cover40engages with the engagement projection27inFIG. 15, and the engagement projection277of the cover27fits in the engagement hole407of the auxiliary cover40inFIG. 14. At the same time, the inserting portion406of the auxiliary cover49passes through the fitting hole39of the cover27and fits in the holding portion36of the first case25.

Hence, the auxiliary cover40is fixed not to move in any direction to the first case25and the cover27on or close to the vehicle-interior side of the cover27in a forward and upward inclined position. The upper and lower conduit fixing portions29,30of the first case25and the upper and lower openings35of the cover27are closed by the auxiliary cover40, so that rain water that flows down along the inner side of the cover27is unlikely to flow into the housing23. Furthermore, as mentioned above, because of labylinth seal formed with the first and second rain-water guide projections273,274, rain water that flows down along the inner side of the cover27is prevented from flowing through the cover27and the auxiliary cover40into the housing23. After the auxiliary cover40is attached, a front watertight wall425of the watertight top cover42is positioned right over the front end of the auxiliary cover40, thereby preventing rain water from flowing into the housing23through surrounding portions for the conduits32,34at the conduit fixing portions29,30inFIGS. 5 and 9.

InFIGS. 1 to 6, 16 and 17, the synthetic-resin watertight top cover42for preventing rain water from flowing into the operation-mechanism holding portion24of the first case25is provided over an area from upper surfaces of the first case25and the cover27of the housing23to the upper conduit fixing portion29. The watertight top cover42comprises an upper covering portion421that covers whole upper surfaces of the operation-mechanism holding portion24and the cover27and front and rear vertical surfaces close to the upper surfaces.

A plurality of fitting holes43is formed through a pair of downward portions421aof the upper covering portion421and a pair of rearward portions422aof the front covering portion422. A plurality of protrusions44on outer sides of the first case25and the cover27fits in the fitting holes43, so that the watertight top cover42covers an upper portion and a front portion of a connecting portion of the first case25to the cover27and surrounds upper parts of the first case25and the cover27inFIG. 11.

InFIGS. 5, 6 and 16, at the rear end of the watertight top cover42, a triangular water-shielding wall423is continuously formed with the rear end of the upper covering portion421. The water-shielding wall423is slightly wider than the upper covering portion421and is approximately as high as the covering portion421. A partition wall424is provided between the water-shielding wall423and the upper covering portion421. By providing the water shielding wall423and the partition wall424, rain water that flows down from the upper surface to the back surface is guided to flow down along a width of the vehicle as shown by arrows inFIG. 6, and is thus prevented from flowing down onto the second case26in which the engagement unit3is attached. Thus, even if a watertight seal45(later described) is deteriorated with aging and is spoiled in watertight capability, rain water is prevented from flowing into the engagement unit3and the housing3.

InFIGS. 4, 5, 8, 9 and 11, at the lower end of the watertight top cover42, there are formed a front water-shielding wall425, an inner water-shielding wall426and an outer water-shielding wall427that are continuous with the lower end of the front covering portion422and the lower ends of the inner and outer rearward portions422arespectively. The front water-shielding portion425is slightly wider than the housing23and is tilted forward and downward to cover the upper ends of the conduit fixing portion29of the first case25and the auxiliary cover40. Thus, rain water that flows down on the front covering portion422of the watertight top cover42is prevented from flowing into the casing23through the spaces for the conduits32,34of the conduit fixing portions29,30.

The inner water shielding wall426is approximately as long as the upward projection404of the auxiliary cover40, and the upward projection404is covered with the inner water shielding wall426when the watertight top cover42is attached to the housing23. Thus, rain water that flows down along the inner side of the cover27and the watertight top cover42is guided onto the surface of the auxiliary cover40. Rain water that flows between the cover27and the auxiliary cover40is prevented from flowing into the housing23through the opening35of the cover27.

InFIGS. 1 to 6, 16 and 17, there is attached a watertight seal45over the upper portion of the second case26and the cover27above the engagement unit2. The watertight seal45made of, for example, a compressible sponge-like sufficient-thickness band, and comprises an upper seal portion45athat is disposed over the rear side of the engagement unit2and a side seal portion45bon the inner side of the engagement unit2. InFIG. 6, the upper seal portion45afaces a rear surface of an inner panel D1within the door D, while the side seal portion45bfaces an inner side surface of the inner panel D1. The watertight seal45is adhered with a double-sided adhesive tape or an adhesive coated on a back side.

Above the engagement unit2of the second case26, a seal sticking portion261on which the upper seal portion45aof the watertight seal45is stuck is tilted downward toward the outside of the vehicle. At the side and lower ends of the seal sticking portion261, there are projected a first positioning portion262for receiving and positioning the side end of the watertight seal45; and a second positioning portion263for receiving and positioning a lower surface of the watertight seal45. The first positioning portion262and the second positioning portion263constitute an upper positioning portion. The seal sticking portion262also acts as a water-shielding wall for preventing rain water from flowing down toward the engagement unit2. As shown by the arrows inFIG. 6, the seal sticking portion261is formed on or close to the side end of the water shielding wall423, so that rain water that flows down from the rear surface of the watertight top cover42is guided along the seal sticking portion261and prevented from flowing down toward the engagement unit2.

Above the striker-entering groove10in the middle of the side of the cover27, there is formed a third positioning portion264for positioning the side seal portion45bof the watertight seal45so that the third positioning portion264is inclined forward and downward from the rear end of the watertight top cover42. The third positioning portion264is discontinuous, but may be continuous. The upper end of the third positioning portion264is continuous with the water shielding wall423of the watertight top cover42. A fourth positioning portion265for positioning the side seal portion45bof the watertight seal45is spaced from the third positioning portion264in parallel on the cover27. The third positioning portion264and the fourth positioning portion265constitute a side positioning portion.

In order to attach the watertight seal45, the end and the lower surface of the upper seal portion45ais contacted with the first positioning portion262and the second positioning portion263of the second case, so that the upper seal portion45ais positioned vertically and horizontally. Then, the back surface of the upper seal portion45ais stuck to the rear surface of the seal sticking portion261and the rear surface of the watertight top cover42.

The side seal portion45bis bent over the cover27and extended along the third positioning portion264of the cover27forward and downward. The lower end of the side seal portion45bis positioned between the third positioning portion264and the fourth positioning portion264for vertical and horizontal positioning, and the back surface of the side seal portion45bis stuck to the side of the cover27. An upper end of the first rain water guide projection273also acts as a fifth positioning portion for positioning the lower end of the side seal portion45band can be an end of a stuck position of the side seal portion45b. The lower end of the side seal portion45bmay be on or close to the upper part of the first rain water guide projection273.

Thus, as shown mainly inFIG. 17, the watertight seal45covers parts above the striker-entering groove10formed in the cover member7and the body5of the engagement unit3. In order to attach the door latch device1in the door D, inFIG. 6, because the upper seal portion45band the side seal portion45bare contacted on and compressed by the rear surface of the inner panel D1of the door D and the inner side surface of the inner panel D1, gaps between the engagement unit3and the inner panel D1are closed by the watertight seal45and rain water within the door D is prevented from flowing into the striker entering groove10from above.

As mentioned above, the water shielding wall423is disposed at the watertight top cover42to guide rain water which flows down from the rear surface of the watertight top cover42along the width of the vehicle, and the seal sticking portion261of the second case26acts as a shielding wall for guiding rain water which flows down from the rear surface of the watertight top cover42toward the outside of the vehicle, so that rain water which flows toward the rear surface of the engagement unit3significantly decreases. The watertight seal45stuck on the rear surface of the engagement unit3is enough to comprise only the upper seal portion45a, so that the watertight seal45can be shortened compared with a watertight seal stuck on a conventional door latch device thereby improving sticking performance. Rain water guided by the water shielding portion423of the watertight top cover42flows down forward and downward along the upper surface of the third positioning portion264, so that rain water which flows down toward the side seal portion45bof the watertight seal45can significantly be reduced.

Furthermore, the first to fourth positioning portions262,263,264,265are disposed on the rear surface of the second case26and the side surface of the cover27to position the watertight seal45when it is stuck, thereby making sure of a sticking-start position and a sticking position of the watertight seal45and sticking the watertight seal45on a predetermined position of the engagement unit3and the cover27to improve sticking efficiency.

InFIGS. 7 and 18 to 20, there is a vertical switch plate46within the operation-mechanism holding portion24of the first case25of the housing23. In the switch member46, a plurality of conductive plates47which is conductive with electrical components such as a motor48, the rotary switch60and a limit switch61(later described) in the operation-mechanism holding portion24are embedded in a synthetic resin462by insert molding and integrally molded with a female connector461with exposure of a plurality of terminals471in the female connector461and conductive parts with the motor48, the rotary switch60and the limit switch61. The synthetic resin462used in insert molding is, for example, a mixed resin of PBT (polybutylene telephtalate) resin and ABS resin with a glass fiber.

At the upper end and in the middle of the switch member46, a rotary switch mounting portion463and a limit switch mounting portion464with a pair of switch holding portions464a,464aare integrally molded in the synthetic resin462, and an engagement hole465is formed through the mounting portions463,464along the width of the vehicle. Above the limit-switch mounting portion464, there is projected a contact portion466which can come in contact with a back surface of the cover27when the cover27is attached over the first case25. The upper and lower switch holding portions464aof the switch mounting portion464also acts as an engaged portion which can engage with a first engagement portion256(later described) of the first case25. A terminal of the rotary switch60mounted on the rotary switch mounting portion463and a terminal of the limit switch61on the limit switch mounting portion464are fixed to a conductive portion of the conductive plate47exposed from the synthetic resin462by resistance welding.

The female connector461is inclined forward and downward and has brims461a,461awhich are spaced from each other at its proximal end. At upper and lower ends of an engagement groove461b, there are formed engaged portions467,467which engages with engagement claws257aof a pair of second engagement portions257at the lower end of the first case25.

At an upper part and in the middle of an inner side of the first case25on which the switch member46is mounted, there are projected axial projections255,255which fit in the upper and lower engagement holes465of the switch member46. In the middle of the inner side of the first case25, a pair of engagement portions256,256between which the limit-switch mounting portion464of the switch member46is elastically held faces each other and surrounds the lower projection255.

Furthermore, at a part which faces a base end of the female connector461of the first case25, there are provided a pair of second engagement portions257,257which fit in upper and lower portions of the engagement groove461bof the female connector461, and engagement claws257a,257awhich project from the second engagement portions257,257and fit in a pair of engaged portions467,467in the engagement groove461b. The upper and lower projections255of the first case25, the first engagement portions256, the second engagement portions257, the switch member46, and the upper and lower engagement holes465, the switch holding portions464aand the engaged portions467constitute engagement means.

In order to mount the switch member46to the first case25, the upper and lower engagement holes465are pressed over the upper and lower projections255of the first case25, and the upper and lower holding portions464aof the limit-switch mounting portion464fits between the upper and lower first engagement portions256and elastically held. The engagement groove461bof the female connector461is pressingly fitted with the two second engagement portions of the first case25, and the engagement claw257aof the second engagement portion257is contacted with an inner end face of the pair of engaged portion467in the engagement groove461b. Thus, inFIGS. 19 and 20, the switch plate46is firmly mounted to the inner side of the first case25without floating or loosening. Only by pushing the switch plate46into the first case25, a plurality of upper and lower engagement means can be fitted, thereby mounting the switch plate46to the first case25more efficiently.

The switch plate46formed separately from the housing23by insert molding is mounted to the first case25, thereby exhibiting a single insert molding. Specifically, it was conventionally necessary to provide two insert molding steps comprising a primary step for molding the switch plate46itself by insert molding and a secondary step for fixing the switch plate46to the housing23by insert molding, but a single insert molding reduces manufacturing cost and the number of steps of a die thereby reducing the cost of the door latch device.

The housing23and the switch plate46can be molded by different synthetic resins thereby enlarging the degree of freedom in material. For example, the large housing23is molded of inexpensive synthetic resin thereby saving material cost. Furthermore, integral molding of the female connector461with the switch plate46achieves good watertight capability.

Then, the structure of the operation mechanism28that includes the locking/unlocking actuator4installed in the operation-mechanism holding portion24in the first case25of the housing23will be described.

InFIGS. 1 and 7, the actuator4is vertically disposed in the operation-mechanism holding portion24without play, and comprises a reversible motor48actuated with a remote control switch (not shown); a worm49fixed to a rotary shaft48aextending upward of the motor48; a worm wheel51driven by the worm49, a cross-shaped drive portion50fixed on an inner rotary surface of the worm wheel51; and a vertical actuating member52that moves between an upper lock position and a lower unlock position. The worm wheel51is rotatably supported via a pivot shaft53that projects from an inner side of the operation-mechanism holding portion24.

The knob lever55of the operation mechanism28is pivotally mounted via a pivot shaft54in the middle of the operation-mechanism holding portion24. The knob lever55is connected to the actuating member52, and is connected to a locking knob (not shown) on an inner side of the door. With the locking knob, the actuating member52moves upward or downward. The locking lever19connected to the actuating member52is switched to a lock state or an unlock state.

The inside lever57is pivotally mounted via a pivot shaft56in the middle of the operation-mechanism holding portion24. The inside lever57is connected to a steering wheel (not shown) via the cable33of the conduit34, and rotates in an unlocking direction (counterclockwise inFIG. 7) with opening action of the steering wheel.

A key lever59is mounted through a hole of an upper part of the operation-mechanism holding portion24. A connecting arm59aof the key lever59which projects from the first case25toward the outside of the vehicle is connected to a key cylinder (not shown) of the door. A sector-shaped connecting portion59bwhich is connected with the actuating member52is formed forward, and an arcuate recess59cis formed at a front end of the connecting portion59b. A projection521at the upper end of the actuating member52fits in the recess59c.

When the locking lever19is in a lock state, the key cylinder is operated for unlocking, and the key lever59rotates clockwise from a neutral position inFIG. 7. An upper stop59dof the recess59eof the key lever59comes in contact with the projection521of the actuating member52from above, so that the actuating member52is moved from an upper lock position to a lower unlock position mFIG. 7, and the locking lever19is switched to the lock state via the actuating member52. Switching action to the lock/unlock position is detected by the rotary switch60mounted on a rotary-switch mounting portion463of the switch member46.

When the locking lever19is in an unlock state, the key cylinder is operated for locking, and the key lever59rotates counterclockwise from the neutral position. A lower step59dof the recess59ccomes in contact with the projection521from below, and the actuating member52is moved from the lower unlock position to the upper lock position, so that the locking lever19is switched to the lock state via the actuating member52. The switching action to the lock/unlock position is detected by the rotary switch60mounted on the rotary-switch mounting portion463of the switch member46.

When the actuating member52is moved to the lock position and the unlock position, the limit switch61mounted on the limit-switch mounting portion464in the middle of the switch member46is actuated, so that the motor48of the actuator4stops. Specifically, inFIG. 7, when the actuating member52moves to the lock position and the unlock position, a stretchable projection61aof the limit switch61comes in contact with an actuating projection522projecting on the outer side of the actuating member52, thereby generating “on” or “off” stop signal for stopping the motor48.

InFIG. 1, an axial hole62is formed in the middle of the cover27, and an override lever63connected to the inside lever57is supported in the axial hole62. Regardless of the state of the locking mechanism, the override lever63cancels the engagement of the engagement mechanism9to enable the door to open.

A drive portion50for the worm wheel51comprises two locking/unlocking drive projections501a,501bthat are adjacent to each other and can move the actuating member52to a lock position or an unlock position, and two stopping projections501c,501dthat are opposite to the locking/unlocking drive projections501a,501band can stop rotation of the worm wheel51and the drive portion50.

The locking/unlocking drive projections501a,501band the stopping projections501c,501dextend outward of the worm wheel51around a support shaft53, and are spaced by 90 degrees circumferentially to form a cross. Each of the projections501ato501dis shorter than a radius of the worm wheel51. The locking/unlocking drive projections501a,501bhave a length enough to move the actuating member52to the upper lock position and the lower unlock position.

The actuating member52has a recess64at an upper part opposite the drive portion50. The recess50is open toward the drive portion50, and a noise-reducing buffer member65is fixed in the recess64. The buffer member65has a U-shaped recess65athat is open toward the drive portion50. The locking/unlocking drive projections501a,501b, can get in and out of the recess65a. Upper and lower opposite surfaces of the recess65aare driven surfaces with which the locking/unlocking drive projections501a,501bcan come in contact. The buffer member65is formed of polyester elastomer (TM: Hytrel) with suitable hardness and elasticity.

InFIG. 21, the depth of the recess65ais defined so that the ends of the locking/unlocking drive projections501a,501bcan rotate without contacting the bottom of the recess65awhen the drive portion50is rotating. The vertical distance of the recess65ais defined so that the locking/unlocking drive projections501a,501bmay both come in the recess65awhen the actuating member52is moved upward or downward with rotation of the drive portion50. According to locking/unlocking action of the knob lever55or key cylinder as manually-operating means, the actuating member52is able to move to the lock position inFIG. 21 (d)and the unlock position inFIGS. 21 (a), (g). Thus, when the actuating member51is moved by the manually-operating means from the lock position to the unlock position or vice versa, in order that movement of the actuating member52may be allowed or in order that the upper and lower driven surfaces65bmay not be contacted with the locking/unlocking drive projections501a,501bwhich come and stay in the recess65a, both the driven surfaces65bare spaced from each other, so that there is a space slightly greater than a stroke of the actuating member52between the locking/unlocking drive projections501a,501band the upper and lower driven surfaces65b.

Then, the actuator4will be described with respect to motion inFIG. 21.

FIG. 21 (a)-(d)shows that the actuating member52in the unlock position is moved to the lock position.FIG. 21(a)shows a motion-starting position where the actuating member52is at a lower unlock position and the motor48of the actuator4is at rest with a stop signal of the limit switch61. InFIG. 21(a), the locking/unlocking drive projection501aof the drive portion50gets into the recess65aand is at rest close to the upper driven surface65b. The upper stopping projection501dadjacent to the locking/unlocking drive projection501ais in contact with a front face of an upper part of the buffer member65opposite it, and the drive portion50is at rest and does not rotate.

InFIG. 21(a), the motor48of the actuator4is normally rotated with the remote control switch, and as shown inFIG. 21(b), the worm wheel51and the drive portion50start rotating clockwise. The locking/unlocking drive projection501ain the recess65acomes in contact with the upper driven surface65bof the recess65afrom below. At the same time, the other locking/unlocking drive projection501badjacent to the locking/unlocking drive projection501astarts getting into the recess65a.

The worm wheel51and the drive portion50rotates clockwise further, and inFIG. 21(c), by a rotation force of the locking/unlocking drive projection501a, the actuating member52is pushed up straight, and the actuating member52continues pushing up right before the end of the locking/unlocking drive projection501aleaves the upper driven surface65b. This is an upper-limit push-off position of the actuating member2, and the actuating member52is moved upward to the unlock position. The other locking/unlocking drive projection501bgets into the recess65adeeply.

The worm wheel51and the drive portion50rotates clockwise further fromFIG. 21(c), and the end of the locking/unlocking drive projection501aleaves the upper driven surface65b. Simultaneously, the stopping projection501copposite the locking/unlocking drive projection501acomes in contact with a front face of a lower part of the buffer member65. The drive portion50stops at the lock position. In this state, the other locking/unlocking drive projection501bstops at a position close to the lower driven surface65b. At the same time with the contact, the limit switch61acts, a signal generated thereby stops the motor48, and the actuator4stops. When the actuating member52is moved to the upper lock position by the actuator4, the locking lever19connected to the actuating member52is switched to the lock state, so that the door cannot be opened.

FIG. 21 (e) to (g)shows that the actuating member52is moved from the lock position to the unlock position. InFIG. 21(d), the motor48is rotated reversely with the remote control switch. The worm wheel51and the drive portion50start rotating reversely and the other locking/unlocking drive projection501bwhich is at rest in the recess65acomes in contact with the lower driven surface65bof the recess65afrom above. Simultaneously, the locking/unlocking drive projection501agets into the recess65a.

The worm wheel51and the drive portion50rotate counterclockwise further, and inFIG. 21(f), the actuating member52is pushed down straight by a rotation force of the locking/unlocking drive projection501b. Downward movement of the actuating member52continues right before the end of the locking/unlocking drive projection501bleaves the lower driven surface65b. This is a lower-limit put-off position of the actuating member52which moves down to the unlock position. The locking/unlocking drive projection501agets into the recess65adeeply.

The worm wheel51and the drive portion50rotate counterclockwise further slightly fromFIG. 21(f), and as shown inFIG. 21(g), the end of the other locking/unlocking drive projection501bleaves the lower driven surface65b. Simultaneously, the stopping projection501dopposite the locking/unlocking drive projection501bcomes in contact with a front face of an upper part of the buffer member65, and the drive portion50stops at the unlock position. The motion finishing position is the same as the motion starting position inFIG. 21(a), and thus, with normal rotation of the motor48of the actuator4, the actuating member52can be moved from the unlock position to the lock position. The actuating member52is moved to the lower unlock position by the actuator4, and the locking lever19connected to the actuating member52is switched to the unlock state to enable the door to open.

The foregoing description relates to a case that the actuating member52in the unlock position is moved with normal/reverse rotation of the drive portion50to the lock position and the unlock position. If, inFIG. 21(a), the actuating member52is moved up to an upper lock position inFIG. 21(d)by the manually-operating means such as the knob lever55and is moved down to the lower unlock position by the actuator4, the drive portion50can be rotated counterclockwise inFIG. 21(a). Then, the locking/unlocking drive projection501acomes in contact with the lower driven surface65bof the actuating member52in the upper lock position inFIG. 21(e), so that the actuating member52is moved down to the lower unlock position inFIG. 21(f).

If the actuating member52inFIG. 21(d)is moved down to the lower unlock position inFIG. 21(a)by the manually-operating means such as the knob lever55and moved up to the upper lock position by the actuator4, the drive portion50is rotated clockwise reversely to the above. Then, the other locking/unlocking drive projection501bcomes in contact with the upper driven surface65bof the actuating member52in the lower unlock position such as inFIG. 21(b), so that the actuating member52is moved up to the upper lock position inFIG. 21(c).

As mentioned above, in the actuator4in the embodiment, the drive portion50that moves the actuating member52to the lock position and the unlock position comprises the two locking/unlocking drive projections501a,501b, and the two stopping projections501c,501d. The projections501a,501b,501c,501dare spaced from each other by 90 degrees circumferentially. When the actuating member52is at rest in the lock position and the unlock position, the locking/unlocking drive projections501a,501bare positioned in the recess65aof the actuating member52, and on the way that the actuating member52moves to the lock position or the unlock position, the locking/unlocking drive projections501b,501aget into the recess65atogether. When the drive portion50rotates normally and reversely, the actuating member52is moved to the lock position and the unlock position with the locking/unlocking drive projections501a,501b, and when the actuating member52is moved to the lock position and the unlock position, the stopping projections501c,501dcome in contact with the actuating member52, and the drive portion50stops from rotation, thereby reducing operation time of the motor48and a rotation angle of the worm wheel51until the actuating member52and the locking lever19connected to the actuating member52are moved from the unlock position to the lock position and vice versa and stopped by the actuator4. Thus, it reduces operation time of the actuator4for turning the lock state and the unlock state with the switch such as the remote control switch.

Each of the projections501ato501dcomes in contact with the noise-reducing buffer member65of the actuating member52thereby reducing impact noise at the contact.

The operation starting position inFIG. 21(a)before the actuating member52is moved from the unlock position to the lock position is the same as the operation finishing position inFIG. 21(g)after the actuating member52is moved from the lock position to the unlock position. It is not necessary for the worm wheel51to move back to the starting position after moved to each position, or it is not necessary to provide a return spring.

When the actuating member52is moved to the lock position or the unlock position by the manually-operating means such as the knob lever55and a key cylinder, the upper and lower driven surfaces65bdo not come in contact with the locking/unlocking drive projections501a,501b. Hence, the worm wheel51or the motor48is not rotated with the locking/unlocking drive projections501a,501b, and the actuating member52can be moved by the manually-operating means by a small force.

The foregoing relates to the embodiment of the invention. But the following changes and variations may be made without departing from the gist of the invention as below:

In the embodiment, in order to reduce an axial distance of the drive portion50of the actuator4, the actuating member52is disposed opposite the drive portion50, and the upper and lower surfaces of the recess65aof the actuating member52opposite the drive portion50are the driven surfaces65b,65b. The locking/unlocking drive projections501a,501bcome in contact with the upper and lower driven surfaces65b,65b. Instead of the recess65a, the actuating member52may be spaced axially from the drive portion50, and a pair of upper and lower driven portions which project toward the drive portion50may be provided at the actuating member52. Surfaces of the upper and lower driven portions can be contact portions with which the stopping projections501c,501dcome in contact.

In the foregoing embodiment, a rotating object is the worm wheel51, but may be a spur gear. A small gear which meshes with the spur gear may be fixed to a rotary shaft of the motor48.

In the foregoing embodiment, the noise-reducing buffer member65is disposed on the actuating member52, but may be attached on the two locking/unlocking drive projections501a,501band the two stopping projections501c,501d.