Patent Publication Number: US-11035156-B2

Title: Automobile door latch apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This is the U.S. National Stage of International Application No. PCT/JP2015/054348, filed Feb. 17, 2015. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to a motor vehicle door latch device. 
     A motor vehicle door latch device comprises an engagement mechanism engaging with a striker of a vehicle body to hold a door closed, and an operating mechanism for operating the engagement mechanism, and is classified to a manually releasing type for enabling the engagement mechanism to be released by mechanical elements such as a lever and a link based on operation of mechanical elements such as an outside handle or an inside handle on the door and an electrical release type for enabling the engagement mechanism to be released by electric elements such as a motor for driving on the basis of electric operating elements such as a switch on the door. 
     As described in JP3758929B2, the manually releasing type door latch device comprises a locking motor, and a locking mechanism (operating mechanism in JP3758929B2) that comprises a lever and a link for selectively shifting an unlocking state that validates a door-opening action of the mechanical operating elements to enable the engagement mechanism to be released based on the locking motor and a lock state that invalidates the opening action enabling the engagement mechanism not to be released. 
     The electrically releasing type of door latch device is described in JP4145774B2 and JP4617588B2. 
     The door latch device in JP4145774B2 comprises an electric release mechanism comprising a releasing motor that can be driven with a door-opening switch on the door and an output lever that is rotated by the motor to release the engagement mechanism; and an opening lever pivotally mounted via the same axis for the output lever. A ratchet lever for releasing the engagement mechanism is connected to an outside operating lever positioned outside the vehicle and is not used during usual operation. The opening lever is connected to an inside lever inside the vehicle via a second wire. A control device in the vehicle electrically shifts an unlock state for validating a door-opening switch and a lock state for invalidating it. 
     In the door latch device in JP4145774B2, ID signals are identified through a wireless communication between an electronic key (portable device in JP4145774B2) carried by a regular user for the car and an authenticating portion in the car, and it is authenticated that the regular user approaches the car. The door-opening switch is operated by the regular user and a release motor is driven. The engagement mechanism is released by a ratchet lever to enable the door to open. If an electric system including a linear motor is broken, an external mechanical operating element or an internal mechanical operating element is operated whether the control device control the unlock state or the lock state, to actuate the ratchet lever to release the engagement mechanism to enable the door to open. In this structure, if the regular user who approaches the car is not authenticated by the authenticating portion through the ID signal, a passenger without the electronic key cannot open the door. 
     The motor vehicle door latch device in JP4617588B2 mainly comprises a releasing motor, an opening lever that can be rotated by the motor; an inside lever connected to an internal mechanical operating element (“inside handle” in JP4617588B2) on the door inside the vehicle; an opening link for enabling the engagement mechanism to be released by the inside lever and the opening lever; and a key lever connected to a key cylinder on the door outside the vehicle. Besides electric control of a control device, the door is shifted to an unlock state and a lock state by actuating the opening link for locking, thereby invalidating an opening action of the internal mechanical operating elements. 
     In the door latch device in JP4617588B2, when the control device controls the unlock state, an opening switch on the door is operated and a releasing motor is controlled to release the engagement mechanism to enable the door to open. If trouble occurs in electric systems, regardless of the unlock state or lock state, the key cylinder releases the engagement mechanism to enable the door to open. 
     However, in the motor vehicle door latch device, in order to improve a door-opening activity of a regular user with an electronic key, to improve dealing with trouble in the electric system, and to improve a door-opening activity of a passenger without the electronic key, it is preferable to comprise the releasing motor in JP4145774B2 or JP4617588B2 together with the locking mechanism and locking motor that comprises the mechanical elements in JP3758929B2. However, the releasing motor, the locking motor and the locking mechanism are disposed in the single housing, thereby making a positional relationship among the elements complicated, making the housing larger and making the door latch device itself larger. 
     SUMMARY OF THE INVENTION 
     In view of the disadvantages, it is an object of the invention to provide a motor vehicle door latch device that comprises a releasing motor, a locking motor and a locking mechanism, thereby making the device smaller. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevational view of a motor vehicle comprising a motor vehicle door latch device according to the present invention. 
         FIG. 2  is a perspective view of the door latch device that is the same among Designs. 
         FIG. 3  is a partially exploded perspective view of the door latch device that is the same among the Designs. 
         FIG. 4  is a partially exploded perspective view of the door latch device in the Design 1. 
         FIG. 5  is an exploded perspective view of the door latch device thereof. 
         FIG. 6  is a back elevational view of the door latch device the same in each of the Designs. 
         FIG. 7  is a side elevational view of a main part when the locking mechanism is in the unlock state in the Design 1. 
         FIG. 8  is a side elevational view of the main part when the locking mechanism is in the lock state. 
         FIG. 9  is a side elevational view when the locking mechanism is operated for electric releasing in the unlock state. 
         FIG. 10  is a side elevational view of the main part when the locking mechanism is operated for electric releasing in the lock state. 
         FIG. 11  is a side elevational view of the main part when the locking mechanism is manually released in the unlock state. 
         FIG. 12  is a side elevational view of the main part when the locking mechanism is in the unlock state in the Design 2. 
         FIG. 13  is a side elevational view of the main part when the locking mechanism is the lock state. 
         FIG. 14  is a side elevational view of the main part when the locking mechanism is manually released in the lock state. 
         FIG. 15  is a side elevational view of the main part when the locking mechanism is in the unlock state in the Design 3. 
         FIG. 16  is a side elevational view of the main part when the locking mechanism is in the lock state. 
         FIG. 17  is a side elevational view of the main part when the locking mechanism is manually released in the lock state. 
         FIG. 18  is an exploded perspective view of the main part in the Design 4. 
         FIG. 19  is a side elevational view of the main part when the locking mechanism is in the unlock state and the childproof mechanism is in the childproof unlock state. 
         FIG. 20  is a side elevational view of the main part manually released when the locking mechanism is in the unlock state or the childproof unlock state. 
         FIG. 21  is a side elevational view of the main part when the locking mechanism is in the unlock state or the childproof lock state. 
         FIG. 22  is a side elevational view of the main part when the locking mechanism is in the unlock state and the childproof mechanism is in the childproof unlock state in the Design 5. 
         FIG. 23  is a side elevational view of the main part manually released when the locking mechanism is in the unlock state and the childproof unlock state. 
         FIG. 24  is a side elevational view of the main part when the locking mechanism is in the unlock state and childproof lock state. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     One embodiment of the present invention will be described with respect to drawings. 
     In  FIG. 1 , in a front door FD of a four-door-type motor vehicle V, there are provided a front-door door latch device  1 F for holding a front door FD closed; an outside handle OH as external mechanical operating element on the door outside the vehicle; a detecting switch SW as electric detecting element on the door outside the vehicle; an inside handle IH as internal mechanical operating element on the door inside the vehicle; a key cylinder KC for selectively shifting a locking mechanism (later described) into a lock state and an unlock state from the outside of the vehicle; and a locking knob (not shown) for shifting the locking mechanism into the lock state and the unlock state from the inside of the vehicle. Any one of the following Designs 1 to 3 is set to the door latch device  1 F. 
     A rear door RD comprises a door latch device  1 R for a rear door for holding the rear door closed; an outside handle OH as an external mechanically operating element on the door outside the vehicle; a detecting switch SW as an electric detecting element on the door outside the vehicle; an inside handle IH as an internal mechanical operating element on the door inside the vehicle; and a locking knob (not shown) for shifting the locking mechanism into the lock state and unlock state from the inside of the vehicle. The following Design 4 or 5 is set to the door latch device  1 R. 
     The detecting switch SW as electric detecting element is disposed on a front surface, a back surface or close to the outside handle (OH), and comprises an electrostatic capacitance touch switch that detects that a finger of a user is touched. The regular user with an electronic key exclusively used for the car approaches within a predetermined area around the car, and an ID signal is identified though a wireless communication between the electronic key and a receiver of the car V. Thus, only when it is authenticated that the regular user comes to the car V, the detecting switch is electrically controlled by an ECU (electronic control unit) of the car V so that the user may be detected. The detecting switch is not limited to the touch switch, but may be a proximity switch detecting that part of a human body comes. 
     (Basic Structure of the Door Latch Device  1 F,  1 R) 
     Then, the basic structure of the door latch device  1 F,  1 R will be described. 
     The door latch devices  1 F,  1 R are the same to each other in the basic structure except part (including an internal operating element later described). Thus, the door latch device  1 F in the Design 1 is described, and the door latch device  1 R is interpreted without special description by replacing “door latch device  1 F” with “door latch device  1 R” and “front door FD” with “rear door RD”. Each of the Designs will be described after the basic structure common with each of the Designs and actions therefor are described. 
     The internal operating elements denote a lever and a link that connect a door-opening action of the inside handle IH, which will be described later. 
       FIGS. 2 and 3  are perspective views of the door latch device  1 F common to the Designs;  FIG. 4  is a partially exploded perspective view of the door latch device  1 F in the Design 1;  FIG. 5  is an exploded perspective view of the door latch device  1 F in the Design 1;  FIG. 6  is a back elevational view of the door latch device  1 F common to the Designs; and  FIGS. 7 to 11  are views showing an action of the main part in the Design 1. 
     The directions in the following description show states where the door latch devices  1 F,  1 R are attached in the doors FD, RD respectively. 
     The door latch device  1 F comprises an engagement unit  2  with an engagement mechanism mounted in the front door FD for holding the front door FD closed by engaging with a striker S of the vehicle body; and an operating unit  3  with the locking mechanism comprising mechanical elements, such as a lever and a link, for shifting the front door FD to the lock state and the unlock state. 
     In  FIG. 6 , the engagement unit  2  mainly comprises a body  4  fixed to the rear end in the front door FD with a plurality of bolts (not shown); an engagement mechanism (not numbered) that includes a latch  5  that can engage with the striker S fixed to the vehicle body and a latch  6  that can engage with the latch  5  in the body  4 ; an opening lever  7  that can release the ratchet  6  from the latch  5  in  FIGS. 4 and 5 ; and a metal inertia lever  37  that is pivotally mounted via a shaft  31  that lies longitudinally of the vehicle and supports an outside lever  21  later described. 
     The latch  5  is pivotally mounted in the body  4  via a latch shaft  8  that lies longitudinally of the vehicle, and comprise a full-latch engagement portion  51  and a half-latch engagement portion  52  that can engage with the ratchet  6 , and engagement groove  53  that can engage with the striker S which enters a striker-entering groove  41  of the body  4 . 
     In  FIG. 6 , the striker-entering groove  41  of the body  4  is formed slightly higher than the middle vertically and is open toward the inside of the vehicle to extend outwardly of the vehicle. The symbol “X” in  FIG. 6  shows a striker entering line along which the striker S comes into the striker-entering groove  41  and engages with the engagement groove  53  of the latch  5  when the front door FD closes. 
     With closing of the front door FD, the latch  5  rotates from an open position (a position where it rotates clockwise from  FIG. 6  by approximately 90 degrees) where the latch  5  does not engage with the striker S and the front door FG is open, to a full-latch position in  FIG. 6  where the striker S fully engages with the engagement groove  53  to fully close the front door FD, via a half-latch position where the latch  5  rotates counterclockwise by a certain angle against a spring (not shown) to make the engagement groove  53  slightly engages with the striker S which comes into the striker-entering groove  41  along the striker-entering line X from the left. The striker S leaves the striker-entering groove  41  with opening of the front door FD, and the latch  5  rotates vice versa. 
     The ratchet  6  is pivotally mounted under the striker-entering groove  41  within the body  4  via a ratchet shaft  9  that lies longitudinally of the vehicle and is urged by a spring (not shown) in an engaging direction (counterclockwise in  FIG. 6  to engage the ratchet  6  with the full-latch engagement portion  51  and the half-latch engagement portion  52  of the latch  5 ). The ratchet  6  engages with the full-latch engagement portion  51  for holding the front door FD fully closed, and engages with the half-latch engagement portion  52  for holding the front door FD not completely closed. 
     The inertia lever  37  is pivotally mounted via a shaft  31  such that a center of gravity is positioned at the center of the shaft  31 , and is urged any time clockwise by a spring  38  in which one end engages with a projection  371  on a front face, so that the inertial lever  37  is at rest in a standby position in  FIG. 6 . On a side opposite a side where one end of the spring  38  engages with the projection  371 , an outward end of the opening lever  7  that rotates with the ratchet  6  abuts. (not shown) 
     Thus, when a force of inertia for turning the ratchet  6  in a releasing direction (clockwise in  FIG. 6 ) is exerted by a side crash, a lower end  6   a  of the ratchet  6  immediately comes in contact with an upper end  37   a  of an inertial lever  37  which is at rest in a standby position, thereby blocking the ratchet  6  from turning in the releasing direction. So, at the crash, the ratchet  6  unlikely leaves the latch  5 , and the latch  5  still engages with the ratchet  6 , thereby preventing the front door FD from opening unexpectedly at the crash. In order to prevent the ratchet  6  from rotating in the releasing direction securely, a line of action when the lower end  6   a  of the ratchet  6  contacts the upper end  37   a  of the inertial lever  37  may preferably go through a center of the shaft  31 . 
     When the opening lever  7  and the ratchet  6  are rotated by an outside lever  34  (later described) in the releasing direction, the end of the opening lever  7  comes in contact with the projection  371  counterclockwise in  FIG. 6 , and the inertial lever  37  is rotated counterclockwise against the spring  38 . The upper end of the inertial lever  37  goes out of a moving path of the lower end  6   a  of the ratchet  6  to allow the ratchet  6  to rotate in the releasing direction (clockwise in  FIG. 6 ), so that the front door FD can be opened. 
     In  FIG. 5 , the opening lever  7  is pivotally mounted coaxially with the ratchet  6  on a front face of the body  4  to rotate together with the ratchet  6 , and a released portion  71  is disposed at the end extending toward the interior of the vehicle. 
     Then, an operating unit  3  will be described as below. 
     The operating unit  3  comprises a first L-shaped synthetic-resin cover  10  fixed to the body  4  to cover a front surface of the body  4 ; a second synthetic-resin cover  11  that closes a side of the first cover  10  facing the interior of the vehicle; a synthetic-resin waterproof side cover  12  that closes an upper half of the second cover  11  from the interior of the vehicle; a waterproof top cover  13  that covers a top joining surface of the first cover  10  and the second cover  11 ; and an operating mechanism (not numbered) in the housing. 
     “In the housing” in the description denotes a storage space formed between a side of the first cover  10  perpendicular to a front face of the body  4  and a side of the second cover  11  opposite the side of the first cover  10 . 
     In  FIG. 5 , the operating mechanism comprises, as basic elements, a locking motor  14 ; a locking worm wheel  15  (locking rotor) reversible by the locking motor  14 ; a locking lever  16  movable between an unlock position for allowing the front door FD to open and a lock position for keeping the front door from opening; an opening link  18  movable with the locking lever  16  between the unlock position and the lock position; an inside lever  19  in the Design 1 connected to the inside handle IH of the front door FD; a key lever  20  (no provided in the rear-door door latch device  1 R) cooperating with the key cylinder KC for the front door FD; an outside lever  21  connected to the outside handle OH for the front door FD; a releasing motor  22 ; a releasing worm wheel  23  (releasing rotor) that can be rotated by the releasing motor  22 ; an electric releasing lever  24  that can be released (rotated clockwise in  FIG. 7 ) with rotation of the releasing worm wheel  23 ; a locking motor  14 ; and a distribution plate  25  with circuits electrically connected to the locking motor  22 , the releasing motor  22  and detecting switches. In a storage space between the second cover  11  and the waterproof side cover  12 , there is provided a knob lever  17  connected to a locking knob (not shown) on the front door FD inside the vehicle. 
     The inside lever  19  of the internal operating system is set in each Design as below. The operating mechanism of the operating unit  3  comprises elements except the inside lever  19  (including the key lever  20  in the rear-door door latch device  1 R) from the basic elements. 
     In this embodiment, the locking worm wheel  15 , the locking lever  16  and the knob lever  17  as mechanical elements constitute the locking mechanism. 
     “An unlock state” in the following description means that the locking lever  16 , the knob lever  17  and the opening link  18  are in an unlock position respectively, and “a lock state” means that the locking lever  16 , the knob lever  17  and the opening link  18  are in a lock position respectively. The locking mechanism is not limited to this embodiment, but the locking lever  16  may be connected to the locking knob without the knob lever  17 . 
     The releasing motor  22 , the releasing worm wheel  23  and the electric release lever  24  form an electric releasing mechanism. 
     The locking motor  14  is held in the housing, and a case  14   a  (yoke) is above the striker-entering line X in  FIG. 6 . An output shaft  14   b  pivotally mounted to the case  14   a  is disposed downward and driven with a switch (not shown) on the interior of the vehicle or an electronic key of a user. 
     The locking motor  14  is disposed in the housing such that the case  14   a  is above the striker-entering line X. So rainwater through the striker-entering groove is prevented from coming into the case  14   a.    
     The distribution plate  25  is integrally formed with a coupler  251  connected to an external connector or wire (not shown) connected to a vehicle battery (not shown) and an ECU. At a side of the distribution plate  25  opposite the outside of the vehicle, electric circuits for supplying power and signals into the housing are fixed in the housing to cover the case  14   a  of the locking motor  14  from the inside of the vehicle. The distribution plate  25  is electrically connected to terminals of the locking motor  14  and the releasing motor  22 , and to the external connector connected to the coupler  251  so that the locking motor  14  and the releasing motor  22  may be controlled by the ECU.  FIG. 4  clearly illustrate an internal structure of the operating unit  3  without the distribution plate  25 . 
     The locking worm wheel  15  is pivotally mounted in the housing via a shaft  26  that lies transversely of the vehicle below the case  14   a  of the locking motor  14  and meshes with a worm  141  mounted on an output shaft  14   b  of the locking motor  14 . Thus, the worm wheel  15  is rotated clockwise or counterclockwise by the locking motor  14  from a neutral position (such as in  FIG. 7 ) against of a spring  27  (in  FIG. 5 ) wound on the shaft  26 , and returns to the neutral position again from a position where the worm wheel  15  is rotated by the spring  27  when the locking motor  14  stops. 
     The knob lever  17  is pivotally mounted to a side of the second cover  11  via a shaft  111 , and a connecting arm  171  that extends downward is connected to a manually-operating locking knob via a connecting member  28  comprising a Bowden cable. So, based on an unlocking action and a locking action of the locking knob, the knob lever  17  rotates counterclockwise from an unlock position in  FIG. 7  to a lock position in  FIG. 8 . An action of the locking knob is transmitted to the locking lever  16  and the opening link  18  via the knob lever  17 . 
     After the knob lever  17  is connected to the second cover  11  in  FIG. 3 , the waterproof side cover  12  is fixed to an outer side of the second cover  11 , and the second cover  11  that includes an area where the knob lever  17  is disposed is partially closed thereby preventing rainwater from coming into the housing. 
     The locking lever  16  is pivotally mounted in the housing via a shaft  101  that projects inward of the vehicle from an inner surface of the first cover  10 , and teeth  161  of the locking lever  16  mesh with teeth  151  of the locking worm wheel  15 . An upper part of the locking lever  16  is joined to the key lever  20 , and a connecting projection  162  at an upper front part is connected to a connecting hole  172  of the knob lever  17  through an arc-shaped hole  112  of the second cover  11 . The locking lever  16  has an arm  164  with a guide wall  165  that extends downward from a center of rotation. A shaft  101  or a center of rotation of the locking lever  16  is disposed above the striker-entering line X in the housing. 
     Thus, according to rotation of the key lever  20  with the key cylinder, rotation of the knob lever  17  with the locking knob and rotation of the locking worm wheel  15  with the locking motor  14 , the locking lever  16  can rotate from an unlock position in  FIG. 7  to a lock position in  FIG. 8  to which the locking lever  16  rotates clockwise by a certain angle from the unlock position and is elastically held by an elastic holding force of a holding member  29  in the unlock and lock positions respectively. When the locking worm wheel  15  is at a neutral position, the teeth  161  of the locking lever  16  do not engage with the teeth  151  of the locking worm wheel  16 , so that rotation of the locking lever  16  with the locking knob and the key cylinder is not transmitted to the locking worm wheel  15 . 
     The holding member  29  comprises a torsion spring a coil of which is supported by a cylindrical support  102  (in  FIG. 5 ) integrally formed with an inner surface of the first cover  10 . Both the arms hold the connecting projection  162  of the locking lever  16 . So, when the locking lever  16  rotates from the unlock position (or lock position) to the lock position (or unlock position), an urging direction is converted from the unlock direction (or lock direction) to the lock direction (or unlock direction) with respect to an intermediate position between the unlock position and the lock position. 
     The locking lever  16  stops at the unlock position and the lock position by contacting a part of the locking lever  16  to a rubber stopper (not shown) fixed to the inner surface of the first cover  10 . 
     On an upper circumference of the locking lever  16 , there is formed a cam surface  163  which contacts a detecting portion of a detecting switch  30  of the distribution plate  25 . The detecting switch  30  is in sliding contact with the cam surface  163  relatively, thereby supplying a signal corresponding to the unlock state/lock state of the locking mechanism. The outputted signal is transmitted to the ECU via the circuits on the distribution plate  25 . 
     The opening link  18  has a connecting hole  182  in a lower rotary portion  181 , and a flat connecting portion  211  at the end of the outside lever  21  is inserted into the connecting hole  182 . Hence, the opening link  18  is coupled to the connecting portion  211  of the outside lever  21  to rotate by a certain angle, and an upper coupling projection  183  is coupled to the arm  164  of the locking lever  16 . With a motion of the locking lever  16  between the unlock position and the lock position, the opening link  18  rotates from an unlock position in  FIG. 7  to a lock position in  FIG. 8  to which the opening link  18  rotates clockwise by a certain angle from the unlock position. 
     Furthermore, in the middle, the opening link  18  has a releasing portion  184  which can contact the released portion  71  of the opening lever  7  from below, in the unlock position in  FIG. 7 . A torsion spring  36  is disposed in the rotary portion  181  of the opening link  18 . 
     One end of the torsion spring  36  engages with the opening link  18 , and the other end engages with the connecting portion  211  of the outside lever  21 . So, an urging force is applied to the opening link  18  anytime in the unlocking direction (clockwise in  FIG. 7 ) around the connecting portion  211  of the outside lever  21 . The torsion spring  36  is set to be smaller than a holding force for elastically holding the locking lever  16  of the holding member  29  in the lock position. 
     The coupling projection  183  of the opening link  18  is connected to the arm  164  of the locking lever  16  such that the coupling projection  183  of the opening link  18  can slide vertically along the arm  164  of the locking lever  16  and can contact the guide wall  165  only when the locking lever  16  rotates in a locking direction (counterclockwise in  FIG. 7 ). 
     In the unlock state in  FIG. 7 , when the locking lever  16  rotates to the lock position, the opening link  16  rotates from the unlock position to the lock position in  FIG. 8  by contacting the guide wall  165  of the locking lever  16  with the coupling projection  183  of the opening link  18 . In the lock state in  FIG. 8 , when the locking lever  18  rotates to the unlock position, the opening link  18  rotates from the lock position to the unlock position in  FIG. 7 , following a rotation of the locking lever  16  by the torsion spring  36  without depending on contact relationship between the guide wall  165  and the coupling projection  183 . 
     In the lock state in  FIG. 8 , the torsion spring  36  exerts on the locking lever  16  in an unlocking direction (clockwise). The torsion spring  36  is smaller than elastic holding force for holding the locking lever  16  in the lock position with the holding member  29 . Thus, the locking lever  16  and the opening link  18  are not rotated to the unlock position by the torsion spring  36 . 
     The outside lever  21  is pivotally mounted vertically at a front lower part of the body  4  via the shaft  31  which lies longitudinally of the vehicle, and the connecting portion  211  is connected to the opening link  18  as above. A connecting portion  212  at the inner end is connected to the outside handle OH via a vertical connecting member (not shown). Based on a door-opening action of the outside handle OH, the outside lever  21  rotates against the urging force of a spring (not shown) in a releasing direction (counterclockwise in  FIG. 5 ) by a certain angle thereby applying a releasing action to the opening link  18 . 
     In the housing, a case (yoke)  22   a  of the releasing motor  22  is below the striker entering line X, and an output shaft  22   b  pivotally mounted to the case  22   a  is disposed backward and downward. The regular user with the electronic key comes within a predetermined area around the motor vehicle V, and an ID signal is matched through wireless communication conducted between the electronic key and a receiver in the motor vehicle V. When it is authenticated that the regular user comes around the motor vehicle V, the releasing motor  22  is driven by turning on the detecting switch SW because the user contacts or approaches the detecting switch SW. 
     Because the releasing motor  22  is disposed below the striker-entering line X, rainwater that comes through the striker-entering groove  41  likely attaches to the releasing motor  22 , but the output shaft  22   b  of the releasing motor  22  is disposed obliquely backward and downward. So rainwater that comes into the case  22   a  can be minimized. 
     The releasing worm wheel  23  is like a disc and is pivotally mounted in the housing via the shaft  31  which lies transversely of the vehicle. The worm wheel  23  meshes with a worm  221  fixed to the output shaft  22   b  pivotally mounted to the case  22   a  of the releasing motor  22 . Based on the drive of the releasing motor  22 , the worm wheel  23  is rotated clockwise by a certain angle from a set position (such as a position in  FIG. 7 ) against an urging force of the spring  35  (in  FIG. 5 ) wound on the shaft  31  to the position in  FIG. 9 . The releasing motor  22  stops rotation and returns to the set position again from a position where it is rotated by the spring  35 . In the releasing worm wheel  23 , there is formed a cam surface  231  in an involute curve in which a distance from an axis to an outer circumference gradually increase counterclockwise in  FIG. 7 . 
     The shaft  31  for mounting the releasing worm wheel  23  pivotally is below the case  22   a  of the releasing motor  22  and disposed behind the output shaft  22   b.    
     An electric release lever  24  is pivotally mounted via a shaft  102  (release shaft) in the middle in the housing, and comprises a first arm  241  in which a front end can come in sliding contact with a cam surface  231  of the releasing worm wheel  23  and a second arm  242  in which a rear end can come in contact with a released portion  71  of the opening lever  7  from below. 
     In the housing, the shaft or a center of rotation of the electric release lever  24  is disposed below an upper half of the case  22   a  and the striker-entering line X behind the shaft  31  in front of the opening lever  7 . 
     For example, in  FIG. 7 , when the releasing worm wheel  23  is in the set position, the end of the first arm  241  of the electric release lever  24  comes in contact with a smaller-diameter portion of a cam surface  231  of the releasing worm wheel  23 , and the electric release lever  24  is held in a set position in  FIG. 7 . The releasing worm wheel  23  is rotated clockwise by a certain angle by the releasing motor  22  from the set position in  FIG. 7  to a release position in  FIG. 9 . The end of the first arm  241  of the electric release lever  24  slides on the cam surface  231  to a larger-diameter portion of the cam surface  231 , and the electric release lever  24  rotates to the release position in  FIG. 9 . The end of the second arm  242  comes in contact with the released portion  71  of the opening lever  7  from below to make the opening lever  7  release, and the ratchet  6  disengages from the latch  5 , so that the front door FD can be opened. 
     When the regular user with the electronic key comes within a predetermined area around the car V and it is authenticated that the regular user approaches the car V by identification through a wireless communication between the electronic key and the receiver in the car V, the ECU makes the detecting switch usable, turns on the detecting switch SW by contacting or approaching the detecting switch SW and controls the releasing motor  22  to enable the front door FD to open. When the locking mechanism is in the lock state, the locking motor  14  is controlled and shifted to an unlock state after the releasing motor  22  stops driving. 
     A position of each element that constitutes a basic structure of the operating mechanism is set as below:
         1) The shaft  101  as a center of rotation of the locking lever  16  and the case  14   a  for the locking motor  14  are disposed above the striker entering line X.   2) The shaft  102  as a center of rotation of the electric release lever  24 , the shaft  31  as a center of rotation of the releasing worm wheel  23  and the case  22   a  for the releasing motor  22  are disposed below the striker-entering line X.   3) In  FIG. 7 , if a straight line extending backward from an axis of the shaft  31  is a straight line A; if a straight line extending backward from the top of an outer circumference of the releasing worm wheel  23  is a straight line B; if a range C is defined between the straight lines A and B; if an extension line backward from the upper end of the releasing motor  22  is a straight line D; if an extension line backward from the lower end of the releasing motor  22  is a straight line E; and if a range F is defined between the straight line D and the straight line E, the releasing worm wheel  23  is within the range F, and the shaft  102  is behind the releasing worm wheel  23  and in front of the opening link  18  and the opening link  7  within the range C.       

     The locking mechanism and an electric release mechanism are disposed above and below the striker-entering line X respectively in the housing, and each of the elements can be arranged orderly. Because the shaft  102  is located at the foregoing position, the releasing motor  22 , the releasing worm wheel  23  and the electric release lever  24  can be arranged longitudinally of the vehicle to minimize downward projections, thereby making the housing smaller and, in turn, making the door latch device  1 F smaller. 
     (Basic Action of the Door Latch Device  1 F) 
     Then, basic movements of the door latch device  1 F will be described. 
     &lt;When a Regular User with an Electronic Key Opens the Front Door FD Outside the Vehicle in an Unlock State.&gt; 
     When the front door is fully closed and the locking mechanism is in an unlock state, each element of the operating mechanism is held in  FIG. 7 . 
     In the unlock state in  FIG. 7 , when the ECU authenticates that the regular user with the electronic key approaches the car V, a finger of the regular user touches or approaches the detecting switch SW, and the ECU controls the releasing motor  22  to rotate the releasing worm wheel  23  from the set position in a releasing direction (clockwise in  FIG. 7 ). With rotation of the releasing worm wheel  23  in the releasing direction, the end of the first arm  241  slides on the cam surface  231  of the releasing worm wheel  23 , and the electric release lever  24  rotates from the set position to the releasing position in  FIG. 9 , and the end of the second arm  242  comes in contact with the released portion  71  of the opening lever  7  from below to make the opening lever  7  released. Thus, the engagement mechanism is released, and the front door FD can be opened. 
     &lt;When the Regular User with the Electronic Key Opens the Front Door FD in the Lock State Outside the Vehicle&gt; 
     When the front door FD is fully closed and the locking mechanism is in the lock state, the elements of the operating mechanism are held in  FIG. 8 . 
     In the lock state in  FIG. 8 , when the ECU authenticates that the regular user with the electronic key approaches the car V, the regular user touches or approaches the detecting switch SW, and the releasing motor is controlled as well as the unlock state. In  FIG. 10 , the electric release lever  24  is released, and the front door FD can be opened. However, in this case, taking account of operating activity after the user who gets in the car closes the front door FD, the locking motor  14  is controlled to shift to the unlock state after the releasing motor  22  stops driving. 
     &lt;When the User (Passenger) Without the Electronic Key Opens the Front Door FD Outside the Vehicle&gt; 
     Whether the locking mechanism is in an unlock state or a lock state when the front door FD is fully closed, the ECU does not authenticate the regular user and the releasing motor cannot be driven even if the passenger without the electronic key operates the switch SW. 
     Thus, the passenger without the electronic key can open the front door FD by operating the outside handle OH of the front door FD only when the front door FD is in an unlock state. 
     Specifically, when the outside handle OH is operated to open the door, the door-opening action is transmitted via a connecting member (not shown) to the outside lever  21 , which is released counterclockwise in  FIG. 5 . The opening link  18  connected to the connecting portion  211  of the outside lever  21  is released upward from the set position in  FIG. 7 . With the releasing action, the releasing portion  184  comes in contact with the released portion  71  of the opening lever  7  from below to release the opening lever  7 . Thus, the ratchet  6  disengages from the full-latch engagement portion  51  of the latch  5 , so that the front door FD can be opened. 
     In  FIG. 8 , when the locking mechanism is in the lock state, with releasing action of the outside lever  21  based on door-opening action of the outside handle OH, the opening link  18  rotates upward from the set position, but the releasing portion  184  of the opening link  18  moves from the set position across the released portion  71  of the opening lever  7  without contacting the released portion  91 . The opening lever  7  cannot be released and the front door FD cannot be opened. Thus, in the lock state, the passenger or another user without the electronic key cannot open the front door FD outside the vehicle. 
     The outside handle OH on the front door FD is also usable as outside mechanical operating element for opening the door in an emergency if the releasing motor  22  is incapable of driving due to failure in the releasing motor  22  or an electric system therefor. However, in case of the lock state, it is necessary to shift the locking mechanism to the unlock state with power of the locking motor  14  due to unlocking operation of the key cylinder KC and unlocking operation of the switch in the electronic key. 
     (Description of the Structure and Action in Each Design) 
     The structure and action of an internal operating system in each Design will be described. 
     &lt;Design 1&gt; 
     The internal operating system in Design 1 comprises the inside lever  19  as shown in  FIGS. 7 to 11 . In the housing, the inside lever  19  is pivotally mounted with the electric release lever  24  via the shaft  102  at a position slightly lower than the middle, and comprises a first arm  191  which extends upward and projects outwardly from an arc-shaped opening  113  ( FIG. 3 ) and a second arm  192 , and a second arm  192  which extends downward obliquely. An upper part of the first arm  191  is connected to the inside handle IH via a connecting member  33  such as a Bowden cable. Based on a door-opening action of the inside handle IH, the inside lever  19  rotates by a certain angle counterclockwise from the set position in  FIG. 7  against an urging force of the spring  34  wound on the shaft  102 , and is released as shown in  FIG. 11 . At the end of the second arm  192 , there is formed a contact portion  192   a  which can come in contact with the rotary portion  181  of the opening link  18  when the inside lever  19  is released. 
     The connecting member  33  passes between the case  14   a  of the locking motor  14  located at an upper part of the housing and the case  22   a  of the releasing motor  22  located at a lower part, and is connected to the first arm  191  of the inside lever  19 . So, the connecting member  33  is not over the cases  14   a,    22   a  with a greater thickness transversely of the vehicle, thereby reducing a thickness along the width of the vehicle. 
     In the unlock state in  FIG. 7 , the door is tried to open by the inside handle IH. The door opening action is transmitted to the inside lever  19  via the connecting member  33 . The inside lever  19  is released counterclockwise around the shaft  102  which is the same axis as the electric release lever  24 . In  FIG. 11 , the contact portion  192   a  of the first arm  192  contacts the rotary portion  181  of the opening link  18  from below, thereby moving the opening link  18  upward. The releasing portion  184  of the opening link  18  contacts the released portion  71  of the opening lever  7  from below to release the engagement mechanism by rotating the opening lever  7  in a releasing direction to enable the front door FD to open. 
     In the lock state in  FIG. 8 , even if the inside lever  19  is released with the door-opening action of the inside handle IH and the opening link  18  is moved upward from the set position, the releasing portion  184  of the opening link  18  swings without contact with the released portion  71  of the opening lever  7 , and the front door FD cannot be opened. In order to open the front door FD through the door-opening action of the inside handle IH in the lock state, the locking motor  14  is driven by an unlocking action of the locking knob inside the vehicle, or by a switch inside the vehicle. After turning to the unlock state, it is necessary to open the door with the inside handle IH. 
     Thus, in the door latch device  1 F in the Design 1, when the locking mechanism is the lock state, the locking mechanism is shifted to the unlock state, and then, the inside lever  19  is rotated by the inside handle IH of the front door FD, so that the front door FD can be opened. 
     &lt;Design 2&gt; 
     An internal operating system in the Design 2 comprises an inside lever  19 A in  FIGS. 12 to 14 . The inside lever  19 A is pivotally mounted via a shaft  102  which is the same axis for the electric release lever  24  to form an unlocking portion  193  which is not formed in the inside lever  19  in the Design 1. 
     The unlocking portion  193  is formed on the upper end of the first arm  191  as a shape which can contact a part of the lower portion of the connecting arm  171  of the knob lever  17 . 
     In the unlock state in  FIG. 12 , the door is tried to open by the inside handle IH to release the engagement mechanism to enable the front door FD to open with the same action as the Design 1. 
     In the lock state in  FIG. 13 , by a first door-opening action of the inside handle IH, the inside lever  19 A rotates from the set position in  FIG. 13  against the spring  34  (counterclockwise in  FIG. 13 ). In  FIG. 14 , the inside lever  19 A contacts a part  173  of the knob lever  17 , and moves the locking lever  16  and the opening link  18  from the lock position to the unlock position. 
     With the releasing action of the inside lever  19 A, the opening link  18  goes across upward in front of the released portion  71  of the opening lever  7  without contact, and the opening link  18  rotates with the locking lever  16  in an unlocking direction. So, in  FIG. 14 , part of the opening link  18  comes in contact with part of the opening lever  7  from a direction where the opening lever  7  is not capable of rotating, and an once-stop state occurs where the opening link  18  stops right before the unlock position. 
     In the door latch device  1 F, when the locking lever  16  rotates from the unlock position to the lock position, the guide wall  165  of the locking lever  16  contacts the coupling projection  183  of the opening link  18  to move the opening link  18  to the lock position. But, when the locking lever  16  rotates from the lock position to the unlock position, the opening link  18  is rotated to the unlock position by the torsion spring  36  without depending on a contact relationship between the guide wall  165  and the coupling projection  183 . Even if the once-stop state as above occurs, the locking lever  16  can rotate to the unlock position against the torsion spring  36  while the opening link  18  is still at rest in a position before the unlock position in  FIG. 14 . 
     In  FIG. 14 , the inside handle IH returns to a non-operating position once, and the opening link  18  moves downward, and part of the opening link  18  leaves part of the opening lever  7 . The opening link  18  is moved to the unlock position by the torsion spring  36 . Thus, the locking mechanism is completely shifted to the unlock state. 
     After shifting to the unlock state, the engagement mechanism is released by the inside handle IH again, so that the front door FD can be opened. 
     When the door latch device  1 F in the Design 2 is in the lock state, the device is shifted to the unlock state by the first door-opening action of the inside handle IH, and the engagement mechanism is released by the second door-opening action of the inside handle IH, so that the front door FD can be opened. 
     &lt;Design 3&gt; 
     An internal operating system in the Design 3 comprises an inside lever  19 B in  FIGS. 15 to 17 . The inside lever  19 B is pivotally mounted via a shaft  102  which is coaxial with the electric release lever  24 . An unlocking portion  193  (the same as the Design 2) and a releasing portion  194  which are not formed in the inside lever  19  in the Design 1 are formed, and the second arm  192  in the Design 2 is not formed. 
     The unlocking portion  193  which is the same as in the Design 2 is formed at the upper end of the first arm  191  and as a shape which can contact part  173  of the connecting arm  171  of the knob lever  17 . The inside lever  19   b  is released (rotating counterclockwise in  FIG. 15 ) based on a door-opening action of the inside handle IH, and the electric releasing portion  194  comes in contact with the second arm  242  of the electric release lever  24  counterclockwise to release the electric release lever  24 . 
     In the unlock state in  FIG. 15 , when the door is tried to open by the inside handle IH, the inside lever  19 B rotates by a certain angle counterclockwise from the set position around the shaft  102 , and the electric releasing portion  194  comes in contact with the second arm  242  of the electric release lever  24  counterclockwise. The electric release lever  24  is moved counterclockwise around the shaft  102  from the set position in  FIG. 15 , and the end of the second arm  242  comes in contact with the released portion  71  of the opening lever  7 , thereby releasing the engagement mechanism, so that the front door FD can be opened. 
     In the lock state in  FIG. 16 , when the door is tried to open by the inside handle IH, the inside lever  19 B is released (rotation counterclockwise in  FIG. 16 ) from the set position in  FIG. 16  against the spring  34 , and in  FIG. 17 , the unlocking portion  193  of the inside lever  19 B comes in contact with part  173  of the knob lever  17  in  FIG. 17 . The locking lever  16  and the opening link  18  are moved from the lock position to the unlock position via the knob lever  17 , and the electric releasing portion  194  comes in contact with the electric release lever  24  to release the electric release lever  24  counterclockwise, thereby releasing the engagement mechanism. 
     In the door latch device  1 F in the Design 3, even if the locking mechanism is in the lock state, the locking mechanism is shifted to the unlock state by one-time opening action of the inside handle IH, and the engagement mechanism is released, so that the front door FD can be opened. 
     &lt;Design 4&gt; 
     The Design 4 is set to a door latch device  1 R for a rear door. In  FIGS. 18 to 21 , besides a first inside lever  19 C and a second inside lever  19 D in the internal operating system, there is provided a childproof mechanism that comprises a childproof operating lever  19 E and a connect link  19 F. 
     The first and second inside levers  19 C,  19 D are pivotally mounted via the shaft  102  which is the same axis for the electric release lever  24 . 
     In the first inside lever  19 C, the upper end of the first upward-extending arm  191  (corresponding to the first arm  191  of the inside lever  19  in the Design 1) is connected to the inside handle IH of the rear door RD via the connecting member  33 , and the first inside lever  19 C is released counterclockwise, from the set position in  FIG. 19  based on a door opening action of the inside handle IH. An L-shaped control hole  195  is formed in the first inside lever  19 C. The second arm  192  in the Design 1 is not provided in the first inside lever  19 C. 
     The second inside lever  19 D has a vertical elongate opening  196  partially over the control hole  195  of the first inside lever  19 C and a second arm  192  that extends obliquely downward(corresponding to the second arm  192  of the inside lever  19  in the Design 1). 
     The childproof operating lever  19 E is pivotally mounted via a shaft  103  in the housing, and can rotate between a childproof unlock position in  FIG. 19  and a childproof lock position in  FIG. 21  to which the lever  19 E rotates counterclockwise by a certain angle from the childproof unlock position. The childproof operating lever  19 E has an arc-shaped hole  197  at a front part, and an operating portion  198  that projects outward from the rear end of the rear door RD. 
     The shaft  102  vertically slides in a vertical elongate hole  19 Fa of the connect link  19 Fa; a lower projection  19 Fb slides in an arc-shaped hole  197  of the childproof operating lever  19 E; and an upper projection  19 Fc slides in a control hole  195  and an elongate hole  196 . Hence, when the childproof operating lever  19 E is in the childproof unlock position in  FIG. 19 , the upper projection  19 Fc engages in an upper narrower portion of the control hole  195  to enable a releasing action of the first inside lever  19 C to transmit the second inside lever  19 D, and when the childproof operating lever  19 E is in the childproof lock position in  FIG. 21 , the upper projection  19 Fc is positioned in a lower wider portion of the control hole  195  not to enable a releasing action of the first inside lever  19 C to transmit to the second inside lever  19 D. 
     “A childproof unlock state” described below denotes that the childproof operating lever  19 E is in a childproof unlock position to enable an action of the first inside lever  19 C to transmit the second inside lever  19 D, and “a childproof lock state” denotes that the childproof operating lever  19 E is in a childproof lock position not to enable an action of the first inside lever  19 C to transmit to the second inside lever  19 D. 
     An internal operating system in the Design 4 will be described. 
     In  FIG. 19 , when the locking mechanism is in the unlock state and the childproof mechanism is in the childproof lock state, the door is tried to open by the inside handle IH, and the first inside lever  19 C rotates counterclockwise by a certain angle from the set position around the shaft  102 . The rotation is transmitted to the second inside lever  19 D via the connect link  19 F, and the second inside lever  19 D is released counterclockwise together with the first inside lever  19 C. Thus, the contact portion  192   a  of the second arm  192  of the second inside lever  19 D comes in contact with a lower surface of the rotary portion  181  of the opening link  18  from below, so that the opening link  18  is released upward. The releasing portion  184  of the opening link  18  comes in contact with the released portion  71  of the opening lever  7  from below, thereby rotating the opening lever  7  in a releasing direction, releasing the engagement mechanism and enabling the rear door RD to open. 
     When the locking mechanism in the lock state and the childproof mechanism is in the childproof unlock state, the first inside lever  18 C and the second inside lever  19 D are released, and the opening link  18  is released upward from the set position. But as well as the Design 1, the releasing portion  184  of the opening link  18  swings without contact with the released portion  71  of the opening lever  7 , so that the rear door RD cannot be opened. Thus, in order to open the rear door RD due to a door-opening action of the inside handle IH as well as the Design 1, the locking motor  14  is driven by an unlocking of the locking knob inside the vehicle or with the switch inside the vehicle, the locking mechanism is shifted to the unlock state, and thereafter it is necessary that the door should be tried to open by the inside handle. 
     In  FIG. 21 , when the locking mechanism is in the unlock state and the childproof mechanism is in the childproof lock state, the rear door is tried to open by the inside handle, and the first inside lever  19 C is released. But the releasing action is not transmitted to the second inside lever  19 D, and the rear door RD cannot be opened. Thus, in this state, the rear door Rd can be opened outside the vehicle, but cannot be opened inside the vehicle. 
     &lt;Design 5&gt; 
     The Design 5 is set to a door latch device  1 R for a rear door. In  FIGS. 22 to 24 , besides a first inside lever  19 G and a second inside lever  19 D in an internal operating system, there is provided a childproof mechanism comprising a childproof operating lever  19 E and a connect link  19 F as well as in the Design 4. 
     The first inside lever  19 G is pivotally mounted via a shaft  102  which is the same axis for the electric release lever  24 . The upper end of the first arm  191  extending upward is connected to the inside handle IH of the rear door RD via the connecting member  33 , and due to a door-opening action of the inside handle IH, the first inside lever  19 G is released counterclockwise from the set portion in  FIG. 22 . The first inside lever  19 G has an L-shaped control hole  195  having the same shape as in the Design 4, and an unlocking portion  193  as well as those in the Designs 2 and 3. 
     The second inside lever  19 D, the childproof operating lever  19 E and the connect link  19 F are the same as those in the foregoing Design 4, with the same numerals as those in the Design 4 in  FIGS. 22 to 24  and are not described. 
     The internal operating system in the Design 5 will be described. 
     In  FIG. 22 , when the door is tried to open by the inside handle IH in an unlock state of the locking mechanism and in a childproof unlock state of the childproof mechanism, the first inside lever  19 G and the second inside lever  19 D are both released, and the engagement mechanism is released via the opening link  18  as well as the Design 4, so that the rear door RD can be opened. 
     When the locking mechanism is in the lock state and the childproof mechanism is in the childproof unlock state, the door is tried to open by the inside handle IH, and the first inside lever  19 G and the second inside lever  19 D are both released. As well as the Design 2, based on releasing of the first inside lever  19 G due to a first door-opening action of the inside handle IH, in  FIG. 23 , the unlocking portion  193  of the first inside lever  19 G comes in contact with the part  173  to shift to the unlock state. And based on releasing of the second inside lever  19 D due to a second door-opening action of the inside handle IH, the engagement mechanism is released via the opening link  18 , so that the rear door can be opened. 
     In  FIG. 24 , when the locking mechanism is in the unlock state and the childproof mechanism is in the childproof lock state, the rear door is tried to open by the inside handle IH and the first inside lever  19 G is released. But the releasing action is not transmitted to the second inside lever  19 D, so that the rear door RD cannot be opened. 
     When the locking mechanism is in the lock state and the childproof mechanism is in the childproof lock state, the first inside lever  19 G is released due to a door-opening action of the inside handle IH of the rear door RD. Based on the releasing action, the unlocking portion  193  of the first inside lever  19 G comes in contact with the part  173  of the knob lever  17 , thereby shifting to the unlock state. The childproof lock state is still kept, and if it is not shifted to a childproof unlock state by the childproof operating lever  19 E, the rear door RD cannot be opened by the inside handle IH. Because the locking mechanism is shifted to the unlock state, the rear door can be opened by the outside handle OH on the rear door RD outside the vehicle. 
     When the childproof mechanism is in the childproof lock state, the door latch device  1 R in the Design 5 cannot open the rear door RD even if the rear door RD is tried to open by the inside handle IH, whether the locking mechanism is in the unlock state or the lock state. When the locking mechanism is in the lock state, it can be shifted to the unlock state by the inside handle IH on the rear door RD. 
     From the above, the shaft  102  for pivotally mounting the electric release lever  24  in the housing is positioned within the range C behind the releasing worm wheel  23  below the locking lever  16  in front of the opening link  18  and the opening lever  7 , and an axis for the inside lever  19 ,  19 A,  19 B,  19 C,  19 D,  19 D is the same as the shaft  102  for the electric release lever  25 . Without changing a position of each element forming the basic structure of the operating mechanism, the electric release lever  24  can actuate each element as below:
         The electric release lever  24  can directly actuate the opening link  18 .   In the Design 1, the inside lever  19  can directly actuate the opening link  18 .   In the Design 2, the inside lever  19 A can directly actuate the opening link  18  and the locking lever  16 .   In the Design 3, the inside lever  19 B can directly actuate the locking lever  16  and the electric release lever  24 .   In the Design 4, the first inside lever  19 C and the second inside lever  19 D are provided. The second inside lever  19 D can directly actuate the opening link  18 .   In the Design 5, the first inside lever  19 G and the second inside lever  19 D are provided. The first inside lever  19 G and the second inside lever  19 D can directly actuate the locking lever  16  and the opening link  18  respectively.       

     Thus, the basic structure for the operating mechanism is used among the Designs. The releasing motor  22 , the releasing worm wheel  23 , the electric release lever  24  and the inside lever  19  ( 19 A,  19 B,  19 C,  19 D,  19 G) can be arranged orderly thereby making the housing and the door latch device  1 F smaller.