Patent Publication Number: US-10329807-B2

Title: Electrical vehicle latch

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 14/132,041 filed Dec. 18, 2013 which claims the benefit and priority of European Application No. EP12199307.5 filed Dec. 21, 2012. The entire disclosures of each of the above applications are incorporated herein by reference. 
    
    
     FIELD 
     The present invention relates to an electrical latch for a vehicle door, in particular of the type utilizing a double pawl arrangement. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     As it is known, one of the defining characteristics of an electrical door latch is that it does not have mechanical linkages to outside and inside door handles. Instead, the door is released by an actuator in response to an electric signal coming from the handles. 
     Electrical door latches using double pawl arrangements normally comprise: 
     a ratchet biased by a spring into a release position, wherein the ratchet is positioned to receive or release a striker fixed to a door post, and which can be moved to a partially locked or first-click position and a fully locked or second-click position, in which the striker is increasingly retained inside the ratchet and prevented from withdrawing; 
     a primary pawl movable between a ratchet checking position, wherein the primary pawl is positioned to keep the ratchet in the partially locked or fully locked positions, and a ratchet release position, wherein the primary pawl permits the movement of the ratchet out of the partially locked or fully locked positions; 
     an auxiliary ratchet operatively connected to the primary pawl and movable between an enabling position, in which the primary pawl is enabled to move to its ratchet checking position, and a disabling position, in which the auxiliary ratchet positions the primary pawl to its ratchet release position; 
     a secondary pawl movable between an auxiliary ratchet holding position, in which the secondary pawl is positioned to hold the auxiliary ratchet in its enabling position, and an auxiliary ratchet release position, in which the secondary pawl is positioned to permit movement of the auxiliary ratchet to its disabling position; 
     an electrically-operated actuator assembly which can be selectively activated for moving the secondary pawl to the auxiliary ratchet release position and the auxiliary ratchet to the enabling position; and 
     an electrical control unit comprising a printed circuit board for controlling operation of the actuator assembly. 
     All the above-listed components are normally carried by a support body in turn secured to an edge of the vehicle door facing in use the door post carrying the striker; the latch is normally arranged in a door cavity also housing a window glass when lowered. 
     The double pawl arrangement consists in establishing a connection of a first set formed by the ratchet and the primary pawl with a second set formed by the auxiliary ratchet and the secondary pawl. The connection is configured such that only a portion of the forces experienced by the first set are applied to the second set, thus requiring only a relatively low effort to release the latch. 
     In conventional electrical latches, the support body normally carries the printed circuit board in a position parallel to the ratchet and to the edge of the door to which such latches are normally secured. The other mechanical components, such as the primary pawl, the auxiliary ratchet and the secondary pawl, are also carried in positions parallel to the ratchet and the printed circuit board. 
     Due to this kind of configuration, known latches have a considerable thickness in a direction orthogonal to the door edge to which the latches are secured; such direction is usually critical for the window glass or for the window glass channel path, i.e. the channel path followed by the window glass during its movements between raised and lowered positions. In certain cases, too large sizes of the thickness of the latches may influence the shape and style of the window glass. 
     Moreover, the above-described configuration is also problematic in cases in which it is required to isolate the electric part of the actuator assembly from the part of the latch subject to damp or water in order to prevent latch malfunctions in case the water penetrates into the latch, e.g. during raining or even in case of submerged vehicle. 
     Last but not least, due to the integration of the actuator assembly in the same body containing the ratchet and the other mechanical levers, the packaging of the latch has a significant size in the fixation plane; this could create issues to install the latch in different environments and customizations and may require a deep review or a complete redesign of the latch in case of different footprints, i.e. different positions of the fixation points in the door edge and different shapes and/or lengths of the opening in the door edge for receiving the striker, typically known as “fishmouth”. 
     SUMMARY 
     This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its aspects, objectives, advantages and/or features. 
     It is an object of the present invention to provide an electrical vehicle latch designed to provide a straightforward, low-cost solution to the above drawbacks of known latches. 
     According to the present disclosure, an electric latch for a motor vehicle comprises: 
     a support assembly; 
     a releasable closure mechanism carried by the support assembly and adapted to releasably engage a striker; 
     an electrically-operated actuator assembly carried by the support assembly and which can be selectively activated to release the closure mechanism from the striker or to lock the closure mechanism in a condition of engagement with the striker; and 
     an electrical control unit comprising a printed circuit board for controlling operation of the actuator assembly; 
     wherein the closure mechanism comprises: 
     a ratchet movable between a release position, wherein the ratchet is positioned to receive or release the striker, and at least one lock position, wherein the ratchet is positioned to retain the striker, and a releasable locking mechanism cooperating with the ratchet to prevent disengagement between the striker and the ratchet; 
     wherein the support assembly comprises a first support body carrying at least said ratchet in a position parallel to a first plane (P 1 ), and a second support body carrying at least the printed circuit board in a position parallel to a second place (P 2 ) which is transverse to the first plane (P 1 ). 
     Further areas of applicability will become apparent from the description provided herein. The description and specific example in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which: 
         FIG. 1  is a top plan view of an electrical vehicle latch in accordance with the present invention and in a position of use on the vehicle; 
         FIG. 2  is a front perspective view of the  FIG. 1  latch during an initial stage of an opening manoeuvre; 
         FIG. 3  is the same perspective view of the latch as in  FIG. 2  with a front cover removed for clarity; 
         FIG. 4  is a rear perspective view of the latch of  FIGS. 2 and 3 , with parts removed for clarity; 
         FIG. 5  is a larger-scale side perspective view of the latch of  FIG. 4 , with parts removed for clarity; 
         FIG. 6  is the same side perspective view of the latch as in  FIG. 5  with some levers removed for clarity; 
         FIG. 7  is an opposite side perspective view of the latch of  FIG. 5 , with parts removed for clarity; 
         FIG. 8  is a side perspective view of the latch of  FIGS. 2 and 3 ; and 
         FIG. 9  is an exploded side perspective view of a part of the latch of  FIGS. 2, 3 and 8 . 
     
    
    
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
     Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
     Number  1  in  FIGS. 1 to 3 and 8  indicates as a whole an electrical latch for a vehicle door (not shown). Latch  1  basically comprises: a support assembly  2  fixed, in know manner and in the position of  FIGS. 1 to 3 , to the vehicle door; a releasable closure mechanism  3  carried by support assembly  2  and adapted to releasably engage a striker  4  (only partially shown in  FIG. 2 ) integral with a fixed doorpost (not shown); an electrically-operated actuator assembly  5  carried by support assembly  2  and which can be selectively activated to release closure mechanism  3  from striker  4  or to lock closure mechanism  3  in a condition of engagement with the striker  4 ; and an electronic control unit  6  ( FIG. 8 ) comprising a printed circuit board  7  for controlling operation of actuator assembly  5 . 
     In an alternative embodiment not shown, striker  4  may be fixed to the vehicle door, and support assembly  2 , together with latch  1 , may be fixed to the doorpost. 
     With reference to  FIGS. 1, 2, 3 and 8 , support assembly  2  comprises two support bodies  8 ,  9 , each having a reduced thickness with respect to the other sizes. Bodies  8 ,  9  are arranged transversally, or substantially perpendicular, to one another, so as to define a L-shaped configuration of support assembly  2  when viewed along a plane perpendicular to both the bodies  8 ,  9  (see  FIG. 1 ). 
     In particular, body  8  is substantially plate-shaped and carries closure mechanism  3 , whilst body  9  is a fluid-tight casing internally housing, in a fluid-tight manner, electronic control unit  6  and part of actuator assembly  5 , and externally carrying the rest of the actuator assembly  5 . 
     Plate-shaped body  8  extends parallel to a first plane P 1  and body  9  carries printed circuit board  7  in a position parallel to a second plane P 2 , transversal to plane P 1 ; in particular, planes P 1  and P 2  are substantially orthogonal and, in the example shown, form an angle slightly exceeding 90° (see  FIG. 1 ). 
     Body  8  comprises a structural plate  10  parallel to plane P 1  and delimited by opposite faces  10   a ,  10   b , one of which ( 10   a ) facing towards body  9  and the other one ( 10   b ) externally covered by a thin plate-shaped front cover  11 . 
     More specifically, plate  10  has a peripheral edge  12  protruding from face  10   b  and which defines an abutment surface cooperating with a contour portion of cover  11 . In practice, cover  11  is secured to peripheral edge  12  and extends in use parallel to face  10   b  of plate  10 ; cover  11 , face  10   b  and protruding peripheral edge  12  delimit a cavity  13 , in which some components of closure mechanism  3  are housed, as it will be explained in greater detail later on. 
     As visible in  FIGS. 2, 3 and 8 , body  8  defines a lateral seat  14  extending along plate  10  and cover  11 , delimited by a C-shaped edge and adapted to receive striker  4  when closing the door. 
     More specifically, seat  14  comprises an inlet opening  14   a  extending through the peripheral contour of plate  10 , and a receiving portion  14   b  extending along plate  10  and cover  11  and closed on the opposite side to the inlet opening  14   a.    
     In the example shown, seat  14  is arranged substantially on an intermediate portion of body  8 . 
     With reference to  FIGS. 1 to 7 , closure mechanism  3  basically comprises a ratchet  15  superimposed on seat  14  for receiving striker  4 , and a double-pawl releasable locking mechanism  16  cooperating with ratchet  15  to prevent disengagement between the striker  4  and the ratchet  15 . 
     As shown in  FIGS. 2 and 3 , ratchet  15  is arranged on face  10   b  of plate  10  so being housed in cavity  13  of body  8 ; ratchet  15  is hinged about a fixed pin  17  extending orthogonally through plate  10 , protruding from both faces  10   a ,  10   b  of the plate  10  and having an axis A orthogonal to plane P 1 . In particular, ratchet  15  is defined by a contoured plate hinged at an intermediate portion about pin  17  and provided with a peripheral seat  18 , which has a C-shaped outline, is bounded laterally by two teeth  19 ,  20  and is adapted to receive striker  4 . Ratchet  15  is carried by plate  10  of body  8  in a position parallel to plane P 1  ( FIG. 1 ). 
     A spring  21  ( FIG. 3 ), wound about pin  17 , pushes ratchet  15  in known manner into a release position (not shown), wherein seat  18  faces the same way as seat  14  in body  8 , and so permits engagement and release of striker  4 . Spring  21  has one end (not visible in the enclosed Figures) cooperating with plate  10 , and an opposite end  21   a  cooperating with ratchet  15 . 
     When the door is slammed, ratchet  15  is rotated by striker  4  about axis A to lock or click onto locking mechanism  16 , as explained in detail below, in two different positions: a partially locked or first-click position (not shown), and a fully locked or second-click position ( FIGS. 2 and 3 ), in which striker  4  is locked inside seat  18  and prevented from withdrawing by tooth  19  increasingly closing off receiving portion  14   b  of seat  14 . In the orientation of  FIGS. 2 and 3 , the ratchet  15  will rotate clockwise to enter the release position. 
     In greater detail, in the fully locked position, striker  4  is securely ensconced in seat  18  of ratchet  15  such that the vehicle door is completely closed and door seals (not shown) are compressed. In the partially locked position, striker  4  is loosely secured in seat  18  of ratchet  15  such that the vehicle door is locked but not completely closed against its seals. 
     As ratchet  15  rotates to click onto locking mechanism  16 , the partially locked position is therefore interposed between the release position and the fully locked position. 
     As visible in  FIG. 3 , the fully locked and partially locked positions are defined by locking mechanism  16  engaging respective shoulders  22 ,  23  formed along the peripheral edge of ratchet  15 , on the side delimiting tooth  20  on the opposite side to seat  18 . 
     With reference to  FIGS. 3 to 7 , locking mechanism  16  is arranged in part on face  10   a  of plate  10  and in part on face  10   a  of plate  10 . Locking mechanism  16  basically comprises: a primary pawl  25  movable between a ratchet checking position ( FIG. 3 ), wherein the primary pawl  25  is positioned to keep the ratchet  15  in the partially locked position or in the fully locked position, and a ratchet release position (not shown), wherein the primary pawl  25  permits the movement of the ratchet  15  out of the partially locked position or the fully locked position; an auxiliary ratchet  26  operatively connected to primary pawl  25  and movable between an enabling position ( FIG. 4 ), in which the primary pawl  25  is enabled to move to its ratchet checking position, and a disabling position (not shown), in which the auxiliary ratchet  26  positions the primary pawl  25  to its ratchet release position; and a secondary pawl  27  movable between an auxiliary ratchet holding position (not shown), in which the secondary pawl  27  is positioned to hold auxiliary ratchet  26  in its enabling position, and an auxiliary ratchet release position ( FIG. 4 ), in which the secondary pawl  27  is positioned to permit movement of the auxiliary ratchet  26  to its disabling position. 
     Primary pawl  25 , auxiliary ratchet  26  and secondary pawl  27  are all defined by contoured plates substantially extending along planes parallel to ratchet  15  and to plane P 1 . In particular, primary pawl  25  is arranged on face  10   b  of plate  10  and on one side of ratchet  15  and receiving portion  14   b  of seat  14 , whilst auxiliary ratchet  26  and secondary pawl  27  are arranged on face  10   a  of plate  10 ; in the position in which latch  1  is fixed to the vehicle door ( FIGS. 1 to 3 ), primary pawl  25  is arranged at an upper position than ratchet  15 . 
     As visible in  FIGS. 3 to 7 , auxiliary ratchet  26  is hinged about a fixed pin  28  extending orthogonally through plate  10 , protruding from both faces  10   a ,  10   b  of the plate  10  and having an axis B parallel to axis A. 
     Primary pawl  25  and auxiliary ratchet  26  are operatively connected through a transmission lever  29 , which is arranged on face  10   b  of plate  10  and below the primary pawl  25  and is hinged on the pin  28 . In particular, auxiliary ratchet  26  and transmission lever  29  are hinged on the opposite protruding portions of the same pin  28 ; primary pawl  25  is superimposed on transmission lever  29 . 
     An eccentric element  30 , superimposed on transmission lever  29 , has a central portion  31 , hinged to the portion of pin  28  protruding from face  10   b  of plate  10 , and a radial rounded portion  32  coupled in a complementary seat of primary pawl  25  so as to define a sort of hinging axis for the primary pawl  25 ; in practice, thanks to the connection to eccentric element  30 , primary pawl  25  can rotate about axis B to define ratchet checking position and ratchet release position. 
     Primary pawl  25  defines peripherally a check shoulder  34  extending substantially radially from axis B and adapted to pivot between the ratchet checking position, in which the check shoulder  34  stops the opening urge of the ratchet  15 , as shown in  FIG. 3 , and the ratchet release position, in which the check shoulder  34  does not inhibit rotation of the ratchet  15  to ratchet release position. 
     In the orientation of  FIG. 3 , primary pawl  25  will rotate clockwise to move into the ratchet release position. 
     In particular, check shoulder  34  of primary pawl  25  interacts in use with the shoulders  22 ,  23  of the ratchet  15  to define the fully locked position and the partially locked position, respectively. 
     Transmission lever  29  has one peripheral portion  35 , which is radially spaced from axis B and is coupled to a stub  36  projecting from auxiliary ratchet  26  in a direction parallel to axis B through an opening (not shown) of plate  10 . Transmission lever  29  further comprises an interacting arm  37  angularly spaced from peripheral portion  35  with respect to axis B and adapted to cooperate in use with a protruding arm  38  of primary pawl  25  to move the latter to the ratchet release position. 
     Primary pawl  25  is biased to the ratchet checking position by a spring, known per se and not shown. 
     Auxiliary ratchet  26  ( FIGS. 4 to 7 ) has an elongated shape and extends, for the most part, substantially in a radial direction from pin  28 ; auxiliary ratchet  26  has one end portion  39  hinged to pin and one opposite tooth-shaped end portion  40  cooperating with secondary pawl  27 . 
     In particular, auxiliary ratchet  26  can rotate about axis B between the enabling position, in which the auxiliary ratchet  26  allows the primary pawl  25  to reach and maintain the ratchet checking position, and the disabling position, in which the auxiliary ratchet  26 , through the transmission lever  29 , maintains the primary pawl  25  disengaged from the ratchet  15 . In the orientation of  FIG. 4 , auxiliary ratchet  26  will rotate anticlockwise to enter the disabling position. 
     Auxiliary ratchet  26  is further provided, at its intermediate portion, with a protruding interacting arm  41 , which extends from a peripheral edge of the auxiliary ratchet  26  towards body  9  and is adapted to receive actuating forces from actuator assembly  5 , as it will be explained in greater detail later on. 
     In practice, the intermediate portion of auxiliary ratchet  26  is provided with the stub  36 , which extends through plate  10  to engage peripheral portion  35  of transmission lever  29 , and the interacting arm  41 , which extends transversally with respect to the stub  36  and cooperates with actuator assembly  5 . 
     A spring  42  (only partially shown in  FIG. 4 ), wound about a fixed post extending parallel to pin  28  from face  10   a  of plate  10 , biases auxiliary ratchet  26  to the disabling position. Spring  42  has one end (not shown) cooperating with plate  10 , and one opposite end (not shown) cooperating with stub  36  of auxiliary ratchet  26 . 
     With reference to  FIGS. 4 and 6 , secondary pawl  27  is hinged on a portion of pin  28  protruding from face  10   a  of plate  10  and is arranged to cooperate with tooth-shaped end portion  40  of auxiliary ratchet  26 . 
     With reference to the position of use on the vehicle ( FIGS. 2 to 4 ), secondary pawl  27  is arranged in a position lower than auxiliary ratchet  26  and partially facing the end portion  40  thereof. 
     In particular, secondary pawl  27  defines a check shoulder  45  for interacting with end portion  40  of auxiliary ratchet  26  and comprises an interacting arm  46 , angularly spaced from check shoulder  45  about axis A and adapted to receive actuating forces from actuator assembly  5 , as it will be explained in greater detail later on. 
     Secondary pawl  27  rotates about axis A between the auxiliary ratchet holding position (not shown), in which check shoulder  45  interacts with end portion  40  to stop the urge of the auxiliary ratchet  26  towards the disabling position, and the auxiliary ratchet release position ( FIGS. 4 and 6 ), in which check shoulder  45  is detached from end portion  40  to permit movement of the auxiliary ratchet  26  to its disabling position. Secondary pawl  27  is biased towards the auxiliary ratchet holding position in a known manner by a spring (not shown). 
     With reference to all the enclosed Figures, actuator assembly  5  basically comprises: an electric motor  50 ; a worm gear  51  coaxially coupled to a rotating member  52  of motor  50 ; a first gear wheel  53  meshing with the worm gear  51 ; a second gear wheel  54  angularly integral with gear wheel  53 , i.e. rotating together with gear wheel  53  about a common axis C orthogonal to plane P 2 ; a sector gear  55  meshing with gear wheel  54 ; a first actuating lever  56  driven by sector gear  55  for interacting with arm  41  of auxiliary ratchet  26  so as to move the auxiliary ratchet  26  from the enabling position to the disabling position; and a second actuating lever  57  driven by sector gear  55  for interacting with arm  46  of secondary pawl  27 , so as to move the secondary pawl  27  to the auxiliary ratchet release position (reset function), and with actuating lever  56 , so as to produce movement of the auxiliary ratchet  26  from the disabling position to the enabling position (release function). 
     As shown in particular in  FIGS. 2, 3, 8 and 9 , body  9  internally houses, in a fluid-tight manner, electronic control unit  6 , electric motor  50 , worm gear  51  and gear wheel  53 ; the other components of actuator assembly  5 , i.e. gear wheel  54 , sector gear  55  and actuating levers  56 ,  57 , are all externally carried by body  9 . Gear wheels  53  and  54  are both fitted onto a common shaft  58  of axis C, externally protruding, in a fluid-tight manner, from body  9 . 
     In practice, worm gear  51  and gear wheel  53  define a first transmission  48  housed, in a fluid-tight manner, inside body  9  and directly driven by electric motor  50 , whilst gear wheel  54  and sector gear  55  define a second transmission  49  functionally interposed between transmission  48  and actuating lever  57  and carried externally by body  9 . Transmissions  48  and  49  are operatively coupled by shaft  58 , which crosses body  9  in a fluid-tight manner through the interposition of a sealing element, such as a gasket (known per se and not shown). 
     According to a preferred embodiment of the present invention (see in particular  FIG. 9 ), body  9  has a sandwich structure and defines two distinct chambers  59 ,  60 , one of which (chamber  59 ) houses, in a fluid-tight manner, control unit  6  and the other one (chamber  60 ) houses, in a fluid-tight manner, electric motor  50  and transmission  48 , i.e. worm gear  51  and gear wheel  53 . More specifically, body  9  comprises a central plate  61  and two cover elements  62 ,  63 , arranged on opposite sides of plate  61  and peripherally coupled thereto in a fluid-tight manner to define the opposite chambers  59 ,  60 . 
     As visible in  FIGS. 1 and 8 , cover element  62  faces towards face  10   a  of plate  10  of body  8  and delimits, with plate  61 , chamber  59 ; as shown in  FIG. 9 , chamber  59  houses printed circuit board  7  and a plurality of capacitors  64  connected to printed circuit board  7  and making part of control unit  6 . 
     Cover element  63  delimits, with plate  61 , chamber  60  and carries externally gear wheel  54 , sector gear  55  and actuating levers  56 ,  57 . In particular, shaft  58 , carrying gear wheels  53  and  54 , crosses cover element  63  in a fluid-tight manner through the interposition of the above-mentioned sealing element, such as a gasket (not visible). 
     Plate  61  defines a plurality of seats for capacitors  64 ; the connection of the capacitors  64  to the printed circuit board  7  is made by press-fit connectors, known per se and not shown. 
     Cover element  62  defines a plurality of seats for electric motor  50 , worm gear  51  and gear wheel  53 , which are closed on the opposite side by plate  61 . Cover element  62  also houses an electric connector  65  for connecting control unit  6  to the electric plant of the vehicle. 
     With reference to  FIGS. 2, 3, 4, 8 and 9 , electric motor  50  is housed in the portion of cover element  62  defining the upper part of body  9  in the use position; gear wheels  53 ,  54 , sector gear  55  and actuating levers  56 ,  57  are all arranged inferiorly with respect to electric motor  50 . 
     Moreover, as visible in  FIGS. 1 to 8 , gear wheels  53 ,  54 , sector gear  55  and actuating levers  56 ,  57  lye on planes, which are substantially parallel to plane P 2 ; in particular, gear wheel  54  and sector gear  55  lye on a common plane, whilst gear wheel  53  and actuating levers  56 ,  57  lye on respective distinct planes parallel to one another and to plane P 2 . 
     Electric motor  50  and worm gear  51  have an axis D parallel to plane P 2 , transversal to plane P 1  (see in particular  FIG. 1 ) and orthogonal to axis C. Electric motor  50  and worm gear  51  are rotated in opposite directions to perform release function and reset function respectively. 
     Gear wheels  53  and  54  are mounted for rotation about axis C and receive actuation forces from worm gear  51 ; in greater detail, gear wheel  53  is driven by worm gear  51  and is angularly coupled to gear wheel  54  by means of shaft  58 . 
     Sector gear  55  ( FIGS. 2 to 8 ) is mounted for rotation about a fixed pin  66  having an axis E parallel to axis C and spaced therefrom; sector gear  55  meshes with gear wheel  54  so as to receive driving forces therefrom. 
     As visible in  FIGS. 4 to 6 , sector gear  55  comprises a disk  67  having, along a portion of its outline, a plurality of teeth  68  meshing with corresponding teeth of gear wheel  54 . 
     Sector gear  55  further comprises three cam surfaces  69 ,  70 ,  71  for interacting with actuating levers  56 ,  57 , as it will be explained in detail later on. 
     Cam surface  69  is defined by a protruding edge of disk  67  and is adapted to cooperate with actuating lever  57  to move the latter along a release stroke, during which the actuating lever  57  produces rotation of secondary pawl  27  from the auxiliary ratchet holding position to the auxiliary ratchet release position. 
     Cam surfaces  70  and  71  are provided on the opposite sides of a rib  73  protruding frontally from disk  67  and extending substantially along a radial direction with respect to axis E. 
     Cam surface  70  acts in the same direction as cam surface  69  and is adapted to cooperate with actuating lever  56  to move the latter along a release stroke, during which the actuating lever  56  produces rotation of auxiliary ratchet  26  from the enabling position to the disabling position. 
     Cam surface  71  acts in a direction opposite to direction of action of cam surfaces  69 ,  70  and is adapted to cooperate with actuating lever  57  to move the latter along a reset stroke, during which the actuating lever  57  produces, through actuating lever  56 , rotation of auxiliary ratchet  26  from the disabling position to the enabling position. 
     In particular, sector gear  55  is rotated by electric motor  50 , worm gear  51  and gear wheels  53 ,  54  about axis E in a first direction (clockwise in  FIGS. 4 to 6 ) to produce release of the latch  1 , and in a second direction (anticlockwise in  FIGS. 4 to 6 ), opposite to the first direction, to obtain reset of auxiliary ratchet to the enabling position, in which the auxiliary ratchet  26  allows closure of the latch  1  by slamming the door. In the following description, the rotation of sector gear  55  in the first direction will be referred to as “release rotation” and the opposite rotation of the sector gear  55  in the second direction will be referred to as “reset rotation”. 
     By considering the release rotation of sector gear  55  about axis E, cam surface  69  is arranged downstream of cam surface  70 , which is in turn arranged downstream of cam surface  71 . 
     With particular reference to  FIGS. 5 to 7 , actuating levers  56 ,  57  have elongated shapes and extend along respective longitudinal directions F, G parallel to one another and to both planes P 1  and P 2 . More specifically, actuating lever  57  is arranged adjacent to sector gear  55 , whilst actuating lever is placed on the opposite side of actuating lever  57  with respect to sector gear  55 . Actuating levers  56 ,  57  are carried by body  9  in a displaceable manner along respective longitudinal directions F, G. Release and reset strokes of actuating levers  56 ,  57  are defined by opposite movements of such levers  56 ,  57  along the respective longitudinal directions F, G. 
     In the example shown, the release stroke is defined by movements of actuating levers  56 ,  57  away from electric motor  50 , whilst the reset stroke is defined by movements of actuating levers  56 ,  57  towards electric motor  50 . 
     Actuating lever  57  has, at its opposite end portions, respective through slots  75 ,  76  extending along direction G and comprises, at its intermediate portion, a first protrusion  77 , adapted to receive actuating forces from cam surface  69  during the release rotation of sector gear  55 , and a second protrusion  78  adapted to cooperate with cam surface  71  during the reset rotation of sector gear  55 . In the example shown, slot  75  is adjacent to electric motor  50  and protrusion  78  is adjacent to slot  75 ; protrusion  77  is instead adjacent to slot  76 . 
     Actuating lever  57  further comprises, at its intermediate portion, a protruding arm  79  adapted to cooperate with arm  46  of secondary pawl  27  to move the secondary pawl  27  from the auxiliary ratchet holding position to the auxiliary ratchet release position. 
     It should be noted that slot  76  is longer than slot  75  along direction G for the reason that will be clarified later on. 
     Actuating lever  56  has, at one end portion, a through slot  80  facing slot  76  of actuating lever  57  and extending along direction F; slots  76  and  78  are both engaged, with play along respective directions F, G, by a fixed post  74 , which is carried by body  9  and extends along an axis H parallel to axes C, E; actuating levers  56  and  57  can slide with respect to post  74  along the respective directions F, G through the guiding action performed by slots  76  and  78 . 
     Actuating lever  56  has, at its opposite end portion, a protruding stub  81  engaging slot  75  of actuating lever  57  with play along direction G. Stub  81  and the edge of slot  75  are slidingly coupled to one another along the respective directions F, G. 
     Actuating lever  56  further comprises an intermediate protrusion  82  adapted to receive actuating forces from cam surface  70  during the release rotation of sector gear  55 . 
     Actuating lever  56  finally comprises a fork portion  83  arranged adjacent to stub  81 , protruding towards face  10   a  of plate  10  and engaged by arm  41  of auxiliary ratchet  26  to move the latter from the enabling position to the disabling position and vice versa. 
     According to a preferred embodiment of the present invention, fork portion  83  is defined by a rigid post  84  protruding from actuating lever  56  and by a first tang  85  of a spring  86  wound about stub  81  and having a second tang  87  engaging an opening  88  formed in the end portion of actuating lever  56  carrying the stub  81 . 
     By considering the direction of rotation of auxiliary ratchet  26  about axis B from the enabling position to the disabling position, tang  85  is arranged downstream of rigid post  84 . 
     In practice, auxiliary ratchet  26  is pushed towards the disabling position by rigid post  84  of actuating lever  56  and is displaced to the enabling position by tang  85  of spring  86  interposed between the actuating lever  56  and the auxiliary ratchet  26 . In this way, when auxiliary ratchet  26  has reached the enabling position, a possible undesired stop of electric motor  50  in an overrun position at the end of the reset rotation imparted to sector gear  55  only causes a tensioning of spring  86 , without any undesired stress on the electric motor  50 . 
     Abutment along direction G of opposite edge end portions of slot  76  against fixed post  74  defines a release position and a reset position of actuating lever  57 . 
     In a completely analogous manner, abutment along direction F of opposite edge end portions of slot  80  against fixed post  74  defines a release position and a reset position of actuating lever  56 . 
     Preferably, actuating lever  57  is biased by a spring, known per se and not shown, towards an intermediate position between release and reset position; this intermediate position is defined by abutment between stub  81  and the edge end of slot  75  arranged upstream of the stub  81  along the reset stroke. 
     During a first part of the release rotation of sector gear  55 , imparted by a rotation of electric motor  50  in the direction to perform the release function of the latch  1 , cam surface  69  acts on protrusion  77 , and slot  75  and stub  81  allow an independent displacement of actuating lever  57  along direction G with respect to actuating lever  56  and towards the release position; the subsequent interaction of cam surface  70  with protrusion produces a corresponding displacement of actuating lever  56  in the same direction as actuating lever  57  and towards the release position. 
     During the reset rotation of sector gear  55 , imparted by a rotation of electric motor  50  in the direction to perform the reset function of the latch  1 , cam surface  71  acts on protrusion  78 , and the edge of slot  75  in contact with stub  81  in the intermediate position of actuating lever  57  pushes the stub  81  so as to produce the same displacement of both actuating levers  56 ,  57  along the respective directions F, G towards the reset positions. 
     In practice, slot  75  and stub  81  define coupling means  85  for connecting actuating levers  56 ,  57  and which are active during a reset rotation of sector gear  55  to move said levers  56 ,  57  together and to produce displacement of auxiliary ratchet  26  from the disabling position to the enabling position through the action of fork portion  83 . 
     In use, starting from a closed condition, the latch  1  is released by activating electric motor  50  so as to obtain a rotation of gear wheels  53 ,  54  about axis C in a clockwise direction with reference to  FIGS. 2, 3, 7, 8  and in an anticlockwise direction with reference to  FIGS. 4, 5, 6, 9 . This movement of gear wheels  53 ,  54  produces the release rotation of sector gear  55  about axis E (anticlockwise in  FIGS. 2, 3, 7, 8  and clockwise in  FIGS. 4, 5, 6, 9 ). 
     During a first part of the release rotation of sector gear  55 , cam surface  69  interacts with protrusion  77  of actuating lever  57  so causing the release stroke of the actuating lever  57  along direction G; in practice, actuating lever  57  moves towards its release position, so causing a rotation of secondary pawl  27  about axis A from the auxiliary ratchet holding position to the auxiliary ratchet release position; in particular, the rotation of secondary pawl  27  towards the auxiliary ratchet release position is obtained through the interaction of arm  79  of actuating lever  57  with arm  46  of the secondary pawl  27  ( FIG. 6 ). 
     Under the thrust of spring  42 , auxiliary ratchet  26  is therefore free to rotate about axis B into its disabling position. Should the spring action be insufficient, the interaction of cam surface  70  of rib  73  of sector gear  55  on protrusion  82  of actuating lever  56  produces the release stroke of the actuating lever  56  along direction F with the consequent pushing action of rigid post  84  of fork portion  83  on arm  41  of auxiliary ratchet  26 . 
     At the end of its release stroke, actuating lever  57  is biased by its spring to its intermediate position, in which the edge end of slot  75 , arranged downstream of stub  81  of actuating lever  56  along the release stroke (lower edge end in  FIGS. 2, 3, 5, 7 and 8 ), abuts against the stub  81 . 
     Therefore, the result of the movement imparted by the activation of electric motor  50  is a rotation of secondary pawl  27  into the auxiliary ratchet release position and a consequent rotation of auxiliary ratchet into the disabling position. This latter rotation produces a corresponding rotation of transmission lever  29 , which, through the interaction of its arm  37  with arm of primary pawl  25 , produces the rotation of the primary pawl  25  about axis B so as to free ratchet  15 . 
     In this condition, the ratchet  15  can rotate about axis A into the release position under the thrust of spring  21  so freeing striker  4  and allowing opening of the door. 
     Immediately after the release of the latch  1 , electric motor  50  is again activated in the opposite direction so as to produce a rotation of gear wheels  53 , about axis C in an anticlockwise direction with reference to  FIGS. 2, 3, 7, 8  and in a clockwise direction with reference to  FIGS. 4, 5, 6, 9 . This movement of gear wheels  53 ,  54  produces the reset rotation of sector gear  55  about axis E (clockwise in  FIGS. 2, 3, 7, 8  and anticlockwise in  FIGS. 4, 5, 6, 9 ). 
     During the release rotation of sector gear  55 , cam surface  71  of rib  73  interacts with protrusion  78  of actuating lever  57  so causing the reset stroke of the actuating lever  57  along direction G; in practice, actuating lever  57  moves towards its reset position. Due to the cooperation of the lower edge end of slot  75  with stub  81 , actuating levers  56 ,  57  are moved together in their respective directions F, G along their reset strokes. 
     This movement produces a rotation of auxiliary ratchet  26  about axis B into its enabling position; therefore, the secondary pawl  27  can return to its auxiliary ratchet holding position under the thrust of its spring; in practice, auxiliary ratchet  26  is retained in its enabling position by engagement of its end portion  40  with shoulder  45  of secondary pawl  27 . 
     The reset rotation of auxiliary ratchet  26  is obtained through the pushing action of tang  85  of spring  86  of actuating lever  56  on arm  41  of auxiliary ratchet  26 . 
     When the door is slammed an impact of striker  4  is produced on tooth  20  of ratchet  15  with a consequent anticlockwise rotation of the ratchet  15  about axis A in opposition to spring  21 . As shoulder  22  of ratchet  15  is pushed past primary pawl  25 , the latter clicks further towards the ratchet  15  with its free end positioned in front of the shoulder  22 ; ratchet  15  is thus prevented from being sprung back by spring  21  into the release position by shoulder  22  resting against the free end of the primary pawl  25 , and so remains locked in the fully locked position, in which tooth  19  closes off seat  14  of support body  8  to prevent withdrawal of striker  4  from opening  12  ( FIGS. 2 and 3 ). 
     The advantages of electrical latch  1  according to the present invention will be clear from the foregoing description. 
     In particular, thanks to the fact that printed circuit board  7  is carried by support assembly  2  in a position substantially orthogonal to the plane of ratchet  15 , the thickness of latch  1 , in the direction orthogonal to the door edge to which the latch  1  is secured, is appreciably reduced with respect to the corresponding thickness of known latches. This configuration therefore has no impact on the shape and design of the window glass and the window glass channel. 
     Moreover, the configuration according to the present invention permits to separate the electrical part of the latch  1  from the purely mechanical part (closure mechanism  3 ). In this way, the electronic control unit  6  and the electronic motor  50  can be housed inside a fluid-tight support body  9  completely isolated from the rest of the latch  1 . 
     Preferably, a mechanical part of actuator assembly  5  is also housed inside the support body, so being protected by damp and water, which may transform into ice in case of low temperatures and may cause functioning problems. 
     Last but not least, the mechanical part of the latch  1  is smaller than that of known latches and consists of a very few components that can be easily installed in several different environments and easily customized when required. 
     Clearly, changes may be made to the vehicle latch  1  as described and illustrated herein without, however, departing from the scope of protection as defined in the accompanying claims. 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.