Abstract:
A motor vehicle wiper articulated on a wiper arm by a connector provided with a sliding lock co-operating with a transverse element of the blade for fixing the connector on the blade. The lock includes a control plate capable of elastic deformation along a direction perpendicular to the lock sliding direction and bears means for blocking the lock which, when the lock is free in the locking position, co-operate with matching means integral with the blade for blocking the lock, and, further, when the control plate is deformed, are released from the matching means for enabling the lock to slide.

Description:
BACKGROUND 
     The invention concerns a motor vehicle wiper having a safety lock. 
     The invention more specifically concerns a motor vehicle windshield wiper of the type in which the wiper blade is articulated at a free end of a wiper arm by means of a connector which straddles a blade connection portion and which is provided with two parallel longitudinal wings between which a transverse element extends. The connector has a lock that slides between an unlocked position and a locked position in which it cooperates with the transverse element of the blade in order to ensure the attachment of the connector on the blade, and the lock having an upper manipulation plate. 
     A windshield wiper of this type is known, for example, from FR-A-2700 309. This type of wiper is particularly advantageous in that it makes easy mounting and removal of the wiper blade possible even by a user with little experience. 
     SUMMARY 
     The invention aims to propose a new improved design of the sliding lock which makes it possible to further increase the reliability of the catching thus brought about without increasing its complexity or cost. 
     For this purpose, the invention proposes a windshield wipe of the initially described type characterized by the fact that the upper manipulation plate is elastically deformable in a direction perpendicular to the sliding direction of the lock, and by the fact that the upper manipulation plate carries a means of immobilizing the lock that, when the lock is in the free state in a locked position, cooperates with a complementary means connected to the blade in order to immobilize the lock, and that, when the plate is deformed, disengages from the complementary means in order to make possible the sliding of the lock. 
     According to other characteristics of the invention: 
     the lock has a catching means that extends downward from a bottom surface of the manipulation plate and is intended to cooperate, when the lock is in locked position, with a bottom surface of the transverse element, with the catching means carrying the means of immobilizing the lock; 
     the immobilization means consists of a finger with a vertical orientation, and the complementary means consists of a complementary recess in which the finger is held when the lock is in the free state; 
     the immobilization finger extends vertically upward from the catching means, and the recess is formed in the lower surface of the transverse element; 
     the upper manipulation plate comprises, at each of its longitudinal ends, a guide means for sliding the lock on the connector, and a central part of the plate, which carries the catching means and which can be vertically displaced by elastic deformation of the plate; and 
     in the free state, the upper plate has a cross section in the form of an arc of a circle with downward concavity. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     Other characteristics and advantages of the invention will appear upon reading the detailed description which follows, for whose comprehension reference will be made to the appended drawings in which: 
     FIG. 1 is an exploded perspective view of a wiper according to the present invention; 
     FIG. 2 is a longitudinal cross section of the wiper of FIG. 1, with the lock in a locked position; 
     FIG. 3 is a view similar to that of FIG. 2, of the lock when its manipulation plate is deformed; and 
     FIG. 4 is a view similar to that of FIG. 3, with the lock in unlocked position. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 shows connection portion  10  of motor vehicle wiper blade  12 . Connection portion  10  is formed, e.g., by the central portion of a main stirrup piece of blade  12 . Connection portion  10  essentially has two parallel longitudinal wings  14  that run along the longitudinal direction of blade  12 . 
     Blade  12  is intended to be mounted at free longitudinal end  16  of wiper arm  18  that has the function, on the one hand, of laying blade  12  against the glass to be wiped, and, on the other hand, of moving the blade in an alternating sweeping motion so that it moves along the glass. 
     Blade  12  is intended to be articulated on arm  18  by means of connector  20 , which is mounted in an articulated manner so as to rotate about transverse axis Al on arm  18  and which is attached on connection portion  10  of blade  12 . 
     Connector  20  is generally fabricated from plastic, and it essentially has two lateral flanges  22  joined by transverse upper back  24 . The connector thus has the form of an upside-down U in cross section and connector  20  is intended to straddle connection portion  10  of blade  12 , the two wings  14  of which are held between the two flanges  22  of connector  20 . 
     Each of flanges  22  of connector  20  has a cylindrical trunnion  26  that extends transversely outward so that it can be held in opening  28  formed in each of two cheeks  30  of free end  16  of arm  18 . The two cheeks  30  are longitudinally parallel and form a fork, and flanges  22  of connector  20  are held transversely between the two cheeks  30 . 
     Trunnions  26  therefore ensure the mounting of connector  20  so that it can rotate with respect to arm  18 . In the embodiment example illustrated in FIG. 1, intermediate piece  32  is interposed between connector  20  and free end  16  of arm  18  in order to limit operating play and, at the same time, to reduce the wear and tear and noise which can result from the relative movement of connector  20  with respect to arm  18 . 
     In a known manner, connector  20  has some means for ensuring its close attachment to connection portion  10  of blade  12 . 
     As can be seen in FIG. 1, the stirrup piece of blade  12  has transverse upper back  34  which connects the two wings  14  outside of connection portion  10 , which is therefore delimited longitudinally by two transverse edges  36 ,  38  of back  34 . 
     In order to ensure the complete immobilization of connector  20  with respect to arm  12 , it is therefore sufficient to prevent any movement of upward vertical withdrawal of connector  20  from connection portion  10 . 
     For this purpose, connector  20  has sliding lock  40  which is mounted so that it can slide in opening  42  formed in upper back  24  of connector  20 . Lock  40  is intended to cooperate with transverse element  44 , which connects the two wings  14  of connection portion  10 . 
     In this embodiment example of the invention, transverse element  44  of blade  12  is produced in a single piece with wings  14  of connection portion  10 . 
     Transverse element  44  is in the form of a horizontal plate that connects the two upper longitudinal edges of wings  14  over a part of the length of connection portion  10 . 
     Moreover, transverse element  44  has longitudinal slot  50  that extends longitudinally over approximately three-quarters of its length and that opens longitudinally into front edge  52  of transverse element  44 . Slot  50  is formed to be symmetrical with respect to the center of the two wings  14  along the transverse direction. 
     Sliding lock  40  essentially has approximately horizontal upper manipulation plate  54 , from the bottom surface of which extends vertical foot  56 , which, when connector  20  is mounted on connection portion  10  of blade  12 , extends between the two wings  14  of blade  12 . 
     At its lower end, foot  56  has two opposing protuberances  64  that extend transversely outward. 
     Lock  40  is intended to slide with respect to connector  20  and with respect to blade  12  between a moved-forward unlocked position, in which at least protuberances  64  are arranged longitudinally ahead of front edge  52  of transverse element  44 , and a moved-back locked position, in which foot  56  is arranged across slot  50 , with protuberances  64  arranged below the level of transverse element  44 . Thus, as can be seen in FIG. 2, upper surfaces  66  of protuberances  64  vertically face lower surfaces  68  of transverse element  44  which are arranged transversely on both sides of slot  50 , preventing any withdrawal upward of the connector  20  and lock  40  assembly with respect to blade  12 . 
     Furthermore, longitudinally, immediately behind slot  50 , transverse element  44  has hole  74  that is intended to hold finger  76  that extends vertically at the free end of horizontal bar  78  that extends longitudinally towards the rear from a lower end of foot  56 , approximately in the same horizontal plane as protuberances  64 . As can be seen in FIG. 2, when the connector is moved back in the locked position, finger  76  of bar  78  engages with hole  74  in order to ensure the immobilization of lock  40 . In contrast, as can be seen in FIG. 4, when the lock is in moved-forward unlocked position, bar  78  and its finger  76  are arranged vertically facing slot  50 , which ensures the possibility of mounting or removal of connector  20  and of its lock  40  with respect to blade  12  by simple vertical displacement. 
     According to the teachings of the invention, the passage of lock  40  from its locking position to its unlocked position cannot occur unintentionally. 
     In effect, bar  78  is relatively rigid so that when finger  76  engages with hole  74 , lock  40  cannot move forward toward its unlocked position. 
     In contrast, it is provided that the upper manipulation plate of lock  40  is elastically deformable between a free position illustrated in FIGS. 2 and 4 and a deformed position illustrated in FIG.  3 . 
     In its free state, manipulation plate  54  extends approximately in the form of an arc of circle with downward concavity so that it cooperates with guide rails  62 , which form the longitudinal edges of opening  42  of connector  20 , only at its two longitudinal ends. As can be seen particularly in FIG. 1, manipulation plate  54  of lock  40  in effect has, at each of its longitudinal ends, a means  60  guiding its longitudinal sliding along rails  62  of connector  20 , without preventing the vertical displacement of the central part of plate  54  when it is deformed. 
     The central part of manipulation plate  54 , from which catching foot  56  extends downward, therefore at that time extends above the level of its two longitudinal ends, so that foot  56  occupies a high position with respect to blade  12 . In this position, when lock  40  is in the locked position, finger  76  is completely engaged in hole  74 , as can be seen in FIG.  2 . 
     In contrast, as represented in FIG. 3, when the user compresses plate  54  by pressing vertically downward on its central portion, a flattening of plate  54  occurs, so that catching foot  56  is brought towards a low position with respect to blade  12 . With horizontal bar  78  connected to the lower end of catching foot  56 , finger  76  is then disengaged vertically downward from hole  74 . 
     Once finger  76  disengages, the user can then make lock  40  slide forward toward its unlocked position illustrated in FIG.  4 . 
     This design of lock  40  makes it possible to ensure that lock  40  cannot accidentally go from its locked position to its unlocked position, even under the effect of intense vibration or of impact from an object. 
     In the embodiment of the invention, the immobilization of lock  40  is only provided in its locked position. However, it is also possible, without deviating from the scope of the invention, that lock  40  be immobilized in its unlocked position. 
     Likewise, it is also possible that the immobilization of lock  40  be ensured by the cooperation of an element of lock  40  with connector element  20 .