Abstract:
A wiper blade rubber for a windshield wiper has a holding portion held by a plurality of supporting members, a wiping portion for wiping the surface of a windshield and a connecting portion connecting the holding portion and the wiping portion. The connecting portion is narrowed in a middle part thereof providing a neck portion, and has an inside hollow. The hollow extends vertically in the neck portion and horizontally above the neck portion, with respect to the windshield, thereby having a T-shaped cross-section in the connecting portion. Preferably, the hollow extends into the wiping portion. Therefore, when the wiper blade rubber turns over the inclining direction of the wiping portion, the wiper blade rubber can suppress changes in the height of the wiper blade rubber by deforming the hollow, while keeping an appropriate inclining angle of the wiping portion.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application relates to and incorporates herein by reference Japanese Patent Application No. 9-177757 filed on Jun. 18, 1997. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a wiper blade rubber for a windshield wiper which turns back and forth on the windshield of a vehicle. 
     2. Related Art 
     A conventional windshield wiper for wiping the windshield of a vehicle has a wiper blade rubber. The wiper blade rubber is inclined against the windshield while wiping the windshield so that the windshield is wiped effectively. The wiper blade rubber has a neck portion having a narrowed shape, and a wiping portion connecting to the neck portion. When the wiper blade rubber wipes the windshield, the neck portion is bent so that the wiping portion is inclined, leading to an effective wiping. 
     Further, the conventional windshield wiper turns back and forth. Therefore, when the windshield wiper turns over, an inclining direction of the wiping portion against the windshield is also reversed while changing the height of the wiper blade rubber from the windshield. Specifically, the inclining direction of the wiping portion is reversed with a top end of the wiping portion as a center. The top end of the wiping portion contacts the windshield surface to be wiped. Therefore, the height of the wiper blade rubber is maximum when the wiping portion stands upright during changing of the inclining direction, and is minimum when the wiping portion is inclined to a maximum degree. However, when the height of the wiper blade rubber changes, a harsh noise may sounds. 
     To decrease the noise, JP-A-2-162142 proposes to form an arc portion in a wiper blade rubber so that the inclining direction of a moving portion (i.e., wiping portion) is turned over smoothly using the arc portion. However, in the wiper blade rubber according to JP-A-2-162142, the moving portion and a fixed portion of the wiper blade rubber may slide in a lateral direction, resulting in that the moving portion fails to be inclined. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a wiper blade rubber which suppresses changes in the height of the wiper blade rubber when the inclining direction of the wiper blade rubber is reversed, while keeping a wiping portion of the wiper blade rubber being inclined appropriately. 
     According to the present invention, a wiper blade rubber has a holding portion being held by a supporting member, a wiping portion for wiping the windshield of a vehicle and a connecting portion for connecting the holding portion and the wiping portion. The connecting portion has a neck portion having a narrowed cross-section, and has an inside hollow. The hollow extends vertically in the neck portion and horizontally above the neck portion, with respect to the windshield, thus having a T-shaped cross-section. Therefore, the connecting portion is readily bent due to the neck portion so that the wiping portion is inclined. Further, the connecting portion is readily deformed vertically with respect to the windshield due to the hollow. Therefore, the wiper blade rubber can suppress changes in the height of the wiper blade rubber when turning over the inclining direction of the wiper blade rubber, reducing a harsh noise generated due to friction between the wiper blade rubber and the windshield. 
     Preferably, the wiping portion has a shoulder portion for limiting the inclining angle of the wiping portion. When the wiping portion is inclined during wiping, the shoulder portion touches the connecting portion so that the wiping portion is inclined at an appropriate angle. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects and features of the present invention will become more readily apparent from a better understanding of the preferred embodiments described below with reference to the accompanying drawings, in which: 
     FIG. 1A is a cross-sectional view showing a wiper blade rubber in a first embodiment of the present invention; 
     FIG. 1B is a cross-sectional view showing the wiper blade rubber while wiping a windshield in the first embodiment; 
     FIG. 1C is a cross-sectional view showing the wiper blade rubber while turning over its inclining direction in the first embodiment; 
     FIG. 2A is a cross-sectional view showing a wiper blade rubber in a second embodiment of the present invention; 
     FIG. 2B is a cross-sectional view showing the wiper blade rubber while wiping a windshield in the second embodiment; and 
     FIG. 2C is a cross-sectional view showing the wiper blade rubber while turning over its inclining direction in the second embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention will be described hereinafter with reference to the accompanying drawings. 
     (First Embodiment) 
     As shown in FIG. 1A, a wiper blade rubber  10  has a holding portion  12 , a connecting portion  14  and a wiping portion  16 . These portions are elongated and integrally formed. The holding portion  12  is held by a plurality of supporting members  20  at a plurality of points disposed in a longitudinal direction of the holding portion  12 . The supporting members  20  are part of a wiper blade connector (not shown) and are connected to a wiper arm (not shown) through the wiper blade connector. Therefore, when the wiper arm moves arcuately, the wiper blade rubber  10  moves arcuately as well. 
     The holding portion  12  contains a backing  11  therein extending in a longitudinal direction thereof to provide reinforcement. Due to the backing  11 , pressure (i.e., wiper arm pressure) incurred by the holding portion  12  is dispersed in a longitudinal direction of the holding portion  12 . The wiping portion  16  has a pair of shoulder portions  16   a  and an edge portion  16   b.  The wiping portion  16  is formed in substantially a triangle shape. The edge portion  16   b  of the wiping portion  16  is thinned to improve wiping performance of the wiper blade rubber  10 . 
     The connecting portion  14  has a base portion  14   a  which extends from the holding portion  12  and a neck portion  18 . The neck portion  18  which extends from the base portion  14   a  becomes thinner gradually and is thickened again toward the shoulder portions  16   a  to have a narrowed cross-section, as shown in FIG.  1 A. The base portion  14   a  and the wiping portion  16  are connected by the neck portion  18 . The neck portion  18  can be bent readily due to its reduced thickness. Therefore, the wiping portion  16  can be readily inclined by the bending of the neck portion  18 . 
     The connecting portion  14  has an inside hollow  22 . The hollow  22  extends in the horizontal direction in FIG. 1A in the base portion  14   a,  and in the vertical direction in FIG. 1A in the neck portion  18  so that the hollow  22  has a T-shaped cross-section. Further, the hollow  22  extends downward (i.e., toward the edge portion  16   a ) leading to the wiping portion  16 . In the joint area between the base portion  14   a  and the neck portion  18  the connecting portion  14  is gently curved in section. The hollow  22  is gently curved corresponding to a gentle curve of an outline of the connecting portion  14  so that the neck portion  18  has a substantially uniform thickness. Further, the whole connecting portion  14  has a circular sectional shape facing the hollow  22 . Therefore, the connecting portion  14  can be deformed continuously while preventing stress from being applied intensively due to deformation. 
     Further, the width of a cross-section of the hollow  22  in the base portion  14   a  in the horizontal direction in FIG. 1A is larger than the width of a cross-section of the neck portion  18  in the horizontal direction in FIG.  1 A. This enables the neck portion  18  to be readily deformed in the vertical direction in FIG.  1 A. Furthermore, the hollow  22  in the base portion  14   a  has an acute angle on the side of the connecting portion  14 . This also enables the neck portion  18  to be readily deformed in the vertical direction in FIG.  1 A. 
     Thus, the neck portion  18  can be bent readily due to the hollow  22  formed inside of the neck portion  18 . Further, the connecting portion  14  can also be deformed in the vertical direction in FIG. 1A because of the hollow  22  formed inside of the base portion  14   a.    
     Next, an operation of the wiper blade rubber  10  will be explained specifically. As shown in FIG. 1B, when the wiper arm (not shown) moves arcuately, the wiper blade rubber  10  moves as the supporting member  20  connected to the wiper arm moves in the direction indicated by arrow I. The wiping portion  16  of the wiper blade rubber  10  wipes a surface  24   a  to be wiped of a windshield  24 . 
     During this wiping, the wiping portion  16  is inclined so that the edge portion  16   b  is left behind with respect to a moving direction of the holding portion  12 . This inclining of the wiping portion  16  is made possible by deformation of the connecting portion  14 . That is, the wiping portion  16  is inclined by the bending of the neck portion  18  of the connecting portion  14 . The hollow  22  formed inside the connecting portion  14  enables the neck portion  18  to bend more readily. 
     Further, the whole connecting portion  14  can also be bent readily because the hollow  22  extends in not only neck portion  18  but also the base portion  14   a.  Thus, the wiping portion  16  can be readily inclined by the bending of the whole connecting portion  14 . 
     Furthermore, the shoulder portion  16   a  of the wiping portion  16  touches the lower end of the base portion  14   a  of the connecting portion  14 , limiting the inclining angle of the wiping portion  16 . Therefore, the wiping portion  16  can be inclined at an appropriate angle. 
     Next, as shown in FIG. 1C, when the wiper arm turns over while moving back and forth, the connecting portion  14  of the wiper blade rubber  10  is deformed in the vertical direction in FIG.  1 C. Specifically, the connecting portion  14  is deformed so that the neck portion  18  is inserted inside the base portion  14   a.  This is made possible by the hollow  22  extending in the horizontal direction in FIG. 1C in the base portion  14   a.    
     Thus, the connecting portion  14  can suppress changes in the height of the wiper blade rubber  10 . That is, the height of the wiper blade rubber  10  is tentatively increased when inclining direction of the wiper blade rubber  10  is turned over. However, the changes in the height of the wiper blade rubber  10  can be decreased by the connecting portion  14 . This reduces a harsh noise when the wiper blade rubber  10  turns over the inclining direction. 
     In the first embodiment, the neck portion  18  is greatly deformed when the wiper blade rubber  10  turns over the inclining direction. Therefore, if snow is filled in a recess existing around the neck portion  18 , snow can be removed readily when the wiper blade rubber  10  turns over the inclining direction. When a surface of the neck portion  18  has a repellency, snow can be removed more readily. 
     (Second Embodiment) 
     As shown in FIG. 2, similarly to the first embodiment, a wiper blade rubber  30  has a holding portion  32 , a connecting portion  34  and a wiping portion  36 . The connecting portion  34  has a neck portion  38 . A hollow  42  is formed extending both inside the connecting portion  34  and the wiping portion  36 . The holding portion  32  is held by a plurality of supporting members  40 . The holding portion  32  and the supporting members  40  respectively have the same structures as the holding portion  12  and the supporting members  20  in the first embodiment. The wiping portion  36  operates substantially similarly to the wiping portion  16  in the first embodiment although a shoulder portion  36   a  is more sloping in section compared to the shoulder portion  16   a.  The neck portion  38  also operates substantially similarly to the neck portion  18  in the first embodiment although the neck portion  38  has a more roundish sectional shape compared to the neck portion  18  due to the shape of the shoulder portion  36   a.    
     In the second embodiment, a shape of the hollow  42  is different from the shape of the hollow  22  in the first embodiment. As shown in FIG. 2A, the hollow  42  extends in the horizontal direction in FIG. 2A in the base portion  34   a,  and extends in the vertical direction in FIG. 2B in the neck portion  28 . The hollow  42  further extends downward to the wiping portion  36 . In the second embodiment, the hollow  42  extends in the horizontal or lateral direction in the wiping portion  36 . Therefore, the hollow  42  is narrowed in the middle corresponding to the outline of the neck portion  38 . 
     According to the second embodiment, the connecting portion  34  can be readily bent at the neck portion  38 . Therefore, as shown in FIG. 2B, when the wiping portion  36  wipes the surface  24   a  to be wiped of a windshield  24 , the wiping portion  36  is readily inclined by the bending of the neck portion  38 . Moreover, the neck portion  38  can be readily bent due to the hollow  42 . 
     Further, the connecting portion  34  can also be deformed in the vertical direction in FIG. 2C because the hollow  42  is narrowed in the middle and can be crushed in the vertical direction in FIG. 2C when the wiper blade rubber  30  turns over the inclining direction. Furthermore, the hollow  42  in the wiping portion  36  has an acute angle on the side of the connecting portion  34 . This enables the connecting portion  34  to be readily deformed in the vertical direction in FIG.  2 C. Thus, changes in the height of the wiper blade rubber  30  can be suppressed to reduce a harsh noise. Other effects of the wiper blade rubber  30  in the second embodiment are the same as those of the wiper blade rubber  10  in the first embodiment. 
     In the above-described embodiments, the shoulder portions  16   a,    36   a  of the wiping portions  16 ,  36  may or may not touch the base portion  14   a,    34   a  of the connecting portion  14 ,  34 , respectively, while the wiper blade rubber  10 ,  30  wipes the windshield  24 . However, even if the shoulder portions  16   a ,  36   a  do not touch the base portion  14   a ,  34   a , harsh noise can be reduced. 
     Although the present invention has been fully described in connection with preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. 
     Such changes and modifications are to be understood as being within the scope of the present invention as defined by the appended claims.