Wiper apparatus

A wiper apparatus includes an arm shank pivotably supported at its proximal end portion on a vehicle and an arm piece mounted at its proximal end portion to a distal end portion of the arm shank and having a wiper blade attached to the other end portion remote from the distal end portion of the arm shank. The wiper apparatus also includes an arm piece cover covering the arm piece having an outer peripheral surface flush with an outer peripheral surface of the distal end portion of the arm shank.

FIELD OF THE INVENTION

The present invention relates to a wiper apparatus for wiping a vehicular window glass with a wiper blade.

BACKGROUND OF THE INVENTION

In wiper apparatus for vehicles, an arm shank is pivotably supported at its proximal end portion on a vehicle body, an arm piece is mounted to a distal end portion of the arm shank, and a wiper blade is mounted to the arm piece. Window glass is wiped with the wiper blade through pivoting movement of the ark shank.

Generally, such wiper apparatus are mounted on a vehicle body with the arm piece swaged to a distal end portion of the arm shank. Therefore, a step or level difference would be formed between the distal end portion of the arm shank and the arm piece, which impairs the outer appearance of the wiper apparatus.

To eliminate such an undesired level difference between the distal end portion of the arm shank and the arm piece, it has been proposed to form a sectional shape of the arm piece such that a portion of the arm shank to be swaged to the distal end portion of the arm shank has a relatively small size and another portion of the arm shank projecting from the distal end portion of the arm shank has a greater size (see, for example, the wiper apparatus disclosed in Japanese Patent Application Laid-Open Publication No. 2000-344057). By thus appropriately changing the sectional shape of the arm piece, it is possible to minimize or eliminate the level difference between the distal end portion of the arm shank and the arm piece; in this way, the outer peripheral surface of the arm piece can be made flush with the outer peripheral surface of the arm shank.

However, with the wiper apparatus disclosed in the 2000-344057 publication, which requires a particular sectional shape of the arm piece, it is difficult to appropriately shape the arm piece. Thus, formation of the arm piece tends to be complicated. Therefore, it has also been proposed to form the arm piece of resin so that it can be readily molded into the particular sectional shape. If the arm piece is formed of resin like this, however, a sufficient rigidity of the arm piece can not be secured, and as a consequence, the arm piece can not appropriately press the wiper blade against a window glass. Therefore, the window glass can not be appropriately wiped with the wiper blade of the wiper apparatus.

SUMMARY OF THE INVENTION

In view of the foregoing prior art problems, it is an object of the present invention to provide an improved wiper apparatus which can not only eliminate an undesired level difference between a distal end portion of an arm shank and an arm piece but also secure a sufficient rigidity of the arm piece.

In order to accomplish the above-mentioned object, the present invention provides an improved wiper apparatus provided near a vehicle for wiping a window glass of the vehicle by means of a wiper blade, which comprises: an arm shank pivotably supported at a proximal end portion thereof by the vehicle; an arm piece mounted at one end portion to a distal end portion of the arm shank and having the wiper blade attached to another end portion thereof remote from the distal end portion of the arm shank; and an arm piece cover covering the arm piece and having an outer peripheral surface generally flush with an outer peripheral surface of the distal end portion of the arm shank.

In the wiper apparatus of the present invention, where the outer peripheral surface of the arm piece cover is flush with the outer peripheral surface of the distal end portion of the arm shank, no step or level difference is formed between the distal end portion of the arm piece cover and the arm shank, and thus, it is possible to provide a sense of unity or oneness between the arm piece cover and the arm shank and thereby significantly enhance the outer appearance of the wiper apparatus. Further, because the arm piece and the arm piece cover are formed as separate component parts, the arm piece can be significantly simplified in shape and thus can be readily formed of a material having a greater rigidity. With the arm piece formed of a high-rigidity material, it is possible to secure a sufficient rigidity of the arm piece and appropriately press the wiper blade against the window glass by means of the arm piece. In this way, the window glass can be appropriately wiped with the wiper blade.

In an embodiment, the arm piece cover has a cover body that covers a surface of the arm piece opposite from the window glass, and a side wall that extends from one of opposite side edges of the cover body to cover a side surface of the arm piece. In assembly of the wiper apparatus, the side wall of the arm piece cover is caused to abut against the side surface of the arm piece so that the cover can be positioned in a predetermined mounting position using the side wall. Thus, the arm piece cover can be readily positioned in the predetermined mounting position and attached to the arm piece with an increased ease. Further, by causing the side wall to abut against the side surface of the arm piece, the arm piece cover can be attached to the arm piece with an increased accuracy and increased stability.

In an embodiment, the side wall of the arm piece cover covers a front side surface, facing forward as viewed in a front-rear direction of the vehicle, of the arm piece. Thus, an air stream produced during travel of the vehicle (“traveling air stream”) can be received by the side wall, so that the arm piece cover can be reliably kept attached to the arm piece with an increased stability during travel of the vehicle.

In an embodiment, the arm piece cover has a projecting wall section that projects from the side wall of the arm piece cover along a surface of the arm piece facing the window glass. Thus, in assembly of the wiper apparatus, the arm piece cover can be attached to the arm piece with the arm piece sandwiched between the projecting wall section and the arm piece cover.

In an embodiment, one end portion of the arm piece cover is held in end-to-end abutment against the distal end portion of the arm shank in an abutment region between the arm piece cover and the arm shank. The projecting wall section of the arm piece cover has, in a portion thereof adjacent to the distal end portion of the arm shank, a positioning portion and an expansion/contraction permitting portion located remoter than the positioning portion from the abutment region. The expansion/contraction permitting portion has an expansion/contraction margin for permitting thermal expansion/contraction of the arm piece cover in a longitudinal direction of the arm piece cover. The positioning portion permits accurate positioning of the arm piece cover, and the expansion/contraction permitting portion permits thermal expansion/contraction of the arm piece cover in the longitudinal direction.

In an embodiment, the arm piece is formed of a material of greater rigidity than the arm piece cover covering the arm piece. Thus, it is possible to effectively prevent the arm piece cover from undesirably swaying relative to the arm shank. Thus, it is possible to attach the arm piece cover to the arm shank with an increased sense of unity or oneness.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference is now made toFIG. 1showing in perspective a vehicle provided with a wiper apparatus according to an embodiment of the present invention, and toFIG. 2showing in perspective the wiper apparatus with a wiper blade removed therefrom. The wiper apparatus10is provided near a front window glass12of the vehicle11to wipe the window glass12.

The wiper apparatus10includes an arm shank14pivotably supported at its proximal end portion14aby the vehicle11, an arm piece16mounted to a distal end portion14bof the arm shank14, a wiper blade18attached to the arm piece16, and an arm piece cover20covering the arm piece16.

The arm shank14includes a head23having the proximal end portion14apivotably supported on the vehicle11by means of a bolt22, and a retainer25connected to a distal end portion23aof the head23by means of a connection pin24. The head23is pivotable about the bolt22along the front window glass12. The retainer25is connected at its proximal end portion25ato the head23by means of the connection pin24in such a manner that it is pivotable generally vertically in a direction perpendicular to the front window glass12.

Tension spring (not shown) extends between and is fixed at its opposite ends to the head23and the retainer25, and the retainer25is normally urged by the not-shown tension spring toward the front window glass12. Thus, through pivoting movement of the arm shank14, the wiper blade18can be moved along the front window glass12to wipe the window glass12.

FIG. 3is an enlarged view of section “3” depicted inFIG. 2,FIG. 4is a plan view showing the wiper apparatus10as viewed from the front window glass12, andFIG. 5is a sectional view of the wiper apparatus10.

Fixation portion (one end portion)27of the arm piece16is mounted to the distal end portion of the arm shank14(i.e., distal end portion of the retainer25). More specifically, the distal end portion14bof the arm shank14is squeezed or pressed so that the fixation portion27of the arm piece16is tightly wrapped in the distal end portion14b; namely, the fixation portion27of the arm piece16is swaged into the distal end portion14bof the arm shank14.

A pair of opposed recesses14dare formed in opposed longitudinal side edges14cof the distal end portion14bof the arm shank14. The opposed recesses14dtogether constitute a fitting hole31with the distal end portion14bof the arm shank14(retainer25) squeezed or pressed in the afore-mentioned manner. Locking pin32is fitted in the fitting hole31so that the fixation portion27of the arm piece16is retained by the distal end portion14bof the arm shank14even more firmly by means of the locking pin32.

The arm piece16is formed of steel having a greater rigidity than the arm piece cover20and has a substantially rectangular sectional shape as shown inFIG. 7. Thus, the distal end portion14bof the retainer25, having the fixation portion27of the arm piece16tightly wrapped therein, also has a substantially rectangular sectional shape.

As shown inFIG. 5, the arm piece16has a piece body28projecting straight, along the front window glass12, beyond the distal end of the retainer25toward the distal end of the arm piece16, and a bent portion29bent toward the front window glass12. Namely, the arm piece16has the fixation portion27, piece body28and bent portion29, and the piece body28and bent portion29together define a generally J shape.

First and second locking pins35and36project from an underside surface28a(i.e., surface facing the front window glass12) of the piece body28, details of which will be discussed later.

The wiper blade18(seeFIG. 1) is attached to the bent portion29of the piece body28, as in the conventionally-known wiper apparatus. The arm piece cover20is attached to the arm piece16.

The arm piece cover20has a proximal end portion20aheld in end-to-end abutment against the distal end portion14bof the retainer25to thereby define an abutment region37. In this condition, the arm piece20is covered with the arm piece cover20.

FIG. 6is an exploded perspective view showing the wiper apparatus10,FIG. 7is a sectional view taken along the7-7line ofFIG. 3, andFIG. 8is a sectional view taken along the8-8line ofFIG. 3.

The arm piece cover20is a resin-made cover which includes: a cover body41covering an outer surface16aof the arm piece16; a front side wall42facing forward as viewed in a front-rear direction of the vehicle and extending from a substantial half region41bof a front side edge41aof the cover body41; a projecting wall section43extending rearward (toward the front window glass12) from the lower end edge of the front side wall42; and a rear side wall44extending from a rear side edge41cof the cover body41. Because the arm piece cover20is formed of resin and elastically deformable, it can be readily attached to the arm piece16.

In the arm piece cover20, the rear side wall44has a small downward projecting dimension L1, and thus, the cover body41, front side edge41aand projecting wall section43together define a laterally-facing U sectional shape (seeFIG. 7). Of the arm piece cover20, a locking section20bof a laterally-facing U sectional shape has an outer peripheral surface20csubstantially flush with an outer peripheral surface14eof the distal end portion14bof the retainer25(see alsoFIG. 3). In this way, no step or level difference is formed between the distal end portion14bof the retainer25and the arm piece16, and thus, it is possible to enhance the outer appearance of the wiper apparatus.

The cover body41extends straight along the outer surface (i.e., surface opposite or remote from the front window glass12) of the piece body28and bends in a substantial laterally-facing U shape along an outer or upperside surface29aof the bent portion29(seeFIG. 6). Namely, the outer surface16a(i.e., upperside surfaces28band29a) of the arm piece cover20is covered with the cover body41.

The cover body41has a distal end portion41dof a thickness gradually decreasing toward a distal end edge41ethereof. The front side wall42extends downward from the substantial half region41b, closer to the retainer25, of the front side edge41aof the cover body41.

Thus, a front side surface28cof the piece body28is covered with the front side wall42of the arm piece cover20. More specifically, a substantial half region28e, closer to the retainer25, of the front side surface28cof the piece body28is covered with the front side wall42of the arm piece cover20. In this way, an air stream produced during travel of the vehicle (hereinafter referred to as “traveling air stream”) can be received by the front side wall42.

Further, a remaining region28fof the front side surface28cof the piece body28and a front side surface29bof the bent portion29are not covered with the front side wall42of the arm piece cover20. Therefore, when operation for mounting the arm piece16to the wiper blade18is to be performed, the front side wall42does not undesirably hinder the mounting operation.

The projecting wall section43, which extends rearward from the front side wall42, includes first and second projecting wall portions46and47extending from the lower end edge42aof the front side wall42in opposed relation to the cover body41and along the underside surface28afacing the piece body28.

Referring back toFIGS. 4 and 5, the first projecting wall portion46extends along a region28g, closer to the retainer25, of the underside surface28aof the piece body28, and it is held in abutment against the distal end of the retainer25. The second projecting wall portion47extends along a region28h, remote from the retainer25, of the underside surface28a.

With the first and second projecting wall portions46and47extending rearward along the underside surface28aof the piece body28, the piece body28can be sandwiched between the first and second projecting wall portions46and47and the cover body41. In this way, the arm piece cover20can be attached to the arm piece16.

The first projecting wall portion46has a positioning hole51formed therein as a positioning means near the distal end of the retainer25, and the above-mentioned first locking pin35is inserted in the positioning

The second projecting wall portion47has an expansion/contraction permitting elongated hole52formed therein as an expansion/contraction permitting means and located remoter than the positioning hole51from the abutment region37, and the above-mentioned second locking pin36is inserted in the expansion/contraction permitting elongated hole52.

The expansion/contraction permitting elongated hole52is elongated, or has a long axis, in the longitudinal direction of the arm piece cover20. The long axis of the expansion/contraction permitting elongated hole52has a length L2greater than a diameter D of the second locking pin36. Thus, the expansion/contraction permitting elongated hole52as an expansion/contraction permitting means has an expansion/contraction margin S(L2−D) for permitting thermal expansion/contraction, in the longitudinal direction, of the arm piece cover20.

Thus, as the arm piece cover20thermally expands in the longitudinal direction, for example, the expansion/contraction permitting elongated hole52can move relative to the arm piece cover20in the longitudinal direction of the cover20within the range of the expansion/contraction margin S. With such movement of the expansion/contraction permitting elongated hole52in the longitudinal direction of the arm piece cover20, the positioning hole51can be held positionally stationary or fixed via the first locking pin35.

Thus, as the arm piece cover20thermally expands or contracts, the expansion/extraction of the arm piece cover20is permitted by the expansion/contraction permitting hole52with the proximal end portion20aof the arm piece cover20held in end-to-end abutment against the distal end portion14bof the retainer25by means of the positioning hole51. In this way, it is possible to secure a good outer appearance of the wiper apparatus10.

Because the arm piece16and the arm piece cover20are formed as separate component parts as noted above, the arm piece16can be significantly simplified in shape. Thus, it is possible to easily form the arm piece16of a material having a greater rigidity than the arm piece cover20.

With the arm piece16formed of a high-rigidity material, such as steel, it is possible to secure a sufficient rigidity of the arm piece16and appropriately press the wiper blade18against the front window glass12by means of the arm piece16as shown inFIG. 1. In this way, the front window glass12can be appropriately wiped with the wiper blade18.

In addition, with the arm piece16and arm piece cover20formed as separate component parts, it is possible to obtain a sense of unity or oneness between the arm piece16and the arm shank14by means of the arm piece cover20while securing a sufficient rigidity of the arm piece16.

More specifically, by attaching the arm piece cover20to the arm piece16formed of a high-rigidity material, such as steel, it is possible to prevent the arm piece cover20from undesirably swaying relative to the arm shank14(retainer25). Thus, it is possible to attach the arm piece cover20to the arm shank14(retainer25) with an increased sense of unity or oneness.

The following lines describe an example manner in which the arm piece cover20of the wiper apparatus10is attached to the arm piece16.FIGS. 9A-9Bare views explanatory of an operational sequence for attaching the arm piece cover20to the arm piece16.

First, the locking section20bof the arm piece cover20is positioned in front of a front side portion of the piece body28in such a manner that a rear opening55of the locking section20bis opposed to the front side portion of the piece body28, as shown inFIG. 9A.

Next, the locking section20bis elastically deformed to move the rear side wall44and the projecting section43(first and second projecting wall portions46and47) away from each other as indicated by arrow A. Then, the arm piece cover20is moved toward the arm piece16, as indicated by arrow B.

Then, as indicated inFIG. 9B, the rear side wall44of the locking section20bis placed on the upperside surface28bof the piece body28, and the projecting wall section43(first and second projecting wall portions46and47) of the locking section20bis placed on the underside surface28aof the piece body28.

In the aforementioned condition, the arm piece cover20is further moved as indicated by arrow B, so that the first projecting wall portion46runs onto the first locking pin35while the second projecting wall portion47runs onto the second locking pin36.

Then, as shown inFIG. 9C, the arm piece cover20is further moved, as indicated by arrow B, until the front side wall42abuts against the front side surface28cof the piece body28. In this way, the arm piece cover20can be positioned in a predetermined mounting position. With the arm piece cover20thus positioned in the predetermined mounting position, the rear wall44gets over the upperside surface28b, and the positioning hole51and expansion/contraction permitting hole52are fitted around the first and second locking pins35and36, respectively.

Also, the locking section20brecovers from the elastic deformation so that the rear wall44abuts against a rear side surface28dand the positioning hole51and expansion/contraction permitting hole52are engaged with the first and second locking pins35and36, respectively. In this way, the arm piece cover20can be attached to the arm piece16.

By positioning the arm piece cover20in the predetermined mounting position using the front side wall42as noted above, the arm piece cover20can be attached to the arm piece16with an increased ease. Further, by causing the front side wall42to abut against the front side surface28cof the piece body28as noted above, the arm piece cover20can be attached to the arm piece16with an increased accuracy and increased stability.

Next, a description will be given about behavior of the wiper apparatus10.FIGS. 10A and 10Bare views explanatory of how a traveling air stream acts on the wiper apparatus10.

As indicated by arrow C inFIG. 10A, an air stream flows as the vehicle11travels, and the traveling air stream acts on the wiper apparatus10.

In the wiper apparatus10, as shown inFIG. 10B, the substantial half region28e, closer to the retainer25, of the front side surface28cof the piece body28is covered with the front side wall42. Thus, the traveling air stream can be received by the front side wall42, as indicated by arrow C. In this way, the arm piece cover20can be kept fixedly attached to the arm piece16with an enhanced stability and reliability during the travel of the vehicle11.

Further, of the front side surface of the arm piece16, the surface portion not covered with the front side wall42of the arm piece cover20is covered with a mounting portion of the wiper blade18. Thus, the mounting portion of the wiper blade18can prevent the traveling air stream from directly acting on the surface portion of the arm piece16not covered with the front side wall42of the cover20. Therefore, there is no possibility of the surface portion not covered with the front side wall42loosing stability due to the influence of the traveling air stream.

Whereas the preferred embodiment of the wiper apparatus10has been described above in relation to the case where the front side surface28cis covered with the front side wall42of the arm piece cover20, the present invention is not so limited, and the rear side surface28dmay be covered with the rear side wall28dof the piece body28.

Further, whereas the preferred embodiment of the wiper apparatus10has been described above in relation to the case where the positioning hole51and expansion/contraction permitting elongated hole52are provided as the positioning means and expansion/contraction permitting means, the present invention is not so limited, and the positioning means and expansion/contraction permitting means may be a positioning projection and expansion/contraction permitting projection. In such a case, a first locking hole for fitting engagement with the positioning projection is formed in the underside surface28aof the piece body28, and a second, elongated locking hole is formed for fitting engagement with the expansion/contraction permitting projection.

The present invention is well suited for use in automotive vehicles provided with a wiper apparatus for wiping a window glass of the vehicle with a wiper blade.