Abstract:
An improved joint bushing device includes a pair of outer pins and a pair of inner pins symmetrically disposed on a pair of walls and a pair of primary yoke members having a pair of downward grooves and yoke apertures for effectively assembling with a bridge member having a pair of bridge apertures and the pair of primary yoke members.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to the construction of a windshield wiper frame and more particularly, to a joint bushing device for use in the windshield wiper frame of the windshield wiper assembly for a motor vehicle for effectively assembling with all parts and improving the performance of the windshield wiper assembly. 
     2. Description of Related Art 
     Various types of windshield wiper frames for a windshield wiper assembly are well known in the art. As shown in FIG. 1., such windshield wiper frames include a bridge 3, a pair of primary yokes 2 pivotally connected to the bridge 3 by using a bushing 1 which contains a pair of depending bushing walls 4, a pair of short inner pins 8 projecting from opposing inside surfaces of the bushing walls 4 and long outer pins 7 projecting from outer surfaces of the bushing walls 4. At this time, the pair of short inner pins 8 are inserted into a pair of inner apertures 9 formed in the primary yokes 2, and the pair of long outer pins 7 are inserted into a pair of outer apertures 9&#39; of the bridge 3. 
     However, even though the conventional bushing 1 has the pair of outer and inner pins 7 and 8, when the primary yoke 2 is inserted into the bushing 1, the pair of inner pins 8 are usually crushed or broken off of the bushing. Due further to the tight fit of the bushing 1 to the primary yoke 2, a substantial amount of power is needed to push the primary yoke 2 to the point where the inner pins 6 will reach the inner apertures 9 for seating therein. Therefore, there are a number of damaged goods and the assembling cost is high. In addition, the windshield wiper frame having such a conventional bushing 1 cannot be expected to improve the performance of the windshield wiper assembly. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide an improved windshield wiper frame for use in a windshield wiper assembly for motor vehicles, which eliminates the above problems encountered with the conventional windshield wiper frame. 
     Another object of the present invention is to provide an improved joint bushing member including a pair of outer pins and a pair of inner pins disposed on a pair of bushing walls for effectively assembling with a bridge member and a primary yoke member with a pair of downward grooves formed in the primary yoke member. 
     A further object of the present invention is to provide a primary yoke member having a tapered configuration at a pair of yoke walls thereof, for smoothly receiving a joint bushing member and securely locking with the pair of inner pins of the joint bushing member. 
     Still another object of the present invention is to provide a joint bushing device for use in a windshield wiper frame, which is simple in structure, inexpensive to manufacture, durable in use, and refined in appearance. 
     Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     Briefly described, the present invention is directed to an improved joint bushing device including a pair of outer pins and a pair of inner pins symmetrically disposed on a pair of walls and a pair of primary yoke members having a pair of downward grooves formed therein and yoke apertures for effectively assembling with a bridge member having a pair of bridge apertures and the pair of primary yoke members. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitative of the present invention, and wherein: 
     FIG. 1 is an exploded perspective view of a conventional windshield wiper frame at a bushing connecting portion thereof; 
     FIG. 2 is an exploded perspective view of the joint bushing device for use in a windshield wiper frame at a bushing connecting portion thereof according to the present invention; 
     FIG. 3 is a perspective view of the windshield wiper frame including the joint bushing device according to the present invention; 
     FIG. 4 is a cross-sectional view of the bushing connecting portion of a primary yoke member according to the present invention, taken along line 4--4 of FIG. 2; and 
     FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 3. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now in detail to the drawings for the purpose of illustrating preferred embodiments of the present invention, the windshield wiper frame 10 for use in a windshield wiper assembly for a motor vehicle as shown in FIGS. 2 and 3, comprises a wiper arm attached to the body of the motor vehicle (see the inventor&#39;s U.S. Pat. No. 5,311,636), a bridge member 13, a pair of primary yokes 12 pivotally connected to the bridge member 13, and a pair of secondary yokes 12&#39; pivotally connected to an inner end of the pair of primary yokes 12. Distal ends of the pair of secondary yokes 12&#39; and the outer ends of the pair of primary yokes 12 are provided with a claw 24, respectively. 
     The bridge member 13 further includes a joint bushing member 11 for pivotal connection to the primary yokes 12, a shaft 25 extended from a central portion of the bridge member 13, and apertures 26 formed in the bridge member 13 for engaging the wiper arm (not shown). The primary yokes 12 are pivotally connected to the secondary yokes 12&#39; by the joint bushing member 11. 
     As shown in FIG. 2, the joint bushing device of the present invention comprises the joint bushing member 11, a downward groove 21 formed on outer side surfaces of each primary yoke 12, and an inner aperture 20 formed in each yoke wall 19 of both the primary 12 and the secondary yokes 12&#39;. If necessary, a third yoke (not shown) may be provided for pivotally connecting to the primary and secondary yokes 12 and 12&#39; or the secondary yokes 12&#39; and third yokes. 
     As shown in FIGS. 2 and 5, the joint bushing member 1 is of a U-shape in cross-section and includes a pair of bushing side walls 14, an opening 15 formed in an end wall, a pair of opposing outer pins 17 and a pair of opposing inner pins 18 disposed on and extended from outer and inner bushing wall surfaces 14, respectively, and a stopper 16 formed at one edge of the bushing member and perpendicular to the side walls 14. The pair of inner pins 18 and the pair of outer pins 17 have a uniform length and are longer than the inner and outer pins 8 and 7 of the conventional joint bushing 1 as shown in FIG. 1, for easily and tightly locking into the inner apertures 20 of the primary yokes 12 and the outer apertures 23 of the bridge walls 22 of the bridge member 13, respectively (FIG. 2). 
     As shown in FIG. 4, the secondary yoke 12 has a tapered configuration since the secondary yoke 12 has the downwardly formed grooves 21, so that when the joint bushing member 11 is locked into both the bridge member 13 and the primary yoke 12, the joint bushing member 11 is easily and smoothly covered onto and locked into the primary yoke 12, and both pairs of outer and inner pins 17 and 18 are tightly and securely locked into both inner and outer apertures 20 and 22 of the primary yoke 12 and the bridge member 13, respectively. (FIG. 5). The bushing member 11 is made of polymer plastics or nylon for eliminating metal to metal contact so as to prevent corrosion and provide quiet operation and longer life thereof. 
     Accordingly, the joint bushing device of the present invention provides a space at the end thereof, when the bushing member 11 is assembled with the primary yoke 12 and the bridge member 13, for providing adequate room for the primary yoke 12 to move flexibly and evenly distribute its pressure, and further enables the inner pins 18 of bushing member 11 to slide within the downward grooves 21 for easily assembling by a snap-fit into the apertures 20, thereby saving labor costs and securely locking into the primary yoke 12 and the bridge member 13 so as to improve the performance of the windshield wiper assembly. 
     Also, the joint bushing device according to the present invention is simple in structure, inexpensive to manufacture, durable in use, and refined in appearance. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included in the scope of the following claims.