Abstract:
In an arrangement for attaching a pair of members to each other, a spacer member provides the function to extend and retract in the axial direction so that the positioning of a first member to a second member is facilitated because a gap may be defined between the two members before joining them to each other, and the dimensional precision between the steering hanger pipe and the front pillar of the vehicle body is not required to be unduly high. This gap is filled by the spacer member as a threaded bolt is fastened owing to the action of a reverse thread, and the two members can be firmly attached to each other without involving any unacceptable deformation of the two members.

Description:
TECHNICAL FIELD  
         [0001]    The present invention relates to an arrangement for attaching two members to each other, and in particular to an attaching arrangement suitable for attaching a steering hanger pipe between two front pillars of a vehicle body.  
         BACKGROUND OF THE INVENTION  
         [0002]    Japanese patent laid open publication No. 10-236336 discloses a structure in which a steering hanger bracket for supporting a steering shaft is attached to a pipe member extending laterally across the vehicle body, and the pipe member is connected between the inner surfaces of the front pillars.  
           [0003]    Typically, the pipe member (steering hanger pipe) is fixedly attached to the vehicle body by attaching a flange fixedly attached to each end thereof to the inner surface of the corresponding front pillar by using threaded bolts, or by attaching the flange to a bracket fixedly attached to the inner surface of the front pillar by using threaded bolts.  
           [0004]    However, according to such a prior art, when joining the steering hanger pipe to the inner surface of the front pillar, threaded bolts are required to be fastened from the inner side of the vehicle body. This work requires the worker to face upward or otherwise take a highly uncomfortable position.  
           [0005]    Furthermore, because variations in the dimension between the opposing inner surfaces of the front pillars are inevitable, means for accommodating such variations is required. If the length of the pipe member is longer than the distance between the front pillars, it is simply impossible to connect the two pillars with the pipe member as it would not fit. If the length of the pipe member is shorter than the distance between the front pillars, a gap is created between an end of the pipe member and the opposing part of the front pillar. If the threaded bolts are fastened under such a condition, the pipe member would not be properly secured and the front pillar may even deform to an unacceptable extent.  
         BRIEF SUMMARY OF THE INVENTION  
         [0006]    In view of such problems of the prior art, a primary object of the present invention is to provide an arrangement for attaching two members to each other which is adapted to accommodate a positional error between the two members.  
           [0007]    A second object of the present invention is to provide an arrangement for attaching two members to each other which facilitates the assembly work.  
           [0008]    A third object of the present invention is to provide an arrangement for attaching two members to each other which is easy to work by allowing the threaded bolts to be fastened from a convenient direction.  
           [0009]    A fourth object of the present invention is to provide an arrangement for attaching two members to each other which is suitable for attaching a steering hanger pipe to front pillars of an automobile.  
           [0010]    According to the present invention, such objects can be accomplished by providing an arrangement for attaching a pair of members to each other, comprising: a nut member attached to or provided on a first member, the nut member being provided with a small normal threaded hole near an axial end of the nut member remote from a second member and a large reverse threaded hole near the other axial end of the nut member adjacent to the second member and axially aligned with the small threaded hole; a substantially cylindrical spacer member defining a central through hole therein, the spacer member being provided with a large reverse threaded part on an outer circumferential surface thereof which is threaded into the large reverse threaded hole of the nut member and a small normal threaded hole having a same configuration as the small normal threaded hole of the nut member and axially aligned with the large reverse threaded hole; and a threaded bolt adapted to be passed through a hole provided in the second member and provided with a normal threaded part which is adapted to be threaded into the small normal threaded holes of the spacer and nut members.  
           [0011]    Thus, a gap that may exist between the two members is filled by the spacer member as the threaded bolt is threaded into the spacer member owing to the presence of the reverse thread, and the two member can be firmly secured to each other as the threaded part of the threaded bolt is threaded into the small threaded hole of the nut member.  
           [0012]    The nut member may comprise a cylindrical main body passed through an opening provided in the first member and a radial flange formed on one axial end of the cylindrical part and abutting an end surface of the first member, the flange being fixedly attached to the end surface of the first member, for instance by projection welding. The spacer member may be provided with a cylindrical main body on which the large reverse threaded part is formed, and a flange portion on an axial end of the cylindrical main body facing the second member. Typically, the threaded bolt is provided with a small diameter part extending from an end of the threaded part thereof remote from a front end thereof, the small diameter part being provided with an outer diameter small than an inner diameter (crest diameter) of the small threaded hole of the spacer member.  
           [0013]    According to a preferred embodiment of the present invention, the second member is provided with a pair of sheet metal members and a collar member extending between the sheet metal members, the hole of the first member being passed through the sheet metal members and collar member in an axial alignment. For instance, the first member consists of a part of a steering hanger pipe, and the second member consists of a front pillar of a motor vehicle.  
           [0014]    For the convenience of unfastening the threaded bolt and separating the first and second members from each other, the nut member may be provided with an engagement portion for engaging a tool such as a wrench for turning the nut member. To enhance the action of the attaching arrangement of the present invention, a friction enhancing agent such as an adhesive agent may be applied to the threaded part of the threaded bolt and/or the threaded hole of the spacer member. This facilitates the action of the spacer member to fill the gap between the first and second member as the threaded bolt is threaded into the threaded hole of the spacer member by virtue of the reverse threaded part formed around the spacer member. Such an agent also helps to prevent the loosening of the threaded part during use as well known in the art. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    Now the present invention is described in the following with reference to the appended drawings, in which:  
         [0016]    [0016]FIG. 1 is a fragmentary perspective view of a steering hanger pipe attached to a front pillar of a vehicle body by an attaching arrangement embodying the present invention;  
         [0017]    [0017]FIG. 2 is a sectional view showing the attaching arrangement before the threaded bolt is fastened;  
         [0018]    [0018]FIG. 3 is a view similar to FIG. 1 when the threaded bolt is in an early stage of fastening;  
         [0019]    [0019]FIG. 4 is a view similar to FIG. 1 when the threaded bolt is fastened halfway through; and  
         [0020]    [0020]FIG. 5 is a view similar to FIG. 1 when the threaded bolt is fully fastened. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    [0021]FIG. 1 shows a steering hanger pipe  18  carrying a hanger bracket  19  and attached to a front pillar  11  of an automotive vehicle body via a side plate  1  provided at an end of the steering hanger pipe  18 , and this side plate  1  is attached to the front pillar  11  via an attaching arrangement according to the present invention.  
         [0022]    [0022]FIG. 2 shows the attaching arrangement in more detail. The side plate  1  is integrally attached to each end of the steering hanger pipe  18  extending laterally across the vehicle body. A plurality of adjust nut assemblies  2  are attached to each side plate  1 .  
         [0023]    Each adjust nut assembly  2  is provided with a nut member  4  including a cylindrical main body fixedly attached to the side plate  1  via a radially outwardly extending flange  3  formed in a bottom part thereof by projection welding, for instance, and a spacer member  5  having a substantially cylindrical shape.  
         [0024]    The nut member  4  is provided with a female normal threaded hole  6  formed centrally in the bottom wall of the nut member  4  facing away from the front pillar  11 , and a female reverse threaded hole  7  formed in the inner circumferential surface of the open end of the nut member  4  facing the front pillar  11 . Of these two female threaded holes  6  and  7 , the female reverse threaded hole  7  is larger in diameter than the female normal threaded hole  6 . The two threaded holes  6  and  7  are axially aligned to each other.  
         [0025]    The spacer member  5  is provided with a through hole  16  extending across the length thereof, and a female normal threaded hole  8  having a same diameter and pitch as the female normal threaded hole  6  of the nut member  4  in the inner circumferential surface of an open end of the spacer member  5  facing the front pillar  11 , and this end of the spacer member  5  is formed with a radially outwardly extending flange  9 . A male reverse threaded part  10  is formed on the outer circumferential surface of the spacer member  5  over the entire axial length thereof, and is threaded into the female reverse threaded hole  7  of the nut member  4 . The female normal threaded hole  6 , female normal threaded hole  8  and male reverse threaded part  10  are axially aligned to each other.  
         [0026]    When attaching the side plate  1  (of the steering hanger pipe) fitted with the adjust nut assembly  2  to the front pillar  11 , the outer end surface of the spacer member  5  is placed opposite the inner surface of the front pillar  11 , and a threaded bolt  12  is passed into a through hole  17  defined in the front pillar  11  from outside the front pillar  1 , and is threaded into the female normal threaded hole  8  of the spacer member  5  (see FIG. 2). The part of the front pillar  11  for attaching the steering hanger pipe is reinforced by a tubular collar  13  which extends between a pair of sheet metal members opposing each other, and the through hole  17  of the front pillar  11  is passed through the sheet metal members and collar member in an axial alignment.  
         [0027]    The front end of the bolt  12  is provided with a male normal threaded part  14 , and a reduced diameter portion  15  having a smaller diameter than the valley diameter of the male normal threaded part  14  extends from an end of the male normal threaded part  14  remote from the front end of the threaded bolt. The through hole  16  of the spacer member  5  is provided with an inner diameter greater than the ridge diameter of the threaded part  14  of the threaded bolt  12 .  
         [0028]    When the male threaded part  14  of the bolt  12  having an adhesive agent or other friction enhancing agent applied thereto is threaded into the female threaded hole  8  on the open end of the spacer member  5 , the frictional force produced by the adhesive agent causes the spacer member  5  to turn fast with the threaded bolt  12 . Because the spacer member  5  is threaded into the nut member  4  by a reverse thread, if the threaded bolt  12  is threaded in clockwise direction, the spacer member  5  moves axially in the direction to be pulled out of the nut member  4  (see FIG. 3).  
         [0029]    As the threaded bolt  12  is threaded, the outer end surface of the spacer member  5  abuts the inner surface of the front pillar  11  facing the side plate  1 , and the resulting frictional resistance prevents any further rotation of the spacer member  5  (see FIG. 4). Then, the male threaded part  14  of the threaded bolt  12  passes through the female threaded hole  8  of the spacer member  5 , and reaches the female threaded hole  6  of the bottom wall of the nut member  4 . Because the reduced diameter portion  15  of the threaded bolt  12  is smaller in diameter than the inner diameter of the female threaded hole  8  of the spacer member  5 , the male threaded part  14  of the bolt  12  is threaded into the female threaded hole  6  of the nut member  4 . If the bolt  12  is then fully threaded, the spacer member  5  pushes apart the front pillar  11  and the nut member  4  away from each other, and the side plate  1  of the steering hanger pipe is firmly attached to the front pillar  11  (see FIG. 5). The adhesive agent may also be applied to the threaded hole  8  of the spacer member  5 . In any event, the adhesive agent applied to the male threaded part  14  of the bolt  12  or the threaded hole  8  of the spacer member  5  also adheres to the female threaded hole  6  of the nut member  4 , and this prevents the loosening of the fastened part during use.  
         [0030]    Thereby, the threaded bolt  12  can be fastened from outside the vehicle body, and this significantly improves the work efficiency.  
         [0031]    When the side plate  1  (of the steering hanger pipe) is required to be removed, the bolt  12  can be removed by turning the bolt  12  in counter clockwise direction. At this time, because the reverse threaded part may be prevented from turning by the axial force acting on the spacer, the spacer member  5  may continue to push apart the opposing parts. By providing a pair of parallel surfaces on the outer circumferential surface of the flange  9  of the spacer member  5  or other engagement portion for engaging a tool such as a wrench for turning the spacer member  5 , the work for unfastening the attaching arrangement is simplified.  
         [0032]    The adjust nut assembly  2  can perform its function even when it is provided only on one end of the steering hanger pipe, but may also be provided on each end of the steering hanger pipe as can be readily appreciated.  
         [0033]    Thus, according to the foregoing embodiment, because the spacer member is provided with the function to extend and retract in the axial direction, the positioning of the steering hanger pipe is facilitated because a gap may be defined between the side plate and front pillar when attaching the steering hanger pipe to the front pillar, and the dimensional precision between the steering hanger pipe and the front pillar of the vehicle body is not required to be unduly high because the gap is filled as the bolt is fastened and the two parts are firmly attached to each other. The threaded bolt can be fastened from the axial direction for each end of the frame structural member, and the frame structural member can be directly attached to the vehicle body without the intervention of an auxiliary member such as a bracket without compromising the rigidity of the surrounding frame structure.  
         [0034]    Although the present invention has been described in terms of a preferred embodiment thereof, it is obvious to a person skilled in the art that various alterations and modifications are possible without departing from the scope of the present invention which is set forth in the appended claims.