Abstract:
A spring restraining clip mounts the axial terminus of a coil spring on the chassis via a spring seat. At least two of three spring restraining members that are circumferentially spaced on the spring restraining clip are the open type of spring restraining member so configured as to clasp and hold coil springs inserted in the axial direction, and one of the spring restraining members is a closed spring restraining member that receives the tip of a coil spring when the coil spring is rotated in the circumferential direction after having been inserted in the open type spring restraining members.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of PCT Application No. PCT/JP2012/78999, filed Nov. 8, 2012, which claims priority of Japanese Patent Application No. 2011-250678, filed on Nov. 16, 2011, the disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention concerns a spring restraining clip, specifically a spring restraining clip used when incorporating a coil spring in a device such as an automotive hydraulic shock absorber. 
     A coil spring is attached to a spring restraining clip in conventional hydraulic shock absorbers. The spring restraining clip is mounted on the chassis side and the wheel side via spring seats. A plurality of spring restraining members are installed in the spring restraining clip in order to increase the spring restraining force. For example, Patent Reference 1 discloses a spring restraining clip provided with four spring restraining members. 
     In addition, a plurality of spring seat locking pawls are mounted in the spring restraining clip in order to increase the spring seat retention force. For example, Patent Reference 2 discloses a spring restraining clip provided with five spring seat locking pawls (mounted member 42). Patent Reference 3 discloses a spring restraining clip provided with six spring seat locking pawls (positioning member 45). 
     PRIOR ART 
     Patent References 
     Patent Reference 1: Japanese Kokai Publication 2008-24158, Gazette 
     Patent Reference 2: Japanese Kokai Publication 2005-155808, Gazette 
     Patent Reference 3: Japanese Kokai Publication 2011-63200, Gazette 
     The spring restraining clip of Patent Reference 1 is stiff since it has four spring restraining members. It requires great force to fit in place and is a burden on workers. An additional problem is the need to apply a certain level of depressing force on a spring in order to disengage the spring when attached to the spring restraining clip if it is too loose. 
     A burden is also imposed on workers when a plurality of spring seat locking pawls are used, as in the spring restraining clip of Patent References 2 and 3, since attaching a spring seat to a spring restraining clip involves manual work. 
     Another problem is that a spring can catch on a spring retaining pawl and the spring retaining pawl can be damaged when inserting a spring from above in a spring restraining member of a spring restraining clip in other conventional technology. Another problem is that it is difficult to insert a spring in a spring restraining member if the spring inner diameter is great when spring restraining members are disposed on the restraining clip so that they are diametrically opposed to one another. The spring restraining members are turned up when insertion is difficult in this manner, and they no long carry out their clip role. A final problem is that distortion develops in the spring seat locking pawls due to the spring weight, which results in their susceptibility to detachment. 
     An object of the present invention is to resolve the aforementioned issues associated with the known art by providing a spring restraining clip that improves operational efficiency when mounting springs and spring seats and that enhances the restraining force of the spring and the retention force of the spring seat. 
     SUMMARY OF THE INVENTION 
     The present invention provides a spring restraining clip for mounting the axial terminus of a coil spring on the chassis via a spring seat, said spring retaining clip comprising at least three spring restraining members separately placed in the circumferential direction, wherein two of the aforementioned spring restraining members are the open type of spring restraining member structured so as to clasp and hold coil springs inserted in the axial direction, and one of the aforementioned spring restraining members is a closed spring restraining member that accepts the tip of a coil spring due to rotational movement in the circumferential direction of the coil spring inserted in the aforementioned axial direction. 
     In one embodiment of the present invention, the aforementioned closed spring restraining member has a loop structure in which the travel path in the circumferential direction of a coil spring that is moved rotationally is covered by a bridge. It has a spring tab that extends obliquely downward in the direction of travel of the coil spring from the bridge. It is structured so that said spring tab will contact the coil spring to apply thrust force to the coil spring. 
     In another embodiment of the present invention, the aforementioned open type of spring restraining member has a spring retaining pawl to arrest looseness of the coil spring that had been inserted, and it has ribs to prevent the aforementioned spring retaining pawl from turning up during spring insertion. 
     In still another embodiment of the present invention, at least three spring locking pawls are provided on the side opposite the side provided with the aforementioned spring restraining member in order to attach the spring seat. 
     Still another embodiment of the present invention is structured so that the aforementioned spring locking pawls all have different structures. 
     A further embodiment of the present invention is structured so that the aforementioned spring locking pawls extend in the radial direction inwardly so as to compensate for deformation due to the spring load. 
     Yet another embodiment of the present invention is structured so that the aforementioned spring restraining members will not be disposed on the restraining clip so that they are diametrically opposed to one another. 
     These arrangements of the spring restraining clip of the present invention yield several benefits. The burden on workers is reduced, and operational efficiency is improved since there are fewer spring restraining members in the present invention in comparison with the known art. Furthermore, the spring restraining force is not reduced, since one of the spring restraining members is a closed spring restraining member. 
     The final structure facilitates spring insertion and renders removal more difficult by mounting a spring tab in the aforementioned closed spring restraining member that extends obliquely downward in the direction of travel of the coil spring from the bridge, and the spring can be reliably restrained independently of the size of the spring. 
     The spring retaining pawl can be prevented from turning up and subsequently suffering damage by mounting ribs in the aforementioned open type of spring restraining member to prevent the spring retaining pawl from being turned up during insertion of the spring. 
     The burden on workers is reduced, and operational efficiency is improved by reducing the number of spring locking pawls in comparison to the known art. 
     The structure facilitates spring insertion and renders removal more difficult by restricting the mounting sequence since the spring locking pawls all have different structures, which thus prevents reduction in the retention force of the spring seat. 
     Furthermore, detachment of the spring seat from the spring restraining clip can be prevented even if deformation develops in the spring locking pawls by providing a structure such that the spring locking pawls extend radially inwardly so as to compensate for deformation due to the spring load. 
     The spring restraining members can be prevented from turning up even if the spring inner diameter is great by providing a structure in which the spring restraining members are not disposed on a diagonal line. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of a hydraulic shock absorber that incorporates a spring restraining clip pursuant to one embodiment of the present invention. 
         FIG. 2  is an oblique view of the spring restraining clip pursuant to the first embodiment of the present invention viewed from the spring insertion side. 
         FIG. 3  is an oblique view of the spring restraining clip of  FIG. 2  viewed from the spring seat insertion side. 
         FIG. 4  is a plan view of  FIG. 2 . 
         FIG. 5  is a right side view of  FIG. 4 . 
         FIG. 6  is a plan view of  FIG. 3 . 
         FIG. 7  is an A-A cross-sectional view of  FIG. 4 . 
         FIG. 8  is a B-B cross-sectional view of  FIG. 4 . 
         FIG. 9  is a C-C cross-sectional view of  FIG. 4 . 
         FIG. 10  is a D-D cross-sectional view of  FIG. 4 . 
         FIG. 11  is an enlarged diagram of area E of  FIG. 7 . 
         FIG. 12  is an F-F cross-sectional view of  FIG. 6 . 
         FIG. 13  is a G-G cross-sectional view of  FIG. 4 . 
         FIG. 14  is an oblique detail view for illustrating the shape of the rib in  FIG. 11 . 
         FIG. 15  is a cross-sectional view similar to  FIG. 11  to illustrate the guiding action of the rib in  FIG. 14 . 
         FIG. 16A  is a partial enlarged diagram of  FIG. 3  illustrating an example of the structure of the spring locking pawl. 
         FIG. 16B  is a partial enlarged diagram of  FIG. 3  illustrating an example of a structure that differs from that of  FIG. 16A . 
         FIG. 16C  is a partial enlarged diagram of  FIG. 3  illustrating an example of a structure that differs from those of  FIG. 16A  and of  FIG. 16B . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The spring restraining clip pursuant to the first embodiment of the present invention shall now be explained with reference to the appended figures. 
     As shown in  FIG. 1 , spring restraining clip  1  is used in a hydraulic shock absorber  2  of an automobile. Hydraulic shock absorber  2  is provided with a wheel side mounting bracket  3  mounted to the wheel, and a chassis side mounting bracket  5  mounted to the chassis. Thrust bearing  6  is supported on the chassis side mounting bracket  5  on the back side, and upper spring seat  7 , defining a curved contour portion, is attached to the thrust bearing  6 . At the other end, lower spring seat  9  is attached to the wheel side mounting bracket  3 , and coil spring  10  is interposed between the upper spring seat  7  and the lower spring seat  9 . Concretely, the coil spring  10  is supported on the lower spring seat  9  and is supported on the upper spring seat  7  via the spring restraining clip  1 . 
       FIGS. 2 and 3  are oblique views of the spring restraining clip  1 .  FIG. 2  is a view from the lower (wheel) side of  FIG. 1 .  FIGS. 3 and 6  are views from the spring seat insertion side, specifically from the upper side of  FIG. 1 . The spring restraining clip  1  has a ring-shaped structure with an internal space to house part of the upper spring seat, and a curved upper surface contoured to conform to the curved contour portion of the upper spring seat, as shown in  FIG. 1 . 
     Three spring restraining members are separately placed in the circumferential direction of the spring restraining clip  1  to restrain the terminus of the coil spring  10  in the axial direction, as shown in  FIG. 2 . Two of the spring restraining members are the open type of spring restraining members  11 ,  13  while the other one is a closed spring restraining member  14 . 
     The tops of the open type of spring restraining members  11 ,  13  are open from above in  FIG. 2  (from below in  FIG. 7  and  FIG. 11 ) in order to allow the insertion of the coil spring  10 . Retaining space  15  ( FIGS. 2 and 7 ) is formed within in order to retain the coil spring  10 . As shown in  FIGS. 4, 5 and 8 , inner spring retaining pawl  17  and outer spring retaining pawl  18  are mounted at the inner and outer edges, respectively, of the entry of the retaining space  15  in the radial direction. Loosening of the coil spring  10  fitted in the retaining space  15  is prevented by inner and outer spring retaining pawls  17  and  18 . 
     A pair of ribs  19  is mounted in the open type of spring restraining members  11 ,  13  adjacent to both edges of the inner spring retaining pawl  17  in the circumferential direction (see  FIG. 14 ). The ribs  19  act as guides when inserting the coil spring  10  in the open type of spring restraining members  11 ,  13  (see  FIG. 15 ). By so doing, the inner spring retaining pawl  17  can be prevented from turning up when inserting the spring. 
     The upper section of the closed spring restraining member  14  has a loop structure covered by bridge  20 , as shown in  FIG. 2 . The tip of the coil spring is received therein by rotating the coil spring that had been inserted in the open type of spring restraining members  11 ,  13  in the circumferential direction. The arrows a, b and c in  FIG. 2 ,  FIG. 4  and  FIG. 10 , respectively, illustrate the direction of rotational movement of the spring at that time. 
     A spring tab  21  that extends obliquely downward in the direction of travel of the coil spring  10  from the bridge  20  is mounted in the closed spring restraining member  14 . It is structured so that the spring tab  21  would contact the coil spring  10  to apply thrust force to the coil spring  10 . By so doing, movement of the coil spring  10  in the direction of movement denoted by the arrows ( FIG. 2 ,  FIG. 4 , and  FIG. 10 , a, b and c respectively) would be facilitated while movement in the opposite direction would be impeded, thus completing a structure that renders insertion easy and removal difficult. 
     In addition, stopper  23  is mounted in the spring restraining clip  1  in order to arrest the tip of coil spring  10  that had been inserted in the closed spring restraining member  14 , as shown in  FIGS. 5 and 13 . 
     As shown in  FIGS. 2, 4 and 6 , spring restraining members  11 ,  13 ,  14  are structured so as not to be disposed on the restraining clip  1  on an imaginary diagonal line through the center of the restraining clip, and are thus disposed on the restraining clip so as not to be diametrically opposed to one another. By so doing, the spring restraining members are not turned up even if the spring has a large internal diameter. 
     As shown in  FIGS. 3 and 6 , three spring seat locking pawls  25 ,  26 ,  27  are mounted on the spring restraining clip  1  on the side opposite from the side shown in  FIG. 2 . These three spring seat locking pawls  25 ,  26 ,  27  have mutually different structures. For example, they have the structures shown in  FIGS. 9, 12, 16A, 16B and 16C . In this case, a worker could easily insert the upper spring seat  7  in the spring restraining clip  1  by following the insertion sequence of spring seat locking pawls  25 ,  26 ,  27  so that the final insertion would be of the spring seat locking pawl  27  with the structure shown in  FIG. 16C  (for example,  25 → 26 → 27 ) (See  FIG. 6 ). 
     In addition, when deformation due to a spring load develops in the spring seat locking pawls  25 ,  26 ,  27 , detachment of the spring seat  7  from the spring restraining clip  1  can be prevented even if deformation develops in the spring seat locking pawls, by providing a structure (see the structure shown in  FIG. 16A ) such that the spring seat locking pawls  25 ,  26 ,  27  extend inwardly in the radial direction so as to compensate for deformation due to the spring load. 
     It will be appreciated by persons skilled in the art that the above embodiments have been described by way of example only, and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims.