Patent Publication Number: US-7909305-B2

Title: Suspension strut removal device

Description:
This is a continuation-in-part of application Ser. No. 11/800,766 filed May 8, 2007, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to the field of motor vehicles, and more particularly, to a device used to facilitate the removal and replacement of a suspension strut in a suspension strut assembly by employing means to compress the coiled springs of different sizes to release the tension of the coiled spring against the strut and enable the strut to be safely removed and replaced. 
     2. Description of the Prior Art 
     A preliminary patentability and novelty search conducted for the present invention found U.S. Pat. Nos. 3,982,730; D259,538; 4,541,614; 4,872,644; and, 4,516,303, which disclose the following: 
     1. U.S. Pat. No. 3,982,730. This reference is directed to a manually crank strut spring compressor. This compressor has an elongate hollow housing that receives a threaded rod member that is rotatably supported at each end of the housing and driven by a bevel gear arrangement. A pair of spring engaging plates are U-shaped with a large notch adapted to fit over the shaft of the strut. The U-shaped claws are angled to correspond to the slope of the strut&#39;s coil spring. One of the spring engaging plates is fixed to the housing and the other is fixed to a threaded block that rides on the threaded rod and slides within the body of the compressor. 
     2. U.S. Pat. No. D259,538. This reference is directed to the ornamental design for a spring compressing tool, as shown in  FIGS. 1-4 . The compressor has a hand crank and apparently a bevel gear arrangement to drive a threaded rod. One plate is fixed to the tubular body and the other plate apparently is driven by a threaded block. The spring engaging plates are angled to correspond to the slope of the spring being compressed. 
     3. U.S. Pat. No. 4,541,614. This reference is directed to a coil spring compressor that has a pair of clamping jaws that are generally horseshoe shaped and angled to be in conformity with the slope of the coil springs being compressed. One of the clamping jaws is fastened to the guiding tube and the other is fastened to a collar that engages a slide ring inside the guide tube that engages the threaded rod. The threaded rod has a hexagonal head provided on its lower end to be engaged by a driving means, such as a wrench. 
     4. U.S. Pat. No. 4,872,644. This reference is directed to a tool for compressing the coil spring of motor vehicle suspension struts. The body of the tool is a rack made from a hollow channel having bearings at either end to support a threaded bar. A block sized to be a close fit for the inside of the hollow channel has a threaded aperture to engage the threaded bar. A pair of spring engaging members in the form of angled arms is provided. One pair of arms is welded to one end of the hollow channel and another pair of arms is fitted to the block that rides inside the channel. Mounted on each of the arms are cleats shaped to insert between the grip of the coils of a spring. The threaded rod has a hand crank. 
     5. U.S. Pat. No. 4,516,303. This reference is directed to a spring compressor that can be utilized for compressing coil springs on strut suspension assemblies. The spring compressor has a pair of threaded guide shafts that are secured in a parallel arrangement between a top support and bottom support. Mounted on the pair of guide shafts is a gear drive assembly adapted to move along the threaded supports when its input shaft is rotated. A pair of spring engaging shoes are provided, one being secured to the top support and the other being secured to the gear drive assembly. 
     Also pertinent to the art are U.S. Pat. Nos. 4,276,684; 4,909,480; 4,976,416; 5,172,889; 5,680,686; 6,129,339; and 6,616,126 B1. 
     An examination of the aforesaid patents discloses that the respective teachings are different in material respects from the structure and function of the present invention. In particular, but by no means the only difference between these other devices and the device of the present invention, is the unique ability of the structure of the present invention to accommodate strut coiled springs comprised of coils with different diameters. 
     Devices of all kinds have been used in the prior art to facilitate the safe removal of a motor vehicle suspension strut. Many of these devices, including those described in some of the above-cited references, are crude, clumsy, inefficient and/or extremely unsafe to use. Where a particular device may seem safe and effective, it generally lacks the element of portability or ease of use. Further, none of these devices provides the means to accommodate a suspension strut with coils of different sizes. For example, it is common knowledge in the automobile industry that the coils used with suspension struts for domestic vehicles are usually larger than the coils used with suspension struts for some, if not most, import models. Thus, what the prior art is lacking is a device that is easily portable, easy to operate and functions at a high degree of effectiveness to enable the user to achieve the intended objective, namely to safely remove a strut from the suspension strut assembly and maintain the compressed or tensioned coil spring safely in place while a replacement strut is installed. In addition, the prior art lacks a device that can accommodate suspension struts with coils having different diameters. 
     Accordingly, nothing in the prior art provides the device that is as capable, versatile, portable and accommodating as the device of the present invention, as taught in detail in the specification and defined in the appended claims. 
     SUMMARY OF THE INVENTION 
     The present invention provides a device for compressing a coiled spring comprised of multiple coils used in combination with a motor vehicle suspension strut under tension from the coiled spring. The device includes a first hollow tube having a certain diameter, and a first end and a second end. A second tube, which may also be entirely or partially hollow, is included and has a diameter that is smaller than the diameter of the first hollow tube with the second tube being adapted to fit slidably into the first hollow tube. The second tube also has a first end and a second end with a threaded section formed at or along the interior side walls of the first end. Also provided is a rotatable threaded drive shaft, which is coaxially mounted within the first hollow tube at one end of the tube, for engaging the threaded section. A first compressor plate is attached to the first hollow tube to engage one of the coils of the coiled spring and a second compressor plate is attached to the second tube to engage a second such coil. A means is provided to drive the rotatable threaded drive shaft. The drive shaft is employed to compress the coiled spring for the purpose of reducing the tension of the coiled spring against the strut&#39;s retention end plates to enable the safe, quick and easy removal and replacement of the strut with a new one. 
     In one embodiment of the present invention, each of the two compressor plates consists of an open ended slotted central portion defined by two side sections. In another embodiment of the present invention, the side sections of each of the two compressor plates define an upper slotted section and a narrower bottom slotted section with an annular interior edge. The upper slotted section is provided to engage and seat coils of a certain relatively large diameter, while the bottom slotted section is provided to engage and seat coils of a relatively small diameter. An opening, which is defined where the sides of the upper and bottom slotted sections converge, is provided to enable coils with relatively smaller diameters to pass through the opening into the bottom slotted section where it is received and seated. 
     Openings are formed within the side sections of each of the compressor plates to receive elongated rods utilized to prevent personal injury and damage to property by keeping the tensioned coiled spring from slipping from its placement while the suspension strut is being removed and awaits the installation of a substitute. 
     A handle and a drive gear assembly are mounted at one end of the rotatable drive shaft to impose rotation and axial movement to the shaft causing it to engage and rotate through the threaded section in diametrically opposed directions to either compress or decompress the coiled spring, as the operator desires. 
     Accordingly, it is the object of the present invention to provide a device for compressing a tensioned coiled spring with multiple coils used in combination with a motor vehicle suspension strut. 
     Another object of the present invention is to provide a device for compressing a tensioned coiled spring with multiple coils used in combination with a motor vehicle suspension strut that can accommodate coils having different diameters. 
     Another object of the present invention is to provide a device for compressing a tensioned coiled spring with multiple coils used in combination with a motor vehicle suspension strut that is easily portable. 
     Another object of the present invention is to provide a device for compressing a tensioned coiled spring with multiple coils used in combination with a motor vehicle suspension strut that is effective, safe and easy to use. 
     Still another object of the present invention is to provide a device for compressing a tensioned coiled spring with multiple coils used in combination with a motor vehicle suspension strut that is easy and cost effective to manufacture. 
     Other objects and advantages of the present invention will become apparent in the following specifications when considered in light of the attached drawings wherein the preferred and another embodiment of the invention is illustrated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevational view of a suspension strut assembly installed in a motor vehicle. 
         FIG. 2  is a perspective view of a suspension strut assembly. 
         FIG. 3A  is a perspective view of one embodiment of the device of the present invention. 
         FIG. 3B  is a perspective view of the same embodiment of the device of the present invention shown immediately before compression the coiled spring relieves tension against the retention end plates of the strut. 
         FIG. 4A  is a perspective view of a more preferred embodiment of the device of the present invention. 
         FIG. 4B  is a front perspective view of a compressor plate used with the more preferred embodiment of the present invention shown in  FIG. 4A . 
         FIG. 5  is a perspective view of the more preferred embodiment of the device of the present invention shown immediately before compression of the coiled spring relieves tension against the retention end plates of the strut. 
         FIG. 6  is a perspective view of the more preferred embodiment of the device of the present invention shown with the coiled spring compressed just prior to the removal of the strut. 
         FIG. 7  is a perspective view of the more preferred embodiment of the device of the present invention shown with the coiled spring compressed and the strut removed. 
         FIG. 8  is a perspective view of the more preferred embodiment of the device of the present invention shown with the new strut installed and the decompressed coiled spring tensioning against the strut&#39;s retention end plates after installation. 
         FIG. 9  is a side perspective view of the device of the present invention with the compressor plates shown with their side sections offset to accommodate the slopes of the coils. 
         FIG. 10  is a perspective view of the embodiment of the device of the present invention shown in  FIGS. 4A through 8  in combination with a suspension strut having a coiled spring with coils of a relatively smaller diameter. 
         FIG. 11  is an enlarged perspective of the device and suspension strut shown in  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  illustrates a conventional suspension strut assembly  10  installed in a section of a motor vehicle (not shown). 
       FIG. 2  illustrates the uninstalled version of strut assembly  10 , which comprises strut  12  and coiled spring  14 . Coiled spring  14  is comprised of individual coils, including, among others, individual coils a, b, c and d. 
       FIGS. 3A and 3B  illustrate one preferred embodiment of suspension strut removal device  16  of the present invention. Device  16  comprises hollow tube  18  and tube  20  with a diameter smaller than the diameter of tube  18  to enable tube  20  to fit slidably into hollow tube  18 . Tube  20  has a first end  22  and a second end  24  with threaded nut  26 . Alternatively, tube  20  may be hollow throughout or, at least, include a hollow section at one end with a threaded interior wall (not shown). Rotatable threaded drive shaft  28  is coaxially mounted within hollow tube  18  at end  30  and is adapted to engage threaded nut  26  or the threaded interior wall (not shown) of tube  20 . Compressor plate  34  is attached to hollow tube  18  to engage a single coil of coil spring  14 , such as coil c or d. Compressor plate  36  is attached to tube  20  to engage a single coil of coil spring  14 , such as coil a or b. Compressor plate  34  comprises central portion  38  and side sections  40  and  42 , which are laterally offset from one another with each section having a pre-determined slope to conform to the slope of the individual coil it engages. Slotted opening  44  is formed through central portion  38 . Openings  46  and  48  are formed in side sections  40  and  42 , respectively. Compressor plate  36  comprises central portion  50  and side sections  52  and  54 , which are laterally offset from one another with each section having a pre-determined slope to conform to the slope of the coil it engages. Slotted opening  56  is formed through central portion  50 . Openings  58  and  60  are formed in side sections  52  and  54 , respectively. Openings  46 ,  48 ,  58  and  60  are provided to receive elongated rods  62  and  64  through aligned openings  46  and  58 , and  48  and  60 , respectively. Rods  62  and  64  are provided to keep coiled spring  14  from slipping or bursting from its placement and possibly causing personal injury or property damage while spring  14  awaits the installation of a new strut. 
     In the application of this embodiment of the present invention, suspension strut removal device  16  is positioned so that openings  66  and  68  of slotted openings  44  and  56 , respectively, are oriented upwardly. A mounting plate  17  is provided for use with a table mounted vice (not shown). Compressor plate  34  then engages either coil c or d, and compressor plate  36  engages either coil a or b, offered here only as a hypothetical. The slopes of side sections  40 ,  42 ,  52  and  54  conform to the individual slopes of the coils seated in slotted openings  44  and  56 . 
     In another preferred embodiment of the present invention shown in  FIGS. 4A and 4B , first compressor plate  80  comprises first side section  82  with interior edge  84  and second side section  86  with interior edge  88 . First and second side sections  82  and  86  define a vertically extending open ended first slot  89  with integral bottom section  90  having annular interior edge  92 , which defines second slotted opening  94 . Second slotted opening  94  gradually expands outwardly as opposing sides  96  and  98  diverge to form first shoulder section  100  and second shoulder section  102 , respectively. Opening  103  is formed between the points where opposing sides  96  and  98  begin to diverge. First and second shoulder sections  100  and  102  define seating surfaces  104  and  106 , respectively, adapted to engage and support coils c, d, etc. having a pre-determined relatively large diameter. 
     In the same embodiment, second compressor plate  110  is also provided. Plate  110  comprises, respectively, first side section  112  with interior edge  114  and second side section  116  with interior edge  118 . First and second side sections  112  and  116  define a vertically extending open ended first slot  120  with integral bottom section  122  having annular interior edge  124 , which defines second slotted opening  126 . Second slotted opening  126  gradually expands outwardly as opposing sides  128  and  130  diverge to form first shoulder section  132  and second shoulder section  134 , respectively. Opening  136  is formed between the points where opposing sides  128  and  130  diverge. First and second shoulder sections  132  and  134  define seating surfaces  138  and  140 , respectively, adapted to engage and support coils a, b, etc. having a pre-determined relatively small diameter. 
     Using first compressor plate  80  as an example, with first slot  89  having a width of approximately 7″, a coil having a diameter of between 5″ and 7″ would have the capability of sliding easily into first slot  89  eventually coming to rest and seating itself securely upon seating surfaces  104  and  106 . If the coil is smaller in diameter, smaller in fact than the width of opening  103 , which is typical of the coils used in suspension struts for foreign automobiles, the coil could then easily fit through opening  103  passing through the opening and eventually coming to rest and seating itself securely upon annular interior edge  92 . 
     Handle  70  and drive gear assembly  72  are mounted at end  30  of hollow tube  18  to impose rotation to drive shaft  28  and urge drive shaft  28  to engage and rotate through threaded nut  26  in diametrically opposed directions to either compress or decompress coil spring  14 , as desired. 
     Thus, as shown in  FIG. 5 , device  16  engages strut assembly  10  by first turning handle  70 , which rotates drive shaft  28  to adjust the positions of compressor plates  80  and  110  (or compressor plates  34  and  36 ) to enable them to engage the individual coils. In  FIG. 6 , handle  70  is then rotated to draw compressor plates  80  and  110  (or  34  and  36 ) towards each other to compress coiled spring  14 . This action removes the tension from coiled spring  14  against retention end plates  72  and  74 . With the elimination of this tension, strut  12  can be safely and easily removed from device  16  ( FIG. 7 ). A new strut then can be installed in its place ( FIG. 8 ). 
     While the invention will be described in connection with a certain preferred embodiment, it is to be understood that it is not intended to limit the invention to that particular embodiment. Rather, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.