Abstract:
A lightweight and portable service tool and method of use is provided for facilitating bushing replacement without removal of suspension from a vehicle. A tool end removably straddles the suspension and anchors the tool to the suspension. An actuator end, connected to the tool end, imparts a bushing jacking force along a common tool axis for extracting a bushing from, or installing a bushing into an eyelet of the suspension. The actuator end can form a jack or form a bore for receiving a portable jack as the source of the jacking force.

Description:
FIELD 
       [0001]    A service tool and method of use is provided for the extraction and installation of bushings into vehicular suspension. 
       BACKGROUND 
       [0002]    The suspension for heavy vehicles, including trucks and trailers, is typically supported with leaf springs and beam suspensions. Beam suspension and leaf springs are positioned between an axle, or axle assembly, and the load carrying frame. Beams and leaf springs are normally terminated at each of two ends with a circular eyelet. A bushing passes though the eyelet and connects at bushing pin ends to a hanger or other structure secured to the vehicle frame. The bushing includes an annular elastomeric element (rubber or polyurethane) about the pin to provide some vibration isolation and permit some limited rotation at the eyelet. 
         [0003]    As an example, leaf springs are manufactured of spring steel and, over time, rust can form between the eyelet and the bushing, causing difficulty during eventual replacement. In highway trailer axle assemblies, which operate in severe conditions, bushings can require replacement at frequent intervals. 
         [0004]    Applicant&#39;s experience has been that bushing replacement, such as that for suspensions including a variety of Henrickson suspension (Hendrickson Truck Systems Group, Woodridge, Ill., USA), can require removal of the suspension and use of a hydraulic press, typically found in a service shop environment, to force the bushing from the eyelet. 
         [0005]    For example, refurbishing of bushings for a tri-axle trailer entails: removal of the six leaf springs, press removal of the bushings, installation of a new bushings and reinstallation of the six leaf springs on the trailer. This operation can take as much as 6 to 8 hours and require access to a shop press. 
       SUMMARY 
       [0006]    In embodiments described herein, a service tool is provided for facilitating bushing replacement without removal of suspension from a vehicle, including trucks and trailers. The tool is lightweight and usable by one person for reducing the time needed for bushing replacement to about one-half of that currently required. For example, re-bushing a tri-axle trailer can now take as little as 3 hours. The tool can be used in the field or in a shop environment. 
         [0007]    In one aspect, a service tool for extracting and installing a bushing in an eyelet of a vehicular suspension comprises a frame having a actuator end and a tool end, the actuator end and tool end aligned along a longitudinal tool axis. The tool end forms a housing port, open laterally to a side of the frame, and is aligned along the tool axis between an anchor plate and the actuator end. The anchor plate is connected to the actuator end and has an extraction port therethrough along the tool axis. The housing port is sized to accept the suspension from the side of the frame with the housing adjacent the anchor plate. A bushing is aligned along the tool axis, and the actuator is operable between the actuator end and the bushing. When actuated, the actuator, supported at the actuator end, urges the suspension to bear against the anchor plate for support. For installation, the bushing is urged into the supported suspension. For extraction, the bushing is urged out of the supported suspension and at least partially through the through port. 
         [0008]    The actuator can be a portable hydraulic jack, the actuator end having an open side for removably receiving the jack therein. 
         [0009]    In another aspect, a method for insitu extraction and installation of bushings from and into an eyelet of a vehicular suspension using a service tool is provided comprising disconnecting the suspension bushing from the vehicular frame, the bushing supported in a suspension eyelet and orienting the service tool&#39;s tool end over the eyelet and bushing. Then one commences jacking against an actuator end of the service tool to drive against the bushing. The eyelet is supported at the tool end and, for installation, one drives the bushing into the eyelet suspension, and, for extraction, one drives the bushing out of the eyelet. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1A  is a perspective view of an eyelet end and bushing of a two leaf, leaf spring arranged within a service tool according to one embodiment; 
           [0011]      FIG. 1B  is a partial side view of the eyelet end of the leaf spring according to  FIG. 1A ; 
           [0012]      FIG. 1C  is a cross-sectional view of the leaf spring of  FIG. 1B , and bushing extending therethrough; 
           [0013]      FIG. 2A  is a side, cross sectional view of a housing for an embodiment of a bushing service tool; 
           [0014]      FIG. 2B  is a side view of a conventional portable power hydraulic ram, an actuating pump not shown; 
           [0015]      FIG. 2C  is a side cross-sectional view of a bushing extraction adapter complementary to the service tool and hydraulic ram of  FIGS. 2A and 2B ; 
           [0016]      FIG. 2D  is a perspective view of a service tool according to  FIGS. 2A to 2C ; 
           [0017]      FIG. 3A  is a side, cross sectional view of the housing for a bushing removal tool along A-A of  FIG. 3B ; 
           [0018]      FIG. 3B  is a first end view along B-B of  FIG. 3A ; 
           [0019]      FIG. 3C  is a second end view along C-C of  FIG. 3A ; 
           [0020]      FIG. 3D  is a perspective view of the service tool according to  FIGS. 3A to 3C ; 
           [0021]      FIGS. 4A through 4J  are successive views of the extraction of a bushing from a leaf spring, namely 
           [0022]      FIG. 4A  orienting the tool about the suspension spring, 
           [0023]      FIG. 4B  aligning the tool and bushing, 
           [0024]      FIG. 4C  positioning the adapter, 
           [0025]      FIG. 4D  inserting the portable hydraulic ram, 
           [0026]      FIG. 4E  preparing to actuate the ram, 
           [0027]      FIG. 4F  engaging the ram and adapter with the bushing, 
           [0028]      FIG. 4G  taking up the tool anchor plate to spring slack, 
           [0029]      FIG. 4H  breaking the bushing eyelet connection, 
           [0030]      FIG. 4I  pushing the bushing from the eyelet, and 
           [0031]      FIG. 4J  recovering the bushing; 
           [0032]      FIGS. 5A through 5G  are successive views of the installation of a new bushing into a leaf spring eyelet, namely: 
           [0033]      FIG. 5A  arranging the tool about the suspension spring and positioning a new bushing and adapter in the service tool, 
           [0034]      FIG. 5B  engaging the bushing with the eyelet, 
           [0035]      FIG. 5C  inserting the portable hydraulic ram, 
           [0036]      FIG. 5D  engaging the ram with the adapter, 
           [0037]      FIG. 5E  pressing the bushing into the eyelet, 
           [0038]      FIG. 5F  recovering the hydraulic ram and adapter, and 
           [0039]      FIG. 5G  removing the service tool. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0040]    Replacement of a vehicular suspension bushing without the need to remove the suspension from the vehicle saves significant time and is convenient. A service tool is described herein in the context of a leaf spring suspension, however the tool is equally applicable to other eyelet and bushing arrangements such as that in beam-type and other forms of suspension S. 
         [0041]    As shown in  FIGS. 1A ,  1 B and  1 C, a bushing  10  is shown fit to an eyelet  12  of a leaf spring  14  embodiment of suspension S. As shown in  FIG. 1A , a service tool  20  is provided for extracting or installing the bushing  10  from or into an eyelet of the suspension S. The service tool  20  can be used in-situ, brought to the location of the vehicle requiring a bushing replacement, or alternatively, if the vehicle is already in a shop, or the suspension has been removed, the tool can be also be used in a shop location. Similarly, a replacement or new bushing  10  can be installed with the service tool  20 , the service tool functional as an extraction tool, an installation tool, or both. 
         [0042]    As shown in  FIGS. 2A and 2D , the service tool  20  comprises a frame  22  having a first suspension or first tool end  24 , and a second actuator end  26 . The tool end  24  and actuator end  26  are aligned along a longitudinal tool axis A. 
         [0043]    The first tool end  24  has an open, C-shape housing port  28  for straddling the suspension S and bushing  10 . The bushing  10  has a bushing axis BA which is concentric with the eyelet  12 . The bushing axis BA is alignable with the tool axis A. 
         [0044]    The second actuator end  26  provides a support from which to exert a bushing-extraction force. The service tool  20  is used in combination with an actuator  30  such as a jack for imparting the bushing-extraction force. The jack may be incorporated into the actuator end  26  or be removably positioned therein. A suitable jack is a portable hydraulic ram or power pack. The tool end  24  has an anchor plate  40  spaced apart from an interface plate  42  forming first and second straddle plates for forming the housing port  28  therebetween. The anchor plate  40  and interface plate  42  are connected by a wall or spacer  41  extending between the plates  40 , 42 . The spacer  41  is circumferentially discontinuous for forming the housing port  28 , yet structurally connects the anchor plate  40  and interface plate  42  together to transfer sufficient jacking forces to extract or install a bushing  10  from or into the suspension S. 
         [0045]    The housing port  28  is open laterally to a side of the frame  22 , the housing port sized to accept the suspension from a side of the frame  22  with the suspension arranged generally adjacent the anchor plate  40  and the bushing  10  aligned along the tool axis A. 
         [0046]    As shown in  FIGS. 2B and 2C , the actuator  30  is compatible for cooperation with the actuator end  26 , removably situate with a bore  27  between a base plate  44 , secured at a distal end of the actuator end  26 , and the bushing  10 . Depending upon the configuration of an axially movable and drivable working end  32  of the actuator  30 , an adapter  34  can be provided to aid in coupling the bushing  10  and the actuator  30 , such as to aid in separating an elastomeric portion of the bushing and the suspension S. 
         [0047]    The frame&#39;s actuator end  26  comprises a tubular structure fit with a base plate  44  connected to, and spaced from, the tool end  24  for receiving the actuator  30  in bore  27  therebetween. The actuator end  26  is formed with an open side  46  for access to the bore  27  and receiving the jack  30  therein. The interface plate  42 , connected to the actuator end  26  opposing the base end  44 , is formed with a passage  48  therethrough sized to freely pass the bushing  10  and access to the suspension S. The anchor plate  40  is similarly formed with an extraction port  50  sized to freely pass the bushing  10  during extraction. 
         [0048]    One form of actuator  30  is a linear actuator such as a hydraulic ram having a ram base or supported end  36 , and a ram working end  32  movable relative to the supported end  36   
         [0049]    When imparting force to the bushing, the actuator  30  is supported at an actuator&#39;s supported end  36  against the frame&#39;s base plate  44  for enabling a driving movement of the working end  32  away from the baseplate  44 . Initially, the working end  32  urges the bushing  10 , eyelet  12  and suspension S to bear against the anchor plate  40 , and once the suspension is braced, the bushing can be driven relative thereto. The actuator  30  has an actuator diameter D. The hydraulic ram form of actuator comprises a hydraulic cylinder having laterally extending hydraulic line  38 . The open side  46  is available for receiving and accommodating the line  38 . 
         [0050]    Best seen in  FIG. 3D , the open side  46  can be one-sized ( FIG. 2A ) or stepped ( FIGS. 3A and 3D ) to permit entry and positioning of the bushing  10 , adapter  34  and of the actuator  30  within the bore  27 , each component of which can have similar or different lateral dimensions. As shown in  FIG. 3D , the open side  46  has at least a first slot  46   a  having width Wa adjacent the tool end  24  for receiving the actuator  30  therein and having a longitudinal length L for receiving the actuator  30 . A second slot  46   b  has a width Wb extending longitudinally from the first slot  46   a  to a location the adjacent the base plate  44 , width Wb being smaller than width Wa. In an embodiment, width Wb can be smaller than that of the actuator  30  while accommodating the hydraulic line  38 . 
         [0051]    The actuator  30  provides the jacking force necessary to move the bushing  10  out of or into supported suspension S. The actuator can be a pushing device such as a portable power hydraulic unit (such as that represented in  FIG. 2B ). The actuator end  26  include a length of conduit or pipe that forms a connective spacer  52  between the interface and base plates  42 , 44 . A portion of the connective spacer&#39;s side wall is removed, providing the open side  46  for accessing the bore  27  and tool axis A. The open side  46  enables insertion of new bushing  10 , the bushing cup or adapter  34  ( FIG. 2C ) and the portable power hydraulic unit. 
         [0052]    As shown in  FIGS. 3A and 4B , the longitudinal tool axis A of the service tool  20  can be aligned with the bushing axis BA of a bushing  10  fit to the suspension S. The tool end  24  comprises the anchor plate  40  and interface plate  42  spaced axially sufficiently to be arranged about or straddle the suspension S. The plates  40 , 42  can be circular for minimizing material, avoiding sharp corners and maximizing visibility into the housing port  28  during use. The plates  40 , 42  are connected by the spacer  41 , such a length of an arc of a large conduit or pipe, leaving about one-half or more of the circumference free for receiving the suspension S. As shown in  FIG. 3B , the anchor plate  40  has a through extraction port  50 , aligned with the passageway  48  for passing a bushing  10  therethrough. 
         [0053]    As shown in  FIG. 3C , gussets  54  can be located between the connective spacer  52  and interface plate  42  to resist reactive jacking forces from the base plate  44 , through the connective spacer  52  and into the tool end. Note that the tool end  24  forms a housing port  28  deep enough to accommodate the suspension while aligning the busing axis BA with the tool axis A. The actuator end  26  need not be as deep as the tool end  24 , therefore can comprise smaller structure, offset from the tool end  24  yet with it&#39;s axis A coincident with the tool axis A overall. The gussets  54 , 54  can aid if providing structural rigidity to the resulting offset. 
         [0054]    In brief and as illustrated in  FIGS. 4A through 4J , for extraction of the bushing  10  from the eyelet  12 , the actuator  30  urges the bushing  10  along the axis A towards the anchor plate  40 . While there is any space or slack between the suspension S and the anchor plate, the eyelet  12  and suspension S are urged to move with the bushing  10  towards the anchor plate  40 . When the suspension S engages and is supported by the anchor plate  40 , the actuator  30  can generate enough force to free and urge the bushing  10  axially from the eyelet  12 . The bushing  10  is extracted from the eyelet  12  and moved at least partially through the extraction port  50 . When the bushing  10  is free of the eyelet, it can be retrieved for refurbishing or disposal. 
         [0055]    In brief and as illustrated in  FIGS. 5A through 5G  for installation, the bushing  10  is forcibly driven into the eyelet  12 . Again, as the bushing  10  is forced into the suspension S, should there be any space or slack between the suspension S and the anchor plate  40 , the suspension S moves with the bushing  10  towards the anchor plate  40 . When the suspension S is supported by the anchor plate  40 , the actuator  30  can urge the bushing  10  into the eyelet  12 . 
       Extraction 
       [0056]    As shown in the steps set forth in  FIGS. 4A through 4J , the bushing  10  and suspension S have already been disconnected from the vehicle&#39;s frame hanger. A vehicle jack and jack stands are typically employed to suspend the vehicle frame during the bushing replacement. In an embodiment, the bushing  10  and a leaf spring  14  are hanging or otherwise supported under the vehicle. 
         [0057]    In  FIG. 4A , the tool end  24  of the service tool  20  is oriented or manipulated over the leaf spring  14  and old bushing  10 . In  FIG. 4B , the tool axis A is aligned with the bushing axis BA of the bushing  10 . 
         [0058]    In  FIG. 4C , the bushing cap or adapter  34  is inserted through the open side  46  of the actuator end  26  for positioning in the bore  27 . 
         [0059]    In  FIG. 4D , the portable power unit or actuator  30  is fit through the open side  46  into the bore  27  of actuator end  26 . 
         [0060]    Also, as shown in  FIG. 4D , the bushing  10  typically has a pin  60  portion having first and second pin ends  61 ,  62  for removable connection to the vehicle suspension hangers (not shown). An annular elastomeric portion  64 , hereinafter referred to rubber, regardless of the elastomer used, surrounds the pin  60  and is sized to the eyelet  12 . The adapter  34  can be positioned between the working end  32  of the actuator and the bushing  10  for directing the jacking force at least partially into the annular elastomeric portion  64 . 
         [0061]    One end of the bushing, such as the first end  61 , may have a washer portion  66  extending radially beyond the pin and over the rubber portion  64 . The adapter  34  is generally cylindrical and has a recess  70  at a first bushing end  72  and a pushing surface  74  at the opposing working end  76 . The bushing end  72  has an annular shoulder  80  about the recess  70 . The adapter recess  70  is aligned to receive the pin&#39;s second end  62  and the annular shoulder  80  engages the rubber portion  64 . During extraction, the adapter&#39;s annular shoulder  80  pushes on the rubber to avoid merely extracting the pin  60  from the rubber and instead ensures both pin  60  and rubber  64  are extracted from the eyelet  12 . 
         [0062]    In  FIG. 4E , the support end  36  of the actuator  30  is resting against the base plate  44  of the actuator end. When actuated, as shown in  FIG. 4F , the working end  32 , or ram, extends from the actuator  30  to engage the adapter  34  and commence pushing the bushing  10  from the suspension S. 
         [0063]    In  FIG. 4G , the actuator  30  pushes the adapter  34  against the bushing  10 . As the bushing  10  tends to resist extraction, the service tool  20  moves reactively back to take up the slack between the anchor plate  40  and the suspension S. Once the anchor plate  40  presses against the suspension S, such as the eyelet  12  of the leaf spring  14 , then the full force of the actuator  30  can be applied to extract the bushing  10  from the eyelet  12 , the reactive load path being between the working end  32  of the actuator  30 , the actuator&#39;s support base  36 , the base plate  44 , the connective spacer  52 , and to the anchor plate  40  of the tool end  24 . 
         [0064]    In  FIG. 4H , the bushing  10  finally begins to move axially from the eyelet  12 . Sometimes, one may have to hammer on the actuator end  26  at the base plate  44  to apply a sharp loading into the bushing  10  to jar the bushing/eyelet interface loose. In  FIG. 4I , the old bushing  10  passes through the extraction port  50 , and in  FIG. 4J  the old bushing is shown freed from the eyelet  12 . The adapter  43  falls out of the tool, or is otherwise retrieved from the eyelet  12 , the actuator  30  removed and the frame of the service tool  20  removed from about the suspension S. 
       Installation 
       [0065]    Typically a new bushing  10  is installed from the same side of the suspension S that the old bushing was extracted, particularly where the bushing incorporates the washer  66  at the pin&#39;s first end  61 . Accordingly, and having reference to  FIGS. 5A through 5G , the service tool  20  frame is reversed as necessary to push a new bushing  10  into the eyelet  12  from which the old bushing was extracted. Successive views are shown of the insertion of a new bushing  10  into the eyelet  12  of the leaf spring  14 . 
         [0066]    In  FIG. 5A , the tool end  24  of the service tool  20  is manipulated over the suspension eyelet  12 . A new bushing  10  is provided and inserted into the actuator end&#39;s open side  46 . In  FIG. 5B , the adapter  34  is oriented for placing the recess  70  over the pin end  61  and engaging the annular shoulder  80  with the rubber  64  or washer portion  66 . 
         [0067]    In  FIG. 5C , the actuator  30  (initially shown external to the actuator end  26  in dotted lines) is inserted through the open side  46  into bore  27 , the actuator  30  being lowered with its support end  36  into the second slot  46   b  (shown in solid lines) for placing the actuator&#39;s support end adjacent the base plate  44 . The hydraulic line  38  extends laterally through the second slot  46   b . The balance of the actuator  30  is fit entirely within the bore  27  of actuator end  26  through the first slot  46   a . The working end  32  of the actuator engages the bushing  10 , or adapter  34  if so fit, and actuated to more axially and take up the slack between the suspension S and the anchor plate  40 . 
         [0068]    In  FIG. 5D , the bushing  10  is aligned with the eyelet  12  and the actuator  30  is ready to push. 
         [0069]    In  FIG. 5E , the actuator  30  has been actuated, in one continuous movement or in increments, and has fully positioned the bushing  10  into the eyelet  12 . In  FIG. 5F , the user recovers the actuator  30  and adapter  34  from the actuator end  26 . In  FIG. 5G , the service tool  20  is removed from the suspension S. 
         [0070]    The pins  60  of the new bushing  10  can be reconnected and reinstalled to the vehicle&#39;s frame hangers and the service personnel can move to the next bushing. 
         [0071]    Example dimensions for a service tool  20  suitable for servicing Hendrickson suspensions include a frame having an actuator end connecting spacer  52  formed of 16 inch length of four inch Sch. 40 pipe. The diameter and structural spacer portion  41  of the tool end  24  is formed by a six inch length of eight inch Sch. 80 pipe, the circumference of the pipe being discontinuous and forming an arc, being about 270 degree or sufficient to form about a seven inch opening to admit a leaf spring eyelet  12 . In this embodiment, the pipe axes are parallel, yet offset by about ¾ inches. The tool end  24  pipe arc spaces the straddle plates of the anchor and interface plates  40 ,  42 . The anchor plate can be an eight inch diameter, ¾ inch plate and the interface plate can be an eight inch diameter, ½ inch plate situate between the tool end  24  and the actuator end  26 . The actuator end  26  is fit with a ¾ inch base plate  44 , the base plate being spaced from the interface plate by the connecting spacer  52  formed of the four inch pipe. The interface plate  42  is fit with a 3⅜ inch diameter passage  48 , aligned with the tool axis A, suitable to pass a bushing  10  therethrough. The anchor plate  40  is fit with the extraction port  50 , again sized to pass a bushing  10 , the extraction port  50  being aligned with the tool axis A. The open side  26  of the actuator end pipe is sized to accept a hydraulic ram, for example, the first slot  46   a  extending longitudinally away from the interface plate  42  having a slot width Wa of about 3¼ inches and a length of 6½ inches. The remaining open side or second slot  46   b  extends longitudinally towards the base plate  44  and can be sized smaller than the cylinder diameter of the hydraulic ram actuator  30 , but sufficient to pass the hydraulic hose  38  without interference. A slot width Wb of 2½ inches is suitable. The four inch pipe  52  to interface plate  42  connection is strengthened with a pair of ¼ thick gusset plates  54 , 54  straddling the open side  46  of the jack housing. The entire tool  20  can be formed of steel for ease of manufacture using welding techniques although other suitably strong materials of construction and machined components and assembly are contemplated.