Abstract:
A tool for removing a first shaft from a second shaft, in which the first and the second shafts are coupled by fasteners. The tool generally includes the flanged connection and a driving rod. One or more apertures extend completely through a first portion extend into the second flange portion a distance less than the thickness of the second flange portion. The driving rod has first and second ends, with a removable cap adapted to engage the second end to provide a striking surface. At least one removable driver tip is also provided, having a connecting end adapted to engage the first end, and a driver tip, sized to fit into the aperture and extending outward from the connecting end. The driver tip is angled such that the second end of the driving rod is accessible when the driver tip is inserted into the aperture.

Description:
TECHNICAL FIELD 
     Embodiments of the present disclosure generally relate to automotive tools, and, more particularly, to a tool for maintenance activities on an automotive power train. 
     BACKGROUND 
     Driveshafts, also referred to as propeller shafts, are employed in vehicles to transfer rotary motion to the wheels. In general, a driveshaft couples to the vehicle transmission on one end via a power take off unit (PTU), and to a differential gear assembly on the other end. Universal joints generally form couplings at both ends. The resulting arrangement facilitates energy transfer from the engine to the wheels. 
     In keeping with contemporary engineering practice of reducing weight and thickness of components, the end caps on driveshaft universal joints and the PTU are now fashioned from thinner and lighter gauge materials than formerly. These components are relatively lower in stiffness as well. The newer materials do reduce vehicle weight, but they can also pose difficulties for maintenance personnel in working with these components without damaging them. 
     Service operations that require removing the driveshaft generally require traditional dis-assembling techniques. One such technique involves the well-known method of separating the yoke ends, typically by prying them. Often, however, this technique irreversibly damages the end caps. Corrosion, which has the effect of requiring increased force to separate the yoke ends, along with the incorporation of lighter gauge material, increases the risk of damage and deformation. 
     Thus, the art stands in need of improved tools for removing a driveshaft from a vehicle with minimum risk of damage. No current practice addresses this difficulty encountered during service and repairs. 
     SUMMARY 
     One aspect of the present disclosure describes a tool for removing a first shaft from a second shaft, in which the first and the second shafts are coupled by at least one fastener element extending through a flanged connection formed on the first and second shafts. The tool generally includes the flanged connection and a driving rod. The flanged connection includes one or more apertures, each aperture extending completely through a first shaft flanged connection portion and extending into the second shaft flanged connection a distance less than the thickness of the second shaft flanged connection. The driving rod has a first end, including a first connection arrangement, and a second end, including a second connection arrangement. In addition, a removable cap is adapted to engage the second connection arrangement, the cap fitting over the driving rod and having a striking surface. At least one removable driver tip is also provide, having a connecting end adapted to engage the first connection arrangement and a driver tip, sized to fit into the aperture and extending outward from the connecting end. The driver tip is angled such that the second end of the driving rod is accessible when the driver tip is inserted into the aperture. 
     Additional aspects, advantages, features and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative embodiments construed in conjunction with the appended claims that follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The figures described below illustrate a number of exemplary embodiments of the disclosure. Throughout the drawings, like reference numerals refer to identical or functionally similar elements. The drawings are illustrative in nature and are not drawn to scale. 
         FIG. 1A  is a pictorial view of an exemplary driveshaft removal tool according to the aspects of the present disclosure. 
         FIG. 1B  is an exploded view of the driveshaft removal tool of  FIG. 1A . 
         FIG. 2A, 2B, and 2C , are cross-sectional views of the driveshaft removal tool in an exemplary application. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is made with reference to the figures. Exemplary embodiments are described to illustrate the subject matter of the disclosure, not to limit its scope, which is defined by the appended claims. 
     Overview 
     In general, the present disclosure describes an apparatus for removing a driveshaft from a Power Take off Unit (PTU) in a vehicle. This disclosure addresses a driveshaft removal tool having an angled driver tip insertable into an access aperture, formed in an end cap flange. The end cap flange is attached to a flange on the driveshaft. Once the punch tip is inserted into an access aperture, repeated taps on the driving cap pushes against the driveshaft flange, thereby separating the driveshaft from the PTU output shaft. This operation advantageously removes the driveshaft while producing only limited or substantially negligible damage to the driveshaft end caps. 
     Exemplary embodiments 
     The following detailed description illustrates aspects of the disclosure and its implementation. This description should not be understood as defining or limiting the scope of the present disclosure, however, such definition or limitation being solely contained in the claims appended hereto. Although the best mode of carrying out the invention has been disclosed, those in the art would recognize that other embodiments for carrying out or practicing the invention are also possible. 
       FIGS. 1A and 1B  illustrate an exemplary driveshaft removal tool  100  according to the present disclosure.  FIG. 1A  presents an assembled view, and  FIG. 1B  depicts an exploded view. Portions that facilitate the tool&#39;s assembly, therefore, can be visualized more clearly in  FIG. 1B . The driveshaft removal tool  100  includes a driving rod  102 , in the form of an extended rod. A driving cap  110  is fitted to one end of driving rod  102 , and a removable tip  112  is carried at its opposite end. 
     In the illustrated embodiment, the driving rod  102  has a circular cross-section, but other forms can be employed, based upon the needs of the particular tool. Also, the illustrated embodiment includes a base member  106  and an extension member  104 . These members are structurally similar and connect to form an integrated driving rod  102 . A knurled portion  108  may be provided to offer an improved gripping surface. 
     In one embodiment, the length of the extension member is 9 inches, while the base member measures 16 inches. The exact dimensions, and the combination of dimensions, can be chosen to fit a particular automotive vehicle or series of automotive vehicles. 
     One end of both extension member  104  and base member  1064  provide threaded recesses  118 , 118 ′, and the opposite end of each rod carries a threaded stud  116 ′,  116 ″. Using these elements, the two rods can be screwed together to form driving rod  102 . This configuration provides three tool lengths, including a short length, employing extension member  104 ; a medium length, employing base member  106 ; and a long length, employing driving rod  102 . A user can select the length most suitable for a particular job. Further, lengths of each member may be chosen with an eye to providing the most useful lengths, based on the expected vehicles to be serviced. Moreover, although three possible combinations are illustrated in the depicted embodiment, it will be clear to those in the art that any number of different lengths can be made available to a user, based on anticipated requirements. If only a single vehicle is to be serviced, of course, a single driving rod  102 , fashioned to the appropriate length, could be provided. 
     Structurally, the extension and base members  104 , 106  include a solid steel body, which may be formed by machining or similar manufacturing processes. Although a threaded connection between the extension member  104  and the base member  106  is illustrated, other connection types, such as, luer-locks, snap fits, and the like, may be employed. In the illustrated embodiment, both members  104  and  106  are substantially cylindrical in cross-section, but those in the art may envision other suitable shapes and configurations. 
     A driver tip  112  is carried on an end of the driving rod  102 . In the depicted embodiment, the driver tip  112  includes a stud  116  that can threadably assemble into the recess  118  of the extension member  104  or into recess  118 ′ of base rod  106 . When so assembled, driver tip  112  extends outward from the extension member  104 . In form, this element tapers from the diameter of extension member  104  to a punch tip  114 . In some embodiments, punch tip  114  will form the major portion of the length of driver tip  112 , and that element will generally be formed with a circular cross-section having a smaller diameter than that of extension member  104 , as explained below. Particular dimensions and forms can be altered to fit particular scenarios. 
     Punch tip  114  bends or curves, forming an angle to the driving rod longitudinal axis  120 . The purpose and employment of this angle is described below in connection with  FIGS. 2A and 2B . Alterations to this design are possible based on individual requirements and practices. Thus, additional curvatures, extension trims, bends, flexures, etc., may be contemplated. In an exemplary embodiment, the bend angle lies in the range of 0°-30°. In some applications, the maximum bend angle may be restricted to about 20° to assure delivery of optimum force without bending the driver tip. Further alterations to this design will be detailed below. 
     The opposite end of driving rod  102 , (i.e., the end of base member  106  not threadably engaging extension member  104 ), carries a driving cap  110 . A stud  116 , formed in an end of base member  106 , as discussed below, threadably attaches the driving cap  110  to the base member  106 . Driving cap  110  generally continues the form of base member  106 , and in some embodiments it may have a greater diameter than the latter element. This cap provides a surface for tapping with a hammer or other suitable striking object, for transferring a longitudinal force without damaging the threads of either extension member  104  or base member  106 . Also, driving cap  110  has a suitable thickness that will stand up under repeated hammer blows. 
       FIGS. 2A, 2B, and 2C  illustrate an exemplary employment of the driveshaft removal tool  100 . Here, a driveshaft  202  is connected to a PTU end cap  205 , located at the end of PTU output shaft  204 . Generally, the driveshaft  202  connects the vehicle powertrain to the wheels and is positioned in the vehicle underbody. It will be understood by those in the art that a gear assembly, such as a universal gear or similar device, is carried within end cap  205 . Selection of the particular device employed is not relevant to the present disclosure, and thus that device has been omitted from the drawings and will not be discussed further. Both the driveshaft  202  and end cap  205  have generally matching flanges  212 ,  210 , respectively, except that end cap flange  212  is formed with both a flat portion and a lip portion, with the lip portion fitting over the sides of driveshaft flange  210 . The flat portions of both flanges are aligned, and the flanges are secured in position by bolts  206 . In the illustrated embodiment, six bolts  206  are provided, threadably engaged into tapped recesses in the mating surface of driveshaft flange  210 . It will be understood that fewer or more than six bolts may be employed in particular embodiments, as desired. In addition to apertures to accommodate the bolts, two access apertures  207  formed through end cap flange  212 , as explained below. Two access apertures are provided in the illustrated embodiment, spaced around the periphery of end cap flange  212 . 
       FIG. 2A  depicts a generic layout of the driveshaft  202  coupled to the PTU output shaft  204  via end cap  205 . Services and repairs requiring driveshaft removal require the driveshaft&#39;s total disengagement from the PTU output shaft  204 . Accordingly,  FIG. 2B  depicts an initial driveshaft disengagement stage, where an operator removes bolts  206 , thereby freeing driveshaft flange  210 . Typically, however, driveshaft flange  210  and end cap flange  212  adhere to one another, as a result of corrosion or simple buildup of contaminants around the flange joint. This increased friction requires additional measures to separate these two elements. That separation is accomplished with driveshaft removal tool  100 . I 
     Initially, a user must configure the various items included with driveshaft removal tool  100  to assemble a tool suitable for use in a particular situation. To accomplish that goal, a user must determine the length required to extend from the PTU/driveshaft junction to a position where a user can employ the driveshaft removal tool. Determining that length allows a user to select the appropriate combination of base member  106  and extension member  104  to form an appropriate driving rod  102 . Additionally, a user must determine an appropriate angle for punch tip  114 , leading to the selection of the most useful of the specific punch tips  114  available to the user. The user then assembles the selected punch tip  114 , the selected combination of base member  106  and extension member  104 , together with driving cap  110 , to form an appropriate driveshaft removal tool  100 . 
     Then, an operator inserts the punch tip  114  into an available access aperture  207 . The end of punch tip  114  bottoms against the surface of end cap  210 . The user then taps driving cap  110  with a hammer or other suitable tool, in direction B, which delivers a force to driveshaft flange  210  in direction A. If end cap flange  212  and driveshaft flange  210  are tightly adhered, a number of taps may be required, delivered at access apertures  207  around the periphery of end cap flange  212 . Eventually, however, this process will produce the desired separation of driveshaft  202  from the (PTU output shaft  204 . Service and repair operations can then commence. 
     In some embodiments, access aperture  207  may extend into driveshaft flange  210 . To effectively remove the driveshaft, of course, there must be some structure provided to absorb the force delivered by punch tip  114 . That structure could be provided by having access aperture  207  extend only part way through driveshaft flange  210 . In embodiments where it is deemed expedient to extend access aperture  207  completely through driveshaft flange  210 , some other structure, such as a welded ear or the like, could be provided, and punch tip  114  would then be able to deliver force to that structure. 
     Driveshaft removal rod  100  may be delivered to a user as a modular unit, or kit that is portable, incorporating ease of use. For example, such a kit can include multiple driver tips, each having a punch tip  114  structured with different angular bends and lengths. Also, such kits may include variations in the number of members that jointly make the driving rod  102 . When accompanied by instruments such as torches, fixtures, hammers, slide hammers, etc., the kit&#39;s usability may be enhanced. Additionally, a carrying case may facilitate the kit&#39;s portability. 
     The disclosed driveshaft removal tool  100  may be applied to a variety of other applications. For example, any similar application, requiring the removal of a first shaft from a second may make use of the disclosed subject matter. Applications, however, need not be limited to the separation of shafts alone. Therefore, it may be well known to those in the art that the description of the present disclosure may be applicable to a variety of other environments as well, and thus, the environment disclosed here must be viewed as being purely exemplary in nature. 
     Further, the tool  100  discussed so far is not limited to the disclosed embodiments alone, as those skilled in the art may ascertain multiple embodiments, variations, and alterations, to what has been described. Accordingly, none of the embodiments disclosed herein need to be viewed as being strictly restricted to the structure, configuration, and arrangement alone. Moreover, certain components described in the application may function independently of each other as well, and thus none of the implementations needs to be seen as limiting in any way. 
     Accordingly, those skilled in the art will understand that variations in these embodiments will naturally occur in the course of embodying the subject matter of the disclosure in specific implementations and environments. It will further be understood that such variations will fall within the scope of the disclosure. Neither those possible variations nor the specific examples disclosed above are set out to limit the scope of the disclosure. Rather, the scope of claimed subject matter is defined solely by the claims set out below.