Patent Publication Number: US-6665921-B2

Title: Puller apparatus and method for pulling

Description:
FIELD OF THE INVENTION 
     The present invention relates to puller devices generally, and more particularly to devices for pulling automotive pitman arms. The present invention also relates to methods for pulling automotive pitman arms. 
     BACKGROUND OF THE INVENTION 
     Various puller devices have been utilized over the years to remove articles mounted in surrounding relationship around an interiorly disposed object. For example, pullers have been utilized to extricate such items as various pulleys, gears, bearings, and specific automotive parts such as differential bearings, bushings, pulleys, and pitman arms. Such pulling devices have a wide array of applications, but have particular usage in machinery or automotive applications. 
     In general, pullers of various designs effectuate a common functionality. In many cases, typical pullers operate by simultaneously pulling on the surrounding articles to be extracted and bearing or “pushing” against the interiorly disposed object. A common technique for providing this simultaneous pulling and pushing dynamic is to utilize a pulling frame which grasps a rearward surface of the article to be extracted, and a pushing device disposed substantially centrally within the pulling frame to bear against the interiorly disposed stationary object. The pushing device is positioned relative to the pulling frame such that a user may axially move the pushing device with respect to the pulling frame. In many instances, the pushing device is a threaded rod that is threadably received through an aperture in the pulling frame, such that rotation of the threaded rod axially moves the rod in a respective direction toward or away from the article to be extracted. Typically, the user rotates the threaded rod to axially move the rod into a bearing or pushing relationship with the interiorly disposed object, while positioning the pulling or grasping frame on a rearward surface on the article to be extracted. Continued rotation of the threaded rod causes the pulling frame to move in a direction opposite of the threaded rod axial motion, such that the article to be removed axially moves with respect to the interiorly disposed object. In such a manner, articles may be “pulled” from surrounding relationship with interiorly disposed objects. 
     A variety of puller device configurations are employed for particular applications. Typically, puller frame configurations are adapted for use in particular pulling applications. For example, the puller frame may include hinge opposing jaws, or adjustable width jaws, wherein the jaws generally comprise opposing parallel arms forming a jaw. In some applications, the puller frame may include a semi-circular or circular pulling surface for transmitting force against the articles to be extracted. In still other pulling applications, the pulling frame may comprise a fixed dimension jaw having parallel and opposed gripping arms fixedly attached to the frame base. 
     A particular pulling application pertinent to the present invention is the pulling of automotive pitman arms. Several puller frame configurations have been utilized in pitman arm pullers to date. Pitman arm pullers presently used include semi-conical housings utilizing semi-circular pulling surfaces, dual-arm adjustable width jaws, and fixed dimension dual arm jaws. Fixed-dimension puller frame jaws typically reflect desired strength and durability characteristics necessary for relatively heavy duty pulling applications. In particular, pitman arms exposed to environmental conditions over extended periods of time may become corroded, and therefore difficult to remove. In such situations, a relatively heavy duty and durable puller device is desired. Thus, heavy duty fixed-dimension jaw puller frames are desirable for pulling automotive pitman arms. 
     Pitman arm pullers in use today, however, utilize a pushing device, typically a threaded rod, that is threaded through a respective aperture in the puller frame, wherein the threaded rod has an integral nut for rotating the threaded rod external from the puller frame. For example, common puller devices utilize a threaded rod threaded through a base structure of the puller frame, wherein the threaded rod may be actuated at a location external to the jaws of the puller frame. Such positioning of the integral nut requires actuation of the threaded rod at a position external to the puller frame jaws. 
     In many automotive pitman arm pulling applications, the pitman arms are positioned in relatively compact environments. For example, many automotive pitman arms are positioned such that one or more parts must be removed before access to the pitman arm is possible. The difficulty in access to the pitman arm is primarily due to the fact that the threaded rod (pushing means) of typical puller devices extend outwardly from the puller frame, thereby increasing the space required to correctly position the puller frame on or around the article to be pulled. In many cases, an entire assembly including the pitman arm must be removed from the automobile prior to extracting the pitman arm from the assembly. Often times, such assembly removal requires disassembly of power steering fluid lines from the steering box, which adds significantly to the time and effort need to extract the pitman arm. Such disassembly and removal of parts to access the pitman arm is necessary due to the external configurational nature of the actuation means on the threaded rod. 
     Therefore, it is a principle object of the present invention to provide a puller apparatus for pulling articles in compact environments. 
     It is another object of the present invention to provide a puller apparatus which is sized and configured to extract automotive pitman arms positioned in compact environments. 
     It is a further object of the present invention to provide a puller apparatus that is sized and configured to extract automotive pitman arms without first removing or disassembling surrounding parts. 
     It is a still further object of the present invention to provide an improved puller apparatus incorporating a pushing means having an actuation means disposed within the jaws of the puller frame. 
     It is a further object of the present invention to provide a puller apparatus utilizing a threaded rod as a pushing means having an integral nut disposed on a proximal portion of the threaded rod, within the jaws of the puller frame. 
     It is a still further object of the present invention to provide a puller apparatus incorporating a pushing means having an actuation means immediately adjacent a pressure tip used to transmit pushing forces on an object around which the article to be pulled is mounted. 
     Another object of the present invention is to provide a puller apparatus incorporating a pushing means having an actuation means with a pressure tip formed integrally thereon, which pressure tip transmits pushing force to an object around which the article to be pulled is mounted. 
     It is yet a further object of the present invention to provide a threaded rod for use in a puller apparatus, which threaded rod has an actuation means proximal to the object around which the article to be pulled is mounted. 
     Another object of the present invention is to provide a puller apparatus sized and configured to allow a user to actuate a threaded rod at a position within the jaws of the puller frame. 
     SUMMARY OF THE INVENTION 
     By means of the present invention, the efficiency for pulling various articles mounted in surrounding relationship around an interiorly disposed object is greatly enhanced. Through the utilization of the puller apparatus of the present invention, articles such as automotive pitman arms may be more easily accessed and removed. In essence, the user of the present invention may directly pull certain articles, including automotive pitman arms, in relatively compact environments without first removing extraneous parts. The puller apparatus of the present invention incorporates a pushing means disposed in a pulling frame, which pushing means includes an actuation means disposed within the confines of the puller frame on a portion of the pushing means proximal to the interiorly disposed object. In such a manner, the user may actuate the pushing means at a location within the puller frame, thereby eliminating the necessity of having access space surrounding the puller frame. 
     In a particular embodiment of the present invention, the improved puller apparatus includes a puller frame having a base and at least one outstanding arm extending therefrom, wherein the arm has an inwardly extending gripping projection for transmitting pulling force to an article being pulled, and the base having an aperture extending therethrough, which aperture is sized and configured to threadably receive a threaded rod therein. The threaded rod, which acts as a pushing means, preferably includes an actuation means disposed at a portion of the rod proximal to the article being pulled. The actuation means is preferably configured to impart pushing force directly upon the relatively stationary interiorly disposed object around which the article to be pulled is mounted. 
     The puller apparatus preferably incorporates a plurality of upstanding arms, and more particularly, two generally opposing arms. In some embodiments, the upstanding arms include recessed portions to allow improved access to the actuation means by engaging tools. 
     In preferred embodiments of the present invention, the actuation means includes a pressure tip formed integrally with the actuation means for operably transmitting pushing force against the interiorly disposed object. 
     In another embodiment of the present invention, the puller apparatus includes a substantially u-shaped frame having a base and a plurality of gripping arms extending substantially perpendicularly from opposing ends of the base, wherein the gripping arms extend in substantially parallel relationship with one another, and respective ends of the gripping arms which are distal from the base include inwardly disposed gripping projections extending substantially toward one another. The base preferably includes an aperture formed therein, which aperture forms an open channel extending between an upper and a lower surface of the base, the aperture being sized and configured to receive pushing means therein, which pushing means includes an actuation means disposed on a proximal portion thereof at a position within the u-shaped frame, such that actuation of the actuation means axially moves the pushing means with respect to the base. 
     In a further embodiment of the present invention, pushing means are provided for use in a puller apparatus, wherein the pushing means includes a distal end and an opposed proximal end, with the proximal end having an actuation means disposed thereon. The actuation means preferably includes a pressure tip extending from an upper surface thereof. The pushing means is adapted to be disposed in an aperture in the pulling frame such that actuation of the actuation means causes axial motion in the pushing means, whereby the pressure tip moves coaxially with the pushing means to bear against a stationary object around which an article to be pulled is mounted. In more preferred embodiments, the pushing means is a threaded rod and is threadably received in the aperture, which is correspondingly threaded to mate with the threads of the threaded rod. 
     The present invention also contemplates a method for pulling various articles from surrounding mounted relationship with an interiorly disposed object, whereby the puller apparatus of the present invention is situated with respective pulling projections positioned on a rearward surface of the article to be pulled. Actuation of the actuation means axially moves the pushing means in a direction toward the interiorly disposed object. Continued actuation of the actuation means creates a pressure between the pressure tip and the object, which results in a corresponding pulling force that is transmitted to the article to be pulled via the pulling protrusions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view showing the puller apparatus of the present invention. 
     FIG. 2 is a perspective view of a threaded rod in accordance with the present invention. 
     FIG. 3 is a perspective view of a puller apparatus of the present invention. 
     FIG. 4 is an end view of the apparatus illustrated in FIG. 1, as taken along cut line  4 . 
     FIG. 5 is a top view of the apparatus illustrated in FIG. 1, as taken along cut line  5 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The objects and advantages enumerated above together with other objects, features and advances represented by the present invention will now be presented in terms of detailed embodiments described with reference to the attached drawing figures which are intended to be representative of various possible configurations of the invention. Other embodiments and aspects of the invention are recognized as being within the grasp of those having ordinary skill in the art. 
     Referring now by characters of reference to the drawings, and first to FIG. 1, a puller apparatus  10  of the present invention is shown. Puller apparatus  10  includes a frame  12 , which frame  12  includes a base portion  14  and first and second gripping arms  16 ,  18  respectively. The first and second gripping arms  16 ,  18 , in combination, form jaws  20  of puller frame  12 . First and second arms  16 ,  18  preferably extend from opposing ends of base portion  14  in substantially parallel relationship with one another. In preferred embodiments, first and second arms  16 ,  18  extend generally perpendicularly from base portion  14 . 
     As shown in FIG. 1, first and second arms  16 ,  18  each include pulling protrusions  22 ,  24 , respectively. Preferably, pulling protrusions  22 ,  24  extend inwardly toward one another in jaws  20 . Protrusions  22 ,  24  have an inner surface  26  upon which rearward surfaces of articles to be pulled bear against in the pulling sequence. In preferred embodiments, protrusions  22 ,  24  are disposed in opposing orientation, such that pulling forces are distributed equally upon the article to be pulled. In this manner, puller apparatus  10  does not impart undesirable oblique forces onto the article to be pulled. Direct, linear pulling is desired to avoid binding or torquing of the article with respect to the interiorly disposed object around which the article to be pulled is mounted. Therefore, a diametrically opposed configuration for gripping arms  16 ,  18  and pulling protrusions  22 ,  24  is desired. However, other pulling arm configurations are contemplated in the present invention, including a unitary gripping arm having a relatively large surface area pulling protrusion, or a puller apparatus utilizing more than two gripping arms. In all cases, however, substantially linear force imposition along a plane parallel to the gripping arms is preferred. 
     Frame  12  preferably includes an aperture  30  disposed in base portion  14  thereof. Aperture  30  preferably forms an open channel extending between an upper surface  34  and a lower surface  35  of base portion  14 . Aperture  30  is preferably sized and configured to receive pushing means  40 , which may be utilized to progressively push against an interiorly disposed object around which the article to be pulled is mounted. Such pushing on the interior object by means  40  creates the countervailing pulling force with which pulling protrusions  22 ,  24  transmit to the article to be pulled. Such a pulling force is developed between means  40  and frame  12  when means  40  is progressively pushed against the relatively stationary interior object, such that frame  12  is urged in an opposite direction of the pushing force being applied to the interiorly disposed object. 
     A variety of other means for developing a pushing force upon the interiorly disposed object are contemplated in the present invention. Such pushing means may include, for example, ratcheted rods, compression springs, and any other pushing means which may be actuated or initiated at a position with frame  12 . In preferred embodiments, however, pushing means  40  comprises a threaded rod. 
     As illustrated in FIG. 1, aperture  30  is preferably threaded to receive pushing means  40  therein. Aperture  30  is desirably threaded to create axial motion for pushing means  40  upon rotation of pushing means  40  while at least partially disposed in threaded aperture  30 . Such axial motion is the source for pushing force transmitted by pushing means  40  upon the interiorly disposed object. In a particular embodiment, pushing means  40  includes threads corresponding with threaded aperture  30 , which threads may be of any desired pitch and spacing. Preferably, the threads are of metric dimension to be standard across a wide variety of applications. Other dimensions, however, may be similarly used. 
     As illustrated in FIG. 1, pushing means  40  further includes an actuation means  42  disposed on a portion of pushing means  40  proximal to jaws  20 . Actuation means  42  is preferably integrally formed with pushing means  40  such that rotation of actuation means  42  correspondingly rotates pushing means  40 . Actuation means  42 , however, may instead be operably coupled to pushing means  40  without being integrally formed with pushing means  40 , such that rotation of actuation means  42  axially moves pushing means  40  while actuation means  42  remains axially stationary. In either case, rotation of actuation means  42  progressively moves pushing means  40  axially so as to create desired levels of pushing force upon an interiorly disposed object. A corresponding resistive force directed oppositely of the pushing force is developed by pressure between pushing means  40  and the interiorly disposed object when pushing force is applied thereto. The resistive force is transmitted through pushing means  40  to frame  12  via threads  41  on pushing means  40 . Such resistive force creates the pulling force which is transmitted from frame  12  to the article to be pulled at surface  26  of pulling protrusions  22 ,  24 . The pulling force preferably acts to extract the article in a linear manner. 
     In preferred embodiments, actuation means  42  substantially comprises a hexagonal nut formed integrally with pushing means  40 . A variety of other embodiments for actuation means  42  are contemplated in the present invention, including fittings configured to receive tools other than typical wrenches. The hexagonal nut is preferably a standard size for mating with typical hand or power tools. The threaded rod with integral actuation means may be more easily viewed in FIG. 2, which illustrates pushing means  40  in an isolated view. As can be seen in FIG. 2, actuation means  42  further includes a pressure tip  44  disposed substantially centrally on a top surface  43  of actuation means  42 . In preferred embodiments, pressure tip  44  provides a location for transmitting pushing force from pushing means  40  to the interiorly disposed object. Pressure tip  44  is preferably centrally located on top surface  43  of actuation means  42  for providing uniform pushing force on the object. Preferably, pressure tip  44  is formed integrally with actuation means  42 . In some embodiments, pressure tip  44  may be disposed on a proximal portion of pushing means  40 , whereby pressure tip  44  is relatively more proximal to the interiorly disposed object than actuation means  42  such that pressure tip  44  alone comes into contact with the object upon axial motion of pushing means  40 . 
     In an alternative embodiment of the present invention, pressure tip  44  is formed integrally with pushing means  40 , while actuation means  42  is not integral with pushing means  40 . In such an embodiment, rotation of actuation means  42  axially displaces pushing means  40  in a direction generally perpendicular toward or away from the interiorly disposed object, whereby pushing force upon the object is transmitted through the pressure tip disposed on a proximal surface of pushing means  40 . 
     As illustrated in FIGS. 1 and 3, gripping arms  16 ,  18  preferably include recessed portions  52 ,  54  respectively. Recessed portions  52 ,  54  are preferably disposed in respective gripping arms  16 ,  18  adjacent base portion  14 . Recessed portions  52 ,  54  are preferably provided to allow a wrench or other tool engaging actuation means  42  to more fully rotate about a longitudinal axis of pushing means  40 . In such a manner, a relatively larger degree of axial motion of pushing means  40  may be obtained in each rotational stroke of the engaging tool, due to the fact that each rotating stroke can pass through a longer arcuate segment between distal rotation points  53 ,  55  in respective gripping arms  16 ,  18 . As shown in FIG. 3, recessed portions  52 ,  54  preferably extend only partially through a depth “d” of gripping arms  16 ,  18 . Such partial extension through gripping arms  16 ,  18  is preferably maintained to retain overall strength of frame  12 . 
     Frame  12  of puller apparatus  10  is preferably fabricated from a strong and durable material such as stainless steel, nickel steel, or other hardened metal substance. Materials utilized in the present invention may vary, so long as strength and durability are maintained. Similarly, pushing means  40 , along with actuation means  42  and pressure tip  44 , is preferably fabricated from a strong and durable material, such as steel or any other durable metal material. 
     For further reference, FIGS. 4 and 5 illustrate a side view and an end view, respectively, as taken along respective cut lines  4  and  5  of FIG.  1 . 
     A particular example for the use of puller apparatus  10  is in the pulling of automotive pitman arms. In use, puller apparatus  10  is situated with pulling projections  22 ,  24  positioned on a rearward surface of the portion of the pitman arm mounted in surrounding relationship to a splined socket joint bolt. Due to the grooved nature of the socket joint bolt, the pitman arm must be pulled in a direction parallel to a longitudinal axis of the bolt. Upon placement of the puller apparatus on the pitman arm, a user then rotates actuation means  42  with the use of a wrench or other tool. Rotation of actuation means  42  axially moves  40  in a direction perpendicularly toward a facing surface of the joint bolt. Continued rotation of actuation means  42  transmits a pushing force upon the joint bolt surface via pressure tip  44 . Since the joint bolt is substantially stationary in an axial direction, a corresponding pulling force is developed and transmitted to the pitman arm via pulling protrusions  22 ,  24  of frame  12 . Further rotation of actuation means  42  results in relative opposing movement between  40  and puller frame  12 , such that the pitman arm is extracted from surrounding relationship of the joint bolt. 
     The above described process saves the user a significant amount of time in pulling the pitman arm. The utilization of puller devices in use today requires the user to remove the assembly including the attached pitman arm from the automobile which process typically entails disconnecting power steering lines and the pitman arm assembly from the steering box. Such a process to pull and replace the pitman arm typically requires up to two hours of labor by a skilled mechanic. Through the utilization of the puller apparatus of the present invention, the same procedure may be completed in substantially less time, thereby saving expense for both the mechanic and the automobile owner. Such timesavings are a result of the elimination of the requirement of removing parts from the automobile prior to extracting the pitman arm, as well as the subsequent reassembly of such parts. 
     Additionally, utilization of the present invention greatly simplifies pulling procedures, in that relatively easy access to an actuation means for developing a pushing force upon an interiorly disposed object is provided. Further, the apparatus of the present invention is preferably designed to withstand high levels of torque required in many automotive and other mechanical applications. 
     The invention has been described herein in considerable detail in order to comply with the patent statutes, and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use embodiments of the invention as required. However, it is to be understood that the invention can be carried out by specifically different devices and that various modifications can be accomplished without departing from the scope of the invention itself.