Abstract:
This invention relates to the art of machine repair. The present invention relates to an expandable, automated, welding device and methods used to build up material on the inner surface of a bore so that the bore can be restored to original working order. More particularly, the invention relates to the welding and repair of bearing or bore surfaces. The present invention is designed to allow easy setup and use through means of easy adjustment of the apparatus through manual adjustment of the significant positioning parameters, simple linear controls to adjust process parameters of the buildup process, and, relatively small in size. Moreover, the device allows for easy expansion of the welding torch allowing for a very broad range of engagement sizes. The present invention has a compressed air cooling means to prevent operation failure under high temperature conditions. Furthermore, a non-conductive coating has been applied to the welding torch making it less prone to damage, and safer to operate. Finally, the presentinvention&#39;s clutch control mechanism can be locked to allow for single plane welds such as face welds.

Description:
The present invention is continuation-in-part of U.S. Patent application Ser. No. 09/421,206 filed Jul. 21, 1998, which claims priority from provisional application Ser. No. 60/053,388, Jul. 22, 1997. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to the art of machine repair. More particularly, the invention is related to the welding and repair of beating or bore surfaces. 
     BACKGROUND OF THE INVENTION 
     A wide variety of machinery exists in working conditions throughout the world and is exposed to abrasive and stressful conditions. Large work loads, open and corrosive conditions and time all work to wear out bearing surfaces and require replacement and or repair. For large bearing surfaces, there is often a need to buildup material in the inner surface of a bearing bore. Various attempts have been made to provide automated machinery for depositing welding beads in a uniform manner on the inner bores of bearing journals. 
     For instance, U.S. Pat. No. 4,527,039 to Fuwesi teaches and apparatus and method for restoring the surfaces blind or through surfaces of metallic workpieces. Fuwesi teaches a method be which tools, including welding torches, can be connected to a rotating spindle. The effective radii of rotational movement of the welding torch in Fuwesi is fixed by combination of a length of the welding attachment itself, and the spindle mechanism. Fuwesi does not disclose a manually adjustable axial positioning mechanism. 
     U.S. Pat. No. 4,687,899 issued to Acheson teaches an apparatus for restoring the inner surfaces of bores in metallic workpieces that has an adjustment means that relies on fixed pieces connected with a gear mechanism for adjusting the effective radii of the welding torch. This mechanism will be either quite large or will have a small range of adjustable radii. As another embodiment Acheson&#39;s apparatus, there is provided two part mechanism for adjusting the radius of the welding arm, a radial arm and an arm parallel to the axis of rotation of the axis of the apparatus. It is clear that Acheson requires several embodiments of the device in order to provide a wide range of radii. 
     U.S. Pat. No. 5,298,710 issued to Acheson also teaches an apparatus for building up material in a large bore of a metallic workpiece. In developing the Acheson technology of previous patents, including U.S. Pat. Nos. 4,873,419; 4,892,990; and 4,925,769; Acheson has relied upon additional setups to provide a greater radii range and has developed and claimed a specific method of sweeping the inner bore that sweeps approximately 359 degrees and then makes a step, effectively equal to the welding bead. 
     Each of the systems is complicated and requires careful attention to setup parameters in order to insure proper operation. The typical trend has been to make devices that are capable of doing many operations, including building up bore surfaces and little attention has been paid to providing equipment that is responsive to the needs and conditions imposed by day to day operations. However, none of the prior art references are specifically configured to be easy to set up in the field, their primary working condition. Each of the systems is complicated and requires careful attention to setup parameters in order to insure proper operation. 
     SUMMARY OF THE INVENTION 
     The present invention is designed to allow easy setup and use through means of easy adjustment of the apparatus through manual adjustment of the significant positioning parameters, simple linear controls to adjust process parameters of the buildup process, and, be relatively small in size. The present invention relates to an expandable, automated, welding device and methods used to build up material on the inner surface of a bore so that the bore can be restored to original working order. 
     The apparatus is characterized in having various improvements over the state of the art devices specifically including an expandable welding extension arm that has a first hollow arm and a expandable welding torch joined with a swivel bearing that allows radial adjustment of an expandable welding torch nozzle that extends from an expandable hollow arm. The apparatus is further characterized in having a unitary mechanical mechanism that coordinates the rotation of the expandable welding extension arm and the axial movement of the expandable welding torch; a manually releasable mechanism for adjusting the initial radial position of the welding arm and readjustment of the same; and a conductive path that provides current flow in external portion of the device is limited to the first hollow arm, the swivel bearing means, and the expandable welding torch. The welding torch is coated with a non-conductive material resulting in a more reliable, effective, longer lasting, and safer device. Further, the present invention joins a threaded guide and an extension tube by a spindle ferrule clamp. This hollow extension tube passes through a control housing that rotates the extension tube assembly by motor and pulley means, thereby effectuating the rotation of the first arm, and the welding arm. The apparatus also employs a compressed air means to force cool air through an air line, into the control housing. The cool air allows the present invention to be used in hostile or hot conditions. The air cooling results in a device that is more reliable. 
     The method of welding to build up material with automated welding apparatus comprises the steps of: clamping the apparatus to a fixed surface and in position as desired; positioning manually the apparatus axially in line with a radial axis of a desired working surface; adjusting the adjustable support bracket means; disengaging a clutch mechanism; positioning manually and axially an extension tube to a desired length; engaging the clutch mechanism; attaching additional expandable hollow arm segments to an expandable welding torch for additional length as required; expanding manually the radial reach of the expandable welding torch to a desired length; disposing manually and radically and expandable welding torch to a desired length; positioning manually the expandable welding torch of the apparatus near a desired surface; providing and coupling manually a power, wire, and gas source; selecting a rotational direction by engaging a directional controller; selecting a rotational speed by engaging a rotation speed controller; selecting a state of engagement for a clutch control mechanism; engaging the expandable welding torch; manipulating the clutch control mechanism as desired; disengaging the expandable welding torch. 
     It is an object of the invention to provide an expandable device for uniformly building up the inner surface of a bore, which is easy to setup. 
     It is a further object of the invention to provide an expandable apparatus that provides a uniform buildup of material on the inner surface of a bore. 
     It is also an object of the invention to provide an expandable apparatus for the buildup of material that is easy to position and reposition or to change direction of the movement of the apparatus along an axis. 
     It is also an object of the invention to provide an expandable apparatus that will create a spiral buildup mechanism, simple manual axial position adjustment, and simple manual radial adjustment. 
     It is also an object of the invention to provide an easily expandable welding torch. 
     It is also an object of the invention to provide externally non-conductive welding torch. 
     It is also an object of the invention to provide an apparatus capable of performing single plane welds. 
     It is also an object of the invention to provide an expandable apparatus capable of operating in high temperatures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     In the drawing, 
     FIG. 1 A three-quarters view of one embodiment of the present invention clamped a bore. 
     FIG. 2 A view of the lower assembly of the present invention. 
     FIG. 3 A view of the upper assembly of the present invention&#39;s rotation control. 
     FIG. 4 A view of the present invention&#39;s swivel control and lower portion of the welding material supply mechanism. 
     FIG. 5 A diagrammatic partial cross-sectional view of the conduit assembly of the present invention. 
     FIG. 6 A cross-sectional view of the hollow spindle assembly. 
     FIG. 7 A top plan view of the motor-pulley assembly. 
     FIG. 8A A diagrammatic top plan view of the control box with the clutch mechanism illustrated in the engaged state. 
     FIG. 8B A diagrammatic top plan view of the control box with the clutch mechanism illustrated in the disengaged state. 
     FIG. 9A A diagrammatic cross-sectional view of the expandable hollow arm, the manual locking member and the diffuser shown in an assembled state. 
     FIG. 9B A diagrammatic cross-sectional view of the manual locking coupler and the diffuser. 
     FIG. 9C A diagrammatic exploded cross-sectional view of the diffuser, the torch, the torch locking nut and the torch adapter. 
     FIG. 10A A diagrammatic front elevational view of the material prior to bending for forming the housing. 
     FIG. 10B A diagrammatic top plan view of the housing following completion of the bending process of the material. 
     FIG. 11A A diagrammatic top plan view of the clutch controller, the clutch controller hinge and the control arm. 
     FIG. 11B A diagrammatic front elevational view of FIG. 11 shown in the operative position. 
     FIG. 11C A diagrammatic front elevational view of FIG. 11 shown in the inoperative position. 
     FIG. 12A An exploded diagrammatic cross-sectional view of a liner coupler for coupling two wire guide liners with one another. 
     FIG. 12B A diagrammatic cross-sectional view showing coupling of two wire guide lines with one another via the liner coupler. 
    
    
     DETAILED DESCRIPTION 
     As can be seen in FIG. 1, the present invention is an apparatus for providing a uniform welding bead on a desired surface of a circular bore  110  or single plane. The device is comprised of several elements. An expandable welding extension arm  115  is comprised of a first hollow arm  101  rotatable along a radial axis  116 ; a swivel bearing means  113  attached at a first point to the first hollow arm aligned on said radial axis; and an expandable welding torch  114 . The expandable welding torch is comprised of an expandable hollow arm  112  attached to a second point of the swivel bearing means so as to be disposed away from said radial axis; and a nozzle  111 . Further, this expandable hollow arm is further comprised of expandable hollow arm segments  119 ,  120  that allows a field operator to manually, quickly, cheaply, and effectively expand or reduce the radial reach of the apparatus by attaching or removing additional expandable hollow arm segments in the work environment. The expandable hollow arm is comprised of a first hollow arm segment, wherein the first hollow arm segment is selected from the group consisting of an intermediate expandable hollow arm segment, and a final expandable hollow arm segment. An intermediate expandable hollow arm segment  119  can be joined to the last expandable hollow arm segment  120 , or to another intermediate expandable arm segment  119 ; the intermediate expandable arm segments can be attached to one another, end to end, to further extend the radial reach of the torch arm; the last expandable hollow arm segment can be attached to either the last most intermediate expandable hollow arm segment or directly to the second point of the swivel bearing means. This simple mechanism allows an operator in the field to adjust the mechanism to work in bores of varying radii. The operator will align the axis of the first hollow arm along the desired axis of the bore and placing the nozzle  111  of a expandable welding torch  114  at the starting point of the bore where material is to be built up. Adjustment of the effective radii of the apparatus is achieved by swinging the expandable hollow arm at a swivel bearing means  113  and positioning the nozzle of the expandable welding torch in working proximity of the bore surface. Moreover, the effective radii of the expandable welding torch can be significantly expanded or reduced by adding or removing expandable hollow arm segments. 
     The first hollow arm is clamped by a second clamp  121  to an extension tube  102 . The extension tube extends through a housing control unit  103  and threaded guide  104 . A spindle ferrule clamp  106  clamps the threaded collar. A wire/power/gas conduit  105  extends into the extension tube. 
     The apparatus can be conveniently aligned with the bore by fixing a clamping means  109  to a fixed surface and then adjusting and adjustable support bracket means  107  including adjusting the effective length of a mounting rod  108 . Once fixed, the radial position of the welding arm can be finely adjusted in the invention by a clutch mechanism,  322  in FIG. 3, that releases the welding carrier mechanism to be freely moved to its desired position. 
     The clutch mechanism engages a threaded guide  104  that controls the axial movement of the welding mechanism as the welding mechanism is rotated about its axis. Clearly, the rate of axial movement depends upon the size of the thread on said threaded guide. Those skilled in the art would find it straightforward to adjust the thread size for particular welding operations. In the practice of the present invention the screws range from 6 to 12 turns per inch. The invention may be practiced with screw dimensions outside this range as conditions might require. 
     As shown in FIG. 3, the housing  103  for the control unit surrounds the extension tube  102  which extends through the control unit and carries the welding material carrier mechanism. The control box has a clutch control mechanism  322  attached to the clutch means, a rotational speed control  324  attached to the control mechanism in the controller and a directional controller  323  for moving the spindle forward or in reverse. The clutch control mechanism extends from the housing through a clutch lock  327  passage. The spindle  102  has a screw mechanism portion  326 , and a portion at the opposite side of the controller  103 . There may be disposed at opposing ends of the spindle, a spindle ferrule clamp or positioning means  106  and a second clamp  325  that also provides an indication of the position of the spindle. The spindle ferrule clamp once engaged will limit the position of the extension tube, and as a consequence the expandable welding torch. 
     FIGS. 8 a  and  8   b  show a horizontal cross-section of the control box and illustrates the working of the clutch mechanism. As can be seen, the clutch controller  861 , is connected to a clutch pivot point  862  through an arm  863  that is tensioned through a tensioning means pressing a nut section  864  against the threaded portion of the spindle  865 . As shown in the figures, the tensioning means is a simple spring. In FIG. 8 a,  the nut section is engaged into the treads and in FIG. 8 b,  the clutch arm is pivoted disengaging the nut section out of the threads. If an operator engages a single plane weld locking mechanism such as a clutch locks  327  that locks the clutch controller in the disengaged position  866 , it would allow single plane welds such as face welds. In this embodiment, one disengages the clutch controller by moving it until the clutch controller moves the nut section  864  out from the spindle support bushing  871  and away from the threaded portion of the spindle  865 . Then one may lock the clutch controller in the disengaged state by positioning the clutch controller to abut the clutch lock flange. The clutch controller is connected to a clutch controller hinge,  1101  in FIG. 11, which in turn is connected to the control arm  863 , which affects the clutch pivot point. This disengagement results in the extension tube rotating the expandable welding torch axially stationary while being held in position by the spindle ferrule clamp. Regardless, any locking mechanism, such as a clutch lock, that allows an automated welding apparatus&#39; expandable welding torch to remain stationary will allow for single plane welds. Furthermore, a coupling  869  (a ⅛ National Pipe Thread (NPT) coupling is currently used, but other couplings known and used by those skilled in the art may also be used) is attached to the housing&#39;s air cooling inlet,  1001  in FIG.  10 . The top end of an air line  868  is attached to the coupling. A bottom end of the air line is connected to a compressed air means  872 . When the compressed air means is engaged, air is forced into the housing cooling the contents within before escaping from an air escape passage  867 . This air cooling conduit and system allows for safer and more reliable operation under harsh and hot environments. The air escape passage forms a clutch lock  327  locking flange, which in this embodiment acts as the clutch lock, through which the clutch controller protrudes and engages. However, the clutch lock need not act as an air escape. Further, the air escape need not act as a clutch lock. An air escape need not be specifically provided as air will escape through various gaps and joints throughout the device. A cooling air flow is provided within the housing resulting in improved performance under extreme temperature conditions. 
     The welding materials supply mechanism comprises a welding wire guide liner; an welding current path; and a welding gas conduit. FIG. 2 shows the expandable hollow arm  112  attached to the swivel bearing means  113  and the hollow first arm  101 . A liner passes through the first arm, the swivel bearing means  113  and the expandable hollow arm and through a gas diffuser  217  to a welding tip  218  and through the welding nozzle  219 . The welding guide liner can be extended by a liner coupler,  1201  in FIG. 12, which attaches to the end of the welding wire guide; another piece welding wire guide liner can be clamped to the guide wire clamp so that the liner coupler will provide a continuous extended conduit when extending the expandable hollow arm. When using the liner coupler to extend the welding guide liner as a necessity for extending the expandable hollow arm, an operator inserts the end of the welding guide liner into the liner coupler, and then an extending piece of welding guide liner in the other end of the coupler until both ends meet within the sight window  1203  and tighten each of set screw  1204 ,  1205 . 
     The current implementation of the last expandable hollow arm segment  120  ends in a 45 degree angle from which the welding wire guide liner protrudes. Further, the last expandable hollow arm segment has an angled guide wire cavity.  901  in FIG.  9 . This angled guide wire cavity in the current implementation 1.2 degrees off from the radial axis. This provides a gentle slope for the welding wire guide liner and prevents wire feed failures from occurring by reducing the likelihood of acute bending and kinking. This implementation increases the reliability of the apparatus in general, and eases and reduces setup time. 
     The gas diffuser attaches to the last expandable hollow arm segment over the welding wire guide. The welding current runs through the wall of the first hollow arm, the swivel bearing means and the second hollow arm to the nozzle and tip. However, the welding torch is coated with a non-conductive material. Currently, a hard anodizing coating applied to the outside surface approximately 0.0005 inches thick is applied, however, other non-conductive coatings may be used. This coating prevents abrasions and undesirable arcs being struck between the part being welded (negative polarity) and the torch body (positive polarity). Such an arc can potentially damage the torch and end the weld. Such a coating resolves these problems and results in a safer device for operation. Gas is supplied through the first and second hollow tubes to the gas diffuser. 
     The first hollow arm and expandable welding torch are attached to the swivel hinge  214  and a manual locking coupler  216  and are tightened in the desired position with locking nut  215 . Tightening the locking nut will immobilize the swivel hinge so that the welding torch is radially stationary. Tightening the manual locking coupler will secure the expandable hollow arm onto the second point of the swivel bearing means. Allowing a field operator a manual adjustment for securing the expandable welding torch with a manual locking coupler allows for easy and quick set up in the field. 
     FIG. 4 shows the rotating portion of the welding materials supply mechanism including the female electrical conductor  426 , the hollow first arm wall  427 , the flexible, wire conductor  224  and a locking nut  429  for attaching the arm to the swivel bearing. 
     FIG. 5 shows wire/power/gas conduit  105  with the wire guide liner  224  attached to an adapter  532 , a retainer ring  533  and the stationary current transfer connector (or male electrical connector)  534 . It is important to note that the current path in the present invention does not follow an exterior surface until it reaches the swivel bearing. The welding core is carried in the spindle by an extension tube and the welding core is isolated from the extension tube by a plurality of o-rings. 
     In operation, the apparatus of the present invention may be easily setup, by first positioning the apparatus along the axis of the bore to be rebuilt. This is accomplished by any number of methods. In one method the workpiece is fixed to a stationary object and the axis of the apparatus is aligned with the bore. This may be accomplished initially by sight and then adjusted when the apparatus is setup by adjusting the ball joint anchor and he adjustable brackets. In many instances, the workpiece will include more than one bore that needs to be refurbished. In many instances, such as in construction equipment, there will be two bores that share a common axis. Alignment can be accomplished by use of a rod with two opposing conical slidable attachments (a first and second slidable conical attachments). The first cone is placed into the first bore and the second cone is slid along the rod into the second bore. A portion of the rod passes through the hollow spindle of the apparatus to allow fixturing of the apparatus to both bore axis. 
     After aligning the apparatus axially, the bore tip can be placed in the desired starting point by releasing the clutch of the apparatus (if the alignment rod was used it is removed and the welding core is slid into the apparatus and fit into the spindle). Upon placement, the welding core is re-engaged to the spindle by engaging the clutch. 
     The effective radius of the welding core is then adjusted by adjusting the nozzle of the expandable welding torch to an optimal working distance by swiveling the second arm of the welding core through the swivel bearing means. 
     In operation, after the apparatus has been aligned along the axis of the bore, the welding torch has been adjusted for radius and initial starting position by engaging the spindle at the correct axial position and swinging the welding torch into working position by pivoting through the swivel bearing, the apparatus starts its operation. The spindle is rotated about is I axis and welding materials (welding current, welding wire and welding gas) are supplied through the welding core to the welding torch which then deposits a strip of metal to the inner bore surface as the torch rotates around the inner circumference of a bore. Because the spindles axial position is a function of the clutch mechanism&#39;s contact with the threaded screw portion of the spindle, as the spindle rotates its axial position changes. The screw portions thread density determined the number of spirals per inch that the torch moves. A spiral pattern of material is built up on the inner bore surface. When the desired portion of the bore is built up, the process is shut off. Clearly, the bore can also be built up with several layers by repeating the above process. 
     The removable welding core of the present invention, showing in FIG.  4  and FIG. 5, is comprised of a first hollow arm rotatable along a radial axis; a swivel bearing means attached at a first point to the first hollow arm aligned on said radial axis; and a second hollow arm attached to a second point of said swivel bearing means so as to be disposed away from said radial axis where said first hollow arm attaches to a rotatable electrical connector comprising a first female portion and a second male portion wherein the electrical contact is formed between an outer radial surface of said male portion and an inner surface of said female portion and the male portion connects to flexible conduit that carries the welding wire and welding wire conduit, a conduit to transport the welding gas mixture and an electrical conductor. This welding core is insertable and removable from the control and rotation controller; this controller comprises a hollow spindle; a drive mechanism for rotating the hollow spindle; and fixturing means for holding the welding core. Specifically the controller further comprises a manual clutch mechanism for allowing slideable adjustment along the axis of rotation and a screw mechanism that coordinates the axial and radial movement of the spindle. The spindle may be connected to the welding core through electrically insulated means in order to isolate the spindle from electrical current and minimize the exposure of welding current to the lower portion of the welding core. 
     FIG. 6 shows the spindle assembly which is comprised of the spindle tube  640 , a keyway  641  disposed on the exterior surface of the spindle tube, a key  642  disposed in said key, a pulley  643  fixed to said key and positioning means. The drive v-belt,  751  in FIG. 7, runs around the pulley  643  and the motor pulley,  752  in FIG.  7 . 
     FIG. 7 shows a top plan view of the motor-pulley, v-belt and spindle drive pulley. The figure also shows the spindle, with the key and keyway with the spindle bushing disposed between spindle and the spindle drive pulley. 
     One of the advantages of the invention is that it may be easily assembled, disassembled and positioned. Because the system is dedicated to specific applications, it is relatively light and is capable of being easily transported. It is configured to use existing welding equipment of a particular user and is because of its dedicated purpose an easier system to maintain. 
     Having now described the an embodiment of the invention, it should be apparent to those skilled in the art that the foregoing is merely illustrative and not limiting, having been presented by way of example only. Numerous modifications and other embodiments are within the scope of one of ordinary skill in the art and are contemplated as falling within the scope of the invention as defined by the appended claims. The preferred embodiments have been disclosed in the foregoing.