Abstract:
A method and apparatus for deburring a metallic surface is disclosed. The method and apparatus utilizes a handheld orbital sander that is compact so that machine marks disposed in tight places can be reached. Additionally, a conformable sanding pad is utilized to allow the sanding pad to conform to the unique contours of the metallic surface to eliminate the machining marks.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefits of U.S. provisional patent application Ser. No. 62/020,903, filed on Jul. 3, 2014, the entire contents of which is expressly incorporated herein by reference. 
    
    
     STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT 
     Not Applicable 
     BACKGROUND 
     The various embodiments and aspects described herein are directed to a method and apparatus for deburring a surface. 
     In machining a metallic component, the component may have a series of machine marks such as swirls and ridges. To eliminate these machine marks, the marks are typically sanded by hand or with a rotary grinder. However, these methods are slow and sometimes ineffective due to the contour of the machined surface. 
     Accordingly, there is a need in the art for an improved method and apparatus for deburring a metallic surface. 
     BRIEF SUMMARY 
     The various embodiments and aspects described herein address the needs discussed above, discussed below and those that are known in the art. 
     A handheld orbital sander is disclosed. The handheld orbital sander may be operated with one hand and have a sanding attachment that is capable of conforming to the contour of the metallic surface. In particular, the sanding attachment has a threaded shaft that engages a chuck of the handheld orbital sander and a flat landing that helps to stabilize the sanding attachment during use. The flat landing engages the chuck to provide additional support to mitigate wobbling of the sanding attachment during rotational movement thereof. Additionally, the orbital sander is operable with one hand and the orbital sander is a compact unit. As such, the chuck of the orbital sander must optimize space to prevent interference with rotational movement of the sanding attachment. In order to do so, the chuck has an offset cylindrical recess to impart orbital motion to the rotational movement of the sanding attachment. A bearing with threaded inner race is retained within the offset cylindrical recess with a retaining ring that does not protrude inward toward the inner race. This mitigates any interference between the sanding attachment and the chuck that might prevent rotational movement of the sanding attachment during operation of the handheld orbital sander. 
     More particularly, a sanding attachment attachable to an orbital sander for deburring machine marks on a metallic surface is disclosed. The attachment may comprise a sanding disc and a pad. The sanding disc may have a circular configuration defining a periphery. The disc may have a rough side and a mounting side. The rough side may be substantially flat and have a grit selected for sanding down the machine marks. The mounting side may have a threaded nub. 
     The pad may have a flexible support for the sanding disc, a rigid base removably attachable to the sanding disc and a threaded shank removably attachable to a chuck of the orbital sander. The base may have a flat area adjacent to the threaded shank that contacts the chuck of the orbital sander to provide additional support during orbital rotation of the chuck. 
     An outer peripheral portion of the flexible support may be more bendable compared to the rigid base. The outer peripheral portion of the flexible support may be sufficiently bendable so that the sanding disc is capable of deburring an inside corner having a ¼ inch radius. 
     A central portion of the support may have a threaded hole for receiving the threaded nub of the sanding disc. 
     The flat area of the base may contact a face of the chuck of the orbital sander. 
     In another aspect, a deburring kit for deburring machine marks on a metallic surface is disclosed. The kit may comprise a mini orbital sander and a sanding attachment. The mini orbital sander may be small enough to be held and operated with one hand. The sander may have an orbital attachment. The orbital attachment may have an inner member that rotates with respect to an outer member. The outer member may be retained within a housing. The inner member may have a flat face for engagement with a sanding attachment. The inner member may have a threaded hole. 
     The sanding attachment comprise a sanding disc and a pad. The sanding disc may have a circular configuration defining a periphery. The disc may have a rough side and a mounting side. The rough side may be substantially flat and have a grit selected for sanding down the machine marks. The mounting side may have a threaded nub that can be engaged to the threaded hole of the inner member. 
     The pad may have a flexible support for the sanding disc, a rigid base removably attachable to the sanding disc and a threaded shank removably attachable to a chuck of the orbital sander. The base may have a flat area adjacent to the threaded shank that contacts the flat face of the inner member to provide additional support during orbital rotation of the sanding attachment and the housing. 
     An outer peripheral portion of the flexible support may be more bendable compared to the rigid base. The outer peripheral portion of the flexible support may be sufficiently bendable so that the sanding disc is capable of deburring an inside corner having a ¼ inch radius. 
     A central portion of the support may have a threaded hole for receiving the threaded nub of the sanding disc. 
     The inner and outer members may form a bearing held within the chuck with a retaining ring. The retaining ring may have a generally circular shape and be sized and configured to fit within a groove formed in an inner surface of the chuck. The general circular shape of the retaining ring defines curved opposed distal portions so that the retaining ring does not protrude inward and interfere with rotation of the pad. The retaining ring protrudes inward a constant distance around the entire periphery to provide a constant clearance when the sanding attachment is screwed onto the chuck so that the sanding attachment freely rotates during use. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which: 
         FIG. 1  is a perspective view of a handheld orbital sander with a conformable sanding pad for eliminating machining marks on a metallic surface; 
         FIG. 2  is an exploded perspective view of the handheld orbital sander and the sanding pad; 
         FIG. 2A  is an enlarged perspective view of a chuck of the handheld orbital sander; 
         FIG. 3  is an exploded perspective view of a chuck of the handheld orbital sander; 
         FIG. 4  is an exploded perspective view of the chuck of the handheld orbital sander illustrating insertion of a retaining ring within a groove of the chuck; 
         FIG. 5  is a perspective view of the Chuck of the handheld orbital sander with the retaining ring inserted into the groove of the chuck; 
         FIG. 6  is a perspective view of the chuck of the handheld orbital sander with a screwdriver used to remove the retaining ring from the groove of the chuck; 
         FIG. 7  is a perspective view of the chuck of the handheld orbital sander with the retaining ring partially removed from the groove of the chuck; 
         FIG. 8  is an exploded perspective view of the sanding attachment; and 
         FIG. 9  is a front perspective view of the sanding attachment. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, a compact handheld orbital sander  10  with a sanding pad  12  for deburring a machine mark  14  off a metallic surface  16  is shown. The sanding pad  12  rotates in two different rotational axes which are parallel to each other. Also, the sanding pad  12  has an outer peripheral portion which is conformable to the metallic surface  16  so that the user may press down on the metallic surface  16  to conform the outer peripheral portion  68  of the sanding pad  12  to the contour of the metallic surface  16  for deburring machine mark  14 . To operate the orbital sander  10 , the user grips the body  18  of the sander  10  and depresses the trigger  20 . The orbital sander  10  is a pneumatic operated sander and rotates the sanding pad  12  about a first rotational axis. Also, the first rotational axis is rotated about a second rotational axis which is parallel to the first rotational axis. By providing a compact handheld orbital sander  10  with the sanding pad  12 , the user may efficiently and effectively deburr and eliminate machine marks  14  from a metallic surface  16 . 
     Referring now to  FIG. 2 , the orbital sander  10  has a chuck  22 . This chuck  22  rotates about rotational axis  24  in the direction of arrow  26 . Additionally, the chuck  22  has an inner bearing  28  having an outer race  30  and an inner race  32 . The outer race  30  is secured to the chuck  22  and rotates off of its central axis  34 . The inner race  32  rotates about the central axis  34 . Moreover, the inner race  32  is attached to the outer race  30  by way of ball bearings. As such, the inner race  32  does not necessarily rotate at the same rotational speed as the outer race  30 . When the sanding pad  12  is attached to the chuck  22 , the sanding pad  12  rotates about both axes  24 ,  34 . This provides superior deburring capabilities to remove machine marks  14  on a metallic surface  16 . 
     The orbital sander  10  may have a custom chuck  22  for allowing the sanding pad  12  to be securely mounted to the chuck  22  so that the sanding pad  12  does not wobble during deburring operations and rotates freely. More particularly, the chuck  22  may have a cylindrical configuration and may be mounted to an arbor of the orbital sander  10 . The arbor of the orbital sander  10  rotates the chuck  22  about its central axis  34  which is also the rotational axis  24 . The chuck  22  has a cylindrical recess  36  which receives the inner bearing  28 . The inner bearing  28  is frictionally mounted to the chuck  22  in that an outer diameter of the inner bearing  28  may be press fit into the cylindrical recess  36 . To retain the inner bearing  28  in the cylindrical recess  36 , an retaining ring  38  may be disposed within a groove  40  formed in the inner surface of the cylindrical recess  36 . 
     The retaining ring  38  may be a resilient elongate curved member. The retaining ring  38  when not disposed within the grooves  40  (i.e., in its natural state) is larger than an inner diameter  42  of the cylindrical recess  36 . When the retaining ring  38  is installed, the inner bearing  28  is completely disposed within the cylindrical recess  36  and the groove  40  is exposed. The retaining ring  38  is pushed into the groove  40  and springs outward so that the retaining ring  38  is retained within the grooves  40  to prevent the inner bearing  28  from being dislodged out of the chuck  22  during use. 
     The retaining ring  38  is slender and does not protrude inward to provide as much space for the sanding pad  12 . Moreover, the retaining ring may have a constant diameter so that the retaining ring  38  protrudes inward at most a thickness of the retaining ring  38 . The sanding pad  12  is connected solely to the inner race  32  so that during rotation of the chuck  22 , the sanding pad  12  does not contact other parts to prevent rotation of the sanding pad  12  during operation. 
     To assemble the chuck  22 , the inner bearing  28  is pushed into the cylindrical recess  36 . The inner bearing  28  is completely disposed within the cylindrical recess  36  and the groove formed on the inner surface of the cylindrical recess  36  is exposed and can receive the retaining ring  38 . Referring now to  FIG. 3 , once the inner bearing  28  is disposed within the cylindrical recess  36 , the retaining ring  38  is positioned in the cylindrical recess  36  as shown in  FIG. 4 . Initially, one side of the retaining ring  38  is disposed within the grooves  40 . The other side of the retaining ring  38  overhangs the chuck  22 . The user pushes the portion of the retaining ring  38  that overhangs the chuck  22  with his or her thumb  44  toward the center of the chuck  22 . The retaining ring  38  material is selected so that pressure from the thumb may be capable of sufficiently deflecting the retaining ring  38  to lodge the retaining ring  38  into the groove  40  of the cylindrical recess  36 . When the retaining ring  38  is disposed within the groove  40 , as shown in  FIG. 5 , the retaining ring  38  protrudes inward and blocks the inner bearing  28  from vibrating out of the cylindrical recess  36  during operation. The opposed distal end portions do not protrude inward as in prior art retaining rings. In this manner, the sanding pad  12  does not contact the retaining ring  38  or any other part to prevent or hamper rotation of the sanding pad  12  during operation. 
     To remove the retaining ring  38  from the groove  40 , the chuck  22  has a notch  46  that extends at least partially into the groove  40 . When the retaining ring  38  is disposed within the grooves  40 , the notch  46  provides space so that a screwdriver  48  may be inserted into the notch  46  to push in the retaining ring  38  in the direction of arrow  50  to dislodge the retaining ring  38  out of the groove  40 , as shown in  FIG. 7 . The retaining ring  38  is removed from the chuck  22  to fix or maintain the orbital sander  10  or the internal parts of the chuck  22 . 
     The sanding pad  12  includes a sanding disk  52  and sanding bit  54 . The sanding bit  54  and the sanding disk  52  are removably attachable to each other through a threaded connection. In particular, the bottom side of the sanding bit  54  has a threaded hole  56 . Also, the sanding disk  52  has a threaded nub  58 . The threaded nub  58  is screwed into the threaded hole  56  to attach the sanding disk  52  to the sanding bit  54  or unscrewed from the threaded hole  56  to remove the sanding disk  52  from the threaded hole  56 . 
     The sanding bit  54  may be fabricated from a resilient polymeric material (e.g., rubber). The outer peripheral portion  60  of the sanding bit  54  may encapsulate an inner central portion  62  fabricated from a metallic or nonrigid material. The threaded hole  56  may be formed in the inner central portion  62 . The inner central portion  62  may extend from the bottom surface of the sanding bit  54  to the upper side of the sanding bit  54 . The inner central portion  62  provides stability and rigidity to the sanding pad  12  as the user applies pressure onto the metallic surface  16  to conform the outer peripheral portion  60  of the sanding pad  12  to the contour of the metallic surface  16 . The inner central portion  62  may have a flat landing  64 . The flat landing  64  of the inner central portion  62  may butt up against the flat face of the inner race  32  when the sanding pad  12  is attached to the sander  10 . The flat landing  64  provides additional stability during rotation of the sanding pad  12  by the sander  10 . This prevents the sanding pad  12  from wobbling during operation. 
     The sanding pad  12  may have a generally rigid central portion  66 . An outer peripheral portion  68  may be flexible and conform to the underside of the outer peripheral portion  60  of the sanding bit  54  as the user pushes down on the sanding pad  12  to conform the sanding pad  12  to the metallic surface  16 . 
     The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein, including various ways of attaching the sanding disc  52  to the sanding bit  54 . Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments.