Patent Publication Number: US-10307811-B2

Title: Apparatus for protectively holding an elongated object during bending and stretching of the elongated object

Description:
BACKGROUND OF INVENTION 
     1. Field of Invention 
     The present invention relates to deformation of an elongated object and, more particularly, to an apparatus for protectively holding an elongated object during bending and stretching of the elongated object. 
     2. Related Prior Art 
     It is sometimes desired to bend an elongated object such as a rod and a tube. For example, a straight plastic tube can be heated and softened before it is bent. A bent plastic tube can be heated and soften before it is stretched. However, such heating is often not even so that a portion of a plastic tube is excessively soft while another portion of the plastic tube is excessively hard. It is troublesome to bend or stretch the portion of the plastic tube that is excessively soft or hard. 
     A straight metal tube can be bent by forging or another proper method for fabrication in a mechanical or hydraulic mold. For example, Taiwan Patent Application Publication No. 353988 discloses a mold 10 for use with a machine 6 to bend a tube 5. The mold 10 includes a desired number of pairs of semi-circular leaf springs 1 and 2 provided on two rods 3 and 4 so that the mold 10 is flexible. The tube 5 is inserted in the mold 10 before the tube 5 is bent by the machine 6. The leaf springs 1 and 2 can be removed from the flexible rods 3 and 4 after the tube 5 is bent by the machine 6. However, the use of the mold 10 is not without any problem. Firstly, it is troublesome to place the pairs of leaf springs 1 and 2 on the flexible rods 3 and 4 or remove the pairs of leaf springs 1 and 2 from the flexible rods 3 and 4 because of the large number of pairs of leaf springs 1 and 2. Secondly, the tube 5 might be scratched by some of the leaf springs 1 and 2. 
     The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art. 
     SUMMARY OF INVENTION 
     It is the primary objective of the present invention to provide an apparatus for protectively holding an elongated object during bending and stretching of the elongated object. 
     To achieve the foregoing objective, the apparatus includes a shell, sleds and roller sets. The shell includes a wall, support portions longitudinally extending on an internal face of the wall, peripheral tunnels each extending in a corresponding one of the support portions, and grooves separated from one another by the support portions. Each of the sleds is inserted in a corresponding one of the grooves. Each of the roller sets includes rollers attached to a corresponding one of the sleds. Each of the rollers includes a tread. The treads together provide an axial tunnel. A surface of the elongated object is in contact with the concave treads of the rollers when the elongated object is rolled in the axial tunnel during bending or stretching of the elongated object. 
     Other objectives, advantages and features of the present invention will be apparent from the following description referring to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The present invention will be described via detailed illustration of two embodiments referring to the drawings wherein: 
         FIG. 1  is an exploded view of an apparatus for protectively holding an elongated object during bending and stretching of the elongated object according to the first embodiment of the present invention; 
         FIG. 2  is an enlarged partial view of the apparatus shown in  FIG. 1 ; 
         FIG. 3  is a cross-sectional view of the apparatus shown in  FIG. 1 ; 
         FIG. 4  is another cross-sectional view of the apparatus shown in  FIG. 1 ; 
         FIG. 5  is a cross-sectional view of the apparatus taken along a line A-A shown in  FIG. 4 ; 
         FIG. 6  is a cross-sectional view of the apparatus taken along a line B-B shown in  FIG. 4 ; 
         FIG. 7  is a cross-sectional view of the apparatus in another position than shown in  FIG. 4 ; 
         FIG. 8  is an enlarged partial view of the apparatus shown in  FIG. 3 ; 
         FIG. 9  is a perspective view of the apparatus shown in  FIG. 1 ; and 
         FIG. 10  is an enlarged partial cross-sectional view of an apparatus for protectively holding an elongated object during bending and stretching of the elongated object according to the second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Referring to  FIGS. 1 through 8 , there is an apparatus  10  for protectively holding an elongated object during bending and stretching of the elongated object. The apparatus  10  includes a shell  20 , four sleds  30 , four roller sets  40 , two rings  50  and  60 , a lock  70  and a cover  80  according to a first embodiment of the present invention. 
     The shell  20  is preferably made of aluminum by extrusion and includes a wall  22 , four ribs  21  and four support portions  24 . The ribs  21  are evenly arranged and extend on an internal face of the wall  22 . The support portions  24  are also evenly arranged and extend on the internal face of the wall  22 . Each support portion  24  includes a peripheral tunnel  28  made therein. Each support portion  24  includes two faces extending parallel to each other on the outside and two flanges  29  each extending on a corresponding face. Each rib  21  is located in a corresponding peripheral tunnel  28 . The wall  22  and the support portions  24  together provide a longitudinal space separated from the peripheral tunnels  28 . The longitudinal space looks like an “X” in a cross-sectional view, i.e., it includes four grooves  26  in communication with an axial tunnel  14 . 
     The shell  20  includes, at a first end  25 , four screw holes  23  each made in a corresponding support portion  24 . The shell  20  includes, at the second end  27 , four more screw holes  23  each made in a corresponding support portion  24 . 
     Each sled  30  includes a back portion  32 , two flank portions  34  and a fin  38 . The back portion  32  is formed on the flank portions  34 . Each flank portion  34  includes four apertures  36 . The fin  38  is formed on the back portion  32 . 
     Each roller set  40  includes four rollers  42  and four axles  48 . Each roller  42  includes a concave tread  44  and an axial aperture  46 . The rollers  42  of each roller set  40  are placed between the flank portions  34  of a corresponding sled  30 . Each axle  48  is inserted the axial aperture  46  of a corresponding roller  42  and a corresponding aperture  36  of a corresponding flank portion  34 , thereby connecting each roller set  40  to a corresponding sled  30 . 
     Each sled  30  is movably inserted in a corresponding groove  26 , between two corresponding support portions  24 . The concave tread  44  together render the axial tunnel  14  circular in a cross-sectional view. 
     Each sled  30  further includes three elastic elements  90  for contact with two corresponding flanges  29  to keep the sled  30  in the corresponding groove  26 . Each elastic element  90  includes a coil spring  92  and a rod  94 . The coil spring  92  is formed on a corresponding flank portion  34  of a corresponding sled  30  by making a helical slot in the flank portion  34 . The rod  94  extends transversely at an end of the coil spring  92 . Each rod  94  includes two ends kept in contact with two corresponding flanges  29  because the rod  94  is biased by the corresponding coil spring  92  that is loaded. Each sled  30  is movable in two senses of a direction M in the corresponding groove  26 . The coil springs  92  of each sled  30  are further loaded when the rollers  42  of the corresponding roller set  40  are moved deeper in the corresponding groove  26  under a force. The coil springs  92  of each sled  30  recover when the force stops. 
     The ring  50  includes a funnel-shaped portion  52  and several peripheral apertures (not numbered). The peripheral apertures are located around the funnel-shaped portion  52  of the ring  50 . 
     The ring  60  includes a funnel-shaped portion  62  and an annular lip  64 . The funnel-shaped portion  62  is formed at a center of the ring  60 . The annular lip  64  extends around the funnel-shaped portion  62 . 
     The lock  70  includes a circular opening  72  and bosses  74  formed on an internal face. The bosses  74  are preferably in the form of barbs. 
     The cover  80  includes a countersink hole  82  and four strip sets. The countersink hole  82  is centrally made in the cover  80 . Each strip set includes three strips  83 , strips  84  and  85 . The strips  83 ,  84  and  85  extend from a face of the cover  80 . The strips  83 ,  84  and  85  extend longer than the shell  20 . The strips  83 ,  84  and  85  are separated from one another by slits  88 . Each of the strips  83 ,  84  and  85  includes a groove  81  in an internal face of the back portion. Each of the strips  83 ,  84  and  85  includes a recess  86  in an external face of the back portion. 
     Referring to  FIG 5 , each of the strips  83 ,  84  and  85  includes a back portion extending perpendicularly between two flank portions. The flank portions of each strip  83  are made with height H1. The flank portions of each strip  84  are made with height H2. The flank portions of each strip  85  are made with height H3. The height H1 is smaller than the height H2, and the height H2 is smaller than the height H3. Reasons for difference in the height of the flank portions of the strips  83 ,  84  and  85  are to be described. 
     Several screws  16  are inserted in the screw holes  23  at the first end  25  of the shell  20  via the ring  50 , thereby detachably connecting the ring  50  to the first end  25  of the shell  20 . The sleds  30  and the roller sets  40  are kept in the shell  20  by the ring  50 . The funnel-shaped portion  52  of the ring  50  is communication with the axial tunnel  14 . 
     Selectively, the fins  38  of the sleds  30  are inserted in the grooves  81  of the strips  83 ,  84  or  85  before the strips  83 ,  84  or  85  are inserted in the grooves  26 . For example, the fins  38  are inserted in the grooves  81  of the strips  83  before the strips  83  are inserted in the grooves  26  and the strips  84  and  85  are inserted in the peripheral tunnels  28 . Each of the ribs  21  is inserted in a selected one of the slits  88  so that the cover  80  cannot be rotated relative to the shell  20 . Now, the recesses  86  are placed out of the shell  20 . The sleds  30  are movable in a radial position of the shell  22  within a small range because the thickness of the strips  83  is marginally smaller than a gap between the wall  22  and the sleds  30 . The cover  80  protects the ring  50  as the cover  80  is connected to the first end  25  of the shell  20 . The countersink hole  82  of the cover  80  is in communication with the funnel-shaped portion  52  of the ring  50 . 
     The lock  70  is placed at the second end  27  of the sell  20 . The bosses  74  of the lock  70  can be inserted in the recesses  86  of the strips  83 ,  84  and  85  to lock the cover  80  to the lock  70 . Thus, the cover  80  can be locked to the shell  20  by the lock  70 . 
     Other screws  16  are inserted in the screw holes  23  at the second end  27  of the shell  20  via the ring  60 , thereby detachably connecting the ring  60  to the second end  27  of the shell  20 . The ring  60  retains the lock  70  near the second end  27  of the shell  20  but allows the lock  70  to rotate between a locking position and an unlocking position. The annular lip  64  is inserted in the circular opening  72  to guide the lock  70 . The diameter of the funnel-shaped portion  62  gets smaller as the funnel-shaped portion  62  extends toward the cover  80 . 
     Referring to  FIGS. 3 and 6 , the lock  70  is in the locking position. The bosses  74  are inserted in the recesses  86 , thereby locking the cover  80  to the shell  20 . 
     Referring to  FIGS. 4 and 7 , the lock  70  is in the unlocking position. The bosses  74  are located out of the recesses  86  to allow detachment of the cover  80  from the shell  20 . 
     Referring to  FIGS. 3 and 9 , in a sense of direction indicated by an arrow head S, a first section of an elongated object  12  is inserted in the axial tunnel  14  via the countersink hole  82  of the cover  80 . The first section of the elongated object  12  is moved out of the axial tunnel  14  via the funnel-shaped portion  62  of the ring  60 . 
     A second section of the elongated object  12  is inserted in the axial tunnel  14 . The second section of the elongated object  12  is in contact with the concave treads  44  of the rollers  42  of the roller sets  40 . 
     A third section of the elongated object  12  is bent in a sense of direction as indicated by an arrow head C. Thus, the elongated object  12  can be smoothly bent to a desired angle. The elongated object  12  can be metal tube or a metal rod. 
     The back portions  32  of the sleds  30  are supported by the flank portions of the strips  83  and the fins  38  are inserted in the grooves  81  of the strips  83  if the diameter or external diameter of the elongated object  12  is large. The back portions  32  of the sleds  30  are supported by the flank portions of the strips  84  and the fins  38  are inserted in the grooves  81  of the strips  84  if the diameter or external diameter of the elongated object  12  is medium. The back portions  32  of the sleds  30  are placed against the flank portions of the strips  85  and the fins  38  are inserted in the grooves  81  of the strips  85  if the diameter or external diameter of the elongated object  12  is small. Thus, the apparatus  10  is useful for protectively holding elongated objects of various sizes. 
     Referring to  FIG. 10 , there is an apparatus  10  for protectively holding an elongated object  12  during bending and stretching of the elongated object  12  according to a second embodiment of the present invention. The second embodiment is identical to the first embodiment except for several things. Firstly, each sled  30  does not include any coil spring. Secondly, each flank portion  34  includes three grooves  98  near the flanges  29 . Thirdly, compression springs  96  are used instead of the elastic elements  90 . The compression springs  96  are inserted in the grooves  98 . Each compression spring  96  includes an end abutted against the flanges  29  and another end in contact with a closed end of a corresponding groove  98 . The elastic elements  90  can bias and hence turn the sleds  30  back to the normal position in the sense of direction indicated by the arrow head M. 
     The present invention has been described via the illustration of the embodiments. Those skilled in the art can derive variations from the embodiments without departing from the scope of the present invention. Therefore, the embodiments shall not limit the scope of the present invention defined in the claims.