Patent Publication Number: US-2011061759-A1

Title: Adjustable tube assembly

Description:
FIELD OF THE INVENTION 
     The present invention relates to a tube assembly, and more particularly, to an adjustable tube assembly wherein the inner tube is adjustable axially relative to the outer tube by operation of an operation unit in the outer tube. 
     BACKGROUND OF THE INVENTION 
     A conventional tube assembly is shown in  FIGS. 8 and 9 , and generally includes an outer tube  5 , an inner tube  6 , a locking collar  7  and a control sleeve  8 , wherein a seal member  61  is located in the outer tube  5  so as to seal between the inner and outer tubes  6 ,  5 . The outer tube  5  includes a connection member  51  located at an end thereof and the connection member  51  includes outer threads  52 . The locking collar  7  is mounted to a plan section at the end with the outer threads  52 . The control sleeve  8  is mounted to the inner tube  6  and includes inner threads  81  so as to be threadedly connected to the outer threads  52 . The locking collar  7  includes a tapered end  72  which includes axial slots  71 . The control sleeve  8  includes a tapered inner periphery  82  which movably presses the tapered end  72  so as to lock the inner tube  6 . 
     When adjusting the inner tube  6  relative to the outer tube  5 , the control sleeve  8  is first rotated to remove the tapered inner periphery  82  from the tapered end  72  of the locking collar  7 , and the inner tube  6  is moved relative to the outer tube  5 . When the desired position of the inner tube  6  is reached, the user rotates the control sleeve  8  in reverse direction to press the tapered end  72  again to tighten the inner tube  6  again. However, in order to reduce risk of wearing of the inner tube  6 , the user has to make sure that the tapered inner periphery  82  is completely separated from the tapered end  72  he or she adjust the inner tube  6 . This is not convenient for the user and wastes time because of low efficiency. 
     The present invention intends to provide a tube assembly which is easily to adjust the inner tube relative to the outer tube. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a tube assembly and comprises an outer tube with a sleeve having an end fixedly connected to the outer tube. An operation unit is located in the outer tube and includes a first part and a second part. The first part is threadedly connected to the second part. The second part includes multiple expandable plates extending axially from a second end thereof and slits are defined between the expandable plates which contact an inner periphery of the outer tube when being expanded. An inner tube unit includes an inner tube and a connection member which is connected to a first end of the inner tube. The connection member is inserted into the operation unit and fixed to the first part of the operation unit. A tapered flange extends radially from the connection member so as to expand the expandable plates outwardly when rotating the inner tube. 
     The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view to show the tube assembly of the present invention; 
         FIG. 2  is another exploded view to show the tube assembly of the present invention, wherein the connection member on the inner tube is connected to the operation unit; 
         FIG. 3  is a perspective view to show the tube assembly of the present invention; 
         FIG. 4  is a cross sectional view to show the connection member and the operation unit; 
         FIG. 5  is a cross sectional view to show that the inner tube is rotated; 
         FIG. 6  is a cross sectional view to show that the tapered flange is moved away from the expandable plates and the inner tube is able to move relative to the outer tube; 
         FIG. 7  is a cross sectional view to show that the inner tube is moved a desired position and the inner tube is rotated to expand the expandable plates to contact the outer tube; 
         FIG. 8  is an exploded view to show the conventional tube assembly, and 
         FIG. 9  is a cross sectional view of the conventional tube assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1 to 4 , the tube assembly of the present invention comprises an outer tube  1  which includes multiple ribs  11  extending axially on the inner periphery of the outer tube  1 . A sleeve  2  has includes a tapered inner periphery and includes a stepped opening  21  in a first end thereof. The outer tube  1  is inserted into and fixed to the sleeve  2  via the stepped opening  21 . Another opening is defined in a second end of the sleeve  2  and an inner tube  41  is inserted into the sleeve  2  via the another opening. A seal ring  22  is engaged within the sleeve  2  and mounted to the inner tube  41  so as to prevent leakage between the inner and outer tubes  41 ,  1 . 
     An operation unit  3  is located in the outer tube  1  and includes a first part  31  and a second part  32 , wherein the first part  31  has outer threads  314  on a first end thereof and the second part  32  has inner threads  321  in a first end thereof. The inner threads  321  of the second part  32  are connected to the outer threads  314  of the first part  31 . The first part  31  includes an enlarged head  311  on a second end thereof and two first holes  312  are defined through a wall of the enlarged head  311 . A pin  313  extends through the first holes  312 . The second part  32  include multiple expandable plates  323  extending axially from a second end thereof and slits  322  are defined between the expandable plates  323  which contact an inner periphery of the outer tube  1  when being expanded. A seal ring  324  is mounted onto the expandable plates  323  of the second part  32 . The second part  32  of the operation unit  3  includes multiple grooves  325  defined in an outer surface thereof and the ribs  11  of the outer tube  1  are engaged with the grooves  325  such that the second part  32  does not rotate relative to the outer tube  1  and can move along the ribs  11 . 
     An inner tube unit  4  including the inner tube  41  mentioned above and a connection member  42  which is connected to a first end of the inner tube  41 . The connection member  42  is inserted into the operation unit  3  and the connection member  42  includes two second holes  421  defined in a first end thereof. The pin  313  extends through the second holes  421  which are in alignment with the first holes  312  of the first part  31  so as to connect the connection member  42  with the first part  31 . A tapered flange  422  extends radially from the connection member  42  so as to expand the expandable plates  323  outwardly when the tapered flange  422  moves. 
     A connection portion  423  is located on a second end of the connection member  42  and beside the tapered flange  422 . The outer diameter of the connection portion  423  is smaller than that of the tapered flange  422 . The connection portion  423  is inserted into the inner tube  41 . A seal ring  424  is mounted to the connection portion  423 . 
     When assembling, the connection member  42  is inserted into the inner tube  41  and the pin  313  extends through the aligned first and second through holes  312 ,  421  to connect the connection member  42  to the first part  31  of the operation unit  3 . The expandable plates  323  of the second part  32  are located outside of the tapered flange  422 . The outer tube  1  is inserted into the sleeve  2  and fixed to the sleeve  2  and the outlet end “B” which is the second end of the inner tube  41  is inserted into the outer tube  1  from the end “A” as shown in  FIG. 2 . The ribs  11  of the outer tube  1  are engaged with the grooves  325  of the second part  32 , so that the inner tube  41  can be moved axially along the ribs  11  relative to the outer tube  1 . 
     As shown in  FIG. 5 , before adjusting, the expandable plates  323  are in contact with the inner periphery of the outer tube  1  so as to position the inner tube  41  relative to the outer tube  1 . When adjusting, the user rotates the inner tube  41  relative to the outer tube  1  and the first part  31  is rotated with the inner tube  41 . Because the first part  31  is threadedly connected to the second part  32  which cannot be rotated, so that the inner tube  41  and the first part  31  are moved relative to the outer tube  1 . The tapered flange  422  is then moved relative to the expandable plates  323  on the second part  32 . When the tapered flange  422  is moved away from the expandable plates  323  on the second part  32  as shown in  FIG. 6 , the expandable plates  323  are not expanded outward, so that the inner tube  41  can be moved along the ribs  11  relative to the outer tube  1 . 
     As shown in  FIG. 7 , when the inner tube  41  is moved to a desired position, the inner tube  41  is rotated in opposite direction, the expandable plates  323  are pushed outward by the tapered flange  422  so as to contact the inner periphery of the outer tube  1  again to position the inner tube  41 . The tube assembly can also be more than two tubes. 
     Because the second part  32  is not rotatable relative to the outer tube  1  and is threadedly connected with the first part  31  by the pin  313 , so that when rotating the inner tube  41 , the connection member  42  is moved with the first part  31 , the tapered flange  422  can be moved toward or away from the expandable plates  323  to control the of the inner tube  41 . The inner tube  41  is moved axially by movement of the second part  32  along the ribs  11  when adjusting, so that the inner tube  41  is moved in stable manner without shaking. 
     While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.