Patent Publication Number: US-2010123305-A1

Title: Telescopic coupling tube for a vacuum cleaner

Description:
BACKGROUND OF THE INVENTION 
     1. Fields of the Invention 
     The invention relates to a telescopic coupling tube for a vacuum cleaner, and more particularly, to a structure that ensures an easy adjustment of the assembly length, thereby meeting the use requirements. 
     2. Description of the Related Art 
     The conventional vacuum cleaner (not shown) normally includes a plurality of extension tubes and different kinds of suction heads that are engaged into the rear end surface of the body of the vacuum cleaner. In this way, they can be employed in accordance with user requirements. The plug-type connection belongs to the prior art so that no further descriptions thereto are given hereinafter. The invention relates to a dust absorption head for a vacuum cleaner. 
     As well-known in the art, the conventional extension coupling tube for a vacuum cleaner has a fixed length. It&#39;s not possible for further extension if required. In other words, the user has no other way for extension even when the length is not sufficient. As a result, this structure requires further improvements. 
     SUMMARY OF THE INVENTION 
     A primary object of the invention is to provide a telescopic coupling tube for a vacuum cleaner that improves the conventional extension tube and allows a more easy and convenient use of the vacuum cleaner. 
     According to the invention, a mounting tube and a telescopic tube are attached together. Moreover, a locking assembly is employed for an easy adjustment of the assembly length of the mounting tube and the telescopic tube. In this way, the use requirement is fulfilled without affecting the original storage effect. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accomplishment of this and other objects of the invention will become apparent from the following description and its accompanying drawings of which: 
         FIG. 1  is an exploded perspective view of a telescopic coupling tube for a vacuum cleaner in accordance with the invention; 
         FIG. 2  is a perspective assembly view of a telescopic coupling tube for a vacuum cleaner in accordance with the invention; 
         FIG. 3  is a schematic drawing of the telescopic coupling tube in partial cutaway view; and 
         FIG. 4  is a partial sectional view side of the invention, showing the operation way thereof. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown in  FIGS. 1 and 2 , a telescopic coupling tube for a vacuum cleaner in accordance with the invention includes a mounting tube  10 , a connecting sleeve  20 , a sealing sleeve  30 , a telescopic tube  40 , a locking assembly  50 , and a positioning cap  60 . 
     The mounting tube  10  has a mounting portion  11  at one end thereof for attaching to an inserting part of accessories of a vacuum cleaner (not shown) and an insertion portion  12  at the other end thereof. A slot  13  is formed in the second insertion portion  12 . 
     The connecting sleeve  20  is mounted on the insertion portion  12  of the mounting tube  10 . The connecting sleeve  20  includes an opening  21  corresponding to the slot  13  of the insertion portion  12 . 
     The sealing sleeve  30  fits into an internal hole  14  of the insertion portion  12  of the mounting tube  10 . The sealing sleeve  30  is provided with a locking portion  31  facing to the slot  13  of the mounting tube  10  for the connection to the locking assembly  50 . The locking portion  31  includes a locking slot  32  at both sides thereof. The locking assembly  50  includes a push knob  51  with an engaging hook  54  that fits into the locking slot  32  in place. Two projections  33  are positioned near the center of the sealing sleeve  30 . The locking assembly  50  includes an engaging element  52  with positioning holes  55  into which the projections  33  fit in place. Moreover, a notch  34  is disposed at the side portion of the projections  33 . 
     The positioning cap  60  is plugged into one end of the telescopic tube  40 . A mounting portion  41  is positioned at the other end thereof for attaching to an inserting part of accessories of a vacuum cleaner (not shown). A guide slot  42  is axially formed at the end surface of the locking assembly  50 . One side of the guide slot  42  is provided with toothed engaging holes  43 . 
     The locking assembly  50  includes a push knob  51 , an engaging element  52 , and an elastic element  53 . An engaging hook  54  is positioned at both sides of the internal surface of the push knob  51 . Meanwhile, a push lug  56  is disposed at a certain position of the locking assembly  50 . The engaging element  52  is substantially curved and includes positioning holes  55  at both sides thereof. A push piece  57  is positioned near the center of the engaging element  52 . A push surface  571  is disposed at one side of the push piece  57  while an engaging cambered surface  572  is positioned at the other side thereof. The engaging cambered surface  572  of the push piece  57  is extended downward to pass through the notch  34  of the sealing sleeve  30  and then to engage into the engaging hole  43  of the guide slot  42  of the telescopic tube  40 . Moreover, the elastic element  53  is supported against a portion between the push lug  56  of the push knob  51  and the locking portion  31  of the sealing sleeve  30 . 
     The positioning cap  60  is plugged into and positioned within an internal hole  44  at one side of the telescopic tube  40 . 
     Based upon the assembly of the above-mentioned components, as shown in  FIGS. 3 and 4 , the elastic element  53  normally applies a force acting backward such that the push knob  51  is constantly compressed in a pushed position. At that time, the push lug  56  is just pushed against the push surface  571  of the push piece  57  of the engaging element  52  while the engaging cambered surface  572  at the other end of the push piece  57  is engaged into one of the toothed engaging hole  43  of the guide slot  42  of the telescopic tube  40 , thereby creating an engaging effect. When the push knob  51  is pushed, the push lug  56  is free from the contact with the push piece  57  of the engaging element  52  such that the engaging element  52  is returned to the original bent position. In this way, the engaging cambered surface  572  of the push piece  57  is released from the toothed engaging hole  43  of the guide slot  42  of the telescopic tube  40 . In other words, the user only requires to slightly push the push knob  51  for adjusting the telescopic tube  40  to a required length. Thereafter, the push knob  51  is released. Thus, the assembly length can be adjusted as required. 
     The guide slot  42  of the telescopic tube  40  has a certain length. The push piece  57  of the engaging element  52  is constantly extended into the guide slot  42 . Therefore, an automatic limit of the telescopic travel is ensured when the telescopic travel reaches the end stop at both sides of the guide slot  42 . 
     Many changes and modifications in the above-described embodiment of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claim.