Patent Publication Number: US-2005126136-A1

Title: Device for fixing a dust-collecting bag on a dust-collecting machine

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      This invention relates to a device for fixing a dust collecting bag on a dust-collecting machine, particularly to one having a simple structure and able to assemble a dust collecting bag on or disassemble it from a dust-collecting machine quickly.  
      2. Description of the Prior Art  
      A conventional dust-collecting machine  10 , as shown in  FIG. 1 , includes a wind-exhausting box  11  having a wind-exhausting vent  111  in its topside for fitting a dust-collecting bag  12  thereon and a fan motor  13  connected with the wind-exhausting box  11 . Thus, when the fan motor  13  operates, dust can be sucked into the dust-collecting bag  12  through the wind-exhausting box  11 . The dust-collecting bag  12  is fitted around the outer circumferential edge of the exhausting opening  111  of the wind-exhausting box  11  and has its opening portion  121  firmly secured thereon by means of a clasping strap  14  so as to fix the dust-collecting bag  12  on the wind-exhausting box  11 .  
      However, the way of assembling the dust-collecting bag  12  on the wind-exhausting box  11  by the clasping strap  14  has some drawbacks described below.  
      1. The clasping strap  14  is composed of a strap body  141 , two clasps  142  respectively secured at the opposite ends of the strap  141  and a pull-press member  143  provided at the end of the clasp  142 , having too many components, complicating structure and increasing cost.  
      2. The components of the clasping strap  14  are buckled with one another to be pulled and pressed; therefore these components are most likely to become loose and damaged after long term of use. Under the circumstances, the opening portion  121  of the dust-collecting bag  12  can hardly be secured firmly on the outer circumferential edge of the wind-exhausting vent  111  of the wind-exhausting box  11 , easy to cause leakage of air and dust.  
      3. To assemble the dust-collecting bag  12  on the wind-exhausting box  11 , firstly, the opening portion  121  of the dust-collecting bag  12  has to be fitted around the outer circumferential edge of the wind-exhausting vent  111  of the wind-exhausting box  11 . Subsequently, the two clasps  142  at the opposite ends of the strap  141  are buckled with each other and then the pull-press member  143  is pressed inward to fix the strap  141  in place to finish assembly of the dust-collecting bag  12 . On the contrary, to disassemble the dust-collecting bag  12  from the wind-exhausting box  11 , the clasps  142  of the strap  141  have to be unbuckled and the pull-press member  143  has to be released to finish disassembling of the dust-collecting bag  12 , complicated in operation.  
     SUMMARY OF THE INVENTION  
      A first objective of the invention is to offer a device for securing a dust-collecting bag on a dust-collecting machine, able to quickly and directly assemble a dust-collecting bag on a wind-exhausting box without help of any additional tightening component and firmly fix the dust-collecting bag on the wind-exhausting box by increase of a vacuum sucking force and also able to remove the dust-collecting bag from the wind-exhausting box with ease and with less force.  
      A second objective of the invention is to offer a device for securing a dust-collecting bag on a dust-collecting machine, in which the dust-collecting bag has its opening portion wrapped therein with a tightening ring, and the wind-exhausting box has its wind-exhausting vent formed with a curve engage surface on the upper inner wall. Thus, the dust-collecting bag can be fixed on the curved engage surface of the wind-exhausting vent of the wind-exhausting box, simplifying structure, saving cost of machine parts and lowering probability of component damage. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
      This invention will be better understood by referring to the accompanying drawings, wherein:  
       FIG. 1  is a partial exploded perspective view of a conventional dust-collecting machine:  
       FIG. 2  is perspective view of the clasping strap of the conventional dust-collecting machine:  
       FIG. 3  is a perspective view of a dust-collecting machine in the present invention:  
       FIG. 4  is perspective view of the dust-collecting machine in the present invention, showing the dust-collecting bags separated from the wind-exhausting box:  
       FIG. 5  is a cross-sectional view of the dust-collecting machine in the present invention, showing the dust-collecting bag assembled on the wind-exhausting box:  
       FIG. 6  is a magnified cross-sectional view of the opening portion of the dust-collecting bag closely stuck on the engage surface of the wind-exhausting box in the present invention: and  
       FIG. 7  is a cross-sectional view of the dust-collecting machine in the present invention, showing the opening portion of the dust-collecting bag tightly stuck with the engage surface of the wind-exhausting box when the dust-collecting bag is pulled upward. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      A preferred embodiment of a device for fixing a dust-collecting bag on a dust-collecting machine in the present invention, as shown in  FIGS. 3 and 4 , includes a wind-exhausting box  20  and two dust-collecting bags  30  combined together.  
      The wind-exhausting box  20  is provided with an upper and a lower cover  21  respectively having a horizontal base plate  211 . The two horizontal base plates  211  have their circumferential edges respectively extending vertically to form a side wall  212  to be correspondingly combined: together and their opposite sides respectively bored with a through hole  213  having an annular fit base  22  provided thereon to form a wind-exhausting vent  221  for securing a dust-collecting bag  30  thereon.  
      The annular fit base  22 , as shown in  FIGS. 5 and 6 , has its upper inner wall near the wind-exhausting vent  221  formed with a curved engage surface  222  shrinking inward gradually and then extending outward to form a curved expanding surface  223 , which is then bent outward to form an arc-shaped edge  224 .  
      The dust-collecting bag  30  has a tightening ring  33  with a proper flexibility wrapped inside the bag body  32  of its opening portion  31 .  
      In assembling, as shown in  FIG. 7 , only press inward the opening portion  31  of the dust-collecting bag  30  to make the opening portion  31  and the tightening ring  33  slightly deformed to enable the opening portion  31  to be entirely deposited in the wind-exhausting vent  221  of the annular fit base  22  of the wind-exhausting box  20  and then release the opening portion  31  to let the bag body  32  and the tightening ring  33  inside recover their original shape. What should be noted is that the outer diameter of the opening portion  31  of the dust-collecting bag  30  is a little larger than the shortest diameter of the gradually shrinking engage surface  222  of the wind-exhausting vent  221 ; therefore when the dust-collecting bag  30  is entirely pulled outward and the tightening ring  33  recover its resilience, the opening portion  31  and the tightening ring  33  will be firmly stuck on the engage surface  222  in the wind-exhausting vent  221  to secure the dust-collecting bag  30  on the wind-exhausting box  20 .  
      In this invention, the opening portion  31  of the dust-collecting bag  30  is designed in an engage-in mode. In other words, the opening portion  31  of the dust-collecting bag  30  is firmly engaged with the curved engage surface  222  of the wind-exhausting vent  221  of the wind-exhausting box  20  after it is received in the wind-exhausting vent  221 . Therefore, when the dust-collecting bag  30  is expanded outward by a vacuum sucking force, the opening portion  31  of the dust-collecting bag  30  will be urged to push against the engage surface  222  comparatively tightly to ensure the dust-collecting bag  30  to be firmly secured on the exhausting box  22 . To remove the dust-collecting bag  30  from the wind-exhausting box  22 , only press inward the opening portion  31  of the dust-collecting bag  30  to make it deformed and then move it inward to disengage from the engage surface  222  in the wind-exhausting vent  221 , quick and easy in assembling and disassembling of the dust-collecting bag  30 .  
      While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover such modifications that may fall within the spirit and scope of the invention.