Abstract:
For mounting on the beam of a mobile stand to hold a machine, a bracket assembly includes a bracket body supportable on the beam of the mobile stand, a front clamp mounted in the bracket body and clamped on the beam of the stand, a rear clamp pivoted to the bracket body, and a locking control device pivotally mounted in the bracket body for operation by the user to impart a biasing force to the rear clamp for enabling the rear claim firmly clamped on the beam of the stand so as to further hold down the machine on the beam between the front clamp and the rear clamp.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a stand for supporting a machine and more particularly, to a bracket assembly for a mobile stand for supporting a machine.  
         [0003]     2. Description of the Related Art  
         [0004]      FIG. 1  shows a conventional mobile stand  1 . The stand  1  comprises a beam  2 , four legs  3 , and two brackets  4 . The legs  3  support the beam  2  in horizontal above a flat surface. The two brackets  4  are mounted on the beam  2  at the top to hold a machine such as a circular sawing machine (not shown). Referring to  FIG. 2 , the beam  2  has two protruding portions  2   a  and  2   b  longitudinally arranged in parallel at two sides. The bracket  4  comprises a rectangular body  4   a,  a front clamping plate  4   b,  a rear clamping plate  4   c,  and a spring member  4   d.  The bracket body  4   a  has a bottom opening  4   e  for receiving the beam  2 . The front clamping plate  4   b  is pivoted to the bracket body  4   a  and attached to one protruding portion  2   a  of the beam  2 . The rear clamping plate  4   c  is pivoted to the bracket body  4   a  and attached to the other protruding portion  2   b  of the beam  2 . The spring member  4   d  is fastened to the bracket body  4   a  and stopped against the rear clamping plate  4   c  to force the rear clamping plate  4   c  downwards.  
         [0005]      FIG. 2  shows the front clamping plate  4   b  and the rear clamping plate  4   c  clamped on the two protruding portions  2   a  and  2   b  of the beam  2 . At this time, the circular sawing machine for example is mounted on each bracket  4 . When wishing to remove the circular sawing machine from the stand  1 , the rear clamping plate  4   c  of each bracket  4  is turned upwards from the protruding portion  2   b  of the beam  2 , and then the circular sawing machine with the two brackets  4  are removed from the beam  2 .  
         [0006]     In the aforesaid design, the spring member  4   d  imparts a downward pressure to the rear clamping plate  4   c,  holding the rear clamping plate  4   c  in engagement with the protruding portion  2   b  of the beam  2 . However, the limited spring force of the spring member  4   d  is insufficient to hold down the bracket  4  on the beam  2  against an unexpected external biasing force, and the circular sawing machine may be forced out of place accidentally during working.  
         [0007]     Therefore, it is desirable to provide a bracket assembly for mobile stand that eliminates the aforesaid drawbacks.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention has been accomplished under the circumstances in view. It is the main objective of the present invention to provide a bracket assembly for a mobile stand, which holds the machine on the mobile stand firmly assuring high safety of work.  
         [0009]     To achieve this objective of the present invention, a bracket assembly for a mobile stand having a long beam and a plurality of legs that support the long beam for supporting a machine is provided. The bracket assembly comprises a bracket body mountable on the long beam of the mobile stand. A front clamp is mounted in the bracket body and has a front stop face contactable with the long beam of the mobile stand. A rear clamp is pivoted to the bracket body and has a rear stop face contactable with the long beam of the mobile stand and a guide face opposite to the rear stop face. A locking control device has an eccentric member and a follower rotatably coupled to the eccentric member. The eccentric member is pivoted to the bracket body and has an operating handle extending out of the bracket body. The follower has a push face kept in contact with the guide face of the rear clamp.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a perspective view showing two brackets fastened to a beam of a stand according to the prior art.  
         [0011]      FIG. 2  is a schematic sectional view of a part of  FIG. 1 , showing the connection between the bracket and the beam.  
         [0012]      FIG. 3  is an exploded view of a bracket assembly according to the present invention.  
         [0013]      FIG. 4  is a perspective assembly view of the bracket assembly according to the present invention.  
         [0014]      FIG. 5  is a sectional view of the present invention before pressing of the operating handle of the locking control device.  
         [0015]      FIG. 6  is similar to  FIG. 5  but showing the operating handle of the locking control device pressed down.  
         [0016]      FIG. 7  shows two bracket assemblies fastened to the beam of the stand according to the present invention.  
         [0017]      FIG. 8  corresponds to  FIG. 7 , showing a circular sawing machine supported on the two bracket assemblies.  
         [0018]      FIG. 9  is a side view of  FIG. 8 .  
         [0019]      FIG. 10  corresponds to  FIG. 9 , showing removal of the circular sawing machine from the stand. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]     FIGS.  7  and show two bracket assemblies mounted on a mobile stand to hold a circular sawing machine. The stand, referenced by  200 , comprises a long beam  201 , and four legs  202  that support the beam  201  above the floor. The beam  201  is formed of two parallel round rods  201   a.  The two bracket assemblies, referenced by  100 , are mounted on the top side of the beam  201  to hold a circular sawing machine  300 , as shown in  FIG. 8 .  
         [0021]     Referring to  FIGS. 3-5 , the bracket assembly  100  is comprised of a bracket body  10 , a carrying handle  18 , a front clamp  20 , an adjustment device  30 , a rear clamp  40 , a locking control device  50 , and three pivot pins  61 - 63 .  
         [0022]     The bracket body  10  comprises a horizontal top wall  12  and two vertical sidewalls  14 . The horizontal top wall  12  has two longitudinal slots  121  and  122  through which screws  16  are inserted and threaded into the base  301  of the circular sawing machine  300  to affix the circular sawing machine  300  to the bracket body  10  (see  FIG. 8 ). The vertical sidewalls  14  each have a bottom opening  141  deviated from the middle part for receiving the two round rods  201   a  (see  FIG. 5 ), and a plurality of through holes, namely, the first through hole  142 , the second through hole  143 , the third through hole  144  and the fourth through hole  145 . The carrying handle  18  is fixedly fastened to one vertical sidewall  14  at an outer side and remote from the bottom opening  141 .  
         [0023]     The front clamp  20  is an arched block, having a through hole  21 , a front stop face  22 , two protruding spring strips  23 , and a backboard  24 . During installation, the front clamp  20  is set in between the two vertical sidewalls  14 , and then one pivot pin  61  is inserted through the two second through holes  142  of the bracket body  10  and the through hole  21  of the front clamp  20  to pivotally secure the front clamp  20  to the bracket body  10 . At this time, the front stop face  22  faces the bottom openings  141  and the two protruding spring strips  23  are stopped against the bottom surface of the horizontal top wall  12 . When fastening the bracket body  10  to the beam  201 , the front stop face  22  of the front clamp  20  is forced into contact with the surface of one round rod  201   a.    
         [0024]     The adjustment device  30  is installed in the bracket body  10  and located between one end of the bracket body  10  and the front clamp  20 . The adjustment device  30  comprises a locating plate  31 , a stop block  32 , a movable member  33 , and a nut  34 .  
         [0025]     The locating plate  31  is fixedly connected between the two vertical sidewalls  14 , having a through hole  311 . The stop block  32  is set between the backboard  24  and the front stop face  22  of the front clamp  20 . The movable member  33  comprises a threaded shank  331  and a head  332 . The threaded shank  331  is inserted in proper order through the nut  34 , a through hole  311  of the locating plate  31  and the backboard  24  and then fastened to the stop block  32 . Therefore, when loosened the locknut  34 , the movable member  33  can be moved forwards or backwards relative to the locating plate  31  to bias the front clamp  20  forwards or backwards. After adjustment, the locknut  34  is fastened tight again to lock the front clamp  20 .  
         [0026]     The rear clamp  40  is an arched clamping plate having a through hole  41 , a rear stop face  42 , a guide face  43 , and two protruding spring strips  44 . During installation, the rear clamp  40  is set in between the two vertical sidewalls  14 , and then one pivot pin  62  is inserted through the two second through holes  143  of the bracket body  10  and the through hole  41  of the rear clamp  40  to pivotally secure the rear clamp  40  to the bracket body  10 . At this time, the rear stop face  42  faces the bottom openings  141  opposite to the front stop face  22  of the front clamp  20 ; the guide face  43  is disposed opposite to the rear stop face  42 ; and the two protruding spring strips  44  are stopped against the bottom surface of the horizontal top wall  12  of the bracket body  10 .  
         [0027]     When fastening the bracket body  10  to the beam  201 , the rear stop face  42  is kept in contact with the other round rod  201   a.  Further, in order to keep the circular sawing machine  300  in balance, the rear stop face  42  extends over the bottom side of the respective round rod  210   a,  i.e., much contact area is provided between the rear stop face  42  and the respective round rod  201   a.    
         [0028]     The locking control device  50  is installed in the racket body  10  closer to the rear clamp  40 . The locking control device  50  comprises an eccentric member  51 , a follower  52 , a back cover  53 , and a locating pin  54 .  
         [0029]     The eccentric member  51  comprises an axle hole  511 , a contacting portion  512 , and an operating handle  513  outwardly extending from a middle part of the contacting portion  512 .  
         [0030]     The follower  52  comprises two coupling rings  521  and a push face  522 . The coupling rings  521  are disposed at two sides relative to the operating handle  513 , each having a center through hole  521   a  that receives the contacting portion  512 , and a front surface  521   b  that forms a part of the push face  522 . The push face  522  is an arched face matching the arched guide face  43  of the rear clamp  40 . During installation, the pivot pin  63  is inserted through the two third through holes  144  of the bracket body  10  and the axle hole  511  of the eccentric member  51  to pivotally secure the eccentric member  51  to the bracket body  10 , allowing the follower  52  to be synchronously moved with the eccentric member  51 .  
         [0031]     The back cover  53  is covered on the two vertical sidewalls  14  of the bracket body  10 , having a mounting hole  531 . The locating pin  54  is inserted through the mounting hole  531  of the back cover  53  and the two fourth through holes  145  of the bracket body  10  to affix the back cover  53  to the two sidewalls  14  of the bracket body  10 . The back cover  53  reinforces the structural strength of the bracket body  10 . The locating pin  54  is adapted to support the operating handle  513  when the operating handle  513  is pressed downwards.  
         [0032]     The structural features of the bracket assembly  100  have been well described above.  FIG. 5  shows the bracket body  10  attached to the two round rods  201   a,  the operating handle  513  kept in the released position, and the follower  52  giving no pressure to the rear clamp  40 . At this time, the front stop face  22  of the front clamp  20  and the rear stop face  42  of the rear clamp  40  are respectively kept in slight contact with the periphery of the two round rods  201   a,  therefore the user can move the bracket body  10  along the two round rods  201   a  to the desired location or even remove the bracket body  10  from the two round rods  201   a.    
         [0033]     Referring to  FIG. 6 , the eccentric member  51  is turnable about the pivot pin  63 . When the user pressed the operating handle  513  downwards to rotate the eccentric member  51 , the follower  52  is driven by the eccentric member  51  to force the push face  522  against the guide face  43  of the rear clamp  40 . At this time, the bracket body  10  is held down on the two round rods  201   a  by the front clamp  20  and the rear clamp  40  and the eccentric member  51 , assuring high safety of work.  
         [0034]      FIG. 7  shows two bracket assemblies  100  fastened to the beam  201  of the work table  200 .  FIGS. 8 and 9  show a circular sawing machine  300  supported on the two bracket assemblies  100 .  
         [0035]      FIG. 10  is a schematic drawing showing removal of the circular sawing machine  300 . Because the circular sawing machine  300  is heavier on the rear side, the invention has the operating handle  18  set opposite to the locking device  50  for easy operation, and the bracket body  10  will be instantly separated from the beam  201  when lifting the circular sawing machine  300 .