Abstract:
A folding framework for the cutter includes two opposite and symmetric brackets. Each of the brackets has a first crossed rack and a second crossed rack, that connect across and swing at their intersections. Two limiters mounting at the intersections and crutching between the crossed racks are used to limit the spreading angle of the crossed racks. Each of the first and the second crossed racks has a upper slide-bar and a lower stock. The distance of sliding telescopically of the upper slide-bars in the lower stocks is controlled by a particular device. When the brackets fold crosswise and the upper slide-bars slide into the lower stocks respectively, the mass of the folding framework would be minimums. That would save the holding space for the folding framework.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a collapsible stand for supporting a machine, and more particularly the collapsible stand can easily and conveniently be spread for use and folded for carry and/or storage.  
         [0003]     2. Description of the Related Art  
         [0004]     An U.S. Pat. No. 6,942,229B2, discloses a collapsible stand for a bench-top power tool. In the patent, as shown in  FIGS. 10 and 11 , the stand  80  includes a platform  81  on which a table saw  82  is mounted, two first legs  83  pivotally connected to the bottom side of the platform  81 , two second legs  84  respectively connected to the two first legs  83  with a crossed manner, and two wheels  85  bilaterally connected to the front part of the platform  81 . When wanting to move the table saw  82 , the user must turn the table saw  82  and the platform  81  from horizontal to vertical to have the front side of the table saw touch the floor, and then fold the first legs  83  and the second legs  84 . After finishing the operation procedure, the user can pull or push the stand  80  to move. This way, turning and then folding stand  80 , is complicated and inconvenient. Moreover, the user is not easy and further in danger to turn the table saw  82  and the platform  81  from horizontal to vertical by himself because of the heavy weight of table saw  82  and the stand  80 .  
         [0005]      FIG. 12  shows a foldable stand for a threading machine according to a U.S. Pat. No. 5,560,582. In the patent, the foldable stand  90  has a gas spring  91  and a piston rod  92  installed in the gas spring  91 . By means of the relative action between the gas spring  91  and the piston rod  92 , a damping resistance is provided to buffer the weight of the threading machine for preventing an accident when folding up the foldable stand  90 . However, it is expensive to use the gas spring  91  and the piston rod  92  to produce a damping resistance.  
         [0006]     Further, the stand  90  has two wheels  94  respectively pivotally provided at the bottom ends of two legs  93  to make the stand  90  easy to move when collapsed. When the stand  90  is spread, the two wheels  94  form bearing points to support the stand  90  on the floor. However, this pivotal connection with the wheels  94  and the bottom ends of two legs  93  is not stable. The stand  90  may be vibrated easily upon an external force.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention has been accomplished under the circumstances in view. It is therefore one objective of the present invention to provide a collapsible stand that can be conveniently and easily spread for use and folded for carry and/or storage.  
         [0008]     To achieve this objective of the present invention, the collapsible stand provided by the present invention comprises a platform for supporting thereon a machine, two first legs, two second legs, at least one first springy member and a locking means. The platform has two sleeves pivotally connected thereon. The two first legs each have a top end pivotally connected to the platform. Each second leg is pivotally connected to each first leg at a pivotal point and has a top part inserted through the sleeve and slidable along the sleeve resulting in relative movement to the platform. The first springy member is sleeved onto one of the second leg, located between the sleeve and the pivotal point, and stopped against the sleeve. The locking means is connected to the platform for fixing the second legs after spreading the stand such that the first legs and second legs support the platform at a predetermined height. The top parts of the second legs are protruded out of the platform and the first springy member is compressed after the locking means releases the second legs and then the stand is folded.  
         [0009]     By means of the locking means, the two second legs can be conveniently locked relative to the platform after the stand is spread and released from the lock when the user wants to fold the stand. By means of the assembly of the locking means, the two sleeves and the two pairs of the first leg and the interconnected second leg, the user can easily spread or fold the collapsible stand without turning over it. Further, when the user folds the stand, the springy member provides a damping resistance to the platform to help the user smoothly and stably lower the platform and the machine supported on the platform. Furthermore, when the stand is spread, the springy member provides a rebound force to the platform, thereby enabling the user to lift the platform and the machine with less effort. In a preferred embodiment of the present invention, the springy member is a spring so as to save the manufacturing cost of the stand. In addition, after the stand is spread, the stand is steady supported on the floor by the stable structure thereof. Thereby, the present invention improves the disadvantages of the prior arts. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0010]      FIG. 1  is a perspective view showing a collapsible stand in spreading in accordance with a first preferred embodiment of the present invention.  
         [0011]      FIG. 2  is a side view of the collapsible stand in spreading according to the first preferred embodiment of the present invention.  
         [0012]      FIG. 3  is a bottom view showing the structure of a locking device of the collapsible stand in the first preferred embodiment of the present invention.  
         [0013]      FIG. 4  is a top view showing the collapsible stand in folding in the first preferred embodiment of the present invention.  
         [0014]      FIG. 5  is a side view showing the collapsible stand in folding in the first preferred embodiment of the present invention.  
         [0015]      FIG. 6  is a bottom view showing the collapsible stand in folding in the first preferred embodiment of the present invention.  
         [0016]      FIG. 7  is a perspective view showing a collapsible stand in spreading in accordance with a second preferred embodiment of the present invention.  
         [0017]      FIG. 8  is an enlarged view of part A of  FIG. 7 .  
         [0018]      FIG. 9  is a top view showing the collapsible stand in folding in the second preferred embodiment of the present invention.  
         [0019]      FIG. 10  is a perspective view showing a collapsible stand according to the prior art.  
         [0020]      FIG. 11  is a schematic drawing showing a used status of the collapsible stand of  FIG. 10 .  
         [0021]      FIG. 12  is a side view of a collapsible stand according to another prior art. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]     As shown in  FIGS. 1 and 2 , a collapsible stand  10  in accordance with a first preferred embodiment of the present invention has a platform  20 , two first legs  30 , two second legs  40 , two first springy members  42 , and a locking device  50 .  
         [0023]     The platform  20  is adapted to carry a machine (not shown), such as a wood working machine (e.g., table saw, miter saw, scroll saw, band saw, drill press, sander, etc.). The platform  20  can be a plate or frame. According to this embodiment, the platform  20  is a rectangular frame, having a front frame part  21 , a rear frame part  22 , a left frame part  23 , and a right frame part  24 . An outside wall  201  of each of the left frame part  23  and the right frame part  24  has an arched notch  25 . Two swivel hooks  26  are respectively pivotally mounted to the outside walls  201  of the left frame part  23  and the right frame part  24  adjacent to the arched notches  25 . Each of the swivel hooks  26  has a hooked portion  264  pivotally connected to the outside wall  201  over and near the arched notch  25 , and a handle  262  extending outward from the hooked portion  264 . Two sleeves  28  are respectively pivotally connected to a portion of the platform  20  that is adjacent to the junction of the front frame part  21  and the left frame part  23  and another portion of the platform  20  that is adjacent to the junction of the front frame part  21  and the right frame part  24 .  
         [0024]     The top ends of the first legs  30  respectively pivotally connected to the junction of the rear frame part  22  and the left frame part  23  and the junction of the rear frame part  22  and the right frame part  24 , and their bottom ends are bent forward for contacting the floor. Further, a transverse handlebar  32  is connected between the bottom ends of the first legs  30 .  
         [0025]     Each of the second legs  40  is pivotally connected to each of the first legs  30  by a pin  60  as the pivot at a pivotal point in a crossed manner. The pin  60  is inserted through the first leg  30  and the interconnected second leg  40  at the pivotal point, and has a part protruding from the first leg  30  that is located at an outside relative to the interconnected second leg  40 . The second legs  40  each have a top part slidable through the sleeve  28  relative to the platform  20 , and a bottom part with a bent portion  45  curved upwards and pivotally connected to a wheel  46  near its terminal. When the stand  10  is spread and positioned on the floor, the bottom ends of the first legs  30  and the bent portions  45  of the second legs  40  are respectively served as bearing portions of the stand  10  on the floor, and the wheels  40  are spaced above the floor. Each second leg  40  has a locating hole  44  near its top part through its inner side (see  FIG. 3 ), a flange  43  extending around its periphery between the locating hole  44  and the pin  60 , and a buffer  48  disposed above the bent portion  45 . Further, a transverse connecting bar  47  is connected between the bent portions  45  of the second legs  40  for stabilizing the second legs  40  when they stand on the floor.  
         [0026]     In this preferred embodiment, the first springy member  42  is a spring sleeved onto the top part of the second leg  40 , located between the sleeve  28  and the pivotal point, and stopped against the sleeve  28  and the flange  43  of the second leg  40 .  
         [0027]     The locking device  50  is adapted to fix the second legs  40  after the stand  10  is spread as shown in  FIG. 1 . In this preferred embodiment, as shown in  FIG. 3 , the locking device  50  comprises an operating handle  52 , a locating frame  54 , two first links  58 , and two second links  56 . The operating handle  52  has an elongated handle body  524 , and a head  526 . The locating frame  54  is inserted through the front wall  212  of the front frame part  21  of the platform  20 , having two mounting lugs  542  disposed at its two sides and affixed to the front wall  212  of the front frame part  21  of the platform  20 . The elongated handle body  524  is inserted through the front and rear sides of the locating frame  54  and the front wall  212 . A second springy member  528 , for example, a spring is put around the elongated handle body  524 , having one end stopped at the rear side of the locating frame  54  and the other end stopped at the rear end of the elongated handle body  524 . The head  526  is fixedly connected to the front end of the elongated handle body  524  and disposed outside the locating frame  54  and the platform  20  for operation by the user.  
         [0028]     The two second links  56  are respectively made of a metal strip and arranged at two opposite sides of the elongated handle body  524  of the operating handle  52 . Each second link  56  has a front end pivotally connected to the elongated handle body  524  and a rear end pivotally connected to the first links  58 . The first links  58  are respectively made of a round metal rod, and the axial direction of the first link  58  is substantially perpendicular to the axial direction of the handle body  524 . Each first link  58  has a front end inserted through the locating frame  54  and pivotally connected to the rear end of the corresponding second link  56 , and a rear end inserted into the locating hole  44  of the corresponding second leg  40  to fix the second legs  40  relative to the platform  20 , such that the first legs  30  and the second legs  40  support the platform  20  at a predetermined height above the floor. In other words, the operating handle  52  is movable between a first position, as shown in  FIG. 3 , for moving the first links  58  to a locking position to lock the second legs  40  and a second position, as shown in  FIG. 6 , for moving the first links  58  to an unlocking position to release the second legs  40 . In addition, two third springy members  582 , which are springs in this preferred embodiment, are respectively sleeved onto a front end of the first links  58  and stopped against the locating frame  54  and a protrusion  584  of the first links  58 .  
         [0029]     Referring to  FIGS. 4-6 , when wanting to fold the stand  10 , pull the head  526  of the operating handle  52  outward with one single hand and make the spring  528  compressed. At this time, the two second links  56  are carried by the elongated handle body  524  toward the front wall  212  of the front frame part  21  of the platform  20  (see  FIG. 6 ), and the two first links  58  are pulled by the second links  56  out of the locating holes  44  of the second legs  40 , and the third springy members  582  are compressed. Therefore, the stand  10  is gradually lowered. At this time, the top parts of the second legs  40  are guided by the corresponding sleeves  28  and project outward from the outside of the front wall  212  of the front frame part  21  of the platform  20 , and the first legs  30  are rotated relative to the platform  20  till that the two pairs of the first leg  30  and the interconnected second leg  40  are respectively received in two receiving spaces  29  defined by the inner side of the left frame part  23  and right frame part  24 . After the first legs  30  and the second legs  40  are received in the receiving spaces  29 , the top parts of the second legs  40 , the two wheels  46  at the bottom ends of the second legs  40 , and the bottom ends of the first legs  30  are disposed outside the platform  20 . As a result, the handlebar  32  is disposed outside the platform  20  and spaced away from the front wall  212  of the front frame part  21  of the platform  20  at a predetermined distance.  
         [0030]     When the stand  10  is folded, the two pins  60  that extend through the first legs  30  are respectively received in the arched notches  25  and protrude from the platform  20 . At this time, the user can turn the handles  262  of the swivel hooks  26  to make the corresponding hooked portions  264  hook the protruding parts of the pins  60  respectively to fix two pairs of the first leg  30  and the interconnected second leg  40  relative to the platform  20 . Therefore, the platform  20 , the first legs  30  and the second legs  40  are locked together, not separated from each other due to the first springy members  42 , as shown in  FIGS. 4-6 .  
         [0031]     Further, when folding the stand  10 , the two first springy members  42  that are respectively sleeved onto the top parts of the second legs  40  and stopped between the sleeves  28  and the flanges  43  of the second legs  40  are compressed to provide a damping resistance to the platform  10 , and therefore the platform  10  can be lowered gradually and smoothly. After the stand  10  has been collapsed, the buffers  48  of the two second legs  40  are disposed between the second legs  40  and the platform  20 , absorbing impact of the platform  20  against the second legs  40 . After the stand  10  has been collapsed and locked, the user can lift the handlebar  32  and move the stand  10  on the floor by means of the wheels  46 .  
         [0032]     When wanting to use the stand  10 , the user can turn the handles  262  of the swivel hooks  26  to make the hooked portions  264  of the swivel hooks  26  release the corresponding pins  60 , step the handlebar  32  to hold down the handlebar  32  on the floor, and then lift the platform  20  with the hands. At this time, the compressed first springy members  42  provide a rebound force to the platform  20 , and therefore the user can lift the platform  20  with less effort. After lifting the platform  20  from the folded status toward the spread status, the top parts of the second legs  40  move backward into the sleeves  28  inside the front frame part  21  of the platform  20 , and the third springs  582  in compressed around the first links  58  and the second springs  582  in compressed around elongated handle body  524  provide an outward force to force the first links  58  to move into the locating holes  44  of the second legs  40 . Thereby, the locking device  50  fixes the second legs  40  relative to the platform  20  so that the stand  10  is supported at a predetermined height.  
         [0033]     According to the aforesaid embodiment, the springy members  582  and  528  are used to return the two first links  58  and the handle  52  so as to force the two first links  58  to lock the two second legs  40 . In another practice, simply using the third springy members  582  or the second spring member  528  can also achieve the same effect.  
         [0034]     By means of the locking device  50 , the two second legs  40  can conveniently be locked relative to the platform  20  after the stand  10  is spread. When wanting to fold the stand  10 , the user can also operate the locking device  50  to release the lock to the second legs  40  from the platform  20 . By the assembly of the locking device  50 , the sleeves  28 , and the two pairs of the first leg  30  and the interconnected second legs  40 , the user can fold and spread the stand  10  conveniently without turning over the stand  10 . Further, when folding the stand  10 , the first springy members  42  provide the damping resistance to the platform  20 , thereby enabling the user to lower the platform  20  and the machine carried on the platform  20  smoothly. When spreading the stand  10 , the first springy members  42  provide the rebound force to the platform  20 , thereby enabling the user to lift the platform  20  and the machine carried on the platform  20  with less effort. Further, after the stand  10  is spread, it is more stable to bear the stand  10  on the floor by the bent portions  45  of the second legs  40  than the wheels  94  in the prior art, and the first springy members  42  of springs is inexpensive in the embodiment.  
         [0035]     Furthermore, each the second leg  40  can be opened another locating hole at its inner side. When the stand  10  is folded in the collapsed status, the compressed third springy members  582  force the first links  58  into the other locating holes at the second legs  40  to lock the second legs  40  at the collapsed status. This design can be used to substitute for the design of the swivel hooks  26  and the arched notches  25 .  
         [0036]      FIGS. 7-9  show a collapsible stand  70  in accordance with a second preferred embodiment of the present invention. This second embodiment is substantially similar to the aforesaid first preferred embodiment with the exceptions outlined hereinafter.  
         [0037]     According to this embodiment, the two first legs  71  are not arranged in parallel. One first leg  71  has a lower half part curved outward at an angle and obliquely extending forward relative to the platform  73 . The two second legs  72   a  are not arranged in parallel too. One second leg  72   a  has a lower half part curved outward at an angle and obliquely extending backwards relative to the platform  73 . The two outward curved legs  71  and  72   a  are preferably set opposite and away from the side to which the user approaches when operating the machine. The arrangement enables the stand  70  to stably stand on the floor when the user pushes the stand  70 . Under the requirement of stability, it can eliminates the aforesaid bent portions  45  of the second legs  72   a  and makes the wheels  46  directly contact the floor to support the stand  70  stably on the floor.  
         [0038]     Further, there are some difference between the locking device  74  of this second embodiment and the locking device  50  of the aforesaid first embodiment. According to this second embodiment, the locking device  74  is installed on the front wall  734  of the front frame part  732  of the platform  73 , and the two first links  742  are disposed outside the front frame part  732  to make the rear ends of the two first links  742  visible from the outside of the stand  70 . After the stand  70  is folded, the rear ends of the first links  742  respectively press against the side surfaces of the top parts of the second legs  72   a  to hold the stand  70  in the collapsed status. After the stand  70  is spread, the rear ends of the first links  742  respectively press against terminal surfaces of the top parts of the second legs  72   a . The terminal surface of the top part of each second leg  72   a  is provided with a locating groove  722  for accommodating the rear end of the corresponding first link  742 . Thereby, the locking device  74  fixes the two second legs  72   a  relative to the platform  73  at the spread status to make the first legs  71  and the second legs  72   a  support the platform  73  above the floor at a predetermined height. The locking device  74  further comprises an auxiliary frame  76 . The auxiliary frame  76  has a U-shaped profile, which is fixedly connected to the platform  73  and surrounds the operating handle  77 . When wanting to pull the operating handle  77 , the user can stop the palm of the hand against the auxiliary frame  76  and then use the fingers to pull the operating handle  77 .  
         [0039]     Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.