Abstract:
A collapsible stand includes a base frame, a first supporting frame pivotally connected to the base frame, a first supporting unit pivotally connected between the base frame and the first supporting frame, a second supporting frame pivotally connected to the first supporting frame, a second supporting unit pivotally connected between the base frame and the second supporting frame. When operating the base frame, the second supporting frame is able to be extended away from the first supporting frame, and it is easily operating the collapsible stand from a collapsed position to an extended position; or the second supporting frame is able to be received toward the first supporting frame to a collapsed position by lifting up the first supporting frame.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of priority from U.S. provisional application No. 61/498,086, filed on Jun. 17, 2011, the entirety of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates to a stand for supporting a machine tool thereon and more specifically, to a collapsible stand for supporting machine tools. 
     BACKGROUND 
     For providing portability to conventional machine tools/power tools (i.e. table saws), conventional stands for supporting said machine tools are often provided with a collapsible structure for allowing the machine tools to be conveniently transported and used in a variety of different work sites. 
     U.S. Pat. Nos. 6,942,229, 5,560,582, and U.S. Patent Application Publication No. 2005/0199768A1 disclosed various collapsible stands. Additionally, the Applicant&#39;s prior Taiwan Invention Patent No. 1311520 disclosed a Supporting Stand for Machine Tools which includes a supporting platform adapted to support a machine tool, a pair of first legs pivotally disposed on one lateral side of the supporting platform, a pair of second legs pivotally disposed on another lateral side of the supporting platform and each of the second legs has one end pivotally and respectively connected with the first legs, a pair of resilient members respectively sleeved on the second legs; and a securing unit. The securing unit includes a handle slidably disposed on the supporting platform, two link members pivotally connected with the handle, two coupling members pivotally and respectively connected to the two link members, and two spring members disposed between the two coupling members and the supporting platform respectively. When the supporting stand is in an extended position, pulling the handle will drive the link members to pivotally rotate, the two link members will drive the coupling members to linearly approach each other, such that end tips of the link members are disengaged from the second legs for allowing the second legs to slide along a pair of sleeve members respectively such that the supporting stand is folded. 
     The aforementioned supporting stands are able to support the machine tool, and can be easily extended and can be easily stored when not in use. Therefore, in view of the functionality and increasing demands for the supporting stands, the present disclosure has arisen. 
     SUMMARY 
     The present disclosure has been accomplished under the circumstances in view. It is therefore the main object of the present disclosure to provide a collapsible stand, which has a simple structure, is easy to operate, and can be quickly folded/extended. 
     To achieve these and other objects of the present disclosure, the collapsible stand in accordance with the present disclosure comprises a base frame which is adapted for supporting a machine tool. The base frame has a first lateral portion and a second lateral portion which are respectively located on two opposite sides thereof. A handle is mounted on the first lateral portion of the base frame. A first supporting frame includes two first legs which are pivotally engaged with the first lateral portion of the base frame and a bottom bracket which is disposed between the two first legs. Each first leg includes a main shaft which engages with the bottom bracket and a sliding shaft which has two opposite ends slidably engaging with the main shaft and pivotally connecting with the first lateral portion respectively. Each of the main shafts has a bending portion formed thereon and adapted to for corresponding to a ground surface. The bending portion is located between the first leg and the bottom bracket. Two pin members are respectively mounted on the bending portions. The first legs are perpendicularly arranged relative to the bottom bracket. A first supporting unit is pivotally disposed between the second lateral portion of the base frame and the first supporting frame. The first supporting frame includes two pairs of pivoting plates which are respectively mounted on the two first legs. Each pivoting plate has a substantially plate-shaped positioning member fixedly disposed thereon. A second supporting frame includes two second legs pivotally and respectively engaging with the first legs. Each second leg has an end section formed on one end thereof and oppositely corresponds to the bottom bracket of the first supporting frame. Two wheels are respectively and pivotally disposed on the end sections. Each second leg has an axial portion respectively formed thereon. The axial portion is located on an opposite end relative to the end section. The axial portion pivotally engages with the pivoting plates. A second supporting unit which is adapted for positioning the second supporting frame relative to the first supporting frame is pivotally disposed between the first lateral portion of the base frame and the second legs of the second supporting frame. An operating unit is mounted on the first supporting frame. The operating unit includes a driving shaft, a push lever, a coupling member, and a spring member. The driving shaft has a pedaling portion and a pivoting portion respectively formed on two opposite ends thereof. The pivoting portion pivotally engages with the first supporting frame such that the driving shaft is pivotable relative to the first supporting frame. The push lever has a first end which is pivotally engaged with one of the first legs of the first supporting frame and a second end for corresponding to the base frame. The push lever has a pawl surface which extends from the second end toward the first end thereof. A roller is disposed on the first end of the push lever. The second supporting frame has a guiding shaft disposed thereon for corresponding to the roller. The first supporting unit has a guiding wheel disposed thereon for corresponding to the pawl surface. The push lever having a spaced distance relative to the driving shaft. The coupling member is pivotally disposed between the driving shaft and the push lever. The coupling member has a first pivoting section and a second pivoting section formed on two opposite ends thereof. The first pivoting section and the second pivoting section are respectively and pivotally engaging with the push lever and the driving shaft. The operating unit further includes a spring member which has two ends respectively abutting against the pedaling portion of the driving shaft and the first end of the push lever. A resilient force of the spring member constantly biases the pedaling portion and the first end to orient toward each other. 
     In an extended configuration, the first supporting frame and the second supporting frame are outwardly extending away from each other such that the bottom bracket of the first supporting frame and the end sections of the second supporting frame are located at their farthest distance apart. The second supporting unit securely positioned the second supporting frame relative to the first supporting frame. 
     In a folded configuration, the first supporting frame and the second supporting frame are oriented toward each other in a substantially parallely arranged manner; the base frame is arranged in a substantially upright manner such that the second lateral portion of the base frame is located adjacent to the first supporting frame. 
     The present disclosure can achieve the following effects: by utilizing the first supporting unit and the second supporting unit, the first supporting frame and the second supporting frame are outwardly extended relative to the first supporting frame such that the are the first supporting frame and the second supporting frame are positioned outwardly away from each other for extending the collapsible stand. By lifting the first supporting frame, the second supporting frame is retractedly movable toward the first supporting frame, such that the collapsible stand can be easily folded. Thereby, the collapsible stand in accordance with the present disclosure can be easily and quickly folded/extended. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a collapsible stand in accordance with a preferred embodiment of the present disclosure. 
         FIG. 2  is an assembled side view of the collapsible stand in accordance with the preferred embodiment of the present disclosure, wherein the collapsible stand is in an extended configuration. 
         FIG. 3  is a side view of the collapsible stand in accordance with the preferred embodiment of the present disclosure, wherein the collapsible stand is operated to covert from the extended configuration to a folded configuration. 
         FIG. 4  is a side view of the collapsible stand in accordance with the preferred embodiment of the present disclosure, wherein the collapsible stand is in the folded configuration. 
         FIG. 5  is a partial enlarged view of  FIG. 4 . 
         FIG. 6  is a side view of the collapsible stand in accordance with the preferred embodiment of the present disclosure, wherein the collapsible stand is operated to convert from the folded configuration to the extended configuration. 
         FIG. 7  is a partial enlarged view of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment of a collapsible stand according to the present disclosure is shown in  FIGS. 1-2 , the collapsible stand includes a base frame  10  which is adapted for supporting a machine tool  100 . The base frame  10  is substantially rectangular. The base frame  10  has a first lateral portion  11  and a second lateral portion  12  which are respectively located on two opposite sides thereof. A pair of first pivot ears  111  is mounted on the first lateral portion  11  and downwardly extending from a bottom surface thereof. A pair of second pivot ears  121  is mounted on the second lateral portion  12  and downwardly extending from a bottom surface thereof. A handle  20  is mounted on the first lateral portion  11  of the base frame  10 . The handle  20  is substantially U-shaped for providing an ergonomic gripping purpose. 
     A first supporting frame  30  includes two first legs  31  and a bottom bracket  32 . The two first legs  31  are pivotally engaged with the first pivot ears  111  of the first lateral portion  11 . The bottom bracket  32  is disposed between the two first legs  31 . Each first leg  31  includes a main shaft  311  which engages with the bottom bracket  32  and a sliding shaft  312  which has two opposite ends slidably engaging with the main shaft  311  and pivotally connecting with the first pivot ears  111  respectively such that the sliding shaft  312  is telescopically slidable relative to the main shaft  311 . Each main shaft  311  has a bending portion  33  formed thereon for corresponding to a ground surface. The bending portion  33  is substantially arc-shape and is located between the bottom bracket  32  and the main shaft  311  of the first leg  31 . Two pin members  34  are respectively mounted on the bending portions  33 . A pivoting rod  315  is disposed between the first legs  31  and is located adjacent to the bending portions  33 . The first legs  31  are perpendicularly arranged relative to the bottom bracket  32  such that the first legs  31  and the bottom bracket  32  configured a L-shape. Two pairs of pivoting plates  313  are respectively mounted on the two first legs  31  and are intermediately located on the main shaft  311 . Each pivoting plate  313  has a substantially plate-shaped positioning member  314  fixedly disposed thereon. 
     A first supporting unit  40  is pivotally disposed between the second lateral portion  12  of the base frame  10  and the first supporting frame  30 . The first supporting unit  40  includes a pair of supporting shafts  41 . Each supporting shaft  41  has two ends respectively and pivotally engaging with the second pivot ears  121  of the second lateral portion  12  and the main shaft  311  of the first supporting frame  30 . A guiding wheel  42  is disposed on one of the supporting shafts  41 . 
     A second supporting frame  50  includes two second legs  51  pivotally and respectively engaging with the pivoting plates  313  of the first legs  31  of the first supporting frame  30 . Each second leg  51  has an end section  512  formed on one end thereof and oppositely corresponds to the bottom bracket  32  of the first supporting frame  30 . Each second leg  51  has an axial portion  511  formed thereon which is located on an opposite end relative to the end section  512 . Each axial portion  511  pivotally engages with the corresponding pivoting plate  313  of the first supporting frame  30 . A guiding shaft  53  is axially disposed on one of the second legs  51 . Two wheels  52  are respectively and pivotally disposed on the end sections  512  of the second legs  51 . 
     A second supporting unit  60  which is adapted for positioning the second supporting frame  50  relative to the first supporting frame  30  is pivotally disposed between the first lateral portion  11  of the base frame  10  and the second legs  51  of the second supporting frame  50 . The second supporting unit  60  includes a pair of supporting members  61 , each supporting member  61  has two ends respectively and pivotally engaging with the corresponding first pivot ear  111  of the first lateral portion  11  and the second leg  51  of the second supporting frame  50 . 
     An operating unit  70  is mounted on the first supporting frame  30 . The operating unit  70  includes a driving shaft  71 , a push lever  72 , a coupling member  73 , and a spring member  74 . The driving shaft  71  has a pedaling portion  712  and a pivoting portion  711  respectively formed on two opposite ends thereof. The pivoting portion  711  is pivotally engaged with the pivoting rod  315  of the first supporting frame  30  such that the driving shaft  71  is pivotable relative to the first supporting frame  30 . The push lever  72  has a first end  721  which is pivotally engaged with one of the first legs  31  of the first supporting frame  30  and a second end  722  for corresponding to the base frame  10 . The push lever  72  has a pawl surface  7  which extends from the second end  722  toward the first end  721  thereof. The pawl surface  723  corresponds to the guiding wheel  42  of the first supporting unit  40 . A roller is disposed on the first end  721  of the push lever  72  for corresponding to the guiding shaft  53  of the second supporting frame  50 . The push lever  72  has a spaced distance from the driving shaft  71  such that that push lever  72  is not interfered by the driving shaft  71  during operation and vice versa. The coupling member  73  is pivotally disposed between the driving shaft  71  and the push lever  72 . The coupling member  73  has a first pivoting section  731  and a second pivoting section  732  formed on two opposite ends thereof. The first pivoting section  731  and the second pivoting section  732  are respectively and pivotally engaging with the push lever  72  and the driving shaft  71 . The first pivoting section  731  is pivotally connected to the first end  721  of the push lever  72  whereas the second pivoting section  732  is located between the pivoting portion  711  and the pedaling portion  712  of the driving shaft  71 . The spring member  74  has two ends respectively abutting against the pedaling portion  712  of the driving shaft  71  and the first end  721  of the push lever  72 . A resilient force of the spring member  74  constantly biases the pedaling portion  712  and the first end  721  to orient toward each other. 
     As shown in  FIG. 2 , when the collapsible stand in accordance with the present invention is in an extended configuration, the first supporting frame  30  and the second supporting frame  50  are positioned outwardly away from each other such that the bottom bracket  32  of the first supporting frame  30  and the end sections  512  of the second supporting frame  50  are located at their farthest distance apart. The first supporting frame  30  and the second supporting frame  50  are tiltedly positioned on the ground surface for stably supporting the base frame  10 . The base frame  10  is substantially in a horizontal position relative to the ground surface. By securely position the axial portions  511  of the second legs  51  on the corresponding positioning members  314 , the first supporting frame  30  and the second supporting frame  50  are retained tiltedly positioned relative to the ground surface such that the collapsible stand is stably maintained in the extended configuration. The pin members  34  rest on the ground surface for ensuring the collapsible stand is stably positioned. 
     When an user wishes to transport the machine tool  100  from one location to another, he/she simply needs to exert a downward force to the handle  20 , such that the pin members  34  mounted on the bending portions  33  are lifted from the ground surface, thereby the user can easily transport the machine tool  100  via the wheels  52  on the second supporting frame  50 . 
     Further referring to  FIGS. 3-5 , in order to convert the collapsible stand in accordance with the present invention from the extended configuration to a folded configuration, the user simply lifts up the handle  20  such that the first lateral portion  11  is lifted and the first supporting frame  30  is driven to pivotally retract. The second supporting frame  50 , driven by the movement of the first supporting frame  30 , is likewise pivotally retracted toward the first supporting frame  30 . The first supporting frame  30  and the second supporting frame  50  are brought closer together until the first supporting frame  30  and the second supporting frame  50  are uprightly positioned relative to the ground surface and are substantially parallely arranged relative to each other. The sliding shafts  312  thereby telescopically slide into the main shafts  311 . The second supporting unit  60  is driven by movement of the second supporting frame  50  such that the supporting members  61  of the second supporting unit  60  jostle the first lateral portion  11  of the base frame  10 . The base frame  10  is therefore pivotally tilted from the horizontal position to a fully upright position with the second lateral portion  12  orienting toward the ground surface and closely located adjacent to the first supporting frame  30 . The bottom bracket  32  and the end sections  512  which are located at their farthest distance apart in the extended configuration are drawn toward each other and are closely located adjacent to each other in the folded configuration. 
     As shown in  FIGS. 4 and 5 , when the collapsible stand in accordance with the present invention is fully folded, it is reduced to a compact size for convenient storage. Furthermore, the bottom bracket  32  of the first supporting frame  30  rests on the ground surface for stably supporting the collapsible stand in the folded configuration. 
     Further referring to  FIGS. 6 and 7 , when the user intends to convert the collapsible stand in accordance with the present invention from the folded configuration to the extended configuration shown in  FIGS. 1 and 2 , the user pedals on the pedaling portion  712  of the driving shaft  71  such that the driving shaft  71  is pivotally rotated to drive the coupling member  73  for pivotally driving the push lever  72  (When the pedaling portion is pedaled, the spring member  74  is expanded to store resilient force for elastic discovery). The pawl surface  723  is thereby by urged into engagement with the guiding wheel  42  disposed on the supporting shaft  41 . The guiding wheel  42  glides along the pawl surface  723  to drive the first supporting unit  40  and the base frame  10  upwardly away from the first supporting frame  30 . The sliding shafts  312  telescopically and slidably extends from the main shafts  311 . Simultaneously, the roller  724  disposed on the first end  721  of the push lever  72  glides along the guiding shaft  53  for driving the second supporting frame  50  to pivotally and radially extending outward and away from the first supporting frame  30 . The base frame  10  is therefore driven by the first supporting unit  40  to return to the horizontal position relative to the ground surface as shown in  FIGS. 1 and 2 . The second supporting unit  60  is pivotally driven by the base frame  10  and the second supporting frame  50  such that the supporting members  61  of the second supporting unit  60  are pivotally and appropriately rotated for positioning the second supporting frame  50 . By continuously exerting downward force on the handle  20 , the first supporting frame  30  and the second supporting frame  50  continue to move outwardly away from each other until the bottom bracket  32  of the first supporting frame  30  and the end sections  512  of the second supporting frame  50  are located at their farthest distance apart as in the extended configuration shown in  FIGS. 1 and 2 . 
     When the pedaling portion  712  is released, the spring member  74  elastically recovers such that the driving shaft  71 , the push lever  72 , and the coupling member  73  are driven to return to their original positions as shown in  FIGS. 4 and 5 . 
     In view of the above, the collapsible stand in accordance with the present invention is easy to operate, and can be folded/extended quickly. 
     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.