Lifting platform

Abstract

A lifting platform includes a base, two “T”-shaped parallel sliding grooves in supporting bars, two wheels, a platform, and a cylinder. Each wheel is held away from the internal far rolling surface of each sliding groove in an original position because of the orientation of the connected platform, but can contact and rest upon the rolling surface and further roll along the rolling surface when the platform is rotated. A hydraulic or air-driven piston rod of the cylinder can push the platform to first rotate and then move upward. The platform is transitionable between: (i) an inclined configuration in which each first wheel is in the original position; (ii) a horizontal configuration in which each first wheel contacts and rests upon a sliding groove; and (iii) a lifting configuration in which each first wheel rolls along a sliding groove.

What is claimed is: 
     
         1 . A lifting platform comprising:
 a base;   at least one supporting bar connected to the base at an angle;   at least two parallel sliding grooves defined in the at least one supporting bar;   at least two first wheels each spaced from an internal surface of one sliding groove in an original position, and configured to contact the internal surface of the sliding groove and further roll along the internal surface of the sliding groove;   a platform coupled to the at least two first wheels, configured to be rotated by a preset angle to cause each first wheel to contact the internal surface of the sliding groove, and further configured to be moved away from the base to cause each first wheel to roll along the internal surface of the sliding groove; and   a cylinder having a piston rod configured to extend out of the cylinder to cause a rotation or movement of the platform;   wherein the platform is further transitionable between: (i) an inclined configuration in which each first wheel is in the original position; (ii) a substantially horizontal configuration in which each first wheel contacts the internal surface of the sliding groove; and (iii) a lifting configuration in which each first wheel rolls along the internal surface of the sliding groove.   
     
     
         2 . The lifting platform of  claim 1 , wherein the base comprises a supporting portion and two arms extending from opposite ends of the supporting portion, each arm comprises at least one second wheel at a bottom thereof. 
     
     
         3 . The lifting platform of  claim 2 , wherein at least two supporting bars are secured to the supporting portion, substantially perpendicular to the supporting portion, and spaced from each other; and each sliding groove is defined in one supporting bar. 
     
     
         4 . The lifting platform of  claim 2 , wherein a pump is coupled to the cylinder and comprises an operating portion; the piston rod extends outward by a preset distance to push against the platform each time the operation portion is operated. 
     
     
         5 . The lifting platform of  claim 4 , wherein the pump further comprises a button, when the button is pressed, the piston rod retracts inward by a preset distance to release the platform each time the operation portion is operated. 
     
     
         6 . The lifting platform of  claim 1 , wherein the platform is coupled to each first wheel via a connecting member; each connecting member comprises a first portion and an opposite second portion; the first portion of each connecting member is rotatably connected to one first wheel; the second portion of each connecting member is secured to the platform; and the connecting members are configured to rotate/move with the platform. 
     
     
         7 . The lifting platform of  claim 6 , wherein the platform is integrally formed with the connecting members. 
     
     
         8 . The lifting platform of  claim 6 , wherein each of the at least two sliding groove retains a sliding block; the at least two sliding blocks are configured to slide with the first wheels along the at least two sliding grooves; each connecting member further comprises a third portion between the first portion and the second portion; each sliding block is rotatably connected to the third portion of one connecting member. 
     
     
         9 . The lifting platform of  claim 8 , wherein each sliding block is rotatably connected to the third portion of the connecting member via a first shaft. 
     
     
         10 . The lifting platform of  claim 8 , wherein each sliding groove is substantially “T”-shaped in cross section and comprises a main body and two limiting portions extending from opposite sides of the main body; the limiting portions of each sliding block creates a dimension wider than an internal width one sliding groove, thereby preventing the sliding blocks and the platform coupled thereto from disengaging from the sliding grooves. 
     
     
         11 . The lifting platform of  claim 6 , wherein each first portion is rotatably connected to one first wheel via a second shaft. 
     
     
         12 . The lifting platform of  claim 1 , wherein a back surface of the platform is rotatably connected to the piston rod. 
     
     
         13 . The lifting platform of  claim 12 , wherein the back surface of the platform comprises a first securing member; the first securing member comprises a third shaft; and the back surface of the platform is rotatably connected to the piston rod via the third shaft. 
     
     
         14 . The lifting platform of  claim 1 , wherein a back surface of the platform comprises a rib substantially perpendicular to the piston rod; the piston rod abuts against the rib and pushes against the platform via the rib. 
     
     
         15 . The lifting platform of  claim 2 , wherein the supporting portion further comprises a second securing member, the second securing member comprises a fourth shaft; an end portion of the cylinder opposite to the piston rod is rotatably connected to the fourth shaft. 
     
     
         16 . A lifting apparatus comprising:
 a base;   at least two supporting bars connected to the base at an angle, each of the at least two supporting bars having a sliding groove;   at least two first wheels rollably fitted within the sliding grooves;   a platform coupled to the at least two first wheels; and   an extending device attached to the platform;   wherein, each sliding groove includes an opening slit along the supporting bar and a flat internal surface opposite the opening slit;   wherein, when the extending device is un-extended, the at least two first wheels are not in contact with the sliding groove internal surface and the platform is in an inclined position;   wherein, when the extending device initially extends, the at least two first wheels make contact with the sliding groove internal surface moving the platform into a substantially horizontal position; and   wherein, when the extending device continues to extend, the at least two wheels roll along the sliding groove internal surface lifting the platform.   
     
     
         17 . The lifting platform of  claim 16 , wherein the extending device is a cylinder having a piston rod, the piston rod is configured to extend out of the cylinder to moving or lifting the platform.