Abstract:
The present provides a lift and align table, having an adjustable support for positioning a piece of equipment, comprising a base frame, a middle plate, and an upper plate, a lifting mechanism disposed between the base frame and the middle plate, and a sliding mechanism disposed between the middle plate and an upper plate.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to an apparatus and a method for transferring heavy or awkward objects to a desired destination, and more particularly, to a lift and align table capable of moving an object in multiple directions.  
         BACKGROUND OF THE INVENTION  
         [0002]    In many areas of commercial industry, it is necessary to move objects that are too heavy, or awkwardly shaped to a final destination. One such application, where moving and positioning a heavy object is necessary, is the semiconductor industry where test heads, for testing semiconductor chips, require precise alignment with a handler.  
           [0003]    Stationary jacking mechanisms exist that can lift heavy objects vertically, while stationary conveyers exist that can move a heavy object in a horizontal direction. However, there exists a need for a device, and a method, that can enable the transfer a heavy object, such as a semiconductor chip test head, on one compact mobile device that integrates mechanisms that can lift and align the object adjacent to a desired location.  
         SUMMARY OF THE INVENTION  
         [0004]    The present invention solves this need by providing, in one embodiment, a lift and align table having an adjustable support for positioning a piece of equipment comprising a base frame, a middle plate, and an upper plate, a lifting mechanism disposed between the base frame and the middle plate, and a sliding mechanism disposed between the middle plate and an upper plate.  
           [0005]    The lift and align table of the present invention can be used for positioning an object, such as a semiconductor chip test head, to a desired destination, such as a handler, by placing the object on a support section of the table, moving the table toward a desired destination for said object, operating a lift mechanism to move the support section vertically and operating a slide mechanism to move the support section horizontally, thereby delivering the object to its desired location.  
           [0006]    Additional features and advantages of the present invention will be more clearly apparent from the detailed description which is provided in connection with accompanying drawings which illustrate exemplary embodiments of the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 is a perspective view of a lift and align table in accordance with an embodiment of the present invention;  
         [0008]    [0008]FIG. 2 is a top view of a base frame in accordance with an embodiment of the present invention;  
         [0009]    [0009]FIG. 3 is a perspective view of a base frame in accordance with an embodiment of the present invention;  
         [0010]    [0010]FIG. 4 is a schematic view of a lift mechanism in accordance with an embodiment of the present invention;  
         [0011]    [0011]FIG. 5 is a side view of a jacking mechanism in accordance with an embodiment of the present invention;  
         [0012]    [0012]FIG. 6 is a side view a gas cylinder assembly in accordance with an embodiment of the present invention;  
         [0013]    [0013]FIG. 7 is a perspective view of a slide mechanism in accordance with an embodiment of the present invention;  
         [0014]    [0014]FIG. 8 is a perspective view of an upper plate in accordance with an embodiment of the present invention;  
         [0015]    [0015]FIG. 9 is an illustration a lift and align table in accordance with an embodiment of the present invention in use; and,  
         [0016]    [0016]FIG. 10 is another illustration a lift and align table in accordance with an embodiment of the present invention in use. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]    In the following detailed description, reference is made to various specific embodiments in which the invention may be practiced. These embodiments are described with sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be employed, and that structural and procedural changes may be made without departing from the spirit or scope of the present invention.  
         [0018]    Referring now to the drawings, where like elements are designated by like reference numerals, FIG. 1 depicts an assembled lift table generally designated by the numeral  10 . The lift table  10  has a base frame  20 , a middle plate  30 , and an upper plate  40 . A lift mechanism  60  is provided between the base frame  20  and the middle plate  30 . In use, and as will be discussed in greater detail herein, the lift mechanism  60  operates to move middle plate in a vertical direction, indicated by arrows  61 , with respect to the base frame  20 . The lift table  10  also has gas cylinder assemblies  50  disposed between the base frame  20  and the middle plate  30 . As will be described herein, the gas cylinder assemblies  50  may be used to assist the lift mechanism  60  to move the middle plate  30  in the direction of arrows  61 . Alternatively, the gas cylinder assemblies  50  alone can be utilized to move the middle plate  30  in a vertical direction.  
         [0019]    The base frame  20  has wheels  21  that allow the lift table  10  to roll along a surface supporting the lift table  10 . In an exemplary embodiment, the lift table  10  has four wheels  21 , one disposed in each corner, as illustrated in FIG. 1. In the embodiment shown the wheels  21  are non-swivel type, allowing for precise movement in a direction indicated by arrows  25 . However, the wheels  21  can be of the swivel-type, allowing for movement of the lift table  10  in various directions. Also, the number of wheels  21  can be increased to provide additional stability or ease of movement of the lift table  10 , if so desired.  
         [0020]    The lift table  10  is further provided with an upper plate  40 , as illustrated in FIG. 1. A slide mechanism  70  is disposed between the upper plate  40  and the middle plate  30 . In use, as will be described in greater detail below, the slide mechanism  70  operates to move the upper plate  40  relative to the middle plate  30  in a direction indicated by arrows  71 .  
         [0021]    An exemplary embodiment of the base frame  20  is illustrated in greater detail in FIGS. 2 and 3, that show top and perspective views, respectively. The base frame  20  has two side braces  28  located at opposite sides of base frame  20 . The side braces  28  can be made from a material such as flat-bar steel, and are straight throughout most of their length. Each side brace  28  has, at both ends, cupped recesses  128  to accommodate the wheels  21 . The recesses  128  may alternatively, or additionally, be provided closer to the mid-span of the side brace  28 .  
         [0022]    The base frame  20  further has two x-braces; a rear x-brace  24  and a front x-brace  22 . The front x-brace  22  has a recess  27  that can accommodate a shaft associated with the lift mechanism  60 , as will be discussed below. The x-braces  22 ,  24  are attached to the side braces  28  at the top of the cupped recesses  128 , as shown in FIG. 3. The base frame  20  also has two y-braces  26  installed between the x-braces  22 ,  24  as shown in FIGS. 2 and 3.  
         [0023]    Because the x-braces  22 ,  24  are mounted on top of the cupped recesses  128 , a clearance space indicated by arrows  23  is created between the x-braces  22 ,  23  and the surfaces on which the lift table  10  is positioned. This clearance space  23  is a useful feature of the present invention because it enables the lift table  10  to move along, or over, obstructions such as bundles of cables (not shown) that can be present on a working surface.  
         [0024]    Base frame  20  structural components  22 ,  24 ,  26 ,  28  may be connected to one another using arc or gas welding, mechanical connections using bolts, or any other suitable fastening technique. The structural components of the base frame  20 , as illustrated, are made from flat metal bar. Alternatively, the base frame  20  components may be made from C-channel or I-beam, or another type of metal stock, that would allow flexibility of handling various types of loads. The comparative strength characteristics of such structures and materials are known in the art and are not discussed herein.  
         [0025]    Next, the lift mechanism  60  will be described. The lift mechanism  60 , which is disposed between the base frame  20  and the middle plate  30 , is shown from a top view in a schematic representation in FIG. 4. The lift mechanism  60  has a handwheel  62  connected to an input shaft  64 . The lift mechanism  60  has three gearboxes  68   a ,  68   b ,  68   c , multiple couplings  66  and transmission shafts  67 ,  167 ,  267 , and four jacking mechanisms  80   a ,  80   b ,  80   c ,  80   d  arranged as shown.  
         [0026]    In use, the handwheel  62 , and thereby input shaft  64 , are rotated by an external rotational force. Gearbox  68   a  transmits the rotational force from the input shaft  64  in two directions, perpendicular to input shaft  64 , to transmission shaft  67 . In one direction, the transmission shaft  67  transmits the rotational force to the jacking mechanism  80   a , and in the other, to jacking mechanism  80   b . Prior to reaching the jacking mechanism  80   b , the transmission shaft  67  passes through gearbox  68   b  which also directs the rotational force from shaft  67  onto transmission shaft  167 , which is perpendicular to transmission shaft  67 . Transmission shaft  167  connects to gearbox  68   c , which in turn transmits the rotational force from transmission shaft  167 , in two directions, onto transmission shaft  267 . Transmission shaft  267  is perpendicular to shaft  167  and parallel to shaft  67 . Transmission shaft  267  transmits the rotational force to jacking mechanisms  80   c  and  80   d.    
         [0027]    Couplings  66  are provided at various locations on shafts  67 ,  167 , and  267 , as shown. The couplings  66  make semi-permanent connections between sections of shafts and facilitate assembly and disassembly of the multiple shaft sections, gearboxes, and jacking mechanisms of the lift mechanism  60 . The couplings  66  may by rigid type (for perfectly aligned shafts), flexible type (for misaligned shafts), fluid type (with no mechanical connection between the shafts), or any other type of coupling suitable for transmitting a rotational force.  
         [0028]    The jacking mechanisms  80   a, b, c, d,  will be described collectively with reference to FIG. 5 which shows the construction of each. The jacking mechanisms  80  are disposed between the side braces  28  of the base frame  20  and the middle plate  30  (FIGS. 1 and 5). The jacking mechanism  80  comprises a lower mount block  82  that is mounted atop the side brace  28 , an upper mount block  84  that is mounted underneath the middle plate  30 , and a transmission module  88  which is located beneath the lower mounting block  84 . The mount blocks  82 ,  84  may be attached to side braces  28  and middle plate  30  using various welding techniques, mechanical fasteners, or other suitable fastening methods. A threaded jacking screw  86  extends from the lower mount block  82 , through the transmission module  88  and upper mount block  84 , and into a jacking screw housing  89 . The transmission shafts  67 ,  267  connect to transmission modules  88  as shown in FIG. 5. The threaded jacking screws  86  are perpendicular to transmission shafts  67 ,  167 ,  267 .  
         [0029]    In use, as rotational force is inputted to the input shaft  62 , the rotational force is transmitted through transmission shafts  67 ,  267  to the jacking mechanisms  80   a, b, c, d . The rotational force causes shafts  67 ,  267  to rotate in the direction of arrows  85 , as shown in FIG. 5. The rotational force of shafts  67 ,  267  is transmitted, through a linkage, such as a worm gear (not shown), to a jacking nut  81  disposed within the transmission module  88 , causing the jacking nut  81  to rotate in a direction indicated by directional arrows  181 . The jacking nut  81  has internal threads that are engaged with threads on the threaded jacking screw  86 . Rotation of jacking nut  81  causes the transmission module  88  to travel vertically along the jacking screw  86  in a direction indicated by direction arrows  87 . The upper mount block  84 , middle plate  30 , and jacking screw housing  89  are not engaged with jacking screw  86  and move freely along the jacking screw  86 . Therefore, as the transmission module  88  moves vertically along the jacking screws  86  of each one of four jacking mechanisms  80   a, b, c, d , cause the middle plate  30  to move vertically relative to the base frame  20 .  
         [0030]    The lift mechanism  60  alone is sufficient to move vertically the middle plate  30  relative to the base frame  20 . The illustrated and described configuration for lift mechanism  60  is only illustrative. Clearly, as will be evident to a person skilled in the art, many variations can be implemented to the lift mechanism  60 , i.e. adding input or transmission shaft sections, increasing the number of jacking mechanisms, etc., to accommodate changing structural, spatial, and end use requirements.  
         [0031]    Referring now to FIG. 6, gas cylinder assemblies  50  will be described. Each gas cylinder assembly  50  comprises a gas cylinder  52 , a piston  54 , a piston block  56 , and a gas supply line  59  that connects to the cylinder  52  through a fitting  58 . The gas cylinder  52  is mounted on the side brace  28 , and the piston block  56  is mounted on the middle plate  30 , using welding or mechanical fasteners or other suitable techniques. In use, pressurized gas is administered from an external source (not shown) through a supply line  159  to a 3-way valve  57 . The supply line  159  may also incorporate a check valve  158  that prevents the pressurized gas from flowing back to the source. The 3-way valve  57  functions to permit flow of pressurized gas into the gas cylinder  52  when it is being pressurized, and to vent pressurized gas from the gas cylinder  52 , through a vent port (not shown), when the gas cylinder  52  is being depressurized.  
         [0032]    Pressurized gas is admitted, via gas supply line  59 , to the gas cylinder  52 . The pressurized gas acts against the bottom surface  55  of the piston  52  to cause the piston to move vertically, in the direction indicated by arrows  53 , in response to increasing and decreasing gas pressure. Because the piston  54  is fixed to the middle plate  30  by the piston block  56 , the middle plate  30  is also urged to move in the direction of arrows  53  corresponding to the movement of the piston  54 .  
         [0033]    In an exemplary embodiment of the present invention, two gas cylinder assemblies are provided at midspans of the side braces  28 , as illustrated in FIG. 1. In this embodiment, the function of the gas cylinders  50  is to assist with the vertical movement of middle plate  30  relative to the base frame  20 . The force exerted by the pistons  54  on the middle plate  30  will be complementary to the force applied to the middle plate  30  by the jacking mechanisms  80 , as described above. As noted above, the lifting force provided by lift mechanism  60  alone can be sufficient. The force supplied by the gas cylinder assemblies is complementary because, when the jacking mechanisms  80  and the associated components of lift mechanism  60  are engaged, the jacking screws  86  and associated shafts  67 ,  167 ,  267  must turn in order for the middle plate to move vertically.  
         [0034]    The above described lifting method is merely illustrative and is not meant to suggest that this invention is so limited. The vertical movement of plate  30  can be accomplished, for example, solely with four gas cylinders disposed in place of the jacking mechanisms  80 . Alternatively, hydraulic cylinder assemblies may be used instead of gas cylinder assemblies  50 . Also, although an exemplary embodiment is described having a pressurized gas (or hydraulic fluid) source external to the lift table  10 , a pressurized gas source may be installed within the lift table  10 .  
         [0035]    Referring now to FIG. 7, the slide mechanism  70  will be described. The slide mechanism is disposed on the top surface  34  of the middle plate  30 . The slide mechanism includes a support frame that has two side supports  178  and two rail supports  180  arranged as shown. Two slider block rails  182  are attached to top of the two rail supports  180 . The slider block rails  182  can be inserted into slots in rail supports  180 , or may be welded or mechanically attached. Four slider blocks  190  are slidably engaged with the slider block rails, two on each rail,  182  as shown. The slider blocks  190  have a top surface  192  to which the upper plate  40  is mounted, as will be discussed herein.  
         [0036]    The slide mechanism  70  further has a handwheel  172  attached to a shaft  174 . The shaft  174  is disposed along one of the side supports  178 , as shown. The shaft  174  is supported by bushing blocks  176 , and by a gearbox  194 . The gearbox  194  transmits rotational force from shaft  174  onto threaded lead screw  196 , which is perpendicular to shaft  174 . Lead screw  196 , in turn, is attached to a lead block  198 . Lead block  198  has internal threads and is engaged with threaded lead screw  196 .  
         [0037]    In use, rotational force is applied to the handwheel  172 , and thereby shaft  174 , to rotate the shaft  174  in a direction indicated by arrows  73 . Rotational force is transmitted from shaft  174 , through gearbox  194 , to lead screw  196  causing the lead screw  196  to rotate in the direction indicated by arrows  193 . Lead block  198 , being threadably engaged with lead screw  196 , thereby moves in a direction indicated by arrows  71 . The lead block  198  is attached to the bottom surface of upper plate  40  and therefore imparts movement to the upper plate  40  in the direction of arrows  71 .  
         [0038]    The upper plate  40  is illustrated in FIG. 8. The upper plate  40  may be mounted to the slider blocks  190  and lead block  198  by mechanical fasteners through holes  48 ,  49 , respectively, or by other methods such as welding. In use, the upper plate  40  is moved by movement of the lead block  198 , as described above. Slider blocks  190  move together with the upper plate  40  and enable smooth motion of the upper plate. The upper plate further has four slots  46 , as shown, that can accommodate the jacking screw housings  89  as the upper plate  40  moves in the direction of arrows  71 . The spatial relation between the jacking screw housings  89  and slots  46  is best illustrated in FIG. 1. The upper plate  40  further has openings  44  that offer weight savings for the resulting structure.  
         [0039]    The lift and align table in accordance with the present invention can further include a second slide mechanism  70  to enable alignment in a direction perpendicular to the direction indicated by arrows  71 . For example, a second slide mechanism can be mounted on the top surface  42  of the upper plate  40 . The second slide mechanism would be installed so that the direction of the movement of the lead block  198  is perpendicular to the direction of arrows  71 . Then, another top plate would be installed over the second slide mechanism, as described above, thereby allowing adjustments of the top plate, using the two slide mechanisms, in two directions within the same plane, namely in the direction of arrows  71  and in a direction perpendicular to arrows  71 .  
         [0040]    The lift table described herein can lift and align a heavy or awkward object to another abject, or storing area, as follows. With reference to FIGS.  1 - 8 , an object to be aligned (not shown) is placed onto the upper mounting plate  40  of the lift table  10 . The lift table  10  is then rolled toward the desired destination of the object in a direction  25  utilizing the wheels  21 . Alternatively, the lift table  10  can be rolled in various directions if wheels  21  are swivel-type wheels. After the table  10  within desired proximity of the destination for the object, the lift mechanism  60  is operated by rotating handwheel  62  to raise or lower the middle plate  30 , and thereby the upper plate  40 , in a direction indicated by arrows  61 . After the object is at a desirable height, final adjustments are made to bring the upper plate  40  adjacent the destination for the object. As described above, handwheel  172  is rotated, thereby translating lead block  198  and attached upper plate  40  in a direction indicated by arrows  71 . After the object on the upper plate  40  is in a desirable position, the object is transferred to its destination by either manual or mechanical means.  
         [0041]    An exemplary use for the lift and align table of the present invention is to align a test head to a handler unit as used in semiconductor chip industry. With reference to FIGS. 9 and 10, a test head  200 , loaded onto the lift and align table  10  using a manual or mechanical means, is moved toward a handler unit  210 . As the lift and align table  10  reaches a desired destination within the handler unit  210 , lifting and aligning operations are performed as described above. When the test head  200  is in a desirable position, handler unit support mechanisms  214  engage test head brackets  202  to secure the test head  200  in place. The lift and align table is then lowered and removed form the handler unit  210 . Thereafter, testing or processing of semiconductor chips may be carried out. FIG. 10 also shows cables  250  that are cleared by the lift and align table of the present invention.  
         [0042]    While exemplary embodiments of the invention have been described and illustrated, it should be apparent that many modifications can be made to the present inventions without departing from its spirit and scope. For example, while rotational force to operate handwheels  62  and  172  is manual, shafts  64  and  174  can be attached to a mechanical source of rotational force, such as a motor. Additionally, top surface  42  of the upper plate may be differently shaped to support objects having unique surfaces. Accordingly the invention is not limited by the foregoing description or drawings, but is only limited by the scope of the appended claims.