Abstract:
An apparatus and associated method for lifting a workpiece. An upright frame operably supports a lead screw for selective rotation. A carrier threadingly engages the lead screw so that rotation of the lead screw in one rotational direction linearly advances the carrier in a lifting direction and rotation of the lead screw in the opposite rotational direction linearly advances the carrier in a lowering direction. A mechanical power inlet is adapted for receiving an input torque from a user. A mechanical power transmission assembly has a first gear fixed in rotation with the mechanical power inlet and a different second gear fixed in rotation with the lead screw, the first and second gears sized so that the input torque imparted on the first gear is less than an output torque imparted by the second gear to the lead screw.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/550,400, filed on Oct. 22, 2011, the contents of which are hereby incorporated by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention generally relates to methods and devices for material handling, and more particularly without limitation to lifting a spool of flexible elongate material, so that the spool can be rotated around a horizontal axis to wind or unwind the flexible elongate material contained therein. 
       SUMMARY OF THE INVENTION 
       [0003]    Some embodiments of the present invention are directed to an apparatus for lifting and supporting a workpiece. Such an apparatus includes an upright frame and a lead screw that is supported for selective rotation by the frame. A carrier threadingly engages the lead screw so that rotation of the lead screw in a first rotational direction linearly moves the carrier in a lifting direction and rotation of the lead screw in a second rotational direction linearly moves the carrier in a lowering direction. A mechanical power inlet feature is adapted for receiving an input torque from a user. A mechanical power transmission has a first gear fixed in rotation with the mechanical power inlet and a different second gear fixed in rotation with the lead screw, the first and second gears sized so that the input torque imparted on the first gear is less than an output torque imparted by the second gear to the lead screw. 
         [0004]    Other embodiments of the present invention are concerned with a jack stand having a frame with a longitudinal base beam defining a proximal end and an opposing distal end. The frame has an upright support beam connected to the base beam between the proximal end and a base beam midpoint and extending substantially orthogonal from the base beam. A lead screw is supported by the frame for selective rotation. A carrier threadingly engages the lead screw so that rotation of the lead screw in a first rotational direction linearly advances the carrier in a lifting direction and rotation of the lead screw in a second rotational direction linearly advances the carrier in a lowering direction. 
         [0005]    Still other embodiments of the present invention contemplate a method including obtaining an apparatus that includes an upright frame and a lead screw supported by the frame for selective rotation. A carrier threadingly engages the lead screw so that rotation of the lead screw in one rotational direction linearly advances the carrier in a lifting direction and rotation of the lead screw in the opposite rotational direction linearly advances the carrier in a lowering direction. A mechanical power inlet is adapted for receiving an input torque from a user. A mechanical power transmission has a first gear fixed in rotation with the mechanical power inlet and a different second gear fixed in rotation with the lead screw, the first and second gears sized so that the input torque imparted on the first gear is less than an output torque imparted by the second gear to the lead screw. The method further includes rotating the mechanical power inlet feature to align the carrier with the workpiece; and after aligning the support member with the workpiece, rotating the mechanical power inlet to linearly advance the carrier against the workpiece and thereby lift the workpiece. 
         [0006]    These and other features, aspects, and advantages of the present invention will become better understood with reference to the following drawings, description, and claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is an isometric depiction of an apparatus that is constructed in accordance with illustrative embodiments of the present invention; 
           [0008]      FIG. 2  is a side elevational depiction of the apparatus of  FIG. 1 ; 
           [0009]      FIG. 3  is a rear isometric depiction of an apparatus that is constructed in accordance with alternative embodiments of the present invention; 
           [0010]      FIG. 4  is a view similar to  FIG. 1  but with the covers and supports removed to depict the underlying structural framework and working components; 
           [0011]      FIG. 5  is a side elevational depiction of an enlarged portion of  FIG. 4  more particularly depicting the carrier; 
           [0012]      FIG. 6  is a cross sectional depiction of a one-axis dynamic attachment of the follower to the lead screw; 
           [0013]      FIG. 7  is a cross sectional depiction of a two-axis dynamic attachment of the follower to the lead screw; 
           [0014]      FIG. 8  is an isometric depiction of the bearing supporting the top end of the lead screw in rotation; 
           [0015]      FIG. 9  is an isometric depiction of the mechanical power transmission with the cover removed to reveal the working components; 
           [0016]      FIG. 10  is an isometric depiction of a collar attached to the top and bottom of the upright frame for attaching the removable covers, according to an embodiment of the invention; and 
           [0017]      FIG. 11  is an isometric depiction of another embodiment showing a collar attached to the top and bottom of the upright frame for attaching the removable covers. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    The following detailed description is of the best currently contemplated modes of carrying out the invention. The floor jacking concepts herein are not necessarily limited to use or application with any specific workpiece and associated methods, although the illustrative embodiments are well suited for lifting a spool of wire as the workpiece. Thus, although the instrumentalities described herein are shown and described with respect to exemplary embodiments for the convenience of explanation, the principles herein may be applied equally in other types of workpieces and associated methods of material handling. The description is thus not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
         [0019]    Referring now to  FIG. 1 , isometric depiction of a jack stand  10  is shown constructed in accordance with illustrative embodiments of the present invention. The jack stand  10  may generally have an upright frame  12  which may include removable covers  14 ,  16  that operably safeguard a user from moving parts enclosed within the covers  14 ,  16 . An opening  18  may be provided between the covers  14 ,  16  to permit selective movement of a carrier  20  to raise a workpiece off a generally horizontal support surface such as a floor. Note that although in these illustrative embodiments the carrier  20  movement is vertical in relation to the horizontal support surface, the contemplated embodiments are not so limited in that alternative embodiments can selectively move a carrier or like lifting mechanism in a direction other than vertical. 
         [0020]    The jack stand  10  may also include a mechanical power transmission  22  that converts a force supplied by the user to a force on the carrier  20  that is sufficient to move the desired load either upwardly or downwardly with respect to the support surface. The force supplied by the user may be a torque applied to a protuberant mechanical power inlet  24 . 
         [0021]    The jack stand  10  of the present embodiments may be well suited, in these teaching examples, for lifting a spool around which a workpiece is spooled, such as wire, tubing, or some other flexible elongate material. It may be advantageous to buy such spooled workpieces in bulk quantity to reduce material cost and improve quality by reducing the number of spliced joints. However, bulk quantities require larger and heavier spools. It is not unusual for a user to have a need to handle six foot diameter spools weighing three thousand pounds or more. 
         [0022]    Referring now to  FIG. 2 , one of a pair of jack stands  10  is depicted, which cooperatively lift such a large and heavy spool  26  upon an axle  28  placed through the spool&#39;s  26  center bore  30 . It will be understood that the other jack stand  10  is placed in like manner on the opposing side of the spool  26 , and as such it is hidden in the depiction of  FIG. 2 . The jack stands  10  may be capable of lifting the spool  26  off the ground (or other support surface) so that the spool  26  may be rotationally free to rotate as the workpiece  31  is pulled off the spool  26  in a direction denoted by reference arrow  33 . In order to handle a variety of different size spools, the carrier  20  may in some embodiments be selectively positionable from about six inches above the support surface to a little over thirty-six inches above the support surface. Note that in these illustrative embodiments the carrier  20  may include support rollers  32  to facilitate rotation of the axle  28  as the workpiece  31  is removed from the spool  26 . 
         [0023]    A sufficient inlet torque for lifting the spool  26  can be imparted to the mechanical power inlet  24  by use of a standard power tools found around a typical work site for imparting torque to items, such as power drills (both corded and cordless), hammer drills, and ordinary cordless screwdriver hand tool (tools not depicted). Torque may also be applied to the mechanical power inlet  24  by means of unpowered hand tools, such as a lug wrench, a detachable handle, or a socketed wheel. To accommodate the use of such torqueing tools, the mechanical power inlet  24  may be preferably configured with a working end that defines a surface engageable with a standard size tool bit or socket in a close mating relationship, such as a standard size bolt head configuration. 
         [0024]      FIG. 2  shows the carrier  20  which may further include a retainer  34  depicted in a closed position to operably retain the axle  28  supported on the carrier  20 . Without the retainer  34 , the unwinding force on the workpiece in direction  33  and/or some resistance to spool  26  rotation might disadvantageously pull the axle  28  off the carrier  20 . The retainer  34  may be selectively moveable to an open position. In these illustrative embodiments, for example, the retainer  34  may be connected to a structural base  36  at a rotational joint  38 . A removable pin  40  may be inserted into aligned holes in the retainer  34  and the base  36  to lock the retainer  34  in the closed position depicted in  FIG. 2 . Removing the pin  40  may permit rotating the retainer  34  to an open position, making it possible to move the carrier  20  into place for lifting the axle  28 . For example, by the force of gravity the hooked end of the retainer  34  in the open position may point vertically downward, permitting an operable movement of the jack stand  10 , and hence the carrier  20 , in direction  42  to slide unencumbered under the axle  28  into an aligned position, where raising the carrier  20  may place the support rollers  32  in contact with the axle  28 . 
         [0025]      FIGS. 1 and 2  further depict an upright frame  12  which includes a longitudinal base beam  44  with spreader plates  46 ,  48  individually attached to proximal and distal ends of the longitudinal base beam  44 , respectively. The spreader plates  46 ,  48  may operably contact the support surface upon which the jack stand  10  is lifting, typically upon the ground surface which can be notoriously non-level. The spreader plates  46 ,  48  may effectively distribute the weight of the lifted spool  26  to a two-point contact with the ground in order to minimize the effects of uneven ground between the spreader plates  46 ,  48 . The spreader plate  46  also supports a pair of transport rollers  50  that are operably offset above the ground by a distance  52  to prevent them from bearing any weight of the lifted spool  26 . When the lifting is complete, the jack stand  10  may be pivoted rear-ward to bring the transport rollers  52  into contact with the support surface, so that upon the transport rollers  52  the jack stand  10  can be transported to the next desired location. A handle  54  may be provided for the user to pivot the jack stand  10  upon the transport rollers  52 , and then for the user to guide the jack stand  10  as it is rolled upon the transport rollers  52 .  FIG. 3  depicts an alternative U-shaped handle  54 ′ 
         [0026]      FIG. 4  is an isometric depiction of the jack stand  10  similar to  FIG. 1  but with portions of the upright frame  12  removed for clarity to reveal working components inside the enclosure of the covers  14 ,  16 . The longitudinal base beam  44  supports an upright support beam  56 . In these illustrative embodiments, both beams  44 ,  56  may be constructed of square tubing, and the beams  44 ,  56  may be joined together by any substantial means, such as by welding or bolting. The upright beam  56  may extend substantially orthogonally from the base beam  44  at a position between a proximal end  58  of the base beam  44  and a midpoint of the base beam  44 , in order that the support rollers  32  are distributed substantially above the midpoint of the base beam  44 . 
         [0027]    A threaded lead screw  60  may be supported for rotation at a lower end upon the base beam  44  and at an upper end by a driven gear  62  in the mechanical power transmission  22 . The lower end of the lead screw  60  may be preferably supported for rotation by a load-bearing member  64 , such as a bushing or a thrust bearing and the like. As depicted in  FIG. 8 , the upper end of the lead screw  60  may be likewise preferably supported in rotation by a load bearing member  64  such as a bushing or a thrust bearing in like manner. 
         [0028]    Still referring to  FIG. 6 , the carrier  20  may have a threaded follower  66  attached to the base  36 . A rotation of the lead screw  60  in a first direction may cause a threaded advancement of the follower  66  in a first linear direction. The base  36 , being affixed to the follower  66 , may be likewise linearly advanced by the linear advancement of the follower  66 . In the same manner, a rotation of the lead screw  60  in the opposite direction (i.e. a second direction) may cause a threaded advancement of the follower  66 , and in turn a linear advancement of the carrier  20 , in the opposite linear direction. In this manner, rotation of the lead screw  60  in one direction may raise the carrier  20  away from the support surface, and rotation of the lead screw  60  in the opposite direction may lower the carrier  20  towards the support surface. 
         [0029]    Opposing web plates  68 ,  70  may be attached individually at one end to the base  36  and extend therefrom to distribute the weight lifted by the carrier  20  to the upright beam  56 .  FIG. 5  is an enlarged and partially cutaway elevational depiction of the carrier  20  showing the web plates  68 ,  70  (only web plate  68  visible in  FIG. 5 ) supporting a pair of guide rollers  72 ,  74  against opposing sides of the upright beam  56 . In these illustrative embodiments, the follower  66  may be rigidly affixed to the base  36 , such as by a weld  76 . Even so, the weight lifted by the carrier  20  may be transferred through the web plates  68 ,  70  to the guide rollers  72 ,  74  that pressingly engage against the upright beam  56  to unload the follower  66 , so that follower  66  may be threadingly advanced by the selective rotation of the lead screw  60 . That is, the weight lifted by the carrier  20  may be supported by the upright beam  56  so that the follower  66  is free to threadingly advance along the lead screw  60  without undue pressure of the threadingly engaged components against each other. Protuberant positive stop bumpers  73 ,  75  may abuttingly engage the web plate  68  to limit the carrier  20  travel at the upper and lower extents of travel, respectively. 
         [0030]    In an alternative embodiment, the follower  66  may be dynamically attached in the carrier instead of rigidly attached as described above. A dynamic, or floating, attachment permits the axial alignment of the follower  66  and lead screw  60  to vary as the follower  66  advances longitudinally along the lead screw  60 . This dynamic adjustment can aid in compensating for positional variance of the lead screw  60 , and in compensating for part-to-part variation in manufacturing processes, resulting in reduced frictional resistance between the threadingly engaged components. 
         [0031]    Referring now to  FIG. 6 , a cross-sectional view of a portion of a carrier  20 ′ is shown, constructed in accordance with alternative embodiments of the present invention. Here, a follower  66 ′ may be dynamically connected by pins  78 ,  80  to corresponding blocks  82 ,  84  that are, in turn, affixed to the web plates  68 ,  70 . The pins  78 ,  80  and corresponding bores in the blocks  82 ,  84  may be sized to permit operable rotation of the follower  66 ′ around an axis  86  that is substantially orthogonal to the longitudinal base beam  44  ( FIG. 1 ). 
         [0032]    Where  FIG. 6  depicts embodiments dynamically mounting the follower  66 ′ for longitudinal compensation around one axis of rotation,  FIG. 7  depicts alternative embodiments dynamically mounting a follower  66 ″ for longitudinal compensation around two different axes of rotation. Here, the follower  66 ″ may be dynamically connected by pins  88 ,  90  to a frame  92 . The pins  88 ,  90  and corresponding bores in the frame  92  may be sized to permit operable rotation of the follower  66 ″ around an axis  94  that is substantially parallel to the longitudinal base beam  44  ( FIG. 1 ). The frame  92  may be pinned to the blocks  82 ,  84  as described above to permit operable rotation of the follower  66 ″ around the axis  86  that is substantially orthogonal to the longitudinal base beam  44 . 
         [0033]      FIG. 8  depicts the upper end of the lead screw  60 , which may have a non-threaded end that passes through a hole  93  in a bearing support  94  extending from the upright support beam  56 . A thrust bearing  96  may be secured to the end of the lead screw  60  by a locking collar  98 . The distal end of the lead screw  60  may extend upwardly into the mechanical power transmission  22 . 
         [0034]      FIG. 9  is a top isometric depiction with the cover removed from the mechanical power transmission  22  to reveal the gearing components contained therein. A drive gear  100  may be connected to the protuberant mechanical power inlet  24  ( FIG. 1 ) to directly receive the torque supplied by the user. The drive gear  100  may be meshingly engaged with the driven gear  62  affixed in rotation with the lead screw  60 . The drive gear  100  may be smaller than the driven gear  62  in order to slow the rotational speed while stepping up the torque that is ultimately imparted to the lead screw  60 . Preferably, the number of gear turns of the drive gear  100  to the number of gear turns of the driven gear  62 , the gear turn ratio, may preferably be at least one and a half to one, and more preferably at least three to one. That mechanical power transmission arrangement may permit a torque transfer from an ordinary cordless drill working on the mechanical power inlet  24  to impart a sufficient torque on the lead screw  60  by the driven gear  62 , which may be capable of lifting a spool weighing about three thousand pounds or more. 
         [0035]    Finally,  FIGS. 10 and 11  depict the upright frame  12  ( FIG. 1 ) and further include a collar  104  attached to the top of the upright beam  56  and another collar  106  attached to the base beam  44 . The collars  104 ,  106  may support fastening features  108 , such as threaded inserts, sized and positioned to receive removable fasteners for attaching the covers  14 ,  16 . 
         [0036]    It is to be understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description, together with the details of the structure and function of various embodiments of the invention, this disclosure is illustrative only, and changes may be made in detail, especially in matters of structure and arrangement of parts within the principles of the present invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. For example, interfacing support components other than the carrier disclosed herein are contemplated while still maintaining substantially the same functionality without departing from the scope and spirit of the claimed invention. Further, although the illustrative embodiments described herein are directed to handling workpiece spools, such as wire spools and related technology, it will be appreciated by those skilled in the art that the claimed invention can be applied to other workpieces requiring a handling assist device as well without departing from the spirit and scope of the present invention.