Abstract:
A linear drive mechanism is configured with a vertical column mounted on a mobile base containing a reversible electric motor that is coupled to drive a threaded shaft located centrally within the column. A driving member, engaging the threaded shaft and constrained to vertical travel in a longitudinal slot in a side of the column, can be driven by the motor in a linear path in either direction between the ends of the column. The drive mechanism is adaptable to power a wide variety of auxiliary mechanisms linearly and/or rotationally to perform specific tasks with substantial reductions of manual labor in construction and material-moving tasks including shoveling, picking, hoeing, digging trenches and holes, lifting, e.g. as with a hoist, crane or vertical conveyor, pulling, mixing, e.g. concrete, handling and installing panel workpieces such as drywall, and driving posts.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the field of powered utility machines and more particularly a versatile motor-driven linear drive utility machine that supplants manual labor in a variety of construction and material-moving tasks including shoveling, digging trenches and drilling holes, lifting and setting concrete blocks, setting posts, picking, lifting, e.g. as with a hoist or crane, pulling, mixing, e.g. concrete, and handling drywall or other panels. 
     BACKGROUND OF THE INVENTION 
     There are many tasks in the fields of construction, soil-moving and the like that fall into a category that although they are particularly difficult to perform manually, they do not merit deployment of regular heavy duty powered equipment such as tractors, bulldozers, cranes, hoists, winches, and the like, either because of prohibitive costs, inaccessible location, space limitations, or any of a number of other reasons or circumstances. 
     DISCUSSION OF KNOWN ART 
     Examples of powered devices that supplant manual labor include concrete mixers, power saws, powered lawn mowers, powered hedge clippers, leaf blowers, roto-tillers, etc. Despite these and other labor savers, there remain many manual tasks that are overly strenuous for manual labor and that would become more efficient overall if a moderate amount of machine power were made available in versatile manner to apply to the various physical tasks. 
     OBJECTS OF THE INVENTION 
     It is a primary object of the present invention to provide a versatile and readily portable motorized mechanism to assist with a variety of heavy duty tasks that are customarily performed manually for various reasons including excessive size, cost or unavailability of known machines such as tractors, cranes, etc. 
     It is a further object of the present invention to provide a utility drive power source that is inexpensive and readily portable and yet high versatile and readily adaptable to avoid or supplement manual labor in a wide range of labor-intensive tasks. 
     SUMMARY OF THE INVENTION 
     The objects of the invention have been met by a linear drive mechanism having an elongated column mounted on a mobile base and extending upwardly therefrom when the base is in a normal attitude on horizontal ground, containing a motor that drives a threaded shaft located centrally within the column and engaging a driving member that, under user control, can be driven by the motor in a linear path in either direction between the ends of the column, and that can be coupled to any of a variety of auxiliary mechanisms dedicated to perform specific tasks. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and further objects, features and advantages of the present invention will be more fully understood from the following description taken with the accompanying drawings in which: 
         FIG. 1  is a three-dimensional view of a linear drive machine according to the present invention. 
         FIG. 2  is three-dimensional view showing the linear drive machine of  FIG. 1  operationally connected to a shoveling mechanism. 
         FIG. 3  is a three-dimensional partial view of a pick attachment that can be utilized in place of the shovel attachment in  FIG. 2 . 
         FIGS. 4A and 4B  depict, in an elevational side view, two sequential steps in the process of deploying the shoveling mechanism of  FIG. 2 . 
         FIG. 5  is a three-dimensional view of a vertical conveyer accessory of the present invention. 
         FIG. 5A  is an enlarged view of a lower portion of  FIG. 5  and a portion of an associated enclosure. 
         FIG. 6  is a three-dimensional view showing three linear drive machines of the present invention as in  FIG. 1 , deployed together to support a variable-height utility platform or scaffold. 
         FIG. 7  is a three-dimensional view of a reinforced block wall under construction utilizing the present invention as a hoist. 
         FIG. 8  is a three-dimensional view of a concrete mixing apparatus powered by the linear drive machine of the present invention. 
         FIG. 8A  is a three-dimensional view of a sliding yoke portion of the mixing apparatus in  FIG. 8 . 
         FIG. 9  is a three-dimensional view showing a height-adjustable platform system for installing ceiling panels such as drywall utilizing two linear drive machines of the present invention. 
         FIG. 10  is a three-dimensional view of the platform of  FIG. 9   
         FIG. 10A  is a side view of one of the two spacer strips of  FIG. 10 . 
         FIG. 10B  is an and end view of the platform of  FIG. 10  and a portion of the spacer strip of  FIG. 10A , supporting a panel workpiece with pre-inserted nails. 
         FIG. 11  is a three-dimensional view of a ground hole drill assembly that can be driven from the linear drive machine of the present invention. 
         FIG. 12  is an enlarged top view of the gearbox of  FIG. 11 , shown partially cut away to reveal the internal worm gear set. 
         FIG. 13  is a cross-section of the gear box of  FIG. 12   
         FIG. 14  is a three-dimensional view of a post driver assembly for hammering a post into the ground. 
         FIG. 15  is a three-dimensional view of an offset pivot portion of the post driver assembly of  FIG. 14 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a three-dimensional view of the a linear driver machine  10  representing the primary element of the present invention in basic form. A base enclosure  10 A supported by a pair of wheels  10 B and fitted with a handle  10 C supports a firmly fastened hollow column  10 D that is generally square in cross-section and contains a centrally-located threaded shaft  10 E shown in the cutaway region. Shaft  10 E runs in bearings in the top and bottom regions of column  10 D, and is drivably coupled by a reduction gear set to a reversible electric motor located in base enclosure  10 A. A driving member  10 F, engaging the threads of shaft  10 E is thus driven by rotation thereof to travel vertically in the elongated slot shown that runs the length of column  10 D. 
     Drive machine  10  is made adaptable to be removably coupled operationally to supply drive power to any of a variety of machine loads in either or both of two modes: 
     (1) in the linear mode via driving member  10 F for variable-height and reciprocating activities such as a shoveling system, a pick system, a lift platform/scaffold, a concrete block installing system, a handler and installer for construction panels such as hardwall workpiece sheets, a concrete mixer and a post driver; 
     (2) in the rotational mode, with the addition of a bevel gear attachment at the top end of shaft  10 E for continuous rotation as required by machines such as a vertical conveyor, a hoist, a winch, and a ground drill. Drive power can be delivered by the drive machine  10  in both the linear and rotational modes simultaneously if necessary. 
     An on-off switch to control the motor may be provided preferably located on or near the handle  10 C. For many purposes it would be preferable to utilize a remote control, which may be wired or wireless, e.g. as applied to door openers. 
       FIG. 2  is three-dimensional view showing the linear driver  10  of  FIG. 1  operationally connected to a shoveling mechanism  12  including a tubular main beam  12 A fitted with a handwheel  12 B and supported adjustably on a pair of wheels  12 C joined by an axle as shown. The right hand end of beam  12 A, shown at its upper location, receives drive power from driving member  10 F of linear driver  10  which is removably attached in a manner to allow pivoting in a vertical plane. The opposite lower left hand working end of beam  12 A serves the handle of an attached shovel  14  which can be rotated by handwheel  12 B for purposes of dumping loaded material via rotation of beam  12 A which can be made rotatable about an inner shaft at the driving end. For other purposes where rotation of the beam  12 A and handwheel  12 B is not wanted, it may be locked against rotation by a fastener such as a pin that still allows the vertical pivot action between beam  12 A and drive member  10 F. 
     Linear driver  10  is provided at bottom and top with electro-mechanical toggle mechanisms  10 H and  10 J providing stop point with the capabilities of automatic reversal for cyclic or continuous reciprocation and/or release of the driving member  10 F from the threaded drive shaft as an alternative to manual on-off motor control by the user for purposes of automatic reciprocating action or rise/fall freedom, e.g. for hammering or tamping. 
     A hook  12 H is provided near the working end of beam  12 A for direct hoisting capability. 
       FIG. 3  is a three-dimensional partial view of a pick attachment  16  that can be installed on beam  12 A of  FIG. 2  instead of shovel  14 , with beam  12 A locked against rotation, for tasks that are often performed manually with a pickaxe or hoe, such as breaking up hard soil. For this operation the motor is utilized to drive member  10  to the bottom so as to lift the pick attachment  16  to its highest location. Lower toggle mechanism  10 H ( FIG. 2 ) is operated in a manner to disengage drive member  10 F from the shaft threads, allowing the pick attachment  16  to fall to the ground and perform the pick function, while upper toggle mechanism  10 J re-engages the shaft threads so that the process repeats and continues automatically. 
     Additional weights  16 A can be added on top of pick attachment  16  as required for difficult work: the annular weights are retained by a cap member  16 B. 
     Furthermore pick attachment  16  (optionally along with beam  12 A) can be released, rotated a half turn and re-fastened so that the weights  16 A may be used as a tamper for soil compaction by operating in a manner similar to the pick. 
       FIG. 4A  depicts, in an elevational side view utilizing simplified “stick” representation, the shoveling mechanism  12 , shown with shovel  14  having been directed manually via handwheel  12 B into ground  16 , where shovel  14  can be forced further to load it with soil. Then, to lift the shovel  14 , the linear driver  10  is activated in a direction to move driving member  14 F downward so that wheels  12 C and their axle form a fulcrum that enables the beam  12 A to rotationally tilt and lift the shovel  14  along with any contained load. 
       FIG. 4B  depicts the items in  FIG. 4A  with driving member  10 F having been driven down to the lower position shown so that the end of beam  12 A with loaded shovel  14  becomes elevated to the location shown. In this condition the shoveling mechanism  12  and the linear driver  10  may be moved to a desired location, where the shovel  14  can then be rotated via handwheel  12 B to dump the shovelful. This process is repeated as required. 
       FIG. 5  is a three-dimensional view of a vertical conveyer accessory  16  of the present invention. A vertical conveyor belt  16 A, made to be adjustable in length, extends between a driven sprocket  16 B at the bottom and an idler sprocket  16 C at the top, mounted on a bracket assembly  16 E which is typically attached to and/or supported by building structure. A hinged member  16 F is shown in its vertical position as it would be utilized in hanging over a wall or roof parapet, i.e. a low peripheral wall around a flat roof of a building. Member  16 F can be hinged to a horizontal position and weighted or fastened on an ordinary flat roof. 
     An S-shaped lift hook  16 D can be inserted into any one of the series of perforations configured in conveyor belt  16 A over its entire length. Load items such as bucket  20  are hung on hook  16 D near the lower or upper end of conveyor  16  and then the motor of the linear drive machine is operated by the user accordingly to elevate or lower the load. 
     Sprocket  16 B is attached by a short shaft to bevel gear  18 A which is driven by engagement with bevel gear  18 B, installed as an accessory onto the top end of the threaded shaft ( 10 E,  FIG. 1 ) of the linear drive machine  10  of the present invention. Typically for such continuous rotation, the driving member ( 10 F,  FIG. 1 ) may be removed or otherwise disengaged from the threaded shaft  10 E, e.g. by the toggling mechanisms  10 H  10 J ( FIG. 2 ) and/or by providing a non-threaded portion at the top or bottom end of threaded shaft  10 E. 
       FIG. 5A  is a three-dimensional view of sprocket  16 B attached by a short shaft to bevel gear  18 A which is contained in a metal enclosure box  10 G, shown partially cut away to reveal a bearing  10 K surrounding the short shaft. The enclosure box  10 G, open at the bottom, fits over and fastens onto the top end of column  10 D of the drive machine  10  ( FIG. 1 ). 
       FIG. 6  is a three-dimensional view showing three linear drive machines  10  of the present invention as in  FIG. 1 , deployed together to support and elevate or lower a support structure  22  which can be a platform, scaffold or load container which in this example is triangular in shape and attached at each vertex to a corresponding driving member  10 F. The motors of the three linear drive machines  10  are operated simultaneously and in the same direction to keep the support structure  22  level. The platform structure  22  can be equipped with corner posts  22 A of any desired height, and may support a chain railing  22 B, as indicated by the dotted line, for purposes of personal safety when used as a scaffold. Alternatively the railing could be made solid. Also sidewalls could be added to form a container instead of a platform. 
       FIG. 7  is a three-dimensional view of a block wall  24  being constructed from concrete blocks  26  and vertically oriented rebars (steel reinforcing bars)  28 , utilizing a linear drive machine of the present invention (not shown in  FIG. 7 : refer to  FIG. 1 ) serving as a hoist or crane. Two blocks  26 , having been picked up simultaneously from their previous resting place, are suspended as shown by a pickup clamp  30 , ring  32  and a chain  34  which is ultimately attached operationally to the driving member ( 10 F) of the linear drive machine ( 10 ,  FIG. 1 ). The blocks  26  are elevated as required, moved into place over the rebars  28  then lowered, as shown part way down, into their final place on wall  24 . Pickup clamp  30  can also seize and hoist a single concrete block  26 . 
       FIG. 8  is a three-dimensional view of a concrete mixing apparatus  36  powered by a linear drive machine  10  of the present invention. A long, generally cylindrical barrel  38 , loaded with wet concrete to be mixed, is generally supported as shown by a four-legged stand  40  while an end region is supported by an agitating harness including a slider box  42  with a pair of internal roller sliders connected to a hook on the driving member  10 F of linear drive machine  10 . Vertical movement of driving member  10 F up and down in response to motor drive causes the barrel  38  to move up and down as well as left and right in a rolling motion to mix the concrete in barrel  38 . 
       FIG. 8A  is an enlarged three-dimensional view of the slide box  42  of  FIG. 8 , showing the main enclosure  42 A, slotted cover  42 B and a pair of roller sliders  42 C captivated inside, connected by a cable link  42 E. 
       FIG. 9  is a three-dimensional view showing two linear drive machines  10  of the present invention, stabilized by base extension members  10 H, utilized to handle a platform  44  to support a panel workpiece such as drywall or other sheet board to be installed in an unfinished ceiling above. 
       FIG. 10  is a three-dimensional view of the platform  44  of  FIG. 9  showing a pair of spacer strips  48  for handling the panel workpiece and a pair of end supports  46  extending downwardly to engage the driving members of the drive machines and made long enough to raise platform  44  to the required ceiling height. 
       FIG. 10A  is a side view of a spacer strip  48  showing a downward portion  48 A at corner  48 B and a main horizontal portion  48 C to which is removably attached an upward end portion  48 D, for supporting and retaining a panel workpiece on the platform  44  of  FIG. 10 . 
       FIG. 10B  is an end view of the platform of  FIG. 10  showing a panel workpiece  50  in place with previously started nails  50 A resting on the main portion  48 E of spacer strips  48  after removal of the upward end portion  48 D. At this point in the procedure the spacer main portion  48 E is withdrawn to the left so that the nails  50 A drop down with their heads in recessed regions shown in platform  44 , such that now platform  44  with panel workpiece  50  can be raised to the ceiling level, pushing nails  50 A further through panel workpiece  50  and at least partially into wood ceiling joists (not shown) sufficiently to support the panel workpiece in place, where final nailing can be performed as required after platform  44  is removed. This general procedure can also be adapted for purposes of installing workpiece panels such as drywall sheets onto walls. 
       FIG. 11  is a three-dimensional view of a ground hole drill assembly  52  that can be driven from a linear drive machine ( 10 ,  FIG. 1 ) of the present invention. The auger  52 A is mounted on drill-shaft  52 B which is driven by a worm and pinion gear set inside gearbox  52 C. The pinion is driven by input drive-shaft  52 D which receives torque from the motor of the drive machine via a pair of bevel gears ( 18 A and  18 B as shown in  FIGS. 5 and 5A ) via either a solid shaft or alternatively a flexible drive cable  52 F. 
       FIG. 12  is top view of the items in  FIG. 11  with a portion of gearbox  52 C cut away to reveal worm  52 G, on drive-shaft  52 D, engaging pinion  52 F. 
     A radially-extending fitting  52 E is provided for attachment to a suitable structural mass via a bar inserted in the socket opening; the bar may be braced for stabilization by a large mass such as the drill rig frame or alternatively it may be hand-held. 
     Drill-shaft  52 B is seen to have a hexagonal cross-sectional shape that allows it to be shifted up or down in operation while receiving driving torque from pinion  52 F. This sliding rotational coupling could also be implemented with other non-circular shape of the main drive-shaft  52 B and the mating opening in the pinion gear, such as triangular, square or fluted, etc. 
       FIG. 13  is a cross-section of gearbox  52 C taken through axis  13 - 13  of  FIG. 12  showing worm  52 G, on drive shaft  52 D engaging pinion  52 F which engages the drill-shaft  52 B in a vertically slidable manner. 
       FIG. 14  is a three dimensional view of a post driver assembly having a weighted hammer head  44  formed as a sleeve sized to fit loosely over a post  58  and having a massive top end to provide weight and receive hammering. Hammer head  44  is firmly attached by a short connection member  46  to pick attachment  16 , pinned in place. 
     The coupling between beam  12 A (see  FIG. 2 ) and pick attachment  16  is provided by the telescopic/pivot attachment of rod  48  fitted with an attached circular end disk  50  at the left hand end that fits in a sliding manner inside the tubular attachment sleeve opening of pick attachment  16  (shown partially cut away). A pair of screws  52 , extending through the attachment sleeve wall near its open end, serve to captivate rod  48  within the sleeve. The right hand end of rod  48  is attached in a pivoted manner to sleeve member  54  which is attached securely to the end of beam  12 A. Sleeve  12 G, which forms the main fulcrum point of beam  12 A, is preferably mounted on a pivot joint  56 . 
       FIG. 15  is an enlarged view of the pivoted assembly of sleeve member  54 , and rod  48  with ring  50 . 
     The above described telescopic/pivot mechanism provides the degrees of freedom required to enable the hammer head  44  to travel in a straight vertical line as required for driving post  58  downwardly, while the pivot sleeve  54  and the end of beam  12 A travel in an arcuate path with appreciable horizontal displacement. 
     In addition to the foregoing implementations in which the linear drive machine of the present invention is utilized in the vertical orientation shown, there are other implementations in which it may be oriented other than vertical; e.g. it may oriented horizontally for use in pulling or pushing a load item directly or indirectly from the driving member  10 F. 
     There are many ways in which the linear drive machine of the present invention may be utilized to facilitate many difficult tasks that are presently performed manually only because of excessive size, cost, non-versatility and/or non-availability of existing known powered work machines. 
     The invention may be embodied and practiced in other specific forms without departing from the spirit and essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description; and all variations, substitutions and changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.