Abstract:
A mobile lifting table having a pivoting tabletop is claimed. A support frame is attached to the base of a cart having a plurality of wheels. A support arm attached to the frame on one end is pivotally attached to a tabletop. The tabletop is in turn pivotally attached to a control arm which raises and lowers the tabletop from an inclined position for loading and carrying materials, to a horizontal position for maneuvering and unloading said material. The control arm is also attached to an operator controlled electric hoist via a pulley system and cable, which translates a force generated by said hoist to said control arm, thus raising and lowering said control arm and causing the tabletop to raise or lower as the operator so desires. The tabletop includes a means for rolling the material across the table such that said material is easily maneuverable by the operator.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/740,445, filed on Nov. 29, 2005 and is incorporated by reference herein. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to an apparatus for carrying and lifting materials, and in particular, to a mobile lifting table having a mechanized pivoting tabletop which is configured to carry said material in an inclined position, and to rotate to a raised horizontal position for maneuvering and unloading said material.  
       DESCRIPTION OF THE RELATED ART  
       [0003]     Artisans in the home construction and improvement business must often transport and lift heavy materials during the course of their work. Due to limited space within the home and the need to prevent damage to existing structures and furnishings within the home, a plurality of persons, instead of machinery, have traditionally provided the required muscle to lift and maneuver materials used in such work. For example, during the installation of a stone countertop into a home&#39;s kitchen, it is often necessary to utilize many persons in the carrying and lifting of the countertop which could weigh in excess of five hundred pounds. Persons involved with such carrying and lifting often suffer from various injuries resulting from the strain of their work.  
         [0004]     Various apparatus are revealed in the prior art which are adapted for lifting heavy materials. These apparatus include a horizontal table on which material may be loaded while the tabletop is at an inclined position. A user controlled lifting means raises the tabletop and material to a desired height where it may then be unloaded or otherwise manipulated. Although the prior art horizontally lifting tables may be effectively used in work areas designed for their use, such tables, even if made mobile, are often too large to enter into and navigate the tight confines of a home. Another drawback of such prior art tables is that they are often quite heavy themselves, thus making it impractical for an artisan to easily transport them to different jobsites.  
         [0005]     Therefore, a need exists for a mobile lifting table which is capable of transporting and lifting heavy materials while at the same time being configured to minimize the size of the table so as to be able to effectively navigate the tight confines of a home or other similar work area.  
       SUMMARY OF THE INVENTION  
       [0006]     Accordingly, there is provided herein, a mobile lifting table that, in its preferred embodiments, is capable of carrying heavy materials through areas with little room to maneuver, and of lifting said materials to a height where they may be easily unloaded.  
         [0007]     In one aspect of the invention, a cart having a plurality of wheels is configured to serve as a platform upon which a tabletop supporting frame is attached. At least one support arm having two ends is attached to the upper portion of the support frame on one end, and pivotally attached to a tabletop on the other end. The support frame is dimensioned with respect to the cart such that said frame rests over only a rearward portion of the cart, thus allowing the tabletop to pivot, via a hinge, on the support arm to a inclined position for carrying materials. By carrying materials on the tabletop in the inclined position, as opposed to the horizontal position, the apparatus may be easily maneuvered through tightly confined work areas. The increased maneuverability exhibited by the present invention demonstrates one advantage over lifting tables revealed in the prior art.  
         [0008]     In another aspect of the invention, at least one control aim is attached to the rear portion of the table, said control arm delivering the force necessary to pivot the table between horizontal and inclined positions. An electric hoist connected to a pulley system, which is in turn connected to the control arm, generates the force necessary to raise and lower said control arm of the presently preferred embodiment. The electric hoist is mounted on a support plate which is attached to the base of the cart. An electric cord which is wound around a retractable spool that is mounted to the support plate, supplies the electric hoist with the electricity to power said hoist. A control device connected to the hoist allows an operator to control raising and lowering of the table. A removable covering having openings for the passage of the electric cord, the control device, and the control arm, is attached to the frame resting on the base of the cart.  
         [0009]     In yet another aspect of the invention, the table is comprised of a plurality of horizontal and vertical bars, such that when the table is lowered, the horizontal bars are parallel with the ground and the vertical bars are nearly perpendicular with the ground. Rolling sleeves are fitted around a substantial number of the horizontal bars such that when the table is in the raised position, material may be easily rolled over the sleeves and unloaded with minimal effort by the operator. The edge of the table closest to the ground when in the lowered position includes a means for supporting the material on said table, thus preventing the material from rolling off the tabletop before the operator intends to do so. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     A more complete understanding of the mobile lifting table of the present invention may be had by reference to the following detailed description when taken in conjunction with the accompanying drawings, wherein:  
         [0011]      FIG. 1  is a side view (surface of plated cover not visible) of the mobile lifting table according to a preferred embodiment of the present invention;  
         [0012]      FIG. 2  is a side view of the mobile lifting table shown in  FIG. 1  showing the plated cover;  
         [0013]      FIG. 3  is a rear view of the mobile lifting table shown in  FIG. 1  with the cover removed;  
         [0014]      FIG. 4  is a rear view of the mobile lifting table shown in  FIG. 1  with the cover installed;  
         [0015]      FIG. 5  is a top view of the mobile lifting table shown in  FIG. 1 ; and  
         [0016]      FIG. 6  is a top view of the tabletop according to a preferred embodiment of the present invention. 
     
    
       [0017]     Preferred embodiments of the mobile lifting table according to the present invention will now be described in detail with reference to the accompanying drawings.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]     Referring to  FIG. 1 , a side view of the mobile lifting table  100  according to a preferred embodiment of the present invention; a cart  101  comprising a platform  102  having a plurality of wheels  104  attached thereto, provides a mobile base for the table. The wheels  104  of the presently preferred embodiment are configured to swivel, thus allowing the table  100  to move in any direction as the operator positions the material for unloading. However, as those skilled in the art will appreciate, one or more wheels  104  may include brakes for securing the movement of the table, and directional locking mechanisms to prevent the swiveling of the locked wheel  104  when desired, thus allowing the cart  101  to be more easily controlled during movement over greater distances. It should be noted that although not contained within the presently preferred embodiment, a mechanized means for propelling the mobile lifting table  100  may be included within alternate embodiment of the invention. The platform of the presently preferred embodiment is constructed of steel tubing under which a steel base plate  103  is securely attached.  
         [0019]     A support frame  106  is also attached to the platform  102  and is constructed of square steel tubing which has been positioned both horizontally and vertically (not shown). It should be noted and appreciated by those skilled in the art that materials other than those specifically described herein may be utilized to construct the elements of the table  100 . For example, those skilled in the art may choose to construct the support frame  106  with a material other than steel tubing. In fact, the materials used to construct the table  100  should be chosen with regard to their properties including, but not limited to properties such as strength and density.  
         [0020]     A support arm  108  having two ends is attached to the support frame  106  on one end and attached to a pivoting tabletop  110  on the other end. Although the support arm  108  of the presently preferred embodiment of the invention is integrally attached to the support frame  106 , it should be noted that alternate embodiments of the invention may include a support arm  108  which may be adjusted with respect to said support frame  106  such that the height of the tabletop  110  in the horizontal position may be raised or lowered to suit the needs of the operator. Such alternate embodiments may include a support arm  108  which is capable of being secured at a plurality of positions with respect to the support frame  106 .  
         [0021]     The tabletop  110  is attached to the support arm  108  via a hinge  112 , allowing said tabletop  110  to pivot between a lower inclined position, and a raised horizontal position. The support frame is positioned over only a portion of the cart  101 , thus allowing the inclined tabletop  110  to rest over the cart  101  while the material is carried. Because the tabletop  110  does not extend further than the platform  102  when it is in the inclined position, the mobile lifting table  100  effectively minimizes the space it needs in which to maneuver. This provides an advantage over other lifting tables revealed in the prior art in that it may more easily pass through narrow passageways and navigate around other obstacles common in work areas such as homes. The tabletop  110  of the presently preferred embodiment is constructed of steel tubing which has been positioned both horizontally  113  and vertically (not shown). A roller sleeve  114  surrounds each horizontal crossbar  113 , thus providing a means for easily moving material along the tabletop  110  when unloading or otherwise positioning said material (not shown). The roller sleeves  114  of the presently preferred embodiment are constructed of “PVC” material which is sized to allow the material to roll across the tabletop  110  with only moderate resistance. Those skilled in the art will appreciate that a roller sleeve  114  which is more tightly fit around a horizontal crossbar  113  will provide more rotational resistance than a roller sleeve  114  which less tightly fit around said crossbar  113 . Therefore, roller sleeves  114  of alternate embodiments may be constructed of other materials and sized to provide increased or decreased rotational resistance to the material to be rolled thereon. Furthermore, any means for decreasing frictional resistance between the tabletop  100  and the materials placed thereon is contemplated and may be implemented in alternate embodiments.  
         [0022]     The tabletop  110  includes a means for supporting the material on said tabletop  110  while not in the horizontal position, as well as preventing said material from rolling off the tabletop prior to unloading it. The tabletop of the presently preferred embodiment includes two fixed support tubes  116  which provide the means for supporting the materials when said tabletop is in the inclined position. However, alternate embodiments of the invention may include support tubes that may be lowered or removed.  
         [0023]     A support beam  117  is integrally attached to the underside of the tabletop  110  and further pivotally attached to a control arm  118  via a hinge  120 . The end of the control arm  118  not attached to the support beam  117  is attached to two pulleys  122 . The pulleys  122  attached to the control arm are connected to a steel cable  123  which is in turn connected to a system of pulleys  124 . One end of the cable is anchored  126  to the platform and the other end is connected to an electric hoist  128  that is configured to extend or retract said cable  123 , thus lowering or raising said control arm  118  respectively. The electric hoist  128  is controllable by the operator and thus provides the means by which the tabletop  110  and any material supported thereon, is raised and lowered. The electric hoist  128  of the presently preferred embodiment has a power rating of 1.5 horsepower and is capable of retracting a single line at a rate of 33 feet per minute. The electric hoist  128  is securely mounted to the top of the base of the platform  102 . Although, the electric hoist  128 , in combination with the pulley system  124 , is capable of hoisting a line with over 10,000 pounds of tension, the presently preferred embodiment is limited by the limitations of the steel cable  123  (2,200 lb. test rating) and the pulleys  122 ,  124  (1000 lb. rating). Nevertheless, the mobile lifting table  100  of the presently preferred embodiment is capable of lifting materials in excess of 800 pounds. It should be noted that any means for generating and applying a rotational force to said tabletop is contemplated and may be implemented in alternate embodiments of the mobile lifting table  100 . For example, it is contemplated that pneumatic and hydraulic means for rotating the tabletop  110  may be implemented with respect to alternate embodiment of the invention.  
         [0024]     Although the mobile lifting table of the presently preferred embodiment utilizes only one control arm and one pulley system, alternate embodiments of the invention may be easily configured to include a plurality of control arms with connected pulley systems such that greater loads may be lifted by the hoist. Furthermore, alternate embodiments may be configured to include electric hoists  128  having power ratings different from that which is described herein in order to lift materials of varying weight. Similarly, various pulley configurations comprising various types of pulleys may be implemented with respect to the invention. However, the pulleys used in the presently preferred embodiment are drop-side snatch blocks having 2 inch diameters. It should be noted that unless otherwise noted, integral attachments of the elements of the table  100  are made by welding said elements together.  
         [0025]     Referring to  FIG. 2 , a side view of the mobile lifting table  100  having a cover  200  over those elements resting within the support frame  106 . The cover is removably attached to the support frame, thus providing access to the electric hoist  128 , the pulley system  124 , and the control arm  118 . Although not seen in  FIG. 2 , covers  200  surround the support frame on at least four sides of the presently preferred embodiment. An opening  202  is formed on the side of one of the covers to allow the passage of a retractable electric cord (not shown) which supplies the electric hoist  128  with electricity.  
         [0026]     Referring to  FIG. 3  and  FIG. 4 , rear views of the mobile lifting table without and with a cover respectively. A control device  300  is connected to the electric hoist  128 , providing the operator of the table  100  with the ability to control the raising and lowering of the tabletop  110 . Such control devices  300  are well known in the art and may include one or more switches for controlling the hoist  128 . A second opening (not shown) is formed in one of the covers, allowing the conductor  304  which electrically connects the control device  300  and the electric hoist  128 , to pass through said cover. Brackets  302  formed on the support frame  106  are utilized in mounting the rear cover as shown in  FIG. 2 . A retractable spool  306  houses an electric cord  308  which provides electricity to the electric hoist. The electric cord  308  may be conveniently stored on the spool  306  when not in use.  
         [0027]     Referring to  FIG. 5 , a top view of the mobile lifting table is shown having a top cover  500  attached to the support frame  106 . An opening  502  is formed in the cover and sized to allow the control arm to freely move during the raising and lowering of the tabletop  110 .  
         [0028]     Referring to  FIG. 6 , a top view of the tabletop  110  according to a preferred embodiment of the invention, said tabletop  110  is comprised of both vertical  600  and horizontal  113  crossbars. Both the horizontal  113  and vertical  600  crossbars are evenly spaced to provide a structure upon which the operator may load material to be carried and lifted. The roller sleeves surround each horizontal  113  crossbar, allowing material to roll across the tabletop  110 . Although the arrows  602  indicate the preferred direction that materials are to be unloaded, it is contemplated that an operator may roll and unload said materials in the opposite direction of the arrows  602  as well.