Abstract:
Method and apparatus for gripping and lifting heavy and cumbersome objects is disclosed. A slotted safety latch lever assembly permits the pivoting action of an upper tube relative to a main tube, facilitating the gripping and releasing action of arm assemblies at either end of the main tube. The length of the main tube is adjustable, permitting the main tube to shorten or lengthen as needed for gripping the object. The upper tube has a lifting device connector selectively positioned longitudinally relative to the upper tube for achieving correct balance point for lifting.

Description:
FIELD OF THE INVENTION 
     The present invention pertains to a gripping and lifting system for moving cumbersome articles, such as stone or concrete slabs and other large, heavy, construction materials or equipment of varying shapes and sizes. 
     BACKGROUND OF THE INVENTION 
     The construction industry today uses many heavy and cumbersome articles, such as pre-cast concrete structures, natural stone, wood, and metal objects, which may be square, rectangular, or even round in shape. Unfortunately, there currently is no method of lifting these items safely. Common practice in the pre-cast concrete industry, for example, is to wrap a log chain or strap of some form around the structure to lift the object. 
     Many times in this process, it is necessary to attempt to lift the object several times in order to balance or stabilize it. This can result in both injuries to members of the construction crew and damage to the object being lifted. When the object is being set in place, there is an element of risk to the construction workers as they undo the chains or straps. In particular, workers have to use pry bars and wedge blocks to remove the chains and straps from the object, and the positioning of the object is very labor intense. Hand, finger, and back injuries are common results of the current method of lifting cumbersome articles in construction. 
     The transportation and delivery of these products commonly are achieved with some type of boom truck or lift truck, and normally require a wooden pallet to serve as the lifting surface or support for the object being moved using current methods. 
     Accordingly, there is a need in the art for an apparatus for lifting cumbersome articles. It is to such that the present invention is directed. 
     SUMMARY OF THE INVENTION 
     The present invention meets the need in the art by providing an apparatus for gripping and lifting cumbersome articles comprising a lifting member pivotably connected to a main tube and movable from an open position to a gripping position by movement of the lifting member, a slotted safety latch lever assembly pivotably connected to the main tube and connected to the lifting member by a link extending through the slot in the safety latch lever assembly, with arm assemblies attached at an end of the main tube opposing the pivotable connection between the lifting member and the main tube and attached at the pivotable connection between the lifting member and the main tube for gripping contact of an object to be lifted upon pivoting the lifting member to the gripping position. 
     In another aspect, the present invention provides a method of gripping and lifting cumbersome objects comprising pivoting an upper tube relative to main tube, and having a slotted safety latch lever assembly pivotably connected to the main tube and movably connected to the upper tube with a linkage extending through the slot in the safety latch lever assembly, such that arm assemblies at either end of the main tube close around an object to be gripped and lifted. 
     Those skilled in the art will further appreciate the important features and advantages of the invention upon reading the detailed description of the preferred embodiments hereof that follows with reference to the accompanying drawing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a perspective view of the gripping and lifting system of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the description that follows, like elements are marked throughout the specification and the drawing with the same reference numerals. 
     DETAILED DESCRIPTION 
     The purpose of the gripping and lifting apparatus of the present invention is to provide a safe, efficient, economical, and versatile way to maneuver heavy or cumbersome items. The present invention may be utilized in construction, shipping, manufacturing, or other applications. One of the features of the present invention is that it is capable of being adjusted along its length to accommodate different sized objects and provide multiple balance points, enhancing its adaptability to different uses. 
     The present invention provides a construction device capable of gripping and lifting heavy, cumbersome objects of any shape, including round, square, triangular, or rectangular shapes. The invention is manufactured in different size ranges to accommodate a large range of objects, and provides a safe way to pick up, transport, and place heavy objects. Because the invention safely grasps the top edges of the heavy object from above, there is no need to have multiple workers in harm&#39;s way handling the object while attempting to secure or release heavy chains, straps, or other fastening devices. Moreover, the invention is an enhanced time saver when moving any heavy object due to the ease of grasping the object from above. In addition, the present invention eliminates the need to transport such items on wooden pallets. 
     Referring to  FIG. 1 , an embodiment of the gripping and lifting apparatus  100  of the present invention is shown gripping object  16 . Sliding arm  1  is a steel structure drilled incrementally to provide spaced-apart holes along its length to allow multiple positions for pin  23  to engage sliding arm  1  telescopically within main tube  2 , which also is a steel structure having multiple spaced-apart holes for engaging pin  23 . Sliding arm  1 , steel bar  3 , and round steel bars  5  are welded together to form one piece. 
     Upper tube  4 , round bars  5   a , pivot pins  6 , spacers  7 , pivot block  8 , steel cross bar  9 , and pivot block  12  are one welded assembly that forms the pivoting clamp mechanism. Upper tube  4  is a steel structure lifting member drilled incrementally to provide spaced-apart holes along its length to allow multiple positions for pin positioner  13  to be placed and pinned by pin  23   a , providing multiple balance points when objects  16  are lifted. The bolt  24  in the end of upper tube  4  is for safety, to prevent pin positioner  13  from sliding completely off upper tube  4 . In an alternate embodiment (not illustrated), a lifting device connector extends from the upper tube  4  for connecting to a lifting device. 
     Safety latch lever  11  moves between a first position and a second position.  FIG. 1  depicts the safety latch lever  11  in an intermediate position. In the first position, the safety lever latch  11  keeps the gripping and lifting apparatus  100  open until activated by an operator. Safety latch lever  11  is pivotably held onto the main tube  2  at bolt receptacle  10  with a bolt and washer  18  and connects with a linkage  26  through the slot  25  in the safety latch lever  11 . Pivot pin  6  defines a pivot axis and permits the pivoting of upper tube  4  and pivot block  8  relative to the main tube  2  at the pivot point/latch works. The lifting member or upper tube  4  and the pivot block  8  pivots on the pivot axis by virtue of the forward and backward movement of safety latch lever  11  in V-shaped slot  25 . A roller pin/bolt and washer assembly  19  connects to block  8 , and as the linkage  26 , permits the movement of the safety latch/lever  11  along the V-shaped slot  25 . In an alternate embodiment, the roller pin is a member extending through aligned openings in the opposing block  12 , spacers  7 , and tube  4 . Grade  8  steel is preferred for the fabrication of bolt and washers  18  and  19 . 
     Objects to be lifted  16  are protected from damage by sleeves  20  attached to the bars  5  and  5   a , such as held onto the bars by washers and bolts  22 . Grade  8  steel is preferred for the fabrication of washers and bolts  22 . The sleeves  20  serve both to protect object  16  as well as provide enhanced gripping. Urethane is preferred for the fabrication of sleeves  20 , but other resilient or cushion materials are suitable. 
     When the gripping and lifting apparatus  100  of the present invention is adjusted properly onto object  16 , the operator pushes safety latch lever  11  forward (a direction away from the pivot pin  6 ).  FIG. 1  depicts the safety latch lever  11  in an intermediate position after the safety latch lever  11  is pushed forward. As the operator then starts the lifting action, the main tube assembly  4  and pivot block  8  pivots on pin  6 , creating a clamping action between the bars  5 ,  5   a  and resulting in a gripping force exerted on object  16 , allowing object  16  to be lifted and moved as desired. It will be appreciated that as soon as safety latch lever  11  is pushed forward, the release and consequent upward movement of upper tube  4  will cause the item  16  to be frictionally held between the inner surfaces of sleeves  20 . 
     When object  16  is ready to be placed in position, the operator simply lowers object  16  to its desired resting point. It is contemplated that a conventional crane is used to lift object  16  by attaching a hook or other device to lifting device receptacle  14 . Upon placement, the gripping and lifting apparatus  100  of the present invention releases. This is accomplished by upper tube  4  that pivots on pin  6  towards the main tube assembly, opening the clamping action of the apparatus  100 . When upper tube  4  drops to stop item  15 , the safety latch lever  11  releases the latching. The gripping and lifting apparatus  100  is then in the open position for removal from the object  16  that was moved. 
     A major difference between previous gripping and lifting methodology and the present invention is the way in which the inherent problem of lifting from underneath a heavy or cumbersome article is eliminated. This is a key difference that allows the present invention to be safer, faster, and far less expensive in terms of labor cost savings, workers&#39; compensation claim savings, medical expense savings, and savings from reduced damage to moved items. 
     The operation of the gripping and lifting device for the advantageous purposes set forth herein is believed to be understandable to those of ordinary skill in the art based on the foregoing description. 
     The benefits of the instant invention are many, and include the following: (1) usable with objects of any shape and size; (2) reduces manpower needed to perform lifting and moving heavy or cumbersome objects; (3) reduces time needed to perform lifting and moving heavy or cumbersome objects; and (4) eliminates the need to transport moving heavy or cumbersome objects on wooden pallets. Further, the present invention is the only such device and method that accomplishes all these advantages, despite the existence of a worldwide, ancient, construction industry faced with the problem of moving heavy and cumbersome objects on a daily basis. Although preferred embodiments of the invention have been described in detail herein, those skilled in the art will also recognize that various substitutions and modifications may be made without departing from the scope and spirit of the appended claims.