Patent Document

This application claims priority from Provisional Application Serial No. 60/092,709, filed Jul. 14, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     a. Field of Invention 
     The present invention relates generally to apparatus for removal of heavy covers and lids, and, more particularly, to an apparatus for removal and replacement of vault lids, manhole covers, and similar lids/covers with minimal physical strain on the operator. 
     b. Related Art 
     Vault lids, manhole lids, grates, and similar heavy covers (referred to collectively in this description and the appended claims as “lids” ) have traditionally been removed either by hand (which is very difficult) or using only very basic tools, such as pry bars and hooks. 
     When using a pry bar, the operator tries to find a hole or notch in the lid into which the end of the bar can be wedged, and then attempts to pry the heavy lid off of the opening. This requires a great deal of physical effort, and presents a very real possibility of the operator suffering a strain injury. Moreover, the lid may not have any seam, notch or other feature near its edge which is suitably sized or shaped for the end of the pry bar, so that the end of the bar may damage the lid and/or the surrounding lip in the course of the efforts to get the lid off the opening. 
     Furthermore, the ends of conventional pry bars offer little grip and very poor stability when removing lids. As a result, the bar can easily slip off of the lid and allow it to drop, very possibly causing damage to the lid and/or access opening, or serious physical injury to the operator. Moreover, operators often resort to using some form of makeshift, ill-shaped fulcrum for the pry bar (such as a rock or piece of wood) in order to generate the necessary leverage, further increasing the likelihood of an accident. 
     Still further, pry bars do not provide the operator with any convenient means for moving the lid out of the work area once it has been pried from the opening. As a result, the heavy lid is typically “manhandled” out of the way, presenting further opportunities for back injuries and smashed fingers. 
     The second type of lid removal tool in common use consists of a simple lifting hook. The operator inserts the hook through an opening or ring in the lid, and then heaves the lid up and away from the access hole. Again, this involves considerable exertion and risk of back injury, hernia, or spinal compression, especially since the operator must bend over the heavy lid when removing it with a hook. Moreover the hook, like the pry bar, offers no easy way to transport the lid after it has been removed. 
     Accordingly, there exists a need for a lid removal tool that permits easy and convenient removal and replacement of heavy lids and similar covers without requiring heavy lifting, so as to provide improved operator comfort and reduced risk of injury. Furthermore, there exists a need for such a lid removal tool that provides improved stability when lifting and lowering the lid, so as to reduce the risk of the lid slipping off and falling. Still further, there exists a need for such a tool which provides for easy and convenient transportation of the lid away from an opening after removal. Still further, there exists a need for such a tool which is capable of removing/replacing various vault lids, manhole covers, grates and other types of covers without causing damage to such covers or the surrounding openings. 
     SUMMARY OF THE INVENTION 
     The present invention has solved the problems cited above, and is an apparatus for lifting and removing heavy lids and similar articles. 
     In a broad sense, the apparatus comprises: (a) an elongate lever arm member having a handgrip portion at an upper end thereof for application of force in a rearward and downward direction, (b) a pivot head member mounted to a lower end of the lever arm member and having at least one wheel member which is configured to rest on an underlying surface so as to provide a pivot axis for the head member, (c) a foot plate member mounted to a rearward side of the pivot head member for application of force in a downward direction, and (d) a hook member mounted to a forward side of the pivot head member for engaging and lifting a lid or similar article as the head member pivots about the wheel axis in response to application of the forces in the downward and rearward directions to the lever arm and footplate members of the apparatus. 
     The at least one wheel may also form a rolling axis for transporting the lid after lifting and removal, by rolling the pivot head member along the underlying surface while the lid is suspended from the hook member thereon. 
     The apparatus may further comprise at least one stabilizer portion for arresting movement of the lid during lifting and removal, and for preventing movement of the lid during transport. The stabilizer portion may comprise at least one notch area at the forward side of the pivot head member for receiving and engaging a rearward edge of the lid as the lid is being lifted and removed. The notch area may comprise at least one generally vertical face portion for abutting an outer edge of the lid so as to arrest movement of the lid in the rearward direction, and at least one generally horizontal face portion for abutting an upper surface of the lid so as to arrest movement of the lid in the upward direction. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a lid removal tool in accordance with the present invention, showing the elongate lifting handle, and the pivot head which provides a fulcrum for raising the lid and wheels for transporting the lid to and from the opening; 
     FIGS. 2A-2B are sequential, elevational views of the lower end of the lid removal tool of FIG. 1, showing this being used to remove and transport an exemplary vault lid; 
     FIG. 3 is a perspective view of the lower end of the removal tool of FIGS. 1-2, showing the configuration of the pivot head and hook member in greater detail; 
     FIG. 4 is a cross sectional view, taken along line  4 — 4  in FIG. 3, showing the manner in which the first and second, spread apart stabilizer plates at the bottom of the pivot head engage the edge of the lid as it is removed; 
     FIG. 5 is a side, elevational view showing the pivot head of the tool of FIGS. 1-4, but fitted with a second, two-pronged hook member which is configured for removal of grates and similar types of lids; 
     FIG. 6 is a front, elevational view of the two-pronged hook member of FIG. 5, showing the manner in which this fits between the bars of a grate to be removed; 
     FIG. 7 is a side, elevational view of the tool of FIGS. 1-5, but with the pivoting hook members removed, showing the manner in which a lid having a D-ring handle is lifted and removed using fixed hook portions which are formed on the forward end of the pivot head of the tool; 
     FIGS. 8A-8B are sequential, cross sectional views showing the D-ring handle of the lid in raised and lowered positions; and 
     FIGS. 9A-9B are sequential, elevational views showing the pivot head of the tool of FIGS. 1-5 fitted with a J-hook and chain attachment for use with large diameter lids having perimeter openings, and showing the manner in which this is used to raise and remove such lids. 
    
    
     DETAILED DESCRIPTION 
     a. Overview 
     FIG. 1 shows a lid removal tool  10  in accordance with the present invention. As can be seen, this includes three principal components: an elongate handle member  12 , a pivot head  14 , and a hook member  16 . 
     The operation of the tool is illustrated in FIGS. 2A,  2 B, which show the foot of an operator  01  who is removing an exemplary manhole lid  02 . As can be seen, the operator inserts the hook member  16  through a lift hole  03  in the lid and then pulls the handle member  12  rearwardly and downwardly through an arc, as indicated by the arrow, so that the hook member engages the lid and lifts it from its seat  04 . Simultaneously, the operator places his foot on plate  18  at the back of the head assembly and presses downwardly and forwardly using his body weight. In combination, these forces cause the head assembly to pivot on the fulcrum which is formed by wheels  20   a ,  20   b , raising the hook at the front of the assembly and the lid which is supported therefrom. The leverage provided by the long, generally vertical handle member, combined with the effective employment of body weight, thus enables the operator to raise the lid with a minimum of physical exertion. 
     As the lid is raised, the edge nearest the tool swings upwardly and rearwardly until it strikes and comes to rest against stabilizer plates  22   a    22   b  at the front of the pivot head. The stabilizer plates are spaced apart and are generally level with one another in the horizontal plane, and consequently stabilize the lid and prevent any unsafe tilting or wobbling movement as it is being lifted and/or transported. 
     In addition to providing the fulcrum for the pivot head, wheels  20   a ,  20   b  also enable the operator to easily and quickly transport the lid away from the opening after it has been removed. To do this, the operator simply maintains the downward pressure on the handle after the lid has been lifted out of the opening, and rolls the entire unit away while steering with the handle. As can be seen in FIG. 1, the upper portion  24  of the handle is preferably bent somewhat to the rear, away from the hook member, for an improved, less awkward angle when lifting the lid, and also to provide additional ground clearance at the back of the footplate when transporting the lid. 
     b. Structure 
     The handle member of the tool may suitably be formed of tubular metal material, although it will be understood that other types of material may be used in various embodiments of the invention. The handle member  12  is preferably provided with a resilient sheath or handgrip  26  at its upper end for ease of handling and enhanced operator comfort. 
     As is shown in FIGS. 2A-2B, the pivot head is mounted to the lower end of the elongate handle member, and includes the footplate  18 , the pivot/transport wheels  22   a ,  22   b , and a hook frame  28 . 
     The footplate is mounted to the hook frame generally behind the handle member and above the wheels  22   a ,  22   b . The footplate extends in a generally horizontal direction (when the tool is upright), and preferably widens towards its rearward edge and is provided with surface texturing so as to provide a secure, stable area for applying foot pressure. 
     As is also shown in FIGS. 2A-2B, the rotational axis of the pivot/transport wheels is located beneath the footplate  18 , behind the long axis  30  of the handle, and extends generally perpendicular to the hook frame  28 . In the embodiment which is illustrated, the wheel axle  32  extends through an axle support tube  34  which is mounted across the bottom of hook frame  28 . 
     As is shown in FIG. 3, the hook frame itself is formed of two generally parallel plates  36   a ,  36   b  which are mounted on opposite sides of the shaft of the handle member. As was noted above, the footplate is mounted across the rearward end of the plates and the axle tube is mounted across the bottom. At the forward end, in turn, the plates extend to form a lifting arm  38  which supports the pivoting hook member  16 . Notches are formed in the upper edges of the lifting arm so as to form fixed upper hooks  40   a ,  40   b , which can be used to remove lids having “D” style lifting rings or similar fittings, as will be described in greater detail below; tabs  42   a ,  42   b  at the ends of the arms help to prevent the rings or other fittings from slipping off of the hook area as they are being lifted. 
     The upper end of the hook member  16  is pivotally mounted to the frame  28 , by means of a pivot pin  44  which extends through one of a plurality of corresponding bores  46   a ,  46   b ,  46   c  in the two plate members  36   a ,  36   b . As a result, the lower end of the hook member can pivot as the lid is being raised, and can also be pivoted to accommodate various sizes and positions of lids and lift holes. The series of pivot bores  46   a ,  46   b ,  46   c  are set at parallel, spaced apart locations, so as to permit adjustment of the depth/distance of the hook member relative to the stabilizer plates  22   a ,  22   b , not only to allow the location of the hook member to be adjusted to match the configuration of the lid, but also to allow for attachment of additional lifting fittings, as will be described in greater detail below. 
     The embodiment which is shown in FIG. 3B has a single-pronged hook member, the upper end of which has a collar portion  44  which accommodates the pivot pin and which fits closely in the gap between the two plate members so as to limit side-to-motion. A relief area  40  and end tab  42  at the lower tip of the hook member help to prevent lids from slipping off during lifting. 
     As can be seen in FIG. 4, the stabilizer plates  22   a ,  22   b  are formed by outwardly flared or spread portions of the two side plates  36   a ,  36   b , in the area generally below and behind the lifting arm  30 . The stabilizers serve to arrest upward and rearward movement of the lid: as the lid is lifted and removed, generally horizontal shoulders  54  at the back of the lifting arm abut the top of the lid so as to arrest vertical movement, and generally vertical faces of the stabilizer plates abut the outer edge  56  of the lid to limit rearward and lateral movement. In conjunction with the hook member  16 , the stabilizers form a “three point” connection to the lid which effectively prevents any rocking or wobbling motion while the lid is being raised/lowered or transported. Furthermore, the bottoms of the stabilizing plates are preferably provided with downwardly extending, rounded tabs  57   a ,  58   b  at their leading edges which engage the ground adjacent to the manhole during the initial phase of the lifting movement, until the weight is transferred onto the wheels  24  which provide the main pivot axis. 
     FIGS. 5-6 show the lifting tool  10  fitted with another form of hook member  58 , this having first and second prongs  60   a ,  60   b  which are joined by an upper hoop  62 . Each of the prongs is generally similar to the single prong described above, and the hook member  58  can be mounted to the frame  58  interchangeably with the single-pronged hook  16 , with the two vertical legs of the hook  58  fitting fairly close against the outside of the plates  36   a ,  36   b  for stability. The two-pronged hook member  58  is particularly adapted for removal/replacement of heavy gratings, such as the grate  64  which is shown in FIG. 5, with the spacing between the prongs being selected so that these will enter separate, laterally-spaced openings in the grate (see FIG.  6 ). It will be understood that other, specially configured hook members can also be provided for use with a variety of other types/styles of lids and lift fittings. 
     FIG. 7, in turn, illustrates the use of the fixed hooks  40   a ,  40   b  which are formed at the forward end of the lifting arm  30 . As was noted above, the fixed hooks are configured principally for removing manhole covers and other lids which are fitted with “D” type lifting rings, rather than having holes or other openings as shown above, for ease of use, the pivoting hook member  16 , can be removed when the fixed hook portions are to be used. Accordingly, FIG. 7 shows the D-ring handle  70  of such a lid  72  having been raised and placed over fixed hooks  40   a ,  40   b , with the pivot head being tilted in the forward direction. 
     As can be seen in FIG. 8A the fixed hooks  40   a ,  40   b  engage the upper leg  74  of the D-ring at separate, laterally spaced locations. This stabilizes the lid against rocking or slipping back and forth during the initial phases of the lifting motion, until the stabilizer plates and shoulders come into contact with the edge of the lid. 
     With the D-ring thus engaged by the fixed hooks, the operator pulls back on the handle of the tool and applies downward pressure on the footplate  18 , raising and removing the lid in the same manner as described above. When the lid is returned to its opening, the hooks are removed from the D-ring, which then falls back to its retracted position, as shown in FIG.  8 B. 
     FIGS. 9A-9B show the lifting tool  10 , fitted with a hook-and-chain attachment for removal of comparatively large lids, such as large utility covers. Such covers are commonly on the order of 36 inches in diameter, and can weigh in the hundreds of pounds. The tool of the present invention, using the hook and chain attachment which is shown in FIGS. 9A-9B, has been demonstrated to generate a lifting ratio, of approximately 4:1 making it possible for a single operator to remove such covers, which has heretofore been extremely difficult when using conventional tools. 
     As can be seen in FIG. 9A, the hook-and-chain attachment  80  includes a J-hook  82  which is mounted to the rearmost attachment point  36   a  of the lifting arm  30 , using a first pin  84 . The J-hook includes a comparatively long shank  86  which is sized to pass through a pick hole  88  at the edge of the lid  89 , and a sharply curved lower end  90  which is configured to pass under and engage a downwardly extending ring  92  which is located a spaced distance inwardly from the edge of the lid. The pick hole and ring are conventional features of utility covers and similar lids, being provided for use with an ordinary pry-bar. 
     A pivoting link  94 , in turn, is mounted to the forward attachment point  46   c  on lifting arm  30 , using a second pin  97 . The lower end of the length includes a keyhole opening  96  through which a link of chain  98  is passed; the keyhole opening allows for adjustment of the length of the chain which spans the top of the lid, and a ring or fitting (not shown) is preferably attached to the other end of the chain to prevent it from falling out of the link during transportation or storage. An edge hook  100  is attached to the outer end of the chain, and is configured to pass through a corresponding pickhole  102  on the opposite side of the lid from J-hook  90 . As can be seen, the shank  104  of edge hook, lies generally flat on the top of the lid  89  while its end  106  extends downwardly through the pick opening to engage a rim portion  108  of the lid. 
     To use the tool, the operator inserts the J-hook into the first pickhole and rotates it so that the lower end of the hook engages the inner ring. The chain hook  100  is then set in the second pickhole opposite the first, and the chain length is adjusted so that the handle is approximately 45° to 60° to the ground when the chain is tensioned and the link  94  pivots outwardly as shown in FIG.  9 B. Then, using both hands, the operator grasps the handle of the tool and draws it towards the center of his chest, in the direction indicated by arrow  110  in FIG. 9B, using his body weight to pull downwardly and outwardly to raise and slide the cover from the access hole. To replace the cover, the chain hook is released, and while holding, the chain the pivot head  14  of the tool is used to lift one edge of the lid and push it back into the access hole. The J-hook is then disengaged from the inner ring and withdrawn. 
     The tool of the present invention may be formed of any sufficiently strong and durable material, with welded steel being eminently suitable for this purpose. 
     It is to be recognized that various alterations, modifications, and/or additions may be introduced into the constructions and arrangements of parts described above without departing from the spirit or ambit of the present invention.

Technology Category: 7