Abstract:
Shield apparatus for a fork lift truck includes a flat stiff plate securable to the mast or vertical portion of a carriage of a fork lift truck. The shield apparatus includes fasting elements which are adjustable to fit different sized mast elements of fork lift trucks made by different manufacturers. The shield apparatus comprises a relatively large and flat plate to fit the entire width of the carriage, including the vertical mast elements for the purpose of protecting material with relatively delicate edges, such as wall board, from being damaged while the material is being transported by the fork lift truck. Included are handle elements which allow the shield apparatus to be easily placed on and removed from a fork lift truck.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to fork lift trucks and, more particularly, to a shield for protecting materials from being damaged by the mast of a fork lift truck. 
   2. Description of the Prior Art 
   U.S. Pat. No. 2,956,701 (Larson) discloses a fork lift truck with a vertical element adjacent to the horizontal forks for protecting a pallet while the pallet is being lifted. 
   U.S. Pat. No. 3,625,385 (Ide) discloses a limit plate secured to the forks of a fork lift truck to limit the distance that a pallet may move on the forks. The purpose of the limit element is to protect adjacent cargo while the fork lift truck is loading pallets from rows of cargo laden pallets. 
   U.S. Pat. No. 4,102,464 (Schuster) discloses an impact bumper for protecting pallets and the cargo disposed on pallets. 
   U.S. Pat. No. 4,478,314 (Dorman) discloses a safety shield for a fork lift truck to protect the operator of the truck. The safety shield is transparent and is designed to protect the operator from hazardous cargo handled by the fork lift truck, such as explosives, dangerous chemicals, and the like. 
   U.S. Pat. No. 5,560,451 (Hincks) discloses shock absorber apparatus for a fork lift truck for protecting pallets. 
   U.S. Pat. No. 5,618,159 (Wilson) discloses another type of protective element for protecting materials transported by a fork lift truck. The protective element is flexible and fits around the vertical portion of the carriage of a fork lift truck. 
   SUMMARY OF THE INVENTION 
   The invention described and claimed herein comprises a shield securable to the vertical portion of a carriage of a fork lift truck. The shield is flat and relatively stiff and comprises a flat surface against which cargo being lifted by the fork lift trucks may be disposed and which will prevent damage to such cargo. When drywall, or wall board, is moved by a fork lift truck, the edges of the drywall are subject to damage, thus essentially ruining each sheet which has an edge damage. The shield apparatus of the present invention comprises a solid surface against which the drywall or other material having relatively fragile edges may be disposed and accordingly which prevents damage to the relatively fragile edges of the load, such as drywall or wallboard. 
   Among the objects of the present invention are the following: 
   To provide new and useful shield apparatus for a fork lift truck; 
   To provide new and useful shield apparatus easily disposed on the vertical mast or carriage of a fork lift truck; 
   To provide new and useful shield apparatus having a flat and solid surface against which material moved by a fork lift truck may be disposed; and 
   To provide new and useful shield apparatus for a fork lift truck having adjustable fastening elements to allow the shield apparatus to be secured to masts of different makes of fork lift trucks. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
       FIG. 1  is a perspective view of the apparatus of the present invention in its use environment. 
       FIG. 2  is a side view in partial section of a portion of the apparatus of the present invention. 
       FIG. 3  is a front view illustrating the installation of the apparatus of the present invention on a fork lift truck. 
       FIGS. 3A ,  3 B, and  3 C are front views sequentially following  FIG. 3  in the installation process. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  is a perspective view of a fork lift truck  2 , shown in dashed line, with a fork lift shield  20  of the present invention disposed on the truck  2 . The truck  2  includes a pair of generally horizontally extending forks  4  and  8  secured to a pair of generally vertically extending mast elements  6  and  10 , respectively. Extending between the vertical members  6  and  10  is a horizontal member  12 . The mast elements  6  and  10  move vertically upwardly and downwardly on a lift frame  16  by hydraulic power, as is well known and understood. Since the lift frame  16  and its hydraulic elements are well known and understood, and since they are not directly a part of the present invention, they are not shown or discussed further. 
   The mast elements  6 ,  10  and  12  are secured to other elements, as well as to the lift frame  16 , but for clarity and understanding of the present invention, such other elements are also not illustrated or discussed. 
   The shield apparatus  20  includes a flat plate center portion  22  which extends between the vertical mast elements or members  6  and  10  and above the horizontal forks  4  and  6 . Extending upwardly from the center portion  22  are upper arms  24  and  28 . At the upper ends of the upper arms  24  and  28  are rearwardly extending flanges  26  and  30 . The flanges  26  and  30  extend over the cross member  12 , while the arms  24  and  28  are disposed against the vertical mast members  6  and  10 . The flanges  26  and  30  are generally perpendicular to the arms  24  and  28  and to the center portion  22 . 
   A flange  40  extends from the arm  24  at about the juncture of the arm  24  to the center portion  22 . The flange  40  is disposed generally against the side of the mast element or member  6 . A handle  42  extends generally outwardly from the flange  40 . The purpose of the handle  42  is for the installation and removal of the apparatus  20  to and from the fork lift truck  2 . This will be explained below in conjunction with  FIGS. 2 ,  2 A,  2 B, and  2 C. 
   Another handle  46  extends outwardly from a flange generally parallel to the flange  40 . The handle  46  is generally parallel to and aligned with the handle  42 . 
   Extending below the center portion  22  are two lower arms  60  and  64 . The arms  60  and  64  are also disposed against the vertical mast members  6  and  10 , respectively. The arm  60  includes a flange  62  which is disposed generally perpendicularly to the arm  60 . Similarly, the arm  64  includes a side flange (not shown) which is also disposed generally perpendicularly to the arm  64 . The flange  62  and its parallel flange are disposed against the sides of the mast elements  6  and  10 , respectively, while the arms  60  and  64  are disposed against the front of the arms  6  and  10 , respectively. The apparatus  20  is in a general “H” configuration, with the portion  22  comprising the cross bar and the arm portions  24 ,  28  and  60 ,  64  comprising the vertical elements of the “H.” 
   For securing the apparatus  20  to the forklift unit  2 , six lock brackets are disposed in conjunction with the flanges  26 ,  30 ,  40 , and a flange generally parallel to the flange  40  and to which the handle  46  is secured, and the lower flange  62  and its parallel flange extending from the arm  64 . Each of the flanges includes a pair of elongated slots which receive threaded studs. The studs extend from lock brackets. 
   The flange  26  includes a pair of slots  80 , the flange  30  includes a pair of slots  82 , the flange  40  includes a pair of slots  84 , the flange  62  includes a pair of slots  88 , and the two flanges (not shown) on the arms  28  and  64  also includes slots. 
   The purpose of the slots is to allow for different sized elements on the different makes of fork lift trucks. The apparatus  20  may thus be easily mounted on fork lift trucks of different sizes. 
   The lock brackets include a pair of top lock brackets  100  and  110  and a pair of upper side lock brackets, including a bracket  120  and a bracket  130 , and a lower side bracket  140  and a parallel side bracket  150 . The side brackets  130  and  150  are, as indicated, disposed in conjunction with the side flanges not shown in FIG.  1 . 
   The lock brackets  100 ,  110 ,  120 ,  130 ,  140 , and  150  are disposed against the mast elements or members and beneath their respective flanges. Thus, the statements above regarding the disposition of the respective flanges “against” the mast members should be thus modified by the disposition or interposition of the lock brackets. 
   The lock brackets are substantially identical to each other. They comprise an angle bracket having two elements or legs disposed substantially perpendicular to each other. One element or leg is disposed beneath a flange and against the side of its mast member, and the other element or leg is disposed directly against the rear of its mast member. 
     FIG. 2  is a fragmentary side view in partial section through the lock bracket  100  and the flange  26 . Since the lock brackets are substantially identical,  FIG. 2  is representative of all of the lock brackets and their associated elements. The bracket  100  is disposed beneath the flange  26  and on the top of the cross member  12 . The bracket  100  includes a leg  102  and a leg  104 . A pair of threaded studs  106 , one of which is shown in  FIG. 2 , extends upwardly from the leg  104  and into a pair of slots  80 . A nut  108  is tightened against the flange  80  to help lock the bracket  100  and the flange  26 , and accordingly the apparatus  20 , to the member  12 , and thus to the fork lift truck  2 . 
   Each flange also includes another locking element, namely a threaded bolt which extends through an internally threaded aperture in the flange outboard of the two slots through which the threaded studs extend. In  FIGS. 1 and 2 , a lock bolt  160  is shown tightened against the arm  104  of the lock bracket  100 . In  FIG. 1 , a lock bolt  164  is shown on the flange  40 , and a lock bolt  168  is shown on the flange  62 . 
   For securing the apparatus  20  in place, the lock brackets are secured to their respective flanges by the pairs of threaded studs extending from the lock brackets and through their aligned slots in the flanges. Nuts are then tightened on the studs against the flanges. A pair of nuts  108  is shown on the flange  26 , and a pair of nuts  118  is shown on the flange  30 . A pair of nuts  128  is shown on the flange  40 , and a pair of nuts  148  is shown on the flange  62 . 
   The installation of a shield  20  on a fork lift truck  2  is sequentially illustrated in  FIGS. 3 ,  3 A,  3 B, and  3 C. The four  FIGS. 3 ,  3 A,  3 B, and  3 C are front views of the forklift truck  2  and the shield apparatus  20 . For the following discussion, reference will primarily be made to  FIGS. 3 ,  3 A,  3 B, and  3 C. 
   Two people grasp the apparatus  20  by the handles  42  and  46  and lift the shield  20  above the cross member  12 . The shield  20  is then lowered on the member  12  and on the side mast members  6  and  10 . The lowering is illustrated sequentially in  FIGS. 3A and 3B . The shield is lowered on the mast elements until the lower side arms  60  and  64  are disposed on the forks  4  and  6 , as shown in FIG.  3 C. 
   With the shield apparatus  20  in place on the mast members and the forks, the lock brackets are adjusted against the respective members and the nut pairs and lock bolts are tightened to lock the apparatus  20  to the fork lift truck  2 . 
   The shield apparatus  20  may be made of appropriate material, such as aluminum, plastic, etc. While weight may be a consideration, the ability of the material to withstand the impact of a load bearing against the shield is also an important consideration. The shield apparatus  20  is especially useful in protecting the edges of a load, such as wall board (or drywall), or other material which has relatively fragile edges, from being damaged while being moved by a fork lift truck. The central portion  22  of the shield apparatus  20  extends the full width of a fork lift truck carriage, including the forks and lift members, and thus protects the exposed edges of a load from impacting against the mast elements or members while the load is being transported or moved. 
   The arms  24 ,  28  and  60 ,  64  define, with the center portion  22 , open viewing areas for the operator of the fork lift truck  2  to which the apparatus  20  is secured. The purpose of the open areas is to provide the operator or driver viewing areas through which the operator may view the material being loaded onto or picked up by the fork lift truck. Thus, an upper viewing area is defined above the center portion  22  and the arms  24  and  28 , and a bottom or lower viewing area is defined between the lower arms  60  and  64  and below the center portion  22 . 
   The arms  24 ,  28 , and  60 ,  64  are sufficiently wide so as to provide the desired protection for exposed edges of whatever load is being transported by the fork lift truck  2 . If desired, the lower arms  60  and  64  may extend almost the full width or distance between the mast elements, and thus essentially become part of an extended central portion  22 , but reserving or still providing a viewing area for safety purposes. Thus, there may be a minimum width but not necessarily a maximum width, except for the safety viewing areas in the center. 
   The shield apparatus  20  is illustrated as having sloping shoulders on the outer corners of the respective upper arms, the shield apparatus may eliminate the sloping shoulders to provide generally rectangular arms, or the outer corners may be rounded, or otherwise, as desired. Similarly, the inner corners, i.e., the junctures of the arms and the center portion, may be rounded, sloping, etc., rather than the generally perpendicular inner corners as illustrated. 
   While the principles of the invention have been made clear in illustrative embodiments, without departing from those principles there may occur to those skilled in the art many modifications of structure, arrangement, proportions, the elements, materials, and components used in the practice of the invention, and otherwise, which are particularly adapted to specific environments and operative requirements. The appended claims are intended to cover and embrace any and all such modifications, within the limits only of the true spirit and scope of the invention.