Abstract:
An equipment loading plank that is detachably mounted on a machine tool table and used for easy and safe installation and removal of equipment on and off the machine tool work tables. The equipment loading plank includes a flat rectangular shaped body with an upper loading surface and a lower seating surface and a leg downwardly extending at an angle from one end of said loading plank. The leg is inserted into a T-slot in the machine tool table to detachably mount the loading plank to the machine tool table. The leg has a front face and a lower face that converge such that the leg can be wedged into the T-slot when the loading plank is seated on the machine tool table parallel to the upper surface of the machine tool table. The leg ends in a foot that prevents the leg from slipping from the T-slot whenever loads are placed on the loading plank.

Description:
This patent application claims priority based on U.S. provisional patent application serial no. 60/070,329, filed in the name of Daniel F. O&#39;Brien on Jan. 2, 1998, entitled “Equipment Loading Aid Plank”. 
    
    
     BACKGROUND 
     In the machine tool trade, such as computer numerical controlled machining (CNC machining), the work pieces and work piece holding devices, i.e., vices, are manually loaded and unloaded onto the work table of the machine tool. Machine operators commonly load and unload work pieces or holding devices, which may weigh up to 200 pounds, several times in a normal workday without assistance. Machine tools in general are poorly designed to ease the loading and unloading of auxiliary equipment and tooling. Typically, a machine tool operation cell is located inside an enclosure, which forces the operator to lean into and over the enclosure opening when loading or unloading work pieces and holding devices. Machine operators can suffer strains, back injuries, hernias, or other similar injuries while loading heavy and awkward tooling or work pieces onto the machine tool&#39;s work table. Moreover, machine operators can drop the heavy and awkward tooling or work pieces during loading, resulting in damage to the machine tool as well as the tooling or work piece. 
     Thus, there is a need for a device that will easily and conveniently assist a machine operator in the safe loading and unloading of work pieces and auxiliary equipment. 
     SUMMARY 
     A cantilever loading plank is used for loading and unloading equipment onto a machine tool table. The equipment loading plank includes a flat rectangular shaped body with an upper loading surface and a supporting bottom surface and a leg at one end of the loading plank. The leg extends downward from the plank and is inserted into one of the T-shaped slots that are conventionally found on machine tool tables. The leg has a front face and a lower face that may converge such that the leg can be wedged into the T-slot when the loading plank is seated on the machine tool table parallel to the upper surface of the machine tool table. A foot that extends from the end of the leg assists in holding the leg in the T-shaped slot. When the foot and leg are inserted into a slot in the machine tool table, a portion of the bottom supporting surface rests on the top surface of the machine tool table. 
     The loading plank may also include guide grooves in the top loading surface to provide tracks for keys or other protuberances on the item being loaded. The guide grooves prevent undesirable or accidental slippage of the item while an item is slid along the top loading surface of the loading plank. The loading plank may be corrugated, which decreases the material and therefore the cost of the loading plank while maintaining the strength of the loading plank so that it may support heavy items with a minimal amount of bending. The corrugation may also form the guide grooves. 
     The loading plank is easily and conveniently mounted onto a machine tool table by tilting the loading plank with respect to the surface of a machine tool table and inserting the foot and leg into a T-slot groove. The loading plank is then untilted so that a portion of the supporting bottom surface rests on the machine tool table. When mounted on the machine tool table, the loading plank protrudes outward from the machine tool table into the machine operator work zone. Advantageously, the operator can manually load heavy items onto the loading surface of the loading plank while practicing safe lifting methods, i.e., lifting with the legs, not the back, and holding the item close to the body. Thus, there is less likelihood of injury to the operator or accidentally dropping the item, resulting in damage to the machine tool table or the item. Of course, if desired the item may also be lifted and placed on the loading plank with forklifts, automated lifts or cranes. The item can then be easily and safely slid along the top loading surface of the loading plank and onto the machine tool table. Once the item is positioned on the machine tool table, the loading plank is easily disengaged from the table. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying figures, where: 
     FIG. 1 illustrates a top perspective view of an “L” shaped loading plank; 
     FIG. 2 shows a bottom perspective view of the loading plank; 
     FIGS. 3A,  3 B, and  3 C are respective top plan, side, and end views of the loading plank; 
     FIG. 4 illustrates a top perspective view of an embodiment of the loading plank installed in a machine tool table; 
     FIG. 5 illustrates a cross-sectional view of the loading plank affixed to a T-slot in a machine tool table; 
     FIG. 6 illustrates a cross-sectional view of the loading plank affixed to a different sized T-slot in a machine tool table; 
     FIG. 7 illustrates a cross-sectional view of the loading plank affixed to a different sized T-slot in a machine tool table; 
     FIG. 8 illustrates a cross-sectional view of the loading plank as affixed to yet another different sized T-slot in a machine tool table; 
     FIG. 9 illustrates the loading plank as it is being mounted on (or removed from) a T-slot in a machine tool table; 
     FIG. 10 shows an end view of a machine vise supported by the loading plank; 
     FIG. 11 shows an end view of a machine vise supported by the loading plank; and 
     FIG. 12 shows an end view of a machine vise mounted on a graduated adjustable angle vise base supported by the loading plank. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 illustrates a top perspective view of an “L” shaped loading/unloading plank  10  (“loading plank”) for loading and unloading tooling, equipment, and work parts onto and off the work table of a machine tool in accordance with an embodiment of the present inventions. Loading plank  10  includes a rectangular body  11  having an upper loading surface  12 , a leg  14  with front surface  15  used to hold the loading plank  10  onto the work table surface, and a foot  16  at the terminus of the leg  14 . Of course, body  11  need not be rectangular, but may be oval, square or any desired other shape. The leg  14  extends from one end of body  11  at a slight angle, while foot  16  is generally parallel with the loading surface  12 . Leg  14  is shaped to extend into T-slots on a conventional machine tool table. At the end of foot  16  is a toe  18  that prevents loading plank  10  from unintentionally slipping out of a T-slot in the machining tool surface during use. Several longitudinal grooves  20 - 22  are formed in the loading surface  12  of loading plank  10 . Grooves  20 - 22  lighten loading plank  10  while also reinforcing and stiffening loading plank  10  by increasing the cross-section thickness, thereby eliminating the need for a thick and heavy plank. In one embodiment a central groove  21  may be used as a guide for equipment, and is flanked on both sides by two flat loading surfaces  24 ,  26 . Additional loading surfaces  28 ,  30  are provided outside flat surfaces  24 ,  26  to further stiffen loading plank  10 . Grooves  20  and  22  may also be used to as guide grooves for a vise loaded longitudinally on loading plank  10 . It should be understood that the specific number of grooves  20 - 22  shown in loading plank  10  in FIG. 1 is exemplary and that any number of grooves may be used if desired. Moreover, loading plank  10  may have no grooves if desired. 
     FIG. 2 shows a bottom perspective view of a loading plank  10 . Loading plank  10  includes a bottom supporting surface  32  a portion of which rests against a machine tool table when loading plank  10  is affixed to a machine tool table. The leg  14  is shown with a lower face  34  that transitions into a heel  36  of the foot  16 . The forward end of foot  16  terminates in the toe  18 , which may be finished as a rounded edge. 
     The underside of loading plank  10  includes two longitudinal grooves  38 ,  40 . Grooves  38 ,  40  are between three flat surfaces  42 ,  44 , and  46 . Flat surfaces  42 ,  44 , and  46  form the bottom supporting surface  32 , a portion of which rests upon the work table surface during use. 
     FIGS. 3A,  3 B, and  3 C are respective top plan, side, and end views of loading plank  10 . The loading plank  10  is approximately 22 inches in length (dimension A shown in FIG. 3A) and the width is approximately 7.2 inches (dimension B shown in FIG.  3 A). Each grooves  20  and  22  in the top surface are approximately 1.25 inches (dimension C in FIG. 3C) and groove  21  is approximately 1 inch (dimension D), while flat surfaces  24  and  26  are approximately 1.6 inches each (dimension E). On the bottom surface, grooves  38  and  40  are approximately 1.3 inches (dimension F) and flat surface  44  is approximately 1.25 inches (dimension G). Body  11  has a total thickness of approximately 0.75 inches (dimension H) while the material forming body  11  is approximately 0.2 inches thick (dimension I). Loading plank  10  has a total thickness, including body  11  and leg  14  of approximately 1.65 inches (dimension J). 
     As shown in FIG. 3B, leg  14  extends downward from bottom supporting surface  32  by approximately 0.9 inches (dimension K). Foot  16  is approximately 0.5 inches long (dimension L) from toe  18  to heel  36 , 0.275 inches thick (dimension M), and has a top portion from toe  18  to the front face  15  of leg  14 , that is approximately 0.25 inches (dimension N). The lower face  34  of leg  14  has an angle of approximately 20 degrees from vertical (angle θ) and the front face  15  has an angle of approximately 10 degrees from vertical (angle γ). 
     In one embodiment of the present invention, loading plank  10  is constructed from 6061T6 forged aluminum. The 6000 series aluminum material assures maximum strength with ease of construction, provides freedom from corrosion without secondary coating or corrosion protection measures, and it allows for a relatively light devise for ease in handling. In another embodiment, loading plank  10  is casted out of  356 T 6  aluminum. Other materials and construction techniques may also be employed including molded plastic, fiber reinforced resin, hard pressure treated wood, and casting a wide range of metals. While the present invention does not require or rely upon any particular material or dimensions, the chosen material and dimensions should be suitable for the use intended. 
     FIG. 4 illustrates a top perspective view of an embodiment of cantilever loading plank  10  installed in a machine tool table  48 , such as the type commonly found in computer controlled machining centers. Loading plank  10  is used to support a machine vise  50  as the machine vise  50  is loaded or unloaded onto machine tool table  48 . Loading plank  10  is shown attached to the machine tool table  48  with leg  14  inserted in a T-slot  52 . As illustrated in FIG. 4, when loading plank  10  is affixed to machine tool table  48  it is cantilevered with a portion of loading plank  10  extending off the machine tool table  48  and into the machine operating work zone. Thus, the machine vise  50  can be easily lifted and placed onto loading plank  10  and slid onto machine tool table  48  at the desired position. Thus, there is no need for the machine operator to lean over machine tool table  48  to load machine vise  50 . Machine vise  50  is prevented from sliding off loading plank  10  by a protuberance known as a key on the underside of the machine vise  50 , (not visible in this view) that is slideably engaged with groove  21 . It should be noted that loading plank  10  can be installed on machine tool table  48  at any T-slot at any desired location, e.g., the center of table  48  or at the side of table  48 . 
     FIG. 5 illustrates a cross-sectional view of loading plank  10  affixed in a T-slot  52  in machine tool table  48 . A portion of supporting surface  32  of loading plank  10  rests on the top surface of machine tool table  48 . The leg  14  of the plank  10  extends into the T-slot  52 . The front face  15  of the leg  14  rests against one side of the throat  54  of T-slot  52 , with the other side of the throat  54  abutting against the lower face  34  of leg  14  at the entry of throat  54 . The foot  16  and toe  18  hook under the edge formed at the transition between the throat  54  and the head space  56 . The wedging action of the front face  15  and lower face  34  of leg  14  in the throat  54  of T-slot  52 , along with the toe  18  being hooked in head space  56 , securely affix loading plank  10  to machine tool table  48 . With loading plank  10  thus affixed to table  48 , the loading planks  10  longitudinal axis is parallel to the surface of the machine tool table  48 . 
     Loads, such as machine vise  50  (shown in FIG. 4) placed on the loading surface  12  cause the loading plank  10  to be depressed against the table&#39;s upper surface, which further wedges the leg  14  into the T-slot  52  and firmly holds the toe  18  in place under the ledge of the throat  54  and head space  56 . Thus, loads on loading surface  12  will not lever the leg  14  from the T-slot  54 . 
     In one embodiment, the transition from the loading surface  12  to the forward face  15  of the leg  14  is rounded to provide a smooth transfer of the equipment from loading surface  12  to the machine tool table  48 . The transition between the loading surface  12  and the forward face  15  could be made with a smaller or larger radius or even an angular chamfer to suit the desired use of the loading plank  10 . Moreover, the heel  36  of foot  16  is beveled or rounded to permit clearance for toe  18  during installation and removal of loading plank  10  from the T-slot  52 . 
     The front face  15  and the lower face  34  of the leg  14  are angled at slightly less than ninety degrees to the loading surface  12  of the loading plank  10  so that leg  14  may interface with differing sizes of machine table T-slot throats. In one embodiment of the present invention, the front face  15  of the leg  14  has a slightly different angle than lower face  36 , with front face  15  closer too vertical. The differing angles for front face  15  and lower face  35  of leg  14  cause the cross section of leg  14  to narrow near the foot  16 . The narrowing of the leg  14  along with the general angled orientation of leg  14  with respect to loading surface  12  permits loading plank  10  to fit reliably and interchangeably with a range of machine tool table T-slot sizes. The range of fit, in one embodiment of the present invention, coincides with the size of T-slots used by the most common machine tools in use, with which the machine operator normally manually lifts heavy and bulky items onto the tool&#39;s tables. 
     FIG. 6 illustrates a cross-sectional view of the loading plank  10  affixed in a T-slot  52  in a machine tool table  48 , where the T-slot  52  represents a standard ½″ T-slot dimension, as used in many small machine tools. FIG. 6 shows a portion of the bottom supporting surface  32  of loading plank  10  resting on the top surface of the machine tool table  48  with the leg  14  extending into the T-slot  52 . The front face  15  rests against one side of throat  54  with the other side of the throat  54  abutting lower face  34  at the entry of the throat  54 . The toe  18  is under the edge formed at the transition between the T-slot&#39;s throat  54  and head space  56  and the toe  18  is wedged against the end of the head space  56 . Thus, loads placed on the loading surface  12  cause the loading plank  10  to be depressed against the table&#39;s upper surface, which further wedges toe  18  against the end of head space  56  holding loading plank  10  firmly in place in T-slot  52 . Consequently, a load on loading surface  12  will not lever the leg  14  from ½″ T-slot  52 . 
     FIG. 7 illustrates a cross-sectional view of the loading plank  10  affixed in a T-slot  52  in a machine tool table  48 , where the T-slot  52  represents a standard ⅝″ T-slot dimension. A ⅝″ T-slot is commonly found in large machine tools where operators are expected to manually load tooling and parts without the aid of cranes, hoists, fork lifts, and the like. Again, a portion of the supporting surface  32  rests on the top surface of machine tool table  48  with the leg  14  extending into the T-slot  52 . As shown in FIG. 7, the front face  15  of the leg  14  comes near, but does not actually touch one side of the throat  54  of T-slot  52 . The other side of the throat  54  abuts lower face  34  at the entry of the throat  54 . The toe  18  hooks under and presses against the edge formed at the transition between the T-slot&#39;s throat  54  and head space  56 . Thus, loads placed on loading surface  12  cause the loading plank  10  to be depressed against the table&#39;s top surface and toe  18  to be pressed against the edge formed at the transition between the T-slot&#39;s throat  54  and head space  56 , holding loading plank  10  firmly in place. Consequently, a load on loading surface  12  will not lever the leg  14  from a ⅝″ T-slot  52 . 
     FIG. 8 illustrates a cross-sectional view of the loading plank  10  affixed to yet another different sized T-slot  52  in a machine tool table  48 . The T-slot  52  is the size used in small knee milling machines, such as those made by Bridgeport. A portion of the supporting surface  32  rests on the top surface of the machine tool table  48  with the leg extending into the T-slot  52 . The front face  15  rests against one side of the throat  54 , while the other side of the throat  54  abuts against the lower face  34  at the entry of the throat  54 . As shown in FIG. 8, toe  18  and foot  16  are within head space  56  but do not contact the sides of head space  56 . Therefore, the leg  14  is held in place in the throat  54  of T-slot  52  solely by the wedging action of the front face  15  and lower face  34  in the throat  54 . Loads placed on the loading surface  12  cause the loading plank  10  to be depressed against the table&#39;s upper surface, which further wedges the leg  14  into the T-slot  52 , preventing loads on loading surface  12  from levering the leg  14  from the T-slot  52 . 
     FIG. 9 illustrates the loading plank  10  as it is being mounted on (or removed from) a T-slot  52  of a machine tool table  48 . As shown in FIG. 9, the loading plank  10  has the end opposite leg  14  raised so that the loading surface  12  is tilted in relationship with the surface of the machine tool table  48 . The tilting of loading plank  10  allows the leg  14  and foot  16  to clear both sides of throat  54  of T-slot  52  while leg  14  and foot  16  are inserted into or removed from T-slot  52 . Moreover, the converging planes of the front face  15  and lower face  34  reduce the longitudinal cross-section thickness of the leg  14  at the foot  16  to further facilitate insertion into and removal from T-slot  52 . During installation, once toe  18  enters head space  56 , loading plank  10  may be tilted back so that loading surface  12  is parallel with the upper surface of the machine tool table  48 , which hooks toe  18  under the edge formed at the transition between the T-slot&#39;s throat  54  and head space  56 . During removal, loading surface  12  is already parallel with the upper surface of machine tool table  48  and is tilted so that toe  18  and heel  36  can clear throat  54 . Leg  14  and foot  16  (including toe  18  and heel  36 ) are then lifted out of T-slot  52 . In an embodiment in which both the toe  18  and heel  36  have rounded edges, the rounded edges advantageously facilitate the passage of foot  16  into and out of the throat  54  and head space  56  of the T-slot  52 . 
     In one embodiment of the present invention, loading plank  10  includes at least one longitudinal groove  21  in the upper loading surface  12  to provide a guide track for a key or locating pin of tooling or equipment, such as a vise. FIG. 10 shows an end view of loading plank with a machine vise  50  supported on the upper loading surface  12 , as viewed from the end opposite leg  14  on loading plank  10 . FIG. 10 shows loading plank  10  as it would be used for installing equipment, e.g., vise  50 , onto a machine tool table (not shown for the sake of clarity), with vise  50  being positioned perpendicular to the length of loading plank  10 . As shown in FIG. 10, the location key  58  provided on vise  50  is slideably engaged with central groove  21 , which acts as a guide to prevent vise  50  from accidentally slipping off loading plank  10  as vise  50  slides along loading surface  12  of loading plank  10 . 
     In one embodiment of the present invention, the central guiding groove  21  is configured to accommodate the locating key  58  of a standard six inch size machine vise. A typical six inch size machine vise, for example, is the Model D675, 7.5″ jaw capacity, Anglock 6″ Vise manufactured by Kurt Manufacturing Co. located in Minneapolis, Minn. 
     Loading plank  10  includes two additional grooves  20 ,  22  on loading surface  12 , which may also accommodate the locating keys  58  of a standard six inch size machine vise, or any other desired size vise or equipment. FIG. 11 shows an end view of loading plank  10  with a machine vise  50  supported on the upper loading surface  12 , as viewed from the end of loading plank  10  opposite leg  14 . FIG. 11 is similar to FIG. 10 except that vise  50  is orientated parallel with loading plank  10  and location keys  60 ,  62  are slideably engaged with respective grooves  20 ,  22 , which act as guides to prevent vise  50  from accidentally slipping off loading plank  10 . 
     FIG. 12 shows an end view of a loading plank  10  with a machine vise  50  mounted on a graduated adjustable angle vise base  64  supported by the upper loading surface  12 , as viewed from the end of loading plank  10  opposite leg  14 . The width of loading plank  10  is configured to accommodate locating keys  66 ,  68  of the conventional graduated adjustable angle vise base  64  for machine vise  50 , which may for example be a typical six inch size machine vise. The angle vise base  64  permits the operator to place vise  50  in any desired orientation. The location keys  66 ,  68  provided on graduated adjustable angle vise base  64  ride along the outside of the side edges of loading plank  10  to prevent base  64  and machine vise  50  from accidentally slipping off loading plank  10 . 
     Although the present invention has been described in considerable detail with reference to certain versions thereof, other versions are possible. For example, the shapes and dimensions of loading plank  10  are exemplary, and other shapes and dimensions may be used if desired. Further, it should be understood that any suitable material and method of manufacture may be used. In addition, it should be understood that multiple loading planks may be used in tandem to assist in loading and unloading of particularly heavy items. Therefore, the spirit and scope of the appended claims should not be limited to the description of the versions depicted in the figures.