Abstract:
A drill block and a method for drilling a hole through a workpiece using the drill block. The drill block may include a mounting leg for mounting the drill block, a drilling support leg having a round hole therethrough operable to receive a drill bit during a drilling operation, and a height variability leg interposed between the mounting leg and the drilling support leg, wherein the height variability leg is adjustable to select a vertical height of the drilling support leg relative to the mounting leg.

Description:
TECHNICAL FIELD 
       [0001]    The present teachings relate to the field of drilling tools and, more particularly, to a drill block for aligning a drill bit to a surface of a structure to be drilled. 
       BACKGROUND 
       [0002]    During the manufacture and assembly of performance vehicles such as aircraft, a subassembly must be attached to a supporting substrate with a high degree of precision to ensure efficient operation. To assist with precision alignment, one or more reference holes may be molded into, or predrilled through, the subassembly during manufacture. The reference holes in the subassembly are used to identify the location of holes that are to be drilled through the supporting substrate. 
         [0003]    To attach the subassembly to the supporting substrate, an edge of the subassembly may be placed in physical contact with an edge of the supporting substrate to ensure the subassembly is properly aligned with the supporting substrate. A drill bit is inserted through the reference hole in the subassembly, and then a hole is drilled through the supporting substrate using the reference hole in the subassembly to properly locate the hole through the supporting substrate. Any remaining holes are then similarly drilled using the reference holes in the subassembly to properly locate the holes in the supporting substrate. 
         [0004]    Even though the reference holes through the subassembly are effective in ensuring that the entrance location of each hole drilled through the supporting substrate is correct, maintaining the drill bit exactly perpendicular to the supporting substrate to ensure the proper exit location of each hole is more difficult. For example, if a drill bit is improperly angled 7° away from vertical during drilling through a material that is 2.5″ thick, the hole will exit the material almost 3/16″ away from its correct location. 
         [0005]    Assembly personnel may simply attempt to maintain the drill bit in a vertical position without any mechanical aid other than the reference holes through the subassembly, but this method is inaccurate and varies greatly with the attention and experience of individual assembly personnel. A handheld drill block may be used but the drill block may be only slightly larger than the hole to be drilled, and thus manual alignment of the drill block is difficult and misaligned holes is common. Further, the drill may pitch and yaw during drilling, thereby resulting in an oversized hole. Alignment jigs can be effective in assisting with maintaining perpendicularity of the drill bit with a supporting surface. However, alignment jigs are typically customized for the shape, topography, and desired hole location of one particular surface and are thus not functional with surfaces having a different shape, topography, or desired hole location. Further, alignment jigs may rely on proper alignment and stabilization by assembly personnel as the hole is being drilled. Additionally, during the assembly of aircraft or other structures, many different types of subassemblies must be attached to a supporting substrate which would require different alignment jigs of varying designs, and thus the use of customized alignment jigs is not practical. 
         [0006]    A tool that assisted with reliably drilling vertical holes through surfaces having different surface shapes and topographies would be desirable. 
       SUMMARY 
       [0007]    The following presents a simplified summary in order to provide a basic understanding of some aspects of one or more embodiments of the present teachings. This summary is not an extensive overview, nor is it intended to identify key or critical elements of the present teachings, nor to delineate the scope of the disclosure. Rather, its primary purpose is merely to present one or more concepts in simplified form as a prelude to the detailed description presented later. 
         [0008]    In an embodiment, a drill block can include a mounting leg for mounting the drill block, a drilling support leg having a round hole therethrough operable to receive a drill bit during a drilling operation, and a height variability leg interposed between the mounting leg and the drilling support leg, wherein the height variability leg is adjustable to select a vertical height of the drilling support leg relative to the mounting leg. The drill block may further include a first swivel leg attached to the mounting leg and the height variability leg, wherein the first swivel leg is adjustable to select a first horizontal placement of the drilling support leg, and a second swivel leg attached to the height variability leg and the drilling support leg, wherein the second swivel leg is adjustable to select a second horizontal placement of the drilling support leg. In an embodiment, the drill block may further include a first fastener that extends through the mounting leg and the first swivel leg, wherein the first fastener is configured to be loosened to adjust the first swivel leg to position the drilling support leg, and is further configured to be tightened to secure the first swivel leg to the mounting leg, and may further include a second fastener that extends through the first swivel leg and the height variability leg, wherein the second fastener is configured to be loosened to adjust the height variability leg to position the drilling support leg, and is further configured to be tightened to secure the height variability leg to the first swivel leg. The drill block may further include a third fastener that extends through the height variability leg and the second swivel leg, wherein the third fastener is configured to be loosened to adjust the height variability leg to position the drilling support leg, and is further configured to be tightened to secure the height variability leg to the second swivel leg. The drill block may also include a fourth fastener that extends through the second swivel leg and the drilling support leg, wherein the fourth fastener is configured to be loosened to adjust the drilling support leg and is further configured to be tightened to secure the drilling support leg to the second swivel leg. In an embodiment, the drill block may include at least one drill bushing including the round hole therethrough operable to receive the drill bit during the drilling operation and an elongated cavity through the drilling support leg, wherein the elongated cavity through the drilling support leg is configured to receive the drill bushing during the drilling operation, and may include an elongated cavity through the mounting leg and a main mounting bolt, wherein the elongated cavity is configured to receive the main mounting bolt during the drilling operation. 
         [0009]    In another embodiment, a method for drilling a hole through a workpiece can include attaching a mounting leg of a drill block to the workpiece, loosening a first fastener that attaches a first swivel leg to the mounting leg, and adjusting a horizontal position of a drilling support leg by swiveling the first swivel leg on the first fastener, then tightening the first fastener to secure the first swivel leg to the mounting leg. The method can further include loosening a second fastener that attaches the first swivel leg to a height variability leg, and adjusting a vertical position of the drilling support leg by pivoting the height variability leg on the second fastener, then tightening the second fastener to secure the height variability leg to the first swivel leg. The method may further include loosening a third fastener that attaches a second swivel leg to the height variability leg, adjusting the vertical position of the drilling support leg by pivoting the second swivel leg on the third fastener, then tightening the third fastener to secure the second swivel leg to the height variability leg. An embodiment may include loosening a fourth fastener that attaches the second swivel leg to the drilling support leg, and adjusting a horizontal position of a drilling support leg by swiveling the second swivel leg on the fourth fastener, then tightening the fourth fastener to secure the drilling support leg to the second swivel leg. Additionally, the method may include positioning a drill bushing within an elongated cavity in the drilling support leg, placing a drill bit within a round hole in the drill bushing, and drilling a hole in the workpiece with the drill bit within the round hole in the drill bushing. An embodiment may further include aligning a component including a preformed reference hole to the workpiece, adjusting the horizontal position and the vertical position of the drilling support leg to position the round hole in the drill bushing with the preformed reference hole and, with the round hole in the drill bushing positioned over the preformed reference hole, placing the drill bit within the reference hole and drilling the hole in the workpiece. In an embodiment, the reference hole may be a first reference hole and the hole in the workpiece may be a first hole in the workpiece, and the method can further include placing a temporary fastener through the first reference hole and the first hole in the workpiece to secure the component to the workpiece, repositioning the drill block using a method including loosening at least one of the first fastener, the second fastener, the third fastener, and the fourth fastener to position the round hole in the drill bushing over a second reference hole, after repositioning the drill block, tightening at least one of the first fastener, the second fastener, the third fastener, and the fourth fastener, and placing the drill bit within the round hole in the drill bushing, and drilling a second hole in the workpiece with the drill bit through the second reference hole 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The accompanying drawings, which are incorporated in, and constitute a part of this specification, illustrate embodiments of the present teachings and, together with the description, serve to explain the principles of the disclosure. In the figures: 
           [0011]      FIG. 1  is a side view, and  FIG. 2  is a top view, of a drill block in accordance with an embodiment of the present teachings; and 
           [0012]      FIGS. 3 and 4  are perspective depictions of a drill block in accordance with an embodiment of the present teachings during use. 
       
    
    
       [0013]    It should be noted that some details of the FIGS. have been simplified and are drawn to facilitate understanding of the present teachings rather than to maintain strict structural accuracy, detail, and scale. 
       DETAILED DESCRIPTION 
       [0014]    Reference will now be made in detail to exemplary embodiments of the present teachings, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
         [0015]    As discussed above, drilling a perpendicular hole through a substrate is difficult to perform, even with the use of preformed reference holes through the subassembly that is being attached to the substrate. Assembly personnel may attempt to maintain the drill bit in a vertical position without any mechanical aid other than the reference holes through the subassembly, which is inaccurate, or an alignment jig may be used, but an alignment jig must be tailored for the topography of the subassembly that is being attached to the substrate. 
         [0016]    A drill block according to an embodiment of the present teachings can be used to drill a vertical hole reliably and accurately through a substrate. Additionally, the drill block can be set into a number of different configurations to enable its use with subassemblies having different topographies. 
         [0017]      FIG. 1  is a side view, and  FIG. 2  is a top view, of a drill block  100  according to an embodiment of the present teachings. In this embodiment, the drill block  100  may include a mounting leg  102 , a first swivel leg  104  rotatably secured to the mounting leg  102  with a first fastener  106 , a height variability leg  108  hinged with, and movably secured to the first swivel leg  104  with a second fastener  110 , a second swivel leg  112  hinged with, and movably secured to, the height variability leg  108  with a third fastener  114 , a drilling support leg  116  movably secured to the second swivel leg  112  with a fourth fastener  118 , one or more drill bushings or drill guides  120  each having a round hole  134  therethrough that receives a drill bit (not depicted for simplicity), and a main mounting bolt  122  that may be secured to the mounting leg  102  with a wing nut  124 . 
         [0018]    The first fastener  106  may be a bolt, quick release skewer, etc., that may be loosened such that the first swivel leg  104  may rotate back and forth within a groove or slot  126  in the mounting leg  102  and tightened to secure the first swivel leg  104  within the groove  126  and onto the mounting leg  102 . The first fastener  106  may include a grooved or knurled surface to facilitate hand tightening, or a slotted recess to facilitate tightening with a tool such as a hex key or star key. In an embodiment, the first swivel leg  104  may swivel or pivot horizontally within the groove  126  through about 175°, depending on the design. 
         [0019]    The second fastener  110  and third fastener  114  may each be bolts, quick release skewers, etc. The second fastener  110  attaches a first end of the height variability leg  108  to the first swivel leg  104  and the third fastener  114  attaches a second end of the height variability leg  108  to the second swivel leg  112 . The second fastener  110  may be loosened to allow the height variability leg  108  to pivot on the second fastener  110  and tightened to secure the height variability leg  108  to the first swivel leg  104 . The third fastener  114  may be loosened to allow the second swivel leg  112  to pivot on the third fastener  114  and tightened to secure the second swivel leg  112  to the height variability leg  108 . The second fastener  110  and the third fastener  114  may each include grooved or knurled surfaces to facilitate hand tightening, or a slotted recess to facilitate tightening with a tool such as a hex key or star key. In an embodiment, the height variability leg  108  may swivel or pivot on the second fastener  110  through 180° or more, and the second swivel leg  112  may pivot on the third fastener  114  through 180° or more, depending on the design. 
         [0020]    The second swivel leg  112  may be positioned within a groove or slot  128  in the drilling support leg  116 . The fourth fastener  118  may be a bolt, quick release skewer, etc., that may be loosened such that the drilling support leg  116  may rotate back and forth within the groove  128 . Further, the fourth fastener  118  may be tightened to secure the second swivel leg  112  within the groove  128  and to secure the drilling support leg  116  to the second swivel leg  112 . The second fastener  118  may include a grooved or knurled surface to facilitate hand tightening, or a slotted recess to facilitate tightening with a tool such as a hex key or star key. In an embodiment, the drilling support leg  116  may swivel or pivot horizontally through about 175°, depending on the design. 
         [0021]    The main mounting bolt  122  may be placed through an elongated hole or cavity  130  that extends through the mounting leg  102 . The one or more drill bushings  120  may be placed into an elongated hole or cavity  132  that extends through the drilling support leg  116 . 
         [0022]    The drill block  100  may be used during a drilling operation to drill one or more holes into or through a workpiece such as a substrate. In the exemplary depiction of  FIG. 3 , the drill block  100  may be used to attach a component  300  such as a stiffening component to a substrate  302  such as a composite skin of an aircraft. In this embodiment, a frame structure  304  has been attached to the substrate  302 , and an edge  306  of the frame structure  304  may be used as an alignment aid to attach the component  300 . The component  300  may have one or more predrilled reference holes  308 . 
         [0023]    To attach the component  300 , the drill block  100  is attached to the substrate  302  and to the frame structure  304  by inserting the shaft of the main mounting bolt  122  through the elongated cavity  130  in the mounting leg  102  and through a hole  310  in the frame component  304  and the substrate  302 . The main mounting bolt  122  may be secured with the wing nut  124  on the opposite side of the substrate  302 . During the attachment of the drill block  100  to the substrate  302 , the elongated cavity  130  allows the position of the mounting leg to be adjusted rotationally and laterally (back and forth) to work around any surface features that may otherwise prevent positioning of the drill block  100 . 
         [0024]    Either before or after attachment of the drill block  100  to the substrate  302 , the component  300  may be positioned on the substrate  302 . In this embodiment, an edge  312  of the component  300  may be placed against the reference edge  306  of the frame structure  304  to properly orient the frame structure  304  relative to the substrate  302 . The component  300  may be held in place using, for example, a clamp or other temporary attachment (not individually depicted for simplicity). 
         [0025]    Next, the drill block  100  and drill bushing  120  are adjusted so that the hole  134  through the drill bushing  120  is aligned over one of the reference holes  308  in the component  300 . Adjustment of the drill block  100  may be performed by loosening each of the fasteners  106 ,  110 ,  114 , and  118 , and pivoting the first swivel leg  104  and the second swivel leg  112 , and adjusting the height of the drilling support leg  116  by pivoting the height variability leg  108  on the second fastener  110  and the third fastener  114 . A surface  314  of the drilling support leg  116 , such as a flat lower surface, rests on a surface, such as a flat surface, of the component  300 . The elongated cavity  132  which receives the drill bushing  120  allows the position of the drill bushing  120  to be adjusted in a horizontal direction, thereby improving adjustability of the drill bushing  120  and drill block  100  to work around any surface features that may otherwise prevent positioning of the drill block  100 . A drill bit  316  may be positioned through the hole  134  in the drill bushing  120  and into the reference hole  308  to properly align the hole  134  in the drill bushing  120  with the reference hole  308 . 
         [0026]    Once the drill bushing  120  is properly positioned over the component  300 , for example, over one of the reference holes  308 , each of the first fastener  106 , the second fastener  110 , the third fastener  114 , and the fourth fastener  118  are tightened to secure the aligned position of the drill block  100 . 
         [0027]    Subsequently, a drill bit  316  attached to a drill (not individually depicted for simplicity) is placed through the hole  134  in the drill bushing  120 , and is used to drill a hole into or through the substrate  302 . During a drilling operation, the drill bushing  120  rests on an upper surface of the drilling support leg  116 . The drill bushing  120  may be secured manually during the drilling to prevent any back and forth movement within the elongated cavity  132 , while a relatively tight tolerance of the drill bushing  120  within the elongated cavity  132  prevents side-to-side movement. To or more drill bushings  120  may be used to drill successively larger holes until a hole  400  ( FIG. 4 ) of a desired size is formed into or through the substrate  302 .  FIG. 4  depicts the reference hole  308  prior to drilling, and the completed hole  400  after drilling, in phantom. 
         [0028]    After the hole  400  is drilled into or through the substrate  302 , the component  300  may be permanently secured to the substrate  302  using a bolt or other fastener, or the component  300  may be temporarily secured using, for example, a blind grip fastener  402  such as an alignment cleco. Any other fastener such as a clamp used to temporarily secure the component  300  to the substrate  302  may be removed to permit access to other drill locations, or left in place if it does not obstruct access to the other drill location. 
         [0029]    If additional holes are to be drilled, one, some, or all of the fasteners  106 ,  110 ,  114 , and  118  and main mounting bolt  122  may be loosened as necessary or desired to permit readjustment of the drill block  100  and, particularly, the drill bushing  120 , to another hole location. 
         [0030]    When placed in a flat with surface  314  of the drilling support leg  116  level or coplanar with a surface with a surface  318  of the mounting leg, the drill block  100  may have a length of from, for example, about 6.0 inches to about 9.0 inches, or about 7.0 inches. The drill block  100  may further have a height of from about 1.0 inch to about 2.0 inches, for example, about 1.25 inches (excluding bolt  122 , wing nut  124 , and fasteners  106 ,  118 ). Additionally, the drill block  100  may have a width of from about 0.75 inches to about 1.25 inches, for example, about 1.0 inch. The drill block  100  may thus have a compact size that can fit within tight or enclosed spaces and around obstructions. It will be appreciated that a drill block  100  according to the present teachings may have other dimensions outside of these stated ranges, depending on the design and intended use of the drill block  100 . 
         [0031]    The drill block may be manufactured from one or more materials, including, for example, a metal or metal alloy such as stainless steel or aluminum, or a synthetic polymer. Different subassemblies of the drill block may be manufactured from different materials. It will be appreciated that the FIGS. are schematic depictions, and a drill block in accordance with an embodiment may include other elements that are not depicted for simplicity, while depicted elements may be removed or modified. 
         [0032]    As depicted in  FIG. 1 , the first swivel leg  104  is attached to, and interposed between, the mounting leg  102  and the height variability leg  108 , and the second swivel leg  112  is attached to, and interposed between, the height variability leg  108  and the drilling support leg  116 . The first swivel leg  104 , the height variability leg  108 , and the second swivel leg  112  are each interposed between the mounting leg  102  and the drilling support leg  116 , and the height variability leg  108  is interposed between the first swivel leg  104  and the second swivel leg  112 . 
         [0033]    The drill block according to the present teachings may thus include a swivel head and height adjuster that may enable an assembly personnel to fasten the drill block to the existing structure, align the drill block guide over the hole to be drilled, and drill a vertical hole that is 90° or perpendicular to the surface being drilled. The drill block is thus configurable to lift the drilling support leg  116  to the height level of the component  300  being drilled while also swiveling to maneuver around obstructions from supporting panels and other structures that are on, or a part of, the substrate  302 . The first swivel leg  104  may be swiveled on the first fastener  106 , and the second swivel leg  112  may be swiveled on the fourth fastener  118 , to adjust a horizontal position of the drilling support leg  116 . The height variability leg  108  may be pivoted on the second fastener  110  and the third fastener  114  to adjust a vertical position of the drilling support leg relative to the mounting leg  102 . In some implementations, the drill block may be only slightly larger than the drill hole, and the drill block may fit between structures and into small spaces where prior alignment jigs could not, thus enabling faster, more precise drilling and decreased rework and manufacturing costs. 
         [0034]    Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the present teachings are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all sub-ranges subsumed therein. For example, a range of “less than 10” can include any and all sub-ranges between (and including) the minimum value of zero and the maximum value of 10, that is, any and all sub-ranges having a minimum value of equal to or greater than zero and a maximum value of equal to or less than 10, e.g., 1 to 5. In certain cases, the numerical values as stated for the parameter can take on negative values. In this case, the example value of range stated as “less than 10” can assume negative values, e.g. −1, −2, −3, −10, −20, −30, etc. 
         [0035]    While the present teachings have been illustrated with respect to one or more implementations, alterations and/or modifications can be made to the illustrated examples without departing from the spirit and scope of the appended claims. For example, it will be appreciated that while the process is described as a series of acts or events, the present teachings are not limited by the ordering of such acts or events. Some acts may occur in different orders and/or concurrently with other acts or events apart from those described herein. Also, not all process stages may be required to implement a methodology in accordance with one or more aspects or embodiments of the present teachings. It will be appreciated that structural components and/or processing stages can be added or existing structural components and/or processing stages can be removed or modified. Further, one or more of the acts depicted herein may be carried out in one or more separate acts and/or phases. Furthermore, to the extent that the terms “including,” “includes,” “having,” “has,” “with,” or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term “comprising.” The term “at least one of” is used to mean one or more of the listed items can be selected. As used herein, the term “one or more of” with respect to a listing of items such as, for example, A and B, means A alone, B alone, or A and B. The term “at least one of” is used to mean one or more of the listed items can be selected. Further, in the discussion and claims herein, the term “on” used with respect to two materials, one “on” the other, means at least some contact between the materials, while “over” means the materials are in proximity, but possibly with one or more additional intervening materials such that contact is possible but not required. Neither “on” nor “over” implies any directionality as used herein. The term “conformal” describes a coating material in which angles of the underlying material are preserved by the conformal material. The term “about” indicates that the value listed may be somewhat altered, as long as the alteration does not result in nonconformance of the process or structure to the illustrated embodiment. Finally, “exemplary” indicates the description is used as an example, rather than implying that it is an ideal. Other embodiments of the present teachings will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the present teachings being indicated by the following claims. 
         [0036]    Terms of relative position as used in this application are defined based on a plane parallel to the conventional plane or working surface of a workpiece, regardless of the orientation of the workpiece. The term “horizontal” or “lateral” as used in this application is defined as a plane parallel to the conventional plane or working surface of a workpiece, regardless of the orientation of the workpiece. The term “vertical” refers to a direction perpendicular to the horizontal. Terms such as “on,” “side” (as in “sidewall”), “higher,” “lower,” “over,” “top,” and “under” are defined with respect to the conventional plane or working surface being on the top surface of the workpiece, regardless of the orientation of the workpiece.