Patent Abstract:
Embodiments of a sheath for a pointed tool are described, which tool may be a combination string/chalk line anchor and plumb bob. The sheath includes a cavity for housing the pointed needle or spike that extends out from the combination tool, and a cavity for at least partially encircling the body of the tool. A locking mechanism is included to secure the tool in the sheath until removed is desired. The sheath may include a system for attaching it to a chalk box, and a slot defining an exit-point for string line to extend out from the sheath to the chalk box or other container or spool.

Full Description:
[0001]    This application is a continuation-in-part of, and claims priority from, U.S. patent application Ser. No. 09/847,614, filed on May 2, 2001, entitled “A Combined String Line Anchor and Plumb Bob,” the disclosure of which is incorporated herein by this reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This invention relates generally to construction and carpentry equipment and tools, and more particularly to anchoring devices for string/chalk lines and/or to plumb bobs. In particular, this invention relates to a protector and holder for a pointed, multifunction tool that serves both as a chalk line anchor and as a plumb bob.  
           [0004]    2. Related Art  
           [0005]    In building construction and carpentry projects, alignment strings and chalk lines are frequently used to confirm or establish straight lines. Such string or line systems have one portion that serves to store the unused portion of the string, e.g. a simple ball of string or, as is often the case, a reel of some sort to pay-out and pay-in the line. The other “free” end of the line is usually held by an assistant or anchored by a mechanical device. Such mechanical devices typically include a nail, an awl, or a stickpin, for example. Frequently, commercial chalk lines include an L-shaped hook with an eyelet tied to the line&#39;s free end. The hook is used to anchor the line over the edge of a workpiece. After the chalk line is properly positioned, the line is plucked near its center to cause a chalk mark to be left on the surface of the underlying material.  
           [0006]    All of the above-mentioned anchoring devices see considerable use at construction job sites. The stickpin is one of the more commonly-used string line anchoring devices. These pins are about the size of an adult finger and have the general shape of the body of a dart (without feathers). The forward end of the stickpin, as in a dart, includes a highly sharpened needle like point. In use, the string is tied around an annular groove in the stickpin, the pin is pressed by hand into the work surface and the line is then looped around the needle portion immediately adjacent to the work surface. The other end of the line is then pulled to tighten the string against the stickpin. The needle portion of the stickpin is typically formed from a high strength steel so that it may be pushed by hand, without damaging the point, into a variety of non-metallic materials, such as wood, plywood, sheet-rock, etc.  
           [0007]    Plumb bobs are also frequently used by carpenters and other construction industry professionals. As is well known, a plumb bob is used to determine the “plumbness” or verticality of a wall, stud column, etc. It also is used to vertically transfer a point at one elevation to another elevation.  
           [0008]    In laying out construction projects, plumb bobs are frequently used in concert with string lines and chalk lines. The instant inventor has previously invented combined string line anchor and plumb bob tools, such as in U.S. Pat. No. 5,720,113 (issued Feb. 24, 1998) and in the application from which this application claims priority, Combined String Line Anchor and Plumb Bob, Ser. No. 09/847,614. These tools integrate features of a string/chalk line stickpin anchoring device and a plumb bob, to increase the efficiency of the carpenter and reduce overall expenses to the project.  
           [0009]    In U.S. Pat. No. 5,720,113 (“&#39;113”), the multi-function tool has a point at its distal end, and a recess and clamping system for mounting on the tool an L-shaped hook of the type conventionally used for attaching a string line over an edge of a work-piece. The &#39;113 tool includes a channel through the proximal end of the tool so that the string line may extend out of the tool at the axial centerline, and a cap on the proximal end that may be removed to reveal the channel, and may be tightened onto the tool to move a slidable jaw to hold the hook in place in the tool.  
           [0010]    The tool of Ser. No. 09/847,614 (“&#39;614”) includes an external channel system through which the string line may extend to exit the tool at the axial centerline of the tool. In addition, the &#39;614 tool includes an adjustable pointed spike that may be moved axially to protrude various amounts out from the body of the tool. This adjustability feature allows the tool body to serve as a fixed stop for the insertion of the needle into materials of differing hardness so that the sharpened spike is not inserted into the wood or other material farther than is needed to satisfactorily anchor the string. Also, the adjustability feature reduces the risk of breaking the point when it is inserted too far. If the sharpened spike is broken, it may be removed from the tool and replaced with another adjustable spike, further increasing the efficiency of the carpenter and decrease his/her equipment costs.  
           [0011]    Thus, the integrated string line anchoring device and a plumb bob provides a simple, but useful, economical, and efficient tool that is reusable and effective for a long period of time. As a means of protecting the tool and preventing dulling or breakage of the tool point, and preventing injury by the tool point, a cover or sheath for the tool is needed. The instant invention meets this need, in an effective, economical, and easily-used sheath that allows the tool to be safely and comfortably carried in a tool box, on a chalk box, or by other means.  
         SUMMARY OF THE INVENTION  
         [0012]    This invention comprises a sheath for a pointed tool, such as a combination string line anchor and a plumb bob. The sheath serves as a cover for the point of the tool, a protector for the tool in general, and a system for connecting/mounting the covered tool on a chalk box or other container or workplace item. In this Description and in the claims, the terms “string line” or “string” includes strings, cables, cords, strips, lines, or other elongated flexible members for attachment to the tool, and used with or without chalk or other materials and substances. In the Description and in the claims, the term “pointed spike” includes the preferred needle-like member, but also may be other sharpened elongated members.  
           [0013]    The sheath is generally elongated and comprises an internal cavity with a spike-receiving portion for receiving the distal (forward) end of the tool including the pointed needle or spike, and a body-receiving portion for receiving the central body of the tool. The sheath also includes a lock system that secures the tool in the sheath until the user purposely releases the lock to remove the tool. The sheath preferably includes a base with a generally planar outer surface for resting on an object or for attachment to a chalk box or other surface. The sheath preferably includes a slot for the string line that allows the string line to exit the sheath to extend to a chalk box or a take-up reel and that helps prevent tangling of the string line.  
           [0014]    By inserting and locking the tool in the invented sheath, the point of the tool is much less likely to become dull or broken from abrasion or impact by nails, other tools, or other objects in a tool box, nail box, or vehicle bed, for example. Also, when the sheath covers the point, the tool is unlikely to hurt people, animals, or materials and surfaces. With the tool secured via the sheath to a chalk box, for example, the tool is easily located when needed and is kept close to the equipment with which it is normally used.  
           [0015]    A preferred feature of the sheath is that it is sized and shaped in such a way that the tool will not fit or lock into the sheath if the point spike or needle of the tool extends out from the tool beyond a certain length. This way, the sheath may be designed to cooperate only with a tool that has a spike sized or adjusted to what may be considered a relatively safe length.  
           [0016]    These and many other features and attendant advantages of the invention will become apparent as the invention becomes better understood by reference to the following detailed descriptions and accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    [0017]FIG. 1 is a rear perspective view of one embodiment of the invented sheath.  
         [0018]    [0018]FIG. 2 is a front perspective view of the sheath of FIG. 1, with one embodiment of a combined anchor and plumb bob tool inserted and locked into the sheath.  
         [0019]    [0019]FIG. 3 is a rear perspective view of the sheath of FIGS. 1 and 2, with the tool of FIG. 2 distanced from the sheath.  
         [0020]    [0020]FIG. 4 is a rear perspective view of the sheath of FIGS.  1 - 3 , with the tool of FIGS. 2 and 3 inserted and locked into the sheath.  
         [0021]    [0021]FIG. 5 is a rear perspective view of the sheath of FIGS.  1 - 4 , attached to a top surface of a carpenter&#39;s chalk box.  
         [0022]    [0022]FIG. 6 is a rear perspective view of the sheath of FIGS.  1 - 5 , attached to a side surface of the carpenter&#39;s chalk box.  
         [0023]    [0023]FIG. 7 is a top view of the sheath of FIGS.  1 - 6 .  
         [0024]    [0024]FIG. 8 is a side view of the sheath of FIGS.  1 - 7 .  
         [0025]    [0025]FIG. 9 is a bottom view of the sheath of FIGS.  1 - 8 .  
         [0026]    [0026]FIG. 10 is a side, cross-sectional view of the sheath of FIGS.  1 - 9 , with the tool of FIGS.  2 - 6  shown in cross-section in the sheath.  
         [0027]    [0027]FIG. 11 is rear perspective view of the sheath of FIGS.  1 - 10 , at an angle that allows viewing deep into the tool-receiving cavity of the sheath.  
         [0028]    [0028]FIG. 12 is an alternative embodiment of a combined anchor tool and plumb bob that may be used with an embodiment of the invented sheath. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0029]    Referring to the Figures, there is shown one, but not the only, embodiment of the invented sheath for a pointed tool. In particular, the preferred sheath is adapted to receive, cover, and protect a combination string line anchor and plumb bob tool. While various combination string line anchor and plumb bob tools may be used in the invented sheath, the preferred tool is shown in the Figures as the type described in U.S. Pat. No. 5,720,113 by the present inventor. The combination anchor and plumb bob tool described in U.S. patent application Ser. No. 09/847,614 and portrayed in this application&#39;s FIG. 12, or other tools with pointed tips, may also be used with various embodiments of the invented sheath, wherein some adaptation may be made to the sheath or to the tool so that the sizes and lengths of the cavities in the sheath are appropriate and so that the locking system of the sheath catches properly on a recess or protrusion of the tool.  
         [0030]    In FIG. 1, there is shown the preferred sheath  10 , in an empty state. The sheath  10  comprises a cavity wall  12  with a front portion  11  and a rear portion  13 , wherein the cavity wall  12  surrounds and defines an interior cavity. The interior cavity comprises a forward cavity portion  14  at the sheath front end (distal end)  15 , a rearward cavity portion  16  generally central between the front end  15  and the sheath rear end (proximal end)  17 , and an opening  18  into the interior cavity at the rearward cavity portion. Forward and rearward cavity portions  14 ,  16  and opening  18  preferably lie in series coaxially on the sheath longitudinal centerline or “longitudinal axis.” The forward cavity portion  14  is adapted to receive the pointed end of the tool  50 , particularly, the portion of the pointed spike  52  protruding from the tool body  54 . The rearward cavity portion  16  is adapted to receive the forward end of the tool body  54  so that the generally conical surface  56  of the tool abuts against the front, inside surface of the rearward cavity, herein also called the limiting surface  20 . This surface  20  serves as a stop to limit forward movement of the tool, so that the tool may only be inserted to a certain extent, no matter how small a distance the pointed spike  52  extends from the body  54 . The limiting surface  20  results in a certain location for the tool body  54  along the longitudinal axis of the sheath, which certain location is preferably the proper location for locking of the tool in the sheath by the preferred locking system  40 , as further discussed below. In embodiments in which the spike  52  is adjustable in and out from the body, this limiting surface feature is beneficial as it prevents a tool from being placed in the sheath with the spike  52  extended far outward from the body. While the preferred limiting surface  20  and cooperating tool surface  56  are described as generally conical, they may also be called “conoidal” or “bullet-shaped” as their conical walls are curved as in a conventional bullet shape. Alternatively, other cooperating/mating shapes may be used, which preferably do not allow “wiggle” or “rattling” of the tool in the sheath.  
         [0031]    When the tool is inserted into the sheath and locked into place with the generally conical surface  56  against the limiting surface  20 , there is preferably only ⅝ inch of distance from the front tip  60  of the tool body to the forward inner surface  22  of the forward cavity portion  14 . This way, only a maximum of ⅝ inch of spike  52  may protrude from the tool if the tool is to fit in, and lock into, the sheath  10 . A protruding spike length of ⅝ inch is sufficient for nearly all construction materials, and the inventor believes that this adjustment is useful as well as safe, if handled in a reasonable way. With the sheath being designed for this maximum spike protrusion length, the tool is more likely to remain in the relatively safe ⅝ inch maximum spike configuration, so that it is less likely to be used in an unsafe way. If the spike  52  is adjusted outward farther than ⅝ inch, the tool will no longer fit into the preferred sheath  10 . If the spike  52  is adjusted inward to less than ⅝ inch, then the tool may be even safer, and the tool will fit and lock properly into the sheath.  
         [0032]    The limiting surface  20  also serves to stabilize the tool inside the sheath, due to the generally conical shape of the surface  20  corresponding to the generally conical surface  56  of the tool. The sheath conical surface  20  preferably curves at least about 200 degrees around the tool, and, more preferably, at least about 260 degrees. The embodiment shown in the Figures features a rearward cavity portion wall that extends about 280 around the tool. Once the tool is in place in the sheath, these closely adjacent and curved surfaces  20 ,  56  tend to prevent movement transverse to the longitudinal axis, and, most preferably, to prevent other than longitudinal movement of the tool in a rearward direction relative to the sheath.  
         [0033]    The forward cavity  14 , on the other hand, serves mainly to contain and cover the pointed spike, rather than to stabilize the tool by preventing movement of the tool. Preferably, the spike does not abut or stick into the inner surface  22 . The forward cavity exterior has a generally elongated shape of a smaller width and height than the rearward cavity portion  16 , with a curved top surface  28  and front surface  30 . The inner surface of the rearward cavity preferably transitions smoothly to the inner surface of the forward cavity, so that, during insertion of the tool, if the spike slides along the cavity interior surface, it slides smoothly and is, in effect, guided from the rearward cavity portion into the narrower forward cavity portion.  
         [0034]    The locking system  40  preferably automatically engages or sets when the tool  50  is inserted into the sheath  10 , and is released only manually when the user wishes to remove the tool. Preferably, the locking system  22  comprises a latch  41  that catches in a recess  62  in the tool body  54  when the tool slides into place against the limiting surface  20 . The latch is preferably biased into the closed position, that is, biased inward toward the center of the cavity, and, hence, toward the tool surface. The latch preferably “snaps” into the tool recess when the tool is properly in place in the sheath. This way, the tool is easily and conveniently sheathed, and yet is not easily accidently unlocked or dropped out of the sheath. The recess  62  into which the latch  41  snaps is preferably the recess in which the L-shaped hook (call-out  64  in this application) resides when captured in the tool as described in U.S. Pat. No. 5,720,113. The forward wall  65  of the recess  62  is the wall against which the latch abut, thus preventing rearward movement of the tool out of the sheath.  
         [0035]    When the user wishes to remove the tool from the sheath, he/she may actuate an unlatching means, such as a manual handle that lifts the latch  41  out of the recess  62 . The preferred lock mechanism comprises a lock member  43  that integrally connects to the top of the cavity wall at a connection region  44  (also called “hinge region”). The lock member  43  extends generally parallel to the longitudinal axis of the sheath above the top surface of the cavity wall  12 . From the connection region  44 , the lock member extends forward to form the handle  45  and rearward to form the latch  41 . The handle  45  extends in a forward direction generally parallel to the top surface  28  of the forward cavity wall, with the handle being distanced from the top surface  28 . Pressure on the handle  45  toward the top surface  28  causes the connection region and/or the cavity wall in that area to flex slightly, so that the lock member  43  pivots generally at the connection region  44  to raise the latch  41  up out of the recess  62 . Thus, the connection region may be considered a hinge, hinge region, or pivotal connection, as the connection region  44  acts to allow the lock member  43  to pivot relative to the rearward cavity wall portion  13 . Tool  50  can then be pulled longitudinally rearward outward of the sheath. When the pressure on the handle is released, the resiliency of the connection region and the cavity wall near region  44  returns the lock member  43  to its starting position, with the latch  41  biased toward the centerline of the sheath to be slightly closer to the centerline than is the inner surface of the rearward cavity portion at the rearward edge of the cavity wall, as best shown in FIG. 10. In effect, a fulcrum is created at or near the attachment of the lock member  43  to the sheath wall (“cavity wall”), allowing the lock member  43  to be biased into the latched position and to pivot to raise the latch into the unlatched position.  
         [0036]    One may note that the rear edge  46  of the cavity wall curves, from a position P 1  on the base  48  about ⅓ of the base length from the rear end  17 , upwards and forward to a position P 2 , which is about ⅔ of the base length from rear end  17  and which is forward from the latch end of the lock member. In other words, the lock member extends rearward beyond the rear edge  46  of the cavity wall, so that, in effect, the rearward latch end of the lock member extends rearward past the cavity wall, over the opening  18 , substantially unsupported by, and unconnected to, the cavity wall except at the connection region  44 . This way, the lock member connection region flexes more readily relative to the rest of the sheath, allowing the biased latching and handle-actuated unlatching described above.  
         [0037]    The lock member  43  is long enough and extends rearward enough that, when it is biased to pivot the latch end down toward the longitudinal axis of the sheath, the latch end preferably extends down in back of the opening. While the latch end does not necessarily extend into the plane of the opening itself, it may be said to extend “across the opening” when it is rearward and near to the opening.  
         [0038]    While various ways of attaching the lock member  43  to the cavity wall may be used, and various ways of forming the biasing means and the pivoting fulcrum may be used, the preferred ways comprise integral molding of the plastic lock member as part of the plastic sheath. This way, the natural resilience of the plastic of the sheath wall, and the lock member connection region may be used to create the biasing that latches the tool in place. Preferably, the sheath is made by molding plastic, preferably a plastic or plastics that are durable and that allow the hinge area (“connection region”) to be sufficiently flexible and resilient to properly operate the lock system. The plastic may be chosen and the thickness and shape of the lock bar attachment area and the adjacent cavity wall areas are chosen so that the flexing moves the latch upwards a sufficient distance to unlatch the tool. The biasing of the latch system into the closed, locked position against the tool wall may comprise the resilience of the plastic that moves the lock bar back into its original position when the handle is no longer being pressed.  
         [0039]    While the preferred recess  62  of the tool, into which protrudes the latch  41 , is the recess adapted to also receive the L-hook of the tool from U.S. Pat. No. 5,720,113, other recesses or fasteners for cooperating with a latch or lock on the sheath may be used. For example, an alternative recess, such as the thumb-hole recess of the tool in patent application Ser. No. 09/847,614, may be used, in which case the tool  80  thumb-hole recess  90  may be adapted to have a recess front wall  95  that is transverse to the longitudinal axis of the tool or slanted forward from the top of the wall to the bottom of the wall, so that the latch of the sheath “catches” on the recess wall.  
         [0040]    A slot through the cavity wall is preferably provided for passage of the string line from the interior cavity to outside the sheath. As shown in FIG. 3, the string line  47  is normally wrapped around or otherwise connected to the spike  52  when the tool is inserted into the sheath. The string line, therefore, extends rearward from the spike and out of the internal cavity through the slot  49 . Preferably, the slot  49  extends at its forward end to approximately the border between the forward cavity portion and rearward cavity portion, so that the string line  47  may exit the interior cavity without lying between the conical surface  56  of the tool body  54  and the limiting surface  20  of the internal cavity. This way, the string line  47  is not trapped or pinched between the conical surface  56  and the limiting surface  20 . The slot  49  is sized so that the string line  47  is not pinched or pressured to an extent that would, even after repeated sheathings, damage or weaken the string. After passing through the slot, the string line preferably extends into a chalk box  70  or is taken-up by other means, such as being wound on a spool or other object. By positively locating the string line&#39;s exit from the sheath and by containing/taking-up the length of the string line in a chalk box or other container or holder, tangling and knotting of the string line are minimized.  
         [0041]    As illustrated in FIGS. 5, 6 and  9 , the sheath  10  preferably is adapted for attachment to a chalk box  70  or other object, to further aid in preventing tangling of the string line and/or damage to the sheath and tool that might otherwise occur if the sheath and tool are stored or transported loose in a tool box or vehicle. The preferred adaptation comprises a base  48  positioned underneath the cavity wall that has a generally planar platform surface  72  upon which the sheath may rest. The base  48  includes means for attachment to the chalk box or other object, preferably, an aperture  74  for receiving a screw or bolt that may extend, for example, into an attachment hole  73  in the chalk box. The sheath  10  is preferably fastened by means of a screw (not shown) through the aperture  74  to a carpenter&#39;s chalk box  70 , either on a top surface  76  or on a side surface  78 . The string line extends from the slot  49  to the string line hole (not shown) in the chalk box  70  and preferably all of the length of the string line is contained within the chalk box until use of the tool and the string line. This way, the chance of tangles and damage to the string line and to the tool is minimized, and the tool is unlikely to be lost or to do damage to people or materials. Alternatively, the sheath  10  may be molded or otherwise formed as an integral part of a chalk box  70  or tool box, for example.  
         [0042]    Preferably, the base  48  is sized to provide a stable platform for the sheath. The base  48  preferably extends forward beyond the front portion  11  of the cavity wall to be the frontmost extremity of the sheath. The base  48  preferably extends rearward beyond the rear edge  46  of the rear portion  13  of the cavity wall to be the rearmost extremity of the sheath. Also, the base  48  extends transversely to the longitudinal axis to extend at least underneath, or out past, both sides of the sheath cavity wall.  
         [0043]    With the tool  50  housed in the sheath  10  attached to the chalk box  70 , the tool may be easily withdrawn from the sheath, as detailed above, by pressing on the handle  45  and pulling out the tool. Because the sheath is secured to the chalk box, the tool may be easily removed without the sheath tipping over or moving during the operation. The tool  50  may then be moved away from the chalk box  70  to pull the string line out of the chalk box, coated with chalk, for use. Use of the tool, either as an anchoring device for chalk line marking or as a plumb bob, may be done according to the techniques described in U.S. patent application Ser. No. 09/847,614, from which this application claims priority and which is incorporated herein, and/or described U.S. Pat. No. 5,720,113.  
         [0044]    The inventor envisions that other tools, and especially other combined anchor and plumb bob tools, may be used in the invented sheath. Some modification to the sheath may be necessary, for example, to lengthen or adapt the locking mechanism. Or, some modification to the tool may be necessary, for example, to supply a recess or other structure for cooperating with a locking system to retain the tool in the sheath.  
         [0045]    Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the scope of the following claims.

Technology Classification (CPC): 6