Abstract:
A axis alignment device has been provided which permits a laser beam to be precisely aligned with a gun bore whose axis is being projected, for the purpose of aligning an optical sight. The axis alignment tool&#39;s onepiece body inherently improves the accuracy of the design, while being adaptable to mate with a large variety of gun bore sizes. The alignment device includes a universal seating mechanism for mounting in a muzzle. A bore adapter fits over one end of the one-piece body and is adjusted to snugly fit inside the bore. The alignment devices is designed to operate with an array of bore adapters, that fit a corresponding array of bore diameters. The alignment device also includes a rotary switch which acts as a battery housing, so that batteries can be changed without the disassembly of the alignment device.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to a device which projects the axis of a bore, cylinder, or pipe and, more particularly, to an apparatus for aligning the bore of a gun for the purpose of calibrating the gun sights. 
     Several prior art devices exist for the operation of a laser sighting mechanism as a gun is actually fired. Once the laser is properly sighted, the laser-aided targeting scheme effectively increases a shooter&#39;s accuracy. Of course, a shooter must still account for the drop of a bullet as it loses velocity over distance, and for wind. However, a calibration process must first be performed which aligns the laser with the true alignment of the gun bore axis. This alignment process requires that several shots be fired so that the laser beam can be adjusted to alight on a target point that intersects the bullet path. Typically, the laser is used in conjunction with a conventional optical or iron sighting system. 
     Many other sighting systems exist which manage to co-align a laser beam with the gun bore axis. Then, the optical sighting system can be calibrated without the necessity of shooting, as the actual bullet path, excluding the effects of gravity and wind, can be clearly seen on a target surface. For these bore axis alignment systems to work properly, the laser must be supported so that the laser beam precisely aligns with the bore axis. 
     Some bore axis laser alignment systems build a laser into a simulated cartridge. However, the laser-cartridge does not always seat precisely, so that the bore alignment can be inaccurate. Further, different caliber laser-cartridges must be used for each different caliber gun which must be sighted. Each laser-bullet must also be independently powered. 
     Other alignment systems attempt to use a single laser for a variety of gun calibers, typically by loading an elongated laser alignment mechanism into the bore. To define a line, the laser alignment mechanism must be supported in at least two positions in the gun bore axis. The use of the muzzle is a logical point to both support and center the laser, and the body of a laser can easily be designed with a universal seating mechanism to seat in a variety muzzle diameters. Some seating mechanisms engage a tapered or conical body surface against the inside diameter of the bore. Other universal seating mechanisms form a ringlike trough to seat around the outside surface of the bore muzzle. A second support point is typically in the gun bore itself. This support point is especially critical if the first support point fits a number of bore sizes, so that it must be firmly lodged against the muzzle for proper centering of the alignment device. Thus, the problem with the second gun bore support mechanism is that it must fulfill the contradictory goals of precisely centering and seating the laser alignment device, while fitting a variety of bore diameters. 
     Prior art systems have solved this problem by making a laser alignment mechanism with detachable parts. A stem part of the laser mechanism, for insertion into the gun bore as the second support point, can be designed with a variety of diameters. Thus, a different diameter stem can be used for each diameter of gun bore that must be aligned. Although the laser and first (muzzle) support remains the same, a variety of stems must be maintained. As with the multiple laser-bullet solution, the number of parts required make it likely that some will be lost. Other systems reduce the number of parts by making the stem diameters deformable, so that one stem will fit in bores having very similar diameters. However, a variety of stem diameters are still required. 
     Even more critically, a system built of assembled parts can affect the accuracy of the laser alignment. A bore-mounted laser alignment system is not useful if the laser beam does not precisely follow the line of the bore axis. Even small differences between the alignment of the laser beam and the bore axis can seriously degrade accuracy in the process of optical sighting. Further, the error between the path of the laser beam and the actual bore axis increases as the distance between the gun and target increases. 
     Prior art systems typically comprise multi-piece housing which may include a laser, power supply, switch, and bore and muzzle support points. For the alignment system to work properly, the parts must be assembled in such a way that the laser beam is in consistent alignment with respect to the alignment device body axis, and that the alignment device body axis always match the bore axis. However, every part interface creates a potential laser beam alignment error. For example, if the system requires that the housing be disassembled to replace batteries, then the potential exists that the system will be misaligned every time the batteries are changed. Also, if the system requires the use of multiple stem-like parts to interface with a variety of bore diameters, then the possibility exists that the system will be misaligned every time a stem is changed. These errors can be reduced by producing parts to exacting tolerances, but rigid tolerance specifications increase the cost of the system. Alternately, the number of parts to be assembled can be minimized, but then the system may not be universal enough for use with all guns. 
     It would be advantageous if the axis of a bore or pipe could be sighted with a laser device, adaptable to fit into a wide variety of inside diameters. 
     It would be advantageous if a variety of guns, with different bore diameters, could be efficiently sighted, with the use of a single laser aligning device. 
     It would be advantageous if the number of parts interfaces in the alignment device could be minimized to reduce the source of potential errors and to minimize fabrications costs. To that end, a one-piece body, enclosing a laser would be effective. 
     It would be advantageous if the above-mentioned alignment process could be conducted in populated areas without firing a shot. Likewise, it would be advantageous if the axis sighting process could be conducted quickly. 
     SUMMARY OF THE INVENTION 
     Accordingly, an aligning device for projecting an axis is provided which can be used to align a gun&#39;s sights with the bore axis. The aligning device comprises a one-piece body to minimize the errors inherent in assembling multiple parts, as mentioned above. The body is elongated along an axis which is aligned with the gun bore axis. The body has a proximal end in which the laser is mounted and a distal end, which is inserted into the gun bore. Between the two ends is a universal seating mechanism to form a first contact region. It is called a universal seating mechanism because it seats the aligning device in a large range of bore diameters. 
     A bore adapter is attached to the body distal end. The outside diameter of the adapter forms a contact region with the inside diameter of the bore. The formation of the first and second contact regions by the universal seating mechanism and the bore adapter define the alignment of the body axis. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1 a  and  1   b  are side-views illustrating the present invention alignment device. 
     FIG. 2 illustrates the alignment device of FIG. 1 a  or  1   b  mounted in a cylinder or gun bore whose axis alignment is being projected. 
     FIGS. 3 a  and  3   b  illustrate the variable diameter feature of the bore adapter. 
     FIG. 4 illustrates an end view of bore adapter. 
     FIG. 5 illustrates a plurality of differently sized bore adapters. 
     FIGS. 6 a  and  6   b  are partial cross-sectional illustrations of the alignment device of FIGS. 1 a  or  1   b , depicting the first cylindrical cavity. 
     FIG. 7 is a partial cross-sectional view of the switch of FIG. 6 b.    
     FIG. 8 is a partial cross-sectional view of the body of FIG. 6 a.    
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 a  and  1   b  are side-views illustrating the present invention alignment device. The alignment device  10  includes a laser, mounted so that its beam is precisely aligned in the alignment device tool, and the device itself can be precisely aligned in the gun bore or cylinder whose axis is being projected. If either of the above-mentioned alignments is improper, it is unlikely that the laser beam will correctly align with the bore axis. 
     To that end, device  10  comprises a one-piece body  12  with a generally elongated shape along a body axis  14 . The body  12  has a proximal end  16  and a distal end  18 . At the proximal end  16  the body surface has a first diameter  20 , while at the distal end  18  there is a second diameter  22  which is less that the first diameter  20 . Between the proximal end  16  and distal end  18  is a conically-shaped universal seating mechanism  24 . 
     FIG. 2 illustrates the alignment device of FIG. 1 a  or  1   b  mounted in a cylinder or gun bore whose axis alignment is being projected. The universal seating mechanism  24  is tapered to form a first, ring-like contact region  26 , received in a gun muzzle or pipe end. The tapered surface of the universal mechanism  24  permit it to be interfaced with a large variety of inside bore diameters, from bores having an inside diameter  28  slightly less that the first diameter  20 , to an inside bore diameter slightly greater the second diameter  22  (see FIGS. 1 a and  1   b ). 
     Returning to FIGS. 1 a  and  1   b , alignment device  10  also comprises a bore adapter  30  which is attached to the distal end  18 . Bore adapter  30  has an adapter diameter  32 . As shown in FIG. 2, the bore adapter  30  forms a second, substantially ring-like contact region  34  with the bore inside diameter  28 . That is, the adapter diameter  32  is substantially the same as bore inside diameter  28 . The first contact region  26  and the second contact region  34  define the alignment of body axis  12 , and help ensure that the body axis  12  is aligned with the bore axis  36 . 
     FIG. 1 a  illustrates an aspect of the invention where distal end  18  is a conically shaped part of the one-piece body  12 . FIG. 1 b  illustrates a slightly different aspect of the invention where a conical shape is specifically formed into bore adapter  30 . Then, the shape of distal end  18  becomes less critical. In some aspects of the invention, distal  18  has a small chamfer to interface with the internal cone shape of the bore adapter  30  of FIG. 1 b . Note that once the bore adapter  30  of FIG. 1 b  is mounted on one-piece body  12 , the device of FIG. 1 b  functions the same as the device of FIG. 1 a.    
     FIGS. 3 a  and  3   b  illustrate the variable diameter  32  feature of the bore adapter  30 . The same size bore adapter  30  is shown in FIGS. 3 a  and  3   b . The bore adapter  30  includes deformable fingers, such as fingers  38  and  40 . Note that although only two fingers are shown in these figures, and four fingers are shown in figures described below, the invention is not limited to a specific number of fingers. The bore adapter fingers  38  and  40  sidably overlie body distal end  18 . A screw  42  is used to attach bore adapter  30  to distal end  18 . A screw head  44  captures bore adapter  30  and forces it against the distal end  18 , regardless of whether the distal end  18  is part of the one-piece body (FIG. 1 a ) or a bore adapter  30  with an internal cone shape is used (FIG. 1 b ). The adapter diameter  32  and the deformation of fingers  38  and  40  are responsive to the pressure, applied by the screw  42 , to the bore adapter  30 . Alternately stated, the fingers  38  and  40  are splayed to form differently sized adapter diameters  32 . In some aspects of the invention, as shown in FIGS. 3 a  and  3   b , the distal end second diameter  22  is tapered, with a smaller diameter at the extreme distal end  18 . This taper cooperates with the splayed fingers  38  and  40  to increase the adapter diameter  32  in response to pressure applied by the screw  42 . In this manner, the same bore adapter  30  can be used with a variety of similar inside bore diameters. 
     FIG. 4 illustrates an end view of bore adapter  30 . The particular bore adapter  30  shown in FIG. 4 has four fingers, fingers  38 ,  40 ,  46 , and  48 . The bore adapter  30  also includes a ring  50 , or some similar structure to accept the screw  42  (not shown) in a hole  52 . The fingers  38 ,  40 ,  46 , and  48  are axially disposed and attached to ring  50 . In other aspects of the invention, not shown, the ring  50  is only slightly larger than the screw hole  52 , and the fingers, where attached, are not perpendicular, but are more gradually bent into a position perpendicular to the ring  50 . 
     FIG. 5 illustrates a plurality of differently sized bore adapters  30 . As shown in FIGS. 3 a  and  3   b , the adapter diameter  32  can be varied with the use of screw  42 . However, to cover a wide range of bore inside diameters it may be more practical to provide a plurality of differently sized bore adapters  30 , which all have different nominal adapter diameters  32 , which each can be varied with adjustment screw  42 , as discussed above and shown in FIGS. 3 a  and  3   b . A user selects a bore adapter  30  with a diameter  32  that approximately conforms with the bore inside diameter, and then that specific adapter  30  is modified with screw  42  for an exact fit. Even without adjustment of screw  42 , the bore adapter  30  fits to conform with a large variety of bore inside diameters. 
     It should be noted that the bore adapter  30  is made out of a flexible material such as nylon or plastic. Even though the bore adapter is a moving part, it adds very little to the inaccuracy of the system since the bore adapter  30  generally conforms to the precision-formed device distal end  18  (FIG. 1 a ) or the bore adapter  30  has an internal cone shape (FIG. 1 b ) which remains substantially the same as adjustments are made to fit the alignment device  10  into a gun bore. 
     FIGS. 6 a  and  6   b  are partial cross-sectional illustrations of the alignment device  10  of FIG. 1 a  or  1   b , depicting the first cylindrical cavity. For clarity, FIG. 6 a  shows the first cavity  60  without components, while FIG. 6 b  shows the first cavity  60  with components. The first cavity  60  has an axis that is aligned with body axis  12 , and is located between the proximal end  16  and the, universal seating mechanism  24  (see FIG. 1 a ). As shown in FIG. 6 b , the first cavity  60  houses a light source  62 , typically a laser, an electrically conductive spring  64 , and a rotary switch  66 . The light source  62  is permanently mounted in the housing so that it need not be removed to change batteries or to make support adjustments. The light source  62  emits a beam that is alignment with the body axis  12 . The switch  66  is rotated to selectively connect the light source  62  to a power supply. As is explained below, the spring keeps switch  66  locked into a position, either on or off, and provides an electrical path to the laser light  62 . As is shown more clearly in FIG. 1 a , the body  12  includes a channel  70  formed between the body surface and the first cavity  60  to expose the switch  66 . The switch  66  can be accessed for rotation through channel  70 . 
     Also shown in FIGS. 6 a  and  6   b , the body proximal end  16  includes a second cylindrical cavity  68  connected to the first cavity  60 . The second cavity  68  is aligned with the body axis  12  to form an opening from which the light source beam is projected. 
     The first cavity  60  has a cavity diameter  72  (FIG. 6 a ). The switch  66  is a cylinder with a switch diameter  74  (see FIG. 6 b ) which is less than the cavity diameter  72 , so that switch  66  has the freedom to rotate. The switch  66  has an axis substantially aligned along the body axis  12 . The switch  66  rotates through the switch axis to selectively connect the power source to the light source  62 . 
     FIG. 7 is a partial cross-sectional view of the switch  66  of FIG. 6 b . The switch  66 , which is substantially shaped like a cylinder which has a “top”, or first outside surface  80  which is radially disposed around the switch axis  82 . The first surface  80  has a conductive area  84 . A conductive rod  84  is specifically shown, but other connection means could also be used. The first surface  80  also includes a cam  86 . 
     FIG. 8 is a partial cross-sectional view of the body  12  of FIG. 6 a . The first cavity  60  (see FIG. 6 a ) has a second surface  88  which interfaces with the switch first surface  80 , see FIG. 7, which is radially disposed around the body axis  12 . The second surface  88  includes a second conductive area  90 . An electrical connection is made between the body  12  and the switch  66  when the second conductive area  90  interfaces with the first conductive area  84  (FIG.  7 ). The second surface  88  also includes a channel, or recessed area  92 , represented as the area in the exterior ring which is not double cross-hatched. When the channel  92  receives the switch cam  86 , an electrical connection is made between first conductive area  84  and second conductive area  90 . Note, that the conductive areas are not limited to any special shape or placement on the surface for operation. For example, the conductive areas can be centered around the axis. When the cam  86  is not in the channel  92 , the first surface  80  and second surface  88  are forced apart, and no electrical connection is made. It should also be noted that the shapes of the cam  86  and the channel  92  are not limited merely to the depicted example. 
     Returning to FIG. 7, the switch  66  has a third outside surface  100  radially disposed around the switch axis  82 , having a third conductive area  101 . In the simpler aspects of the switch  66 , where the switch  66  operates as a passive electrical conductor, the third conductive area  101  can be a conductive rod, such as the depicted first conductive area  84 . In some aspects, the conductive rod passes all the way through switch  66  from the first surface  90  to the third surface  100 . Alternately, the switch can be a metal, such as aluminum, which is anodized or coated with an insulator, except for areas on the first surface  80  and third surface  100  which act as conductive areas  84  and  101 , so that the switch body  66  acts as a conductor. As explained in more detail below, the switch  66  acts as a battery housing in some aspects of the invention, and the third conductive area can be considered the battery terminal, the spring  64 , or the combination of battery and spring  64 . 
     Returning to FIG. 6 b , the first cavity  60  has a fourth surface  102  radially disposed around the body axis  12 , having a fourth conductive area which is not explicitly shown. The fourth surface can be a part of the body  12 , as is the second surface  88  (see FIG.  8 ). However, as depicted in FIG. 6 b  the fourth surface is actually the light source  62  electrical terminal. Also as shown, the electrically conductive spring  64  is substantially aligned along the body axis  12  between the third surface  100  and fourth surface  102  surfaces. Therefore, when the switch  66  is “on”, with the cam  86  being engaged with channel  92 , the second conductive area  90  is connected to the fourth conductive area  102  through the switch  66  and spring  64 . 
     In some aspects of the invention the power supply is housed elsewhere in the body  12  (not shown). The switch  66  acts as a selectively engagable passive conductor which completes an electrical circuit between the second conductive area  90  and fourth conductive area  102 , from a battery, to the light source, with the return ground path from the light source  62  being through the electrically conductant body  12 . However, in a preferred aspect of the invention the batteries are housed in the switch  66 . Since the switch  66  is already a moving part, and not involved in aligning the body axis  12  with the bore axis, the removal the switch  66  to replace batteries does not affect the accuracy of alignment device  10 . The switch  66  is easily removed through channel  70 . 
     As shown in FIG. 7, a number of “wristwatch” type batteries  110  are arranged end-to-end in a battery cavity  112 . The cavity  112  can also be designed to accommodate other battery styles. The battery  110 , or series combination of batteries  110  have a first polarity (+) connected to the switch&#39;s first conductive area  84  and a second polarity (−) connected to the switch&#39;s third conductive area  101 . In some aspects of the invention an axial plug  114 , with a center hole to admit spring  64 , seals the end of battery cavity  112   
     A laser alignment device, useful for sighting the true axis of a bore has been described. However, the device is also useful in civil engineering tasks, such as construction projects using pipe or tubing, in oil field pipe applications, large machine construction, or prefabricated housing. A unique rotary switch/battery housing combination has also been described. An example of a one-piece body and rotary switch has been provided as an example. However, the present invention is not limited to merely the depicted examples. Other variations and embodiments of the above-described invention will occur to those skilled in the art.