BACKGROUND OF THE INVENTION 
     The present invention relates to alignment devices for construction purposes and more specifically to a novel, portable, self-powered laser alignment device which can simultaneously generate plumb, square and level laser reference points. 
     Traditional instruments used to locate reference points on job sites, such as 3-4-5 triangles, plumb bobs, bubble vial levels, theodolites and transits, are time consuming and often require at least two individuals to obtain the locations of the desired reference points. These prior methods typically require specialized training to obtain accurate measurements. Laser diodes that can produce a linear light beam have been mounted to a leveled surface, to produce a horizontal line from which vertical or lateral measurements of objects or surfaces can be made. These laser devices only produce a single reference line and still require the laser to be leveled to obtain a true horizontal or vertical output beam. Other devices utilize a single diode in conjunction with reflective surfaces to divide up the laser beam creating multiple output beams. The division of a single beam weakens the output beams rendering them difficult to see in high light conditions, such as outdoors. These devices do not create bright output beams that allow the operator to simultaneously determine level, plumb, and square reference points. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a portable, self-powered laser alignment device which can simultaneously generate plumb, square and level laser reference points. The laser alignment device is comprised of a main body that is pendulously suspended in a housing. In the preferred embodiment, the main body is adapted to house five orthogonally oriented laser diodes that, when energized, produce five output beams that are orthogonal to adjacent beams to allow the operator to easily mark plumb, square and level reference points. The laser alignment device is self-leveling, which eliminates the time consuming calibration previously required for instrument setup. The movement of the main body is dampened by use of a magnetic dampening system that is comprised of a non-magnetic metallic plate that passes through a permanent magnetic field. 
     The housing of the laser alignment device contains the main body, the laser diodes, the dampening system and a power supply to energize the diodes. 
     These and other aspects of this invention are illustrated in the accompanying drawings and are more fully described in the following specification. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the laser alignment device of the present invention; 
     FIG. 2 is another perspective view partially broken away illustrating the left cover half and the internal components of the laser instrument of the present invention; 
     FIG. 3 is top view of the laser instrument of the present invention; 
     FIG. 4 is a side cross-sectional view of the laser instrument of FIG. 3, which is taken along line  4 — 4  as shown in FIG. 3; 
     FIG. 5 is another perspective view illustrating the internal components of the laser instrument of the present invention; 
     FIG. 6 is a side view of the laser instrument of the present invention; and 
     FIG. 7 is an exploded view of the laser instrument of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     For the purpose of promoting an understanding of the principles of the invention, references will be made to the embodiment illustrated in the drawings. Specific language will also be used to describe the same. It will, nevertheless, be understood that no limitation of the scope of the invention is thereby intended, such alterations and further applications of the principles of the invention illustrated herein being contemplated as would normally occur to one skilled in the art to which the invention relates. 
     The laser alignment device  10 , as illustrated in FIG. 1, is adapted to be positioned on a reasonably level and stable support surface and can simultaneously produce a plurality of beams having a perpendicular relationship with the other. The laser alignment device  10  is designed to be primarily used by the construction trade but may also be used by decorators or other individuals attempting to quickly and accurately determine level, plumb and square reference points. The preferred embodiment of the laser alignment device  10 , as illustrated in FIG. 2, is comprised of a housing  12 , a laser instrument  14 , a dampening system  16  and a pivot system  18  and is designed to produce five laser output beams. If, for certain operations, more or fewer than five beams are required, additional lasers can be added or subtracted as needed. 
     The housing  12  of the laser alignment device  10  is designed to contain the laser instrument  14 , the dampening system  16  and the pivot system  18  and is designed to seal out dust and moisture, as shown in FIG.  2 . The housing  12  is also designed as a bumper to help protect the internal components in the event the device  10  is bumped or dropped. The housing  12  includes a switch  22  that is used to power the unit on and off. The switch  22  is also used to activate a locking mechanism  24 , best shown in FIGS. 5 and 6, that prevents movement of the laser instrument  14  during transport. The housing  12 , as shown in FIG. 1, also includes openings  26  that contain lenses  28 , which allow laser generated light beams to pass through. The housing  12  further includes apertures  30  that permit access to weighted adjustment screws  32  used to balance the laser instrument  14 , as shown in FIG.  2 . Within the housing  12  is an adjustment wheel  33 , which allows the base portion  35  to be connected to the top portion  37  of the housing  12 . Also included in the housing  12  are bushings  39  adapted to allow for the passage of screws so the housing  12  can be fastened to a wall or other surface. The bushings  39  prevent the base portion  35  from deforming when the fastening screws are tightened. 
     The laser instrument  14  is positioned within the housing  12  and is designed to produce the desired orthogonal output beams. The laser instrument  14 , as shown in FIGS. 4-7, is comprised of a main body  34  and multiple laser diodes  36 A,  36 B,  36 C,  36 D and  36 E. Use of individual diodes creates brighter output beams, which produce highly visible reference points at much greater distances, in brighter light conditions. The diodes are arranged so that the light beams A, B, C, D and E emanating from the laser instrument are orthogonal to adjacent light beams, as shown in FIG.  5 . For purposes of explanation, when we use the term “orthogonal beams” we mean the resultant beams which lie in three planes which are orthogonal to each other. For example, a horizontal plane which passes through beams A, B and D is orthogonal to the vertical plane which passes through beams A, B, C and E. Furthermore, the vertical plane which passes through beams C, D and E is orthogonal to the plane which passes beams A and B. When we reference beams as being “adjacent” we mean output beams that are oriented within 90° of each other. For example, beam A is adjacent to beams C, D and E but is coaxial with beam B. The main body  34  includes a plurality of posts  38 ,  40 ,  42 ,  44 ,  46  and  48  that include chambers  37 A,  37 B,  37 C,  37 D,  37 E, and  37 F all of which intersect at a central cavity  50 , as shown in FIGS. 4 and 7. The chambers  37  extend outwardly from the central cavity  50  and are in a highly precise perpendicular relationship with each adjacent chamber  37 . Posts  38 ,  40 ,  42 ,  44  and  46  each contain one of the diodes  36 A-E as illustrated in FIG.  7 . The diodes  36  connect with an electrical connector  52  located within the central cavity  50 . The one word post  40  includes openings  54  that are adapted to accept bearings  56 , which are used to pivot the laser instrument  14  about a first axis of rotation, as shown in FIG.  7 . The lowest post  44  includes apertures  58  that are adapted to accept threaded shafts  60  and the weighted adjustment screws  32 . The weighted adjustment screws  32  allow the laser instrument  14  to be calibrated during assembly as well as out in the field in the event the laser alignment device  10  becomes out of balance from a decalibrating impact. 
     The main body  34  of the laser instrument  14  is pendulously suspended from the housing  12 , as shown in FIG.  2 . The pivoting of the laser instrument  14  is accomplished by use of an inner gimbal  62  and an outer gimbal  64 , as shown in FIGS. 5-7. The inner gimbal  62  includes a central opening  66  that is adapted to surround the uppermost post  40  of the main body  34 . The inner gimbal  62  also includes apertures  68  that are adapted to accept inner gimbal pins  70 . The inner gimbal pins  70  thread through the apertures  68  and engage the bearings  56  positioned within the post  40 . The connection between the main body  34  of the laser instrument  14  and the inner gimbal  62  allows the laser instrument  14  to pivot about a first axis of rotation. The inner gimbal  62  also includes a second set of apertures  72  that are adapted to accept bearings  74 . 
     The outer gimbal  64  is connected to the housing  12 , best shown in FIGS. 2 and 7, and includes apertures  76  that are adapted to accept inner gimbal pins  78 . The inner gimbal pins  78  engage the bearings  74  to allow the main body  34  of the laser instrument  14  to pivot about a second axis of rotation as shown in FIG.  7 . The outer gimbal  64  also includes a central opening  80  that allows the outer gimbal  64  to be positioned around the inner gimbal  62 , aligning the apertures  76  with the bearings  74  positioned within the inner gimbal  62 . The outer gimbal  64  further includes inwardly extending brackets  82  that allow the attachment of a circuit board  84 . The circuit board  84  includes springs  86  that extend downward through the openings  66  and  80  of the inner gimbal  62  and outer gimbal  64 . The springs  86  contact a second circuit board  88  to transfer power from a power source  90  located in the housing  12  to the laser instrument  14  without inhibiting the movement of the laser instrument  14 . The power source  90  used is a battery positioned within the housing  12  but an external source of power can also be used. The bearings  56  and  74  have very low resistance to allow the laser instrument  14  to pivot freely and reach equilibrium once the laser instrument  14  is placed upon a support surface. Even if the housing  12  is not level, the laser instrument  14  will pivot and naturally seek a level equilibrium. To reduce the amount of time required for the laser instrument  14  to reach equilibrium, the dampening system  16  is used. 
     The dampening system  16  is comprised of a damper plate  94 , supports  96  and magnets  98 , as shown in FIG.  7 . The damper plate  94  is a rectangular non-magnetic metal plate that includes a centrally positioned opening  100  surrounded by four apertures  102 . The damper plate  94  is typically made from copper or aluminum. The apertures  102  allow the damper plate  94  to be connected to the bottom post  44  with fasteners  104 . The opening  100  in the center of the damper plate  94  allows laser light produced from the diode  36 C positioned within the bottom post  44  to pass through. The damper plate  94  is curved to allow the plate  94  to remain a constant distance from the magnets  98  when passing through the magnetic field. The magnetic supports  96  are fastened to the housing  12  and each are adapted to support a magnet  98 . The magnets  98  are arranged so that the damper plate  94  can freely pass over the magnets  98 . Resistance is created when the damper plate  94  passes through the magnetic field. The resistive force slows the pendular movement of the main body  34  which aids the plate in reaching equilibrium. The dampening system  16  allows the laser instrument  14  to quickly level in the event the device is bumped during use. Alternate leveling systems can also be used to level the laser instrument  14 . Electronic sensors interfaced with electric motors are used to sense the position of the laser instrument  14  with respect to the horizon and control the electric motors to level the laser instrument  14 . 
     The laser alignment device  10  further includes the locking mechanism  24  that locks the damper plate  94  when the device is not in use, as shown in FIGS. 5 and 6. The locking mechanism  24  is comprised of a lock arm  106  and two lock arm brackets  108  and  109 . The lock arm  106  includes a long shaft  110  that is pivotally connected to the lock arm bracket  108  at a first end and is rigidly connected to a fork member  112  at a second end. The shaft  110  further includes 2 outwardly extending lugs  114  that are designed to engage when the shaft  110  is in the locked position, preventing the main body  34  from moving. The fork member  112  of the shaft  110  engages the lock arm bracket  109  and the switch  22 . When the switch  22  is moved upward to the on position, the fork member  112  is pivoted upward, causing the lugs  114  to pivot away from the damper plate  94 , allowing the laser instrument  14  to pivot freely. Moving the switch  22  upward also engages electric switch  116 , as shown in FIG. 2, which completes a circuit between the power source  90  and the laser diodes  36 . 
     To operate the laser alignment device  10 , it is first placed upon a tripod or other support surface. The device  10  does not have to be level but it is required to be oriented within five degrees of horizontal. Once the device  10  is properly supported, the switch  22  is slid upward. The sliding of the switch  22  causes the lug  114  on the lock arm  106  to pivot outward, releasing the damper plate  94  and the laser instrument  14  allowing them to freely pivot until equilibrium is reached. Sliding the switch  22  also causes engagement with the electric switch  116  which completes a circuit from the power source  90  through wiring and the circuit boards  84  and  88  to the laser diodes  36 . Within a short duration after the switch  22  is moved to the “on” position, the laser instrument  14  reaches an equilibrium aided by the dampening system  16  and projects five orthogonal laser beams illustrated as beams A, B, C, D and E in FIG.  5 . These beams produce level, plumb, and square reference points. 
     Various features of the invention have been particularly shown and described in connection with the illustrated embodiment of the invention, however, it must be understood that these particular arrangements merely illustrate, and that the invention is to be given its fullest interpretation within the terms of the appended claims.
This invention is directed to a novel, portable, self-powered laser alignment device which can simultaneously generate plumb, square and level laser reference points. The laser alignment device is comprised of a main body that is pendulously suspended from a unit housing. The main body is adapted to house a plurality of orthogonally oriented laser diodes that, when energized, produce a plurality of orthogonal output beams to allow the operator to easily mark plumb, square and level reference points. The laser alignment device is self-leveling, which eliminates the time consuming calibration previously required for instrument setup. The movement of the main body is dampened by use of a magnetic dampening system that is comprised of a non-magnetic metallic plate, which is passed through a permanent magnetic field. The housing of the laser alignment device contains the main body, the laser diodes, the dampening system and a power supply to energize the diodes.