Patent Publication Number: US-2006002233-A1

Title: Combination tool for aligning, measuring distances and sensing objects under a surface

Description:
The present invention is related to tools used in a construction environment and is more particularly related to electronic tools used for aligning, measuring distances and sensing objects under a surface.  
      There are many different tools used in the construction and home improvement industries. One well-known tool for measuring linear distances is a tape measure, which includes a housing and a flexible measuring tape, which may be drawn from the housing for measuring distances. Another well-known tool includes a bubble level for insuring that surfaces are level in horizontal and/or vertical planes. Yet another device is a T-Square, which is generally used for forming 90° angles between objects. Still further construction tools include sensors such as stud sensors, metal sensors and electric current sensors. Recently, there have been a number of advances in tools that combine one or more of the features listed above.  
      For example, U.S. Pat. No. 6,157,591 to Kranz discloses a sonic range finder with laser pointer. As shown in FIG. 2 thereof, the range finder 30 projects an acoustic beam 12 and a cone-shaped laser beam 34 of about the same size and direction as the acoustic beam 12. The laser pattern 36 also includes a central dot 38 that indicates the center of the acoustic beam.  
      U.S. Pat. No. 4,700,489 to Vasile discloses a combination tool including a tape measure, a bubble level, a stud locator and marker, and a square.  
      U.S. Pat. No. 6,402,319 to Goodrich et al. discloses an apparatus for producing a visible line of light on a surface. As shown in FIGS. 4 and 5 thereof, a laser diode 2 is positioned above a surface 4 to be marked, with the wide divergence angle of the laser perpendicular to the surface. Cylindrical lenses 6, 8 and 10 project a beam 11 from the laser diode 2 onto a continuous line 14. The widths of the lenses are chosen to collect all of the light from the narrow divergence angle of the diode. The use of a plurality of lenses in the direction of the wide divergence (long axis) allows most of the light to be collected, thereby enhancing the efficiency of the system. Focus adjustment for distance can be accomplished either by using different focal length lenses or by adjusting the distance from the diode to each lens.  
      U.S. Pat. No. 6,606,798 to El-Katcha discloses a laser level. Referring to FIG. 1 thereof, the laser level 10 includes a frame assembly 30, an engine assembly 40 rotatably attached to the frame assembly 30, a laser diode assembly 41 disposed within engine assembly 40, a protective assembly 20 connected to frame assembly 30, a shoe assembly 50 slideably attached to protective assembly 20, a clamp assembly 80 disposed on shoe assembly 50 and a multi-battery adapter assembly 70 for receiving a battery 60.  
      U.S. Pat. No. 6,259,241 to Kranz discloses a hand-held detector unit that detects the presence of an object behind a surface and projects a visible pattern onto the surface behind which the sensed object is located. The projected pattern, such as a line, represents a characteristic of the detected object. Similarly, U.S. Patent Application Publication No. U.S. 2001/0007420 to Bijaw discloses a hidden object sensor that senses and locates hidden objects behind the surface of an architectural structure. The sensor includes a circuit for detecting the presence of live wires, metal objects and wood studs.  
      U.S. Pat. No. 5,894,675 to Cericola discloses a combination tool for use in measuring, leveling, squaring and plumbing operations. Referring to FIGS. 1-9 thereof, the combination tool 10 including a housing 12 adapted to encase a tape measure 2 having an extendable tape 3 and a laser source 5 capable of projecting a visible light beam 6. The extendable tape 3 and the visible light beam 6 extend in directions that are perpendicular to one another. The tool also includes a horizontal bubble-leveling vial 41 and a vertical bubble-leveling vial 42 mounted on the housing for leveling in horizontal and vertical planes.  
      U.S. Pat. No. 6,581,296 to Ponce discloses a tape measure with laser beam. Referring to FIG. 2 thereof, tape measure includes a case 12, a laser device 70 carried in the case that produces a laser beam 10 and a roll 24 of measuring tape 25 supported in the case.  
      In spite of the above advances, there remains a need for a tool that more efficiently combines multiple functions related to alignment, measuring distances and sensing objects under a surface. There also remains a need for a tool that makes it easier to perform such alignment, measuring and sensing functions.  
      In certain preferred embodiments of the present invention, a combination tool includes a housing, and a laser device rotatably mounted to the housing, whereby the laser device is rotatable to a first position for projecting a laser line and a second position for projecting a laser beam. The tool also desirably includes a sonic device connected to the housing and being adapted to project signals for measuring distances between the tool and a spaced object.  
      In certain preferred embodiments, the tool may include a microprocessor in communication with the laser device and the sonic device, whereby the microprocessor determines a first distance between the laser line and the surface when the laser device is in the first position and a second distance between a predetermined point on the housing and the surface when the laser device is in the second position. The predetermined point may be the first end of the housing. In other preferred embodiments, the predetermined point may be the second end of the housing or any point between the first and second ends of the housing.  
      The tool may also include an orientation element in communication with the microprocessor for determining whether the first end of the housing is above the second end of the housing in an upright orientation or the first end of the housing is below the second end of the housing in an inverted orientation. The orientation element may include one or more mercury switches in communication with the microprocessor. In certain preferred embodiments, the orientation element includes a pair of mercury switches.  
      The tool may also include a visual display in communication with the microprocessor, whereby the visual display presents data in a first direction when the housing is in the upright orientation and in a second direction when the housing is in the inverted orientation.  
      The tool may also include a bracket attached to the housing for supporting the tool over a surface, the bracket having a first mode in which the housing is free to move over the surface and a second mode in which the housing is secured in place over the surface. The bracket desirably has at least one anchoring element movable between a retracted position for enabling the housing to freely move over the surface and an extended position for securing the bracket to the surface. The at least one anchoring element preferably includes a pin having a pointed end adapted to engage the surface when the at least one anchoring element is in the extended position.  
      The tool may also include a sensor coupled with the housing for detecting objects hidden behind a surface. The hidden object sensor may be a wood stud sensor, an electrical current sensor for detecting live electrical wires and/or a metal sensor for detecting reinforcing bar in concrete or metal studs in walls.  
      The sonic device may be used to measure distances by sending sonic waves at an object and then detecting the rebounding waves. The sonic device preferably sends the waves along an axis. The sonic device may be located at an end of the housing. In certain preferred embodiments, when the laser beam is projected from said laser device, the sonic waves/signal projected from the sonic device extend in directions that are substantially co-axial with the laser beam.  
      The laser device desirably includes a laser and at least one optical element for diffracting light from the laser for projecting the laser line. The laser is optically coupled with the at least one optical element when the laser device is rotated to the first position. In certain preferred embodiments, the laser device includes a plurality of optical elements at various angles such as 90° left, 45° left, 30° left, 0°, 30° right, 45° right and 90° right. The optical element may be selected from the group consisting of a lens, a diffraction grating and a holographic element.  
      The tool may also include a sensor coupled with the housing for detecting objects hidden behind a surface. The sensor may be an electrical current sensing circuitry for detecting electrical wires, a metal sensing circuitry for sensing metal objects and a wood sensing circuit for sensing wood objects. The tool may also include one or more control buttons accessible at an outer surface of the housing for controlling operation of the tool, and a visual display provided on the housing for displaying measuring, aligning or sensing data.  
      In certain preferred embodiments, the tool includes a first leveling device for leveling the tool in a horizontal plane and a second leveling device for leveling the tool in a vertical plane. The laser device preferably includes a rotatable cover having a transparent portion, whereby the first and second leveling devices are visible through the transparent portion.  
      In another preferred embodiment of the present invention, a combination tool includes a housing, a laser device rotatably mounted on the housing, and a sonic device connected to the housing and being adapted to project sonic signals for measuring distances between the tool and a spaced object, whereby in a first rotated position the laser device is adapted to project a laser line and in a second rotated position the laser device is adapted to project a laser beam used for aiming the sonic device. The housing has a longitudinal axis and the laser device is preferably rotatable for projecting a plurality of laser lines at various angles relative to the longitudinal axis. The housing desirably has a first end and a second end and the sonic device is positioned at the second end, whereby the laser device is oriented toward the second end of the housing when in the second rotated position for aiming the sonic device. The tool may include a bracket attachable to the housing for selectively mounting the tool over a surface, the bracket having at least one anchoring element movable between a retracted position in which the tool is freely movable over the surface and an extended position in which the tool is anchored in place over the surface. The housing is desirably releasably attachable to the bracket. The bracket has one or more slots and the housing has one or more projections that are adapted to be snap-fit into the one or more slots.  
      In certain preferred embodiments, the tool may include a visual display, such as a LED or LCD screen, for displaying information related to operation of the tool. For example, the visual display may show a distance measured by the sonic device, an angle at which the rotatable laser device is set or the type of hidden object (e.g. live wire) sensed by the hidden object sensor. The tool may also include one or more keys or buttons for operating the tool. A first set of keys may be used for activating and deactivating the tool, and a second set of keys may be used for measuring distances, aligning, sensing, etc. The tool may also include a microprocessor coupled with the various devices such as the sonic distance measuring device, the visual display, the keys for controlling the tool, the sensing device for sensing hidden objects and the rotatable laser.  
      In yet another preferred embodiment of the present invention, a combination tool includes a housing, a laser device rotatably mounted on the housing, the laser device being rotatable to a plurality of first angles for projecting a laser line used for aligning and being rotatable to a second angle for projecting a laser beam used for aiming. The tool also desirably includes a sonic device coupled with the housing for measuring distances between the tool and a spaced object, a sensor coupled with the housing for sensing objects hidden behind a surface, and a bracket attachable to the housing, the bracket having a first position in which the housing is free to move over the surface and a second position in which the housing is secured in place over the surface. The bracket preferably has at least one anchoring element movable between a retracted position for enabling the housing to move freely over the surface and an extended position for securing the bracket to the surface. The bracket desirably has a safety cover slidable between a closed position when the at least one anchoring element is retracted and an open position when the at least one anchoring element is extended. 
    
    
      The invention will now be described by way of example with reference to the drawings, in which:  
       FIG. 1  shows a perspective view of a combination tool, in accordance with certain preferred embodiments of the present invention.  
       FIG. 2  shows a top plan view of the combination tool of  FIG. 1 .  
       FIG. 3  shows a front elevational view of the combination tool of  FIG. 1 .  
       FIG. 4  shows an expanded view of a first end of the combination tool of  FIG. 1 .  
       FIGS. 5A-5D  show the combination tool of  FIG. 1  including a rotatable laser device.  
       FIG. 5D-1  shows a perspective view of the combination tool of  FIG. 5D  projecting a laser beam on a wall.  
       FIG. 6  shows a perspective view of a mounting bracket for the combination tool of  FIG. 1 , in accordance with certain preferred embodiments of the present invention.  
       FIG. 7  shows the combination tool of  FIG. 1  coupled with the mounting bracket of  FIG. 6 .  
       FIG. 8  shows an expanded view of the combination tool and mounting bracket of  FIG. 7 .  
       FIG. 9  shows a perspective view of one end of the mounting bracket and combination tool of  FIGS. 7 and 8 .  
       FIG. 10  shows a cross-sectional view of the mounting bracket and combination tool of  FIG. 9 .  
       FIG. 11  shows a bottom plan view of the mounting bracket of  FIG. 9 .  
       FIGS. 12A-12C  show a combination tool, in accordance with other preferred embodiments of the present invention.  
       FIG. 13A  shows a top plan view of the combination tool of  FIGS. 12A-12C .  
       FIG. 13B  shows a front elevational view of the combination tool of  FIGS. 12A-12C .  
       FIG. 14  shows a schematic view of the internal circuitry of a combination tool, in accordance with certain preferred embodiments of the present invention.  
       FIGS. 15A-15D  show a method of using the combination tool and mounting bracket of  FIG. 7  to locate an object hidden behind a wall, in accordance with certain preferred embodiments of the present invention.  
       FIG. 16  shows a perspective view of a laser diode subassembly for a combination tool, in accordance with certain preferred embodiments of the present invention.  
       FIG. 17  shows a top plan view of the subassembly shown in  FIG. 16 .  
       FIG. 18  shows a bottom perspective view of the subassembly shown in  FIG. 16 .  
       FIGS. 19A-19D  show a schematic view of the laser diode subassembly of  FIG. 16  at various positions, in accordance with certain preferred embodiments of the present invention.  
       FIG. 20A  shows a combination tool in an upright orientation, in accordance with certain preferred embodiments of the present invention.  
       FIG. 20B  shows the combination tool of  FIG. 20A  in an upside down or inverted orientation.  
       FIG. 21  shows a combination tool having a laser device rotated to different positions, in accordance with certain preferred embodiments of the present invention.  
       FIGS. 22A-22C  show a schematic view of a combination tool having a laser head pointing upwards, in accordance with certain preferred embodiments of the present invention.  
       FIGS. 23A-23C  show a schematic view of a combination tool having a laser head pointing downwards, in accordance with certain preferred embodiments of the present invention.  
       FIG. 24  shows a top plan view of the combination tool shown in  FIG. 22B .  
       FIG. 25  shows a top plan view of the combination tool shown in  FIG. 22C .  
       FIG. 26  shows a top plan view of the combination tool shown in  FIG. 23B .  
       FIG. 27  shows a top plan view of the combination tool shown in  FIG. 23C . 
    
    
       FIG. 1  shows a combination tool  20  including a housing  22  having a first end  24  and a second end  26  remote therefrom. The housing  22  also includes a top surface  28  and a bottom surface  30 . The top and bottom surfaces  28 ,  30  extend between the first and second ends  24 ,  26  of housing  22 . The combination tool includes a laser device  32  that is rotatably mounted on housing  22 . The laser device includes a laser (not shown) that generates a laser beam. The laser device also preferably includes one or more optical elements  34  that interact with the light beam created by the laser. The optical element may be an optical lens that intercepts the light beam. The optical element may diffract the light beam to generate a laser line on a surface. In other embodiments, the optical element may interact with the light beam to generate a dot of light on a surface.  
      The combination tool also includes a sonic device  36  provided at the second end  26  of housing  22 . The sonic device  36  desirably generates sonic waves for measuring various distances between the housing  22  and a spaced object. The sonic device may measure distances between walls, between a ceiling and a floor or between any two points. The tool may be hung on a wall and the sonic device used to measure a distance between the tool and a ceiling, wall, floor, surface or object. The sonic device may also be used to determine the height of an object above a point, such as the height of a picture frame above the floor.  
      Housing  22  also includes a visual display  38 , such as a LED or LCD display. The visual display may present information such as a distance measured by sonic device  36  or an alignment angle designated by laser device  32 . The visual display  38  may also show any information related to the operation of the combination tool  20 , such as what type of object is sensed under a surface. In certain preferred embodiments, the orientation of the information presented on the display may change depending upon the orientation of the tool  20 . The combination tool  20  also includes control buttons  40 A- 40 E. The control buttons may be depressed and/or manipulated for activating and/or controlling the combination tool  20 .  
      The combination tool  20  also preferably includes one or more sensors for detecting a hidden stud through a structure, an electrical wire through a structure and/or a reinforcement bar through concrete. The combination tool  20  preferably includes a switch  42  for activating the stud/current/rebar sensor (not shown).  
      Referring to  FIG. 2 , the housing  22  has a length L extending between first end  24  and second end  26 . The housing  22  has a width W extending between first sidewall  44  and second sidewall  46 . The rotatable laser device  32  is provided adjacent the first end  24  of housing  22  and the sonic distance measuring device  36  is located adjacent the second end  26  of housing  22 . In a particular preferred embodiment shown in  FIG. 2 , the laser device includes a first optical element  34 A, a second optical element  34 B and a third optical element  34 C. The first optical element  34 A is provided at 90° left, the second optical element  34 B is provided at 0° and the third optical element  34 C is provided at 90° right. The laser device may be rotated 90° to the left for projecting light through the first optical element  34 A. The laser device may also be rotated to the position shown in  FIG. 2  for projecting light through the second optical element  34 B. The laser device may also be rotated 90° to the right to project light through the third optical element  34 C. In other preferred embodiments, the optical element may be placed at 90° left, 60° left, 45° left, 30° left, 15° left, 0°, 15° right, 30° right, 45° right, 60° right and 90° right.  
      The laser device  32  preferably includes a transparent cover  48 . As will be described in more detail below, the transparent cover  48  enables leveling vials to be observed therethrough for leveling the combination tool in vertical and horizontal planes. The transparent cover  48  also includes one or more elongated projections  50  formed thereon. The elongated projections  50  preferably facilitate gripping and rotation of the transparent cover  48 . In certain preferred embodiments, manipulating and/or depressing one or more of the control buttons  40  may activate the combination tool.  
      Referring to  FIG. 3 , combination tool  20  includes housing  22  having first end  24 , second end  26  and intermediate region  27  disposed between the first and second ends. Housing includes top surface  28  and bottom surface  30  remote from the top surface  28 . Adjacent first end  24 , combination tool  20  has a height H 1  extending between the apex  52  of cover  48  and the bottom surface  30  of housing  22 . The combination tool  20  includes a second height H 2  in the intermediate region  27  of housing  22 . The second height H 2  extends between top surface  28  and bottom surface  30  of housing  22 . Housing  22  also includes an upwardly sloping surface  54  extending between intermediate region  27  and second end  26 . Laser device  32  includes first optical element  34 A that cooperates with light generated by a laser (not shown) to project a laser line or a laser beam. In preferred embodiments, the first optical element  24  diffracts light from the laser to project a laser line onto a surface such as a floor, wall or ceiling.  
      Referring to  FIG. 4 , housing  22  includes first end  24  and laser device  32  rotatably mounted on the housing  22 . Laser device  22  includes transparent cover  48 , which facilitates visual observation of leveling devices  56 A- 56 E through the transparent cover  48 . The leveling devices  56 A- 56 E assist a user in leveling the combination tool  20  in horizontal and vertical planes.  
      Laser device  32  includes a first optical element  34 A for projecting a laser line at 90° left, a second optical element  34 B for projecting a laser line at 0° and a third optical element  34 C for projecting a laser line at 90° to the right. In order to project a laser line at 90° to the left, the head  58  of cover  48  is rotated counterclockwise until pointer  60  is aligned with first optical element  34 A. A laser line may be projected at 0° relative to the housing  22  by rotating the head  58  until pointer  60  is aligned with second optical element  34 B. The combination tool  20  may project a laser line 90° to the right by rotating the head  58  until pointer  60  is aligned with third optical element  34 C. As will be described in more detail below, the laser device may be rotated so that the pointer  60  of head  58  is pointing toward the second end  26  of housing  22 . In this position, the light beam emitted by the laser is not diffracted so that it is projected as a dot of light on a surface. In other words, the light beam emitted from the laser is not diffracted to produce a laser line when the head  58  of the laser device  32  is directed toward the second end  26  of housing  22 . In this orientation, the combination tool  20  may be used to measure a distance between the first end  24  of the tool  20  and a spaced object. For example, the second end  26  may be directed toward a remote, vertically extending wall. The laser device may be rotated so that the pointer  60  faces the second end  26  of the housing. The laser device will then produce a dot of light on the vertically extending wall. The dot of light indicates the direction of the sonic waves emitted by the sonic device. The sonic device  36  will then emit sonic waves toward the vertically extending wall and internal components of the combination tool  20  will determine the distance between the vertically extending wall and the first end  24  of the housing  22 . In another embodiment, the combination tool  20  may be hung on a wall, aligned with features to the left or right of the device by projecting laser lines at 90° left or 90° right, leveled using the bubble levels and then the sonic device may be used to determine a distance between a floor or ceiling and the projected laser line at 90° left or 90° right.  
       FIG. 5A  shows combination tool  20  with laser device  32  being oriented toward first end  24  of housing  22 . The laser device  32  generates a laser line  60  projected at 0° relative to a longitudinal axis of housing  22 .  FIG. 5A  also shows sonic distance measuring device  36  emitting sonic waves  62  from the second end  26  of housing  22 . The sonic waves  62  are directed along an axis  64  that is preferably parallel to the longitudinal axis Y of the housing  22 .  
       FIG. 5B  shows laser device  32  being rotated 90° to the right relative to the first end  24  of housing  22 . The laser device  32  generates a laser line  66  that may be projected onto a surface such as a floor or wall.  FIG. 5C  shows laser device  32  rotated 90° to the left relative to the first end  24  of housing  22  for projecting laser line  68  onto a surface such as a floor or wall.  
       FIG. 5D  shows combination tool  20  having laser device  32  rotated 180° so that the laser is directed toward the second end  26  of housing  22 . In this mode, the light generated by the laser device acts an aiming tool to indicate where the direction of the sonic waves  62 . As is evident in  FIG. 5D , laser device  32  is directed along an axis that is substantially similar to the axis  64  of sonic wave  62 .  FIG. 5D-1  shows a perspective view of combination tool  20  projecting a dot of light on a wall  61 . The laser device  32  is rotated 180° so that it is directed toward the second end  26  of housing  22 . The laser device is activated for generating a laser beam that is projected as a dot of light  63  on wall  61 . Simultaneously, sonic device (not shown) propagates sonic waves  62  along axis  64 . Because the laser beam and the sonic waves share a common axis, the dot of light  63  serves as an aiming point for indicating where the sonic waves  62  are striking wall  61 . As a result, a distance d between the wall  61  and the first end  24  of housing  22  can be accurately determined.  
       FIG. 6  shows a mounting bracket  70  for mounting the combination tool of  FIGS. 1-4  on a surface. The mounting bracket  70  includes a top surface  72  and a bottom surface  74  facing away from top surface  72 . Mounting bracket  70  has a first leg  76  including a first push pin  78  and a first slot  80 . Mounting bracket  70  includes a second leg  82  having a second push pin  84  and a second elongated slot  86 . Mounting bracket  70  also includes a third leg  88  having a third push pin  90  and a third elongated slot  92 .  
      In operation, the mounting bracket  70  may be used for positioning the combination tool on a surface, such as a wall or a floor. The elongated slots  80 ,  86  and  92  are adapted to receive projections extending from the bottom surface of the combination tool so that the tool can be attached to the mounting bracket. The projections preferably snap fit into the elongated slots  80 ,  86  and  92  for securing the combination tool to the mounting bracket  70 . The push pins  78 ,  84  and  90  are extended for securing the mounting bracket  70  to a surface.  
      Referring to  FIG. 7 , mounting bracket  70  is secured to a surface such as a vertically extending wall  96 . The push pins  78 ,  84  and  90  are extended for biting into the wall  96  for securing the mounting bracket  70  to the wall. As the mounting bracket  70  is secured to the wall  96 , a user may observe the leveling vials (not shown) through the transparent cover  48  of laser device  32 , so as to insure that the combination tool is properly leveled in horizontal plane X and vertical plane Y. The second end  26  of housing  22  is oriented toward the ground (not shown) so that the sonic device  36  can project sonic waves at the ground. As a result, a distance between the ground and the first end  24  of housing  22  may be determined. The distance may be displayed on visual display  38  of combination tool  20 .  
      Referring to  FIG. 8 , the three legs  76 ,  82  and  88  of mounting bracket  70  extend beyond the housing  22  so that the push pins  78 ,  84  and  90  and accessible. As will be described in more detail below, the mounting bracket  70  includes a safety feature that normally covers the pointed ends of the push pins. The safety feature prevents the push pins from being extended until a user takes affirmative steps. Furthermore, the safety feature locks the push pins in an extended position when desired by the user.  
      The transparent cover  48  of laser device  32  enables an operator to observe the respective leveling devices  56 A- 56 C therethrough. The leveling devices facilitate horizontal and vertical alignment of the combination tool  20 .  
      In a particular preferred embodiment shown in  FIG. 8 , laser device  32  includes five optical elements  34 A′- 34 E′. The first optical element  34 A′ is located at 90° left, the second optical element  34 B′ is located at 0° and the third optical element  34 C′ is located at 90° right. The laser device  32  also includes a fourth optical element  34 D′ located at 45° left and a fifth optical element  34 E′ located at 45° right. As a result, the laser device is able to project laser lines at 90° left, 45° left, 0° (toward the first end  24  of housing  22 ), 45° right and 90° right. The pointer  60  formed in head  58  is transparent so that a user can observe whether the laser (not shown) is operational.  
       FIG. 9  shows combination tool  20  secured to mounting bracket  70 . The first arm  76  of mounting bracket  70  includes push pin  78  having cap portion  98  and pin holder portion  100 . The housing  22  is mounted on mounting bracket  70  so that first end  24  of housing  22  faces push pin  78 .  
       FIG. 10  shows a cross-sectional view of the push pin  78  provided in the first leg  76  of mounting bracket  70 . The push pin  78  includes cap  98  that is secured atop a pin holding member  100  holding pin  102 . Pin  102  includes a first end  104  having a sharp point and a second end  106  adjacent cap  98 . The push pin  78  includes a retraction spring  108  that normally holds the push pin  78  in a retracted position. Push pin  78  also includes a safety lock  110  having a slideable safety cover  112  and a safety spring  114  that normally holds the safety cover  112  in a closed position for covering pin opening  116 .  
       FIG. 11  shows a bottom view of the mounting bracket  70  including first arm  76 . The underside of first arm  76  includes safety lock feature having a slideable cover  112  that normally covers pin opening  116  which prevents the pointed end  104  of pin  102  from being accidentally extended from the bottom of mounting bracket  70 . First arm  76  also includes elongated slot  80  adapted to receive a projection  118  extending from a bottom surface of housing  22 . The projection  118  preferably snap fits into the elongated slot  80  for securing the housing  22  to mounting bracket  70 .  
      Referring to  FIGS. 12A-12C , in another preferred embodiment of the present invention, a combination tool  120  includes a housing  122  having a first end  124  and a second end  126  remote therefrom. The combination tool  120  includes a laser device  132  rotatably mounted to housing  122  adjacent the first end  124  thereof. The laser device  132  includes a cover  148  having a transparent section  149  provided therein. The transparent section  149  enables a user to visually observe leveling devices (not shown) located underneath the cover  148 . The cover  148  also includes a head  158  having a pointer  160  that indicates the direction to which the laser device has been rotated. The pointer  160  is preferably transparent so that a user may observe whether the laser is operational. Laser device  132  also includes an optical element  134  that is optically aligned with the emission end of the laser. In certain preferred embodiments, the optical element diffracts the light beam from the laser to project a laser line onto a surface such as a floor or vertical wall. Unlike the previous embodiment, the optical element  134  rotates with the laser and the cover  148  so that only one optical element is needed for 360° rotation of the laser device.  
      Referring to  FIG. 12B , laser device  132  may be rotated 360° for projecting laser light at any angle relative to a longitudinal axis of the housing  122 . The housing includes top surface  128  extending between first end  124  and second end  126  of housing  122 . The top surface  128  includes a sloping portion  154  that slopes upwardly between an intermediate region  127  and the second end  126  of housing  128 .  
      Referring to  FIG. 12C , the combination tool  120  includes a sonic distance measuring device  136  provided at the second end  126  of housing  122 . The sonic distance measuring device  136  projects sonic waves in a direction away from the second end  126  of housing  122 . In preferred embodiments, the sonic distance measuring device  136  projects sonic waves in a direction that is substantially parallel to a longitudinal axis of the housing  122  that extends between first end  124  and second end  126 . The sonic distance measuring device may be used to measure distance between a distant object, such as a wall, ceiling or floor and a point on the housing  122 . In one preferred embodiment, the sonic device may be calibrated to indicate the distance between the first end  124  of housing  122  and the distant object, even when the sonic device  136  is located at the second end  126 . In order to aim sonic distance measuring device relative to a distant surface, the laser device  132  is preferably rotated 180° from the orientation shown in  FIG. 12C , whereby the laser device projects light toward the second end  126  of housing  122 . As the light is projected from laser device  132 , the sloping surface  154  of the housing  122  at least partially obstructs the light so that only a dot of light is projected on the distant surface. The dot of light may be used as an aiming tool because the dot of light and the center point of the sonic waves are substantially co-axial.  
       FIG. 13A  shows a top plan view of the combination tool  120  shown in  FIGS. 12A-12C . Combination tool  120  includes housing  122  having first end  124 , second end  126  and sloping surface  154  formed in top surface  128  of housing  122  between intermediate region  127  and second end  126 . The combination tool includes rotatable laser device  132  having a cover  148  with a transparent section  149  that enables a user to observe level devices  156 A- 156 C. As noted above, the level devices enable a user to level the combination tool  120  in horizontal and vertical planes. Cover  148  also desirably includes transparent pointer  160 , which shows an operator the direction that the laser is pointed and enables an operator to confirm that the laser is operational. In a particular embodiment shown in  FIG. 13A , the laser device is oriented at 0° relative to first end  124  of housing  122  to project laser line  166  onto a surface such as a floor, wall or ceiling.  
      Referring to  FIG. 13B , when the pointer  160  is oriented toward the second end  126  of housing  122 , the laser light is directed along a path designated P. The laser light is at least partially obstructed by sloping surface  154 . The sloping surface  154  at least partially blocks the laser light so that a beam of light is projected onto a remote surface. The beam of light will appear as a dot of light on the remote surface. The dot of light may be used for aligning the sonic distance measuring device  136  provided at the second end  126  of combination tool  120 . The dot of light indicates the direction of the sonic waves generated by the sonic distance measuring device  136 . After the sonic waves are emitted, the waves bounce back from the distant surface and are sensed by the sonic device for estimating the distance between the distant surface and the first end  124  of housing  122 .  
       FIG. 14  shows a simplified, schematic view of a combination tool  220 , in accordance with certain preferred embodiments of the present invention. The combination tool  220  includes a housing  222  having a first end  224 , a second end  226 , an upper surface  228  and a bottom surface  230 . The combination tool includes a laser device  232  including a laser  233  that selectively projects light, such as a light beam. The combination tool includes a microprocessor  235  having one or more integrated circuits. The combination tool includes sonic distance measuring device  236  provided adjacent to second end  226  of housing  222 . The sonic distance measuring device  236  projects sonic waves from the second end  226  in a general direction indicated by axis A. The combination tool  220  also includes sensing device  245 , including a first sensor  247  for sensing wood studs, a second sensor  249  for sensing electrical wires and a third sensor  251  for sensing metal in a structure, such as reinforcement bar in concrete. The combination tool  220  also includes a visual display  238  for presenting data related operational use of the tool. The combination tool  220  also includes one or more buttons or keys  240  for activating and operating the tool  220 . The elements are interconnected with one another using communication lines  253 . In certain preferred embodiments, the communication lines  253  include conductive traces for passing electrical signals between the above-described components.  
       FIG. 15A  show a method of using the combination tool of the present invention, in accordance with certain preferred embodiments of the present invention.  FIG. 15A  shows wall  361  having a hidden stud  365  underneath an exterior surface of the wall. The combination tool  320  is attached to the mounting bracket  370 . After the device for sensing wood studs is activated, the tool and bracket are moved over the wall until an audible or visual signal is generated by the tool for indicating that the tool is over a stud  365 .  
      Referring to  FIG. 15B , when the user has confirmed that the tool  320  and bracket  370  are positioned over stud  365 , the user observes the level devices to insure that the tool is leveled in the X and Y planes. Once the user has confirmed that the tool is positioned over stud  365  and is leveled in the X and Y planes, the user extends the push pins  378 ,  384  and  390  for at least temporarily securing the mounting bracket  370  to the wall  361 . The user may also activate the sonic device  336  so that the second end of the tool is at a distance d over floor  367 .  
      Referring to  FIG. 15C , the user may then activate the laser device  332  to generate a laser level for alignment purposes. In  FIG. 15C , the laser level  368  is 90° to the left. The laser level  368  may be used for aligning a picture frame  369  on wall  361 . Referring to  FIG. 15D , after the first picture frame  369  has been positioned on the wall  361 , the laser device may be rotated 180° so that the laser device produces a laser level  366  at 90° right. The laser level  366  can be used for aligning a second picture frame  371  that is at the same height as the first picture frame  369 . The laser device may also be used in a similar fashion for locating metal and/or electrical wires behind a wall.  
      In a first mode of operation, a user operates the tool  220  to detect wood studs under a surface, such as dry-wall. The user would interact and/or manipulate buttons  240  to select activation of the wood stud sensor  247 . The bottom surface  230  of the tool  220  is then placed over the dry-wall surface until the tool generates an audible beep or visual symbol. In another mode of operation, the current sensor  249  can be activated for detecting live wires hidden behind a surface such as dry-wall. In yet another mode, the metal sensor  251  can be activated for detecting the presence of metal underneath a surface. In still another preferred embodiment of the present invention, all three sensors can be activated at one time and the visual display can indicate which type of object, i.e. wood, electrical wire, metal, has been detected. The system may also generate a unique audible sound for each particular type of material sensed. For example, a first audible sound can be generated when wood is sensed, and a second audible sound may be generated when an electrical wire is sensed.  
       FIG. 16  shows a perspective view of a laser device subassembly  432  including a rotatable element  433 . Mounted on the rotatable element  433  is a laser diode assembly  435  that is adapted for generating laser light. The rotatable laser device  432  also includes level vials  456   a ,  456   b  and  456   c  for leveling the device in horizontal and vertical planes. The subassembly  432  also includes a first mercury switch  437  and a second mercury switch  439  that are used for sensing the orientation of the combination tool. As will be described in more detail below, depending upon the orientation of the tool, the respective mercury switches  437 ,  439  will be in either an open or a closed position. This information is sent to internal circuitry for sensing the orientation of the device. In a first upright orientation, the visual display screen will show information in an upright orientation. In a second orientation of the tool, the visual display will show the information in an inverted orientation. As a result, the user of the device may read the visual information presented in an upright orientation regardless of whether the tool is oriented in an upright orientation or an inverted orientation.  
      Referring to  FIG. 17 , the laser device subassembly  432  may be mounted atop a printed circuit board  441  including one or more integrated circuits (not shown). The leveling devices  456   a ,  456   b  and  456   c  are mounted atop rotatable platform  433 . The device includes mercury switches  437 ,  439  that are used for determining the upright or inverted orientation of the tool. As will be described in more detail below, the mercury switches may also be used to determine the angle of the laser diode  435  relative to the tool.  
       FIG. 18  shows laser device subassembly  432  including rotating contacts  443 . The rotating contacts  443  enable a reliable electrical interconnection to be maintained between the laser device subassembly  432  and a power source (not shown) as the rotatable platform  433  is oriented at different positions. Thus, the laser device may be rotated 360° or more and still maintain a reliable electrical interconnection.  
       FIG. 19A  shows the laser device oriented 90° to the left at a horizontal left position. In this orientation, a laser beam is directed along a horizontal plane to the left. The first mercury switch number  1  is in an open position and the second mercury switch number  2  is in a closed position. As a result, information is sent to the internal circuitry that any distance measurement displayed on visual display is for the distance measured between the laser beam and an object spaced from the second end of the housing.  FIG. 19B  shows the laser device positioned in a vertical orientation so that the first mercury switch is closed and the second mercury switch is also closed. This information is also sent to the internal circuitry.  FIG. 19C  shows the laser device in a horizontal right position or 90° right so that the laser beam is directed in a horizontal plane. In this orientation, the first mercury switch is in a closed position and the second mercury switch is in an open position. This information is also sent to the internal circuitry for calibrating the device.  FIG. 19D  shows the laser device in a 180° position with the laser head pointing downwards or toward the second end of the housing. In this orientation, the first mercury switch is in an open position and the second mercury switch is an open position. Thus, the switch position of the mercury switches is constantly sent to the internal circuitry of the device so that the internal circuitry may determine the angle or orientation of the rotatably laser device. The mercury switch information may also be used to determine whether the tool is oriented upright or is inverted. This information will be used to alter the orientation of information displayed on the visual display. For example, if the tool is in an upright orientation, the visual display will present the measuring information in an upright orientation. If the tool is inverted so that the first end faces toward the ground, the information presented on the display will be inverted so that a user can easily read the measuring data.  
       FIGS. 20A and 20B  show a combination tool  520  in accordance with another preferred embodiment of the present invention. In  FIG. 20A , the combination tool includes a housing  522  having a first end  524  and a second end  526  remote therefrom. The housing is in an upright position so that the first end  524  is above the second end  526 . The housing also includes a visual display  538  for displaying measuring data such as distance measurements. The mercury switches (not shown) determine the orientation of the housing  522  and relay the information to the internal circuitry. The internal circuitry thus determines that the data  539  to be displayed on visual display  538  is to be presented in an upright orientation. When the housing  522  is inverted, the first end  524  is below the second end  526 . Once again, the mercury switches (not shown) relay information to the internal circuitry that the housing  522  is inverted. Thus, the data  539  presented on visual display  538  is inverted. Although the present invention is not limited by any particular theory of operation, it is believed that modifying or altering the orientation of the data on visual display in response to the orientation of the housing will make it easier for an individual to read the information in the visual display  538 . This will prevent an individual from having to turn his or her head upside down in order to read the visual display  538 .  
       FIG. 21  shows combination tool  520  positioned on a wall over floor  573 . The laser device  532  produces a laser  568  at 90° left in a horizontal plane. The mercury switches (not shown) relay their open/close status to the internal circuitry so that the device can be properly calibrated for taking measurements. Based upon the angle of the laser  568  (i.e. 90° left), the internal circuitry knows that the distance to be measured D 1  will be between the laser line  568  and floor  573 . Sonic measuring device  536  emits a signal toward floor  573  from second end  526  of housing  522 . The sonic device  536  then receives the signals when they bounce off of floor  573 . The information is relayed to internal circuitry that calculates the distance between laser line  568  and floor  573 . The information is presented on visual display  538 . The second combination tool  520 ′ shows laser device  532 ′ at 90° right. The tool operates substantially the same as described above to measure the distance between laser line  568 ′ and floor  573 . The distance is represented as D 2 . The third combination tool  520 ″ has laser device  532 ″ directed toward the second end  526 ″ of housing  522 ″. At this particular angle for the laser device  532 ″, the mercury switches relay information to the internal circuitry that the laser is directed toward the second end  526 ″ of housing  522 ″. As a result, the internal circuitry recalibrates so that the measured distance will be from the first end  524 ″ of housing  522 ″. This distance is represented by the line designated D 3 . Thus, the present invention provides operational hardware that will recalibrate the tool based upon the angle of the laser device. The various points on the housing from which the distance is measured will change depending upon the angle of the laser device. At 90° left and 90° right, the distance will be between the laser line generated by the laser device and the floor. When the laser device is at 180° and points toward the second end of the housing, the measured distance will be from the front end of the housing to the floor  573 . It is contemplated that various points between the first end  524  and the second end  526  of the housing may be used for the different angle settings of the laser device.  
       FIGS. 22A-22C  show a schematic diagram for a combination tool, in accordance with further preferred embodiments of the present invention. Referring to  FIG. 22A , the combination tool includes an element for indicating whether the tool is upright or inverted. In one particular preferred embodiment, the tool has two mercury switches, designated mercury switch # 1  and mercury switch # 2 . The mercury switch # 1  and mercury switch # 2  are preferably provided on the housing of the combination tool, however, the switches may be provided elsewhere on the tool. In other preferred embodiments, the mercury switches may be provided on the rotatable laser head. The combination tool also includes another switch, such as a mechanical switch designated switch # 3 , that is designed to indicate the position of the rotatable laser head. The two mercury switches and the mechanical switch are interconnected with the controller for sending information to the controller.  
      In  FIG. 22A , the combination tool is in an upright orientation and the laser head is rotated 90° to the left for projecting a laser line to the left of the tool. In the state shown in  FIG. 22A , the mechanical switch # 3  is activated to send a signal to the controller that the rotatable head is rotated 90° to the left. The two mercury switches # 1  and # 2  are in the closed position to indicate that the laser head is in an upright orientation.  
      Referring to  FIG. 22B , the rotatable head is rotated so that the laser beam is projected at 0° relative to the combination tool. In this orientation, the mechanical switch # 3  is open for sending a signal to the controller that the laser beam is at 0°. The mercury switches # 1  and # 2  are in the closed position to indicate that the tool is in an upright orientation.  
      In  FIG. 22C , the laser head is rotated 90° to the right so that the mechanical switch # 3  is activated. In addition, the mercury switches # 1  and # 2  are in the closed position to indicate that the combination tool is in an upright orientation.  
       FIGS. 23A-23C  show a schematic diagram when the combination tool is inverted or upside down, whereby the laser head is closer to the ground than a second end of the tool. Referring to  FIG. 23A , the mercury switches # 1  and # 2  are open to indicate that the tool is inverted or upside down. The laser head is rotated 90° to the right, whereby the mechanical switch # 3  is activated. Information regarding the position of the mechanical switch # 3  is preferably sent to the controller of the tool.  
       FIG. 23B  shows the rotatable head with the laser at 0°. In this position, the mechanical switch # 3  is open and the two mercury switches # 1  and # 2  are also open to indicate that the combination tool is inverted.  
      Referring to  FIG. 23C , the rotatable laser head is rotated 90° to the left so that the mechanical switch # 3  is activated. In addition, the mercury switches # 1  and # 2  are open to indicate that the combination tool is inverted.  
      Referring to  FIG. 24 , the combination tool  620  is positioned in an upright orientation, whereby the laser device  632  is positioned above the second end  626  of the housing  622 . The laser device  632  generates a laser line  660  that is at 0° and is pointing upwards. In the position shown in  FIGS. 22B and 24 , the mercury switches # 1  and # 2  are closed to indicate that the tool  620  is in an upright orientation. In response to the rotated angle of the laser device  632 , the mechanical switch # 3  is open to indicate that the laser line is pointed at 0°. When the information regarding the angle of the laser line is forwarded to the controller (not shown), the controller recalibrates the sonic measuring device  636  so that any measurement appearing on display screen  638  reflects a measurement made from the first end  624  of the housing to the floor  673 , represented by the letter “A”.  
      When the laser device  632  is rotated to the position shown in  FIGS. 22C and 25 , the mechanical switch # 3  is activated. As a result, the sonic measuring device  636  is recalibrated so that any distance measurement displayed on display screen  638  is from the laser line  666  to the floor  673 , represented by the letter “B”. In addition, the mercury switches # 1  and # 2  are closed to provide an indication that the combination tool  620  is in an upright orientation, whereby the information displayed on the display screen  638  is displayed in an upright orientation.  
      The tool shown in  FIGS. 26 and 27  is associated with drawing  FIGS. 23A-23C , wherein the combination tool  620  is inverted.  FIG. 26  is associated with  FIG. 23B , having laser device  632  rotated at 0° so that mechanical switch # 3  is open. In addition, because the combination tool  620  is inverted, the mercury switches # 1  and # 2  are open. With the laser device  632  rotated at 0°, the measurements taken by the sonic measuring device  636  are between the first end  624  of the housing  622  and the ceiling  675 , designated by the letter “A”. The information presented on the display screen  638  is inverted for easy reading by a user. If the information were not inverted, a user may have to turn his or her head upside down in order to read the visual display  638 . Thus, the present invention changes the orientation of the information shown on the visual display  638  based upon the upright or inverted orientation of the combination tool  620 .  
       FIG. 27  shows an inverted combination tool  620  with the laser device  632  rotated in the position shown in  FIG. 23C . In this position, the combination tool  620  measures the distance from the laser line  668  to the ceiling  675 , designated by the letter “B”. In addition, because the mercury switches # 1  and # 2  are open, the information displayed on visual display screen  638  is inverted relative to the housing  622 .  
      In preferred embodiments where one of the mercury switches is open and one of the mercury switches is closed, the information displayed on the visual display may be upright. In other preferred embodiments, the information may be inverted on the visual display when one mercury switch is open and one mercury switch is closed.  
      Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.