Abstract:
A laser level including a housing. A laser generator assembly is housed in the housing and generates a laser beam. A projector projects the beam from the laser generator outside of the housing onto a target surface. The laser is a rotary laser and the projector rotates to rotate projection of the beam. The laser level also includes protective arms extending from the housing, the protective arms blocking projection of the beam along part of its path as the projector rotates. A width of the beam is at least twenty percent greater than a width of the leg where the beam contacts the leg.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/308,490 filed on Mar. 15, 2016, entitled Laser Level. The entire contents of U.S. Provisional Application No. 62/308,490 are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to laser levels. 
       BACKGROUND 
       [0003]    There are various existing laser levels. It is desired to provide a laser level with an improved output. 
       SUMMARY 
       [0004]    According to an aspect of an exemplary embodiment, there is a laser level. The laser includes a housing. A laser generator assembly is housed in the housing and generates a laser beam. The laser level further includes a projector configured to project the beam from the laser generator outside of the housing onto a target surface. The laser is a rotary laser and the projector rotates to rotate projection of the beam. The laser level also includes at least one protective leg extending from the housing, the protective leg blocking projection of the beam along part of its path as the projector rotates. A width of the beam is at least 10% greater than a width of the at least one protective leg where the beam contacts the at least one protective leg. 
         [0005]    The at least one protective leg may include two protective legs and the width of the beam is at least 20% greater than the width of each of the two protective legs where the beam contacts the two protective legs. 
         [0006]    The width of the beam may be at least 30% greater than the width of the at least one protective leg. 
         [0007]    The width of the beam may be at least 50% greater than the width of the at least one protective leg. 
         [0008]    The laser beam may have a perpendicular cross section which is a cross section taken perpendicular to an axis of the laser beam, the perpendicular cross section having a first dimension and a second dimension perpendicular to the first dimension, the first dimension of the cross section being at least 20% larger than the second dimension. 
         [0009]    The first dimension of the cross section may be at least 35% larger than the second dimension. 
         [0010]    The first dimension of the cross section may be at least 50% larger than the second dimension. 
         [0011]    The first dimension of the cross section may be at least 75% larger than the second dimension. 
         [0012]    According to another aspect of an exemplary embodiment, there is a laser level with a housing. A laser generator assembly is housed in the housing and generates a laser beam. A projector is configured to project the beam from the laser generator outside of the housing. The laser further includes a motor, the motor connected to the projector and selectively driving the projector in a rotary motion whereby the beam is rotated. The laser level further includes protective legs which protect the projector and are situated between the projector and a target surface along part of a path of the beam as the projector is rotated. A width of the beam is greater than a width of the leg where the beam contacts the leg. 
         [0013]    The width of the beam may be at least 10% greater than the width of the leg. 
         [0014]    The width of the beam may be at least 30% greater than the width of the leg. 
         [0015]    The width of the beam may be at least 50% greater than the width of the leg. 
         [0016]    The laser beam may have a cross section with a first dimension and a second dimension perpendicular to the first dimension, the first dimension of the cross section being at least 20% larger than the second dimension. 
         [0017]    The first dimension of the cross section may be at least 50% larger than the second dimension. 
         [0018]    According to another aspect of an exemplary embodiment, there is a laser level which includes a housing. A laser generator assembly is housed in the housing and generates a laser beam. The laser level includes a projector configured to project the beam from the laser generator outside of the housing. The laser level also includes a motor, the motor connected to the projector and selectively driving the projector in a rotary motion whereby the beam is rotated. Protective legs protect the projector and are situated between the projector and a target surface along part of a path of the beam as the projector is rotated. The laser beam has a perpendicular cross section which is a cross section taken perpendicular to an axis of the laser beam, the perpendicular cross section having a first dimension and a second dimension perpendicular to the first dimension, the first dimension of the cross section being at least 20% larger than the second dimension. 
         [0019]    The first dimension may be at least 35% larger than the second dimension. 
         [0020]    The first dimension may be at least 50% larger than the second dimension. 
         [0021]    The first dimension may be at least 75% larger than the second dimension. 
         [0022]    The protective legs may include two protective legs and a width of the beam may be at least 20% greater than a width of the two protective legs where the beam contacts the two protective legs. 
         [0023]    The protective legs may include three protective legs and a width of the beam may be at least 30% greater than a width of the three protective legs where the beam contacts the three protective legs. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]      FIG. 1  illustrates a perspective view of an exemplary embodiment of a laser level; 
           [0025]      FIG. 2  is cut-away sectional view of the exemplary embodiment of the laser level; 
           [0026]      FIG. 3A  is a schematic view of a comparative example of a laser assembly for a laser level; 
           [0027]      FIG. 3B  is a schematic view of an exemplary embodiment of a laser assembly for the laser level; 
           [0028]      FIG. 3C  illustrates the prism of the exemplary embodiment; 
           [0029]      FIG. 4A  is a schematic view of a comparative example of a projecting laser beam for a laser level; 
           [0030]      FIG. 4B  is a schematic view of an exemplary embodiment of a projecting laser beam for the exemplary embodiment of the laser level; 
           [0031]      FIG. 5A  is a cross section of an exemplary embodiment of a laser beam; 
           [0032]      FIG. 5B  is a cross section of another exemplary embodiment of a laser beam; 
           [0033]      FIG. 5C  is a cross section of another exemplary embodiment of a laser beam; 
           [0034]      FIG. 6A  is an exemplary embodiment of a mask; 
           [0035]      FIG. 6B  is another exemplary embodiment of a mask; 
           [0036]      FIG. 6C  is another exemplary embodiment of a mask; 
           [0037]      FIG. 7A  is an exemplary embodiment of another mask; 
           [0038]      FIG. 7B  is an exemplary embodiment of a cross section of a laser beam; 
           [0039]      FIG. 8A  is perspective view of another exemplary embodiment of a laser level; 
           [0040]      FIG. 8B  is another perspective view of the exemplary embodiment of a laser level of  FIG. 8A ; 
           [0041]      FIG. 8C  is side view of the exemplary embodiment of a laser level of  FIG. 8A ; and 
           [0042]      FIG. 9  is perspective view of another exemplary embodiment of a laser level. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0043]    A first exemplary embodiment according to the present application is shown in  FIGS. 1-7B . As shown in  FIGS. 1 and 2  there is a rotary laser level  10 . Rotary laser levels are known, for example, as shown in U.S. Pat. No. 4,854,703; U.S. Pat. No. 4,751,782; and U.S. Pat. No. 6,338,681, which are herein incorporated by reference in their entirety. Another rotary laser level is shown in US Patent Application Publication No. 2014/0203172, which is also hereby incorporated by reference. The present application may also be applicable to other types of lasers, such as those shown in U.S. Pat. No. 7,665,217; U.S. Pat. No. 7,076,880; U.S. Pat. No. 6,964,106; U.S. Pat. No. 7,481,002; U.S. Pat. No. 7,027,480; U.S. Pat. No. 8,640,350; U.S. Pat. No. 6,606,798; U.S. Pat. No. 7,013,571; U.S. Pat. No. 7,111,406; U.S. Pat. No. 7,296,360; and U.S. Pat. No. 7,571,546, which are herein incorporated by reference in their entirety. 
         [0044]    In rotary laser levels, such as the rotary laser level  10  of the exemplary embodiment, the laser level projects a laser beam against a surface. Additionally the laser beam is quickly rotated about 360 degrees. Rotating the laser beam in this manner creates a line on a target surface such as a wall. 
         [0045]      FIG. 1  is a perspective view of the rotary laser level  10  and  FIG. 2  illustrates a cross-section of the rotary laser level  10  to show internal parts. As shown in  FIGS. 1 and 2 , the rotary laser level  10  includes a housing  20  which is generally shaped as a rectangular cube. The housing  20  includes a bottom  24 , sides  25  and a top  26 . An exposed projector  103  extends from the top  26  of the housing  20 . The projector  103  includes a hole  101  through which a laser beam can be projected. The beam will generally be projected parallel to the surface on which the housing  20  is disposed. The projector  103  rotates 360 degrees so that the projected beam produces a line. 
         [0046]    The laser level  10  also includes a protective structure  70 . The protective structure  70  extends from a top  26  of the housing  20  and provides a measure of protection for the projector  103  against falls or the like. The protective structure  70  includes a number of legs  71  and a roof  72 . The roof  72  includes a hole  73 , so that the projector  103  may project a beam upwardly through the hole  73 . In the exemplary embodiment, the protective structure  70  includes four legs  71 , one at each corner of the housing  20  (one of the legs is hidden in the perspective view). As will be appreciated, the legs  71  will block the projected beam as the rotated beams passes through the legs  71 . Because the beam is blocked by the legs  71 , there are several discontinuities in the line which is projected on the wall. 
         [0047]    On the one hand, it may be advantageous to provide a protective structure with protective legs so as to protect the projector of a laser level. It may also be advantageous for the legs to have a width that allows them to be robust and adequately protect the projector. However, as noted above, the legs present a discontinuity and legs of a larger width may provide a larger discontinuity. The exemplary embodiment of the present application limits the discontinuities introduced by the blocking of such protective structures including when legs of various widths are used. 
         [0048]    The general layout of the rotary laser  10  is shown in  FIG. 2 . As shown in  FIG. 2 , a motor  30  is housed in the housing  20 . The motor  30  is supported in the housing  20  by supporting structures  21  and  22 . These supporting structures  21 ,  22  hold the motor  30  in place. The motor  30  includes an output shaft  31  which drives a driving pulley  32 . The driving pulley  32 , in turn, drives belt  33 . The belt  33  is connected to the projector housing  100 . The projector housing  100  is fitted onto a laser tube  50  via bearings  105 . The projector housing is fixed in an axial direction, but is able to rotate about the laser tube  50  via the bearings  105 . Accordingly, when the motor  30  is operated, it turns the output shaft  31 , which turns the driving pulley  32 . The driving pulley  32  drives the belt  33  which rotates the projector housing  100  and the components contained therein. In this manner, the projector  103  is rotated about 360 degrees so that the projected beam forms a line. In this case, the projector  103  is driven by a belt drive. As will be appreciated, other configurations are possible. For example, the motor  30  could be coupled to drive the projector housing  100  by a gear drive. 
         [0049]    The laser tube  50  supports a laser generator  200  and a lens  201  (see  FIG. 3B ). The laser tube  50  is supported on the housing  20  by supports  21 . The laser generator  200  may be, for example, a laser diode. As is further seen in  FIG. 2 , the laser  10  also includes a lower laser tube  60 . The lower laser tube  60  includes another laser generator (not shown) which projects a laser beam downward through opening  23  in the bottom  24  of the housing  20 . This creates a plumb beam. A prism  110  is located above the laser tube  50 . As will be discussed in greater detail later, the prism  110  divides a beam from the laser generator  200  to produce a horizontal beam BH which is projected out of the laser projector at opening  101  and a vertical beam BV which is projected out of the laser projector at opening  102 . As shown in  FIGS. 3A-3C , the prism  110  includes a pentaprism  111  and a wedge portion  112 . The masks  120  and  121  are also supported in the projector housing  100  and help to shape beams, as will be discussed in more detail below. 
         [0050]    The beam BH is a horizontal beam and beam BV is a vertical beam when bottom surface  24  is placed on a flat horizontal surface. In some instances, at least some of the components such as the laser generator  200 , lens  201  and prism  110  or the projector housing or the projector housing and laser tube  50  may be on a pendulum so that the beam BH remains horizontal when the bottom surface  24  of the housing  20  is placed on a surface that is not level. Also, the pendulum may be selectively locked. As will be appreciated, the beam BH will not be horizontal when the housing  20  is placed on one its sides  25  or if a pendulum is locked and the housing is placed on a sloped surface. 
         [0051]    Operation of the laser of the exemplary embodiment and a comparative example will now be explained with reference to  FIGS. 3A-4B .  FIGS. 3A and 4A  illustrate a comparative example and  FIGS. 3B and 4B  illustrate the exemplary embodiment. Both the comparative example of  FIGS. 3A and 4A  and the exemplary embodiment of  FIGS. 3B and 4B  are used with the laser level  10  described and shown with respect to  FIGS. 1 and 2 , though in the comparative example ( FIGS. 3A and 4A ) the later described masks  120  and  121  are not necessary. In  FIG. 3A , a laser generator  200 ′ generates a laser beam B 1 ′ with non-parallel light beams. The laser beam B 1 ′ travels through lens  201 ′ which focuses the beam B 1 ′ into parallel rays to produce beam B 2 ′. Beam B 2 ′ has the cross-section of a circular dot (the cross-section being perpendicular to an axis of the beam B 2 ′). In this case, the diameter of the circular dot cross-section is 4 millimeters (mm). 
         [0052]    The parallel ray beam B 2 ′ continues on to prism  110 ′, which includes a pentaprism  111 ′ and a wedge portion  112 , and the beam B 2 ′ is split into a vertical beam BV′ and a horizontal beam BH′. In order to split the beam B 2 , the pentaprism  111 ′ reflects about 90% of the beam about the surfaces of the pentaprism  111 ′ and out the front face as BH′. The remaining 10% of the beam travels through the pentaprism  111 ′, the trajectory of this 10% is slightly altered by the pentaprism  111 ′ and the wedge portion  112 ′ corrects the beam back to a vertical orientation. When utilized in the laser level  10  of the exemplary embodiment, the comparative example vertical beam BV′ projects through opening  73  to form a dot on a ceiling. The horizontal beam BH′ travels horizontally from the laser level  10  when the laser level  10  is placed on a flat surface, as discussed above. As can be appreciated, the horizontal beam BH′ will generally project between legs  71 , but will periodically be blocked by one of the legs  71 . This creates a discontinuity in the line that is projected by the horizontal beam BH′ on a target surface such as a wall, as is illustrated in  FIG. 4A . 
         [0053]      FIG. 4A  illustrates the gap G′ created by leg  71  in the comparative example.  FIG. 4A  illustrates a beam BH′ projecting from the projector  103 ′ at three different points in time as it is rotated. The beam BH′ at the three different points in time are identified as BH 1 ′, BH 2 ′ and BH 3 ′. The beam BH 1 ′ is shown at a point just before it reaches the leg  71 . Beam BH 2 ′ is shown at a point where the beam BH′ directly hits leg  71 . Beam BH 3 ′ is shown passing at a point right after the beam BH′ passes past the leg  71 . As shown, because the beam BH′ is blocked at position BH 2 ′, a gap G′ is created between the projections BH 1 ′ and BH 3 ′. The gap G′ increases in size as the beams travel away from the projector  103 , as is shown in  FIG. 4A . In the comparative example, with a leg  71  having a width LW of 4 mm and the beam BH′ having a diameter of 4 mm, the inventors for the present application found that a gap G′ of 2 feet was created at a distance of 100 feet from the projector  103 . 
         [0054]    In the exemplary embodiment of the present application shown by  FIGS. 3B and 4B , a laser beam with an expanded cross section is used to help minimize the gap created by the leg  71  of the protective structure  70 . As shown in  FIG. 3B , laser generator  200  generates a laser beam B 1  with non-parallel light beams. The laser beam B 1  travels through lens  201  which focuses the beam B 1  into parallel rays to produce beam B 2 . As with the comparative example beam B 2  of  FIG. 3A , the beam B 2  has a cross-section of a circular dot. However, the beam B 2  has a diameter of eight (8) millimeters (mm), which is twice the diameter of the beam B 2 ′. In the exemplary embodiment, the larger cross section is created by having the laser generator  200  farther away from the lens  201  than the laser generator  200 ′ and lens  201 ′ of the comparative example. The lens  201  is also larger than the lens  201 ′. It is also possible to create a larger diameter beam in different ways. All of the discussed beam cross-sections being taken perpendicular to an axis of the beam. 
         [0055]    As shown in  FIG. 3B , the parallel ray beam B 2  continues on towards the prism  110 . However, before reaching the prism, beam B 2  passes through a mask  120  to create a beam B 3 . The mask  120  blocks part of the beam B 2  so that beam B 3  no longer has a circular cross section, but instead has a first dimension D 1  which is larger than a second dimension D 2  that is perpendicular to the first dimension D 1 . Several exemplary masks are shown in  FIGS. 6A through 6C  with the corresponding cross sections of beam B 3 -B 3 ″ being shown in  FIGS. 5A through 5C . As shown in  FIG. 5A , the mask  120  may have an opening  130  that has an elliptical shape. The elliptical shape opening  130  would create a beam B 3  with an elliptical cross section, as shown in  FIG. 5A . The opening  130  may be, for example, a hole in the mask or a transparent portion which allows the beam to pass through it. 
         [0056]    There are also other possibilities for the shape of the mask and the resultant beam.  FIGS. 6B and 6C , for example, show alternatives for a mask. The mask  120 ′ of  FIG. 6B  includes a rectangular shaped opening  130 ′. Accordingly, as shown in  FIG. 5B , it produces a beam B 3 ′ with a rectangular cross-section. The mask  120 ″ of  FIG. 6C  includes an opening  130 ″ with the shape of a rectangle with rounded corners (a rounded rectangle). Accordingly, as shown in  FIG. 5C , it produces a beam B 3 ″ with a rounded rectangular cross-section. As will be appreciated, other masks and shapes are also contemplated. Additionally, the masks may be disposed at different locations. For example, with reference to  FIG. 3B , mask  120 A could be substituted for mask  120  and located at the outlet of pentaprism  111 . 
         [0057]    As shown in  FIGS. 5A-5C , the cross-sections of beams B 3 -B 3 ″ include a first dimension D 1  and a second dimension D 2  which is perpendicular to D 1 . As shown, the first dimension D 1  is larger than the second dimension D 2 . The first dimension D 1  may be greater than the second dimension D 2  by, for example, 20% or more; 30% or more; 40% or more; 50% or more; 60% or more; 70% or more; 80% or more; 90% or more; 100% or more; or 150% or more. In the particular exemplary embodiment, the dimension D 1  of beam B 3  is twice as large as the dimension D 2 . Particularly, the dimension D 1  is approximately 8 mm versus a length of 4 mm for the dimension D 2 . 
         [0058]    Turning back to  FIG. 3B , the beam B 3  enters the prism  110 , which includes a pentaprism  111  and a wedge portion  112 . The prism  110  divides the beam B 3  into a vertical beam BV and a horizontal beam BH. In order to split the beam B 2 , the pentaprism  111  reflects about 90% of the beam about the surfaces of the pentaprism  111  and out the front face as BH. The remaining 10% of the beam travels through the pentaprism  111  and the wedge portion  112  corrects the beam back to a vertical orientation. The horizontal beam BH travels horizontally from the laser at least when the laser level  10  is placed on a flat horizontal surface. As can be appreciated, the horizontal beam BH will generally project between legs  71 , but will periodically be blocked by one of the legs  71 , creating the previously discussed discontinuity. However, due to the shaping of the beam with the mask  120 , the horizontal beam BH creates a smaller gap G than the gap G′ caused by the beam BH′ at similar distances. As with the comparative example of  FIGS. 3A and 4A , the vertical beam BV projects through opening  73  to form a dot on a ceiling. However, after leaving the prism  110  in the exemplary embodiment of  FIG. 3B , the beam passes through another mask  121 . The mask  121  has a circular hole  131  as shown in  FIG. 7A , which produces a vertical beam BV with a circular cross section as shown in  FIG. 7B . In the exemplary embodiment, the circular cross section of BV has a diameter of approximately 4 mm. As will be appreciated, other diameters and shapes are possible. 
         [0059]    With reference to  FIG. 4B , the projector  103  projects out a beam BH. The beam BH has the same cross section as the beam B 3  as beam B 3  is beam BH redirected by the prism  100 . As previously discussed, beam B 3  has a dimension D 1  of about 8 mm which is about twice as large as dimension D 2 . Additionally, the dimension D 1  (8 mm) is larger than the width of the leg  71  (4 mm). As a result of these relative dimensions, as shown in  FIG. 4B , when the beam BH is pointed directly at leg  71 , the beam BH is not entirely blocked by the leg  71 . Instead, parts of the beam BH pass along either side of the leg  71 . In contrast, in the comparative example of  FIG. 4A , the beam BH′ is entirely blocked when it is in the position BH 2 ′. Furthermore, as shown in  FIG. 4B , the gap G caused by the leg  71  does not increase in size the farther away beam BH is from the projector  103 . Rather, the gap G stays the same size. Accordingly, the gap G is about 4 mm wide and does not vary depending upon how far the laser  10  is from a wall. That is, while the gap G′ is approximately 2 feet at a distance of 100 feet, the gap G is approximately 4 mm at a distance of 100 feet. This allows the laser level  10  to create a line with significantly less significant discontinuities. As should be appreciated from the above description,  FIG. 4B  illustrates beam BH at only a single point in time, whereas  FIG. 4A  illustrates beam BH′ at three different points in time as the projector is rotated. 
         [0060]    As discussed above, the exemplary embodiment with the construction of  FIGS. 3B and 4B  will produce a horizontal line with less notable discontinuities. In the exemplary embodiment, the width D 1  of the horizontal beam BH is 8 mm, which is about twice as large as a width of a leg  71 . The dimension D 1  may also be other sizes. For example, D 1  may be 3 mm or more; 4 mm or more; 5 mm or more; 6 mm or more; 7 mm or more; 8 mm or more; 9 mm or more; 10 mm or more; 12 mm or more; 13 mm or more; 14 mm or more; 15 mm or more; 16 mm or more; 18 mm or more; or 20 mm or more. 
         [0061]    As also, noted above, it may be advantageous to have a leg  71  with a robust width LW in order to provide a robust protective structure  70 . In the exemplary embodiment, the legs  71  have a width LW of 4 mm where the beam BH contacts the legs  71 . In various embodiments, the width of the leg  71  where the beam BH contacts the leg may be at least 3 mm; at least 4 mm; at least 5 mm; at least 6 mm; at least 7 mm; at least 8 mm; at least 9 mm; at least 10 mm; at least 11 mm; at least 12 mm; at least 13 mm; at least 14 mm or at least 15 mm. 
         [0062]    As described above, having a beam BH with a width which is greater than the width of the leg  71  helps prevent discontinuities in a line produced by the laser  10 . In the exemplary embodiment, the width D 1  of the beam BH is about twice as large as the width of leg  71 . In some embodiments, the width D 1  may be, for example, at least 10% greater than the width of the leg  71 ; the width D 1  may be at least 20% greater than the width of the leg  71 ; the width D 1  may be at least 30% greater than the width of the leg  71 ; the width D 1  may be at least 40% greater than the width of the leg  71 ; the width D 1  may be at least 50% greater than the width of the leg  71 ; the width D 1  may be at least 60% greater than the width of the leg  71 ; the width D 1  may be at least 70% greater than the width of the leg  71 ; the width D 1  may be at least 80% greater than the width of the leg  71 ; the width D 1  may be at least 90% greater than the width of the leg  71 ; the width D 1  may be at least 100% greater than the width of the leg  71 ; the width D 1  may be at least 110% greater than the width of the leg  71 ; the width D 1  may be at least 120% greater than the width of the leg  71 ; or the width D 1  may be at least 150% greater than the width of the leg  71 . 
         [0063]    The expanded beam may be used with other rotary lasers and achieve similar benefits. For example, the configuration of  FIGS. 3B and 4B  may be used with the laser level  210  shown in  FIGS. 6A and 6B . As shown in  FIGS. 6A and 6B , the laser level  210  includes a housing  220 , a projector  203  and a protective structure  270  with legs  271 . In this case, the protective structure  270  has a pair of legs at each corner of the housing  220 . As will be appreciated the rotary laser beam of the laser level  210  will likewise pass through the protective structure  270  with legs  271  and the features of the above-described embodiment of  FIGS. 3B and 4B  could be applied to minimize the disruption from the legs  271 . Another exemplary embodiment is shown in  FIG. 7 . In the exemplary embodiment of  FIG. 7 , the laser level  310  has a housing  320 , a projector  303  and a protective structure  370  with a plurality of legs  371 . The features of the above-described embodiment of  FIGS. 3B and 4B  could likewise be applied to the laser level  310  to minimize the disruption from the legs  371 . 
         [0064]    While the invention has been described by way of exemplary embodiments, it is understood that the words which have been used herein are words of description, rather than words of limitation. Changes may be made within the purview of the appended claims, without departing from the scope and spirit of the invention in its broader aspects.