WO1997007381A1

WO1997007381A1 - Plumb level with laser light projection

Info

Publication number: WO1997007381A1
Application number: PCT/CA1996/000553
Authority: WO
Inventors: Harvey Lilke
Original assignee: Harvey Lilke
Priority date: 1995-08-17
Filing date: 1996-08-16
Publication date: 1997-02-27

Abstract

A leveling device comprises a leveling head (13) on which is mounted a laser diode (22) for generating a laser beam in a horizontal direction. The head (13) is suspended from a spherical bearing (43) at the end of a horizontal rod (42) so that the head acts as a plumb and thus maintains its position with the beam horizontal while the head is rotated about a vertical axis. The rod is attached to a vertical rod portion (40) which is carried in a housing (10) with screws (70, 71, 72) for attachment to the housing to a support surface. The vertical rod can move vertically within the housing (10) from a deployed position projecting from a top (50) of the housing with the horizontal rod portion (40) extending outwardly therefrom to a retracted stored position in which the rod is within the housing and the horizontal rod portion (40) and the head (13) are moved into receptacles (56, 57) within the housing.

Description

PLUMB LEVEL WITH LASER LIGHT PROJECTION

This invention relates to a plumb level with laser light projection which allows a laser beam to be projected across a work area so as to define a point of illumination of the laser beam which is at a required height relative to another point of the work area.

Levels have been available for many years including spirit levels and plumb lines which allow the worker to define a horizontal or vertical axis and to relate other items to one of those axes. Lasers have become readily available in recent years for generating a narrow beam which can be projected from the laser onto a surface some distance from the laser and define a relatively narrow point on the projection surface. Attempts have been made therefore to accommodate a laser beam projection system of this type onto a level so that the beam can identify a required position relative to the axis determined by the level.

It is one object of the present invention to provide a level of this general type which is simple and convenient to manufacture and yet provides an accurate mounting of the laser relative to a predetermined orientation so that the beam therefrom is accurately projected to a required location relative to the predetermined orientation.

According to one aspect of the invention there is provided a level comprising: a support body having mounting means thereon for mounting the support body in stable position on a support surface and means defining an outstanding support point; a level head; head mounting means mounting the level head on the support point of the support body so as to be suspended freely therefrom, the head mounting means being arranged to allow free tilting movement of the level head about the support point such that a level head takes up a position with the centre of gravity of the level head lying on an axis of the level head extending directly vertically downwardly from the support point, the head mounting means allowing rotation of the level head about said axis; and a laser mounted on the level head for projecting a beam from the level head substantially at right angles to the axis.

One embodiment of the invention will now be described in conjunction with the accompanying drawings in which:

Figure 1 is an isometric view showing the level according to the present invention.

Figure 2 is a cross-sectional view along the lines 2-2 of Figure 1.

Figure 3 is a cross-sectional view along the lines 33 of Figure 1 .

The laser level apparatus of the present invention comprises a container 10, a support body 11 and a level head 12.

The level head comprises a molded plastics body 13 for housing the various elements of the head which is molded into a suitable shape, one example of which is shown in Figures 1 and 2 so as to suitably contain and locate the elements. The body contains a bearing sleeve 14 which contains a bearing 15 providing rotation between the sleeve 14 and a support shaft 16. The shaft 16 comprises a screw with a head 17 at its Iower end butting against one end of the bearing 15. At an upper end a nut 18 locates the shaft 16 in a holder on the support 11 as described hereinafter. The bearing sleeve 14 is mounted in a cylindrical bore in the housing 13 and is held in place by releasable set screw 19.

The body 13 defines a front face 20 and a rear face 21 which are opposed and parallel. At the rear face 21 is provided a press button switch 22 which can be set on and off by pressing the button 23 exposed at the rear face. Also at the rear face is provided an opening 24 with a cover 25 housing a battery 26 inserted into a bore within the body 13. In the front face 20 is provided a laser diode module 27 with a diode element 28 for generating a fine laser beam 29. The module 27 is received within a bore defined within the body and breaking out on the front face 20. The laser module is spring biased upwardly by a spring 30 and its height can be adjusted by a set screw 31 pressing against the bias of the spring 30 and thus holding the diode 28 at a required orientation relative to the front face 20.

The battery 26 powers the laser module 27 through the switch 22 so that the module can be switched on and off as required. At the same time the battery illuminates an LED 32 positioned underneath the battery centrally of the body 13.

A bore 33 extends through the body from the front face to the rear face at a height just below the LED 32. The bore receives a conventional spirit level tube 34 with a bubble 35 which defines a level of the head 12. The bubble is illuminated by the LED 32 so that when the bubble is centered an illuminated line extends through the bubble and when the bubble moves to one end, the line disappears in view of the presence of the Iiquid. Underneath the level 34 is provided a mirror 36 which reflects the illumination from the LED 32 so as to enhance the illumination of the bubble when the bubble is properly centered.

In the area of the bore 33, the front and rear faces diverge outwardly to form Iower surface portions 20A and 21 A which are parallel to the surface portions 20 and 21 but have increased width relative thereto. Between the spaced portions is defined a recess 37 which receives a screw 38 extending across the recess in a direction parallel to the level 34 with a screw carrying a spherical weight 39 which can be moved along the length of the screw by rotation of the weight about the axis of the screw. The weight thus effects adjustment of the position of the centre of gravity of the head underneath the shaft 16.

The support member 11 comprises a vertical rod 40 mounted within the housing 10 and slidable relative thereto in vertical direction. At the top of the rod 40 is mounted a horizontal rod portion 41 which thus lies at right angles to the vertical rod 40 and extends outwardly therefrom to an end portion 42 threadeadly engaged with the rod portion 41. The end portion 42 carries a spherical bearing 43 receiving the shaft 16 so as to allow free pivotal movement of the shaft about an axis at a centre of the spherical bearing to allow two degrees of freedom of pivotal movement of the head relative to the support member 11.

At one point along the length of the rod portion 41 is mounted a support block 44 which supports a vertical shaft 45 with a thumb screw 46 at its upper end. At the bottom of the shaft 45 is mounted a pulley 47 which carries an endless band 48 extending from the pulley 47 to a similar pulley 49 formed at the top of the sleeve 14. Thus rotation of the thumb screw 46 by manual operation causes rotation of the pulley 47 about the axis of the shaft 45 so as to drive the pulley 49 and the head about the vertical axis of the shaft 16. This technique for effecting the rotation of the shaft 16 and the head avoids the application of sideways forces on the head so that the centre of gravity of the head remains properly suspended beneath the centre of the spherical bearing and thus holds the beam 29 in a constant horizontal plane set by the spirit level 34. Thus rotation of the head caused by operation of the thumb screw 46 causes the beam 29 to scan around an area to be marked so that the beam passes over positions of constant height in that area.

The housing 10 comprises a generally rectangular body 50 with a flat front face 51 , a flat rear face 52, vertical sides 53, a top face 54 and a bottom face 55. Within the front face 51 is defined a recessed receptacle 56 which is shaped to match the head 12. The receptacle is inclined relative to the side and bottom surfaces so as to receive the head in a minimum space and to minimize the size of the container.

The front face further includes a recessed receptacle 57 which is shaped to receive the rod portion 41 , the end portion 42 and the rotational mechanism including the thumb screw 46.

It will be appreciated therefore that the support 11 and the head 12 have two separate positions that is the extended position for use and the retracted position for storage. For simpler viewing of the drawing, the apparatus is shown simultaneously in both positions.

The rod 40 is located within a bore 60 which extends along substantially the full length of the housing from the top face 54 to the bottom face 55 adjacent one side 53. The rod 40 is a sliding fit within the bore and the rod 40 carries an end cap 61. The end cap 61 slides within a counter bore 62 coaxial with the bore 60. Thus the end cap 61 can move from a position at the bottom face 55 or can move upwardly with the rod 40 to a position approximately halfway up the housing. This movement moves the rod between the storage and deployed positions. In the storage position with the rod at the bottom of the housing, the rod portion 41 can be rotated through 180° to enter the receptacle 57. With the rod 40 moved to the deployed position, the rod portion 41 can be rotated to the extended position extending outwardly away from the housing. Depending upon the orientation of the housing on the support surface, the rod portion 41 may extend at 90° to the storage position or 180° for storage position. The rod 40 passes through a loop 63 mounted within the housing at the bore 60 with that loop being movable at right angles to the length of the rod 40 by a screw 64 and nut 65 with a nut being operable by a lever 66 to tighten the loop against the rod in either the deployed or stored positions. Thus the rod is held by the loop 63 against sliding and rotational movement to remain in the deployed position when so set. The housing carries three screws 70, 71 and 72 at suitable positions spaced apart across the front face and located around the receptacles. The screws are held in place by washers 73 so that the screws remain in place within a respective bore 74 and projecting through the bore and through a narrower bore portion 75 so as to be extendible through the rear face 52 of the housing to engage into a support surface. By rotation of the screws, therefore, the housing can be attached to the support surface (not shown) and remain in place while the leveling action is carried out. When complete, the screws can be retracted by simply reversing the rotation of the screws so as to pull them back into the bore 74 to release the housing from the support surface.

A threaded bore 80 in the bottom surface 55 allows the housing to be attached directly to a conventional construction type tripod mount.

In an alternative arrangement (not shown) the single dot laser is replaced with a laser arrangement which can generate a line so that a line can be projected onto the wall in place of the ingle dot thus reducing the amount of movement of the body which is necessary to mark a required line. The line can be generated by a lens arrangement which can be attached in front of the dot laser. The line laser or lens can be rotated to generate a vertical or horizontal line.

In a further alternative (not shown) the pulley 49 can be mounted on the arm 42 and can communicate rotational movement to the body by way of abutting elements which project downwardly from the pulley to the top of the body; thus avoiding application of twisting forces tending to mis-align the body and the laser to the body from the pulley.

Claims

CLAIMS:

1. A level comprising: a support body having mounting means thereon for mounting the support body in stable position on a support surface and means defining an outstanding support point; a level head; head mounting means mounting the level head on the support point of the support body so as to be suspended freely therefrom, the head mounting means being arranged to allow free tilting movement of the level head about the support point such that a level head takes up a position with the centre of gravity of the level head lying on an axis of the level head extending directly vertically downwardly from the support point, the head mounting means allowing rotation of the level head about said axis; and a laser mounted on the level head for projecting a beam from the level head substantially at right angles to the axis.

2. The level according to Claim 1 including means for adjusting the position of the centre of gravity of the level head.

3. The level according to Claim 2 wherein the means for adjusting comprises a screw extending parallel to the beam and a weight mounted on the screw such that rotation of the weight about the screw moves the weight longitudinally of the screw.

4. The level according to Claim 1 , 2 or 3 including a spirit level with an axis of level parallel to the beam.

5. The level according to Claim 1 , 2, 3 or 4 wherein the support body includes an elongate arm with the support point at an outer end of the arm.

6. The level according to Claim 1 , 2, 3, 4 or 5 wherein the support body includes a rod mounted on a spherical joint allowing tilting movement and a bearing rotatable about an axis longitudinal of the rod, the bearing being mounted in a housing and the housing being releasably connected to the head.

7. The level according to Claim 1 , 2, 3, 4, 5 or 6 including a container for receiving for storage therein the support body and the head, the container including means for mounting the container on a support wall and means connecting the container to the support body for supporting the support body in position relative to the support wall.

8. The level according to Claim 7 wherein the container includes a plurality of mounting holes extending therethrough through which screws can extend for engaging into the support wall and wherein the container includes means for retaining the screws in position in the container when retracted from the support wall.

9. The level according to Claim 7 or 8 wherein the support body includes a post, means mounting the post on the container at one end thereof so as to stand upwardly therefrom and an arm for mounting on the post so as to extend substantially horizontally outwardly therefrom to the support point.

10. The level according to Claim 7, 8 or 9 wherein the container includes a receptacle for receiving and storing the head and wherein the post is mounted on the container so as to be retractable into a channel therein and wherein the head is mounted on the post so that the head remains in position on the post when the post is retracted and the post is rotated to cause the head to move into the receptacle.