Laser level assembly

Details Laser level assembly Laser level assembly

2001-03-02

2004-07-13

Stafira, Michael P. (Department: 2877)

Optics: measuring and testing

Angle measuring or angular axial alignment

Reexamination Certificate

active

06762830

ABSTRACT:

FIELD OF THE INVENTION
The invention disclosed herein relates to a laser level assembly. The laser level assembly is an apparatus that provides a laser beam which can be used for applications including but not limited to surveying and construction levelling and marking out.
BACKGROUND OF THE INVENTION
The use of a rotating laser beam to define a plane is well known. These devices have typically incorporated a semiconductor laser fixed within a housing projecting its laser light beam into a spinning prism which effects translation of a typically vertically projected beam into a rotating horizontal beam. Attachments have been available which in like manner effect a rotating vertical laser beam, however these require the dismantling of a set up device to permit fitting. Therefore the device must be relocated and reset when changing from a horizontal rotating laser beam to a vertical rotating laser beam.
In such arrangements the laser beam is projected along the axis about which a platform supporting a prism rotates. An electric motor is used to drive the platform typically through a belt or gear cog arrangement. Thus, the known devices rotate fully about an axis defining a full plane. This means that there can be a significant delay at a remote sensing location for the beam to rotate between each transversing of the location. The speed of rotation may be variable but this can lead to a further problem. The effective angular velocity can be very high with the effect that the laser radiation flux experienced by a sensor may be too low to be reliably sensed. Thus increasing the speed of rotation can lead to unreliable sensing of the laser beam so requiring a slower speed of rotation, and slowing the speed of rotation increases the time between each transversing by the beam of the sensor. Electronic design of the sensor may accommodate some of these problems.
Further problems are exhibited by the known systems. The use of quality optical elements such as a prism leads to an expensive device. Further, the mechanical supporting structure also typically needs to be to a very high tolerance with the result again that the device is expensive.
To overcome some of these problems a number of devices have been proposed.
U.S. Pat. No. 5,287,365 to Nielsen et al describes a laser apparatus where a semiconductor laser is mounted onto a platform which is rotated by an electric motor. The platform has a central shaft which is driven by an electric motor through a belt drive. Electrical power is transferred to the shaft and thus to the laser through slip rings. Control of the electrical motor is limited to on/off and speed control.
As disclosed the apparatus provides essentially a horizontal plane in which the laser beam rotates.
In U.S. Pat. No. 4,973,158 to Marsh an instrument is disclosed which is intended to be fitted to a surveyor's transit and telescope. It is disclosed as rotating in a vertical plane aligned with the plane of view of a telescope. There is no disclosure of being able to change the plane of laser beam rotation in a convenient and simple manner. Rather the instrument is limited to improvements related to a transit level rather than a more general instrument.
The disclosed device utilises a rotatable shaft which has a platform at each end. A semiconductor laser is mounted on one platform with drive and control circuitry mounted on the other platform. To power the laser, electrical power is supplied to the platforms through electrical brushes to the shaft. The shaft and the platforms are rotated by an electric motor through gear cogs.
In U.S. Pat. No. 5,400,514 to Imbrie et al an apparatus is disclosed where a laser pointer is centrally supported on a shaft. The shaft is belt driven to rotate by an electric motor within a rectilinear body. The electrical and electronic circuitry for the electric motor and the laser pointer are completely separate. The laser pointer includes drive circuitry and battery for electrical power supply independent of the rest of the apparatus. Accordingly, the electrical motor must rotate the semiconductor laser and the necessary circuitry.
The body of the apparatus disclosed does include means to set up the apparatus so that the plane within which the laser radiation projects is either vertical or horizontal. For this purpose three orthogonally mounted spirit bubble levels are provided with two sets of adjustable feet projecting from adjacent sides. To change the plane within which the laser beam rotates the apparatus must be set up afresh.
It is a proposed object of this invention to provide an apparatus to obviate or minimise at least one of the aforementioned problems, or at least provide the public with a useful choice
SUMMARY OF THE INVENTION
The invention may be said to reside, not necessarily in the broadest or only form, in laser level apparatus including body means, platform means supported by the body means and selectively pivotable about a first axis, drive means supported by the platform means and selectively pivotable about a second axis transverse to the first axis, head means rotatably supported by the drive means and adapted to be selectively rotated by the drive means about a third axis transverse to the second axis, laser means supported by the head means to selectively project laser radiation from the head means transverse the third axis, laser means includes a semiconductor laser adapted to produce the laser radiation, and the apparatus includes a first rotatable electrical connection means and a second rotatable electrical connection means through which electrical power is supplied to the semiconductor laser.
In another preferred form, the drive means includes a motor with a rotatable shaft driven thereby which is coaxial with the second axis and the head means is supported by the shaft.
In one preferred form, wherein the shaft has two partly coaxial electrically conductive parts insulated one from the other, and the first rotatable electrical connection means and the second rotatable electrical connection means each includes a respective one of the parts. According to a preferred form, the first rotatable electrical connection means and the second electrical connection means respectively includes electrical brush arrangements. It will be appreciated that other arrangements known to the art similar in effect to the electrical brush arrangement can be used as desired.
The separation of the laser means and the electrical power source means the weight of the laser means can be reduced so easing the load experienced by the drive means during rotating the laser head. In one preferred form, the laser means may be rotated and varying and relatively high speeds and dithered within an arc. For such action it is desirable for the rotating laser means to have a relatively low inertia.
It will be appreciated that the ability to rotate the various parts of the apparatus with respect to other parts permits flexibility and ease of use.
In a preferred form, the laser radiation projected by the laser means is substantially perpendicular to the third axis, the third axis is substantially perpendicular to the second axis, the second axis is substantially perpendicular to the first axis, and the drive means may be selectively rotated to a first configuration where the third axis is substantially parallel or coaxial with the first axis and to a second configuration where the third axis is substantially perpendicular to the first axis.
In a further preferred form, the body means has levelling means to enable adjustment of the support of the platform means such that the first axis is within a vertical plane, and thereby when the apparatus is in the first configuration the laser radiation projected by the laser means is substantially within a horizontal plane and when the apparatus is in the second configuration the laser radiation projected by the laser means is substantially within a vertical plane. By levelling the body means so that the first axis is vertical the laser beam can be rotated in a horizontal or vertical plane. In the case of a verti

Affiliated with

Also associated with

Rating

Laser level assembly does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Laser level assembly, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Laser level assembly will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3204017