Patent Application
20060277768
The invention generally relates to an electric tool, such as a circular saw, a jigsaw or a milling machine, comprising a housing and a shaping tool that can be placed in a dismountable and movable way in the housing, and a laser unit is installed on or in the housing, which is configured to project a reference line onto the surface of a relatively flat object or work piece to be shaped on one or both sides of the installed shaping tool in its working direction and of which at least one side runs in or very close to and preferably coextensive with the plane of a side of the shaping tool.
Such an electrical tool in the form of a manual circular saw is known from patent U.S. Pat. No. 5,461,790. In this, the laser unit projects a reference line by means of a rapidly back and forth movable, “fanning out” laser beam. The purpose of the projected reference line is to allow accurate positioning of the circular saw at the beginning of the saw cut. However, a saw cut has not only a direction but also a width. The known circular saw does not take account of this so that it cannot be guaranteed that the dimensions of the object to be sawn will be obtained correctly. There are known saws that attempt to solve this problem through shadow effects by the saw blade, but these are inaccurate or insufficiently obvious to the user.
Embodiments of the present invention comprise an electric tool of the type which has a movable shaping tool for cutting at least a surface of a work piece, wherein the tool is configured to make a cut of a predetermined width when moved in a working direction during operation, and comprises a housing in which the movable shaping tool can be installed, a laser unit installed in the housing, the laser unit being configured to project onto the generally flat surface a first reference line that runs in the working direction, the first reference line having an outside edge on or very close to the plane of one side of the shaping tool, the laser unit also being configured to project onto the generally flat surface a second reference line that runs in the working direction, the second reference line having an outside edge on or very close to the plane of the other side of the shaping tool.
Other embodiments are directed to other aspects of the invention.
Broadly stated, an electric power tool such as a circular saw, jigsaw or milling machine is disclosed which has a housing to which a laser unit is provided, with the laser unit being configured to project a reference line onto the plane of the object to be shaped which would generally be a flat work piece or a work piece having a generally flat surface which would be cut. The laser unit projects at least one reference line on the two sides of the installed shaping tool in its working direction, and at least one outer edge of which runs on or very close to the outer reach of one side of the shaping tool. It is preferred that outer edges reference lines located on both sides of the shaping tool be on or very close to the outer reach of the shaping tool. In this manner, both sides of the cut to be made to the object can be indicated in a very clear and accurate manner and a user can see precisely where the material will be removed as a result of the cut. This reduces the chance of errors.
In this regard, by the sides of the installed shaping tool is meant more particularly, that two parallel planes are defined by the outermost sides or reaches of the cutting teeth of the saw blade or the cutting bit.
The laser unit can have its own power supply, for example, in the form of a battery, but it can also be fed by the main supply of the electric tool. The electrical power for the laser unit can also be generated by means of a dynamo driven by the rotation of the motor. Preferably, the laser unit can be switched on and off independently of the operation of the motor of the electric tool. The distance between the outer edges of the reference lines projected on the work piece on first and second sides is preferably adjustable to suit the dimensions of the installed shaping tool.
In a third preferred embodiment, the first side of the reference line is the side of a first reference line projected by a first laser beam and the second side of the reference line is the side of a second reference line projected by a second laser beam. Both reference lines do not necessarily have to project the same length. For instance, the second line can be set shorter because it indicates the width of the cut, whereas the first line also indicates the direction of the cut.
In a third preferred embodiment, the laser unit comprises two lasers, wherein the first laser unit is configured to project the first laser beam and the second laser unit is outfitted to project the second laser beam. In a fourth preferred embodiment, the laser unit comprises a laser and optical devices to split a source laser beam exiting from the laser unit into a first laser beam and a second leaser beam.
Preferably, the optical devices comprise two mirror planes of which one is semi-permeable. The mirror planes are preferably placed parallel to each other and at an oblique angle with the source laser beam. Furthermore, the mirror planes are preferably formed by two side planes of a transparent prism. Application of a transparent prismatic body has the advantage that the mutual position of the mirror planes is very stable. Additionally, the distance between the first reference line and the second reference line is preferably settable by adjusting the oblique angle between the mirror planes and the source laser beam. Also, the distance is also a function of the thickness of the prism, i.e., the distance between the mirror planes. In a variation of the fourth preferred embodiment, a third mirror plane is placed in the path between the laser and the semi-permeable mirror. This third mirror reverses the source laser beam, so that the first two mirror planes can be placed alongside the laser. This allows a more compact construction of the laser unit. The mutual positions of the mirror and the mirror planes with semi-permeable mirror can also be reversed.
In a fifth preferred embodiment, the first side of the reference line and the second side of the reference line are two different sides of the same reference line extending over the width of the shaping tool. Preferably, the width of the reference line can be set by means of a lens.
Preferably, the first laser beam and the second laser beam each have a different color. For instance, the projected reference line at the side of the waste portion can have a red color and the reference line at the side of the part to be manufactured can have a green color.
Preferably, the angle of the laser unit with the plane of the object to be shaped is adjustable. This also applies to the angle of the laser unit with the plane of the saw blade. Furthermore, the laser unit is preferably adjustable sideways with reference to the saw blade. By this, the position with respect to the saw blade of the reference lines can be set precisely. The start point of the projected lines lies as close as possible to and is preferably coextensive with the point where the electric shaping tool is performing its work, such as the saw cut.
Preferably, an optical lens is placed in the path of the laser beams. By doing so, the quality of the projected reference lines can be manipulated and controlled, such as adjustment of the start point and line length, clarity, width, mutual distance and parallelism.
Turning now to the drawings, and particularly
The circular saw is provided with a laser unit 11 that, through the use of optical devices, can project two fanning out laser beams 12 and thus project two parallel reference lines 13, 14 on the object to be cut. The reference lines 13, 14 can also be formed by the sides of the projection line of a single wide laser beam 12 or by the sides of the projection lines of two separate laser beams 12. At the beginning of the sawing operation, the circular saw is directed in such way that one of the reference lines 13, 14 preferably coincides with a line 15 that was previously put on the object, for instance with a pencil 16.
The distance between the outside edges of the reference lines 13, 14 is preferably adjustable to coincide with the saw cut width to be obtained, so that the user can clearly see what will be cut away and what will become the associated waste. Stated in other words, the distance between the outside edges of the reference lines indicates the saw cut width, i.e., the distance between the outer sides of the saw teeth. In line with the saw blade to be used, the distance between the outside edges of the reference lines can be set at the saw cut width. In fact, such setting can be performed at the factory or by the user.
The housing of the laser unit 11 or the laser unit 11 as such is attached in accordance with arrow 18 in a movable way in a groove 17 located in the circularly shaped part of the upper part of the front side of the housing 1. The laser unit 11 can also be rotated around the radial axis according to arrow 19, and can be slid in a sideways direction according to arrow 20 to allow accurate setting of the laser beams 12. The laser beams are set at both sides of the saw blade according to the direction of the saw blade and the position of the saw teeth.
In a second embodiment according to
In a third embodiment according to
In a fourth embodiment according to
In a variation of the fourth embodiment according to
In the fifth embodiment shown in
The invention is not limited to the embodiments shown in the drawings. For instance, in the embodiment in
While various embodiments of the present invention have been shown and described, it should be understood that other modifications, substitutions and alternatives are apparent to one of ordinary skill in the art. Such modifications, substitutions and alternatives can be made without departing from the spirit and scope of the invention, which should be determined from the appended claims.
Various features of the invention are set forth in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1028920 | Apr 2005 | NL | national |
