Woodworking – Special-work machine – Combined
Reexamination Certificate
1999-09-27
2001-03-06
Bray, W. Donald (Department: 3725)
Woodworking
Special-work machine
Combined
C144S039000, C144S367000, C144S369000, C144S242100, C144S245100, C144S250130, C409S215000, C269S056000
Reexamination Certificate
active
06196283
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a woodworking machine for working elongated workpieces such as timbers, beams, boards, round timbers or the like, the workpiece resting on a support and a longitudinally movable coupling element guiding the workpiece to one or more working units.
DESCRIPTION OF THE PRIOR ART
A woodworking machine, in particular a trimming machine, is known from German Patent Specification 34 20 080. The task of such a trimming machine is to prepare the timber pieces appropriately, as, for example, required for the construction of a roof truss, on the basis of a work plan designed, for example, by a CAD program. Such woodworking machines or trimming machines work fully automatically, which means that complex marking-out of the timber pieces is no longer necessary.
To convey the workpieces, it is known to effect, for example, frictional or positive connection, for example by a ram guided towards the workpiece from above. The workpiece rests, for example, on a table or roller track. The ram, serving as a coupling element, moves on a rail, with the result that the movement of the workpiece through the trimming machine is effected. The workpiece is guided by a longitudinally running fence.
The invention relates to a woodworking machine for working elongate workpieces as described above, a longitudinally movable coupling element guiding the workpiece to one or more working units. Such a woodworking machine is known, for example, from European Patent Application 608 746. Here, elongated workpieces are clamped on at least two clamping carriages which are movable on a guideway arranged below the workpiece and move the workpiece through a stationary portal-like working centre.
In the case of the above-described machines, there is the problem that the workpiece must be sufficiently guided in the region of the working machines, these are, for example, saws, borers, millers, planers or the like, to achieve reasonable working accuracy. For this purpose, it is known to guide or hold the workpiece in the region of the working unit by stationary stops. The working units here are generally multi-axis machines which may have a considerable working radius, and the stops must of course be arranged outside this working radius to ensure 100% that the stops are not reached by the working tools and damaged or the working tools are not damaged by the stops, which are produced from metal. Stationary clamping means are situated in the region of the working tools to guide the relatively long workpieces with a certain degree of accuracy in the region of the working units. However, the stationary clamping means must likewise remain outside the working radius of the working units to avoid damage.
The result of this is a relatively large distance between the point of guidance of the workpiece and the actual working, and this may lead to dimensional tolerances, particularly in the case of curved workpieces, with the risk that rejects might arise. It should also be noted that the workpiece, which projects beyond the fixing point, tends to vibrate during working and therefore accurate working may not be ensured.
BRIEF SUMMARY OF THE INVENTION
The object of the invention therefore is to improve a woodworking machine as described above such that it provides greater accuracy, even in the case of curved workpieces, and in particular reduces rejects.
This object is achieved firstly by a woodworking machine as described above in which a clamping carriage equipped with at least one movable clamping jaw serves as a coupling element and the coupling element clamps the workpiece with its clamping jaws. In the case of this arrangement of the invention, the timber workpiece rests on a table or roller track. The coupling element grips the workpiece from two sides, one clamping jaw, for example the non-movable clamping jaw, serving as the zero line and thus replacing the stop. The width dimension is thereby precisely fixed and it is possible to dispense with the complex longitudinally running fence. At the same time, it is possible to position the coupling element so close to the workpiece that optimal guidance or firm clamping of the workpiece in the region of the working unit is possible, without the risk of the coupling element being in the region of the working unit.
The solution according to the invention furthermore achieves the effect that the timber to be transported is gently gripped. In the case of the known embodiments, a point or a cutting edge is pressed into the timber, which may lead to visible marks. With regard to this proposal, the timber is treated gently and no visible impressions are produced.
The proposal according to the invention permits the positioning of workpieces with a coupling element as described. It is thereby also possible to position relatively short workpieces with the same accuracy as relatively long workpieces. With such an arrangement, it is possible to work workpieces up to 6 meters or greater in length, but it is also possible at the same time to work workpieces of less than 80 centimeters. The result of this is a woodworking machine of enormous variability.
The measure according to the invention has created a high-quality and highly versatile woodworking machine. The woodworking machine is not only capable of being used as a trimming machine as described at the beginning, i.e. of performing essentially carpenter's work, but is also to be seen at the same time as a woodworking centre on which complex working operations can be performed. For example, it is possible to use the above-described woodworking machines to produce elements for stair manufacture, balustrade manufacture, wooden boxes, but also, for example, toys etc. The woodworking machine according to the invention is therefore capable of performing both carpentry-type working operations and joinery-type working operations. There results a very high degree of flexibility of this woodworking machine, which promotes in particular cost-effective operation of the machine.
In a variant of the invention there is provision for there to be provided, in addition to the coupling element, a guiding element which is likewise longitudinally movable and can be positioned in such a manner at a working unit that, on the one hand, optimal workpiece guidance is achieved and, on the other hand, the coupling element and the guiding element remain outside the operative region of the working unit. The guiding element is provided as a second element besides the coupling element. If required, the workpiece is moved by the two elements simultaneously, the guiding element functioning as a coupling element in this case. By using these two elements, however, it is also possible to perform a relative movement of the workpiece with respect to the guiding element, with the result that the guiding element is positioned as close as desired to the working unit and thus enables optimal guidance of the workpiece. In this embodiment, the guiding element may be of the same design as the coupling element, i.e. in the form of a clamping carriage, with at least one movable clamping jaw, the cooperation of the two clamping jaws defining in particular the zero line (Y direction).
Furthermore, this object is achieved by a woodworking machine as described above in which there is provided a guiding element which is likewise longitudinally movable and can be positioned in such a manner at a working unit that, on the one hand, optimal workpiece guidance is achieved and, on the other hand, the coupling element and the guiding element remain outside the operative region of the working unit.
The arrangement according to the invention achieves the effect that the guiding element is always positioned optimally relative to the working unit and the working operation performed on the working unit, for it is to be ensured that the working unit does not require the maximum working space for each working operation. However, the control system, which after all controls the working unit in accordance with the steps to be carried out, may at the same ti
Bray W. Donald
Jacobson Price Holman & Stern PLLC
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