Gear cutting – milling – or planing – Milling – Randomly manipulated – work supported – or work following device
Reexamination Certificate
1996-11-25
2001-02-20
Briggs, William (Department: 3722)
Gear cutting, milling, or planing
Milling
Randomly manipulated, work supported, or work following device
C144S119100, C144S136400, C144S219000, C409S180000
Reexamination Certificate
active
06190099
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a motor-driven hand tool for machining of workpieces, in particular planar workpieces, having a guide surface which can be placed on the workpiece to be treated, and with a face milling cutter for processing projecting past the guide surface, which has an axis of rotation extending perpendicularly with the guide surface.
BACKGROUND OF THE INVENTION
A quite frequent requirement is for having to remove a comparatively thin layer, which can be a layer of old lacquer or a damaged surface layer of the workpiece, from a planar workpiece, for example a table top, a door, a window frame or a parquet floor. Grinding machines, such as belt grinders or orbital sanders, have been employed for this purpose for a long time, but deeper scratches, dents or similar damage cannot be removed by these devices or they can be removed only with a large expenditure of time. The troubling generation of dust must always be tolerated with grinding work. The non-directional cutting edges of the grinding bodies have been shown to be disadvantageous for some types of application. In addition, under strong pressure it is particularly difficult for an untrained layman to guide a grinder, in particular a belt grinder, free of tilt and evenly, so that a level surface is generated. Processing by machining and cutting is given preference for the above mentioned reasons.
A manual planing machine with a roller-shaped planing tool is known from German Patent Publication DE 35 41 728 A1, . This machine defines an axis of rotation which extends parallel with the surface to be worked. However, manual planing machines of this type have the disadvantage that for all practical purposes they can only be moved in the circumferential direction of the planing roller, which extends parallel with the workpiece surface.
Finally, a device defining the species and available in commerce is known by the name “Lamello-Plano”, in which a face milling cutter with an axis of rotation extending perpendicularly with the workpiece surface is provided. However, this tool is suitable and intended for a purpose different from that of the present invention. The tool is not intended to be employed for planar removal of a surface layer, but for the removal of a spatially limited overhang, such as is created, for example, by the insertion of a filler claw into a cut-out irregularity of the workpiece. The face milling cutter is disposed with the guide surface to be placed on the workpiece to be processed in an open-edged recess, so that the overhang extends into the cutting range of the face milling cutter in this open-edged recess. When using the known hand tool in accordance with this purpose, the face milling cutter is placed back away from the guide surface. This known hand tool has the further disadvantage that, aside from its purpose of use which is different from that of the present invention, working up to an area of the inner edge is not possible, because housing elements make the approach of the face milling cutter to an edge or step area impossible.
Surface milling cutters are also known which, however, are used in accordance with their purpose for machining surface profiles, such as grooves, dovetailed guides or the like, and furthermore do not permit surface treatment right up to a fold, and edge or a step.
OBJECT AND SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved motor-driven hand tool of the type mentioned at the outset in with respect to the above explained details, and to embody it particular in such a way that it will become possible to work a surface to be treated by machining up to a shoulder, an edge or a step, and that the hand tool can be used in an advantageous manner, particularly for working a fold area in any arbitrary workpiece.
In connection with a hand tool of the mentioned type this object is attained by means of providing cutting edges on its radial circumference and a face milling cutter projects past a tangent plane delimiting the entire hand tool toward one side, so that it can approach a shoulder, a step or a wall with the tangent plane.
The mentioned plane which is tangent to the device is understood to be an imaginary plane which is tangent to a side of the device at the outside, so that with this plane or up to this plane the device can be brought close to a shoulder, a step or a wall. It is therefore possible to work a surface to be treated, for example a parquet floor, with the cutter on the front of the face milling machine right up to the lateral walls of the room. It is also possible to work a right-angled fold area right up into the fold edge of, for example, the surface of a wing of a window or an area of a stair step, simultaneously with front surface cutting, wherein the face milling cutter simultaneously performs a milling treatment with its radial cutters on the side of the fold facing the radial tool circumference.
In a preferred embodiment of the present invention the face milling cutter projects at several exterior sides past the tangent plane which respectively delimits the tool laterally. If these exterior sides extend approximately at right angles to each other, a very extensive machining treatment of not only a fold area, but also a fold corner area is possible.
It has been shown to be particularly advantageous for the hand tool to have a support plate, which constitutes the guide surface facing the workpiece surface. In a preferred embodiment of the present invention the lateral boundary of the support plate defines at least one of the tangent planes which laterally delimit the device. In that case the face milling cutter then projects with the orbit of its radial cutters past the lateral boundary of the support plate by the amount of the desired milling depth. In this case it has been shown to be particularly advantageous if the lateral boundary of the support plate is embodied flat and therefore can be guided along a flat step area or the like.
The face milling cutter could possibly be disposed in a break of the support plate, however, the support plate preferably has a recess open toward at least one side.
It has been shown to be advantageous, particularly in the case where the face milling cutter has a comparatively large diameter, if a milling head with cutters fixed thereon is used. In this case it is possible to design the cutters in such a way and to fix them releasably on the milling head so that they have cutting edges assigned to the front as well as the circumferential surface of the milling cutter. It often occurs in the course of machining that nails, screws or other interfering insets in the workpiece to be treated are caught by the cutting edges of the milling cutter, which can result in heavy damage to the cutters or the milling cutter, so that they have to be replaced. For this reason it is suggested to use both cutters which are assigned to the front of the milling head, as well as cutters which are assigned to the radial circumference of the milling head.
If only front surface cutting is intended to be performed and therefore the radial cutters extending past the tangent plane are not used, it is recommended to provide a removable safety cover in the area of the lateral overhang of the face milling cutter in order to reduce the danger of injury.
In accordance with a preferred embodiment of the present invention a pivotable protective cover is provided which in its pivoted-out position, which exposes the area of the radial overhang of the face milling cutter, does not project past the tangent plane. For this purpose the protective cover is advantageously designed as a rocker-like component and is arranged so it is pivotable around a pivot axis which preferably extends parallel with the guide surface. Preferably the rocker-like component has a level cover section and an operating surface situated in the area of the pivot axis. By means of manual pressure it is possible to pivot the rocker-like component around the pivot axis, preferably over 180°, so that the cover section
Bartmann Klaus
Schulz Manfred
Vollweiter Ralf
Briggs William
Jones Tullar & Cooper P.C.
Metabowerke GmbH & Co.
LandOfFree
Motor-driven hand tool does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Motor-driven hand tool, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Motor-driven hand tool will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2579606