DE4209778A1 - Hand driven machine for cutting fibre panels etc. - has rotatable circular cutter which is pushed along upwardly loaded guide beam pivoted at one end on baseplate - Google Patents

Abstract

The machine has a rotatable circular cutter (2) mounted in a slide (16) which can be pushed along a straight guide beam (10). The panel to be cut is held on a baseplate (4) and located against an adjustable angle stop (5,6). The rotational axis of the blade coincides with the lower edge (18) of the guide beam, giving maximum depth of cut and favourable cutting geometry. At one end the guide beam is pivoted in bearings which are elastically loaded to swing the beam upwards out of the cut. USE/ADVANTAGE - For making straight cuts in foam or fibre material panels. Produces clean, straight cut and requires no power source.

Description

The invention relates to a cutting tool according to the Preamble of claim 1.

The problem arises when cutting flat material precise guidance of the cutting blade, in particular when the material is substantially plate-shaped. "In the essentially plate-shaped "should mean that it is flat and of a not inconsiderable thickness is that but it is not necessarily limited by flat surfaces must, but that within the scope of the invention without further such material can be understood that with Depressions or elevations on at least one of his Surfaces can be provided. This problem of keeping the Cutting blade is particularly serious when it is flexible, at most even elastic material acts that tends to dodge when cutting, so that it is difficult to achieve a smooth cut surface.

The invention is based, in such cases to improve the cut, and this succeeds according to the invention by the characterizing features of Claim 1.

Various straight-line guidance devices are in themselves known that are used for the purposes of the invention can. For example, it would be conceivable to use one to provide an articulated arm, one end of which is connected to the holding or Locking device is connected, whereas the free End through a flat surface in a straight direction is. Such a straight line is bulky on the one hand and unwieldy, on the other hand the spherical bearings tend to some play to deflect the cutting blade. Therefore an embodiment according to claim 2 preferred, the one  ensures more accurate and safer guidance, in addition but especially for thicker plate-like material, like Insulating or foam, a deep cut, at Favorable cutting angle guaranteed because the middle tangent in the area between the one facing the material Cutting edge and the one near the axis of rotation In any case, the area is below 45 ° to the material. This allows, if necessary, a motorized operation of the To dispense with the cutting blade entirely, as in claim 5 is the case, especially since insulation panels are often used on construction sites are to be cut where electrical connections are either wide removed or nonexistent.

With cutting tools it is always difficult to do that To hold the cutting blade so that the plate-shaped material can easily be slid underneath (where the expression "This" is to be understood relatively, because the material too held vertically and the cut perpendicular to it can be made). Usually a person has to Hold the cutting blade while the other person is using the Alignment of the plate-shaped material is busy.

Now to ensure that the material to be cut is under easily brought under the cutting blade in all circumstances can be cut, but on the other hand does not hinder cutting is preferably the features of claim 7 intended.

Often it is also desirable to have the cuts under one certain angle relative to the plate-shaped material to be able to make. An angle adjustability is admitted not unknown, but it is difficult to each set the desired angle exactly. This problem will by the configuration according to claim 8, in particular in the preferred embodiments according to claim 9 or 10 remedied.

Further details of the invention will become apparent from the following description of schematically in the drawing illustrated embodiments. Show it:

Fig. 1 shows an inventive cutting tool according to a first embodiment in an oblique view, to the

Figure 1A illustrates the cutting geometry;

Fig. 2 is a section along the line II-II of Fig. 1;

Fig. 3 is a section along the line III-III of Fig. 2;

FIGS. 4A and 4B are respectively a possible two positions of the adjustable stop rail;

Figure 5 is a partial view of a variant embodiment in an axonometric view, which illustrates a guide beam with a carriage guided thereon.

Fig. 6 is a further partial view of a bearing end of another embodiment of a guide beam; and

Fig. 7 shows a variant for defining the pivot angle of the stop rail shown in Figs. 4A and 4B.

Referring to FIG. 1, a cutting tool having a circular, rotatable about a rotation axis 1 blade 2 is shown, that of a (not shown) a retaining or locking means 3 for determining the relative position to be cut plate shaped material has. This holding device 3 has a support board 4 with a stop rail 6 which can be pivoted about a pivot axis 5 and which determines the rearmost position of the material to be cut.

The anchorage rail 6 is to be inclined at an angle, in particular of 90 °, more engaging abutment 7 and can be locked by means of a clamping screw. 8 The stop 7 or its stop surface 9 can also assume an angle to the rail 6 deviating from 90 °, for example an angle of 45 ° or 30 °, in which case it is then more favorable to make the stop surface 9 longer than shown. The area 9 serves the align a side edge surface to be cut material, so that the relative position is uniquely determined to be cut material to the cutting blade 2 by the rail 6 with its abutment surface 9 and the material is locked in this position. In order to avoid slipping away of the material plate, the support plate 4 can be provided with a rough coating or if necessary, may press the plate against the surface 4 of a (per se known) clamp arm.

A guide bar 10 for guiding the cutting blade 2 is pivotally connected to the holding or locking device 3 . In order to make it easier to place the material to be cut on the support surface 4 without having to hold the guide beam 10 up , it is advantageous if the swivel joint is formed by a rubber joint 11 known per se, preferably by two rubber joints 11 has a cage 12 with a polygonal opening 13 (usually square), in which a number of elastic beads 14 are arranged in the corners of the opening 13 and comprise a polygonal shaft 15 , which is thus held elastically in the position shown removed from the support board 4 and can be pivoted downwards, if desired, but also upwards against the force of the elastic deformation of the beads 14 .

A slide 16 , on which the rotatable cutting blade 2 is fastened, can be moved straight on the guide bar 10 . In itself, a fixed blade for cutting would also be conceivable, but it is still clear why the arrangement shown is particularly advantageous. The guide bar 10 namely has a lower guide shoulder 17 which forms the bottom edge 18 of the guide bar 10 . The axis of rotation 1 of the cutting blade 2 lies in the region of this lower edge 18 , and FIG. 1A illustrates which cutting geometry results from this.

Because practically the entire radius of the cutting blade 2 is now available, a relatively thick material plate 19 can be cut, as is often the case with insulating plates, but also with foam plates. After all, the top surface 19 'of this material will have to run below the axis of rotation 1 . This in turn results in the fact that, when an angular symmetry beam s is arranged, an average tangent t is found which, with the horizontal (corresponds to the course of the contact surface 4 ), encloses an angle alpha which is less than 45 °. This has the consequence that the force K acting tangentially on the cutting blade 2 is greater than the force component k acting perpendicularly thereto, so that the force K acts on the cutting blade 2 in the sense of a rotary drive. If desired, a motor drive for the blade 2 can thus be dispensed with, and it is only necessary to press the carriage 16 against the pivot axis 11 from the front with the aid of a push rod 20 arranged obliquely to the guide beam 10 , the cutting blade 2 rotating along one Edge 4 'of the bearing surface 4 moves and performs the cut.

Fig. 1 shows that the guide bar 10 is relatively long, as well as insulating plates, for. B. made of glass wool, are relatively large. It is therefore advantageous to take measures to save weight in order to improve the manageability. For this purpose, it is preferred if the guide beam is designed in the manner shown in FIG. 2 as a hollow profile, preferably as an open box profile, as a profile of generally rectangular or square cross-section with an open longitudinal slot 21 is called in furniture construction. Fig. 2 clearly shows that this longitudinal slot 21 is arranged asymmetrically on the box profile of the guide beam 10 according to a favorable arrangement, and offset by a same downwards with respect to a central plane.

Within the box section 22 , a carriage 23 is slidable, which, according to FIG. 3, has two sliding pieces 24 , which have caps 25 made of low-friction material, in particular of plastic, such as polyamide or polyethylene, e.g. B. low-pressure polyethylene, are provided. The two sliders 24 are held at a distance from one another by a central support part 26 , which is connected to the sliders 24, for example by means of screws 27 or also by welding. The distance given by the support part 26 ensures good, tilt-free guidance.

A bearing holder in the form of two support bolts 28 , which penetrate the slot 21 , projects from the support part 26 . Of these bolts 28 , a bearing plate 29 is held outside the box section 22 such that it protrudes against the lower edge 18 . The bearing plate 29 can be supported on the approximately L-shaped guide projection 17 with a slide shoe 30 (or a guide roller) in order to avoid tilting of the slide 23 . The axis of rotation 1 (preferably a rotating shaft) is supported on this bearing plate 29 with one end. The opposite bearing can be formed by a plate 31 which, together with an angle piece 32 , forms a covering hood 33 for the upper side of the cutting blade 2 . The cover 33 is fastened to the bearing plate 29 with the aid of the angle piece 32 and two fastening bolts 34 , which can best be seen in FIG. 1. The asymmetry of the slot 21 ensures that all of these parts connected to the slide 23 via the bolts 28 can be of relatively small dimensions outside the box section 22 .

As already mentioned, the stop rail 6 can be pivoted about a pivot axis 5 . Normally, the stop rail 6 is in the position shown in FIG. 4A in plan view, so that a material plate 19 placed on the support surface 4 (see FIG. 1A) on the one hand through a stop surface 6 'and on the other hand through the stop surface 9 with respect to the cutting edge 4th 'The bearing surface 4 is precisely positioned. This position of the stop rail 6 is expediently secured by a detent guide 37 provided with detents 35 , 36 , which cooperates with a detent pin 38 provided on the surface 4 , which in FIG. 4A engages in the not visible catch 36 (see FIG. 4B) intervenes. Tilting of the rail 6 can be prevented by a guide strip 39 spanning the short end or in another way, for example by a roller arranged under the rail 6 .

As FIG. 4B shows, the rail 6 can be brought into at least one further position, which is precisely predetermined by a stop edge 40 (cf. FIG. 1). This stop edge 40 forms an angle of 135 ° with the stop edge 41 which comes into effect according to FIG. 4A, ie that the rail 6 in the position according to FIG. 4B has pivoted by 45 ° relative to FIG. 4A, so that now along the cutting edge 4 'a cut can be made at exactly 45 °. The position according to FIG. 4B is again secured by the locking bolt 38 , which now engages in the locking recess 35 (cf. FIG. 4A).

Although the invention is preferably carried out with the aid of the described box profile 22 , it is not restricted to it, nor is it restricted to the use of a slide 23 . Fig. 5 shows a full, cross-sectionally square guide bar 110 on which a carriage 123 with rollers 42 with a horizontal axis 43 is guided.

Of course, such a carriage 123 could also be used within a box section 22 , and it would also be possible to provide not only the rollers 42 with a horizontal axis 43 but also those with a vertical axis which roll on the side surfaces of the box section 22 . Whether a slide or a carriage is selected depends on the forces that the cutting tool is intended for, the desired machining of the treads and the materials used.

To reduce its weight, the carriage 123 shown in FIG. 5 consists of bracket-like parts, namely two roller holder brackets 124 spaced apart from one another by a horizontal carrying belt 126 and a central bearing bracket 129 which corresponds to the bearing plate 29 of the previous exemplary embodiment, like parts in general Similar function have the same reference numerals, but with the addition of a hundred digit.

According to FIG. 6, the polygon shaft 15 (cf. FIG. 1) is not directly connected to the guide bar 210 , but rather a swivel bearing block 44 to which the guide bar 210 is fastened in a rotatable manner and lockable in any desired position. The block 44 therefore still forms part of the holding or locking device 3 . For the exact determination of the swivel position of the guide beam 210 , either an angle scale 45 and a pointer 46 are provided and / or stops are provided which - similar to the stop surfaces 40 , 41 - determine the relative position of the cutting blade and material plate ( 19 in FIG. 1A). Such stops can be formed by pins 140 , which can be inserted into holes 47 , so as to avoid errors when turning the guide bar 210 . This guide bar can then be fixed with the aid of a clamping screw 48 after pivoting into the desired position. In this way it is possible to miter the edge surfaces of a plate 19 . The guide beam 210 has, for example, an approximately circular cross section, wherein grooves 48 (or protruding projections) prevent a carriage rolling on it from rotating.

Incidentally, the invention is not limited to only two different positions of the stop rail 6, as they were described with reference to FIGS. 4A, 4B. FIG. 7 illustrates how it is possible to preset very different angular masses for the stop edge 240 , and thus for the stop rail 6 . The stop edge 240 can be pivoted about a pivot axis, preferably about the pivot axis 5 of the rail 6 (see FIGS. 4A, 4 B), and is formed on a sector 50 . The sector 50 is retractable in a groove or recess 51 of the support board 4 and has a graduation 145 , which can be read on the cutting edge 4 '. The sector 50 can thus be brought into any position and then fixed by clamping with a worm screw 148 . Of course, other means for fixing or locking would also be possible, for example in that the peripheral edge of the sector 50 is provided with ratchet teeth which interact with a pawl falling therein.

Numerous variants are possible within the scope of the invention; for example, the cutting blade can be designed differently, for example also have saw teeth on its circumference, although this is generally not preferred, in particular for insulating mats and foam boards, because of the unsightly cut edges that arise in this way. Further, the cutting edge 4 can 'of the supporting board be reinforced by a hard insert, such as a metal strip to the cutting edge 2' cooperating scissor-like manner (Fig. 2) of the cutting blade 2, in which case the cutting blade 2 at the cutting edge 4 'facing Side is not ground, but has only one-sided grinding in the manner of scissors. It is also understood that with an articulated arm straight guide (as described above) each of the joints could also have a bearing 11 .

Among the numerous advantages of the invention, it should also be emphasized that the use of a box profile 22, in addition to the low weight, has the advantage of protecting against the entry of dust and dirt into the sensitive bearing surfaces, which is particularly advantageous for use on construction sites. Furthermore, the arrangement of the spring bearing 11 allows not only the easy positioning of the plate material 19 , but also protects the sensitive cutting edge 2 'of the cutting blade 2 (see FIG. 2) against being inadvertently pressed against an underlying object under the weight of its own weight.

Claims (10)

1. Cutting tool for performing linear cuts in a substantially plate-shaped material with the aid of a cutting blade with a cutting edge, characterized in that a straight guide device ( 10 , 23 ; 110 , 123 ; 210 ) is provided for the cutting blade ( 2 ), and that Relative position of the cutting blade ( 2 ) and plate-shaped material ( 19 ) can be fixed with the aid of a holding or locking device ( 3 ). 2. Cutting tool according to claim 1, characterized in that the straight guide device ( 10 , 23 ; 110 , 123 ; 210 ) has a straight guide bar ( 10 ; 110 ; 210 ) along which the substantially circular, rotatable about an axis of rotation ( 1 ) Cutting blade ( 2 ) is guided displaceably, and that the axis of rotation ( 1 ) in the region of the part ( 4 ) of the holding or locking device ( 3 ) which receives the material ( 19 ) to be cut ( 18 ) of the guide bar ( 10 ; 110 ; 210 ) is arranged, the cutting blade ( 2 ) having a free cutting depth up to the region of the axis of rotation ( 1 ). 3. Cutting tool according to claim 2, characterized in
that on the guide bar ( 10 ; 110 ; 210 ) a guide carriage ( 23 ) or carriage (123) is displaceable, on which an axis of rotation ( 1 ) at the level of the area of the holding or locking device ( 3 ) facing edge ( 18 ) of the guide beam ( 10 ; 110 ; 210 ) holding bearing bracket ( 29 ; 129 ), in particular a bearing plate ( 29 ), is attached, and
that the guide carriage ( 23 ) preferably has two sliding pieces ( 24 ) which engage the guide bar ( 10 ) at a distance from one another and which are connected to one another via a central supporting part ( 26 ; 126 ) to which the bearing bracket ( 29 ; 129 ) is expediently fastened. 4. Cutting tool according to claim 2 or 3, characterized in that the guide bar ( 10 ) is designed as an open box profile ( 22 ) in which a rotating blade ( 2 ) bearing driving or sliding part ( 23 ) in particular in the form of the guide carriage ( 23 ) or carriage. 5. Cutting tool according to one of claims 2 to 4, characterized in that the rotatably mounted cutting blade ( 2 ) is free of a motor drive. 6. Cutting tool according to one of the preceding claims, characterized in that the cutting blade ( 2 ) is mounted in a substantially circular manner on a bearing part ( 29 ; 129 ) guided on the straight guide ( 10 , 23 ; 110 , 123 ; 210 ), and that with a handle, in particular for pushing, expediently in the form of a protruding rod ( 20 ), which is optionally arranged at an angle to a guide bar ( 10 ) forming the straight guide, is attached to the bearing part ( 29 ). 7. Cutting tool according to one of the preceding claims, characterized in that the straight guide ( 10 , 23 ), in particular with a guide bar ( 10 ), has at least one swivel joint ( 11 ), and that this swivel joint ( 11 ) from a spring bearing with a cage ( 12 ) and in its corners arranged elastic beads ( 14 ) and a polygonal shaft ( 15 ) arranged between them, through which the cutting blade ( 2 ) in one of the part to be cut the material ( 19 ) receiving ( 4 ) of the holding or locking device ( 3 ) remote position is durable. 8. Cutting tool according to one of the preceding claims, characterized in that the holding or locking device ( 3 ) has a pivot axis ( 5 ; 5 ') with a device determining the pivot angle ( 40 , 41 ; 140 , 445 , 46 ; 240 ) for making cuts at predetermined angles. 9. Cutting tool according to claim 8, characterized in that the holding or locking device ( 3 ) has a stop rail ( 6 ) for engaging an edge surface of the plate-shaped material ( 19 ), and that this stop rail ( 6 ) about the pivot axis ( 5 ) can be pivoted into at least one further angular position, which is preferably predetermined by a stop surface ( 40 ; 240 ). 10. Cutting tool according to one of the preceding claims, characterized in that the holding or locking device (3) has a stop rail (6), and in that said stop rail (6) to the rail (6) at an angle, in particular of 90 °, located stop surface ( 9 ) is displaceable and lockable by means of a locking device ( 8 ).