DE7206897U - CUTTER SHAFT FOR WOOD CHIPPING MACHINES - Google Patents

Description

Patent attorney ■ "Λ

Dipl.-Ing. J

Werner Gramm

G 72 06 897.4 33 Braunschweig, March 29, 1976 ~ . Theodor-Heuss-Strasse 1

numuan naabiiuicuxuui.j.ii i »^ leieiun. UJJrouuir

6550 Bad Kreuznach

"Knife shaft for wood cutting lawyer files 1728 Gm machines"

The innovation concerns a knife shaft for wood cutting machines for the production of high-quality chips, the knives via wedge-shaped clamping elements in the knife shaft body that are subject to centrifugal force are held and between the knife and the clamping element are each a movable, positively held in the knife shaft body Intermediate holder for the transfer of the applied by the clamping element Clamping force is provided.

Such a knife shaft can be, for example Take DT-AS 1 195 934. There are clamping elements and intermediate brackets viewed in the direction of rotation of the shaft each arranged in front of the associated knife. Under the influence of the The centrifugal forces resulting from the high number of revolutions of a machining shaft are pulled radially outwards. Depending on Manufacturing tolerance, the individual clamping elements therefore protrude irregularly far beyond the flight circle of the knife shaft surface or back under this, so not exactly aligned with the knife shaft surface. This preserves the wood to be machined

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the actual machining process a restless and to the knife edges different position, which leads to an impairment of the chip quality. It should be noted that on Such devices flat chips with a thickness tolerance of less than 1/10 are now to be produced. Restlessness and dimensional deviations in the wood layer must therefore inevitably lead to a significant deviation from the desired chip thickness. the Restless position of the wood during the cut also affects the service life of the knives.

The innovation is thus based on the task of improving a cutter block of the type described above so that a quiet position of the wood during the cut, a long service life of the knives and a high chip quality can be achieved.

This object is achieved according to the innovation in that the clamping element and the intermediate holder with its upper end flush with the knife shaft body, viewed in the direction of rotation of the shaft, each arranged behind the associated knife are.

The main advantage of the new device lies in the absolute quiet wooden surface in front of the chipping knives. Due to the arrangement of the intermediate holder behind the knife and its form-fitting Storage in the knife shaft body also guarantees an absolutely quiet wood support directly behind the knife. As a result, the desired thickness of the flat chips to be produced can be adhered to very precisely. Thanks to the vibration-free When the wood is placed on the surface, the service life of the knives is increased at the same time.

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By the Norwegian patent 7 9 836 is already the proposal become known, in a knife shaft for a woodworking machine, the clamping elements in the direction of rotation of the shaft seen behind the associated knives. However, these clamping elements change under the action of centrifugal force also their position relative to the surface of the knife shaft body, so that the disadvantages explained above result. Disadvantageous is also that in this embodiment, the clamping elements lie directly against the back of the knife, so that the danger there is that the knife move due to this direct action together with the clamping elements during tensioning. A however, an exact and, above all, constant knife protrusion is essential to achieve the desired chip thickness.

Practice has shown that the we sent .1. '.' Hey, by chipping wood Wear caused in the surface of the knife shaft lies directly behind the knives. This wear is at the new embodiment caught by the intermediate holders, which thus represent replaceable wear parts. These parts are cheaper than the heavy wedges. It is also advantageous that the knife can no longer be moved by the clamping wedge when clamping.

According to the innovation, the intermediate holder can be designed as a lever that can be pivoted about a stationary axis or else from a lever Exist.

In order to avoid the last impairment in the quiet wood surface during the cut, the intermediate holder can be used according to the innovation with its upper end partially or completely cover the clamping wedge while maintaining an intermediate distance. Of the

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Intermediate spacing prevents radial displacement of the centrifugal wedge Effect of centrifugal forces without affecting the intermediate holder and thus changing the surface of the knife shaft will. This construction has the additional advantage that the clamping means are protected from contamination by their cover are protected.

To make it easier to loosen the intermediate holders when changing the knives, a spring element acting on the intermediate holder against the direction of rotation can be provided.

The intermediate holders can also serve as knife carriers if the knives are firmly connected to them.

In the drawing, some exemplary embodiments of the innovation are shown in cross-section. It shows

Figure 1 shows a knife tension in a knife shaft,

Figure 2 shows another embodiment in a representation according to Fig. 1,

FIG. 3 shows a knife tension with a semi-covered centrifugal wedge and

FIG. 4 shows a knife tension with a completely covered centrifugal wedge.

According to FIGS. 1 to 4 are in a knife shaft 1 for wood cutting machines Knife 2 attached, the tensioning elements of which

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direction of rotation d-3r shaft arranged behind the knives are. The clamping force is generated by the wedge effect, which is applied by centrifugal wedges 3. Between knife 2 and centrifugal wedge 3 an intermediate holder 5 is usually provided, with which the knife 2 can be screwed. This intermediate holder can according to 2 designed as a lever 5a pivotable about a fixed axis 6 or as shown in FIG. 3 as a bar 5b, which is held in its subsurface in a form-fitting manner in the knife shaft body. Another embodiment is shown in Fig. 4, where the intermediate holder with its inner, fork-like end 5c the Centrifugal wedge 3 grasps on both sides.

In the embodiments according to FIGS. 1 to 4, the intermediate holder 5 ends flush with the cutter shaft body 1 ^{with its upper end 5 1.} According to FIGS. 1, 2, the outer end of the centrifugal wedge 3 is also flush with the knife shaft body. Fig. 3 shows an embodiment in which the bar 5b with its upper end 5 ¹ partially covers the centrifugal wedge 3 while maintaining an intermediate distance 7. In the solution according to FIG. 4, the centrifugal wedge is completely covered.

The centrifugal wedges are under the action of a compression spring 8. According to FIG. 2, moreover, the lever 5a can counter to the direction of rotation the shaft can be acted upon by a spring element 10.

FIG. 2 also shows shaped pieces 11 screwed into the knife shaft body 1 to form chip pockets arranged in front of the knives 2 12, the partitions of which are used as webs 13 to support wood to serve.

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Claims (7)

Protection claims: 1. Knife shaft for wood cutting machines for the production of high-quality chips, the knives being held in the knife shaft body by wedge-shaped clamping elements subject to centrifugal force, and a movable intermediate holder held in a form-fitting manner in the knife shaft body for transmitting the clamping force applied by the clamping element is provided between knife and clamping element , characterized in that the clamping element (3) yjid the intermediate holder (5), which with its upper end (5 ¹ ) is flush with the knife shaft body (1), seen in the direction of rotation of the shaft behind the associated y ^ zzex (2) are arranged. 2. Knife shaft according to claim 1, characterized in that the intermediate holder (5) can be pivoted about a fixed axis (6) Lever (5a) is formed. 3. Knife shaft according to claim 1, characterized in that the intermediate holder (5) consists of a bar (5b). 4. Knife shaft according to claim 1, characterized in that the intermediate holder (5) with its upper end (5 *) the wedge (3) partially or completely covered while maintaining an intermediate distance (7). 5. Knife shaft according to claim 4, characterized in that the intermediate holder (5) with its internal, fork-like design The end (5c) encompasses the wedge (3) on both sides. 7208897 07/29/76 6. Knife shaft according to one of the preceding claims, characterized by a spring element (10) acting on the intermediate holder (5) counter to the direction of rotation. 7. knife shaft nar'i one of the preceding claims, characterized characterized in that the knife (2) with the intermediate holders (5J are firmly connected. > 1.-Ing. Werner Gramm patent attorney
Gr / Gr. 7706897 29.B7.76