DE2730801C2 - Knife shaft for wood cutting machines - Google Patents

Description

35

The invention relates to a knife shaft for wood cutting machines each with between a knife carrier and a wear strip by means of a Tongue / groove joint held knife, one each made of wear strip, knife and knife carrier The unit formed is clamped against the knife shaft by means of centrifugal wedges.

For the purpose of exchanging knives, it is known in a knife shaft of this type to remove the knife carrier to lift out or pull out the knife shaft, causing the knife to close outside of the knife shaft come and the knife carrier can be removed (DE-OS 25 14 548). This way of working requires a lot of time, however, since the knife carrier readjusts after every knife change Need to become. If the knife carrier built into the knife shaft against a stop of the Knife shaft are supported, the knife carriers must be removed from clinging chips or dust before reinstalling them cleaned in order to ensure the exact position of the knives on the flight circle. Furthermore, care must be taken be that when inserting new knives with their corresponding knife holders no chips in the Penetrate knife shaft. For lifting out or reinserting the knife carrier are mechanical Additional equipment is necessary, which makes the known system complicated and particularly careful work requires.

Also known are Mcsscrwelle (I) L-AS 2 ^ά 11 978 and D CjM 72 34 252), in uemn the 'lie knife supporting and the measuring'"(■'·: ·. Lemmendcn parts

steering body are used. Such knife shafts can be dismantled or assembled because of the parts to be inserted individually into the knife shaft body and the necessary manipulations laborious. When the knives are removed, the centrifugal wedges can become loose after they have been pushed back loosen some of these parts. These parts have to be specially kept when replacing the knife, which also is awkward

The object of the invention is to provide a knife shaft To create the type described above, in which the knife replacement in a simple, problem-free manner is feasible, wherein the knife can be used in the knife shaft without the knife carrier to have to lift out the knife shaft.

This object is achieved according to the invention in that the wear strip on the knife carrier with in Clamping direction provided game is supported, the size of which is at least the thickness of the protruding Part of the tongue and groove connection between the knife carrier and knife corresponds. In addition to the simple and achieved with this training of the knife shaft quick knife change is seen as an advantage that, for example, during a general cleaning of the Blade shaft not many individual parts removed from the blade shaft after the centrifugal wedge was pushed back will have to.

According to a preferred embodiment, the knife carrier and the wear strip are screwed connected to one another, with the game being applied to the knife carrier or the wear bar coming screw head is limited.

In this case, spring elements are expediently arranged between the knife carrier and the wear strip, which act against the clamping direction of the centrifugal wedge, whereby the knife carrier after loosening the centrifugal wedge is automatically moved away from the wear strip.

It is advantageous to have a knife carrier pressed against the wear strip and the wear strip Collection space provided for wood dust. This causes dust to build up on the knife shaft fixtures largely avoided, as dust penetrating the knife shaft is deposited in the collecting space. The removal of the knife carrier for cleaning the same is only necessary in this embodiment relatively long operating times are required.

The invention is explained in more detail with reference to the drawing of an embodiment. It shows

F i g. 1 shows a partial representation of a cut transversely to the axis of a knife shaft with built-in knives,

F i g. 2 shows an analogous representation of the knife shaft during a knife change.

1 with the knife shaft is referred to, the obliquely to its circular cylinder surface 2 directed recesses 3 has, in the circumferential direction over the Knife shaft are evenly distributed and each serve to hold a knife 4. At the bottom 5 of the A retaining strip 6 is screwed into recess 3, to which a knife carrier is attached by means of a tongue and groove connection 7 8 is supported. The knife carrier 8 consists of two mutually adjustable parts 9 and 10, which through Screws 11. which lie one behind the other in the longitudinal direction of the shaft, are fixed against one another the part of the knife carrier 8 that is closer to the shaft surface is that made of strip steel An odometer 4 is held by means of a tongue and groove connection 12 and can be adjusted by adjusting the two

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can be adjusted relative to the retaining bar 6 and thus relative to the shaft surface 2. On the knife carrier 8 is a wear strip 13 with play 14 in the direction perpendicular to the facing Faces 15 and 16 of these parts attached The size of the game 14 corresponds approximately to the thickness' 7 of the protruding Part of the tongue and groove connection 12 between the knife carrier 8 and the knife 4. The game! 14th is by screws 18 (the number of which is chosen according to the wavelength) with their threaded parts Sitting in the wear strip, limited. Turning the screws can adjust the size to be adjusted.

Disk springs 19 are located on the screws between the wear strip and the knife carrier provided, which press the knife carrier in the open position shown in Figure 2.

The knife carrier 8 is during the operation of the knife shaft by centrifugal wedges 20 in the direction against Wear strip 13 printed So that a secure fit of the knives is guaranteed even when the shaft is at a standstill, the centrifugal wedges 20 are pressed outward by springs 21.

To replace a knife, the centrifugal wedges 20 must be pressed in against the action of the springs 21 be, whereupon due to the action of the disc springs 19 of the knife carrier 8 from the wear strip 13 removed; these parts unfold and the knife 44 can be removed and be exchanged. After inserting the new knife, the centrifugal wedges are released, whereby they are again in the in F i g. 1 position shown and the knife carrier in the direction against Press the wear strip.

Since the game 14 is limited by the screws 18 to such an extent that after unfolding of the knife carrier 8 and the wear strip 13 just the knife 4 can be removed, the Penetration of chips into the knife shaft during the knife change largely prevented

Very fine wood dust penetrates "creeping" into knife shafts so that the individual parts, such as knife carriers, centrifugal wedges, etc. had to be cleaned more often. This was especially when processing short-fiber wood or resin-rich wood sons, e.g. B. of maritime pine, necessary. Such wood dust leads to so-called caking. The wood dust forms through compression finally, hard layers that can change the position of the cutting edges on the knife shaft.

The knife shaft takes these facts into account in such a way that a collecting space 22 between knife carrier and wear strip is provided, into which the dust can penetrate, but again by blowing out Will get removed. This saves you from having to expand the knife carrier to the Purpose of cleaning, whereby the advantages of the knife shaft come to the fore to a greater extent.

For this purpose 2 sheets of drawings

Claims (4)

Patent claims: 1. Knife shaft for wood cutting machines, each with between a knife carrier and a Wear bar held by means of a tongue and groove connection knife, one made of wear bar, Knife and knife carrier formed unit by means of centrifugal wedges against the knife shaft is clamped, characterized in that the wear strip (13) on the knife carrier (8) with in the clamping direction provided game (14) is supported, the size of which is at least the thickness (17) of the protruding part of the tongue and groove connection (12) between knife carrier (8) and knife (4) is equivalent to. 2. Knife shaft according to claim 1, characterized in that the knife carrier (8) and the Wear bar (13) are connected to one another by screws (18), the play (14) through the on the knife carrier (8) or on the wear strip that comes into contact with the screw head is. 3. Knife shaft according to claim 1 or 2, characterized in that between the knife carrier (8) and the wear strip (13) spring elements (19) are arranged opposite to the clamping direction of the centrifugal wedge act. 4. knife shaft according to claims 1 to 3, characterized in that between the counter the wear bar (13) pressed knife carrier (8) and the wear bar a collecting space (22) for Wood dust is provided.