The invention is explained hereinafter on the basis of FIGS. 1 to 4. These explanations are for example only, do not restrict the general thinking of the invention, and apply equally to the inventive knife, the inventive cutter head disk, the inventive cutter head, and the inventive checking device.
FIG. 1 shows the inventive knife
FIG. 2 shows two original knives which are arranged on a cutter head disk
FIG. 3 shows the combination of knives and cutter head disk according to FIG. 2, whereby, in the present case, however, these knives have been shortened at the tips
FIG. 4 shows the inventive checking device
In FIG. 1 the inventive knife 8 is represented, which rotates in a cutter (not shown) according to an arrow represented by the reference FIG. 9. Accordingly, the knife has on its lower radius a blade 10. The knife is located in the cutter head disk by the two holes 4. According to the invention, the knife has a longitudinal hole 5, which is arranged offset to the mid-axis of the knife 8. This longitudinal hole 8 has a scaling with which the position of the knife relative to the cutter head disk can be identified, which is explained in greater detail in FIGS. 2 and 3.
FIG. 2 shows two knives 8, which are arranged in a cutter head disk 1. The cutter head disk 1 has four cut-outs or apertures, which each accommodate an eccentric retaining pin 4, with which the knives 8 are located in the cutter head disk 1. The eccentric retaining pins 4 have a circular disk-shaped head 4′, which is arranged eccentrically at its foot 4″, whereby the areas marked in black project further from the middle than the areas marked white. This eccentric arrangement allows for the knife with the pins to be arranged in two different positions in the cutter head disk. A cutter head disk is supplied as a set with several eccentric retaining pins, which, however, only differ in the degree of their eccentricity. The head 4′ and the foot 4″ are in each case identical. In addition to this, a pin 7 is arranged in the cutter head disk, which projects into the aperture 5. The pin is arranged on none of the axes of symmetry of the cutter head disk, and offset to the mid-axis 3 of the knife, so that the knives cannot be located mirror-image reversed in the cutter head disk, which would result in the blade 10 of the knife not being arranged in the direction of rotation of the cutter disk head. In addition, the pin prevents knives being fitted on the cutter head disk which do not have a corresponding hole. As can be seen from the enlarged circular section, the aperture 5 has a scaling, which corresponds to the eccentric retaining pin in each case. The upper scaling is selected for an eccentric retaining pin with which the knife can be arranged on the cutting head disk in a 0 setting or displaced 6 mm outwards. Correspondingly, the lower scaling is provided for an eccentric retaining pin with which the knife can be arranged in the 0 setting or displaced 3 mm outwards. In the present case, this involves knives which have never yet been shortened in their length. Accordingly, the line on the pin corresponds to the scaling 0. The cutter head disk consists of a metallic core 16, which is surrounded by a plastic ring 17. In the present case, the plastic ring is shrunk onto the metallic core. For this purpose, the core 16 is cooled and/or the plastic ring is heated.
FIG. 3 shows the cutter head disk/knife arrangement according to FIG. 2, whereby the knife tips in the present case have been shortened by 6 mm. Accordingly, the eccentric pins have been rotated from their 0 setting into the 6 mm setting, in order to guarantee that the distance interval between the knife tip and the cutter key remains constant. This rotation of the eccentric disk can also be identified by way of the scaling, because the line on the pin 7 is no longer located in the 0 setting but in the 6 mm setting. The person skilled in the art will recognise that the scaling allows on the one hand for a check to be made as to whether the knife is located on the correct pin, and whether, with the pin located correctly, a shortened knife must be used, or a knife of the original length.
FIG. 4 shows the inventive device for checking the knife length after grinding. To do this, the knife 8 is laid on a rotating table 13 and secured to the device by means of a pin 11, which in turn projects into the aperture 5. At a distance from the rotating table 13, the inventive device has a template, with which the length of the knife can be checked. The template 12 can be rotated about the screw 14 clockwise and anti-clockwise by 90° in each case and fixed in the corresponding position. Depending on the size of the cutter, the template 12, as well as being fixed, can also be displaced in the direction represented by the double arrow 15. In the upper representation an original knife, the tip of which has not yet been shortened, is tensioned on the device. Accordingly, the template is in the 0 setting, which also corresponds to the arrangement according to FIG. 2. The lower representation illustrates the situation after the knife has been shortened. By means of the template, it has been determined that the knife has been shortened by 6 mm, and the operator knows that the eccentric pin must be brought into a corresponding position.
REFERENCE LIST
1 Cutter head disk
2 Projection
3 Mid-axis
4 Means for attaching the knife to the cutter head disk
5 Cut-out or aperture
6 Scaling
7 Pin
8 Knife
9 Direction of rotation of knife
10 Blade
11 Means for securing a knife to the checking device
12 Means for determining the correct setting of the eccentric pins
13 Rotating table
14 Screw
15 Double arrow
16 Core
17 Casing
Patent Application
20080029629
