Cutter wheel

Abstract: A cutter wheel which can form a deep slit on an article to be cut so that the article can be broken easily along the slit and a perpendicular cut surface can be formed reliably when the article is broken along the slit. The cutter wheel is a disk-shaped member having a cutting edge along the outer edge and formed with a mounting hole extending therethrough along its axis and having an irregular shape so that the cutter wheel vibrates when it rolls due to steps between adjacent sides of the polygonal hole. The edge of the wheel can thus penetrate more deeply into the glass plate so that a deeper and smoother slit can be formed in the glass plate. This in turn makes it possible to more easily break the glass plate along the slit and to form a perpendicular cut surface.

Description: BACKGROUND OF THE INVENTION This invention relates to a cutter wheel for use in a glass cutter or a glass cutting device for cutting a glass plate or a liquid crystal plate, according to the preamble of claim 1. In order to cut, either manually or automatically, various glass plates such as those used in cars, buildings and industries, glass plates, and liquid crystal plates, a glass cutter having a cutter wheel rotatably mounted on the tip of a head member is used to form a slit on the surface of the plate by pressing the wheel against the plate and rolling it thereon. Then, by pushing down the plate on both sides of the slit, the plate can be cut along the slit. A conventional cutter wheel of this type is a disk member having a cutting edge along its outer periphery and formed with a circular mounting hole extending therethrough at its center. The cutter wheel is rotatably mounted to the head member of the glass cutter by a mounting shaft having a circular section and inserted through the circular mounting hole. For the cutting of liquid crystal plates and hard glass plates, high degrees of accuracy in straightness and perpendicularity of the cut surface are required. To meet this requirement, it is necessary to form a slit that is sufficiently smooth, straight and deep. To form a deep slit, the wheel has to penetrate deep into the glass plate. But none of the conventional cutter wheels can form such a deep slit because the mounting shaft and the mounting hole are both circular in section and thus the wheel rolls smoothly on the glass plate without penetrating. Since the slit is shallow, it is difficult to form a perpendicular cut surface when the glass plate is broken along the slit. An object of this invention is to provide a cutter wheel which can form a deep slit on an article to be cut so that the article can be broken easily along the slit and a perpendicular cut surface can be formed reliably. SUMMARY OF THE INVENTION According to this invention, there is provided a cutter wheel comprising a disk-shaped cutter wheel formed with a mounting hole extending therethrough along its axis and having an irregular shape so that the cutter wheel vibrates when it rolls, according to the characterizing part of claim 1. Other features and objects of the present invention will become apparent from the following description made with reference to the accompanying drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1A is a front view of a cutter wheel embodying the invention; Fig. 1B is its side view; Fig. 1C is an enlarged sectional view of a different cutting edge; Fig. 2 is an enlarged sectional view showing the relationship between the mounting hole and the mounting shaft; Fig. 3 is a partial front view of a glass cutting device using the cutter wheel; and Fig. 4 is a front view of another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Fig. 1 shows a disk-shaped cutter wheel 1 having a cutting edge 2 along the outer periphery and formed with a mounting hole 3 extending therethrough along its central axis. The cutting edge 2 of the cutter wheel 1 may be a V-shaped single-step edge as shown in Fig. 1B or a two-step edge as shown in Fig. 1C. One of the two types is selected according to the hardness of the material to be cut. The cutter wheel 1 is made from a cemented carbide or a diamond crystal, and typically has an outer diameter of about 2-6 mm. The mounting hole 3 is shaped irregularly so that the wheel will vibrate while rotating. The illustrated mounting hole is hexagonal with each side arcuately convexed inwardly. The mounting hole 3 may be of any polygonal shape depending on the thickness and material of the article to be cut. For example, it may be selected from among square to dodecagonal. The curvature of each side is not limited either. Fig. 2 shows the relationship between a mounting shaft 4 rotatably supporting the cutter wheel 1 and the mounting hole 3. The outer diameter of the mounting shaft 4 is determined with respect to the minimum inner diameter of the mounting hole 3 such that the shaft 4 fits loosely in the hole 3. Fig. 3 shows the cutter wheel 1 used in the glass cutting device. The glass cutting device comprises a table 11, an X-axis guide 12 movable in a Y-axis direction over the table 11, a cutter head 13 mounted on the X-axis guide 12 so as to be movable in an X-axis direction, and a holder 14 vertically movably mounted to the bottom of the cutter head 13 and having the mounting shaft 4 inserted through the mounting hole 3 of the cutter wheel 1 to rotatably support the wheel 1. By . moving the X-axis guide 12 and the cutter head 13 with the cutter wheel 1 pressed against a glass plate A placed on the table 11 at a predetermined pressure, the wheel cutter 1 rolls on the glass plate A, thus forming a slit therein. The glass plate A is then broken along the slit. Since the cutter wheel 1 mounted to the bottom of the holder 14 by means of the mounting shaft 4 has a polygonal mounting hole 3 of a non-circular shape, when the wheel rolls on the glass plate A, it vibrates due to steps between adjacent sides of the polygonal mounting hole. The cutting edge of the wheel can thus penetrate more deeply into the glass plate, so that a deeper and smoother slit can be formed in the glass plate A. This in turn makes it possible to more easily break the glass plate along the slit and to form a cut surface which is rectangular to the top surface of the glass plate. Fig. 4 shows another example of the mounting hole which is octagonal with round corners.

Claims: A cutter wheel assembly for cutting glass comprising a disk-shaped cutter wheel (1) and a mounting shaft (4), said cutter wheel having a cutting edge (2) along its outer periphery and formed with a mounting hole (3) extending therethrough along its axis, said cutter wheel being rotatably supported by said mounting shaft (4) inserted through said mounting hole, characterized in that said mounting hole (3) has a non-circular shape and that said mounting shaft (4) has a diameter smaller than the minimum inner diameter of said mounting hole (3), whereby said cutter wheel is adapted to vibrate during its movement over a glass plate to form a slit in the glass plate when said mounting shaft (4) is moved in a direction perpendicular to the axis of said mounting shaft (4) with said cutting edge pressed against the glass plate. A cutter wheel as claimed in claim 1, wherein said mounting hole (3) has a polygonal shape with each side arcuately convexed inwardly.

Inventors: ARAI ASAKO, ARAI, ASAKO
Applicants: TOYO SANGYO CO LTD, TOYO SANGYO CO., LTD.
Application year: 1999
Main classification: C03B33
IPC codes: C03B33, B26D1, B28D1