Apparatus and method for producing a reliable breaking line for the industrial cutting to length of glass sheets

Abstract

Apparatus and method for producing a reliable breaking line for the industrial cutting to length of glass sheets by means of a cutting wheel running on a float glass line under pressure imposed from above, with the following features: a) the location of the beginning of a breaking line is determined and a cutting wheel holder (20) with a cutting wheel (2) is brought into position, b) the cutting wheel holder (20) is lowered and the cutting wheel (2) is lowered onto the glass sheet (1) concerned with the desired pressing pressure, wherein the pressing pressure is set by means of a swing arm (3) and is monitored by means of a strain gauge (4) secured thereto, c) a change in the height of the glass sheet (1) prompts a control signal for an actuating motor (12) to be derived from the change in the resistance of the strain gauge (4), and the actuating motor brings about a corresponding change in the pressing pressure of the cutting wheel (2).

Claims

1. A device for producing a reliable breaking line for the industrial cutting to length of glass sheets on a float glass line, the device comprising: a) a cutting wheel (2) that moves under load pressure on a float glass line; b) a base console (11) which has a rotation axis (19) at the lower side and in which there is rotatably supported a rotation head (5) which operates at one side and which is connected at the operating side by means of a resilient element (17) and a horizontally fixedly supported but vertically movably supported connection element (16) to a threaded spindle (15) which can move vertically in a connection sleeve (14), c) a servo motor (12) at the upper side of the base console (11) having a motor shaft (13) which is securely connected to the connection sleeve (14), d) a rocker bar retention member (6) which is constructed in a bar-like manner and which is connected at one side to the operating side of the rotation head (5) by means of connections (8) and which carries at the other opposite side a cutting wheel retention member (20) having the cutting wheel (2), e) a rocker bar (3) in the form of a zone which is weakened in a selective manner by means of 4 large cylindrical holes and a small cylindrical hole between them in the central region of the rocker bar retention member (6), wherein these holes constitute in the side view circles having a large radius (22) and a circle having a small radius (23) and these holes merge seamlessly into each other in the longitudinal axes thereof, f) an expansion measurement strip (4) at the upper side of the rocker bar (3) in order to detect the oscillations thereof, an electronic measurement system (21) relating thereto and a data cable (26) for controlling (27) the servo motor (12).

2. The device as claimed in claim 1, wherein two of the 4 large cylindrical holes intersect in the rocker bar (3) to form a vesica piscis in the plane of section; wherein the distance between the center point of the small cylindrical hole from the center points of the two large cylindrical holes is equal to double the radius (23) of the small cylindrical hole; and wherein the ratio between the radius (23) and the radius (22) is 1 to 1.55.

3. A device for producing a reliable breaking line for the industrial cutting to length of glass sheets on a float glass line, comprising a tool changing head (24) and a plurality of devices as claimed in claim 1, wherein the devices as claimed in claim 1 are arranged in a turret-like manner in the tool changing head (24).

4. The device as claimed in claim 1, further comprising a sensor that can detect the height position of the glass sheet 1 when the glass sheet 1 is located directly upstream of the cutting operation.

Description

(1) The invention is described in greater detail below with reference to the Figures, in which:

(2) FIG. 1: is a perspective illustration of the entire device,

(3) FIG. 2: is a sectioned drawing through the entire device,

(4) FIG. 3: is a sectioned, drawing through the rocker bar retention member 6,

(5) FIG. 4: is a sectioned drawing through a tool change head according to the invention.

(6) FIG. 1 is a perspective illustration of the entire device. In this instance, in the horizontal bearing, it is possible to see a glass sheet which is intended to be cut and by means of which a cylindrical servo motor is supported on an L-shaped carrier arm. At the base of this carrier arm, there is secured a bearing block which enables the support of the actual cutting device. The additional retention member of the carrier arm and the connection thereof to other machine components are not illustrated here.

(7) In FIG. 2, details of the perspective illustration of FIG. 1 can be seen by means of a sectioned drawing.

(8) Above a glass sheet 1 which moves on transport rollers 25, it is possible to see in the free position a base console 11 which substantially corresponds to the L-shaped carrier arm and the bearing block from FIG. 1. There is supported, on the base console 11 a servo motor 12, to the motor shaft 13 of which a connection sleeve 14 having an inner thread is securely connected. In the inner thread of the connection sleeve 14, there is screwed a threaded spindle 15 which is connected to a connection element 16 which has a guiding pin 9. The guiding pin 9 is supported, in a guiding slot 10 of the base console 11 in an almost play-free manner. This illustration shows that the connection element 16 can be vertically adjusted in a stepless manner by means of a rotation of the motor shaft 13.

(9) In the bearing block of the base console 11 mentioned in FIG. 1, there is introduced in a horizontal position a rotation axis 19 to which a rotation head 5 is secured by means of a clamping screw 18. This rotation knob 5 is connected by means of a resilient securing member 7 via a resilient element 17 to the connection element 16.

(10) At the lower side of the rotation head 5, there is secured by means of two screw connections 8 a rocker bar retention member 6, at the opposite side of which there is arranged a cutting wheel retention member 20 which in turn carries the cutting wheel 2. The rocker bar retention member 6 has in the central region a zone which is referred to as a rocker bar 3 and which substantially comprises an arrangement of cylindrical recesses which engage one inside the other and which reduce this zone in terms of cross section and consequently enable the receiving of bending torques. This results in almost the entire rocker bar retention member 6 resiliently giving way with respect to impacts which act from the region of the cutting wheel retention member 20, and acting as a rocker bar. The view through the recesses mentioned shows the lower edge of the base console 11. An expansion measurement strip 4 is secured to the upper side of the rocker bar 3 in order to receive the oscillations of the rocker bar 3.

(11) In this manner, the vertical positional changes of the cutting wheel 2 detected by the expansion measurement strip 4 can be further processed and evaluated.

(12) FIG. 3 is a sectioned drawing through the rocker bar retention member 6. The structural unit which is referred to as an entire component as a rocker bar retention member 6 has in the central portion thereof according to FIG. 2 a recess which is referred, to as a rocker bar 3 and which substantially comprises 5 individual cylindrical recesses which merge into each other in a specific arrangement, wherein the radii of the end faces of these cylinders are located in a specific relationship with respect to each other and are illustrated in FIG. 3 substantially as circles. The radius of a large circle is designated 22, the radius of the small circle 23.

(13) These cylindrical recesses comprise four larger recesses of which two pairs of these recesses merge into each other and overlap in the manner of a vesica piscis (air bladder), and wherein both pairs are connected to each other by means of a smaller cylindrical recess.

(14) The spacing of the distance from the center point of the small circle to the center point of a large circle corresponds to double the radius 23 of the small circle. The relationship of the radius of the small circle behaves with respect to the radius of a larger circle as 1 does to 1.55.

(15) From the expansion measurement strip 4, an electrical connection leads to an associated electronic measurement system 21 and, from there, a data cable 26 leads to the control unit 27 which sends corresponding control signals in order to actuate the servo motor 12. In this manner, by changing the position of the connection element 16 in a vertical direction and corresponding rotation of the rocker bar retention member 6 via the helical spring 17, the pressure of the cutting wheel 2 on the glass sheet 1 rapidly changes and changing relationships are adapted.

(16) This may, for example, be necessary when the transport rollers 25 travel in a bumpy manner and/or glass splinters are introduced between the glass sheet 1 and a transport roller 25. However, there may also be as a result of quite imperceptible thickness changes in the float glass sheet 1 which have to be compensated for in order to achieve a constant scoring depth.

(17) Regardless of this, it is naturally possible to readily react to a change in thickness of the float glass strip which can be foreseen in the production process in terms of control technology.

(18) It is thus possible using the device according to the invention to readily establish the glass thickness in the present case and to store and use it as a process parameter.

(19) This involves the following operating sequence: 1. The cutting wheel 2 touches the glass sheet 1. 2. The expansion measurement strip 4 produces a signal which corresponds to the thickness of the glass sheet 1. 3. The established position of the cutting wheel 2 is stored in the system. 4. For each additional processing operation, the required, pressing force for the relevant glass sheet 1 can be calculated and adjusted. 5. The processes 1 to 4 consequently enable rapid approach of the cutting wheel 2 and also rapidly optimized and reliable introduction of the cutting wheel 2 into the respective glass sheet 1.

(20) In the electronic measuring system 21, there are substantially a device for producing the supply voltage required for the actuation of the expansion measurement strip 4, an electric bridge circuit which is required to detect the resistance change of the expansion measurement strip 4 and an amplification circuit which is required to transmit the measurement signal. Since the operation of an expansion measurement strip is also dependent on the ambient temperature, there is also a temperature sensor in the region of the electronic measurement system 21.

(21) There are various measurement methods for expansion measurement strips, from which the person skilled in the art can select the appropriate one in the present case. With the device described, it is possible by means of immediate reaction to react at high speed to changes which can influence the cutting result.

(22) FIG. 4 is a sectioned drawing through a tool change head according to the invention.

(23) In this instance, there is illustrated a device for rapidly changing tools with different sizes of cutting wheels 2 or different, equipment in terms of expansion measurement strips 4 or helical springs 17. It is thus possible, for example, to react quickly to changes in the thickness of the float glass plate to be cut.

(24) In a specific embodiment, there may be provision, by means of a sensor which is not described in greater detail, for the height position of the glass sheet 1 which is located directly upstream of the cutting operation to be detected and any changes in the positive or negative direction to be used to correct and/or determine the control signals of the servo motor 12.

(25) The control of the complex movement, operations and the signal processing of the sensors used require a specific control program.

LIST OF REFERENCE NUMERALS

(26) 1 Glass sheet 2 Cutting wheel 3 Rocker bar 4 Expansion measurement strip 5 Rotation head 6 Rocker bar retention member 7 Resilient securing member 8 Screw connection for the rocker bar 9 Guiding pin 10 Guiding slot 11 Base console 12 Servo motor 13 Motor shaft 14 Connection sleeve with inner thread 15 Threaded spindle 16 Connection element, for resilient adjustment 17 Resilient element 18 Clamping screw 19 Rotation axis 20 Cutting wheel retention member 21 Electronic measurement system for the expansion measurement strip and thermal sensor 22 Large radius of the aperture 23 Small radius of the aperture 24 Tool change head 25 Transport rollers 26 Data cable 27 Control unit (servo motor)