GB2204577A

GB2204577A - Glass cutting machine and method

Info

Publication number: GB2204577A
Application number: GB08804664A
Authority: GB
Inventors: Derek Henry Ross; Michael Moore
Original assignee: A E Ross & Son Ltd
Current assignee: A E Ross & Son Ltd
Priority date: 1988-02-27
Filing date: 1988-02-27
Publication date: 1988-11-16
Also published as: GB8804664D0

Abstract

A machine for cutting an arcuate groove in a sheet of glass comprises a table 14 on which the glass sheet is placed, the table 14 being movable longitudinally relative to a bed 10 by means of a stepping motor 16. A bridge 18 extends across the bed 10 above the table 14 and a carriage 21 is movable from side to side of the bed 10 along the top member of the bridge 18. The carriage 21 carries a grinding head 26 which is movable vertically towards and away from the glass sheet and which is rotatable about a vertical axis 30 so that the grinding wheel 29 is continuously disposed tangentially relative to the arcuate groove being cut in the glass sheet. <IMAGE>

Description

GLASS CUTTING MACHINE AND METHOD Field of the Invention This invention relates to a machine for cutting grooves in sheets of glass and to a method of cutting a groove of a predetermined configuration in a sheet of glass.

Background of the Invention There are at present machines for cutting linear grooves in glass sheets. There is, however, an increasing requirement for non-linear groove designs, for example, in glass panels used in the doors of kitchen cabinets.

At present, arcuate grooves are cut manually. This involves a considerable degree of skill, results in a degree of inconsistency in the thickness and curvature of the grooves and is extremely time-consuming.

It is accordingly an object of the present invention to provide a machine which can be used to cut an arcuate groove in a sheet of glass, and to provide an improved method of cutting an arcuate groove in a sheet of glass.

Summary of the Invention According to a first aspect of the present invention, there is provided a machine for cutting a groove in a sheet of glass comprising:1. a bed having support means for supporting the glass sheet, 2. a grinding head having means for mounting a grinding wheel for rotation about an axis parallel to the surface of the glass sheet, 3. a carriage on which the head is mounted, 4. means for providing relative linear movement along three co-ordinate axes between the head and the glass sheet support means, and 5. means providing for rotation of the head relative to the carriage about an axis which intersects the point of contact between the grinding wheel and the sheet of glass.

The carriage is preferably mounted on a bridge which is disposed above the bed and the support means for supporting the glass sheet is preferably in the form of a table mounted for linear movement relative to the bed. The bridge preferably extends at right angles to the direction of travel of the table relative to the bed. Computer is preferably provided for controlling movement of the table relative to the bed and the carriage relative to the bridge, with stepping motors providing for the required movement, the two stepping motors being arranged for simultaneous movement to effect the required positioning of the carriage relative to the sheet of glass.

Thus, to simplify the controls for movement of the grinding head relative to the glass sheet, the table carrying the glass sheet is moved in the direction of the X axis and the carriage is moved along the bridge which extends over the table in the direction of the Y axis.

The computer control system for the machine is such that movements of the carriage relative to the bridge and of the table relative to the bed are so co-ordinated with rotation of the grinding head that the grinding wheel is continuously positioned in such manner that it is tangential to the path of movement of the point of contact between the grinding wheel and the sheet of glass. The grinding wheel can thus be moved relative to the sheet of glass along an arcuate path, the radius of curvature of which is variable dependent on the required form of groove to be cut in the sheet of glass.

According to a second aspect of the present invention there is provided a method of cutting a groove in a sheet of glass which comprises placing the sheet of glass on support means of a bed of a machine, which machine includes a carriage carrying a grinding head having means for mounting a grinding wheel, moving the grinding wheel into contact with the sheet of glass with the grinding wheel rotating about an axis parallel to the surface of the glass sheet, effecting relative movement between the head and the glass sheet in a horizontal plane and rotating the head relative to the carriage about a vertical axis which intersects the point of contact between the grinding wheel and the sheet of glass, such movement of the grinding wheel and the sheet of glass being so arranged that the grinding wheel is continuously located tangentially relative to the groove being cut in the sheet of glass.

Brief Description of the Drawings Figure 1 is a plan view of a machine for cutting arcuate grooves in sheets of glass, Figure 2 is a side view of the machine shown in Figure 1, Figure 3 is an end view of the machine shown in Figures 1 and 2.

Description of the Preferred Embodiment The machine shown in the drawing comprises a bed 10 which includes a pair of main frame members 11 and 12 interconnected by a number of transverse frame members 13. A table 14 is mounted by means of linear bearings 15 on the longitudinal frame members 11 and 12, which together define a track along which the table 14 is movable. Movement of the table 14 is effected by means of a stepping motor 16 operation of which is controlled, as hereinafter explained, by means of a computer which can be programmed independent on the groove configuration which is required. The bed 10 also houses a water coolant tank 17 which contains a circulating pump for the supply of coolant water to the position on the sheet of glass which is being ground.The table 14 is provided with locating formations which serve to position the sheet of glass and to hold it firmly in position during a grinding operation.

A Bridge 18 is carried by the bed 10 and includes a pair of upright members 19 interconnected by a horizontal member 20 which serves as a track for movement of a carriage 21 across the bridge 18 in a direction at right angles to the axis of movement of the table 14 relative to the bed 10.

Relative movement between the carriage 21 and the table 14 is thus effected in the direction of the X axis by movement of the table 14 along the track afforded by frame members 11 and 12, and movement in the direction of the Y axis by movement of the carriage 21 along the track afforded by the horizontal member 20 of the bridge 18.

Movement of the carriage 21 along the track afforded by the horizontal member 20 of the bridge 18 is effected by means of a stepping motor 22 mounted on the carriage 21 and cooperating with a rack on the bridge 18 to provide for controlled movements of the carriage 21. The carriage 21 includes a vertical table 23 on which a turret 24 is mounted. The turret 24 being movable in the vertical direction relative to the table 23 by means of a stepping motor 25. The turret 24 provides a mounting for a grinding head 26 which is rotatable relative to the turret 24 under the control of a further stepping motor 27.The grinding head 26 carries a belt drive system 28 arranged for the transmission of drive to a grinding wheel 29 so positioned that its lowest point, i.e. the point of contact with the glass sheet, is in line with the axis 30 about which the grinding head 26 is rotatable relative to the carriage 21.

Four degrees of movement of the grinding head 26 relative to the table 14 are thus provided under the control of the stepping motors 16, 22, 25 and 27, i.e. three degrees of linear movement together with rotary movement about the axis 30.

The grinding head 26 carries a supply tube 31 whereby coolant water from the tank 17 is continually projected onto the surface of the grinding wheel 29 to avoid overheating of the grinding wheel 29.

The required parameters for controlling operation of the four stepping motors 16, 22, 25 and 27 are programmed into a computer controlling operation of the grinding head. The glass sheet is placed in position and the grinding head is then moved by the stepping motors 16 and 22 into the position at which it is required that the arcuate groove in the glass sheet should commence. The grinding head 26 is then lowered under control of the stepping motor 25 so that the grinding wheel 29 contacts the surface of the glass sheet and thereafter movement of the grinding head is effected under the controlled movements of the four stepping motors to form the desired orientation of groove in the glass sheet. As the grinding wheel 29 is driven about an axis which intersects the axis 30 and as the point of contact of the grinding wheel with the glass sheet remains on said axis 30, the grinding wheel 29 remains disposed tangentially relative to the arcuate groove and smooth travel of the grinding wheel 29 relative to the thus formed groove is thereby obtained.

Claims

CLAIMS:

1. A machine for cutting a groove in a sheet of glass comprising: - (1) a bed having support means for supporting the glass sheet, (2) a grinding head having means for mounting a grinding wheel for rotation about an axis parallel to the surface of the glass sheet, (3) a carriage on which the head is mounted, (4) means for providing relative linear movement along three co-ordinate axes between the head and the glass sheet support means, and (5) means providing for rotation of the head relative to the carriage about an axis which intersects the point of contact between the grinding wheel and the sheet of glass.

2. A machine according to claim 1, in which the carriage is mounted on a bridge which is disposed above the bed.

3. A machine according to claim 2, in which the support means for supporting the glass sheet is in the form of a table mounted for linear movement relative to the bed.

4. A machine according to claim 3, in which the bridge extends at right angles to the direction of travel of the table relative to the bed.

5. A machine according to claim 4 in which computer controls means are provided for controlling movement of the

5. A machine according to claim 4 in which computer control means are provided for controlling movement of the table relative to the bed and of the carriage relative to the bridge.

6. A machine according to Claim 5 in which a stepping motor is provided for effecting movement of the table relative to the bed and a further stepping motor is provided for effecting movement of the carriage relative to the bridge.

7. A machine according to Claim 6, in which a stepping motor is provided for effecting vertical movement of the grinding head relative to the carriage and a further stepping motor is provided for effecting rotation of the grinding head relative to the carriage about a vertical axis.

8. A method of cutting a groove in a sheet of glass which comprises placing the sheet of glass on support means of a bed of a machine, which machine includes a carriage carrying a grinding head having means for mounting a grinding wheel, moving the grinding wheel into contact with the sheet of glass with the grinding wheel rotating about an axis parallel to the surface of the glass sheet, effecting relative movement between the head and the glass sheet in a horizontal plane and rotating the head relative to the carriage about a vertical axis which intersects the point of contact between the grinding wheel and the sheet of glass, such movement of the grinding wheel and the sheet of glass being so arranged that the grinding wheel is continuously located tangentially relative to the groove being cut in the sheet of glass.

9. A machine for cutting an arcuate groove in a sheet of glass, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

10. A method of cutting an arcuate groove in a sheet of glass, substantially as hereinbefore described with reference to the accompanying drawings.

Amendments to the claims have been filed as follows CLAIMS: 1. A machine for cutting a groove in a sheet of glass comprising: (1) a bed having support means for supporting the glass sheet, (2) a grinding head having means for mounting a grinding wheel for rotation about an axis parallel to the surface of the glass sheet, (3) a carriage on which the head is mounted, (4) means for providing relative linear movement along three co-ordinate axes between the head and the glass sheet support means, and (5) means providing for rotation of the head relative to the carriage about an axis which intersects the point of contact between the grinding wheel and the sheet of glass such that the grinding wheel is continuously located tangentially relative to the groove being cut in the sheet of glass.