GB2147530A - Glassware grinding & polishing apparatus - Google Patents

Abstract

A crystal wine glass 24 with a chipped rim is placed on a table 21, and an indicator 14 is set in dependence upon the amount of chipping to be removed. The glass 24 is then placed in a chuck 6, rotated by a motor 5, and lowered onto a spinning grinding disc 1. When the rim has been ground down by the preset amount, the spinning glass 24 is moved over spring loaded grinding and polishing bobbins 2 and 3, which provide a smooth bevelled finish to the rim. The apparatus operates under automatic control to perform a predetermined cycle. Also disclosed is a polishing device that accepts the chipped rim of a glass and can be operated manually. <IMAGE>

Description

SPECIFICATION Polishing apparatus This invention relates to polishing apparatus, and is concerned particularly with apparatus which is suitable for grinding and polishing glasses.

Preferred embodiments of the invention aim to provide apparatus which may operate in an automatic manner to remove unsightly and dangerous chips or flakes from the rim of a glass, in a simple, safe and reliable manner.

Such embodiments of the invention may be used with particular advantage for repairing chipped crystal glassware, which tends to be rather expensive and difficult to repair effectively.

More generally, according to one aspect of the present invention, there is provided apparatus for grinding and polishing glasses, comprising: gripping means adapted to grip a glass; grinding means for grinding the rim of a glass; polishing means for polishing the rim of a glass; and transport means arranged to cause relative movement between the gripping means, grinding means and polishing means, such as to place a glass in the gripping means in a first relative position where its rim may be ground by the grinding means and then in a second relative position where its rim may be polished by the polishing means.

Preferably, the apparatus includes drive means for rotating a glass when gripped in the gripping means. The gripping means may include detector means for detecting when a glass is gripped by the gripping means, in a correct orientation.

The apparatus preferably includes calibration means arranged to co-operate with a glass to be ground and polished, and thereby to set a desired degree of grinding to be carried out by the grinding means.

At least one of the grinding and/or polishing means may comprise a grinding or polishing bobbin having a working surface which is at least partly convex. At least one of the grinding or polishing means may have a working surface which, in use, is resiliently biased towards a glass to be ground or polished.

Preferably, the apparatus includes control means for controlling operation of the apparatus in an automatic, pre-determined cycle.

According to another aspect of the present invention a polishing device is adapted to receive the rim of a glass whereby relative movement between the rim of the glass and the polishing device causes the rim of a glass to be ground and/or polished.

The glasses may need supporting during the polishing due to their thinness. The polishing device may have a groove corresponding in shape to the rim of a glass whereby the rim of the glass can be received in the groove.

One advantage of this arrangement is that the area of contact between the polishing device and the rim of a glass can be arranged to include the whole of the portion of the glass defining the rim at any one circumferential portion. The polishing device may include a plurality of grooves, each arranged to receive the rims of glasses of different diameters. The groove or grooves may be continuous to enable the whole of the rim of a glass to be received in the groove, the annular groove acting as a guide for the glass.

Where a plurality of continuous grooves are provided, the different grooves may be arranged to be concentric with each other whereby the number of rims of different diameters which may be polished by the device is increased.

The abrasive substance used to polish the rim of the glasses could comprise an abrasive secured to the polishing device. Where the polishing device includes a groove or grooves, the abrasive substance could extend completely around each groove or grooves. Alternatively, each groove could include a plurality of spaced abrasive pellets located around the groove, and preferably include three generally equi-spaced pellets located around the groove.

Providing the three pellets around the groove increases the chances of the rim of the glass being polishheed evenly when the relativve movement between the rim of the glass and the polishing device is achieved by a to-and-for twisting movement by hand.

Instead of securing the abrasive substance to the polishing device, an abrasive paste could be arranged to be located between the rim of the glass and the polishing device. The paste could be introduced into the grooves referred to above or, alternatively, the device, or a portion thereof could be made of resiliently deformable material which allows the deformable material to conform to the shape of the rim of the glass and thus achieve a generally even polishing action between the polishing device and the rim. A further alternative is to locate a resilient pad or pads in the groove or grooves of the polishing device.

Abrasive paste could then be located between the resiliently deformable material or the resilient pads and the glass or, alternatively, the deformable material or resilient pads could themselves be made of abrasive material.

One advantage of using abrasive paste is that the grade of the abrasive can be selected in dependence upon the size or nature of the chip or flake. Furthermore, the abrasive paste may be successively changed for a finer grade as the polishing operation proceeds.

More than one side of the polishing device may be arranged to receive the rim of a glass.

Where the polishing device includes a number of grooves, more than one groove may be provided on more than one side of the device to increase the number of rims of different diameters which may be polished by a single device.

The polishing device may include a body of plastics moulding for ease and cheapness of manufacture. The abrasive which may be secured to the polishing device may be adhered to the body or, alternatively, the plastics may be moulded around the abrasive to hold the abrasive thereto, or loose so as to be removable for cleaning of abrasive or insertion of new abrasive of different grade.

In order to polish the rim of a glass with the polishing device, the two may be held together and manually twisted. Alternatively, one of the glass or the polishing device may be caused to rotate by mechanical or electrical means. and the other of the glass or polishing device brought into contact therewith to polish the rim of the glass. Where the rotation of one of the glass or polishing device is effected by electrical means, the rotation may be caused to be initiated by a switch which is activated upon contact with the rim of the glass and the polishing device.

In another aspect, the invention provides apparatus for grinding and/or polishing the rim of a glass, the apparatus being adapted to provide a bevelled or rounded finish to the rim when ground or polished.

The invention may optionally have any of the further features that are apparent from the following description.

For a better understanding of the invention and to show how the same may be carried into effect,reference will now be made, by way of example, to the accompanying diagrammatic drawings, in which: Figure 1 is a schematic plan view of apparatus embodying the invention: Figure 2 is a schematic representation of one polishing means of the apparatus; Figure 3 is a schematic side view of the apparatus; Figure 4 illustrates an adapter for use with the apparatus; and Figure 5 shows a polishing device which may be used by hand.

The apparatus illustrated in Figures 1 to 3 comprises a grinding means in the form of a substantially horizontal grinding disc 1, which is adapted to be driven directly by a motor 4 at a speed of, for example, 2800 rpm. The grinding disc 1 may be of, for example, 100 grit. and preferably has a degree of resilience.

A pulley 15 is driven in rotation by the shaft of the motor 4. anda light flexible belt 16 transmits drive from the pulley 15 to a drum 8. In turn. respective light flexible belts 17 and 18 transmit drive from the drum 8 to a grinding bobbin 2 and a polishing bobbin 3.

As mentioned above, the drawings are only diagrammatic. The ratio of the belt drives is preferably such that the bobbins 2 and 3 rotate at a speed of, for example, 15000 rpm.

As may be seen particularly in Figure 2, each of the bobbins 2. 3 is mounted at one end of a pivot arm 10, which in turn is pivotally mounted on bearings 11 in bearing blocks 12. The free end of each pivot arm 10 is biassed upwardly by a light spring 1 3. Each bobbin 2. 3. is mounted for rotation at the free end of the respective pivot arm 10.

By way of example. the grinding bobbin 2 may be of 120 grit. and the polishing bobbin 3 of 1200 grit. Preferably, there is also provided an intermediate bobbin between the bobbins 2 and 3. mounted in just the same way but having a grit of, for example, about 800. However, this intermediate bobbin is not shown in the drawings. for the sake of clarity.

The bobbins 2 and 3 may be of resilient material.

As may be seen in Figure 3. a further motor 5 carries on its shaft a chuck 6, which is specially adapted to grip around the base of a stemmed glass.

in Figure 3. the jaws of the chuck 6 are shown only schematically. In practice. they are preferably so mounted as to be adjustable radially of the chuck 6, and have radially inner faces which define an acute angle with the base of the chuck, thereby to grip over the base of a stemmed glass. The jaws are preferably of resilient material, at least on the aforementioned radially inner faces. Thus, as the chuck 6 is tightened. the jaws grip the base of a stemmed glass firmly and safely.

and pull the base of the glass onto the base of the chuck 6.

A light finger 7 (shown in chain lines in Figure 3) depends from the chuck 6. The motor 5 is mounted for horizontal movemen t--e.g. along rails 9. It is also mounted for vertical movement by suitable means (not shown). An indicator 14, comprising a first finger 19 and a second finger 20 is mounted above a table 21. The position of the indicator 14 is sensed by a sensor 22, the output of which is fed to a control means 23, which is adapted to control the position of the motor 5.

The illustrated apparatus is contained within an enclosed housing (not shown), and means (not shown) are provided for spraying water over the apparatus, at least in the vicinity of the grinding disc 1 and the bobbins 2 and 3.

Preferably, the housing has a transparent front, through which operation of the apparatus may be observed.

The apparatus shown in Figures 1 to 3 operates as follows.

Firstly. a wine glass 24 having a stem is placed upright on the table 21. It is assumed that the wine glass 24 has a chipped rim, and that it is desired to grind down the glass to a level below that of the chipping. The indicator 14 is lowered until the first finger 19 is at the desired level to which the glass is to be ground. The second finger 20 protrudes within the bowl of the glass 24, and this ensures that the glass 24 has been placed on the table 21 the correct way up. Alternative means of ensuring this are possible. For example, a lightly spring-biased finger may protrude upwardly from the table 21, such that the finger is depressed by the base of the glass 24 when placed on the table 21 the right way up, thereby to enable the apparatus to operate.

When the first finger 19 of the indicator 14 has been set at the desired level, the sensor 22 is actuated to pass the respective positional information to the control means 23.

The apparatus is thus calibrated, in that the control means 23 contains the necessary information to control the subsequent degree of grinding.

Once this calibration step is finished, the wine glass 24 is gripped firmly in the chuck 6 of the motor 5. To this end, the wine glass 24 is inverted, and its base is placed into the chuck 6, the jaws of which are adapted specially to clamp around the base of the glass, as mentioned above. Provided that the glass 24 is placed in the chuck 6 in the correct orientation (i.e. inverted, in this case), the light depending finger 7 is pressed upwardly by the base of the glass 25, and activates a sensor to enable the apparatus to operate.

With the glass 24 firmly gripped in the chuck 6, the apparatus commences an automatic sequence of operations, under the control of the control means 23. As mentioned above, the housing within which the apparatus is enclosed is preferably provided with a transparent portion, through which operation of the apparatus can be viewed. Such a transparent portion may typically include a door, and suitable interlocks are provided to ensure that the apparatus does not operate unless the door is closed.

The first step of the automatic sequence of operations is for the motor 5 to commence spinning the glass 24 in the chuck 6, at a speed of approximately 120 rpm. The motor 4 also starts to rotate, causing the disc 1 and the bobbins 2 and 3 to rotate at their respective speeds. The aforementioned water sprays (not shown) are started up, at least in the vicinity of the parts 1. 2 and 3.

The starting position of the glass 24 is generally as illustrated in Figure that is, just above the grinding disc 1. The glass 24 is lowered slowly onto the rotating disc 1 (for example, at a rate of about Smm/sec, by means of a viscous damper). The rim of the glass 24 is then applied against the grinding disc 1-for example, at a force of approximately Ikg. If desired, a feedback control loop is provided to maintain the force of the glass 24 against the disc 1 at a predetermined and constant level.

Grinding of the rim of a glass 24 continues until the desired amount of glass has been removed. As will be appreciated, this desired amount is determined by the initial setting of the indicator 14. By way of a simple example, the adjustment of the indicator 14 may cause corresponding adjustment of a limit switch which responds to vertical position of the chuck 6.

When grinding of the glass rim has been finished at the grinding disc 1, the motor 5 is then caused to move horizontally, in such a path as to bring the rim of the glass into engagement with the bobbins 2 and 3. In the illustrated example, the motor 5 is adapted to move in a substantially horizontal plane, in a substantially straight line between the centres of the grinding wheel 1 and the bobbin 3.

It will be seen that the bobbins 2 and 3 are each positioned at a level which is somewhat above that of the grinding disc 1. Therefore, as the glass 24 is moved horizontally with the motor 5 (still spinning) away from the grinding disc 1, a leading edge of the spinning glass 24 will initially come into contact with the curved surface of the grinding bobbin 2.

As the spinning glass 24 continues to move horizontally, the bobbin 2 is pushed downwardly againt the force of the light spring 13, until the leading edge of the spinning glass clears the highest point of the bobbin 2. It will be appreciated that, during this movement, the spinning bobbin 2 works against the outer surface of the spinning glass 2, to provide a bevelled finish to the rim of the glass. As the spinning glass 24 continues to move horizontally with the motor 5, the bobbin 2 is allowed to rise again under the influence of the light spring 13, until the leading edge of the spinning glass 24 clears the bobbin 2 altogether. During this latter movement, there is also some grinding work done by the spinning bobbin 2 on the inner surface of the spinning glass 24.

As the spinning glass 24 continues its horizontal travel further, its trailing edge then comes into contact with the curved surface of the spinning bobbin 2, which is again depressed against the force of the spring 13.

until the trailing edge of the glass passes the highest point of the bobbin 2. During this time, the spinning bobbin 2 works against the inner surface of the rim of the glass 24, again to provide a bevelling effect on the rim of the glass. As the spinning glass 24 continues its horizontal travel, the bobbin 2 progressively rises, working again on the outer surface of the spinning glass 24 as it does so.

Thus, the bobbin 2 serves to bevel or round off the rim of the glass 24.

This routine is repeated as the glass 24 passes into engagement and over the second bobbin 3 which, being of a much finer grit, performs a final polishing operation on the rim of the glass 24. As mentioned above. it is preferred that an intermediary bobbin of, for example, 800 grit is positioned between the two bobbins 2 and 3, in a similar manner, to perform an intermediate grinding or polishing operation.

When the glass 24 has been worked upon by the grinding disc 1, and bobbins 2 and 3, the apparatus shuts off automatically. Before doing so. however. the motor 5 may be moved back to its original (or any other) position under control of the control means 23, if desired. as another optional feature, the glass 24 may be subjected to rinsing and/or drying operations after leaving the bobbin 3.

For rinsing, the glass may be subjected to a high pressure wash, together with a rinsing additive if desired. Drying may be effected by blowing warm or hot air over the glass 24.

Drying may be assisted by maintaining the water in the apparatus at an elevated temperature.

It will be appreciated that various modifications may be made to the apparatus illustrated in Figures 1 to 3. For example, although the motor 5 is shown as moving in substantially rectilinear paths with respect to the components 1, 2 and 3, any other suitable system for providing the necessary relative movement between the motor 5, grinding disc 1 and bobbins 2 and 3 may be employed. As one particular example. the motor 5 may be caused to move in an arcuate path.

It will be appreciated that the chuck 6 is specially adapted to grip the base of a stemmed glass. In order to cope with nonstemmed glasses, there may be provided an adapter 25 as illustrated in Figure 4.

In this figure, the adapter 25 is provided with a base 26, similar to the base of a stemmed glass.

However, the adapter 25 is provided with a cup 27 of resilient material, which is adapted to engage closely around the base of a tumbler 28 (or other non-stemmed glass).

In use, the base of the tumbler 28 is engaged in the cup 27, preferably by means of suction. The suction may be afforded by the resilience of the material from which the cup 27 is formed and the close fit of the tumbler 28 therein, and/or means may be provided for evacuating the space between the tumbler 28 and the cup 27.

It will be appreciated that the spring-loaded bobbins 2 and 3 provide a particularly effective way of grinding and/or polishing the rim of a glass. Preferably, the bobbins 2 and 3 are arranged to be readily interchangeable, such that a new bobbin may be used for each new grinding or polishing operation, to ensure a consistent light quality finish. The grinding disc 1 (or at least the grinding surface thereof) may be similarly interchangeable. By way of example, each bobbin 2 may have embedded therein a rectangular shaft which is adapted to engage in a correspondingly shaped socket mounted for rotational movement on the end of the respective pivot arm 10. Each such rectangular section shaft may be magnetic to secure the shaft in the socket, and afford ready changover of bobbins.

The spherical working surface of the bobbins 2 and 3 is particularly important, as it facilitates the transmission of forces between the rim of a glass and the respective bobbin.

The pivoting action of the arms 10 is important. to mimimise frictional effects on the movement of the bobbins 2, 3. The arms 10 are preferably so arranged that. in a neutral position, they are substantially horizontal.

It is to be appreciated that the peripheral surface of the drum 8 is of cylindrical shape.

such that the belts 17 and 18 may run up and down that surface as the bobbins 2 and 3 move up and down.

Although the above described apparatus is for grinding and polishing glasses, it is to be appreciated that it may be used for grinding and polishing any other article or material.

Figure 5 shows a polishing device comprising a plastics disc 110 whose surface 11 2 (facing upwardly in the drawing) includes three concentric annular grooves 11 4. 116 and 118. Three abrasive pellets 120. 122 and 124 extend radially over. and lie flush with the surface 112. each of the pellets extending across each of the grooves and conforming to the shape of the grooves at points equidistant from each other around the grooves. The grooves 114. 116 and 118 are curved in cross-section, their shape corresponding to the shape of the rim of a glass.

In order to polish the rim of a glass which has been chipped or flaked. the rim of the glass is placed into one of the grooves 114, 11 6 or 11 8 of corresponding diameter and the polishing device and the glass twisted toand-fro relative to each other. Each of the pellets in the groove in which the rim is located engages that portion of the glass defining the rim at that part of the glass whereby the twisting movement causes the pellets to polish the rim of the glass as the rim passes the pellets. That portion of the walls of groove defined by the plastics material acts as a guide for the rim of the glass and ensures that no undue transverse force can be applied to the thin walls of the glass such as might tend to break the glass. The abrasive may have grooves cut to the shape of the rim of the glass. A separate machine may be used to cut the glass in the abrasive.

The abrasive pellets may be adhered into correspondingly shaped recesses formed in the upwardly facing surface 112. Alternatively, the plastics may be moulded about the pellets in order to retain the pellets in position.

Instead of providing the generally rigid abrasive pellets which conform substantially to the shape of the grooves, flexible abrasive pads could be provided which extend across the grooves. When the rim of a glass is to be polished it can be pushed lightly into the groove of corresponding size, against the force of flexible pads. The pads then surround and lightly engage the rim of the glass whereby a twisting movement of the glass relative to the polishing device causes the abrasive pads to polish the rim of the glass.

Instead of, or in addition to the pads or pellets being abrasive, abrasive paste can be introduced into the grooves in order to provide or enhance the polishing effect provided by the device. If desired, the surface facing downwardly in the drawing may also be provided with concentric grooves, the grooves either being of different shape or diameter than those on the upwardly facing surface, whereby a larger variety of rims may be polished by the device, or of the same shape and diameter whose abrasiveness is of a finer or coarser grade than that provided on the upwardly facing surface 112, whereby the rim of a glass may be first coarsly polished by one side and then finely polished by the other side.

It is to be understood that the present invention has numerous different aspects, and embraces every novel feature or novel combination of features disclosed herein. In particular, it is believed that the part spherical bobbins 2 and 3 are novel in themselves.

A common feature of the apparatus shown in Figures 1 to 4 and the device shown in Figure 5 is that, in each case, the arrangement is such as to grind and/or polish the rim of a glass with a bevelled or rounded-off effect.

Claims (11)

1. Apparatus for grinding and polishing glasses, comprising: gripping means adapted to grip a glass; grinding means for grinding the rim of a glass; polishing means for polishing the rim of a glass; and transport means arranged to cause relative movement between the gripping means, grinding means and polishing means, such as to place a glass in the gripping means in a first relative position where its rim may be ground by the grinding means and then in a second relative position where its rim may be polished by the polishing means.

2. Apparatus according to Claim 1, including drive means for rotating a glass when gripped in the gripping means.

3. Apparatus according to Claim 1 or 2, wherein the gripping means includes detector means for detecting when a glass is gripped by the gripping means, in a correct orientation.

4. Apparatus according to Claim 1, 2 or 3, including calibration means arranged to cooperate with a glass to be ground and polished, and thereby to set a desired degree of grinding to be carried out by the grinding means.

5. Apparatus according to any preceding claim, wherein at least one of the grinding and/or polishing means comprises a grinding or polishing bobbin having a working surface which is at least partly convex.

6. Apparatus according to any preceding claim, wherein at least one of the grinding or polishing means has a working surface which, in use, is resiliently biased towards a glass to be ground or polished.

7. Apparatus according to any preceding claim, including control means for controlling operation of the apparatus in an automatic, pre-determined cycle.

8. A polishing device adapted to receive the rim of a glass whereby relative movement between the rim of the glass and the polishing device causes the rim of a glass to be ground and/or polished.

9. Apparatus for grinding and/or polishing the rim of a glass, the apparatus being adapted to provide a bevelled or rounded-off finish to the rim when ground or polished.

10. Apparatus for grinding and polishing glasses, substantially as hereinbefore described with reference to Figures 1 to 3, optionally as modified by Figure 4, of the accompanying drawings.

11. A device for polishing the rim of a glass, substantially as hereinbefore described with reference to Figure 5 of the accompanying drawings.