GB2210652A - Applying self-adhesive lead to glass - Google Patents

Abstract

A machine for applying lead strip to window glass, comprising a trestle (10) carrying an inclined supporting surface (12) for the glass and a datum bar (16) on which the glass (14) stands on one edge, a counterbalanced guide bar (20) movable up and down the supporting surface, a carriage (22) including means for applying to the glass lead strip drawn from a supply reel, the carriage being movable along the guide bar, and a detecting means (33, 52) for indicating the level of the guide bar relative to the datum and thus the position on the glass at which the lead strip is being applied. <IMAGE>

Description

Apparatus for Applying Self-Adhesive Lead to Glass This invention relates to apparatus for applying selfadhesive lead to glass.

In the production of leaded window glass, it is conventional practice to apply self-adhesive lead strip to the glass by hand. The glass is laid over a pattern bearing lines which precisely indicate the lines along which the lead strip is to be applied, typically a rectangular or diamond grid, a suitable length of lead strip is drawn from a reel thereof, an adhesive-covering release paper stripped away, the lead strip laid in position along one line of the pattern, a pressure roller run along the strip by hand in order to press the lead into position, this process repeated until the pattern is fully covered, and finally the joints at which one lead strip crosses another are pressed down with a suitable tool.

A machine has been proposed in which a carriage bearing a reel of lead strip is mounted on a guide bar which can be manually positioned over a line of the pattern, whereafter movement of the carriage along the bar causes application of the lead strip along the line, the lead strip being drawn from the supply reel and the release paper being stripped therefrom automatically during hand transport of the carriage along the bar.

The proposed machine is advantageous as far as the speed of application of the lead strip is concerned, but leaves unsolved the problem that an underlying pattern has to be provided for each sheet of glass, with the related problem that the operative has to align the guide bar with the lines of the pattern by eye. This first-mentioned outstanding problem is a substantial one, because for different window types and sizes, different windows within which a plurality of glass lights or panes must have matched and aligned patterns, and according to the customer's requirements, a vast number of patterns are required, often unique to individual installations, and the cost of producing the patterns indirectly makes a very substantial contribution to the cost of the final product.

According to the invention, there is provided a machine for applying self-adhesive lead strip to window glass, comprising a supporting surface for the glass, a datum on said surface for locating at least one edge of the glass, a lead strip applicator, a support by means of which the applicator is linearly movable to apply a line of lead strip to the glass, means for mounting the support for movement at least in a direction transverse to the direction of linear movement of said applicator, and detector means responsive to movement of the support to detect, at any position in its range of: movement, the position relative to the datum, and thus relative to the glass, at which the applicator will apply the lead strip.

The invention thus obviates the requirement for a pattern to underlie the glass. All that the operative requires is a series of measurements or numbers at which the support is successively locatable, these locations being identifiable by use of the detecting means, and the lead strip can readily be applied in any required grid over the glass. In a simple machine having a support movable at right angles relative t-o the datum and an applicator movable along the support in a.

transverse direction parallel to the datum, a relative rotation of the glass and datum is required to enable a complete grid pattern to be produced, but it is practicable to provide a movable support, for example on the lines of a pantograph, which will enable lines of lead strip to be applied in transverse directions without relative rotation of the glass, given that the datum simultaneously locates two non-parallel glass edges. However, on a factory production line, it will often be convenient to provide two lead application machines side by side, and provide for rotation of the glass, commonly through 90 degrees, during passage of the glass from the first machine to the second machine.When a diamond grid pattern, as distinct from a rectangular grid pattern, is being produced, both machines will have the datum and the strip applicator support extending at an angle to one another, which angle may be adjustable, and the glass may require rotation through an angle other than a right angle during passage from the first machine to the second machine.

The detecting means may, for example, include a simple numerical indicator effectively zeroed on the datum, and which indicates the lead application position as a number which varies in accordance with the position of the support.

In this case a sensor is required to detect movement of the support and provide a suitable output to the indicator.

The sensor, indicator and the coupling between them may be of a mechanical, electrical or electronic, or an electromechanical type.

A more complex machine may be power controlled via a microprocessor, which reads a program of measurements input to it, as by a keyboard, and automatically moves the support successively to match the datum-based outputs of a support movement detector to the program of measurements. A prime mover which provides the power may also operate to move the applicator to effect application of the lines of lead strip at the successive positions of the support, given that the dimensions of the glass are also input to the microprocessor.

In one simple embodiment in accordance with the invention, the lead applicator is carriage mounted for movement along a support in the form of a guide bar adjustably movable transverse to its length. The glass is supported on a supporting surface inclined, in the manner of a draughtsman 5 drawing board, to the vertical plane, and the guide bar, carrying the carriage incorporating the lead strip applicator, is counterbalanced for movement up and down said inclined supporting surface. This counterbalancing may be effected, again in a manner analogous to counterbalancing means on a draughtsman's drawing board, by means of an endless line passing round upper and lower pulleys at one side edge of the supporting surface and attached to the lead strip applicator support at the front and the counterweight at the back. One of the pulleys, or alternatively the line, may then be used to drive a simple encoder which provides an output to the numerical indicator. Alternatively, a toothed wheel counter or other suitable sensor may detect the position of the support relative to the datum on the glass supporting surface and provide an output, conveniently an electrical output, which is utilised to control.

an adjacent LED or LCD indicator. The operative moves the support successively to positions which give a required numerical output at the indicator, in accordance with a predetermined table of numbers with which the operative is supplied. At each position of the support, the operative moves the carriage along the guide bar to effect application of a line of lead strip. The carriage carries a supply reel for lead strip, and guide rollers through which the strip is fed to an application roller which runs across the glass, pressing the lead strip into position and drawing strip from the supply reel as it does so. The guide rollers include a roller pair at which release paper is stripped from the adhesive on the lead strip, and wound on to a release paper take-up reel.The necessary pressure for causing the application roller to press the lead strip on to the glass may be derived from gravity, due to a turning moment acting on the carriage about a pivotal connection thereof to the guide bar, this pressure possibly being supplemented, in use of the machine, by manual pressure applied by the operative. More preferably, however, and to ensure a consistent and uniform application pressure, a biassing spring is employed, typically acting on the pivotally mounted carriage rather than the application roller itself.

It will be appreciated that the carriage is preferably pivotally mounted to the support bar so that, after application and cutting of one line of lead strip, it can be pivotted to a retracted position to facilitate its movement back to the leading edge of the glass.

The carriage may carry a manually retractable toggle mounted pressure roller for ensuring adhesion of the lead strip at the beginning of each line of application thereof. This initial adhesion is necessary to ensure that the strip is drawn from the supply reel as movement of the carriage is commenced along the bar. More preferably, however, the pressure roller is movable towards and away from the glass under the action of a pneumatic actuator. This actuator may again be manually controllable by an on/off switch, but alternatively may be automatically controlled in accordance with a timed cycle, the pressure roller being applied towards the glass when the cycle is commenced responsively to the carriage being pivotted towards the glass when application of a line of lead strip is to be started.

The pressure roller is then retracted at the end of the cycle, which is set to occur after a predetermined time or after a predetermined travel of the carriage along the guide bar has been effected. Thus, the pressure roller automatically becomes operative to assist adhesion of a previously cut end of lead strip when the support has been moved and the carriage is pivotted back to its operative position when application of the next line of lead strip is to be commenced. In this way, wastage of lead strip is minimised.

The support surface may include a slot housing a spring mounted cutting bar for automatically cutting the lead strip after the applicator has run off the trailing edge of the glass. In a preferred arrangement, however, a cutting mechanism is provided on the carriage. This preferably operates in conjunction with the aforedescribed pressure roller.Thus, a fixed cutting blade is mounted on the carriage with its cutting edge disposed just rearwardly of the normal path taken by the lead strip in feed from the retracted pressure roller to the application roller, and a hooked head is operable by a pneumatic actuator, which may be manually or automatically actuatable, to perform a rapid forward and reverse movement in course of which it engages the lead strip and pulls it back against the cutter blade to sever said lead strip, leaving the cut end pulled back against the retracted pressure roller, ready for application to the glass when the pressure roller is pushed forward at the start of application of the next strip of lead.

The construction of the application roller is also important.

The lead strip applied to window glass conventionally has a convexly curved face on the side of the strip remote from the face applied to the glass, and it is advantageous for the application roller to have a substantially matching concave peripheral surface, in order to avoid any deformation of the strip. A further advantage then arises that the joints or cross-overs in a grid pattern of applied lead strip can be pressed down by use of the same lead applicator, but without supply of lead strip to the application roller.

The pressure roller may have a like concave peripheral surface.

An embodiment of machine for applying self-adhesive lead strip to window glass is diagrammatically shown in the accompanying drawings, in which: Figure 1 is a pictorial perspective view of an embodiment of machine in accordance with the invention; Figure 2 is a plan view of the machine carriage; Figure 3 is a side view of the carriage; and Figure 4 shows e detail of an application roller.

Referring to Figure 1, a bench or trestle 10 carries an inclined supporting surface 12 for a rectangular sheet of window glass 14. The bottom edge of the glass sheet is located against a horizontal abutment member 16 which constitutes a datum as hereinafter explained.

The side edges of the supporting surface carry slides 18 enabling up and down movement of a horizontal guide bar 20.

Mounted on the guide bar 20 is a carriage 22 slidable back and forth along the length of the guide bar 20. A handle 24 on the carriage 22 enables the latter to be manually moved back and forth; this same handle enables the guide bar 20 to be moved up and down. Friction between the guide bar and the slides on which it is slidably supported may maintain the guide bar at a chosen level of adjustment, but preferably the guide bar and carriage are counterbalanced, as later described.

The general layout of the carriage 22 is shown in Figures 2 and 3, with the handle omitted. It comprises a generally flat platen 24 rotatably supporting a supply reel 26 for self-adhesive lead strip backed by a release paper, a take-up reel 28 for the release paper, guide wheels 30 at which the release paper is separated from the lead strip, and an application roller 32 at which the lead strip is applied to the glass sheet. The lead strip/release paper combination is referenced 36, the lead strip 38, and the release paper 40. The application roller 32 may be mounted within a guard having side cheeks which guide the lead strip around the roller. Drive belts and pulleys for the reels on the carriage are referenced 33 in Figure 3.

In this connection, attention is drawn to Figure 4, showing the concave form 44 of the circular periphery of the application roller 32, enabling it to apply flat/ convex lead strip 38 efficiently and without distorting the form and shape of the lead strip.

Reverting to Figure 2, there is also shown a pressure roller 46 which is employed for the purpose hereinafter described, and a cutter 47 the use of which is also later described.

A pivotal mounting 48 via which the carriage 22 is mounted to the guide bar 20 is shown in Figure 3.

For production of a Georgian-type leaded window, lead strip has to be applied to the glass sheet in a rectangular grid formation, consisting of two mutually perpendicular sets of parallel lines of lead. Figure 1 shows the machine during the course of application of the first of the two sets of lines of lead strip.

The lines of lead strip have to be applied at predetermined positions on the glass sheet, in accordance with the size of the sheet, dimensions of the final pattern required and the location of the pattern relative to the edges of the sheet. Normally, the desired result is achieved by laying the glass over a paper pattern drawn out specifically for the leaded window which is being produced.

In accordance with the present invention, the guide bar 20 has a counterbalancing mechanism 32, similar to that employed on a draughtsman's drawing board, having an upper pulley to which is attached an encoder 33 which in effect reads the position or level of the guide bar relative to the datum 16. The encoder 33 supplies an output signal on cable 50 to a display device in the form of a numerical LED or LCD display 52 mounted on the supporting surface 12, at a position where the display is readily visible to the operative.

The operative is also supplied with a list of measurements or numbers indicative of the positions at which lines of lead strip must be applied relative to the edge of the glass sheet located against the datum 16.

The operative successively moves the guide bar to the levels at which the display 52 indicates measurements or numbers corresponding to those on the list, and at each such level applies a line of lead strip to the glass.

The application of each line of lead strip is by movement of the carriage 22 forwardly along the guide bar 20, which in this embodiment lies strictly parallel to the datum 16. During forward movement, the application roller 32 is at the leading end of the carriage, and pressure on the carriage by hand or more preferably by releasable spring loading urges this roller against the glass to cause the lead strip to be firmly adhered thereto.

Once adhesion of the line of lead strip has been commenced, further lead strip/release paper is automatically drawn from the supply reel, release paper taken up by the take-up reel, and lead strip supplied to the application roller to progress the adhered line of lead strip across the glass.

The purpose of the pressure roller 46 on the carriage 22 is to initiate adhesion of the lead strip. This roller 46 is shown in a retracted position, but it is forwardly displaceable by a pneumatic actuator 60 controlled by switch 62 to press the lead strip against the glass at the beginning of the application of a line. By means of the control switch 62, the actuator 60 can be operated to retract the pressure roller 46 any time after the application roller 32 has ten or the function of adhering the lead strip to the glass.

Less preferably, the pressure roller may be toggle mounted and spring loaded, to bear on the starting portion of a line of lead strip, maintaining a static position during a short initial part of the movement of the carriage along the guide bar before withdrawing to its retracted position on over-reaching the dead centre afforded by the togglemounting.

The pressure roller mechanism 46, 60, operates in conjunction with a cutter mechanism of which the cutter 47 forms part.

When the trailing edge of the glass is reached, or at any time after the pressure roller 46 has been retracted, the cutter mechanism may be operated to sever the lead strip.

The mechanism operates over the glass, avoiding wastage of lead strip and, when necessary, severing the lead strip after application part way across the glass, as may be necessary during application of complex patterns.

The cutter mechanism includes dual pneumatic actuators 70, 72, operable by control switch 74 via logic means 76 (Figure 3) which causes an actuator head 78 to perform a timed, cyclic sequence of movements. The head 78 incorporates a hooked formation which, during the cyclic sequence of movements, is first displaced laterally out of line with the lead strip, then displaced forwardly, then displaced laterally to engage the lead strip, and finally displaced rearwardly to pull the lead strip back against the cutter 47 to sever the lead strip. As a result, the cut end of lead strip is left pulled back against the retracted pressure roller 46, ready to be pressed against the glass at the commencement of application of the next line of lead strip when the pressure roller is actuated forwardly.Then, when the pressure roller has been so actuated, as lead strip is drawn from the supply thereof as the carriage is moved along the guide bar, the application roller engages over the end of the lead strip to continue the adhesion process, and the pressure roller may be retracted, ready for initiation of the next cycle of the cutter mechanism at any time thereafter.

In an alternative, less preferable arrangement, at the end of a line of lead strip, the latter is cut by a cutting bar housed in a slot in the supporting surface. This cutting bar may be automatically operated after the lead strip applicator has run off the far edge of the glass from the starting edge. The cutting bar leaves a tail on the lead strip emergent from the application roller; this tail.is utilised by the pressure roller 46 at the beginning of application of the next line of lead strip, at the next level of the guide bar.

The pivotal mounting 48 of the carriage enables said carriage, and thus the application roller in particular, to be withdrawn from the glass sheet during return movement of the carriage back to the starting edge of the glass, applied spring pressure being relieved during this return movement.

When application of the first set of lines of lead strip has been completed, the glass is turned through ninety degrees to enable application of the second set, the operative utilising a second list of measurements or numbers to set the levels of the guide bar with the aid of the LED or LCD display. Alternatively, the glass may be turned on passage from the first machine to a second-machine at which the second set of lines of lead strip is applied.

Finally, after both sets of lines of lead strip have been applied, pressing down of junctions where the lines of lead strip intersect can be effected by a repeat running of the application roller over the second set of lines, but with the supply of lead strip disconnected.

While the above-described embodiment is for application of lead strip in a Georgian type window, it will be appreciated that either the glass or the guide bar could be supported at an angle, conveniently by means of a suitable mounting which enables the angle to be adjusted, in order to adapt the machine to application of lead strip in a diamond pattern.

Various other modifications of the above-described machine are possible within the scope of the invention defined in the appended claims.

Claims (19)

Claims

1. A machine for applying self-adhesive lead strip to window glass, comprising a supporting surface for the glass, a datum on said surface for locating at least one edge of the glass, a lead strip applicator, a support by means of which the applicator is linearly movable to apply a line of lead strip to the glass, means for mounting the support for movement at least in a direction transverse to the direction of linear movement of said applicator, and detector means responsive to movement of the support to detect, at any position in its range of movement, the position relative to the datum, and thus relative to the glass, at which the applicator will apply the lead strip.

2. A machine according to claim 1, having a support movable at right angles to the datum and an applicator movable along the support parallel to the datum.

3. A machine according to claim 1 or claim 2, wherein the detector means includes a numerical indicator effectively zeroed on the datum.

4. A machine according to any of claims 1 to 3, wherein the support takes the form of a guide bar adjustably movable transverse to its length and the applicator takes the form of a carriage movable along the guide bar.

5. A machine according to any of claims 1 to 4, having a trestle carrying a blackboard for supporting the glass in a plane inclined to the vertical.

6. A machine according to claim 5 when appendant to claim 4, wherein the guide bar is movable up and dozy the inclined supporting surface.

7. A machine according to claim 6, wherein the weight of the guide bar and carriage thereon is counterbalanced.

8. A machine according to claim 7, wherein the counterbalancing means includes a wheel driven by movement of the guide bar and driving an encoder forming part of the detector means.

9. A machine according to any of claims 1 to 8, wherein the carriage carries a supply reel for release paper backed lead strip, guide rollers for stripping the release paper, a take up reel for the release paper, and an application roller for applying the lead strip to the glass under pressure.

10. A machine according to any of claims 1 to 9, wherein the carriage is mounted to the guide bar via a pivotal mounting.

11. A machine according to claim 10 when appendant to claim 9, wherein the carriage is spring biassed about its pivotal mounting to urge the application roller towards the supporting surface.

12. A machine according to claim 11, wherein the spring pressure can be relieved during reverse movement of the carriage along the guide bar.

13. A machine according to any of claims 9 to 12, including a pressure roller mounted on the carriage for forward and backward movement relative to the supporting surface.

14. A machine according to claim 13, wherein the pressure roller is controlled by a pneumatic actuator.

15. A machine according to any of claims 1 to 14, including a cutter mechanism mounted on the applicator.

16. A machine according to claim 15 when appendant to claim 4, wherein the cutter mechanism comprises a fixed cutter blade on the carriage, and a pneumatic actuator including a hook-shaped head for engaging the lead strip and retracting it away from the supporting surface against the cutter blade.

17. A machine according to claim 16 when appendant to claim 13, wherein the cutter mechanism is positioned adjacent the pressure roller to leave the cut end of the lead strip pulled back against the pressure roller when the latter is retracted.

18. A machine according to claim 9 or any claim appendant thereto, wherein the application roller has a concave peripheral surface for the application of flat/convex lead strip.

19. A machine for applying leat strip to Window glans~, substantially as hereinbefore described with reference to the accompanying drawings.