US3870499A

US3870499A - Apparatus for manufacturing solid double layer sheet glass

Info

Publication number: US3870499A
Application number: US444185A
Authority: US
Inventors: Otto Stehl
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-03-24
Filing date: 1974-02-20
Publication date: 1975-03-11
Anticipated expiration: 1992-03-11
Also published as: DE2314715A1; ATA31674A; DE2314715C3; JPS49122521A; CA1011557A; AT326288B; DE2314715B2; JPS5722904B2; SE402905B

Abstract

An apparatus is provided for manufacturing solid double layer sheet glass by fusing together the longitudinal and transverse edges of single sheets drawn vertically through a tunnel oven, having a lower guide track to support and guide the lower edges of the sheets, an upper, vertically adjustable guide track to guide the upper edges of the sheets, and a fusing device which is vertically adjustable relative to sheet height and serves to fuse the upper edges of the sheets.

Description

United States Patent l 3,870,499 Stehl 1 Mar. 11, 1975 APPARATUS FOR MANUFACTURING 3.201056 9/1965 Rocttcr ct a] .r 65/58 SOLID DOUBLE LAYER SHEET CLASS [76] Inventor: Otto Stehl, Brucker Holt 46, D Kellogg Essen Bredeney Germany [22] Filed: Feb. 20, 1974 [2!] Appl No.: 444,185 [57] ABSTRACT I I An apparatus is provided for manufacturing solid dou- Apphumm prmmy ble layer sheet glass by fusing together the longitudinal M111 1973 (wrmlmy 3314715 and transverse edges of single sheets drawn vertically through a tunnel oven, having a lower guide track to U-S- (ll 65/156, 65/160 upport and guide [he lower edges of [he 5hee[5 an v r r 4 uppgr vertically adjustable guide truck to guide [58] new of Search 65/587 160 upper edges of the sheets, and a fusing device which is vertically adjustable relative to sheet height and serves {56] References cued to fuse the upper edges of the sheets.

UNITED STATES PATENTS 3 l()3 429 9/1963 Kruger ct al .v 65/58 X 5 Claims, 5 Drawing Figures I 5 H 16 H 20 -22 9 d P 24 i i 40 T 44 ii 5 t 36 0 cu uuuodoouuou Tim ononnnnnnnnnonnonnoonoormonnononnnnnonn r -mononoooonononoooonnnnooooooonn I T 1r 1 TI' 'TI' 1 I q, 1H,, 1. Any/.11, Uri y 74 H I m. h v I PATENTEU MR? 5 SHEET 2 BF 5 g'g-ugmggmm 1 i975 3'870'499 su ar 5 or s I UPPER TORCH ARM 1 ma LOW RELATIVE TO swear UPPH? TORCH ARM AT m5 RIG HEIGHT OOOOOOQ W UPPER 70/? H 42M 700 HIGH E514 Tll/E 7'0 SHEE 7' 7' 72 Fig.5

APPARATUS FOR MANUFACTURING SOLID DOUBLE LAYER SHEET GLASS BACKGROUND OF THE INVENTION The manufacture of solid double layer sheet glass by fusing single sheets along their longitudinal and transverse edges presupposes a very exact guidance of the sheets within the zones in which the preliminary heating and then the actual processing take place. In known devices designed to carry out the heating, the fusing, the cooling of such sheets, individual vertical glass sheets are introduced to lower and upper guide tracks, whereupon they are transported through a tunnel oven, usually on slide or roller devices comprising the lower guide track.

ln order to be able to guide the sheets with exactitude at both lower and upper edges, it is necessary to adjust the distance of the upper guide track from the lower guide track in conformity with the height of the glass sheets. To this end, it is conventional in known devices to adjust the whole upper guide track as one integral unit relative to height in such a way that secure guidance of the upper sheet edges is assured. As soon as the upper guide track has been adjusted at a determined distance relative to the lower guide track, the fusing device (consisting of a burner arm) for fusing the upper sheet edges is adjusted accordingly, whereupon sheets of predetermined height may then be processed by means of the apparatus.

If sheets having a different height from that of an existing run of a particular sheet height are to be produced, the entire production line of sheets at the existing sheet height being conveyed through the oven must leave the tunnel oven, and the'guidetracks at the exit end of the apparatus, before the continuous upper guide track together with the burner arm can be readjusted to conform to the new sheet height. Furthermore, because the readjustment of the entire continuous upper guide track in such apparatus is not possible without a lengthy interruption of the operation of the production line, such known devices are suitable only for the economical production of large orders; whereas processing of a small order in which only a relatively small number of sheets of a stated sheet height are to be produced, is uneconomical because of the labor costs or set-up time arising from the readjustment of the upper guide track.

The production of a small order of, for example, fifty pieces (and such short batches are inevitable in meeting production quotas in a windowglass factory) requires 2 hours oven time. Readjustment for the next batch of a different sheet height takes roughly half an hour with prior art devices of the type described.

lt is therefore self-evident that there would be much advantage in having a devicethat could be adjusted for height without the time-loss required to adjust for different sizes of glass.

The time-consuming readjustment of sheet height has the following additional economic disadvantage in devices of the prior art. If, for example, an order of 100 pieces of identical dimensions is to be supplied, several extra sheets must always be produced in order to account for rejects or production waste. Accordingly, there are generally a few sheets left over which cannot be disposed of. A device in which the adjustment of sheet height does not require any additonal time can be helpful in remedying this problem, because it permits the subsequent replacement of only the defective pieces in a given batch of the pieces being processed.

SUMMARY OF THE INVENTION The basic object of the present invention is to provide a device of the above-described type which permits the economical production of solid double layer sheet glass even in small batches and in fact even in individual sheets.

In accordance with the present invention an upper guide track is subdivided into mutually independent, vertically adjustable portions or sections whose length in the direction of the production line substantially corresponds to the maximum length of individual sheets to be fused.

This facilitates independent readjustment of the upper guide track in sections according to the height of the individual sheet that happens at that moment to be inside a given section. For example, the section of the upper guide track lying in front of the tunnel oven entrance may be initially adjusted to a given initial sheet height. After the subsequent (adjacent) guide track section which is already inside the tunnel ovenhas discharged the individual sheet of possibly different height which was also in the oven, this subsequent guide track section is brought to the same level as that of the guide track section lying at the tunnel oven entrance, whereupon the pair of single sheets may move into said first guide track section which is inside the tunnel oven. After the two have come together as a solid double layer glass sheet for fusing in the first guide track section within the oven, then the guide track section in front of the oven entrance may be again readjusted to accommodate individual sheets of possibly different height. The individual sheets can be tranported out of the first guide track section (which is located in the heating station within the oven) into the second guide track section within the oven as soon as the latter guide track section (after the forwarding of the previous sheet which may have exhibited a different height) has been adjusted to the level of the sheet now inside the first guide track. section within the oven.

This mode of operation facilitates the processing of small batches or even individual double layer glass sheets in an economical manner, without having to stop the machine and interrupt production.

DESCRlPTlON OF THE PREFERRED EMBODIMENTS In accordance with one preferred embodiment, the individual guide track sections are automatically, vertically, adjustable dependent on respective sheet heights of individual glass sheets by means of respectivedrive mechanisms connected with each guide track section. It is at the same time advantageous that each guide track section be automatically height-adjustable dependent on the respective setting of the guide track section preceding it in forward sequence. It is further advantageous in accordance with the present invention that the individual guide track sections are controlled by sensing devices to determine relative height-adjustment of two subsequent guide track sections, and to equalize the adjustment of the guide track section next along the production line relative to that which preceded it. The sensing devices can be limit switches applied to vertical switching strips arranged in pairs relative to each other.

Said limit switches influence the drive mechanisms causing equalization of height-adjustment.

A particularly advantageous embodiment of the in vention as set forth above is characterized by a plurality of supporting frames arranged above the upper guide track and above the tunnel oven, by means of two spindle drives actuated by a drive motor independently height-adjustable relative to each other, and corresponding in their length substantially to the maximum length of the sheets which are to be fused. From said supporting frames there extend downwardly into the tunnel oven two guide support pins, to which the upper guide track segments are secured and supported. Each guide track segement is rigidly connected at one end thereof with one of the guide support pins, and at the other end with the other guide support pin in slidably track segment. In addition, a vertical switching strip movable relationship in the direction of the conveyer. 1

By this means it is possible to absorb the heat expansion of the guide track segments, which, for example, consist of bracing tubes with attached guide rails secured to the two guide support pins.

Because the guide support pins (against which the guide track segments are hung) thermally lengthen or shorten during the height adjustment of the guide track segments (during height adjustment the portion of the guide support pins inside or outside the tunnel oven varies), it is advantageous to provide means for continuous fine-height-adjustment of the individual guide track segments dependent on the relative position of each individual guide track segment relative to the sheet it happens to be guiding at the moment. By such means the relative position of the respective upper guide track segments with respect to the upper edge of each glass sheet, is continually controlled. For example, with the guide tracks depending from a vertically adjustable bracing tube, by means of the fine-height-adjustment of the relevant guide track segment, it becomes possible to carefully provide that the sheet edges are always lying correctly in the guide tracks at the proper elevation with respect to the tracks.

The mode of operation of the aforesaid device is further improved if for every guide track segment a sensing device is provided to determine the position of each respective segment, the sensing device controlling the further advancement of the glass sheets in coordination with the means for the adaptation of height adjustment in neighboring guide track segments. These sensing devices, which are preferably in the form of air gates, feed signals to a central control unit indicating when a certain given guide track segment does not carry a glass sheet. This signal then initiates the height adjustment of the said guide track segment in such a way that said segment is adjusted to the level of the preceding segment which contains a sheet of determined height, whereupon subsequently the sheet or sheets which until then occupied the preceding guide track segment are further advanced into the properly height-adjusted and adapted guide track segment.

The fusing device for the fusing of the upper sheet edges is in the form of an automatically heightadjustable torch arm which adjusts relative to the height of each respective sheet. Coarse adjustment and fine adjustment for the height of the torch arm may also be provided at this juncture. The coarse adjustment is preferably actuated in such a way that the torch arm is automatically height-adjustable dependent on the height adjustment of the neighboring, preceding guide may be connected to the torch arm, said switching strip being coordinated with limit switches which are hooked up with a corresponding switching strip of the guide track segment preceding said torch arm, and said limit switches serving to adapt the height adjustment of the torch arm to those of the preceding guide track segment. For fine height-adjustment of the torch arm dependent on the relative position of said torch arm relative to the upper glass sheet edge, it is possible to proceed in similar fashion as for the fine adjustment of the guide track segments, dependent on the relative position of the segments with respect to the upper sheet edge, by providing a sensing device which responds to the position of the torch arm relative to the upper glass sheet edge. Then, the signals which represent deviation of the upper sheet edge from its predetermined setting actuate (by means of a motor attached to the torch arm, which may be constructed similar to the device for height adjustment of the guide track segments) a continuous vertical regulation of the torch arm in accordance with the height level of the upper glass sheet edge.

The foregoing and other features and objects of the invention will be more apparent from the following more detailed description, taken in conjunction with the accompanying drawings which form an integral part thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 represents a longitudinal side elevation, partly in section, showing a portion of a tunnel oven in accordance with this invention with a continuous lower guide track and five upper guide track segments which are at varying levels;

FIG. 2 represents a side elevation of a portion of a typical upper guide track suspension shown in FIG. 1;

FIG. 3 represents a right end elevation of the guide track segment shown in FIG. 2, partly in section;

FIG. 4 represents an enlargement of a portion of FIG. 2, showing various positions-of a guide track in relation to glass sheet; and

. FIG. 5 represents a partial view of various positions of the upper torch arm with air gates connected to it for fine adjustment.

As shown in FIG. 1, the apparatus of this invention comprises a tunnel oven designated overall by reference numeral 10, through which glass sheets 12 are guided on a lower guide track 14 consisting of rollers. The upper edges of sheets 12 are guided in an upper guide track consisting of individual segments or stations which in their several entireties are generally designated at the top of FIG. 1 by

reference numerals

16, 18, 20, 22 and 24.

on occasion, as shown by the dotted lines in FIG. 1 (segment 16), it is possible that two shorter glass sheets may simultaneously connect with each guide track segment.-

Each of the guide track segments 16 through 24 consists, as may specifically be seen in FIGS. 1, 2 and 3 of a horizontal bracing tube 26 on which is mounted a guide strip 28 (consisting of three individual strips), which effectively provide two upper guide means for every individual sheet of the double layer sheet being manufactured. Bracing tube 26 is braced against two

guide support pins

30 and 32, so as to be rigidly connected with guide support pin 30, while on the other hand, slidably connected to the other guide support pin 32 to permit longitudinal movement of tube 26 with respect thereto and yet give vertical support for the tube.

Guide support pins

30 and 32 are braced and guided by a frame 34 which is arranged above the level of the cover of tunnel oven 10, while the individual guide support

pins

30 and 32 are guided through corresponding sliding bearings 36 at frame 34. The upper ends of

guide support pins

30 and 32 connect respectively with a horizontal support frame 38 which may be elevated or lowered by means of both a drive motor 42 and two gears 44 which actuate vertical spindles 40 respectively.

The suspension of individual bracing tubes 26 relative to guide

support pins

30 and 32 may be more readily understood from FIG. 2. As may be seen in this representation, each of the bracing tubes 26 is rigidly connected with guide support pin 30 as by means of screws or bolts 48. If bracing tube 26 should expand during heating in the direction indicated by the arrow (rightwards, in FIG. 2) then a corresponding displacement of bracing tube 26 for the compensation of this thermal expansion is made possible by the fact that bracing tube 26 is not rigidly connected with the second guide support pin 32, but slidably mounted relative to said guide support pin 32. This slidable mounting is made possible by rollers 50 (shown in FIG. 3), which can roll back and forth in longitudinal direction on a mounting surface 52 which is connected with and carried by guide support pins 32. By this means any dislocation of bracing tubes 26 and of guide tracks 28 mounted thereon is avoided during temperature changes in the tunnel oven, so as to insure that the glass sheets are guided from track segment to track segment precisely and in an exactly straight path.

As shown in FIG. 1, the preferred embodiment for height adjustment of the individual guide track segments 16-24 includes a coarse adjustment means for adjusting each guide track segment dependent on the setting of the preceeding guide track segment, as well as a means for fine adjustment of each guide track segment dependent on the setting of guide strips 28 relative to the upper edge of glass sheets 12. The coarse adjustment of guide track segment 18 relative to guide track segment 16, for example, includes two

limit switches

56 and 58 attached at the end of a switching strip 54 carried by one frame 38, said limit switches being acted upon by means of a switching strip 60 which actuates them directly and is connected with guide track segment 16 by means of the other frame 38. Similar devices are also provided between guide track segments of 18 and 20, and 22, 22 and 24, etc.

For the fine adjustment of the guide track segments with respect to the relative position of the upper sheet edge,

air gates

62 and 64 are employed, as shown in FIGS. 3 and 4. Another air gate 66 is provided for determination of the occupancy status of each respective provided to fuse together the upper vertical sheet edges dependent on the position of guide track segment 20. In a manner similar to that described for vertical adjustment of the guide track segments, torch arm 68 is continuously adjusted by means of two limit switches 70 and 72 and a corresponding switching strip 74 at guide track segment 20, depending on the position of guide track segment 20, to achieve a coarse adjustment. A fine adjustment is then obtained by means of two

air gates

76 and 78 depending on the position of the upper glass sheet edge relative to burner nozzles 80 (FIG. 5).

Air gates

76 and 78 operate in a manner similar to airgates 62 and 64.

Drive motors 42 with gears 44 and spindles 40 (for the height adjustment of individual guide track segments), as well as the drive for the height adjustment of torch arm 68 are operationally connected with the

several sensing devices

54, 56, 58, 60; 62, 64, 66; 70, 72, 74; 76, 78, and with the drive for the advancement of sheets 12 in forward direction through the oven by means of a central control unit, in such a way that the coarse adjustment, fine adjustment, and height adjustment of guide track segments 16 through 24 as well as of torch arm 68 and the forward advancement of the sheets is achieved after appropriate level-adjustment of the individual components.

The apparatus thus described operates in the following manner:

As soon as guide track segment 16 (which is at the entrance to tunnel oven 10) has been adjusted to a height corresponding to the height of glass sheets 12 which are about to be fused together, the glass sheets are picked up by the guide means. As shown in FIG. 1, at this point in time there is no sheet left in guide track segment 18, so that the open air gate 66 signals that guide track segment 18 is unoccupied.

Thereupon guide track segment 18 moves downwardly, following the signal emitted by open limit switch 56 which signals that guidetrack segment 18 is standing too high relative to guide track segment 16, causing segment 18 to move downwardly until both

limit switches

56 and 58 are actuated by switching strip 60. This indicates that

guide track segments

16 and 18 are now at substantially the same level. As soon as the corresponding signal is given, via

limit switches

56 and 58, to the central control unit (thereby announcing that sheets 12 can be further advanced), glass sheets 12 are moved ahead from guide track segment 16 into guide track segment 18. Finally, air gate 66 signals that guide track segment 18 is loaded so that further sheet advancement is blocked.

At the time of the downward movement of guide track segment 18, guide support pins 30 and 32 (to which bracing tube 26 is fixed) expand in consequence of heating as they progress downwardly into the more intense heat of the oven. At the same time, sheets 12 themselves expand in the opposite direction as soon as they have been moved out of guide track segment 16 and into guide track segment 18, in other words into the oven, with the result that optimal height-adjustment of guide strips 28 relative to sheets 12 is no longer en sured, without further adjustment.

In consequence of the above-described relative motion of sheet 12 in relationship to guide strips 28, air gate 62 is closed, whereupon drive motor 42 for the height adjustment of support frame 38 pushes guide track segment 18 upwardly until air gate 62 is opened,

which signals the optimum height of segment 18 in relation to the glass sheet height, whereupon guide strips 28, are secured in the proper vertical position.

In like manner the level of guide track segment 20, which is shown as set too low in FIG. 1, is adapted to the adjusted setting of guide track segment 18. In addition, guide track segment 20 will travel upwardly until limit switches 56 and 58, in conjunction with switching strip 60, signal an equal level for

guide track segments

18 and 20, so that the glass sheets (after a corresponding unloaded signal has been received from air gate 66 of guide track segment 20) may be advanced from guide track segment 18 into guide track segment 20. Because support pins 30 and 32 of guide track segment 20 are withdrawn further out of tunnel oven 10, they contract, so that guide strips 28 stand too high in this segment in relationship to the upper edge of the glass sheets. At this point airgate 64 is opened, whereupon guide track segment 20 is lowered by means of drive motor 42 far enough to shut air gate 64 once more. The foregoing operations are successively repeated in all of the following guide track segments.

After the glass sheets have reached guide track segment 20 and thereby have reached the point of readiness for fusing, the upper torch arm 68 must be vertically adjusted so as to be at the correct height. For this purpose the actuated limit switch 70 causes torch arm 68 to travel upwardly until both limit switches 70 and 72 are actuated by means of switching strip 74. When the corresponding signal is delivered to the central control unit, then sheets 12 are moved forward into fusing position. Because the welding process requires a very precise setting of the upper torch arm 68 relative to the upper sheet edge, the coarse adjustment by means of limit switches 70 and 72 is followed by a fine adjustment by means of

air gates

76 and 78. The precise relative positioning of the torch arm relative to the sheet edge is achieved if air gate 76 is opened and air gate 78 is interrupted. lf air gate 76 is at the same time interrupted, an unacceptably low positioning of the torch arm 68 is indicated, which causes said torch arm to move upwardly until air gate 76 opens once more. If, however, air gate 78 is opened, this signifies that torch arm 68 is positioned too high, whereupon said torch arm 68 is moved downwardly until air gate 78 is once again interrupted.

Resort may be had to such modification and equivalents as fall within the spirit of the invention and the scope of the appended claims.

What is claimed and desired to be secured by Letters Patent is:

1. Apparatus for the manufacture of all-glass double windowpanes by welding the longitudinal and transverse edges of single panes carried upright through a tunnel oven, having a lower guide track for the support and guidance of the lower pane edges, a vertically adjustable upper guide track for the guidance of the upper pane edges, and fusing means that is adjustable in height according to the pane height for fusing the upper, horizontal pane edges, the upper guide track being divided into sections which are each automatically and vertically adjustable independently of one another by means of a driving device associated with each guide track section according to the height of the particular pane therein contained, the length of said sections in the conveying direction being substantially the same as the length of the individual panes to be fused together, each guide track section further having means for sensing the relative heights of any two adjacent guide track sections and for equalizing the vertical position of the guide track section next following in the direction of conveyance to that of the preceding one.

2. The apparatus of claim 1, wherein the sensing means are limit switches arranged on vertical switching strips disposed and coordinated in tandem, the positioning of the limit switches regulating drive devices for vertical adjustment of the guide track sections.

3. The apparatus of claim 1, wherein a plurality of supporting frames are disposed above the guide track sections and above the tunnel oven, which are vertically adjustable independently of one another by a drive motor through two spindle drives each, which are elongated in the direction of conveyance of the panes, and which correspond in their length substantially to the maximum length of the panes to be fused, and from each of which two guide support pins extend downwardly into the tunnel oven, the upper guide track sections being fastened thereto.

4. The apparatus of claim 3, wherein means is provided for the continuous fine height adjustment of the individual guide track sections in accordance with the relative position of each guide track section with respect to the pane that is guided on it, the said means having air gates for sensing the relative position of the particular guide track section with respect to the top edges of the panes.

5. The apparatus of claim I, wherein a torch arm is provided for fusing together the upper pane edges, which is automatically and vertically adjustable in accordance with the particular pane height and there is associated with said torch arm a vertical control rail having limit switches which cooperate with a corresponding control rail of the guide track section preceding the torch arm for matching the height adjustment of the torch arm to that of the preceding guide track section. I