DE1471876A1 - Method of bending glass sheets - Google Patents

Description

Disclosure Notice

Berlin, May 26, 1964
Pf / j * ü

LIBBBI-OfBHS-FORD ULASS COJPAKI

811 Madison Avenue, TOLSiX), Ohio, U.3.A.

Method of bending glass sheets

for this registration, the priority is the corresponding U.S. application, aerial No. 283 737 of May 28, 1963 claimed.

The invention relates generally to the bending of glass panes, in particular, an improved method of making pre-cut curved sheets of glass.

The main object of the invention is a process for the production of cut curved glass sheets of heightened strength, the hand edge sections of which are more resistant to breakage.

Another object of the invention is an improved one Process to increase the edge feature of cut-to-size bent panes of glass by controlling the local area that occurs in them during the bending and tempering of the panes Tensions.

New documents (Art 7 11 para. 2 No. 1 sentence 3 dot Xnderungsgee. V. 4. 9, ößy

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The invention is described below with reference to the attached, but not limiting example of its export ungsforaen illustrative drawing explained in more detail. Show it:

Fig. 1 is a plan view of a Biegefora for bending the raw size glass panes according to the invention,

Fig. 2 is a side view of the Biegefora,

Fig. 3 shows a vertical part through the Bending fora,

Flg. 4 is a plan view of a Biegefora for the cut curved panes of glass,

Flg. 5 shows a vertical partial section through the bending form according to Fig. 4,

Fig. 6 is a vertical cross section through a

Bending furnace and
>

Flg. 7 shows a partial section through one according to the invention produced cut curved glass sheets formed laminated glass sheet.

Bas method for bending glass sheets, in which one fioh Maßsoheibe at its bending temperature down to a predetermined one Curvature bends, the pane cools and the curved ÜohmaB eye disk is cut to size to size characterized in that the curved cut to finished size

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Disc on the shaping surface of a Hingform with the same curvature as the curved disc and with substantially the same outer circumference as the disk "but of a smaller size than the disk" and again is heated, whereupon the pane while maintaining contact between the forming surface and the pane their entire outer circumference, but within the outer edge of the disc, is cooled, so that their hand edge sections pressurized, d. H. compacted, are *

In Figs. 1, 2 and 3, a generally designated 15 is Bending device illustrated, which has a support frame 16 and a bending form 1? for bending raw-dimension discs contains. Since the invention is in no way related to the exact design execution of the bending form is limited, it can be a ^ iegeform with a massive outer circumference or a Ring shape or a shape whose outer circumference consists of individual sections from an open position to a closed position are movable against each other. Di «Fora is therefore a form consisting of several sections with a central section 16 and end sections 19 and 20, which can be pivoted on the central section 16 with the aid of hinges 21 in bezuft. The central section 16 consists of the substantially parallel, duroh Verstrebungsatangen 23 interconnected shaping Rails 22, while the modification sections 19 and 20 expire of substantially U-shaped shaping rails 2A and 25 exist, the band sections of which are essentially continued

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the lateral shaping rails 22 form. The shaping ones In plan view, rails have one of the line of the Rohmaö glass panes corresponding outer catch line and «iron a curvature that corresponds to the curvature, ropes into which the discs are thrown.

Oer support frame 16 has Seitensohienen 26 and Läng · rails 27 and is provided at its respective Bcken with senkreoht arranged Stiiteen 28 on which the form 17 is held by ψ ι pivotable members 29, the upper at its, finding the Stuteen fortified Rods 30 are held and received in their lower Jfetie of the Sndabschnitt 19 and 20 of the form-supported rods 31.

fig · 2 shows the fully absorbed form in its closed form Position and the dash-dotted form in its open Position. The -Ormabechnitte 16, 19 and 20 are self-

■ understandable xon the inclusion of the flat, sub-bending Glaasdhei-

ι ben brought into the open position. Sine dash-dotted lines The flat pane of glass 33 shown is placed at its opposite ends on the straps 19 and 20 the shape undeaiäerdem within its ends by means of abrasion * Freelance Klötsehen 34 held by the final delegates 49 and L 20 attached to the mold and adjustable with these Arms 35 are carried. > n the fully extended ^.! shown closed position of ^ orm 17 are the Stiitsklötsohen 3 <t below the shaping surface 32 of the ι shape and out of touch with the pane of glass.

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In plan view, the central portion 16 and form Snd sections 19 and 20 of the form essentially one continuous form surface, that of the surface and the outer perimeter originally to a so-called raw size (blook-size) cut glass panes approximates that is larger than the area of the pattern size sheets that will later be made from them. Ss has It turned out that bending a sheet of glass or a pair of glass sheets in Boh size improves the quality of the finished cut pane is improved to the extent that each of the contact of the glass with the bending shape is relatively spoilage or warping attributable to high bending temperatures is limited to the hand area of the disc or discs * This is in real contact with the bending form standing areas on the sides and ends of the Rohrnass-Soheibe are of course outside of the central area from which the finished size slice will later be cut. Am Another reason for this is that originally a sufficiently large central area should be formed, see above that an unforeseen displacement of one pane in relation to the other during the bending process

en /

Corresponding curvature in the central areas of the curved discs does not prevent

It has proven to be desirable when bending the high-measure pulleys proved to have a compression band of essentially the same circumferential line in the disks within their edges like those to be cut from the raw dimension disks

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make ready-made mats see below. For theeea purpose let dl · bending shape 17 with one * essentially continuous heat absorbing ends Metal part 36 provided, daa separated τοπ the shaping Rails 22, 24 and 25 arranged inwards lat and one with the cut from the raw size disk finished mafleoheibe coinciding »in its area however has a slightly smaller outer circumference. Bas heat absorbing Part 36 consists of · with the help of τοη on the Veratrebunga poles 23 existing sttttsen 38 held Mittelaohienen 37 and the end descendants 19 and 20 of the opposite form End rails 39 and 40 · The soles 39 and 40 are held by the formabechnitten 19 and 20 su worn for the purpose that they are during the opening and bottom-laying process of the mold with you Create ▼. The arrangement of the heat absorbing member · 36 in a separate position from the shaping rails 22, 24 and the form leads to a continuous open area swisohen them; in which the fleas of the curved cheeks during The locking process increases the controlled cooling temperatures are or are subject to the tempering furnace. As shown in FIG. 3, Ines goes with it ο designated continuous Verdiohtungbereichee or -bandea swieohen with t rewarded voltage ranges · The residual heat in the shaping rails causes a « Delay in cooling in the peripheral areas of the glass or that there is a difference in the cooling speed on the outskirts of the Glaaee. oil-containing affects the heat-absorbing part dl over, i.e. on, area of the sole or disks lying in it,

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that the cooling along a line within the band areas of the glaea is delayed in the same way. This delay the cooling of the glass panes in different directions *

separated, in the longitudinal direction, the areas with the shaping soles and the heat-absorbing part coincide, causes the areas with displaced cooling to be put under tension during the Creep the area lying under pressure breathed, i.e. condensed ^ is.

In general, the bending process can be carried out in an oven 41 illustrated in FIG. 6, which contains a heating chamber 42, in which a horizontally mounted roller conveyor 43 is arranged, which carries the molds with the bent-out Qlaao heads through the chamber. The chamber 42 is provided with heat sources 44 in its rare walls and its Daoka, which are controlled in such a way that the temperature of the glass panes is increased as they wander through the furnace, blah ala have been mowed through the case in auareichendem Mafia, ao that eic As a result of their sigengewidhta, that is, by the force of gravity, they bend and match the shape-giving surface of the forms. In general, the bending temperature of glass and afelglae is 615 ⁰ C and 675 ⁰ O.

Erflndungageaäaa be the glass panes allmählloh from room temperature bla to a temperature of about 505 ⁰ C heated to aue them all voltages su remove, whereupon

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they should be heated up to a temperature that is sufficient _for the panes to adjust so that they adapt to the forums providing information in their complete position.

When they are bent, the glass panes are tempered, whereby their area 0 and t (flg. 3) eur manufacture of the above described twisting area or strip 0 can be cooled differently · The curved Rohaaflsoheiben are then removed from the molds and attached to the desired external angle Section is generally along a line extending through the compression step 0 in FIG. 3 old jp line guided «This enables a much cleaner breaking of the glass · at the cutting line and guarantees relatively free from faults, children who are unrelated to fertility curved discs

When carrying out the »broad phase of the invention, the glass panes cut open on ready-made sheets are held on a bending device of the type shown in FIGS. 4 and 5, which is generally designated as 46 Ring shape 50 held with the help of vertical posts 51 The bending mold 50 preferably has a massive, shaping ring rail 52 which, in plan view, has the same Uafangaline as the curved, sun-sited to finished dimensions, but has a relatively smaller location, so that is

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Edge sections of the glass panes, as in Flg. 5 shown protrude beyond the shaping sole *

In side view, the shaping surface 53 of the shaping sole 52 agrees with the curvature of the shaping The surface | 2 of the bending form 17 and thus also coincides with the curvature of the curved sole plate cut disks 54 shown in curved and matching pairs on the foragebend · The surface 53 of the shape 50 are placed, they are laid by it in accordance with the curvature up to which they were before have been bent on the form 17 of the bending device 15, worn within its circumference

The bending mold 50 is then hindurohgefUhrt with the supported of its glass sheets by a bending furnace, the glass sheets to be heated again and again produce a Terdichtungsstreifen in their fiandabsohnitten · More specifically, the glass panes _a uf a predetermined temperature of over 500 C are reheated to sämtliohe in tensions existing in them, including those in the

/ the pane of glass
Edge cuts to eliminate compression areas formed during the original bending process * The glass panes, however, are not reheated to a temperature that is sufficient for any further bending of the pane

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Temperature have been heated, they are subjected to a controlled cooling or tempering · As discussed above, the bending form has a smaller outer circumference than the glass panes with the result "that the band areas of the panes protrude beyond the outer edge of the norm and do not come into contact with it" Folglioh the projecting marginal edge portions are on cooling of the bent glass sheets 'ψ neither with the form into contact nor they are affected by the present in the form of residual heat, characterized the Randkantenabsohnitte can cool more quickly, so that, as indicated in fig · 5 at d' put under pressure, that is to say compressed, so that a solid and non-fracture continuous antenna absorption is produced in the glass panes.

The two-step process of bending and strengthening glass panes according to the invention has several clear advantages. As a result of the bending of the glass panes, the finished dimension panes that are then made from them are free of distortions, damage or other defects that normally arise from the contact between the glass and the mold, as these sections of the glass are removed when the apexes are cut to size. Also has been found SiOH that d ^ raw form a continuous or _{Verdiohtungsbereiohs:} -Streifens in Rohmaßsoheiben, who in his AuBenfurnfang corresponds to the Fertigmaflsoheiben and dtujbh, 2u ·

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cut the slices along a line running through the compression area a better, cleaner one Sonality is achievable "In addition, any minor, mutual displacement occurring between the two raw dimension disks * during the bending process (slippage) the clean fitting of the two eu-cut do not adversely affect curved panes or the coincidence of their edges «Let this particularly important when, as shown in FIG. 7, two cut curved sheets of glass 54 "to form one composite safety glass structure underlay one & unatetoffswiaohenaohicht 55 put together · Furthermore, nan has found that by rewarming of the cut slices their accuracy of match alt the curvature of the shape can be controlled certain, although the panes in their temperature nioht to the same degree required to cause the raw mafle loaf to bend. Even the consolidation in the Kandkantenabohnungen of the Slices made more perfect because after heating, the slices have the upper, lower and vertical surfaces the edges of the panes, which protrude beyond the shaping rail of the iorm, are exposed and cooled more quickly are than the area of the discs located above the shaping rail.

During the tempering process, the above de? shaping rail 52 located area of the glass panes put under »tension, if desired

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the rate of heat release from the glass panes can be controlled to create a stress pattern in the central area of the disc, which has a predetermined gradient in its tension wheel. To this In a way, the tension rangefrom the one above the forming rail located area from inside by using a shield in the form of a relatively thin, η perforated metal plate 56, the within the boundaries of the shaping rail 52 gradually decrease. At the! Bottom and the Ends of the form in relation to their direction of advance by F

the furnace, the thickness of this shield can be increased by adding a strip 57 of similar perforated material provided v. is. Immediately adjacent to the inner surface de: shaping rail and also on the back

of the mold can au3saerdem layers 58 made of glass wool, asbestos or mixtures Daraud the heat shield may be used for further propagation of the thickness, resulting calibration a gradual reduction in tension in the glass from the region of the strongest 3pannung above the * fjrmgebenden rail yields inwards.

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Claims (1)

Patent claims Iy) Vtrfehren for the production of bent glass panes, in which a Hofceaßecbeibe is bent into a certain curvature while being heated to its bending tea temperature, cooled and the bent size is cut to the finished size, characterized in that the cut to finished size pane on one of its curvature corresponding with a annular forming surface except equipped mold to form a circumferential, freely projecting over the molding surface edge portion, re-heated and cooled while maintaining contact with the form of a tension compression in the freely over the forming surface projecting K _e is ntenbereicbt purpose of achieving. 2 ·) Method according to claim 1, characterized in that the Gebfcgene, cut to finished size disc during their heating on the mold brought to a »temperature sufficient to remove all tension from it, but not strong enough to bend of the glass. 5.) The method according to claim 1, wherein the curved Rob Maßscheibe is cooled in such a way that an im substantially continuous strip or band-like area of the disk, which is spaced within it Outer edge runs around them, is cooled faster New documents {Art. 7 Section I, Paragraph 2, No. I, Clause 3 of the Amendment Act. v. & 9.EJfZJ •• 14 ·· 909813/1033 1471878 than the adjacent areas so that one over the thickness of the disc is created under local pressure, i.e. compressed area, before the curved one Raw haass disk along one of these Verdicbtungsbereicb running line is cut to finished size, characterized in that the cut to - "final size curved disc on the shaping surface of a ring shape with the same curvature as the curved disc and with essentially the same outer circumference, never the The disc, but of a smaller size than the disc, is held and heated in the process, whereupon the disc is underneath Maintaining the contact between the shaping surface and the pane on its entire outer catch, However, cooling takes place within the outer edge of the disc, so that its peripheral edge sections are pressurized, i.e. be compressed. 4- ·) Method according to claim 3, characterized in that the curved, cut-to-size slice is brought to a temperature while it is being heated on the mold sufficient to absorb all stresses, including that arising during the bending of the raw dimension disk or to remove the resulting Verdicbtungsbereicbs from it, but is not high enough to bend the glass. 909813/1033 ORIGINAL INSPECTED