JPS6154732B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the bending of sheets of thermoplastic material, particularly glass. Many techniques for bending glass sheets are already known. Probably the simplest technique is
The glass plate is heated while supported on a contoured mold to allow it to sag to conform to the mold. However, it is often desired to speed up the process by applying mechanical bending forces, for example by pressing the glass sheet between a pair of contoured molds. A particularly advantageous press bending method is S.
No. 3,846,104 to L. Saimer, in which a horizontally oriented glass plate is heated and lifted by a lower mold into contact with an upper mold, The vacuum holds it in the upper bend die while the bend die is retracted. A tempering ring then receives the bent glass sheet and transports it from the bending station to the tempering station. Such a mechanism provides a contoured support for the glass sheet during the tempering process and allows the bending station to be used to initiate the next bending cycle while the first glass sheet is being tempered. It is particularly advantageous in releasing One drawback of such a mechanism is that its three main components, namely the upper and lower molds and the tempering ring, are all custom-made for each different shape made in such a bending and tempering line. It must be manufactured. In addition to reducing the cost of fabricating these elements for each shape change, it is desirable to reduce the downtime of the bending and tempering line required by the installation of said elements for each product change. That's true.

A similar mechanism is disclosed in U.S. Pat. No. 3,713,799 to HA Matsukumaster, in which the lower mold serves to convey the glass sheet into the tempering station, thus: The lower bending ring delays the start of the next bending cycle until the glass sheet is placed in the tempering station and returned to the bending station. Similarly, in this arrangement, product changes require extensive retooling of the bending station. This is because the upper and lower molds and the gas support block on which the lower mold is placed must all correspond to the shape of the glass sheet to be processed. US Patent No. HA Matsuku Master et al.
A similar mechanism described in US Pat. No. 3,573,889 also suffers from the same drawbacks.

SL Seymour U.S. Patent No. 3507639 and HR
Hall, U.S. Pat. No. 3,676,098, each shows a horizontal press bending mechanism that requires only two elements, an upper and lower bending die, to be custom-fabricated for each glass sheet shape to be processed. has been done. It would be desirable to have fewer custom parts. Furthermore, in any of the above mechanisms, the edges of the bent glass sheet are unsupported while the glass sheet is transported from the bending station to the tempering station.

U.S. Pat. No. 3,476,540 to Ritter et al. discloses a glass bending mechanism in which bending is effected by the inertia of a single vertically rising lower bend die.
This mechanism is disadvantageous in that the bent glass sheet must enter the tempering station without being edge supported along the roller conveyor.

No. 3,600,150 to Rougeille, heat-softened glass sheets are transferred from a roller conveyor onto a flexible hammock by a sliding motion, and then pressed between upper and lower molds. A glass bending mechanism being bent is illustrated. The purpose of the flexible hammock is initially to support the glass sheet without contacting the rigid mold surface. It is clear that extensive reassembly of the mechanism is required when a change in the shape of the glass plate is desired.

In the present invention, a single mold conforming to the outside shape and contour of the bent glass sheet is employed onto which the heat-softened glass sheet is dropped to provide bending force thereto. Immediately after each glass plate leaves the furnace, the glass plate is lifted by a flat vacuum platen that is brought into contact with its upper side. When the vacuum platen and glass plate are lifted into a raised position, the mold is transported into position below the glass plate, the vacuum is released, and the glass plate falls onto the mold causing bending. The mold is then withdrawn from below the vacuum platen into a tempering station where a blast stream of air is directed against opposite sides of the glass sheet to temper the glass sheet. Such a mechanism greatly simplifies changeover from one shape to another since the single mold is the only main element that must be reassembled. Another important feature of the invention is that the mechanism is easily adapted to bend and temper multiple glass sheets simultaneously, thereby greatly increasing the productivity of the equipment.

In FIG. 1, a bending and tempering line is shown, which includes a furnace 10 (only its outlet end is shown), a bending station 11, a tempering station 12, and a product grating station 13. including. The furnace, tempering station, and product grating station are not part of the present invention, and therefore, the description of specific embodiments herein is for illustrative purposes only. Any apparatus known in the art for heating and tempering a series of horizontally arranged glass sheets G can be used in conjunction with the bending method of the present invention. Therefore, a very brief description of the furnace, tempering station and product grating station will be given here.
More detailed details regarding these aspects of the entire bending and tempering line can be found in U.S. Patent No. 3,846,104 to Samer.
Disclosed in the issue.

The furnace 10 is preferably of the gas-supported type, in which a plurality of glass plates G are heated while supported on a layer of hot glass and transported through the furnace. Practical examples of gas-supported furnaces for heating glass sheets G are disclosed in U.S. Pat. No. 3,223,501 to Freddley et al. and U.S. Pat. As can be seen in the broken section of the furnace shown in FIG. 1, the gas support bed is defined by a hearth block 21 which is formed with a number of vertical holes. Some of the holes communicate the top surface of the hearth block with pressurized hot gas from the material-filled space chamber 22, and the remaining holes connect the top surface of the hearth block 21 with cross-hole exhaust passages 23. communicate with. The hearth block structure continues beyond the furnace outlet to an extension 24 and support block 25 located on the bending station 11. More detailed details of the hearth block construction are shown in the cross-sectional view of support block 25 in FIG. As can be seen in FIG. 3, a vertical hole 26 extends completely through the support block 25, and a hole 27 extends from the surface to a horizontally extending exhaust passage 23.

Referring again to FIG. 1, one typical mechanism for propelling glass sheets through a furnace while supported on a film of hot gas is illustrated. The conveying mechanism has a pair of parallel endless chains 30 located on the sides of the glass plate passage inside the furnace 10 and connected by a plurality of push rods 31. At the exit of the furnace, each glass plate is connected to chain 3
As well as being released from the transport device consisting of 0,
It is fed across the extension block 24 and into the bending station 11, driven by take-off rolls 32 and registration rolls 33 at an accelerated speed. The passage of the glass plate from the furnace 10 is carried out through the hearth block 21, with a slight downward inclination (e.g. 1 to 2 degrees).
Supported by 24 and 25. Typically, sufficient gas pressure is maintained between the hearth block and the glass plate such that approximately 1.6 mm above the top of the hearth
(1/16"). The take-off roll 32 and registration roll 33 protrude above the top surface of the hearth block just enough to contact the bottom surface of the glass sheet.

When the glass plate reaches the bending station,
Its advancement is stopped by a positioning frame 35 located above the hearth 25. The positioning frame 35 defines at least one open-ended "pocket" in which the front portion of the glass plate can be received. As shown in FIG. 2, the positioning frame 35 includes glass plates G,
It has two such pockets for receiving G'. Each of these pane-receiving pockets is contoured to generally match the contour of the front of each glass pane, so that when the glass pane is pushed into engagement with the positioning frame, Seated tightly in the pocket with little or no freedom of movement. The positioning frame 35 is spaced from the registration roll 33 by a precisely determined distance so that the trailing edge of a properly registered glass sheet is located generally directly over the center of the registration roll 33 as shown in FIG. has been done. The registration roll 33 continues to rotate to force the glass sheet into the pocket of the registration frame while the glass sheet floats on the hot gas layer. The frictional force between the alignment roll 33 and the glass plate is minimized to prevent scratches on the glass and is confined to the trailing edge of the glass plate, but to an equilibrium position that aligns with the pocket of the positioning frame. , is chosen well enough to propel the floating glass plate and hold it there. Such a registered arrangement is useful for processing multiple sheets of glass side by side. For example, the positioning frame of FIG. 2 is configured to receive two panes of glass, while in FIG. 10 the positioning frame is illustrated as receiving four panes of glass. It will be clear that the positioning frame can be adapted to receive any number of glass panes that are fitted and arranged on the hearth block 25 side by side. Positioning frame 35
is held in place by a rod 36. The rod 36 is
As shown in FIG. 2, it extends laterally toward support devices located on each side of the hearth block 25. Preferably, the rods 36 are supported at their ends by some adjusting means, for example by clamping between a pair of plates 37 as shown. Other mechanisms for attaching positioning frame 35 will be described later with reference to FIGS. 10 and 11. The positioning frame mechanism itself
No. 960,403 (title: Glass Plate Aligning Apparatus and Method) filed by SL Samer on November 13, 1978.

The use of a positioning frame and alignment rolls as described above is the recommended method for repeatedly establishing a precisely determined position for each glass sheet as it enters the bending station 11. However, other methods may serve the same purpose. For example, U.S. Patent No. 3,573,889 and
It is possible to use pins that can be retracted vertically as shown in No. 3,676,098. Also, if a roller conveyor is used in place of a gas support bed, the need for precise alignment of the glass sheets within the bending station is less critical. This is because the glass plate has a greater tendency to drift out of engagement when it is floating freely above the gas support bed. When a roller conveyor is used to convey a glass sheet into a bending station, the final orientation of the glass sheet may be oriented upstream from the bending station, as disclosed, for example, in U.S. Pat. No. 3,701,643 to RG Frank. obtain.

A vacuum platen 40 is located directly above the positioning frame 35. The vacuum platen 40 is comprised of a hollow chamber having a flat bottom plate 41 with a large number of small holes 42 extending therethrough. To protect the surface of the hot glass plate, the lower side of the vacuum platen 40 is covered with a protective cover 43. Protective cover 43 is JH
It may be a stretchable knit fiberglass fabric such as that disclosed in Seifer et al., US Pat. No. 3,148,968. The cover 43 is held in place by a plurality of clamps 44.
The hollow interior of the vacuum platen 40 has a flexible conduit 4
5 communicates with a vacuum source. Vacuum platen 4
The area of 0 must be larger than the total area of the largest glass plate that can be received in the positioning frame 35 at one time. For maximum versatility,
Vacuum platen 40 may be made to cover substantially the entire area of hearth block 25.

The flatness and stiffness of the bottom plate 41 of the vacuum platen 40 are important factors for the successful implementation of the present invention. Any significant deviation from flatness can result in distortion of the glass plate. Therefore, the bottom plate 41 must be constructed with great care to provide a flat bottom surface, and be sufficiently rigid to prevent any bending or warping during its use. Should. Preferably, the base plate 41 is a relatively thick single piece of heat resistant metal, such as stainless steel, although in some cases it is possible to use a thicker stock material with reinforcing members welded to the interior surface. As an example of said single piece structure, at least 13mm
(1/2″), preferably at least 16mm (5/8″) stainless steel thickness was found to be suitable for a bottom plate of 81×198cm (32×78″). In this example In the vacuum platen, the interior had a height of 7.5 cm (3″).

The vacuum platen 40 is provided with means for vertical reciprocating movement, such as a hydraulic cylinder 5 as shown in FIG.
0 and a guide rod 51 are provided. The guide rod 51 slides through a fixed annular sleeve 52. The hydraulic cylinder 50 is in the raised position as shown in FIG.
The vacuum platen 40 is reciprocated between the lower position and the lowered position in which it is brought into close proximity to or in contact with the glass plate G held thereby. When the vacuum platen 40 is in its lowered position, suction is applied to the glass plate into contact with the platen 40 and as the platen 40 is lifted, a vacuum sufficient to cause the glass plate to be lifted by the platen 40. Vacuum is supplied. The platen 40 does not require contact with the glass plates to lift them. It has been found that an approach within the range of about 0.8 mm (1/32") to about 1.6 mm (1/16") is sufficient to lift the glass plate. However, this depends on the amount of vacuum provided and the weight of the glass. Further, the amount of vacuum required, the number of small holes 42 formed in the vacuum platen 40, and the diameter of the small holes 42 are interdependent. Although it is desirable to keep the perforations 42 small in number and diameter to minimize the power requirements for maintaining a vacuum within the vacuum platen 40, a relatively even distribution of perforations 42 should be handled. Sufficient pores should be formed to obtain in each portion of the smallest piece of glass plate. Approximately 1 small hole for every 6.5cm ² (1in ² )4
A spacing of 2 has been found to be suitable for most purposes. A pore diameter greater than approximately 1.9mm (0.075″), such as approximately 2.3mm (0.090″)
was found to be satisfactory for a vacuum of approximately 10 cm (4'') water (gauge).
This relates to the processing of plates with a thickness of .

One or more glass plates are pulled by a vacuum against their undersides and the vacuum platen 40 has a sufficient gap between the hearth block 25 and the platen 40 to insert the profile mold 60 therein. 1 to the raised position as shown in FIG. The mold 60 conforms to the desired shape and contour for the desired bent glass sheet and is preferably as described in SL Samer's U.S. Pat.
Made in accordance with the disclosure of No. 3973943. The disclosure is incorporated herein by reference. The mold 6
0 is preferably formed into a lightweight contoured ring and is notched along its upper edge to minimize interference with air flow during tempering.
The mold is carried on a shuttle 61, by means of which the mold 60 is translated horizontally through the bending station 11, the tempering station 12 and the product grating station 13. In the particular embodiment shown, the shuttle 61 is supported at one end by a longitudinal brace 63.
It is constructed with a pair of cantilever beams 62, and the upper end portion of the vertical brace 63 is adapted to slide along a pair of horizontal guide rods 64. shuttle 61
along the horizontal path is an electric motor (not shown) driving a continuous chain 65 to which the upper end of said brace 63 is connected.
Composed by. Lateral braces 66 support one or more molds 60 on shuttle 61 . FIG. 9 shows an end view of the shuttle 61, in which two molds 60 and 60' are arranged to simultaneously receive the glass plates G and G' shown in FIG. It is arranged.

When the vacuum platen 40 is raised to a height above the height of the mold 60, the shuttle 61 is driven to the left as viewed in FIG. Displaced into direct alignment beneath the lifted glass pane. Typically, the distance between hearth block 25 and vacuum platen 40 at this point is about 6-8''. This distance affects the rate at which the glass plate loses heat. This is because the higher altitude lifts the glass sheet into a cooler environment. When the glass plate is released from the vacuum platen 40 by a distance greater than the minimum distance required for passage, it therefore creates significant bending forces in the glass plate upon impact. In the typical case where the mold profile has points of maximum height, the falling glass sheet first contacts these points of maximum height and bending moments about these points and between the vacuum platen 40 and the high point of the mold. It has been found that the preferred distance is approximately 2.5-5 cm (1-2") and approximately 5-15 cm (2-6") at the low point of the mold.The exact distance at which the glass plate falls is , the weight and temperature of the glass pane, the degree of curvature to be imparted to the glass pane and the dimensions of the particular shape, and in special cases can be different distances beyond the above distance range.

Releasing the glass plate from the vacuum platen 40 is accomplished by reducing the vacuum to an amount insufficient to support the glass plate. This is easily accomplished by opening a valve to communicate the interior of vacuum platen 40 with atmospheric pressure. Alternatively, in some cases it may be desirable to facilitate release of the glass plate from platen 40 by rapidly building up positive pressure following a rapid decay of vacuum. Another optional feature is to provide platen 40 with a plurality of individually controllable vacuum zones so that the vacuum is released non-uniformly. For example, in some cases it may be advantageous to release the edge portions and central portions of the glass pane at different times. By delaying the release of the center portion, a slight back bend is imparted to the glass sheet, such back bending causing excessive center sag when the glass sheet is dropped onto an inner round contoured mold. Helps prevent. In contrast, differential vacuum release can be used to selectively define relatively deep bends that are difficult to create by impact forces alone.

Preferably, the moment imparted to the glass sheet by free fall onto the mold provides essentially the only bending force to conform the glass sheet to the contour of the mold. After the glass plate comes to rest on the mold, some small degree of sag may occur due to gravity, but the magnitude is due to the force generated by the moment in the ideal operating mode. This is insignificant compared to bending. Drooping is a relatively slow process;
In the present invention, tempering is preferably initiated after a minimum amount of time, so that sufficient time is not provided to cause any significant amount of gravity sag. On the other hand, to obtain certain difficult bends, it is desirable to delay the start of tempering to allow a significant amount of additional sag to occur after the glass sheet has fallen onto the mold. Although slower than the ideal mode of operation, such techniques are significantly faster than gravity droop-only methods. This is because the primary drop of the glass sheet onto the mold causes a substantial portion of the bending to be accomplished very quickly.

Upon receiving the glass sheet, the mold is immediately moved from the bending station 11 to the tempering station 1.
Moved to 2. The tempering station 12 has an upper blow head 70 and a lower blow head 71.
These blow heads direct jets of tempering medium (usually air) against opposite sides of the glass sheets, thereby rapidly cooling and tempering the surface portions of each glass sheet. In a tempering station 12 of the type shown in FIG.
Each blow head has a plurality of tube modules 72 which are supplied at their ends with pressurized tempering fluid through manifolds 75 and 76. Each tube module 72 has a plurality of tubes oriented to guide a jet of tempering fluid towards the position occupied by the glass sheet introduced into the space between the upper and lower blow heads 70, 71. It has small holes. Pipe module 72
The manifolds 73, 74 are arranged so that a more uniform gap is defined between them and the glass plate surface.
It is freely adjustable in the vertical direction relative to the . The lower blow head 71 has a support 8 pivotally attached to one end thereof.
1 and is provided with a cylinder device 81 at the opposite end, which allows the lower quench module to be tilted when it becomes necessary to keep the glass pane out of contact with the blower head. ing. Preferably, a relative movement is produced between the blowing head and the glass sheet while the jet of tempering medium is directed against the glass sheet in the tempering station. This is done by horizontally reciprocating the shuttle device 61, in which the mold and the glass plate are carried.

After the tempering is completed, the shuttle device 61
is advanced to the rightmost position shown in FIG.
will be moved to At the product unloading station 13, the glass sheet is removed from the mold by hand or by suitable mechanical means.

4-8 illustrate one operating cycle in the method of bending a glass sheet according to the invention. First, in FIG. 4, the glass plate G is emerging from the furnace 10. At the same time, the already bent and tempered glass sheet G' is about to be removed from the shuttle 61. In FIG. 5, the glass sheet G has entered the bending station 11, with its front end in contact with the positioning frame 35 and driven at its trailing edge by the alignment roll 33. At the same time, the vacuum platen 40
is being lowered into contact with the glass plate.
The preceding glass plate has been removed from the shuttle 61, and the shuttle 61 is attached to the bending station 11.
They have already started moving towards. In FIG. 6, the glass plate G has been lifted from the gas support bed 25 by the vacuum platen 40, and the shuttle 61 is stationary with the mold 60 positioned directly below the glass plate G. In FIG. 7, the vacuum has been removed from the vacuum platen 40 and the glass sheet G has therefore fallen onto the mold 60, thereby being bent to the desired curvature. The shuttle 61 immediately removes the glass sheet from the bending station 11 and feeds it into the tempering station 12, where the glass sheet G is rapidly cooled by a jet of air as shown in FIG. . Thereafter, the shuttle 61 transports the glass plate G into the product unloading station 13.

The following operating parameters are an example of successful operation of the above described preferred embodiment of the invention in the case of a 3 mm thick glass plate. Under different conditions the data will be different. Furnace temperature is approximately 700℃
The temperature was maintained at (1300〓). The gas emanating from the hearth block 25 at the bending station 11 is at a temperature of about 1100-1350°C, typically about 1250°C. Vacuum platen 4
0 after a period of operation due to its proximity to the hot gases from the hearth block 25.
Temperatures of 260-400℃ (500-750〓) were reached. Glass plate G was typically at about 650°C (1210°) when captured by the vacuum platen. Approximately 6 seconds elapsed from the time the glass plate was captured until the start of tempering. By the time tempering started, the glass plate had cooled to approximately 640°C (1190°C). Approximately 3 seconds passed from when the glass plate was dropped onto the mold until tempering started. The total time required for the glass sheet to exit the furnace exit, bend, and enter the tempering station was approximately 10 seconds. Such rapid bending speeds are advantageous not only because they represent high production rates, but also because they achieve high degrees of temper. This is because the rapidity of the bending process allows tempering to begin before the glass sheet has lost a significant amount of heat.

FIG. 10 shows an alternative arrangement for attaching the positioning frame to the hearth block 25 at the bending station 11. To demonstrate the versatility of the positioning frame apparatus, FIG. 10 shows a positioning frame 85 provided with four pockets 87 that allow simultaneous alignment and bending of four glass sheets. To hold positioning frame 85 in place, two or more pins 86 are welded to the leading edge of positioning frame 85 and can be inserted into holes drilled in hearth block 25. These holes may be holes already present in the hearth block for gas passage, or special holes may be drilled for the purpose of receiving pins 86.

FIG. 11 shows a further modification of the mounting device for the positioning frame. In this case, the positioning frame is
A pivoting support is provided so that the positioning frame can be easily lifted above the surface of the hearth block 25 if it becomes necessary to remove glass fragments from the hearth block. a pair of rods 91
is removably inserted into the end of the tubular hinge bracket 92 so that it can be freely adjusted laterally. Hinge bracket 92 pivots through a sleeve 93 which is mounted to support arm 94 for vertical adjustment.
The outer ends of hinge brackets 92 are engaged by mechanical actuation means, such as hydraulic cylinders 95, to provide remote control of the positioning frame lifting mechanism. In the embodiment of Figure 11, the positioning frame is preferably constructed of two halves, each half being adapted to be lifted by its own hinge arrangement.

FIG. 12 depicts an alternative arrangement that incorporates some, but not all, of the features and advantages of the preferred embodiment of the present invention. In FIG. 12, elements that are identical to those described in connection with the preferred embodiment of FIG. 1 are numbered the same. In particular, the furnace 10, tempering station 12 and product grating station are exactly the same as those shown in FIG. 1, so there will be no need to describe them again. However, in the bending station 100 of FIG. 12, the vacuum platen 40 is not reciprocated in the vertical direction, but is fixedly suspended by the beam 101. Similar to the embodiment shown in FIG. 1, the vacuum platen 40 is flat and does not need to be modified when changing the shape of the glass plate. However, instead of being captured by the vacuum platen, the glass plate is lifted into contact with the underside of the vacuum platen in this embodiment by a lifting ring 102. The lifting ring 102 is vertically reciprocated by a hydraulic cylinder 104, which is connected to the lifting ring 102 by a laterally extending projection 103. Lifting ring 102 is mounted around gas support hearth block 125. Hearth block 125 is of essentially the same construction as the hearth block previously described, but with reduced dimensions. Alternatively, the lifting ring 102 may fit into a groove cut into the top of a larger sized hearth. The upper side of the lifting ring 102 defines a flat support surface for the glass sheet along a line of connection or non-continuous contact with the edge portion of the glass sheet. The glass plate is registered on the hearth block 125 by means of a positioning frame 35 and registration rolls 33 in the same manner as previously described. Each glass plate is lifted by the ring 102 and placed on the vacuum platen 4.
0, the ring 102 is retracted to its lower position, a mold 60 is placed in alignment under each glass plate, and the glass plates are moved to give it the desired profile. Dropped onto the mold. The present mechanism differs from the prior art in that the vacuum platen is flat and does not require reassembly when product changes are made, and that it can be easily adapted to process multiple glass sheets simultaneously. This has advantages over bending mechanisms that utilize an underlying vacuum. However, the arrangement of FIG. 12 is not as advantageous as that of the embodiment of FIG. This is because the hearth block 125 and lifting ring 102 must be replaced each time the shape or number of glass sheets to be processed is changed.

Other modifications of the embodiment of FIG. 1 contemplated by the present invention include the use of a roller conveyor in place of the glass support apparatus for supporting and transporting the glass sheets. 1 in place of all gas support bed areas in furnaces and bending stations
A separate roller conveyor system may be used, or it may be advantageous to simply use a roller conveyor in place of the gas support bed in the furnace and a gas support hearth block such as 25 in the bending station.

It will also be appreciated that the step of aligning the mold with the glass sheet prior to dropping the glass sheet may optionally employ translation of the platen rather than the mold.

Another alternative method within the scope of the invention is:
The process involves heating the glass plate while it is supported in a generally vertical orientation. For example, as disclosed in R. W. Wheeler, U.S. Pat. can be passed through a furnace. The vacuum platen can be pivoted to receive the glass sheet in a vertical orientation and then rotated in a horizontal orientation to drop the glass sheet onto the mold.

While the foregoing description of specific embodiments has been set forth to illustrate the best mode and other illustrative examples for carrying out the invention, other changes and modifications will occur to those skilled in the art. It is to be understood that modifications may be made to the present invention without departing from the spirit of the invention or the scope of the appended claims.

[Brief explanation of the drawing]

FIG. 1 is a side view of a particular recommended embodiment of an apparatus for bending and tempering glass sheets, incorporating the drop forming method of the present invention and flat vacuum capture means; FIG. FIG. 3 is a cross-sectional view of the gas support block disposed in the forming area taken along line 3--3 in FIG. 2; FIGS. 4 to 8 The figures are drawings showing the sequential steps in the operating cycle of the apparatus of figure 1; figure 9 is an end view of the bending form and support structure taken along line 9-9 of figure 1; figure 10 is a four stage view. A perspective view of a gas support bed on a forming station showing an alignment frame and an alternative mounting arrangement for a four-tier alignment frame; FIG. 11 shows another alternative mounting for an alignment frame on a forming station. A perspective view of the apparatus; FIG. 12 is a side view of an alternative embodiment for drop forming glass sheets using a flat lifting ring. In the drawing, 10 is a ``furnace''; 11 is a ``forming station''; 12 is a ``tempering station''; 13 is a ``product grating station''; 21 is a ``heart block''; 24 is an ``extension block''; 25 is a ``support''Block”; 30 is “Endless Chain”;
32 is the "take-out roll"; 33 is the "alignment roll"; 35 is the "positioning frame"; 36 is the "rod"; 37 is the "plate"; 40 is the "vacuum platen"; G is the "glass plate"; 41 is the " Bottom plate”;42
is a "small hole"; 45 is a "conduit"; 50 is a "hydraulic cylinder"; 51 is a "guide rod"; 60 is a "molding mold";
61 is “Shuttle”; 65 is “Chain”; 7
2 is "pipe module"; 73 is "manifold";
70 indicates a "blow head"; 75 indicates a "duct".

Claims (1)

[Claims] 1 heating a glass plate to approximately its softening point and placing the glass plate on a support device; translating a vacuum platen having a flat porous surface toward the support device to bring the flat porous surface into contact with the glass plate; drawing a vacuum through the flat perforated plate to hold the glass plate to the platen; translating the platen away from the support device; lifting the glass sheet from the support device and positioning the glass sheet under the platen in a generally horizontal orientation; forming a mold having a contour defining a desired contour for the glass sheet; , vertically aligning below a glass plate held by the platen;
Releasing the glass sheet from the platen and dropping the glass sheet onto the mold from a sufficient height above the mold so that the impact force is required to obtain the desired shape of the glass sheet. conforming the released glass sheet to a contour defined by the mold so as to constitute a majority of the bending force applied to the sheet.