Method and apparatus for pressing laminated glass

A method and apparatus for pressing curved laminated glass having an adhesion interlayer between curved sheets of plate glass by passing the curved laminated glass through a pair of press rolls. A level of a contact position between said pair of press rolls and an inclination angle of a line connecting axes of said pair of press rolls with respect to a curved surface of the laminated glass are controlled to control a posture of said pair of press rolls upon movement of the laminated glass so as to correspond to controlled rotation of said pair of press rolls. A line of action of a press pressure is directed along a direction substantially normal to the curved surface of the laminated glass, and the location of application of the press pressure is level-shifted along the curved surface of the laminated glass. The posture of the press rolls is controlled in accordance with prestored data sampled along the curved surface of the laminated glass.

CROSS REFERENCE TO RELATED APPLICATIONS 
This application discloses subject matter disclosed in copending 
application Ser. No. 627,769, filed July 5, 1984 in the names of the same 
inventors and entitled METHOD AND APATUS FOR CLEANING A CURVED GLASS 
SHEET, now U.S. Pat. No. 4,558,480. 
BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a method and apparatus used in an adhesion 
process for adhering laminated glass (safety glass) such as a windshield 
of a vehicle. 
2. Description of the Prior Art 
In a conventional windshield of a vehicle, a plurality of sheets of plate 
glass are adhered together through a plastic film such as a polyvinyl 
butyral film to prepare so-called safety glass. Such laminated glass is 
prepared such that adhesion interlayers are inserted between the plastic 
film and the sheets of plate glass and are preliminarily adhered thereto. 
The resultant structure is finally pressed in an autoclave. The 
preliminary adhesion is performed to remove bubbles, water content and 
residual steam from the adhesion layers. In principle, an apparatus is 
used wherein the laminated glass is passed through a pair of press rolls. 
According to the most basic press roll apparatus, a pair of press rolls are 
vertically disposed, and a worker at the insertion side inserts laminated 
glass into the pair of press rolls and another worker at the exhaustion 
side picks it up from the pair of press rolls. This apparatus has 
disadvantages in that the operation requires much labor and a uniform 
pressure cannot be obtained when the laminated glass has a complicated 
three-dimensional surface. 
A conventional automatic press roll apparatus has been used to 
automatically perform the preliminary adhesion process for a 
three-dimensional glass surface. According to this press roll apparatus, 
each of the pair of press rolls is divided into a plurality of annular 
segments. Some of the roll segments can then be inclined in accordance 
with the curved surface of the laminated glass. In addition, all the roll 
segments are supported by a rotational frame. When the glass passes 
between the press rolls, the rotational frame swings in accordance with 
the curved surface of the glass so as to apply a constant press pressure 
to the glass surface in the direction perpendicular to the glass surface. 
This conventional automatic press roll apparatus also has a counterbalance 
mechanism for cancelling the weights of the press rolls so as to obtain a 
constant press pressure when the rotational frame swings and the pressure 
application direction is inclined with respect to the vertical direction 
(the direction of gravity). 
This press roll apparatus is effective for automatically pressing the 
laminated glass having a relatively simple three-dimensional surface. 
However, the rotational frame and the counterbalance mechanism are driven 
by a guide cam corresponding to each three-dimensional surface. The guide 
cam must be replaced with another guide cam corresponding to the surface 
of the windshield in accordance with the type of vehicle. Therefore, this 
conventional press roll apparatus is not suitable for mass production of 
different types of windshield. 
SUMMARY OF THE INVENTION 
It is, therefore, a principal object of the present invention to provide a 
method and apparatus wherein laminated glass having a three-dimensional 
surface is pressed uniformly without using a guide cam. 
It is another object of this invention to improve press performance for the 
complicated three-dimensional surface of the laminated glass by providing 
good flexibility and reproducibility to follow the curved surface. 
It is a further object of this invention to improve the press efficiency 
for laminated glass sheets having different three-dimensional surfaces by 
providing flexibility based on control data corresponding to respective 
glass sheets. 
In order to achieve the above objects of the present invention, there are 
provided press rolls which receive laminated glass having an adhesion film 
between sheets of plate glass. The press rolls are rotatably supported on 
a roll frame, and the roll frame can be pivoted such that the direction of 
pressure application is substantially normal to the curved surface of the 
laminated glass. The roll frame is supported by a support frame such that 
the pressure application point can be vertically displaced along a 
direction perpendicular to the major three-dimensional surface. The 
rotation of the press rolls, the angular displacement of the roll frame, 
and the level change of the roll frame are performed by respective driving 
sources which are controlled by a control device in accordance with 
prestored data. When the data representing the curved surface of the 
laminated glass is stored in the control device, the press roll apparatus 
can automatically press laminated glass having any three-dimensional 
surface in accordance with the prestored data without the need for 
partially modifying the apparatus. 
Other and further objects of this invention will become obvious upon an 
understanding of the illustrative embodiments about to be described or 
will be indicated in the appended claims, and various advantages not 
referred to herein will occur to one skilled in the art upon employment of 
the invention in practice.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The present invention will be described in detail with reference to a 
preferred embodiment. 
FIG. 1 is a perspective view of a windshield of a vehicle which has been 
subjected to preliminary adhesion. A windshield comprising a glass plate 1 
typically has a complicated three-dimensional surface curved along x-, y- 
and z-axes. A central portion a of the glass plate 1 is substantially 
flat, and two wing portions b and c are greatly bent. An intermediate 
portion from the wing portion b to the wing portion c is moderately bent 
in a convex shape. The radius of curvature in an upper side portion d is 
different from that in a lower side portion e. An intermediate portion 
from the upper side portion d to the lower side portion e is also 
moderately bent. 
FIG. 2 is a side view schematically showing the preliminary adhesion press 
roll apparatus according to an embodiment of the present invention. 
Referring to FIG. 2, the two-layer glass plate 1 having an adhesion 
interlayer between two sheets of plate glass is fed by a supply conveyor 2 
along the x-axis in FIG. 1 and is pressed between upper and lower rolls 4 
and 5 of a press roll unit 3. The glass plate 1 passing through the press 
roll unit 3 is taken up by a take-up conveyor 6. The upper and lower rolls 
4 and 5 are rotatably supported by a roll frame 7. The roll frame 7 is 
mounted on a support frame to be vertically movable (along directions 
indicated by arrows A and A' in FIG. 2) and to be pivotal about a contact 
line between the upper and lower rolls 4 and 5 along the directions 
indicated by arrows B. 
The pivotal and vertical movements of the roll frame 7 are controlled by an 
NC (numerical control) machine in accordance with numerical data prestored 
in correspondence to the shape of the glass plate 1. The pivot angle of 
the roll frame can be automatically controlled such that a line connecting 
the axes of the upper and lower rolls 4 and 5 (i.e., the line of action of 
the press pressure) is normal to the glass plate 1. In addition, the 
height (i.e., the height of the point of action of the press pressure) of 
the roll frame 7 is automatically controlled such that the glass plate 1 
will not be vertically moved while passing through the press roll unit but 
instead will be fed along only in the horizontal direction. 
Furthermore, the rotational speed of the upper and lower rolls 4 and 5 is 
controlled by the NC machine in accordance with the prestored numerical 
data. When the rolls are rotated in opposing directions, the glass plate 1 
is transported at a predetermined speed during pressing. The roll frame 7 
is controlled to be movable relative to the glass plate 1 along the x-axis 
(horizontal) and the y-axis (vertical) of FIG. 1. The line of action of 
the press pressure acts on the glass surface in a direction perpendicular 
thereto. This can be readily understood if it is assumed that an NC 
machine deals with the glass plate 1 as a workpiece placed on an X-Y table 
and has the upper and lower rolls 4 and 5 as tools. However, it should be 
noted that a displacement (alignment) along the x-axis corresponds to the 
angular interval of the upper and lower rolls 4 or 5 and that the upper 
and lower rolls 4 and 5 as tools are moved along the y-axis. The above 
assumption can be applied if these two differences are excluded. 
The preliminary adhesion press roll apparatus of this embodiment has a pair 
of glass hold rolls 8 for firmly holding the glass plate 1 so as to feed 
it to the press roll unit 3. The pair of glass hold rolls 8 are disposed 
along the width of the supply conveyor 2 in the vicinity of the terminal 
portion of the conveyor 2 and are vertically movably and rotatably mounted 
at bifurcated distal ends of rod 10 of air cylinder 9, respectively. The 
glass hold rolls 8 are moved downward immediately before the glass plate 1 
is clamped between the upper and lower rolls 4 and 5. The glass plate 1 is 
urged by the glass hold rolls 8 against the supply conveyor 2. As a 
result, the glass plate 1 can be properly inserted between the upper and 
lower rolls 4 and 5 along the x-axis without being distorted (rotated) 
within the horizontal plane. The glass hold rolls 8 are moved upward 
immediately after the glass plate 1 is firmly fed into the press roll unit 
3. 
Glass hold rolls 11 having the same construction as the rolls 8 are mounted 
above the take-up conveyor 6. The rolls 11 are vertically movably and 
rotatably mounted at distal ends of rods 13 of air cylinders 12, 
respectively. The glass plate 1 passing through the press roll unit 3 is 
temporarily held on the conveyor 6 by the rolls 11. Therefore, the glass 
plate 1 can be taken up by the take-up conveyor 6 without being distorted 
on the horizontal plane. 
FIG. 3 is a side view of the press roll apparatus when viewed from the same 
side as illustrated in FIG. 2, but showing a different state of 
preliminary adhesion. Upon horizontal displacement of the glass plate 1, 
the roll frame 7 is gradually pivoted such that the press pressure acts on 
the surface of the glass plate 1 in a direction perpendicular to the 
surface thereof. The press roll unit 3 stands substantially upright when 
it is located at the center of the glass plate 1 along the feeding 
direction, as shown in FIG. 3. The height of the roll frame 7 also changes 
in accordance with the height of the surface of the glass plate 1. It is 
apparent from the shape of the glass plate 1 that the inclination and 
height of the roll frame 7 are inverted after the state shown in FIG. 3. 
Further illustration need not be provided since the symmetrical view about 
the vertical line corresponding to the arrows A and A' (FIG. 2) shows the 
end of preliminary adhesion. 
FIG. 4 is a front view of the press roll unit 3, FIG. 5 is a sectional view 
thereof along the line V--V of FIG. 4, FIG. 6 is a sectional view thereof 
along the line VI--VI, and FIG. 7 is a side view thereof along the arrow 
VII of FIG. 4. 
As shown in FIG. 4, each of the upper and lower rolls 4 and 5 is divided 
into a plurality of segments. Three central segments comprise drive rolls 
4a or 5a, and right six segments and left five segments comprise free 
rolls 4b or 5b which can be inclined along the curved surface of the glass 
plate 1 and which cannot be externally driven. 
As shown in FIG. 5, each pair of drive rolls 4a and 5a are rotatably 
supported by shafts 16a and 16b at distal ends of a pair of support arms 
15a and 15b, respectively. The pair of drive rolls 4a and 5a are mounted 
on the roll frame 7 so as to clamp the glass plate 1 through the support 
arms 15a and 15b, respectively. The upper roll 4a is biased by a bellofram 
cylinder 17. The lower roll 5a is driven by a timing belt 21 looped 
between a gear 19 mounted on a drive shaft 18 and a gear 20 mounted on the 
roll 5a. 
As shown in FIG. 6, each pair of free rolls 4b and 5b is supported by 
support arms 24a and 24b having orthogonal axes 22a and 22b, and 23a and 
23b to be rotated along the feed direction of the glass plate 1 and to be 
inclined along the curved surfaces of the glass plate 1, as shown in FIG. 
6, respectively. The upper roll 4b is biased downward by a corresponding 
bellofram cylinder 25. 
As shown in FIG. 4, the roll frame 7 for supporting the drive rolls 4a and 
5a and the free rolls 4b and 5b is pivotally supported by lift frames 29 
and 30 respectively through a shaft 28 and a hollow shaft 27 whose axes 
correspond to a contact line between the upper roll 4 and the lower roll 
5. The drive shaft 18 for rotating the drive rolls 5a extends at the side 
surface of the roll frame 7 and is coupled to a shaft 32 extending through 
a space of the hollow shaft 27 through a transmission mechanism 31 made of 
a chain and sprockets. The shaft 32 is driven by a motor 26 fixed at the 
distal end of the lift frame 30. The shaft 28 of the roll frame 7 extends 
through a bearing of the lift frame 29 and is coupled to a swinging 
mechanism 33, thereby swinging the roll frame 7 about the shafts 27 and 
28. 
The lift frames 29 and 30 are slidably mounted in columns 34 and 35 and can 
be vertically moved by a lift mechanism 37 mounted on a beam 36 extending 
across the distal ends of the columns 34 and 35. 
FIG. 7 is a side view of the press roll unit and its peripheral components. 
The lift frame 29 is slidably supported in the column 34 through two guide 
rods 39 and 40 and can be vertically moved upon rotation of a screw rod of 
the lift mechanism 37. Screw rods 41 and 42 of the lift frames 29 and 30 
are driven by a motor 46 through reduction gear mechanisms 44 and 45 (FIG. 
4) coupled through a shaft 43. Air cylinders 47 and 48 are mounted as 
dampers at the lower ends of the lift frames 29 and 30, respectively. The 
swinging mechanism 33 is mounted at the lower end of the lift frame 29. 
The swinging mechanism 33 comprises a worm wheel 50 mounted at the distal 
end of the shaft 28 of the roll frame 7, a worm 51 and a motor 52 for 
driving the worm 51, as shown in FIG. 7. 
FIG. 8 is a block diagram of a control section of a preliminary adhesion 
press roll apparatus. As shown in FIG. 8, the control section comprises a 
microcomputer which includes a CPU 54, a RAM 55 and data bus 56. The 
control section is connected to the press roll unit 3 of FIGS. 2 to 7 
through a plurality of interfaces. Posture control (inclination angle and 
height) of the roll frame 7, rotational speed control of the rolls 4 and 
5, and conveyor speed control are performed in accordance with the control 
data stored in a data floppy disk 57 and the control program stored in a 
program floppy disk 58. The data read out from the floppy disks 57 and 58 
are stored in the RAM 55 through an floppy disk interface 59. The CPU 54 
controls the overall operation of the roll press apparatus in accordance 
with the program stored in the RAM 55. The data are sequentially read out 
from the RAM 55 and are supplied to NC control interfaces 60 to 62. Servo 
controllers 63 to 65 are operated in response to control outputs from the 
NC control interfaces 60 to 62 so as to drive the motors 26, 52 and 46, 
respectively. 
A tachogenerator TG and a pulse generator PG are connected to each of the 
motors 26, 52 and 46. An output from the tachogenerator TG is fed back to 
the corresponding one of the servo controllers 63 to 65, so that the 
corresponding one of the motors 26, 52 and 46 is controlled to have a 
specified rotational speed. The output generated from each of the pulse 
generators PG corresponding to the corresponding one of the motors 26, 52 
and 46 is fed back to the corresponding one of the NC control interfaces 
60 to 62. The posture (height and rotational angle) of the roll frame 7 
and the angular interval of the rolls are NC-controlled in accordance with 
the outputs from the pulse generators PG and the control data from the CPU 
54. The control data represents 20 sampling points of the glass plate 1 
along the x-axis, as will be described later. The NC control interfaces 60 
to 62 perform interpolation (primary or secondary interpolation) between 
every two adjacent sampling points in the same manner as in the 
conventional NC machine. 
In the control section shown in FIG. 8, the synchronous operation of 
conveyor motors 68 and 69 is controlled so as to synchronize the 
translational speed of the glass plate 1 with the feeding speed of the 
supply and take-up conveyors 2 and 6 when the glass plate 1 is inserted 
between the upper and lower rolls 4 and 5 and passes therethrough. A 
horizontal translational velocity V.sub.x of the glass plate 1 is 
calculated by the CPU 54 in accordance with function Vx=V.sub.R sin 
.theta. where V.sub.R is the roll rotational velocity data and .theta. is 
the angle data of the roll frame 7. Data representing the speeds of the 
conveyors 2 and 6 in accordance with the calculated results are supplied 
to D/A converters 70 and 71, respectively. Outputs from the D/A converters 
70 and 71 are supplied to servo controllers 72 and 73, respectively, 
thereby synchronizing the speeds of the conveyor motors 68 and 69. 
The control of the glass hold rolls 8 and 11 at the time when the glass 
plate 1 is inserted between the press rolls 4 and 5 or removed therefrom 
can be performed such that a limit switch (to be described later) detects 
the position of the glass plate 1 on the corresponding conveyor and that 
the output of the pulse generator PG for the conveyor motor 68 or 69 is 
counted to estimate the insertion or removal position. An output from the 
limit switch is supplied to the CPU 54 through an input port 74. A pulse 
generator counter 75 is started under the control of the CPU 54 to count 
the PG output from the pulse generator of the motor 68 or 69. A count of 
the PG counter 75 is supplied to the CPU 54 and when it reaches a 
predetermined value, the drive signal is supplied to the rolls 8 or 11 
through an output port 76. 
The input port 74 receives operation command inputs (e.g., automatic, 
manual and stop commands) of the apparatus and outputs display signals to 
monitor lamps for indicating the operating state. A teaching box 77 is 
coupled to the input and output ports 74 and 76, so that the command or 
instruction data for teaching (to be described later) are supplied to the 
NC control interfaces 60 to 62 through the CPU 54. 
The operation of the preliminary adhesion press roll apparatus will be 
described in detail with reference to the flow chart (FIG. 9) of overall 
operation, the flow chart (FIG. 10) of the operation of the glass hold 
roll 8 and the press rolls 4 and 5, and the flow chart (FIG. 11) of 
velocity synchronization of the supply conveyor 2 and the take-up conveyor 
6. It should be noted that the operation block numbers of FIGS. 10 and 11 
correspond to the surfaces of figure numbers of FIG. 9, respectively. 
Predetermined data .theta..sub.0 and h.sub.0 are supplied from the CPU 54 
to the NC control interfaces 61 and 62 so as to determine that the posture 
(inclination angle .theta. and height h) of the rolls 4 and 5 are set so 
as to allow insertion of the glass plate 1 therebetween, as shown in FIG. 
9I. The position of the press rolls on the glass plate 1 along the x-axis 
(horizontal direction) is represented by an angular rotational interval l 
of the roll. In the insertion standby state described above, the rolls 4 
and 5 are stopped, so that l=l.sub.0 =0. 
In this standby mode, when the glass plate 1 on the supply conveyor 2 
reaches a limit switch LS, as shown in FIG. 9I, the position measurement 
of the glass plate which corresponds to the vertical movement timing of 
the glass hold rolls 8 and the glass plate insertion timing are started in 
accordance with the detection output from the limit switch LS and the PG 
output of the supply conveyor 2. When the glass plate 1 reaches a position 
where the glass hold rolls 8 are moved at their lower positions, the rolls 
8 are also moved downward, as shown in FIG. 9II. When the glass plate 1 
reaches the insertion position, as shown in FIG. 9III, the NC control is 
started to calculate the roll rotational velocity, the inclination angle 
.theta. and height h of the rolls 4 and 5. The glass plate 1 is inserted 
between the upper and lower press rolls 4 and 5, thereby starting the 
preliminary adhesion operation. In the position where the insertion of the 
glass plate between the press rolls 4 and 5 is completed, the glass hold 
rolls 8 are moved upward, as shown in FIG. 9IV. Subsequently, as shown in 
FIGS. 9IV, 9V and 9VI, the inclination angle of the press rolls, the roll 
height, the angular rotational interval of the roll, and the roll 
rotational velocity (.theta..sub.n, h.sub.n, l.sub.n and v.sub.n) are 
NC-controlled in accordance with the data supplied from the CPU 54. 
The velocities of the supply conveyor 2 and the take-up conveyor 6 are 
synchronized at the roll rotational velocity while the press rolls 4 and 5 
are brought into tight contact with the glass plate 1, as shown in blocks 
III, IV and V of FIG. 10. This synchronization control is performed in 
accordance with the flow chart of FIG. 11. The rotational velocity V.sub.R 
(peripheral velocity) of the press roll is calculated, the horizontal 
translational velocity V.sub.R sin .theta. (.theta. is the inclination 
angle of the press rolls 4 and 5 with respect to the vertical direction) 
of the glass plate 1 fed by the press rolls 4 and 5 is calculated, and a 
velocity command is supplied to the D/A converters 70 and 71 of FIG. 8 so 
as to match the horizontal translational velocity of the glass plate with 
the conveyor velocity V.sub.c. The conveyor velocity is gradually 
increased immediately after the glass plate 1 is inserted between the 
press rolls 4 and 5 (i.e., with a decrease in the inclination angle 
.theta.) in accordance with the synchronization control. As shown in FIG. 
9V, the velocity becomes a constant high speed at the flat portion 
(.theta.=90.degree. and sin .theta.=1) of the glass plate 1. In addition, 
the conveyor velocity V.sub.c at the trailing end of the glass plate 1 is 
gradually decreased in accordance with an increase in inclination angle 
.theta.. 
When the glass plate 1 is not inserted between the press rolls 4 and 5, as 
shown in FIGS. 9I, 9II and 9VI, the velocity signal is supplied to the D/A 
converters 70 and 71 in such a manner that the conveyor velocity V.sub.c 
becomes a maximum velocity V.sub.max, as shown in the flow chart of FIG. 
11. More particularly, referring to FIG. 9I, until the leading end of the 
glass plate 1 reaches the limit switch LS, the supply conveyor 2 is driven 
at the maximum velocity V.sub.max. However, when the leading end of the 
glass plate 1 reaches the press rolls 4 and 5, as shown in FIG. 9III, the 
velocity of the supply conveyor 2 is reduced from the maximum velocity 
V.sub.max to the predetermined insertion velocity. Subsequently, when the 
glass plate 1 is fed by a distance (d.sub.0 -.alpha.) of FIG. 9I after the 
trailing end of the glass plate 1 passes the limit switch LS (i.e., when 
the glass plate 1 is not present on the supply conveyor), the velocity of 
the supply conveyor 2 is increased to the maximum velocity V.sub.max. At 
the same time, when the glass plate 1 is fed by a distance (d.sub.0 
+.alpha.) after the trailing end of the glass plate 1 has passed the limit 
switch LS (i.e., when the glass plate is removed from the press rolls 4 
and 5), the velocity of the take-up conveyor 6 is increased to the maximum 
velocity V.sub.max. The position of the glass plate 1 can be calculated by 
the CPU 54 in accordance with the detection output from the limit switches 
LS and the PG outputs of the conveyor motors 68 and 69. 
The teaching operation of the press roll apparatus will now be described. 
The press roll apparatus described above has a property of flexibility and 
so can be used for a glass plate having substantially any 
three-dimensional surface. The apparatus can first be taught to give the 
necessary preliminary adhesion in individual glass plates having different 
three-dimensional surfaces. When the apparatus has learned all possible 
different three-dimensional surfaces of the glass plates, complete 
playback can be performed. In addition, the control data obtained from the 
different three-dimensional surfaces may be selectively used to 
perform-preliminary adhesion of any type of glass plates having different 
three-dimensional surfaces. 
The teaching operation is performed by using 15 to 20 sampling points 
P.sub.0, P.sub.1, . . . along the cross section of the glass plate 1, as 
shown in FIG. 12A. The position of each sampling point is represented by 
absolute coordinates with respect to an origin O in the x-y coordinate 
system. More precisely, the x coordinate is plotted along the curve of the 
glass plate 1. As shown enlarged in FIG. 12B, distances between every two 
adjacent sampling points are given by angular displacements l.sub.1, 
l.sub.2, . . . of the contact position between the press roll 4 and 5, 
respectively. The y coordinates correspond to positions representing the 
heights h.sub.0, h.sub.1, h.sub.2, . . . of the contact positions between 
the press rolls, respectively. Teaching data at the respective sampling 
points also include inclination angles .theta..sub.0, .theta..sub.1, . . . 
of the line connecting the axes of the press rolls and rotational velocity 
data v.sub.0, v.sub.1, . . . at the contact positions between the press 
rolls, in addition to the above-mentioned angular displacement and height 
data. Therefore, the respective sampling points are defined by the 
following teaching data: 
##EQU1## 
The teaching data of each sampling point of FIG. 12A is supplied to the 
CPU 54 every time a teaching operation is performed and is stored in a 
memory table of the RAM 55. It should be noted that the real storage data 
in the RAM 55 is count data corresponding to the PG outputs from the pulse 
generators of the motors 26, 46 and 52 with respect to the reference 
position, excluding the rotational velocity data of the rolls. This 
rotational velocity data is arbitrarily preset in accordance with the 
command from the teaching box 77. 
In the preliminary adhesion (playback mode), the respective teaching data 
are supplied to the NC control interfaces 60 to 62 so as to perform 3-axis 
NC control in synchronism with the outputs from the PGs of the respective 
motors 26, 52 and 46. The velocity data is supplied as a pulse rate 
(frequency) of a reference pulse generator of each NC control interface so 
as to distribute the reference pulses in accordance with a ratio of the 
relative coordinate data (h and l) of the sampling point P.sub.i to those 
of the adjacent sampling point P.sub.i+1. The motors 26 and 46 are rotated 
to drive the press rolls 4 and 5 from the point P.sub.i to the point 
P.sub.i+1 in accordance with the distributed pulses. On the other hand, 
the motor 52 is driven in accordance with the inclination angle data 
.theta. irrespective of the x-y coordinate system. The interpolation 
between the two adjacent sampling points can be linear or arc 
interpolation. 
FIG. 13 is a plan view of an operation panel 78 of the teaching box 77. 
FIGS. 14A to 14C are respectively flow charts for explaining the teaching 
operation. The teaching box 77 is started when an ENBL (enable) key 80 
shown in FIG. 13 is depressed. As shown in FIG. 14A, when the ENBL key 80 
is depressed, an enable flag is set at logic "1" to enable key input 
operations by other keys. However, when the enable flag is set at logic 
"0", the key input operations by other keys are disabled. When an 
F.rarw.(forward) key 88 or an R.fwdarw.(reverse) key 89 is depressed, the 
rolls 4 and 5 are rotated in the forward or reverse direction so as to 
move the glass plate 1 forward or backward. The keys 88 and 89 are used to 
select an x coordinate. An .uparw.U (up) key 92 or .dwnarw.D (down) key 93 
is depressed to move the roll frame 7 upward or downward to select a y 
coordinate. An N (counterclockwise) 90 or an N (clockwise) key 91 is 
depressed to preset the inclination angle .theta. (swinging angle) of the 
roll frame 7. The rotational velocity of the rolls 4 and 5 can be 
controlled by an SPD.uparw. (speed up) key 86 or an SPD.dwnarw. (speed 
down) key 87 in, for example, 16 steps. The velocity data is displayed on 
a display 97. 
When the data (.theta..sub.i, h.sub.i,l.sub.i,v.sub.i) of the sampling 
point P.sub.i are preset in accordance with the series of operations 
described above, an INS (insert) key 81 and an REC (record) key 84 are 
depressed to store the data of the sampling point P.sub.i in the RAM 55 
through the CPU 54. As shown in FIG. 14B, when the INS key 81 is 
depressed, an INS flag is set at logic "1". Subsequently, when the REC key 
84 is depressed, the data of the sampling point P.sub.i are stored in the 
RAM 55. In this case, when the previous data of the sampling point P.sub.i 
are stored in the RAM 55, an ALT (alter) key 85 is depressed to set an ALT 
flag at logic "1". Thereafter, when the REC key 84 is depressed, the data 
of the sampling point P.sub.i are updated. This teaching process is used 
to correct the locus of the contact points between the press rolls 4 and 
5. 
In order to preset teaching data of the next teaching point P.sub.i+1 after 
the teaching of the sampling point P.sub.i is finished, a STEP NEXT (step 
next) key 82 is depressed, as shown in FIG. 14C. On the other hand, in 
order to return to the previous step, a STEP BACK (step back) key 83 is 
depressed. The current step number (reference number of the sampling point 
P) is displayed on a display 96 in the operation panel 78. When an ERS 
(erase) key 94 is depressed, the storage data of the sampling point 
P.sub.i are erased, and the teaching point position is returned to the 
immediately preceding point. When teaching of the last sampling point is 
finished, an END (end) key 95 is depressed, thereby inserting the data of 
the start sampling point P.sub.1 after the data of the end sampling point 
P.sub.n, as shown in FIG. 14C. In other words, the following loop is 
formed, and the NC operation loop is completed. 
##STR1## 
The NC control data stored by the teaching operation described above are 
stored in the data floppy disk 57 for each glass plate 1 having a 
different three-dimensional surface. Every time the type of glass plate 
conveyed along the preliminary adhesion production line changes, the 
corresponding data are read out from the floppy disk 57 and are stored in 
the RAM 55, thereby reproducing (playing back) the learned preliminary 
adhesion process in accordance with NC control. 
FIG. 15 is a flow chart for explaining the NC control of preliminary 
adhesion. The NC operation command is generated from the CPU 54 when the 
glass plate 1 is inserted between the upper and lower press rolls 4 and 5, 
as shown in FIG. 9III. The 3-axis NC operation is thus started. Since the 
absolute coordinate data of the respective sampling points are given by 
teaching, the relative coordinates of the contact position between the 
press rolls are calculated in accordance with the absolute coordinates of 
the respective axes and the current coordinates thereof. The NC control 
interfaces 60 to 62 receive the corresponding relative coordinate data. 
The frequencies of the reference pulse generators of the NC control 
interfaces 60 to 62 are set in accordance with the rotational velocity 
data of the corresponding roll, thereby presetting the locus from the 
current point to the next point. The operation commands are simultaneously 
supplied to the 3-axis NC control interfaces 60 to 62. As a result, the NC 
control of the press rolls 4 and 5 is performed in accordance with linear 
or arc interpolation. When one step is finished, the end pulses from the 
NC control interfaces 60 to 62 are supplied to the CPU 54, and the 
position pointer is incremented by one. The next point data are read out 
under the control of the CPU 54, and the coordinate calculation or the 
like is performed again. When the above operation is repeated to complete 
all the steps, preliminary adhesion of one glass plate is completed. The 
press roll apparatus is then set in the standby state for receiving the 
next glass plate. 
The present invention is exemplified by the above embodiment. However, 
various changes and modifications may be made within the spirit and scope 
of the invention. In the above embodiment, the rotational speed data of 
the roll is specified in units of teaching points (sampling points). 
However, NC control may be performed at a constant velocity. In addition 
to this modification, NC control may be performed such that the 
inclination angle .theta., the angular displacement l and the rotational 
velocity v are specified in units of teaching points, and the height data 
h (y-axis) may be calculated in accordance with vcos.theta. so as to 
synchronize the lift frames 29 and 30. 
Furthermore, when the number of sampling points for teaching is 
sufficiently large, interpolation by NC need not be performed. In this 
case, the motors 26, 52 and 46 can be driven in response to outputs from 
the D/A converters 70 and 71 in the same manner as in the conveyor motors 
68 and 69 of FIG. 8. 
According to the press roll apparatus of the present invention, the roll 
frame is angularly displaced such that the line of action of the pressure 
of the press rolls is directed toward substantially normal to the curved 
surface of the laminated glass, and the roll frame is level-shifted such 
that the point of action of the press pressure follows the curved glass 
surface. The rotation of the press rolls and the angular displacement and 
height of the roll frame are controlled in accordance with the preset 
data. Even if the laminated glass has a complicated three-dimensional 
surface, it can be pressed so as to follow the curved surface in 
accordance with the control data, thereby improving the press performance. 
In addition to this advantage, laminated glass sheets having different 
three-dimensional surfaces can be properly subjected to high-speed 
preliminary adhesion by merely changing the control data. As a result, the 
press efficiency can be greatly improved.