JPH0140772B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a glass product forming machine that includes:
It concerns the detection of gobs of molten glass entering the mold.

In a glassware forming machine known as an IS or individual section machine, each individual section has a
A plurality of means are involved for performing a predetermined sequence of steps in a certain temporal relationship to form a glass product. The forming means was typically powered by an air motor controlled by a valve block controlled by a rotating timing drum.
The glass is melted, formed into gobs, and directed into individual sections by a gob distributor. Each section of the machine produces glassware from gobs, which are placed on a dead plate for extrusion onto a flight conveyor. The conveyor transports the glassware to a lehr for annealing, cooling, and other processing.

The individual sections are operated in relatively different phases and according to a predetermined sequence to receive gobs from the gob distributor in an ordered sequence. When one of the partitions is accepting gobs from a gob distributor,
One of the divisions will be feeding the finished glass product onto a conveyor, and another division will be performing various forming steps.
Furthermore, each section can be provided with two molds, whereby the gobs are received for the initial process of forming the parison into a first mold, called a blank or parison mold. , and subsequently the parison is transferred to a second mold, called a blow mold, for the final blowing of the product. Each mold is 1
Having more than one cavity, each section of the machine can be operated on multiple gobs simultaneously to form glassware.

Although timing drums or electronic control systems have been used to define the timing of the segment, the prior art has not been known to synchronize the timing of the segment to the timing of the gob feeder and gob distributor. was. Not only are the sections operated in phase with a relative difference to receive gobs in an ordered sequence, but the phase difference must be preadjusted for differences in the transfer times of gobs relative to the individual sections. Nakatsuta. The sections are typically arranged in a line along the conveyor, and even as few as two sections can be equal distances from the gob feeder.

This invention relates to an apparatus for detecting the presence of a gob of molten glass as it enters a glassware forming machine. The heated gob radiates heat visible into the infrared spectrum, which is sensed by a phototransistor. The phototransistor responds by generating an electrical signal that is compared to the magnitude of the threshold voltage to generate a sense signal. This sensing signal is then independent of the actual arrival of the gob into the mold, rather than according to the formation time of the gob plus the expected transfer time to the mold, as was done in the prior art. It can be used to adjust the timing of partitioning. For molds containing two or more cavities, the sense signals from separate detectors for each cavity are NANDed to indicate when the final gob has arrived. .

It is an object of this invention to improve the efficiency of glassware forming machines by timing the glassware forming cycle from the actual arrival of gobs of molten glass into the mold.

Timing the glassware forming cycle from sensing the final gob of molten glass entering a multi-chamber mold improves the efficiency of a glassware forming machine and is the subject of a separate application from this application. be.

Another object of this invention is to improve the efficiency of individual section glassware forming machines by adjusting the phase difference between the timing cycles to the section for the actual arrival of the gob of molten glass to the mold. It's about doing.

FIG. 1 shows a block diagram of a two section glassware forming machine including a gob detector according to the present invention. The first individual section 11 and the second individual section 12 are each adapted to receive gobs of molten glass from a gob distributor 13 which in turn receives gobs from a gob feeder (not shown). There is. The gob distributor 13 is mechanically driven by a drive motor 14 coupled to a variable frequency power supply generated by an inverter 15. The gob feeder is driven in a similar manner. The driving frequency of the inverter is the individual category 1.
1 and 12 to determine the ratio in which the gobs are formed and distributed.

The individual sections 11 and 12 are associated with separate valve blocks 16 and 17, respectively. Each valve block is provided with a valve coupled to move a plurality of glass article forming means in the associated individual section. The valves in the valve block are energized by solenoids controlled by a machine control circuit 18 which times step formation according to a predetermined sequence of steps. The control circuit 18
is the control switch or computer
It accepts information about the sequence of steps and the time between steps from a source (not shown) such as a program. A position transducer 19 is mechanically coupled to the drive motor 14 and generates a signal representative of the relative position of the gob distributor 13.
A similar position transducer (not shown) is also provided for the gob feeder. Forming the gob is related to the rotational position of the drive motor of the gob feeder;
Furthermore, since the distribution of any gob is related to the rotational position of the gob distributor, each position transducer determines when a certain gob is formed and in which section it is distributed. generate a signal indicating the

The machine control circuit also includes a source 2 that provides signals that provide a reference for the timing of machine cycles and step sequences.
1, the clock signal is accepted.
Typically, machine timing is expressed in degrees, with one machine cycle being 360 degrees. Although the cycle for each segment is also 360°, the cycle for that segment is offset by a different angle from the start of the machine cycle to compensate for the difference in gob feed times for each segment. It is set. As of February 8, 1977, the glass product forming apparatus shown in FIG.
U.S. Patent No. issued to ATBublity et al.
Details are given in issue 4007028.

FIG. 1 also shows a gob sensor 22 and associated gob sensor 22 according to the present invention. A detector circuit 23 is shown. The gob sensor 22 is positioned adjacent the path between the gob distributor 13 and the first individual section and near the opening of the mold (not shown). When a gob reaches the mold, the sensor 22 generates a sensor signal to the gob detector circuit 23 in response to the presence of the gob. The detector circuit compares the magnitude of the sensor signal to the magnitude of a threshold signal and generates a detection signal to machine control circuit 18 when a gob is sensed. The control circuit 18 can then adjust the start of the first discrete section glassware forming cycle in relation to the machine cycle in which the gob reaches the mold. gob sensor 24
and gob detector circuit 25 is provided for the second individual section and is adapted to adjust the starting point of the glassware forming cycle for that section in a similar manner.

FIG. 2 shows a plan view of the gob sensor 22 of FIG. 1 with a portion cut away to reveal the phototransistor. The gob sensor 2
2 includes a housing 31 having a first longitudinal opening 32 and adapted to connect one end of the housing therein with a central cavity 33. A phototransistor 34 is mounted in the cavity 33 adjacent to the inner end of the opening 32 . A second longitudinal opening 35 is formed within the housing 31 and couples the cavity 33 to the other end of the housing 31. A standard female BNC connector 36 is attached to housing 31 at the outer end of opening 35 and has a central pin 37 extending into the opening. The phototransistor 34 has a pair of leads, a collector lead and an emitter lead.
These are coupled to a BNC connector 36, the collector lead to pin 37 and the emitter lead to shell 38. The opening 35
is larger in diameter than either the opening 32 or the cavity 33 in order to facilitate the assembly of leads into the BNC connector 36 before the connector is attached to the housing 31.

Typically, housing 31 is formed from a non-conductive material such as a phenolic material. The photosensitive base of phototransistor 34 is positioned facing along the longitudinal axis of aperture 32 such that the aperture directs the heated gob of molten glass passing therethrough. It is designed to form a ``window'' through which you can ``see''. Typically, the opening 32 has a diameter of
3.175mm (1/8 inch), length 12.7mm (1/2 inch)
This narrows the field of view, making the phototransistor more sensitive, allowing the tip of the gob to be more sensitively detected, and protecting it from airborne contaminants produced by the glass forming process. ing. However, since a pressurized air source is used to operate the machine's aerodynamic motor,
This source can be utilized to create an air flow for cleaning the opening 32.

FIG. 3 shows the gob sensor 22 in FIG.
and a schematic diagram of the gob detector circuit 23. The collector of the phototransistor 34 is
Coupled to pin 37 of the BNC connector, this
Then, the comparator 4 through the capacitor 42
1 input section 41-1. The emitter of the phototransistor is coupled to shell 38, which in turn is coupled to system ground potential. A resistor 43 is coupled between a positive polarity power supply (not shown) and pin 37 to limit the current through phototransistor 34. A resistor 44 is coupled between the power supply and input 41-1. The second input section 41-2 of the comparator 41 is a current limiting resistor 4
7 to the connection of a pair of resistors 45 and 46. The resistors 45 and 46 are coupled between the power supply and ground potential. The output part 41-3 of the comparator 41 is connected to the gob detection signal output line 48, to the power supply part through a resistor 49, and to the input part 41-2 through a resistor 51.
is combined with

When no gob is present, phototransistor 34 is turned off and both sides of capacitor 42 are equal to the voltage of the power supply, which is also applied to input 41-1. Resistors 45 and 46 act as a voltage divider and generate a threshold voltage at input 41-2. Input section 41
-1 is an inverting input section and input section 41-2 is a non-inverting input section, the magnitude of the power supply section voltage at input section 41-1 is greater than the magnitude of the threshold voltage at input section 41-2. is also large, so the comparator 41 is at the system ground potential. or generate a similar signal. When a gob is detected, phototransistor 34 is turned on and its collector is brought close to system ground potential. Since the voltage across the capacitor cannot change instantaneously, input 41-1 is also brought close to system ground potential. Thus, comparator 41 changes its output signal to the power supply voltage and resistor 49
will create a current path to the drive circuitry that is coupled to the output line 48 at the power supply voltage.

While the gob passes the sensor 22, the capacitor 42 is charged to the power supply voltage through the resistor 44 and the comparator is switched back to a signal at or near system ground potential. However, the time the gob passes through the detector is typically less than the charging time constant for the capacitor. Therefore, phototransistor 34 is turned off at the back end of the gob and the magnitude of the signal at input 41-1 again exceeds the magnitude of the threshold signal, switching the output of the comparator. Thus, line 4
The gob sense signal generated on 8 is of magnitude at or near the power supply voltage;
It is in the form of a square wave pulse with a duration determined by the time it takes for the gob to pass through the "window" of the sensor. Resistors 47 and 51 are connected to input section 41
-2, creating a dead band between the voltage levels at which comparator 41 switches output states. This dead band, or hysteresis, prevents any oscillations that may occur during output state transients.

In the circuit of Fig. 3, phototransistor 3
As comparator 41, Texas Instruments' TI-L66 can be used, and as comparator 41,
National Semiconductor's LM399 can be used. Typical values for the circuit components are 120kΩ for resistor 43 and 120kΩ for resistors 44 and 47.
220kΩ, 3.3MΩ for resistors 45 and 49,
13kΩ for resistor 46, and 13kΩ for resistor 51.
3.3 MΩ and 5 μF for capacitor 42. The positive polarity power supply is typically 15V.

For reference, FIG. 4 shows a schematic diagram of a multi-lumen gob detector circuit. Detector A61
represents a gob sensor and gob detector circuit as shown in FIG. The gob-sensing square wave pulses generated by the detector A are the input to a monostable multivibrator 62. The multivibrator 62 generates a square wave pulse of a predetermined duration to the input 63-1 of the OR gate 63, thereby detecting the gob detection pulse obtained by the passage of the gob through the detector A. It responds to a transient signal from "1" to "0" such as at the edge. The OR gate 63 generates "0" at the output section 63-3 when both of the pair of inputs 63-1 and 63-2 are "0",
When one or both of the inputs is "1", "1" is generated at the output section 63-3. The input section 6
3-2 is coupled to the selection line 64, and the output 63-3 is connected to the input 65- of the NAND gate 65.
1. The NAND gate 65 generates a ``0'' when all of its inputs are ``1'', and generates a ``1'' for all other combinations of inputs. Output 65-4 is coupled to the input of a monostable multivibrator 66 which has an output coupled to a final gob sense signal output line 67.

Detector B68, which is similar to detector A, has an OR
An output is provided which is coupled to an input of a monostable multivibrator 69, which has an output coupled to an input 71-1 of gate 71. The OR gate 71 has an input 71-2 coupled to a selection line 72 and an input 6 of a NAND gate 65.
An output section 71-3 coupled to 5-2 is provided. This is also a detector C similar to detector A.
73 includes an input section 65-3 of the NAND gate 65.
There is an output coupled to the input of a monostable multivibrator 74 having an output coupled to.

The circuit of FIG. 4 is suitable for use with one, two or three cavity molds. It is recognized that this circuit can be expanded when the mold has more than three cavities. When the mold has three cavities, a "0" selection signal is applied to each of selection lines 64 and 72;
OR gates 63 and 71 are enabled respectively.

The "0" selection signal may be generated by any suitable means, such as a switch or a computer coupled to ground potential of the system. When no gob is detected, all of the detector outputs will be "0" and the output of the associated monostable multivibrator will also be "0", resulting in a "0" at the input of the NAND gate 65.
The NAND gate is thus in the "1" state and the monostable multivibrator 66 produces a "0" on the output line 67. “0” indicates that the gob does not exist, and “1” indicates that the gob exists.

As each gob enters the mold cavity, an associated detector generates a square wave sensing signal. The associated monostable multivibrator is triggered on the back edge of the gob, and the duration of the multivibrator's pulses varies between sensing the trailing edge of the first gob entering the mold and detecting the trailing edge of the last gob entering the mold. )
When the time between
All inputs to the output section 6 become "1" and the output section 6 becomes "1".
The signal at 5-4 is changed from "1" to "0". When the multivibrator associated with the first gob to be sensed times out, the associated one of the inputs to NAND gate 65 returns to "0" and output 65-
4 returns to "1" and forms a "0" square wave pulse. The multivibrator 66 generates a “1” signal in response to the leading edge of the “0” pulse.
This indicates that the back end of the last gob to enter the mold has been detected and that all gobs are in the mold.

When one of the mold cavities is inactive, or when the mold has only two cavities, the associated selection line activates the NAND gate 65 for the detection of gobs entering two cavities. To enable this, a "1" signal applied thereto is maintained so as to generate a "1" at the associated input to the NAND gate 65.
When two of the cavities of the mold are inactive, or when the mold has only one cavity, both selection lines 64 and 72 are NAND gated to detect gobs entering a given cavity. 6
5 is added to it to enable it. A “1” signal may be held. The "1" selection signal may be generated by any suitable means, such as a switch coupled to a positive polarity power supply or a computer.

FIG. 5 shows a block diagram of an alternative version of a two section IS machine containing a gob detector according to the present invention. Elements labeled with like reference numerals as used in FIG. 1 are similar to corresponding elements in FIG. However, the position transducer 19 in FIG. 1 has been removed and the clock section 21 has been replaced by a timing circuit 81. The timing circuit 81 is responsive to the frequency of the inverter where the power is generated and generates a timing signal for the machine control circuit 18 to operate the IS machine along with the gob distributor 13.
synchronize with the cycle. As an example of a two-segment machine, the segment cycle could be set to a 180° phase difference in a 360° machine cycle;
The starting point of each parting cycle is adjusted to the actual arrival of the gob in the mold.

In summary, the present invention relates to a gob sensing means for generating a sensing signal in response to the presence of a gob of molten glass in the forming means of a glassware forming machine. The machine includes means for dispensing gobs of molten glass in a predetermined ratio from a source of gobs, and forming a glass article from gobs received from the distributing means in a predetermined sequence of timed steps. and control means responsive to the rate of gob dispensing for periodically controlling the excitation of the forming means with cycles of a predetermined sequence of steps spaced apart. . The control means is responsive to a sensing signal for activating a subsequent cycle of steps in a timed predetermined sequence. The advantage of this invention is that a reliable system that indicates the exact moment when a gob actually arrives in the mold and a signal output at that moment provides an electronic machine timing system with the ability to track its forming cycle. It gives a positive signal to start, which increases the efficiency of the machine.
Where the forming means includes a multi-chamber mold, a gob detection means is associated with each cavity, and the means responsive to the simultaneous occurrence of all sensing signals is coupled to the control means. A final gob sense signal is generated to initiate the next cycle.

In accordance with the provisions of patent law, the principles and modes of operation of this invention have been explained based on its preferred embodiments. However, this invention
It is to be understood that the invention may be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a two section IS machine including a gob detector according to the present invention. FIG. 2 is a top view of one of the gob sensors in FIG. 1. Figure 3 shows the gob according to this invention.
FIG. 2 is a schematic diagram of a detector. FIG. 4 is a schematic diagram of a multi-lumen gob detector. and FIG. 5 is a block diagram of a variant of a two section IS machine including a gob detector according to the present invention. 13... Gob distributor, 18... Machine control circuit, 23, 25... Gob detector circuit, 22, 24... Gob sensor, 34... Phototransistor, 41... Comparator, 11,
12... First (2) individual division, 31... Housing,
32...Opening, 33...Central cavity, 63, 71...
OR gate, 65...NAND gate, 67...Final gob detection signal output line.

[Claims]

1. A method for forming a glass sheet heated to a temperature high enough to allow deformation, the method comprising: heating a horizontally oriented heated glass sheet downwardly in a first position within a heating chamber. releasing from the facing surface onto the first curved mold and first forming the glass sheet under its own weight on the first curved mold; the first curved mold together with the glass sheet above it to a second position in the heating chamber; forming a heated glass sheet, comprising: moving the first formed glass sheet horizontally; engaging a second curved mold from above at a second position within the heating chamber to further form the glass sheet; Method. 2. A method for forming a glass sheet heated to a temperature high enough to allow deformation, the method comprising: a heated glass sheet in a horizontally extending orientation being lowered in a first position within a heating chamber; release from the facing surface onto the first curved mold and first form the glass sheet under its own weight on the first curved mold; move to a second position in the heating chamber below a second curved shape having a different curvature;

Claims (1)

A housing is provided having a phototransistor for generating the sensor signal in response to incident light, a central cavity formed therein, and an aperture formed therein, the aperture being connected to the central cavity. A cavity is connected to the exterior of the housing, and the phototransistor is mounted in the central cavity so that the opening forms a window to provide a field of view so that the tip of the gob can be sensitively detected. 2. A device according to claim 1, characterized in that the device is limited to: 4 The opening has an approximate diameter of 3.175 mm (1/8
4. The apparatus of claim 3, wherein the device has a length of 12.7 mm (1/2 inch).