JPH0251431A - Detector of gob for glass product forming machine - Google Patents

Abstract

PURPOSE: To improve the efficiency of a glassware forming machine by combining a first and a second gob detectors and a device for generating signals in response with the detection signals thereof in such a manner that these devices act specifically.

CONSTITUTION: When the gob is detected, a phototransistor 34 is turned on and its collector is brought to a potential approximate to the grounding potential of the system. Since the voltage passing a capacitor cannot be instantaneously changed, the potential of an input section 41-1 is made approximate to the grounding potential of the system as well. A comparator 41 changes the output signal thereof to a power supply voltage and a resistor 49 eventually forms the current path to a driving circuit coupled to an output line 48 by the power supply voltage. The capacitor 42 is charged up to the power supply voltage through a resistor 44 while the gob passes a sensor 22. The power supply voltage is turned back to the grounding potential of the system or the signal approximate thereto at this potential with the comparator 41.

COPYRIGHT: (C)1990,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to the detection of gobs of molten glass entering a mold in a glassware forming machine.

In glassware forming machines, known as Is or individual section machines, each individual section includes a plurality of means for performing a predetermined sequence of steps in a certain temporal relationship to form a glassware. The forming means were - for boat fishing, 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 to individual sections by a gob distributor. Each section of the machine produces glassware from gobs, which are extruded onto a flight conveyor.
placed on a plate.

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. While one of the divisions is receiving gobs from the gob distributor, one of the divisions is feeding the finished glassware onto the conveyor, and another division is performing various forming steps. There will be. Furthermore, each section can be provided with two molds, whereby the gob can be blank or parison.
A first mold, called a mold, is received for the initial process of forming the parison, which is subsequently transferred to a second mold, called a blow mold, for the final blowing of the product. Since each mold has more than one cavity, each section of the machine can be operated on multiple gobs simultaneously to form a glass product.

Timing drums or electronic control systems are used to define the timing of the sections; the prior art synchronized the timing of the sections to the timing of the gob feeder and gob distributor. . 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. There wasn't. The sections are typically arranged in a line along the cone, so that even though there are only two sections, the distances from the gob feeder are equal.

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 a threshold voltage to generate a sense signal. This sensing signal then follows 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. In the present invention, the mold includes two or more cavities, and the sensed signals from separate detectors for each cavity are NANDed to indicate when the final gob has arrived.

The invention of the original application relates to improving the efficiency of glassware forming machines by timing the glassware forming cycle from the actual arrival of gobs of molten glass into the mold.

It is an object of the present invention to improve the efficiency of glassware forming machines by timing the glassware forming cycle from sensing the final gob of molten glass entering a multi-chamber mold.

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

For reference, FIG. 1 shows a block diagram of a two-section glass product forming machine including a gob detector. 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). 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 similarly birch driven. The drive frequency of the inverter is controlled to determine the ratio at which the gobs are formed and distributed to the individual sections 11 and 12.

The individual sections 11 and 12 are separated by separate valves.
associated with blocks 16 and 17, respectively. Each valve block is provided with a valve coupled to move a plurality of glass article forming means in associated discrete sections. The valves in the valve block are energized by solenoids controlled by a machine control circuit 18 that times the step formation according to a predetermined sequence of steps. The control circuit 18 accepts information about the sequence of steps and times between steps from a source (not shown) such as a control switch or a computer program. The position transducer 19 is connected to the drive motor 1
4 for generating a signal indicative 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 involves the drive of the gob feeder.
Because the rotational position of the motor is related to the rotational position of the motor, and the distribution of any gob is related to the rotational position of the gob distributor, each position transducer can determine when a particular gob is formed and in which section. Generates a signal indicating whether the distribution is distributed.

The machine control circuit is also adapted to receive a clock signal from a source 21 which provides a reference signal for the timing of machine cycles and step sequences. Typically, machine timing is expressed in degrees, with one machine cycle being 360e. Although the cycle for each segment is also 360°, the cycle for that segment is offset from the start of the machine cycle by a different angle to compensate for the difference in gob feed times for each segment. It is set. The glass product forming apparatus as shown in FIG.
No. 4,007,028 issued to Ty et al.

Also shown in FIG. 1 is a gob sensor 22 and associated gob detector circuit 23. The gob
The 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 knack 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. A gob sensor 24 and gob detector circuit 25 are provided for the second individual section and are adapted to adjust the start 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 22 includes a housing 31 having a first longitudinal opening 32 adapted to couple one end of the housing with a central cavity 33 therein. The phototransistor 34 is connected to the opening 3
It is mounted within the cavity 33 adjacent the inner end of 2. 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.
The 128 N C connectors 36 are coupled to the collector lead to pin 37 and the emitter lead to shell 38. The diameter of the opening 35 is larger than either the opening 32 or the cavity 33, which facilitates the assembly of the leads into the BNC connector 36 before the connector is attached to the housing 31. It's for a reason.

Typically, housing 31 is formed from a non-conductive material such as a phenolic material. Phototransistor 3
The phototransistor bases of 4 are positioned facing each other along the longitudinal axis of the aperture 32 such that the 8 phototransistors direct the heated gob of molten glass passing therethrough. It is designed to form a ``window'' through which you can ``see.'' Typically, the opening 32 is 1/88-f. in diameter and 1/2 in length.
inch (12,7 mm), which improves the sensitivity of the phototransistor and allows the tip of the gob to be sensitively detected, protecting it from airborne foreign objects generated by the glass forming process. is being done. However, since a pressurized air source is used to operate the machine's aerodynamic motor, this source
It can be used to create an air flow for cleaning the opening 32.

FIG. 3 shows a schematic diagram of gob sensor 22 and gob detector circuit 23 in FIG. The collector of the phototransistor 34 is pin 3 of the BNC connector.
7, which in turn is coupled through capacitor 42 to input 41-1 of comparator 41. 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. A second input 41-2 of comparator 41 is coupled through a current limiting resistor 47 to the junction of a pair of resistors 45 and 46. The resistors 45 and 46 are coupled between the power supply and ground potential.

Output 41-3 of comparator 41 is coupled to gob sense signal output line 48, to a power supply through resistor 49, and to input 41-2 through resistor 51.

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 supplied to input 41-1. Resistors 45 and 46 act as voltage dividers;
A threshold voltage is generated at the input section 41-2. When the input section 411 is an inverting input section and the input section 41-2 is a non-inverting input section, the magnitude of the power supply voltage at the input section 41-1 is equal to the magnitude of the threshold voltage at the input section 41-2. Comparator 41 generates a signal at or near system ground potential. 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 creates a current path to the drive circuit coupled to 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 resistor 44,
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 shorter 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, the gob detection signal generated on line 48 is a square wave of magnitude at or near the power supply voltage and with a duration determined by the time it takes for the gob to pass through the sensor's "window." It is in the form of a pulse.Resistor 47
and 51 form a positive feedback path to the input section 41-2, creating a dead hand between the voltage levels at which the comparator 41 switches its output state. This dead hand, or hysteresis, prevents any oscillations that may occur during output state transients.

In the circuit of FIG. 3, the phototransistor 34 is a TI-L6 manufactured by Texas Instruments.
6 can be used, and as the comparator 41, Na
tional Semlconductor's LM
399 can be used. Typical values for circuit components are:
120 Ω for resistor 43, 220 Ω for resistors 44 and 47, 3 Ω for resistors 45 and 49
．． 34 Ω, 13 Ω for resistor 46, 3.3 MΩ for resistor 51, and 5 for capacitor 42.
μF. Positive polarity power supply is typically 15V
It is.

FIG. 4 shows a schematic diagram of a multi-lumen gob detector circuit according to the present invention. Detector 8 61 represents a gob sensor and gob detector circuit as shown in FIG. The gob sensing square wave pulse generated by the detector A is a monostable multi-high break 62.
It becomes human power for The multi-high break 62 is O
By generating a square wave pulse of a predetermined time width to the input section 63-1 of the R gate 63, the trailing edge of the gob detection pulse obtained when the gob passes through the detector A is set to 0. ”. The OR gate 63 has a pair of inputs 63-1 and 63
-2 is "0°°," the output section 63-3 generates "0", and one or both of the human power outputs "1 ++
When , "'1" is generated at the output section G3-3. The input 63-2 is coupled to the select line 64, and the output 63-3 is coupled to the input 651 of the NAND gate 65.
is combined with The NAND gate 65 generates “0” when all of its inputs are “1”, and generates “B” for all other combinations of inputs. Output section 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 86B similar to detector A includes OR game) 7
A monostable multivibrator 699 having an output coupled to one input 71-1 is provided with an output coupled to the input. The OR gate 71 has a selection line 7
2 and the NAND gate 6
An output section 71-3 coupled to the input section 65-2 of No. 5 is provided. This is also a detector C similar to detector 8.
73 is provided with an output coupled to an input of a monostable multivibrator 74, which has an output coupled to input 65-3 of NAND gate 65.

The circuit of FIG. 4 is suitable for use with one, two or three cavity molds. It is observed that when the mold has more than three cavities, this circuit becomes enlarged. When the mold has three cavities,
A "0" selection signal is applied to each of select lines 64 and 72 to enable OR gates 63 and 71, 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 detector outputs are “0”
In addition, the output of the related monostable multivibrator becomes 0, and the input of the NAND gate 65 becomes 0.
will occur. Thus, the NAND gate is “′1
``state,'' and monostable multivibrator 66 produces a ``0'' on output line 67. ``0'' indicates no gob is present, and ``1'' indicates gob is present.

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. ), all human input to NAND gate 65 goes "lo" and changes the signal at output 65-4 from "°1" to "0". When the multivibrator associated with the first gob times out, N
One of the relevant inputs to the AND gate 65 is “
The output 654 returns to "0'" and the output 654 returns to "1".
0"' square wave pulse. Multivibrator 66 generates a "°1" signal in response to the tip of the "0°° pulse, which occurs after the last gob to enter the mold. This indicates that the edge 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 is the NA for detection of gobs entering two cavities.
To enable the ND gate 65, the NAND gate 65
A ``1'' signal is maintained at the associated input to generate a ``1'' signal thereto. When two of the cavities of the mold are inactive, or when the mold has only one cavity, both select lines 64 and 72 are NAND gated to detect gobs entering a given cavity. A ``1'' signal may be maintained applied thereto to enable 65. The ``1'' selection signal may be applied to any suitable device, such as a switch coupled to a positive power supply, or a computer. It can also be generated by means.

FIG. 5 shows a block diagram of an alternative version of a two-section IS machine that includes a gob detector. 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. Accordingly, the timing circuit 81 is responsive to the frequency of the powered inverter and generates a timing signal for the machine control circuit 18 to synchronize the Is machine cycle with the gob distributor 13. As an example of a two section machine, the section cycles could be set to a 180" phase difference in 360 DEG machine cycles, with the origin of each section cycle adjusted relative 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 for forming a glass article from gobs received from the dispensing 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. In the present invention, where the forming means includes a multi-limbed mold, a gob sensing means is associated with each cavity, and the means responsive to the simultaneous occurrence of all sensing signals is a final control means. A gob detection 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 embodiment. However, it must 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 the drawing]

FIG. 1 is a block diagram of a two section IS machine including a gob detector. FIG. 2 is a top view of one of the gob sensors in FIG. 1. FIG. 3 is a schematic diagram of a gob detector. FIG. 4 is a schematic diagram of a multi-limb gob detector according to the present invention. and FIG. 5 is a block diagram of an alternative version of a two-section Is machine that includes a gob detector. 13... Gob distributor, 18... Machine control circuit, 23.25... Gob detector circuit, 22.24... Gob sensor, 34... Phototransistor, 41... Comparator , 11°1
2... First (2) individual section, 31... Housing, 32... Opening, 33... Central cavity, 63.71
...OR gate, 65...NAND gate, 67.
...Final gob detection signal output line. 1 layer 6.1 F■6.4 "■6.5

Claims (4)

[Claims] (1) A device for detecting the presence of a gob within a cavity of a multi-chamber mold in a glassware forming machine, the device being positioned adjacent to a first cavity of the mold;
a first gob detection device for generating a first detection signal in response to the presence of a gob in a cavity of the mold; a second gob generating a second detection signal in response to the presence of the second gob;
a detection device; and a device for generating a signal indicative of the presence of both the gob in the first and second cavities in response to generation of the first and second detection signals. A device for the detection of the presence of said final gob. (2) the final gob detection signal generating device includes a device for generating a selection signal when the second cavity is not in use, and the signal generating device for indicating presence includes a device for generating the selection signal and 2. The apparatus of claim 1, wherein the apparatus generates the presence indicating signal in response to the first detection signal. (3) the final gob detection signal generator includes a first monostable multivibrator that generates a first square wave pulse of a predetermined period in response to the delayed end of the first detection signal;
a second monostable multivibrator that generates a second square wave pulse of a predetermined period in response to a lagging edge of the second detection signal; and at least one of each of the first and second square wave pulses. 2. The apparatus of claim 1, further comprising means for generating said presence indicating signal in response to a match of said portions. (4) The signal generation device indicating the presence includes a first monostable multivibrator that generates a first square wave pulse of a predetermined period in response to the lagging edge of the first detection signal; a second monostable multivibrator that generates a second square wave pulse of a predetermined period in response to the lagging edge of the detection signal;
an OR gate having one input connected to receive said second square wave pulse and another input connected to a source of a selection signal, said selection signal being connected to said second cavity; generated as “0” when the second cavity is active and “0” when the second cavity is inactive.
and the OR gate generates the second square wave pulse as an output signal in response to the simultaneous occurrence of the second square wave pulse and the “0” selection signal; Also, in response to the “1” selection signal, “1” is selected.
the OR gate generating an output signal; and the first
NAND generating the signal indicating the presence in response to the simultaneous occurrence of the first square wave pulse by the monostable multivibrator and the second square wave pulse or the "1" output signal by the OR gate; An apparatus according to claim 1, comprising a device.