GB2272215A - Safety device - Google Patents

Abstract

A safety device for a section of an I.S. machine comprises a motion sensor having a directional radiation pattern which is sensitive to movement in the pattern. The pattern is directed across a blank end of the section and is connected into the control system of the machine in such a manner that on an operator moving a limb into the radiation pattern, if such movement takes place at a dangerous time, an alarm signal is activated. <IMAGE>

Description

Safety Device This invention is concerned with safety devices for use with I.S. machines for the manufacture of glass ware.

An I.S. machine comprises a number of identical sections arranged alongside each other each of which is arranged to receive gobs of molten glass, to form the gob into a parison in a blank mould, to transfer the parison to a blow mould, to blow the parison into an article of glass ware and to remove the blown article from the blow mould and transfer it to a conveyor. A machine may comprise from 6 to 12 sections which operate out of phase with each other so that a continuous sequence of articles of glass ware is produced.

It is the nature of an I.S. machine that the stoppage of the operation of a section is to be avoided, and consequently an operator will from time to time attempt to make adjustments or corrections to the component parts of a section while the section is operating. Because of the presence of molten glass and because of the continual movement of the parts of a section, such attempts by the operator run a considerable risk of accident to the operator.

It is one of the objects of the present invention to provide an improved safety device for use with a section of an I.S. machine.

The present invention provides a safety device for a section of an I.S. machine having an electronic control system for controlling the operation of the section, the section comprising a blank mould a funnel for directing a gob into the blank mould and movable between an operative and a remote position a blow mould an invert/revert mechanism for transferring a glass parison from the blank mould to the blow mould, a baffle movable between an operative position over the blank mould and an inoperative position remote from the blank mould the safety device comprising a motion sensor having a directional radiation pattern which is sensitive to movement in the pattern, the pattern being directed across the blank end of a section and terminating just above the level of the section the sensor being connected into the control system in such a manner that on an operator moving a limb into the radiation pattern, if such movement takes place at a dangerous time,an alarm signal is activated.

There now follows a- description, to be read with reference to the'accompanying drawings, of a section of an I.S. machine embodying the present invention.

In the accompanying drawings Figure 1 shows, schematically, a side view of a section of an I.S. machine; Figure 2 shows, schematically, a plan view of a section of an I.S. machine; Figure 3 shows schematically a radiation pattern of a radar motion sensor.

Figure 4 shows a block diagram of certain circuitry.

Figure 5 shows, diagrammatically the operation of various mechanisms of a section of an I.S. machine throughout one cycle.

An I.S. machine comprises a series of sections, mounted side by side, which are controlled in operation by an electronic control system. Each section comprises a blank mould 2, a funnel 4 for directing a gob into the blank mould and a baffle 5 for closing the blank mould, both movable between operative positions over the blank mould and out of the way remote positions, a blow mould 6 and an invert/revert mechanism 8. In the operation of the section a glass gob, provided from a feeder (not shown) via a gob distributor gob guide and a deflector (not shown), is dropped through the funnel 4, which is in its operative position, into the closed blank mould 2. The funnel 4 is then removed to its out of the way position and replaced by the baffle 5 which closes the blank mould 4.The gob of glass is then formed into a parison on either by blowing or pressing with a plunger, the baffle 5 moves out of the way, the blank mould 4 opens and the formed parison, held by its neck portion in a neck ring mechanism of the invert/revert mechanism 8 is translated and inverted through about 1800 into the blow mould 6, which then closes. The invert/revert mechanism 8 then returns the neck ring mechanism to its position under the blank mould 2 while the parison is blown in the blow mould 6 into the desired shape. The blow mould then opens and the formed glass article is removed by a take out mechanism 10 and placed upon a dead plate 12 from which it is pushed out on to a conveyor and removed from the machine.

In the interest of speed of operation, each section is arranged to operate so that before a formed glass article is removed from the blow mould, a further gob, for the formation of the next succeeding article, is delivered to the blank mould.

The section alongside each other operate at the same speed but out of phase with each other so that the machine continuously provides formed glass articles to the conveyor.

Because of the presence of the conveyor, and the hot formed containers on the conveyor, no operator will attempt to gain access to the moving parts of the section from the blow mould end. The side by side location of the sections prevents access to a section from the side, and therefore an operator will only attempt to gain access to a section from the blank mould end of the section.

A radiation sensor 14 is mounted on the machine frame over the blank mould end of the section pointing downwardly.

This sensor 14 is a radar motion sensor SMX-1 obtainable from Siemens A.G., and produces a directional radiation pattern which is sensitive to movement in the pattern and which can be collimated by a generally triangular wave guide 20 to produce a pattern which is generally rectangular in cross section. By adjustment of the input to the sensor 14 the effective downward length of this pattern can be adjusted, and it is so arranged that the pattern stops just short of the upper surface of the blank end of the section, with no moving parts of the section entering the pattern as shown in Figure 3.

The sensor 14 is connected into the electronic control system of the machine, and consequently, when an operators limb is moved towards the section through the radiation pattern of the sensor 14, a signal is passed to the electronic control system. The electronic control system comprises a section control 16 for each section which passes signals to a valve block 18 of the section to cause the valve block to operate to cause operation of the various mechanism of the section.

The signal from the section controller 16 is also passed to NAND gate 22: any warning signal from the radar sensor 14 is also passed to the NAND gate 22, so that if both signals are present warning signal is passed to an emergency control 24, which is arranged to cause an appropriate alarm signal to be operated whenever the operator will be in danger of his limbs is within the radiation pattern. It will be seen that no emergency action is taken unless both an appropriate signal from the section controller 16 and an emergency signal from the sensor 14 occur at the same time.

The alarm signal conveniently comprises both a high pitched audible signal (loud enough to be heard over the prevailing noise of the machine in operation) and a flashing light signal which supplements the audible signal. If desired, the warning signal may be used to operate a switch to shut the whole machine down, though in general such a shut down is to be avoided.

While it would theoretically be possible for an operator to put his hands through the radiation pattern at a time which is not dangerous and still have them there when it becomes dangerous, as the sensor 14 is sensitive to movement in the radiation pattern, and the operator will be attempting to perform some operation on the parts of the section, it is very improbable that movement of his limbs in the pattern during the dangerous time will not take place and an appropriate signal developed.

Figure 5 shows, diagrammatically, the operation of various mechanisms of a section of an I.S. machine throughout one cycle.

A indicates a time when the revert movement of the invert mechanism has reached a 900 position in its movement to carry the neck ring mechanism into position (at 00) over the parison mould B indicates a time when the blank mould is beginning to close and the funnel to move into its operative position, C indicates a time approximately halfway through the mould closing movement.

D indicates a time when the blank mould has completely closed, shortly before supply of a gob to the blank mould E indicates a time when the blank mould has completely opened and the invertmechanism is about to carry a formed parison away from the blank mould F indicates a time where the invert mechanism has carried the parison through approximately 90" in its invert movement.

The period of time when it is most dangerous for an operator to be approaching the mechanisms of the Section is during the latter part of the closing movement of the blank mould, that is from just before the point C, and while a gob is being supplied to the blank mould (LOAD). This period occurs just after the time when conventionally neckring swabbing would be carried out, i.e. when the neckring is open and part way through its revert movement.

A time when an operator may need to exercise considerable care, which time overlaps with the period in which blank swabbing is conventionally carried out, is when the invert revert mechanism is performing its invert motion.

Figure 5 shows, diagrammatically, the period of danger and of care.

Consequently, it is convenient to arrange that if an operator puts a limb into the radiation pattern during one of the periods of danger a powerful alarm signal is activated - for example a recurrent high pitched intermittent audible signal, accompanied by a flashing light, and that if an operator puts a limb into the radiation pattern during the period of care, a less powerful warning signal, differentiated from the alarm signal but sufficient to alert the operator, is activated, for example a lower pitched intermittent audible signal.

If desired, the machine can also be provided with a switch which, if the powerful alarm signal is activated, also causes the section to cease operating according to a conventional shut down sequence.

Claims (2)

1. A safety device for a section of an I.S. machine having an electronic control system for controlling the operation of the section, the section comprising a blank mould a funnel for directing a gob into the blank mould and movable between an operative and a remote position a blow mould an invert/revert mechanism for transferring a glass parison from the blank mould to the blow mould, a baffle movable between an operative position over the blank mould and an inoperative position remote from the blank mould the safety device comprising a motion sensor having a directional radiation pattern which is sensitive to movement in the pattern, the pattern being directed across the blank end of a section and terminating just above the level of the section the sensor being connected into the control system in such a manner that on an operator moving a limb into the radiation pattern, if such movement takes place at a dangerous time, an alarm signal is activated.

2. A safety device according to claim 1 wherein the sensor is connected into the control system in such a manner that, on an operator moving a limb into the radiation pattern, if such movement takes place when the operator should exercise particular care, a warning signal, differentiated from the alarm signal, is activated.