Parison screening in a glassware forming machine

A glassware forming machine having a blank station (A) at which a parison is formed, an intermediate station (B) at which the parison is allowed to reheat, and a blow station (C) at which the parison is formed into an article of glassware as a patter plate (12) at the intermediate station (B). The patter plate (12) is movable between an operative position in which it screens the underside of the parison from updraughts of air and an inoperative position in which the patter plate (12) is not beneath the parison. The machine also comprises moving means (17) operable to move the patter plate (12) between its operative and inoperative position at appropriate times in the cycle of operation of the machine.

TECHNICAL FIELD 
This invention is concerned with a glassware forming machine having three 
stations, namely a blank station at which a parison is formed from a gob 
of molten glass, an intermediate station at which the parison is allowed 
to reheat, and a blow station at which the parison is formed into an 
article of glassware. 
BACKGROUND ART 
A glassware forming machine of the so-called "Individual Section" type 
normally has a blank station at which a parison is formed from a gob of 
molten glass and a blow station at which the parison is formed into an 
article of glassware. The parison formed at the blank station is 
transferred to the blow station to be blown. It has long been recognised 
that it is desirable to allow the parison to reheat before being moulded 
at the blow station. This reheating serves to allow portions of the 
parison which where in contact with a mould at the blank station and have 
therefore become chilled to be reheated by other parts of the parison 
transferring heat thereto. In a more recently proposed type of individual 
section machine, see U.K. Patent Specification No. 1599801, a reheating 
intermediate station is provided between the blank station and the blow 
station so that parisons can be allowed to reheat at the intermediate 
station without causing delay in the operation of the blow station. 
However, it has been found that parisons at the intermediate station are 
subject to being chilled by up drafts of cold air created by the cold air 
displacing air heated by the parison. The provision of a fixed screen 
beneath the parison to prevent such up drafts is not practical because of 
the possibility that the parisons may need to be dropped from the 
intermediate station in the event of a malfunction of the machine. 
DISCLOSURE OF INVENTION 
According to the invention the glassware forming machine comprises a patter 
plate movable between an operative position in which it screens the 
underside of the parison from upraughts and an inoperative position in 
which the patter plate is not beneath the parison, and moving means 
operable to move the patter plate between its operative and inoperative 
positions at appropriate times in the cycle of operation of the machine. 
For convenience, the patter plate is pivotally movable between its 
operative and inoperative positions and is moved to its operative position 
by the action of a pneumatic piston and cylinder device and is moved to 
its inoperative position by the action of a spring. 
Where the machine is operative to form more than one article of glassware 
at a time, in order to prevent adjacent parisons at the intermediate 
station from heating one another, the machine also comprises a shroud 
assembly at the intermediate station, the shroud assembly being movable 
between an open position and a closed position in which the shroud 
assembly co-operates with stationary structure of the machine to 
substantially surround a parison at the intermediate station. 
In order to prevent the shroud assembly from becoming overheated and itself 
heating the parisons, the shroud assembly is provided with internal 
passages through which cooling water is passed. 
In order to allow for parisons of different lengths, the operative position 
of the patter plate is vertically adjustable.

BEST MODE OF CARRYING OUT THE INVENTION 
The glassware forming machine shown in FIG. 1 is a triple gob three station 
machine of the individual section type. Gobs of molten glass are fed to 
three blank moulds at a blank station A where the gobs are formed into 
parisons. The parisons are formed in an inverted position by pressing or 
blowing in a conventional manner. A transfer and invert mechanism 1 moves 
the three parisons formed at the blank station A to an intermediate 
reheating station B. The mechanism 1 is rotatable about a transverse 
horizontal axis 2, with a neck ring arm 3 of the mechanism swinging 
through 180.degree. to transfer the parisons from the blank station A to 
the intermediate station B. At the intermediate station B, the parisons 
are received in an upright position by support jaws of a transfer carriage 
4. The transfer carriage 4 is horizontally movable along spaced guide 
rails (one of which is shown at 5 in FIG. 1) between the intermediate 
station B and a blow station C of the machine. After the support jaws have 
released the parisons at the blow station C, the parisons are formed into 
articles of glassware in three blow moulds at the blow station C, the 
glassware articles being removed from the blow station C and transferred 
to a dead plate 6 by take-out means 7. FIG. 1 also shows superstructure 8 
which applies air to the blow moulds at the blow station C to form the 
reheating parisons into articles of glassware. 
At the intermediate station B, a sub-assembly frame 9 is bolted to the main 
frame of the machine. As shown in FIG. 2, the sub-assembly frame 9 
comprises four spaced lugs 10 projecting towards the central longitudinal 
axis X--X of the machine. The sub-assembly frame 9 supports three patter 
plates 12 each of which comprises a substantially rectangular plate of 
cast iron the shape of which is shown in plan view in FIG. 2. The three 
patter plates 12 are pivotly mounted about a horizontal axis Z--Z and are 
capable of pivoting between the raised, operative, position shown in FIG. 
2 (and in full line in FIG. 3) and the lowered, inoperative, position 
shown in broken lines in FIG. 3. 
Referring to FIGS. 3 and 4, the sub-assembly frame 9 supports a vertically 
adjustable assembly 13 on which the three patter plates 12 are pivotally 
mounted about the axis Z--Z. The vertically adjustable assembly 13 
comprises a plate 14 guided for vertical movement with respect to the 
frame 9, and a block 15 to which is pivotally attached the cylinder of a 
pneumatic piston and cylinder device 17. The piston rod 18 of the device 
17 carries a cap 19 movable within a shroud 20 forming part of the 
assembly 13. One end of a swing arm 22 is pivotally attached to the cap 
19, the other end of the swing arm 22 being attached to a shaft 23 which 
defines the axis Z--Z and on to which are clamped three support stems 24 
of the respective patter plates 12. Air under pressure supplied to the 
piston and cylinder device 17 causes the three patter plates to be moved 
to their raised, operative, positions shown in full line in FIG. 3, the 
patter plates 12 pivoting to their lowered, inoperative, positions shown 
in broken line in FIG. 3 under the action of a return spring when the air 
under pressure is disconnected from the piston and cylinder device 17. In 
modifications of the glassware forming machine shown in the drawings, the 
device 17 is double acting (dispensing with the return spring). The whole 
of the assembly 13 is capable of being adjusted in a vertical direction by 
means of a further pneumatic and piston cylinder device 25 the piston rod 
26 of which is attached to the vertically adjustable assembly 13 at 27. 
FIG. 3 shows the vertically adjustable assembly 13 and the patter plates 
12 carried thereby in its uppermost position, and FIG. 4 shows the 
vertically adjustable assembly 13 and the patter plates 12 in their 
lowermost position. In FIG. 4 the patter plates are shown in their 
lowered, inoperative, positions in full line and in their raised, 
operative, positions in broken line. 
Referring to FIG. 2, a shroud (or shield) assembly 28 is also provided at 
the intermediate station B. The shroud assembly 28 comprises a back plate 
29 which carries a finned shroud 30 and which at one end is extended to 
constitute a movable cylinder 32 of a pneumatic piston and cylinder device 
33 arranged laterally across the machine. As can be seen from FIG. 2, the 
piston and cylinder device 33 has a stationary piston rod 34 to which is 
attached a block 35 formed with ports 36, 37 which cooperate with 
respective bores 38, 39 in the piston rod 34 so as to direct air to one 
side of the block 35 or to the other side thereof. FIG. 2 shows the shroud 
assembly in its closed position in which the extreme end of the fins 
oppose, with a small clearance, the respective lugs 10 on the sub-assembly 
frame 9. The open position of the shroud assembly 28 is shown in broken 
line in FIG. 2. Additional guidance for the transverse movement of the 
shroud 70, 28 is provided by a guide rod which extends across the machine 
frame above the piston rod 34 and one end of which is shown at 40 in FIG. 
1. The shroud assembly 28 is thus movable between an open position and a 
closed position in which the shroud assembly cooperates with stationary 
structure of the machine to substantially surround a parison at the 
intermediate station B. 
The shroud assembly 28 is provided with internal passages which extend into 
the fins, as indicated at 42, and in the operation of the machine water is 
circulated through these passages to cool the shroud assembly 28. 
The raising and lowering movement of the patter plates 12, and the opening 
and closing movement of the shroud assembly 28, are performed in timed 
relationship with other events of the machine. As soon as the three 
parisons are delivered to the intermediate station B and are received by 
the support jaws of the transfer carriage 4, air under pressure is 
supplied to the pneumatic cylinder 16 to raise the patter plates 12 from 
their lowered, inoperative, positions to their raised, operative, 
positions. At the same time, air under pressure is supplied to the lower 
side of the block 35 (as viewed in FIG. 2) of the piston and cylinder 
device 33 to cause the shroud assembly 28 to move to its closed position 
shown in full line in FIG. 2. As a result, the parisons supported by the 
support jaws at the intermediate station B are substantially enclosed 
around their sides and are thereby protected from heating one another and 
the undersides of the parisons are protected from updraughts. Thus, the 
exchange of heat between parisons is minimised, and the patter plates 12 
prevent any substantial updraught of air within the recesses between the 
fins of the shroud assembly 28, thereby avoiding chilling of the parisons. 
Thus, even reheating of the parisons at the intermediate station is 
promoted. Just before the transfer carriage 4 is due to move from the 
intermediate station B to the blow station C, the shroud assembly 28 is 
opened and the patter plates 12 are lowered to their inoperative position, 
allowing the parisons to move away from the station B to the station C. 
The removal of the patter plates 12 to their inoperative position allows 
the parisons to be dropped at this stage in the operation of the machine 
in the event that a malfunction of the machine has been detected. If a 
series of parisons are to be dropped as cullet at the intermediate station 
B, as a result of a prolonged machine malfunction, the patter plates 12 
are held in their inoperative position all the time, enabling the parisons 
to fall without obstruction at the station B. The opening and closing 
movement of the shroud assembly 28 is not suspended since the shroud 
assembly 28 does not obstruct the parisons as they are dropped at the 
intermediate station B. 
The main function of the patter plates 12 is to prevent an updraught of air 
from cooling the parisons. The patter plates 12 are positioned at such a 
level, by means of the piston and cylinder device 25, that the patter 
plates in their operative position are spaced just below the lowest level 
to which the parisons are expected to stretch whilst they are reheating at 
the intermediate station B. However, the patter plates 12 may assist in 
the further forming of the parisons by carrying inserts which contact the 
parisons to further form the base or bottom of each parison. Furthermore, 
the patter plates 12 may be provided with a heat resistent coating, for 
example of a polytetrafluroethylene carbon material, to protect the patter 
plates 12 and to prevent the glass of the parisons from sticking to the 
patter plates 12. This prevents defects in the parisons resulting from 
contact of the parisons with the colder cast iron of the patter plates 12.