Title: Electrically actuated blow-moulding machine
Abstract: Machine for moulding containers (
Patent Number: 6,884,059 Issued on 04/26/2005 to Giacobbe
| Inventors:
|
Giacobbe; Ferruccio (Monza, IT)
|
| Assignee:
|
Magic MP S.p.A. (Seregno, IT)
|
| Appl. No.:
|
262917 |
| Filed:
|
October 2, 2002 |
Foreign Application Priority Data
| Oct 24, 2001[IT] | MI2001A2230 |
| Current U.S. Class: |
425/192R; 425/182; 425/451.9; 425/541 |
| Intern'l Class: |
B29C 049//56 |
| Field of Search: |
425/541,451.9,182,192. R,195
|
References Cited [Referenced By]
U.S. Patent Documents
| 3749541 | Jul., 1973 | Mehnert.
| |
| 3883286 | May., 1975 | Kinslow et al.
| |
| 4421472 | Dec., 1983 | Martin, Jr.
| |
| 5368462 | Nov., 1994 | Kiefer et al.
| |
| 5478229 | Dec., 1995 | Kato et al.
| |
| 6102685 | Aug., 2000 | Miura et al.
| |
| Foreign Patent Documents |
| 4223314 | Jan., 1994 | DE.
| |
| 0913244 | May., 1999 | EP.
| |
| 1060865 | Dec., 2000 | EP.
| |
| 06000869 | Jan., 1994 | JP.
| |
| 07032366 | Feb., 1995 | JP.
| |
| 11286043 | Oct., 1999 | JP.
| |
| 11286043 | Oct., 1999 | JP.
| |
Other References
Partial English machine translation of JP 11-286043A obtained from the JPO website,
no date.
|
Primary Examiner: Davis; Robert B.
Attorney, Agent or Firm: Keefer; Timothy J, Seyfarth Shaw LLP
Claims
1. A machine for moulding containers (
3a) made of plastic material,
comprising an assembly (
2) for extruding tubes (
3) of plastic material,
a blowing assembly (
5), a mould for containing containers (
3a)
formed by two half-moulds (
4a, 4b) movable upon actuation
of associated first means (
100), in a longitudinal direction (X—X)
and symmetrically with respect to a fixed axis (Z—Z) perpendicular to said
longitudinal direction, the assembly formed by the mould (
4) and the associated
first actuated means (
100) being movable, upon actuation of second actuating
means (
200), in a transverse direction (Y—Y) from a position corresponding
to the extrusion assembly to a position corresponding to the blowing assembly and
vice versa, said first means for actuation of the half-moulds (
4a, 4b)
in the longitudinal direction are of the electric type, and means (
110)
for symmetrically adjusting the distance of the two half-moulds (
4a,
4b) from said fixed axis (Z—Z), wherein said means (
110)
for adjusting the relative distance of the two half-moulds (
4a,
4b)
comprise a sleeve (
112) which is parallel to the longitudinal direction
(X—X) and a first end of which is joined to the rod (
105b)
actuating the front carriage (
106b) and the other end of which is
constrained to the base of the said carriage (
106b) by means of a
screw/internal thread coupling (
112a).
2. The machine of claim 1, wherein said first means (
100) for moving the
two half-moulds comprises an electric motor (
101a), and a shaft coupled
to the motor (
101a) and joined to a transmission assembly connected
to associated carriages (
6a,
6b) carrying the two half-moulds.
3. The machine of claim 2, wherein said transmission assembly comprises at least
two rods (
105a, 105b) connected respectively to the
said carriages (
106a, 106b) and to respective connecting
rods (
104a, 104b;
1104a, 1104b).
4. The machine of claim 3, wherein said connecting rods (
104a, 104b;
1104a, 1104b) are located opposite each other in the
longitudinal direction (X—X).
5. The machine of claim 3, wherein said connecting rods (
104a, 104b)
have an axis of rotation parallel to the axis of symmetry (Z—Z) and are
actuated by a gear (
103) on which they are pivotably mounted and which is
rotationally moved by the said drive shaft (
101a).
6. The machine of claim 3, wherein said connecting rods (
1104a, 1104b)
are actuated by a flat member (
1102a) joined to the shaft of a reducer (
1102).
7. The machine of claim 6, wherein said flat member (
1102a) rotates
about a horizontal axis.
8. The machine of claim 6, wherein said motor (
1101) actuating the reducer
(
1102) has an axis parallel to the direction (X—X) of displacement
of the two half-moulds (
4a, 4b).
9. The machine of claim 2, wherein said first actuating means (
100) are
mounted on a slide (
120) movable in the longitudinal direction on associated
fixed rails (
121).
10. The machine of claim 9, wherein said means (
110) for adjusting the
relative distance of the two half-moulds (
4a,
4b) are
arranged in between said slide (
120) and the front carriage (
106b).
11. The machine of claim 1, wherein said sleeve (
112) has, passing through
it, a splined shaft (
113) extending parallel to the longitudinal axis of
the machine.
12. The machine of claim 11, wherein a screw/internal thread coupling (
122a)
is provided at the rear end of the splined shaft (
112), between the said
splined shaft and a support (
122) in turn joined to said slide.
13. The machine of claim 3, wherein the pitch of the front screw/internal thread
coupling (
122a) is double the pitch of the rear screw/internal thread
coupling (
122a) and the two couplings operate in the opposite sense
to each other.
14. The machine of claim 11, wherein the front end of the splined shaft (
113)
is provided with a hexagonal member (
113a) for actuation of the said shaft.
15. The machine of claim 1, wherein said second means (
200) for actuating
the moulding assembly (
4) in the transverse direction are of the electric type.
16. The machine of claim 15, wherein said second means (
200) for actuating
the mould (
4) in the transverse direction consist of a motor reducer unit
(
210,
210a) connected to a movement transmission assembly.
17. The machine of claim 16, wherein said transmission assembly comprises a connecting
rod (
211), the small end of which is pivotably mounted on the shaft (
210a)
of the reducer and the big end of which is pivotably mounted on the first end of
a rod (
212), the other end of which is pivotably mounted on the mould-support assembly.
18. The machine of claim 17, wherein the rod (
212) is interrupted and
its continuity is restored by means of a sleeved joint (
213), the ends of
which are coupled to the respective rod portions (
212) by means of a screw/internal
thread coupling operating in the opposite sense.
Description
FIELD OF THE INVENTION
The present invention relates to a machine for blowing plastic containers, with
electric means for moving the mould.
DESCRIPTION OF RELATED ART
It is known in the technical sector relating to the packaging of liquid products
and the like that there exists the need to manufacture containers made of plastic
material suitable for this purpose.
It is also known that said containers are formed in suitable blow-moulding machines
provided with associated moulds (formed by two movable half-moulds) into which
a tube of plastic material extruded upstream is introduced.
These machines envisage the use of oil-hydraulic members for movement of the
various movable parts and, although they perform their intended function, they
have certain drawbacks essentially arising from the contamination which the pressurised
oil inevitably causes in the surrounding environment and on the various parts of
the machine, thereby making the latter unsuitable for use in the pharmaceutical
and/or food industry.
The technical problem which is posed, therefore, is that of providing a machine
for blowing plastic containers which does not cause contamination of the various
parts of the machine and the surrounding environment.
Within the scope of this problem a further requirement is that the machine
should ensure the possibility of adjusting in a precise and simple manner the distance
of the two half-moulds with respect to a reference axis of symmetry, in order to
ensure precision in closing of the mould and a constant closing force thereof,
also upon variation in the thickness of the two half-moulds in relation to the
container models to be blown.
SUMMARY OF THE INVENTION
These technical problems are solved according to the present invention by a
machine for moulding containers made of plastic material, comprising an assembly
for extruding tubes of plastic material, a blowing assembly, a mould for containing
containers, formed by two half-moulds movable, upon actuation of associated first
means, in a longitudinal direction and symmetrically with respect to a fixed axis
perpendicular to said longitudinal direction, the assembly formed by the mould
and the associated first actuating means being movable, upon actuation of second
actuating means, in a transverse direction from a position corresponding to the
extrusion assembly to a position corresponding to the blowing assembly and vice
versa, wherein said first means for actuation in the longitudinal direction are
of the electric type and means for symmetrically adjusting the distance of the
two half-moulds from said fixed axis are provided.
BRIEF DESCRIPTION OF THE DRAWINGS
Further details may be obtained from the following description of a non-limiting
example of embodiment of the invention, provided with reference to the accompanying
plates of drawings in which:
FIG. 1 shows a schematic front view of the machine according to the invention
during pick-up of the extruded tubes;
FIG. 2 shows a partially sectioned side view of the machine according to FIG. 1;
FIG. 3 shows a schematic front view of the machine according to the invention
during moulding;
FIG. 4 shows a partially sectioned side view of the machine according to FIG. 3;
FIG. 5 shows a partially sectioned side view of a further embodiment of the
machine according to the invention in the condition with the mould open; and
FIG. 6 shows a view similar to that of FIG. 5 with the mould closed.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the machine according to the invention comprises a
support frame
1 which has, constrained thereto, the means
2 for extrusion
of the tube
3 of plastic material, the means
100 for moving the mould
4 in the longitudinal direction X—X, the means
200 for moving
the mould
4 in the transverse direction Y—Y, the blowing nozzles
5 and the means
6 for removal of the moulded containers
3a.
Said mould
4 is formed by two half-moulds
4a,
4b
symmetrically arranged with respect to a fixed reference axis of symmetry Z—Z.
Referring to FIG. 2, in greater detail, said means
100 for performing
movement in the longitudinal direction comprise an electric motor
101 which
is arranged parallel to the axis Z—Z and the shaft
101a of
which carries a gear
101b suitable for engagement with a corresponding
toothed wheel
102b mounted on a shaped sleeve
102 in turn
arranged parallel to the axis Z—Z.
The sleeve
102 has suitable opposite and externally open seats
102a
which receive internally respective spindles
103 having, mounted at
their free end, the small end of a respective connecting rod
104a, 104b,
the big end of which is pivotably mounted on one end of a respective rod
105a,
105b.
Whereas the upper rod
105a is directly constrained to the carriage
106a supporting the half-mould
4a and sliding on a
rail
107, the lower rod
105b is connected to the carriage
106b supporting the half-mould
4b and sliding on the
said rail
107 by means of the arrangement, in between, of a device
110
for adjusting the distance of the two half-moulds with respect to the fixed axis
of symmetry Z—Z.
Said adjustment device
110 comprises a bracket
111 to which the
other free end of the rod
105b is fastened; the bracket
111
is in turn connected to one end of a sleeve
112, the other end of which
is constrained to the base of the carriage
106b of the half-mould
4b by means of a screw/internal thread coupling
112a.
The sleeve
112 has passing through it a splined shaft
113 extending
parallel to the longitudinal axis of the machine.
The rear end of the splined shaft
113 is provided with a screw/internal
thread coupling
122a connecting the splined shaft itself and a support
122 in turn joined to a slide
120 movable on longitudinal rails
121,
which slide carries all of the part of the actuating assembly
100 formed
by the kinematic chain comprising motor
101 and rods
105a, 105b.
The pitch of the front screw/internal thread coupling
112a is double
the pitch of the rear screw/internal thread coupling
112a and the
two couplings operate in the opposite sense to each other so as to ensure the correct
relative displacement of the two carriages
106a,
106b,
as will appear more clearly below.
At the front end of the splined shaft
113a hexagonal member
113a
is provided for actuation of the said shaft by suitable means (not shown).
Referring to FIGS. 2 and 4, the movement, in a longitudinal direction,
of the mould occurs as follows:
- with the machine stopped and depending on the thickness of the mould
4 in the longitudinal direction, the front hexagonal member 113a
is operated, rotating it in either direction in order to determine:
- both rotation of the front coupling 112a in one direction
or the other with consequent displacement of the carriage 106b away
from/towards the axis Z—Z;
- and rotation, in the opposite direction and with a halved pitch, of
the rear coupling 122a so as to cause displacement of the slide 120
and therefore the carriage 106a by an identical amount towards/away
from said axis Z—Z;
thus providing the correct relative position of the two half-moulds 4a,
4b for a perfect closing action following actuation by the motor 101.
Actuation by motor
101 to close the mould is performed as follows:
- Referring to FIGS. 1, 2 and 4, in a co-ordinated and controlled
sequence by suitable programming and control means 1000;
- the motor 101 is actuated (FIGS. 1, 2) so as to cause
a rotation of the upper connecting rod 104a and the lower connecting
rod 104b, such that the carriage 106a and the carriage
106b are respectively pushed and pulled away symmetrically from the
axis Z—Z so as to cause opening of the two half-moulds 4a,
4b.
- the entire mould-carrying assembly 4 is positioned underneath
the extruded tubes 3 of plastic material by means of the actuating means 200;
- the motor 101 is operated in the opposite direction to the previous
direction so as to cause counter-rotation of the two connecting rods 104a,
104b so that the carriage 106a and the carriage 106b
are respectively pushed and pulled towards the axis of symmetry Z—Z
in order to cause closing of the two half-moulds 4a, 4b
around the tubes 3;
- the devices 200 for performing displacement in the transverse
direction Y—Y are actuated so as to cause displacement of the said assembly
underneath the blowing station 5 where moulding of the containers is performed;
- the actuating assembly 100 is actuated again in the longitudinal
direction so as to cause opening of the two half-moulds 4a, 4b
and allow discharging of the moulded containers 3a by associated
evacuation means 6 and resumption of the cycle described above.
Referring to FIGS. 1 and 3, the devices
200 for displacement of
the moulding assembly in the transverse direction Y—Y consist of a motor-reducer
unit
210, the shaft
210a of which supports the small end of
a connecting rod
211, the big end of which is pivotably mounted on the first
end of a rod
212, the other end of which is pivotably mounted on the mould-support assembly.
In a preferred embodiment the rod
212 is interrupted and its continuity
is ensured by a sleeved joint
213, the ends of which are coupled to the
respective rod portions
212 by means of a screw/internal thread coupling
operating in the opposite sense.
In this way, rotating said sleeved joint
213 produces a precise adjustment
in the length of the rod
212 which ensures correct operation thereof depending
on the dimensions envisaged.
Although the description has been provided in relation to single elements
visible in the figures, it is envisaged in a preferred embodiment that the connecting
rods, the rods, the splined shafts and the associated accessories may be duplicated
so as to ensure an improved alignment and supporting and actuating capacity using
elements which, although greater in number, may nevertheless be made with smaller
dimensions which comply with normal production standards.
It is therefore obvious how, with the machine according to the invention, it
is
possible to perform opening/closing of the half-moulds with a constant force and
independently of the thickness, in the longitudinal direction, of the said half-moulds,
ensuring at the same time hygienic conditions of the machine and the surrounding environment.
FIGS. 5 and 6 show a second embodiment of the machine according to the invention,
in which the actuating motor
1101 is arranged with its axis horizontal and
operates a reducer
1102, the horizontal shaft of which supports a flat member
1102a to which two pins
1102b arranged at 180°
with respect to each other are constrained.
One end of a connecting rod
1104a,
1104b is pivotably
mounted on each pin
1102b, the other end thereof being respectively
joined to:
- the rod 105a connected to one 4a of the
two half-moulds 4a, 4b of the mould 4;
- a column 1100 for transmission to a rod 105b connected
to the other 4b of the two half-moulds 4a, 4b.
It can be seen how this second configuration allows basically the actuating devices
of the two half-moulds to be simplified, while the means for adjusting the distance
of the two half-moulds from the fixed axis of symmetry remain unchanged.
It should be understood that the preceding is merely a detailed description of
one embodiment of this invention and that numerous changes to the disclosed embodiment
can be made in accordance with the disclosure herein without departing from the
spirit or scope of the invention. The preceding description, therefore, is not
meant to limit the scope of the invention. Rather, the scope of the invention is
to be determined only by the appended claims and their equivalents.
*
