GB2357726A

GB2357726A - Arrangement for removing the trimming portions of a plastics blow-moulded bottle

Info

Publication number: GB2357726A
Application number: GB0029908A
Authority: GB
Inventors: Lizarralde Beitialarrangoitia
Original assignee: UROLA S COOP
Current assignee: UROLA S COOP
Priority date: 1999-12-10
Filing date: 2000-12-07
Publication date: 2001-07-04
Also published as: ES2169639A1; ES2169639B1; ZA200007263B; GB0029908D0; IE20000982A1

Abstract

The neck trimmer 1 removes the surplus blow-dome 2b from the neck 2a of a plastic bottle 2 by means of a plain vertical rotary blade 10, leaving a concentric radial inner edge 2c of precise diameter in a radial neck flange, and comprises a gripping mechanism 4 for securing and aligning the neck 2a during trimming, a rotary axially sliding cutting device 5, provided with said blade 10 attached to a central body 5a at an exact radial distance, a blow-dome removal device 8 coupled to the cutting device 5, and means 11,12,13 for ejecting the trimmed blow-dome 2b downwards onto a collection system 9. The body 5a is coaxially linked to an upwardly/downwardly axially movable rotary drive spindle 6. The action of the cutting device 5 is synchronised with that of the jaws 4a of mechanism 4. Device 8 includes means (8a,16) (figures 3,4 - not shown) for retaining trimmed blow-dome 2b for its detachment from neck 2a.

Description

2357726 Trimmer for removing a blow-dome from the neck of a plastic

blow-moulded bottle The present invention relates to the severing of a plastics bottle shaped by the blow-moulding of a parison and, in particular, to the ancillary outof-the-mould operations for the removal of the surplus material from the neck portion.

US-5749275-A discloses a machine for trimming the mouth of a plastic bottle neck, which leaves an inner edge at the circular cut mouth flange concentric with the centreline of the neck. This trimmed edge has to have a precise diameter too because it contributes towards the tight seal of the bottle with the threaded cap, which has an annular inner wall that is in contact with this trimmed edge and seals the mouth of the bottle on the inside. The cutting of the flange is done by a punching action once the blow-domes remaining in the neck have been removed after the bottle moulding operation.

US-5787772-A describes a method for trimming off the surplus material on the neck of a vertical ly-positioned plastic blow-moulded bottle, where a rotary cutting head moves vertically over a slide covering the blow-dome of the bottle, while it has a horizontal inner blade that is in contact with the neck of the trimmed bottle and removes the blow-dome from the neck, withdrawing it afterwards by means of a vacuum system inside the cutting head. Here the cutting surface is horizontal and does not have to comply with any concentricity requirement, as the actual neck is cut horizontally, nor with the prerequisite of an even cut surface of precise inside diameter.

2 It is an object of the present invention to provide an improved system for trimming the neck of a plastics bottle blow-moulded from a parison.

The present invention provides a trimmer for removi r 9 a surplus blow-dome from the neck of a plastics blowmoulde d bottle comprising:

means for positioning and keeping the bottle with its neck in the required position during the trimming operation; a cutting device provided with a cutting blade adapted to penetrate an inwardly extending radial neck flange of the bottle neck and perform a circular cut in a rotary manner around the flange to sever the blow-dome and leave an inwardly facing edge in the flange; and, a removal device for removing the trimmed blow-dome.

The radial neck flange will usually extend inwardly in C direction substantially perpendicular to the axis of the bottle.

The trimming operation is preferably conducted with the bottle in a substantially vertical position. Ideally, the bottleneck is uppermost and disposed beneath the trimmer.

The positioning means may hold the bottle or similar container stationary while the cutting blade performs a circular cut in a rotary manner by moving in a circumferential direction around the neck of the bottle. rhe rotary blade may be arranged to slide axially towards and away from the stationary bottleneck, before and after the trimming operation, along the axis of rotation of the blade.

The cutting device may have its action synchronised with the positioning means. It may be driven by a vertically sliding upright rotary drive spindle. The cutting device may comprise a rotary cutting blade supported by a cylindrica central body coupled axially to the drive spindle. The cutting blade may have a cutting edge that performs a circular cut at a radial distance relative to the centreline 3 of the cylindrical body. Preferably, the cutting device comprises a single blade that passes 3600 around the flange to completely sever the blow-dome.

The removal device may be coupled to the cutting device and may be arranged to slide vertically with the cutting device; usually, the action of the removal device will be synchronised with that of the cutting device. The removal device may include an ejection device also coupled to the cutting device.

The removal device may retain the blow-dome until the bottle is removed and will preferably transfer the blow-dome to a collection system. If the bottleneck is severed by a trimmer disposed above it, the collection system may be located beneath the bottle and the removal means may comprise ejection means which eject the blow-dome downwardly into the collection system. - In a preferred arrangement, the neck trimmer removes a surplus blow-dome from the neck of a plastic bottle by means of a plain vertical rotary blade, leaving a concentric radial inner edge of precise diameter, and comprises a gripping mechanism for securing and aligning the neck, a rotary axially sliding cutting device, provided with said blade attached to a central body at an exact radial distance, a blow-dome removal device coupled to the cutting device, and means for ejecting the trimmed blow-dome downwards onto a collection system.

In an especially preferred apparatus according to the present invention, a plastics bottle whose neck is to be severed by the trimmer leaves the mould with a surplus bottle neck blow-dome, made up of two parts, the outer one being removed ahead of the trimming system. The part of the dome to be trimmed for the severing of the mouth of the bottle neck is an axial salient or projection of the bottle neck and has to be cut off and removed from the trimmer, while the 4 severing operation is completed at the same time. The trimmed bottle is intended for holding such food products as water or milk. It is an essential requirement that, after the trimming of the neck, no wastepiece or scrap of plastic should drop into the bottle. To achieve this, the preferred, trimmer comprises a device for removing the trimmed blow- ome that is coupled to the cutting device and works in 1 synchronisation with a system for collecting the successive trimmed domes. The trimmed bottle neck will be closed with a threaded cap and the mouth plugged internally by means of a, vertical inner ring in the cap with a tight seal. The trinmer therefore makes a vertical cut in an inner surface in the radial neck flange, which is perfectly circular and concentric with the neck, in synchronisation with a neck gripping and aligning mechanism, and every one of the cutting operations has to be -absolutely faultless.

The trimmer cutting device comprises a rotary vertical plain blade, which is axially sliding, and a removal device that ejects the trimmed dome downwards, when the severed bottle has been moved on and before the next one is set in place.

A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG.1 is a sectional view of a bottle neck trimmer according,l to the invention; FIG.2 is a sectional view of the cutting device comprised in the trimmer of figure 1. FIG.3 is a sectional view of the cutting device of figure 2, according to line III-III. FIG. 4 is a view of the device of figure 3, with the neck dome severed; and, FIG.5 shows a partial section of the neck of a bottle tri ed with the trimmer of f igure 1.

With reference to figures 1-3, the trimmer 1 for trimming the neck of a blow-moulded bottle or container 2 represented in figure 5, comprises a bottle feeder (not represented in the drawings) that moves the bottles horizontally by means of a rotary feed screw in their vertical position with the neck to be trimmed upwards, a gripping mechanism 4 for securing and aligning the neck driven by a cam shaft 3, a rotary cutting device coupled coaxially to a vertical drive spindle 6 with an axis of rotation E, both supported on a horizontal fixed table 7 and an ejection device 8 coupled to the cutting device, which works together with a system 9 for collecting the successive severed blow-domes.

After the moulding process, on the bottle 2 (fig. 1 and 5) there remains a coaxial dome 2b linked to the neck by a horizontal radial flange, sealing the mouth of the neck 2a. The dome 2b is trimmed by making a circular cutting line 17, which leaves a perfectly round, precise diameter inner surface 2c on the mouth flange concentric with the neck. The severed dome 2b is then removed from the cutting device 5 and ejected from the cutting area towards the collection system 9. Every bottle 2 to be trimmed is set in place in the cutting area under the cutting device 5, and the gripping mechanism 4 secures the neck 2a and aligns it in respect of the axis of rotation E by means of a pair of jaws, which have a shape moulded to the outline of the neck 2a. Both the horizontal closing movement of the jaws 4a against the neck 2a and their opening movement are synchronised with the cam shaft 3 and with the action of the cutting device 5.

The rotary drive spindle 6 is located above the table and moves axially up and down by way of a hollow bushing 11 that traverses the table 7. The cutting device 5 is situated under the table and has a cylindrical central body 5a, linked to the drive spindle 6 and coaxial with it, and a vertical 6 plain cutting blade 10 attached to the outside edge of the central body Sa (fig. 3). The radial distance llrll of the cutting edge 10a to the axis of rotation E is equal to tl e radius of the severed inner edge 2c. The blade has the cutting edge 10a protruding below the central body 5a, arranged with an edge profile facing the inner edge 2c of the mouth, so that the inner cutting edge 2c will be smooth and even. For the trimming of the bottle neck the drive spindle descends and the edge loa of the blade is inserted into the radial flange of the neck 2a down to a depth exceeding b'Y, for instance, 0.5 mm the flange thickness, which is between 0.3 and 1 mm, turning at the same time at high speed whil e the bottle remains stationary.

The blade 10 is supported (figure 3) by the central body 5a and is integral with it. A lateral flat or flange 14 on the side diametrically opposed to that of the blade 10 has a, salient or protrusion 14a, the end of which lies above the edge loa of the blade and prevents the dome 2b getting out of alignment when the blade is inserted for cutting.

With reference to figures 3 and 4, ejection device 8 fo removing the dome 2b trimmed from the neck comprises a done retaining member 8a, a support disc 12 concentric with the central body Sa and coupled to a bearing 20, which comes ip against the table bushing 11 in its upward movement, and an ejection plate 13, which comes up against the dome 2b in its downward movement prior to cutting and then ejects the severed dome retained by the member 8a in an ascending movement.

The retaining member 8a is spindle-shaped and is par:ly housed in the lower end of the central body 5a of the cut--ind device. It protrudes from under the ejection plate 13 and has a built-in retaining yoke 16 both to receive the trimmed lome 2b when the cutting device 5 rises and to detach it from:he neck 2a. The retaining yoke is composed for instance of al 7 spring wire, which is secured by passing through the retaining member 8, and it has two converging tips facing downwards that are inserted through the mouth of the dome 2b and two counterposed arched portions, which are compressed on entering the dome and which, on being expanded afterwards when it has been severed, holding it against the ejection plate 13 and raise it when the central body Sa starts its upward travel.

The retaining member 8a is coupled to the central body Sa by means of a pair of bearings 22 (fig. 2), which prevent the rotational traction of the dome 2b during cutting, and the dome 2b is kept stationary with the retaining yoke 16 already inserted. The bearings permit the rotation of the member 8a accompanied by the dome 2b after trimming. The support disc 12 and the ejection plate 13 are joined together for simultaneous movement by means of two ejection plate guide pins 18, which cross the central body 5 parallel to the axis of rotation E and are fixed to a support bush 21, which is in turn sliding on the central body Sa.

When the cutting device Sa performs its upward movement to sever or trim the dome 2b, the ejection plate 13 comes up against the dome 2b and the removal device is retained while the cutting device continues descending. When the support disc 12 comes up against the bush 11 in its upward travel, the cutting disc 5 continues its upward movement and the retaining member 8a discharges the dome, ejecting it to the collection system.

8

Claims

Claims

1 Trimmer for removing a surplus blow-dome from the ne k of a plastics blow-moulded bottle comprising:

means for positioning and keeping the bottle with its neck in the required position during the trimming operation; a cutting device provided with a cutting blade adaptId to penetrate an inwardly extending radial neck flange of he bottle neck and perform a circular cut in a rotary manner around the flange to sever the blow-dome and leave an inwardly facing edge in the flange; and, a removal device for removing the trimmed blow-dome.

2. Trimmer for the neck of a plastic bottle blow-moulde from a parison, which removes a surplus blowdome from th bottle neck, comprising:

a vertically sliding upright rotary drive spindle; means for positioning the bottles with the neck upwai and aligning in respect of the sliding vertical drive spir and holding it there stationary; a cutting device with its action synchronised with t positioning and alignment means, provided with a cylindri central body coupled coaxially to the vertical drive spin and with a rotary cutting blade supported by said cylindr central body, the cutting edge of which penetrates in a radial neck flange extended inwards, and performs a circu cut at a radial distance relative to the centreline of sa cylindrical body; a vertically sliding removal device coupled to the cutting device, for removing the trimmed neck dome from t cutting device; wherein the trimmer leaves an inner edge concentric the neck radial flange for the tight seal of the bottle means of a threaded cap.

9 3. The trimmer of claim 2, wherein the trimmed dome removal device comprises trimmed dome retaining means, coupled coaxially in a nonrotary way with said central body of the cutting device, for detachment of dome from the bottle neck.

4. The trimmer of claim 2 or claim 3, wherein the vertically sliding rotary drive spindle is located above a fixed horizontal table belonging to the trimmer, being traversed in the vertical movement, and the cutting device is situated below the fixed horizontal table, and said removal means comprise means for ejecting the trimmed blow-dome that slide relatively to the cutting device until coming up against a stop on the f ixed table. 5. The trimmer of any one of claims 2 to 4, wherein the blade supported by the central body of the cutting device, has a cutting edge for penetration into the neck mouth on the cutting line and pointing in the direction of said radial bottle sealing surface so as to leave a smooth even surface. 6. Trimmer for the neck of a plastic bottle blow-moulded from a parison which removes a surplus blow- dome from the bottle neck, comprising:

a vertically sliding upright rotary drive spindle; means for positioning the bottles with the neck upwards and aligned in respect of the vertically sliding drive spindle and for keeping it stationary; a cutting device provided with a cylindrical central body coupled coaxially to the vertical drive spindle, and a rotary cutting blade supported by said cylindrical central body, which performs a circular cut in a radial neck flange, extended inwards; a vertically sliding removal device coupled to the cutting device, for removing the trimmed neck dome from the cutting device, comprising means for detaching the trimmed neck dome from the bottle neck, and means for ejecting the detached dome in cooperation with said vertically sliding spindle and with the central body of the cutting device; wherein the trimmer system leaves an inner edge concentric to the radial neck flange for the tight seal of 5 the bottle by means of a threaded cap. 7. Trimmer for the neck of a plastic bottle blow-mouldel from a parison which removes a surplus blow-dome from the bottle neck, comprising: a vertically sliding upright rotary drive spindle; means for positioning the bottles with the neck upwa-ds:

and aligned in respect of the vertically sliding drive spindle and for keeping it stationary; a device provided with a cylindrical central body coupled coaxially to the vertical drive spindle, and a rozary cutting blade supported by said cylindrical central body, which performs a circular cut in a radial neck flange, 1 extended inwards; a trimmed dome removal device coupled to the cutting device and axially sliding with it, provided with means oE retaining the trimmed blow-dome for its detachment from tie bottle neck and with ejection means sliding relatively to the cutting device for withdrawing the trimmed blow-dome towacds a collection system situated under the cutting device, wherein the trimmer system leaves an inner edge concentric to the radial neck flange for the tight seal of the bottle by means of a threaded cap. 8. The trimmer of claim 7, wherein said trimmed blow-do'ne retaining means comprise a retaining member coupled in a ion: rotary manner coaxially with said cutting device central body, which is inserted inside the blow-dome before the cutting operation. 9. The trimmer of claim 7 or 8, wherein the vertical sliding rotary drive spindle is located above a fixed horizontal table belonging to the trimmer, being traversed it the vertical movement, and the cutting device is located below the fixed horizontal table, and said trimmed blow-dome ejecting means comprise a support disc and an ejector plate surrounding the cutting device and linked by vertical guides, which carry out an ascending movement after the cutting operation together with the cutting device, raising the trimmed blow-dome, so that the support disc comes up against a stop bushing in the fixed table, thus actuating the trimmed blow-dome ejector plate.

10. Trimming apparatus substantially as hereinbefore described with reference to the accompanying drawings. 11. A method of removing a surplus blow-dome from the neck of a plastics blow-moulded bottle, which method involves the use of a trimmer as claimed in any one of claims 1 to 10.

12. A bottle whenever produced by the method as claimed in claim 11. 13. A method of operating trimming apparatus substantially as hereinbefore described with reference to the accompanying drawings.

14. Any novel feature or novel combination of features hereinbefore described.