ZA200106900B - De-skirting of bottles. - Google Patents

Description

! woounmn PCT/IB00/01770

DE-SKIRTING OF BOTTLES

This invention relates to the de-skirting of bottles. More particularly, it relates to a method of de-skirting a bottle and to apparatus for use in the method.

In bottles having tamper-evident screw-top closures, the closure has a cap or top part and a skirt which is attached to the top part along a circumferentially extending line of weakening. When the cap is unscrewed upon opening the bottle, the cap separates from the skirt along the line of weakening, and the skirt remains behind on the bottle neck. If it is desired to refill these bottles, the bottles have to be de-capped (in the event of the cap having been screwed back on by the consumer) by removing the cap, de-skirted by removing the skirt, and then washed before being returned to the bottling plant for re-filling.

De-capping and washing can readily be achieved in a mechanised manner. Mechanised de-skirting, however, is problematic, and heretofore the only effective way to de-skirt bottles has been to remove the skirts manually.

It is an object of the present invention to achieve the de-skirting of bottles in a mechanised manner, so that the entire process of de-capping, de-skirting, and washing of bottles can be automated.

Accurding to the invention there is provided a method of de-skirting a bottle having a downwardly widening neck and having the skirt of a closure in place on the neck, which comprises forcibly displacing the skirt towards the bottom of the bottle, whereby the relative displacement of the skirt with respect to the neck causes the skirt to split, and thereafter removing the skirt from the bottle.

The skirt may be displaced towards the bottom of the

CONFIRMATION COPY bottle by means of a plurality of jaws which are caused to move radially inwardly with respect to the skirt and then downwardly with respect to the bottle.

The jaws may, upon said radially inward movement, grip - the skirt between them. _ Where the skirt has a circumferentially extending tuck- - ~ under indentation, the jaws may engage the skirt in the region of the Fes : . tuck-under indentation. :

The bottle may be centred with respect to the jaws before the jaws engage with the skirt. oo

The bottle may be centred by means of a bottle top guide which has a male part that, as it moves down, enters with little clearance into the mouth of the bottle.

The skirt may, after it has been split, be removed from the bottle neck by means of a jet or jets of air. . The jet or jets of air may be directed to the split skirt from underneath, thereby to blow the skirt upwardly off the neck of the bottle. : Further according to the invention there is provided apparatus for de-skirting a bottle having a downwardly widening . neck and having the skirt of a closure in place on the neck, the apparatus comprising a de-skirting head having a plurality of circumferentially spaced jaws, and means for displacing the jaws radially inwardly with respect to the skirt and then downwardly with respect to the bottle, thereby to displace the skirt down the neck of the bottle and so cause the skirt to split.

The jaws may have a semi-circular profile in plan view, the radius of curvature of the jaws corresponding to the outer radius of the skirt.

The head may comprise a top body, a centre body underneath the top body, and one or more head pressure springs

4 WO 01/39901 PCT/IB00/01770 f -3- between the top body and the centre body, the jaws each being carried at the lower end of an arm which is mounted on the centre body so as to be pivotally displaceable with respect to the centre body about a horizontal pivot axis, the top body being axially displaceable with respect to the centre body against the pressure of the head pressure spring or springs, and the top body carrying a cam element which co-operates with the upper ends of the arms to displace the upper ends of the arms radially outwardly as the top body is displaced axially downwardly with respect to the centre body and thereby displace the lower ends of the arms and therewith the jaws carried by them radially inwardly.

Each jaw may be mounted on the corresponding arm via a push rod which is axially displaceable with respect to the arm against the pressure of a jaw return spring, the top body being provided with means which act on the upper ends of the push rods, to displace the jaws downwardly as the top body is displaced axially downwardly with respect to the centre body.

The apparatus may further comprise guide means for guiding displacement of the centre body towards and away from the top body, and a centrally arranged head pressure spring between the top body and the centre body.

The guide means may comprise a pair of concentrically arranged guide elements, one of the elements being fast with the top body and the other guide element being fast with the centre body, the cam element forming part of or being carried by the radially outer guide element, the radially outer and radially inner guide elements being hollow, and the head pressure spring being accommodated in the hollow interior of the guide elements.

The apparatus may further comprise means for removing the skirt, after it has been split, from the neck of the bottle, said means comprising one or more jet nozzles for directing a

-4- 4 jet or jets of air to the split skirt from underneath, thereby to blow the skirt upwardly off the neck of the bottle.

The invention will now be described in more detail, by way of example, with reference to the accompanying drawings.

In the drawings: i Figure 1 is a diagrammatic side. view of apparatus for.de- . : - capping and de-skirting bottles in accordance with the invention; : Figure 2 is a vertical section of a de-skirting head forming part of the apparatus of Figure 1, according to a first embodiment of the invention;

Figure 3 is a section on lll-lil in Figure 2;

Figure 4 is a section on IV-1V in Figure 2;

Figures 5 and 6 are vertical sections illustrating how the jaws of the de-skirting head operate;

Figure 7 is a side view of a de-skirting head according to a second embodiment of the invention; and

Figure 8 is a vertical section of the de-skirting head of Figure : 7.

Referring first to Figure 1, reference numeral 10 generally indicates apparatus for de-capping and de-skirting bottles B having the skirt S of a tamper-evident bottle cap still in position thereon. The apparatus comprises a de-capping station 12, a skirt splitting station 14, and a skirt removal station 16. - At the de-capping station there is a de-capping head 18 which, in operation, descends onto the bottle B and, in the event of there still being a cap on the bottle, grips the cap and, by rotating the cap in a left hand direction, unscrews the cap from the bottle.

Thereafter the de-capping head rises again. The de-capping head 18 can be of the type that is conventionally used for the de-capping of bottles. The apparatus may have a number of such de-capping heads, these being mounted on a rotating carousel.

4d WO 01/39901 PCT/IB00/01770 4 5.

From the de-capping station the bottle moves to the skirt splitting station 14.

At the skirt splitting station 14 there is a de-skirting head 20 which, in operation, descends onto the bottie B. As will be described in more detail hereinafter, with reference to Figures 2 to 6, the de-skirting head has a pair of opposed arms, each carrying a skirt gripping jaw at the lower end thereof. These jaws grip the skirt

S from opposite sides, and then push it down. Because of the widening neck of the bottle, and provided a sufficient downward force is applied, this action causes the skirt to split. There may be a number of such de-skirting heads, these being mounted on a rotating carousel.

Whilst the de-skirting head 20 is effective to split the skirt from top to bottom, the split is not wide enough for the skirt to be able to fall off the bottle neck. The split skirt is therefore still in place on the bottle neck as the bottle leaves the de-skirting station 14.

From the skirt splitting station 14 the bottle moves to the skirt removal station 16. This comprises a pair of upwardly and inwardly directed air jet nozzles 21 mounted on opposite sides of the path along which the bottles B travel, and only one of which is visible in the drawing. As the bottle passes between the two nozzles, a short pulse of air through the nozzles blows the skirt off ‘the neck of the bottle.

The de-skirting head 20 can conveniently be made by modifying a conventional bottle sealing head of the type used in a bottle capper.

A conventional sealing head comprises a top body, a centre body below the top body, and a bell guide below the centre body. The centre body carries four circumferentially spaced vertical pillars which extend upwardly from the centre body and are slidable

-6- = along guides in the top body. Each pillar carries a coil spring. These springs are referred to as the head pressure springs and serve to urge the centre body downwardly with respect to the top body. The bell guide is fixed to the centre body by means of four circumferentially spaced, vertical posts, and has a central opening ~~ therein into which the neck-of a.bottle-enters-as-the sealing-head-- descends onto the bottle during operation. The centre body carries a pair of diametrically opposed thread roller arms, each thread roller arm in turn carrying a thread roller at its lower end. The thread roller is rotatable about a vertical axis of rotation and the thread roller arm ~ is mounted on the centre body so as to be pivotal about a horizontal pivot axis.

That part of the thread roller arm which extends up from the centre body has, on the inside thereof, a cam follower arm. 15. The lower end of the cam follower arm is mounted on the thread roller arm so as to be pivotal about a horizontal pivot axis parallel to the pivot axis about which the thread roller arm can pivot with respect to the centre body. Between the upper ends of the thread roller arm and the cam follower arm there is a side pressure spring _ which urges the upper ends of the thread roller arm and the corresponding cam follower arm apart. The cam follower arm carries, at the upper end thereof, a cam follower roller which is rotatable about a horizontal axis of rotation, parallel to the pivot axis referred to earlier in this paragraph.

The upper ends of the two opposed thread roller arms are drawn towards one another by means of an arm return spring.

The centre body further carries a pair of opposed tuck- under arms. The tuck-under arms have a construction similar to the thread roller arms and are displaced through 80° with respect to the thread roller arms, about the vertical axis of the sealing head. Like the thread roller arms, each of the tuck-under arms carries a cam

4 WO 01/39901 PCT/IB00/01770 4 -7- follower arm with a cam follower roller at its upper end. Each tuck- under arm in turn carries a tuck-under roller at its lower end, the tuck-under roller being rotatable about a vertical axis of rotation.

The entire assembly of top body, centre body, bell guide, thread roller arms, and tuck-under arms is rotatable on a central spindle. The spindle has a pressure block at the lower end thereof for seating on the top of a bottle closure, and there is a thrust bearing between the spindle and the centre body. The top body is slidable up and down the spindle. Centrally ot the top body there is a downwardly extending hollow cam element. The cam element is fixed with respect to the top body, and the spindle passes axially through the hollow centre thereof. The cam element has an external cam formation thereon which co-operates with the four cam rollers referred to earlier. Thus, as the top body is displaced vertically downwardly with respect to the centre body, against the pressure of the head pressure springs, the cam formation urges the upper ends of the cam follower arms, and hence the upper ends of the thread roller arms and the tuck-under arms, radially outwardly.

As a consequence, the lower ends of these arms (with the thread rollers and tuck-under rollers respectively) are urged radially inwardly to perform their thread rolling and tucking under operations.

The following modifications are made to such a conventional sealing head to turn it into a de-skirting head in accordance with the invention,

The top body is retained but mounted so as to be fixed against rotation. The spindle and its associated bearings are removed, and the hollow cam element replaced with a solid downwardly extending cam element having a similar external cam formation thereon.

Two of the arms (either the thread rolling arms or the tuck-under arms) are removed, and the remaining two arms are

-8- 2 modified by cutting off those ends thereof which protrude down from the centre body. The bell guide and its mounting posts are also removed.

On the outside of each of the arms there is mounted a guide block which carries a vertical push rod. The push rod can __._._ _.. slide up and down with respect to the-guide block. - The-lower-end of the push rod carries a jaw holding block on which there is mounted a skirt gripping jaw. On the push rod, spaced above the guide block, there is a collar, and between the collar and the guide block there is a jaw return spring which urges the push rod upwardly. The upper end of the push rod carries a cam roller.

The top body is fitted with a pair of oppositely extending cam blocks. These are short lengths of square section bar that project radially outwardly from the top body. The cam blocks are arranged to act downwardly on the push rods, via the cam rollers at the upper ends of the push rods, as the top body in operation moves down towards the centre body, against the pressure of the head pressure springs.

The centre body is fitted with an adaptor and a bottle top guide so that the bottle top guide is fixed with respect to the centre body. The bottle top guide comprises an upper, inverted cup- shaped part which is able to seat on the top end of the bottle, and a male part which is able to enter with little clearance into the mouth : of the bottle. The arrangement is such that the bottle top guide can easily be replaced, as different bottle top guides are required for different types of bottles. In other words, the different bottle top guides are readily interchangeable.

The modified de-skirting head is illustrated in Figures 2 to 4. The following reference numbers are used to indicate the various part already referred to above: 20 de-skirting head

4d WO 01/39901 PCT/IB00/01770 22 top body 24 centre body 26 pillar 28 head pressure spring 30 upper part of thread roller arm, which has been modified by having had the lower part thereof cut off 32 pivot whereby the modified thread roller arm 30 is mounted on the centre body 24 34 cam follower arm 36 pivot whereby the cam follower arm is mounted on the modified thread roller arm 37 cam follower roller 38 side pressure spring 40 guide block mounted on the modified thread roller arm 30 42 push rod 44 jaw holding block 46 jaw 48 collar on push rod 42 50 jaw return spring 52 cam roller at the upper ends of the push rod 42 54 cam block 56 solid cam element 658 cam formation on the cam element 56 60 adaptor 62 upper part of the bottle top guide 64 lower, male part of the bottle top guide

Each of the arms 30 has, at the upper end thereof, a projection 66. An arm return spring (not shown in the drawings) extends between the two projections 66, to urge the upper ends of the arms towards one another.

Operation of the de-skirting head 20 will now be described, with reference also to Figures 5 and 6. When a bottle B is in position underneath the de-skirting head 20, the head starts to descend. The male part 64 of bottle top guide, by entering into the mouth of the bottle, serves to align the bottle accurately with the centre-line of the head. Eventually, when the upper part 62 of the bottle top guide seats on the top end of the bottle, the centre body 24 can no longer move any further down. Further downward pressure is, however, applied to the top body 22 and this causes the head pressure springs 28 to compress and the cam element 56 to move downwardly with respect to the centre body 24. The cam formation 58 will now engage the cam follower rollers 37 and urge the cam follower arms 34, and hence the arms 30, radially outwardly, against the tension in the arm return spring which, as mentioned above, acts between the projections 66. As the upper ends of the arms 30 move radially apart, the lower ends of the push rods 42, and hence the jaws 46, move radially inwardly as indicated by the arrows C in Figure 5, to grip the skirt S in the region of the annular tuck-under indentation that is formed by the tuck-under rollers referred to above during capping. The tuck-under indentation is indicated by reference numeral 68 in Figure 5. As can be seen in

Figure 4, the leading edges of the jaws have a semi-circular profile in plan view. The radius of curvature corresponds to the outer radius of the skirt, ensuring that the jaws obtain a good purchase on the skirt.

Further downward movement of the top body 22 with respect to the centre body 24 causes the cam blocks 54 to contact the cam follower rollers 52 and so push the push rods 42 downwardly, against the pressure of the jaw return springs 50.

Downward movement of the push rods 52 and hence of the jaws 46, as indicated by the arrows D in Figure 6, forcibly displace the

4d WO 01/39901 PCT/IB00/01770 skirt S down the neck of the bottle. Because the neck widens, this will cause the skirt to split. There is a recess 70 in the cam element 56, above the cam formation 58, that allows the jaws 46 to move radially outwardly again, in order to accommodate the increased width of the bottle neck as the jaws 46 move downwardly.

Once the skirt has been split, the de-skirting head 20 moves up again and is ready to perform the same operation on the next bottle in the line.

Referring now to Figures 7 and 8, reference numeral 20.1 generally indicates a de-skirting head which, in certain respects .is similar to the de-skirting head 20 described with reference to

Figures 2 to 4, the same reference numerals being used to indicate the same or similar parts. The de-skirting head 20.1 forms part of apparatus for de-capping and de-skirting bottles, the remainder of which apparatus is as described hereinbefore.

The de-skirting head 20.1 differs from the de-skirting head 20 as follows: The four pillars 26 each with its head pressure spring 28 are omitted and substituted by a single, centrally arranged, pillar 80 with a head pressure spring 82 thereon. The pillar 80 has a collar 84 thereon, and the lower end 86 thereof is threaded. The lower end 86 passes through an opening in the centre body 24 and is screwed into a threaded socket in the adaptor 60. The upper end of the pillar 80 is also threaded and passes slidably through a central opening in the top body 22. The upper end carries a nut 88 and a lock nut 90. The nut 88 and lock nut 90 serve as an end stop, to limit downward displacement of the centre body 24 with respect to the top body 22.

Furthermore, the solid cam element 56 is replaced by a hollow cam element 92 which is fixed to the top body 22 by means of a clamping plate 94. The cam element 92 has an annular cam formation 96 whereby it co-operates with the cam follower arms 34 via the cam follower rollers 37, in a manner similar to that described with reference to Figures 2 to 4. It has been found that a recess in the cam element above the cam formation 96, as in the Figures 2 and 3 embodiment, is not necessary and is therefore not provided in the Figures 7 and 8 embodiment.

The de-skirting head 20.1 further comprises a guide element 98 having an upright cylindrical wall 100 and, at the lower end thereof, a horizontal wall 102 with an opening therein through which the pillar 80 can pass. The collar 84 seats on the horizontal wall 102 so that, when the threaded lower end 86 of the pillar 80 is tightened into the threaded socket of the adaptor 60, the piltar 80, the guide element 38, the centre body 24, and the adaptor 60 are secured together so that, during operation, they will all move in unison.

The guide element 98 has a cylindrical outer surface, and the cam element 92 has a cylindrical inner surface, the guide element 98 being a close sliding fit in the cam element 92.

Cooperation between the cam element 92 and the guide element 98 thus serves to guide movement of the centre body 24 towards and away from the top body 22. The head pressure spring 82 is accommodated in the hollow interior of the cam element 92 and the guide element 98.

To prevent rotation of the centre body 24 with respect to the top body 22, the cam element 92 is provided with a pair of diametrically opposite, vertically extending slots 104 (only one of which is visible in the drawings), and a pair of screws 106 are screwed into the upright wall 100 of the guide element 98, the head of each screw 106 being slidable along a corresponding one of the slots 104.

Whilst guidance for the jaw holding block 44 is provided by the corresponding push rod 42 sliding through close fitting y 1s passages in the corresponding jaw-carrying arm 30, additional guidance is provided bv a guide rod 108 which is parallel to the push rod 42, the upper end of the guide rod being threaded and screwed into the corresponding arm 30. The guide rod 108 passes through a close fitting passage in the jaw holding block 44 and the jaw 486.

Operation of the de-skirting head 20.1 is similar to the operation described above with reference to Figures 2 to 6. Thus, when the de-skirting head 20.1 descends onto a bottle, the upper part 62 of the bottle top guide comes to rest on the top end of the bottle and, when further downward pressure is applied, the guide element 98 moves telescopically into the cam element 92, compressing the head pressure spring 82. The cam formation 96 now engages the cam follower rollers 37 and urges the cam follower arms 34, and hence the upper ends of the arms 30, radially outwardly, against the tension in a pair of arm return springs, one of which is indicated by reference numeral 110 in Figure 1. The other arm return spring is on the other side of the de-skirting head. As the upper ends of the arms 30 move radially apart, the lower ends of the push rods 42, and hence the jaws 46, move radially inwardly, thereby to grip the skirt that is on the bottle neck (as illustrated in

Figures 5 and 6).

Further downward movement of the top body 22 with respect to the centre body 24 causes the cam blocks 54 to contact the cam rollers 52 and so push the push ruds 42 downwardly against the pressure of the jaw return springs 50, thereby forcibly displacing the skirt down the neck of the bottle.

Claims (15)

CLAIMS:

1. A method of de-skirting a bottle (B) having a downwardly widening neck and having the skirt (S) of a closure in place on the neck, characterised in that the skirt is forcibly displaced towards the bottom of the bottle, whereby the relative displacement of the skirt with respect to the neck causes the skirt to split, and is thereafter removed from the bottle.

2. A method as claimed in claim 1, characterised in that the skirt (S) is displaced towards the bottom of the bottle (B) by means of a plurality of jaws (46) which are caused to move radially inwardly with respect to the skirt and then downwardly with respect to the bottle.

3. A method as claimed in claim 2, characterised in that the jaws (46), upon said radially inward movement, grip the skirt (S) between them.

4. A method as claimed in claim 3, wherein the skirt (S) has a circumferentially extending tuck-under indentation (68), characterised in that the jaws (46) engage the skirt in the region of the tuck-under indentation.

5. A method as claimed in claim 3 or claim 4, characterised in that the bottle (B) is centred with respect to the jaws (46) before the jaws engage with the skirt (S).

6. A method as claimed in claim 5, characterised in that the bottle (B) is centred by means of a bottle top guide (62, 64) which has a male part (64) that, as it moves down, enters with little

4 WO 01/39901 PCT/IB00/01770 clearance into the mouth of the bottle.

7. A method as claimed in any one of the preceding claims, characterised in that, the skirt (S), after it has been split, is removed from the bottle neck by means of a jet or jets of air (21).

8. A method as claimed in claim 7, characterised in that the jet or jets of air (21) are directed to the split skirt (S) from underneath, thereby to blow the skirt upwardly off the neck of the bottle.

9. Apparatus for de-skirting a bottle (B) having a downwardly widening neck and having the skirt (S) of a closure in place on the neck, characterised in that it comprises a de-skirting head (20, 20.1) having a plurality of circumferentially spaced jaws (46), and means for displacing the jaws radially inwardly with respect to the skirt and then downwardly with respect to the bottle, thereby to displace the skirt down the neck of the bottle and so cause the skirt to split.

10. Apparatus as claimed in claim 9, characterised in that, the jaws (46) have a semi-circular profile in plan view, the radius of curvature of the jaws corresponding to the outer radius of the skirt

(S).

11. Apparatus as claimed in claim 10, characterised in that, the head (20, 20.1) comprises a top body (22), a centre body (24) underneath the top body, and one or more head pressure springs (28, 82) between the top body and the centre body, the jaws (46) each being carried at the lower end of an arm (34, 30) which is mounted on the centre body so as to be pivotally displaceable with respect to the centre body about a horizontal pivot axis (32), the top body being axially displaceable with respect to the centre body against the pressure of the head pressure spring or springs, and the top body carrying a cam element (56) which co-operates with the upper ends of the arms to displace the upper ends of the arms — radially outwardly as the top body is displaced axially downwardly with respect to the centre body and thereby displace the lower ends of the arms and therewith the jaws carried by them radially inwardly.

12. Apparatus as claimed in claim 11, characterised in that, each jaw (46) is mounted on the corresponding arm (34, 30) via a push rod (42) which is axially displaceable with respect to the arm against the pressure of a jaw return spring (50), the top body (22) being provided with means (50) which act on the upper ends of the push rods, to displace the jaws downwardly as the top body is displaced axially downwardly with respect to the centre body.

13. Apparatus as claimed in claim 11 or claim 12, characterised in that it further comprises guide means (92, 100) for guiding displacement of the centre body (24) towards and away from the top body (22), and a centrally arranged head pressure spring (82) between the top body and the centre body.

14. Apparatus as claimed in claim 13, characterised in that the guide means comprises a pair of concentrically arranged guide elements (92, 100), one of the elements (92) being fast with the top body (22) and the other guide element {100) being fast with the centre body (24), the cam element (96) forming part of or being carried by the radially outer guide element (92), the radially outer and radially inner guide elements being hollow, and the head pressure spring being accommodated in the hollow interior of the

J WO 01/39901 PCT/IB00/01770 guide elements.

15. Apparatus as claimed in any one of the preceding claims, characterised in that, it further comprises means for removing the skirt (S), after it has been split, from the neck of the bottle (B}, said means comprising one or more jet nozzles (21) for directing a jet or jets of air to the split skirt from underneath, thereby to blow the skirt upwardly off the neck of the bottle. ‘ }