GB2100236A

GB2100236A - Finish for twist-off crown closures

Info

Publication number: GB2100236A
Application number: GB8118649A
Authority: GB
Original assignee: REDFEARN NAT GLASS Ltd
Current assignee: REDFEARN NAT GLASS Ltd
Priority date: 1981-06-17
Filing date: 1981-06-17
Publication date: 1982-12-22

Abstract

A finish provided on glass bottles for receiving a twist-off crown closure comprises a single or multi-start thread (3) on to which the crown- closure may be crimped, and a raised bead (2) around the finish immediately below the threads (3) having an external diameter D which is greater than the maximum diameter d across the multi-start threads 3. Said bead immediately abuts the lower rim of the skirt of a closure (not shown) and so prevents the user from trying to lever the closure off in the traditional manner, instead of twisting it off, with the consequential risk of breaking the neck of the bottle. <IMAGE>

Description

SPECIFICATION Finish for twist-off crown closures This invention relates to bottles having a finish designed to receive a 'Twist-off' crown closure.

Twist-off crown closures are known, see for example U.K. Patent No. 1,202,788. In such closures the neck of the bottle is provided adjacent the mouth with a finish comprising a helical thread rather than an annular shoulder. In securing the closure to the bottle the skirt of the crown closure is crimped into engagement with the thread and is deformed therearound, thereby to secure the closure firmly to the bottle whilst permitting the closure to be subsequently removed or replaced by a twist action.

Twist-off crown closures have, however, not found common acceptance in the art for the reason that the would-be user, not recognising that the closure is of the twist-off variety, will try the traditional method of levering off the closure with the customary crown closure opener.

However, the twist-off crown closure as described above is not susceptible to removal in the traditional manner, due to the crimping of the skirt into the threads, with the consequent risk that, upon applying leverage to the closure, the neck of the bottle will break.

In the present invention this problem is solved or alleviated by providing on the neck of the bottle a finish designed to receive a twist-off crown closure, said finish comprising an annular bead extending around the neck of the container space from the mouth thereof and a helical thread or threads located between said bead and the mouth of the container, said bead having a maximum diameter greater than the maximum diameter measured across the helical thread and said bead abutting the bottom edge of the skirt of the closure when secured on said finish. Preferably, the maximum diameter of said bead is substantially equal to the diameter of the skirt of the closure.

With such arrangement the close proximity of the annular bead to the bottom edge of the skirt substantially prevents the engagement of a traditional crown closure opener or other levering instrument with the closure, thereby substantially thwarting attempts by the user to open the closure by leverage rather than twisting.

Also provided in accordance with this invention are bottles having a finish as described and having a crown closure crimped thereon into engagement with said threads.

In a particularly preferred embodiment of the invention the finish provided on the neck of the bottle comprises said bead spaced from the mouth of the bottle and from which emanate the threads of a multi-start thread equispaced around the neck of the bottle and extending from said bead towards the mouth of the bottle, each thread of the multi-start thread subtending an angle of less than 3600 around the bottle neck. Preferably the thread is a four-start thread with the four threads equispaced around the neck of the bottle and each thread subtending an angle less than 1 Boo, e.g.

90 to 1 550, thereby permitting the closure to be removed and replaced by a partial, e.g. quarter, turn.

The invention is further described with reference to the accompanying drawings in which: Fig. 1 shows a conventional finish for receiving a twist-off crown closure; Fig. 2 shows a finish in accordance with this invention, and Fig. 3 shows the closure in position on the finish of Fig. 2.

Referring to Fig. 1 , the conventional finish on the neck 1 of a bottle (not shown) comprises a bead 2 extending around the neck of the bottle and spaced from the mouth thereof. From the bead emanate the four equispaced threads 3 of a four-start thread, each thread extending toward the mouth of the bottle and subtending an angle of substantially 900 around the neck of the bottle.

The finish is adapted to receive a crown closure crimped thereon in the position shown in phantom. As will be seen the lower rim of the closure skirt stands proud of the bead 2 and can easily be engaged by the traditional crown cap opener or other levering instrument.

In contrast, in the finish of the present invention shown in Fig. 2, the same reference numerals applying, the annular bead 2 is radially enlarged and has external diameter D which is greater than the maximum diameter 'd' across the multi-start threads 3.

As shown in Fig. 3, the enlarged bead 2 immediately abuts the lower rim of the skirt 4 of the closure 5 when crimped thereon, with the maximum diameter D of the raised bead 2 being substantially equal to the diameter of the skirt 4 of the cap 5. It is thus substantially impossible to engage a crown closure opener, or other levering instrument, under the edge of the closure, thereby frustrating attlempts to remove the closure by leverage. The closure can, of course, be easily removed and replaced by a quarter turn.

Although, as shown the threads 3 run right into the bead 2, in an alternative embodiment with a so-called smooth finish, the threads 3 may commence a short distance from the bead towards the mouth of the container. Also, as will be apparent to those skilled in the art, the threads of the multi-start thread may extend a greater distance around the neck of the container, e.g.

1 50--1 550 rather than the 900 illustrated.

1. A bottle having a finish designed to receive a twist-off crown cap, said finish comprising an annular bead extending around the neck of the container spaced from the mouth thereof and a helical thread or threads located between said bead and the mouth of the container, said bead having a maximum diameter greater than the maximum diameter measured across the helical thread and bead lying immediately below the bottom edge of the skirt of the closure when secured on said finish.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Finish for twist-off crown closures This invention relates to bottles having a finish designed to receive a 'Twist-off' crown closure. Twist-off crown closures are known, see for example U.K. Patent No. 1,202,788. In such closures the neck of the bottle is provided adjacent the mouth with a finish comprising a helical thread rather than an annular shoulder. In securing the closure to the bottle the skirt of the crown closure is crimped into engagement with the thread and is deformed therearound, thereby to secure the closure firmly to the bottle whilst permitting the closure to be subsequently removed or replaced by a twist action. Twist-off crown closures have, however, not found common acceptance in the art for the reason that the would-be user, not recognising that the closure is of the twist-off variety, will try the traditional method of levering off the closure with the customary crown closure opener. However, the twist-off crown closure as described above is not susceptible to removal in the traditional manner, due to the crimping of the skirt into the threads, with the consequent risk that, upon applying leverage to the closure, the neck of the bottle will break. In the present invention this problem is solved or alleviated by providing on the neck of the bottle a finish designed to receive a twist-off crown closure, said finish comprising an annular bead extending around the neck of the container space from the mouth thereof and a helical thread or threads located between said bead and the mouth of the container, said bead having a maximum diameter greater than the maximum diameter measured across the helical thread and said bead abutting the bottom edge of the skirt of the closure when secured on said finish. Preferably, the maximum diameter of said bead is substantially equal to the diameter of the skirt of the closure. With such arrangement the close proximity of the annular bead to the bottom edge of the skirt substantially prevents the engagement of a traditional crown closure opener or other levering instrument with the closure, thereby substantially thwarting attempts by the user to open the closure by leverage rather than twisting. Also provided in accordance with this invention are bottles having a finish as described and having a crown closure crimped thereon into engagement with said threads. In a particularly preferred embodiment of the invention the finish provided on the neck of the bottle comprises said bead spaced from the mouth of the bottle and from which emanate the threads of a multi-start thread equispaced around the neck of the bottle and extending from said bead towards the mouth of the bottle, each thread of the multi-start thread subtending an angle of less than 3600 around the bottle neck. Preferably the thread is a four-start thread with the four threads equispaced around the neck of the bottle and each thread subtending an angle less than 1 Boo, e.g. 90 to 1 550, thereby permitting the closure to be removed and replaced by a partial, e.g. quarter, turn. The invention is further described with reference to the accompanying drawings in which: Fig. 1 shows a conventional finish for receiving a twist-off crown closure; Fig. 2 shows a finish in accordance with this invention, and Fig. 3 shows the closure in position on the finish of Fig. 2. Referring to Fig. 1 , the conventional finish on the neck 1 of a bottle (not shown) comprises a bead 2 extending around the neck of the bottle and spaced from the mouth thereof. From the bead emanate the four equispaced threads 3 of a four-start thread, each thread extending toward the mouth of the bottle and subtending an angle of substantially 900 around the neck of the bottle. The finish is adapted to receive a crown closure crimped thereon in the position shown in phantom. As will be seen the lower rim of the closure skirt stands proud of the bead 2 and can easily be engaged by the traditional crown cap opener or other levering instrument. In contrast, in the finish of the present invention shown in Fig. 2, the same reference numerals applying, the annular bead 2 is radially enlarged and has external diameter D which is greater than the maximum diameter 'd' across the multi-start threads 3. As shown in Fig. 3, the enlarged bead 2 immediately abuts the lower rim of the skirt 4 of the closure 5 when crimped thereon, with the maximum diameter D of the raised bead 2 being substantially equal to the diameter of the skirt 4 of the cap 5. It is thus substantially impossible to engage a crown closure opener, or other levering instrument, under the edge of the closure, thereby frustrating attlempts to remove the closure by leverage. The closure can, of course, be easily removed and replaced by a quarter turn. Although, as shown the threads 3 run right into the bead 2, in an alternative embodiment with a so-called smooth finish, the threads 3 may commence a short distance from the bead towards the mouth of the container. Also, as will be apparent to those skilled in the art, the threads of the multi-start thread may extend a greater distance around the neck of the container, e.g. 1 50--1 550 rather than the 900 illustrated. CLAIMS

2. A bottle according to claim 1, wherein the finish comprises a multi-start thread, each thread of the multi-start thread subtending an angle of less than 360" around the bottle neck.

3. A bottle according to claim 2, wherein said thread is a four-start thread with the four threads equispaced around the neck of the bottle and each thread subtending an angle of from 900 to 1 550.

4. A bottle according to any one of the preceding claims, wherein said threads emanate from said bead.

5. A bottle according to any one of claims 1-3, wherein said threads commence a short distance from said bead towards the mouth of the container.

6. A bottle according to any one of claims 1-5, including a crown closure the skirt of which is crimped into engagement with said thread, said closure being removable therefrom by twisting.

7. A bottle according to claim 6, wherein the diameter of said bead is substantially equal to the diameter of the skirt of the crown closure.

8. A bottle according to any one of the preceding claims, wherein the finish is substantially as hereinbefore described with reference to Figs. 2 and 3 of the accompanying drawings.