GB2275024A

GB2275024A - Roll-on dispenser with integral PET ball seat

Info

Publication number: GB2275024A
Application number: GB9302702A
Authority: GB
Inventors: Michael Coleman
Original assignee: ROCKWARE PLASTICS Ltd
Current assignee: ROCKWARE PLASTICS Ltd
Priority date: 1993-02-11
Filing date: 1993-02-11
Publication date: 1994-08-17
Also published as: GB9302702D0

Abstract

A roll-on dispenser comprises a container (20) and a ball housing (21) for a ball roller (22). The ball housing has a ball seat (23) which is integral with the container (20) and a retaining ring (24) which retains the ball roller (22) on the ball seat (23). The container (20) and ball seat (23) are made from polyethylene terephthalate (PET) with the ring (24) being made from low density polypropylene. The container is manufactured in two stages; an initial injection moulding of the ball seat (23) and a subsequent blow moulding of the neck (N) and screw threads (S). <IMAGE>

Description

DISPENSER This invention relates to dispensers of the kind known as roll-on dispensers.

A roll-on dispenser comprises a container which is filled with liquid, such as personal deodorant and is fitted with a dispensing roller. In use, the dispensing roller serves to transfer liquid from the interior of the container and to apply a thin film of the liquid to a desired surface.

Figure 1 of the accompanying drawings shows a longitudinal sectional view through the upper part of a known roll-on dispenser.

The dispenser comprises a container 10 and a ball-housing 11 in which a ball-roller 12 is freely supported. During assembly, the container 10 is filled with liquid and the ball-housing fitted around the neck 13 of the container, as shown in the drawing.

Container 10 is made from polyethylene terephthalate (PET), whereas the ball-housing 11 is made from low density polyethylene. Customers prefer containers made from PET on account of the glass-like appearance of the material. However, PET is a relatively brittle material, and hitherto it has been the practice to manufacture the ball-housing from a more resilient material, such as low density polyethylene in order to achieve a satisfactorily wiping action on the ball-roller and to facilitate the assembly procedure, and this increases manufacturing costs.

According to a first aspect of the invention there is provided a roll-on dispenser comprising a container and a ball housing for freely supporting a ball roller, wherein the ball housing comprises a ball seat which is integral with the container and a retaining ring for retaining the ball roller on the ball seat.

In a preferred embodiment, the container and the ball seat are both made from polyethylene terephthalate (PET) and the retaining ring is made from a more resilient plastics material, such as low density polyethylene.

Preferably the retaining ring is a snap-fit on the ball seat. To that end, an external surface of the ball seat has a circumferential groove or flange and the retaining ring has a complementarily-shaped circumferential formation which is snap-fit with the groove or flange of the ball seat.

The retaining ring may have an inwardly directed circumferential lip which is configured to have a wiping action on the ball roller.

Preferably, the ball seat is formed by injection moulding during an initial moulding stage and the container is formed by blow moulding during a subsequent moulding stage.

In the case of a ball seat having a said circumferential groove, the groove provides support for the pre-formed ball seat during the subsequent blow-moulding stage.

According to another aspect of the invention there is provided a method of manufacturing a roll-on dispenser, according to the first aspect of the invention, including the steps of forming the ball seat by injection moulding during an initial moulding stage and forming the container by blow moulding during a subsequent moulding stage.

An embodiment of the invention is now disclosed, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a longitudinal sectional view through the upper part of a known roll-on dispenser; Figure 2a shows a longitudinal sectional view through the upper part of a roll-on dispenser according to the invention; Figure 2b is a side elevation view of the upper part of the roll-on dispenser shown in Figure 2a, and Figure 2c shows a longitudinal sectional view through the upper part of a preform produced during manufacture of the dispenser.

Referring now to Figures 2a and 2b, the roll-on dispenser comprises a container 20 and a ball housing 21 which freely supports a dispensing roller in the form of a ball roller 22. The ball housing 21 comprises a ball seat 23 and and a retaining ring 24 for retaining the ball roller 22 on the ball seat 23.

The container 20 and the ball seat 23 are formed integrally from polyethylene terephthalate (PET), whereas the retaining ring 24 is a separate piece-part made from the more resilient, low density polyethylene.

The retaining ring 24 is formed with a circumferential flange 25 which is a snap-fit in a complementarily-shaped circumferential groove 26 formed in an external surface of the ball seat 23. The retaining ring 24 also has an inwardly directed lip 27 which is so shaped and dimensioned as to have a wiping action on the ball roller 22.

The retaining ring 24 is the only component of the dispenser to be made from low density polyethylene, the rest of the dispenser (apart from the ball roller itself) being made from PET. Accordingly, as compared with hitherto known designs such as that described with reference to Figure 1, the proportion of the low density material in the dispenser can be reduced significantly (typically by up to a factor of 5) giving a a significant saving in manufacturing costs. Furthermore, a customer who fills the container and completes its assembly, will be supplied with a near-complete dispenser, and is simply required to fit the retaining ring after the container has been filled and the ball roller has been positioned on the ball seat. Therefore, the assembly procedure is simplified considerably.

In this embodiment, the container is manufactured in two stages; an initial injection moulding stage, when the ball seat 23 is formed, and a subsequent blow moulding stage when the container 20, including the neck N and associated screw threads S, is formed. The hatched region in Figure 2c shows the shape of the preform following the initial injection moulding stage. As this drawing shows, the preform comprises the finished ball seat 21 and a part B for the subsequent blow-moulding stage. The profile of the neck N and screw threads S produced by blow-moulding is shown in broken outline.

The ball seat has a tapered external surface 28. This surface and the circumferential groove 26 provide support for the preform during the blow-moulding stage.

As is customary, a protective cap (not shown in the drawings) will be fitted to the container, being a screw fit on threads S.

It will be appreciated that although the described roll-on dispenser comprises a container and ball seat made from PET, and a retaining ring made from polyethylene, roll-on dispensers in accordance with the invention may be made from other suitable materials.

Claims

1. A roll-on dispenser comprising a container and a ball housing for freely supporting a ball roller, wherein the ball housing comprises a ball seat which is integral with the container and a retaining ring for retaining the ball roller on the ball seat.

2. A dispenser as claimed in claim 1 where the ball housing and the container are both made from polyethylene terephthalate (PET).

3. A dispenser as claimed in claim 1 or claim 2 when the retaining ring is a snap-fit on the ball seat.

4. A dispenser as claimed in claim 3 wherein an external surface of the ball seat has a circumferential groove or flange and the retaining ring has a complementarily-shaped circumferential formation which is a snap-fit with the groove or flange of the ball seat.

5. A dispenser as claimed in claim 3 or claim 4 wherein the retaining ring has an inwardly directed circumferential lip which is configured to have a wiping action on the ball roller.

6. A dispenser as claimed in any of claims 1 to 5 where the ball seat is formed by injection moulding during an initial moulding stage and the container is formed by blow moulding during a subsequent moulding stage.

7. A dispenser as claimed in claim 6 where the ball seat is so shaped as to provide support for the preformed ball seat during the subsequent blow moulding stage.

8. A method of manufacturing a roll-on dispenser as claimed in claim 1 including the steps of forming the ball seat by injection moulding during an initial moulding stage and forming the container by blow moulding during a subsequent moulding stage.

9. A roll-on dispenser substantially as herein described with reference to Figures 2 of the accompanying drawings.

10. A method of manufacturing a roll-on dispenser substantially as herein described with reference to Figures 2 of the accompanying drawings.