IMPROVEMENTS IN ROLLER BALL APPLICATORS

Abstract

Several improvements on roller ball applicators on glass bottles have been described. A unique mechanical design of the roller ball housing to obtain minimal leak of the bottle ingredients is described. Also described is a hidden tamper evident band.

Claims

1. A two-piece leak-minimizing roller ball housing comprising a ball receptacle part having one dispensing end to house a roller ball and a distal end that fits into a bottle typically containing the liquid to be dispensed, and a ball retainer piece fitted onto the dispensing end of the ball receptacle part with a roller ball enclosed in the cavity formed by the ball receptacle and the ball retainer.

2. The roller ball housing of claim 1 wherein the ball receptacle is made from Polyethylene and the ball retainer is made from Polypropylene.

3. The two-piece roller ball housing of claim 1 wherein the leak is measured to be less than 0.01 gm with the leak testing protocol.

4. A roll-on applicator using the two-piece leak minimizing ball housing of claim 1.

5. A roll-on applicator cap assembly with a tamper evident band.

6. The roll-on applicator cap assembly of claim 5 wherein the tamper evident band remains hidden when the bottle cap assembly is screwed close on its bottle.

7. The cap assembly of claim 6 comprising an inner cap and an outer cap, wherein the inner cap has a tear away tamper evidence band.

Description

DRAWINGS

[0025] FIG. 1 Roller Ball Housing

[0026] FIG. 2a Outer Cap

[0027] FIG. 2b Inner Cap

[0028] FIG. 2c Cap Assembly

[0029] FIG. 2d Bottle with Tamper Bead

[0030] FIG. 3 Leak Test Recording Sheet

DETAILED DESCRIPTION OF THE INVENTION

[0031] The following description supplies specific details with a view to provide a thorough understanding. A skilled artisan would understand that the apparatus design can be implemented without using these specific details. The apparatus can be practiced by modifying the illustrated apparatus and can be used conjunctively with other apparatus conventionally used in the industry. For example, the description below focuses on a two piece roller ball housing, one can use more than two piece housing that can provide additional flexibility in movement of the ball.

[0032] Improvement in Roller Ball Housing

[0033] FIG. 1 illustrates the inventive two piece construction of the roller ball housing 1. The roller ball housing 1 is made up of two parts—a ball receptacle 2 and a ball retainer 3. The ball receptacle 2 is typically fitted into the mouth of a liquid container bottle 41 at its distal end. There are four protrusions 9 on the outer surface of distal end of the ball receptacle 2 which allow the distal end of the ball receptacle 2 to be press fitted into the neck 44 of the bottle creating a leak proof assembly. The ball receptacle 2 holds the roller ball 4. The ball 4 can rotate freely when placed in the receptacle cavity while being seated on the bottom seat in the receptacle of the roller ball housing. After placing the ball in the receptacle cavity, the ball retainer 3 is fitted around the ball receptacle 2 such that only a spherical dome of the roller ball is exposed at the top of the assembly. The sealing lip 5 of the Ball Retainer 3 has a chamfered edge that matches the curvature of the ball

[0034] In a completed assembly as described above, the ball can be in two positions. When the assembly is upright the ball is well seated on the receptacle seat 7 at the bottom and no liquid flows past this seal that is formed. When the assembly is turned upside down, the ball is now very well seated in the opening in the retainer seat 8. No liquid flows past the lip seal 5 that is formed. The ball can be in one of these two positions at any one time. This play between the positions allows the liquid to fill the receptacle seal is open and flow out of the lip seal when the receptacle seal is closed.

[0035] Additionally, a donut structure 25 is located on the inside surface 26 of the top 27 of inner cap 21. When the cap is screwed close the donut 25 presses against the roller ball 4 allowing the roller ball to completely seat in the receptacle seat 7 allowing no fluid communication between the liquid in the bottle 41 and the fluid in the roller ball housing 1.

[0036] This two-part design allows us to choose different materials for the two parts. The ball retainer 3 is made of rigid stiff material that forms a rigid seat for the roller-ball. stiff materials for the ball retainer 3. The ball retainer 3 is made such that the sealing lip 5 is thick and stiff and remains in place with respect to the ball with a controlled clearance d and is essentially parallel to the curvature of the roller ball 4 and the roller ball seats well in the cover opening if the housing is turned downward. The stiff thick sealing lip 5 section also reduces leaks by providing longer paths L for fluids to go through when the ball is not being rotated. Thus liquids do not leak through this gap very easily. We can select optimal values of d and L to minimize leakage for different viscosities of liquids to eliminate leakage.

[0037] Additionally, reservoir 6 are contoured into the inner walls of receptacle 2 to provide a sink for any liquid trapped between the ball and the wall. This volume is provided to provide ample room for liquid that has passed the receptacle seat 7 but has not gone past the retainer seat 8—a holdup volume.

[0038] The chamfered edge of the retainer sealing lip 5 and the curvature of the ball 4 are carefully matched to leave no gaps when the ball 4 is seated in the retainer seat 8. This fit produces a zero clearance for the liquid and stops leaks across the seal. The stiffness of the retainer lip 5 ensures that this close match is preserved during the life of the applicator ensuring a tight shutoff when needed, especially for reduced leaks.

[0039] Yet during application over a substrate, when the ball 4 is pushed down towards the bottle end, a clearance with the retainer seat 8 is created and this clearance allows the wetted layer on the ball 4 to rotate through the seal without being scraped clean by the stiff retainer seat 8. The d and L parameters in design of the stiffness of retainer sealing lip 5 provides control the flow of the liquid through the retainer seal 8 to the outside.

[0040] The inventive two-piece construction of the roller ball housing 1 allows greater flexing control with proper stiffness choices in polymers. The ball retainer 3 is ideally made from polypropylene (PP) while the ball receptacle 2 is made of polyethylene (PE). PP generally has high resistance to cracking, acids, organic solvents. The two piece construction allows the material choice in the design of a stable, rigid and long-lasting retainer seat 8 to provide no leakage.

[0041] Sometimes in the art, a single piece roller ball housing is used which is expedient for cost reasons. The ball is forced into the receptacle through the top circular opening of the housing. Sufficient deflection capabilities are provided in the circular seal portion of the housing so that the ball snaps into place under the circular seal, and once in, the ball cannot come out of the opening it just came through. This works due to the snapping back action of the circular seal edge. However, this assembly technique needs sealing sections that are flexible and not stiff. Such flexing sealing sections deteriorate the chamfer integrity leading to poor fit with roller ball curvature over time. With the deterioration of the chamfer edge, the initial proper fit degrades, and liquid leaks develop.

[0042] Thus, an improved mechanical design is provided to achieve this optimal combination of a loose fit of ball and yet leak-proof fit by designing the roller ball housing from proper material with the right stiffness modulus and play.

[0043] Hidden Tamper Evident Band

[0044] FIG. 2 a shows the outer cap 11 which is attached to the inner cap 21 shown in FIG. 2 b as shown in the assembly 31 in FIG. 2 c. All the figures show axial sections. Plan views also shown in FIGS. 2 a and 2 b.

[0045] The inner cap 21 shows tabs 28 that stick out radially and longitudinally in several places on the inside surface 26 of the inner cap. These tabs interleave similar number of tabs on the inside surface 13 of the outer cap 11. When the two caps are assembled together the both sets of interleaving tabs lock the two caps in place enabling the cap assembly 31 to move a one unit in cap screwing and unscrewing action.

[0046] The outer cap 11 of FIG. 2 a and the inner cap 21 of FIG. 2 b have the same vertical height. The inner diameter of the outer cap 11 is such that it fits over the inner cap 21 when making the cap assembly 31 of FIG. 2 c.

[0047] The inner cap 21 has a tamper evident breakable band 22 at its bottom and the inner wall of the inner cap 21 above the band is threaded for screwing the cap onto a bottle neck with matching threads 43. The outer cap 11 has an inner diameter designed to snap fit over the inner cap 21 and is fitted over the inner cap with snap fit protrusions 12 provided circumferentially on the inside of the outer cap 11.

[0048] When the assembly of FIG. 2 c is screwed onto a bottle 41, the assembly 31 provides a clean look with the tamper evident band 22 not being visible. When one unscrews the cap assembly to open the bottle, the tear off tamper band 22 tears away and separates from the inner cap 21 leaving the band on the neck 44 of the bottle below the tamper bead 42. This tearing action is mechanically accomplished by the design of the tamper bead 42 on the bottle shown in FIG. 2 d. The tamper band now remains on the bottle neck 44 after the cap assembly separates from it when the cap is unscrewed to open the bottle.

[0049] The tamper bead 42 is made specially on the bottle during the molding and fabrication of the glass bottle. It is part of the glass bottle. This band works in conjunction with the innovative tamper evident band to form an innovative tamper band system.

[0050] In closing the bottle back, the cap assembly (now without the tamper band portion) is screwed back completely onto the bottle 41, the bottom of outer cap 11 skirts over the tamper evident band 22 which was earlier lodged on the bottle 41. The tamper evident band 22 of the inner cap is now completely covered by the outer cap 11. The “hidden” look is obtained because one is unable to see the tamper evident band 22 from the outside anymore with the bottle 41 closed.

[0051] FIG. 3 shows a table used to record for Leak Test Data.

[0052] Leak Test is done at ambient temperature with the liquid filled bottle capped with the inventive cap assembly and being subjected a pressure of 0.5 kpa for 15 minutes. The weight (gm.) difference between the capped bottle before and after exposure to the vacuum is the amount of liquid that has leaked. This is quantified as the leakage.