GB2068884A - Dispensing tip - Google Patents

Abstract

A dispensing tip for a container of cyanoacrylate adhesive (45) has a stopper initially attached to the tip at a weakened junction which is broken, the stopper inverted and then replaced, whereby a plunger (32) penetrates a passageway (58) to force excess adhesive back into the container, prevent clogging, and close the passageway. The stopper is retained on the tip by engagement of ridge (40) in groove (28). A two phase interlock secures a rotatable cap (60) to the container and includes flanges (84) extending from the cap for releasably engaging lugs (82) located about the mouth of the container. A key extends from the cap (60) into a key way in the container to prevent rotation of the cap relative to the container unless the key is deliberately withdrawn from the key way by flexing of the cap. <IMAGE>

Description

SPECIFICATION Dispensing tip The present invention relates to dispensing tips and dispensers and, more particularly, to dispensing tips and dispensers for fluids.

As a result of safety regulations, variously locked caps for containers have been developed to prevent inadvertent ingestion of the container contents by a child. Wide mouthed pill containers often incorporate a cap which is rotatably mounted and removable only upon alignment of an index on the cap with a corresponding index on the container. Upon such alignment, the cap may be pried off with relative ease. With screw on caps, a locking detented mechanism is often used which requires simultaneous depression and rotation of the cap for the cap to come into threaded engagement with the container and to be removable therefrom. Various adaptations of mechanisms which require the above described simultaneous dual repositioning of the cap relative to the container have been developed.All of them however, require a certain degree of looseness in fit of the cap when the cap is lockingly in place. Moreover, the above described caps are primarily used with wide mouth containers for pills and like medications.

Cyanoacrylate adhesives have been used for a number of years for adhesively mating closely fitted components. A basis for selecting a cyanoacrylate adhesive in such applications in preference to some other adhesive is that the cyanoacrylate adhesive will wick or creep through tightly fitted joints before polymerizing and effecting a bond therebetween. Moreover, the volume of the resulting cured adhesive is essentially commensurate with the space between tightly fitting components and will not impede, dislodge or otherwise reposition or reorient the mated components.

One of the problems attendant to any dispenser for cyanoacrylate adhesive is that of polymerization or crusting of the adhesive in proximity to the dispensing tip and discharge outlet. This problem is well recognized in United States Patent No. 3,523,628. This particular Patent describes an invention in which a spring loaded ball sealingly bears against the discharge outlet to evacuate the cyanoacrylate adhesive from within the outlet after dispensation of quantity of cyanoacrylate adhesive.

In some dispensers for cyanoacrylate adhesives, the passageway has been flared from the discharge outlet toward the container itself in the belief that by having a large passageway diameter, bridging of the cyanoacrylate adhesive across the passageway would be avoided and polymerization or crusting would be precluded. By conducting experiments, it has become evident that crusting will still occur.

It has now been found that the present invention enables the provision of a non-clogging dispensing tip, in particular for cyanoacrylate adhesives which is also self-draining.

According to the present invention there is provided a dispensing tip attachable to the mouth of a container of liquid adhesive for dispensing the adhesive, said dispensing tip comprising in combination: (a) a boss for sealingly engaging the mouth of the container; (b) a tip extending from said boss for dispensing the adhesive; (c) a passageway extending through said tip for discharging the fluid to be dispensed; (d) sealing means detachably attached to the end of said tip for hermetically sealing said passageway prior to detachment of said sealing means from said tip; and (e) a break away junction between said tip and said sealing means for detaching said sealing means from said tip.

Preferably the break away junction includes an annular indentation, which is advantageously V-shaped in cross-section about the tip and circumscribing the passageway.

The passageway of the dispensing tip of the present invention includes a single or segmented constant diameter passageway having sharp edged annular terminations for dispensing cyanoacrylate adhesives.

The dispensing tip of the present invention may also be provided with a plunger for initiating evacuation of any cyanoacrylate adhesive from within the passageway and outlet thereof, and a detachably attachable stopper for evacuating the passageway of the cyanoacrylate adhesive dispensing tip.

Generally, the present invention also provides a stopper and dispensing tip configuration which is fabricatable by molding processes as a single unit with a breakaway junction which junction creates a sharp edged discharge orifice at the dispensing tip.

The present invention will be further illustrated with reference to the following drawings, in which: Figure 1 is a side view of a dispensing tip and stopper of the present invention prior to separation therebetween; Figure 2 is an isometric view of the components of a dispenser for cyanoacrylate adhesives incorporating the present invention; Figure 3 is a cross-sectional view of the dispenser shown in Fig. 2; Figure 4 is a partial cross-sectional view illustrating the mating of the stopper with the dispensing tip of the arrangement of Fig. 3; Figure 5 is a partial cross-sectional view illustrating a stoppered dispensing tip of the present invention mounted in a container; Figure 6 is a partial cross-sectional view of a dispensing tip of the present invention inserted within a container prior to detachment of the stopper and enclosed within a cap for the container;; Figure 7 is a cross-sectional view taken along the line 7-7, of Fig. 3 looking in the direction of the arrows; Figure 8 is a cross-sectional view taken along the line 8-8, of Fig. 3 looking in the direction of the arrows; Figure 9 is a partial cross-sectional view illustrating one part of a two part lock securing the cap to the container; Figure 10 is a cross-sectional view taken along the line 10-10, of Fig. 9 looking in the direction of the arrows; Figure 11 is a partial cross-sectional view illustrating the unlocked disengagement upon relative rotation between the cap and the container; Figure 12 is a cross-sectional view taken along the line 12-12, of Fig. 11 looking in the direction of the arrows; Figure 13 is an isometric view of a variant of the dispenser; and Figure 14 is a partial cross-sectional view of the variant shown in Fig. 1 3.

Fig. 1 illustrates a dispenser tip 10 and a stopper 1 2 molded as a single unit and severable from one another either before or after prior attachment of the base of the tip to a container.

In the preferred embodiment described herein, the unit is attached to the container and severance is made by the ultimate user of the product, which delay maintains the container hermetically sealed until first use of the fluid. By molding the dispenser tip and stopper as a unit, the number of units that must be handled in fabrication and assembly is reduced by one half, which brings about handling, storage and assembly economies. The dispenser tip includes a hollow boss 14 extending downwardly from a disc section 16, which boss includes a constant diameter cylindrical section 1 8 and a radially inwardly tapered section 20.Diametrically oriented lugs 21, 22 extend upwardly and provide structural support intermediate the base 24 of the tip 26 and disc section 16; they are also employed as means cooperating with apparatus for welding the dispensing tip to the container. The tip 26 is tapered and it includes an annular groove 28 disposed in proximity to the base 24 and a passageway extending through the tip.

The stopper 1 2 is formed by a hollow cone shaped section 30 for mating with the tip 26. A plug 32 (see Fig. 4) extends from the apex interior of the cone shaped section. A disc 34 is disposed in proximity to the apex of the cone shaped section 30. Flanges 36 and 38 extend from the disc to the exterior surface of the cone shaped section 30 to provide structural rigidity to the stopper 12; additionally, these flanges 36, 38 tend to restrain diametric expansion of the lower end of the cone shaped section 30 and aid in handling the stopper 1 2. In proximity to the interior and base of the cone shaped section 30, there is disposed an inwardly oriented annular ridge 40 (see Fig. 3) dimensioned to grippingly mate with the groove 28 of the tip 26.The ridge 40 and groove 28 serve in the nature of detent means to maintain the stopper 1 2 upon the tip 26.

The junction between the end of the tip 26 and the disc 34 is defined by an annular indentation 42 which, in cross-section, is V-shaped and defines a small angle at the apex. One leg of the "V" may be the planar surface of the disc. Nominally, the wall thickness between the interior dimension of the indentation and the circumscribed passageway is 0.1 08mm (-0.020 inches).

After attachment of the dispenser tip within the neck of a container, the dispenser tip and the stopper are readily manually or otherwise severed from one another, as is shown in Fig. 4. Upon severance, the exposed orifice 56 (see Fig. 2) at the tip 26 is left smooth, rather than ragged or torn because of the thin wall defined by the indentation 42. For reasons which will be described in further detail below, plug 32 of stopper 20 extends into orifice of passageway 58 and mates with the passageway on attachment of the stopper to the tip.

The major component parts of a dispenser constructed in accordance with the present invention are shown in Figs. 2, 3, 4, and 5. A container 44 for the fluid 45 to be dispensed, such as one of the family of cyanoacrylate adhesives, includes a mouth 46 defined by an internal cylindrical surface 48 of the container neck 50 extending from the shoulder -52 thereof.

The diameter of the cylindrical surface 46 is the same as or somewhat less than the diameter of cylindrical section 1 8 of the dispenser tip 10 to ensure a frictional or force fit therebetween; tapered section 20 aids in insertion of the cylindrical section within the cylindrical surface and mates with a correspondingly tapered shoulder 54 (see Fig. 3).

The stopper 1 2 engages the tip 26 which engagement brings about insertion of plug 32 through orifice 56 into passageway 58 (see Fig. 3) in the tip and mating of the ridge 40 in the stopper with groove 28 of the tip.

A cap 60 encloses the dispenser tip 10 and its attached stopper 1 2 upon engagement of the locking mechanisms disposed in the cap with the locking mechanisms disposed about cylindrical neck 50.

Fig. 6 illustrates the tip 10 attached to a container 44 and enclosed within a cap 60. It will be noted that stopper 1 2 has not been detached from the tip. That is, the cap is specifically dimensioned so as to permit shipment of the dispenser from the manufacturer through various distribution channels to the ultimate user while maintaining the dispenser hermetically sealed.

By experimentation, it has been learned that evacuation of the cyanoacrylate adhesive within the passageway in a dispensing tip leading to the discharge outlet is a complex function of several variables, including propensity for rapid polymerization, surface tension, configuration of the passageway and the degree of surface energy of the material defining the passageway and discharge outlet. Initially, it was believed that by having the passageway flare toward the container, bridging thereacross of the cyanoacrylate adhesive would be avoided and polymerization or crusting sufficient to clog the passageway would be constrained. Such is not the case.

Contrary to the expectations of those skilled in the art, essentially total drainage of a cyanoacrylate adhesive will occur in a constant or segmented constant diameter passageway provided each downstream passageway termination is sharp edged. Moreover, evacuation appears to be aided if forced gravity flow is initiated. To the extent presently understood, it is believed that this phenomenon is primarily a function of surface tension of the cyanoacrylate adhesive and that the surface tension, in combination with the other parameters discussed above, will support continuing drainage after an initial flow is provided by means of a plunger or the like.

Accordingly, as noted in various of Figs. 1 to 6, the plug 32 is formed within the stopper 1 2 to penetrably engage an upper part of the passageway 58 upon mating of the stopper with the dispensing tip. The initial insertion of the plug within the passageway will initiate forced downward flow of any cyanoacrylate adhesive coming into contact therewith or by a pressure rise of the air within the passageway between the penetrating end of the plunger and any cyanoacrylate adhesive within the passageway. The initial downward flow, on co-mingling with any further cyanoacrylate adhesive in the remainder of the passageway will, by means of what is believed to be an "avalanche" effect, initiate and maintain essentially complete drainage of the cyanoacrylate adhesive from the passageway back into the container.

As may be deduced from the above description of the structure of the stopper 1 2 and the dispenser tip 10, engagement of the ridge 40 with the groove 28 will maintain the stopper attached to the dispensing tip to prevent inadvertent opening of the passageway 58 by withdrawal of the plug 32. Additionally, the combined effect of plug 32 mating with passageway 58, tapered tip 26 mating with the interior cone-shaped surface of cone-shaped section 30 and ridge 40 mating with groove 28 will provide an air tight or near air tight seal to prevent flow of fluid, whether cyanoacrylate adhesive or air, into and out of container 44.

The various parameters attendant the configuration of passageway 58 will be reviewed with joint reference to Figs. 3, 5 and 6. For reasons stated above, the wall defining the passageway should not be tapered or else clogging and crusting will often occur due to the poor drainage and subsequent "bridging" of the cyanoacrylate adhesive.

Because of the necessary tolerances, injection molding is employed to fabricate the tip and stopper as a single unit. The tolerance obtainable thereby permits the formation of a very smooth wall for passageway 58 and allows maintenance of a constant diameter in the range of from 0.406mm to 1 .346mm (-0.016 to 0.053 inches) throughout. To aid and encourage separation of any drained cyanoacrylate adhesive from the passageway 58 back into the container 44, the inlet orifice 62 is deliberately sharp edged. Such a sharp edge substantially eliminates dependency therefrom of any residual drops or droplets.

The limitations extant and attendant injection molding place a constraint upon the maximum length of the passageway 58 which can be formed to the tolerance required in conjunction with the diameter of the passageway and the decreasing wall thickness and diameter of the tip 26.

To solve this problem for extended length tips, extensive experimentation led to the configuration of passageway 58a illustrated in Fig. 6. This passageway avoids the constraints imposed by injection molding limitations and provides a passageway which will drain and not become clogged. Passageway 58a includes a plurality of ascending diameter constant diameter sections 64, 66, 68 and 70. At the junction of adjoining sections sharp edged annular shoulders 72, 74, 76 and 78, respectively, are formed. Drainage of any residual cyanoacrylate adhesive through each of the sections 64, 66, 68 and 70 will occur for the reasons stated above. At each shoulder, the sharp edge provides insufficient purchase for the surface tension attendant any drop or droplet to support in depending relationship the drop or droplet.Thus, drainage is assured. In one embodiment of passageway S8athe dimensions of the sections are: diameter length Section 64 0.040" (~1.016mm) 0.295" (~7.493mm) Section 66 0.084" (~2.134mm) 0.305" (~7.747mm) Section 68 0.09375" (~2.381mm) 1.267" (~32.182mm) Section 70 0.250" (~6.350mm) 0.123" (~3.124mrn) As briefly discussed above, the termination of the tip 26 defining orifice 56 should be smooth and sharp edged to prevent retention thereat of a cya.loacrylate adhesive droplet which might crust or clog the orifice. With break away junctions, formation of such an edge is usually a problem. The solution to this problem embodied i the present invention is two fold.Firstly, the passageway 58 or 58a is formed to extend completely through the tip 26 and partially into the disc section 34 of the stopper 12, as particulag ',,"'trated in Figs. 5 and 6. Annular indentation 42 has a V-shaped cross-section of a smel! apex angle and circumscribes the tip 26 adjacent the planar surface of the disc section 16. Such an indentation, when the stopper 12 is manually or non-manually broken away from tip 10, will result in a sharp edged termination of the tip 26 having a cone shaped configuration and an essentially smooth surface that is not jagged or torn and which defines the orifice 56, as EJarticularly illustrated in Fig. 4.A small recess 80, formerly an tension of the passageway formed in the dispenser/stopper unit when manufactured, exists within the surface of the disc 34, which recess is of no import to the operation of the stopper. However, the extension o the passageway past identation 42 into the disc ensures that the orifice resulting after breal:swa',' of the tip is well defined and smoothly circumscribed.

The elements of the locking mechanisms intermediate the cap 60 and the container 44 will now be described with joint reference to Figs. 2, 3, 7, 8, 9, 10, 11 and 12. Four lugs 82 are equiangularly disposed about the surface of the cylindrical neck 50. These lugs 82 are shaped in the nature of downwardly oriented louvers, as illustrated. The cap 60 includes four flanges 84 extending inwardly from the inner walls thereof which positionally correspond with the lugs 82 to obtain a mating interlock therebetween on positioning of the bottom edge 86 of the cap 60 with the shoulder 88 of the container 44. These flanges 84 are upwardly oriented louver-like elements, as illustrated.

In cross-section, the cap 60 is square and the lOs r edge 88 is dimensioned generally commensurate with the square cross-sectional conTiguration of the container 44. Abuttments 90 are disposed proximate each corner edge of the coniainer 44 and extend upwardly from the shoulder 88. Each of these abuttments 90 defines a channel 92 extending upwardly from the shoulder 88 which is in radial alignment with the cylindrical neck 50. Cap 60 includes, in two opposed corners, invvardly extending ribs 94. These ribs are dimensioned in width and breadth to engage diametrically opposed ones of channels 92 on positioning of the cap 60 upon the container 44 when the bottom edge 86 is adjacent the shoulder 88. As may be noted from Fig.

10, the ribs are configured not to interfere with disc 34 of stopper 12.

Attachment and detachment of the cap 60 on container 44 will be described with reference to Figs. 9, 10, 11 and 12. To detach the cap from iE73 esontainer, diametrically opposed corners 96 of the cap, which corners do not include any ribs 94, are squeezed together. The resulting flexing of cap 60 causes the diametrically opposed corners 98 to be laterally displaced from one another. The resulting displacement withdraws ribs 94 from their mating channels 92. On disengagement, the constraints intermediate the cap and container relative to rotation therebetween are removed.Simultaneous with the squeezing of corners 96 and after disengagement of the ribs, cap 60 is rotated relative to container 44 about the longitudinal axis of the cap and container. Such rotation will result in angular displacement of the flanges 84 relative to the lugs 82 and is continued until the flanges are no longer in contacting relationship with the respective lugs. This position is illustrated in Fig. 1 2. The cap 60 may now be removed from container 44.

Assembly of cap 60 on container 44 is a reverss implementation of the above described operation. That is, the cap 60 is placed upon the container 44 such that the flanges 84 are in general alignment with the abutments 90; therea.C(er, the cap 60 is rotated about its longitudinal axis relative to the container 44 until the flanges slidably engage and interlock with lugs 82.

Simultaneously, corners 96 of the cap are squeezed toward one another to allow clearance between ribs 94 and the pertaining one of the abutrments 90. Upon sufficient rotation of the cap 60 with respect to the body to align the corner edges of the cap with the corner edges of the container, the ribs 94 will become aligned WLI irLe channels 92 and the cap 60 may then be released. At this point, rotation of the cap Q with respect to the container is constrained by the mating of the ribs 94 with tne channels 92 in -' abuttments; vertical displacement of the cap 60 with respect to the container is preven".d by ;he interlocking relationship between the lugs 82 and the flanges 54.

From the above descrin-tion it wil become apparent that the edge 86 of the cap 60 may be a force fit against the shoulder 88 by appropriate location of the lugs 82 and/or the flanges 84 to rigidly retain the cap 60. Moreover, the tightness of fit between the cap 60 and the container has no effect upon leakage since stopper 10 is employed to seal the dispensing tip passageway.

The extensive contact area between the cylindrical section 18, the tapered section 20 and the underside radial surface of the disc section 1 6 with the corresponding surfaces of the cylindrical neck 50 of the container 44 permits a weld therebetween to be formed to ensure a total seal between the dispenser tip and the container, despite variations in manufacturing tolerances and possible deformation of the mating surfaces due to, for example, scratches.

Figs. 1 3 and 1 4 illustrate a variant of the dispenser. In the variant, both the container 100 and the cap 102 are circular rather than square in cross-section. The container supports a cylindrical neck 104 for receiving a tip 10 and an attached stopper 12, as above described. The mechanism for detachably attaching cap 102 to the container 100 includes an annular ridge 106 disposed about the cylindrical neck 104, and having a sloping surface 108 and a surface 110 normal to the longitudinal axis of the neck 104. A radially inwardly oriented protrusion 11 2 is formed proximate the edge of the cap for detachable snap fit engagement with the ridge 106. Thereby, the cap can be readily removed and reattached to the container.

Claims (31)

1. A dispensing tip attachable to the mouth of a container of liquid adhesive for dispensing the adhesive, said dispensing tip comprising in combination: (a) a boss for sealingly engaging the mouth of the container; (b) a tip extending from said boss for dispensing the adhesive; (c) a passageway extending through said tip for discharging the fluid to be dispensed; (d) sealing means detachably attached to the end of said tip for hermetically sealing said passageway prior to detachment of said sealing means for said tip; and (e) a break away junction between said tip and said sealing means for detaching said sealing means from said tip.

2. A dispensing tip as claimed in Claim 1 wherein the break away junction includes an annular identation about the tip and which circumscribes said passageway.

3. A dispensing tip as claimed in Claim 2 wherein the difference in radius between the indentation and the passageway is 0.0508mm (-0.0020 inches).

4. A dispensing tip as claimed in Claim 2 or Claim 3 wherein the indentation is V-shaped in cross-section.

5. A dispensing tip as claimed in Claim 4 wherein the apex of the V-shaped indentation is an acute angle.

6. A dispensing tip as claimed in any of Claims 1 to 5 wherein the sealing means comprises a stopper, the stopper including capping means for capping said tip after detachment thereof and intermediate periods of dispensation of the fluid.

7. A dispensing tip as claimed in Claim 6 wherein the stopper includes a disc section and a hollow cone shaped section attached to the centre of said disc section and extending longitudinally therefrom along the axis of said disc section.

8. A dispensing tip as claimed in Claim 7 wherein the disc section is attached to the tip end.

9. A dispensing tip as claimed in Claim 7 or Claim 8 wherein the axis of the passageway, the disc section and the cone shaped section are in alignment.

10. A dispensing tip as claimed in any of Claims 7 to 9 wherein the passageway extends into said disc section.

11. A dispensing tip as claimed in any of Claims 2 to 10 wherein one side of the indentation is coincident with a surface of said disc section.

1 2. A dispensing tip as claimed in any of Claims 1 to 11 wherein the passageway has a constant diameter.

1 3. A dispensing tip as claimed in Claim 1 2 wherein the diameter of the passageway is in the range of from 0.406mm to 1.346mm (-0.016 to 0.053 inches).

1 4. A dispensing tip claimed in any of Claims 1 to 11 wherein the passageway includes a plurality of constant diameter sections arranged in ascending diameter from the said tip end to the boss.

1 5. A dispensing tip as claimed in Claim 14 having four constant diameter sections.

16. A dispensing tip as claimed in Claim 14 or Claim 15 wherein each junction between the constant diameter sections includes a sharp edged shoulder.

1 7. A dispensing tip as claimed in any of Claim 1 to 16 wherein the boss includes a sharp edged inlet in fluid communication with the passageway.

1 8. A dispensing tip attachable to the mouth of a container of liquid adhesive for dispensing the adhesive substantially as herein described with reference to the accompanying drawings.

CLAIMS (10 Mar 1981)

1 9. A two phase lock for securing a cap to a container, said lock comprising in combination: (a) lug means disposed about the mouth of the container; (b) flange means disposed within the cap for disengageably engaging said lug means upon angular displacement of the cap relative to the container; and (c) key means and keyway means disposed intermediate the cap and the container for precluding rotation of the cap relative to the container, said key means and said keyway means being laterally displaceable relative to one another to effect disengagement of said key means from said keyway means and permit angular displacement of the cap relative to the container; whereby the cap may be removed from the container upon rotation of the cap relative to the container after disengagement of said key means with said keyway means.

20. A lock as claimed in Claim 1 9 wherein the mouth of the container includes a hollow section and the lug means are located upon the exterior surface of said section.

21. A lock as claimed in Claim 20 wherein the keyway means includes at least one channel disposed upon the hollow section and the key means includes at least a rib extending from the cap for engagement with one of the channels.

22. A lock as claimed in Claim 21 wherein the channel extends parallel to the longitudinal axis of the hollow section and includes an opening for receiving the rib.

23. A lock as claimed in Claim 22 wherein the container includes two of the channels in opposed relationship to one another and the cap inlcudes two of the ribs in opposed relationship to one another.

24. A lock as claimed in Claim 23 wherein the hollow section includes four lugs located thereabout and the cap includes four flanges located within the cap for mating engagement with said four lugs.

25. A lock as claimed in Claim 24 wherein the pair of channels are not in alignment with a line extending through any two of the four lugs.

26. A lock as claimed in Claim 25 wherein the cap includes a lower edge and the container includes a shoulder about the hollow section for engaging the lower edge of the cap upon locking engagement of the cap with the container.

27. A lock as claimed in Claim 26 wherein the container and the cap are substantially square shaped in cross-section and have corner edges, the pair of channels being disposed adjacent opposed ones of the corner edges of the container and the pair of ribs being disposed adjacent opposed ones of the corner edges of the cap.

28. A lock as claimed in any of Claims 20 to 27 wherein the section is a cylindrical section.

29. A dispenser for dispensing cyanoacrylate, said dispenser comprising in combination: (a) a container for housing the cyanoacrylate, said container including an element defining the mouth of said container; (b) a dispensing tip secured to the mouth of said container and defining a passageway for dispensing the cyanoacrylate from said container; (c) a removable stopper for sealing said passageway; (d) a cap for shielding said dispensing tip; and (e) a two phase lock means for securing said cap to said container.

30. A dispenser as claimed in Claim 29 wherein the two phase lock means is a two phase lock as claimed in any of claims 1 9 to 28.

31. A dispenser as claimed in Claim 29 or Claim 30 wherein the passageway comprises a constant diameter passageway.