RESERVOIR AND APPLICATOR FOR A LIQUID

Abstract: A combined storage reservoir and applicator has a tubular reservoir (10) open at one end (11) and external threads (16) over a part of its length. A tubular applicator (13) is arranged to receive a part of the reservoir (10) including the open end (11) thereof, the applicator (13) having internal screw threads (18) which engage the reservoir threads (16). The applicator also has a closure (26) which defines a circular sealing surface to engage and seal the open end (11) of the reservoir. A stop arrangement (17, 20) resists complete withdrawal of the reservoir from the applicator on fully unscrewing the threads (16, 18) of the applicator and reservoir.

Description: RESERVOIR AND APPLICATOR FOR A LIQUID This invention relates to a combined storage reservoir and applicator for a liquid, particularly - but not exclusively - for use with a liquid adhesive. Adhesives are being used on an increasing scale in the medical field, to assist the healing of wounds inflicted either accidentally or during the course of surgery. The selection of an appropriate grade of an adhesive for the intended use is critical, and the adhesive must be stored under sterile conditions, until required for use. To this end, there have been various proposals for medical grade liquid adhesive storage reservoirs, to allow a medical practitioner or surgeon to release a quantity of adhesive at the time it is required for use. One particular adhesive has been used very successfully in an operating theatre, to assist the bonding of strips to a patient at the site of a wound whereby the strips may hold together the cut tissues. This adhesive is supplied in a glass vial contained in a thin-walled clear plastic tube closed at one end and containing an applicator pad at the other end. When the adhesive is to be used, the plastic tube is squeezed to break the glass vial and release the adhesive. Continued pressure on the plastic tube urges the liquid on to and through the applicator pad. The above-described arrangement is not entirely satisfactory. It can be difficult to break the glass vial through the plastic tube unless significant pressure is applied at exactly the required site. Also, there is the attendant risk that the plastic tube might be penetrated by a sharp edge of the broken vial, which can lead to an operator injury, as well as leakage of unused adhesive. The present invention aims at providing a combined storage reservoir and applicator which is particularly suitable for use in a medical or surgical environment, for use with liquid adhesives, and which overcomes the disadvantages discussed above of the known arrangement using a glass vial. According to one aspect of the present invention, there is provided a combined storage reservoir and applicator for a liquid, comprising a tubular reservoir open at one end and closed at the other end, the reservoir having extemal threads over at least a part of its length, a tubular applicator arranged to receive therewithin at least a part of the reservoir including one end portion thereof having the open end, the applicator having internal screw threads with which the external threads of the reservoir may engage, the applicator further having an internal closure which defines a circular sealing surface adapted to interengage and form a seal with the one end portion of the reservoir when fully threaded into the applicator, there being retaining means to resist complete withdrawal of the reservoir from the applicator on performing unthreading relative rotation of the applicator and reservoir. The arrangement of the present invention allows the containment of the adhesive in a sealed chamber, until it is required for use. Then, the applicator may be threaded away from the reservoir, so opening the reservoir and allowing the flow of liquid into the applicator, but the retaining means serves to prevent complete disengagement of the reservoir from the applicator. In this way, adhesive may leave the combined assembly only through the applicator itself. In a preferred form of reservoir and applicator assembly of this invention, the retaining means serves to restrain complete withdrawal of the reservoir from the applicator only after the reservoir threads have been disengaged from the applicator threads. In this way, continued relative rotation between the reservoir and applicator will not impart any axial load on the retaining means. According to a second aspect of the present invention, there is provided a combined storage reservoir and applicator for a liquid, comprising a tubular reservoir open at one end and closed at the other end, the reservoir having external threads over at least a part of its length and at least the end portion of the reservoir adjacent the open end thereof being formed of a relatively rigid material, and a tubular applicator arranged to receive therewithin at least said end portion of the reservoir, the applicator having internal screw threads with which the extemal threads of the reservoir may engage, the applicator further having an internal closure which defines a circular sealing surface adapted to interengage and form a seal with said end portion of the reservoir when fully threaded into the applicator, at least a part of the applicator which overlies said reservoir end portion when the seal is effective being deformable inwardly but such inward deformation being resisted by said end portion until said end portion has been threaded away from the internal closure of the applicator. This second aspect of the invention has the advantage that pressure cannot be applied to the applicator until such time as the applicator has been unthreaded from the reservoir, so opening that reservoir to allow the flow of liquid from the reservoir to the applicator. However, once the applicator has been released from the reservoir, that applicator may be squeezed inwardly to assist the ejection of adhesive from the applicator, to the required site of use. Preferably, the one end portion of the reservoir defines an extemal sealing surface arranged to effect a seal to the internal tubular wall of the applicator. For example, said extemal sealing surface may upstand from the one end portion of the reservoir, there being an internal shoulder within the applicator with which the upstanding extemal sealing surface of the reservoir cooperates. This may thus perform the combined function of a retaining means and a further seal to prevent leakage from the joint between the reservoir and the applicator. A preferred embodiment of reservoir and applicator assembly of this invention has an internal substantially annular surface defined by the one end portion of the reservoir. In this case, the circular sealing surface of the applicator should comprise an external substantially annular surface, so that both substantially annular surfaces may interengage on threading the reservoir into the applicator so as to close the open end of the reservoir. Advantageously, at least one of said substantially annular surfaces has a conical form to increase the sealing effect the deeper the reservoir and applicator threads are interengaged. To facilitate the use of the applicator to apply a liquid such as a medical grade adhesive to a required site, the applicator may include a holder for an applicator pad, the holder communicating with the interior of the reservoir when the one end portion of the reservoir has been threaded away from the circular sealing surface. This invention extends to a combined storage reservoir and applicator assembly of this invention as described above and including a liquid adhesive formulation contained within the reservoir. By way of example only, one specific embodiment of the present invention will now be described in detail, reference being made to the accompanying drawings in which - Figure 1 is a side view of a combined reservoir and applicator assembly constructed and arranged in accordance with preferred aspects of the invention, Figure 2 is a longitudinal sectional view through the assembly of Figure 1 and showing the reservoir closed by the applicator; Figure 3 is similar to Figure 2 but shows the reservoir opened; Figure 4 is a general perspective view of the applicator of Figure 1 ; Figure 5 is similar to Figure 4 but partially cut away to show internal constructional features; Figure 6 is an end view on the applicator shown in Figures 1 and 4; and Figure 7 is a detailed view showing the applicator pad used in the arrangement of Figures 1 to 5. The combined reservoir and applicator shown in the drawings is intended for use in the medical environment, to allow accurate dispensing of a liquid adhesive to a required site in the vicinity of a wound, to permit the adhesion of a dressing to the skin of a patient. The assembly comprises a tubular reservoir 10 open at one end 11 and closed at the other end 12, the one end 11 being fitted into a tubular applicator 13 having an applicator pad 14 fitted to its end further from the reservoir 10. The reservoir 10 includes four fins 15 to assist gripping of the reservoir when the applicator is to be used, and external threads 16 formed at a location partway between the two ends 11 and 12 of the reservoir At the open one end 11 of the reservoir, there is formed an external annular rib 17 for a purpose to be described below. The applicator has internal threads 18 arranged for interengagement with the external threads 16 of the reservoir, and also has a cylindrical substantially parallel surface 19 against which the rib 17 engages That surface 19 terminates in a shoulder 20 adjacent the internal threads 18 Externally, the applicator 13 is formed with four slots 21 to facilitate gripping of the applicator when it is to be turned relative to the reservoir 10 The applicator also includes markings 22 to indicate the direction in which the applicator should be turned relative to the reservoir, to open the reservoir End 23 of the applicator is formed as a holder for the applicator pad 14, shown in greater detail in Figure 7, the pad including an external surface 24 which may be sprung behind a lip 25 formed at the free end 23 of the applicator The pad has a general wedge-shape, to facilitate accurate placement of adhesive There is also a groove extending along the pad, to permit air to enter the reservoir after dispensing some adhesive. Within end 23 of the applicator there is formed a conical sealing member 26 disposed on the applicator axis, and with an annular groove 27 therearound. The open one end 11 of the reservoir 10 may engage in that groove in order that the sealing member 26 may close that open one end of the reservoir. The deeper the threads 16 and 18 are interengaged, the more the open end 11 of the reservoir is pushed into the narrowing groove 27, so increasing the sealing effect between the conical member 26 and the end 11 of the reservoir. Passageways 29 are formed through the conical sealing member 26 in the region thereof adjacent the base of the groove 27, to permit the through-flow of adhesive from the groove 27, to the applicator pad 14. The reservoir 10 is moulded from a relatively rigid grade of plastics material such as a rigid PVC and the applicator 13 is moulded from a softer grade of a similar plastics material, in order to permit inward deformation of that part 28 of the applicator clear of the reservoir. The applicator pad 14 is made from a slightly soft, sintered polyethylene, in order that it may have sufficient porosity to permit the through-flow of the liquid adhesive. In use, the reservoir 10 is charged with a sterile liquid adhesive formulation and the applicator 13 is threaded on to the reservoir until the open one end 11 of the reservoir is tightly sealed by interengagement of the conical sealing member 26 with the inner wall of the reservoir at said one end The applicator pad 14 is snapped into the applicator holder and then the entire assembly is packaged for example in a bubble pack including instructions and so on, on the backing card The final packaged product may be sterilised for example by exposure to gamma radiation. When the applicator is to be used to dispense adhesive, the entire assembly is removed from the bubble pack and the reservoir is opened by relatively twisting the reservoir 10 and the applicator 13. This separates the reservoir and the applicator, to the position shown in Figure 3. Here, the threads 16 and 18 have separated and the rib 17 has slid back along surface 19 until the rib engages the shoulder 20 of the applicator. That interengagement prevents further separation of the reservoir and applicator and relative rotation between the two components imparts no axial forces to either component. The region 28 of the applicator 13 is now clear of the relatively rigid reservoir 10 and so may by squeezed inwardly. This applies pressure to the liquid adhesive, to encourage flow of the adhesive through the applicator pad 14. After use, the reservoir and applicator may be pushed together and turned in the opposite sense, to re-engage the threads and then close the reservoir 10, to prevent unwanted leakage of adhesive. In the alternative, by holding the device with the applicator lowermost, re-engaging the threads and turning the reservoir relative to the applicator, the effectively reducing volume of the reservoir will drive adhesive out of the reservoir through the pad 14. This could be useful, for example to flood a bandage or an area of skin with adhesive.

Claims: CLAIMS 1. A combined storage reservoir and applicator for a liquid, comprising: -a tubular reservoir open at one end and closed at the other end, the reservoir having external threads over at least a part of its length; -a tubular applicator arranged to receive therewithin at least a part of the reservoir including one end portion thereof having the open end, the applicator having internal screw threads with which the extemal threads of the reservoir may engage, the applicator further having an internal closure which defines a circular sealing surface adapted to interengage and form a seal with the one end portion of the reservoir when fully threaded into the applicator, there being retaining means to resist complete withdrawal of the reservoir from the applicator on performing unthreading relative rotation of the applicator and reservoir. 2. A combined storage reservoir and applicator as claimed in claim 1 , wherein the retaining means restrains complete withdrawal of the reservoir after the reservoir threads are disengaged from the threads of the applicator. 3. A combined storage reservoir and applicator as claimed in claim 1 or claim 2, wherein the applicator .pa is manufactured from a deformable grade of a plastics material. 4. A combined storage reservoir and applicator as claimed in claim 3, wherein the reservoir is manufactured from a relatively rigid material and resists inward deformation of the applicator until at least partially unthreaded from the applicator. 5. A combined storage reservoir and applicator as claimed in any of the preceding claims, wherein the one end portion of the reservoir defines an extemal sealing surface arranged to effect a seal to the internal tubular wall of the applicator. 6. A combined storage reservoir and applicator as claimed in claim 5, wherein said external sealing surface upstands from the one end portion of the reservoir, and there is formed an internal shoulder within the applicator with which the upstanding external sealing surface of the reservoir co-operates to form therewith said retaining means 7 A combined storage reservoir and applicator for a liquid, comprising -a tubular reservoir open at one end and closed at the other end, the reservoir having external threads over at least a part of its length and at least the end portion of the reservoir adjacent the open end thereof being formed of a relatively rigid material, and a tubular applicator arranged to receive therewithin at least said end portion of the reservoir, the applicator having internal screw threads with which the external threads of the reservoir may engage, the applicator further having an internal closure which defines a circular sealing surface adapted to interengage and form a seal with said end portion of the reservoir when fully threaded into the applicator, at least a part of the applicator which overlies said reservoir end portion when the seal is effective being deformable inwardly but such inward deformation being resisted by said end portion until said end portion has been threaded away from the internal closure of the applicator 8 A combined storage reservoir and applicator as claimed in claim 7, wherein the one end portion of the reservoir defines an external sealing surface arranged to effect a seal to the internal tubular wall of the applicator 9 A combined storage reservoir and applicator as claimed in claim 8, wherein said external sealing surface upstands from the one end portion of the reservoir, and there is formed an internal shoulder within the applicator with which the upstanding external sealing surface of the reservoir co-operates to form therewith retaining means to resist complete withdrawal of the reservoir from the applicator on performing unthreading relative rotation of the applicator and reservoir 10 A combined storage reservoir and applicator as claimed in any of the preceding claims, wherein the one end portion of the reservoir defines an internal substantially annular surface, and the circular sealing surface of the applicator is an external substantially annular surface, said substantially annular surfaces being adapted to interengage on threading the reservoir into the applicator so as to close the open end of the reservoir 1 1 A combined storage reservoir and applicator as claimed in claim 10, wherein at least one of said substantially annular surfaces has a conical form to increase the sealing effect the deeper the reservoir and applicator threads are interengaged 12 A combined storage reservoir and applicator as claimed in any of the preceding claims, wherein the applicator includes a holder for an applicator pad, the applicator holder communicating with the interior of the reservoir when the one end portion of the reservoir has been threaded away from the circular sealing surface 13 A combined storage reservoir and applicator as claimed in claim 12 and further comprising an applicator pad held within the applicator pad holder and arranged to receive liquid from the reservoir when the reservoir has been threaded away from the circular sealing surface 14. A combined storage reservoir and applicator as claimed in any of the preceding claims and including a liquid adhesive formulation contained within the reservoir

Inventors: SAMS BERNARD, WOOLSTON ROBERT, SAMS, BERNARD, WOOLSTON, ROBERT
Applicants: SAMS BERNARD, WOOLSTON ROBERT, SAMS, BERNARD, WOOLSTON, ROBERT
Application year: 1997
Main classification: G01F11
IPC codes: A45D34, A61M35, B05C17, B43M11, B65D83, G01F11