WO2001060518A1

WO2001060518A1 - Fluid sample receptacle

Info

Publication number: WO2001060518A1
Application number: PCT/GB2001/000638
Authority: WO
Inventors: Roy Taylor
Original assignee: Camlab Limited
Priority date: 2000-02-18
Filing date: 2001-02-16
Publication date: 2001-08-23
Also published as: GB0003882D0; AU3386401A

Abstract

A microtube (10) comprises a body (12) defining a chamber (14) with an opening (16), and a closure cap (18). The closure cap (18) has a ring-shaped collar (24) attached to it by frangible connections (26). The ring-shaped collar (24) is of a size to be a tight fit over ridge (22) around the rim (20) of opening (16). Once the opening (16) is first capped by the closure cap (18), access to the chamber (14) can only be regained by breaking frangible connections (26). The closure cap (18) includes stopper (19) which plugs the opening (16) with a snap-fitting action to provide for re-use and re-sealing of the microtube (10).

Description

TITLE : FLUID SAMPLE RECEPTACLE

DESCRIPTION

TECHNICAL FIELD

The present invention relates to receptacles for receiving fluid samples, particularly but not exclusively during laboratory experiments. BACKGROUND ART A receptacle such as the (1.5 ml ^ microtuoe - also known as the microcentπfuge tube or the Eppendorf tube - is a widely used, everyday laboratory commodity which is not application specific. A diverse array of instrumentation, including centrifuges, shakers, neating blocks, tube racks and homogenisers, have evolved for use with the raicrocubes. Although the overall size of the microtube has been standardised to fit the instrumentation, various design features may be regarded as optional . For example, microtubes may be provided with or without caps, the caps may be "snap-fit" or "screw- fit " ; and "cap-locks" may be provided, either of retrofit or integrally mouldec αesign. The cap- ocks are by there very nature reusable. The present applicant has appreciated that the provision of a tamper-evident feature would be a novel and potentially significant improvement to laboratory receptacles, especially Known microtube designs.

Closures for containers which include means for indicating whether the container has been opened after the closure has been applied to the container are known from U.K. patent specif cations GB 698,992, GB 1,128,815 and GB 1,163,203. All tnree documents disclose a cap arrangement for a container wnich includes an inner skirt or plug for bearing against tne inner periphery of the container, and an outer skirt for positively engaging the outer periphery of the container. The outer skirt includes a lower annular section whicπ is connection to an upper annular section cy a tear strip or otner frangible connection. The tear strip provides a secure connection between the upper and lower annular sections until deliberately removed or broken to permit access to container contents. After detachment of tne lower annular section, the upper annular section engages the outer peripnery of the container such that the cap arrangement may be firmly replaced after being removed. DISCLOSURE OF INVENTION

In accordance with a first aspect of the present invention, tnere _s provided a receptacle (.e.g. microtube for receiving a fluid sample, comprising a first part defining a chamber with an opening, a second part having a stopper for plugging the opening, a collar attached to one cf the parts by at least one frangible connection, and a ridge member associated with the other part, the collar cemg a tight fit over the ridge member when the opening is first plugged, with the at least one frangible connection fracturing when the opening is first unplugged, leaving the collar with the ridge member, characterised m that the first part includes m the chamber a profile configured tc engage with a snap- fit action a corresponding profile on tne stopper when plugging the opening, the profiles providing a re-usable seal between the first and second parts . The ridge member may be associated with or integral with the first part (hereinafter the "body" of the "icrotuoe) ; and the collar may be attached to the second part Hereinafter the "closure cap" of the microtube) . Initially, the collar provides for secure closure of the opening m the body; the closure cap is "locked" m the closed position by the collar nesting under the ridge -ember. The closure cap may even be positively biased m tne closed position by making the collar a tight fit under tne ridge member when the opening is first capped. Ir. addition, the collar provides a tamper-evident device; once tne microtube is sealed, the only way to regain access to tne chamber is to break the at least one frangible connection. The secure closure and tamper-evident features cring, for the first time, the benefits of sample integrity as well as a hold- fast arrangement m laboratory applications, e.g. during centrifugmg and cold storage. After detachment of the collar from the closure cap, the microtube may be reused as a conventional product, either with or without the closure cap.

The closure cap may be a push fit onto the body m order to cap the opening. Such a push fit mecnanism provides for single-handed opening and closing cf the icrotuϋe.

The closure cap may be connected to the body by a coupling which allows the closure cap to cap and uncap the opening m the body. The coupling may comprise a resilient strip. The coupling may abut the body m a position spaced from the ridge member. The body spacing between the ridge member and the coupling may accommodate the collar when nesting under the ridge member. The collar may have a recess for accommodating part of the coupling, tneredy nelpinσ to reduce the body spacing between the ridge member and the coupling.

The ridge member may be integral with a rim around the opening m the body. The closure cap may also include a recess for snap- fit engagement by the rim. The collar may be ring snaped, and may be integrally formed with the closure cap. The at least one frangible connection may be part of an array for frangible connections, fastening the collar to the closure cap prior to first use. The array may comprise two components, distributed on each side of a tab for prising the closure cap off the body. By not having frangible connections under the tab, it may be easier to initiate detachment of the collar from the closure cap. The mterengagmg profiles of the first and second parts may be rib-like, with each one raised proud of its surroundings. The rib-like profiles may be circular, with the inner diameter of the rib- like profile on the first part being less tnan the outer diameter of the rib-like profile on the second part to provide the snap-fit action.

In one embodiment, a portion of the stopper is a free or loose fit m the opening to facilitate fracturing the at least one frangible connection. In this way, the loose fitting portion of the stopper allows sufficient play between the parts to break the at least one frangible connection without having to exert an excessive force to remove the stopper from the opening. The loose fitting portion of the stopper may also assist with re-sealmg and re-separatmg the parts by allowing the profiles to be brought into engagement at a slight angle instead of squarely head-on.

In accordance with a second aspect of the present invention, there is provided a receptacle for storing fluid, comprising a first part defining a chamoer witn an opening, a second part for capping the opening, means for coupling the first part to the second part even when the opening is uncapped, a collar attached to one of the parts by at least one frangible connection, and a ridge member integral with the other part, the collar being a tight fit over the ridge member and nesting under the ridge member when the opening is first capped, wherein the at least one frangible connection fractures when the opening is first uncapped, leaving the collar nesting under the ridge member. The receptacle may be laboratory apparatus for use m laboratory experiments, and may even be a microtube. Features of the first aspect of the invention are applicable mu ta ti s mutandi s to the second aspect of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will now be described by way of example, with reference to the accompanying figures, m which: Figure 1 shows a perspective view of a microtube embodying the present invention m the open configuration;

Figure 2 shows a cross-sectional view through the microtube of Figure 1;

Figure 3 shows a bottom plan view of the microtube of Figure 1 (stabilisers omitted for sake of clarity) ; and

Figure 4 is a side view of a laboratory receptacle according to a second embodiment of the invention. BEST MODES FOR CARRYING OUT THE INVENTION

Figure 1 illustrates a microtube (10) embodying the present invention, comprising a body (12) defining a chamber (14) with an opening (16), and a closure cap (18) having as stopper (19) for plugging the opening (16) . The opening < 16 ) has a π™ 20) wnich projects radially c_^twardly to provide a step or ridge (22) . Initially, the closure cap (18) has a ring-shaped collar (24) attacned tc it by frangible connections (26) . The ring-shaped collar

24) is of a size so as to be a tight fit over the rι~ 20), and becomes nested under the ridge (22) when opening

16) is fully capped by the closure cap (18) . In this way, fluid placed m the microtube 10 ) is securely sealed inside with stopper (19) plugging the opening (16) . When access to the chamber (14) is required, and the closure cap 13) is removed, the frangible connections (26) oreaκ, detaching the collar (24) from the closure cap (18/ , and leaving the ring-shaped collar (24) trapped around the body

12) . In this way, it is immediately evident that the

-icrotube has been reopened after first sealing, thereby providing a one-off "tamper-evident" feature.

The stopper (19) of the closure cap (18) includes a cylindrical portion (30) which extends axially proud of the frangicle connections (26) and collar (24) . The cylindrical portion (30) is a snug fit m the opening (16 cf the body (12), but not a friction fit therein. This relatively free- fitting arrangement enables the stopper

19) to be pushed out of the opening (16) slightly off-axis v.T.ich makes it easier to break the frangible connections. A raised, rib-like profile (32) is provided on the curved cuter periphery of the cylindrical portion (30), adηacent tne leading end thereof. The rib-like profile (32) extends radially proud of the cylindrical portion (30) and is configured to engage with a snap- fit action a corresponding raised, rib-like profile (34) m the inner periphery (36) of the chamber (14) . Once the profiles (32,24) are engaged, the cap (18) is urged into sealing engagement with tne body (12), positively retaining the stopper (19) m place m the opening (16) even m the absence of ring- shaped collar (24) . This may be useful if the microtube (10) is re-used after the tamper-evident feature has been used and discarded.

The ring-shaped collar (24) is initially coupled to the closure cap (18) by an array of frangible connections (26 . The ring-shaped collar is integrally moulded with the frangible connection (26) to the closure cap (18) . The array of frangible connections (26) has two components, disposed symmetrically on either side of tab (40) . In the underside plan view, Figure 3, the frangible connections (26) are gust visible through apertures (42) which also highlight the two components of the array either side of tao (40). The ring-shaped collar (24) has a recess (44), tne role of which is explained below. The closure cap (18) is coupled to the body (12) by a resilient strip (50) . The resilient strip (50) engages the body (12) below the rim (20) , leaving a body space (52) between the ridge (22) and point of attachment (54) . The resilient strip (50) acts as a hinge by folding m region F, allowing the closure cap (18) to rotate m direction A relatively to the body (12) to bring ring-shaped collar (24) into position facing the rim (20) . The ring-shaped collar 24) whose inner diameter is the same as, or ever so slightly smaller than, the outer diameter of the rim (20) is a tight, stretch fit over the rim (20) . As the ring- shaped collar (24) is pushed over the rim (20) until it nests under tne rim (22), the ring-shaped collar (24) becomes trapped m the body space (52) between the ridge '22) and the point of attachment (54) where tne resilient strip (50) engages the body (12). In fact, part of the resilient strip (50) is accommodated in recess (44) .

The closure cap (18) is removed by applying substantially upward pressure (usually witn the user's thumb) to the tab (40) . In doing so, the frangible connections (26) come under tension, being stretched between the ring-shaped collar (24) - anchored under the ridge (22) - and the closure cap (18) as it is pushed upwards. Ultimately, the tension causes the frangible couplings (26) to break, leaving the ring-shaped collar (24) under the ridge (22), even though the closure cap has been removed from the opening.

Figures 1 and 2 show tne microtube with stabilisers v/nich support the microtube m the upright position, enabling it to be free-standing. However, the stabilisers are m no way essential to the invention, and the conventional conical bottom microtube (as illustrated m Figure 3) may be the more popular arrangement. Figure 4 shows a second embodiment of the present invention. A laboratory receptacle (110) consists of a body (112) and closure cap (118). The receptacle (110) differs from tne microtube (1C¹ only in that the body (112) and closure cap (118) are not coupled together when the stopper (119) is not plugging the opening (116) m the chamber (114) . Accordingly, features m common between the two embodiments share the same reference numbers, except that features m the second embodiment are prefixed by "1".

Claims

1. A receptacle (e.g. microtube) for receiving a fluid sample, comprising a first part defining a chamber with an opening, a second part having a stopper for plugging the opening, a collar attached to one of the parts by at least cne frangible connection, and a ridge member associated '.ith tne other part, the collar being a tight fit over the ridge member when the opening is first plugged, with the at _east one frangible connection fracturing when the opening is first unplugged, leaving the collar with the ridge re ber, characterised in that the first part includes m tne chamber a profile configured to engage with a snap- fit action a corresponding profile on the stopper when plugging tne opening, the profiles providing a re-usable seal between the first and second parts.

2. A receptacle according to claim 1, m which the ridge member is associated with or integral with the first part .

3. A receptacle according to claim 2, in which the collar is attached to the second part .

4. A receptacle according to any one of claims 1 to 3 , in wnich the second part is a push-fit onto the first part m order to plug the opening.

5. A receptacle according to any one of the preceding claims, m which the second part is connected to the first part by a coupling which allows the second part to cap and uncap the opening.

6. A receptacle according to claim 5, m which the coupling comprises a resilient strip.

7. A receptacle according to claim 5 or 6 when appendent to claim 2, m which the coupling abuts the first part m a position spaced from the ridge member.

8. A receptacle according to claim 7, m which the collar 5 has a recess for accommodating part of the coupling.

9. A receptacle according to any one of claims 2 to 8 , m which the ridge member is integral with a rim around the opening m the first part.

10. A receptacle according to claim 9, m which the second 10 part includes a recess for snap-fit engagement by the rim.

11. A receptacle according to claim 3, m which the collar is ring-shaped and integrally formed with the second part.

12. A receptacle according to claim 11, m which the at least one frangible connection is part of an array of

15 frangible connections, fastening the collar to the second part prior to first use.

13. A receptacle according to claim 13, m whicn the array comprises two components, distributed on each side of a tab for prising the second part or the first part.

20 14. A receptacle according to any one of the preceding claims, m which the profiles are rib-like, with each one raised proud of its surroundings.

15. A receptacle according to any one of the preceding claims, in which a portion of the stopper is a free-fit m

25 the opening to facilitate fracturing the at least one frangible connection.

16. A receptacle according to any one of the preceding claims, m wnicn the first and second parts are formed from blastics material.