AU655310B2 - Histology cassette and lid - Google Patents

Description

P/00/01 1 2 AUSTRALIA Rglto Patent Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invenion Ttle:HISTOLOGY CASSETTE AND LID Invention..... The following statement Is a full description of this invention, including the best method of performing it known to me:- I I -1- This invention relates generally to a utility product for the biomedical field and relates in particular to a histology cassette used for the processing and embedding in wax of human and animal tissues for specimen storage. The cassette has a snap-on lid which may be hingedly connected to the cassette and drainage holes are provided in an end wall for drainage when the cassette loaded with a processed specimen is stood up vertically in a basket for draining processing liquid.

Large numbers of histology tissue specimens have to processed for clinical reaction tests and microscopic observation and when specimen tissues are taken from different patients are processed together, it 15 is essential that the cassettes have a firmly yet easily fitted lid so that specimen tissues do not come loose and fall out of holding containers to be lost or confused with those of other patients. It is essential Se also that specimen-loaded and lid-closed cassette sets by picked up by forceps the right way up gripping the cassette and lid as a unit and not the lid by itself as it can be dislodged.

A problem which occurs with existing histology :f cassette and lid sets formed by injection moulding from synthetic polymeric material and with a matrix or gridwork of fine slots and webs or ribs formed in the surface extending between or bounded by two side and two end walls is that of air bubble entrapment during Vprocessing of a specimen. Another problem is that some rN -2lids have a. fine gridwork of slots and ribs which weakens the lids and when steel forceps are used to close such a lid onto -the cassette the forceps break -through the gridwork or break the lid and damage the specimen. Another problem is that of residual processing liquids remaining in a lidded, specimenloaded cassette after processing when loaded, lidded cassettes are stood up in a basket with one end facing downwards.

It is an object of this invention to provide a disposable histology cassette for use with a snap-on lid and which has one or more drainage apertures in the region of an end wall which faces downwards when the lidded cassette containing a processed specimen is stood up vertically in a basket for drainage of processing liquid.

so...According to the invention there is provided a 0s disposable histology specimen embedding cassette in the form of a substantially rectangular tray with two side walls and two end walls framing a base provided with a matrix or gridwork of a plurality of -two-way liquid passage holes for passage into and out of the cassette, in association with a correspondingly apertured lid, of processing liquids when closed with the lid and holding a specimen therein, the loaded, lidded cassette being adapted to be stood up when stacked with an end wall facing down in a basket, one or more drainage apertures being formed in the region of F, l the down%, Aly-facing end wall.-\c orners between the

P

-i -2o said end wall and side walls of the cassette for endwise draining of residual processing liquids from the cassette after processing and via the drainage apertures while the cassette is closed by the lid and upstanding g- with the said end wall facing downwards.

According to one form of the invention, two drainage holes extend through a downwardly-facing end wall during the step of drainage of processing liquid.

*I

-3of a apecimen-loaded casaette closed with a lid, According to another form of the invention drainage holes are provided in the region of each corner of the cassette formed between the end wall facing downwards during drainage and two side walls of the specimen-loaded cassette which are adapted to be closed with a lid.

According to yet another, form of the invention drainage holes are provided exctending through an edge at the junction between that end wall of the cassette which faces downwards during drainage of processing liquids o p and the base portion surface of the cassette.

According to another form of the invention an end wall is provided with a rolled over, resilient, split-bearing sleeve hinge component adapted to receive in a snap-fitting arrangement with the lid a hinge rod integrally moulded with and projecting from and parallel to one end wall of the lid.

Preferably, the lid is a snap-fit onto the 20 cassette and has a resilient tongue depending from one end thereof and inclined to the general plane of the lid and which engages within a slot between double end walls of the cassette and forms a partial hinge with the 4 U cassette, In an alternative hinge arrangement, the lid also has a resilient prong depending from the end opposite the tongue forming a latch which is adapted to snap fit under a transverse external projection or projections formed at and near the top o~f one end wall -4of the cassette and near each side edge of the lid there is a strengthening rib and also for opening the lid a finger tab projects from one end of the lid.

Some non-limiting examples of embodiments and/or practical arrangements of the invention will now be described with reference to the accompanying drawings, in which: Figure I is a full-scale inverted plan view of one embodiment an assembled but opened histology specimen embedding cassette and lid set constructed, arranged and adapted to operate in accordance with the invention, Figures 2 and 2A are fragmentary side views of the snap-on hinge arrangement of Figure 1.

Figure 3 is a perspective exploded partial view on an enlarged scale of a cassette and lid of Figures 1i, 2 and 2A with lid detached.

Figure 4 is an end elevation of the hinge end 20 C., o a «o a a a a ,Id wall of the cassette of Figures 1 and 2.

Figure 5 is an inverted plan view of another embodiment of an histology embedding cassette with lid detached.

Figure 5A is an inverted plane view of a snap-on lid for the cassette of Figure Figure 6 is a side elevation of the cassette of Figure Figure 6A is a side elevation of the lid fo Figure Figure 7 is a perspective exploded partial view 1 of the cassette of Figures 5 and 6.

Figure 8 is an end elevation of the cassette of Figures 5, 6 and 7.

Figure 9 is is an inverted plan view of another or third embodiment of snap-on lid for the cassette of Figures 6 to 8 Referring to the drawings and firstly to Figure 1 there is shown a disposable, histology specimen cassette 10 with a snap-on hinged lid 11, the cassette and the lid both being formed by injection moulding from synthetic polymeric material, suitable materials include homopolymers, copolymers, polyesters, polyamides, olefins, such as polypropylene, polyethylene, and fluorocarbons a suitable material being an acetal polymer based on trioxane and sold under the registered trade mark CELCON. The cassette is in the form of a substantially rectangular tray with side walls 12, 13 and end walls 14, 14a, 15 one end wall being double and has an outer sloping wall 14a serving as a labelling surface and the other or opposite end wall 15 is provided with a rolled over, resilient, split-bearing sleeve hinge component 16 adapted to receive in a snap-fitting arrangement with the lid 11 a hinge rod 26 integrally moulded with and projecting from and parallel to one end wall 24 of the lid as explained hereinafter.

The cassette walls frame a perforated base portion surface 17 provided with a matrix or gridwork of a plurality of relatively large holes (in this example thirty four holes approximately 2mm in diameter) such as C I those labelled 18, 19 for passage therethrough and into the cassette of processing liquids when closed with the lid and holding a specimen therein and being adapted to be stood up when stacked with one end wall 15 of the cassette 10 facing down, the hinged end wall of the cassette 10 is provided with two drainage holes 20, 21 extending completely through the end wall and also the base potec 4 'c 17 of the cassette one hole being positioned in the region of each lower corner for draining of processing liquids from the cassette after 0 processing. The lid 11 has two side walls 22, 23, and 0° two end walls 24, 25 these four walls forming a Srectangular locating skirt with respect to the top edge o to wall of the cassette. One end wall 24 of the lid has integrally formed therein a hinge component fixed pin 26 supported between and integrally moulded with two brackets 27, 28 and which snaps into or out of) the split sleeve hinge component 16 on the end wall 15 of the cassette. The brackets 27, 28 of the lid 11 fit into 20 slots 29, 30 formed in the end wall 15 of the cassette.

The walls of the lid frame a perforated surface portion 31, which like that of the cassette, is also provided with a matrix or gridwork comprised of a plurality of relatively large diameter circular holes such as those labelled 32, 33 for two-way passage therethrough of histology processing liquids.

The preferred snap-lock arrangement between the cassette and the lid is provided by the interaction F\ of the resilient latch 34 of the lid 11 into the slot between inner and outer end walls 14 and 14a of the cassette to be retained by the outer edge of the slot.

The resilient latch of the lid projects downward into the hollow space formed between the double end walls of the cassette. For opening the lid a finger tab 36 projects from one end of -the lid, The releasable hinge and snap-locking lid arrangements are generally as described in my patent Nos. 610,486 and 545,607.

Referring to the embodiment of cassette and lid shown in Figures 5 to 8, the cassette is labelled 110 and the lid is labelled 111, The cassette comprises side walls 112, 113, and has a double end walls 114 and 114a at one end, the opposite end wall 115 (Fig. 5) has a moulded-in, transverse external projection or rib 116, to.

4.A flat base portion 117 has a matrix of holes of relatively large diameter formed therein such as the two too.

labelled 118, 119. The lid Ill has side walls 120, 121 and end walls 122, 123 on a flat plate 124 with a matrix 20 of relatively large diameter holes such as the one labelled 125 and is a snap-fit onto the cassette 110 by means of resilient latch 12? co-operating with latch means on the cassette by latching around the projection 116 which is an extension of the end wall 115 of the cassette and together with a resilient, inclined tongue 128 which forms a partial hinge arrangement to allow partial closing of the cassette when inserting a specimen and is adapted to engage within the slot 129 between inner and outer end walls 114, 114a, of the -8casaette 110 to clos the lid, A finger tab 126 to facilitate opening the lid 111 projects from one end of the lid. Both the cassette and the lid are similar in structural features to the embodiment of Figures 1 to 4 but the rolled over split sleeve and pin hinge arrangement is omitted and replaced by the resilient tongue and slot.

Referring to the third embodiment of the snap-on lid shown in Figures 9 and 10 of the drawings, thc, lid 210 is not hingable to the the cassette but is aL .00* snap-fit onto the second embodiment cassette 110 of Figures 5, 6 '7 and 8 has a flat plt&.te portion 211 with o large-diameter holes such as the one labelled 211a extending therethrough for passage of processing liquids. The lid 211 also has a resilient tongue 218 which engages within the slot 129 of the cassette 110 and the lid 210 also has a resilient prong or prongs 220 forming a latch under a transverse external projection 0404 116 formed at one end wall 115 of the cassette 110.

Near each side edge of the plate portion 211 of the lid 210 there is a longitudinally-extending strengthening ribs 228 and 229.

According to another aspect of the invention jfwhich may be preferred for use with colour-coded cassettes with matching lids, the lid may be manufactured in the same colour as that of the casse~tte but in a paler shade of plastic so as to facilitate correct handling during processing by indicating wh.-en either a cassette or lid is being contacted by tongs.

m mmm m -9- As an alternative, for smaller biopsy specimens the plate of the lid and the cassette may be provided with a gridwork of holes of smaller diameter such as for example 168 holes approximately of imm diameter.

Although two drainage holes for draining processing fluids located in the end wall of the cassette have been described in relation to the illustrated embodiment, it will be understood that more or less holes or apertures of any suitable shape or I I S. location may be provided in the end wall or corners between the end wall and the side walls or even in the Sside walls of the cassette or at or within or between the edges of adjoining surfaces such as between the base plate and end wall of the cassette.

The invention includes within its scope a separate, perforate histology cassette provided with processing liquids drainage apertures in at least ore erd wall which happens to face downwards when cassettes loaded with specimens and with a lid in place are stood up or stacked vertically in a drainage basket. The end-wall drainage holes feature of the invention may be applicable to histology or biopsy specimen cassettes and S7 lids other than those described or illustrated in this specification or those of the cross-referenced specifications. Drainage or air bubble escape holes may be provided in a top wall or walls of a lidded cassette containing a processed specimen.

Claims (2)

1. A disposable histology specimen embedding cassette in the form of a substantially rectangular tray with two side walls and two end wal',s framing a base la-rtig-A provided with a matrixc or gridwork of a plurality of two-way liquid passage holes for passage into and out of the cassette, in association with a correspondingly apertured lid, of processing liquids when closed with the lid and holding a specimen therein, the loaded, lidded cassette being adapted to be stood up when stacked with an end wall facing duwn in a bas!1.et, one or more drainage apertures being formed in the region of the downwardly-facing end wall7'=eFcorners between the said end wall and side walls of the cassette for endwise draining of residual processing liquids from -the cassette after processing and via the drainage apertures while the cassette is \closed by the lid and :*upstanding with the said end. wall facing downwards. 0*

2. The cassette according to claim I wherein, drainage holes are provided in and exctend through an end wall whicb faces' downwards during processing-liquid drainage of -the specimen-loaded cassettL c ~V3. The cassette according to claim I wherein drainage holes are provided in the region of each corner of the cassette formed between one end wal.l which faces downwards during drainage and two side walls of the AL spec imen- loaded cassette~ sb* 4 S4. The cassette according to claim 1 wherein NI ot; Use form P/00/008b where details for PCT, convention priority, microorganism deposit, aaamnonal or divisional applcation, are required. -11 drainage holes are provided which extend through an edge at the junction between an end wall of the cassette which faces downwards during drainage of processing liquids a d the cassette, The cassette according to any preceding claim wherein an, end wall is provided with a rolled over, resilient, split-bearing sleeve hinge component adapted to receive in a snap-fitting arrangement with the lid, a hinge rod integrally moulded with and projecting from Sand parallel to one end wall of the lid. -do0. The cassette according to claim 1 wherein the I lid is a snap-fit onto the cassette and has a resilient tongue depending from one end thereof and inclined to the general plane of the lid and which engages within a slot between double end walls of the cassette and forms a partial hinge with the cassette. S. The cassette according to claim 1 or 5 wherein the lid also has a resilient prong depending from the end opposite the tongue forming a latch which is adapted to snap fit under a transverse external projection or projections formed at and near the top of one end wall of the cassette. S. The cassette according to any preceding claim wherein near each side edge of the lid there is a strengthening rib. oThe cassette according to any preceding claim i wherein for opening the lid a finger tab projects from one end of the lid. the cassette after processing and via the drainage apertures while the cassette is clo2zed by the lid and upstanding with the said end wall facing downwards. -12- The cassette according to any preceding claim wherein the end wall opposite to the end wall with one or more drainage apertures therein, is provided with one or more entrapped air ese -enuent holes, ii. A disposable histology specimen embedding cassette substantially as hereinbefore described with reference to Figures 1 to 4 of the accompanying drawings 12, A disposable histology specimen embedding cassette substantially as hereinbefore described with *ei reference to Figures 5, 7 and 8 of the accompanying drawings. o I I o1 Dated this 4th day of August, 1994 BARRY JOHN WEBBER and SUZANNE DAWN WEBBER o I BY Our Patent Attorney JOHN L.DAVIES CO. 11j