GB2308841A

GB2308841A - Dispensing mechanism for tissue processing cassettes

Info

Publication number: GB2308841A
Application number: GB9600281A
Authority: GB
Inventors: Thomas Fergus Hughes; Hughes Sarah Frances Lamb
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-01-08
Filing date: 1996-01-08
Publication date: 1997-07-09
Also published as: GB9600281D0

Abstract

A mechanism for dispensing tissue-processing cassettes comprises a rotatable member 1 mounted on a drive shaft 2 at the bottom of a holder 3 for retaining a packaged stack of cassettes 4. The rotatable member 1 has four platforms 5 which extend non-radially from the rotational axis 8 and are spaced equiangularly around the rotational path of the member 1 about the axis 8. Surface 6 of one of the platforms 5 supports the lowermost cassette 4 in the stack. When cassettes are required to be dispensed, the member 1 is rotated and the platform 5 supporting the lowermost cassette 4 moves out of engagement with the cassette which drops away from the stack. Simultaneously, the following platform moves to a position to support the cassette immediately above the dropped cassette. The cassettes are orientated within a packaging at a suitable angle to enable them to be dispensed directly from the packaging by the dispensing mechanism.

Description

DISPENSING MECHANISM FOR TISSUE - PROCESSING CASSETTES The present invention relates to a dispensing mechanism for dispensing tissue-processing cassettes used to contain laboratory tissue samples.

Such a mechanism is designed to dispense single cassettes on demand from a hopper or tube used for storing a stack of the cassettes. A known mechanism of this type is disclosed in British Patent No. 2235163B, in which the mechanism consists of a single stepped block at the base of a metal hopper or tube used to store the cassettes. The lowermost cassette rests with its front edge on the lower step of the block and the width of the hopper is such that the back edge of the cassette rests higher up on the back wall of the hopper so as to prevent any other cassettes stacked up on top of it from falling out. To dispense a single cassette from the hopper the stepped block is rotated. This lowers the lowermost cassette until the back edge is no longer supported by the back wall, while the top step of the block rotates forward into the hopper stopping the remaining cassettes from moving down the hopper. Once the lowermost cassette is clear, the stepped block rotates back to its original position which causes the new lowermost cassette to drop down onto the bottom step, and the other cassettes follow down the remain stacked on top of the lowermost cassette.

However, in this known mechanism, the length of the cassette is critical because if it is too long, the cassettes will not fall out of the hopper at all, and if it is too short, more than one cassette will be dispensed at a time. Additionally, the cassettes fall out of the hopper with their bottom face first, whereas it would be preferable for them to fall out front face first in order to facilitate marking of the cassettes. Furthermore, the hopper is required to be filled manually, which slows down the whole dispensing process.

It is therefore an object of the present invention to provide a dispensing mechanism which does not have the afore-mentioned problems of the known type of dispenser.

Accordingly, from one aspect, the present invention consists in a mechanism for dispensing tissue processing cassettes from a stack of said cassettes, said mechanism comprising a rotatable member having a plurality of projections extending outwardly from the axis of rotation of said member and spaced at substantially equiangular intervals around said axis, each of said projections in turn being arranged to support the lowermost cassette in the stack and, upon rotation of said rotatable member, to move away from said lowermost cassette so that said lowermost cassette can drop from the stack, the following projection moving to support the cassette immediately above said lowermost cassette during said same rotation.

Preferably, the projections comprise plafforms each having a generally flat surface for supporting the cassettes. In one embodiment, the projections extend non-radially with respect to the rotational path of said member about said axis, that is, they extend at an angle to the radii of said path.

Advantageously, the rotatable member is capable of rotating continuously in one direction so as to dispense successive cassettes.

From another aspect, the invention consists in a system for dispensing tissue processing cassettes, the system comprising the combination of a dispensing mechanism as stated hereinabove and a packaging containing a stack of tissue processing cassettes, the mechanism being arranged to dispense the cassettes individually directly from the packaging.

Preferably, the packaging comprises a square-ended tube. The system also preferably includes means for holding the packaged stack in a generally vertical position adjacent to said dispensing mechanism.

According to a third aspect there is provided a packaging containing a stack of tissue processing cassettes for use in a dispensing mechanism as stated hereinabove, said cassettes being orientated within the packaging at a suitable angle to enable them to be dispensed directly from the packaging by said mechanism.

Preferably, each cassette of the stack is orientated at an angle of between 28- to 30 to the horizontal when the stack is substantially vertical. Each cassette may comprise a generally rectangular base and four side faces with one face being angled relative to the other faces and the cassettes may be orientated in the packaging such that said angled face engages with said mechanism during dispensing of said cassettes.

The packaging may be provided with one or more cut-outs which may, for example, be used to allow the removal of tabs or stops during loading of the packaging onto the dispensing mechanism or to trigger sensors on the mechanism which can be used to detect the presence of cassettes.

The invention will now be described by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a sectional view of a dispensing mechanism in accordance with one embodiment of the invention, Figure 2 shows a side view in the direction of arrow "A" as shown in Figure 1, and Figure 3 to 7 show schematic views of the mechanism in successive operative positions.

Referring firstly to Figures 1 and 2, a dispensing mechanism comprises a rotatable member 1 mounted on a drive shaft 2 at the bottom of a holder 3 for retaining a packaged stack of tissue processing cassettes 4.

The rotatable member 1 has a number of platforms 5, in this example four platforms, extending outwardly from its axis of rotation 8 and each having a generally flat surface 6. The platforms 5 extend non-radially from the axis of rotation, that is, they extend at an angle to the radii of the rotational path of the member 1 about the axis 8. The platforms 5 are also spaced equiangularly around the rotational path of the member 1 about the axis 8. The flat surface 6 of one of the platforms 5 supports the front face 7 of the lowermost cassette 4 in the stack, and hence supports the entire stack.

Referring now also to Figures 3 to 7, when cassettes are required to be dispensed, the rotatable member 1 is rotated by means of the drive shaft 2 about the axis 8 in a clockwise direction as viewed in the Figures. The platform 5 supporting the lowermost cassette 4 moves out of engagement with the cassette 4, through the positions shown in Figures 4 to 6, until the lowermost cassette 4 drops down away from the bottom of the stack. Simultaneously the following platform 5' moves to a position in which the cassette 4' immediately above the lowermost cassette 4 can drop down onto the flat surface 6 of the platform 5' to support the rest of the stack. Further rotation of the member 1 in the same direction repeats the sequence of movements shown in Figures 3 to 7, so that the cassettes are successively dispensed whilst the rest of the stack remains supported.

The present dispensing mechanism advantageously enables the lowermost cassette to drop straight down front face first while the remaining cassettes are held in place. Moreover, the dispensing mechanism of the present invention can be used in combination with a packaged stack in which the cassettes are dispensed individually directly from the packaging. This removes the need for the manual filling of a hopper and enables the cassettes to be packaged in disposable plastic tubes.

In the packaging, the cassettes are orientated at an angle of between 28- to 30 to the horizontal when the packaging is generally vertical and the angled front face 7 of each cassette faces downwards in the packaging so that this face engages with one of the platforms 5 of the mechanism as the cassette is dispensed. The packaging may also have one or more cut-outs (not shown) which may be used to allow the removal of tabs or stops during the process of loading the packaging onto the dispensing mechanism or to trigger sensors (also not shown) on the mechanism which may be used to detect the presence of cassettes.

Once loaded into the dispensing mechanism, the packaging becomes the delivery hopper for the mechanism and the cassettes are dispensed directly therefrom. This therefore allows the user to load a number of cassettes into the dispensing mechanism in a single action. Additionally, the length of the cassette is no longer critical, as the back wall of the packaging or tube now plays no part in the release of the lowermost cassette. This allows the packaging to be a basic square-ended tube, keeping its cost to the minimum.

The present invention thus comprises a "paddle wheel" type arrangement including a number of platforms symmetrically spaced around a central shaft which are indexed round in order to dispense the cassettes. This mechanism provides a much smoother and potentially faster dispensing action, whilst remaining simple and reliable. This is due to the wheel rotating in one direction only as opposed to rotating backwards and forwards which can cause the cassettes to bounce and misfeed. In addition to being usable with the cassette packaging, the dispensing mechanism can also be used with the many different cassette types and sizes.

Whilst a particular embodiment has been described, it will be appreciated that modifications may be made within the scope of the invention.

Claims

1. A mechanism =r dispensing tissue processing cassettes from a stack of sad cassettes, said mecharsm comprising a rotatable member h--ning a plurality of prof otions extending outwardly from th- axis of rotation of said member and spaced at substantally equiangular inter-als around said axis, each of sad projections in turn being arranged to support the lowerost cassette in the stack and, upon rotation of said rotatable member, to moe away from said lowermost cassette so that said lowermost cassette can drop from the stack, t-.e following projection moving to support the cassette imr..ediately above said lowermost cassette during said same rotation.

2. A mechanism as claimed in claim I, wherein the projections comprise platforms each having a generally flat surface for supporting the cassettes.

3. A mechanism as claimed in claim 1 or 2, wherein the projections extend non-radially with respect to the rotational path of said member about said axis.

4. A mechanism as claimed in claim 1, 2 or 3, wherein the rotatable member is capable of rotating conrinuously in one direction so as to dispense successive cassettes.

5. A system for dispensing tissue processing cassettes, the system comprising the combination of a dispensing mechanism as claimed in any preceding claim and a packaging containing a stack of tissue processing cassettes, the mechanism being arrange to dispense the cassettes individually directly from the packaging.

6. A system as claimed in claim 5, wherein the packaging comprises a square-ended tube.

7. A system as claimed in claim 5 or 6, including means or holding the packaged stack in a generally vertical position adjacent to sa-d dispensing mechanism.

9. A packaging containing a stack of tissue processing cassettes for use in < dispensing mechanism as claimed in any one of claims 1 to 5, said cassettes being orientated within the packaging at a suitable angle to enable them to be dispensed directly from the packaging by said mechanism.

9. A packaging as claimed in claim 8, wherein each cassette of the stack is orientated at an angle of between 28 to 300 to the horizontal when the stack is substantially vertical.

10. A packaging as claimed in claim 8 or 9, wherein each cassette comprises a generally rectangular base and four side faces with one face being angled relative to the other faces, the cassettes being orientated in the packaging such that said angled face engages with said mechanism during dispensing of said cassettes.

11. A packaging as claimed in claim 8, 9 or 10, including one or more cut-outs which may be used to allow the removal of tabs or stops during loading of the packaging onto the dispensing mechanism or to trigger sensors on the mechanism which can be used to detect the presence of cassettes.

12. A mechanism for dispensing tissue processing cassettes from a stack of said cassettes, said mechanism being substantially as herein described with reference to the accompanying drawings.

13. A system for dispensing tissue processing cassettes comprising a combination of a dispensing mechanism and a packaging containing a stack of tissue processing cassettes, substantially as herein described with reference to the accompanying drawings.

14. A packaging containing a stack of tissue processing cassettes substantially as herein described wir reference to the accompanying drawings.