GB2411894A

GB2411894A - Dispensing device

Info

Publication number: GB2411894A
Application number: GB0405448A
Authority: GB
Inventors: Clive Loynes
Original assignee: Mast Group Ltd
Current assignee: Mast Group Ltd
Priority date: 2004-03-11
Filing date: 2004-03-11
Publication date: 2005-09-14
Anticipated expiration: 2024-03-11
Also published as: GB2411894B; GB0405448D0

Abstract

A device for dispensing discrete items, such as antibiotic sensitivity discs, comprises an actuator and a body moveable between a dispensing configuration and a non-dispensing configuration. The device is capable of carrying a plurality of magazines, each of which houses a plurality of discrete items, and can dispense a plurality of items simultaneously and in a predetermined configuration. In operation a single actuation means brings a plurality of dispensing rods each in line with a dispensing channel and a dispensing aperture and extends the rods therethrough.

Description

241 1 894 DESCTI1PTTON

DISPENSING DEVICE

The present invention relates to dispensing devices for dispensing discrete items. In particular, the present invention concerns devices for dispensing a plurality of sensitivity discs, each impregnated with one or more different substances, for

example antibiotics.

Disc dispensers are used in e.g. antibiotic susceptibility testing, whereby a number of discs are positioned on the surface of an agar gel petri dish, the agar acting as a sterile nutrient medium for the organism being analysed. The organism is introduced onto the surface of the agar, and a number of discs are distributed over the surface of the gel by means of the dispenser. Typically, each disc contains a different antibiotic, so that the effects of the different antibiotics on the organism can be simultaneously studied.

Several dispensers for simultaneous dispensing of a plurality of discs are already known. The discs are generally stacked one on top of another in an elongate cylindrical cartridge or magazine. The discs are biased to an open end of the cartridge by means of an internal coil spring and typically any one cartridge contains discs impregnated with one particular antibiotic.The dispenser typically receives a plurality of cartridges and dispenses one disc from each cartridge during a single dispensing operation. However, known dispensing systems all suffer from a number of draw backs which include: I) the release of two discs from any one cartridge, which can jam the mechanism; 2) irregularities in the bore of the magazine which can cause either the internal coil spring or the discs to "hang up" and not enter the zone where a dispensing finger can contact them. In the first instance this causes the dispenser not to "lock off" when a cartridge is empty. In a second instance it causes the cartridge in question not to dispense a disc; 3) flash on the internal coil spring or a plunger attached thereto, which has a similar effect to the case above that may result in a failure to dispense discs; 4) poorly cut discs - in order to dispense the disc, the mechanism requires to push the disc along a horizontal track until it is positioned over an exit hole.

Poorly cut discs have a large radius on the bottom edge which compromises the ability of the dispenser to push them out of the cartridge, since there is no vertical face to push against. The pushing finger also has a tendency to deflect downwards under the action of the cartridge spring jamming the device.

5) in known dispensers, the height of the pushing finger relative to a disc to be dispensed is set deliberately high to compensate for these effects but this can result in an unacceptable level of damage or "leafing" being inflicted on the next disc to be dispensed in the stack. The large radius and severe leafing can both result in the disc not being pushed far enough and thus causing jamming or edging; 6) discs not stacked correctly - it is important that the discs are stacked uniformly and that the bottom disc lies in a substantially horizontal plane. If the bottom disc is not level the cartridge will present either too little or too much of the stack to the pushing finger. If too little is presented there is a possibility that the pushing finger will slide under the stack and not displace a disc from the magazine.

This situation is made worse if the discs are poorly cut. If too much of the disc is presented, there is a danger that two discs will be forced out of the cartridge or that the second disc in the stack will receive an unacceptable level of damage.

It is an object of the present invention to overcome or alleviate one or more of

the problems associated with the prior art.

In accordance with the first aspect of the present invention, there is provided a dispensing device for dispensing a plurality of discrete items in a substantially predetermined configuration, the device comprising: 1. a base having a plurality of spaced apart dispensing channels; 2. a magazine carrying member having a plurality of magazine housings, corresponding in number to the dispensing channels, for receiving magazines carrying the discrete items, the magazine carrying member having a plurality of dispensing slots, each comprising a dispensing aperture, corresponding in number with the magazine housings, the magazine carrying member co-operating with the base so as to effect displacement of the magazine carrying member relative to the base, removal of a discrete item from each of the magazines loaded in the device and substantial alignment of each dispensing aperture with the corresponding dispensing channel; 3. a plurality of dispensing rods corresponding in number with the magazine housings, each of which is associated with one of the dispensing apertures; and, 4. actuating means operatively connected with the magazine carrying member and the dispensing rods so that displacement of the actuating means causes displacement of the magazine carrying member relative to the base, bringing about alignment of each of the dispensing rods and dispensing apertures with the corresponding dispensing channel, and causes the dispensing rods to extend therethrough.

The magazine carrying member may be rotatably displaceable relative to the base.

Preferably, the magazine carrying member is slidably rotatably displacable relative to the base.

The dispensing rods are preferably mounted on the actuating means.

The base and the magazine carrying member may comprise substantially circular plates.

The upper face of the base may have a shaft centrally mounted thereon.

Preferably, the magazine carrying member is mounted on the shaft. More preferably, the magazine carrying member is rotatably mounted on the shaft.

In a preferred embodiment, the number of discrete items which can be dispensed corresponds to the number of dispensing channels and thereby the number of magazine housings, and thereby the number of dispensing slots, and thereby the number of dispensing rods.

The device is preferably biased into a non dispensing configuration whereby each dispensing aperture and its corresponding dispensing channel is misaligned and not in dispensing alignment i.e. a discrete item cannot be dispensed from the device without damage to its integrity.

The means to bias the device into a non-dispensing configuration preferably comprises resilient means. Preferably, the resilient means comprises a helical spring.

In one embodiment, the resilient means is mounted on the shaft of the base and is received by the actuating means. In an alternative embodiment, the resilient means is nounted on the actuating means and is received by the shaft of the base.

The actuating means preferably comprises a stem having at one end a handle and at the other means for operably engaging the magazine housings of the magazine carrying member such that rotational displacement of the actuating means brings about rotational displacement of the magazine carrying member.

The actuating means may be mounted for axial displacement at substantially right angles to the plane of the upper face of the base.

Preferably, the base comprises means for substantially retaining a discrete item in place during displacement of the magazine carrying member. Preferably, the means is associated with each dispensing channel. More preferably, the means comprises at least one retaining member. The retaining member may comprise an upstanding ridge, Em or a blade. Preferably, the retaining member comprises an upstanding ridge. More preferably still, the means comprises two or more retaining members. The means may comprise an abutment face of two adjacent retaining members.

In a preferred embodiment, each retaining member is arcuate in shape and adjacent retaining members are separated by a dispensing channel.

Each dispensing slot preferably comprises means for supporting a discrete item to be dispensed. More preferably, the means comprises a supporting surface of a ledge disposed in the dispensing slot.

The magazine carrying member may comprise a complementarily shaped groove for receiving the means for retaining a discrete item in place. In one embodiment the groove Preferably the distance the means for retaining a discrete item during displacement of the magazine carrying member extends beyond the supporting surface of the dispensing slot corresponds to the thickness of a discrete item to be dispensed. More preferably, the distance is less than the thickness of a discrete item to be dispensed.

The discrete item may be a substantially disc shaped unit or any similarly shaped unit which can be housed in a magazine. Preferably, the discrete item is substantially disc shaped. More preferably, the discrete item is a sensitivity disc for use in a method to determine the sensitivity of an organism to a particular reagent.

Even more preferably, the discrete item is impregnated with an antibiotic.

The discrete item may be manufactured from any suitable material, such as those materials capable of carrying a reagent. Preferably, the discrete item is manufactured from a porous and/or absorbent material, such as nitrocellulose, filter paper and/or nylon.

The device may comprise two or more magazine housings. Preferably, the device comprises at least 6 magazine housings. More preferably, the device comprises 8 magazine housings.

Each magazine which can be received in a magazine housing preferably comprises a magazine body and biasing means for biasing discrete items contained therein towards an open end of the magazine. More preferably, the magazine comprises means for retaining a discrete item within the magazine body. More preferably still, the means comprises at least two magazine retaining lugs overlying the open end for retaining a discrete item carried in the magazine. Even more preferably still, the lugs comprises at least two stirrups.

The magazine biasing means may comprise any suitable resilient means, but preferably comprises a helical spring. The magazine may further comprise means for locating it in the correct orientation in the device. The means preferably comprises a lug located on the magazine body.

The dispensing slot may further comprise means for receiving the lugs of a magazine. Preferably, the means comprises two complementarily shaped apertures for receiving the lugs of a magazine.

The dispensing aperture and/or dispensing channel may be over-sized in relation to a discrete item to enable a discrete item to be dispensed whilst maintaining the discrete item's structural integrity during dispensing. Preferably, both are oversized.

The device is preferably a hand held device whereby movement between the dispensing and non-dispensing configurations is actuated manually by an operator.

In one embodiment, depression of the actuating means against a bias causes the device to move between its non-dispensing and dispensing configurations, dispensing a discrete item.

The actuating means may further comprise means for engaging the magazine housings of the magazine carrying member. Preferably, the means comprises a plurality of arms. More preferably still, the means comprises a plurality of arms equal to the number of magazines the device is capable of carrying.

In one embodiment, the magazine housings are disposed between adjacent arms of the handle. Rotation of the arms may thus bring about rotation of the magazine housings and thereby the magazine carrying member about the base.

Each magazine housing preferably comprises a substantially cylindrical body having a bore complementarily shaped with respect to a magazine for receiving the magazine. Most preferably, the magazine housing is shaped to accommodate the lug of the magazine to correctly orientate and lock the magazine in the device.

The device may further comprise means for determining the height, relative to the substrate upon which the discrete item is to be dispensed, from which a discrete item is dispensed from the device. Preferably the means comprises a skirt having a stepped edge upon which the device may be supported. The substrate is preferably a petri dish containing nutrient agar.

Rotation of the magazine carrying member about the base may be brought about by depressing the handle moving the device between its nondispensing and dispensing configurations. Rotation of the magazine carrying member may be brought about by the co-operation of a locating pin disposed on at least one arm and a guidance slot in which the pin is received. Preferably, the device comprises two or more pins each cooperating with a guidance slot.

Preferably the guidance slot comprises a portion which is substantially inclined with respect to the direction of displacement of the actuating means and/or the longitudinal axis of the device thereby bringing about rotation of the magazine carrying member about the base. More preferably, the guidance slot further comprises a portion which is substantially parallel to the longitudinal axis of displacement of the actuating means and/or the longitudinal axis of the device, such that the dispensing rod can engage the discrete item and push it through the dispensing aperture and channel without fouling the device.

The device preferably reciprocates between a non-dispensing configuration whereby the dispensing aperture and dispensing channel are misaligned, and a dispensing configuration, whereby the dispensing aperture and dispensing channel are substantially aligned to enable a discrete item to be pushed therethrough.

A specific embodiment of the present invention will now be described, by way of example only, with reference to the accompanying figures, in which: Fig. I shows a perspective view of a device in accordance with the present invention in a non-dispensing configuration; Fig. 2 shows the device of Fig. I in a dispensing configuration; Fig. 3 is an exploded view of the same device; Fig. 4 shows a magazine suitable for use with a device in accordance with the present invention; Fig. 5 is an exploded cut away view of the device; and Fig. 6 a-c are schematic illustrations showing the dispensing of a discrete item.

Fig. I shows a dispensing device 10 having an actuator 12 and a body 14 returned to its non-dispensing configuration overlying petri dish 16 having simultaneously dispensed a plurality of discs 18 from a plurality of magazines 20 loaded in device 10 onto a layer of agar 22 contained within the petri dish 16. Fig. 2 shows the dispensing device 10 of Fig. 1 in its dispensing configuration in which actuator 12 has been depressed into body 14.

Fig. 3 shows an exploded view of device 10 having five coaxially disposed parts: a body cover 28, an actuator 12, a drum 30, a magazine carrying member 32 and a base 34.

Base 34 is a substantially planar circular plate having substantially parallel upper and lower faces 42, 44 and a circumferentially extending lip 46 having a plurality of apertures 48 spaced equidistantly about its circumference for receiving screws when device 10 is assembled. Extending from the upper face 42 of base 34 are upwardly depending arcuate ridges 50 and a centrally disposed shaft 52, both of which extend in a direction substantially orthogonal to the plane of the upper face 42.

Shaft 52 has an axial blind bore. Ridges 50 are disposed between shaft 52 and lip 46.

Adjacent ridges are spaced apart by circular dispensing channels 54. Each dispensing channel 54 extends between upper and lower faces 42 and 44. Dispensing channels 54 are slightly oversized with respect to the diameter of a disc to be dispensed to enable a disc to be pushed therethrough.

Magazine carrying member 32 has a substantially planar circular base plate 58 having substantially parallel upper and lower faces 60, 62, a centrally disposed circular aperture 64 for receiving shaft 52 and six magazine housings 66. Magazine housings 66 extend from the upper face 60 of plate 58 in a direction substantially orthogonal to the plane of face 60. The number of magazine housings 66 corresponds to the number of dispensing channels 54.

Each magazine housing consists of an elongate substantially cylindrical body 67 having a slot 68 extending substantially along the body's length.

Drum 30 has a substantially cylindrical body 70 having a side wall 72 and, at one end 74, a thickening of side wall 72 forming a flange 76. When device 10 is assembled, screws which extend through apertures 48 are received in correspondingly threaded blind bores (not illustrated) in flange 76. At the other end 78 of body 70 are four elongate slots 80. Slots 80 extend substantially the length of side wall 72 and are spaced equidistantly from one another around side wall 72. Each slot 80 has three sections, the first 82 of which is adjacent to end 78 of body 70 and extends in a direction substantially parallel to the longitudinal axis of device 10. The second section 84 is inclined to the longitudinal axis of device 10. The third section 86 is parallel to the longitudinal axis of device 10.

Actuator 12 has a handle 90 and a stem 92 from which extends a helical spring 93. Shoulders 94 extend radially from stem 92 in a plane substantially orthogonal to the longitudinal axis of the actuator 12 and are spaced equidistantly apart from one another. Between each adjacent pair of shoulders is a recess 101 shaped to accommodate a respective magazine housing 66. Shoulders 94 each have an upper and a lower face 96, 98 and a side wall 100. Disposed on four of shoulders 94 are respective radially projecting locating pins 102, each of which is shaped to be received by one of the elongate slots 80 of drum 30. Each shoulder 94 has a downwardly depending dispensing rod 104 extending in a direction parallel to the longitudinal axis of device 10 from lower face 98.

Body cover 28 has a substantially cylindrical body 110 and rests upon a skirt 112. The skirt 112 has upper and lower edges 114, 116. The upper edge 114 of skirt 112 has a number of stepped ridges 118 of varying height arranged in a repeated pattern about the circumference of skirt 112 such that a plurality of stop members 120 disposed on the inner face 122 of body 110 can each engage the ridges 118 at the same height. By adjusting the skirt to change the height at which stop members 120 engage a ridge 118, the relative height from the lower edge 116 of body 110 can be adjusted. Thus the relative height of a substrate from the point at which a disc is dispensed can be adjusted.

When assembled, the magazine carrying member 32 is mounted on the shaft 52 of base 34. The locating pins 102 of actuator 12 are located in slots 80 of drum 30 and the magazine carrying member/base assembly is inserted into drum 30. The helical spring 93 of actuator 12 is received in the blind bore of shaft 52. The base 34 is then secured to the drum 30 via screws which extend through apertures 48 and are received in threaded bores in flange 76 as describe above. The device 10 is thus biased under the action of spring 93 in its non-dispensing configuration and the upper face 96 of shoulders 94 is substantially flush with the tops of the magazine housings 66. Body cover 28 is then placed over the assembly and drum 30 and held in place by interference fit with drum 30.

Fig. 4 shows a magazine 20 having a cylindrical elongate body 150, open at one end 152, closed at the other by a cap 156 and carrying a plurality of discs 18 to be dispensed. Inside body 150 is a helical spring 154, disposed between cap 156 and a plunger. The discs 18 are stacked one on top of another within the magazine 20 and are biased towards one end 152 by the helical spring 154. A pair of lugs 158, 160 extend slightly into the path of a disc 18 to be dispensed preventing spring 154 from ejecting discs 18 loaded into the device.

The distance between the open end 152 of the body 150 and lugs 158, 160 forms a window which is lightly larger than the thickness of a disc 18 to be dispensed. However, the lugs 158, 160 are so positioned as to permit one disc at a time to be removed from the stack in a direction substantially orthogonal to the longitudinal axis of the magazine body 150 i.e. the distance between the open end 152 of the body 150 and lugs 158, 160 is less than two times the thickness of a disc 18 to be dispensed.

On the exterior surface of the magazine body 150 is a locating lug 162 which helps orientate the magazine in the correct location within the magazine housing 66 during loading of the device 10. Locating lug 162 cooperates with the correspondingly shaped slot 68 in magazine housing 66.

Fig. 5 is an exploded, sectional view showing a magazine 20 which has been loaded into the device with the magazine housing 66 omitted for clarity. Fig. 5 shows the magazine carrying member 32 located on top of base 34. Plate 58 of magazine carrying member 32 has a annular groove 190 (only part of which is shown) on its lower face 62 which is shaped and disposed to accommodate upstanding ridges 50 of base 34, such that the lower face 62 of the magazine carrying member 32 is in contact with the upper face 42 of base 34. Owing to the co-operation of the ridges 50 and groove 190, the magazine carrying member 32 can be slidably rotatably mounted on base 34.

For each magazine housing 66 and consequently for each dispensing channel 54, there is a recessed, arcuate, dispensing slot 192 in the upper face 60 of plate 58.

Each slot 192 is bisected by groove 190 and has at one end a circular throughgoing dispensing aperture 194 extending between the upper and lower faces 60, 62 of the magazine carrying member 32. Dispensing rod 104 overlies the dispensing aperture 194 in the device's non-dispensing configuration. At the other end of the dispensing slot 192 are two apertures 196, 198, which extend between upper and lower faces 60, 62 of plate 58, for receiving the lugs 158, 160 of magazine 20. Between apertures 196, 198 and dispensing aperture 194 is a platform 200 forming a supporting surface 202, upon which a disc 18 which is to be dispensed may be supported.

Each ridge 50 has two sidewalls 202, 204, two end abutment faces 206 and an upper face 208. The depth of platform 200 from upper face 60 of plate 58 is determined by the thickness of a disc 18 to be dispensed and the height of upper face 208 of ridges 50 from the upper face 42 of base 34.

Adjacent abutment faces 206 of adjacent ridges 50 form retaining means for substantially retaining a disc in position during displacement of the magazine carrying member 32 relative to base 34. Thus the relative distance between the supporting surface 202 of platform 200 and the upper face 208 of ridge 50 is no greater than the thickness of a disc 18. This ensures that only one disc is stripped from a magazine during use of the device 10, since the abutment faces 206 of each ridge 50 can only engage one disc 18 at a time. Thus, the mechanism is less likely to lam.

Additionally, the depth of apertures 196, 198 relative to the thickness of lugs 158, 160 is such that when a magazine 20 is located in the device 10, owing to the depth of apertures 158, 160 being slightly greater than the thickness of lugs 158, 160, support surface 202 of platform 200 displaces a disc 18 to be dispensed against the action ofhelicalspring 154, raisingdisc 18Off lugs 158,160suchthatthedisc 18is disposed between the helical spring 154 and support surface 202. Consequently, any errors in the loading of the magazine 20 or imperfections in the magazine 20 itself can be negated since the device is not reliant on correct loading of the magazine 20 etc. as only one disc at a time can be engaged by ridges 50.

As illustrated in Figs. 5 and 6a-c, dispensing rod 104 overlies dispensing aperture 194 and magazine housing 66 overlies apertures 196, 198 of dispensing slot 192.

Figs. 6 a-c show a cross-sectional schematic of device 10 dispensing a disc 18. Fig. 6a shows the device 10 in a non-dispensing configuration. A disc 18 is supported on support surface 202 of platform 200. Dispensing aperture 194 and dispensing channel 54 are mix-aligned, and disc 18 is received between abutment faces 206 of adjacent ridges 50.

Fig. 6b shows the device 10 ready to dispense a disc 18. Plate 58 has been displaced relative to base 34 and disc 18 has been substantially retained in place. The actuator 12 has been depressed and locating pins 102, in co-operation with the second section 84 of slots 80, have brought about clockwise rotational displacement of plate 58. Magazine housing 66 being mounted on plate 58 has also been displaced, stripping disc 18 from magazine 20. The relative height of ridges 50 and support surface 202 has ensured that only one disc 18 has been engaged by ridges 50 and stripped from the magazine 20. Dispensing rod 10, which is mounted on actuator 12,which itself is operably connected to magazine carrying member 32 such that rotational displacement of the actuator 12 brings about rotational displacement of magazine carrying member 32, is displaced relative to base 34 such that it overlies disc 18 and the dispensing aperture 194 is in alignment with the dispensing channel 54.

Fig. 6c shows the dispensing configuration of the device whereby dispensing rod 104 is displaced in a direction substantially orthogonal to the plane of the direction of displacement of the magazine carrying member 32 ie. parallel to the longitudinal axis of the device 10. The actuator 12 is further depressed and locating pins 104 in co-operation with the third section 86 of slots 80, permit dispensing rod 104 to extend through dispensing aperture 194 and dispensing channel 54, pushing disc 18 through it.

Once the actuator 12 has been released, the device 10 is returned to its non- dispensing configuration under the action of spring 93 which will rotate the magazine carrying member 32 in the opposite direction to that described above, i.e. counterclockwise, owing to the co-operation between locating pins 104 and slots 80.

In use, a petri dish typically containing a layer of nutrient agar gel upon which an organism to be tested has previously been innoculated. The device 10 of the present invention can be used to simultaneously deposit onto the surface of the agar gel an array of evenly distributed sensitivity discs, such as antibiotic sensitivity discs.

Once the discs have been dispensed, the petri dish carrying the deposited discs dispensed thereon are further cultured to determine the effect of each sensitivity disc on the organism.

In an alternative embodiment, the device l0 may be adapted to receive 8 magazines. It will be understood by the skilled person that any number of discs can be dispensed at ant one time depending upon the number of magazines loaded into the device l 0 and the number of magazines the device l 0 is capable of receiving.

Claims

I. A dispensing device for dispensing a plurality of discrete items in a substantially predetermined configuration, the device comprising: a base having a plurality of spaced apart dispensing channels; a magazine carrying Homer having a plurality ot magazine housings.

SP? __.!. ., A1. .U. {her L<, tile d A|- e. Hi. .g alla. GIL. s, fc, . . CVA ills;llclgz. 11 e.> carrying the discrete items, the magazine carrying member slaving a plurality of dispensing slots, each comprising a dispensing aperture, corresponding in number with the magazine housings, the magazine carrying member co-operating with the base so as to effect displacement of the magazine carrying member relative to the base, removal of a discrete item from each of the magazines loaded in the device and substantial alignment of each dispensing aperture with the corresponding dispensing channel; a plurality of dispensing rods corresponding in number with the magazine housings, each of which is associated with one of the dispensing apertures; and, actuating means operatively connected with the magazine carrying member and the dispensing rods so that displacement of the actuating means causes displacement of the magazine carrying member relative to the base, bringing about alignment of each of the dispensing rods and dispensing apertures with the corresponding dispensing channel, and causes the dispensing rods to extend t]leretllrougil.
2. dispensing device as claimed in claim i, wherein the magazine carrying member is rctatably displaceable relative to the base.
3. A dispensing device as claimed In claim 1, wherein the magazine carrying member is slidably rotatably displacable relative to the base.
4. A dispensing device as claimed in claim l, 2 or 3, wherein the dispensing rods are mounted on the actuating means.
5. I-\ clspensin: Clerics as claimed i,, any preceding claim, wherein the base and the maga-,Tine carrying member cerise substantially circular plates.
6. A dispensing device as claimed in any preceding claim, wherein the upper face of the base may have a shaft centrally mounted thereon.
7. A dispensing device as claimed in claim 6, wherein the magazine carrying member is mounted on the shaft.
8. A dispensing device as claimed in claim 6 or claim 7, wherein the magazine carrying member Is rotatably mounted on the shaft.
9. A dispensing device as claimed in any preceding claim, wherein the number of discrete items which can be dispensed corresponds to the number of dispensing channels.
10. A dispensing device as claimed in any preceding claim, wherein the device is biased into a non dispensing configuration whereby each dispensing aperture and its corresponding dispensing channel is misaligned.
I]. A dispensing device as claimed in claim 10, wherein the means to bias the device into a non-dispensing configuration comprises resilient means.
12. A dispensing device as claimed in claim I I, wherein the resilient means composes a helical spring.
3. A dispensing device as claimed in claim i 2, wherein the resilient means is mounted on the shaft of the base and is received by the actuating means.
14. A dispensing device as claimed in claim 13, wherein the resilient means is mounted on the actuating means and is received by the shaft of the base.
15. A dispensing device as claimed in any preceding claim, wherein the actuating means comprises a stem having at one end a handle and at the other means for operal:'ly eilgagmg tile maga:zi;le housings of tlZC magazine carrying member such that rotal:rQnal dist?laccment of the actuating' means hring.s about rotational displacement of the magazine carrying member.
16. A dispensing device as claimed in any preceding claim, wherein the actuating means is mounted for axial displacement at substantially right angles to the plane of the upper face of the base.
17. A dispensing device as claimed in any preceding claim, wherein the Base comprises means for substantially retaining a discrete item in place during displacement of the magazine carrying member.
18. A dispensing device as claimed in claim 17, wherein the means is associated with each dispensing channel.
19. A dispensing device as claimed m claim 17 or 18, wherein the means comprises at least one retaining member.
20. A dispensing device as claimed in claim 19, wherein the retaining member comprises an upstanding ridge, fin or a blade.
21. A dispensing device as claimed in any one of claims 17 to 20' wherein the means comprises two or more retaining members.
22. A dispensing device as claimed in arty one of claims 17 to 21, wherein the means relay comprise an abutment face of two adjacent retaining members.
23. A dispensing device as claimed in claims 19 to 22, wherein each retaining member Is arcuate in shape and adjacent retaining members are separated by a dispensing channel.
24. A dispensing device as claimed in claim 23, wherein each dispensing slot preferably comprises cleans '-, supporting a discrete item to be dispensed.
2 A dispensing, device as claimed in claim 24. wherein the means comprises a supporting surface of a ledge disposed in the dispensing slot.
26. A dispensing device as claimed in any one ofthe previous claims wherein the magazine carrying member may comprise a complementarily shaped groove for receiving the means for retaining a discrete item in place.
27. A dispensing device as claimed in any one of the previous claims wherein the distance the means for retaining a discrete item during displacement of the magazine carrying member extends beyond the supporting surface of the dispensing slot corresponds to the thickness of a discrete item to be dispensed.
28. A dispensing device as claimed in claim 97, wherein the distance is less than the thickness of a discrete item to be dispensed.
29. A dispensing device as claimed in any one of the preceding claims, wherein the discrete item Is be a substantially disc shaped unit.
30. A dispensing device as claimed in claim 29, wherein the discrete item is a sensitivity disc for use in a method to determine the sensitivity of an organism to a particular reagent.
3 A dispensing device as claimed in claim 30, wherein the discrete item is manufactured from a porous and/or absorbent material.
32. A dispensing device as claimed in any preceding claim wherein the discrete item is impregnated with an antibiotic.
33. A dispensing device as claimed in any preceding claim, wherein the device may comprise two or more magazine housings.
34. A dispensing device as claimed in claim 33, vvlicrein the device cc'npriqe- s at least 6 mag-/;ne hr,!sirlos.
35. A dispensing device as claimed in claim 33, wherein the device comprises 8 magazine housings.
36. A dispensing device as claimed in claim 33, 34 or 35, wherein each magazine which can be received in a magazine housing comprises a magazine body and biasing means for biasing discrete items contained therein towards an open end of the magazine.
37. A dispensing device as claimed in claim 36, wherein the magazine comprises means for retaining a discrete item within the magazine body.
38. A dispensing device as claimed in claim 37, wherein the means comprises at least two magazine retaining lugs overlying the open end for retaining a discrete item carried in the magazine.
39. A dispensing device as claimed in claim 38, wherein the magazine further comprises means for locating it in the correct orientation in the device.
40. A dispensing device as claimed in any preceding claim, whereby depression oi the actuating means against a bias causes the device to move between its non-dispensing and dispensing configurations, dispensing a discrete item.
41. A dispensing device as claimed in any preceding claim, wherein the actuating means further comprises at least one aria for engaging the magazine housings of the magazine carrying member.
42. A dispensing device as claimed in claim 41, comprising a plurality of arias Hi cngag.ilg tl magazine housings, equal in namer t:o tile la!nher of magazines the device is capable of carrying.
43. A dispensing device as claimed in claim 43, wherein rotation of the magazine carrying member is brought about by the co-operation of a locating pin disposed on at least one arm and a guidance slot in which the pin is received.
44. A dispensing device as claimed in claim 43, wherein the device comprises two or more pins each of which co-operates with a guidance slot.
45. A dispensing device as claimed in claim 44, wherein the guidance slot comprises a portion which is substantially inclined with respect to the direction of displacement of the actuating means and/or the longitudinal axis of the device thereby bringing about rotation of the ina.gazine carrying member about the base.
46. A dispensing device substantially as described herein with reference to and as illustrated by the accompanying drawings.