FORM-2
THE PATENT ACT, 1970
PROVISIONAL SPECIFICATION
[See Section 10]

A Sensitivity Disc Dispenser used to dispense the Sensitivity Discs in Petri
Dish to find out required proper Antibiotics and the Dose of the same.

Span Diagnostics Limited, an Indian Company of 173-B, New industrial Estate, Udhna, Surat-394210,india

The following specification describes the nature of this invention:

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Field of Invention;
This invention relates to a sensitivity disc dispenser used to dispense the sensitivity discs in petri dish to find out required proper antibiotics and the dose of the same.
Background;
Conventional disc dispenser shown in figure (2), which dispenses only 6 sensitivity discs at a time in one pitch circle diameter as shown in figure (6a). The sensitivity discs, which are to be dispensed, are readily available and packed in the form of cartridges, which generally contains 50 numbers of sensitivity discs (D) as shown in figure (1). In this type of disc dispenser, the filled cartridges of its make are loaded in the disc dispenser, referring figure (2), by locating the guide (G) available on the cartridge and its counter locating guide/portion (GC) on to the disc dispenser as shown in figure (2). After loading the desired cartridges at the given location the loaded dispenser is placed on the top of petri dish (P) as shown in figure (6) which contains the media (M) in it. (Petri dishes are readily available in market with varying diameter ranging from 85mm to 100mm). Now the top (T) of dispenser is pressed in downward direction till it stops and as a result the internal mechanism will compel the sensitivity disc to fall in the petri dish at the desired locations, as shown in figure (6a). Simultaneously the plunger inside the dispenser will press the sensitivity disc onto the media in the petri dish. In this disc dispenser, at a time only 6 discs can be dispensed in one pitch circle diameter as shown in figure (6a) (@ 53.5 which give zone diameter of 26mm around each sensitivity disc in petri dish of 85mm). Similar make of dispenser is available in market, which can dispense 8 sensitivity discs at a time, in one pitch circle diameter. (This can accommodate in petri dish of 85mm). These disc dispensers do not dispense the disc on the space available on center part of the media available on the petri dish and as a result more media is consumed per test. This not only increases the labor cost but also plays an important role in time spent per test. Also the design seems to be bulky due to more number of components involved in it (@ 15 plus) and finally the direction of the applied force for operation is vertically downwards which is not suitable from ergonomics point of view for this application.
Another conventional disc dispenser shown in figure (3) & (3a) can dispense only 8 sensitivity discs at a time in one pitch circle diameter as shown in figure (6b). The sensitivity discs, which are to be dispensed, are readily available in the cartridge form, which generally contains 50 numbers of sensitivity disc (D) as shown in figure (1). In this type of disc dispenser, the filled cartridges of its make are loaded in the disc dispenser by locating the guide (G) available on the cartridge and its counter locating guide/portion (GC) on to the dispenser as shown in figure (3). After loading the desired cartridges at the given location the
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top cover (T) shown in figure (3a) is closed onto the bottom half (B) [figure (3 a)] of the dispenser. Then the loaded dispenser is placed on the top of petri dish (P) as shown in figure (6), which contains the media (M) in it. (Petri dishes are readily available in market with varying diameter ranging from 85mm to 100mm). Now the top cover (T) [figure (3a)] of dispenser is pressed in downward direction till it stops and then rotated in clockwise direction till it stops. As a result the internal mechanism will compel the sensitivity disc to fall in the petri dish at the desired locations as shown in figure (6b).
In this disc dispenser, at a time only 8 discs can be dispensed and in one pitch circle diameter, as shown in figure (6b) (@ 46.5 which give zone diameter of 18.5 mm around each sensitivity disc in petri dish of 85mm). This disc dispenser does not dispense the disc on the space available on center part of the media available on the petri dish and as a result more media is consumed per test. This not only increases the labor cost but also plays an important role in time spent per test. Also the design seems to be bulky due to more number of components involved in it (@ 10 Plus) and finally the direction of the applied force for operation is vertically downwards plus rotational which is not suitable from ergonomics point of view for this type of application.
The objective of this invention is to provide maximum number of disc to be dispensed in two different pitch circle diameter in single operation with more convenient direction of application of force and also to maximize the utilization of the media prepared on the dish.
To achieve the said objective, this invention provides a disc dispenser comprising of outer case, pusher plate, base plate, two torsion springs, one compression spring and three sets of nut-bolt assembly or screw (See figure 4, 5, 6 & 6C)
(a) Outer case :
Outer case is made from Plastic (High Impact Polystyrene) and it has at least 11 cutouts on its top for location or guiding the cartridges. The cartridges to be inserted in these 11 cutouts and they are pressed downward till the locating guide (G) on the cartridges is stopped by the counter locating guide (GC) on the cutouts of outer case. There is an angular slot (S) on the bottom right side of the outer case, which is meant for guiding the lever while in operation.
On the inner side of outer case there are 11 round cylinder, just below the 11 cutouts on top part of outer case. The cutouts hold the bottom part of cartridges firmly in their predefined positions while the other parts are in operation. One round protrusion provided at the center of the inner side of outer case which is meant for holding the compression spring and three other
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cutouts which are used for fixing the pusher plate and base plate to the outer case by the means of nut-bolt or screw.
(b) Pusher Plate:
Pusher plate is made from plastic (ABS - Acrylonitrile Butadiene Styrene) and has 11 cutouts, which are more or less elliptical in form, and they are meant for allowing the free fall of sensitivity discs into the hole of base plate. The pusher plate has 4 angular cutouts, which are acting as guide for finalizing the start and stop position of the pusher plate (along with internal stoppers provided on the base plate).
The pusher plate has two circular ribs at two different pitch circle diameter which actually plays an active role in pushing the disc out of the cartridges when lever (L) provided on pusher plate is moved in the clockwise direction. There is one circular groove, which acts as the guide for two torsion springs provided.
There are also two vertical protrusions provided between the circular groove on the pusher plate which are used to hold one end of each torsion spring. At the center a circular protrusion is provided to hold the other end of the vertical compression spring coming from center of the outer case. At the center of the other side of pusher plate there is one protrusion which act as guide for locating the pusher plate in to the base plate.
(c) Base Plate:
Base plate is made from plastic (ABS - Acrylonitrile Butadiene Styrene) and has 11 cutouts, which are more or less round in form, and they are meant for allowing the free fall of sensitivity discs into the petri dish. The base plate have three cutouts which are used for fixing the pusher plate and base plate to the outer case by means of the nut-bolt or screw.
There are four vertical protrusions provided on the base plate which are used for defining start and stop position of the pusher plate (along with the four angular slots provided on the pusher plate). Out of this four protrusions two protrusions are to be used to hold one end of each torsion spring. At the center a circular groove is provided which acts as a guide for locating the pusher plate onto the base plate.
Operations:
When cartridges with sensitivity discs filled in it are placed into disc dispenser by means of the locating guide available on the cartridges and its counter part on the dispenser and pressing it in downward direction till the cartridge
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movement is stopped. After loading the cartridges properly in to the disc dispenser, hold the dispenser above the petri dish containing media such as agar gel to find out required proper antibiotics and the dose of the same for pathogenic bacteria presents in the patient sample. Disc dispenser has a spring loaded lever (L) on its right side as shown in figure 5. The lever (L) is to be pulled in clockwise direction till its motion is restricted by the slot (S) on the outer case (O) and the internal stoppers/protrusions which are provided on the base plate, (not shown in figure). During this action the circular ribs on the pusher plate will compel the sensitive discs (D) from all the cartridges (C) to slide from them onto the hole of pusher plate elliptical slots/cutouts and than subsequently onto the hole of base plate's slot/cutouts (more or less round) and finally, onto the petri dish (P) in two different pitch circle diameter as shown in figure (6c).
Once the lever motion is stopped by means of internal stoppers on base plate and angular slots on the pusher plate than the two torsion springs are stretched and due to their tendency to regain their original position they will pull the pusher in anti-clockwise direction. So when we release the lever (L) then it will regain its original position (PI) due to spring force exerted by the two torsion springs (not shown in figure) and the dispenser will be ready to dispense the next lot of sensitivity discs as before.
The invention will now be described with reference to the accompanying drawings.
Figure (1) shows the conventional cartridge filled with sensitivity discs in it, generally 50 in numbers. The cartridges are specifically made for the particular type of disc dispenser, i.e. cartridge of one make fits only into the disc dispenser of its own make. It also shows the sensitivity disc (D) which are pre coated with antibiotics.
Figure (2) shows the conventional disc dispenser with one cartridge loaded in it. However it is capable of dispensing 6 disc at a time in one pitch circle diameter by pressing the top (T) of the dispenser in downward direction till it stops.
Figure (3) shows the conventional disc dispenser without its top cover. It is capable of dispensing 8 disc at a time in one pitch circle diameter.
Figure (3a) shows the conventional disc dispenser with its top cover closed. However, as mentioned above with reference to figure (3) it is capable of dispensing 8 disc at a time by pressing the top (T) of the dispenser in downward direction till it stops and further rotating the top cover (T) in clockwise direction.
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Figure (4) shows the disc dispenser with 11 cartridges placed in the 11 positions provided, which dispense 11 disc at a time in two different pitch circle diameter according to this invention.
Figure (5) shows the disc dispenser without cartridges being placed in it, according to this invention.
Referring to the drawings, the disc dispenser shown in figure (2), (3) & (3a) are the conventional disc dispenser and are described on background given above.
In figure (4) & (5) the disc dispenser with 11 positions for cartridge (C) according to this invention is shown. It may be seen from figure (5) that locating guides (GC) is provided on the disc dispenser and counter guide (G) is provided on the cartridge as seen from the figure (4). The cartridge (C) is loaded in the disc dispenser as seen in figure (4). Now from figure (5) it is seen that, initially lever (L) is at position (PI). Once the cartridges are loaded then the complete disc dispenser is placed over the petri dish (P) which is containing media (M) in it as shown in figure (6). Once this is done then, pull lever (L) in clockwise direction, till it stops automatically. This position is (P2) as shown in figure (5), wherein lever (L) slides in the slot (S) and internal mechanism (consisting of outer case, pusher plate, base plate and springs) compel the sensitivity Disc to fall at the desired location as shown in figure (6c). Thus, 11 sensitivity discs are located at the desired position in two different pitch circles. Viz. 8 in exterior pitch circle (Diameter 65.5mm) and 3 in interior pitch circle (Diameter 23.25mm). And as a result the media available on the center part of the petri dish is utilized more effectively and thus it reduces the volume of media consumed per test. This subsequently results in lesser media required per test as compared to other conventional disc dispenser.

The advantage of using the above said disc dispenser is that it can dispense 11
disc at a time, i.e. 11 disc in numbers in two different pitch circles. Viz. 8 in exterior pitch circle (Diameter 65.5mm) and 3 in interior pitch circle (Diameter 23.25mm).

The other advantages are its compactness in design, easy to operate and lesser number of components involved. Also it minimizes the amount of media required per test. As a result the effective volume of media preparation required per disc will be reduced. Also, we can use petri dish of varying diameter
ranging from 90mm to 100mm.
Dated this 31st day of March, 2006

of ANAND & ANAND, Advocates Agents for the Applicants
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