BLISTER SHEET LOADING APPARATUS WITH BOUNCE PREVENTION MEANS

Abstract

Apparatus for loading medication doses (4′) into a cavity (15′) of a blister sheet (12′) made from a resilient plastics material, is provided with a number of horizontally-arranged containers one of which is shown at (6′). Each container can be operated to release a solid medication dose (4′) into a cavity (15′) of a selected blister. The blister sheet to have its cavities loaded with medication doses is supported horizontally on a table spaced beneath the level at which the containers (6′) are located. A thick horizontal plate (1) is disposed between the level of the containers and the level of the table, and an array of inclined and axially-parallel bores (2′) are formed through the plate. The upper ends of the bore associated with each blister cavity can be located beneath the container which is to deliver a dose to the cavity so that a released dose travels down the bore and impacts against one side of the bore which acts to deflect the dose and thus reduce its vertical momentum. The dose is released from the lower end of the bore and impacts against the inside upper, wall of the cavity. The risk of damage by impact of released doses with one another in the cavity is reduced and the risk of a dose bouncing back out of the cavity through impacting on its resilient floor is avoided.

Description

FIELD OF THE INVENTION

THIS INVENTION relates to the prevention of bounce occurring when small objects are loaded into pockets into which they may be subsequently sealed. The invention is particularly well-suited, although not exclusively so, to preventing solid medication doses, such as tablets, from bouncing when falling into a pocket formed by the cavity of a blister of a blister sheet.

For convenience and ease of understanding, the description of the invention which follows has been limited to its use in loading medication doses into blister cavities of a blister sheet but it is to be understood that the invention is applicable to a much wider range of usage than this particular activity.

STATE OF THE ART

The provision of prescribed medication to a patient by means of a pre-loaded blister package is commonly used to enable the patient to carry several days supply of prescribed doses of medication. The doses are prescribed by a doctor and appropriately packaged by a pharmacist to provide the patient with a sealed blister sheet having individual blisters marked with the days and times at which the doses in each blister are to be administered to the patient.

It is convenient to mechanize the loading of the blister sheet with the prescribed doses to save time and apparatus to achieve this has been devised which relies on a large number of storage containers having bottom openings from which tablets are released into the cavities of blisters in accordance with a computerized program. The program determines which blister of the blister sheet is to be loaded at a particular moment with a particular prescribed medication. The blister sheet is normally loaded while inverted and has its blisters extending downwardly into respective openings provided in a horizontal support table. The table can be indexed horizontally in its own plane by a mechanism to bring each blister in turn to a pre-arranged loading position at which the appropriate medication dose selected from one of the containers can be released into its cavity.

The blister sheet is normally made from a plastics material which has a natural resilience, and it is convenient to rely on gravity to transfer a dose from a selected storage container to the blister cavity. However the natural resilience of the blister sheet can cause a dose to bounce back out of the blister cavity if it is the first dose to be placed in it, and there is also a risk that the descending dose will impact on a dose already in the cavity and damage one or both doses as a consequence.

To reduce the risk of damage occurring when a dose is dropped into a blister, the distance through which the dose drops from the underside of the container should be made as small as is practical. However there is a limit to the reduction of this distance if there is to be no risk of a dose bouncing out of the cavity interfering with the operation of the indexing mechanism.

OBJECT OF THE INVENTION

An object of this invention is to reduces the risk of problems occurring during loading of doses or other hard objects into a blister cavity.

THE INVENTION IN ITS BROADEST ASPECT

In accordance with the broadest aspect of the invention apparatus for loading individual cavities of a blister sheet with small hard objects released into the cavities from above, includes: first means for locating individual containers holding the objects at a level above the position of the blister cavity to be loaded; second means for releasing an object from the container so that it follows a path leading downwards towards the cavity; and, third means located in the path of descent of the object and acting to retard its rate of descent to an acceptable level (as below defined) before it reaches the cavity. The expression “acceptable level” referred to above, is a level at which a released object will not bounce back out of the cavity nor will its impact on other objects already loaded into for different objects to be loaded into the blister cavity.

PREFERRED FEATURES OF THE INVENTION

Preferably the third means is formed by a deflector which is struck by the object during its descent to absorb part of its momentum and thus slow it down.

Suitably the deflector is in the form of an elongated opening such as a bore, extending downwardly through a plate and at an angle to the plane of the plate, the upper end of the opening being located beneath a bottom outlet of the container and the lower end of the opening being located above a loading position at which the blister cavity to be loaded is positioned.

Conveniently the lower end-portion of the opening is shaped to direct an object descending through it towards a side-wall of the blister cavity

A Narrower Aspect of the Invention

In accordance with a narrower aspect of the invention apparatus for loading cavities of a blister sheet with prescribed doses of medication, includes: a support table provided with means for positively locating respective blisters of the blister sheet at a level spaced beneath and displaced horizontally with respect to a position at which dose-storage containers can be located, and a deflector positioned between the storage containers and the table to deflect a dose falling from the storage container laterally towards a blister cavity intended to receive it.

Preferred Features of the Narrower Aspect of the Invention

Preferably the deflectors referred to immediately above, are provided by the internal surfaces of respective axially parallel bores formed through a relatively thick and horizontal plate located between the level of the blister sheet on the table, and the level of the dose-discharge position of the container.

The portion of the lower end-portion of the bore opposite the side first struck by a descending tablet may be rebated to avoid the risk of tablets stacking up against one side of the cavity and possibly interfering with the correct operation of the apparatus.

When a particular dose is to be loaded into a selected blister cavity, an indexing mechanism of the table may be operated to bring the cavity of the blister to be loaded and its associated deflector, to a position at which the deflector is located beneath the lower end of a storage container from which the dose is to be released. The dose then strikes the deflector during its descent, and its momentum is reduced as a consequence. The deflection also preferably deflects the descending dose towards a side-wall of the selected blister. Impact with the side wall slows down the descent still further so that the risk of the descending dose damaging itself or other doses which may already be in the blister is reduced still further.

INTRODUCTION TO THE DRAWINGS

The invention will now be described in more detail, by way of examples, with reference to accompanying partly-diagrammatic drawings, in which:

In the drawings

FIG. 1 is a perspective view from above of a relatively thick plate penetrated by an array of axially-parallel bores inclined to the plane of the plate and providing one form of deflecting means;

FIG. 2 is a diagrammatic plan view of the plate of FIG. 1;

FIG. 3 is a side view of the plate of FIG. 2;

FIG. 4 is an end view of the plate of FIG. 2;

FIG. 5 shows diagrammatically, and to a greatly enlarged scale, the path of descent of a dose through one bore of the plate, the dose being released from a dose-storage container above the plate and striking against a deflecting surface provided by the interior wall of the bore so that the dose is deflected towards the upper internal wall of a blister cavity beneath; and,

FIG. 6 shows a modification of FIG. 5 and where identical parts bear identical reference numerals but they are primed, and the lower end of the bore is rebated.

DESCRIPTION OF FIRST EXAMPLE OF THE INVENTION

For convenience the example of the invention now to be described is designed to be used in conjunction with apparatus of the general design described in U.S. Pat. Nos. 7,225,597 B1; 7,426,814 B2; and, 7,510,099 B2. These specifications are hereby inserted by way of reference to enable the reader to understand how the apparatus works and to avoid burdening the present specification with unnecessary detail well known in the art. In the first two of the above-numbered prior art patent specifications a blister support table is identified in FIG. 1 by the reference number ‘thirty’ and the same reference numeral is used in FIG. 5 of the present specification to denote a like part. The support table 30 of FIG. 5 is provided with openings 14 for the reception of respective blisters 15 of an inverted blister sheet 12 moulded from a resilient plastics material and placed blistered-side down on the table 30.

FIGS. 1 to 4 show a flat thick nylon plate 1 formed with an array of identical cylindrical and axially-parallel bores 2 inclined at an angle to the plane of the plate of about sixty degrees. The plate 1 is slightly less than two centimeters thick. The diameter of each hole is slightly more than sixteen millimeters. None of these dimensions or angles is critical and are only given as one example of the invention.

FIG. 5 shows one of a number of dose-storage containers 6 located at a level spaced above the plate 3 and at a dose-discharge position vertically above the upper end of a bore 2. A mechanism (not shown) at the lower end of the container 6 and controlled by a computerized control system (also not shown) allows a dose to be released from the container 6 in response to a control signal generated by the system and controlling operation of the apparatus.

Operation of the First Example of the Invention

A dose in the form of a hard solid medication tablet or pill, shown at 4 in FIG. 5, is dropped from the lower end of the container 6 into the upper end of the bore 2 immediately beneath, and descends along the fall line indicated by a broken line in FIG. 5. As the axis of the bore 2 is at thirty degrees to the vertical, the dose strikes against the inside wall of the bore intermediate its ends, at a location 7. The distance through which the dose falls before striking the location 7 is found empirically and ensures that the momentum of the dose 4 is, insufficient to cause damage to I when impacting on the location 7. This fall distance may be varied in the apparatus to achieve this result and it will be found empirically and changed to suit different types of dose. The contact of the dose with the location 7 acts to reduce the vertical momentum of the dose 4 and deflects it down the inclined bore 2 towards its lower end. The dose leaving the lower end still has a horizontal component of velocity so that it impacts on the side wall of the blister cavity positioned beneath the lower end of the bore 2 and associated with it.

Were the dose 4 allowed to fall vertically onto the floor of the cavity, there would be a risk that the resilience of the material from which the blister sheet is made, might bounce the dose 4 back out of the cavity. It might then cause damage to an indexing mechanism used to move the table 30. There is also risk that a dose descending vertically into the blister cavity from the bore 2 could have sufficient momentum to impact against, and possibly damage itself and/doses already in the blister cavity.

First Modification of Described Example

In the modification of FIG. 5 shown in FIG. 6, a rebate 100 is provided on the side of the lower portion—of the bore 2 opposite the location 7. This rebate 100 serves to accommodate overflow of doses within the cavity of a blister being loaded, and also to prevent doses from stacking up at one side of the blister and possibly blocking the lower end of the bore 2.

Interpretation of the Width of the Wording Used in This Specification

Although the invention has been specifically described in the above examples with reference to medication doses being loaded into blister cavities, it is to be understood that its usage is not limited to this application. The invention is capable of being used in any apparatus where it is required to reduce the velocity of descent of hard solid objects which might otherwise free-fall with an undesirably high velocity. The deflecting bores of such apparatus may, for example, be used to reduce the velocity with which tablets or other solid medication doses are inserted into respective single dose blisters, or to orientate the dose to a desired position required for entry into a blister.

Claims

1. Apparatus for loading individual cavities of a blister sheet with small hard objects released into the cavities from above, including: first means for locating individual containers holding the objects at a level above the position of a blister cavity to be loaded; second means for releasing an object from the container so that it follows a path leading downwards towards the cavity; and, third means located in the path of descent of the object and acting to retard its rate-of descent to an acceptable level before it reaches the cavity.

2. Apparatus as claimed in claim 1, in which the third means is formed by a deflector which is struck by the object during its descent to absorb part of its momentum and thus slow it down

3. Apparatus as claimed in claim 2, in which the deflector is in the form of a bore inclined downwardly through a horizontal plate, the upper end of the bore being located beneath a bottom outlet of the container and the lower end of the bore being located above a loading position for the blister cavity.

4. Apparatus as claimed in claim 3, in which the bore is shaped to direct an object descending through it towards an upper side-wall of the blister cavity.

5. Apparatus for loading cavities of a blister sheet with prescribed doses of medication, including: a support table provided with first means for positively locating respective blister cavities of the blister sheet at a level spaced beneath and displaced horizontally with respect to the position at which dose-storage containers can be located, and a deflector positioned between the storage containers and the table to deflect a dose falling from the storage container laterally towards a blister cavity intended to receive it.

6. Apparatus as claimed in claim 5, in which the deflectors are provided by the internal surfaces of respective axially-parallel and inclined bores extending between upper and lower surfaces of a relatively thick horizontal plate disposed between the dose-discharge position of the containers and the position of the blister sheet.

7. Apparatus as claimed in claim 5, in which the lower end-portion of the bore opposite its side first struck by a descending dose, is formed with a rebate.

8. Apparatus as claimed in claim 5, including an indexing mechanism for traversing the deflectors and table horizontally to bring the cavity of a selected blister to be loaded together with its associated deflector, to a position beneath the dose-discharge position of the dose-storage containers.