GB2294924A

GB2294924A - Conveying Tablets

Info

Publication number: GB2294924A
Application number: GB9522504A
Authority: GB
Inventors: Carlo Papera
Original assignee: Zanchetta and C Srl
Current assignee: Zanchetta and C Srl
Priority date: 1994-11-09
Filing date: 1995-11-02
Publication date: 1996-05-15
Also published as: GB9522504D0; DE19541674A1

Description

1.

2294924 Device for conveying loose medicinal tablets or similar products from one machine to another on different levels The present invention relates to a device for conveying loose products such as tablets or similar products, especially pharmaceutical, from one machine to another located on different levels, for example on different floors of a factory.

In many factories, especially in the pharmaceutical sector, machines working on different stages of the same process cycle often need to be located on different floors or levels. This means the product being processed has to be conveyed from an upper to a lower level or vice versa. When a product has to be transferred from an upper to a lower level, the conveyor often consists of a gravity feed system of some kind. When a product has to be transferred from a lower to an upper level, conveying is effected using suction systems capable of generating a vacuum inside a tube fed with product and leading into the machine which the product is to be transferred to.

Certain products, typically medicinal tablets, tend 2 to pulverize or lose powder as they travel up or down in the conveyor, making contact with each other and with the walls of the conveyor as a result of the flowing motion and/or of the turbulence which may be created inside the conveyor itself. This not only has negative effects on the quality of the end product but also contaminates the working atmosphere with the powder lost by the products.

To overcome these problems in transferring product from an upper to a lower level, several systems have been devised to control the downward flow of the product in such a way as to effectively transfer it and at the same time prevent the damage caused by the grinding effect of the products coming into contact with the conveyor and with each other.

For example, the conveyor may choking devices such as valves opened and closed synchronously the fall of the product and can for the product at one or more slow the fall. In another known deformable diaphragms placed inside the convevor tube and be equipped with The valves are in order to break narrow the passage points in order to solution, there are at various levels designed to create 3 steps on which the product stops temporarily during its downward flow.

In actual f act, the conveyor systems with valves have not proved to be very effective in reducing damage to the product and have the considerable disadvantage of being difficult to assemble and to adjust to different conveyor heights. Moreover, these systems involve high costs of production, installation and maintenance and are not very reliable.

The deformable diaphragms require lengthy and complicated manufacturing processes, and, in addition, the diaphragms themselves tend to wear out very quickly.

The aim of the present invention is to overcome the disadvantages of the conventional conveyors mentioned above by providing a conveyor for loose products which is simple and economical in construction and which is capable of offering a high degree of reliability.

A further aim of the invention is to provide a conveyor for loose products which is easy to install and to adapt to any configuration where two machines located on two different levels must be connected to each other.

4 Yet another aim of the invention is to provide a conveyor which allows the speed at which the loose product falls to be easily adjusted.

These and other aims and advantages, which will be evident for experts in the trade reading the text that follows, are achieved in a device for conveying a loose product, for example pharmaceutical tablets, from one machine to another on different levels, for example on two floors of a factory, characterized in that it has a conveyor tube made of a flexible material, connecting the said two machines and forming a spiral feed path round a central mounting column (1) which supports the tube (3) itself.

In a preferred embodiment of the invention, in order to enable the angle of successive sections of the said tube to be adjusted according to individual requirements, the device disclosed is further characterized by the fact that it envisages preferably a plurality of supporting arms projecting radially from the column, one end of each arm being attached to the mounting column in such a way that the height of the arm itself can be adjusted and the other end being attached to the conveyor tube.

This arrangement makes it possible to modify the feed path defined by the conveyor tube at any time by simply changing the position of the supporting arms. That means the conveyor can be adapted to any installation configuration and, especially in the case of product transferred from an upper to a lower level by gravity, the speed of the falling product can easily be varied, for example when changing over from one product to another in the same installation, by adjusting the angle of the conveyor tube. The absence of intercepting elements, whether static or dynamic, makes the device extremely reliable and reduces production, installation and maintenance costs to a minimum.

For the best results, the conveyor tube is made of a transparent plastic material, preferably transparent, reinforced, food-safe PVC.

In a possible embodiment of the invention, the central mounting column may be equipped with a vibrator operated uninterruptedly, or only when necessary, to facilitate the feeding of poorly flowable products, or to loosen up product that has accumulated in the conveyor tube or to completely empty the conveyor tube after product infeed has been stopped, for example when changing over from 6 one product to another. The said vibrator is particularly useful to loosen up blocks of product which may form in the conveyor tube after a period of machine idleness: in such a case, the vibrator restores the flowability of the product so it can travel smoothly inside the conveyor tube.

Each of the aforesaid supporting arms may have a first fastening element (for example, a collar) at one end to secure it to the central column and a second fastening element at the other end to secure it to the conveyor tube.

The second fastening element may example, of two rings set at an other, one ring being clamped round arm and the other round the conveyor The invention will now be described consist, for angle to each the supporting tube.

with reference to the accompanying drawings, which illustrate two preferred embodiments by way of example only, and in which:

- Figure 1 is a side view of the device disclosed by the present invention connecting two machines and used to gravity feed loose product from the upper machine to the lower one; - Figure 2 is a cross section along the line II-II shown in Fig.1; 7 - Figure 3 shows a detail of the end of the conveyor tube; - Figure 4 shows a detail of one of the supporting arms holding the conveyor tube to the central mounting column; - Figures 5 and 6 are a front view and a side view of the fastening element which secures the conveyor tube to the supporting arm, Fig. 6 being a view along the line VI-VI shown in Fig. 5; - Figure 7 is a side view of the device disclosed by the present invention connecting two machines and used to transfer loose product upwards from the lower machine to the upper one by means of a pneumatic feeder operated by a suction unit located on the upper level where the machine receiving the product is.

The illustrations are drawn to different scales.

The mounting of the product conveyor tube 3 consists basically of a central column 1, made from a steel tube, for example, which supports the tube 3 by means of supporting arms 5 that project radially outwards from the central column 1.

The conveyor tube 3 is made preferably of transparent, reinforced, foodsafe PVC. This material has the following qualities making it 8 suitable for the purposes of the present invention: - it is sufficiently flexible to allow the spiral conveyor tube to be stretched or compressed as necessary; - it is resistant; - it has a low friction coefficient to facilitate product flow; - its fine surface finish prevents any grinding action on the product as the latter slides along the conveyor; - being transparent, it is possible to check the product flowing inside the conveyor tube so that prompt action can be taken in the event of need.

In the embodiment illustrated in Fig. 1, the central column 1 is fixed to both the floor P and the ceiling S of the room where the conveyor is installed. The central column 1 might, however, be secured to the floor only or to the ceiling only. On the upper floor (above the ceiling S) there is a first machine which, in the embodiment being described, is a generic source of loose product and is not illustrated (for example a tablet maker). The product must be transferred from the first a second machine, which, in the being described, is illustrated machine to embodiment 9 schematically as a machine M and which is located on the lower floor.

The top end of the conveyor tube 3 is connected to a rigid tubular element 7 by means of a tube union 11. The rigid tubular element 7, which is curved at its bottom end where it joins the conveyor tube 3, passes through the floor which divides the room above where the loose product source is installed from the room below where the machine that receives the loose product is installed. At the inlet at the top end of the tubular element 7 there is a hopper 13. The tubular element 7 also allows the product to reach an appropriate speed before entering the conveyor tube 3 as a result of gravity acting on it.

The loose product is gravity fed along the conveyor tube 3, following an initial vertical path defined by the rigid tubular element 7 and then a substantially helical path defined by the conveyor tube 3, which can be set in the most suitable position by adjusting the height and angular position of the individual supporting arms 5 along the central column 1. The fact that the geometry of the conveyor tube, and hence the angle of the feed path, can be adjusted, makes it possible to control the speed at which the product moves down the conveyor according to the density and type of product (size, shape, texture) and to its brittleness and resistance to pulverization.

The supporting arms 5 also make it possible to adjust the height of the bottom end of the conveyor tube 3, which is connected by means of a tube union 15 to an outfeed element 17 which, in the embodiment illustrated, consists of a cover 19 attached to a suitably shaped outfeed tube 21 (Fig. 3). The shape of the outfeed tube is designed to appropriately change the direction of the product as it drops out of the conveyor in such a way as to dampen its impact against the side of the container of the machine M when the container is still empty or just starting to be filled. In addition, the opening 21a made in the upper portion of the outfeed tube 21 facilitates emptying of the tube when the container of the machine M is almost full.

To permit the height and angle of the supporting arms 5 to be adjusted along the central column 1, each of the said arms 5 has a collar 23 (Fig. 4), equipped with screws or equivalent fastening means and designed to be secured to the central column 1.

11 The conveyor tube 3 is secured to each arm 5 by means of a double collar 25 (Figs. 5 and 6) consisting of a first ring 27 and a second ring 29 set at 900 to each other.

means 27a, consisting elements, to secure it corresponding arm 5, The ring 27 has fastening of screws or equivalent to the distal end of the whilst the ring 29 has fastening means 29a, consisting of screws or equivalent elements, to secure it to the conveyor tube 3. To prevent damage to the conveyor tube 3, the inside of the ring 29 has a scratchproof lining 29b.

The ring 27 may be lined in the same way to prevent damage to the arm 5 and the collar 23 may also have a similar lining to prevent damage to the central column 1.

For special applications, the conveyor tube 3 can be lengthened by connecting one or more extensions to it using, for example, a Teflon sleeve to join two lengths of tube 3.

The conveyor tube 3 may be equipped with a vibrator, for example attached to the central column 1, as shown schematically by the numeral 30 in Fig. 1. The vibrator facilitates the flow of product inside the conveyor tube 3, to avoid 12 blockages for example, or to completely empty the conveyor when necessary.

It is understood that Figs. 1 to 6 illustrate an embodiment of the invention which is given by way of example only and which can be subject to variations without departing from the scope of the inventive concept.

In the embodiment illustrated in Fig. 7, which, like Figs. 1 to 6, is also given purely by way of example, the conveyor tube 3 is used to connect a first machine, located on a lower level or floor, which delivers the loose product and which is illustrated schematically as ME, to a second machine, for example, the hopper of a machine MI. In the case illustrated, the conveying tube 3 is connected to the machine ME through a hopper 30 which feeds the product into the inlet of the tube 3 under the action of the vacuum inside the tube created by a suction unit 31 connected to a pneumatic conveyor 32 whose inlet is connected to the outlet of the tube 3. The outlet of the said pneumatic conveyor 32 leads into the hopper 33 of the machine MI.

The vacuum created inside the conveying tube 3 by the suction unit 31 causes the product fed by the considerablv 13 hopper 30 to travel upwards along the tube 3 sliding on the tube's inner surface which, being in the shape of a coil divided into numerous helical sections whose angle is adjustable, guides the product to the outlet of the conveyor and reduces, or may. even completely eliminate, the turbulence caused by the suction, allowing the product to flow without excessive friction.

In the embodiment shown in Fig. 7, the characteristics of the central column 1, of the arms 5, and of the tube 3 (as regards its flexibility and the material it is made of) may be the same as in the embodiment illustrated in Figs. 1 to 6.

14

Claims

Claims

1) 2) 3) A device for conveying loose products, especially medicinal or pharmaceutical tablets, from one machine to another on different levels, for example, two floors of a factory, characterized in that it envisages a conveyor tube made of a flexible material, connecting the said two machines in such a way as to form a spiral feed path round a central mounting column which supports the tube itself.

The device for conveying loose products according to claim 1, characterized in that it envisages the said central mounting column, with a plurality of supporting arms projecting radially from the column, one end of each arm being attached to the mounting column and the other end to the conveyor tube.

The device for conveying loose products according to claim 1, characterized in that the said 4) 5) 6) conveyor tube is made of a transparent plasti material.

The device for conveying loose products according to claim 1, characterized in that the said conveyor tube is made of transparent, reinforced, food-safe PVC.

The device for conveying loose products according to claims 1 and 2, used for transferring the said product by gravity from a first machine located on a first level to a second machine located on a second level below the first, characterized in that the top end of the conveyor tube is connected to a substantially vertical, rigid tubular element connected to the outfeed of the said first machine.

The device for conveying loose products according to claims 1, 2 and 5 characterized in that the central mounting column is equipped with a vibrator unit.

The device for conveying loose products according to claim 2 characterized in that each of the said 16 supporting arms has a first fastening element at one end of it to secure it to the central column and a second fastening element at the other end to secure the said conveying tube to the said supporting arm itself.

8) 9) 10) 11) The device for conveying loose products according to claim 7 characterized in that the said second fastening element consists of two rings set at an angle to each other, one ring being clamped round the supporting arm and the other round the conveyor tube.

The device for conveying loose products according to claim 8 characterized in that at least the second of the said rings is internally lined with scratchproof material.

The device for conveying loose products according to claims 1 and 5 characterized in that the bottom end of the conveyor tube is connected to an adjustable outfeed tube.

The device for conveying loose products according to claims 5 and 10 characterized in that the bottom end of the conveyor tube is connected to an outfeed tube with a first end outlet, from which the loose product feeds out in a direction that is coaxial with the outfeed tube itself and another outlet between the inlet and the said end outlet.

12) 13) The device for conveying loose products according to claim 1 or 2 and 6 characterized in that, to convey the loose product from a first machine, located on a lower level, to a second machine, located on a second level above the first, the inlet of the conveyor tube is connected to a hopper, which feeds the said product, and its outlet to a pneumatic conveyor connected to a suction unit and to the infeed of the second machine.

The device for conveying loose products substantially as described with reference to the accompanying drawings.