CN1122594C - Batching device for tablets making compression machine - Google Patents

Abstract

This device, which can be used in a pharmaceutical tablet press, consists of a turntable (1) which rotates around a vertical axis and which is equipped with a series of die holes (3) for filling powder or granular raw materials, a pair of upper and lower punches (5, 6 ) are respectively slidably introduced into the turntable relative to each die hole, and are engaged with each die hole by each opposite working head (5a, 6a). The driving cam mechanism (9) in the device drives at least one punch and determines the reciprocating distance between the working heads of each pair of punches; the driving cam mechanism moves axially relative to the turntable so as to adjust the distance. A further drive cam mechanism (11, 12) is provided with a variable profile guide (15) for easy entry into the drive cam mechanism (9) and is mechanically connected to each other for changing profile depending on the adjusted position of the drive cam mechanism (9).

Description

Dosing unit for pharmaceutical tablet presses

The present invention relates to a tablet press for manufacturing tablets.

Known tablet presses for the manufacture of pharmaceutical tablets consist of a turntable which is driven such that it rotates about its vertical axis and which is coaxially provided with an orifice or packing plate at an intermediate level.

The die holes machined on the plate comprise a plurality of holes whose axes are regularly spaced along a circumference coaxial with the turntable and which are parallel to the axis of the turntable.

Each die hole has two related upper and lower punches, which are respectively guided by the shell on the turntable. The shell is coaxial with each die hole.

The working heads of each pair of punches are opposed to each other, and the working heads are sized to fit into the associated die holes from above and below.

As is well known, the sequence of processes for producing tablets by a tablet press consists of filling a die hole with powdered or granular material, filling a defined volume of material into the die hole to form a tablet, pre-compressing the tablet material, and then finally compressing the tablet The raw material must form a tablet of predetermined thickness. Finally, the formed tablet is ejected from the die orifice.

The above processes are performed sequentially while each die hole moves along a predetermined arc of a circle. This arc generally extends along the full circle formed by the turntable.

Specifically, an appropriate drive mechanism is connected to the punch, and specifically guides the axial stroke of the punch in the housing, and its action is consistent with the filling, batching and ejection stations.

A tablet press for pharmaceutical tablets of the type described above is disclosed in US Patent No. 4,943,227 owned by the same applicant.

This machine consists of a cylindrical cavity machined on the turntable and coaxial with the axis of the turntable. above and preferably radially relative to the axis of the turntable.

The cylindrical chamber contains the material to be delivered to the die orifices for making tablets.

The centrifugal force generated by the rotation of the turntable makes the die holes filled quickly. In actual operation, once the working head of the upper punch does not cover the opening of the infeed slot, the raw material is pushed into the die hole. In the charging stage, the distance between the working heads of the two opposing punches determines the volume of the die hole, that is, the volume of the formed tablet is determined.

The punches are moved by a drive mechanism comprising fixed cam grooves integral with the machine structure and designed to engage the rollers which are rotatably supported on radial axes by the same punches.

In known tablet presses for pharmaceutical tablets, it is difficult to vary the dosing of the raw material feed for making a single tablet as required. In order to change the distance between the working heads of the punch, it is necessary to work on the drive of the lower punch. This operation requires the replacement of the drive for the punch as a whole group in the charging and dosing process after the prepared tablet is ejected.

Obviously, this will result in high construction and operating costs and limited production capacity.

An improved tablet press for pharmaceutical tablets is disclosed in Italian Patent Application No. BO93A000493 owned by the same applicant. The machine includes a punch with rotating roller pairs mounted on opposite ends of a cross pin and engaging cam grooves formed in the machine's stationary structure.

The above-mentioned rollers can be fitted into the cam grooves either from the height of the lower wall of the channel defined by the cam groove or from the height of the upper wall of the channel.

The object of the present invention is to provide a device enabling simple and rapid adjustment of the operation of the dosing mechanism in a tablet press for pharmaceutical tablets, which is achieved by an effective and reliable technical solution.

According to the present invention, the above object is achieved by a batching device for a pharmaceutical tablet press, which device comprises: a rotating turntable driven to rotate around a vertical axis; a series of die holes spaced apart along the circumference of the turntable, the The die holes are filled with powder or granular raw materials, and each die has a pair of upper and lower punches. The punches are characterized by opposing working heads and are smoothly introduced into the turntable so that the working heads are in contact with the die. Hole engagement; the driving mechanism connected with the punch is used to adjust the mutual distance between the working heads, and the driving cam mechanism is used to make at least one of the punches determine the distance between the working heads in the batching and charging process. distance from each other, the driving cam mechanism can move axially relative to the turntable so as to adjust the distance; in addition, another driving mechanism is formed by the charging operation cam, and these cams cooperate with each other to determine a variable shape and lead to the The connecting passage of the driving cam mechanism, the charging operation cams are mechanically connected to each other so as to change the shape of the connecting passage according to the adjustment position of the driving cam mechanism.

The distinctive features of the present invention are specified in the following description with specific reference to the accompanying drawings, in which:

Fig. 1 is the top view of the dispensing device mentioned in the present invention;

Fig. 2 illustrates the working steps of the device when viewed from the X direction of Fig. 1 unfolded on a plane;

Figure 3 represents the same working steps, but in different batching adjustment positions;

Figure 4 shows a view taken along section IV-IV of Figure 3;

FIG. 5 shows a view taken along the V-V section of FIG. 2 .

Referring to the accompanying drawings, a rotary carousel 1 of a tablet press is driven to rotate in direction M about a vertical axis;

The axes of the plurality of die holes 3 on the die orifice plate 2 are parallel to the axis of the turntable 3, and these die holes are neatly spaced apart from each other along a circumference coaxial with the turntable.

The die hole 3 consists of a through hole made in the tube 4 connected to the plate 2 .

Respectively have upper and lower two punches 5,6 in each die hole 3, and this pair of punches imports corresponding housing from the upper and lower sides of the die hole 3 and coaxial with the die hole respectively on the turntable.

Each pair of punches is equipped with working heads 5a, 6a respectively, which are opposite to each other and whose diameter is smaller than that of the die hole so as to fit in the respective die hole 3 .

In addition, the die hole 3 communicates with the channel for supplying the powder or granular raw material to be compressed.

This transverse groove is arranged radially with respect to the axis of the turntable 1 and opens into the upper part 3a of the die hole, the diameter of which is locally widened.

The punches 5, 6 are integral with a pin 7 which runs radially across each punch.

The pair of rollers 8 are rotatably supported by the pin 7 so that the pair of rollers 8 are fitted to opposite ends of the pin. Only the roller 8 of the upper punch 5 is shown in the drawings. These rollers roll in respective drive cam grooves machined in the stationary structure of the machine.

These drive cam slots act as drive guides for at least an angular portion of the circular path along the turntable 1, so as to force the punches 5, 6 to make a guided axial stroke and define the working heads 5a, 6a of each pair of punches the mutual distance between them.

More precisely, the dosing device that is the subject of the invention is characterized by a dosing adjustment and a drive cam 9 machined on the inner wall of a section of drum 10 fixed to the machine's stationary structure.

The drive cam 9 can be moved vertically in order to adjust the distance between the working heads of the punches 5, 6 with respect to the type of tablet to be dosed.

With respect to the moving direction of the roller 8, the lower wall of the entrance (inlet) of the cam 9 is horizontal, while the upper wall thereof is inclined downward.

The roller 8 can enter the cam 9 in its vertical position varying in height from a minimum height level with the lower cam wall to a maximum height level with the upper cam wall.

Thus, an additional movement of the punch relative to the position determined by the position of the cam 9 is made in order to increase the material introduced into the die hole 3 .

Obviously, without this additional movement, the roller 8 would enter the drive cam 9 at a level level with the lower wall, ie at a determined minimum level, as seen in FIG. 3 .

Upstream of the cam 9 in the direction of rotation M there are respectively inner and outer first and second charging operating cams 11, 12 formed by respective drum-shaped parts 13, 14 locked to the machine's stationary structure.

Rollers 8, respectively the inner and outer rollers of the punch 5, roll on cams 11,12. The combined position of the cams 11 and 12 defines a channel 15 of variable shape which connects a pre-feeding cam 16 to the cam 9 . The pre-feed cam 16 is machined on a drum 17 fastened to the machine.

The outer displacement charging cam 12 is slidably guided in the vertical direction along a pair of rods 18 supported by a frame 19 fastened to the stationary structure of the machine.

The first section 12a of the lower wall of the (displacement) cam 12 is inclined upwards, the second section 12b of the lower wall is straight, and the upper walls of the two sections of the (displacement) cam 12 are not straight, but in the vertical direction They are arranged in a staggered manner, and the middle is connected by an upwardly inclined section 12c along with the moving direction of the roller 8 .

The inclined section 12c determines the minimum height difference h applied to the axial movement of the punch.

A pair of lower and upper guides 20 , 21 fastened respectively to the fixed structure of the machine allow the inner loading cam 11 to slide angularly on a circular path concentric with the turntable 1 . Suitable stops 22 limit the displacement of the cam 11 .

The first section 11a of the upper wall of the cam 11 is straight, while the second section 11b of the upper wall is inclined upward.

The two sections of the lower wall of the cam 11 are not straight, but are vertically staggered and connected by an inclined section 11c so as to determine the minimum height difference h.

The cams 11 and 12 are mechanically locked by means of a toothing 23 fastened obliquely upwards to the front of the drum 13 and extending longitudinally relative to the drum 13 .

The toothed member 23 slides in a groove 24 formed on the surface of the drum member 14 facing the cam and also inclined upwards.

Thus, the angular movement of the charging cam 11 determines the vertical displacement of the cam 12 via the ramp of the toothing 23 .

The operation of the device will now be described, starting with the process following the ejection of a formed tablet from its orifice 3 .

In this process, the outer roller 8 of the upper punch 5 engages the pre-feed cam 16 so that the axial position of the punch relative to the roller 8 is at a fixed reference height, indicated by Lo in FIG. 2 .

Assuming that the working heads 5a, 6a of the punch are at position P1, the upper part 3a of the die hole 3 is blocked by the working head 5a of the upper punch 5.

The punch 5 must rise to the height Ld before engaging with the cam 9 . The height Ld changes in relation to cam position adjustment and charging. (See Figure 2)

The punch 5 is raised by the charging operation cams 11, 12, and the combined position of the cams defines a channel 15, whose shape changes are related to the mutual positions of the cams 11, 12.

The angular movement of the inner cam 11 determines the corresponding vertical displacement of the outer (displacement) cam 12 , since the two cams are mechanically linked by means of teeth 23 which engage ramps defined by grooves 24 .

When the inner cam 11 moves away from the angular position of the outer cam 12, the latter gradually rises and subsequently gains increased engagement with the corresponding inclined section 12a due to the increased height difference.

Conversely, when the inner cam 11 moves toward the angular position of the outer cam 12, the height difference decreases.

It should be noted that the combined use of the cams 11 and 12 is permitted, since in fact what is important for the punch 5 is a pair of coaxial rollers 8 respectively engaged with said cams (see FIGS. 4 and 5 in particular).

When the upper punch 5 is raised, the upper part 3a of the die hole 3 is opened so that the die hole can be filled, as shown in the figures with the position P2 of the punch heads 5a, 6a.

The vertical displacement of the cam 9 makes it possible to adjust the distance between the working heads 5a, 6a during the hole filling process in relation to the characteristics of the tablet to be formed.

Specifically, when the cam 9 is in the minimum position of the punch stroke shown in FIG. 3, the roller 8 must rotate through the minimum height h in order to pass from the reference height Lo to the height Ldo so that it can be in line with the bottom wall. Enter drive wheel 9.

In this case, therefore, no additional displacement of upper punch 5 occurs during the normal stroke.

When the cam 9 is at the maximum stroke position Ldm of the punch as shown in FIG. 2, the movement of the punch increases accordingly. In addition, in the case described here, a height increment S has been applied to the roller 8, which causes the upper punch 5 to perform an additional displacement.

This causes the roller 8 to go beyond the height H in order to pass from the reference height Lo to the height Ld at which it can enter the cam 9 at a position between the upper and lower walls of the drive cam 9 .

After entering the cam 9, the roller 8 reaches engagement with the inclined upper wall of the cam and then returns to the aforementioned height Ldm.

Therefore, the charging operation cams 11, 12 must allow the roller 8 to go over a maximum height H or a minimum height h. The outer roller 8 can enter the drive cam 9 at any intermediate position between the position where the lower wall or the upper wall of the path defined by the cam 9 is aligned.

As mentioned above, this enables the punch to carry out an additional displacement S integrated with the displacement of the cam 9 in order to increase the supply of material to the die hole 3 .

The first lowering of the upper punch 5 occurs when the roller rolls along the cam 9, as shown in FIG. 2 with the position P3 of the working heads 5a, 6a.

During the adjustment operation, the vertical position of the drive cam 9 is varied according to the properties of the tablet to be formed. Therefore, possible additional displacements are determined for the upper punch 5 . The combination of the two values defined in this method determines the height difference to be overcome by the charging operation cams 11 , 12 . This height difference is determined by suitably changing the mutual position of the cams 11,12.

Obviously, in the filling or charging process, the determined distance between the working heads of the punch defines the die hole volume, that is, the volumetric dose that constitutes the tablet.

In this way, the device can be used for simple and quick adjustment of raw material ingredients in a pharmaceutical tablet press. This can be achieved by effective and reliable technical solutions.

It can be understood that the above description is not a limiting example, therefore, all possible structural changes are protected by the technical solution, as stated in the above and appended claims.

Claims (9)

1. proportioner that the pharmacy tablet press machine is used, it comprises:

One is driven the rotary turnplate (1) of rotating around vertical axis;

A plurality of nibs of opening along the circle spacing of described rotating disk (3), described nib are equipped with Powdered or granular raw material;

Each nib (3) respectively has a pair of upper and lower drift (5,6), described drift have relative working head separately (5a, 6a) and imported rotating disk (1) smoothly and make that (5a 6a) engages with nib (3) described working head;

Driving mechanism connects in order to regulate described working head (5a, 6a) the phase mutual edge distance between with drift (5,6);

Described device is characterised in that, also comprises:

Driving cam means (9) is used to make at least one described drift (5,6) to limit described working head in batching and stocking process, and (this driving cam means (a) can axially move to regulate described distance with respect to rotating disk (1) for 5a, 6a) the phase mutual edge distance between;

By loading operation cam (11,12) this cam of another driving mechanism of Zu Chenging connecting path (15) of being bonded to each other and having determined to have variable geometry and led to described driving cam means (9), described loading operation cam (11,12) each other mechanical connection so that change the profile of described connecting path (15) according to the adjusting position of driving cam means (9).

2. by the described device of claim 1, it is characterized in that, described another driving mechanism comprises the first and second loading operation cams (11 that are respectively inside and outside, 12), they as with by drift (5,6) each roller (8) of rotatable support is meshed, and the described first and second loading operation cams (11,12) combine each other and limit a tank circuit that has variable geometry and lead to described driving cam means (9) (15).

3. by the described device of claim 1, it is characterized in that, an outer displacement loading operation cam (12) of described another driving mechanism is guided in vertical direction slidably with respect to the fixed structure of machine, and an intrinsic displacement loading operation cam (11) of this driving mechanism with the circular path of rotating disk (1) concentric on slide angularly with respect to fixed structure.

4. by the described device of claim 3, it is characterized in that, first section (12a) of the lower wall of displacement loading operation cam (12) is for being inclined upwardly, and second section (12b) of this lower wall is straight, and two sections of the upper wall of this cam (12) are straight, but vertically staggered and by acclivitous with the rotation direction (M) of roller (8) and one section (12c) that define minimum constructive height poor (h) be connected to each other.

5. by the described device of claim 3, it is characterized in that, first section (11a) of the upper wall of described intrinsic displacement loading operation cam (11) is straight, second section (11b) of this upper wall is for being inclined upwardly, and two sections lower walls of this intrinsic displacement loading operation cam are straight, but staggered in vertical direction and be connected to each other by tilting section (11c), so that determine described minimum constructive height poor (h).

6. by the described device of claim 1, it is characterized in that, described another driving cam means (11,12) makes because moving both vertically of displacement loading operation cam (12) determined the angular movement of interior charging cam (11) by the mutual mechanical connection in inclined-plane.

7. by the described device of claim 6, it is characterized in that, described inclined-plane is formed by a joggle piece (23), this joggle piece is inclined upwardly, be fastened on described in charging cam (11) go up and longitudinal extension, be used for and feed by described displacement that cam (12) limits and upwardly extending groove (24) is meshed.

8. by the described device of claim 1, it is characterized in that, this another loading operation cam mechanism (11,12) driving cam means (9) is led at the height place on the lower guide wall of driving cam means (9), the stroke that is limited with respect to driving cam means (9) produces the additional displacement of drift (5,6) so that increase nib (3) base feed like this.

9. by the described device of claim 1, it is characterized in that described driving cam (9) and described loading operation cam (11,12) work to upper punch (5).

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