GB2048159A

GB2048159A - Apparatus for portioning dough for bread rolls or small loaves

Info

Publication number: GB2048159A
Application number: GB8012217A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-04-14
Filing date: 1980-04-14
Publication date: 1980-12-10
Also published as: AT373759B; DE2915348C2; ATA166780A; IT1175392B; IT8009403A0; GB2048159B; DE2915348A1

Abstract

Apparatus for the uniform portioning of dough for bread rolls or small bread loaves comprises a dough charging container 1 and a piston, which supplies the dough from the container 1 via a corresponding compression chamber 4 to a metering chamber or a group of metering chambers disposed radially in a rotatably supported drum and each metering chamber is provided with a metering piston 14 whose position in the metering chamber can be varied in dependence on the rotating motion of the drum, characterised in that the compression chamber or chambers 4 is/are frusto conical in at least one longitudinal cross-section. <IMAGE>

Description

SPECIFICATION Apparatus for portioning dough for bread rolls or small loaves The invention concerns a device for uniform portioning of dough for bread rolls or small loaves with a dough feed container and a piston feeding the dough from the container to a measuring chamber or a group of measuring chambers and in which a plurality of measuring chambers or groups of adjacent measuring chambers are disposed radially in a drum mounted so that it can rotate and in which each measuring chamber exhibits a measuring piston whose position in the measuring chamber can be modified depending on the rotary movement of the drum.

Such a device is disclosed for example in DE-OS 2 244 469 where the dough undergoes preliminary portioning underneath a dough feed shaft by being squeezed out in portions with the aid of two star wheels driven in opposite directions and passes into a chamber in which a sliding element mounted for reciprocating movement and capable of being isolated from the shaft by means of a knife presses the dough into a measuring chamber or group of measuring chambers. The star wheels for preliminary portioning of the dough are driven according to the position of a sensor which is located underneath these star wheels and interrupts the star wheel drive when the chamber contains more than a predetermined amount of dough.To safely avoid insufficient dough portions, the chamber must always be filled with an amount exceeding the volume of the chamber, the surplus being pushed back out of the chamber by the sliding element during which the dough is squeezed considerably. If the amount of dough between the dividing tool and the chamber increases, the surplus dough is forced upwards through an opening where the sensor is located and this stops the feed through the dividing tool and only starts it up again once the level of dough has fallen. It is particularly disadvantageous that the delivery piston may have to compiete a plurality of working strokes before the star wheels have cut off the required amount of dough so that the machine has to work with a surplus of dough in every case and certain surplus amounts of dough are repeatedly squeezed upwards.

However, when the dough is squeezed, organic dough cells are destroyed in disadvantageous fashion, resulting in a thicker crust, a denser heart and dark discolouration of the heart when the dough is subsequently baked.

DE-OS 24 61 892 discloses another device of the kind named at the start which is also equipped with two contra rotating star wheels for preliminary portioning of the dough and in which no accumulation occurs between the feeding device and the inlet chamber, however the dough is subjected to disadvantageous squeezing by the preliminary portioning operation with the star wheels. The dough inlet chamber is also closed off with a knife and any dough still projecting out of it in front of the sliding element used to introduce the dough into the measuring chambers is cut off.

Since the inlet chamber in which the sliding element moves is not the same size as the measuring chamber, the dough is cut again through the rotation of the drum and the dough remaining in front of the measuring chamber is picked up by the sliding element as it returns and is mixed with the following dough.

Such devices are not only costly in terms of their design, they also handle the dough in a disadvantageous fashion in that this is subjected to repeated squeezing and cutting which has the overall effect of destroying cells. This cell destruction becomes apparent after the subsequent baking process as indicated previously.

Consequently, the underlying objective of the invention is to create a device of the kind named at the start for uniform portioning of dough for bread rolls or small loaves in which the dough is handled extremely gently and the disadvantages of the known devices are eliminated.

This objective is achieved in accordance with the invention in that a compressing chamber with funnel-shaped side walls is disposed between the outlet of the dough feed container and the inlet of a measuring chamber in the position for filling with dough.

Here the invention is based on the knowledge that a uniform all-round pressure on the dough does not have any disadvantageous effects on the dough cells as the dough behaves extremely elastically due to the even gas formation. For this reason, the dough is subjected to uniform compression without destruction of dough cells in the compressing chamber disposed in front of the measuring chamber in question, avoiding celldestroying squeezing operations.

During the subsequent introduction of the dough portions into the measuring cylinders it has been found that the required precision of measurement is not achieved due to the unintentional inclusion of air. Varying amounts of dough, depending on the amount of air included, were passed into the measuring cylinders concerned because of the air unintentionally trapped with it so the portions of dough were subject to fluctuation.

Consequently, another underlying objective of the present invention is to avoid inclusion of air in this way while ensuring that the dough still receives extremely gentle handling.

This objective is achieved with the device of the kind named at the start in that in their respective measuring chambers the measuring pistons are flush with the outlet of the measuring chamber in the dough transfer position and are disposed in this position while the drum rotates through about 1 800 until the dough receiving position is reached.

The result of flush location of the measuring chamber piston in its measuring chamber is that when the drum is turned to the respective dough receiving position the measuring piston is directly adjacent to the compressing chamber so that any inclusion of air is prevented.

To control the movement of the measuring pistons in the area of the dough receiving position, in a development of the invention, there is a thrust lever which can act on the measuring pistons and is operated in synchronisation with the piston by the drive by means of thrust rods through a lever.

This measure ensures that the entire working cycle, namely transfer of the dough from the hopper chamber to the compressing chamber, filling and subsequent movement of the measuring chamber piston, takes place in synchronisation and without harming the dough In another advantageous development of the invention, the thrust rod carries an adjusting nut with a compression spring acting against the thrust lever, and the end of the thrust rod passing through the thrust lever exhibits a return nut, whereas the other end of the thrust rod exhibits a sliding element with a slide in which a driving lug connected to the lever can slide.In particular, the compression spring and appropriate adjustment of its pre-loading ensure that pressures harmless to the dough prevail when the dough portions are introduced in to the measuring chambers through a corresponding movement of the measuring chamber piston.

At its end remote from the compressing chamber, the piston exhibits a thrust element with a slide into which a driving pin fixed to the lever engages. The slides provided ensure that adequate dead times occur at the moment of reversal of the movement when the continuous rotary movement of the drive is converted into reciprocating movement of the piston and the thrust rod.

The invention is explained in detail with reference to the drawings in which embodiment examples are depicted and in which: Fig. 1 is a cross-section through the device with a feed hopper and drum for the measuring chambers in schematic form; Fig. 2 is a plan view of the illustration in fig. 1, also in schematic form; Fig. 3 is an enlarged cross-section through the compressing chamber and Fig. 4 is a view of the compressing chamber from the front corresponding to fig. 3 (swung through 900); Fig. 5 is an embodiment example of the present invention with a feed hopper and drum for the measuring chambers in schematic form, and Fig. 6 is a plan view of the embodiment shown in fig. 5.

The dough feed container 1 is securely connected to the chamber section 2 and at the bottom end of the dough feed container there is a piston 3 which can be moved to and fro and is driven by means of a piston lever 5, a piston lever arm 6 and a crankshaft 8. The motor used to drive the crankshaft is not shown in detail. A compression spring 7 ensures the piston 3 has a cushioned action so that this engages in the dough softly and moves it gently.

The crankshaft 8 exhibits two limit switches 1 9 and 20. Limit switch 1 9 sets the crankshaft 11 in motion by means of a drive not shown in detail and moves the sliding element 9 upwards by means of linkage 10. When the crankshaft 8 turns through 1 800, limit switch 20 is actuated by cam and the knife 9 moves again in the opposite direction.

The dough feed container 1 is adjoined by the compressing chamber 4 which can be cut off by the sliding element 9 and works with a drum 12 with radially mounted measuring chambers 1 3.

The drum 12 is mounted so as to be rotatable about its shaft 21 by a drive also not shown in detail, so that the different measuring chambers 13 disposed radially at its periphery pass through the various stations in steps in the direction of the arrow 25'.

The dough, which is fed in through the dough feed container 1, fills the lower chamber completely and is pushed towards the compressing chamber 4 by the piston 3. At this moment the measuring chamber 13 is in the position shown in fig. 1 so that as a result both the measuring chamber and the compressing chamber 4 are completely filled with dough. The dough undergoes a certain amount of preliminary compression through the filling operation and the charging of the compressing chamber 4. When the piston 3 has reached its advanced position shown in Fig. 1, the sliding element 9 is operated through the switch 19 and the dough in the compressing chamber 4 is detached from the dough in the dough feed container 1.The drum 12, and thus all the measuring chambers, moves in the direction of the arrow 25' and the dough in the measuring chamber 13 is separated from the compression chamber 4 by this operation so that the compressing chamber 4 is closed by the drum wall 12 at one end and by the knife 9 at the other During this movement of drum 12, piston 3 also moves backwards again so that the dough above the piston can immediately fill the space left vacant by the piston 3. As soon as the piston 3 has reached its most retracted position and the dough has thereby been allowed to fill the space vacated by the piston 3, the knife 9 is moved downwards through the limit switch 20. By this time the next measuring chamber is also lined up flush with the outlet of the compressing chamber 4 so that the filling operation can be repeated.

Inside the drum 12 there is a cam 15 which acts on the measuring pistons 14 as the drum 12 rotates and moves the measuring pistons 14 outwards until the dough in the measuring chamber is fully ejected after the drum 1 2 has rotated through 1 800. A roller guide segment 1 6 then ensures that the measuring chamber piston 14 is retracted in the measuring chamber as the drum 12 turns so that the chamber can be refilled with dough on reaching the compressing chamber.

The dough pushed out of the measuring chambers 1 3 passes directly to the following, schematically illustrated kneading machine 26 and is moved on after the kneading operation by the conveyor belt 27.

It can be seen in fig. 2 that the measuring pistons 1 4 are actuated by means of a piston guide rail 17 and a guide roller 18 by the cam 1 5 and thereafter by the roller guide segment 1 6. This arrangement ensures that the measuring pistons of a group adopt the same position. Fig. 2 also shows the conical or funnel-shaped design of the compressing chamber 4.

In Figures 3 and 4 the compressing chamber 4 is shown larger than in Figures 1 and 2. The side walls 24 run conically or like a funnel relative to the axis 25, the cross-section at right angles to the axis 25 being rectangular at the inlet 22 and round at the outlet 23. The transition from the rectangular to the round form is continuous that as the dough moves through the chamber it is subjected to a continuously increasing pressure which, however, does not have any disadvantageous effects on the dough since these pressures stay within the range of elasticity of the dough.

Fig. 5 shows an embodiment example of the present invention. Here the design of the dough feed container 1 with the chamber section 2 and the reciprocating piston 3 is the same as in the embodiment shown in fig. 1. Where the components of fig. 5 are the same as in the embodiment in fig. 1. the same reference numbers are used. The measuring pistons 14 which move to and fro in the measuring chambers 13 are flush with the outlets of their respective measuring chambers 13 in the dough transfer position and remain in this position while the drum moves through 1 800 until the dough receiving position is reached. Each measuring piston in a group is connected to a measuring piston roller 1 8 which is supported displaceably in a guide slot 41.The length of the slot 41 is such that it is slightly greater than the maximum stroke of the measuring pistons 14. The desired stroke in the measuring chamber is set with a hand-crank 32 by means of a cross-piece 31, bearings 29 and 30 and the stop 16'. At its end the stop 16' exhibits a face 44 for roller movement whose function will be explained in detail further on.

To control the movement of the measuring pistons 14 in the area of the dough receiving position there is a thrust lever 38 which is capable of acting on the measuring pistons 14 and is operated by the drive 8 in synchronisation with the piston 3 by means of thrust rods 35 through a lever 5. The thrust rod 35 carries an adjusting nut 36 for adjusting the pre-loading of a spring 37 and there is a return nut 40 at the end of the thrust rod 35 passing through the thrust lever 38, whereas the other end of the thrust rod 35 exhibits a sliding element 34 with a slide in which a driving lug 33 connected to the lever 5 can slide. As in the embodiment shown in fig. 1, at its end remote from the compressing chamber 4 the piston 3 is provided with a thrust element 42 which also exhibits a slide into which a driving pin 43 fixed to the lever 5 engages so as to slide.

Opposite chamber section 2, a part projecting towards the chamber of the hopper 1 and provided with an oblique face is fixed with the wall of the hopper chamber, preventing the ingress of ambient air as the piston moves towards the measuring pistons. When the piston 3 moves towards the measuring pistons 14, the thrust rod 35 also starts to move at the same time by virtue of the mechanical link with the lever system 5 via the driving lug 33 and the slide 34 so that at the very moment when the dough pressure rises through the piston 3, the thrust lever 38 engages against the rollers 18 of the measuring pistons and opens (retracts) the pistons 14 through their roller 18 as far as the stop 1 6'.On further forward movement of the piston 3, the thrust rod 35 is also moved in the same direction, the front end of the thrust rod 35 passing through the thrust lever 38 so that further movement of the thrust rod 35 brings the compression spring 37 against the thrust lever 38 so that this forces the measuring piston rollers 18 against the stop 1 6', through which the stroking movement of a row of measuring pistons 14 preset with the head wheel 32 is obtained. This stroke is used to give the desired weight of dough. The return nut 40 on the thrust rod 35 becomes active during the backward movement. The pre-loading of compression spring 37, which can be changed using the adjusting nut 36, is such that the forward movement of the measuring pistons takes place smoothly and not abruptly, working with the pressure exerted on the dough by the piston 3.

The movement of the piston 3 is also guided by means of a thrust element 42 fitted with a slide. This part has the advantage that the piston can be held for a certain length of time in both its forward pressure position and its backward end position. While the piston 3 is in its pressure position, the knife 9 closes, and in the backward position of the piston 3 the step-by-step forward movement of drum 12 takes place, with a step of 900 in the case of the embodiment example shown here. The slide paths in thrust element 42 and part 34 are proportional to one another so that synchronous movement is ensured. In this way it is impossible to use the continuous drive to produce a reciprocating movement with dead times at the ends of the movement, these being necessary for the movement of other parts.

When the measuring chambers 13 are filled, the dough is under a certain pressure. Shortly before the movement of the drum 1 2 is initiated, the knife 9 is run in so that the compression chamber 4 is closed off from the hopper 1. The stop 16' has a face 44 for roller movement which is inclined relative to the drum axis. Now when the drum makes an anti-clockwise movement, the compression spring 37 ensures that the thrust lever 38 exerts a pressure on the measuring piston rollers 18 and these are held on the face 44. So, during their anti-clockwise rotary movement, the measuring pistons 14 move slightly towards the axis so that the dough in the measuring chambers 13 can expand. When the drum rotates further, the row of pistons reaches the cam 1 5 which now takes charge of the ejecting movement of the pistons 14. At the end of this movement the measuring pistons 14 reach a position in which they are flush with the ends of the chambers. This position is maintained until the dough charging position is reached again. The result of this flush location of the measuring pistons is that the measuring pistons reach right to the compressing chamber 4 without trapping any air so that the filling operation already described above can then be repeated. To enable the measuring piston rollers to move towards the drum axis slightly by an amount which per se is more than the set maximum stroke when the measuring chambers just filled with dough are moved on, the guide slots 41 are made correspondingly larger.

Overall this results in extremely gentle handling of the dough and constant precision in the weights set and desired for the portions of dough.

Claims

1. Apparatus for the uniform portioning of dough for bread rolls or small bread loaves with a dough charging container and a piston; which supplies the dough from the container to a metering chamber or a group of metering chambers, and a plurality of metering chambers or groups thereof are disposed radially in a rotatably supported drum and each metering chamber is provided with a metering piston whose position in the metering chamber can be varied in dependence on the rotating motion of the drum, characterised in that a compression chamber (4) with sidewalls (24) in hopper configuration is disposed between the exit (22) of the dough charging container (1) and the inlet (2) of a metering chamber (1 3) which is situated in the dough charging position.

2. Apparatus according to Claim 1, characterised in that the inlet cross-section of the compression chamber (4) perpendicuar to its axis is rectangular and its exit is circular and the change of cross-sectional shape is uniform.

3. Apparatus according to Claim 1 or 2, characterised in that the inlet of the compression chamber (4) or the exit (22) of the dough charging container (1) is closable by means of a knifeshaped slide part (9) in dependence on the position of the dough feed piston (3).

4. Apparatus according to Claim 1, 2 or 3, characterised in that the outlet (23) of the compressing chamber (4) adjoins the wall of the drum (12) or the edges of the inlet of the measuring chamber (13) hermetically so as to give a seamless smooth transition from the compressing chamber (4) to the measuring chamber (13).

5. Apparatus according to Claim 1 or one of the preceding Claims, characterised in that in their respective measuring chambers the measuring pistons (14) are flush with the outlet of the measuring chamber in the dough transfer position and are disposed in this position while the drum rotates through 1 800 until the dough receiving position is reached.

6. Apparatus according to Claim 5, characterised in that to control the movement of the measuring pistons (14) in the area of the dough receiving position there is a thrust lever (38) which can act on the measuring pistons (14) and is operated by the drive (8) in synchronisation with the piston (3) by means of thrust rods (35) through a lever (5).

.

7. Apparatus according to Claim 6, characterised in that an adjusting nut (36) is disposed on the thrust rod (35) with a compression spring (37) acting against the thrust lever (38) and in that there is a return nut (40) on the end of the thrust rod (35) passing through the thrust lever (38) whereas the other end of the thrust rod (35) exhibits a sliding element (34) with a slide in which a driving lug (33) connected to the lever (5) can slide.

8. Apparatus according to Claim 7, characterised in that at its end remote from the compressing chamber (4) the piston (3) exhibits a thrust element (42) with a slide into which a driving pin (43) fixed to the lever (5) engages.

9. Apparatus according to Claim 5, 6, 7 or 8, characterised in that a lever (16') serving as a stop for the measuring piston rollers (18) and adjustable by means of handwheel (32) exhibits a surface (44) for roller movement.

1 0. Apparatus according to Claim 5, characterised in that the side faces of the drum (12) exhibit slots (41) for guidance of the measuring piston rollers (1 8).

11. Apparatus for the uniform portioning of dough, substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.