WO2007001175A1

WO2007001175A1 - Device for measuring dough, and control system for controlling the device

Info

Publication number: WO2007001175A1
Application number: PCT/NL2006/000322
Authority: WO
Inventors: Johannes Maria Wilhelmus Gerardus Siebers
Original assignee: Werner and Pfleiderer-Haton BV
Current assignee: Werner and Pfleiderer-Haton BV
Priority date: 2005-06-29
Filing date: 2006-06-28
Publication date: 2007-01-04
Anticipated expiration: 2007-12-29
Also published as: NL1029361C2

Abstract

The invention concerns a device for measuring dough, comprising a stock container (4) for the supply of dough to be measured, a primary chamber (2) connecting to the stock container (4), a main piston (5) movable within the primary chamber (2), a knife member (β) also movable within the primary chamber (2) and being mounted between the main piston (5) and the stock container (4), at least one secondary chamber (8) having a measuring piston (9) movable therein, with separate driving members (10, 11) for main piston (5) and knife member (6) being provided, and being operable independently of one another. Further, a control system is provided by which the driving member (10) for the main piston (5) is driven based on the pressure measured in the dough by a pressure sensor (17) in the primary chamber (2).

Description

Device for measuring dough, and control system for controlling the device

The present invention relates to a device for measuring dough, said device comprising a stock container for the supply of dough to be measured, a main piston movable within a primary chamber, said chamber connecting to the stock container, a knife member also movable within the first chamber and being mounted between the main piston and the stock container, at least one secondary chamber having a measuring piston movable therein, said secondary chamber being intended for connecting to the primary chamber in at least one position and said secondary chamber being movable in relation to the primary chamber.

Such devices have been used in bakeries for years . Driving this known device is effected with the help of a driving mechanism in which the main piston and the knife member are coupled to a common crank shaft. Here, movements of the main piston and the knife member follow a course, which, when represented graphically, both have a sinusoidal shape, in which only a difference of phase and a difference in amplitude are possible. Thus, the driving movement is fixedly set. Further measures should be taken in order to limit the stroke of the knife member, or of the knife member and the main piston, in order to prevent them from contact- ing fixed parts of the device. This is achieved by providing a stop and a spring structure in the transmission so as to limit the stroke and simultaneously allow for continuing rotation of the crank shaft.

The invention aims to provide a simpler structure, which also allows for fully arbitrary adjustment of the operation of main piston and knife member independent from one another.

Accordingly, the invention provides for separate driving members for main piston and knife member, which can be operated independently. According to a further development, it is provided for that a separate driving member for the main cylinder or the knife member substantially comprises a hydraulic cylinder or an electrial servo.

The driving members can engage main piston and knife member, respectively, either through a transmission or directly. In order to allow for a compact construction, it can further be provided for that at least one driving member is coupled to the main cylinder and/or the knife member through a lever or levers. There, the levers of main cylin- der and knife member are preferably mounted on a common shaft.

The advantage of separate driving members for main piston and knife member goes much further than just a simpler construction. Namely, it is possible to arrange control of the device in such a way that the device can always be optimally adjusted for the units to be measured and the number of units, in which the stroke length and/or length of parts of the stroke can be adjusted exactly. This is not only important for the main piston, but also for the knife member, that should release or close-off an opening between the stock container and the primary chamber in the correct moment .

With the known device, an almost continuous movement of the main piston, knife member as well as of primary chamber or chambers in relation to the fixed portion of the device is performed, which means that a secondary room is filled while moving during definitely a part of the filling time, but often while moving during the entire filling period. When using the drive according to the invention, this can be eliminated completely, which prevents dough from getting unevenly fed into the secondary chamber and thus prevents the quality of the dough and accordingly the quality of the final product from being adversely affected.

According to a preferred embodiment, the invention further provides for that at least one pressure sensor is mounted in the primary chamber. A further development prov- ides for, that at least one pressure sensor is mounted near the end of the primary chamber, the end situated at the side of the transition to the secondary chamber. Such a pressure sensor combined with the independent driving member has the advantage that operation of the main piston can be controlled entirely by way of the pressure in the dough in the primary chamber. This is a great advantage in relation to a fixedly set operation with a fixedly set stroke of the main piston and opening and closing of the secondary chamber during fixed time units. By controlling filling of the secondary chamber depending on the pressure or the variation of the pressure of the dough in the primary chamber within predetermined limits, the quality of the dough and thus the quality of the final product too can be guaranteed constant- Iy.

According to a further development, a separate driving member for moving the secondary chamber in relation to the primary chamber is provided, with the separate driving member being operable independently. Such a separate driving member for moving the secondary chamber can also substantially comprise a hydraulic cylinder.

Apart from that, means for moving and positioning the measuring piston within the secondary chamber are provided. These means function to adjust the volume of the secondary chamber by positioning of the measuring piston and to remove the measured dough from the secondary chamber after, to this end, the secondary chamber has been brought in a position spaced from the primary chamber. Additionally, these means can be employed in order to move along with the dough when dough from the primary chamber is being brought into the secondary chamber. These means can be arranged in such a way, that there will always be enough back pressure, without any upper limit of pressure is reached before the measuring piston has returned in its correct measuring position. Further, positioning data of the measuring piston in the secondary chamber can be used when adjusting the proper stroke of the main piston.

Further, means allowing for determining the position of main piston and/or knife member in relation to the primary chamber in time are provided. This is important for drawing the desired amount of dough from the stock container and for closing the primary chamber in relation to the stock container. On bringing the dough from the primary chamber to the secundary chamber, these positioning means can be employed for determining the degree of filling of the secondary chamber. However, it is preferred to do this with the help of the pressure sensor, in which a maximum applicable pressure for each dough composition is entered in the control system for the device. The positioning data may be used as additional check for the data from the pressure sensor.

Further, means for determining the position of the secondary chamber in relation the primary chamber in time are provided, so that filling it is not started earlier than when it is in front of the primary chamber, and preferably with its maximum opening. Additionally, means for determining the position of the measuring piston in the secondary chamber in time are provided.

The invention further provides for a control system for the device in order to enable actuation of the independently acting driving members in a desired sequence or in a synchronous way. According to a first development, the control system is arranged for moving the main piston in a direction away from the secondary chamber, the direction of suction, depending on the positioning data of the main piston in relation to the primary chamber. Preferably, it is further provided for that the suction stroke of the main cylinder is determined by the adjusted volume of the secondary chamber, in which the suction stroke volume equals a integral number of times the adjusted volume of the secondary chamber, multiplied by a predetermined buffer volume or not. Such a buffer volume may be necessary if the stroke of the main piston does not reach up to the extremity of the primary- chamber and/or for allowing to compensate any variation in the dough volume, which is drawn into the primary chamber. Depending on the specific composition of the dough, one can choose if enough dough is drawn from the stock container for filling the secondary chamber (s) once or a number of times successively, before dough should be drawn from the stock container again. With dough compositions in which the properties of the dough are easily affected by pressurizing it, one will choose to draw only as much dough as is necessary for filling the secondary chamber (s) once. In this way, the dough will experience the maximum pressurization achieved on filling the secondary chambers only once, the maximum pressure being the predetermined maximum pressure for the dough composition being measured at that time.

According to a preferred embodiment, the control system is arranged for moving the main piston in the direction of the secondary chamber, the direction of filling, depending on data from the pressure sensor in the primary chamber. The control system is adjusted in such a way that movement of the main piston in the direction of filling will be stopped when the predetermined pressure is reached. This predetermined pressure depends on the composition of the dough which is to be measured and will be preset in the control system. Basically, the main piston can also be moved in the direction of filling based on the positioning data of the main piston in relation to the first chamber, however, this produces a less accurate control than when this occurs based on data from the pressure sensor. It is possible to use the data for checking the movement of the main piston if a malfunction of the pressure sensor would occur.

On starting measuring of a dough one should always determine the proper suction stroke allowing for filling the secondary chamber (s) once or an integral number of times. A first method is to have the main piston make the maximum suction stroke and subsequently to fill the secondary cham- ber(s) as many times as will be possible with the maximum drawn volume. Subsequent positioning data of the main piston will indicate the suction stroke to be performed which is required for filling the secondary chamber (s) once or a desired number of times . A second method is to determine the suction stroke of the main piston on the basis of positioning data of the measuring piston in the secondary chamber. A first filling can further be used for verification of the suction stroke. A first suction stroke should always com- prise te buffer volume required.

In order to bring the dough into the secondary chamber (s) as undisturbed as possible, according to a further development it is provided for that the control system is arranged for moving the main piston in the filling direction only when the secondary chamber completely connects to the primary chamber. Additionally, it is provided for that the control system is arranged for not moving the secondary chamber in relation to the first chamber until the secondary chamber has been filled completely. The invention is further explained by way of the cross- section of a possible embodiment of the device illustrated in the drawing.

The device comprises a fixed frame 1 in which the primary chamber 2 has been accommodated and in which a filling opening 3 connects to said primary chamber, having a stock container for the dough in the shape of a funnel receptacle 4 onto which a funnel not further illustrated in the drawing can be positioned. A main piston 5 and a knife member 6 are movably mounted in the primary chamber. Connec- ting to fixed frame 1, a back slide 7 is mounted in which a number of secondary chambers 8 extending in parallel have been provided. Each of these secondary chambers 8 holds a measuring piston 9 by which the desired volume of a secondary chamber 8 can be adjusted. The back slide 7 can be moved up and down with the help of driving members not further indicated, from the illustrated position after the primary chamber to a position in which the secondary chambers will be released completely and the dough can be slid from the secondary chambers by moving the measuring pistons 9 to the left in the drawing. The main piston 5 and the knife member 6 are driven with respective hydraulic cylinders 10, 11. Through respective levers 12, 13 and drive rods 14, 15, hydraulic cylinders 10, 11 are coupled to the main piston 5 and the knife member 6. The levers 12, 13 are rotatably mounted on a shaft 16 connected to fixed frame 1.

A pressure sensor 17 is mounted in the primary chamber 2 near its extremity. Pressure sensor 17 measures the pressure in the dough within the primary chamber 2 continuously, the hydraulic cylinder 10 driving the main piston 5 through a control system not further illustrated in the drawing on the basis of said pressure. Further, positioning means not further illustrated in the drawing have been provided by which the positions of back slide 7 and/or measuring piston 9 can be fed to the control system. Such positioning means can e.g. comprise reading members for angular rotations, reading members for linear displacements or reading members transmitting information of arrivals at end positions to the control system.

On drawing the dough, positioning means allowing to determine reaching of the desired stroke length of the main piston 5 will be employed. In this movement, knife member 6 will be displaced simultaneously with the main piston 5, in which, on reaching the desired position of the main piston 5, knife member 6 will be returned again to the original position for closing off the filling opening 3. After this, filling of the secondary chamber 8 can be started, in which the main piston 5 performs one or a number of successive partial strokes, before dough will be drawn again.

- claims -

Claims

C L A I M S

1. Device for measuring dough, said device comprising a stock container (4) for the supply of dough to be measured, a main (5) piston movable within a primary chamber (2) , said chamber (2) connecting to the stock container (4) , a knife member (6) also movable within the first chamber (2) and being mounted between the main piston (5) and the stock container (4) , at least one secondary chamber (8) having a measuring piston (9) movable therein, said secondary chamber (8) being intended for connecting to the primary chamber (2) in at least one position and said secondary chamber (8) being movable in relation to the primary chamber (2) , characterized in that separate driving members (10, 11) for the main piston (6) and knife member (6) are provided, which can be operated independently.

2. Device according to claim 1, characterized in that a separate driving member (10, 11) for the main cylinder (5) or the knife member (S) substantially comprises a hydraulic cylinder or an electrial servo.

3. Device according to claim 2, characterized in that at least one driving member (10, 11) is coupled to the main cylinder (5) and/or the knife member (6) through a lever (12, 13) or levers (12, 13) and a driving rod (14, 15) , respectively .

4. Device according to claim 3, characterized in that the levers (12, 13) of main cylinder (5) and knife member (6) are mounted rotatably on a common shaft (16) .

5. Device according to claims 1-4, characterized in that at least one pressure sensor (17) is mounted in the primary chamber (2) .

6. Device according to claim 5, characterized in that at least one pressure sensor (17) is mounted near the end of the primary chamber (2) , which is situated at the side of the transition to the secondary chamber (8) .

7. Device according to claims 1-6, characterized in that a separate driving member for moving the secondary chamber (8) in relation to the primary chamber (2) has been provided.

8. Device according to claim 7, characterized in that said separate driving member for moving the secondary chamber (8) comprises substantially a hydraulic cylinder or servo .

9. Device according to claims 1-8, characterized in that means for moving and positioning the measuring piston (9) within the secondary chamber (8) have been provided.

10. Device according to one or more of the claims 1-9, characterized in that means for determining the position of the main piston (5) and/or knife member (6) in relation to the secondary chamber (8) in time have been provided.

11. Device according to claim 10, characterized in that means for determining the position of the secondary chamber (8) in relation to the primary chamber (2) have been provided.

12. Device according to claim 10, characterized in that means for determining the position of the measuring piston

(9) in the secondary chamber (2) in time have been provided.

13. Control system for a device according to one or more of the preceding claims 1-12, characterized in that the control system is arranged to move the main piston (5) in a direction away from the secondary chamber (8), the suction direction, depending on positioning data of the main piston (5) in relation to the primary chamber (2) .

14. Control system according to claim 13, characterized in that the suction stroke of the main piston (5) is determined by the adjusted volume of the secondary chamber (8) .

15. Control system according to claim 14, characterized in that the volume of the suction stroke equals an integral number of times the adjusted volume of the secondary chamber (8), multiplied by a predetermined buffer volume, or not.

16. Control system according to claims 13-15, characterized in that said control system is arranged to move the main piston (5) in the direction towards the secondary chamber (8) , the filling direction, depending on data from the pressure sensor (17) in the primary chamber (2) and/or positioning data of the main piston (5) in relation to the first chamber.

17. Control system according to claims 13-16, characterized in that said control system is arranged to move the main piston (5) in the filling direction only when the secondary chamber (8) fully connects to the primary chamber (2) .

18. Control system according to claims 13-17, characterized in that the control system is arranged to displace the secondary chamber (8) in relation to the primary chamber (2) after the secondary chamber (8) has been filled completely.

19. Control system according to claims 13-18, characterized in that the control systeem is arranged to have the measuring piston (5) move along in the secondary chamber (8) during filling of the secondary chamber (8) , across at least a part of the filling stroke.