Kneading machine for food doughs with emergency stop device and method for controlling a kneading machine for food doughs

Description

[0001] The present invention relates to a kneading machine for food doughs having the features of the preamble of claim 1 and a method for controlling a kneading machine for food doughs. US2846045A discloses a generic kneading machine according to the preamble of claim 1 and a method therewith.

[0002] Dough kneading machines, especially for baking dough, feature a kneading bowl of varying sizes for dough masses from 100 to 3000 kg. Each bowl contains a motor-driven kneading tool for carrying out the kneading process. The kneading bowl is rotaryally driven. It can be part of a bowl trolley, allowing for easy movement between individual processing stations. Alternatively, the kneading bowl can be permanently installed.

[0003] The kneading bowl drive can be designed as a friction wheel drive or a gear drive. Gear drives have one or two engagement points, which must be protected against access by safety devices. Traditionally, a bowl disc designed as a gear, as well as the drive gear, are covered with a sheet metal plate. This prevents the operator from accessing the engagement area of ​​the two gears, thus securing the hazardous area.

[0004] However, for hygienic reasons, it is desirable to design the kneading machine to be as open as possible so that cleaning is easy.

[0005] It is therefore an object of the present invention to provide a kneading machine that is as easy to clean as possible and offers a high degree of safety during operation.

[0006] This problem is solved by a kneading machine for food doughs with the features of claim 1 and a method for controlling a kneading machine for food doughs with the features of claim 11.

[0007] Accordingly, a kneading machine for food dough comprising a kneading machine frame, a kneading tool, and a drive that drives the kneading tool, a tub drive for rotating a kneading tub, wherein the tub drive is a gear drive with a gear that is or can be brought into engagement with a tub disc of the kneading tub. The kneading machine comprises an emergency stop device that is assigned to the gear of the tub drive and that comprises at least one device with a fixed element and a movable element mounted on the fixed element, wherein the at least one device is designed such that it covers a feed point between the gear of the tub drive and the tub disc. The at least one device has a sensor that is configured to detect a movement of the movable element and to communicate with a control device of the tub drive.

[0008] The emergency stop device with its movable element can detect movement toward the feed point and communicate this to the bowl drive, allowing the mixing bowl to be stopped at a later time. Completely covering the bowl disc is no longer necessary, making the gear area visible and easy to clean.

[0009] The kneading tub can be part of a tub trolley or it can be permanently installed.

[0010] It is possible that the kneading machine has a lower part and a head part, whereby the head part can be pivotably held on the lower part.

[0011] Preferably, the kneading machine comprises a kneading tool with at least one spiral or helical kneader.

[0012] It is conceivable for the movable element to be pivotably or rotatably mounted on the stationary element. The movable element can preferably pivot from 0-20°, more preferably from 0-15°, with the pivoting range preferably being limited by stops. The sensor is preferably part of a safety switch having a switching range of 2-20°, preferably from 4-10°. The movable element can be designed to be pivotable back by means of a spring element. The movable element can be a plate or roller, for example. A pivoting or rotational axis is preferably oriented parallel to the rotational axis of the gear wheel of the tub drive, so that a movement in the tangential direction of the tub disc towards the engagement point can be reliably detected.A large part of the kneading machine frame is preferably exposed, whereby the exposed kneading machine frame has struts between which free spaces are formed which are openly accessible from the outside and thus make cleaning particularly easy.

[0013] Furthermore, a kneading unit comprising the aforementioned kneading machine and a tub carriage with a kneading tub or a permanently installed kneading tub is provided, wherein the kneading tub has a tub disk designed as a gear, which is freely accessible throughout its entire circumference. To minimize the risk of injury, the tub drive gear is preferably completely covered around its circumference.

[0014] It is advantageous if the gap formed between the movable element and the tub disc is no more than 20 mm, preferably 10 mm to 12 mm, so that the movable element does not create any further danger point.

[0015] The tub trolley is preferably held on the kneading machine by means of a clamping mechanism.

[0016] In a preferred embodiment, the kneading tub is designed to hold food dough with dough masses of 100 kg to 3000 kg.

[0017] Furthermore, a method for controlling a kneading machine or a kneading unit is provided, which comprises the following steps: a. Detecting a movement in the area of ​​a feed point between the gear of the tub drive and the tub disc by means of a sensor, wherein the movement of the movable element of a device of an emergency stop device that covers the feed point is detected, b. Communicating the sensor with a control device of the tub drive and stopping the rotational movement of the kneading tub, c. Restarting the rotation of the kneading tub through user input.

[0018] A preferred embodiment of the invention is explained in more detail below with reference to the drawings. Similar or functionally equivalent components are designated by the same reference numerals in the figures. The figures show: Figure 1: a spatial representation of a kneading machine with an open concept, Figure 2: a detailed view of the tub carriage of the kneading machine of the Figure 1 , Figure 3: a plan view of a gear drive of the tub carriage, and Figure 4: a spatial view of a part of the kneading machine without the tub carriage.

[0019] The Figure 1 and 2The illustrated kneading machine 1 is designed for processing food dough, in particular baking dough. The kneading machine 1 has a kneading machine frame 2, the head section 3 of which is pivotable about a pivot axis 100 relative to a lower section 4. The head section 3 carries the kneading tool (not shown) and the drive required for rotating the kneading tool, as well as a lid 5, which is provided for covering the kneading bowl 6, which is open at the top. A bowl drive 7 is arranged in the lower section 4 of the kneading machine 1. The bowl drive 7 rotates the kneading bowl 6 about a rotation axis (not shown) relative to the kneading machine frame 2. The kneading bowl 6 is part of a bowl trolley 8. It is connected to a shaft (not shown). Below the kneading bowl 6, a bowl disc 9 is mounted on the shaft, which is non-rotatably connected to the shaft and is designed as a gear with a circumferential toothing 10.The tub disc 9 can be operatively connected to a gear (not shown) of the tub drive 7 of the kneading machine 1 for rotating the kneading tub 6. Below the tub disc 9, the shaft is concentrically surrounded by a hub disc (not shown), which is connected to a base frame of the tub carriage 8 and thus held in a fixed position. When the kneading tub 6 rotates, the hub disc does not rotate with it. A clamping mechanism 11 of the kneading machine 1 engages the hub disc to hold the kneading tub 6 in position.

[0020] The kneading machine 1 has a housing 12 made of stainless steel sheets. The housing 12 only covers the drive of the kneading tool. A plastic cover could also be used. The kneading machine frame 2 itself is exposed and easily accessible. It is not enclosed by the housing 12.

[0021] The kneading machine 1 includes a device 13 of an emergency stop device 14. The bowl disc 9 and the gear of the bowl drive 7 mesh (not shown) and rotate in opposite directions. In the area where the teeth of the two gears meet, a pinch point forms during operation. If the kneading machine 1 is configured so that the kneading bowl 6 rotates in only one direction around the axis of rotation, only one pinch point is formed. However, if the kneading bowl 6 is designed to rotate in both directions, the pinch point can be located on one side of the engagement area or the other, and both sides must be protected. The device 13 of the emergency stop device 14 covers the engagement area radially outwards, thus protecting against direct contact with the engagement area of ​​the two gears.The device 13 comprises a stationary element 15 and a movable element 16. The movable element 15 is pivotally mounted on the stationary element 16 about a pivot axis. The pivot axis runs parallel to the axis of rotation of the kneading bowl 6. The movable element 16 is dimensioned such that, during operation of the kneading machine 1, it forms a gap with the bowl disc 9 that is less than 20 mm. The device further includes a sensor that detects movement of the movable element 16. The bowl drive 7 has a control unit. The sensor communicates with the control unit.

[0022] In the event that an operator gets caught on the bowl disc 9 or engages in the engagement area of ​​the two gears and is carried along by the bowl disc during its rotating movement, the operator or an object carried along by the bowl disc will strike the movable element 16, which will then pivot about the pivot axis in the direction of the engagement area of ​​the two gears. The movement of the movable element 16 is detected by the sensor, and the sensor sends a corresponding signal to the control device of the bowl drive 7, which then executes an emergency stop of the bowl drive 7. The kneading bowl comes to a stop, thus preventing the operator or the machine from having an accident or being damaged. In order to return to normal operation, the operator of the kneading machine can give a command that returns the bowl drive 7 to a normal operating state.

[0023] Figure 3 Figure 14 shows in detail, in a top view from below, the engagement area 17 of the two gears 9 and 70 and the emergency stop device 14. The emergency stop device 14 consists of two devices 13, each having a fixed element 15 and a movable element 16. The two devices 13 are attached to the kneading machine. They cover the gear 70 of the tub drive 7 radially outwards. The gear 70 is covered circumferentially by at least 250°. The only free area is that of engagement with the tub disc 9 and the area covered by the movable elements 16. The movable element 16 projects radially beyond the gear 70 of the tub drive 7. Figure 3The state with the tub carriage inserted is shown. The two gears 9, 70 mesh with each other. In this state, the gear 70 of the tub drive 7 is completely secured against access in the radial direction. The tub disc 9, however, is freely accessible except for the area defined by the two movable elements 16.

[0024] It is possible to form the two fixed elements 15 as a single piece and thus continuously, or to form them as in Figure 3The stationary element 15 is connected to the movable element 16 by an intermediate element 18. Since the intermediate element 18 is located inside the kneading machine, it only needs to extend above the height of the gear 70 of the tub drive 7. In contrast, the stationary element 15 has a significantly greater height in the area where it connects to the movable element 16, in order to prevent unauthorized access to the tub drive 7 from above. The movable element 16 also only extends above the height of the gear 70 of the tub drive 7. The movable element 16 can pivot between two stops (not shown). The stops define and limit the movement to prevent damage to the kneading machine and the device. The sensor is preferably a magnetic proximity sensor. However, it can also be designed, for example, as a rotary angle sensor.The sensor is part of a safety switch with a performance level appropriate for its intended use in personal protection. The magnetic proximity sensor 19 shown here has a first part 20, which is attached to the movable element 16, and a second part 21, which is fixedly mounted on the kneading machine, in particular on the stationary element 15. The sensor 19 detects a relative movement between the two parts 20, 21.

[0025] In Figure 3 the normal operating state of the movable element 16 and a state triggering the emergency stop are shown.

[0026] Figure 4 The diagram shows part of the kneading machine 1 without the tub carriage. The gear 70 of the tub drive 7 is partially accessible and can therefore be easily cleaned. Since there is also space between the two devices 13 and the gear 70, cleaning can also be carried out easily there. Figure 4The figure also shows the normal operating state of the moving element 16 and a state that triggers the emergency stop. Furthermore, the stops 22 that limit the movement are shown.

Claims

1. Kneading machine (1) for food doughs, comprising a kneading machine frame (2), a kneading tool, a drive that drives the kneading tool and a vat drive (7) for rotating a kneading vat (6), wherein the vat drive (7) is a gear drive with a gear (70) that is or can be brought into engagement with a vat disk (9) of the kneading vat (6), characterized in that the kneading machine (1) comprises an emergency stop device (14) that is assigned to the gear (70) of the vat drive (7) and that comprises at least one device (13) with a fixed element (15) and a movable element (16) mounted on the fixed element (15), wherein the at least one device (13) is designed such that it covers a feed point between the gear wheel (70) of the vat drive (7) and the vat disk (9), and wherein the at least one device (13) has a sensor (19) which is designed to detect a movement of the movable element (16) and to communicate with a control device of the vat drive (7).

2. Kneading machine according to claim 1, characterized in that the kneading machine (1) comprises a kneading tool with at least one spiral or helical kneader.

3. Kneading machine according to claim 1 or 2, characterized in that the movable element (16) is pivotably or rotatably mounted on the fixed element (15).

4. Kneading machine according to claim 2, characterized in that a pivoting or rotation axis is oriented parallel to the rotation axis of the gear wheel (70) of the vat drive (7).

5. Kneading machine according to one of the preceding claims, characterized in that a large part of the kneading machine frame (2) is exposed, wherein the exposed kneading machine frame has struts (4) between which free spaces are formed which are openly accessible from the outside.

6. Kneading unit comprising a kneading machine (1) according to one of the preceding claims 1 to 5 and a vat carriage (8), wherein the vat carriage (8) has a vat disk (9) designed as a gear wheel, which is designed to be freely accessible over its entire circumference.

7. Kneading unit comprising a kneading machine (1) according to one of the preceding claims 1 to 5 and a non-removable kneading vat, wherein the kneading vat has a vat disk designed as a gear wheel, which is designed to be freely accessible over its entire circumference.

8. Kneading unit according to claim 6 or 7, characterized in that the gear wheel (70) of the vat drive (7) is completely covered on the circumference.

9. Kneading unit according to one of claims 6 to 8, characterized in that a gap formed between the movable element (16) and the vat disc (9) is at most 20 mm.

10. Kneading unit according to one of claims 6 to 9, characterized in that the kneading vat (6) is designed to accommodate food dough with dough masses of 100 to 3000 kg.

11. Method for controlling a kneading machine (1) for food doughs, comprising a kneading machine frame (2), a kneading tool (5), a drive that drives the kneading tool (5), a vat drive (7) for rotating a kneading vat (6), wherein the vat drive (7) is a gear drive with a gear (70) which is or can be brought into engagement with a vat disk (9) of the kneading vat (6), characterized in that the method comprises the following steps: a. detecting a movement in the region of a feed point between the gear wheel (70) of the vat drive (7) and the vat disc (9) by means of a sensor (19), wherein the movement of a movable element (16) of a device (13) of an emergency stop device (14) is detected, which covers the feed point, b. communicating the sensor (19) with a control device of the vat drive (7) and stopping the rotational movement of the kneading vat (6), c. restarting the rotation of the kneading vat (6) by user input.