Patent Application
20060054460
This application claims priority from German Patent Application No. 10 2004 042 443.8 dated Aug. 31, 2004, the entire disclosure of which is incorporate herein by reference.
The invention relates to an apparatus for operating a feed device for fibre material.
In practice, in the manufacture of nonwoven products, hopper feeders are used for opening the bales of raw fibre. In one known form of hopper feeder, a drivable, endless conveyor belt guided around two rotatable rolls is provided. The conveyor belt is associated at one end, looking in the conveying direction, with an endless, upwardly inclined spiked lattice, and upstream of the other end of the conveyor belt, looking opposite to the conveying direction, there is an endless feed belt (reserve belt), on which fibre bales or the like can be placed. The bales of raw fibre supplied to the process are in many cases presented unseparated, in the form of whole bales. To be able to carry out this process with as few reloading operations as possible, long feed belts for holding several bales are required (U.S. Pat. No. 3,939,929). This procedure does reduce the number of reloading operations, but, depending on the batch size, cannot avoid them altogether. The following problem occurs during a reloading operation: so that the mixing chamber is not overfilled, the supply bales are fed from the feed belt in relatively small portions to the mixing chamber. This is achieved owing to the fact that the transport path of the feed belt is adjusted to the desired amount of fibre stripped off. Only when the last portion of raw fibre bale has left the feed belt can the feed belt be fully loaded again. In this case, first of all the raw fibre bales have to be prepared (removal of packaging and bindings), and then placed as close together as possible on the feed belt. This process normally takes up more time than offered by the running reserve in the mixing chamber. The inevitable result is that the hopper feeder will run with no load, which has undesirable effects on the processing process (for example, a variation in the mix or a dip in production).
It is an aim of the invention to produce an apparatus of the kind described initially that avoids or mitigates the said disadvantages and in particular in a simple manner enables fibre material to be supplied to the hopper feeder without interruption to production.
The invention provides a feed apparatus for fibre material comprising:
The features according to the invention enable the transition belt to be moved independently of the reserve belt. The transition belt can thus deliver fibre material to the conveyor belt so that the mixing chamber does not run without load. At the same time, that is, as the transition belt is running, the reserve belt can be loaded with fibre bales whilst at a standstill. Running with no load is in this manner advantageously reliably avoided, and re-loading of the reserve belt can be effected within an adequate buffer time. By isolating the reserve belt, the belt flight that is feeding fibre to the mixing chamber can be moved independently of the reserve belt. A sensor preferably monitors the end of the belt flight that is feeding fibre material and indicates when the reserve belt has run empty. As the last bale portion present on the belt flight that is feeding fibre material is being worked off in the normal way, the upstream reserve belt can be reloaded independently of the process still under way.
Advantageously, a sensor or the like is used to detect the absence of fibre material. Advantageously, the sensor is an optical barrier, photocell or the like. Advantageously, the sensor is associated with the front end of the reserve belt, looking in the conveying direction. Advantageously, an electronic control and regulating device is provided, to which the sensor and the drive motors for the conveyor belt, the transition belt and the reserve belt are connected. Advantageously, the transition belt is drivable independently of the reserve belt. In particular, it is preferred that the transition belt revolves substantially continuously during operation, and in particular that it continues to revolve when the reserve belt is stationary for reloading. Advantageously, the conveyor belt, the transition belt and the reserve belt are drivable independently of one another. Advantageously, the sensor emits an electronic signal in the absence of fibre material on the feed belt and the drive motor for the reserve belt is stopped. Advantageously, the drive arrangement for the conveyor belt and/or the transition belt is discontinuously controllable. Advantageously, the drive arrangement for the conveyor belt and/or the transition belt can be shut down briefly. Advantageously, the sensor, looking in the conveying direction, is associated with the rear end of the transition belt. Advantageously, the sensor is arranged between the reserve belt and the transition belt. Advantageously, a gap is present between the reserve belt and the transition belt. Advantageously, the front end of the transition belt overlaps the rear end of the conveyor belt from above. Advantageously, the upper belt flights of the reserve belt and the transition belt are arranged substantially at the same level. Advantageously, the drive motor for the spiked lattice is connected to the electronic control and regulating device.
The invention also provides an apparatus for operating a feed device for fibre material, for example, a hopper feeder, in which a drivable, endless conveyor belt guided around two rotatable rolls is provided, which conveyor belt is associated at one end, looking in the conveying direction, with an endless, upwardly inclined spiked lattice and upstream of the other end of which conveyor belt, looking opposite to the conveying direction, there is arranged an endless feed belt (reserve belt), wherein between the conveyor belt and the feed belt (reserve belt) there is arranged a continuously circulating transition belt and the absence of fibre material on the feed belt (reserve belt) is detectable.
With reference to
Referring to
Using the apparatus according to the invention, no-load running of the mixing chamber 1a of the hopper feeder 1 is reliably avoided, and within an adequate buffer time the reserve belt 8 is reloaded. Separating the function of the feed belt 8 from the function of the transition belt 7 according to the invention provides an opportunity for the belt portion 7 feeding the mixing chamber 1a to be moved independently of the reserve belt 8. The sensor 10 monitors the end of the portion of belt 7 that is being fed, and signals when the reserve belt 8 has run empty. As the last bale portion 9d present on the belt portion 7 that is feeding fibre is being worked off in the normal way, reloading of the upstream reserve belt 8 can be carried out independently of the process still under way.
Only when the last raw fibre bale portion 9b has left the reserve belt 8 can the reserve belt 8 be completely loaded again. The raw fibre bales first have to be prepared (removal of packaging and bindings) and then placed as closely together as possible on the feed belt 8.
The function of the conveyor belt 2 is to feed the fibre material to the spiked lattice 3. The function of the reserve belt 8 is to make available a supply of material in the form of bale layers or whole bales 9a, 9b. The function of the transition belt 7 is twofold: it feeds fibre material 9c to the conveyor belt 2 and holds a supply of fibre material 9c ready even when the empty reserve belt 8 is being loaded with new fibre bales 9, 9b while at a standstill.
Although the foregoing invention has been described in detail by way of illustration and example for purposes of understanding, it will be obvious that changes and modifications may be practised within the scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2004 042 443.8 | Aug 2004 | DE | national |
