Dispensing – Automatic control – Material level control
Reexamination Certificate
2001-02-09
2001-10-09
Derakshani, Philippe (Department: 3754)
Dispensing
Automatic control
Material level control
C239S654000, C239S071000
Reexamination Certificate
active
06299021
ABSTRACT:
DESCRIPTION
The invention concerns a powder device for powder coating printed sheets, with a powder container in which powder is stored and from which powder is taken, where the powder container in particular is designed as a replaceable container and can be removed from the powder device, and with a metering mechanism by means of which a specified quantity of powder is dispensed into a current of air.
It is generally known that printed sheets of paper are powder coated after they leave the printing press so that the printing ink is not smeared as the sheets are being stacked. To do this, a sheet delivery device has a powder device with which the powder is applied to the sheets.
Normally the powder devices have a powder container in which the powder is stored. This powder container has an opening at its lower end, which is sealed, for example, by a ball (DE 38 11 309 A1). In order to be able to take powder from the container, the ball is driven into the container and thus into the powder stored in it, whereby the powder is loosened up. In addition, compressed air is blown in when the container is opened. The powder taken from the container falls into a mixture preparation area in which the compressed air is enriched with powder, and a powder-air mixture is created.
Another device provides for the discharge opening of the powder container to be sealed by a moveable disk. When the disk is moved, a specific quantity of powder trickles out of a gap between the disk and the discharge opening of the powder container. This powder is picked up and carried along by a current of air rushing by. If the powder container on this device is removed, for refilling, for example, the air cannot be enriched with powder. Continuous operation is not possible.
The object underlying the invention is to provide a powder device with which continuous operation is ensured even when the powder container is being replaced.
The object is achieved under the invention by having the powder container empty into an intermediate container and positioning the intermediate container between the powder container and the metering mechanism.
It is essential to the invention that the powder taken from the powder container is not carried directly into the air stream but ends up in an intermediate container, from which the powder is fed through the metering mechanism into the air stream proper. The intermediate container acts as an additional supply chamber, so that powder can continue to be taken from the intermediate container when, for example, the powder container is being replaced, whereby continuous operation is ensured even when the powder container is (briefly) removed.
A further advantage can be seen in that the powder in the intermediate container has a constant density as far as possible, independent of whether the powder was filled into the powder container only a short time previously and therefore still contains a relatively high percentage of air, or whether the powder was filled into the powder container a considerable time previously and has a higher density.
Since the powder from the powder container runs into the intermediate container, and the time spent in the intermediate container is relatively constant, the powder is transferred into the metering mechanism with almost consistent density and consequently with an almost constant percentage of air. In this way, the amount of powder in the compressed air is adjusted even more precisely to the desired value.
A further embodiment provides that the powder container, the intermediate container and the metering mechanism are positioned vertically one above the other, and the powder is transferred downward from one element to the next. In this way, the powder flows from the powder container by way of the intermediate container to the metering mechanism solely by means of gravity, and no transport air is required. This has the considerable advantage that the powder is not stirred up and that the individual elements do not have to be sealed, or only with conventional means, to atmosphere.
REFERENCES:
patent: 3091368 (1963-05-01), Harley et al.
patent: 3604981 (1971-09-01), Saito
patent: 5090626 (1992-02-01), Platsch
patent: 5178333 (1993-01-01), Barber et al.
patent: 1 611 317 (1967-07-01), None
patent: 66 05 019 (1971-01-01), None
patent: 38 11 309 (1989-10-01), None
patent: 38 19 203 (1989-12-01), None
patent: 0 528 613 (1993-02-01), None
patent: 0 540 402 (1995-03-01), None
patent: 2 76738 (1990-03-01), None
patent: WO99/10177 (1999-03-01), None
Bui Trach H
Derakshani Philippe
Weitmann & Konrad GmbH & Co.
Young & Basile PC
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