Sheet feeding or delivering – Feeding – Separators
Patent
1992-09-22
1994-01-11
Olszewski, Robert P.
Sheet feeding or delivering
Feeding
Separators
271 90, B65H 308
Patent
active
052774147
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The invention relates to lifting nozzle and tracer bearings for fast running sheet feeders in particular, simultaneously embodying the function of bearing and the function of resilience.
The sequential feeding of individual sheets from a stack of sheets to a sheet-processing machine, such as an offset printing press, is performed in such a way that the individual sheets are lifted by means of lifting nozzles, are transferred to the tractor nozzles and are brought into a scale-like position by the latter. During this process the tracer has a hold-down and a height sensing function of the stack to be processed,.
DESCRIPTION OF THE PRIOR ART
A separator suction device for a feeder can be found in European Patent Publication EP 03 21 720 A2, wherein a support pipe supporting a separator suction device is moved upwards and downwards by means of rods.
German Patent Publication DE 36 34 659 A1 discloses a tracer device for a sheet feeder with a tracer holder and a tracer foot. On the one hand the tracer holder is connected by means of a joint with an upper and a lower rocker, and on the other hand it is pivotable around a respectively frame-connected journal. The bearings are of the conventional type.
Known lifting nozzle and tracer bearings are embodied as sliding or rolling bearings in such a way, that they absorb the upward and downward oscillating movements. These upward and downward oscillating movements are generated by cam plates via cam rollers and corresponding levers. Because the cam rollers rest frictionally connected on the cam plates, they are pressed against the latter by pressure or torsion springs. To avoid jumping of the cam rollers at high clock frequencies, they have to be pressed against the cam plates with great force, which results in high wear of the cam plates and in the danger of breakage of springs. On account of the fairly high clock frequencies of sheet feeders, the direction of rotation of the rotating parts in the rolling bearings must be reversed correspondingly often. These very fast directional changes place high acceleration forces on the rotating parts provided in the bearing and worsen the lubricant supply to the latter so that the bearings tend to form nicks.
SUMMARY OF THE INVENTION
It is therefore the object of the present invention to improve a lifting nozzle and tracer bearing for sheet feeders of the previously mentioned type by simple means in such a way that a long service life and high clock frequencies can be achieved.
This object is attained in accordance with the invention in that rubber-metal bushings are used as bearings, which absorb the upward and downward oscillating movements and take over the resilient pressing of the cam roller against the cam plate as well.
Bushings of this type are bearing elements consisting of an inner and an outer sleeve, which are firmly connected with each other by means of a resiliently deformable mass. Rubber-metal bushings of this type can be stressed for torsion and act resiliently in both torsional directions. Such rubber-metal bushings are known to be structural elements, they have a damping effect on oscillations and are free of maintenance and wear.
Thus the invention is based on the knowledge that it is possible to construct sheet feeders using such rubber-metal bushings which reduce the oscillations occurring at high clock frequencies and permit oscillating movements free of wear and maintenance without any lubrication. Because of pre-stressing of the rubber-metal bushings, an additional spring for pressing the cam roller against the cam plate can be omitted. Thus the rubber-metal bushing acts as bearing, spring and damping element. Clock frequencies of the lifting nozzles and the tracer of more then 18,000 up-and-down movements per hour have been realized in fast running sheet feeders equipped with such a resilient bearing. Further characteristics and advantages of the invention ensue from the further characteristics recited in the claims as well from the exemplary embodiments below.
BRIEF DE
REFERENCES:
patent: 2251416 (1941-08-01), Parker
patent: 2772104 (1956-11-01), Thiry
patent: 4940221 (1990-07-01), Wirz et al.
Koenig & Bauer Aktiengesellschaft
Milef Boris
Olszewski Robert P.
LandOfFree
Separator suction device for sheet feeders using rubber-metal bu does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Separator suction device for sheet feeders using rubber-metal bu, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Separator suction device for sheet feeders using rubber-metal bu will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1626405