Inhibiting noise in sheet spreaders
AssigneeBeloit Corporation
InventorRoger C. Brendemuehl
Life of this patent
Estimating the term…
Abstract
Objectionable noise is inhibited in sheet spreaders of the type wherein strips of a slit traveling web are laterally separated by running the strips over spaced, bowed hollow spreader bars, frictional resistance being alleviated by floating the strips on a layer of air covering the areas of the bars wrapped by the strips. Tendency toward high frequency vibration and thus noise experienced in high speed operation is inhibited by ventilation in the tangency angles between the bars and the running strips.
Claims22
A method of inhibiting noise in the operation of a sheet spreader of the type wherein just-slit web strips running at high speed are separated laterally by travelling in limited wrapping relation across curvate flotation zones on complementary spaced spreader bars with respect to which the web strips approach and leave tangentially, so that there are tangency angle areas between the bars and the strips outside of the flotation zones, said flotation zones being supplied with strip-lifting antifriction lubricating air layers between the flotation zones and the strips in the flotation zones, said method comprising:
- effecting air layer distribution in said flotation zones;
- ventilating said tangency angle areas between the bars and the running strips by supplying to the tangency angle areas a sufficient volume of ventilating air for delaying pressure decay in said tangency angle areas;
- and thereby avoiding sudden tension fluctuations in the running strips and thus inhibiting noise generating vibrations in the running strips.
A sheet spreader having complementary spaced spreader bars having thereon curvate flotation zones across which just-slit web strips run at high speed in limited wrapping relation to the bars and are spread laterally, the web strips approaching and leaving said curvate flotation zones tangentially, so that there are tangency angle areas between the bars and the strips outside of the flotation zones, the bars having means for supplying the flotation zones with strip-lifting anti-friction lubricating air layers between said flotation zones and the strips, and comprising:
- means for effecting air layer distribution in said flotation zones;
- and
- means for supplying to said tangency angle areas between the bars and the running strips a sufficient volume of ventilating air for delaying pressure decay in said tangency angle areas;
- whereby to avoid sudden tension fluctuations in the running strips and thus to inhibit noise generating vibrations in the running strips.
A method of inhibiting noise in the operation of a sheet spreader of the type wherein just-slit web strips running at high speed are separated laterally by travelling in limited wrapping relation across curvate floation zone on complementary spaced spreader bars with respect to which the web strips approach and leave tangentially, so that there are tangency angle areas between the bars and the strips outside of the flotation zones, said flotation zones being supplied with strip-lifting antifriction lubricating air layers between the flotation zones and the strips in the flotation zones, the method comprising:
- supplying said flotation zones of the bars with air under pressure through an array of ports in said flotation zones;
- applying plastic screens over said flotation zones and extending beyond said flotation zones into said tangency angle areas;
- thus ventilating said tangency angle areas;
- and thereby avoiding noise generating vibrations in said running strips.
A method of inhibiting noise in the operation of a sheet spreader of the type wherein just-slit web strips running at high speed are separated laterally by travelling in limited wrapping relation across curvate flotation zones on complementary spaced spreader bars with respect to which the web strips approach and leave tangentially, so that there are tangency angle areas between the bars and strips outside of the flotation zones, said flotation zones being supplied with strip-lifting antifriction lubricating air layers between the flotation zones and the strips in the flotation zones, the method comprising:
- issuing air into said flotation zones through ports in said spreader bars;
- covering said flotation zones with porous screens;
- mounting air barriers across said tangency angle areas and thereby restraining escape of air moving from said flotation zones into said tangency angle areas;
- thus ventilating said tangency angle areas;
- and thereby avoiding noise generating vibrations in said running strips.
A sheet spreader having complementary spaced spreader bars having thereon curvate flotation zones across which just-slit web strips run at high speed in limited wrapping relation to the bars and are spread laterally, the web strips approaching and leaving said curvate flotation zones tangentially, so that there are tangency angle areas between the bars and the strips outside of the flotation zones, the bars having means for supplying the flotation zones with strip-lifting anti-friction lubricating air layers between said flotation zones and the strips, and comprising:
- said flotation zones of said spreader bars having an array of ports through which air under pressure is supplied to said flotation zones;
- and means for ventilating said tangency angle areas comprising plastic screens over said flotation zones and extending beyond the flotation zones into said tangency angle areas;
- and thereby avoiding noise generating vibrations in said running strips.
A sheet spreader having complementary spaced spreader bars having thereon curvate flotation zones across which just-slit web strips run at high speed in limited wrapping relation to the bars and are spread laterally, the web strips approaching and leaving said curvate flotation zones tangentially, so that there are tangency angle areas between the bars and the strips outside of the flotation zones, the bars having means for supplying the flotation zones with strip-lifting anti-friction lubricating air layers between said flotation zones and the strips, and comprising:
- said spreader bars have ports in said flotation zones through which air is issued to said flotation zones;
- porous screens covering said flotation zones;
- and means for ventilating said tangency angle areas comprising air barriers mounted across said tangency angle areas for restraining escape of air moving from said flotation zones into said tangency angle areas;
- whereby to avoid noise generating vibrations in said running strips and thereby inhibiting noise in the operation of the sheet spreader.
A method of inhibiting noise in the operation of a sheet spreader of the type wherein just-slit web strips running at high speed are separated laterally by travelling in limited wrapping relation across curvate flotation zones on complementary spaced spreader bars with respect to which the web strips approach and leave tangentially, so that there are tangency angle areas between the bars and the strips outside of the flotation zones, said flotation zones being supplied with strip-lifting antifriction lubricating air layers between the flotation zones and the strips in the flotation zones, said method comprising:
- ventilating said tangency angle areas between said bars and said running strips by substantially trapping in said tangency angle areas a sufficient volume of ventilating air from said flotation zones for delaying pressure decay in said tangency angle areas;
- and thereby avoiding sudden tension fluctuations in the running strips and thus inhibiting noise generating vibrations in the running strips.
A sheet spreader having complementary spaced spreader bars having thereon curvate flotation zones across which just-slit web strips run at high speed in limited wrapping relation to the bars and are spaced laterally, the web strips approaching and leaving said curvature flotation zones tangentially, so that there are tangency angle areas between the bars and the strips outside of the flotation zones, the bars having means for supplying the flotation zones with strip-lifting anti-friction lubricating air layers between said flotation zones and the strips, and comprising:
- means for supplying from said flotation zone to said tangency angle areas a sufficient volume of ventilating air for delaying pressure decay in said tangency angle areas;
- and means for substantially trapping in said tangency angle areas air supplied by said supplying means;
- whereby to avoid sudden tension fluctuations in the running strips and thus to inhibit noise generating vibrations in the running strips.
Dependencies are inferred from the claim text.