Claims
- 1. In a web material handling apparatus having means for guiding lengths of web material joined by widthwise seams along a path of travel, and nip roll means for engaging web material at a predetermined position along the path of travel, an improvement which controls operation of the nip roll means for of seam detector means mounted adjacent said path of travel, upstream of said nip roll means position, each for sensing widthwise seams in web material guided along said path of travel toward said nip roll means position, and control means operatively connected to said detector means and to said nip roll means for separating said nip roll means relative to web material in response to and in predetermined relation with seam sensing by all of said detector means.
- 2. Apparatus according to claim 1 wherein said detector means are spaced at a predetermined distance along said path of travel from said nip roll means and further wherein said control means comprises delay means responsive to movement toward said nip roll position of a length of web material equal to said predetermined distance and to seam sensing by all said detector means for separating said nip roll means relative to the web material upon movement of a sensed seam from said detector means to said nip roll means.
- 3. Apparatus according to claim 2 wherein said delay means comprises web material movement signalling means for generating pulse signals in proportion to movement of incremental lengths of web material along said path of travel, and counter means responsive to said detector means and to said signalling means for counting such number of pulse signals as represent said predetermined length of web material.
- 4. Apparatus according to claim 1 wherein said detector means generate a signal in response to seam sensing and further wherein said control means comprises coincidence means for distinguishing between signalling by all of said detector means within a predetermined interval of time and indicative of sensing of a web material widthwise seam and signalling by less than all of said detector means and indicative of a false seam sensing signal.
- 5. Apparatus according to claim 4 where said coincidence means comprises timer means responsive to signalling by a first actuated detector means for timing said predetermined interval of time and means responsive to said timer means for permitting a later actuated detector means to actuate said nip roll means.
- 6. In a web handling apparatus for web material such as textile fabric and having means for guiding and advancing lengths of web material joined by widthwise seams along a path of travel, and a pair of cooperating nip rolls between which the web material is advanced at a predetermined position along its path of travel; an improvement which controls the relation between the nip rolls for jumping seams in the web material and comprising: a plurality of seam detector means mounted adjacent said path of travel upstream of said pair of nip rolls, each of said seam detector means being adapted to sense widthwise seams in the web material advancing along said path of travel toward said nip rolls, and control means operatively connected to said detector means and to at least one of said nip rolls for separating the same from the other nip roll and from the web material in response to and in predetermined relation with seam sensing by all of said detector means.
- 7. Apparatus according to claim 6 wherein said detector means comprise a pair of detectors mounted adjacent respective marginal side edge portions of said path of travel and aligned transversely of web material moving therealong.
- 8. Apparatus according to claim 7 wherein said detector means comprise means for sensing variations in thickness of web material as indicative of passage of a widthwise seam.
- 9. Apparatus according to claim 8 wherein said detector means comprise a pair of rolls defining a nip for passage of web material therethrough and electrical switch means responsive to increased separation of said rolls by passage of a thickened seam therebetween for electrically signalling sensing of a seam.
- 10. In a web handling apparatus having means for guiding lengths of web material joined by widthwise seams along a path of travel, and a pair of cooperating nip rolls between which the web material is advanced at a predetermined position along its path of travel; an improvement comprising: a plurality of detector means mounted adjacent said path of travel, each for signalling electrically the passage thereby of widthwise seams in web material guided along said path of travel toward said nip rolls, coincidence circuit means electrically connected to said detector means for distinguishing between signalling by all of said detector means within a predetermined interval of time and indicative of the passage of a widthwise seam and signalling by less than all of said detector means and indicative of a false signal from at least one detector means, and control relay means electrically connected to said coincidence circuit means and operatively connected to at least one of said nip rolls for separating said nip rolls in response to signalling by all of said detector means.
- 11. In a method of handling lengths of web material joined by widthwise seams which includes guiding the material along a path of travel and engaging the material with a pair of nip rolls, an improvement comprising sensing at a plurality of points along the path of travel the passage of a widthwise seam, and responding to and in predetermined relation with the sensing of a seam at all of the points by separating the nip rolls.
- 12. In a method of handling lengths of web material joined by widthwise seams which includes guiding the material along a path of travel and through a nip formed by a pair of rolls, an improvement comprising sensing the passage of a widthwise seam at a point along the path of travel spaced at a predetermined distance from the nip, responding to the sensed passage of a seam by measuring the length of material moving along the path, and moving at least one roll relative to the material in response to the measured length of material equaling the predetermined distance so as to separate the rolls and open the nip in the area of the seam.
Parent Case Info
This application is a continuation-in-part of copending application Ser. No. 809,427, filed June 23, 1977, now U.S. Pat. No. 4,128,212 and entitled "SEAM RESPONSIVE SHEAR AND METHOD".
US Referenced Citations (5)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
809427 |
Jun 1977 |
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