Web supply apparatus

Abstract

Web supply apparatus for supplying relatively stiff web material such as liner board for a corrugator serves the web from one of two supply rolls. The running web passes through a splicing station and a festoon on its way to the web-consuming machine. The leading end of the ready web is prepared on a web positioning bar away from the splicing station and then carried by the bar to the splicing station while the running web is being consumed. When the roll of running web expires, a control system automatically stops the roll of running web and special pressure pads at the splicing station press the running web and ready web together to make a strong splice between them. Immediately thereafter, a knive fires directly behind the splice, thereby cutting the trailing end of the running web. The pressure pads firmly grip the webs above and below the line of the cut so that the knife slices cleanly through the web. Following this, the roll of ready web is accelerated and the trailing end of the running web pulls the ready web into the festoon which then refills to complete the splicing cycle. When the apparatus incorporates roll stands of the rollout type, the web positioning bars are affixed directly to the roll stands and move in and out of the splicing station with them. When the roll stands are of the fixed type, the positioning bars are moved from a remote loading station to the splicing station by a special transport assembly. Also, the positioning bars can be moved manually from the preparation site to the splicing station if the situation demands it. Thus, the splicing is accomplished at zero speed with maximum reliability, yet the stiff web proceeds uninterruptedly and at constant speed to the corrugator.

I claim: 
     
       1. Web supply apparatus comprising A. a first source of web,   B. a second source of web,   C. an inaccessible splicing station through which web travels alternately from the first and second sources, said splicing station including 1 . a first pressure pad,   2. a second pressure pad, said pads being movable toward and away from one another,   3. means for moving the pressure pads toward and away from one another in response to a command,   4. a first knife assembly associated with the first pressure pad, said knife assembly including a first blade movable from a retracted position out of the path of web from the first source through the splicing station to an extended position wherein it projects through the path of web from the first source through the splicing station,   5. a second knife assembly associated with the second pressure pad, said second knife assembly including a second blade movable from a retracted position out of the path of web from the second source through the splicing station to an extended position wherein it projects through the path of web from the second source through the splicing station, each said pressure pad extending above and below the corresponding knife assembly so that when the two pads come toward one another, they retain the web on both sides of the cutting knife blade, and   6. means for moving the two blades between their two positions,     D. means for guiding web from one of the sources through the splicing station between the two pads,   E. a loading station remote from the splicing station at a location accessible to an operator,   F. means for moving the leading end of the web from the other source from the loading station to a position at the splicing station between the two pressure pads,   G. control means for commanding the pressure pad moving means to move the pressure pads toward one another so that the web from the one source is pressed against the leading edge of the web from the other source so that the two become joined, and   H. means for commanding the blade moving means which moves the blade adjacent the path of the web from the one source to move to its second position while the pads are moved toward one another so that said blade severs the web from the one source just behind its joint to the web from the other source.   
     
     
       2. The web supply apparatus defined in claim 1 and further including a knife backup positioned directly between the two knife assemblies against which the cutting knife blade acts when cutting the web from the one source, said knife backup also shielding the web from the other source from said cutting knife blade during the cutting operation. 
     
     
       3. Web supply apparatus as defined in claim 2 wherein the backup is comprised of a rail extending parallel to the knife blades, said rail having A. a first blade receiving slot directly opposite the first knife blade and a second blade receiving slot directly opposite the second knife blade, said first and second knife blades and their slots being offset relative to one another.   
     
     
       4. Web supply apparatus as defined in claim 1 and further including a web accumulator located downstream from the splicing station and further including means for stopping the one source of web so that a joint can be formed at zero web speed, the accumulator providing the web required by a downstream web-consuming machine while the incoming web is stopped. 
     
     
       5. The web supply apparatus defined in claim 1 wherein the means for moving the leading end of the web from the other source from its loading station to the splicing station is comprised of A. a bar to which said leading end is affixed, and   B. means for removably locating the bar at the splicing station between the pressure pads.   
     
     
       6. The web supply apparatus defined in claim 5 wherein the locating means includes a pair of retainers at the splicing station for retaining the opposite ends of the bar between the pressure pads. 
     
     
       7. The web supply apparatus defined in claim 6 wherein the retainers are movable along with the associated pressure pads. 
     
     
       8. The web supply apparatus defined in claim 5 wherein A. the first and second web sources are mounted on roll stands of the rollout type, and   B. the bar locating means is comprised of means on each roll stand for supporting the bar to which the leading end of the web from the other source is affixed so that when the roll stand supporting the other source is moved to its normal position for feeding web, the positioning bar supported by that stand properly locates the leading edge of the web at the splicing station beween the pads.   
     
     
       9. The web supply apparatus defined in claim 5 wherein the bar locating means includes A. transport means connected to each web positioning bar, said transport means communicating between the web loading station and the splicing station, and   B. means for driving the transport means so as to move the positioning bar between its two stations.   
     
     
       10. Web supply apparatus comprising A. a first source of web,   B. a second source of web,   C. a splicing station not conveniently accessible to an operator, said splicing station including 1. first pressure applying means,   2. second pressure applying means, said pressure applying means being movable toward and away from one another,   3. a first knife assembly associated with the first pressure applying means, said first knife assembly including a first blade movable from a retracted position to an extended position wherein it projects beyond the first pressure applying means toward the second pressure applying means,   4. .Iadd.a .Iaddend.second knife assembly associated with the second pressure applying means, said second knife assembly including a second blade movable from a retracted position to an extended position wherein it projects beyond the second pressure applying means toward the first pressure applying means,     D. means for moving the leading end of the web from one of the sources from an .[.inaccessible.]. .Iadd.accessible .Iaddend.loading station to a position at the splicing station between the two pressure applying means, said means for moving the leading .[.eand.]. .Iadd.end .Iaddend.of the web from each source from its loading station to the splicing station being comprised of 1. a .[.movable.]. bar to which said leading end is affixed, and   2. means for removably locating the bar at the splicing station between the pressure applying means,     E. means for moving the pressure applying means toward and away from one another to splice webs trained between them, and   F. means for moving the first and second blades between their two positions.   
     
     
       11. The web supply apparatus defined in claim 10 wherein the locating means are comprised of retainers at the splicing station for supporting the bar between the pressure applying means. 
     
     
       12. The web supply apparatus defined in claim 10 wherein A. the first and second web sources are mounted on roll stands of the roll-out type, and   B. the bar locating means are comprised of means on each roll stand for supporting the bar to which the leading end of the web from a source is affixed so that when the roll stand supporting that web end is moved to its normal position for feeding the web, the positioning bar supported by that stand properly locates the leading end of that web at the splicing station between the pressure applying means.   
     
     
       13. The web supply apparatus defined in claim 10 wherein the bar locating means include A. transport means connected to each .[.web positioning.]. bar, said transport means communicating between each web loading station and the splicing station, and   B. means for moving the transport means so as to carry each .[.positioning.]. bar between its two stations.   
     
     
       14. The web supply apparatus defined in claim 10 wherein the pressure applying means extend above and below the corresponding knife blade so that when the pressure applying means come together, they grip the web between them on both sides of the blade. 
     
     
       15. The web supply apparatus defined in claim 13 and further including means for controlling the transport means so as to locate each .[.positioning.]. bar at one of its two stations. 
     
     
       16. The web supply apparatus defined in claim 13 wherein the transport means are comprised of A. a chain loop extending between one said loading station and the splicing station, and   B. means for driving the chain so that the .[.positioning.]. bar connected thereto is carried by the chain between the two stations.   
     
     
       17. The web supply apparatus defined in claim 11 wherein the bar includes a pair of flexible, resilient end extensions secured to the retainers to permit the bar to flex relative to the retainers. 
     
     
       18. The web supply apparatus defined in claim 13 and further including means for adjusting the path of the transport means to compensate for the change in said path which occurs when the pressure applying means are moved. 
     
     
       19. Web supply apparatus comprising A. a first source of web,   B. a second source of web,   C. a splicing station through which web travels alternately from the first and second sources, said station including, 1. first pressure applying means, and   2. second pressure applying means, said pressure applying means being movable toward and away from one another,     D. a first knife assembly, said first knife assembly including a first blade movable from a retracted position out of the path of the web from the first source through the splicing station to an extended position wherein it projects into the path of the web from the first source through the splicing station,   E. a second knife assembly, said second knife assembly including a second blade movable from a retracted position wherein it is out of the path of the web from the second source through the splicing station to an extended position wherein it projects into the path of the web from the second source through the splicing station, said pressure applying means extending upstream and downstream relative to their corresponding knife blades so that when the pressure applying means are moved to their extended positions, they grip the web between them on both sides of the blades,   F. means for moving the pressure applying means toward and away from one another to splice webs trained between them,   G. means for moving the first and second blades between their two positions, and   H. a web accumulator located downstream from the splicing station, said accumulator providing the web required by a downstream web-consuming machine while the incoming web is temporarily gripped by the pressure applying means. .Iadd. 20. Web supply apparatus comprising   A. a web accumulator;   B. a splicing station located directly underneath the accumulator that is not readily accessible to an operator;   C. a pair of roll stands of the roll-out type for supporting a pair of web rolls one of which is expiring into the accumulator, the other of which is at the ready, each said stand being movable generally parallel to the axes of the rolls between said splicing station and a loading station adjacent the accumulator that is readily accessible to the operator,   D. positioning means supported on each roll stand for positioning the leading edge of the ready web when the roll stand supporting the ready web is located at its loading station;   E. means supporting the roll stand containing the ready web for movement to the splicing station so that the leading edge of the ready web is positioned directly opposite the expiring web, and   F. means permanently suspended from the overhead accumulator at the splicing station for pressing the expiring web and ready web together to splice them so that web can proceed continuously into the overhead accumulator. .Iaddend..Iadd. 21. The web supply apparatus defined in claim 20 and further including means permanently suspended from the overhead accumulator for severing the trailing end of the expiring web upstream from said splice. .Iaddend. .Iadd. 22. The web supply apparatus defined in claim 20 wherein each positioning means comprises an elongated rigid bar extending the full width of the web proceeding into the accumulator. .Iaddend.