Water jet edge cutter with integral trim chute

#The present invention relates to a water jet web edge trimmer having a trim chute integral and moveable therewith for cutting a leader strip and new edge into a travelling web and disposing of the strip into the trim chute.

#In the papermaking industry, knives or water jets are commonly employed to cut through the traveling web or sheet. The knives and water jets are used in edge trimming, slicing, cross-cutting, and tail cutting applications within the papermaking machine. However, when the knives or water jet cutters are used in an edge trimming application, trim chutes or bins are located downstream from the cutter of the strip of web material trimmed from the main portion of the web.

#Typically, a trim chute relies on some form of negative pressure to draw the trim strip into the chute. The higher the machine speed and further the trim chute is located from the edge trimming or cutting point, the more the risk of having the trim either not follow a normal path into the trim chute or the more the requirement for corrective forces to draw or guide the strip into the trim chute.

#For a better understanding of the nature and objects of the present invention reference may be had to the accompanying diagrammatic drawings in which:

#FIG. 1 is a side view of the web cutting and trim chute unit of the present invention;

#FIG. 2 is a bottom view of the web cutting and trim chute unit of the present invention;

#Referring now to FIGS. 1 through 3 there is shown the moveable integral water jet web cutting and trim chute unit 10 that is adapted for relative inward movement in the direction of arrow 11 (FIG. 2) from an outside surface 12 of web 14 travelling in first direction 16 (FIG. 1). It should be understood that the integral water jet web cutting and trim chute unit 10 may be attached to an overhead support arm (not shown or shown as 116 in FIG. 5) that is laterally moveable relative to the web 14 to move unit 10 in the directions of arrows 11 and 15. Alternatively, it is also possible that the web cutting and trim chute unit 10 may remain relatively stationary and that the web 14 can move inwardly or outwardly relative thereto in the direction shown by arrows 11 and 15. Hence for the purposes of the present invention the word “moveable” to describe the water jet cutting and trim chute unit 10 refers to the relative lateral movement between unit 10 and web 14 in the directions of arrows 11 and 15. For the purposes of the present invention the web 14 normally travels in the direction 16 and the web cutting and trim chute apparatus 10 preferably moves into the web from edge 12 in the direction of arrow 11. As the web cutting apparatus 10 moves into the edge 12 it cuts into the edge forming a lead in strip 18. The remainder 17 of the web 14 travels past the web cutting and trim chute apparatus 10 for further processing within the paper making or web processing apparatus.

#The web cutting and trim chute unit 10 comprises a support plate 20 having a relatively flat lead in surface 21 that supports web 14 and a downstream flat surface 23 that supports an edge of the remaining web portion 17 of the web 14. The support plate 20 extends substantially parallel to the plane of the travelling web 14. While the present invention in FIG. 1 shows the web cutting apparatus being supported above the “horizontal” plane of the web 14, it should be understood that the plane of the web 14 maybe vertical or any other angle relative to the horizontal with the web cutting and trim chute apparatus 10 being located to one side of the web 14; whether above or below the web 14. The support plate 20 supports the web immediately prior to and after the strip 18 is cut from the outside of edge 12 of the travelling web 14 as the web cutting and trim chute unit 10 moves inwardly in the direction of arrow 11 relative to the web 14.

#The support plate 20 has a cutting aperture 22 and a plurality of suction apertures 24. The suction apertures 24 are positioned substantially on the inboard side 26 of the cutting aperture 22 relative to the web 14. The suction apertures 24 support the web 14 against the support plate 20 immediately prior to the cutting aperture 22. The suction apertures 24 also support the edge of the remaining web portion 17 of the web 14 against support plate 20 after the trim strip 18 has been cut at cutting aperture 22. This permits the trim strip 18, un-supported by the suction apertures 24, to be directed or discarded away from the remainder portion 17 of the web 14. The suction apertures are positioned as shown both upstream 30 and downstream 32 of the cutting aperture 22 in the first direction 16 of web travel.