US3850069A

US3850069A - Mounting of rotary split slitting knives

Info

Publication number: US3850069A
Application number: US00435336A
Authority: US
Inventors: L Saunders
Original assignee: S&S Corrugated Paper Machinery Co Inc
Current assignee: S&S Corrugated Paper Machinery Co Inc
Priority date: 1974-01-21
Filing date: 1974-01-21
Publication date: 1974-11-26
Anticipated expiration: 1991-11-26

Abstract

A split rotary slitting knife removably mounted to a split annular head is positioned so that the diametrically opposed joints between head portions are angularly offset from the joints where the cutting portions of the blade sections abut. The ends of each of the blade sections extend across both of the head joints for proper alignment of the blade sections.

Description

United States Patent Saunders Nov. 26, 1974 [54] MOUNTING OF ROTARY SPLIT SLITTING 3,246,555 4/1966 Finlay 83/665 KNIVES 3,541,656 11/1970 Devon 83/698 X [75] Inventor: Lawrence J. Saunders, Elmont, N.Y. P E W11 G Ab b rtmary xammer 1 1e ercrom 1e [73] Asslgnee: S & Scorrugmed Paper & Attorney, Agent, or FirmOstrolenk, Faber, Gerb &

Machinery Co., Inc., Brooklyn, NY. soffen [22] Filed: Jan. 21, 1974 [21] Appl. No.: 435,336 57] ABSTRACT A split rotary slitting knife removably mounted to a [52] us Cl 83/665 83/675 6 split. annular head is positioned so that the diametri- [51] Int Cl B26d 1/12 823d 35/00 cally opposed joints between head portions are angu- [58] i 83/663 & 665 675 larly offset from the joints where the cutting portions g of the blade sections abut. The ends of each of the blade sections extend across both of the head joints [56] References Cited for proper alignment of the blade sections.

UNITED STATES PATENTS Antosh 83/675 x 6 Claims, 4 Drawing Figures MOUNTING OF ROTARY SPLIT SLITTING KNIVES This invention relates to knives in general and more particularly relates to rotary knives for longitudinally slitting web material.

In the production of double-faced corrugated board, a corrugated web sandwiched between two flat liner webs is bonded thereto to form a relatively stiff composite web, typically from 85 inches to 105 inches wide. The composite web passes through slitting apparatus which includes sets of opposed cooperating annular knives transversely positioned to trim the edges of the relatively wide web and also slit the web longitudinally into two or more relatively narrow composite webs that are fed to a cutoff means which transversely cuts the relatively narrow webs into sheets of corrugated board.

Since the slitter blades must be repositioned very often, each annular blade is split and is mounted to a split annular head which is clamped to a drive shaft in a manner which permits the clamping forces to be relaxed so that the head with the blade thereon may be transversely positioned with respect to the longitudinal axis of the web to be cut. Relatively rapid wear of the blade requires that it be split to facilitate changing thereof.

In accordance with the prior art, the two splits in the annular blade are aligned with the splits in the head. Unfortunately, this permits misalignment between the cooperating head sections of the annular blade, and because of the engagement between cooperating knives, misaligned knife sections often chip thereby resulting in poor quality slitting and shortened life for the blade sections.

To significantly reduce, if not entirely eliminate, misalignment of split knife sections, the instant invention provides a construction in which the joints between the split knife sections are angularly offset with respect to the joints between the split head sections. Further, each end of each blade section is constructed so that a portion thereof bridges a joint between sections of the split head. It appears that because the blade splits and the head splits do not coincide, as they do in the prior art, there is improved alignment between slitting surfaces of the split knife sections.

Accordingly, a primary object of the instant invention is to provide an improved construction for a split annular knife mounted to a split annular head.

Another object is to provide slitter knife sections mounted to split head sections in a manner such that knife joints are angularly displaced from the head joints.

Still another object is to provide split knives and heads of this type in which portions at each end of each of the split knife sections extend across a split at the boundary between head sections.

These objects as well as other objects of this invention will become readily apparent after reading the following description of the accompanying drawings in which:

FIG. 1 is an exploded perspective of a split annular slitter blade and head therefor.

FIG. 2 is a side elevation of the elements of FIG. 1 in assembled positions.

FIG. 3 is a fragmentary cross-section taken in a plane extending through the diameters of an upper and lower slitter shaft.

FIG. 4 is a side elevation of a prior art slitter knife mounted to a split annular head.

Now referring to the figures. A rotary slitter includes upper and lower driven

shafts

11,12 mounting

annular heads

13, 14, respectively, which carry the respective

annular knives

15, 16. The board being slit travels along path P extending parallel to the longitudinal axes of

shafts

11, 12 and through the engaged

cutting edge areas

17, 18 of the

respective knives

15, 16. The web travels in a direction perpendicular to the plane wherein the longitudinal axes of shafts ll, 12 are disposed.

Since

heads

13, 14 are of identical construction and

blades

15, 16 are of identical construction, for the sake of brevity only the constructions of head 13 and blade 15 will be described in detail. With particular reference to FIGS. 1 and 2, it is seen that head 13 is constructed ot two

arcuate portions

21, 22, each in length, with their ends held in abutting relationship by clamping screws 23, 24 that pass through clearance apertures (not shown) in head portion 21 that are received by threaded apertures 25, 26 in head portion 22 so that the splits or

joints

27, 28 where the ends of

head portions

21, 22 abut are diametrically opposed. As is well known to the art, the tightening of screws 23, 24 clamp head 13 in a selected position along the length of shaft 11. Tongue and groove means (not shown) may be provided in the abutting surfaces of

head portions

21, 22.

Each of the

head portions

21, 22 is provided with a plurality of threaded apertures 28 extending inward from their respective

flat mounting surfaces

31, 32 respectively.

Arcuate shoulders

33, 34 along the board boundaries of the

respective subassemblies

31, 32 serve to partially position

arcuate blade sections

35, 36 constituting split blade 15. Screws 37 pass through clearance apertures 38 in

blade section

35, 36 and are received by apertures 28 to clamp blade section 35 against head surface 31 and clamp blade section 36 against head section 32. The ends of arcuate cutting edges 17 along the outer edges thereof at

blade sections

35, 36 abut at

joints

41, 42, respectively.

Blade section 35 includes

extensions

43, 44 at opposite ends thereof which project across

blade joints

41, 42 and extend across

head joints

27, 28. The ends of blade section 36 at the inner portions thereof are provided with

notches

45, 46 which receive the

respective extensions

43, 44, and end portions of blade section 36

bridge joints

27, 28. Thus,

blade joints

41, 42 are angularly offset from

head joints

27, 28.

The misalignment of

blade joints

41, 42 with respect to

head joints

27, 28 and the constructions of

blade sections

35, 36 so that the ends thereof extend across both

head joints

27, 28 result inimproved alignment between the

cutting edges

17, 17 of

blades sections

35, 36. This is in contrast to the prior art (FIG. 4) in which the joint 51 between

split blade sections

52, 53 is aligned with joint 54 between

split head portion

55, 56.

Although there has been described a preferred embodiment of this novel invention, many variations and modifications will now become apparent to those skilled in the art. Therefore, this invention is to be limand second arcuate sections having, respectively, first and second parts of said cutting edge mated at the ends thereof at first and second blade joints whereat the ends of the cuttingedge parts abut; said blade joints being angularly displaced from said head joints; in the vicinity of each of said blade joints one of said blade sections having an end projection bridging the head joint adjacent thereto, and the other of said blade sections having an end notch to receive the end projection.

2. An assembly as set forth in claim 1 in which the head joints are located at diametrically opposed positions.

3. An assembly as set forth in claim 2 in which both of the end projections are provided by said first section, and both of said notches are provided by said second section.

4. An assembly as set forth in claim 2 in which the blade joints are both positioned on the same side of a line extending between the head joints.

5. An assembly as set forth in claim 4 in which both of the end projections are provided by said first section, and both of said notches are provided by said second section.

6. An assembly as set forth in claim 5 in which the blade abuts a generally flat surface of the head.

Claims

1. An assembly including an annular head selectively mountable along the length of a drive shaft and an annular blade removably mounted to said head; said head including first and second separable arcuate portions mated at the ends thereof at first and second head joints; said blade including a circular cutting edge along the outer edge thereof; said blade also including first and second arcuate sections having, respectively, first and second parts of said cutting edge mated at tHe ends thereof at first and second blade joints whereat the ends of the cutting edge parts abut; said blade joints being angularly displaced from said head joints; in the vicinity of each of said blade joints one of said blade sections having an end projection bridging the head joint adjacent thereto, and the other of said blade sections having an end notch to receive the end projection.