Replacement cheekstrip apparatus for use with cutting cylinder knives

A replacement cheekstrip having an upper part and a lower part for fitting into a knife box assembly that is installed in the rotary cutting cylinder of the folder used on a roll fed printing press. The upper part is made from a hard solid material connected to the lower part which is made from a soft material. The soft material can be open cell sponge rubber. A knife is inserted between the flat surfaces of the replacement cheekstrips. The soft material applies correct tension to the upper part, hard solid material, which in turn contacts the paper, against an adjacent cutting member, and clamps it securely to enable the knife to make a quiet, consistent, distortion free, severance.

BACKGROUND OF THE INVENTION 
This invention relates to a replacement cheekstrip apparatus having an 
upper part made from a hard material such as polyurethane, and having a 
lower part made from a soft material such as open cell sponge rubber. 
DESCRIPTION OF THE PRIOR ART 
A cheekwood is used by the printing industry as a paper holding component 
in a knife box assembly. The knife box assembly is installed in a slot 
provided in the rotary cutting cylinder, located in the folder of a roll 
fed printing press. The rotary knife cylinder is designed to cut the paper 
as it passes, in conjunction with another adjacent cylinder or surface, or 
abutment, against which the paper is held by the spring pressed cheekwoods 
in order to clamp and hold it without undue bending, buckling, or 
distortion, so as to produce a clean and exact severance. 
Components of a typical prior art knife box assembly 10 are shown in FIGS. 
1 and 2. The knife box assembly comprises two knife box halves 10A and 
10B, two cheekwoods 12A and 12B, and a knife 14 fixed between the halves 
of the knife box. Each half of the knife box comprises a channel 16A or 
16B that is defined by a web 18 and a pair of flanges 20 and 22 extending 
in the same direction from opposite edges of the web. The halves of the 
knife box are disposed at opposite sides of the knife 14 with 
corresponding flanges extending toward each other, so as to define a 
hollow, elongated knife box. Flanges 22 support the base of the knife 
therebetween, with the knife bisecting the knife box and projecting 
therefrom through an opening at one side of the knife box between the 
flanges 20. Each cheekwood has a portion 24 of generally rectangular 
cross-section within the corresponding channel 16A or 16B and has a 
portion 26 that projects from the knife box between a flange 20 and the 
knife 14, as shown in FIG. 2. As is apparent, each cheekwood has a flat 
face that is juxtaposed with an opposed face of the knife, and each 
cheekwood rests on a series of coil springs 28 as shown. 
In operation, the cheekwoods, in response to pressure applied to portions 
26, move inwardly of the knife box so that the tip of the fixed knife 14 
is exposed to cut paper as it moves past the knife box assembly. 
In the prior art, cheekwoods typically have been made entirely from hard 
material such as phenolic, and they rest on the springs in the knife box 
assembly. Alternatively, prior art cheekwoods have been made entirely from 
a soft material such as sponge rubber, and used in the knife box assembly 
without springs. 
A major problem with prior art cheekwoods is longevity. Printing presses 
having cheekwoods requiring springs are disabled when springs break. Also, 
the springs are relatively expensive to replace. 
Printing presses using prior art cheekwoods made entirely from sponge 
rubber have had problems because the sponge rubber does not last very long 
in a high speed operation. This is due to the lack of durability of using 
only sponge rubber material. 
OBJECTS AND SUMMARY OF THE INVENTION 
An object of the present invention is to provide an improved cheekstrip for 
use in a high speed, roll fed, printing press. 
Another object of the present invention is to provide a replacement 
cheekstrip having a long lasting service life. 
A further object of the present invention is to provide a replacement 
cheekstrip that is inexpensive and will operate on a high speed printing 
press at any desired speed. 
An additional object of the present invention is to provide a replacement 
cheekstrip that can fit into knife box assemblies without modification of 
the knife box assemblies, and replace prior art cheekwoods. 
In accordance with one aspect of the invention, in a roll-fed printing 
press knife box assembly that includes a hollow, elongated knife box with 
an opening at one side thereof through which a knife of the assembly 
projects, a cheekstrip comprises two elongated strip pieces that are 
contiguous along their length, one of said pieces being composed of a 
relatively hard material and the other of said pieces being composed of a 
relatively soft, resilient material, said one piece including a base 
portion adjacent to said other piece and a protrusion remote from said 
other piece, said base portion in combination with said other piece being 
shaped to occupy substantially the interior of the knife box at one side 
of the knife and said protrusion being shaped to project from said base 
portion through the opening of the knife box at said one side of the 
knife.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 3, a preferred embodiment of a cheekstrip 100 of the 
invention is shown comprising a first elongated strip piece 102 of a hard 
solid material contiguous with a second elongated strip piece 104 of a 
soft material. Typically, the piece 102 is made from a material having the 
hardness of 90 A polyurethane. The piece 104 is made from a soft material 
such as open cell sponge rubber, usually neoprene. The piece 102 is 
connected to the piece 104 along their lengths. 
FIG. 4 shows the two halves 10A and 10B of a knife box assembly 10 clamped 
or fastened together with the respective flanges of the knife box halves 
facing each other as in FIG. 2. Two cheekstrips 100 fit into the knife box 
assembly at opposite sides of knife 14, with a flat face of each piece 102 
juxtaposed with an opposed face of the knife, and with the height of the 
face of piece 102 in a direction extending away from piece 104 being 
coextensive with a substantial portion of the corresponding height of the 
opposed face of the knife in the interior of the knife box, as shown in 
FIG. 4. 
As shown in FIG. 3, piece 102 of each cheekstrip includes a base portion 
102A adjacent to piece 104 and a protrusion 102B remote from piece 104, 
the base portion 102A in combination with piece 104 being shaped to occupy 
substantially the entire interior of the knife box at one side of the 
knife, as shown in FIG. 4, and the protrusion 102B being shaped to project 
from the base portion 102A through the opening of the knife box at one 
side of the knife. The cheekstrips 100 require no springs in the knife box 
assembly. 
In operation, the cheekstrips move in response to pressure applied to 
protrusions 102B of the cheekstrips, causing the tip of the fixed knife to 
be exposed and cut paper passing over the knife box assembly. The pieces 
102 and 104 of each cheekstrip are connected to each other throughout 
their length. Piece 102 is preferably bonded to or molded into piece 104. 
The shape of the cheekstrips 100 is similar to the cheekwoods used in the 
prior art. Note, however, that no springs are required in the knife box 
assembly with the cheekstrips 100 as used in the prior art, since the soft 
material serves to act as a release allowing the cheekstrips 100 to move 
in response to pressure being applied thereto. 
The cheekstrips 100 as described herein may be used, for example, in web 
press folder knife boxes and eliminate the need for springs used with 
prior art cheekwoods and the problems associated therewith. 
In practice, the present invention allows replacement cheekstrips to be 
made at less cost than prior art cheekwoods and springs they replace. 
Further, since no springs are required, the replacement cheekstrips have 
the advantages of quiet operation and longer lasting life, than systems 
having springs which break. Further, the replacement cheekstrips will not 
tear the web and can be used with any weight, coated or uncoated paper. 
Additionally, the replacement cheekstrips can operate in a roll fed 
printing press folder at any speed desired, and since there are no moving 
springs, this reduces wear on all cutting components. 
Additional advantages of the present invention include not having to modify 
the knife boxes for using the replacement cheekstrips. 
From the teachings of the present invention, it will be obvious that 
variations and extensions can be made from the claimed invention. For 
example, in a preferred embodiment, the cheekstrips can be used as either 
one or two units on each side of a knife box assembly, requiring either 
two or four replacement cheekstrips. Further, the total number of 
cheekstrips used can be increased in a knife box assembly. 
It will be apparent to those skilled in the art that various modifications 
can be made to the replacement cheekstrip apparatus of the instant 
invention without departing from the scope or spirit of the invention, and 
it is intended that the present invention cover modifications and 
variation of the replacement cheekstrip apparatus provided they come 
within the scope of the appended claims and their equivalents.