Note: Descriptions are shown in the official language in which they were submitted.
CA 02680722 2009-09-25
KNIFE ASSEMBLY FOR A TRIMMING MACHINE
FIELD OF THE PRESENT INVENTION
This invention relates to an improved knife assembly for use on a trimming or
cutting machine to trim single, multi-page paper products, for example soft
covers books
or periodicals. Specifically, my invention is an assembly of at least two
pieces, a primary
blade and a backbone blade, that allows for score cutting a paper product
binding or
backbone to produce a cleaner cut. My improved knife assembly can be custom
configured for retrofitting to O.E.M. trimming machines.
BACKGROUND OF THE INVENTION
Non-rotary cutting single edged knifes for trimming paper products are known.
These prior art knives are single edged and are typically affixed to
industrial cutting
machines that operate in a reciprocating fashion. A draw back of these singe
edged
knives is that they cause damage to soft cover bindings when trimmed. This
damage
typically manifests itself as small areas of backbone chipping/tearing that
greatly
diminishes the quality of the binding, which can ruin the visual appearance of
the
finished product. Prior art backbone trimming knives dull quickly and require
multiple
change outs resulting in production loss time of from 30 to 60 minutes. With
typical
machinery producing anywhere between 8,000 to 30,000 books per hour, frequent
change outs are very costly.
2
CA 02680722 2009-09-25
Accordingly, there exists a strong need to provide an improved knife design
that
avoids damage to the binding, provides a clean visually appealing trimmed
edge, and
maintains its cutting edge, thus avoiding costly frequent change outs. The
present
invention achieves this goal and overcomes the above-mentioned problems by
providing a combination of a primary blade with at least one beveled edge
backbone
blade where the cutting edge is offset from the primary cutting edge.
These and other advantages of the invention will become evident from the
following more detailed description of the invention.
SUMMARY
My invention substantially reduces the damage caused by conventional single
cutting edge reciprocating knifes. The instant invention includes a knife
assembly for
removable attachment to an industrial cutting or trimming machine that
includes a
primary blade and at least one removable beveled backbone blade, each with a
separate cutting edge. The primary blade has two sides where one side contains
a
beveled portion having a height BEH terminating in a sharp cutting edge. The
primary
blade is defined by a length L and a height H, preferably where length L is in
the range
from about 6 inches to about 36 inches and H is in the range from about 2
inches to
about 24 inches. The BEH can be in the range from about 0.5 inches to about 2
inches,
most preferably 0.75 inches to 1.25 inches. The primary blade preferably is
fabricated
from carbon steel, D-2, high speed steel, carbide inlaid material, ceramics
and other
similar hardened materials. The angle of the beveled edge on at least one side
of the
3
CA 02680722 2009-09-25
primary blade is preferably in the range from about 10 degrees to about 40
degrees,
most preferably from 22 to 30 degrees.
The backbone blade is configured for attachment to the primary blade,
preferably
through a removable fastener to facilitate maintenance or replacement of
either blade.
The backbone blade has a width W and can be fabricated from the same or
different
materials of construction as the primary blade, however, a preferred material
of
construction is carbon steel, D-2, high speed steel, or carbide inlaid
material. At least
one side of the backbone blade has a beveled edge of width BBW, preferably in
the
range of from about 0.5 inches to about 2.0 inches, most preferably 0.75
inches to 1.25
inches, terminating in a backbone cutting edge that is in the same vertical
plane as the
cutting edge of the primary blade. The width W of the backbone blade
preferably is in
the range of from about 3 inches to about 10 inches. The angle of the beveled
edge of
the backbone can be the same as or different that the beveled edge of the
primary
blade, but in any instance preferably is preferably in the range from about 10
degrees to
about 40 degrees, most preferably from 22 to 30 degrees.
When attached to the primary blade a portion of the backbone cutting edge
extends below the primary cutting edge and is offset from the primary cutting
edge by
an angle a. Preferably, angle a is greater than 90 degrees, most preferably at
least
135 degrees as measured from the primary blade cutting edge to the backbone
cutting
edge. As mentioned, the backbone cutting edge is preferably in the same plane
as
the cutting edge of the primary blade.
4
CA 02680722 2012-06-04
76909-399
In one preferred configuration of the knife assembly of the invention, L Is at
least
twice H, BEH is greater than BBW, W is less than H, and the primary blade has
a non-
beveled side opposite the primary beveled side. Additionally, the non-beveled
side
contains a slot configured to accept a portion of the backbone blade. The
backbone
blade can be attached to the slot In any manner that securely holds It in
place during
cutting or trimming, preferably the backbone blade is secured with one or more
bolts,
screws, rivets, pins, or the like fasteners. Alternatively, an adhesive, such
as an epoxy,
can be used alone or in combination with the above-mentioned fasteners. In
situations
where the primary and backbone blades have only one beveled edge, the slot Is
preferably configured to accept the backbone blade such that the two non-
beveled
sides of the primary blade and backbone blade are flush with each other.
The primary blade has a plurality of attachment positions that can be used
with
appropriate fasteners to removably connect the knife assembly to a cutting
machine.
These positions may be holes, slots, grooves, or other attachment means that
are
configured to align and cooperate with similar meant or fasteners located on
the
cutting machine. Preferably, when attached to a cutting machine the knife
assembly is
operated in a reciprocal manner, as opposed to a rotary manner. In other
words, the
cutting machine causes the knife assembly to move in an "up and down" cutting
motion, as opposed to a rotational direction like that of an electric table or
radial arm
saw blade.
5
CA 02680722 2012-06-04
76909-399
In accordance with another aspect of the present invention, there is
provided a knife assembly for a trimming or cutting machine comprising, a. a
primary
blade having a primary beveled side of length L, a height H, a primary beveled
edge
of height BEH, and a primary cutting edge, where the primary blade has a non-
beveled side opposite the primary beveled side that contains a slot; and b. a
backbone blade located in the slot and connected to the primary blade having a
backbone beveled side of width W, a backbone beveled edge of width BBW, and a
backbone cutting edge, wherein a portion of the backbone cutting edge extends
below the primary cutting edge and is offset from the primary cutting edge by
an
angle a that is at least 135 degrees and wherein the backbone blade is
positioned in
the slot such that a side of the backbone that is opposite of the backbone
beveled
side is flush with the non-beveled side of the primary blade.
These as well as other advantages of various aspects of the present
invention will become apparent to those of ordinary skill in the art by
reading the
following detailed description, with appropriate reference to the accompanying
drawings.
5a
CA 02680722 2009-09-25
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments are described herein with reference to the drawings, in
which:
Figure 1 illustrates a side view of the knife assembly of the invention
showing the
beveled edge sides of the primary blade and backbone blade;
Figure 2 illustrates a side view of the knife assembly of the invention
showing the
opposite side of the beveled edge sides of the primary blade and backbone
blade, i.e.
the non-beveled sides;
Figure 3 illustrates a side view of the non-beveled edge side of the primary
blade
only and the slot configured to accept the backbone blade; and
Figure 4 illustrates a side view of the knife assembly of the invention
showing the
beveled edge sides of the primary blade and backbone blade in a position to
trim a
paper product.
6
CA 02680722 2009-09-25
DETAILED DESCRIPTION OF THE DRAWINGS
One possible configuration of the knife assembly of the present invention is
shown
in the accompanying figures where both the primary blade and the backbone
blade
have one side that is beveled. Fig. 1 shows a side view of the beveled side 8
of primary
blade 2. Backbone blade 3 is attached to the primary blade 2 by machine screw
10.
The backbone blade is positioned in slot 13 (see Fig. 3) such that its beveled
side 15 is
facing the same as the beveled side 8 of the primary blade. This positioning
causes the
primary cutting edge 6 to be in the same plane as cutting edge 7 of the
backbone blade.
The primary blade 2 has a height H and a length L, with a beveled edge 4 of
height
BEH. In the embodiment shown in the figures, L>H>BEH. The backbone blade has a
width W and beveled edged 5 width of BBW. In the embodiment shown, W>BBW,
BEH>BBW, and L>H>W. Although the two cutting edges 6 and 7 are in the same
plane, the backbone blade cutting edge 7 is offset from the primary blade
cutting edge 6
by an angle a (see Fig. 2). Preferably this angle is greater than 90 degrees,
most
preferably approximately 135 degrees. This figure also illustrates a plurality
of fastener
means 9 that are employed to secure the knife assembly to a cutting machine
(not
shown).
Fig. 2 shows the non-beveled sides 11 and 12 of the primary and backbone
blades and the positioning of slot 13. This figure also shows that the slot
can be
configured such that the non-beveled sides of the two blades are preferably
flush with
each other. Fig. 3 exemplifies the position of a bound book 14 in contact with
cutting
edges 6 and 7 immediately before trimming.
7
CA 02680722 2009-09-25
Exemplary embodiments of the present invention have been described. Those
skilled in the art will understand, however, that changes and modifications
may be
made to these embodiments without departing from the true scope and spirit of
the
present invention, which is defined by the claims.
8
