Cutting blade

A cutting blade is formed from a rectangular sheet of a rigid material such as metal or plastic. One side of the sheet is formed into a roll or tube giving structural rigidity to the entire cutting blade. The remainder of the sheet extends flat and tangentially from the tube. In cross section, the cutting blade looks generally like the arabic numeral "9". At the top ("rounded head portion") of the "9", a series of holes in one or more rows are punched through the cutting blade so that petals of metal project up and out of the "9" shape at its top. Preferably, for each hole, associated petals are pointed in different directions to provide both a cutting edge and a holding edge for film cut with the blade. The cutting blade may include a series of tangs pointing up (toward the top of the "9") which allow the blade to be easily placed over an edge of the dispenser, but not easily removed therefrom. The blade may be placed on a flat, unfolded insert (of cardboard or a similar stiff material) for a conventional cardboard roll dispenser carton, the insert then inserted between the opening flap and a front edge of the carton, and the head of the "9" shaped blade used as a latch to hold the dispenser cover closed. The petals of the holes may be surrounded with protective bumps to further avoid any possibility of scratching a user of the dispenser.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to cutting blades for cutting sheets of 
material. More particularly, this invention relates to a novel and unique 
cutting blade for use with a roll film dispenser. 
2. The Prior Art 
Dispenser cartons for sheet material are, of course, very well known to the 
prior art. One very wide spread use for such dispenser cartons is in the 
dispensing and marketing of food wrap type sheet material. Typical of such 
food wrap sheet materials are polymeric films which include, for example, 
polyethylene film, and films produced from copolymers of vinylidine 
chloride and vinyl chloride (PVC films). Wax paper and aluminum foil are 
also common food wrap materials available in roll form and suitable for 
use with the type of dispensers discussed herein. This sheet material is 
commonly used for protecting food stuffs and the like in restaurants, 
hotels, and the like. Typically, food wrap sheet material is sold in roll 
form. In the consumer market, the roll is generally positioned in a 
disposable dispenser carton that is sealed during distribution of the 
product from manufacturer to user. Such disposable dispensers are typified 
by that shown and described in U.S. Pat. No. 2,888,180 to Kinker, Jr. 
Commercial users often obtain more durable dispensers and purchase rolls 
of film which fit into the reusable dispensers. Such durable dispensers 
are typified by that shown and described in U.S. Pat. No. 5,292,046 to 
Kaiser et al. Dispensers, whether for the commercial market or for the 
consumer market also incorporate a tearing or cutting blade in their 
structure. In use, and as a user withdraws a desired length of sheet 
material from the dispenser, the sheet is generally positioned to overlie 
the dispenser's cutting blade. The sheet is then torn from one edge of the 
sheet to the other through use of that cutting blade from the continuous 
length left on the roll. 
It is very well known in the prior art to incorporate a cutting or tearing 
blade structure with a roll dispenser carton. Perhaps the most widely used 
structure to date from a commercial standpoint makes use of a separate 
metal blade having a serrated edge along one edge of that blade from one 
end to the other. The serrated blade is permanently attached to a 
paperboard dispenser carton at, for example, a longitudinal corner of the 
carton. The blade is positioned parallel to the roll's axis so that the 
serrated edge extends slightly above the corner. This permits the carton's 
user to easily tear a length of sheet material along the serrated edge at 
the desired length after drawing it off the roll from within the carton. 
See, e.g., U.S. Pat. No. 4,651,911 to Kirkup et al. However, this metal 
serrated blade has a significant disadvantage from a commercial use 
standpoint particularly in connection with polymeric films. 
It is often the case that, after a desired length of polymeric film has 
been torn from a roll by the carton's cutting blade, the leading edge 
section of the film sheet that remains on the roll tends to retract into 
the carton. Accordingly, when it becomes necessary to withdraw additional 
film from the roll by tearing a subsequent desired length therefrom, it is 
necessary to open the carton, locate the leading edge of the film on the 
roll, and thereafter separate the leading edge from that roll. This 
procedure is particularly troublesome when the dispenser carton holds 
polymeric films comprised of a copolymer of vinylidine chloride and vinyl 
chloride. Upon retraction into the carton, the leading or free edge of 
this type film's rolled up sheet tend to cling to the supply roll 
remaining in the carton, thereby making the location of that leading edge, 
as well as the separation thereof from the supply roll, relatively 
difficult when a subsequent sheet length is desired. 
A typical prior art disclosure of a roll dispenser carton for polymeric 
film, where the carton incorporates a metal serrated cutting edge at one 
corner of the carton, is illustrated in U.S. Pat. No. 3,144,970 to 
Beschmann. 
In recent years, there have been attempts to develop roll dispensers for 
the marketplace that incorporate structures by which the film sheet return 
problem is solved. Some of these dispenser carton structures have been 
particularly directed to polymeric films. Each of these carton structures 
incorporates, of course, a tearing or cutting edge at one corner of the 
carton. One such type of carton structure, for example, incorporates a 
tacky substance coated onto one wall of the carton in proximity to the 
carton's cutting blade. The function of this tacky substance is to cause 
the leading edge of the film sheet remaining on the roll to adhere to the 
carton's wall adjacent the cutting blade after a desired length has been 
torn from the roll. This, of course, makes the free edge of the film sheet 
left on the roll easily accessible to the user when it is subsequently 
desired to withdraw another length of sheet material from the roll. 
Typical of prior art carton structures which incorporate a tacky coating 
are those illustrated in U.S. Pat. Nos. 3,549,066 to Wankow and 3,974,947 
to Budny. 
Another solution to this problem involves a dispenser which incorporates a 
hard plastic sheet deployed along the path from the roll of film to the 
blade. The negative charge of the hard plastic sheet will tend to cling to 
the positively charged poly vinyl chloride material. A system such as this 
is taught in U.S. Pat. No. 5,292,046 to Kaiser et al. 
Serrated metal blades, also sometimes referred to in the art as "hacksaw 
blades" pose a serious safety concern. For small cartons as used in the 
consumer market, the safety concern is somewhat attenuated, although it is 
possible to cut ones hand or finger on the dispenser blade. For commercial 
users who employ large and heavy rolls of film, the problem is much more 
serious as such dispensers are often placed on shelves above the work 
surface. When the film is pulled, if the dispenser is inadequately 
secured, the dispenser may move toward the user, fall off of the shelf, 
blade first, and cause injury. 
A new cutting structure capable of overcoming these difficulties and 
adaptable to both the disposable dispenser market and the durable 
dispenser market is taught in U.S. Pat. No. 4,340,162 to Heiman et al. and 
U.S. Pat. No. 4,346,829 to Myers. As taught by Heiman et al. and Myers, 
these dispensers utilize a cutting structure formed of a U-shaped piece of 
metal having holes pierced through the apex of the U. The sides of the 
holes form petals which project upward and either inward or outward from 
the penetration hole. The petals then present a sharp tearing surface for 
the film, yet are not long enough to cause serious harm to someone 
accidentally brushing against the blade or having the dispenser fall, 
blade first, upon him or her. The petals also solve the film sheet return 
problem for PVC films by presenting petals angled toward and away from the 
source of the sheet of film, those angled away acting to hold the sheet 
after cutting. 
While fit for their intended purposes, the cutting blades of the 4,340,162 
and 4,346,829 patents may be improved upon by increasing their stiffness 
as well as by providing an improved attachment structure which obviates 
the need for a U-shaped blade. 
SUMMARY OF THE INVENTION 
A cutting blade is formed from a rectangular sheet of a rigid material such 
as metal or plastic. In the case of plastic, injection processes may be 
used. One side of the sheet is formed into a roll or tube giving 
structural rigidity to the entire cutting blade. The remainder of the 
sheet extends flat and tangentially from the tube. In cross section, the 
cutting blade looks generally like the arabic numeral "9". At the top 
("rounded head portion") of the "9", a series of holes in one or more rows 
are punched through the cutting blade so that petals of metal project up 
and out of the "9" shape at its top. Preferably, for each hole, associated 
petals are pointed in different directions to provide both a cutting edge 
and a holding edge for film cut with the blade. According to another 
aspect of the invention, the cutting blade includes a series of tangs 
pointing up (toward the top of the "9") which allow the blade to be easily 
placed over a cardboard edge, but not easily removed therefrom. According 
to yet another aspect of the invention, the blade may be placed on a flat, 
unfolded insert (of cardboard or a similar stiff material) for a 
conventional cardboard roll dispenser carton, the insert then inserted 
between the opening flap and a front edge of the carton, and the head of 
the "9" shaped blade used as a latch to hold the dispenser cover closed. 
According to yet another aspect of the present invention, the petals of 
the holes may be surrounded with protective bumps to further avoid any 
possibility of scratching a user of the dispenser. 
OBJECTS AND ADVANTAGES OF THE INVENTION 
Accordingly, it is an object of the present invention to provide an 
improved blade for use with a film dispenser. 
It is a further object of the present invention to provide a blade for use 
with a film dispenser which may be attached to a surface at a single plane 
of contact. 
A further object of the present invention to provide a blade for use with a 
film dispenser which is stiffer than prior art U-shaped blades while 
retaining the safety and sheet retention features of the prior art 
U-shaped blades. 
A further object of the present invention is to provide a blade for use 
with a film dispenser which in cross section looks generally like the 
arabic numeral "9". 
A further object of the present invention is to provide a "9"-shaped blade 
for use with a film dispenser which includes a series of tangs pointing up 
(toward the top of the "9") which allow the blade to be easily placed over 
a cardboard edge, but not easily removed therefrom. 
A further object of the present invention is to provide a "9"-shaped blade 
for use with a film dispenser which may be placed on a flat, unfolded 
cardboard insert for a conventional cardboard roll dispenser carton, the 
insert then inserted between the opening flap and a front edge of the 
carton, and the head of the "9" shaped blade used as a latch to hold the 
dispenser cover closed. 
Yet a further object of the present invention is to provide a "9"-shaped or 
"U"-shaped blade for use with a film dispenser including holes with 
outward directed petals at the Apex of the "U" or at the top of the "9" in 
which the petals of the holes are surrounded with protective bumps. 
These and many other objects and advantages of the present invention will 
become apparent to those of ordinary skill in the art from a consideration 
of the drawings and ensuing description of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Those of ordinary skill in the art will realize that the following 
description of the present invention is illustrative only and is not 
intended to be in any way limiting. Other embodiments of the invention 
will readily suggest themselves to such skilled persons from an 
examination of the within disclosure. 
Turning now to the drawings, the cutting blade of the present invention may 
be used with either a reusable film dispenser 10 as depicted in FIG. 4 
(more complete construction details are set forth in U.S. Pat. No. 
5,292,046 and D-347,345 to Kaiser et al., both of which are hereby 
incorporated herein by reference as if set forth fully herein) or with a 
conventional disposable cardboard box 12 as depicted in FIG. 5 (more 
complete construction details are set forth in U.S. Pat. Nos. 2,888,180 to 
Kinker, Jr., 3,137,424 to Finn et al., 3,281,036 to Woodling, 4,340,162 to 
Heiman et al., 4,346,829 to Myers, all of which are hereby incorporated 
herein by reference as if set forth fully herein). 
A cutting blade 16 in accordance with a first presently preferred 
embodiment comprises a rectangular sheet of metal bent into the shape of a 
"9" as shown in FIG. 1. In accordance with a preferred embodiment of the 
present invention, a plurality of holes or "buds" are disposed through the 
head 18 of the "9"-shaped cutting blade 16. The buds may be formed in any 
of a number of conventional ways, but are presently preferred to be 
punched with a square cross-sectioned implement so as to generate four 
distinct petals 20 to each bud. The number of petals may be selected by 
selecting the punch tool. Round, triangle and other shaped holes may be 
achieved in this manner with more or less well defined petals. It is the 
petals which provide the cutting action for the sheet material. A single 
row of buds has been found optimal for cutting aluminum foil. A double row 
of buds, 50% offset with one another has been found optimal for cutting 
PVC-type films. The angle between the petals and the bud axis 
(perpendicular to the surface of the blade and coaxial with the bud hole) 
is determined by the shape and degree of penetration of the die used to 
stamp the buds and, hence, form the petals. This is well known to those of 
ordinary skill in the art of die stamping metal. 
In the embodiment shown in FIG. 4, the cutting blade of the present 
invention is simply attached to a rectangular carrier which may be formed 
of cardboard, plastic, metal, or another stiff, relatively long-lived 
material. The carrier with the blade attached is then substituted for the 
blade of the reusable dispenser (see, e.g., U.S. Pat. Nos. 5,292,046 and 
D-347,345 to Kaiser et al. for the precise design of the insert). 
Turning now to the embodiment depicted in FIG., 5, one method of attaching 
the "9"-shaped cutting blade to a cardboard dispenser carton or to a 
cardboard insert is by means of conventional "starburst" fasteners 22 as 
shown in FIGS. 2 and 3. These fasteners are die cut out of the body of the 
tail end 24 of the blade in a "star" or similar pattern and operate by 
pressing the tail end 24 of the blade into and against cardboard material 
26 so that the two or more "rays" 25 of the stars 22 penetrate and expand 
into the cardboard (or similar) material 26, forming an essentially 
permanent bond. Glue, other adhesives, staple-like devices and the like 
may also be used as are well known to those of ordinary skill in the art 
and can be seen in any grocery store stocking rolls of film in cartons. 
A presently preferred and alternative embodiment of the "9"-shaped blade of 
FIG. 1 is shown at FIGS. 7-8. Blade 28 includes a rounded head portion 30 
in the shape of a partial tube as shown and a flat tail portion 32. A 
series of tangs or barbs 34 are punched in the tail portion 32 as shown. 
Additional barbs 36 are formed along the curved longitudinal end of the 
rectangular sheet which is bent to form the "9"-shaped blade. When the 
sheet is thus bent as shown in FIG. 8, it may be slipped over a piece of 
cardboard, corrugated cardboard, or the like where the tangs or barbs 34, 
36 will easily slip over the surface of the cardboard while the blade is 
being installed, but will resist removal. An advantage presented by this 
mode of operation is that the blade 28 may be packaged inside a carton of 
film. When the consumer buys the carton, he or she may then take the blade 
28 and slip it over a portion of the carton. The advantage here is that 
the installation step need not be performed by the manufacturer, and, 
since it is desired that, in use, the blade 28 protrude above an outside 
surface of the carton, a higher packing density in shipping boxes and 
crates can be achieved by not having blade 28 protrude above the outside 
surface of the carton until actually purchased and in use by the consumer. 
An alternative method of implementing this advantage is shown in FIG. 9. In 
FIG. 9, blade 38 is attached (in any manner) to a cardboard insert 40 
which may be inserted between lid 42 and end wall 44 of a carton such as 
that shown in FIG. 5. The insert and the blade 38 may preferably be 
permanently bonded together at the factory in any convenient manner. The 
insert is inserted into the package in, for example, an inverted position. 
When the consumer opens the package, he or she inverts the insert 40 so 
that the blade protrudes from the top of the carton as shown in FIG. 9. In 
this manner, maximum packing densities are achieved as the shape of the 
shipped product is a rectangular solid, yet the advantage of a protruding 
blade is not lost. An additional advantage of this FIG. 9 design is that 
by making the rounded head portion 30 large enough so that in use it 
overlaps lid 42, it will then provide a latching function keeping the lid 
42 closed as shown in FIG. 9 without any additional latching mechanism 
being needed. 
Turning now to FIG. 10, an alternative arrangement of the cutting buds of 
the blade of the present invention is shown. As taught in U.S. Pat. No. 
4,340,162 to Heiman et al. and U.S. Pat. No. 4,346,829 to Myers, a 
plurality of buds disposed through a blade so that petals extend from the 
holes provides a novel, high performance cutting surface with little 
propensity to injure. While not presently preferred, if additional 
protection against accidental scratching by the blade 46 is desired, buds 
48 may be surrounded on either side as shown by a line of bumps 50 which 
permit the foil to be cut by the petals 52 of buds 48 while making it more 
difficult to accidentally catch the skin of the hand on the petals. 
While illustrative embodiments and applications of this invention have been 
shown and described, it would be apparent to those skilled in the art that 
many more modifications than have been mentioned above are possible 
without departing from the inventive concepts set forth herein. The 
invention, therefore, is not to be limited except in the spirit of the 
appended claims.