Film cutting apparatus and method

A film cutting apparatus includes a guide having a clip for attachment to a film material container and a cutting device designed to travel along said guide to sever the film material in predetermined lengths. The cutting device includes two pairs of guide wheels designed to travel in a channel in the guide beneath the cutting plane defined by a top surface thereof. The cutting device also includes a housing having disposed therein a star cutter, a star cutter driver assembly and a plate assembly attached to the housing providing rotatable support for the star cutter driver assembly and guide wheels. In use, the housing is gripped by a user and driven along the length of the guide. During housing travel, the star cutter driver assembly rotatably engages the guide top surface to rotate the star cutter and sever the film material lying in the path of the star cutter. The guide has a non-slip top surface so that the film material adheres thereto during cutting. The star cutter drive assembly includes a resilient material engaging surface to compensate for variations in film material thickness during cutting.

FIELD OF THE INVENTION 
The present invention is directed to a film cutting method and apparatus 
and, in particular, to a star wheel cutting device in combination with a 
cutting guide to sever film material, such as foodservice wrap. 
BACKGROUND OF THE INVENTION 
In the prior art, various types of film material cutting apparatus have 
been proposed utilizing a traveling cutter. U.S. Pat. No. 4,960,022 to 
Chuang discloses a plastic film cutter comprising a supporting board, a 
sliding furrow formed in the top of the supporting board and a slidable 
cutting means having a lower sliding seat insertable into the sliding 
furrow. In Chuang, rollers are provided for engaging and maintaining the 
plastic film in a tensioned state above the upper surface of the plastic 
film. 
Other patents disclosing film cutters include U.S. Pat. Nos. 5,036,740 to 
Tsai, 5,044,241 to Labrecque and 4,787,284 to Chen. 
However, prior art devices using a cutting blade are ineffective to handle 
or accommodate variations in film material thickness, such as bunched or 
doubled over film. Likewise, apparatus such as disclosed in Labrecque 
involve complex mechanical interaction to achieve effective cutting. 
In response to these deficiencies, a need has developed to provide an 
effective yet simple film cutting apparatus which overcomes deficiencies 
in prior art designs. 
In response to this need, the present invention provides a simple yet 
effective film cutting apparatus design which severs film material easily 
and efficiently. 
SUMMARY OF THE INVENTION 
Accordingly, it is a first object of the present invention to provide an 
improved film cutting apparatus and method. 
It is a further object of the present invention to provide a film cutting 
apparatus and method which includes a star cutter wheel driven by a roller 
assembly which effectively severs film material. 
Another object of the present invention is to provide a film cutting 
apparatus and method wherein the film material is held in place 
independently of the cutting device to permit ease of cutting operation. 
Other objects and advantages of the present invention will become apparent 
as the description thereof proceeds. 
In satisfaction of the foregoing objects and advantages, the present 
invention provides a cutting device comprising a housing and a toothed 
cutting wheel of a first diameter, the toothed cutting wheel disposed in 
at least a portion of the housing. A rotating means for rotating the 
toothed cutting wheel is disposed in at least a portion of the housing and 
includes a resilient film material engaging surface thereon which defines 
a cutting plane coincident with the film material being cut. A plurality 
of guide wheels for guiding the cutting device during travel thereof are 
positioned beneath the cutting plane by a supporting means attached to the 
housing. The supporting means also supports the rotating means which is 
disposed above the cutting plane for rotatable movement thereof as well as 
for driving and rotating the toothed cutting wheel. 
In conjunction with the cutting device, a cutting guide comprises an 
elongated member having a channel therethrough which is sized to receive 
the guide wheels of the cutting device. The elongated member has a top 
surface parallel to the cutting plane, the top surface having a high 
friction surface thereon to adhere the film material thereto during 
cutting thereof. The elongated member also has a slot in the top surface 
in communication with the channel, the slot being sized to receive the 
cutting wheel during rotation thereof, as well as the means for supporting 
the guide wheels. 
In a preferred embodiment, the rotating means for rotating the cutting 
wheel comprises a roller assembly made up of two rollers which 
interconnect to fixedly mount the toothed cutting wheel thereto. Each of 
the rollers has recesses along a circumferential edge thereof to receive 
an O-ring which provide resilient engagement with the film material during 
cutting. A pair of plates, attached to the housing, are also disposed 
between the rollers, the cutting wheel disposed therebetween. The plates 
provide rotatable support for the rollers during travel of the cutting 
device, as well as spaced apart support of the guide wheels during travel 
in the channel of the cutting guide. 
In the method aspect of the invention, the cutting device and cutting guide 
are mounted adjacent to a source of film material for cutting a 
predetermined length. The film material is adhered to the high friction 
surface of the cutting guide. Following the adhering step, the cutting 
device travels along the guide with the O-rings engaging the upper surface 
of the film material, rotation thereof driving the toothed cutting wheel 
to perforate and sever the film material. The guide wheels travel in the 
channel of the cutting guide and provide guidance and stability to the 
cutting device during longitudinal movement thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference to FIG. 1, the inventive film cutting apparatus is generally 
designated by the reference numeral 10 and includes a cutting device 1 
which is designed to travel along a guide 3. The guide 3 has a clip 5 
which forms a recess 7 to receive a sidewall 9 of an elongated film 
material container 11. 
The guide 3 also includes a channel 13 and slot 15. The channel 13 receives 
guide wheels (not shown) of the cutting device 1 with the slot 15 
providing an opening which permits cutting of the film material 17 and 
support of the guide wheels. 
The guide 3 also has a non-slip top surface 19 which retains and tensions 
the film material 17 during cutting thereof. The nonslip surface 19 is 
preferably a urethane tape which is adhered to the guide 3. Of course, 
other coatings or tapes may be used to create a non-slip surface on the 
guide 3, as long as the material provides a sufficiently high friction 
surface such that the film material 17 clings thereto. 
In use, the guide 3 is placed on the sidewall 9. A predetermined length of 
the film material 17, as measured from the free end 21 thereof to the slot 
15, is unraveled from the film material roll 23. The film material 17, 
once contacting the nonslip surface 19, adheres thereto for subsequent 
cutting. The cutting device 1 is then passed through the channel 13 and 
slot 15 to sever the film material 17 while it is tensioned by the 
non-slip surface 19. The function of the cutting device 1 in relation to 
the channel 13 and slot 15 will be described hereinafter. 
The film material 17 may be any known material having a thickness which is 
easily severed by a rotating cutting blade. For example, the film material 
17 may include typical foodservice wraps, such as aluminum foil or plastic 
wrap. 
With reference now to FIG. 2, a side view of the cutting device is 
illustrated depicting a housing 25 enclosing at least a portion of a star 
cutter 27 and a star cutter driver assembly 29. The housing is preferably 
sized for hand holding to facilitate manual cutting action. 
The cutting device further includes two pairs of guide wheels 31, one guide 
wheel of each pair depicted in FIG. 2. The pairs of guide wheels are 
rotatably mounted on axles 32 and supported by the guide wheel support 
plates 33, only one support plate shown in FIG. 2. 
Each of the guide wheel support plates 33 comprises an elongated connector 
34 which positions the guide wheels 31 in a spaced apart relationship from 
each other and with respect to the under surface 35 and which preferably 
extends laterally beyond the guide wheels 31 to protect the guide wheels 
from contacting end stops of channel 13 during movement of the cutting 
device 1 through channel 13. A circular portion 36 of each plate 33 
provides connection between the connector 34 and the housing 25, as well 
as rotatable support for the star cutter driver assembly 29, as described 
hereinafter. 
During cutting of the film material 17, the star cutter driver assembly 29 
rotates and travels along the non-slip surface 19 with the guide wheels 31 
contacting the opposing surface 35 in the channel 13; see FIG. 1. As will 
described hereinafter, travel and rotation of the star cutter driver 
assembly 29 rotates the star cutter 27 during linear movement of the 
cutting device 1 to sever the film material 17 along the slot 15. 
With reference to FIGS. 3 and 4, the star cutter driver assembly 29 is 
designed to provide a fixed mount for the star cutter 27 while still 
rotating with respect to the linearly traveling guide wheel support plates 
33. 
With particular reference to FIG. 4, the star cutter driver assembly 
includes a first roller 35 having a male portion 37 extending therefrom. A 
second roller 39 includes a female opening 41 sized to engage the male 
portion 37 of the first roller 35. In cross section, the male portion 37 
is square in shape; see FIG. 2, to fixedly mount the star cutter 27 
thereon. As can be seen from FIG. 4, the star cutter 27 is fixedly mounted 
on the male portion 37. 
The square cross-sectional male portion 37 is preferably designed to 
pressure fit or snap into the female opening 41 in the second roller 39. 
That is, friction between the outer surface of the male portion 37 and 
female opening 41 maintain connection between the two rollers. Of course, 
other known attachment means, including fasteners or the like, may be 
employed to provide removable attachment between the first and second 
rollers. The removable attachment facilitates star cutter and roller 
replacement or repair. 
Each of the first and second rollers, 35 and 39 respectively, has a recess 
43 in a peripheral edge thereof. The recesses 43 are sized to receive an 
O-ring 45. The O-rings provide a resilient film material engaging surface 
during travel of the cutting device 1 along the guide 3. The O-rings, by 
their resilience, compensate for any tolerance variations that may be 
present in the film material 17 to be cut. Although O-rings are shown as 
the resilient film material engaging surface, other known resilient 
materials, such as a tape, may be used on the peripheral edges of the 
first and second rollers 35 and 39 to provide the requisite resilience and 
compensation described above. Alternatively, the rollers 35 and 39 can be 
made such that at least the peripheral portion thereof are resilient for 
contact with the film material 17. 
The guide wheel support plates 33 also rotatably support the star cutter 
driver assembly 29. With particular reference to FIG. 3, each of the 
plates 33 is mounted to the housing 25 and extends downwardly therefrom. 
Each of the plates 33 has a circular opening 48; see FIG. 2, which 
corresponds to the cylinder defined by the step 47 of the first roller 35 
and step 49 of the second roller 39; see FIG. 4. The steps 47 and 49, when 
the first and second rollers 35 and 39 are connected, form a cylindrical 
surface which permits the star cutter drive assembly to freely rotate 
within the circular openings 48 defined by the plates 33 during linear 
travel of the cutting device 1. It should be understood that FIG. 4, 
showing a cross-sectional view of the first and second rollers 35 and 39 
in conjunction with the star cutter 27, omits the guide wheel supporting 
plates 33 for clarity. 
Preferably, the rollers 35 and 39 are sized in diameter less than the star 
cutter 27 so that the star cutter 27 has a peripheral edge velocity 
greater than the rollers' peripheral edge velocity and linear travel of 
the housing to improve cutting action. 
In a preferred embodiment illustrated in FIG. 3, the guide wheels 31 are 
formed with outer surfaces 60 and spring-like resilient adjustment 
portions 62 to enable the surfaces 60 to firmly engage surface 35 while 
allowing for variations in the thickness of the material forming surfaces 
19 and 35. This is not mandatory, however, as will be shown below. 
With reference again to FIG. 3 and FIG. 5, the star cutter 27 is fixedly 
mounted between first and second rollers, 35 and 39, respectively, by 
virtue of the square opening 51 engaging the square male portion 37 of the 
first roller 35. The star wheel 27 has a plurality of teeth which function 
to sever the film material 17 by the perforating action of the individual 
teeth 53. In FIG. 5, a sixty four tooth star cutter 27 is depicted. 
However, star cutters having different numbers of teeth can also be 
utilized in the inventive cutting device, for example, an eighty tooth 
wheel; see FIG. 2, or a fifty tooth wheel. 
FIG. 6 depicts an alternative embodiment to the invention wherein the guide 
wheel supporting plates 33' are sandwiched by the housing 25'. This 
embodiment also illustrates the guide 3' without the clip 5 for attachment 
to the sidewall of a film material container. In this embodiment, the 
guide 3' can be attached to a surface 61 by a fastener 63 or the like for 
film material cutting. In addition, the guide wheels 31' are solid wheels 
and do not employ the spring-like resilient adjustment portions 62 shown 
in FIG. 3. 
The present invention may be constructed out of any known materials 
including non-metallic and metallic materials. For example, the cutting 
device 1 and guide 3 may be made of a durable plastic to withstand 
repeated traversals of the guide 3 by the cutting device 1. The star 
cutter 27 is preferably made of a metallic material to provide a durable 
cutting edge during use. 
The inventive film cutting apparatus provides improvements over prior art 
cutting apparatus when used with thin film material. Use of a star cutter 
or toothed wheel cuts film material such as foodservice plastics even when 
folded or bunched together. 
Cutting is further enhanced as a result of the star cutter driver assembly 
which causes the peripheral edge of the star cutter to rotate at a speed 
greater than the linear speed of the cutting device when traversing the 
guide. 
Use of a non-slip friction surface eliminates the need for complex 
mechanical arrangements above the cutting plane defined by the non-slip 
friction surface, thereby simplifying manufacturing and reducing 
manufacturing costs. 
Driving the star cutter using a resilient material engaging surface also 
compensates for variances in the film material thickness to be cut. Thus, 
the stability of the cutting device during cutting is maintained in spite 
of any tolerance variations such as doubled up or bunched film material. 
As such, an invention has been disclosed in terms of preferred embodiments 
thereof which fulfill each and every one of the objects of the present 
invention as set forth hereinabove and provide a new and improved film 
cutting apparatus. 
Various changes, modifications and alterations from the teachings of the 
present invention may be contemplated by those skilled in the art without 
departing from the intended spirit and scope thereof. Accordingly, it is 
intended that the present invention only be limited by the terms of the 
appended claims.