Background of the Invention It is becoming increasingly popular for individuals, both personally and commercially, to barbecue chicken, ribs, and other edible foods over a source of heat, typically charcoal, wood, or gas powered briquettes. In order to retain the barbecue flavoring in association with the foods, and to ease the cleanup of the grill, covers or intermediate members can be and are utilized between the food and the briquettes. These covers also serve to temper the nature of the heat transfer between the briquettes and the foods.

Examples of covers include that disclosed in U. S. Patent 4,763,639 entitled Disposable Cover For An Outdoor Barbecue Grill, U. S. Patent 4,969,449 entitled Disposable Barbecue Grill Cover, U. S. Patent 5,399,439 entitled Barbecue Aluminum Foil, U. S. Patent 4,394,410 entitled Disposable Foil Broiling Sheet, and U. S.

Patent 4,979,440 entitled Barbecue Grill Insert.

The covers disclosed in these patents, and otherwise in general use, are serviceable. However, these covers are prone to physical damage during the use thereof due to weaknesses created during the manufacturing process and/or are of a complicated construction necessitating relatively high cost per use.

Summary of the Invention It is an object of this invention to reduce the cost of manufacture of perforated foils; It is an object of this invention to increase the relative strength of perforated foils; It is an object of this invention to increase the service longevity of perforated foils; It is another object of this invention to reduce the cost of perforated foils; It is still another object of this invention to reduce the complexity of machines manufacturing perforated foils; Other objects and a more complete understanding of the invention may be had by referring to the drawings in which: Description of Drawings Figure 1 is a representational view of the main components of the perforation machine; Figure 2 is a top view and figure 3 is a cross-sectional view of part of the drum of figure 1 detailing the generic design of the plug cavity and retention cavity; Figure 4 and 5 are views like figures 2 and 3 showing a female plug in place in a first sized cavity with retention screw; Figures 6 and 7 are views like figures 2 and 3 detailing a male plug in place in a second sized cavity with a retention screw; Figure 8 is a series of views of the interaction of the end of the male plug of figure 7 with the opening of the female plug of figure 5; Figure 9 is a representational view of the design parameters of the plugs of the device; Figures 10-12 are views of various plugs according to the parameters of figure 9;

Figure 13 is a cutaway side view of the foil path through a production machine expanding on the concepts of figure 1; Figure 14 is a top view of the surface of the foil produced by the machine of figure 13; Figure 15 is a side view through the edges of a hole of the foil in figure 14; Figures 16-21 are representational views of various air pressure differential modifications to the rollers 100 of figure 1; and, Figure 22 is a cutaway side view like figure 13 of a modified production machine.

Detailed Description of the Invention There are many applications where perforated foil or other materials are desired for use. The present invention is a machine and a systematically holed material produced thereby for subsequent use.

Although the invention can be utilized with differing flat materials from various sources, the invention will be described in an example perforated foil for barbecue embodiment.

In this preferred embodiment, the perforating machine is directed to producing a series of substantial equal size perforations constantly spaced across and along a length of foil (example fig 14).

The preferred perforating machine is implemented using an input section 10, an output section 50, with intermediate perforation rollers 100 (fig 1).

The input section is designed to provide the foil through the perforation rollers 100 at a speed substantially matching that of the production speed through the perforation rollers (typically the speed

of the outer circumference thereof). Preferably, this foil is provided such that there is a very limited input tension between the perforation rollers 100 and the incoming foil. Further, it is preferred that the input section 10 provide a spreading centering action for the foil-thus also removing this function from the rollers 100.

The actual functioning of the input section 10 differs depending upon the mode of operation of the machine. For example, on start up of the machine, the incoming foil to the perforation rollers 100 is relatively stationary. It is, therefore, preferable for the input section 10 to ramp up matching the speed of the output section 50 (and rollers 100). Further it is preferable that the feed of the material through the device not be compromised by any speed differential (a material that is damaged will not feed very well). This is provided in the preferred embodiment by variably ramping up the speed of the input section 10 (and rollers 100) to match the speed to the output section 50. It could also be provided by keeping the rollers 100 out of contact with the material until the respective speed substantially matches.

Once the machine is operating in a continuous manner, it is desired that the input section 10 provide the material through the perforation rollers 100 at a speed substantially matching that of their outer circumference, at a relatively constant low tension. To control this, once the operating feed speed is reached, the input section is provided with a relatively constant low torque resistance (be it a brake or motor-the reason the word"resistance"is utilized in respect to the foil from the input section 10 is that it is preferred that there be a small amount of tension on the foil

fed through the perforation section. This tension, although slight, requires that there be a positive pulling force on the foil downstream from the input section-a positive force operating on a "resistance". This resistance can be provided by a mechanical brake (fig 13), a tensioning device (fig 22), an active motor having a lower effective foil drive speed or otherwise). The resistance must be low enough to allow the foil to keep up with the speed of the perforation rollers 100 without any physical damage to the foil. Note that the input material is typically taken off of a continuous length roll of material whose outer diameter is steadily reduced during the operation of the machine. The continued resistance torque on the input roll of input section 10 would therefor preferably be adjusted during the operation so as to continually substantially match the speed of input into the perforation rollers 100 during the change in diameter of the input material roll.

In the preferred embodiment disclosed (fig 13), the input section 10 includes a roll of material 11 slowed by a brake 12, an input idler roller 15 and a roller input feed roll 18.

The roll of material 11 is a continuous length of foil spirally wound upon itself to form a cylindrical roll. When this roll is at its initial (and largest) diameter, it is necessary that the brake 12 provide for a very low initial resistance in order to allow to feed the materials off of the outer circumference of the roll at a relatively constant speed as quickly as possible. (Note that as the diameter of the roll is reduced, a braking type resistance on the axis of rotation might have to be adjusted so as to maintain a steady tension on the foil from the input section.) In the embodiment disclosed, this is provided by a spring preloaded disk

brake. A magnetic eddy brake, or other brake could also be utilized. Preferably, an optional sensor 13 located somewhere in the input section 10 adjoining the material fed from the roll 11 determines an attribute representing the tension present on the foil within the input section in order to provide a control parameter for the input section so as to maintain the desired low tension (as later described). The attribute can be the actual tension, the relative speed, the displacement upon application of force, or otherwise.

The input idler roll 15 serves to provide for a slightly resilient connection between the roll 11 and the input feed roll 18 while also providing for a spreading centering operation on the foil traversing same.

In the preferred embodiment disclosed, the input idler roll provides the resiliency function by being of resilient material located between the roll 11 and the input feed roll 18 while providing the spreading by having grooved separation bands of rubber on the outer surface thereof. The grooves angle outwards from a leading point in the direction of roll rotation to provide a sidewards of center lateral tension-type spreading action. Some self-centering is also provided by this roll 15 due to the tension equalization between sides which tend to bias the foil outwards in both directions from the center of the roll 15.

If desired, the resiliency could be provided by having the rotational axis of the input idler roll 15 moveable in respect to the roll of material with a biasing system (such as a pneumatic cylinder, weight or spring) creating a known, constant tension on the foil (see also fig 22). The latter spreading action could also be provided in alternate ways.

The idler roll 15 also provides for a constant input angle in respect to the input feed roller 18 no matter what the diameter of material on the roll 11.

The roller input feed roll 18 provides for a constant angle of feed between the input section 10 and the rolling perforation rollers 100. The input feed roll 18 in addition provides for an additional degree of wrap of the foil in respect to the intersection between the rolling perforation rolls thus to increase the contact between the material and the circumference of the rollers 100. This increase in contact aids the movement of the foil through the perforation rollers 100 and the perforation action.

It also provides a full contact between the foil and female die roller before any contact by the male plug.

Any additional wrap beyond the point of initial contact male/female aids in settling the foil in respect to the rollers 100 (in addition to cooperating with the later described vacuuming action on the punched material-contrast figs 1,13 and 21).

In that it is the purpose of the input section 10 to provide for the foil into the perforation rollers at a speed matching that of the circumference of the rollers with a slight back tension, there is an optional sensor 22 located at the output of the input section 10 between such section and the rollers 100. This sensor 22 insures that there is a slight tension to the material (and also that there is no physical damage to the foil due to any speed and/or torque differential on the foil between the input section 10 and such rollers 100).

In the embodiment disclosed, the sensor 22 is again a sensor determining an attribute representing the tension on the foil. If desired, again alternate sensors can be utilized such as an

optical tension sensor (using the tension between roller 18 and the perforation rollers 100), a pneumatic displacement sensor (blowing air on the foil and reacting to the displacement of the foil produced thereby), a displacement of angle determining sensor in combination with a moveable part in contact with the foil (fig 22) or otherwise as desired.

In the particular embodiment disclosed the film is from. 001 to. 002 thick (. 0015 +/-10% preferred) of 1000 series aluminum alloy, 0 temper.

The speed of this foil from the input section 10 is from 100 to 300 feet per minute.

The output section 50 is designed to take the material formed by the perforation rollers 100 at the same speed as that from the input section 10, preferably with a slight positive tension.

The preferred functions of the output section 50 and input section 10 are interrelated in that it is preferred that the material passing therebetween be under tension (in consideration of any effect of the perforation rollers 100). The input section 10 has thus been set forth as having a relative resistance to foil movement while the output section 15 has been set forth as having a relative positive pull to foil movement. The result is that the foil passing therebetween has a resistance to physical displacement from its plane of movement: it is under tension. This tension should be less than that the elasticity of the material it is acting on (by elasticity it is meant the amount a material can be stretched to return to its original dimensions without physical damage). An amount less than this, 0-5% of elasticity is sufficient (1-25 pounds of tension is sufficient).

As with the input section, the actual functioning of the output section 50 differs depending

upon the mode of operation of the machine (especially since the speed of the foil-and start up torque-is in the preferred embodiment dependent primarily on this section 50 during the necessary range of operations).

On start up of the machine, the incoming foil is stopped. It is, therefore, required for the output section to take the foil and ramp up its speed through the location of the perforation rollers 100.

As start up torque is provided by the output section 50 in the preferred embodiment this torque should ramp up the speed of the incoming foil (within the elasticity limits of the material). Note that as there is typically an empty take up spool at the output of the section 50, this torque can be provided at a lower power at this location (at the input section a heavy full roll is present). In that the output material is typically wound as a continuous length of perforated material whose outer diameter is steadily increasing, the speed of the take up spool must be adjusted to continually downward to maintain the speed of foil through the output section 50. Once the machine is operating in a continuous manner, it is desired that the output section 50 take the foil through the perforation rollers at a speed substantially matching that of the outer circumference of the perforation rollers at a relatively constant low tension.

In the preferred embodiment disclosed (fig 13), the output section includes an intake roller 52, settling rollers 53,54, idler rollers 57,58 and an output roll 63 driven by a motor 64.

The intake roller 52 provides for a constant output angle in respect to the perforation rollers 100. As with the input feed roll 18 this roller 52 in addition provides for an additional degree of wrap of

the foil in respect to the intersection between the perforation rolls, thus to increase the contact between the material and the circumference of the rollers 100. This increase in contact provides the same advantages as previously set forth (again compare figs 1,13 and 21).

In the preferred embodiment disclosed, there is an optional sensor 51 located at the beginning of the output section 50 (this sensor 51 is located after roller 52 primarily due to the physical location of the intake roll 52-ideally the sensor 51 would be located as sensor 22 directly neighboring the perforation rollers 100). The sensor 51 serves to substantially match the foil tension from the rolling perforation rollers 100 to that from the input section 10. As with the input sensor 13 (and 22), this sensor 51 is preferably an attribute sensor, although other sensors could be utilized if desired as previously set forth.

The output of the intake roller 52 is fed to the settling rollers 53,54. These settling rollers provide for a slightly resilient connection between the intake roll 52 and the output drive 60, serve to spread the material and in addition provides for a slight settling action for the foil by physical contact with the opposing surfaces thereof.

In the embodiment disclosed the output idlers provide the resiliency function by being of resilient material. The spreading function is provided by having grooved separation bands of rubber on the outer surface of at least one of the rolls (again the grooves angle outwards from a leading point in the direction of rotation to provide for a sidewards of center lateral tension-type spreading- and self-centering-action). The settling action is provided by the contact of two rolls with both sides

of the material at slightly spaced locations. This smooths the surface of the material. (Note that if both rolls 53, 54 are grooved the angling of the grooves therein are reversed since the relative rotation of the two rolls 53,54 are opposed.) The output drive 60 takes the foil material coming through the output section 50 and provides it to the output roll 63. This output drive 60 preferably insures the constant speed/constant tension is maintained for the output section 50 relative to the perforation rollers 100 and the input section 10.

Note that the output drive 60 in addition provides for a constant angle to both the output idlers 53,54 and the output roll 63. This allows for a constant state function of the output section 50.

The output drive 60 itself is a steel roll 57 and an adjoining resilient roller 58, one of which is driven by a motor 59. In the preferred embodiment, this drive 60 works with and compliments the roll 63 so as to provide for a controllable drive torque for the device. The drive 60 provides for this by being under constant conditions no matter when the foil traverses same. It is thus more amenable to control at a steady rate by set parameters than that of the roll 63 (which due to its ever increasing diameter needs to have its speed continually adjusted or else be driven by a motor having a certain power on the foil).

The output from the output section 50 is a roll 63, which roll 63 is driven by a motor 64 in order to provide for a constant tension output from the output section 50. As the roll 63 will vary in diameter from a small beginning diameter to a large ending diameter, the motor 64 is preferably a controllable amperage drive direct current type motor

64. A spring loaded packing roller 65 insures that the foil is smoothly wound on the roll 63.

In the preferred device (of fig 13) the control provided in the output section 50 (by motors 59 and 64) is that primarily for the machine. This is due to the fact that the material passing from the input section 10 to the output section is under tension-i. e. the output section provides for a pulling action on the foil. This tension can be provided by a number of ways, including active torque differential between the input section 10 and the output section 50, a single ended pulling action (as set forth as preferred) or otherwise as desired.

The foil perforation rollers 100 are the major operating component for the machine. The rollers 100 accomplish the perforating function by pressing a male plug 111 into a female opening 121, with the resultant extract falling into the center of at least the perforation roller having female dies for subsequent disposal.

The outer circumference of the rollers 100 have a speed that preferably matches that of the foil between the input section 10 and the output section 50. This allows the rollers 100 to operate on a foil having a tightly controlled amount of tension (up to the elasticity of the material) as previously set forth. It further separates the perforating function (the rollers 100) from the foil movement function (the input and output sections). This allows the rollers 100 to be optimized for their primary duty of providing holes in the foil.

The particular rollers 100 consist of two rolls 101,102 each having a series of male 110 and/or female 120 dies so as to form the holes 132 in the film 130.

In the preferred embodiment disclosed, the rollers lOCi consist of two substantially identical rolls 101,102 drivingly interconnected by a gear train 103 having an adjustable phase relationship 104.

The rolls are driven by a motor 80.

The use of substantially identical rolls 101,102 reduces the cost of construction of the device.

The use of a separate gear train 103 drivingly interconnecting same removes the synchronization of the rolls from the rolls themselves, thus allowing for a more precise interconnection (i. e., lash is much less with a precision gear train 103 shown in representational form in fig 1 than if the rollers were driven otherwise). The use of the adjusted phase relationship allows the relationship between the two rolls 101,102 to be precision adjusted to insure that the male plug 111 precisely lines up and continues to line up with the respective female opening 121, thus to reduce any alignment problem as well as to control the exact nature of the holes 132 produced by the rollers 100. The phase relationship in the preferred embodiment is adjusted by providing an angular adjustment between a gear and either of the two rolls 101,102 (for example by a circumferentially extending adjustable phase screw between a gear and a given roll).

The motor 80 drives the rollers 100. This motor 80 is driven to provide a speed to the circumference of the rollers 100 substantially equal to that of the speed of the film passing between the input section 10 and the output section 50. Due to this the perforation rolls 101,102 do not impede the passage of foil therethrough. The motor 80 in addition provides the power necessary for the punching

function between the two rolls 101,102, and does so such that this punching function does not substantially effect the flow of film from the input 10 and the output 50 sections. This later is aided by the contact between the film 130 and the female dies prior to any involvement of the male die (later set forth). Due to this, the male die does not have to deflect the film surface before beginning its shearing function.

Each of the two identical rolls 101,102 includes a series of holes 105 which holes can be selectively filled with the later described male die 110 and/or female die 120 so as to create the pattern of holes 132 in the film 130. Note that it is not necessary that every hole 105 contain a die. This would allow for a single set of rolls 101,102 to be used to create a multiplicity of patterns of holes in the film by selectively filling various die holes 105.

One could also allow one to alternate the male dies 110 and the female dies 120 between the various drums, thus to equalize the pressure caused by the die functions (as well as the distribution of the extracts 133) between the two drums. One could even alter die shapes/sizes in and between varying applications (for example the left side of the foil with larger holes than the right side with the consumer able to use either side on the bottom so as to alter the performance of a given cover).

In the embodiment disclosed, the multiplicity of die holes 105 include a corresponding set of retainer holes 107 located immediately adjacent thereto slightly overlapping same. This allows for a bolt 109 inserted into the retainer opening 107 and threaded into a tapped hole centered thereon to retain the various dies 110,120 in a position on the two rolls 101,102, respectively.

The die holes 105 and retainer holes 107 can be of any size including universal for both male and female dies 110,120. Universality would allow for exchange between the two for any particular location.

However, this same universality would also require tighter quality control on set up to insure that male dies were located in the same relative position on two different rolls 101,102. Further each die hole would not be optimized for its function. In the preferred embodiment disclosed, differing diameter die holes are 'utilized for male and female dies 110,120.

The male die 110 and female die 120 each have a lower section and an upper section. The respective lower sections are designed to fit the size of a die opening in diameter with a height slightly less than or substantially equal to the depth of the die opening inwards beyond that of the overlapping retainer opening. This allows a bolt 109 inserted into a tapped hole 108 in the retainer opening 107 to locate the bodies 112,122, respectively of the male die and female die into position in the die openings.

(Note that in the embodiment disclosed the plug 111 of the male die 110 is symmetric and circular. It is, therefore, not necessary that it be located in any angular position in respect to its equally symmetric and circular opening 121 of the female die 120. This is the reason the"slightly less"qualification previously set forth-i. e. it is acceptable for symmetric dies to rotate in their holes-and indeed any rotation will increase the service life of the respective dies by allowing for a wear pattern across the entire circumference of the die.

If asymmetric die shapes were to be utilized (or if it was desired to retain a die in a set angular position), precise positioning can be provided by extending the lower sections of the dies upward of the

retention holes (see the extension of the female die 120 figs 4 and 5), with an arc 131 cut therein allowing for the retaining bolts 109 to be located as previously set forth. The arc 131 would retain this female die in a precise known position and thus provide for the possible asymmetric die functions.

Other location devices such as separate pins between the die and opening, asymmetric dies and die opening cross-sections, interference sizing in height and/or diameter, or otherwise as desired. (Note this arc 131 is in optional upwards extension off of the lower section 123.) With a symmetric die opening 121 as disclosed, the female die 120 could have a circular recessed upper section 124 shape like that of 114 in respect to the male die 110-the angular positioning is not critical.) The upper section 114 of the male die is formed into a plug 111 while the upper section 124 of the female die 120 is made into an opening 121. The diameter of the plug 111 is slightly smaller than the diameter of the opening 121 so as to allow the plug to fit within such opening 121 without substantial contact to the sides of the opening 121 throughout the arc of contact between the two rolls 101,102. In addition, the plug 111 has a slightly arcuate top and angled sides so as to substantially engage the sides 121 of the opening throughout this arc. This optimizes the cooperation between the plug 111 and opening 121 (as later set forth).

A discharge port 106 in the bodies of the rollers loo immediately under the opening 121 in the female die (or optional smaller hole in the male die) allows for the pass through of the hole extracts into the inner cavity of the rolls. Due to the fact that this discharge port 106 is preferably larger than the opening 121, there will be no impediment to the

discharge of the extracts through the ports 106.

Further, due to the sizing of the plug 111 in respect to the opening 121, the edges immediately surrounding the holes 132 are in compression (at a higher density than that of the remainder of the film 130-edge 134 is in compression at an oblique angle while edge 135 is in compression at an acute angle in respect to the plane of the film 130). The reason for this is that the root diameter of the male plug 111 substantially matches the diameter of the top of the upper section 124 of the female opening 121, albeit with a slight relieved section-a relieved section provided by a curving of the male plug 111 (figs 8 and 11) and/or a curved section for the female opening (figs 11 and 12). In addition, this produces a slight tear dropping effect at the lower side of the film 130 on the edges 134 so as to guide the material used to treat the foods through the film 130.

The design and shape of the male plug 111 and female opening 121 are inter-related (figs 8-12).

The three major design criteria are: 1) there is no physical contact therebetween through the range of overlap; 2) there is a compression type meeting between the male plug and top of the female opening; and, 3) some sort of foil breaking shape is formed at the outer tip of the male plug.

In respect to the former, a male plug will generate a clearance area in respect to any female opening. By this it is meant that any set cross-section of one will pass through the other in a generated direction. This in turn creates a clearance area generally greater than the actual shape of the male plug, which clearance'area defines what is necessary to avoid contact between the male and female dies.

In the preferred embodiment disclosed the shape of this clearance area begins with an arbitrary female opening (the reason for this is that the female opening is vastly simpler than the male, such opening typically a simple cavity matching the lateral cross-section of the male plug). As shown in figures 4 and 5, the example female opening 121 is a circle having walls 127 diverging from the outer edge 126 at an angle 128 (also the inner end 129 of this opening is preferably smaller than that of the discharge port 106 so as to eliminate any restriction thereat).

Other than curving the upper edge 126 (figs 11 and 12) or recessing the walls 127 below such edge (figs 9,11 and 12), there is little else that can be done with the female opening.

In the example, the male plug 111 will need a clearance area in respect to this opening 121. This area is defined by extending a phantom shape with a cross-section matching that of the top of the female opening from the center of the roll incorporating the male member (and the selected length) through such opening 121 and running the rolls through their arc of contact (similar to the four entry steps in fig 8 with exit steps also replicated). The length of the male is selected to be more than necessary to extend into the female openings with a shearing contact with the edges thereof after the foil compression: after that a designer's choice. This phantom shape produces a generated envelope 117 (clearance area) within which the male plug 111 must fit in order not to contact the female die 120. (In the example shown, the sides 118 have an arc 150 generated by drawing a curve from the point of intersection 140 of lines 141,142 extended from the male and female mating surfaces through the ends 145 of the male plug 111-shown in representational series in fig 8-mating surfaces

displaced for clarity. The end 119 is defined by the length of the male plug.) In respect to the compression type meeting between the male plug 111 and the top 125 of the female opening 121, these have substantially the same shape and the same diameter for a distance beyond the plane of their meeting. This in combination with a slightly rounded intersection shape causes an initial compression then shearing closing of the edges 134 of the holes 132 in the foil 130. This strengthens these edges (as opposed to a punch or tearing type manufacture at this location). There are three essential factors to this compression action: 1) the cross-section size differential; 2) the distance between the root of the male plug and the top of the female opening; and, 3) the shape of the male die and female die at this critical location.

In respect to the size differential, the foil has a thickness and a breaking point (this latter is the thickness that the material will not sustain itself through the length of the area of overlap between the dies). This differential can be determined by passing a given foil through set cross-section dies and ever decreasing spacing until the desired shearing occurs. For the example. 0015 thickness foil and a 1/8"radiused male die, this differential is substantially. 0005.

In respect to the distance between the root of the male plug and the top of the female opening, the foil preferably has a thickness slightly greater than this distance. This compresses the foil between the perforation rollers 100. For the example. 0015 thickness foil this distance is from. 0015 to. 0010.

In respect to the other shape of the dies, the closer the dies and the sharper the intersecting angles the more different the shapes must be. In

addition, the initial cutting edge of the male die needs be factored in-i. e. the more aggressive the first contact with the foil, the more closely the shape of the dies can match and the angle therein can be sharper.

In respect to the foil breaking shape formed at the outer tip of the male plug 111, this causes an initial point of contact creating a hole in the foil for formation of the remainder of the holes, thus reducing the forces on the foil (as well as the power needed to form the holes). In the example embodiment, this breaking is provided by an edge 116 formed somewhere at the outer extent of the clearance area.

This edge can be external (figs 8,10 and 12), internal (fig 11) or a combination (fig 11). Note asymmetric die, for example forming the left leg longer than the right in figure 15, is one that preferably would be located by the retainer screw being within an arc of the die so as to locate same.

In the particular preferred embodiment the rolls 101,102 are hollow, each some 31"wide and 28" in circumference (for a 26"wide web width). A 3" diameter hole on the center of the roll is provided for a vacuum connection 160 to remove film extracts from the central cavity thereof. The male plug is from 1/8"to 1/2"in diameter (1/4"preferred). The perforations are on 2"centers across and lengthwise of the film with alternating rows staggered by 1" (14 plugs circumferentially across with 12 and 13 plugs respectively in the alternating rows fig 14).

The particular male die 110 has a lower section 1/2"in diameter and. 135" in height. The upper section is. 125" in height. It has a root cylinder. 122" in diameter and a top. 125" in diameter matching the female opening. The top originally was . 128" in diameter set back at a 45° angle to the root

diameter-dashed line in fig 8 left hand male die.

(On initial operation the interaction with the female die shears off the edges of the top of the male die to its reduced diameter and forms it to match the clearance shape of fig 9.) The particular female die is. 685"in diameter and 1/2"in height. The opening in the top is. 125" in diameter increasing to. 375" at a depth of. 137". The top of the female die flat for . 355" in diameter before tapering off at substantially a 30° angle. The bolt 109 has a. 35" diameter hex head and 10/24 thread. 365" long. The die holes 105 and retainer holes are dimensioned to match the above.

In operation, the speed of the rollers 100 exactly matches that of the film from the input section 10 through to the output section 50 so as to allow the pass through of the film 130 under a no load/no torque condition therethrough. This allows the rollers 100 to operate almost solely for their perforation function and not for the passage of material therethrough. This eliminates any tension imbalance for the materials of the film 130 on either lateral side of the holes 132. This further eliminates any stress weaknesses to the edges 134,135 of the holes 132. (Indeed, the compression at the edges 136 strengthens the holes 132 such that they have the strength almost as great as the film 130 without holes.) The operation of the device is under the control of either a skilled operator or a computer.

In respect to the former once the machine is operating, the speed of the output section and perforation rollers would be set to a certain value with the pulling tension of the output section subsequently adjusted as previously described in a veneer control. In the preferred embodiment this would be provided primarily by the operator setting

the eddy torque of the take up spool motor 64 (the motor 59 would provide for the relative speed).

In respect to the latter the sensors 13,22 and 51 would provide the inputs for computer control of the motors 86,59 and 64 to provide for the input resistance tension to and pulling tension from the perforation rollers 100.

The sensor 13 is primarily utilized during initiation (or start up) of the perforation machine.

In specific, when the rollers 100 are initialized, the roll 11 is stationary and the foil 130 has no movement. It is desired to ramp both up as quickly as possible to facilitate production. The sensor 13 provides this by measuring the actual ramp up speed of the incoming foil in the input section 10. During this time the sensor 51 preferably matches the output section 50 to this speed, thus reducing any tension to the foil through the perforation rollers to a minimum (+ 0-5% preferred).

After the input section 10 and perforation rollers 100 are up to speed the sensor 13 drops in importance. At this time the sensor 22 and the sensor 51 are compared for continuous production operation (again + 0-5%). The reason for this is that the desire to remove the foil transportation function (sections 10 and 50) from the perforation function (section 100) while providing the tension therebetween.

All of these sensors control the speed of the foil through the perforation section 100 as previously described so as to essentially eliminate the rollers 100 from the mechanism of foil transport.

In respect to the tension on the foil, for any given material there is a certain resiliency. By this, it is meant that the material can be stretched by an amount and then return to its original dimensions

without damage. The tension within and between the input and output section is selected to be less than this amount. This allows the foil to be processed without physical damage. Typically 0-25,5-10 preferred, pounds of tension is sufficient. It is noted that the action of the dies in the perforation rollers 100 will effect this tension (through their shearing action) due to the sensors 22 and 51. This additional factor is also utilized to control the input and output sections.

The input and output tensions are important for the device. In the machine of figure 22 these tensions are both controlled by rollers 90,95 that have axis of rotation moveable in respect to the remainder of the machine (most particularly movement displaced in respect to the plane of foil movement).

The rollers 90,95 are themselves biased in respect to the foil to provide for a known tension thereat (resiliently biased away from the plane of the foil).

In the embodiment disclosed in figure 22 the rollers 90,95 are mounted on pivot arms 91,96 respectively with an angular sensor utilized to maintain the rollers 90,95 in a preset position with a known force, thus to bias the rollers 90,95 in a preferred position : Movement away from this position is resisted by a set valve of force. This provides for a known tension between the input 10 and output 50 sections.

Note that is would be possible to utilize only one roller 90 or 95. This would be serviceable, albeit with less precise control.

Note also other movement means could be utilized (for example linear). In addition other biasing mechanisms could be utilized (for example springs, pneumatic pistons, weights, direct air

pressure deflection, etc.) with corresponding sensors if appropriate.

The system uses a vacuum or active pumping connection 160 in the roll (s) having openings in dies (normally female openings 121) to provide a pressure differential through the openings and to collect the extracts produced during the making of the holes 132 in the foil. 130. The die openings allow air or other fluid to enter these openings throughout the circumference of the roll including locations other that directly after the extracts are made. While this cools the rolls and provides for a significant dwell time for the extract to pass into the roll, under certain situations it may be desired to increase the relative vacuum. This can be provided by using a compressed fluid source 85 along the length of the roll so as to push the extracts into the roll (as well as agitating them within the roll). This can be outside the circumference of the roller (example at the bottom fig 16 and near the top of fig 21), within the other roller (dashed lines fig 17), within the male roller (fig 17, with the male die having a central opening as in fig 11 leading to a discharge port like 106 in the roller), by concentrating the vacuum within the female roller (via a fixed stationary trough 161 flanked by roll spaced sealing flanges 162-fig 19), by including a fixed stationary wiper 163 physically pealing the extracts off of the interior of the roller (fig 20), by using a separate opening covering belt 88 (this in addition to the foil can cover most of the openings-fig 18) or by positioning the rollers 18 and 52 such that the unholed foil itself covers most of the openings (fig 21-spacing of the rollers 18 and 52 can be adjusted further towards each other or outwards as desired).

Although the invention has been described in its preferred form with a certain degree of particularity, it is to be understood that numerous changes can be made without deviating from the invention as herein after claimed.