Slider-operated fastener with spaced notches and associated preseals

Information

  • Patent Grant
  • 6622353
  • Patent Number
    6,622,353
  • Date Filed
    Monday, September 23, 2002
    21 years ago
  • Date Issued
    Tuesday, September 23, 2003
    20 years ago
Abstract
A slider-operated fastener comprises first and second opposing tracks including respective first and second interlocking profiles and respective first and second fins extending downward from the respective first and second profiles. The first and second fins are sealed to each other by a plurality of spaced preseals. After generating each preseal, a notch is formed in the profiles and upper portions of the fins at the generated preseal. To install a slider onto the fastener, the slider is initially positioned within the respective notch and then threaded onto the fastener in response to relative movement of the slider and the fastener. Either before or after the steps of forming each preseal and respective notch and installing the respective slider, the fastener is attached to a moving web of plastic film. The fastener-carrying web is later folded and sealed to form individual plastic bags. The preseals are advantageous in that they allow the fastener to be controlled during such downstream operations as notch formation and slider installation and when the fastener is tensioned by various rollers in the bag making machine. The preseals keep the interlocked profiles together and prevent them from moving longitudinally relative to each other. In addition, the preseals generally encompass the respective notches to assist in providing a leakproof barrier to entry into an interior of the fastener between the fins via the notches. This leakproof barrier is effective in the ultimately formed plastic bags.
Description




FIELD OF THE INVENTION




The present invention generally relates to reclosable plastic bags and, more particularly, to a slider-operated fastener with spaced notches and associated preseals.




BACKGROUND OF THE INVENTION




In one method of making reclosable plastic bags, a continuous fastener is sealed to a moving web of thermoplastic film. To form individual bags, the web is folded along a fold parallel to the direction of web movement, and the folded web is sealed at bag-width distances apart along side seals that are generally transverse to the direction of web movement. To facilitate opening and closing the fastener, sliders are preferably applied to the fastener at bag-width distances apart.




The fastener includes a pair of interlocking profiles and a pair of fins/flanges extending downward from the respective profiles. In one technique for installing sliders on the fastener, notches are formed in the fastener at bag-width distances apart. The side seals, which are formed later in the bag manufacturing process, are aligned with the respective notches. To install a slider on the fastener via a respective notch, the slider is first positioned within the notch while the web is temporarily stopped, and then the slider is threaded onto an end of the fastener in response to relative movement of the slider and fastener. This installation technique is disclosed in U.S. patent application Ser. No. 09/307,937 (PCOS015) entitled “Zipper and Zipper Arrangements and Methods of Manufacturing the Same”, filed May 10, 1999, now U.S. Pat. No. 6,286,189 and incorporated herein by reference in its entirety.




To form a notch, a short segment of the interlocked profiles and an upper portion of the fins extending from that segment are cut away from the fastener, leaving only a lower portion of the fins bridging opposite sides of the notch. Due to the removal of most of the fastener at the notches, the fastener can be difficult to control during such downstream operations as slider installation and when tensioned by various rollers in a bag making machine. The fastener tends to twist and distort and the fastener profiles tend to shift longitudinally relative to each other. In addition, the notches produce areas where air or liquid can potentially leak into or out of the bags eventually formed by the bag making machine.




SUMMARY OF THE INVENTION




To overcome the aforementioned shortcomings, the present invention provides a unique slider-operated fastener and method of making the same. The slider-operated fastener comprises first and second opposing tracks including respective first and second interlocking profiles and respective first and second fins extending downward from the respective first and second profiles. The first and second fins are sealed to each other by a plurality of spaced preseals. After generating each preseal, a notch is formed in the profiles and upper portions of the fins at the generated preseal. To install a slider onto the fastener, the slider is initially positioned within the respective notch and then threaded onto the fastener in response to relative movement of the slider and the fastener. Either before or after the steps of forming each prescal and respective notch and installing the respective slider, the fastener is attached to a moving web of plastic film. The fastener-carrying web is later folded and sealed to form individual plastic bags.




The preseals are advantageous in that they allow the fastener to be controlled during such downstream operations as notch formation and slider installation and when the fastener is tensioned by various rollers in the bag making machine. The preseals keep the interlocked profiles together and prevent them from moving longitudinally relative to each other. In addition, the preseals generally encompass the respective notches to assist in providing a leakproof barrier to entry into an interior of the fastener between the fins via the notches. This leakproof barrier is effective in the ultimately formed plastic bags.











BRIEF DESCRIPTION OF THE DRAWINGS




Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:





FIG. 1

depicts a method of making a slider-operated fastener;





FIG. 2

depicts a method of forming, filling, and sealing reclosable plastic bags employing the slider-operated fastener;





FIG. 3

depicts a finished bag produced by the form-fill-seal method after the bag's header has been partially removed by an end user;





FIG. 4

is an enlarged view of a U-shaped preseal according to a first embodiment;





FIG. 5

is an enlarged view of a solid preseal according to a second embodiment;





FIG. 6

is an enlarged view of a bracketed preseal according to a third embodiment;





FIG. 7

is an enlarged view of a notch in the U-shaped or solid preseals of

FIGS. 4 and 5

; and





FIG. 8

is an enlarged view of a notch in the bracketed preseal of FIG.


6


.











While the invention is susceptible to various modifications and alternative forms, a specific embodiment thereof has been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.




DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS




Turning to the drawings,

FIG. 1

depicts a method of making a slider-operated fastener for use in reclosable plastic bags. In the method, there is provided a continuous fastener


10


including first and second opposing tracks


12


and


14


. The tracks


12


and


14


include respective first and second interlocking profiles


16


and


18


and respective first and second fins


20


and


22


extending downward from the respective profiles


16


and


18


. The profile


16


preferably includes a rib, and the profile


18


preferably includes a groove for receiving the rib. Further details concerning the construction of the profiles


16


and


18


may be obtained from U.S. Pat. No. 5,007,143 to Herrington, which is incorporated herein by reference in its entirety. The fastener


10


may be unwound from a spool or the like.




The fastener


10


is conveyed by rollers and the like (not shown) to a preseal station. The preseal station includes a pair of reciprocating seal bars


24


and


26


. Either both of the seal bars


24


and


26


move back and forth between open and closed positions, or one of the seal bars is stationary while the other seal bar moves back and forth. At least the seal bar


24


is heated. The other bar


26


may be heated as well, or may simply serve as a backing against which the heated seal bar


24


applies pressure when the seal bars


24


and


26


are brought together. The temperature, pressure, and dwell time of the seal bars


24


and


26


are properly adjusted to allow the seal bars


24


and


26


to impart a preseal


28


. While the fastener


10


is temporarily stopped at the preseal station, the fins


20


and


22


are sealed to each other along the preseal


28


. The preseal


28


preferably does not extend into the profiles


16


and


18


due to the technique for installing sliders on the fastener


10


later in the manufacturing process.





FIGS. 4-6

illustrate different configurations of the preseal. The preseal


28


in

FIG. 4

is generally U-shaped and includes a pair of opposing sides


28




a


,


28




b


and a bottom


28




c


bridging the opposing sides. The opposing sides


28




a


,


28




b


are generally located along an upper portion of the fins


20


and


22


and extend downward from the interlocked profiles


16


and


18


. The bottom


28




c


extends between the lower ends of the sides


28




a


,


28




b


. The seal bar


24


has a U-shaped projection


30


corresponding to the shape of the preseal


28


. The preseal


28


′ in

FIG. 5

is solid such that the rectangular area between the opposing vertical sides of the preseal is sealed. The bracketed preseal


28


″ in

FIG. 6

is similar to the U-shaped preseal


28


in

FIG. 4

except that the bottom of the bracketed preseal


28


″ is interrupted by a gap. The gap has a width W less than or equal to the width X of a side seal later formed in alignment with the preseal


28


″. An advantage of the bracketed preseal


28


″ is that it minimizes the heat imparted to the lower portions of the fins


20


and


22


, thereby minimizing stretching and subsequent shrinkage and wrinkles in the lower fin portions.




After forming the preseal


28


, the fastener


10


is conveyed to a notching station. The notching station includes a pair of reciprocating cutters


32


and


34


. Either both of the cutters


32


and


34


move back and forth between open and closed positions, or one of the cutters is stationary while the other cutter moves back and forth. The cutter


32


forms a rectangular projection, while the cutter


34


forms a rectangular hole for receiving the projection. The fastener


10


is temporarily stopped at the notching station with the preseal


28


aligned between the separated cutters


32


and


34


. While the fastener


10


is stopped, the cutters


32


and


34


are brought together such that the rectangular projection of the cutter


32


punches a rectangular section


36


through the rectangular hole of the cutter


34


, thereby leaving a U-shaped notch


38


in the fastener


10


.




The preseal


28


generally encompasses the notch


38


and defines a periphery thereof such that the preseal provides a leakproof barrier to entry into an interior of the fastener


10


between the fins


20


and


22


via the notch


38


. As discussed below, the leakproof barrier effectively prevents leaks in the reclosable plastic bags ultimately formed by the manufacturing process.

FIG. 7

illustrates the notch


38


in either the U-shaped preseal


28


of

FIG. 4

or the solid preseal


28


′ of FIG.


5


.

FIG. 8

illustrates the notch in the bracketed preseal


28


″ of FIG.


6


. The bracketed preseal


28


″ is still effective to create the aforementioned leakproof barrier because the brackets are sized to overlap the side seal to be formed later in the manufacturing process.




After forming the notch


38


, the fastener


10


is conveyed to a slider insertion station. While the fastener


10


is temporarily stopped at the slider insertion station, a slider


40


from a source of multiple sliders is positioned within the notch


38


. Further details concerning the source of multiple sliders may be obtained from U.S. patent application Ser. No. 09/307,893 (PCOS013) entitled “Assembly and Accumulation of Sliders for Profiled Zippers”, filed May 10, 1999, now U.S. Pat. No. 6,292,986, and incorporated herein by reference in its entirety. The slider


40


is then threaded onto the fastener


10


in response to relative movement of the slider


40


and the fastener


10


. Further details concerning the equipment for installing the slider


40


onto the fastener


10


via the notch


38


may be obtained from U.S. patent application Ser. No. 09/307,937 (PCOS015) entitled “Zipper and Zipper Arrangements and Methods of Manufacturing the Same”, filed May 10, 1999, and incorporated herein by reference in its entirety.




After installing the slider


40


onto the fastener


10


, the fastener


10


is conveyed to an end stop applicator. The end stop applicator applies end stops


42


and


44


to the respective fastener ends


46


and


48


on opposite sides of the notch


38


. In the plastic bags ultimately formed by the manufacturing process, the end stop


42


will be located at the fastener end


46


of one bag, while the end stop


44


will be located at the fastener end


48


of the adjacent bag. The end stops perform three primary functions: (1) preventing the slider


40


from going past the ends of the fastener, (2) holding the profiles together to resist stresses applied to the profiles during normal use of the plastic bag, and (3) minimizing leakage from inside the plastic bag out through the fastener ends.




In one embodiment, the end stop applicator includes a pair of chilled, reciprocating molds


50


and


52


. Either both of the molds


50


and


52


move back and forth between open and closed positions, or one of the molds is stationary while the other mold moves back and forth. While the fastener


10


is temporarily stopped, the molds


50


and


52


close around the fastener ends


46


and


48


. A predetermined amount of flowable plastic material is then forced around and between the profiles


16


and


18


at the fastener ends


46


and


48


by a conventional back pressure device (not shown) coupled to the supply tube. The molds


50


and


52


form channels for receiving the plastic material and guiding it to the fastener ends


46


and


48


. Further details concerning the injection-molded end stops


42


and


44


and the method of making the same may be obtained from U.S. patent application Ser. No. 09/636,244 entitled “Injection-Molded End Stop for a Slider-Operated Fastener”, filed concurrently herewith, and incorporated herein by reference in its entirety.




Instead of applying injection-molded end stops, other types of end stops may be applied to the fastener ends


46


and


48


, including those disclosed in U.S. Pat. Nos. 5,924,173, 5,833,791, 5,482,375, 5,448,807, 5,442,837, 5,405,478, 5,161,286, 5,131,121, 5,088,971, and 5,067,208, which are incorporated herein by reference in their entireties. In U.S. Pat. No. 5,067,208, for example, each end stop is in the form of a fairly rigid strap/clip that wraps over the top of the fastener. One end of the strap is provided with a rivet-like member that penetrates through the fastener fins and into a cooperating opening at the other end of the strap.




While the fastener


10


is temporarily stopped in the method depicted in

FIG. 1

, the various stations simultaneously perform their respective functions on different parts of the continuous fastener


10


spaced approximately at bag-width distances apart. Therefore, as the preseal station forms a new preseal


28


, (1) the notching station forms a new notch


38


within a previously formed preseal, (2) the slider insertion station installs a slider


40


via a previously formed notch, and (3) the end stop applicator applies new end stops


42


and


44


proximate a previously installed slider. After each of the stations has completed its respective function on the stopped fastener


10


, movement of the fastener


10


is resumed. The fastener


10


is moved for approximately a bag-width distance so that the next station can perform its respective function. The preseals


28


are advantageous in that they allow the fastener


10


to be controlled during such downstream operations as notch formation, slider installation, and end stop installation and when the fastener


10


is tensioned by various rollers in the bag making machine. The preseals


28


keep the interlocked profiles


16


and


18


together and prevent them from moving longitudinally relative to each other.




After applying the end stops


42


and


44


, the fastener


10


is preferably applied to a moving web of plastic film that is then formed into individual plastic bags. Alternatively, the fastener


10


may be conveyed to a storage medium, such as a spool, and placed in an intermediate storage facility, and then applied to the moving web at a later time.





FIG. 2

depicts a method of forming, filling, and sealing reclosable plastic bags employing the slider-operated fastener


10


. The fin


20


of the fastener


10


is “tacked” or lightly sealed to a moving web


50


of plastic film unwound from a film roll


52


. To tack the fastener fin


20


to the moving web


50


, there is provided a pair of reciprocating seal bars


54


and


56


. Either both of the seal bars


54


and


56


move back and forth between open and closed positions, or one of the seal bars is stationary while the other seal bar moves back and forth. Both the fastener


10


and the web


50


are temporarily stopped while the seal bars are brought together to tack the fastener


10


to the web


50


. Of course, if the fastener


10


produced by the method in

FIG. 1

is conveyed directly to the web


50


, as opposed to an intermediate storage facility, the stoppage of the fastener


10


and web


50


for tacking can be made to coincide with the stoppage of the fastener


10


in

FIG. 1

for forming the preseal and notch and installing the slider and end stops. In an alternative embodiment, the seal bars


54


and


56


are replaced with a static heat sealing mechanism such as a hot air blower that blows heated air onto the fastener


10


. The tacked fastener


10


is carried with the moving web


50


without shifting relative thereto.




After tacking the fastener


10


to the web


50


, the fastener-carrying web


50


is conveyed to a folding station. At the folding station, the web


50


is folded in half with the fastener


10


inside the web


50


and proximate the fold


51


. To fold the web


50


, the web


50


is conveyed over a horizontal roller


58


, under a triangular folding board


60


, and then between a pair of closely spaced vertical rollers


62


. The folded web


50


includes a pair of overlapping panels


64


and


66


joined along the fold


51


.




After folding the web


50


, the fastener fins


20


and


22


are permanently sealed to the respective web panels


66


and


64


by respective seal bars


68


and


70


. The seal bars


68


and


70


are sufficiently wide that they generate the fin seals across the entire width of a bag produced by the method in FIG.


2


. Either both of the seal bars


68


and


70


move back and forth between open and closed positions, or one of the seal bars is stationary while the other seal bar moves back and forth. The fastener-carrying web


50


is temporarily stopped while the seal bars are brought together to seal the fastener


10


to the web


50


. Both of the seal bars


68


and


70


are preferably heated. The temperature, pressure, and dwell time of the seal bars


68


and


70


are properly adjusted to allow the seal bars


68


and


70


to generate the permanent fin seals. In an alternative embodiment, the seal bars


68


and


70


are replaced with a static heat sealing mechanism such as a pair of hot air blowers that blow heated air onto the respective fastener fins.




After sealing the fins


20


and


22


to the respective web panels


66


and


64


, the web panels


64


and


66


are sealed to each other along a side seal


72


by a pair of reciprocating seal bars


74


and


76


. The side seal


72


is transverse to a direction of movement of the folded web


50


and is aligned with a center of the notch


38


(and preseal


28


). Also, the side seal


72


extends from the folded bottom


51


to an open top


53


of the folded web


50


. Either both of the seal bars


74


and


76


move back and forth between open and closed positions, or one of the seal bars is stationary while the other seal bar moves back and forth. The folded web


50


is temporarily stopped while the seal bars are brought together to seal the web panels


64


and


66


to each other. At least the seal bar


74


is heated. The other bar


76


may be heated as well, or may simply serve as a backing against which the heated seal bar


74


applies pressure when the seal bars


74


and


76


are brought together. The temperature, pressure, and dwell time of the seal bars


74


and


76


are properly adjusted to allow the seal bars


74


and


76


to generate the side seal


72


.




After generating the side seal


72


, the folded web


50


is conveyed to a cutter


78


for separating the folded web


50


into individual plastic bags. While the folded web


50


is temporarily stopped, the cutter


78


cuts the folded web


50


along a center of the side seal


72


to produce the individual plastic bag


80


. The plastic bag


80


is opened with an opening device


79


and filled with a product through its open top


53


at a filling station


82


. Finally, the open top


53


is sealed by a heat sealing mechanism


84


. The end result is a filled and sealed bag


80


ready for shipment to a customer such as a grocery store or convenience store.




While the web


50


is temporarily stopped in the method depicted in

FIG. 2

, the various stations simultaneously perform their respective functions on different parts of the continuous web


50


. For example, as the fastener


10


is tacked to the web


50


by the seal bars


54


and


56


, (1) the fastener fins


20


and


22


of a previously tacked section of the fastener


10


can be permanently sealed to the respective web panels


64


and


66


by respective seal bars


68


and


70


, (2) the web panels


64


and


66


carrying previously sealed fastener fin sections can be sealed to each other along a side seal


72


by the seal bars


74


and


76


, (3) the folded web


50


can be cut along a previously generated side seal, (4) the cut bag is opened, (5) the opened bag is positioned under a filling device that fills the bag, and (6) the filled bag is sealed closed. After each of the stations has completed its respective function on the stopped web


50


, movement of the web


50


is resumed.




The finished bag


80


, with its header


82


partially removed by an end user, is illustrated in FIG.


3


. After the header


82


is fully removed, it can be seen that each preseal


28


intersects both the adjacent side seal


72


and the fastener profiles


16


and


18


. Therefore, the preseal


28


provides a leakproof barrier between an interior and an exterior of the bag


80


. When the profiles


16


and


18


are interlocked but the header


82


has been removed, this leakproof barrier minimizes food spoilage and leakage of any food juices from inside the bag.




While the present invention has been described with reference to one or more particular embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention. For example, the equipment used in the fastener and bag manufacturing processes may be modified so that the processes are entirely continuous with no temporary stoppages in the movement of the fastener or bag making web. Also, the fastener


10


may be attached to the web


50


prior to forming the preseal


28


and notch


38


, installing the slider


40


, and applying the end stops


42


and


44


. To allow the fastener


10


to be accessed for such operations, however, the operations are preferably performed prior to folding the web


50


and enveloping the fastener


10


therein. Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the claimed invention, which is set forth in the following claims.



Claims
  • 1. A slider-operated fastener, comprising:a first track including a first profile and a first fin extending downward from said first profile; a second track including a second profile and a second fin extending downward form said second profile, said second profile adapted to interlock with said first profile, said first and second fins being sealed to each other by a plurality of longitudinally spaced preseals adjacent to said profiles; and a plurality of longitudinally spaced notches periodically interrupting said profiles and proximate portions of said fins at said respective preseals, each of said plurality of longitudinally spaced notches being configured to receive a slider.
  • 2. The fastener of claim 1, wherein each of said preseals is generally U-shaped.
  • 3. The fastener of claim 1, wherein each of said preseals is generally solid.
  • 4. The fastener of claim 1, wherein each of said preseals includes a pair of brackets separated by a gap.
  • 5. The fastener of claim 1, wherein said fins are sealed to each other by said spaced preseals along most of a periphery of each of said notches.
  • 6. The fastener of claim 5, wherein said periphery of each of said notches is generally U-shaped.
  • 7. The fastener of claim 1, wherein each of said notches is defined by a pair of sides and a bottom bridging said sides, said fins being sealed to each other by said spaced preseals along said sides and at least a portion of said bottom.
  • 8. The fastener of claim 1, wherein said preseals provide a leakproof barrier to entry into an interior of said fastener between said fins via said notches.
  • 9. The fastener of claim 1, further including a plurality of sliders mounted to said profiles near said respective notches.
  • 10. The fastener of claim 1, further including a plurality of end stops mounted to said profiles at said respective notches.
  • 11. A slider-operated fastener, comprising:first and second opposing tracks including respective first and second interlocking profiles and respective first and second fins extending downward from said respective first and second profiles; said first and second fins being sealed to each other by spaced preseals and having spaced notches formed therein at least partially encompassed by said respective preseals such that said preseals assist in providing a leakproof barrier to entry into an interior of said fastener between said fins via said notches, said notches for receiving a slider.
  • 12. The fastener of claim 11, wherein each of said preseals is generally U-shaped.
  • 13. The fastener of claim 11, wherein each of said preseals is generally solid.
  • 14. The fastener of claim 11, wherein each of said preseals includes a pair of brackets separated by a gap.
  • 15. A slider operated fastener, comprising:first and second opposing tracks including respective first and second interlocking profiles and respective first and second fins extending downward from said respective first and second profiles; a plurality of space preseals sealing said first and second fins to each other; a plurality of notches interrupting said profiles and proximate portions of said fins at said respective preseals, said notches being at least partially encompassed by said respective preseals; a plurality of sliders for opening and closing said first and second interlocking profiles, each of said sliders being threaded onto said interlocking profiles at a corresponding one of said plurality of notches.
  • 16. The fastener of claim 15, wherein said preseals border on said respective notches.
  • 17. The fastener of claim 15, wherein each of said preseals is generally U-shaped.
  • 18. The fastener of claim 15, wherein each of said preseals is generally solid.
  • 19. The fastener of claim 15, wherein each of said preseals includes a pair of brackets separated by a gap.
  • 20. A slider-operated fastener, comprising:first and second opposing tracks including respective first and second interlocking profiles and respective first and second fins extending downward from said respective first and second profiles; and said first and second fins being sealed to each other by spaced preseals and being notched wit in said respective preseals to a size to accommodate a slider, said first an second profiles also being notched proximate said respective preseals.
  • 21. A slider-operated fastener, comprising:first and second opposing tracks including respective first and second interlocking profiles an respective first and second fins extending downward from said respective first and second profiles; and said first and second fins being attached to each other at spaced attachment regions an being notched proximate said respective attachment regions for receiving a slider, said first and second profiles also being notched proximate aid respective attachment regions.
  • 22. The fastener of claim 21, wherein said first and second fins are notched within said respective attachment regions such that said attachment regions assist in providing a leakproof barrier to entry into an interior of said fastener between said fins where said fins are notched.
  • 23. The fastener of claim 21, wherein lower portions of said fins remain intact beneath where said fins are notched.
REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No. 09/636,421, filed Aug. 10, 2000, now U.S. Pat. No. 6,470,551; which was filed concurrently with U.S. patent application Ser. No. 09/636,244, entitled “Injection-Molded End Stop for a Slider-Operated Fastener,” now U.S. Pat. No. 6,508,969, U.S. patent application Ser. No. 09/637,037, entitled “Method of Applying a Slider to a Fastener-Carrying Plastic Web,” now U.S. Pat. No. 6,526,726, U.S. patent application Ser. No. 09/635,451 entitled “Method and Apparatus for Guiding a Fastener in a Bag Making Machine,” now U.S. Pat. No. 6,494,018, and U.S. patent application Ser. No. 09/637,038 entitled “Method and Apparatus for Making Reclosable Plastic Bags Using a Pre-Applied Slider-Operated Fastener,” all of which are incorporated herein by reference in their entireties.

US Referenced Citations (145)
Number Name Date Kind
3381592 Ravel May 1968 A
3473589 Gotz Oct 1969 A
3532571 Ausnit Oct 1970 A
RE27174 Ausnit Sep 1971 E
3608439 Ausnit Sep 1971 A
3613524 Behr et al. Oct 1971 A
3701191 Laguerre Oct 1972 A
3701192 Laguerre Oct 1972 A
3785111 Pike Jan 1974 A
3839128 Arai Oct 1974 A
3948705 Ausnit Apr 1976 A
4094729 Boccia Jun 1978 A
4196030 Ausnit Apr 1980 A
4240241 Sanborn, Jr. Dec 1980 A
4246288 Sanborn, Jr. Jan 1981 A
4277241 Schulze Jul 1981 A
4341575 Herz Jul 1982 A
4355494 Tilman Oct 1982 A
4372793 Herz Feb 1983 A
4415386 Ferrell et al. Nov 1983 A
4430070 Ausnit Feb 1984 A
4437293 Sanborn, Jr. Mar 1984 A
4517788 Scheffers May 1985 A
4528224 Ausnit Jul 1985 A
4563319 Ausnit et al. Jan 1986 A
4581006 Hugues et al. Apr 1986 A
4582549 Ferrell Apr 1986 A
4601694 Ausnit Jul 1986 A
4617683 Christoff Oct 1986 A
4651504 Bentsen Mar 1987 A
4655862 Christoff et al. Apr 1987 A
4663915 Van Erden et al. May 1987 A
4666536 Van Erden et al. May 1987 A
4673383 Bentsen Jun 1987 A
4691372 Van Erden Sep 1987 A
4703518 Ausnit Oct 1987 A
4709398 Ausnit Nov 1987 A
4709533 Ausnit Dec 1987 A
4710157 Posey Dec 1987 A
4782951 Griesbach et al. Nov 1988 A
4787880 Ausnit Nov 1988 A
4790126 Boeckmann Dec 1988 A
4807300 Ausnit et al. Feb 1989 A
4812074 Ausnit et al. Mar 1989 A
4840012 Boeckmann Jun 1989 A
4840611 Van Erden et al. Jun 1989 A
4844759 Boeckmann Jul 1989 A
4850178 Ausnit Jul 1989 A
4876842 Ausnit Oct 1989 A
4878987 Ven Erden Nov 1989 A
4892414 Ausnit Jan 1990 A
4892512 Branson Jan 1990 A
4894975 Ausnit Jan 1990 A
4909017 McMahon et al. Mar 1990 A
4924655 Posey May 1990 A
4925318 Sorensen May 1990 A
4929225 Ausnit et al. May 1990 A
4941307 Wojcik Jul 1990 A
4969309 Schwarz et al. Nov 1990 A
4974395 McMahon Dec 1990 A
4993212 Veoukas Feb 1991 A
5005707 Hustad et al. Apr 1991 A
5014498 McMahon May 1991 A
5027584 McMahon et al. Jul 1991 A
5036643 Bodolay Aug 1991 A
5042224 McMahon Aug 1991 A
5046300 Custer et al. Sep 1991 A
5063639 Boeckmann et al. Nov 1991 A
5067208 Herrington, Jr. et al. Nov 1991 A
5072571 Boeckmann Dec 1991 A
5085031 McDonald Feb 1992 A
5092831 James et al. Mar 1992 A
5096516 McDonald et al. Mar 1992 A
5105603 Natterer Apr 1992 A
5107658 Hustad et al. Apr 1992 A
5111643 Hobock May 1992 A
5116301 Robinson et al. May 1992 A
5127208 Custer et al. Jul 1992 A
5131121 Herrington, Jr. et al. Jul 1992 A
5147272 Richison et al. Sep 1992 A
5161286 Herrington, Jr. et al. Nov 1992 A
5179816 Wojnicki Jan 1993 A
5188461 Sorensen Feb 1993 A
5211482 Tilman May 1993 A
5247781 Runge Sep 1993 A
5254073 Richison et al. Oct 1993 A
5259904 Ausnit Nov 1993 A
5273511 Boeckmann Dec 1993 A
5322579 Van Erden Jun 1994 A
5334127 Bruno et al. Aug 1994 A
5383989 McMahon Jan 1995 A
5400565 Terminella et al. Mar 1995 A
5400568 Kanemitsu et al. Mar 1995 A
5405478 Richardson et al. Apr 1995 A
5405629 Marnocha et al. Apr 1995 A
5412924 Ausnit May 1995 A
5415904 Takubo et al. May 1995 A
5425216 Ausnit Jun 1995 A
5425825 Rasko et al. Jun 1995 A
5435864 Machacek et al. Jul 1995 A
5448807 Herrington, Jr. Sep 1995 A
5470156 May Nov 1995 A
5489252 May Feb 1996 A
5492411 May Feb 1996 A
5505037 Terminella et al. Apr 1996 A
5509735 May Apr 1996 A
5511884 Bruno et al. Apr 1996 A
5519982 Herber et al. May 1996 A
5525363 Herber et al. Jun 1996 A
5542902 Richison et al. Aug 1996 A
5551127 May Sep 1996 A
5551208 Van Erden Sep 1996 A
5557907 Malin et al. Sep 1996 A
5558613 Tilman et al. Sep 1996 A
5561966 English Oct 1996 A
5564259 Stolmeier Oct 1996 A
5573614 Tilman et al. Nov 1996 A
5592802 Malin et al. Jan 1997 A
5613934 May Mar 1997 A
5628566 Schreiter May 1997 A
5647671 May Jul 1997 A
5669715 Dobreski et al. Sep 1997 A
5682730 Dobreski Nov 1997 A
5722128 Toney et al. Mar 1998 A
5725312 May Mar 1998 A
5745960 Dishner et al. May 1998 A
5782733 Yeager Jul 1998 A
5788378 Thomas Aug 1998 A
5823933 Yeager Oct 1998 A
5833791 Bryniarski et al. Nov 1998 A
5906438 Laudenberg May 1999 A
5924173 Dobreski et al. Jul 1999 A
5956924 Thieman Sep 1999 A
6044621 Malin et al. Apr 2000 A
6138436 Malin et al. Oct 2000 A
6138439 McMahon et al. Oct 2000 A
6209287 Thieman Apr 2001 B1
6216423 Thieman Apr 2001 B1
6286189 Provan et al. Sep 2001 B1
6360513 Strand et al. Mar 2002 B1
6363692 Thieman Apr 2002 B2
6412254 Tilman et al. Jul 2002 B1
6438926 Thieman Aug 2002 B1
6499272 Thieman Dec 2002 B2
6524002 Tomic Feb 2003 B2
Foreign Referenced Citations (5)
Number Date Country
0 939 034 Sep 1999 EP
0 978 450 Feb 2000 EP
1 026 077 Aug 2000 EP
2 085 519 Apr 1982 GB
WO 9924325 May 1999 WO