Energy absorbing protective device that protects areas of articulation

Information

  • Patent Grant
  • 6519781
  • Patent Number
    6,519,781
  • Date Filed
    Friday, September 7, 2001
    23 years ago
  • Date Issued
    Tuesday, February 18, 2003
    21 years ago
  • Inventors
  • Original Assignees
  • Examiners
    • Calvert; John J.
    • Patel; Tajash
    Agents
    • Patton Boggs LLP
Abstract
An energy absorbing, articulated, protective pad with improved articulation for protection of areas of articulation, such as joints of a human body. A pad of energy absorbing material has score lines along a first axis and a second axis. The score lines are cut into said pad to provide articulation of the pad. The pad also has cuts along the second axis at the periphery of the pad that provide flexibility to the pad.
Description




FIELD OF THE INVENTION




This invention relates to devices that absorb the energy of an impact. More particularly, this invention relates to devices used to provide protection to joints and other areas of articulation. Still more particularly, this invention relates to devices that provide protection to joints and other areas of articulation and allow air and moisture to pass through the protection to provide breathable protection to a user that allows evacuation of perspiration.




STATEMENT OF THE PROBLEM




Many sports and occupations require safety equipment such as padding that protects the users from impacts that occur. Some non-limitative examples of sports where padding is needed include bicycling, football, hockey, in-line skating, skiing and snowboarding. A non-limitative example of an occupation that requires safety equipment is construction. Designers of such safety equipment face a number of obstacles.




One area of particular concern to designers of safety equipment is padding. Of particular concern to the designers is padding for areas of articulation. An area of articulation is a joint or other area in which at least two adjacent body parts move in different directions during an activity. For example, one common joint to protect is the knee which must bend when a user is in-line skating, running, or walking. Users prefer padding that allows a full range of motion with minimal discomfort. Users also prefer padding that allows for the evacuation of perspiration, which is known as breathing in the art. Other concerns include that the padding is washable, lightweight and durable.




Prior art padding designs do not adequately meet these needs. One type of pad, such as the pad disclosed in U.S. Pat. No. 6,029,273 issued to McCrane, has a hard outer casing. This type of pad does not allow perspiration to escape. Therefore, this type of pad is not ideal for use in clothing. Further, this type of pad restricts movement, as the outer casing is rigid and inflexible. To allow articulation, some pads with rigid casings do provide articulated plates. Articulated cases include a plurality of plates fitted together that allow the plates to move with respect to one another in order to facilitate movement. These casings may solve the mobility problem. However, the casings with articulated plates still do not allow perspiration to escape, are heavy, bulky, and are still too rigid to insert into clothing. Furthermore, the cost of making the articulated plates is expensive and time consuming.




A second type of casing includes flexible, outer casings of porous, breathable inelastic material overfilled with resilient discrete beads of elastic material. An example of this type of pad is disclosed in U.S. Pat. No. 5,920,915 issued to Bainbridge et al. This material, while breathable, still impedes movement because the overfilled pads are semi-rigid. Therefore, this type is unacceptable for padding an articulated area.




A third type of pad is a foam pad that has score lines cut into the pad to facilitate movement. An example of this type of pad is disclosed in U.S. Pat. No. 6,093,468 issued to Tums et al. Score lines are indentations cut into the material. The cuts allow the foam of the pad to flex to allow the pad to flex. The foam material is breathable and allows perspiration to escape. The score lines improve the flexibility of a pad. However, the range of motion is still impeded as the score lines do not allow the pad to twist or form completely to an area due to the excess material.




It is, therefore, the desire of those skilled in the art to provide a pad that allows perspiration to escape and has a desired flexibility.




STATEMENT OF THE SOLUTION




The above and other problems are solved and an advance in the art is made by a protective pad made in accordance with this invention. A first advantage of a protective pad made in accordance with this invention is that the pad is breathable, meaning that perspiration is allowed to escape. Furthermore, the pad is washable as part of a garment. A second advantage of this invention is that the pad is flexible and may move with an area of articulation to allow a user a full range of motion with minimal discomfort.




In accordance with this invention, an energy absorbing protective pad has a pad of energy absorbing material. The pad has score lines along a first axis and a second axis. The score lines are cut into the pad to provide articulation. Along the second axis, the pad has cuts at the periphery of the pad. The cuts provide flexibility to the pad.




The energy absorbing material may be a foam or any other semi-rigid material. The foam may be single layered or multi-layered. Preferably, the energy absorbing material is a bi-density foam. The bi-density foam has a first layer on a bottom side of the pad having a first density and a second layer on a top side of the pad having a second density that is a higher density than the first density. The score lines are cut through the second layer of foam and through a substantial portion of the first layer. Preferably, the score lines are cut through three-quarters of the pad. However, the score lines may also be cut to any other depth including, but not limited to, one-half and one-quarter through the pad.




The inner side of the pad may be affixed to a piece of stretch or non-stretch fabric. The pad may be sewn or glued to the fabric. A piece of outer fabric may be affixed to the piece of stretch fabric around a perimeter of the pad to enclose the pad. The pad is not affixed to the outer fabric to add flexibility. When the pad is affixed to the stretch fabric, the score lines may completely sever the pad into a plurality of individual members.




The score lines may be cut into the pad in the following manner. A first plurality of score lines are cut into the pad substantially along a first axis. The first axis is substantially longitudinal with reference to the area of articulation being protected. For example, in a knee pad, the first axis would be substantially parallel to the leg. A second plurality of score lines are cut substantially along a second axis. The second axis is substantially perpendicular to the first axis. The first and second plurality of score lines define a plurality of polygons on the pad. The polygons are preferably narrower along the first axis than the second axis to promote flexibility along the first axis.




In a preferred embodiment, the cuts along the periphery of pad along second axis promote flexibility. The Cuts completely sever members at the periphery of the pad along the second axis to allow flexing of the pad. Polygons defined by cuts have reduced dimensions in the direction of the first axis to further promote flexibility and shaping of the pad to the member protected by the pad. The cuts also eliminate excess material in the direction of the first axis. The excess material is removed because this excess material impedes flexing of the pad in the direction of the first axis.




The pad may be molded to have a curvature traversing the second axis. A concave side of the pad is fitted to the area of articulation being protected. In a preferred embodiment, the energy absorbing material of the pad is heat moldable and heat is applied to the pad to form the curvature.




The protective pad may then be inserted in pockets or enclosures in a garment to form any number of pads. For example, a protective pad in accordance with this invention may be incorporated into a knee pad, a hip pad, a shoulder pad, or an elbow pad.











BRIEF DESCRIPTION OF THE DRAWINGS




The above and other advantages and features of this invention are set forth in the detailed description below and the following drawings:





FIG. 1

illustrating an energy absorbing pad in accordance with the invention;





FIG. 2

illustrating a front view of an energy absorbing pad in accordance with the invention;





FIG. 3

illustrating a cross sectional side view of an energy absorbing pad affixed to fabric in accordance with the invention;





FIG. 4

illustrating a top side view of a curved pad in accordance with the invention;





FIG. 5

illustrating a bottom side view of a curved pad in accordance with the invention;





FIG. 6

illustrating an exploded view of a jacket incorporating energy absorbing pads in accordance with the invention;





FIG. 7

illustrating a pair of pants incorporating energy absorbing pads in accordance with the invention;





FIG. 8

illustrating a knee pad incorporating energy absorbing pads in accordance with the invention;





FIG. 9

illustrating a cross section of a foam pad in accordance with the invention;





FIG. 10

illustrating a pad in accordance with this invention attached to a stretch fabric; and





FIG. 11

illustrating a cross sectional view of a member of a pad attached to a stretch fabric.











DETAILED DESCRIPTION





FIG. 1

illustrates a preferred embodiment of energy absorbing protective pad in accordance with the invention. Pad


100


is made of energy absorbing material. The energy absorbing material may be, but not limited to, a single density or multi-density foam. In a preferred embodiment, the energy absorbing material is a bi-density foam. An example of such a foam is described in WO Document No. 00/16652 by Brock, which is incorporated by reference as if set forth herein.

FIG. 2

illustrates a cross section of a side view of pad


100


made of a bi-density foam. As can be seen in

FIG. 2

, pad


100


has a top side or outer layer


201


of high density foam. A second bottom side or inner layer


202


of foam is made of a lower density foam. Bi-density foam is preferred because the foam is breathable, elastic, and provides a softer surface close to the area to be protected and a harder surface on the side exposed to the source of trauma.

FIG. 9

illustrates a cross sectional view of a piece of foam


900


that may be used in pad


100


. The foam


900


is made of discrete beads


900


that are affixed to one at points


906


. One skilled in the art will recognize that the beads may be melted together, glued together, or in some other way connected. The beads may be compressed to form a higher density foam. At the edges and on the surface of sides beads


903


are cut to provide a smooth surface.




Referring back to

FIG. 1

, pad


100


has a first, longitudinal axis


110


that is substantially longitudinal to an area of articulation being protected. For purposes of this discussion, an area of articulation is a joint or other area of a body in which at least two adjacent body parts move in different directions during an activity. Some examples of areas of articulation include, but are not limited to, knees, elbows, shoulders, and hips. For discussion purposes, the longitudinal axis is the line which essentially bisects the body parts that articulate. For example, a longitudinal axis of a knee is the line that bisects the two positions of the leg which are joined at the knee.




A second axis


120


traverses the area of articulation and intersects first axis


110


. Preferably, second axis


120


of pad


100


is substantially perpendicular to the first axis


110


and traverses the area of articulation. Typically, second axis


120


is the shorter width of the pad.




Score lines


101


are articulation lines cut substantially along the first axis. Score lines


102


are articulation lines cut substantially along the second axis. Score lines


101


and


102


allow the pad to bend and flex to match the area of articulation protected. In the preferred embodiment, score lines


101


and


102


are cut to three-quarters (¾) the depth of the pad. Those skilled in the art will recognize that score lines may be cut to other depths including, but not limited to, one-half and one-quarter of the thickness of pad


100


. Those skilled in the art will also recognize that score lines may be cut along any other axis in any other direction according to need.




Score lines


101


and


102


define individual members


105


of pad


100


. Individual members


105


are in the form of polygons. In the preferred embodiment, the polygons are hexagonal to provide enhanced flexibility. Pentagonal polygons have also been found to have flexibility advantages. However, one skilled in the art will recognize that the polygons may be in any shape desired. Also, to promote flexibility of the joint, individual members


105


are preferably reduced in dimension along the first axis


110


than across the second axis


120


. That is, because the individual members are narrower in a direction along the first axis than along the second axis, there are more score lines per unit length along the first axis, increasing flexibility.




To provide better flexibility, pad


100


also has cuts


103


along the periphery of pad


100


along second axis


120


. Cuts


103


completely sever members


105


at the periphery of pad


101


along second axis


120


to allow flexing in pad


101


. Polygons defined by cuts


103


have reduced dimensions in the direction of first axis


110


to further promote flexibility and shaping of pad


100


to the member protected by pad


100


. Cuts


103


also eliminate excess material in the direction of first axis


110


. The excess material is removed because this excess material impedes flexing of pad


100


in the direction of first axis


110


.




Referring back to

FIG. 2

, individual members, such as


209


, are preferably tapered in a direction from the bottom side toward the top, such as at


210


. Individual members also have rounded edges, such as at


211


and


212


. Preferably, the top layer


201


of all elements is tapered and rounded at all edges that are not connected to another element, such as at


214


. The tapering and rounding increases flexibility, facilitates smooth interfacing of elements as they may contact during flexing, makes entry of a pad into a pocket easier, and gives a smooth, finished appearance to the pad.




Sometimes pad


101


is affixed to a fabric for fitting into a garment.

FIG. 3

illustrates a cross section of pad


100


along first axis


110


to show pad


100


affixed to a fabric. Pad


100


is affixed to a piece of stretch fabric


304


. Preferably, pad


100


is glued or laminated to fabric piece


304


, although pad


100


may be affixed to fabric piece


304


in other manners, such as sewing the pad to fabric piece


304


. Fabric piece


304


is made of a lycra polyester blend or other stretch material that is lightweight, breathable, and flexible. A material such as Gore-Tex may also be used, although Gore-Tex is normally not stretchable. When pad


100


is affixed to fabric piece


304


, score lines


101


and


102


may be cut completely through the pad to completely sever members


105


to maximize flexibility.

FIG. 10

illustrates an example of members


105


being severed. In

FIG. 10

, a piece of stretch fabric


1001


has a plurality of members


1002


affixed to piece


1001


via glue


1009


. Gaps


1004


between members


1002


allow piece of fabric


1001


to be flex freely. This allows the fabric to conform to an underlying body easily.

FIG. 11

is a cross sectional view of a member


1002


. Member


1002


has a top layer


1006


of high density foam. Bottom layer


1008


is a low density foam affixed to the top layer


1006


. Epoxy


1009


is then applied to a bottom side of bottom layer


1008


to affix member


102


to fabric


1001


.




A second piece of fabric


302


may then cover pad


100


and be affixed to fabric piece


304


at points


306


,


307


around the perimeter of pad


100


. The second piece of fabric


302


is affixed by glue, stitches, or in some other manner. Preferably, the second piece of fabric


302


is not affixed to a top side


305


of pad


100


. Instead, a gap


310


is formed between pad


100


and the second piece of fabric


302


. This promotes flexibility and breathability of pad


100


. In a preferred embodiment, the construction shown in

FIG. 3

is used for removable protective devices such as the devices shown in FIG.


6


and described below.




In a preferred embodiment, pad


100


is curved to better enclose an area of articulation being protected.

FIGS. 4 and 5

illustrate a curved pad


100


. As can be seen from

FIG. 4

, in the preferred embodiment pad


100


has a curvature


400


along the second axis


120


. The curvature is formed by heat molding pad


100


in the preferred embodiment. To heat mold pad


100


, the energy absorbing material must be heat moldable such as the bi-density foam described above. The pad


100


also may be curved along the first axis


110


, though usually, if there is such curvature, it is less than along the second axis.





FIG. 5

shows concave area


500


of an inner side of pad


100


. Concave area


500


is curved to fit the area of articulation being protected into the concave area and more completely protect the area of articulation. One skilled in the art will recognize that the exact amount of curvature of pad


100


will depend on the area of articulation being protected and the amount of the area desired to be protected.





FIG. 6

illustrates one type of garment that may benefit from a protective pad in accordance with the invention. Jacket


600


is a jacket worn for such activities as skiing and snowboarding. Jacket


600


includes shoulder pad


610


, tricep pad


620


, elbow pad


630


and forearm pad


640


. Shoulder pad


610


and elbow pad


630


are substantially triangular shaped pads as the pad


100


shown in FIG.


1


and incorporate the invention. Tricep pad


620


and forearm pad


640


are smaller pads that protect areas that do not articulate and may or may not incorporate the invention.




An inner side of shoulder pad


610


is affixed to fabric


613


and a second piece of fabric


612


is then affixed to fabric


613


proximate the perimeter of fabric


613


to enclose shoulder pad


610


and to form enclosed shoulder pad


615


. This process is shown in FIG.


3


and described above. Enclosed shoulder pad


615


fits into pocket


611


on the shoulder of jacket


600


. One skilled in the art will recognize that pocket


611


may be sewn or glued shut or have a zipper that allows removal of shoulder pad


610


.




An inner side of tricep pad


620


is affixed to fabric


623


. A second piece of fabric


622


is then affixed to fabric


613


proximate the perimeter of fabric


613


to enclose tricep pad


620


and form enclosed tricep pad


625


. This shown in FIG.


3


and discussed above. Enclosed tricep pad


625


fits into pocket


621


on an upper back side of a sleeve of jacket


600


. Pocket


621


may be sewn or glued shut or have a zipper allowing access to remove tricep pad


620


.




An inner side of elbow pad


630


is affixed to piece of fabric


633


. A second piece of fabric


632


is affixed to fabric


633


proximate the perimeter of fabric


633


to enclose elbow pad


630


and to form enclosed elbow pad


635


. This process is shown in FIG.


3


and described above. Enclosed elbow pad


635


fits into pocket


631


in an elbow of the sleeve of jacket


600


. Pocket


631


may be sewn or glued shut or have a zipper allowing access to remove elbow pad


630


.




An inner side of forearm pad


640


is affixed to piece of fabric


643


. A second piece of fabric is then affixed to fabric


643


proximate the perimeter of fabric


643


to enclose forearm pad


640


and to form enclosed forearm pad


645


. Enclosed forearm pad


645


fits into pocket


641


on a lower end of the sleeve of jacket


600


. Pocket


641


may be sewn or glued shut or have a zipper or other fixture allowing access to remove forearm pad


640


.





FIG. 7

illustrates a pair of pants


700


that incorporates protective pads in accordance with the invention. Pants


700


includes pockets


710


which receive pads


100


to provide hip protection. Pads


100


that fit into pockets


710


are preferably shaped much like pad


100


shown in FIG.


1


. Pockets may have a zipper or other fastener to allow the pads to be removed. Pants


700


also may include pockets


720


that receive pads to protect a knee. As stated above, pockets


720


may have a fastener to allow removal of the pads or may be sewn or glued shut.





FIG. 8

illustrates a configuration of a knee pad in accordance with the invention. A knee pad is made of two protective pads


810


and


820


having score and cut lines in accordance with the invention. Pad


810


protects a top or upper part of a knee and has a substantially triangular end


811


the fits over a knee cap. Pad


820


protects a lower part of the knee and has an upper end


821


that is shaped to mate with part


811


of pad


810


when a knee is straight. When a knee is bent, pads


810


and


820


separate to maximize bending of the knee. Pads


810


and


820


then are fitted into pocket


720


as shown in FIG.


7


.




The above description is of a protective pad in accordance with the invention. It is expected that those skilled in the art can and will design alternative pads that infringe on the invention as set forth in the claims below either literally or through the Doctrine of Equivalents.



Claims
  • 1. An energy absorbing, articulated, protective pad comprising:a pad of energy absorbing material; score lines along a first axis and about a second axis wherein said score lines are cut into said pad to provide articulation of said pad; and cuts through said pad about said second axis at a periphery of said pad that provide flexibility to said pad wherein the cuts about the second axis are in two directions.
  • 2. The energy absorbing protective pad of claim 1 wherein said energy absorbing material is a single density foam.
  • 3. The energy absorbing protective pad of claim 1 wherein said energy absorbing material is a multi-density foam.
  • 4. The energy absorbing protective pad of claim 3 wherein said multi-density foam comprises:a first layer on an outer side of said pad having a first density; and a second layer on an inner side of said pad having a second density that is a higher density than said first density.
  • 5. The energy absorbing protective pad of claim 1, further comprising a piece of stretch fabric affixed to an inner side of said pad.
  • 6. The energy absorbing protective pad of claim 5, further comprising a piece of outer fabric affixed to said piece of stretch fabric around a perimeter of said pad to enclose said pad.
  • 7. The energy absorbing protective pad of claim 5 wherein said score lines sever said pad into a plurality of individual members.
  • 8. The energy absorbing protective pad of claim 1 wherein said score lines comprise:a first plurality of score lines substantially along a first axis that is longitudinal to an area of articulation; and a second plurality of score lines substantially along a second axis that is substantially perpendicular to said first axis.
  • 9. The energy absorbing protective pad of claim 8 wherein said first and second pluralities of score lines are cut at least one-quarter of a way through said pad.
  • 10. The energy absorbing pad of claim 8 wherein said first and said second pluralities of score lines are cut at least one-half of a way though said pad.
  • 11. The energy absorbing pad of claim 8, further comprising a plurality of polygons in said pad defined by said first and said second plurality of score lines.
  • 12. The energy absorbing protective pad of claim 11 wherein each of said plurality of polygons is narrower along said first axis than along said second axis.
  • 13. The energy absorbing protective pad of claim 11 wherein said polygons are selected from the group consisting of hexagons and pentagons.
  • 14. The energy absorbing protective pad of claim 8 wherein said pad further comprises a curvature of said pad traversing said second axis wherein a concave side of said pad is fitted to a body part to be protected.
  • 15. The energy absorbing protective pad of claim 14 wherein said energy absorbing material of said pad is heat moldable and heat is applied to form said curvature.
  • 16. The energy absorbing protective pad of claim 15, further comprising a pocket in a garment that receives said pad.
  • 17. The energy absorbing protective pad of claim 16 wherein said protective pad is a knee pad.
  • 18. The energy absorbing protective pad of claim 16 wherein said protective pad is an elbow pad.
  • 19. The energy absorbing protective pad of claim 16 wherein said protective pad is a hip pad.
  • 20. The energy absorbing protective pad of claim 16 wherein said protective pad is a shoulder pad.
  • 21. The energy absorbing pad of claim 1 wherein said cuts eliminate excess material that impedes flexing at said plurality of score lines.
  • 22. A method for providing an energy absorbing, articulated, protective pad comprising the steps of:defining score lines along a first axis and about a second axis of a pad of energy absorbing material wherein said score lines provide articulation of said pad; and cutting through said pad about said second axis in two directions at a periphery of said pad to provide flexibility to said pad.
  • 23. The method of claim 22 wherein said energy absorbing material is a single density foam.
  • 24. The method of claim 22 wherein said absorbing material is a multi-density foam.
  • 25. The method of claim 24 wherein said multi-density foam has a first layer on a outer side of said pad having a first density and a second layer on an inner side of said pad having a second density that is a higher density than said first density.
  • 26. The method of claim 22, further comprising the step of affixing a piece of stretch fabric to an inner side of said pad.
  • 27. The method of claim 26, further comprising the step of affixing a piece of outer fabric to said piece of stretch fabric around a perimeter of said pad to enclose said pad.
  • 28. The method of claim 27, further comprising the step of severing said pad into a plurality of individual members affixed to said stretch fabric with said score lines.
  • 29. The method of claim 22 wherein said step of defining said score lines comprises the steps of:cutting a first plurality of score lines substantially along a first axis that is longitudinal to an area of articulation; and cutting a second plurality of score lines substantially along a second axis that is substantially perpendicular to said first axis.
  • 30. The method of claim 29 wherein said first and second pluralities of score lines are cut at least one-quarter of a way through said pad.
  • 31. The method of claim 29 wherein said first and said second pluralities of score lines are cut at least one-half of a way though said pad.
  • 32. The method of claim 29 further comprising the step of defining a plurality of polygons in said pad defined by said first and said second plurality of score lines.
  • 33. The method of claim 32 wherein said step of defining comprises defining polygons selected from the group consisting of hexagons and pentagons.
  • 34. The method of claim 33 wherein each of said plurality of polygons is narrower along said first axis than along said second axis.
  • 35. The method of claim 22, further comprising the step of forming a curvature of said pad traversing said second axis wherein a concave side of said pad is fitted to a body part to be protected.
  • 36. The method of claim 35 wherein said energy absorbing material of said pad is heat moldable and said method further comprises the step of applying heat to said pad to form said curvature.
  • 37. The method of claim 22, further comprising the step of inserting said pad into a pocket in a garment that receives said pad.
  • 38. The method of claim 37 wherein said protective pad is a knee pad.
  • 39. The method of claim 37 wherein said protective pad is an elbow pad.
  • 40. The method of claim 37 wherein said protective pad is a hip pad.
  • 41. The method of claim 36 wherein said protective pad is a shoulder pad.
  • 42. The method of claim 22 further comprising the step of:Removing excess material between said cuts to promote flexibility along said plurality of score lines.
  • 43. An energy absorbing, articulated protective pad comprising:a pad of energy absorbing material; and score lines along a first axis and about a second axis wherein said score lines are cut into said pad to provide articulation of said pad, said score lines defining a plurality of polygons having a first dimension along a first axis and a second dimension along a second axis, said first dimension being smaller than said second dimension.
  • 44. An energy absorbing protective pad as in claim 43 wherein said polygons are selected from the group consisting of hexagons and pentagons.
  • 45. An energy absorbing, articulated, protective pad comprising:a plurality of discrete beads of substantially elastic and resilient material, said beads being integrally joined to each other to form a pad; and score lines along a first axis and about a second axis in two directions wherein said score lines are cut into said pad to provide articulation of said pad.
  • 46. An articulated pad as in claim 45 wherein said score lines comprise:a first plurality of score lines substantially along said first axis that is longitudinal to an area of articulation; and a second plurality of score lines substantially about said second axis that is substantially perpendicular to said first axis.
  • 47. The energy absorbing pad of claim 46 further comprising a plurality of polygons in said pad defined by said first and said second plurality of score lines.
  • 48. The energy absorbing protective pad of claim 46 wherein each of said plurality of polygons is narrower along said first axis than about said second axis.
  • 49. The energy absorbing protective pad of claim 46 wherein said polygons are selected from the group consisting of hexagons and pentagons.
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Number Name Date Kind
5488739 Cardinal Feb 1996 A
5500955 Gongea Mar 1996 A
5675844 Guyton et al. Oct 1997 A
5920915 Bainbridge et al. Jul 1999 A
5996115 Mazelsky Dec 1999 A
6029273 McCrane Feb 2000 A
6055676 Bainbridge et al. May 2000 A
6058503 Williams May 2000 A
6079056 Fogelberg Jun 2000 A
6093468 Toms et al. Jul 2000 A
6301722 Nickerson et al. Oct 2001 B1
Foreign Referenced Citations (3)
Number Date Country
0 880 908 Dec 1998 EP
WO0016652 Mar 2000 WO
WO0069293 Nov 2000 WO