Insulated sectional door panel

Information

  • Patent Grant
  • 6772818
  • Patent Number
    6,772,818
  • Date Filed
    Tuesday, December 3, 2002
    22 years ago
  • Date Issued
    Tuesday, August 10, 2004
    20 years ago
Abstract
A sectional garage door panel includes a skin part formed of a rolled metal sheet forming an outer wall and opposed top and bottom edges which may form a pinch resistant joint when adjacent panels are interconnected. Elongated prefabricated insulation parts are inserted in cavities formed by the top and bottom edges and a generally rectangular planar insulation part is insertable in a cavity formed between the top and bottom edges and between the first mentioned insulation parts. Channel shaped brackets are insertable in cavities formed by the top and bottom edges for reinforcing the skin part at a point of attachment of end stiles and hinge parts. A metal backer sheet forms an inner wall to protect the insulation parts. The brackets and one or more of the insulation parts may be secured to the skin part by an adhesive.
Description




BACKGROUND OF THE INVENTION




In the art of sectional doors, such as residential and commercial garage doors, there has been a continuing need to improve the construction of the respective door panels. Sectional door panels are commonly formed of rolled or extruded metal or plastic “skins” to which reinforcing members, hinges and insulation are attached or applied to form the finished door panel. Heretofore, for example, sectional door panels requiring insulation to be applied thereto have been formed by dispensing a quantity of a foamed-in-place polymer into a cavity formed by the rolled or extruded metal or plastic skin. This process may be difficult to control properly to fill all of the void spaces formed by the outer skin of the panel, particularly wherein the top and bottom edges of the panel are configured to provide a pinch resistant edge profile. Moreover, foamed-in-place insulation material may not provide sufficient stiffness or crush resistance for the insulation layer or the panel per se.




Even though reinforced sectional door panels have been previously known there has been a need to provide reinforcing members which are disposed only at critical locations, such as adjacent the points of attachment of other reinforcing members and/or panel hinges, for example. There has further been a need to provide a sectional door panel which includes a proper layer of insulation covering all of the panel void spaces, essentially, together with a skin member covering the insulation layer to minimize damage and deterioration of same.




Still further, there has been a need to provide sectional door panels with pinch resistant edge profiles with an anti-scuffing or anti-scraping coating at critical positions which otherwise would tend to scratch or disfigure the cooperating edge of an adjacent panel.




It is to provide the desiderata mentioned above and overcome deficiencies in prior art sectional door panels of the general type described herein that the present invention has been developed.




SUMMARY OF THE INVENTION




The present invention provides an improved sectional door panel and a method of assembly, particularly a sectional door panel which is thermally insulated.




In accordance with one important aspect of the present invention, a sectional door panel is provided which is characterized by a rolled or extruded metal or plastic outer skin part which forms an outer wall of the panel and top and bottom edges, is reinforced by opposed end stiles and forms a relatively shallow pan like cavity which may be substantially filled with multiple insulation parts which are insertable in spaces defined by the top and bottom panel edges and by space therebetween. The insulation parts may be protected by a reinforcing inner skin or backer part which may be secured to the panel by an adhesive and/or mechanical fasteners.




In accordance with another aspect of the invention a sectional door panel is provided with preinstalled reinforcing brackets for reinforcing the attachment points of panel reinforcing members and/or hinge members for interconnecting the panel with adjacent panels.




The present invention still further provides an improved sectional door panel and method assembly which is advantageous for the production of large quantities of door panels of various selected lengths and widths.




Those skilled in the art will further appreciate the advantages and superior features of the invention upon reading the detailed description which follows in conjunction with the drawings.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is an exploded perspective view of a sectional door panel in accordance with the present invention;





FIG. 2

is an elevation view of the inner side of the panel, assembled;





FIG. 3

is a detail section view taken from the line


3





3


of

FIG. 2

;





FIG. 4

is a detail section view taken generally along the line


4





4


of

FIG. 2

with the insulation parts omitted;





FIG. 5

is a detail section view taken from line


5





5


of

FIG. 1

; and





FIG. 6

is a fragmentary elevation of the panel taken from the same direction as the view of

FIG. 2

, but on a larger scale.











DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT




In the description which follows like parts are marked throughout the specification and drawing with the same reference numerals, respectively. The drawing figures are not necessarily to scale and certain features may be shown in schematic or generalized form in the interest of clarity and conciseness.




Referring to

FIGS. 1 and 2

, there is illustrated a sectional door panel in accordance with the invention and generally designed by the numeral


10


. The door panel


10


is preferably formed of a member


12


which may comprise a rolled or extruded metal or plastic skin part forming an outer, generally planar wall


14


, see

FIG. 3

also, and top and bottom edges


16


and


18


. Top edge


16


,

FIG. 3

, includes a convex curved portion


16


a extending substantially between front wall


14


and a vertically extending offset wall portion


16




b


which is contiguous with a generally horizontal shelf portion


20


. Shelf portion


20


extends to an inclined wall portion


22


which is contiguous with an upper inner wall


24


generally parallel to outer wall


14


. The configuration of the top edge


16


is also disclosed in detail in U.S. Pat. No. 6,328,091 issued Dec. 11, 2001 to L. Blake Whitley and assigned to the assignee of the present invention. The entire disclosures of U.S. Pat. No. 6,328,091 and co-pending U.S. patent application Ser. No. 09/910,992 filed Jul. 23, 2001 by L. Blake Whitley, et al, also assigned to the assignee of present invention, are incorporated herein by reference.




Panel bottom edge


18


includes a convex curved nose part


18




a


and a generally concave part


21


,

FIG. 3

or


4


, which is coextensive with an elongated groove or recess


23


, an inclined inner wall portion


25


and a relatively short lower inner wall


27


generally parallel to outer wall


14


and substantially coplanar with upper inner wall


24


. Inner walls


24


and


27


preferably have rolled reinforced inturned flange parts


24




a


and


27




a


, respectively. Outer wall


14


may be provided with generally coextensive elongated reinforcement recesses


14




a


and


14




b


, FIG.


3


. Skin part


12


may be formed by rolled steel of a selected thickness, such as in a range of about twenty four ga or twenty five ga. Alternatively, skin part


12


may be formed of extruded metal or plastic.




Referring further to

FIG. 1

, the panel


10


is also characterized by opposed end stiles


30


and


32


which are substantially identical mirror image parts. Referring briefly to

FIG. 5

, by way of example, end stile


32


comprises, generally, an elongated angle shaped part including a short outer flange


33


, a web


35


, extending normal thereto and an inner flange


37


normal to web


35


and which is creased and bent slightly at its distal end, as indicated at


39


. Distal flange end


39


and a counterpart flange portion


31


,

FIG. 6

, of end stile


30


are formed so as to fit tightly against an inner wall or backer part to be described further herein. End stile


30


is substantially identical in cross sectional configuration but of an opposite “hand” or comprising a mirror image of end stile


32


. End stiles


30


and


32


may also be formed of rolled or otherwise formed steel having a thickness similar to the thickness of the skin part


12


.




Referring again to

FIG. 1

, the panel


10


is still further characterized by plural formed metal reinforcing brackets


40


and


42


which are somewhat channel shaped and are adapted to nest within respective cavities


17


and


19


,

FIG. 4

, formed generally by the profiles of the upper and lower edges


16


and


18


, and in positions to provide additional support for the end stiles


30


and


32


and respective panel hinge members


44


and


46


, which may be generally of the configuration of the hinge members disclosed in U.S. Pat. No. 6,328,091, respectively. Depending on the width of a panel


10


, hinge members


44


and


46


may be secured to the upper and lower edges of the panel at spaced apart points generally as indicated in

FIGS. 1 and 2

, that is, with hinge members


44


and


46


positioned adjacent opposite side edges


13


and


15


of panel


10


, see

FIG. 2

, and in a position generally intermediate the opposite side edge portions, as indicated in

FIGS. 1 and 2

.




As shown in

FIG. 4

, each reinforcing bracket


40


includes a first flange


41


, an intermediate web


43


, an inclined flange


45


and a further flange part


46


generally parallel to flange


41


. Bracket


40


thus provides reinforcement for the skin part


12


at the point of attachment of a hinge member


44


to the skin part and also strengthens the panel in the area where the opposed end stiles


30


and


32


are secured to the skin part. As shown in

FIG. 4

, for example, hinge part


44


includes a support flange


44




a


which is adapted to be contiguous with inclined wall part


22


and secured thereto by suitable fasteners, such as blind rivets


50


. Blind rivets


50


may be of a conventional type and, particularly, of a type sold under the trademark MULTIGRIP. Plural rivets


50


may be used to secure a hinge member


44


to the continuous inclined wall part


22


which extends across the skin part


12


between the opposite side edges


13


and


15


of panel


10


.




As further shown in

FIG. 4

, support bracket


40


may be initially held in the position shown with respect to the skin part


12


, and further held to reinforce the skin part, by a bead of adhesive


52


between flange


41


and outer wall


14


. Adhesive bead


52


is preferably coextensive with the length of the bracket


40


and which is substantially also the width of flange


37


of the exemplary end stile


32


. Once the hinge parts


44


have been assembled to the panel


10


by the fasteners


50


, the bracket


40


is also completely secured in its working position, as shown in

FIG. 4

, to reinforce the panel


10


at the position of the hinge parts adjacent the opposite side edges


13


and


15


, respectively.




Referring further to

FIG. 4

, support brackets


42


are each characterized by an upturned flange


54


, a web


55


, an inclined web portion


56


and an upturned flange


57


; spaced from and substantially coextensive with flange


54


to form a somewhat channel shaped member. Support bracket


42


is located initially in its working position shown in

FIG. 4

by a bead of adhesive


52




a


between flange


54


and outer wall


14


as shown in the drawing figure. Adhesive bead


52




a


is similar to adhesive bead


52


. Brackets


42


are placed adjacent opposite side edges


13


and


15


of panel


10


to reinforce the skin part


12


and the end stiles


30


and


32


, generally at the point of attachment of hinge members


46


, respectively. As shown in

FIG. 4

, hinge members


46


are each, characterized by a mounting flange


46




a


including a suitable fastener receiving bore which is alignable with cooperating fastener receiving bores formed in inclined wall part


25


and flange part


56


of bracket


42


for receiving a blind rivet type fastener


50


in the same manner that the hinge part


44


, inclined wall part


22


and flange part


45


are operable to receive fasteners


50


for securing the hinge part


44


to the panel


10


at the upper edge


16


.




As shown in

FIG. 3

, hinge parts


44


and


46


include respective locating bosses


44




b


and


46




b


, as described in co-pending patent application Ser. No. 09/910,992, for precisely locating the respective hinge parts


44


and


46


with respect to the panel


10


. In this respect the inclined wall parts


22


and


25


are provided with suitable locating bores or recesses


22




a


and


25




a


, respectively, for receiving the boss portions


44




b


and


46




b


, as illustrated in

FIG. 3

, and as described in co-pending patent application Ser. No. 09/910,992.




Referring again to

FIG. 1

, the panel


10


is further characterized by pre-formed elongated insulation members or parts


60


,


62


and


64


, respectively, which are dimensioned to fit within cavities formed by the skin part


12


. For example, as shown in

FIG. 3

, insulation rail part


60


has a cross sectional shape adapted to be positioned within a substantial portion of the cavity


17


between outer wall


14


and inner wall part


24


, and at least a portion of the area of cavity


17


defined by the upper edge


16


to reinforce the skin part


12


in that area and to also provide acoustic and thermal insulation. In like manner, elongated insulation rail part


64


is dimensioned, as shown in

FIG. 3

, to nest within at least part of cavity


19


delimited by outer wall


14


and inner wall part


27


to occupy a portion of the cavity defined by the lower edge


18


of the panel


10


.




When insulation rail parts


60


and


64


have been positioned, as shown in

FIG. 3

, generally rectangular planar insulation part


62


is interposed the insulation parts


60


and


64


, as shown, to substantially fill a cavity or space


61


formed by the substantially pan shaped skin part


12


between cavities


17


and


19


and between opposite panel side edges


13


and


15


. At least insulation part


62


may be secured in its working position shown in

FIG. 3

by coating a surface


62




a


of insulation part


62


with a suitable hot melt adhesive. In this way insulation part


62


may be permanently adhered to the panel


10


at the inner surface of wall part


14


.




Still further, opposite and parallel surface


62




b


of insulation part


62


may also have a coating of adhesive applied thereto for securing an inner wall sheet or skin part


70


thereto as shown in FIG.


3


. Inner wall skin part or backer


70


may be formed of sheet steel, preferably twenty-eight ga. to twenty-nine ga., or another material of substantial strength to protect the insulation part


62


and to further strengthen the door panel


10


. Opposite side edges


62




c


and


62




d


of skin or backer part


70


are disposed between insulation part


62


and the flanges of the respective end stiles


30


and


32


including, for example, the flanges


37


,


39


of end stile


32


. Backer or inner skin part


70


is of about the same length as outer skin


12


and is dimensioned to substantially overlie inner wall parts


24


and


27


. The insulation parts


60


,


62


and


64


are preferably formed of somewhat rigid polymer foam, such as expanded polystyrene (EPS), for example, and having a density of about 1.0 to 2.0 lb/ft


3


.




Still further, as shown in

FIGS. 1

,


3


and


4


, the panel


10


is preferably formed with an elongated elastomer seal strip


72


which is adapted to be disposed in groove or recess


23


and extending between side edges


13


and


15


. Seal strip


72


is preferably formed of polyethylene foam extrusion and is dimensioned to be a force fit within the groove


23


so that it retains itself therein during operation of a door which includes plural interconnected panels


10


, such a door of the type, generally, as described in U.S. Pat. No. 6,328,091 and co-pending patent application Ser. No. 09/910,992, which are incorporated herein by reference. The seal strip


72


is characterized by a convex contact portion


72




a


,

FIGS. 3 and 4

, may also be modified to have a hollow interior and be formed of extruded or molded polyvinyl chloride.




Referring further to

FIGS. 3 and 4

, the generally concave part


21


of lower edge


18


is preferably provided with at least one elongated wear or anti-scuff strip


76


of a wear resistant material, such as polyurethane, which may be applied by spraying or brushing on the surface of the concave part


21


, and having a thickness of about 0.004 to 0.010 inches. Wear strip


76


extends substantially entirely across the panel


10


between edges


13


and


15


and has a width of about 0.38 inches, by way of example. Wear strip


76


may be provided in an area extending from the lower convex nose part


18




a


, as shown in

FIGS. 3 and 4

, upwardly over at least a portion of the concave part


21


of lower edge


18


so that, when the panel


10


is connected to an adjacent panel, the concave part


21


will not rub forcibly against convex part


16




a


of the adjacent panel and scuff such convex part which would be deleterious to the aesthetic qualities of panel


10


. Moreover, wear strip


76


also assists in providing a seal between concave part


21


and convex part


16




a


when adjacent panels


10


are in a door closed position, as described and shown in U.S. Pat. No. 6,328,091.




As shown in

FIGS. 3 and 6

, distal flange portion


39


of end stile


32


and a distal flange portion


31


of end stile


30


are adapted to receive threaded fasteners, such as self tapping screws


80


, for securing the respective flange portions of the stiles


30


and


32


to the respective upper and lower inner wall parts


24


and


27


with backer part


70


disposed therebetween.




One advantage of the multipart insulation panel comprising the insulation rail parts


60


and


64


and the intermediate panel part


62


is that these parts may be preformed in predetermined lengths and, if necessary, cut to size for various lengths of door panels


10


. Still further, the inconveniences associated with foamed-in-place polymer insulation in sectional door panels is eliminated. A preferred method of assembling a panel


10


, comprises providing the parts illustrated in FIG.


1


and inserting the support brackets


40


and


42


in their respective working positions, as shown in

FIG. 4

, by applying a bead of adhesive


52


and


52




a


to the inside surface of outer wall


14


or to the flanges


41


and


54


of the respective brackets


40


and


42


and placing these brackets in their working positions shown in FIG.


4


. After placement of the brackets


40


and


42


in their working positions, the insulation rail parts


60


and


64


may be positioned generally as shown in FIG.


3


. Typically, a panel


10


, during assembly, will be disposed on a horizontal surface with the wall part


14


in contact therewith. Once the insulation parts


60


and


64


are in place, a pre-formed insulation panel part


62


may be coated with adhesive on opposite surfaces


62




a


and


62




b


thereof and placed in engagement with the inner surface


14




c


of outer wall


14


in the position shown in

FIG. 3

, and substantially filling cavity


61


. At this time backer or inner skin part


70


may be positioned for engagement with the surface


62




b


of insulation panel


62


and overlying the inner wall parts


24


and


27


. Opposed end stiles


30


and


32


may then be placed in their working positions and secured to the backer


70


and the inner wall parts


24


and


27


with fasteners


80


.




Following assembly of the panel


10


to the point indicated hereinabove, the hinge parts


44


and


46


may be assembled to the panel


10


using the locating features provided by the bosses


44




b


and


46




b


and in accordance with methodology, generally as described in U.S. patent application Ser. No. 09/910,992. The hinge parts


44


and


46


may then be secured in place by fasteners, such as the blind rivets


50


, for example, or other suitable mechanical fasteners, if desired.




The door panel


10


may be constructed of conventional engineering materials used in the art of sectional doors and the like and including the materials noted herein. Except as noted herein, conventional manufacturing methods may be used to fabricate the panel


10


and its component parts. Although a preferred embodiment of the invention has been described in detail, those skilled in the art will recognize that various substitutions and modifications may be made without departing from the scope and spirit of the invention as set forth in the appended claims.



Claims
  • 1. A sectional door panel comprising:a generally planar outer wall; opposed top and bottom longitudinal edges joined to said outer wall and spaced apart inner walls spaced from said outer wall and forming opposed spaced apart elongated cavities at said top and bottom edges, respectively, and a cavity disposed therebetween; and plural prefabricated insulation parts including a first elongated insulation part inserted in and extending across a major part of said cavity formed at said top edge, a second elongated insulation part inserted in and extending across a major part of said cavity formed at said bottom edge and a generally planar insulation part disposed between said first and second insulation parts and filling said cavity disposed between said cavities formed at said top and bottom edges, respectively, and operable to restrict movement of said first and second insulation parts into said cavity disposed between said cavities formed at said top and bottom edges, respectively.
  • 2. The door panel set forth in claim 1 including:opposed preformed end stile members secured to said inner walls by mechanical fasteners and closing opposite lateral side edges of said panel.
  • 3. The door panel set forth in claim 1 including:spaced apart reinforcing brackets configured to be inserted in said cavities formed at said top and bottom edges, respectively, for reinforcing said top and bottom edges of said panel.
  • 4. The door panel set forth in claim 3 wherein:said brackets are disposed for engaging hinge retaining fasteners for securing opposed hinge parts to said panel at said top and bottom edges, respectively.
  • 5. The door panel set forth in claim 3 wherein;said support brackets are retained in said cavities formed at said top and bottom edges by an adhesive, respectively, and connecting said support brackets to a surface of said outer wall.
  • 6. The door panel set forth in claim 1 wherein:said generally planar insulation part is secured to a surface of said outer wall by an adhesive.
  • 7. The door panel set forth in claim 1 wherein:said top edge includes a convex curved portion and said bottom edge includes a concave curved portion cooperable with a convex curved portion of an adjacent door panel when said panel is connected to said adjacent door panel, and at least one of said convex and concave curved portions includes a wear strip thereon for minimizing scuffing of the other of said convex and concave curved portions of said edges, respectively, on said adjacent door panel.
  • 8. A sectional door panel comprising:a rolled metal skin part forming a generally planar outer wall; opposed top and bottom longitudinal edges joined to said outer wall and spaced apart inner walls spaced from said outer wall and forming opposed spaced apart cavities at said top and bottom edges and a cavity disposed therebetween; at least two prefabricated insulation parts insertable in said cavities at said top and bottom edges and at least part of said cavity formed therebetween; spaced apart reinforcing brackets inserted in said cavities at said top and bottom edges and engaged with said outer wall and one of said inner walls, respectively, for reinforcing said top and bottom edges of said panel and for engaging hinge retaining fasteners for securing opposed hinge parts to said panel at said top and bottom edges, respectively; and opposed end stile members secured to said inner walls by mechanical fasteners and closing opposite lateral side edges of said panel.
  • 9. The door panel set forth in claim 8 wherein:said brackets are retained in said cavities by an adhesive, respectively, connecting said brackets to a surface of said outer wall.
  • 10. The door panel set forth in claim 8 wherein:at least one of said insulation parts is secured to a surface of said outer wall by an adhesive.
  • 11. The door panel set forth in claim 8 wherein:said top edge includes a convex curved portion and said bottom edge includes a concave curved portion cooperable with a convex curved portion of an adjacent door panel when said panel is connected to said adjacent door panel, and at least one of said convex and concave carved portions includes a wear strip thereon for minimizing scuffing of the other of said convex and concave portions of said edges, respectively, on said adjacent door panel.
  • 12. A method of assembling an insulated door panel for a sectional door comprising the steps of:providing a rolled metal outer skin part forming an outer wall, opposed top and bottom edges extending between opposite lateral side edges and spaced apart inner walls; providing opposed end stile members engageable with said skin part to close said opposite lateral side edges of said panel, respectively; inserting elongated, substantially rigid insulation parts in cavities formed by said top and bottom edges, respectively; inserting a substantially planar and substantially rigid insulation part in a cavity formed between said top and bottom edges between said elongated insulation parts and operable to restrict movement of said elongated insulation parts into said cavity formed between said top and bottom edges from said cavities formed by said top and bottom edges, respectively; and closing opposite lateral side edges of said panel by attaching said end stile members to said skin part, respectively.
  • 13. The method set forth in claim 12 including the step of:securing said substantially planar insulation part to said skin part with an adhesive.
  • 14. The method set forth in claim 12 including the step of:securing a generally planar backer member to at least one of said end stiles and said inner walls to close said cavities with said insulation parts therein.
  • 15. The method set forth in claim 12 including the step of:applying an elongated wear strip to one of said edges to minimize scuffing the other of said edges of an adjacent panel.
  • 16. A sectional door panel comprising:a generally planar outer wall; opposed top and bottom longitudinal edges joined to said outer wall and spaced apart inner walls spaced from said outer wall and forming opposed first and second spaced apart cavities at said top and bottom edges, and a third cavity disposed therebetween; plural prefabricated insulation parts insertable in said cavities formed at said top and bottom edges and at least part of said cavity disposed therebetween, said insulation parts including a first elongated insulation part insertable in said first cavity, a second elongated insulation part insertable in said second cavity and a generally planar insulation part disposed between said first and second insulation parts and filling said third cavity to restrict movement of said first and second insulation parts into said third cavity and secured to a surface of said outer wall by an adhesive; and a backer engageable with said inner walls, respectively, for closing said third cavity, said backer being secured to part of said door panel by one of an adhesive and mechanical fasteners, respectively.
  • 17. A sectional door panel comprising:a rolled metal skin part forming a generally planar outer wall, opposed top and bottom longitudinal edges to said outer wall and spaced apart inner walls spaced from said outer wall and forming opposed spaced apart cavities at said top and bottom edges and a cavity disposed therebetween; prefabricated insulation parts insertable in said cavities formed at said top and bottom edges, respectively, and an insulation part insertable in at least part of said cavity formed therebetween to restrict movement of said insulation parts out of said cavities formed at said top and bottom edges into said cavity formed therebetween; at least one of said insulation parts is secured to a surface of said outer wall by an adhesive; a backer engageable with said inner walls, respectively, for closing said cavity formed between said spaced apart cavities, said backer being secured to parts of said door panel by one of an adhesive and mechanical fasteners, respectively; and opposed end stile members secured to said inner walls by mechanical fasteners and closing opposite lateral side edges of said panel.
  • 18. A method of assembling an insulated door panel for a sectional door comprising the steps of:providing a rolled metal outer skin part forming an outer wall, opposed top and bottom edges and spaced apart inner walls; providing opposed end stile members engageable with said skin part to close opposite lateral side edges of said panel; placing reinforcing brackets within respective cavities formed by said top and bottom edges and into engagement with said outer wall and respective ones of said inner walls, respectively, and securing said brackets, respectively, to one of said outer wall and said inner walls; inserting elongated, substantially rigid insulation parts in said cavities formed by said top and bottom edges, respectively, after placement of said brackets in said cavities formed by said top and bottom edges; inserting a substantially rigid insulation part in a cavity formed between said top and bottom edges; and closing opposite lateral side edges of said panel by attaching said end stile members to said skin part, respectively.
  • 19. The method set forth in claim 18 wherein:said brackets are secured to said one of said outer wall and said inner walls by an adhesive.
US Referenced Citations (20)
Number Name Date Kind
4685266 Mullet Aug 1987 A
4779325 Mullet Oct 1988 A
4995441 Leist et al. Feb 1991 A
5016700 Wegner et al. May 1991 A
5125155 Kyle et al. Jun 1992 A
5177868 Kyle et al. Jan 1993 A
5435108 Overholt et al. Jul 1995 A
5445208 Shaner et al. Aug 1995 A
5509457 Jella Apr 1996 A
5562141 Mullet et al. Oct 1996 A
5709259 Lewis et al. Jan 1998 A
5787677 Bolich et al. Aug 1998 A
5921307 Ford et al. Jul 1999 A
6006817 Stone et al. Dec 1999 A
6024908 Koncelik Feb 2000 A
6076590 Ford et al. Jun 2000 A
6148896 Pinto et al. Nov 2000 A
6276428 Pettersson et al. Aug 2001 B1
6330901 Friesen et al. Dec 2001 B1
6381917 Thielow et al. May 2002 B1