Stuffer cap mechanism for an electrical connector

Information

  • Patent Grant
  • 6338643
  • Patent Number
    6,338,643
  • Date Filed
    Friday, September 29, 2000
    24 years ago
  • Date Issued
    Tuesday, January 15, 2002
    22 years ago
Abstract
A wiring unit for an electrical connector having a housing with a first side and an opposing second side, an attaching portion on the second side and a latching portion adjacent the attaching portion. The latching portion couples the wiring unit to a standard support. Electrical wiring terminals are coupled to the housing and can receive electrical wires. A stuffer cap is selectively coupled to the terminals and the attaching portion. When the stuffer cap is coupled to the attachment portion, attachment of the electrical wires to the terminals using an impact tool can be accomplished without damaging the latching portion since the stuffer cap spaces the latching portion from the support surface when the wires are forced into the terminals. When the stuffer cap is coupled to the terminals, the stuffer cap eliminates or substantially reduces oxidation or corrosion on the terminals and wires.
Description




FIELD OF THE INVENTION




The present invention relates to a wiring unit of an electrical connector for communication and data transmission systems. The wiring unit includes a stuffer cap that may couple to a portion of the wiring unit so that the latch for attaching the wiring unit to a support (e.g., a faceplate) is protected during the termination of electrical wires to electrical wire insulation displacement contact (IDC) terminals of the wiring unit. More particularly, the present invention includes a stuffer cap that can be selectively coupled to one portion of the wiring unit to protect the latch during termination of the electrical wires and to the terminals or IDC of the wiring unit to help stop oxidation and corrosion.




BACKGROUND OF THE INVENTION




Due to significant advancements in telecommunications and data transmission speeds over unshielded twisted pair cables, the connectors (jacks, receptacles, patch panels, cross connects, etc.) have become critical factors in achieving high performance in data transmission systems, particularly at the higher frequencies. Some performance characteristics can degrade beyond acceptable levels at new, higher frequencies in the connectors unless adequate precautions are taken.




Often, wiring is pre-existing. Standards define the geometry for the connectors, such as the size and connection to existing faceplates and other support structures, thus making any changes to the wiring and to the connector geometry cost prohibitive.




The use of unshielded twisted pair wiring was created prior to the need for high speed data transmissions. Thus, while using the existing unshielded twisted pair wiring and complying with the existing standards, connectors must be developed that fulfill the performance requirements of today's higher speed communications, in order to maintain compatibility with the existing connectors.




One method to improve performance has been to use a stuffer cap coupled to the terminals of a jack or interconnection device for an electrical connector. The stuffer cap covers the twisted pair cables after they have been attached to the terminals, and retards or stops oxidation or corrosion on the terminals and termination wires. This retardation of corrosion helps to stop low level contact (voltage resistance) spikes. Examples of this type of stuffer cap are disclosed in U.S. Pat. Nos. 5,186,647 to Denkmann et al and 4,403,200 to Chen.




Generally, the stuffer cap configuration has not changed the geometry of the connector and allows ajack to be coupled to a conventional keystone envelope on a faceplate. The jack typically has a latching mechanism that has one latch or protrusion located on the “bottom” of the jack or opposite side of the wiring terminals and an opposing latch or protrusion located on the “top” of the jack or on the same side as the wiring terminals. The structure of the latching mechanism on the jack is generally perpendicular to the face of the jack that mates with a faceplate or other support. The protrusions couple to recesses in the keystone envelope and thereby hold the jack in place. However, at least one of these latching mechanisms may be damaged during the wire termination process.




Typically the wire termination process is performed using a 10-impact tool. Usually, the jack is positioned with the terminals extending upwardly and away from a support surface to increase efficiency of the wire termination process. However, this orientation typically positions one of the latching mechanisms between the housing of the jack and the support surface on which the jack is placed. The latching mechanism can be damaged by the force of the impact tool forcing the connector and its latching mechanism against the support surface. With a damaged latching mechanism, the jack will not be able to be properly coupled to the faceplate.




Examples of conventional of stuffer caps are disclosed in U.S. Pat. Nos. 6,116,943 to Ferrill et al.; 5,626,490 to Pitts et al.; 5,228,872 to Liu; 5,186,647 to Denkmann et al; and 4,403,200 to Chen.




SUMMARY OF THE INVENTION




Accordingly, an object of the present invention is to provide an electrical connector having a stuffer cap that can couple to the wiring unit in manner that protects the faceplate latching mechanism during wire termination.




Another object of the present invention is to provide an electrical connector having a stuffer cap that couples to the wire-connecting unit to retard or stop oxidation or corrosion on the terminals and termination wires.




Yet another object of the present invention is to provide an electrical connector having a stuffer cap that is simple and inexpensive to manufacture and use.




The foregoing objects are basically obtained by an electrical connector having a housing with opposite first and second sides, a stuffer cap attachment on the second side and a support latching portion adjacent the attachment on the second side. Electrical wire insulation displacement contact terminals are coupled to the housing and extend from the first side. A stuffer cap can be selectively coupled on the housing first surface over the insulation displacement contact terminals and to the attachment overlying the second surface.




The foregoing objects are further obtained by a method for assembling a wiring unit for an electrical connector, the wiring unit including a housing having opposite first and second sides. A stuffer cap attachment extends from the second side and a support latching portion is adjacent the attachment on the second side. Insulation displacement contact terminals are coupled to the housing, the terminals being at least partially covered by a plurality of protrusions on the housing. The method includes, positioning a stuffer cap overlying the second side and coupling the stuffer cap to the stuffer cap attachment, the stuffer cap extending farther from the second surface than the latching portion. The stuffer cap is placed on a surface, the stuffer cap separating the latching portion from the surface. Then electrical wires are positioned on the insulation displacement contact terminals and forces are exerted on the electrical wires, thereby coupling the electrical wires to the insulation displacement contact terminals coupled to the housing. The stuffer cap absorbs the force transferred to the housing and protect the latching portion. The stuffer cap can then be separated from the attaching portion and attached to the protrusions on the housing.




By forming an electrical connector and performing the method according to the invention, the stuffer cap will help retard or stop oxidation or corrosion on the terminals and termination wires. Additionally, the stuffer cap can be coupled to the housing side opposite the terminals so that when an impact tool is used to terminate the electrical wires to the electrical connector, the latching portion is protected to avoid being damaged.




Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the invention.




As used herein, terms, such as “front”, “rear”, “upwardly”, “downwardly”, “forwardly” and “backwardly”, are intended to describe relative directions, and do not limit the electrical connector to any specific orientation.











BRIEF DESCRIPTION OF THE DRAWINGS




Referring to the drawings which form a part of this disclosure:





FIG. 1

is an exploded side elevational view in section of an electrical connector and faceplate support according to the present invention.





FIG. 2

is a side elevational view in section of the electrical connector of

FIG. 1

with a stuffer cap coupled to the stuffer cap attachment portion, prior to engagement of the terminal wires.





FIG. 3

is a bottom perspective view of the electrical connector of

FIG. 2

with the stuffer cap attached to the stuffer cap attachment portion.





FIG. 4

is a bottom view of the stuffer cap of FIG.


1


.





FIG. 5

is a top view of the electrical connector of

FIG. 1

after insertion of the wires, but prior to coupling of the stuffer cap.





FIG. 6

is top view of the stuffer cap of FIG.


4


.





FIG. 7

is a bottom view of the electrical connector of FIG.


5


.





FIG. 8

is an end view of the electrical connector with the stuffer cap of FIG.


3


.





FIG. 9

is a top perspective view of the electrical connector of

FIG. 1

, with the stuffer cap coupled to the IDC terminals, but without the terminal wires coupled thereto.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




A high density electrical connector


10


for telecommunication systems and for coupling to a faceplate


50


or other support according to the present invention is illustrated in

FIGS. 1 and 2

. The connector comprises a connector body or housing


12


and a printed circuit board


16


on which terminals


18


are mounted. The terminals


18


are standard


110


electrical wire insulation displacement contacts (IDC), and couple to standard electrical or terminal wiring or wires


20


, as shown specifically in FIG.


5


. Through printed conductors on the circuit board, terminals


18


are electrically and mechanically coupled to resilient contacts


22


. The resilient contacts extend into the connector body in a configuration for electrical connection to a conventional or standard plug, particularly an RJ plug. A stuffer cap


24


is coupled to the housing


12


, protecting the wires


20


from oxidation or corrosion.




Faceplate


50


is conventional, and has keystone envelope


48


with grooves or indentations


46


.




Connector body


12


is preferably in the form of a jack. However, the connector body can be of any desired form, such as a plug, cross connect or any other connector in the telecommunications or data transmission field.




Connector body or housing


12


is preferably a hollow plastic two piece device having a main portion


23


and a terminal cover portion


25


. However, the housing may be formed from any material that would help insulate the electrical wires, terminals and circuit board from the outside environment, such as rubber or any other polymer. The main portion


23


has a forwardly opening plug receiving cavity


26


for receiving a conventional RJ plug. A shelf


30


extends rearwardly from the main portion


23


of connector body


12


and receives a portion of circuit board


16


, specifically the portion of the circuit board on which the resilient contacts


22


are mounted. Shelf


30


supports circuit board


16


and facilitates the coupling between the circuit board and the connector body. Shelf


30


of main portion


23


also has two indentations


53


along the surface


34


and end face


37


, as seen specifically in

FIGS. 7-9

. Indentations


53


are substantially rectangular recesses in the edge of face


37


and remove a portion of the corner common to face


37


and surface


34


. Housing


12


also has protrusion


40


extending from side


44


.




Faceplate or support latching mechanism or portion


32


extends outwardly from surface


34


of main portion


23


. As seen in

FIG. 1

, member


31


is preferably unitary with and extends substantially perpendicularly from lower surface


34


. Member


31


curves forward towards face


36


and forms latching mechanism


32


. Latching mechanism is preferably integral with and extends from member


31


and is substantially parallel with surface


34


. Tapered protrusion


38


extends from latching mechanism


32


. Adjacent latching mechanism


32


is stuffer cap attachment portion or mechanism


52


. Attachment portion


52


extends from and is preferably unitary with member


31


. Portion


52


extends rearwardly and away from face


36


or toward face


37


of housing


12


and is substantially parallel with lower surface


34


. Portion


52


has a protrusion or portion


54


that curves toward surface


34


. Alternatively, stuffer cap attachment portion


52


can be a separate device and located away from member


31


and latching portion


32


or may couple thereto by any means desired.




Cover portion


25


is preferably placed over the terminals


18


, which are coupled to circuit board


16


. Cover portion


25


is fixed to main portion


23


using adhesive or any other means desired. However, portion


25


does not necessarily have to be fixed to portion


23


and may merely be positioned next to and abut portion


23


.




As seen in

FIGS. 1 and 2

, a portion


55


of the terminals extends from the cover portion


25


, allowing wires


20


to be electrically connected thereto. Cover portion


25


preferably has a plastic, generally rectangular portion or base


56


with twelve protrusions


58


and


60


extending upwardly and substantially perpendicularly from the portion


56


, as seen in

FIGS. 1

,


2


and


5


. Protrusions


58


and


60


are preferably integrally formed with portion


56


and are oriented at an angle of about 30 degrees to a longitudinal axis


62


of the cover portion


25


. Alternatively, the protrusions can be oriented in any direction, whether it is parallel, perpendicular or any other angle to the axis


62


. Preferably, the protrusions are formed in groups of three, as seen specifically in

FIG. 5

, with the middle protrusions


58


extending further upwardly and away from the portion


56


than the protrusions


60


, as seen in

FIGS. 1 and 2

. Additionally, cover portion


25


, preferably has a post


64


positioned at one end and approximately in the center (i.e., along axis


62


) of the cover portion with regard to sides


66


and


68


. Post


64


extends to approximately the same height as protrusions


58


.




As seen in

FIGS. 3

,


4


and


8


, stuffer cap


24


is preferably U-shaped in transverse cross-section and has a substantially rectangular portion or base


70


having a first end


72


and second end


74


. Two sidewalls or arms


76


and


78


extend outwardly and substantially perpendicularly from the base. However, stuffer cap


24


may be any configuration that would protect wires


20


and latching mechanism


32


. First end


72


has a substantially perpendicular semi-cylindrical wall


80


extending away from base


70


to approximately the same height as walls


76


and


78


. Wall


80


preferably extends along an arc of about 180 degrees; however, wall


80


may be any shape, height or size desired. Walls


76


and


78


extend substantially the entire length of sides


82


and


84


and along portions


71


and


73


of second end


74


, as seen in FIG.


4


. At second end


74


, a portion


79


of base


70


is recessed between the facing ends of walls


76


and


78


, forming a substantially rectangular opening, as seen specifically in

FIGS. 4 and 6

. Extending outwardly and substantially perpendicular to base


70


are two parallelepiped protrusions


85


. Protrusions


85


conform in shape to fit in the indentations


53


in main portion


23


of housing


12


, as seen in

FIGS. 2 and 8

. The coupling of protrusions


85


with the indentations


53


fixes the stuffer cap


24


in place overlying surface


34


when the stuffer cap is coupled to the attachment portion


52


.




Stuffer cap


24


is preferably plastic and has a plurality of protrusions or members


86


extending upwardly or inwardly and substantially perpendicularly from base


70


. Protrusions


86


are preferably unitarily formed with base


70


and are oriented at an angle of about 60 degrees to a central longitudinal axis


88


of the base, as seen in FIG.


4


. However, the stuffer cap may be of any material that insulates the electrical wires and terminals from the outside environment, such as rubber or any other polymer. The protrusions can be oriented in any direction, whether it is parallel, perpendicular or any other angle to the axis


88


conforming to the orientations of insulation displacement contact terminals


18


and protrusions


58


and


60


.




The protrusions preferably form pairs


90


,


92


,


94


,


96


,


98


,


100


,


102


and


104


and extend inwardly from either of sidewalls


76


or


78


toward the second end


74


and central axis


88


, as seen in FIG.


4


. Each pair of protrusions in formed along a similar line and each pair is substantially parallel to the other pairs extending from a respective sidewall, as seen in

FIGS. 3 and 4

. For example, pairs


90


,


92


,


94


, and


96


are substantially parallel to each other and pairs


98


,


100


,


102


, and


104


are substantially parallel to each other. Additionally, the protrusions are preferably formed to be oriented approximately perpendicularly to the protrusions


58


and


60


of cover portion


25


and to frictionally fit within spaces created by protrusions


58


and the adjacent protrusions


60


when the stuffer cap is mounted thereon.




Stuffer cap


24


also has five substantially rectangular apertures or holes


106


,


108


,


110


,


112


and


114


extending entirely through the base


70


. However, the holes do not necessarily have to extend through base


70


and may be grooves or depressions in base


70


. Additionally, the holes may be any configuration, such as square, oval, or any other polygon desired. Holes


106


,


108


,


110


and


112


are positioned in the same orientation and direction as the protrusions


86


, that is, extending approximately 60 degrees relative to axis


88


. Each hole is positioned in-between two pairs of protrusions, as seen specifically in FIG.


4


. For example, holes


106


,


108


,


110


and


112


are positioned between pairs


90


and


92


,


94


and


96


,


98


and


100


, and


102


and


104


, respectively. The holes preferably do not extend the entire distance of the pairs of protrusions, but may be any size or dimension desirable. Hole


114


is preferably adjacent second end


74


and extends between the innermost protrusions


86


of pairs


96


and


104


.




Assembly




Initially, electrical connector


10


is preferably shipped with the stuffer cap


24


coupled to the attachment portion


52


. Stuffer cap


24


is attached to the attachment portion by simply sliding the cap along surface


34


such that base


70


engages attachment portion


52


and biases it away from surface


34


. The attachment portion mates with or engages the base


70


by protrusion


54


snapping into hole


114


and the attachment portion returning to is normal position relative to the surface


34


. As seen in

FIGS. 3 and 8

, the protrusion


54


on the attaching portion


52


extends through hole


114


in the stuffer cap


24


, with recess


71


fitting snugly around member


31


of the latching mechanism


32


. Additionally, protrusions


85


of the stuffer cap fit into indentations


53


on housing


12


. As seen in

FIG. 2

, the stuffer cap


24


overlies and extends from surface


34


with stuffer cap sidewalls


76


and


78


extending beyond both the latching mechanism


32


and the attaching portion


52


and extending over half the length of the housing


12


. A majority of the stuffer cap


24


supports the end of the housing


12


that has the cover portion


25


and terminals


18


attached thereon. This positioning of the stuffer cap


24


supports electrical connector


10


and protects the latching mechanism


32


during termination of the wires


20


from damaging engagement with the support surface on which the free edges of sidewalls


76


and


78


engage. Additionally, the fitting of protrusions


85


into indentations


53


along with the coupling to attachment portion


52


and member


31


prevents the stuffer cap from sliding or releasing during wire termination and/or shipping. Since sidewalls


76


and


78


are substantially perpendicular from base


70


, they provide a strong support protecting latching mechanism


32


and protrusions


86


from damage during termination of wires


20


.




Generally, wires


20


are terminated by placing the electrical connector


10


on a level support surface and using a


110


-type impact tool (


116


) to force the wires


20


between the terminals


18


and coupling the wires thereto, as is known in the art. The present invention allows the stuffer cap


24


to be positioned between the surface and the housing


12


, separating the latching portion from the support surface. Additionally, the stuffer cap absorbs the majority of force delivered by the impact tool to the wires and transferred to the housing.




After terminating the wires


20


, the stuffer cap


24


may be removed from the attaching portion


52


by simply applying force to the stuffer cap away from member


31


, such that base


70


forces attachment portion away from surface


34


and out of aperture


114


and protrusions exit from indentations


53


. Stuffer cap


24


is then coupled to the terminals


18


, engaging the wires


20


and securing wires to the terminals


18


. The protrusions


86


on the stuffer cap are adapted to mate or fit in-between and are frictionally held by the protrusions


58


and


60


on the cover portion


25


of the housing


12


, thereby protecting and holding the wires therein. Additionally, as seen in

FIG. 9

, a portion of the protrusions


58


fit within the apertures


106


,


108


,


110


, and


112


and the post


64


fits within the semicylindrical space defined by wall


80


, thereby aligning stuffer cap


24


over cover portion


25


. Alignment of the stuffer cap during the vertical displacement that occurs during termination is critical to consistently achieving a stable termination wire/contact surface. The electrical connector


10


is then coupled to a faceplate or other support, protrusions


38


and


40


engaging keystone envelope


48


of faceplate


50


using grooves or indentations


46


, in a conventional manner.




Stuffer cap


24


may also be used instead of an impact tool. The wires


20


may be partially inserted in-between the terminal, stuffer cap


24


is then positioned over the terminals


18


and forced into position. The protrusions


86


push the wires into position between the terminals, securing the wires


20


to the terminals


18


.




While a specific embodiment has been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.



Claims
  • 1. An electrical connector, comprising:a housing having first and second sides on opposite sides of said housing, a stuffer cap attachment on said second side and a support latching portion adjacent said attachment on said second side; electrical wire insulation displacement contact terminals coupled to said housing and extending from said first side in a direction away from said second side; and a stuffer cap selectively and releaseably coupled on said first side over said insulation displacement contact terminals and to said attachment overlying said second side and extending from said second side beyond said support latching portion.
  • 2. An electrical connector according to claim 1, whereinsaid stuffer cap is substantially U-shaped.
  • 3. An electrical connector according to claim 1, whereinsaid latching portion and said attachment extend in opposite directions from a member depending from said second side.
  • 4. An electrical connector according to claim 1, whereinsaid housing has a front face and a rear face; and said support latching portion extends parallel to and spaced from said second side of said housing, and forwardly toward said front face.
  • 5. An electrical connector according to claim 4, whereinsaid attachment extends parallel to and spaced from said second side of said housing, outwardly and rearwardly toward said rear face.
  • 6. An electrical connector according to claim 1, whereinsaid stuffer cap includes a base and a plurality of members extending therefrom, said plurality of members being coupled to portions of said housing adjacent said contact terminals when said stuffer cap is coupled on said housing over said terminals.
  • 7. An electrical connector according to claim 6, whereinsaid stuffer cap has first and second arms extending outwardly and substantially perpendicularly from said base, said first and second arms extending farther from said base than said plurality of members.
  • 8. An electrical connector according to claim 6, whereinsaid housing has a plurality of protrusions covering at least a portion of said insulation displacement contact terminals.
  • 9. An electrical connector according to claim 8, whereinsaid stuffer cap includes a plurality of apertures, said protrusions of said housing passing at least partially through respective apertures when said stuffer cap is coupled to said housing on said first side thereof.
  • 10. An electrical connector according to claim 8, whereineach of said plurality of members extending from said stuffer cap mates with at least one of said protrusions when said stuffer cap is mounted on said first side.
  • 11. An electrical connector according to claim 10, whereineach of said plurality of members frictionally engages at least one of said protrusions when said stuffer cap is mounted on said first side.
  • 12. An electrical connector, comprising:a housing having opposite first and second sides, a front face, a rear face, a stuffer cap attachment on said second side extending from said second side rearwardly toward said rear face, a support latching portion adjacent said attachment, said latching portion extending from said second side outwardly and forwardly toward said front face, and a plurality of protrusions extending from said first side; electrical wire insulation displacement contact terminals coupled to said housing and extending from said first side, said contact terminals covered at least partially by said protrusions; and a substantially U-shaped stuffer cap selectively coupled on said first side over said insulation displacement contact terminals and to said attachment overlying said second side and extending from said second side beyond said support latching portion.
  • 13. A electrical connector according to claim 12, whereinsaid stuffer cap includes a plurality of apertures, said protrusions of said housing passing at least partially through respective apertures when said stuffer cap is coupled to said housing on said first side thereof.
  • 14. An electrical connector according to claim 12, whereinsaid latching portion and said attachment extend in opposite directions from a member depending from said second side.
  • 15. A electrical connector according to claim 12, whereinsaid stuffer cap includes a base and a plurality of members extending therefrom, said plurality of members being coupled to portions of said housing adjacent said contact terminals when said stuffer cap is coupled on said first side of said housing.
  • 16. An electrical connector according to claim 15, whereinsaid stuffer cap has first and second arms extending outwardly and substantially perpendicularly from said base, said first and second arms extending farther from said base than said plurality of members.
  • 17. A method for assembling a wire unit for an electrical connector, the wire unit including a housing having opposite first second sides, a stuffer cap attachment extending from the second side, a support latching portion adjacent the attachment on the second side, and insulation displacement contact terminals coupled to the housing, the terminals being at least partially covered by a plurality of protrusions on the housing, the method comprising the steps ofpositioning a stuffer cap overlying the second side and coupled to the stuffer cap attachment, the stuffer cap extending farther from the second side than the latching portion, placing the stuffer cap on a support surface, the stuffer cap separating the latching portion from the support surface, positioning electrical wires on the insulation displacement contact terminals, exerting a force on the electrical wires and thereby coupling the electrical wires to the insulation displacement contact terminals coupled to the housing, said stuffer cap absorbing the force transferred to the housing and protecting the latching portion, separating the stuffer cap from the stuffer cap attachment, and attaching said stuffer cap to the protrusions on the housing.
  • 18. A method according to claim 17, further comprisingthe step of coupling the wire unit to a support by the latching portion.
  • 19. A method according to claim 17, whereinthe step of attaching the stuffer cap to said housing secures the electrical wires to the insulation displacement contact terminals.
  • 20. A method according to claim 17, whereinthe step of exerting a force on the electrical wires includes using an impact tool.
REFERENCE TO RELATED APPLICATION

This application is related to U.S. patent application Ser. No. 09/250,186 of John J. Milner, Joseph E. Dupuis, Richard A. Fazio, and Robert A. Aekins, filed Feb. 16, 1999, U.S. Pat. No. 6,193,526 and entitled “Wiring Unit with Angled Insulation Displacement Contacts” and to U.S. patent application Ser. No. 09/250,187 of John J. Milner, Richard A. Fazio, and Robert A. Aekins, filed Mar. 4, 1999, 2000, and entitled “Wiring Unit with Paired In-Line Insulating Displacement Contacts”, the subject matter of both of which arc hereby incorporated by reference.

US Referenced Citations (8)
Number Name Date Kind
5186647 Denkmann et al. Feb 1993 A
5228872 Liu Jul 1993 A
5403200 Chen Apr 1995 A
5624274 Lin Apr 1997 A
5626490 Pitts et al. May 1997 A
5947752 Wu Sep 1999 A
6116943 Ferrill et al. Sep 2000 A
6157574 Wu Dec 2000 A
Non-Patent Literature Citations (1)
Entry
Hubbell Premise Wiring, Inc., Catalog #1100R, published prior to Sep. 1999, pp. 12-19.