WO2001083903A1

WO2001083903A1 - Method of using hinged connector for steel trusses

Info

Publication number: WO2001083903A1
Application number: PCT/US2000/012159
Authority: WO
Inventors: William L. Babich
Original assignee: Alpine Engineered Products, Inc.
Priority date: 2000-05-04
Filing date: 2000-05-04
Publication date: 2001-11-08
Also published as: AU2000246994A1

Abstract

A method of using a hinged connector (10) to form a complex junction in the making of a steel truss is provided. In general, a hinged connector (10) that is suitable for use in the method of the present invention comprises: first and second pieces (100, 200), each piece having a spine (112, 212) and first and second legs (108, 110 and 208, 210) defining a generally U-shaped channel (102, 202) and a longitudinal axis (30); a hinge (300) interconnecting a pivot end portion (104, 106) of the first piece (100) and a pivot end portion (204, 206) of the second piece (200) such that the longitudinal axis (30) of the first and second pieces (100, 200) extend and can be pivoted relative to one another in substantially the same plane; and an opening (232) formed at least partially in the spine (112 or 212) of at least one of the first and second pieces (100, 200) of the hinged connector (10).

Description

METHOD OF USING HINGED CONNECTOR FOR STEEL TRUSSES

Technical Field

This invention relates to a method of using a hinged connector for connecting truss members at a complex junction, such as a "K-web" junction, for making steel trusses.

Background of the Invention

Steel truss systems are sought out as an alternative to conventional wooden truss systems because steel trusses have several desirable characteristics. For example, steel framing is not flammable. Like wood, steel framing allows roof spans typically from about 30 to 40 foot spans, and in some truss designs up to 70 feet. Additionally, components made of steel are reusable and recyclable. Also, lumber pricing can be volatile, whereas the pricing of steel products tends to be more stable and predictable.

Framing systems come into two basic categories. The first category is heavy hot-formed steel systems sections, typically used in the construction of pre-engineered metal buildings. The second category is light-gage steel framing systems. Light-gage components are designed for use in truss systems and cooperate with other common-construction systems such as brick, mortar and/or wood. Light-gage systems are realizing increased interest over hot-formed steel systems because, in a large number of re-roof and new construction jobs, post and beam style systems using hot-formed steel do not make economic sense in comparison to the lower cost alternative provided by light-gage steel.

Light-gage steel chords typically have square cut ends that are not pre-coped to fit with each other at angles other than 180^' degrees. Otherwise, a construction framer must cope the ends with hand tools or with power tools to achieve the desired pitch angle. At times the coping is not precise, requiring additional refining cuts. Regardless of the method used, labor costs are involved to cope the ends. Consumers and builders continue to demand greater design flexibility with light-gage components, and making these cuts for different truss designs becomes excessively expensive.

U.S. Patent No. 5,890,339 invented by DavidR. Willis and issued on April 6, 1999 to Alpine Engineered Products , Inc . , which is incorporated herein by reference in its entirety, discloses a hinged pitch break connector for connecting square-cut chords used in truss systems at a desired pitch without the need for coped ends. However, this hinged pitch break connector has not been used for connecting truss members for making more complex types of connections in steel trusses. For example, it is often desirable to connect truss members at a complex junction, such as a "K-web" type junction, for making a steel truss for providing stepped roof or ceiling structures.

Summary of the Invention

The invention is a method of using a hinged connector for connecting truss members at a complex junction, such as a "K-web" junction, for making steel trusses.

In general, a hinged connector that is suitable for use in the method of the present invention comprises: first and second pieces, each piece having a spine and first and second legs defining a generally U-shaped channel and a longitudinal axis; a hinge interconnecting a pivot end portion of the first piece and a pivot end portion of the second piece such that the longitudinal axis of the first and second pieces extend and can be pivoted relative to one another in substantially the same plane; and a ^"n ^" opening formed at least partially in the spine of one of the first and second pieces of the hinged connector

Using a hinged connector of this type, the method comprises the steps of: positioning a first truss member to extend through the opening of the hinged connector and so that a portion of the first truss member is in overlapping contact with at least a portion of the legs of at least one of the first and second pieces of the hinged connector; positioning an end of a second truss member in overlapping contact with at least a portion of the legs of the first piece of the hinged connector; positioning an end of a third truss member in overlapping contact with at least a portion of the legs of the second piece of the hinged connector; and securing the first, second, and third truss members to the hinged connector. By way of further explanation, as used herein, the defining characteristic of a "complex junction" of truss members in a steel truss is a truss member that extends through an opening formed in the spine or spines of a hinged connector.

The terms "first piece" and "second piece" are to be understood to merely distinguish between two, generally U-shaped, pieces of the hinged connector. The two pieces are adapted and hinged to pivot without interference over a suitable range of angular positions for making various complex junctions of truss members for making steel trusses. More particularly, over at least the desired pivotal range of angular positions, the structures of the two pieces, such as the spines and legs, cannot interfere with one another or with a "first" truss member that can be positioned through the opening of the hinged connector.

It is to be understood that, as used herein, the term "truss member" includes any elongated member used to make a steel truss. For example, the larger truss members used in forming a truss are commonly referred to as chords, and the smaller truss members used in forming a truss are commonly referred to as chords. Furthermore, the words "first," "second," and "third" are arbitrarily assigned to the various truss members that can be used in forming a complex junction for a steel truss according to the invention. While it is contemplated that at least three truss members will be used in practicing the invention, it is within the scope of the invention to include additional steps and truss members. For example, the method optionally includes the step of positioning a "fourth" and even more truss members in forming such a complex junction of truss members for a steel truss.

As used herein, the term "overlapping" includes, for example, both the cases where a portion of an inner surface of a truss member is positioned in contact with a portion of an outer surface of the hinged connector, for example, and where a portion of an outer surface of a truss member is positioned in contact with a portion of an inner surface of the hinged connector.

It is also to be understood that the steps of the method can be performed in any convenient and practical sequence. For example, the step of positioning the "first" truss member through an opening formed in the spine or spines of the hinged connector can be, and sometimes is, performed after positioning one or both of the "second" or "third" truss members.

According to a further aspect of the invention, a steel truss having a complex junction of truss members using a hinged connector is provided. An example of such a complex junction, without limitation, is a "K-web" junction.

The method of using a hinged connector according to the invention greatly increases the flexibility of how the hinged connector can be used in making steel trusses, and has the advantage of allowing for reducing the number of specially-designed connectors that would otherwise be required to make a wide variety of steel truss designs. These and other features and advantages of the present invention will be apparent to aperson skilled in the art upon reading the following detailed description of preferred embodiments and referring to the drawing. Brief Description of the Drawing

The accompanying drawing is incorporated into and forms a part of the specification to illustrate several examples of the present invention. The figures of the drawing together with the description serve to explain the principles of the invention. The drawing is only for the purpose of illustrating preferred and alternative examples of how the invention can be made and used and is not to be construed as limiting the invention to only the illustrated and described examples. The various advantages and features of the present invention will be apparent from a consideration of the drawing in which:

FIG. 1 illustrates an example of the hinged connector used in forming a "K-web" junction in a steel truss design that can provide a stepped roof of a building;

FIG. 2 illustrates an example of a hinged connector used in forming a "K-web" junction in a steel truss design that can provide a stepped ceiling of a building;

FIG. 3 is a perspective view of an embodiment of a presently most-preferred embodiment of a hinged connector suitable for use according to the method of the invention shown in a 180 degree position;

FIG. 4 is an elevational view of the hinged connector shown in FIG. 3 with portions broken out;

FIG. 5 is a top plan view of an embodiment of the hinged connector shown in FIG. 3 taken along line 5-5 in FIG. 4;

FIG. 6 is an elevational view of an embodiment of a hinged connector suitable for use according to the invention pivoted about its hinge in a first direction relative to the 180 degree position shown in FIGS. 3-5;

FIG. 7 is an elevational view of an embodiment of a hinged connector suitable for use according to the invention pivoted about its hinge in a second direction relative to the 180 degree position shown in FIGS. 3-5;

FIG. 8 is a cross-sectional view of an embodiment of a hinged connector suitable for use according to the invention taken along line 8-8 in FIG. 1;

FIGS. 9-13 illustrate the steps of the invention according to a presently most-preferred embodiment using the suitable hinged connector illustrated in FIGS. 3-8 and various truss members to form a "K-web" junction of a steel truss; and

FIGS. 14-16 illustrate three additional examples of the types of complex junctions that can be made according to the method of the present invention. Detailed Description of Preferred Embodiment

A hinged connector, generally designated by the numeral 10, is shown used for interconnecting various truss members, such as chords 20a and webs 22a-c, to form a "K-web" junction of a steel truss design as shown in FIGS. 1 and 2. More particularly, FIG. 1 illustrates an example of the hinged connector 10 used in forming a "K-web" steel truss design that can provide a stepped roof of a building, whereas FIG. 2 illustrates an example of the hinged connector 10 used in forming a "K-web" steel truss design that can provide a stepped ceiling of a building. It is to be understood, of course, that the use of relative orientation terms such as "upper," "lower," "horizontal," and the like are for convenient reference to the orientation of the "K-web" junction of a steel truss design as shown in FIGS. 1 and 2 and that such terms do not necessarily limit the scope of how the hinged connector 10 can be oriented and used according to the method of the present invention.

Chord 20a and webs 22a, 22b, and'22c are secured to connector 10 with sheet metal screws 24, rivets, or the like to form a "K-web" junction. Webs 22a, 22b, 22c, 22d, and 22e are also interconnected to chords 20a, 20b, and 20c as shown with sheet metal screws 24, rivets, or the like, accordingly, forming part of a steel truss assembly. As used herein, the term "truss members" generally includes both chords, such as chords 20a-c, and webs, such as webs 22a-e. As will be appreciated by one skilled in the art of making steel trusses, the remainder of the steel truss, not shown, can be similarly constructed.

Preferably, the chords 20a-c are elongated members of generally a U-shaped cross-section having a base portion 26 and leg portions 28 (see FIG. 8 herein). The presently most-preferred chords for use in this invention are described in more detail in U.S. Patent No.5,771 ,653 issued June 30, 1998, which is incorporated herein by reference in its entirety. It is to be understood, of course, that the chords 20a-c can be of different design, provided the design of at least the chord 20a and the hinged connector 10 are adapted and sized to work together.

Preferably, the webs 22a-e are elongated tubular members of a generally square or rectangular cross-section. It is also to be understood, of course, that the webs 22a-e can have a different design, for example, they can be U-shaped, provided the design of at least the webs 22a-c and hinged connector 10 are adapted and sized to work together.

By way of further example, the chords 20a-c can have a spacing between the lower ends of the leg portions of 0.75 inches (19 millimeters). Similarly, the webs 22a-e can have a square cross- section of 0.75 inches X 0.75 inches (19 millimeters X 19 millimeters) or a rectangular cross-section of 0.75 inches X 1.5 inches (19 millimeters X 38 millimeters). These dimensions provide at least one dimension that is the same as the spacing between the lower ends of the leg portions of the chords 20a-c, which can provide a common dimension for the steel truss as a whole. It is to be understood, of course, that these dimensions are only exemplary, and larger or smaller dimensions for the truss members can be used.

As hereinafter described in detail, the hinged connector 10 is adjustable to provide a desired pitch angle α and then locked or secured in place by a plurality of sheet metal screws 24, rivets, or the like. Preferably, connector 10, and chords 20a and webs 22a-e, are secured in place by sheet metal screws 24 with a dual-thread structure. An example of a suitable double-sheer screw for use in this invention is disclosed in U.S. Patent No.5,746,039, issued May 5, 1998, which is incorporated herein by reference in its entirety.

Referring to FIG. 1, the chords 20a and 20c are oriented such that the base portion of these two U-shaped chords face upward, which provides surface area for attaching roofing or other structural materials to the upperside of the completed steel truss when it is incorporated into a building. The upwardly-facing chords 20a and 20c shown in FIG.l can define a stepped roofing structure for a building. In other words, chords 20a and 20c are supported in the truss at different levels or heights, that is, at "stepped" levels. The bottom chord 20b is oriented such that the base portion of this U-shaped chord faces downward, which provides surface area for attaching ceiling or other structural materials to the lower side of the completed steel truss when it is incorporated into a building.

Similarly, referring to FIG. 2, the chords 20a and 20b are oriented such that the base portion of these two U-shaped chords face downward, which provides surface area for attaching ceiling or other structural materials to the underside of the completed steel truss when it is incorporated into a building. The downwardly-facing chords 20a and 20b of the steel truss can define a stepped ceiling structure for a building. In other words, chords 20a and 20b are supported in the truss at different levels or heights, that is, at "stepped" levels. The upper chord 20c is oriented such that the base portion of this U-shaped chord faces upward, which provides surface area for attaching roofing or other structural materials to the upper side of the completed steel truss when it is incorporated into a building.

In general, a hinged connector that is suitable for use in the method of the present invention comprises: first and second pieces, each piece having a spine and first and second legs defining a generally U-shaped channel and a longitudinal axis ; a hinge interconnecting a pivot end portion of the first piece and a pivot end portion of the second piece such that the longitudinal axis of the first and second pieces extend and can be pivoted relative to one another in substantially the same plane; and an opening formed at least partially in the spine of one of the first and second pieces of the hinged connector.

Although not critical to the practice of the present invention, according to the presently-most preferred embodiment of the invention, the hinged connector 10 is substantially the same as the hinged pitch break connector shown in U.S . Patent No 5,890,339 invented by David R. Willis and issued on April 6, 1999 to Alpine Engineered Products, Inc. An exact embodiment of the presently most- preferred embodiment of the hinged connector 10 for practicing the present invention is hereinafter described in detail, however, which is particularly well adapted to being used for selectively forming either a pitch break connection according to Alpine's prior U.S. Patent No. 5,890,339 or a more complex junction of truss members according to the present invention.

Referring now to FIGS. 3-5, a detailed illustration of the presently most-preferred embodiment of hinged connector 10 is shown. According to the design of this presently most- preferred embodiment, the first piece of the hinged connector 10 can be described as being an "inside" rigid member 100 and the second piece can be described as being an "outside" rigid member 200. Outside member 200 defines a U-shaped channel 202 with first planar leg member 208 , second planar leg member 210, and spine member 212. First and second planar leg members 208 and 210 laterally extend from spine member 212. Inside member 100 is similarly constructed and defines a U-shaped channel 102 with first planar leg member 108, second planar leg member 110, and spine member 112. As illustrated in FIG. 4, a substantially central longitudinal axis 30 extends along the length of members 100 and 200, respectively, which axes 30 coincide as shown when the hinged connector is in the in a 180-degree position as shown in FIGS. 4-6. Connector 10 is made of a durable structural material sufficient to support standard building loads. Such a material is 20-gage cold-formed steel.

First and second pivot end portions 104 and 106 (shown in FIG. 5), accordingly, extend longitudinally from the first and second leg members 108 and 110, respectively, of inside piece 100. Third and fourth pivot end portions 204 and 206 (shown in FIG.5), accordingly, extend longitudinally from the third and fourth leg members 208 and 210, respectively, of the outside piece 200.

Referring to FIG. 5, hinge 300 pivotally connects first and third pivot end portions 104 and 204, respectively, such that they are opposed, and similarly connects second and fourth pivot end portions 106 and 206, respectively. When pivoted about hinge 300, first pivot end portion 104 and second pivot end portion 106 of the inside piece 100 are slidingly accepted into the generally U- shaped channel 202 of the outside piece 200.

Of course, it is to be understood one of the few structural requirements for the hinged connector for use in the method of the present invention is two pieces, such as inside and outside members 100 and 200, be adapted and hinged to pivot without interference over a suitable range of angular positions for making various complex junctions of truss members for making steel trusses. More particularly, over at least the desired pivotal range of angular positions, the structures of the two pieces, such as the spines and legs, cannot interfere with one another or with a "first" truss member that can be positioned through the opening of the hinged connector. Accordingly, although the presently most-preferred embodiment contemplates that the first and second pivot end portions are slidingly accepted into the generally U-shaped channel 202 of the outside piece 200, this is not necessarily required. For example, the pivot end portion 104 of the planar leg 108 can be slidingly accepted into the generally U-shaped channel 202, whereas the pivot end portion 206 of the planar leg 210 can be slidingly accepted into the U-shaped channel 102 of the inside piece 100.

Depending on the size and gage of the hinged connector, each of the planar leg members of the rigid members 100 and 200 can have a hem 114, 214, respectively, for stiffening reinforcement of the connector 10. For a smaller gage sheet metal, a hem 214 preferably extends along the bottom of each planar leg members 208 and 210 and pivot end portions 204 and 206 and has an upper edge 216. Width A of hem 214 is about 0.25 inches (about 6.3 millimeters). Hem 214 is a folded-over portion of first planar leg member 208 and second planar leg member 210 and pivot end portions 204 and 206, respectively. Hem 214 aids to stiffen connector 10 and also covers jagged edges which may be formed on upper edge 216 by the process. The planar leg members 108 and 110 of the inside piece 100 are similarly constructed. A hem is preferably not used, however, when the sheet metal is of a sufficient gage.

Referring again to FIG. 4, according to this presently most-preferred embodiment of the hinged connector 10, the pivotal center PI of the hinge 300 is preferably offset from a longitudinal axis 30 of the inside and the outside pieces and extends through each of the pivot end portions. Referring still to FIG.4, hinge 300 and center point PI , accordingly, are offset from longitudinal axis 30 by distance B, which is from about 0.3 inches (about 8 millimeters) to about 0.4 inches (about 10 millimeters). Preferably, distance B is about 0.34 inches (8.6 millimeters). Respectively, hinge 300 and center PI, accordingly, are offset from spine member 212 by distance C. Distance C is from about 1.45 inches (about 36.8 millimeters) to about 1.55 inches (about 39.4 millimeters). Preferably, distance C is about 1.5 inches (38 millimeters). Hinge 300 is a pivotally-securing device secured through apertures extending through end portions 104, 106, 204, and 206. A suitable securing device is formed of rivets 302. The apertures are generally centered about center point PI and are of a size sufficient to receive rivets 302. Rivets 302 are of a length sufficient to clasp end portions 104 and 204 together and end portions 106 and 206, respectively.

According to this preferred embodiment of this hinged connector 10, the first, second, third, and fourth pivot end portions 104, 106, 204, and 206 are preferably ear shaped. Referring to FIG.3, third and fourth pivot end portions 204 and 206 have terminal edges which are each defined by circular edge portions 218 and substantially linear edge portions 222, respectively. The first and second pivot end portions 104 and 106 are similarly constructed.

For clarity, the outside piece 200 of hinged connector 10 is described in further detail with the understanding that inside piece 100 is substantially similar in proportion and structure. Similar structures and proportions of inside piece 100 have similar nomenclature designations as those of outside piece 200, but are designated in the "100" nomenclature series. For example, the U-shaped channel of outside piece 200 is designated as 202, and the U-shaped channel of inside piece 100 is designated as 102.

Circular edge portion 218 has a center PI at hinge 300, and a radial distance R. Radial distance R is about 1.5 inches (about 38 millimeters). On both end portions 204 and 206, circular edge portion 218 extends to a sloped substantially linear edge 222. Sloped linear edges 222 terminate at hemmed edges 214 of end portions 204 and 206. Still referring to FIG. 4, sloped edge 222 originates at point P2, which is offset from longitudinal axis 30 and generally longitudinally aligned with point PI.

Edge 222 slopes a distance D, which has a value from about 0.88 inches (about 22.3 millimeters) to about 0.90 inches (about 22.9 millimeters). Preferably, distance D is about 0.89 inches (about 22.7 millimeters). Thus, the slope of edge 222 is about 2.45, where distance D serves as the longitudinal reference in calculating the slope value.

Distance E is measured from the intersection of sloped edge 222 and hemmed edge 216 to a point substantially perpendicular (with respect to hemmed edge 214) to origin point PI. Distance E is about 0.606 inches (about 15.4 millimeters).

Distance F is the distance from point PI to edge 250, and has a length sufficient to provide screw contact area between the ends of truss members, such as chord 20a and webs 22a-c, and connector 10. The screw contact area, for example, is the region in which chord 20a and member 100 overlap , as best illustrated in FIGS . 1 and 8. A suitable length F of inside and outside pieces 100 and 200, respectively, is about 6 inches (about 150 millimeters).

Referring now to FIG.5, in the presently most-preferred embodiment of hinged connector 10, a top view of hinged connector 10 is shown illustrating a void or rectangular opening 232 in the spines 112 and 212 of rigid members 100 and 200. Rectangular opening 232 extends from inside piece edge 134 of the spine 112 of the inside piece 100 to outside piece edge 234 of the spine 212 of the outside piece 200. Outside member pivot end portions 204 and 206 extend a distance G from point P2 to at least pivotal center PI. It should be noted that, because the vertical projection of opening 232 changes when angle α varies, the following description of rectangular opening 232 refers to connector 10 when angle α is substantially at 180 degrees, as best illustrated in FIG. 4.

To be used in the method of the present invention, the opening 232 must be at least of sufficient size and shape to permit the cross-section of a truss member, such as web 22a, of a truss in which the hinged connector is adapted to be positioned to extend through the opening 232.

Opening 232 also provides a larger variety of angular positions to which the connector 10 may be formed, as measured by angle α (shown in FIGS. 6 and 7). In the presently most-preferred embodiment of the hinged connector 10, the opening 232 is also formed to be at least sufficiently large to allow a sufficient degree of freedom in the angle α that the rigid members can be pivoted to appropriate angles for forming a complex juncture, such as a "K-web" juncture, without interference between the spines 112 and 212 of the rigid members and a truss member 22a positioned to extend through the opening 232. Accordingly, depending on the location of the opening 232 with respect to the hinge 300, the size of the opening 232 may need to be larger to prevent edges 134 and/or 234 of spines 112 and 212, respectively, from interfering with a truss member 22a to be positioned to extend through the opening 232 when the hinge connector 10 is pivoted to a desired angle α.

As used herein, the term "horizontal" plane is with respect to how a steel truss is typically positioned and used. For example, in FIGS. 1 and 2, chord 20a is oriented to extend in a horizontal plane. As illustrated in FIGS. 1 and 2, the acute pitch or angle between a horizontal plane and either of the webs 22b and 22c, is typically expected to be in the range of about 35 degrees to about 50 degrees. Accordingly, the hinged connector 10 is designed to accommodate a truss member 22a positioned through the opening 232 and to pivot to any angular position having an angle α in the range of 180 degrees plus or minus at least 50 degrees (as angle α is measured in FIGS. 6 and 7).

It is more preferable, however, to be able to accommodate any acute pitch or angle between the horizontal and either of the webs 22b and 22c in the range of about 25 degrees to about 60 degrees. Accordingly, the hinged connector is more preferably designed to accommodate a truss member 22a positioned through the opening 232 and to pivot to any angular position having an angle α in the range of 180 degrees plus or minus at least 60 degrees (as angle α is measured in FIGS . 6 and 7) . Of course, a still broader range of pivotal motion can be desirable in a few steel truss applications.

In addition, the opening 232 is formed and/or positioned to allow a sufficient range or degree of freedom with respect to angle α that the rigid members can be pivoted without interference between the spines 112 and 212 of the inside and outside rigid members 100 and 200, respectively, for use in an application where no truss member is positioned to extend through the opening 232, as in the case of a simple pitch break connection of two chords members, for example. Accordingly, for maximum flexibility of use for the hinged connector 10, it is also most preferred, although not required, that the range of pivotal motion for the hinged connector 10 include a range for angle α of 65 degrees to 297 degrees without interference between the spines 112 and 212 of the inside and outside rigid members when no truss member is positioned through the opening 232 in the hinged connector 10. This broad range of pivotal freedom tends to maximize the usefulness of the hinged connector for both complex junctions and for conventional pitch break junctions.

According to the presently most-preferred embodiment of the hinged connector 10, the void or opening is symmetrically formed in both the spine 112 and 212 of the inside and outside pieces 100 and 200, as best shown in FIG.5. This symmetrical design of the opening 232 increases the flexibility of where truss member 22a can be positioned to extend through the opening 232 and how the hinged connector 10 can be used for connecting truss members of a steel truss. It is to be understood, however, that the exact location of the opening 232 is not critical to the practice of the invention, and that the opening 232 can be formed to be shifted to one side or the other of the pivot point PI. For example, the opening 232 can be formed asymmetrically, and even entirely in the spine 112 of rigid member 100 or entirely in the spine 212 of rigid member 200.

FIGS. 6 and 7 illustrate the ultimate angular positions available by connector 10. Referring to FIG.6, connector 10 is positioned in a pitch break configuration typically encountered for forming ridges in building roofs, as 'described in U.S. Patent No. 5,890,339. Angle α, referenced between edges 126 and 226, respectively (the same, of course, as the angle between^' the axes 30 of the inner and outer pieces 100 and 200) is adjustable in a first direction from the position shown in FIG. 4 where angle α has a value of about 180 degrees. Connector 10 can be adjusted in a first direction to about 65 degrees to accommodate roof spans for building construction.

Referring to FIG.7, connector 10 is adjustable in a second direction from the position shown in FIG. 4, which position can also be used to form a typical pitch break joint, or, used in the method of the present invention. Rectangular opening 232, discussed earlier, allows a further degree of freedom with respect to angle a. The maximum magnitude of angle a between edges 126 and 226, respectively, is about 297 degrees, which is the preferred range of use in a typical pitch break joint. Of course, as previously discussed, such a broad pivotal range is not necessary for forming a typical "K-web" junction between truss members, but the preferred broad range of pivotal freedom increases the flexibility of how the hinged connector can be used in making steel trusses for other complex junctions, and can reduce the number of specially-designed connectors that would otherwise be required to make a wide variety of steel truss designs.

Throughout the angular positions shown in FIGS. 6 and 7, the amount of sheet lapped area remains at least a minimum value. One lapped area, for example, is defined as that area where pivot end portions 104 and 204 overlap. For example, with the dimensions provided above, the lapped area of connector 10 is about 7.5 square inches (about 48 square cm). This lapped area remains relatively constant throughout the positions of connector 10 represented in FIGS. 6 and 7. Thus, for example, the number of #12-size screws that can be used to secure members 100 and 200 in a fixed position is about twenty-five, and the number of #14 size screws that can be used is about nineteen. Preferably, sheet metal screws having a dual-threaded structure are used, described later herein.

Referring to FIG. 8, a cross-section of chord 20a mounted to connector member 100 is shown. Chord 20a is secured to connector 10 with sheet metal screws 24, rivets, or the like. Preferably, sheet metal screws having a dual-thread structure are used such as those shown in FIG. 8. Sheet metal screw 24 has a hexagonal head 42 extending to a first threaded portion 44. First threaded portion 44 is connected to second threaded portion 46 through blank shank portion 48. Sheet metal tip 50 connects to second threaded portion 46. Screws 24 are installed by rotating screw 24 and urging sheet metal tip 50 against the assembly at connector 10 and chord 20a intersection or the connector's sheet screw contact area such that tip 50 taps a hole therethrough. With continuous urging and rotation, sheet metal screw 24 threads into the opposing sides of connector 10 and chord 20a. Blank portion 48 deters expansion and subsequent deformation of the opposing sides of connector 10 and chord'20a. That is, as second threaded portion 46 is ^'threaded through chord 20a and first leg member 108, blank portion 48 slides through the hole until tip 50 encounters second leg member 110. Blank portion 48 extends through the hole made by second threaded portion 46. Although screw 24 is continuously rotated, first threaded portion 44 does not threadingly engage the hole until second threaded portion 46 taps into second leg member 110.

Again, for clarity, the following description of the cross-section of chord 20a and inside U- shaped member 100 is provided with the understanding that similar connections of a chord to the outside piece 200 can be used for making a pitch break connection. Alternatively, or in addition, other chords, such as webs 22a-c, can be connected to the connector 10.

Corner 136 between spine member 112 and first leg member 108 and corner 138 between spine member 112 and second leg member 110 each have radial curves of about 0.04 inches (about 1 millimeters). Member 100 is flared outward such that the general cross-sectional area of member 100 defined by planar leg members 108 and 110 and spine member 112 is generally trapezoidal. That is, length H and length K are substantially similar. But it should be noted that these lengths can vary from one another without departing from the scope and spirit of the invention. Length H is the distance between hem inner surfaces 140. In the illustrated preferred embodiment, length H is about 0.77 inches (19.5 millimeters). Length K is the distance between the outer edge of corner 136 to the outer edge of corner 138. Of course, these lengths H and K are only exemplary, and can be much larger or smaller as a matter of engineering design choice. An advantage of this flared configuration is to allow webs 22a-c to be inserted with ease.

Channel or chord 20a has roll-formed lips 40 which are raised to a level similarly matching top corner edges 54 between base 26 and each of the chord legs 28. That part of each leg 28 of the chords 20a, adjacent the corner edges 54 at the base 26 of the chord cross-section, and the upwardly directed part of the roll-formed lips 40 of each planar leg 108, 110 are co-planar, with the result that the chords 20a will lie flat on either of their sides on an assembly table making truss assembly much easier. This preferable design also enables trusses to be stacked and banded together, either for storage or during transport to a construction site. Also, roll-formed lips 40 avoid dangerous sharp edges and limit damage to objects pulled through the finished trusses.

Referring now to FIGS. 9-13, a representative example of the method of the invention is illustrated. In general, the method comprises the steps of: positi oning a^'f irst truss member to extend through the opening of the hinged connector and so that a portion of the first truss member is in overlapping contact with at least a portion of the legs of at least one of the first and second pieces of the hinged connector; positioning an end of a second truss member in overlapping contact with at least a portion of the legs of the first piece of the hinged connector; positioning an end of a third truss member in overlapping contact with at least a portion of the legs of the second piece of the hinged connector; and securing "the first, second, and third truss members to the hinged connector. Of course, the angle α between the inside piece and the outside piece of the hinged connector 10 can be adjusted according to the desired design of a particular complex juncture in a steel truss.

The order in which these steps are performed is a matter of engineering design preference and is not critical to the practice of the invention. For example, as shown in FIG. 9, the step of positioning an end of chord 20a in overlapping contact with at least a portion of the legs of the inside piece 100 of the connector 10 can be performed first, according to the engineering or personal preference of the person designing or performing the method according to the invention. As shown in FIG. 10, the step of positioning a web 22a to extend through an opening 232 formed in the spine 112 and/or 212 of a hinged connector 10 can be performed next, according to the engineering or personal preference of the person designing or performing the method according to the invention. As shown in FIG. 11 , an optional step of positioning an end of a web 22b in overlapping contact with at least a portion of the legs of the outside piece 200 of the hinged connector 10 can be performed next, again according to the engineering or personal preference of the person designing or performing the method according to the invention. Although using such an optional step provides a full "K-web" junction, this step and the resulting full "K-web" configuration may not be necessary in all complex junctions for a steel truss. As shown in FIG. 12, the step of positioning an end of a web 22c in overlapping contact with at least a portion of the legs of the outside piece 200 of the hinged connector 10 can be performed next, again according to the engineering or personal preference of the person designing or performing the method according to the invention. Finally, as shown in FIG. 13, the step of securing the chord 20a and the webs 22a-c to the hinged connector is preferably performed last.

Regarding the securing step, however, it is to be understood, of course, that this step of securing each of the truss members to the hinged connector 10 can be distributed. For example, the step can be performed interspersed with the other steps of positioning the several truss members with the hinged connector 10. By way of illustration, without limitation, the part of the securing step that involves securing the chord 20a to the inside piece of the hinged connector 10 can be performed after positioning an end of the chord 20a in overlapping contact with at least a portion of the inside piece of the hinged connector but before positioning an end of a web 22a in overlapping contact with at least a portion of the outside piece of the hinged connector 10.

Furthermore, as previously discussed, the step of securing each of the truss members to the hinged connector 10 preferably includes the step of attaching each of the truss members to the hinged connector 10 with screws, rivets, or the like. Most preferably, the method contemplates the use of double-shear screws 24, as previously described, which can be screwed into metal members from one side. This has the advantage of avoiding the need to secure each leg of the inside and outside pieces 100 and 200 to the truss members separately from either side of the steel truss being assembled.

As used herein, the term "overlapping" includes, for example, both the cases where a portion of an inner surface of a truss member is positioned in contact with a portion of an outer surface of the hinged connector 10 as shown in FIG. 9, for example, and where a portion of an outer surface of a truss member is positioned in contact with a portion of an inner surface of the hinged connector 10 (for example, as shown in FIG. 10).

According to a further aspect of the invention, a steel truss having a complex junction of truss members using a hinged connector 10 is provided. The defining characteristic of such a complex junction in a steel truss is a truss member, such as web 22a, extending through an opening formed in the spines, such as spine 112 and/or spine 212, of a hinged connector, such as hinged connector 10. Additional examples of the types of complex junctions that can be made according to the method of the present invention are illustrated in FIGS. 14-16.

Conclusion

The description and figures of the specific examples above do not point out what an infringement of this invention would be, but are to provide at least one explanation of how to make and use the invention. Numerous modifications and variations of the preferred embodiments can be made without departing from the scope and spirit of the invention. Thus, the limits of the invention and the bounds of the patent protection are measured by and defined in the following claims.

Claims

Having described the invention, what is claimed is:

1. A method of using a hinged connector to form a complex junction in the making of a steel truss, wherein the hinged connector comprises: first and second pieces, each piece having a spine and first and second legs defining a generally U-shaped channel and a longitudinal axis; a hinge interconnecting a pivot end portion of the first piece and a pivot end portion of the second piece such that the longitudinal axis of the first and second pieces extend and can be pivoted relative to one another in substantially the same plane; and an opening formed at least partially in the spine of one of the first and second pieces of the hinged connector; the method comprising the steps of: positioning a first truss member to extend through the opening of the hinged connector and so that a portion of the first truss member is in overlapping contact with at least a portion of the legs of at least one of the first and second pieces of the hinged connector; positioning an end of a second truss member in overlapping contact with at least a portion of the legs of the first piece of the hinged connector; positioning an end of a third truss member in overlapping contact with at least a portion of the legs of the second piece of the hinged connector; and securing the first, second, and third truss members to the hinged connector.

2. The method according to Claim 1 , wherein the step of positioning a first truss member is performed after the step of positioning an end of a second truss member.

3. The method according to Claim 1 , wherein the step of positioning a first truss member is performed after the step of positioning an end of a third truss member.

4. The method according to Claim 1 , wherein the step of positioning an end of a second truss member is performed after the step of positioning an end of a third truss member.

5. The method according to Claim 1 , wherein the step of securing the first, second, and third truss members to the hinged connector is performed as the last step of the method.

6. The method according to Claim 1 , wherein the step of securing the first, second, and third truss members to the hinged connector is distributed among the other steps of the method.

7. The method according to Claim 1, further comprising the step of: positioning an end of a fourth truss member in overlapping contact with at least a portion of the first piece of the hinged connector; and securing the fourth truss member to the hinged connector.

8. A steel truss having at least one complex junction of truss members produced by the method of Claim 1.

9. A steel truss having a complex junction of truss members comprising:

(a) a hinged connector further comprising:

(i) first and second pieces, each piece having a spine and first and second legs defining a generally U-shaped channel and a longitudinal axis;

(ii) a hinge interconnecting a pivot end portion of the first piece and a pivot end portion of the second piece such that the longitudinal axis of the first and second pieces extend and can be pivoted relative to one another in substantially the same plane; and

(iii) an opening formed at least partially in the spine of one of the first and second pieces of the hinged connector;

(b) a first truss member positioned to extend through the opening of the hinged connector and so that a portion of the first truss member is in overlapping contact with at least a portion of the legs of at least one of the first and second pieces of the hinged connector;

(c) an end of a second truss member positioned in overlapping contact with at least a portion of the legs of the first piece of the hinged connector;

(d) an end of a third truss member positioned in overlapping contact with at least a portion of the legs of the second piece of the hinged connector; and

(e) the first, second, and third truss members being secured to the hinged connector.

10. The method according to Claim 1 or the steel truss according to Claims 8 or 9, wherein the first and second pivot end portions of the first piece can be pivotally accepted into the generally U-shaped channel of the second piece when pivoted about the hinge.

11. The method according to Claim 1 or the steel truss according to Claims 8 or 9, wherein the opening of the hinged connector is adapted to permit the first and second pieces to be pivoted to pivot to any angular position having an angle α between the longitudinal axes of the first and second pieces in the range of 180 degrees plus or minus at least 50 degrees without interference between the spine of the first piece and the spine of the second piece when the first truss member is positioned through the opening of the hinged connector.

12. The method according to Claim 1 or the steel truss according to Claims 8 or 9, wherein the opening of the hinged connector is adapted to permit the first and second pieces to be pivoted to pivot to any angular position having an angle α between the longitudinal axes of the first and second pieces in the range of 180 degrees plus or minus at least 60 degrees without interference between the spine of the first piece and the spine of the second piece when the first truss member is positioned through the opening of the hinged connector.

13. The method according to Claim 1 or the steel truss according to Claims 8 or 9, wherein the opening is adapted in size and location to permit the rigid members to be pivoted to any angular position having an angle α between about 65 degrees and about 297 degrees without interference between the spines of the inside and outside pieces when no truss member is positioned through the opening in the hinged connector.

14. The method according to Claim 1 or the steel truss according to Claims 8 or 9, wherein the pivot end portion of the first piece and the pivot end portion of the second piece are generally ear shaped.

15. The method according to Claim 1 or the steel truss according to Claims 8 or 9, wherein each of the legs of the hinged connector has a hemmed edge.

16. A method of using a hinged connector to form a complex junction in the making of a steel truss, wherein the hinged connector comprises: an inside and outside rigid member, each having a longitudinally extending spine between first and second planar legs defining a generally U-shaped channel, and each planar leg having a pivot end portion; a hinge pivotally connecting the inside and the outside pieces through the pivot end portions in a generally longitudinally opposing position such that the pivot end portions of the inside piece can be pivotally accepted into the generally U-shaped channel of the outside piece when the members are pivoted about the hinge; and an opening formed in the spine of at least one of the outside and inside rigid members and being adapted in size and location to permit a first truss member to be positioned through the opening; the method comprising the steps of: positioning a first truss member to extend through an opening formed in a spine of the hinged connector and so that a portion of the first truss member is in overlapping contact with at least a portion of the hinged connector; positioning an end of a second truss member in overlapping contact with at least a portion of the inside piece of the hinged connector; positioning an end of a third truss member in overlapping contact with at least a portion of the outside piece of the hinged connector; and securing the truss members to the hinged connector.

17. A steel truss having at least one complex junction of truss members produced by the method of Claim 16.