AU734167B2 - Connector plate and punch for forming - Google Patents

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority 6*e* 0e Related Art: Name of Applicant: Alpine Engineered Products, Inc.

Actual Inventor(s): WILLIAM F LEES, ROBERT N EMERSON Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: CONNECTOR PLATE AND PUNCH FOR FORMING Our Ref 615819 POF Code: 866/319340 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1- W06q CONNECTOR PLATE AND PUNCH FOR FORMING This is a divisional application divided out of Application No. 44209/97, the entire contents of which are incorporated herein by reference.

Technical Field o This invention relates to a connector plate used to connect structural members to form trusses or other structural frames. More particularly, this invention relates to increased connector plate tooth-holding capacity and sinusoidal-wave tooth deployment design features.

5 Background of the Invention Connector plates are used for connecting wood members to form trusses, joists, beams and the like. For convenience, connector plates are discussed herein with respect to truss assemblies.

These plates are made of thin, rigid-sheet steel, such as galvanized steel. These plates have integrally-formed teeth that are embedded into adjacent wood members to form a joint.

The connector plates are typically installed by first laying out the truss members to be connected. A connector plate is positioned to overlap the joint and is then pressed into the wood by a suitable compression clamp or gantry press so that the connector plate teeth are embedded into the wood.

Truss members may be in the form of 2-by-4 lumber, 2-by-6 lumber, or the like, and can be positioned to form different truss designs. For example, two truss members can be arranged sideby-side and joined together to form a double-thick beam. As another example, the abutting ends of aligned truss members may be joined together to form a double-length member. As a further example of a truss construction, the end of one wood member can be cut at an angle that is abutted 10 against a second wood member. These members can be joined together by a connector plate, *forming a V-shaped joint.

.Connector plates are fabricated and sold with known design characteristics. Particularly, connector plate designers seek connector plates having high steel efficiencies for tension and shear forces and high tooth-holding-capacity values. These characteristics dictate the surface area of the 15 connector plate and the number of plates needed to complete a truss design. Commonly, in the presence of higher shear loads, the number of plates, the size and thicknesses of the plates and the number of their teeth are typically increased. But a connector plate designer is limited by the steel material capacities. Accordingly, improved connector designs reduce the cost of the construction in labor costs, materials costs and design costs. With respect to truss designers, computer software is available to select commercial connector plates.

Presently, connector plate designers are guided by truss design standards set by their trade associations, such as the Truss Plate Institute and by the model building codes. These standards have been developed by structural engineers, model building code staff university professors, design professionals, and truss manufacturers. For example, the steel standards, procedures, and production tolerances used for metal connector plate manufacturing established by TPI require a minimum steel grade of ASTM A653, hot dipped galvanized coating of G-60, and a minimum yield stress of 33,000 psi. Furthermore, the quality of the steel used by association member companies in the manufacture of connector plates is monitored by TPI.

Recently, TPI set out the TPI 1-1995 industry standard. This standard specifies that metalplate-connected truss joints shall be designed for a lateral resistance interpolated between design values: Vraa, Vlrae, Vlrea, and Vlree. Referring to Fig. 1, Vlraa is the allowable lateral resistance value for metal connector plates loaded parallel to the grain with the plate axis (tooth slots) parallel to the load. Referring to Fig. 2, Vlrae is the allowable lateral resistance value for metal connector plates loaded perpendicular to the load. Referring to Fig. 3, Vlrea is the allowable lateral resistance value for metal connector plates loaded parallel to the grain with the plate axis (tooth slots) perpendicular to the load. Referring to Fig. 4, Vlree is the allowable lateral resistance value for 0. metal connector plates loaded perpendicular to the grain with the plate axis (tooth slots) perpendicular to the load. The lateral tooth holding resistance of a joint at any arbitrary orientation is S 15 determined through three interpolations. For example, Fig. 5 illustrates a plate connector in an arbitrary orientation with the designated angles 9 and a. Angle 6 is the angle between the force and the grain (piece). Angle a is the angle between the force and the plate.

The first two interpolations are Hanidnson's interpolations between the force and the grain (the piece). The first Hankinson interpolation, Vlra0, calculates the allowable value for metal connector plates loaded at an angle 0 to the grain with the plate axis (tooth slots) parallel to the load, as a function of the Viraa and Virae orientations: (Vraa)(lrae) (Vlraa) sin' 9 (Pirae) cos' 9 The second Harikinson interpolation, Vlree, calculates the allowable value for metal connector plates loaded at an anglce6 to the grain with the plate axis (tooth slots) perpendicular to the load, as a finction of the VI=e and VI=e orientations: (Vrea XV~rre) runL (VWrea)sini 2 B -(V*7ree)coiG The third interpolation is a linear interpolation between the force and the plate, that is, between the Vw and Vu" orientations: 9 y -,ZL) where: a- Plate Angle Force Angle If a then a- a- 180 **If a>90 then a= 6 Piece Angle -Force Angle Ilf 180then0= 180 I~f 6>90 then 61- The Tooth Holding Allowable value is then calculatd by the following: o.

TH Allowable (VLR6Xntmber...f latesXHee leduction)(Plate Area) Some conmmericially-available connector plates have staggered-tooth configurations to toothholding capacity and increase steel e~iciency. For examnple, U.S. Patent No. 4,343,580, issued to Moyer et al., discloses a structural joint connector in which the rows of teeth are offset from ea&ch Other by a Stagger distance. One of the objectives recited is to provide an unproved structuralj joint formed by two wooden member-s abutted together and interconnected by an improved connector plate.

Other connector plates have adopted designs with twisted teeth with bend lines that are offset relative to central longitudinal axis of the slots. For example, U.S. patent No. 4,374,003, issued to Smith, discloses such an offset bend line with the tooth twisted angularly around its bend line, such that the tooth intertwines and twists with the wood fibers to resist loosening when the wood moves, expands, swells, or the like.

But further improvements are always sought that increase connector plate tooth-holding carimity and the steel effciency. Such improvements allow the connector plate size to decrease, in turn recogznizing economic savings in the cost of materials. Further, greater cpcte vi h :creation of a greater variety of truss designs.

The above discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of S these matters formed part of the prior art base or were common general :knowledge in the field relevant to the present invention as it existed in Australia before the priority date of each claim of this application.

6 According to the invention in a first aspect, there is provided a punch for forming teeth in a connector plate comprising: an elongated shank having a metal working tip at one end and a base at the other end; said shank having an elongated cross-section defined by opposing sides and opposing ends, said sides comprising parallel spaced planar side walls, said ends comprising two converging end walls forming an end wall intersection, each end wall intersecting a side wall at an obtuse angle; and said end wall intersection being eccentric to a plane parallel to and midway between said side walls.

According to the invention in a second aspect, there is provided a combination of the punch as defined above with a corresponding mating die, wherein said die comprises a cavity, said cavity having an elongated cross-section defined by opposing die sides and opposing die ends, said die sides comprising parallel spaced planar die side walls, said die ends comprising two converging die end walls forming a die end wall intersection, each die end wall intersecting *a die side wall at an obtuse angle; and said die end wall intersection being eccentric to a plane parallel to and midway between said die side walls.

According to the invention in a third aspect, there is provided a connector plate comprising a metal plate having a plurality of teeth integrally projecting from said plate and an elongated slot adjacent each said tooth, said slots each having an elongated cross-section defined by opposing sides and opposing ends, said sides comprising parallel spaced planar **side walls, said ends comprising two converging end walls forming an end wall intersection, each end wall intersecting a side wall at an obtuse angle; and said end wall intersection being eccentric to a plane parallel to and midway between said parallel side walls.

According to the invention in a fourth aspect, there is provided a method of forming a metal connector plate having teeth, the method comprising: placing a metal plate between a punch and a corresponding die, said punch comprising an elongated shank having a metal working tip at one end and a base at the other end; said shank having an elongated cross-section defined by opposing punch sides and opposing punch ends, said punch sides comprising parallel spaced planar punch side walls, said punch ends comprising two converging punch end walls forming a punch end wall intersection, each punch end wall intersecting a punch side wall at an obtuse angle, said die comprising a cavity, said cavity having an elongated cross-section defined by opposing die sides and opposing die ends, said die sides comprising parallel spaced planar die side walls, said die ends comprising two converging die end walls forming a die end wall intersection, each die end wall intersecting a die side wall at an obtuse angle; Wchsdelete\dMsional Or 4-4209.doC 6a said die end wall intersection and said punch end wall intersection being eccentric to a plane parallel to and midway between said side die walls; and punching said metal working tip and at least a portion of said shank through said metal plate into said cavity in said die, thereby cutting and forming a portion of said metal plate into teeth.

The connector plate of the invention provides improved resistance capacity in both tooth-to-load and tooth-to-wood grain in the four orientations as set out by TPI 1-1995.

Preferably, the connector plate has a rigid, planar base, and a plurality of adjacent elongated slots defined in said metal plate. The slots are offset in a sinusoidal pattern having at least one cycle with a maximum amplitude slot position, a minimum amplitude slot position and at least two zero-point slot position. Each slot has first and second reverse-oriented mirror-image teeth extending from the plate at opposing ends of each slot.

The connector plate of the invention is provided having a metal plate, a plurality of S*o elongated slots with a tooth extending from each opposing end of the slot. The elongated slots are defined in the plate and are arranged in at least one row. Each row forms a generally cyclical waveform. Each tooth extends substantially perpendicular to the plate from each opposing end of each of said elongated slots and has a base with a bend spine. The bend spine originates apart from a longitudinal axis of its slot and extends to a tip. First and second asymmetrical portions having extruded edges extend generally laterally from the bend spine extending to the tip. The first portion having less taper than the second portion. A tapered °o corrugation is formed in the second portion of the tooth adjacent the tooth base. The corrugation extends from the outer edge of the second portion with a tapered end extending towards the bend spine.

In a preferred form, the punch of the invention is provided for forming a staggered struck-out opening, and has a base portion with a longitudinal axis, a shank, and a strike-out tip.

The shank has an elongated cross-section that extends from the base portion such that a shoulder is formed in the transition from the shank to the base portion for supporting the punch in a set of wave die sections. The shank has a longitudinal axis offset from the longitudinal axis of said base portion. The strike-out tip is on an end of the shank for forming a struck-out elongated opening having at least one tooth extending from an end of the opening.

W:\d1risnOldeete\diisional of 44209.doc Brief Description of the Drawing The accompanying drawing is incorporated into and forms a part of the specificaiork to illustrate an example of the 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 example. The various advantages and features of the present invention will be apparent from a consideration of the drawing in which: Fig. 1 is an illustration of a conventional connector plate connecting a joint in an AA orientation for obtaining aVlraa value; Fig. 2 is an illustration of a conventional connector plate connecting a joint in an AE orientation for obtaining a Vlra value; Fig. 3 is an illustration of a conventional connector plate connecting a joint in an EA orientation for obtaining a Vlea value; 5Fig. 5 is an illustration of a conventional connector plate connecting a joint in an y orientation;frotiigaVrevle Fig. 6 is an villstao of a cnetoa connector plate conecing a jiuodlwvetohdpoimnt inng btar boards; Fig. 7 is a perspective view of one pair of teeth formed on the ends of an elongated slot; Fig. 8 is a plan view of an exterior surftce of one of the teeth, Fig. 9 is a plan view of an interior surface of one of the teeth; Fig. 10 is a side plan view of one of the teeth taken along line 10-10 shown in Fig. 9;, Fig 11. is a plan view of die sections arranged to accept the punches for forming a connector plate's sinusoidal-wave tooth deployment; Fig. 12 is a detailed plan view of a connector plate having a sinusoidal-wave tooth deployment; and Fig. 13 is a plan view of offset punches used to form one cycle of the sinusoidal-wave tooth deployment.

Description of a Preferred Embodiment The present invention will be described by referring to examples of how the invention can be .made and used. Like reference characters are used throughout the several figures of the drawing to 10 indicate like or corresponding parts. The invention utilizes an inventive concept to increase tooth holding values and steel efficiency of connector plates.

Referring to Fig. 6, a connector plate, generally designated by the numeral 100, is shown.

Connector plate 100 is employed to join two truss members A and B, respectively, in a butt-joint fashion. Connector plate 100 has a base 102 with a plurality of pairs of teeth struck therefrom such 15 as shown in Fig. 7. Each pair of teeth 104 and 106, respectively, are struck to form an elongated opening or slot 108 defined therebetween. Teeth 104 and 106 extend in a direction substantially perpendicular to the base 102 that forms the connector plate 100. As shown, teeth 104 and 106 are complementary oriented and extending from the connector plate base 102.

Referring to tooth 104, bend spine 110 extends longitudinally from base 102 to tip 116 of tooth 104. Bend spine I 10 is offset from the longitudinal center-axis S (shown in Fig. 7) of slot 108 and is substantially perpendicular to a face plane defined by base 102. Asymmetrical portions 112 and 114 extend from bend spine 110. A substantially arcuate inner surface 117 is formed, as best shown in Figs. 7 and 10. That is, the cross-sectional shape near tooth juncture of tooth 104 and base 102 is generally crescent or cupped-shaped forming an asymmetrical inner-change surface.

Referring to Figure 8, a plane view of the outer surface of tooth 104 is shown. For clarity, only one tooth is described with the understanding that each of the teeth associated with connector plate 100 are substantially similar, but provide complementary pair-orientations as shown in Fig. 7.

Referring to Fig. 9, tooth 104 is shown with two asymmetrical portions 112 and 114, respectively, and bend spine 110 at the juncture of these portions. Extending from tip 116 is extruded edge 122 for facilitating insertion of tooth 104 into a board A, for example. Extruded edge 122 forms a general knife-like edge sufficient to facilitate insertion of tooth 104 into board A, for example. Formed between extruded edge 122 and reference 126 is angle 124. Angle 124 is .l commonly referred to as an air cut angle.

Lower portion of edge 122 extends to dimpled or corrugated region 128 in the general shape ofa Gaussian curve having a base and an apex defined by edge 122. Corrugated region 128 has apex 129 extending inward toward spine 110. The base of the curve is best shown in Fig. Corrugated region 128 extends into the surface plane generally defined by arcuate inner surface 120.

This corrugation region is believed to longitudinally reinforce the tooth 104 when pressed into a board. That is, the corrugation region can flex with respect to the rest of the tooth structure, thereby dispersing some of the longitudinal force through this flexing.

fed. As best illustrated in Fig. 9, opposing asymmetrical portion 114 of spine 1 10 has a second extruded edge 130, which also extends from tip 116. Between second edge 130 and reference 132 is defined a second angle 134. Generally, second angle 134 has a lesser value than that of first angle 124 and is commonly formed by an angle referred to as the secondary flat. First and second edges 122 and 130 extend to substantially parallel to first and second tooth-body edges 120 and 122, accordingly.

As should be noted, the value of first and second angles 124 and 134 can vary respectively depending on fabrication parameters. For example, such parameters are the steel thickness and the material selected. For the preferred embodiment described herein, the material is preferably an ASTM A653 steel plate having a 20-gauge (about 0.91 mm) thickness. In the preferred embodiment, the steel plate is cold punched.

Referring to Fig. 12, a view of the back surface of connector plate 100 is shown illustrating the sinusoidal-slot arrangement of the tooth-pairs struck therefrom (see Fig. Connector plate 100 has a plurality of rows RI, R2 and R3. For illustrative purposes, a sinusoidal waveform M is defined by the slots is represented in a dashed line along row Rl. The sinusoidal waveform M is 10 depicted as intersecting centerline points of the plurality of slots 108. A cycle C of the sinusoidal waveform M is designated by a maximum amplitude slot position D, a minimum slot position E, and at least two zero-point slot positions F. In the preferred embodiment shown, cycle C is about oneinch (about 25.4 mm). The maximum and minimum amplitude slot positions D and E, respectively, are relative to the zero-point slot positions and are offset by about one-sixteenth inch (about 1.58 15 mm), respectively. The distance G between slots 108 is about one-eighth inch (about 3.18 mm).

This sinusoidal-slot configuration has the benefit of increasing the Vlrea and Vlree tooth-holding values. As a result, connector plate 100 can have a reduced base 102 area and yet have similar strength characteristics as larger connector plates.

For the preferred embodiment shown, the length L of the slot is about one-half inch (about 12.7 mm). The width W of slot 108 is about one-eighth inch (3.18 mm). Briefly referring back to Fig. 9, the height H of each tooth is about three-eighth inches (about 9.52 mm).

The punches and dies for forming the teeth and slots are shown in Figs. 11 and 13.

Referring to Figure 7, a set of dies 200 form a cycle C for the sinusoidal-slot pattern (see Fig. 11).

For continuity between Figs. 11 through 13, a nomenclature indicating corresponding manufacturing structures is adopted. For example, tooth pair F (Fig. 12) is formed by die cavity F (Fig. 11) and punch F" (Fig. 13).

A die set 200 cycle has five die partitions 201. As shown, dies 200 define cavities 202 for receiving punches 302 (shown in Fig. 13). The cavities 202 have two substantially parallel, longitudinal side walls 204 and 206, respectively. The distance between the side walls, 204 and 206 is W. Each end of the longitudinal side wails extend into two slanted walls 208 and 210, respectively, forming an eccentric, asymmetrical apex 211 that is offset from a longitudinal center of the cavity 202.

Slanted side wall 208 forms an angle 212 with reference line 214. With respect to slanted .10 side wal208, the apex 211 is spaced apart from first longitudinal side wall 204by the distance T.

Slanted side wall 210 forms an angle 216 with reference line 218. With respect to slanted side wall 210, the apex 211 is spaced apart from longitudinal side wall 206 by the distance U.

In the preferred embodiment, the distance T is about 0.08 inches (about 2.03 mm), the distance U is about 0.04 inches (about 1.02 mm), angle 212 has a value of about 43.6 degrees, and angle 216 has avalue of about 27.7 degrees. The width Wof the cavities 202 are about 0. 12 inches (about 3.08 mmn), and the length of the cavities 202 are about 0.50 inches (about 12.7 mm). As should be noted, both ends of the longitudinal walls 204 and 206 are complementary images of each other. This embodiment is preferred to reduc the amount of machining to produce the die set 200.

But other modifications affecting these relationships still maintain the effects of this invention.

Referring to Fig. 13, the punch set 300 used to produce the slots are shown. Referring to one punch, for example, punch the punch has a cross-sectional area with heel angles that complement the silhouette of the die cavities 202. To punch sheet material through the die set, Punches 302 are machined to have a smaller cross-sectional area suffcient to allow sheet material to be Punched and formed in the die set 200 without causing punches 302 to be wedged and caught in A -11 the die set 200. That is, the structures are designed for a metal forming operation which causes shaping and thinning of the metal material taking place in the region between the slanted walls of the punches 302 to form eccentric bend spines 1 10 and corrugated regions 128 (see Fig 7).

The punch tip surfaces have cutting surfaces and metal shaping surfaces which are known in the art. Of distinction to the invention is the offset centerlines of a standard punch holder used to obtain the sinusoidal pattern in the connector plate 100 as shown in Figs. 11 and 12. Furthermore, the punch shanks 304 have eccentric pieces to that of die cavity 202. To accommodate the sinusoidal pattern the punch set 300 has first and second centerline punches a maximum amplitude punch and a minimum amplitude punch The minimum and maximum amplitude 10 punches D" and have punch shanks 304 with centerlines 306 offset from the punch base 308 centerlines 310. In the preferred embodiment, the offset is about one-sixteenth inch (about 1.59 mm).

In producing the connector plates of the present invention, the sheet metal material, or connector material, from which the connector plate is to be formed is incrementally passed between *15 a series of punches and corresponding dies. The punches and dies are arranged so that each punch will strike the metal material and pass through so as to extend into a cavity of a corresponding die.

When the punch extends into the cavity of the dies, a substantial portion of the space between longitudinal side edges of each punch and corresponding die is less than the thickness of the sheet material. Thus, as the punch enters into the cavity of the die metal forming occurs whereby the teeth are reshaped by wiping the metal between the side walls of the punch and the die cavity. In this manner, the offset spines 110 of the teeth are formed offset from the longitudinal axis S of the slots 108, as shown in Fig 7. As the punch is fully extended into the die cavity, each tooth is forced into a position substantially vertically aligned with its opposing tooth.

From the foregoing disclosed are the various structures of an improved connector plate.

But, various modifications may suggest themselves to those skilled in the art without departing from the spirit and scope of the invention, as defined in the appended claims. Also, those skilled in the ar may prefer to utilize some of the features and advantages of the invention without using all of the features. The invention is not to be restricted to the specific forms shown, or the uses mentioned, except as to the extent required by the claims.

Throughout the description and claims of this specification, the word "comprise" and variations of the word, such as "comprising" and "comprises", is not intended to exclude other additives, components, integers or steps.

.e -13-

Claims (22)

1. A punch for forming teeth in a connector plate comprising: an elongated shank having a metal working tip at one end and a base at the other end; said shank having an elongated cross-section defined by opposing sides and opposing ends, said sides comprising parallel spaced planar side walls, said ends comprising two converging end walls forming an end wall intersection, each end wall intersecting a side wall at an obtuse angle; and said end wall intersection being eccentric to a plane parallel to and midway between said side walls.

2. A punch as defined in claim 1 wherein said punch is for forming first and second reverse-oriented opposing teeth. 15 3. A punch as defined in claim 1 or claim 2 wherein the punch is of a unitary construction. S o 4. A punch as defined in any one of claims 1 to 3, wherein said end wall S intersections are on opposite sides of a plane parallel to and midway between said side walls. A punch as defined in any one of claims 1 to 4, wherein said converging end walls intersect at an angle of about 108 degrees.

6. A punch as defined in any one of claims 1 to 5, wherein one of said converging end walls intersect a side wall at an angle of about 134 degrees.

7. A punch as defined in any one of claims 1 to 6, additionally comprising a mating die having a cavity of similar cross-section as said cross-section of said shank.

8. A punch as defined in claim 7 wherein at least a portion of said shank enters said cavity in said die when forming a connector plate.

9. A punch as defined in any one of claims 1 to 8, wherein said base has a cross- section larger than said cross-section of said shank for mounting in a punch holder. A punch as defined in any one of claims 1 to 9, said metal working tip having a cross-section smaller than said shank and having cutting and shaping surfaces.

11. The combination of the punch of any one of claims 1 to 10, with a corresponding mating die, wherein said die comprises a cavity, said cavity having an elongated cross-section defined by opposing die sides and opposing die ends, said die sides comprising W:\chriS*doeletedMsional of 44209.doc parallel spaced planar die side walls, said die ends comprising two converging die end walls forming a die end wall intersection, each die end wall intersecting a die side wall at an obtuse angle; and said die end wall intersection being eccentric to a plane parallel to and midway between said die side walls.

12. The combination of claim 11 wherein said die end wall intersections are on opposite sides of a plane parallel to and midway between said die side walls.

13. The combination of claim 11 or claim 12 wherein said cross-section of said cavity is larger than said cross-section of said shank.

14. The combination of any one of claims 11 to 13, wherein said converging die o: end walls intersect at an angle of about 1080. *15. The combination as defined in any one of claims 11 to 14, wherein one of said converging die end walls on each end of said cavity intersects a die side wall at an angle of about 1340. .o

16. The combination as defined in claim 17 wherein the other converging die end wall on each end of said cavity intersects a die side wall at an angle of about 1180. .O

17. A connector plate comprising a metal plate having a plurality of teeth integrally projecting from said plate and an elongated slot adjacent each said tooth, said slots each having an elongated cross-section defined by opposing sides and opposing ends, said sides comprising parallel spaced planar side walls, said ends comprising two converging end walls forming an end wall intersection, each end wall intersecting a side wall at an obtuse angle; and said end wall intersection being eccentric to a plane parallel to and midway between said parallel side walls.

18. A connector plate as defined in claim 17 wherein said slots each have first and second reverse-oriented opposing teeth extending from said plate at opposing ends of said slots.

19. A connector plate as defined in claim 17 or claim 18, wherein said end walls intersect at an angle of about 1080 A connector plate as defined in any one of claims 17 to 19, wherein one of said converging end walls at one end of said slots intersects a side wall at an angle of about 134 W:'chrs\nodelete dvlMsional of 44209.doc 16

21. A connector plate as defined in claim 20 wherein the other converging end wall at said one end of said slots intersects a side wall at an angle of about 1180.

22. A method of forming a metal connector plate having teeth, the method comprising: placing a metal plate between a punch and a corresponding die, said punch comprising an elongated shank having a metal working tip at one end and a base at the other end; said shank having an elongated cross-section defined by opposing punch sides and opposing punch ends, said punch sides comprising parallel spaced planar punch side walls, said punch ends comprising two converging punch end walls forming a punch end wall intersection, each punch end wall intersecting a punch side wall at an obtuse angle, said die comprising a cavity, said cavity having an elongated cross-section defined by opposing die Osides and opposing die ends, said die sides comprising parallel spaced planar die side walls, said die ends comprising two converging die end walls forming a die end wall intersection, each 15 die end wall intersecting a die side wall at an obtuse angle; said die end wall intersection and said punch end wall intersection being eccentric to a plane parallel to and midway between said side die walls; and punching said metal working tip and at least a portion of said shank through said metal plate into said cavity in said die, thereby cutting and forming a portion of said metal plate into teeth.

23. A method as defined in claim 22 wherein said punch is for forming first and second reverse-oriented opposing teeth.

24. A method as defined in claim 22 or claim 23 wherein said converging end walls intersect at an angle of about 1080. A method as defined in any one of claims 22 to 24, wherein one said converging end wall of said shank intersects a side wall of said shank at an angle of about 1340

26. A method as defined in claim 25 wherein the other converging end wall on each end of said shank intersects a side wall of said shank at an angle of about 1180.

27. A punch as defined in claim 6 or any one of claims 7 to 10 insofar as dependent on claim 6, wherein the other said converging end wall intersects a side wall at an angle of about 118 degrees.

29. A punch substantially as herein described with reference to any one of the accompanying drawing figures 6 to 13. W:thrIsVodelete\hvisiona of 44209.doc 17 A combination of a punch with a corresponding mating die, substantially as herein described with reference to any one of the accompanying drawing figures 6 to 13.

31. A method substantially as herein described with reference to any one of the accompanying drawing figures 6 to 13. DATED: 3 May, 2000 PHILLIPS ORMONDE FITZPATRICK Attorneys for: ALPINE ENGINEERED PRODUCTS, INC. 0* **00 0 P*e W:\chris\odeletedivisional of 44209.doc