US3347126A - Connector plate for wood trusses - Google Patents

Description

Oct. 17, 1967 G. H. TEMPLIN ET AL 3,347,126

CONNECTOR PLATE FOR woon TRUSSES Filed Oct. 4, 1965 2 Sheets-Sheet 1 INVENTORS m. fifl Oct. 17, 1967 TE ET AL 3,347,126

CONNECTOR PLATE FOR WOOD TRUSSES Filed Oct. 4, 1965 2 Sheets-Sheet 2 FIG. 4 A F/G.6 43

ROLL LOCI? ROLL LO ROL/L LOCK RO L 0 1M IU 475/H O M7047 LOCK [fit LL "k LOC 3! ROLL cr ROLL O'LL LOC LOCK ,H L lam; 1% 9; O |O O O .j OCK iROLL. LOCK: 0c ROLL LOCK ROLL LOCK ROLL LO ROLL LOCK ROLL 45 i A 3 F765 4 H57 I 45 ROLL L K (O oo1 LOCK L oc K E ROLL/ LIOQQI KL LO WW 5% we? FllLL 2 'lwmw'mrl i 9 1 7 new A TTORNEYS United States Patent 3,347,126 CONNECTOR PLATE FOR WOOD TRUSSES Gail H. Templin and Wesley A. Mills, both of R0. Box 917, Vero Beach, Fla. 32960 Filed Oct. 4, 1965, Ser. No. 492,572 1 Claim. (Cl. 85-13) ABSTRACT OF THE DISCLOSURE A connector plate for wood trusses of the type comprising a flat metal plate having a plurality of pairs of elongated teeth extending substantially perpendicularly therefrom. The teeth include a curved body portion having a constant radius of curvature and having a pair of substantially parallel side edges of different lengths with the longer of said edges terminating in a wood penetrating point.

This application is a continuation-in-part of application Ser. No. 246,149, filed Dec. 20, 1962, now abandoned.

This invention relates broadly to the art of metallic connecting structures for wood trusses, and in its more specific aspects, it relates to such connecting structures in the nature of metallic connecting plates for connecting the joints of wood truss members together; and to the method of producing such connecting structures; and the nature and objects of the invention will be readily recognized and understood by those skilled in the art to which it relates in the light of the following explanation and detailed description of the accompanying drawings illustrating what we at present believe to be the preferred embodiment or mechanical expressions of our invention from among various other forms, arrangements, combinations and constructions, of which the invention is capable within the spirit and scope thereof.

It is conventional practice in the production of wood structural members such as trusses to provide metallic plates which extend across the joint between adjacent members of the truss to connect these members together to form the completed truss. Many different types of metallic connecting plates have been used in the-past, however, it has been our experience that most of the prior art connector plates are deficient for a variety of reasons and do not provide a completed integral truss unit having the necessary strength characteristics and forces resistant to tension and compression. The type of connector plate in which we are particularly interested comprises a generally rectangular metallic plate having a plurality of wood penetrating teeth struck therefrom so that .the base of the plate is provided with a plurality of openings therein. The efficiency and connective potential of a plate will be substantially increased in accordance with the number of teeth which are struck therefrom per square inch of the plate. Thus, it has been one of our prime purposes to devise a connector plate which has a greater number of teeth struck therefrom per square inch than any prior art plate of which we are aware.

We have struck our teeth from the plate in a novel manner so as to produce two teeth from a single opening in the plate, and by this novel and ingenious manner of striking and shaping the teeth, we provide more teeth per square inch of plate without having to reduce the size of the teeth or without in any manner whatsoever materially weakening the plate.

The connector plate comprising this invention involves generally a plurality of longitudinally extending transversely spaced rows of wood penetrating teeth which are struck from the body of the plate. The teeth are struck Patented Oct. 17, 1967 in pairs from the plate, and the teeth are so shaped that an elongated opening is provided in the plate between each pair. The points of each pair of teeth are offset with respect to a line extending centrally through the elongated openings which are formed by the struck up teeth, that is the wood penetrating point of one tooth of a pair of teeth is on one side or laterally displaced relative to such center line, while the wood penetrating point of the other tooth is on the opposite side of the center line. This particular shaping and construction of the teeth is significant and endows our connector plate with certain advantageous features not found in former plates, for it tends to reduce splitting of the lumber into which the plate is forced because the tips or points of the pairs of teeth do not usually fall in line with the grain of the wood of the wood truss. It will be understood that it is desirable that these teeth do not in all instances fall into line with the grain of the wood.

It has also been one of our purposes to increase the tensile strength across the width or the transverse dimension of the plate. We have accomplished this purpose by staggering the elongated openings transversely of the plate so that these openings do not appear in an aligned transverse line across the plate. We have not only provided means for adding to the tensile strength of the plate, but we have also provided means which will be fully explained hereinafter whereby the transverse rigidity of the plate is substantially increased. As we have hereinbefore stated, the design of the connector plate which is herein involved provides more teeth per square inch than prior art plates without sacrificing an increase in transverse tensile strength of the plate.

We have designed a plate which has no means or structure thereon which has any tendency whatsoever to open the connecting timbers forming the truss when the plate is pressed into the truss.

The connector plate of this invention also allows narrower teeth without sacrificing tooth rigidity which maintains a greater cross sectional area for greater tensile strength.

It is significant to recognize that the connector plate herein described has been given an allowance of pounds per square inch by the Federal Housing Agency of the United States Government, and since there are four teeth per square inch in our plate, each tooth is therefore credited with 40 pounds per square inch. It will be clear that this is a substantial allowance for each tooth in a plate of this character.

In the production of our connector plate for wood trusses, we so arrange and strike the teeth from the plate that the elongated openings which are formed between each pair of teeth have their longitudinal sides in substantial parallelism with the longitudinal edges of the plate, and every tooth in a plate is struck in the same direction, that is all of the coined or cutting edges of our teeth extend in the same angular relationship with all of the edges of the plate.

The teeth of the connector plate of this invention which are all struck from the plate in the same direction, as mentioned above, are so formed, arranged and struck from the plate that the teeth of every pair of teeth are in staggered relation when viewed on a line substantially parallel to a line extending longitudinally through the elongated openings in the plate. The definite advantages of such a construction will be explained and described hereinafter.

In one form of our invention, we have devised a plate having teeth which are of longitudinally sinuous, serpentine or wavy construction, are of greater length than certain types of teeth which may be used, all of which substantially aid in the holding power of the teeth and 3 the substantial success of the plate in its connecting function.

The teeth of the connector plates which we have developed are of generally curved construction, as will become evident as this description proceeds, and they are formed with a constant radius or curvature, and additionally, the teeth have an inclined cutting edge, and the inclination of each such cutting edge is constant. These structural characteristics greatly add to the holding power of the teeth in the wood due to the fact that because of this construction, substantially less tearing of the wood fibres occurs when the teeth are driven into the wood.

We have also devised an efiicient, economical and rapid method by which we produce the connector plates for wood trusses which are disclosed herein.

The connector plate of this invention may be produced with substantial economy and may be applied or connected into operative position within the wood truss member with little or no difficulty.

With the foregoing general objects, features and results in view, as well as certain others which will be apparent from the following explanation, the invention consists in certain novel features in design, construction, mounting and combination of elements, as will be more fully and particularly referred to and specified hereinafter.

Referring to the accompanying drawings:

FIG. 1 is a top plan view, with parts thereof broken away, of a connector plate of the roll lock type for wood trusses;

FIG. 2 is a view taken on the line 22 of FIG. 1.

FIG. 3 is a view taken on the line 3-3 of FIG. 1.

FIG. 4 is a plan view illustrating a connector plate, with parts thereof broken away, following the first step in the method which is practiced in the production of the plate of FIG. 1.

FIG. 5 is a view similar to FIG. 4 showing the condition of the connector plate following the second step in the method of producing such plates.

FIG. 6 is a view similar to FIGS. 4 and 5 and illustrating the condition of the plate following the third step in the production thereof.

FIG. 7 is a view similar to FIGS. 4, 5 and 6 illustrating the condition of the plate following the fourth step in the method of production thereof.

FIG. 8 is a view similar to FIGS. 4, 5, 6 and 7 and illustrating the final and operative condition of the plate following the last step in the method of production thereof.

FIG. 9 is a view taken on the line 9--9 of FIG. 5.

FIG. 10 is a top plan view, with parts thereof broken away, of a connector plate. of the press lock type.

FIG. 11 is a view taken on the line 1111 of FIG. 10.

FIG. 12 is a detailed view of one of the wood penetrating teeth of FIG. 10 with parts thereof broken away.

In the accompanying drawings, and particularly FIGS. 1 through 3 thereof, we have used the numeral 1 to designate in its entirety our connector plate for wood trusses. The connector plate illustrated in FIGS. 1 through 3 is what is generally known in the trade as a roll lock truss plate and may be formed of 20 gauge hot dipped galvanized steel, and is rectangular in configuration and may be dimensioned to be suitable for various types of truss installations. The plate 1 has what we shall term longitudinal edges 3 and transverse edges 4 which extend between the longitudinal edges and form the end edges of the plate.

Each plate is provided by stamping or otherwise with longitudinally extending rows of pairs of teeth designated in their entirety by the numeral 5 which are struck up from the plate to provide elongated openings 7 between each pair of teeth 5. Consideration of the drawings discloses that the longitudinal sides or edges 8 of each elongated opening 7 are substantially parallel to the longitudinal edges 3 of the plate. It will further be noted that the longitudinally extending rows of pairs of teeth and openings are alternately arranged transversely of the plate so that an elongated opening of one row will not be on a transverse line with respect to an opening in the next longitudinal row of pairs of teeth and openings, but will be on a transverse line with the elongated opening in the next longitudinal row of pairs of teeth and openings. This transversely staggered or alternate arrangement of openings and pairs of teeth is continued throughout the plate.

A nail hole 9 is formed and provided between each pair of teeth 5, preferably in every other row of teeth transversely of the plate, and a longitudinally extending groove 11 is pressed or rolled in the body of the plate 1 and extends between each longitudinal row of teeth and openings. The grooves 11 are formed in the plate from theside thereof from which the teeth project so that a corresponding rib 13 is formed on and extends from the opposite side of the plate.

One tooth of each pairof teeth extends from one transverse end of an elongated opening While the other tooth of the pair of teeth extends from the other transverse end of the elongated opening, and each of the teeth is composed of an arcuate or curved rootor base portion 15 having a constant radius ofcurvature, from which upwardlyextends a curved body portion designated generally by the numeral 17 which has a constant radius of curvature which is the same as the curvature ofthe root or base portion of the tooth. It is to be understood and,

' of teeth.

Each tooth comprises a wood penetrating edge 19 which is sharpened and extends upwardly from the upper end of one side of the base or root portion 15, so that it extends from one longitudinal side of the elongated opening adjacent a transverse end thereof, and each wood penetrating edge extends upwardly to a wood penetrating point 21 at a constant angle of inclination with respect to the plate 1. The wood penetrating point 21 is preferably formed with a burr23 thereon.

It will thus be apparent, from consideration of the drawings, in the light of this description, that each wood penetrating edge 19 extends upwardly at an angle from the top of the root portion at the end of one longitudinal edge of the elongated opening, and due to the angularity thereof with respect to the plate 1, the edge 19 extends toward the end of the other longitudinal edge of the elongatedopening. Due to the angle of inclination of the edge 19, it will be appreciated that each wood penetrating point of each tooth will be positioned and disposed to a series of elongated openings 7 in the plate.

Consideration of the drawings, and particularly FIG. 1 thereof, clearly indicates that the wood penetrating edge 19 of one tooth of a pair of teeth extends at an inclination upwardly from one end of the longitudinal edge of the elongated opening, while the wood penetrating edge of the other tooth of the pair of teeth extends at an inclination upwardly from one end of the other longitudinal edge of the elongated opening, so that the wood penetrating point 21 of one tooth of a pair of teeth is on the opposite side of a center line through a series of openings than the wood penetrating point of the other tooth of the pair of teeth. Thus, in a longitudinal series of teeth 5, the wood penetrating points will be transversely staggered.

The other side of each tooth which extends from the wood penetrating point 21 to the plate 1, we have designated by the numeral 25, andthis side or edge of each tooth extends substantially perpendicular with respect to the body of the plate 1.

It will now be recognized that each tooth is of curved configuration, that the radius of curvature is constant, and that the concave side or surface of each tooth is directed toward the elongated opening which is formed by striking up each pair of teeth. It will be further recognized that each tooth consists of an edge which comprises a wood penetrating edge which extends upwardly from the curved root portion of the tooth at a constant angle of inclination, and the other edge of the tooth is formed substantially perpendicular with respect to the plate 1 of the connector plate. It is also to be appreciated that the inclined wood penetrating edge of one tooth of a pair of teeth extends in the opposite direction from the inclined wood penetrating edge of the other tooth of the pair of teeth so that the wood penetrating points of the teeth are transversely staggered.

Our construction of the teeth which produces the staggered relationship of the Wood penetrating points, and, as a matter of fact, of the entire teeth, results in substantial advantages, for when the plate is pressed into the wood, one tooth of a pair of teeth is well into the wood in one direction while the other tooth will go in the opposite direction, which gives a better holding characteristic to the plate of this invention than is present in prior art connector plates.

It will now be recognized that due to this construction and shaping of each tooth and pairs of teeth, a greater number of teeth are provided on the plate, for by oifsetting the wood penetrating points of the teeth of each pair of teeth with respect to a line drawn centrally through the longitudinal rows of elongated openings, two teeth may be struck at each such opening. It will be evident that were the penetrating points of each pair of teeth not offset as herein disclosed, only one tooth could be struck from the body of the plate instead of the two as illustrated herein. The curved shaping of the teeth allows for a narrower tooth without sacrificing tooth rigidity thereby maintaining a greater cross sectional area for greater tensile strength.

The connector plate which we have illustrated herein is applied to and extends across a joint in a wooden truss, a plate being applied to and extending across each side of the joint. The plates are placed in position on the wood members, and at that time, are nailed to the wood; the nails are not fully driven but stand out of the wood a distance approximately equal to the length of the teeth 5. With a plate applied to each side of the joint as described, the unit is passed through rollers or a press to secure the plates in position to complete the truss.

It will now be apparent from the above description of our invention that we have provided an ingenious and unique shaping of the teeth which are adapted to penetrate the wood of the truss and hold and mechanically connect the members thereof together at the joint whereby the points of the teeth are otfcentered so that two teeth may be produced from a single elongated opening in the plate. It will be appreciated that this produces more teeth per square inch of plate Without reducing the size of the teeth or materially weakening the plate. This offcenter construction of the wood penetrating points of the teeth of a pair of teeth substantially reduces the possibility of splitting the lumber, since the penetrating points of the teeth normally will not fall in line with the grain of the wood.

The staggering of the elongated openings transversely of the plate increases the tensile strength of the transverse dimension of the roll lock truss plate.

It will also be understood from the description of our invention that the longitudinally extending grooves 11 materially add to the rigidity of the plate which produces substantial and obvious advantages and also increases the tensile strength of the transverse dimension of the plate, therefore adding to the structural functioning of the longitudinally extending grooves 11. The curved or arcuate construction of each tooth 5 which 6 Y is struck from the plate also increases the rigidity of the plate and makes a sound, efiicient and strong mechanical connection across the joints of the wooden truss.

In FIGS. 10, 11 and 12, we have illustrated a further form which our invention may take. This form of our invention may be termed a press lock plate and is preferably formed of 18 gauge hot dipped galvanized steel.

In this form of our invention, we have produced a connector plate having teeth which are longer than those described in connection with FIG. 1 of the drawings, and since the holding characteristic of these longer and ingeneously shaped teeth is greater than the shorter teeth, we do not require the nail holes in the plate from which these longer teeth are struck.

The connector plate of this modified form of our invention comprises the plate 27, the pairs of teeth 29, which are struck up from the plate producing the elongated openings 31, and the plate is formed with the grooves 33 therein. Each tooth is curved and comprises the wood penetrating edge 35, the wood penetrating point 37 and the burr 39. The teeth are formed, as are the teeth which have been described in connection with FIG. 1 of the drawings, so that the wood penetrating points 37 are transversely staggered, and, of course, in addition to the inclined edge 35, each tooth is provided with the perpendicular edge 41. Each tooth, which is longer than the teeth hereinbefore described, is of sinuous, serpentine or wavy construction longitudinally, as is clearly illustrated in FIG. 12. This construction greatly adds to the holding power of the tooth in the wood at the joint of tie truss.

In FIGS. 4 through 9 of the drawings, we have illustrated the steps in the method which we practice for producing the connector plates which we have described above in a rapid and etficient manner.

The method which we have evolved operates on a plate in increments, that is, We take a steel plate of the desired gauge, either to form the plate of FIG. 1 of the drawings, or the longer toothed plate illustrated in FIG. 10 of the drawings, and by a die pressing operation, we perform one step on an increment or section of the plate, then the plate is moved and the same operation is performed on the next increment or section thereof. When such first step has been performed on each increment, the plate is moved to position the first increment in position for the second operation, and this process is followed until all of the steps of the method have been completed and the plate is in finished or completed condition. As an example of our incremental method of producing such connector plates, if the steel plate is 10" long, we operate on increments thereof which are on the order of 2 long.

In FIG. 4 of the drawings, we have illustrated the first step in our incremental method of forming the connector plates of this invention. We disclose an increment or section A of the plate 43 of the proper gauge, and with a die press, we first form by the pressure stroke of the press the stencilling af the name 45 or other indicia which we desire to appear on the completed connector plate. The plate is then moved so that the next increment or section thereof is in position to be operated on by the press for the stencilling operation. This movement of the plate continues until each increment thereof has been stencilled.

After the first, or stencilling step, has been completed on each increment of the plate, the plate is moved so that the second step may be performed on each increment. In FIG. 5 of the drawings, we have illustrated the condition of an increment following this second step of the operation.

This second step we have termed the coining step, and consists of producing, by means of chisel punches on the die press, the diagonally disposed cuts 47. The

mechanism is so arranged that the chisel punches out half way through the metal plate when the plate of FIG.

1 is being produced, while it cuts substantially half wayfrom each side of the plate when the connector plate of FIG. is being produced. It will be understood that the coined cuts 47 finally produce the sharpened wood penetrating edges of the teeth. This second coining step is applied, of course, to each increment of the plate.

The third step or operation of our method is illustrated in FIG. 6 of the drawings and comprises the production of the grooves 11 in the plate while also producing or stamping out the nail holes 7 in the plate. It is to be understood that the punching of the nail holes may be done at some other time in the method if desired, -and, of course, no punching of the nail holes will be required in the production of the plate of FIG. 10 of the drawings.

FIG. 7 illustrates the condition of the plate following the fourth step or operation on the plate which is performed by the pressure stroke of the die press. This fourth operation or step may be termed the lancing operation and consists of striking the teeth 49 from the plate. It will be understood that the teeth are so struck from the plate that the cuts 47 which have been formed by chisel punches form the inclined wood penetrating edges of the teeth. In this teeth striking 0r lancing operation, the teeth are curved at the same time, and they are struck up from the plate in such a manner that the opposed teeth of a pair of teeth are inclined,

or lean toward each other slightly, as is clearly shown in FIG. 7 of the drawings. It will be appreciated that this step, as in all the other steps, is performed on all of the increments of the plate prior to the fifth or final operation.

FIG. 8 illustrates the condition of an increment of the plate following the final operation to produce the finished and operative plate. This fifth or final operation may be termed the spreading operation, and the die press, by means of a spreader, operates to spread the opposing teeth apart a distance substantially equal to the amount they were leaning toward each other as shown in FIG. 7 of the drawings. In this spreading operation, the burr 23 is also formed on the teeth.

We claim:

A connector plate for wood trusses, comprising a substantially flat body having a plurality of longitudinally extending transversely spaced rows of wood penetrating teeth extending in the same direction from said fiat body, said teeth being struck from said body in pairs providing an elongated opening between each pair of teeth, and each tooth of each pair of teeth extending from an end of said elongated opening, and each tooth of said pairs of teeth being provided with an arcuately shaped root portion having a constant radius of curvature, and each of said root portions having a pair of vertical edges, each tooth comprising a curved tooth body extending upwardly from said root portion and said body having a constant radius of curvature, one of the edges of said curved body portionextending upwardly from one vertical edge of said root portion at an inclination to said fiat body and terminating in a wood penetrating point, and the other edge of said curved body portion extending from said wood penetrating point to the other vertical edge of said root portion substantially perpendicular with respect to said flat body and each tooth being of sinuous construction longitudinally.

References Cited UNITED STATES PATENTS 2,974,378 3/1961 Lidsky l3 3,242,788 3/1966 Broder 8513 3,277,768 10/1966 Templin et al. 85-13 CARL W. TOMLIN, Primary Examiner.

R. S. BRITTS, Assistant Examiner.

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