US3304106A

US3304106A - Truss and connector plates therefor

Info

Publication number: US3304106A
Application number: US312436A
Authority: US
Inventors: Gerald M Mccormack
Original assignee: Automated Building Components Inc
Current assignee: Gang Nail Systems Inc
Priority date: 1963-09-30
Filing date: 1963-09-30
Publication date: 1967-02-14
Anticipated expiration: 1984-02-14
Also published as: AU408965B2; AU1562066A; GB1169529A

Description

Feb. 14, 1967 G. M- MCCORMACK 3,304,106

TRUSS AND CONNECTOR PLATES THEREFOR Filed Sept. 30, 1963 2 Sheets-Sheet 2 FIG. 8

FIG. I2 70 as o /72 11] :::n A & 74

u:::: u::: o I

[x 41 m::: n::::' & A

INVENTOR.

GERALD M. MCCORMACK BUG/(HORN, BLORE, KLAROU/ST E SPAR/(MAN ATTORNEYS United States Patent 3,304,106 TRUSS AND CONNECTOR PLATES THEREFOR Gerald M. McCormack, Lake Oswego, Oreg., assignor, by

mesne assignments, to Automated Building Components, Inc, Miami, Fla.

Filed Sept. 30, 1963, Ser. No. 312.436 12 Claims. (Cl. 28720.92)

The present invention relates to wood trusses and more particularly to a knockdown type of prefabricated truss and connector plates therefor.

It has become a common practice in the building industry, especially in house construction, to employ prefabricated roof trusses rather than conventional framing. According to present practice the truss members are cut, assembled on jigs and joined together into a truss by connector plates pressed into such members at a fabricating plant, and then the assembled trusses are trucked to the job site and incorporated into the structure. Such prefabricated trusses not only save construction time and costs by eliminating expensive hand nailing on the job, but also are capable of withstanding greater loads than conventional roof framing. However, prefabricated trusses are bulky to transport, and usually only enough trusses for one or two houses can be shipped in a single truckload. This has resulted in truss fabricators having to be located within a relatively few miles of construction sites.

Accordingly, one of the primary objects of the present invention is to provide a new and improved knockdown type of prefabricated truss which may be disassembled for shipment, and then quickly and easily assembled at the job site. A great many more trusses can be transported in a single truckload when disassembled than when assembled due to the reduction in bulk. Consequently a fabricator can operate economically throughout a far greater geographical area if the trusses manufactured by him can be knocked down for shipment. Moreover, very little additional time or handwork is required at the job site to reassemble the knockdown truss, and such truss maintains the superior strength characteristic of conventional prefabricated trusses.

Another primary object of the present invention is to provide a new and improved connector plate for assembling 'a knockdown type of truss, such plate having a plurality of relatively short, integral teeth of low withdrawal strength in wood distributed over at least one-half the plate surface and a plurality of longer, integral teeth of high withdrawal strength in wood provided throughout only the other half of the plate surface. The one-half of the plate with-out long teeth is also provided with a number of nail holes between the short teeth. Initially the plate is permanently fastened by the long teeth to only one of two abutting truss members and removably fastened by the short teeth to the other of such members. The two members may thus be joined at the fabricator, readily separated for shipment with the plate remaining fastened to one of the two members, and then reassembled permanently on the job in exactly their original relationship simply by driving nails into the other of the members through the holes provided in the plate.

Another object of the invention is to provide a new and improved connector plate in which the edges of the elongate teeth are provided with a series of barbs throughout their length, which barbs extend toward the plate surface to provide the plate with an exceptionally high resistance to withdrawal from wood.

Another object of the invention is to provide a new and improved connector plate having integral teeth, the broad sides of some of which face in opposite diagonal directions across the plate and the broad sides of others of which face longitudinally of the plate. Accordingly, the teeth resist shear stresses between the plate and a 3,3041% Patented Feb. 14, 1967 members to which it is fastened regardless of the direction of such stresses and thereby transmit a balanced load from the member to the plate.

Another object of the present invention is to provide a new and improved connector plate having both long and short integral teeth punched there-from, the holes left in the plate by the teeth being so spaced and arranged that a multiplicity of bands of plate metal remain, extending in straight lines laterally, longitudinally and diagonally from edge to edge of the connector plate, thereby providing such plate with a high degree of rigidity and resistance to distortion regardless of the directions of the loads imposed on it or stresses induced in it.

A further object of the invention is to provide a new and improved knockdown joint construction for a structural truss, each joint being composed of two abutting truss members and a pair of the previously described toothed connector plates joining such members, one on each side thereof. The long teeth of one plate are embedded initially in one of the two abutting members only, and the long teeth of the other plate are embedded in the other abutting member only, so that such members may readily be separated by applying lateral pressure against the side of each member in which no long teeth are embedded.

Still another object of the present invention is to provide a new and improved method of making a knockdown structural truss. Briefly, the method includes the steps of first precutting the members to size and shape, then temporarily assembling the truss members using the connector plate previously described, then disassembling the truss members with the connector plateson opposite sides of each joint remaining attached to the opposite ones of the two abutting members of each joint, and then permanently reassembling the truss members in their original relationship by reinserting the unembedded teeth of each connector plate in the original slots made by such teeth and then driving nails through holes provided in one-half of each plate into the abutting truss member.

Other objects and advantages in addition to the foregoing will become obwious upon inspection of the following specification taken in conjunction with the accomp anying drawings wherein like numerals refer to like parts throughout, while the features of novelty will be more particularly defined in the appended claims.

In the drawings:

FIG. 1 illustrates a side elevational view of a portion of a truss made in accordance with the present invent-ion;

FIG. 2 is a top plan view of a toothed connector plate in accordance with the present invention;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a sectional view taken along the line 44 of FIG. 2;

FIG. 5 is an enlarged side elevational view of one of the elongate teeth of the connector plate of FIG. 4;

FIG. 6 is a \front elevational view of the tooth of FIG. 5;

FIG. 7 illustrates a modified form of elongate tooth in accordance with the present invention;

FIG. 8 illustrates a section through a truss joint taken along the line 8-8 of FIG. 1;

FIG. 9 is a view similar to FIG. 8 but showing the joint in a disassembled or knockdown condition;

FIG. 10 is a view similar to FIGS. 8 and 9 showing the joint in a permanently assembled state;

FIG. 11 and 12 are top plan views of modified forms of connector plates made in accordance with the present invention.

Shown in FIG. 1 is a roof truss 10 composed of a plurality of abutting wooden frame members including two top chord members 11, two

bottom chord members

12, 13 and

internal chord members

14 and 16, all of which are joined together at their abutting ends by toothed connector plates 18. As shown more clearly in FIG. 8, a typical joint consists of two abutting

frame members

12 and 13 joined together by a pair of connector plates 18, each of which is fastened to an opposite side of the joint from the other by integral teeth embedded in each member. The truss of FIG. 1 is different from the usual prefabricated roof truss, however, in that it may be preassembled using the connector plates 18, at a fabricating plant, then disassembled for shipment to a construction site, and then easily and swiftly reassembled with the same connector plates and a few hand driven nails in a manner to be more fully described hereinbelow.

As shown in FIG. 2 the connector plate 18 includes a fiat, generally rectangular metal plate member of generally rectangular shape. The plate may be stamped from a thin sheet of galvanized steel or similar corrosion resistant metal and is of varying length and width depending upon the size of truss and particular joint on the truss for which the plate is intended. The plate 18 has a plurality of integral, upstanding short teeth 24 of triangular shape and longer, narrow teeth or spikes 26 struck therefrom which leave a plurality of like-shaped holes 23 in the plate. All of the teeth are bent outwardly from the same side of the plate in a direction substantially normal to the plate surface from which they project as shown more clearly in FIGS. 3 and 4.

The short, triangular teeth 24 are distributed substantially uniformly throughout the surface area of the plate 18, and the elongate teeth 26 are distributed between the triangular teeth 24 over only one-half the surface area beginning at one edge thereof, or in other words over only the portion of the plate that engages one of two abutting frame members joined thereby. Nail holes 28 are punched into the other half of the plate between the triangular teeth whereby such half may be permanently fastened to one of two abutting frame members in a manner more fully explained below. The triangular teeth 24 have a length slightly less than the base width thereof and a pair of relatively broad sides 25 which when em bedded in wood provide a high resistance to shear stresses induced between the wood member and the plate. Such teeth 24 also have smooth, straight edges 27 sloping toward one another and meeting at a relatively blunt point 30. The short length and straight, smooth edges combine to give such teeth 24 when embedded in wood a characteristic low resistance to withdrawal from wood, so that a portion of a connector plate fastened to a memher with only such teeth can easily be disengaged from such member.

The elongate teeth 26 have a length L considerably greater than that of the short triangular teeth 24, preferably about twice as great, so that such teeth have a considerably greater resistance to withdrawal'from wood than do the short teeth. As shown most clearly in the enlarged views of FIGS. and 6, the elongate teeth 26 include a pair of opposed edges 34 meeting at a blunt point 36 and a pair of relatively broad, parallel sides 38. The point 36 is deliberately blunted or squared off during the punching operation to reduce the tendency of the tooth, when embedded in a wood frame member, to split such member. The thickness T of the elongate teeth 26 is equal to the thickness of the plate 18. However, the width W is at least twice the thickness T thereof whereby such teeth, like the shorter teeth 24, present, in a direction perpendicular to the broad sides 38, a considerable resistance to shear stresses in wood.

With reference now to FIG. 6, both edges 34 of the elongate teeth 26 are undercut at intervals along their lengths to provide a series of barbs 40 which extend laterally outwardly of the teeth and toward the plate 18. Each barb 40 includes a subedge 42 extending longitudinally of the tooth and parallel to the other subedges on the same edge, and an abrupt shoulder 44 extending generally laterally outwardly of the tooth.

The barbs 40 provide the elongate teeth 26 with a substantially greater resistance to withdrawal from wood than similar but barbless elongate teeth. One advantage of the barbs 40 is that they do not extend laterally outwardly of the tooth to such an extent as to cut the wood fibers adjacent the barbs as the tooth enters a truss member. Instead, the barbs merely force the wood fibers aside whereby such fibers tend to return to their original positions beneath the shoulders 44 of the barbs to enhance the holding power of the elongate teeth;

FIG. 7 illustrates a modified form of elongate tooth or spike 48 made in accordance with the present invention and having the same length and barbed edge characteristics as the elongate tooth 26 of FIG. 6. However, the elongate tooth 48 has considerably broader sides 50 than the sides of the tooth 26, and barbed edges 52 which taper from a broad base to a point 54. Thus, in addition to having the .same superior resistance to withdrawal as the barbed spike 26, the spike 48 exhibits an exceptionally high resistance to shear in wood in a direction perpendicular to the broad sides 50.

Referring again to FIG. 2, the holes 23 left in the connector plate 18 by the triangular and elongate teeth, and the nail holes 28, are spaced and arranged throughout the plate so that a plurality of continuous, straight bands of plate metal remain, as represented by the metal between the pairs of dashed lines 53 of FIG. 2. A plurality of such bands extend uninterruptedly laterally, longitudinally and in both diagonal directions with respect to the plate 18, from edge to edge thereof between such holes. These bands of metal provide the plate with a unique rigidity and resistance to distortion in all directions of the plate despite the large number of holes punched therein. Some connector plates being manufactured today are provided with as many teeth as possible within the available plate surface area so as to provide the plate with a high gripping strength and resistance to shear in the structural member. However, a factor sometimes overlooked is that the flat plate member itself must have considerable strength and rigidity in order to form a rigid joint and withstand, without distortion, the high stresses induced in it in all directions by the loads imposed by the abutting truss members. Accordingly, by providing the bands 58 of metal in all directions in the plate, a high plate strength is retained while providing an adequate number and arrangement of teeth to provide high gripping strength and resistance to shear in the truss members.

The short teeth 24 of the connector plate 18 are arranged in straight rows extending in both diagonal directions across the plate. The broad sides 25 of all of the short teeth in on diagonal row extend in the same diagonal direction, and the broad sides of the short teeth in adajacent, parallel rows face in opposite diagonal directions, so that about half the total number of short teeth in any portion of the plate face in each of the two diagonal directions. The elongate teeth 26, on the other hand, are arranged in longitudinally extending straight rows, and with the broad sides 38 of such teeth facing longitudinally of the plate. Thus, the broad sides of substantial number of teeth in each pair of plates joining two truss members resist shear forces between the members and the plates which tends to slide the plates relative to such members, regardless of the direction and location of such shear forces with respect to the plates. The uniform distribution of teeth in such directions results in a balanced load being transmitted through the teeth to all portions of the plates at any joint.

FIGS. 8, 9 and 10 illustrate the preassembly, disassembly, and final assembly of a typical knockdown truss joint using a pair of connector plates 18. Each joint is composed of a pair of abutting

frame members

12 and 13, which for purposes of illustration are chord members of the truss of FIG. 1, and a pair of

identical connector plates

18 and 18a, one being on each of the op posite sides of the joint. In the initial assembly of the joint at the fabricator, both plates are applied to the joint simultaneously, by means of a large mechanical press, with the elongate teeth 26 of the plate 18 being pressed into one side of one frame member 12 at the time that the elongate teeth 26 of the other connector plate 18a are pressed into the opposite side of the other frame member 13.

Then following initial assembly, as shown in FIG. 9, the joint is easily disassembled by applying lateral force in opposite directions to opposite sides of the two

members

12 and 13, the lateral force being applied at the joint to the side of each member in which no elongate teeth are embedded. Since the short teeth 24 have very little withdrawal strength, the joint is easily disassembled using a hammer to rap the appropriate side of one of the frame members while the other is supported laterally to resist the hammer blow. Each

plate

18, 18a, will remain fastened, however, to the member in which the elongate teeth 26 of each are embedded.

It has been found in practice that a sh-ort triangular tooth 24 having a length of about five sixteenths of an inch is preferred to provide adequate shear strength but low enough withdrawal strength to permit easy disassembly of a joint. On the other hand, a short tooth 24 more than three eighths of an inch in length will make disassembly difficult. The elongate teeth 26 should be no less than one-half an inch in length or about eight times the plate thickness to provide adequate withdrawal strength, while it is preferred to use an elongate tooth of the order of five eighths of an inch.

As shown in FIG. 10, final, permanent assembly of the joint between the

members

12 and 13 is accomplished easily by realigning such members in their original positions with respect to one another and reinserting the short teeth of the free half of each plate into the slots in the members left by such teeth upon disassembly of the joint. Then, the abutting

members

12 and 13 are permanently fastened together by driving nails 60 by hand through the holes 28 in the free half of each plate and into the

frame members

12 and 13. A relatively few hand driven nails need be used to effect a permanent joint compared with the number of such nails that would be necessary should there be no integral elongate teeth 26 or if the truss were assembled entirely at the construction site using hand driven nails.

With reference again to FIG. 1, the truss is composed of a plurality of frame members the abutting ends of which form joints similar to the one described in detail with reference to FIGS. 8 through 10. In order to easily assemble and disassemble the truss, it is recommended that the connector plates at both ends of each truss member be assembled in the relationship shown with respect to the abutting truss member. That is, the two connector plates on one side at either end of each

internal chord member

14, 16 both have their elongate teeth embedded in the internal member, while on the other side of such internal members the long teeth 26 of each connector plate are embedded in the respective abutting

external chord members

10 and 12. In a similar fashion, the elongate teeth of the two connector plates at opposite ends of one side of the lower chord member 12 are embedded in the abutting

external frame members

10 and 13, whereas the elongate teeth of the connector plates on the opposite side of the member 12, are embedded in such member 12.

In knocking down the truss, the internal members .14 and 16 are removed first, merely by striking each

member

14, 16 on the side thereof opposite the sides shown, or in other Words, on the side in which no elongate teeth are embedded. Then after the

internal members

14 and 16 are removed from the truss, the frame member 12 may 6 be removed by applying force against the side there-of shown. The remaining external members may then be separated easily in a similar manner. Final assembly of the truss can best be performed by fastening the individual members together in reverse order from disassembly, with the internal members being added lastly.

While several of the features of the invention have been described with respect to a connector plate 18 adapted for use in constructing a knockdown truss, these features may likewise be embodied in a connector plate for assembling a conventional prefabricated truss in which a constant tooth pattern exists throughout the entire surface area of the plate.

Accordingly, as shown in FIG. 11, a connector plate 62 is provided with a plurality of triangular teeth 64 and integral elongate teeth 66 having the ame configurations as the

teeth

24 and 26 respectively of plate 18 but with the elongate teeth 66 being distributed throughout the entire plate surface area rather than over only one-half thereof.

The teeth of the plate 62 are also spaced and arranged in the same pattern as are the teeth of plate 18 so as to transmit a balanced load to the plate and to provide the plate diagonally, longitudinally and laterally extending bands of metal from edge to edge thereof for plate strength. The plate 62 requires no nail holes, of course, inasmuch as the elongate teeth 66 are provided throughout the plate, thereby eliminating the necessity for the use of hand driven nails.

FIG. 12 illustrates another modification of a connector plate 68 having only barbed elongate teeth 70 over onehalf the plate surface and only short, triangular teeth and nail holes 74 over the other half of such surface. Thus the plate 68 is also of the knockdown type and may be used to assemble the truss of FIG. 1.

While the invention has been described with reference to certain illustrated embodiments, it is to be understood that such embodiments and the description thereof is illustrative only and that various modifications in arrangement and detail will occur to those having skill in the art. I claim as my invention all such modifications as come within the true spirit and scope of the following claims.

I claim:

1. A toothed connector plate for fastening together and transmitting loads between abutting structural wooden members, said plate comprising:

(a) a flat, :metal plate member,

(b) a plurality of integral, spaced apart fastening means extending unidirectionally from and in a direction substantially normal to said plate member for im-bedding into said abutting members,

(c) said fastening means including a plurality of relatively short tooth means having broad sides and straight edges so as to have a high resistance to shear in wood and a low resistance to withdrawal therefrom,

(d) said short tooth means being distributed substantially uniformly throughout at least one-half the surface area of said plate member,

(e) others of said fastening means including a plurality of elongate tooth means of considerably greater length than said short tooth means so as to have a higher resistance to withdrawal from wood,

(f) said elongate tooth means being distributed throughout at least the other half of said surface area of said plate member,

(g) said elongate tooth means being distributed over only about one-half the surface area of said plate member, beginning at one end thereof, so that said elongate teeth become embedded in only one of two abutting wood members joined by said plate member, the other half of said plate member having nail holes punched therein at intervals between said short tooth means.

2. A toothed connector plate for fastening together and transmitting loads between abutting structural wooden members, said plate comprising:

(a) a flat, metal plate member,

(b) a plurality of integral, spaced apart fastening means extending unidirectionally from and in a direction substantially normal to said plate member for embedding into said abutting members,

() said fastening means including a plurality of relatively short tooth means having broad sides and straight edges so as to have a high resistance to shear in wood but a low resistance to withdrawal there from,

(g) said elongate tooth means being provided with a pair of opposed, relatively broad sides having a width at least twice the thickness thereof, said broad sides of said elongate tooth means facing in a direction longitudinally of said plate member and aid broad sides of said short tooth means facing diagonally across said plate.

3. A toothed connector plate for fastening together and transmitting loads between abutting structural wooden members, said plate comprising:

(a) a flat, metal plate member,

(c) said fastening means including a plurality of relatively short tooth means having broad sides and straight edges so as to have a high resistance to hear in wood but a low resistance to withdrawal therefrom,

(g) said short and elongate tooth means being arranged on said .plate surface so that a plurality of bands of plate metal extend in a straight line between the holes left by said tooth means in said plate in directions laterally, longitudinally and diagonally from edge to edge of said plate member.

4. A toothed connector plate for fastening together and transmitting loads between abutting structural wood members, said plate comprising:

(a) a flat, metal plate member,

(b) a plurality of integral, spaced apart fastening means extending unidirectionally from and in a direction substantially normal to said plate member for embed-ding into said abutting members,

(c) said fastening means including a plurality of relatively short tooth means having broad sides and straight edges so as to have a high resistance to shear in wood but a low resistance to withdrawal therefrom,

(g) both edges of each said elongate tooth means being provided with a plurality of barbs along substantially the entire length of said edges, each of said barbs including an edge portion extending generally longitudinally of said tooth means and an abrupt shoulder extending generally laterally outwardly of said tooth means.

5. A toothed connector plate for fastening together and transmitting loads between abutting frame members of a wooden structure, said connector plate comprising,

(a) a thin metal plate member,

(b) a plurality of short integral teeth bent outwardly in a direction substantially normal to said plate member,

(c) said short teeth having a length no greater than three eighths of an inch,

(d) said short teeth being distributed substantially uniformly throughout at least onehalf the surface area of said plate beginning at one edge thereof,

(e) a plurality of integral elongate teeth bent outwardly from said plate member in the same direction as said short teeth,

(f) said elongate teeth having a length no less than one-halfinch,

(g) said elongate teeth being distributed over no more than the other half the surface area of said plate beginning at an edge opposite said one edge,

(h) and said plate having a plurality of nail holes punched therein between said short teeth over only said one-half said surface area.

6. A toothed connector plate for fastening together and transmitting loads between two or more adjoining wood structural frame members, said connector plate comprising:

(a) a thin metal plate member,

(b) a plurality of teeth struck from said plate member and projecting unidirectionally therefrom,

(c) some of said teeth being relatively short and triangular and the others of said teeth being elongate and narrow,

(d) the elongate teeth being at least about twice as long as the triangular teeth,

(e) both said elongate teeth and said triangular teeth having relatively narrow edges equal in thickness to that of said plate and relatively broad sides of greater width than the thickness of said edges,

(f) said triangular teeth being distributed substantially uiiiformly throughout the entire surface area of said p a-te,

(g) said elongate teeth being interspersed between said triangular teeth, throughout at least one-half the surface area of said plate,

(h) the broad sides of said triangular teeth facing diagonally across said plate, with alternate ones of said triangular teeth longitudinally of said plate extending in one diagonal direction and adjacent ones of said triangular teeth extending in opposite diagonal directions,

(i) the broad sides of said elongate teeth facing longitudinally of said plate.

7. A toothed connector plate for fastening together and transmitting loads between two or more abutting wood structural frame members, said connector plate comprising:

(a) a thin metal plate member,

(b) a plurality of short teeth struck from said plate member to leave like shaped holes in said member, said short teeth being distributed substantially uni- 9 formly throughout the surface area of said plate member,

() a plurality of elongate teeth having a length subtially greater than that of said triangular teeth struck from said plate to leave like shaped holes in said plate member,

(d) said elongate teeth being distributed over at least one-half the surface area of said plate between said short teeth,

(e) the holes in said plate member left by said teeth being spaced and arranged so that in each of the lateral, longitudinal and both diagonal directions of said plate a plurality of continuous bands of plate metal extend in a straight line from edge to edge thereof and between said holes to provide said plate with rigidity and resistance to distortion.

8. A connector plate according to claim 7 wherein said elongate teeth are provided throughout substantially no more than one-half the surface area of said plate beginning from one edge thereof, the other one-half said plate area having nail holes punched therein between said triangular teeth, said nail holes being so spaced and arranged over said plate that said continuous bands of plate metal extend uninterruptedly in said other one-half said plate surface area from edge to edge of said plate.

9. A prefabricated structural joint for transmitting loads and having the capacity to be disassembled after initial assembly, said joint comprising:

(a) a pair of abutting wooden members,

(b) a pair of connector plates, one engaging each side of said abutting members and'spanning the joint there'between,

(c) said plates having a plurality of pointed teeth struck therefrom and embedded in said abutting members,

((1) said teeth including relatively short, broad ones having low withdrawal strength and high shear strength distributed substantially uniformly over at least one-half the surface areas of said plates,

(e) the remainder of said teeth being elongate and substantially longer than said short teeth to provide a higher withdrawal strength and distributed over no more than the other half the surface areas of said plates,

(f) the elongate teeth of one of said plates being embedded in one of said members only,

(g) said elongate teeth of the other of said plate being embedded in the other of said members only,

(h) so that lateral pressure applied to the side of each of said members in which no elongate teeth are embedded will cause said members to separate with said one plate remaining fastened to said one member and said other plate remaining fastened to said other member,

(i) said plates also having nail holes punched therein between said triangular teeth over said onehalf of each plate,

(j) so that said one-half of each said plates may be permanently fastened to the respective abutting member with which said one-half of each plate engages by driving nails through said holes and into opposite sides of said abutting members.

10. A prefabricated, knockdown truss structure composed of a plurality of abutting wooden frame members;

(a) each of said frame members being joined at both ends to an abutting frame member by a pair of toothed connector plates, one on each side of said member at each end thereof,

(b) about one-half the surface area of each plate engaging each of two abutting frame members,

(c) each of said plates having a plurailty of short, integral teeth formed so as to have a high resistance to shear stresses in Wood and a low resistance to withdrawal from wood,

(d) said short teeth being distributed substantially uniformly throughout the entire surface areas of said plates and embedded in both said abuting frame members,

(e) each of said plates also having a plurality of elongate integral teeth formed so as to have a higher resistance to withdrawal from wood than said short teeth and distributed between said short teeth throughout substantially one-half the surface area of each said plate,

(f) said elongate teeth of each said plate being embedded in only one of said two abutting frame members,

(g) the other one-half the surface area of each plate being provided with a series of nail holes between said short teeth for permanently fastening said plate to the other of said abutting frame members,

(h) said elongate teeth of one of said pair of connector plates at each end of each frame member being embedded in one of said two abutting members and said elongate teeth of the other of said pair of connector plates being embedded in the other of said two abutting members,

(i) so that the abutting frame members of said truss may be disassembled by the application of force at each end of each frame member laterally against the side of each said member in which there is an absence of elongate teeth, and subsequently reassembled by driving nails into one side only of each member at each joint through the nail holes provided in said plates.

11. A truss according to claim 10 wherein the elongate teeth of each of the two connector plates joining the internal frame members of said truss to the external frame members thereof on one side of said internal member are embedded in said internal frame member and the elongate teeth of the connector plates on the other side at each end of each said internal frame member are embedded in the abutting external frame members.

12. The method of making a structural truss composed of a plurality of abutting wooden frame members connected together by a pair of toothed metal connector plates at each joint, said connector plates each having short teeth over at least one-half the plate surface area, longer teeth over the other half only of the plate surface area and nail holes between the short teeth over said onehalf the plate area, said method consisting of the following steps:

(a) precutting the frame members to size and shape,

(b) arranging said precut frame members in their correct abutting relationship with respect to one another;

(c) fastening together the abutting frame members with said connector plates, one on each side of each joint, by embedding the long teeth of one connector plate at each joint in one of the abutting members and by embedding the long teeth of the other connector plate at each joint in the other of the abutting members, while simultaneously embedding the short teeth of each plate in said abutting members,

(d) then disassembling said abutting frame members by applying lateral pressure to the side of each frame member at each joint in which no elongate teeth are embedded, said lateral pressure being sufficient to cause the two abutting frame members at each joint to separate laterally, with one connector plate remaining attached to said one abutting frame member and said other connector plate remaining attached to said other abutting frame member,

(e) then permanently assembling said abutting frame members in the same abutting relationship with respect to one another at each joint as in the original assembly thereof, by first reinserting the previously 1 1 1 1 2 embedded but now unem'bedded short teeth of said References Cited by the Examiner one connector plate at each joint into the respective UNITED STATES PATENTS slot made by such short teeth in said other abuttin p 705,626 7/1902 Vogel 20-92 frame member, and doing the same with respect to 29371418 5/1960 Sanford 2O 92 the now unembedded short teeth of said other con- 5 nector plate, and then driving nails into the side of HARRISON MOSELEY, Primary Examiner each frame member at each joint in which no elongate teeth are embedded through the nail holes pro- REINALDO MACHADO Examine vided in said connector plates. A. I. BREIER, Assistant Examiner.

Claims

1. A TOOTHED CONNECTOR PLATE FOR FASTENING TOGETHER AND TRANSMITTING LOADS BETWEEN ABUTTING STRUCTURAL WOODEN MEMBERS, SAID PLATE COMPRISING: (A) A FLAT, METAL PLATE MEMBER, (B) A PLURALITY OF INTEGRAL, SPACED APART FASTENING MEANS EXTENDING UNIDIRECTIONALLY FROM AND IN A DIRECTION SUBSTANTIALLY NORMAL TO SAID PLATE MEMBER FOR IMBEDDING INTO SAID ABUTTING MEMBERS, (C) SAID FASTENING MEANS INCLUDING A PLURALITY OF RELATIVELY SHORT TOOTH MEANS HAVING BROAD SIDES AND STRAIGHT EDGES SO AS TO HAVE A HIGH RESISTANCE TO SHEAR IN WOOD AND A LOW RESISTANCE TO WITHDRAWAL THEREFROM, (D) SAID SHORT TOOTH MEANS BEING DISTRIBUTED SUBSTANTIALLY UNIFORMLY THROUGHOUT AT LEAST ONE-HALF THE SURFACE AREA OF SAID PLATE MEMBER, (E) OTHERS OF SAID FASTENING MEANS INCLUDING A PLURALITY OF ELONGATE TOOTH MEANS OF CONSIDERABLY GREATER LENGTH THAN SAID SHORT TOOTH MEANS SO AS TO HAVE A HIGHER RESISTANCE TO WITHDRAWAL FROM WOOD, (F) SAID ELONGATE TOOTH MEANS BEING DISTRIBUTED THROUGHOUT AT LEAST THE OTHER HALF OF SAID SURFACE AREA OF SAID PLATE MEMBER, (G) SAID ELONGATE TOOTH MEANS BEING DISTRIBUTED OVER ONLY ABOUT ONE-HALF THE SURFACE AREA OF SAID PLATE MEMBER, BEGINNING AT ONE END THEREOF, SO THAT SAID ELONGATE TEETH BECOME EMBEDDED IN ONLY ONE OF TWO ABUTTING WOOD MEMBERS JOINED BY SAID PLATE MEMBER, THE OTHER HALF OF SAID PLATE MEMBER HAVING NAIL HOLES PUNCHED THEREIN AT INTERVALS BETWEEN SAID SHORT TOOTH MEANS.