US3025933A

US3025933A - Constructional elements, particularly such consisting of slotted metal bars of anglesection

Info

Publication number: US3025933A
Application number: US613278A
Authority: US
Inventors: Demetrius Comino
Original assignee: Dexion Ltd
Current assignee: Dexion Ltd
Priority date: 1952-05-09
Filing date: 1956-10-01
Publication date: 1962-03-20
Anticipated expiration: 1979-03-20
Also published as: GB763045A; FR1099299A; FR1080054A; CH312067A; CH312069A; CY164A; MY6000003A; CH312068A; FR1080055A

Description

March 20, 1962 D. COMINO 3,025,933

CONSTRUCTIONAL ELEMENTS, PART LARLY SUCH CONSISTING OF SLOTTED METAL BARS ANGLE SECTION Filed Oct. 1, 1956 3 Sheets-Sheet 1 D. COMINO CONSTRUCTIONAL ELEMENTS, PARTICULARLY SUCH CONSISTING OF SLOTTED METAL BARS OF ANGLE SECTION 3 Sheets$heet 2 Filed Oct. 1, 1956 March 20, 1962 D. COMIN 3,02

ELEMENTS,

CONSTRUCTIONAL PARTIC RLY SUCH CONSISTING OF SLO TED METAL BARS OF ANGLE SECTION Filed Oct. 1, 1956 3 Sheets-Sheet 3 I0 8" l0 f fi 9960 booo 7 6 7 12 d) 6) b C) 9 2 0a 7a 6a 3 0 c) c) 0 0 0 3 0 I I5 70 1/ 10 iCJ' coo c3 EDD 00 -c 0c O-@ 0000 13 5 5 J ZMO. Hal! United States Patent 3,025,933 CONSTRUCTIONAL ELEMENTS, PARTHCULARLY SUCH CONSKSTKNG F SLQTTED METAL BARS 0F ANGLE SECTION Demetrius Cornino, London, England, assignor to Denier! Limited, London, England Filed Oct. 1, 1956, Ser. No. 613,278 Claims priority, application Great Britain May 9, 1952 21 Claims. (Cl. 189--34) This application is a continuation-in-part of application Serial No. 695,103, filed September 6, 1946, now abandoned, and is a continuation-in-part of application Serial No. 258,361, now Patent No. 2,746,780 filed November 27, 1951, as a continuation-in-part of application Serial No. 695,103, filed September 6, 1946, now abandoned, and is a continuation-in-part of his applications, Serial Nos. 351,853; 351,854; and 351,855, all filed April 29, 1953, all now abandoned and as continuation-in-part of his application Serial No. 258,361.

This invention concerns improvements relating to constructional elements of the kind consisting of bars of angular section, preferably an L-section, having lines of holes in their flanges for the insertion of bolts. The invention is particularly, but not exclusively, concerned with improvements upon or modifications of construction-a1 elements such as are described in patent application Serial No. 258,361, now Patent No. 2,746,780 which is a continuation of application No. 695,103 filed September 6, 1946, or of a nature suitable for use in conjunction therewith.

An object of the present invention is to provide constructional elements of the kind set forth which combine the advantages of increased relative strength of element with a high degree of versatility in the number and variety of strong and useful connections which can be made between elements.

In accordance with the invention, such a constructional element consists of a metal bar of angular section comprising two flanges and provided with lines, extending longitudinally of the element, of bolt-accommodating opening means, the widths of the flanges being substantially an integral multiple of half the modular length of the bolt-accommodating means measured longitudinally of the element, said bolt-accommodating means provided in one of the said flanges being spaced from the edges of that flange by substantially one third of the width of the said flange.

The bolt-accommodating opening means may be in the form of elongated holes or elongated groups of holes. By the modular length thereof is meant the basic length of the elongated holes or of the elongated groups measured in the longitudinal direction of the element. The overall length of the elongated holes or of the elongated groups will be equal to the modular length plus the width of the holes or, in practice, plus rather more than the said width. Groups of holes may be provided in any line of holes in an element. As hereinafter described, they may be used in one or two lines, preferably the outer of two lines, of holes in one flange of an element or in both flanges thereof.

Several embodiments of the invention by way of example will now be described with reference to the accompanying drawings, in which:

FIGURE 1 is a developed plan view of one element,

FIGURE 2, a view of one example of a connection made between two such elements,

FIGURE 3, a developed plan view of a second element,

FIGURE 4, a view of another connection,

FIGURE 5, a developed plan view of a third element,

FIGURE 6, a view of a further connection,

FIGURE 7, a diagrammatic view of a connection, and

FIGURES 8 to 11 are developed plan views illustrating alternative forms of groups of holes.

In the constructional element of rectangular L-section illustrated in development in FIGURE 1, the wider flange 1 is approximately twice as wide as the narrower flange 2. Suitably the flanges may have a nominal or approximate width of 3" and 1 /2" respectively, but in practice the dimensions may slightly exceed these figures by an amount depending upon the thickness of the metal. For a steel element of the aforesaid dimensions, metal of about No. 12 gauge would be appropriate. The wider flange 1 has two parallel longitudinal lines of longitudinally extending or longitudinally

elongated holes

3, 4 arranged in evenly staggered overlapping relationship. The lines of

holes

3, 4 are disposed at substantially one quarter of 'the flange width from the respective edges thereof. As illustrated, however, the distance of the holes 4 from the inner edge is advantageously made somewhat more than the quarter width to allow for the thickness of other elements in certain kinds of connections. The distance of the holes 3 from the outer edge may, on the other hand, he made slightly less than one quarter of the flange width. The transverse interval i between the lines of

holes

3, 4 is made equal to half the nominal flange width, i.e., 1 /2 in the above instance. The pitch of the

holes

3, 4 in their respective lines is twice that interval, namely 2i or 3" in the said instance. The modular length of each hole is equal to the interval i and the overall length l of each hole must be at least the said interval i plus the width of the hole, so as to allow two such flanges disposed at right angles to be connected together by a square pattern of four bolts. In practice and as illustrated, however, the holes 3, 4- will be made rather longer than this, so as to allow ample clearance and to facilitate connections between elements at angles other than a right angle. Thus, in the instance considered and using bolts, the

holes

3, 4 may suitably be Wide and have "an overall length l of 2% the distance d between the ends of adjacent holes being thus A The narrower flange 2 has one line of longitudinally extending or longitudinally elongated groups 5 of holes disposed at substantially the middle of the flange, the actual distances from the outer and inner edges being advantageously the same as the distances of the lines of

holes

3 and 4 from respective flange edges. Each group of holes has the same modular length, equal to the transverse iuterval i and the same overall length l as the

holes

3, 4 and the groups are transversely aligned with the holes 4 or, preferably, the holes 3. Each group 5 consists of a round hole 6 equidistant between two short elongated holes 7. The width of the holes 7 is equal to that of the holes 3, 4- and their length is preferably made equal to the overlap between the

holes

3 and 4, that is in the instance specified above, or a little longer than the said overlap. The round holes 6 may be designed to afford a slight clearance around the bolts used and may have a diameter equal to or slightly greater than the width of the

holes

3, 4, 7, e.g. a diameter of As described and claimed in my co-pending application Serial No. 351,854, the wider flange 1 may also be provided with a further series of holes equidistant betweenthe lines of

holes

3, 4, i.e. at a distance of i/2 from each such line. These holes are round holes or holes having slight elongation either longitudinally or transversely of the flange. Preferably and as illustrated, alternate round holes 8 and transversely elongated holes 8' are provided at a pitch i and opposite to the midlengths of the

holes

3 and 4 respectively. The holes 8 may be of the same size as the holes 6 and the holes 8' may suitably be elongated, inwardly of the flange, to a length of 7 Preferably and as illustrated, transversely elongated holes 8" similar to the holes 8 are also 3 provided at the mid-points between the groups in the flange 2.

The element illustrated in FIGURE 1 is stronger than a similar element having one long hole in place of each of the groups 5 in the narrower flange 2 because the narrow strip of metal outside each group is braced at intermediate points and is therefore less liable to buckle under local stress or impact, thus rendering the whole element less liable to fail. In spite of the discontinuity of the group 5, the element is still extremely adaptable in its modes of use and in the variety of connections that can be made. Indeed, for some purposes, simpler connections or effective connections by fewer bolts are made possible. By the

round holes

6, 8, positively located connections can be made between like or unlike flanges at the pitch of the respective holes. The

elongated holes

3, 4, 7, S and S" afford facility in making connections between elements at other intervals and at all angles. The elongated holes preserve a necessary latitude for connections between elements at right angles or between parallel elements, for example for case in which thickness of metal or slight inaccuracies in location of holes might prevent the lining up of round holes. This applies particularly to the transversely elongated holes 8 and S" which are especially useful for splicing elements together in such difficult cases.

FIGURE 2 illustrates one example of a connection, between two elements at right angles, by means of the flanges 1. As will be seen, five bolts can be used in the connection, if required. The central bolt through the round holes 8 affords a positively located connection.

The element illustrated in development in FIGURE 3 has a wider flange 1 identical with the wider flange 1 of the element just described. The narrower flange 9, however, has a nominal width w equal to three quarters the width of the flange 1. The narrower flange 9 has one line of longitudinally elongated groups 10 of holes and one line of longitudinally elongated holes 11. The lines are transversely spaced apart and from the respectively adjacent edges of the flange by approximately one third of the flange width w. The transverse distance w/ 3 between the lines equals i/Z, namely half that between the lines of

holes

3, 4. The actual distances of the lines of groups 10 and holes 11 from the adjacent edges of the flange 9 are advantageously the same as the distances of the lines of holes 3 and 4- from the adjacent edges of the flange 1. Each group 10 consists of a round hole between two elongated holes and advantageously has the same modular length and is otherwise identical with the group 5 in the element shown in FIGURE 1, while the holes 11 are identical with the

holes

3, 4. Transversely elongated holes 8 are also provided. The groups 10 and holes 11 might be arranged in staggered overlapping relationship, but they are advantageously both arranged in transverse alignment with the holes 4 or, preferably and as shown, with the holes 3.

The element illustrated in FIGURE 3 has advantages over the element illustrated in FIGURE 1 in respect of the variety and rigidity of connections which can be made between a flange 9 of one element and a flange, with a pattern of holes like that of the flange 1 or that of the flange 9, of a similar or dissimilar element or with a pattern of holes like that of the flange 2 (FIGURE 1). Rigid connections between elements at right angles involving two flanges 9 or a flange 9 and a flange 1 can be established by two, three or four bolts in a variety of relative positions. In these connections, the bolts are located at two or more corners of squares of side i/2, in contrast to similar connections between flanges 1 in which the bolts are located at corners of squares of side i. In both cases, however, the square or part-square, generally triangular, patterns of bolts permit of very strong multibolt connections, where required. The round holes 6 and 8 again permit of positively located connections. Connections at angles other than a right angle are facil- 4 itated by the additional line of holes 11. The use of groups ll of holes in the outer line is advantageous as regards strength for the reason explained with reference to the groups 5.

FIGURE 4 illustrates one example of a rigid connection, between elements at right-angles, involving a flange 9 and a flange 1. Four bolts 20 can be used, if required.

The element illustrated in development in FIGURE 5 has a wider flange 12 with two lines of holes. This flange is advantageously identical, as regards its width and the nature and disposition of its holes, with the narrower flange 9 of the element illustrated in FIGURE 3. The narrower flange 13 has one line of elongated groups 5 of holes and is advantageously identical with the narrower flange 2 of the element illustrated in FIGURE 1. Its nominal width is thus two thirds of the width w of the flange T2 or the flange 9 (FIGURE 3) or half that of the flange I (FIGURES l and 3). As illustrated in FIG- URE 5, the groups 5 and 1t} and holes 11 are all transversely aligned, but a staggered arrangement of the groups It? and holes 11, with the groups 5 transversely aligned with the groups 10, might be adopted.

The flange 12 of the element illustrated in FIGURE 5 affords the same facilities for making connections as the flange 9 of the element illustrated in FIGURE 3. FIGURE 6 illustrates one example of a connection between flanges 12.

As will be evident, either or each of the flanges 1 connected together in the connection of FIGURE 2 could be a flange 1 of an element such as is shown in FIGURE 1 or of an element such as is shown in FIGURE 3. The flange 1 bolted to the flange 9 in FIGURE 4 could similarly be a flange 1 of either of the said elements. The said flange 9 in FIGURE 4 could similarly be the flange 12 of an element such as is shown in FIGURE 5. Finally, either or each of the flanges 12 connected together in FIGURE 6 could be a flange 9 of an element such as is shown in FIGURE 3. In FIGURES 2, 4 and 6, the flanges of elements which may alternatively be so embodied in the respective connections are indicated in brackets.

The patterns of holes illustrated are each made up of similar units repeated at a pitch of 2i, that is twice the modular length. The pattern of the flange 12, for example, may be regarded as centered around the round hole 6. In this case, the centre of that hole '6 is at the mid-length of the uni-t, i.e. at a distance 1" equal to the modular length from the centres of the holes 8" and at a distance equal to half the modular length from the centres of the holes 7. It is also distant by approximately the modular length i from the flange 13. With reference to the diagrammatic FIGURE 7, which shows two flanges I2, 12 of elements extending at right angles and connected by a bolt 22 through round holes 6 in each flange, if one flange is turned through a right angle, the centre of the adjacent hole 7 will swing at a radius i/2 (half the modular length) and the adjacent hole 8 at a radius i (the modular length). Connections by two bolts at least are always possible and by more than two bolts in many relative angular dispositions of the elements.

As has been shown, the three varieties of element illustrated in FIGURES 1, 3 and 5 can be used very effectively in conjunction with each other and may therefore be applied as a set of elements of which that illustrated in FIGURE 1 may be regarded as the standard element and those in FIGURES 3 and 5 as elements to be used, in particular, where greater or less size and/ or strength is needed. The larger and smaller elements may be of heavier and lighter gauges, for example'about No. 10 and No. 14 gauge respectively. All of the elements described can also be used in conjunction with elements such as are described in application No. 258,361.

In a constructional element having a line of holes which extend parallel to and adjacent to a free edge of the element and comprises longitudinally elongated holes and transversely elongated holes whose dimension longitudinally of the line is less than that of the said longitudinally elongated holes, the distance between the said free edge and the nearest points of the said transversely elongated holes is advantageously made at least as great as the distance between the said free edge and the nearest points of the said longitudinally elongated holes. An ele ment of materially greater strength is obtained if this condition is satisfied. Thus, for example, in the outer of the two lines of holes in the flange 9 of FIGURE 3, the outer ends of the transversely elongated holes 8" do not extend beyond a line 23 drawn through the outer edges of the longitudinally elongated holes 7. It will be seen that the same condition is satisfied in the case of the single line of holes in the flange 2 of FIGURE 1 and in the case of both flanges in FIGURE 5.

Punch marks 14 are preferably provided to facilitate cutting the elements at the preferred points.

Various modifications can be made in the above-described elements. Thus in a flange, similar to 9 or 12, containing two lines of holes, both lines may comprise groups such as it), as illustrated in FIGURE 8 for a flange 12. A group in any flange may alternatively consist (FIGURE 9) of a short elongated hole 7a, similar to the hole 7, equidistant between two round holes 6a, similar to the holes 6, the distance between the centres of the round holes 6a being equal to the interval 1'. Or a group may consist of three short elongated holes 7b (FIGURE 10), two short elongated holes 70, 7d (FIGURE 11) or one round hole and one elongated hole, or may even consist of three round holes spaced at i/Z. In each of FIGURES 9 to 11, the alternative form of group is illustrated by way of example in the inner line of holes in a flange 12. Instead of strictly round holes, holes very slightly elongated longitudinally of the element may be used in any group. The

elongated holes

3, 4 and/or 11, particularly the outer holes 3, may be replaced by elongated groups of holes such as the

groups

5 or 10 or one of the alternatives just described. Round holes may be provided instead of the holes 8', 8" or at other intermediate points.

For some uses, an element may be provided having only one line of holes in each flange, one at least of the said lines consisting of groups of holes such as have been described above, for example, the groups '5. Groups in the two flanges may be transversely aligned. Such elements could be used independently but would be more usefully employed in conjunction with the elements previously described. One flange at least would suitably be of the same width as the

flanges

2, 13.

For some purposes, an element may be useful which has two flanges each similar to the flange 12 (FIGURE 5) and each furnished with patterns of holes similar to those in the said flange 12 or with combinations of other holes or groups of holes such as have been described.

Combinations of patterns of holes such as have been described above can be applied also to elements of channel section, the web of the section being treated as one flange.

Constructional elements in accordance with the invention can be usefully employed, alone or in conjunction with further bracing elements, for producing lattice girders or other braced structures of, for example, Warren or double-Warren form, roof trusses or the like. In structures where maximum strength is important, elements can be arranged so that the stronger flange is located where its strength is most advantageous, for example on the tension side of a beam. In complex members built-up from such elements, for example an I-beam, the stronger flanges can be utilised for the chords, the other flanges being bolted together to form a web of greater or less depth depending upon the holes used for the connections.

I claim: 1. A constructional element comprising an elongated metal bar which is constituted by flanges forming an angular cross section and is provided with at least three lines, extending longitudinally of the flanges, of boltaccommodating opening means elongated longitudinally of the respective flanges and having substantially the same modular length and same width as each other, the Width of each of the flanges being substantially an integral multiple of half the said modular length, one of the said flanges being provided with two of the said lines of boltaccommodating means spaced apart at a distance substantially equal to an integral multiple of half the said modular length, whereby the said flange can be connected to a similar flange of a second such element, crossing the first element at right angles, by four bolts located at the corners of a square, the said bolt-accommodating means of at least one of the three said lines comprising recurring groups each of which are substantially of said modular length and elongated longitudinally of the said flange and consisting each of not less than two and not more than three holes of which one at least is elongated longitudinally of the flange, the other of the said flanges having at least one line of the said bolt-accommodating opening means spaced from an edge of the said other flange by a distance substantially equal to half the said modular length.

2. A constructional element as claimed in claim 1, wherein each group of holes in one of said lines of holes comprises a round hole and two short elongated holes, said round hole being located equidistant between said elongated holes.

3. A constructional element as claimed in claim 1, wherein the outer line of the said two lines of bolt-accommodating opening means in said one flange comprises longitudinally elongated groups of holes.

4. A constructional element as claimed in claim 1, wherein bolt holes slightly elongated transversely of the flange are provided in a line of holes midway between elongated groups of bolt-accommodating opening means in the said line.

5. A constructional element comprising a metal bar of L-section, having lines of holes in its flanges, one line including elongated aligned holes each of a modular length for the insertion of bolts, one of said flanges being provided with at least two lines of holes spaced apart transversely of the flange and the other flange having at least one of said lines of holes, one of the said lines of holes extending parallel to and adjacent to a free edge of the element and comprising holes elongated transversely and groups of holes including holes elongated longitudinally of said element, said groups being of substantially said modular length, the distance between the said free edge and the nearest points of the said transversely elongated holes being at least as great as the distance between the said free edge and the nearest points of the said longitndinally elongated holes, the width of each of the flanges being an integral multiple of the half of said modular length and the lines of holes in the flanges being equally spaced from adjacent edges of said flanges.

6. A constructional element comprising a metal bar of angular section comprising two flanges provided with lines, extending longitudinally of the element, of boltaccommodated opening means elongated longitudinally of the element, said bolt-accommodating opening means each having substantially the same modular length, one flange at least being provided with two lines of the said bolt-accommodating means, which means in one of the said two lines comprises groups of holes each consisting of a round hole between two short holes elongated longitudinally of the element, the distance between the center of the round hole and the center of each short elongated hole of a group being equal to the transverse distance between the center lines of the said two lines of boltaccommodating means, the said two lines of bolt-accommodating opening means being spaced from the edges of the said one flange by substantially the said transverse distance, the other of the said flanges having at least one line of bolt-accommodating opening means spaced from an edge of the said other flange by substantially the said distance, the modular length of the said bolt-accommodating opening means in both flanges being equal to twice the said transverse distance and the width of each of the said flanges being substantially an integral multiple of the said transverse distance.

7. A constructional element comprising a metal bar of angular L-section, having lines of recurring holes in its flanges for the insertion of bolts, wherein one flange at least has two parallel lines, extending longitudinally of the flange, of holes elongated longitudinally of the flange, and each having a modular length substantially equal to the distance between the said lines so that the said flange can be connected to the similar flange of a second such element, crossing the first element at right angles, by four bolts located at the corners of a square, the elongated holes in the two lines being arranged in staggered overlapping relationship, and an additional line of not more than slightly elongated bolt holes, pitched at an interval equal to the distance between the said two lines and located opposite to the mid-lengths of the said elongated holes, is provided parallel to the said two lines and equidistantly between them, the said other flange having at least one line of holes with approximately the same modular length as the holes in the said one flange and spaced at the same distance from an edge of the said other flange as the said two lines of holes in the said one flange, and the width of each of the flanges being substantially an integral multiple of half the said modular length.

8. A constructional element comprising a metal bar of angular section, constituted by two flanges, a first one of said flanges being provided with lines of bolt-accommodating opening means extending therethrough, some of said bolt-accommodating means being elongated holes, said bolt-accommodating means being arranged in a recurring pattern and each having approximately the same modular length, said lines being spaced apart laterally approximately one-third the width of said flange, and being spaced from the respective adjacent edge of said flange by approximately one-third the width of said first flange, the said modular length of said bolt-accommodating opening means being equal to two-thirds of the width of the said first flange, the pitch of said bolt-accommodating opening means being twice their modular length, the end portions of the respective bolt-accommodating means of said lines of said means being laterally opposite each other, whereby there are four bolt openings located at the corners of a square whose sides are spaced from the respectively adjacent edges of said first flange by approximately one-third of the width of said flange, the other of said flanges being provided with a longitudinally extending line of bolt-accommodating opening means extending therethrough, said bolt-accommodating opening means of said other flange being similar to and having the same modular length as the said bolt-accommodating means of a line of said means of said first flange, and being spaced from an edge of the said other flange by approximately one-third of the width of the said first flange, the Width of each of the flanges being substantially an integral multiple of half the said modular length.

9. A constructional element as claimed in claim 8 and in which the other of said flanges has a Width approximately one and one third that of said first flange, said other flange having a second line of bolt-accommodating opening means, the bolt-accommodating opening means of said other flange being comprised of elongated holes, the said lines of bolt-accommodating opening means of said other flange being spaced apart at an interval which is twice that between said lines of bolt-accommodating opening means of said first flange, the centre lines of said lines of bolt-accornmodating means of said other flange being approximately equally spaced from the respectively adjacent edges of said other flange, and

the modular length and pitch of said bolt-accommodating opening means of said other flange being substantially equal to the modular length and pitch of said bolt-accommodating opening means of said first flange.

10. A constructional element as claimed in claim 8 and in which said bar is of L-shaped cross-section and the other of said flanges has a width approximately one and one-third that of said first flange, the other of said flange having a second line of bolt-accommodating opening means the said lines of bolt-accommodating opening means of said other flange including two lines of elongated holes spaced apart at an interval which is twice that between lines of opening means in said first flange, the said lines of holes in said other flange being approximately equally spaced from the respectively adjacent edges of said other flange, said other flange having a third line of holes disposed equidistantly between said first mentioned two lines of holes therein.

11. A constructional element comprising a metal bar of angular section, constituted by two flanges, a first one of said flanges being provided with two lines, extending longitudinally of the element, of bolt-accommodating opening means extending therethrough, some of said boltaccominodating means comprising groups of holes including at least one short hole elongated longitudinally of the element, said groups of holes having approximately the same modular length as each other, said bolt-accommodating means being arranged in a recurring pattern, the width of each of the flanges being substantially an integral multiple of half the said modular length of said groups of holes and the pitch of said bolt-accommodating means being twice the said modular length and the said lines being spaced apart by half of the said modular length, the end portions of the said opening means of said lines being located laterally adjacent each other, respectively, whereby said first flange can be connected to the like flange of another such element, crossing said first element at right angles, by four bolts located at the corners of a square whose sides are spaced from the respectively adjacent edges of said first flange by approximately onethird of the width of said first flange, and the second of the said flanges being provided with at least one line, extending longitudinally of the element, of bolt-accommodating opening means spaced from an edge of said second flange by a distance approximately equal to onethird of the width of said first flange and the modular length of the last-named bolt-accommodating opening means being approximately equal to two-thirds of the width of said first flange, so that said second flange can be connected to the first flange of another such element.

12. A constructional element compris ng a metal bar of angular section, constituted by two flanges, one of said flanges being provided with lines of bolt-accommodating opening means extending therethrough, some of said bolt-accommodating means being elongated holes, said bolt-accommodating means being arranged in a recurring pattern, said bolt-accommodating opening means each having approximately the same modular length as each other, said lines being spaced apart laterally approximately one-third the Width of said first flange, and being spaced from the respective adjacent edges of said flange by approximately one-third the Width of the first flange, the said modular length of said bolt-accommodating opening means being equal to twice the lateral spacing of said lines from each other, the pitch of said boltacconnnodating opening means being twice their modular length, the end portions of the respective bolt-accommodating opening means of said lines of said means being laterally opposite each other, whereby said first flange can be connected to a corresponding flange of another such element, crossing the first element at right angles by bolts located at the corners of a square whose sides are spaced from the respectively adjacent edges of the first flange by approximately one-third of the width of said first flange, the other of the said flanges having at least one of said lines of bolt-accommodating opening means extending longitudinally thereof and spaced from an edge of said other flange by a distance approximately equal to half the said modular length.

13. A constructional element comprising an elongated metal bar of angular section constituted by two flanges, one of said flanges being provided with a line of groups of holes extending longitudinally of said element, the centre line of said group of holes being located approximately one third of the width of said flange from one edge thereof, said flange also being provided with a longitudinally extending line of bolt-accommodating opening means extending therethrough, the centre line of which is located approximately one third of the width of said flange from the other edge thereof, whereby said centre lines are located approximately one third of the width of'the said flange apart, each of said groups of holes comprising three holes, one of which is approximately circular and the other two of which are slightly elongated longitudinally, the modular length of said groups of holes and of said bolt-accommodating means being approximately two thirds the width of said flange in which said modular length of said groups of holes, neglecting clearance allowances, is the overall length of said groups of holes, measured in the longitudinal direction of extent of the elongated bar minus the width of said holes, and each group being in transverse alignment with one of said bolt-accommodating opening means, respectively, the other of said flanges having a width approximately two thirds that of the first flange and having a longitudinally extending line of bolt-accommodating opening means, the centre line of which is located at a distance from the inner edge of said other flange of approximately one third of the width of said first flange, the modular length of said boltaccommodating opening means of said other flange being equal to the modular length of said groups of holes of said first flange, and the width of all of said groups of holes and bolt-accommodating opening means being approximately equal, whereby such elements can be connected together in transversely extending arrangement by bolts extending through said groups of holes or bolt-accommodating opening means with either of said flanges bolted together.

14. A constructional element comprising an elongated metal bar of angular section constituted by two flanges, one of said flanges being provided with a line of groups of holes extending longitudinally of the element, the centre line of said groups of holes being located approximately one third of the width of said flange from one edge thereof, said flange also being provided with a longitudinally extending line of elongated holes extending therethrough, the centre line of which is located approximately one third of the width of said flange from the other edge thereof, whereby said centre lines are located approximately one third of the width of the said flange apart, each of said groups of holes comprising three holes, one of which is approximately circular and the other two of which are slightly elongated longitudinally, the modular length of said groups of holes in the first-named line and of said elongated holes in the second-named line being approximately two thirds the width of said flange, said modular lengths of said groups of holes and of said elongated holes, neglecting clearance allowances, is equal to the overall lengths of said group of holes and of said elongated holes, respectively, measured in the longitudinal direction of extent of said elongated bar, minus the widths of said groups of holes and of said elongated holes, respectively, and each said elongated hole being in transverse alignment with one of said groups of holes, respectively, the other of said flanges having a width approximately two thirds that of the first flange and having a longitudinally extending line of groups of holes, the centre line of which is located at a distance from the inner edge of said other flange approximately equal to one third the width of said first flange, the modular length of said groups of holes of said other flange being equal to the modular length of said groups of holes of said first flange, and the width of all of said groups of holes and elongated holes being approximately equal, whereby such elements can be connected in transversely extending arrangement by bolts extending through said groups of holes or elongated holes with either corresponding or non-corresponding flanges bolted together.

15 A constructional element comprising an elongated metal bar of angular section constituted by two flanges, one of said flanges being provided with a line of bolts accommodating opening means extending longitudinally of the element, the centre line of said line of bolt-accommodating means being located approximately one third of the width of said flange from one edge thereof, said flange also being provided with a longitudinally extending line of groups of holes, the centre line of which is located approximately one third of the width of said flange from the other edge thereof whereby said centre lines are located approximately one third of the width of the said flange apart, each of said groups comprising three holes one of which is approximately circular and the other two of which are slightly elongated longitudinally, the modular length of said bolt accommodating means and of said groups of holes being approximately two thirds the width of said flange, in which said modular length of said groups of holes, neglecting clearance allowances, is the over all length of said groups of holes, measured in the longitudinal direction of extent of the elongated bar minus the width of said holes, and each group being in transverse alignment with one of said bolt-accommodating means, respectively, the other of said flanges being approximately one and one third times the width of said first flange and being provided with two longitudinally extending lines of bolt-accommodating means, the centre lines of which are located approximately one half the said modular length from the two edges, respectively, of said other flange, the centre lines of said lines of bolt-accommodating means of said other flange being spaced apart laterally a distance approximately equal to said modular length, the modular length of said bolt-accommodating means of said other flange being equal to the modular length of said bolt-ac v commodating means and groups of holes of said first flange, and the width of all of said holes being approximately equal, whereby such elements can be connected in transversely extending arrangement by bolts extending through said holes with either the similar or dissimilar flanges bolted together.

16. A constructional element comprising an elongated metal bar of angular section constituted by two flanges, one of said flanges being provided with a line of bolt-accommodating means comprising holes extending longitudinally of the element, the centre line of which line of bolt-accommodating means is located approximately one third of the width of said flange from one edge thereof, said flange also being provided with a line of boltaccommodating means comprising holes extending longitudinally of the element, the centre line of which line of bolt-accommodating means is located approximately one third of the width of said flange from the other edge thereof whereby said centre lines are located approximately one third of the width of said flange apart, the modular length of the bolt-accommodating means being approximately two thirds the width of said flange, the other of said flanges being approximately two thirds as wide as said first flange and being provided with a line of bolt-accommodating means comprising holes extending longitudinally of the element, the centre line of which line of bolt-accommodating means is located approximately at the midwidth of said other flange, the modular length of the boltaccommodating means of said other flange being equal to the modular length of the bolt-accommodating means of said first flange, and the width of all of said holes being approximately equal, whereby such elements can be connected in transversely extending arrangement by bolts extending through said bolt-accommodating means with either the similar or dissimilar flanges bolted together.

17. A constructional element consisting of a metal bar of angular section comprising two flanges and provided with lines, extending longitudinally of the element, of bolt-accommodating opening means elongated longitudinally of the element, the width of the flanges being substantially an integral multiple of half the modular length of the said bolt-accommodating means and one of the said flanges being provided with two of the said lines of bolt-accommodating means spaced from the edges of the flange by substantially one-third of the width of said flange, one of the lines of bolt-accommodating opening means comprising groups of three short holes elongated longitudinally of the element, the other of the said flanges having at least one line of groups of holes spaced from the edge of the said other flange by a distance equal to one-third of the width of the said one flange and the modular length of the said groups of holes in both flanges being equal to two-thirds of the width of the said one flange.

18. A construction element comprising a metal bar of angular section constituted of two flanges, one of said flanges being provided with two longitudinally extending lines of elongated bolt-accommodating opening means, the center lines of which are spaced apart transversely of the said flange, the transverse distances between the said center lines and between each center line and the respectively adjacent edge of said flange being approximately one-third of the width of said flange and the modular length of said bolt-accommodating opening means being approximately twice the distance between the said lines, one of the lines of bolt-accommodating opening means comprising groups of three short holes elongated longitudinally of the element, the other of the said flanges having at least one line of groups of holes spaced from the edge of the said other flange by a distance equal to one-third of the width of the said one flange and the modular length of the said groups of holes in both flanges being equal to two-thirds of the width of the said one flange.

19. A constructional element comprising an elongated metal bar of angular section constituted by two flanges, one of said flanges being provided with a line of groups of holes extending longitudinally of said element, the center line of said group of holes :being located approximately one-third of the width of said flange from one edge thereof, said flange also being provided with a longitu dinally extending line of bolt-accommodating opening means extending therethrough, the center line of which is located approximately one-third of the width of said flange from the other'edge thereof, whereby said center lines are located approximately one-third of the width of the said flange apart, each of said groups of holes comprising three short holes elongated longitudinally of the element, the modular length of said groups of holes and of said bolt-accommodating means being approximately two-thirds the width of said flange, and each group being in transverse alignment with one of said bolt-accommodating opening means, respectively, the other of said flanges having a width approximately two-thirds that of the first flange and having a longitudinally extending line of bolt-accommodating opening means, the center line of which is located at a distance from the inner edge of said other flange of approximately one-third of the width of said first flange, the modular length of said bolt-accommodating opening means of said other flange being equal to the modular length of said groups of holes of said first flange, and the Width of all of said groups of holes and bolt-accommodating opening means being approximately equal, whereby such elements can be connected together in transversely extending arrangement by bolts extending 12 through said groups of holes of bolt-accommodating opening means with either of said flanges bolted together.

20. A constructional element comprising an elongated metal bar of angular section constituted by two flanges, one of said flanges being provided with two lines of groups of holes extending longitudinally of the element, the center lines of said groups of holes being located approximately one-third of the width of said flange from respectively adjacent edges thereof, whereby said center lines are located approximately one-third of the width of the said flange apart, each of said groups of holes in one line comprising three holes slightly elongated longitudinally of the element and each of the said groups of holes in the other line comprising three holes, one of which is approximately circular and the other two of which are slightly elongated longitudinally of the element, the modular length of the said groups of holes in the firstnamed and second-named lines being approximately twothirds the width of said flange and each said group in one line being in transverse alignment with a respective group in the other line, the other of said flanges having a width approximately two-thirds that of the first flange and having a longitudinally extending line of groups of holes, the center line of which is located at a distance from the inner edge of said other flange approximately equal to one-third the width of said first flange, the modular length of said groups of holes of said other flange being equal to the modular length of said groups of holes of said first flange, and the width of all of said groups of holes being approximately equal, whereby such elements can be connected in transversely extending arrangement by bolts extending through said groups of holes with either corresponding or non-corresponding flanges bolted together.

21. A constructional element comprising an elongated metal bar of angular section constituted by two flanges, one of said flanges being provided with a line of boltaccommodating means comprising holes extending longitudinally of the element, the center line of which line of bolt-accommodating means is located approximately onethird of the width of said flange from one edge thereof, said flange also being provided with a line of bolt-accommodating means comprising groups of three holes each elongated longitudinally of the element, the center line of which line of bolt-accommodating means is located approximately one-third of the width of said flange from the other edge thereof whereby said center lines are located approximately one-third of the width of said flange apart, the modular length of the bolt-accommodating means being approximately two-thirds the width of said flange, the other of said flanges being approximately twothirds as wide as said first flange and being provided with a line of bolt-accommodating means comprising holes extending longitudinally of the element, the center line of which line of bolt-accommodating means is located approximately at the mid-Width of said other flange, the modular length of the bolt-accommodating means of said other flange being equal to the modular length of the bolt-accommodating means of said first flange, and the width of all of said holes being approximately equal, whereby such elements can be connected in transversely extending arrangement by bolts extending through said bolt-accommodating means with either the similar or dissimilar flanges bolted together.

References Cited in the file of this patent UNITED STATES PATENTS 2,022,255 Scott Nov. 26, 1935 2,301,306 McDonald Nov. 10, 1942 2,339,515 Parcher Jan. 18, 1944 2,632,533 MacKenzie Mar. 24, 1953 2,733,786 Drake Feb. 7, 1956 2,746,780 Comino May 22, 1956