US1718938A - Charles i - Google Patents

Description

July 2, 1929.

C. l. BATES METAL JOIST AND THE MANUFACTURE THEREOF Filed Oct. 31, 1927 CHARLES I. BATES, OF CHICAGO, ILLINOIS, ASSIGNOR TO BATES EXPANDED STEEL TRUSS COMPANY, OF EAST CHICAGO, INDIANA, A CORPORATION OF DELAWARE.

METAL JOIST AND THE MANUFACTURE THEREOF.

Application filed October 31,1927. Serial No. 229,835.

The invention relates to expanded metal joists or beams and the manufacture thereof.

During the use of joists or beams of the type that is formed of an. integrally flanged metallic structural element, such for eX- ample, as an I-beam, and has the central portion of the web which connects the flanges expanded to form diagonal compression and tension members or trussing, the tension members at the ends of the joists, that is, next to the supported end portions, are generally subjected to the greatest amount of tension. One object of the present invention is to provide a joist or beam of the aforementioned type, in which the end tension mem bers are formed by bending upwardly the end portions of the lower flange and the lower portion of the web so that said members are heavier than the intermediate truss members and hence better able to withstand the additional tension placed'upon them and are reinforced to withstand transverse bending movement.

Another object of the invention is to provide a joist or beam of this character in which the outer ends of the end tension members are extended outwardly and-are secured to the upper portion of the web so as to give additional strength to the ends of the joist and so that the lower flange operates as a bearing member whereby the joist may be supported and held againsttransverse rocking movement.

A further object of the invention is to provide a method ofrmanufacturing joists or bean'is of the aforementioned construction by which the joists may be made at a comparatively low cost and without the necessity of adding non-integral reinforcement to the end portions of the joists.

V A still further object of the invention is to provide a oistor beam of the expanded metal type, which is of new and improved construction and in which the ends are formed so as to give additional strength to the joist against bending movement immediately inwardly of the supported end portions.

Other objects will be apparent from a consideration of the following detailed description.

The invention consists in the several novel features hereinafter set-forth and more particularly defined by the claims at the con clusion hereof.

In the drawing which accompanies and forms a part of this specification: Fig. 1 is a side elevation of an I-beam from which the joist or beam is formed. Fig. 2 is a similar View illustrating the manner of slitting the beam before it is expanded. Fig. 3 is a side elevation of the beam after it' has-been expanded. Fig. 4 is a side elevation of the finished joist. F igf5 is a section taken on the line 55 of Fig. 4. Fig. 6 is an end view of the joist structure shown in Fig. l.

The invention is exemplified in a joist or beam comprising a longitudinal upper member which consists of a vertical web a and a horizontal flange a projecting laterally from both sides thereof and forming the top of the joist; a lower longitudinal member which consists of a vertical web a and a horizontal flange projecting laterally from both sides thereof and forming the bottom of the oist; a series of substantially parallel diagonal trussmembers a which extend between the vertical webs of the upper and lower members; and a series of oppositely extending diagonal truss members a which extend between the webs of the upper and lower members and are medially united with the truss membersa. All of the parts or members which together form the joist proper are in tegral and are formed of a structural steel I-beam or bar A, as, for example, the one shown in Fig. 1. i The upper and lower flanges of this bar correspond to the flanges o and a of the joist.

In the manufacture of the joist, the web of the beam is first sheared to form an upper series of longitudinally aligned slits a", with bonds or intact portions a between them. a lower series of longitudinally aligned slits a", with bonds a between them, and a central or intermediate series of slits a with bonds a between them. The slits of the lower series are parallel and coextensive with the slits of the upper series. The slits of the intermediate series are co-extensive with the slits a and a and are stagger-ed relatively thereto so that the bonds 0. are positioned midway between thebonds a and a The of the beam.

ate series so as to eliminate compression or downwardly and outwardly'extending members adjacent the beam-ends and so that the upper member of the joist is additionally reinforced adjacent the ends thereof. The uncut metal of the web between the top flange a and the extended part of the end slits of the intermediate series forms portions a. These portions are of a height equal to the aggregate height of the vertical web a and the strands between the slits a and a and operate to reinforce the joist atthe places where most needed. A characteristic of terminating or omitting the slits a at the ends of the beam as set forth 15 that there are only tension truss members adjacent the beam-ends and the metal which would otherwise form downwardly and outwardly extending compression members adjacent the ends of the joist, as in the criss-cross trussing of the central portion, is utilized to provide additional reinforcel'nent against bending. The slitting, arrangement so far described exempliiies a method of slitting the joist preparatory to expansiomby which the upper memher is reinforced by an integral web portion adjacent the ends of. the joist.

After the beam A has been slittedas described, it is heated and the upper and lower flanges a and a are spread apart in parallelism by suitable expanding mechanism into the position shown in Fig. 3. This' expanding operation stretches and deflects the strands of the web formed by the slits, into the diagonal truss members a and a, leaving their ends oined to the upper and lower portions of the web and their medial portions joined together. This forms a series of diamond shaped openings in the web and per mits the extent of expansion necessary to form a joist of any desired height. The slits a are spaced from the flange (4 a greater distance than the slits a are spaced from the flange a, to give greater strength to the upper member of the joist. By extending the end slits of the intermediate series so that they intersect the beam-ends the portions a of the web which extend between said end slits and the end slits of the lower series and theportions (4 which comprise the web a and the flange a at the ends of the lower member that is outwardly of the end bonds (4 are not subject to bending during expansion The portions a are sheared on lines a and are removed as scrap. Shear lines a are disposed outwardly of the end bonds at so that the connections between the outer compression members and the web a are not impaired. After the slitting and expanding, operation, the portions a are wholly separated from the portions (L13 and are disconnected with respect to thelatter except through the instrument-ality of the truss members a and a.

T he truss members at the ends of the joist :ends of the joist.

are formed by bending or deflecting the portions e of the lower member adjacent the end bonds a so that they project upwardly and outwardly as shown in' Fig. 4C. In this position the portions (4 operate as tension members. The outer ends of the portions (Z15 are bent at the points a so that they extend outwardly and parallel to the upper member of the joist. The contiguous margins of the web a and the outwardly extend ing parts of the portions a are welded to gether as at a rigidly to connect or secure the upper ends of the end tension members to the upper member of the joist. This arrangement exemplifies a method of forming the end tension members by means of the ends of the lower web and flange member of the joist. A characteristic of this method and a. result is that the metal at the ends of the lower member of the joist which would ordinarily be held in suspension is utilized to form the end trussor tension members. Because the portions (0 embody a greater amount of metal than the criss-cross trussing at the central portion of the joist, due to the horizontal flange a the end truss members are eificiently reinfo ced to withstand the extreme tension or stresses which occur at the During use of the joist the flange a of the'end truss members operates to reinforce the central trussing and the lower member of the joist against transverse bending movement. The portions of the flange a which are embraced in the outwardly extending or welded ends of the portions a form bearing plates for the joist which are adapted to rest upon suitable supports B. These plates serve to hold the joist against transverse rocking and prevent the lower edge of the web a from cutting into the supports B. A characteristic of forming the plates in this manner is that they are integral with the joist, and the use of non-integral plates and the necessary welding is elimi nated. An additional characteristic of this method of forming the end truss members is that the intersection of the stress lines in the upper member and the end tension members (0 are projected endwise closer to the ends of the joist so as to approximately reach or extend beyond the point of support, as in dicated by dotted lines X in Fig. 4.

The act of bending the portions a up wardly and outwardly shortens the portions longitudinally of the joist. So that the web a and the flange (6' do not project beyond the outer ends of the truss members a the metal at the ends of the upper member is sheared off so that it is even or flush with the outer edges of the truss members a. The sheared pieces are thrown away as scrap.

Struts (4 are placed between the upper and lower longitudinal members of the joist in the end openings, to act as compression members between said longitudinal members.

These struts have their upper ends welded as at (r to the inner ends of the portion (L and their lower ends Welded to the end bonds a. 'By positioning the struts a a suitable distance from the ends of the beam, downward stresses are transmitted directly from the up per member to the lower member.

The invention exemplifies, a oist which is formed of a slitted expanded I-beam with diagonal truss members which serve as compression and tension members to increase the strength of the joist, and in which the end truss members are formed by the ends of the lower web and flange so that they are heavier and better reinforced than the central truss members; a joist of this character in which the outer ends of the end truss members are bent outwardly and are welded to the upper web so that the flange at the bottom of said outer end forms bearing plates for the joist and the points of intersection of the stress lines in the upper member and the end tension members is above or outwardly of the supports; and also a method of manufacturing the joist by the manner of slitting the beam prior to expansion, and without the necessity of adding non-integral reinforcement to the portions of the joist near its ends.

The slitting may be advantageously done in a machine of the character set forth in an application for Letters Patent filed Novemher 5, 1926 by Albert J. Bates, J11, and serially numbered 1 l1,702. The expanding may be done in a machine of the type set forth in Letters Patent No. 1,260,857, dated March 26, 1918. i

The invention is not to be understood as restricted to the details set forth, since these may be modified within the scope of the appended claims, without departing from the spirit and scope of the invention.

raving thus described the invention, what I claim as new and desire to secure by Letters Patent, is:

1. That in'iprovement in the manufacture of expanded metal joists which consistiirst in slitting the medial portion of a flanged beam to form a pair of longitudinal mem; bers and a series of expansible strands between and bonded to said members, and

- slitting longitudinally the ends of the beam to intersect the end edges and form separate end portions for the longitudinal members; then expanding the beam to space one member and its end portions from the other member and its end portions and to form of the strands diagonal truss members in the medial portion of the beam; and then bending the end portions of onemember toward the end portions of the other member and securing them in place to form diagonal truss members adjacent the ends of the beam.

2. That improvement in the manufacture of expanded metal joists which consists first in slitting the medial portion of a flanged beam to form an upper and a lower longitudinal member and a series of expansible strands between and bonded to the members, and slitting longitudinally the ends of the beam to intersect the end edges and form separate end portions for the longitudinal members; then expanding the beam to space in parallelism one member and its end portions from the other member and its end portions and to form of the strands diagonal truss members in the medial portion of the beam; then bending the end portions of the lower member upwardly and outwardly to form diagonal truss members adjacent the ends 01' the beam; and finally securing the outwardly bent parts of said end portions of the lower member directly to the end portions of the upper member. I

That in'iprovement in the manufacture of expanded metal joists which consists first in slitting the medial portion of a flanged structural steel beam to form an upper and a lower longitudinal member and a series of expansible strands between and bonded to the members, and slitting longitudinally the ends of the beam to intersect the end edges and form separate end portionsfor the said longitudinal members; then expanding the beam to space one member and its end portions from the other member and its end portions and to form of the strands diagonal truss members in the medial portion of the beam; then removing a longitudinal piece of metal from each of the end portions of the lower member; then bending said end portions of the lower member upwardly and outwardly to form diagonal truss members adjacent the ends of the beam; and finally se-e curing the outwardly bent parts of the aforesaid end portions of the lower member directly to the end portions of the upper member.

4. That improvement in the manufacture of expanded metal joists which consists first in slitting the medial portion of a flanged beam to form a pair of longitudinal members and two intermediate and side-by'side series of expansible strands with bonds between themselves and said members, and slitting the ends of the beam to intersect the end edges and form separate end portions for the longitudinal. members, then expanding the beam to space one member and its end portions from the other member and its end portions and to form of the strands oppositely extending and centrally joined diagonal truss members in the medial portion of the beam; and then bending the end portions of one mem ber toward the end portions of the other member and securing them in place to form diagonal truss members adjacent the ends of the beam.

5. That improvement in the manufacture of expanded metal joists which consists first in slitting the medial portion of a flanged beam on three longitudinal lines to form a pair oi longitudinal members and two intermediate and side-by-side series of expansible strands with bonds between themselves and said members, and slitting the ends of the beam 011 one of the three lines to intersect the end edges and form separate end portions for the longitudinal members; then expanding the beam to space one member and its end portions from the other member and its end portions and to form of the strands oppositely extending and centrally joined diagonal truss members in the medial portion of the beam; and then bending the end portions of one member towards the end portions of the other member and securing them in place to form diagonal truss members adjacent the ends of the beam.

6. That improvement in the manufacture of expanded metal joists which consists first in slitting intermittently the medial portion of a flanged beam on three longitudinal lines to form a pair of longitudinal members and two intermediate and side-by-side series of expansible strands with bonds between themselves and said members, and slitting the ends of the beam to intersect the end edges and the end slits of one of the lines and form sep" arate end portions for the longitudinal members; then expanding the beam to space one member and its end portions from the other member and its end portions and to form of the strands oppositely extendingand centrally joined diagonal truss members in the medial portion of the beam; and then bending the end portions of one member toward the end portions of the other member and se curing them in place toform diagonal truss members adjacent the ends of the beam.

7. That improvement in the manufacture of expanded metal joists which consists first in slitting intermittently the medial portion of a flanged beam on three longitudinal lines to form an upper and a lower longitudinal member and two intermediate and sideby-side series of expansible strands with bonds between themselves and said members,

termediate line to intersect the end edges and the end slits of said intermediate line and form end portions for the longitudinal members, and on the bottom line to intersect said end edgesot the beam; then expanding the beam to space one member and its end portions from the other member and its end portions and to form of the strands oppositely extending and centrally joined diagonal truss members in the medial portion of the beam; then removing the metal of the end portions of the lower member, located above the edge intersecting slits of the lower line; and then bending said end portions of the lower member toward the end portions of the upper member and securing them in place to form flanged beam and comprising an upper and a lower longitudinal member, and oppositely extending diagonal truss members located adjacent the medial portion of the beam and formed integrally with the upper and lower members, the ends of said upper and lower members projecting a substantial distance beyond the truss members, the ends of the lower member being formed separately from the ends of the upper member and being bent to extend upwardly and secured'to said ends of the upper member to form truss members adjacent the ends of the beam.

9. An expanded metal joist formed of a flanged beam and comprising an upper and a lower longitudinal member, and oppositely extending and centrally united diagonal truss members acting as tension and compression elements in the medial portion of the beam and formed integrally with the upper and lower members, the ends of said upper and lower members projecting a substantial distance beyond the truss members, the ends of the lower member being formed separately from the ends of the upper member and being bent so as to extend diagonally upwards and secured to said ends of the upper member to form diagonal tension elements at the ends of the beam.

10. An expanded metal joist formed of an I-beam and consisting of an upper and a lower flanged longitudinal member, oppositely extending and centrally united intern'iediate truss members acting as tension and compression elements in the medial portion of the beam and formed integrally wit-h the upper and lower members, the ends of said upper and lower members projecting a substantial distance beyond the truss members the ends of the lower member being formed separately from the ends of the upperinember and being bent to extend diagonally upward and welded to the said ends of the upper member to form diagonal tension elements adjacent the ends of the beam, and struts extending between said upper and lower members and positionedadjacent the inner ends ot the end tension members.

11. An expanded metal joist formed of an I-beam and consisting of an upper and a lower flanged longitudinal member, oppositely extending and centrally united truss members acting as tension and compression elements in the medial portion 01" the beam and connected to the upper and lower membersby integral bonds or intact portions, the ends of said upper and lower members projecting a substantial distance beyond the truss members, the ends of the lower member being formed separately from the ends of the upper member and being bent to extend diagonally upward and welded to the said ends of the upper member to form diagonal tension elements adjacent the ends of the beam, and struts extending between and Welded to the bonds of the outermost truss members.

12. An expanded metal structure comprising an integral member having flanges upon the two opposite sides thereof, web portions contiguous to said flanges and diagonals connecting said web portions, certain of said flanges and web portions being swedged into proximity to the flanges and Web portions on the opposite side of said expanded metal structure to form a beam.

13. An expanded metal structure co1nprising an integral member having flanges on the two opposite sides thereof and diagonals between said flanges, said diagonals intersecting one another to form diamond shapes, certain of said flanges being swedged into adjacency to the flanges on the opposite sides of the expanded metal structure to form a beam.

14. A beam comprising an expanded metal structure having flanges on the two opposite sides thereof, web portions contiguous to said flanges, and diagonals connecting said Web portions, a flange and a web portion at an end of said beam being swedged int-0 adjacency with the flange and web portion at the opposite side of said beam.

15. A beam comprising an expanded metal structure having opposite flanges parallel throughout a major portion of their length, diagonals connecting said flanges, one of said flanges being inclined into adjacency with the flange upon the opposite side of said expanded metal structure, and struts located adjacent to said inclined portions for reinforcing said expanded metal structure.

Signed at East Chicago, Indiana, this 26th 'day of October, 19271 CHARLES I. BATES.

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