US2465613A - Structural beam system - Google Patents

Description

March 29, 1949. R. E. SPAULDING 2,465,613

STRUCTURAL BEAM SYSTEM Filed Sept. 4, 1945 F'IEJ PIE. 5

FaALF-H E. SPALILEIINE:

' mw d za Patented Mar. 29, 1949 UNITED STATES PATENT OFFICE STRUCTURAL BEAM SYSTEM Fla.

Application September 4, 1945, Serial No. 614,246

15 Glaims. 1

This invention relates to structural beam systems and has as its main object the provision of a restrained cantilever system for floors and the like whereby load stresses are effectively distributed. This object is attained by extending the ends of spaced apart oppositely extending series of stringers past a supporting girder therefor and providing means for transmitting the upward reaction of the projecting ends of each series, resulting from the loading of the system, to the span portions of another series.

In the drawing:

Figure 1 is a schematic plan view of a beam system in accordance with the invention,

Figure 2 is a section on line 2-2 of Figure 1,

Figure 3 is an elevation of the structure shown in Figure 2 as seen from the left of that figure,

Figure 4 is a schematic plan view of another system in accordance with the invention,

Figure 5 is a section in line 55 of Figure 4,

Figure 6 is a section on line 6--5 of Figure 5, and

Figure '7 is an elevation of the structure shown in Figure 5 as seen from the right of that figure.

Referring first to Figures 1, 2 and 3, reference numeral 1 t designates a girder or beam supported horizontally by any suitable means, such as columns therebeneath, and reference numerals H and I2 designate similar girders supported in parallel relation to the girder Hi, the top surfaces of all of the girders being at the same level. Reference numeral l3 designates parallel stringers or beams supported on girders l and H at right angles thereto and having end portions 13 and I3" extending equal distances past the girders respectively. Reference numeral [6 designates the stringers of a second series of parallel stringers supported on girders l0 and 52 at right angles thereto and alternated with the stringers i3 on girder it), the stringers of the two series being equally spaced from each other. Stringers [4 have end portions 14' and I4 extending the same distance beyond girders l0 and 12 as the ends of stringers 13 project beyond girders It and H.

Disposed under the extremities of projecting portions M is a straight continuous beam or member rigidly secured thereto, as by welded straps N3, the beam or member underlying the adjacent span portions of stringers 13 in abutment therewith. A beam or member ll is similarly secured beneath the extremities of the projecting portions 13' of stringers l3 and engaged under the adjacent span portions of stringers 44.

The principles underlying the invention are exemplified at the girder H) where the oppositely all] projecting stringer ends 13 and M are alternated in suitably spaced relation and through beams or members I5 and Il transmit upward reactions, resulting from loading on the spans, to the span portions of the other series of stringers. The best results are secured when the projecting portions l3 and I4 have a length that of their spans. For example, if the distance between girder centers is twenty feet, then the proper overhang is two feet beyond centers.

The upward reaction at the tip of the projecting portions is approximately of the normal load on the stringer when the floor is uniformly loaded. If the girders are spaced at 20 foot centers and the stringers of each series are spaced five feet on centers (2 feet center to center over girder) and the load is 200 pounds per square foot, then the normal load is 200 20 5 or 20,000 pounds, and of this is 7,500 pounds, which is the reaction at the tip of the projecting part of the stringer where the projection is 2 feet. The cross beams or members it and it are sufficiently strong to take the upward reaction.

At the right of Figure 1, reference numeral l8 designates the stringers of a third series supported on girder l2 and assumed to extend across a girder positioned farther to the right, the stringers l8 having portions l8 which project toward girder it the same distance stringers 14 project beyond girder I2. The extremities of portions it are secured to an underlying beam or member l9 engaged under the span portions of girders i l and, similarly, the extremities of stringer portions M are secured to an underlying beam or member 20,

Reference numeral 2! designates a girder parallel to and in the same plane as the other girders and here assumed to define the left-hand end of the beam system. A series of stringers 22 is supported on girders l l and 2! and alternated in equally spaced relation with stringers I3 in parallel relation thereto and having projecting portions 22 equal to the projecting portions H3". The extremities of the latter have fixed therebeneath a continuous beam or member 23 engaged under stringers 22 and portions 22' of stringers 22 have fixed beneath their extremities a continuous beam or member 24 engaged under stringers :3. The left hand ends of stringers 22 terminate above girder 2| and since there is no cantilever provision at this girder, the space between it and girder H should be of the normal span which, in the case under consideration would amount to 15 feet, center to center.

In Fi ure 4 to 7, the arrangement of girders 24, and 26 is the same as the arrangement of girders IE), II and I2, and stringers 2? and 28 correspond in arrangement to stringers l3 and I4 of the first embodiment. However, in this case, instead of using continuous beams or members beneath the stringers, beams or members 29 are arranged parallel to girder 2a with their ends butted against adjacent stringers 2i and secured thereto as by welding and with their middle portions butted flatwise against" the ends of the stringers 28 and rigidly secured thereto asby welding. Each beam extends contiimous13 be tween a pair of adjacent stringers til. beams or members so extend between 'tringers 28 and are secured to the ends or stringers ii; The beams or members as at 29 and 33 take the reaction of the overhanging stringer ends with the same result as in the first embodiment.

It will be noted that the beams or members are located at the extreme outer ends of the projecting ends of the stringers in order that the stringers be unrestrained and free to flex throughout the major portions of the lengths of the projecting ends.

It will be understood that the disclosure herein is intended to be illustrative and that the invention extends to such variations in the form and arran ement of parts as fall within the following claims.

I claim:

1. A beam system comprising three girders supported in side by side parallel arrangement, aseries of stringers supported in parallel spaced relation on the middle and one of the outside girders at right angles to the girders and project-ing beyond the middle girder a distance toward the other outside girder, a second series of stringers supported in parallel spaced relation on the middle girder and on said other outside girder at right angles to the girders and projecting beyond the middle girder a distance toward said one of said outside girders and alternating with the stringers of the first series in spaced relation thereto, and continuous beams transverse to the stringers and secured to the ends of the stringers or" each series of stringers and engaged under adjacent portions of the stringers of each series for the transmission to adjacent portions of the upward reaction of said projecting ends caused by the loading of the system.

2. A system according to claim 1 wherein the girders are equally spaced apart and the stringers or each series project beyond the middle girder a distance substantially one tenth that between the girders.

3. A system according to claim 2 wherein said one of said outside irders is spaced from the middle girder substantially three quarters of the distance said other outside girder is spaced from the middle girder, wherein the stringers of each series project beyond the middle girder a distance substantially one tenth that between said other outside girder and. the middle girder, wherein the stringers of said second series project beyond said other outside girder substantially the same distance as beyond the middle girder, and wherein the stringers oi the first series terminate above said one of said girders.

l. A beam system comprising three girders supported in side by side parallel arrangement, a series of stringers supported in parallel spaced relation on the middle and one of the outside girders at right angles to the girders and projecting beyond the middle girder a distance to- Ward the other outside girder, a second series of Similarly,

stringers supported in parallel spaced relation on the middle girder and on said other outside girder at right angles to the girder and projecting beyond the middle girder a distance toward said one of said outside girders and alternating with the stringers of the first series in spaced relation theretowlrereby the stringers will have span portions between the girders and ends projecting beyond the girders, and beams transverse to said stringers and secured to the projecting ends of the stringers only at the extreme outer ends of said projecting ends and engaged with the span portions oi-the stringers for transmission to said span portion-of the upward reaction of said projecti-ifig ends caused by the loading of the system,

and whereby the projecting ends are unrestrained and free too flex throughout the major portions of their lengths.

5. The combination set forth in claim 4 wherein the beams are continuously integral throughout at least the portions of their lengths which extend between the span portions of adjacent girders of the same series.

6. The combination set forth in claim 5 wherein the entire portions of said projecting ends in wardly of said extreme outer ends are unre strained.

7. The combination set forth in claim 4 wherein the beams are located from the middle girder a I distancesubstantially one-tenth of the length of the span portions.

8. A beam system comprising three girders supported in side by side parallel arrangement, a series of stringers supported in parallel spaced relation on the middle and one or the outside girders at right angles to the girders and projecting beyond the middle irder a distance toward the other outside girder, a second series of stringers supported in parallel spaced relation on the middle girder andon' said other outside girder at right angles to the girders and projecting beyond the middle girder a distance toward said one of said outside girders and alternating with the stringers of the first series in spaced re lation thereto, whereby the stringers will have span portions between the girders and ends projecting beyond the girders, and beams transverse to and located at the extreme outer ends of said stringers and secured thereto by means located at the end faces of the projecting ends of the stringers of each series and engaged with the span portions. of the stringers or each series for transmission to said span portion or the upward reaction of said projecting ends caused by the loading of the system, and whereby the projecting ends are unrestrained and free to flex throughout the major portions of their lengths.

'9. A beam system compr sing three girders in side by side spaced parallel arrangement, a pair or stringer-s supported in parallel spaced relation on the middle one or the outs de girders right angles to the girders, a third stringer between said first two stringers and supported on the middle girder and on the other outside girder in spaced parallel relation to said first two stringers and projecting beyond the middle girder toward said outside girder, and a continuous integral beam transverse to the stringers and secured to the end portion of the projecting end of the third stringer and engaging the span portions of the first two stringers for the transmission thereto of the upward reaction of the projecting end of the third stringer caused by the loading of the third stringer.

1c. The combination set forth in claim 9 wherein the portions of said span portions between the middle girder and the beam are unrestrained.

11. The combination set forth in claim 9 wherein the entire portion of the projecting end j8Ci7iI1g beyond the middle girder a distance toward the other outside girder, a second series of stringers supported in parallel spaced relation on the middle girder and on said other outside girder at right angles to the girder and projecting beyond the middle girder a distance toward said one of said outside girders and alternating with the stringers of the first series in spaced relation thereto whereby the stringers will have span por-" tions between the girders and ends projecting beyond the girders, and a plurality of continuous integral beams each extending across the space between adjacent span portions of stringers of the same series, each beam being transverse to the stringers, the opposite ends of each beam being secured to oppositely-facing surfaces of the adjacent span portions of a pair of adjacent stringers of one series, and an intermediate portion of said beam being secured to the projecting end of a stringer of the series other than the series comprising said pair of stringers.

14. The combination set forth in claim 13 wherein the portions of said span portions between the middle girder and the beams are unrestrained.

15. The combination set forth in claim 14 wherein the beams are located from the middle girder a distance substantially one-tenth of the length of the span portions.

RALPH E. SPAULDING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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