US2060080A - Beam action stringer - Google Patents

Description

Nov. 10, 1936. A C, HORNER BEAM ACTION STRINGER Filed March 4, 1935 3 Sheets-Sheet l NOV. 10, 1936. A C, HORNER BEAM ACTION STRINGER Filed March 4, 1955 5 Sheets-Sheet 2 Nov. 10, 1936. A. c. HORNER BEAM ACTION STRINGER Filed March 4, 1955 3 Sheets-Sheet 3 Patented Nov. 10, 1936 UNITED STATES PATENT OFFICE 5 Claims.

This invention relates to structural stringers and particularly to timber or wooden stringers, and it aims to provide a method and means whereby a line of stringers or simple beams are supported and connected for continuous beam action, or, considered in another light, so that the effect of a load imposed upon that portion of the stringer between any two supports will not be conned or concentrated on that portion, but will extend and be distributed beyond the supports.

Another object is to attain the results stated by splicing the ends of the simple beams in laterally overlapping relationship and in combination with supports, in a manner insuring such a strength to the resulting splices that the splice will be as strong in bending as the remainder of the individual beams.

From a practical standpoint a continuous beam conforming to the invention will be deflected considerably less than simple beams, at any 'loaded point and, presuming the splice to be strong enough to resist bending moment, the continuous beam action permits the use of smaller timbers than if the stringer were a series of simple beams, effecting a material saving in material.

A further aim is to provide a construction wherein driven metallic connectors or cementitious or equivalent matter, either alone or in combination may be effectively used to provide a strong splice in accordance with the invention.

Various additional objects and advantages will become apparent from a consideration of the description following taken in connection with the accompanying drawings illustrating exemplary embodiments thereof, wherein:-

Figure 1 is a fragmentary plan view of a bridge structure illustrating one form of the improved continuous beam stringer;

Figure 2 is a substantially horizontal sectional View of the structure of Figure 1;

Figure 3 is a transverse sectional View taken substantially on the plane of line 3, 3 of Figure 2;

Figure 4 is a detail in side elevation of one form of metallic dowel or connector used;

Figure 5 is an end view of said dowel or connector;

Figure 6 is a detail side elevation of a modied form of the metallic dowel or connector; y

Figures 'l' and 8 are diagrammatic views, the former suggesting simple beam action as in the usual type of stringer and the latter contrasting therewith, the continuous beam action of the stringer produced in accordance with the present invention;

Figure 9 isa fragmentaryy plan viewof a bridge using a second form of continuous beam action stringers;

Figure 10 is a longitudinal sectional view taken through the bridge of Figure 9;

Figure 11 is a cross sectional view taken substantially on the plane of line I I-I I of Figure 9;

Figure 12 is a fragmentary plan view of a bridge utilizing a third form of continuous beam action stringer;

Figure 13 is a longitudinal sectional View taken through the bridge of Figure 12;

Figure 14 is a transverse sectional View taken substantially on the line I4-I4 of Figure 12;

Figure 15 is a fragmentary plan view of a bridge using a further form of continuous beam stringer, and

Figure 16 is a longitudinal sectional view taken on the line IE-IB of Figure 15.

The continuous beam stringer of the present invention is advantageously used in bridge building, and it has been specifically disclosed in that connection by way of example, no limitation however being implied to such use.

Referring specifically to the form of Figures 1 to 3, I0 designates piles or columns surmounted by caps or cap beams II, usually but not necessarily of wood, which support stringer or beam members I2. Each stringer I2 at opposite end portions rests on and is secured to one of the said caps II. Such beams I2 are slightly angularly disposed, and such end portions overlapA end portions of the adjacent stringers, the overlapping, and in this instance, contacting end portions being designated I3. Adjacent the terminal or free ends of each stringer I2 they have metallic dowels or connectors I4 driven into the sides thereof, the connectors I4 joining together the adjacent portions I3 as shown. Specically, such connectors I4 are metallic rings or thimbles provided with sp-urs or points I5 on the opposite edges thereof, the connector being longitudinally corrugated, if desired, as shown in Figure 5. Obviously any form of connector may be substituted for that specifically disclosed at I4. If desired, bolts or the equivalent I6 may be passed through the portions I3, which it will be noted are surrounded by the said connectors I4. A typical loading or overdeck structure is shown as applied to the stringers I2 as at I'I, consisting, for instance, of ties I8 which support railway rails I9.

As a result in the construction described, a continuous beam action is assured throughout the line or lines of stringers I2, inasmuch as the portions I3 are supported and the portions I3 are connected together at a plurality of points and on opposite sides of the supports. Because of the connectors I4 and bolts I5, or other fastening means, the splice produced by the portions I3 and fastenings is at least as strong in bending as the individual stringers or beams I2-I2 Accordingly the action of the continuous beam under a load imposed between any two supports II will be that suggested in Figure 8, and which is to be contrasted from the usual single beam action suggested by the diagram of Figure '7. In said Figures 7 and 8 the supports are designated s. The simple beams in Figure 7 are shown at t While the continuous beam produced by a series of stringers I2, is designated u in Figure 8. It will be seen that instead of a load P having eiect between two supports only, as in Figure '7, that such eect as in Figure 8 extends to and is distributed beyond any two supports so as to attain the continuous beam action. It has been found too that the deection of the continuous beam as in Figure 8, will not be more than one-half of the deflection of a simple beam as suggested in Figure '7.

It is clear that the invention may be produced in various Ways and forms, and that no limitation is to be implied with respect to the ones just specically described. For instance, I may use the forms disclosed in Figures 9 to 11, employing the connector of Figure 6, rather than that of Figures 4 and 5. In such form, the piles or columns are designated I0 and the caps II', supporting wooden stringers I2 at overlapping end portions I3. Instead of the stringers I2' being angularly disposed like those at I2, they are straight and alternately arranged, and the portions I3 are in spaced relation with bodies '2S bonding them together. These bodies 20 are rigid, being cast to the stringers while in a plastic state, and consisting of concrete or other cementitious matter, usually using Portland cement as the bonding material. Prior to the application of the material 20, conductors or anchors 2l, are driven so that teeth 22 thereof will fasten them in the sides of the portions I3. These connectors 2| are preferably of corrugated metal and of ring shape and smooth at their opposite end, thus conforming to the form of Figures 4 and 5, except that the teeth are omitted at one end. The untoothed portion of the connector 2I projects beyond the sides of the Stringer portions I3 and are anchored and embedded in the concrete or bodies 2D. Such bodies, if desired, may be reinforced as suggested at 23.

'Iransversely of the stringers I2 an overdecking, as of timber, may be laid at 24. Braces 25 of wood or cement may be provided between the stringers, for instance, midway of their ends.

It will be realized that the continuous beam action suggested by the diagram of Figure 8, will also take place under a load imposed between any two caps or supports IIl inasmuch as the bonding and connection of the stringers by the bodies 2S render the splice thus produced as strong as any part of the remainder of the stringers, giving the same coaction as the caps II and connections I4 in the preceding form of the invention.

In Figures 12, 13 and 14 another form of the invention is disclosed which conforms in many respects closely to that of Figures 9 to 11. The stringers I2" in this instance are of Wood and are connected and supported identically as in Figures 9 to l1, except that braces 25 corresponcling to those at 25 are of concrete, and such braces as well as bodies corresponding to those at 2i] are widened at the top as at 21 and 28. The stringers i2 have metallic anchors 29 driven into the same, and a concrete or equivalent overdecking 36 is poured over the stringers and bodies 28 and 25', being eiectively held in place by the anchor members 29 when the concrete sets or hardens. Such overdecking 30 may have metallic reinforcement as at SI, if desired. In some instances, with the aid of the appropriate forms, the bodies 2G', reinforcements or braces and the overdecking 3E] may be poured simultaneously and constitute a single unit or integral body when set or hardened.

In the said forms of Figures 12 to 14, it will be realized that the continuous beam action is attained as in the previous forms.

Figures 15 and 16 illustrate a form identical with that of Figures l2 to 14, except that the anchors 29 are omitted and in lieu thereof, ring anchors 32 are employed, for which purpose I use connectors 2| as shown in Figure 6. These anchors or connectors 32 have their teeth 2I driven into the wooden beams here designated I2" at any desired locations or intervals to untoothed portions of such anchors 32 projecting above the beams I2"' and being embedded and anchored in the concrete or equivalent overdecking as best shown in Figure 16. Obviously in this form of the invention, the continuous beam action is attained as in all of the previous forms.

Attention is called to the fact that a material advantage of the present invention is that the continuous beam action which is attained, permits the use of smaller timbers as at I2, I2', I2 and I2" than is the case where the stringer is merely a series of simple beams as in Figure '7. Another point of considerable importance, especially when a concrete oor slab is used as in Figures l2 to 15, the deflection at any loaded point is less than at a correspondingly loaded point in a line of simple beams, experiments having shown that the deflection may be limited to as much as one-half of the deflection of a simple beam.

It is to be also understood that the concrete or equivalent bodies 20 and 2D are not only secured in place by the connectors or anchors 2| but that such concrete is intimately bonded and adhered to the portions of the wooden stringers with which they contact.

Various changes may be resorted to provided they fall within the spirit and scope of the invention.

I claim as my invention:

1. A continuous beam action structure comprising a line of stringers having end portions in overlapping relation, a cementitious body interposed between said end portions and bonded thereto and eiective adjacent the ends of the stringers, and a connector secured to each stringer adjacent its end and anchored in said body.

2. A continuous beam action structure comprising a line of stringers having end portions in overlapping relation, a cementitious body interposed between said end portions and bonded thereto and eiective adjacent the ends of the stringers, a connector secured to each Stringer adjacent its end and anchored in said body, supporting means for said body and end portions, and overdecking on said stringers.

3. A continuous beam action structure comprising a line of stringers having end portions in overlapping relation, a cementitious body interposed between said end portions and bonded thereto and effective adjacent the ends of the stringers, and a cementitious overdeck integral with said body.

4. A continuous beam action structure comprising in combination with rst and second supports and with an intermediate support, stringers supported on the intermediate support and the first support and extending beyond each of them and terminating short of the second mentioned support, stringers disposed on the intermediate support and second mentioned support extending beyond both of them and terminating short of the first mentioned support, means connecting said stringers together on opposite sides of and adjacent the intermediate support, and connecting means for the respective stringers adjacent the first and second supports at the sides thereof facing the intermediate support.

5. A continuous beam action structure comprising in combination with rst and second supports and with an intermediate support, stringers supported on the intermediate support and the rst support and extending beyond each of them and terminating short of the second mentioned support, stringers disposed on the intermediate support and second mentioned support extending beyond both of them and terminating short of the first mentioned support, means connecting said stringers together on opposite sides of and adjacent the intermediate support, and connecting means for the respective stringers adjacent the first and second supports at the sides thereof facing the intermediate support, the stringers being disposed in horizontal rows and each Stringer contacting with the adjacent supports.

ARTHUR C. HORNER.

Images