US2280121A - Structural joint - Google Patents

Description

April 21, .1942. N. P. GREEN 2,280,121

. STRUCTURAL JOINT Filed May 26, 1941 2 Sheets-Sheet l N. P. GREEN STRUCTURAL JOINT April 21, 1942.

Filed May 26, 1941 2 Sheets-Sheet 2 Patented Apr. 21, 1942 UNITED STATES P TENT OFFICE 2,280,1'21 STRUCTURAL JOINT- Nathaniel Green, University City, Mo. Application May 26,1941, SerialNo. 395,122. 7 Claims. (01. 20-92) This invention relates to structural joints, and with regard to certain more specific features, to joints which provide end bearings for wooden compression struts and the like.

Among the several objects of the invention may be noted the provision of a structural joint which applies load to struts in end-grain compression, without shear; the provision of a device of the class described which provides for bearing by compression at any of various angles without the necessity for special end cuts upon the struts; and the provision of a device. of the class described which is simple in form and application. Other objects will be in. part obvious and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which are illustrated several of various possible embodiments of the invention,

Fig. 1 is a front elevation of forming part of the invention;

Fig. 2 is a top plan View of Fig. 1;

Fig. 3 is a right-side elevation of Fig. 2;

Fig. 4 is a side elevation of a heel plate viewed from the upper right as shown in solid lines .in Fig. 5;

Fig. 5 shows a left-side elevation (in solid lines) of the heel plate of Fig. 4 along with. a mating heel plate shown in dotted lines, both an angle plate located in operating position upon the end of a l strut, also shown in dotted lines;

Fig. 6 is a fragmentary side elevation. showing one application of the invention to forming certain joints;

. Fig. '7 is a diagonal section taken on line 1-1 of Fig. 6; p l

Fig. 8 is a view similar to Fig. 6 but showing another application; and, Fig. 9 is a diagonal sectiontaken on line 5--9 of Fig. 7

Similar reference characters indicate corredicated. at. l and 9.

there isshown in. general at numeral 1 an angle plate consisting of, a knee socket portion 3 from extends a pad 5, ribbed for strength, as in- A bolt hole II is provided through. pad 5 in rib 1. l

At. a right angle to the pad 5 extends a second and longer pad. I3, centrally ribbed as indicated at l5 and provided with bolt holes ll. through. a

boss portion 18. The rib l5 and boss l8 terminate one in they other.

The inner contour of the knee 3 is. circular and smooth, as indicated at numerals 15. The radius of. curvature is indicatedat II and the virtual center of curvature at 23.

sponding .parts throughout the several views of the drawings.

Wooden structures such as cooling towers require a large number of angularly positioned compression struts which need to be jointed into the structure as economically as possible without sacrifice of strength. The presentinvention provides an improved form of-joint for the purpose.

Referring now more. particularly to Figs. 1 3,

The rib extends into the circular portions 19 where it takes the form of a flange in which is an arcuate opening 21. The center of the arc of opening 21 is also at 23.

Numerals, indicate integral tongues which are mortised into grooves 33 (Fig. 6). These tongues are chamfered as indicated at 34 Figs.

Sand 7 indicate an example of use of the angle plate. For example, in Fig. 6, there is shown a Wooden column 3| grooved at 33 for mortising in the tongues 29. A bolt 35 passing through one of the openings I'l serves to hold the pad I3 against thecolumn 3|. In Fig. 6 the device is inverted at 'the right and the short pad 5 is mortised into the upper surface or a wooden beam 37, as indicated 1 at 39. The beam is held up by said pad'by" connection with a bolt 4| passing through the openrung l I. Thus the angle plate I holds up the beam 3! but anythrusts thereon which are'angl'ed with respect to the plane of the pad I3 will be resisted axially'by the column 3|,due to the insertion of the tongues 29 into the grooves 33.

Referring now to Figs. 4 and 5, wherei-nthe heel plate is shown, it is to beunderstood that two heelplates 4-3 are used at the end of-each strut in connection with each angle plate 1 (above described). Each heelplate 43 consists of a flat bearing pad 45 from which extends an arcuatebearingheel 4'! having a bolt hole 49 therethrough. At a right angle is located an offset holding pad 5|, also having a bolt hole-53 therethrough. The bearing heels are spaced from the edges 52 and 54.

To prepare astrut 55- for application of the heel plates 43', it is only necessary to trim its end on atright angles and drill a hole 59" at a suitable location to be aligned with holes 53. A pair of heel plates is then applied, as indicated at 51, and since the pad portion 45 of each plate has an extension 6|, a space 63 is left for the reception between the spaced heels 4! of the flange 25 on the angle plate I. This is indicated in Fig. 7, for example.

A bolt 65 passing through the holes 53 holds a pair of the heel plates to the sides of the strut 55 but does not function in shear. A bolt 61 passing through the bolt openings 49 passes freely through the openings 21 in the flange 25. The clearance between the opening 21 and the bolt 61 is ample to permit free movementof the bolt under angling of the strut and also permits of transmitting the load from the end of the strut, by end-grain compression through the flat faces of the pads 45, then by metal contact through the arcuate heels 41, and to the arcuate faces l9.

The radius of curvature of the circular faces 41 of the heels 43 is the same as that of the faces l9, being again indicated by numeral 2| with the In Fig. 6 at the lower left is shown a second joint in direct thrust alignment with the joint shown at the upper right. However, since no beam is used at the left of column 3|, corresponding to the beam 31, a shorter pad 5 may be used, and to this end the angle plate I is shown with a short upper pad ll.

In Fig. 8 is shown at the upper right a joint such as described in connection with the upperright portion of Fig. 6. In this Figure 8, as well as in Fig. 9, there is shown at the lower left the application of the heel plates 43 to largesize timbers.- It will be apparent that the plates are primarily designed for given timber sizes, such as for example 4 x 4 inch timbers (see Fig. 6). needed but the load is no greater and additional timber section is used simply to prevent buckling. In such cases the sam end-grained areas will carry the load. Therefore a timber, such as for example, a 6 x 6 inch timber 14 is trimmed down i by lateral notching as indicated at 13 in Figs. 8 and 9. Chamfers l5 prevent interference with adjacent parts.

Fig. 8 also indicates how the center lines of a pair of struts may intersect a given center 11 on the column 3| even though the strut angles are different. This is accomplished by adjusting the relative positions of the angle plates so that the beams such as 31 and 79 will be coaxial. In such case, a pad 8I is placed above the pad 5 for supporting said second beam 19.

, It is to be emphasized that neither the bolts 65 nor 6! carry any compression loads, but simply serve to position the heel plates 43 upon the end of the respective strut. The bolts 61 serve to hold the extensions 4'! in alignment and to facilitate assembly of the structure during erection. The invention is particularly applicable to the building of cooling towers and the like where a large number, of compression struts are used and which it is desired shall be placed in position with maximum speed and economy of material and labor.

In view of the" above, it will be seen that the Sometimes, longer timber struts are several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A structural joint comprising an angle plate having a supporting pad, arcuate bearing surfaces upon said plate, a rib on the angle plate 7 having an arcuate opening and located between said arcuate bearing surfaces, a pair of heel plates, each of which has an arcuate bearin portion for engaging said arcuate bearing portions on the angle plate on opposite sides of said rib, each of said heel plates having a flat engaging area for engaging the end-grain of a strut, each heel plate having a side wall having an opening for fastening, means fastening said heel plates to opposite sides of the struts, said arcuate extensions on the heel plates having openings for receiving a bolt which is movable freely in said arcuate opening of said rib in the angle plate.

2. A structural joint comprising an angle plate consisting of a supporting pad, a right-angular member extending therefrom, arcuate bearing surfaces formed on said plate between the pad and extension, a rib attached to the angle plate and separating said bearing surfaces and having an arcuate opening therein, a pair of heel plates, said plates having flat compression areas abutting end-grain area of the end of a strut, arcuate extensions from the heel plate members having openings therethr-ough and accommodating a bola-said arcuate extensions abutting the arcuate portions of the angle plates, said arcuate opening in the rib of the angle plate freely accommodating the bolt in the heel plates, and sideward portions on said heel plates engageable with sideward portions of saidv struts, said sideward portions and strut having coaxial openings for reception of a holding bolt.

3. A structural joint comprising a plate having an angle portion, a knee socket portion at the angle, said socket portion being arcuately formed, a pair of heel plates each of which has an arcuate edge bearing portion for engaging an angle portion, a tongue extending from the plate for mortising into a timber, a knee socket portion at the angle, said socket portion being arcuately formed, a pair of heel plates each of which has an arcuate edge bearing portion for engaging said arcuate form of the knee socket portion, each of said heel plates having a flat engaging area for engaging the end grain of a strut, and each heel plate having a side wall with means for fastening said wall to the strut.

5. A structural joint comprising a plate having an angle portion, a knee socket portion at the angle; said socket portion being arcuately formed with an intermediate rib, a pair of heel .plate's each of which has an arcuate edge bearing portion for engaging said arcuate form of .the knee socket portion on opposite sides of said fastening said heel plates to opposite sides of the struts, said arcuate edge bearing portions on ing an angle portion, a knee'socket portion at the angle, said socket portion being arcuately formed with an intermediate rib,said rib having for attachment to adjacent structuralmembers,

ing a vertical and a horizontal extension angled one extension at least having a tongue for mortising into its structural member, and a knee socket portion at the juncture between said angled extensions, said socket portion being arcuately formed with an intermediate rib, said rib having a ridge and an arcuate opening therean opening therethrough, a pair of heel plates each of which has an edge bearing portion for engaging said arcuate socket form oithe knee socket portion on opposite sides of said rib, each of said heel plates having a fiat engaging area perpendicular to its edge for engaging the end grain of a strut, each heel plate having means through, a pair of heel plates each of which has an arcuate edge bearing portion for engaging said arcuate socket form of the knee socket portion on opposite sides of said rib, each of said heel plates having a flat engaging area for engaging the end grain of a strut, said flat portions clearing saidridge on the rib, each heel plate havinga side wall having an opening for fastening, means fastening said heel plates to opposite sides of the struts, said arcuate extensions on the heel plates having openings for receiving a bolt, said arcuate opening in the rib being large enough to accommodate free'move- NATHANIEL P. GREEN.

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