US3036347A

US3036347A - Joist hanger

Info

Publication number: US3036347A
Application number: US663331A
Authority: US
Inventors: Findleton Ronald James
Original assignee: Easybow Engineering & Res Co
Current assignee: Easybow Engineering & Res Co; Easybow Engineering & Research Co
Priority date: 1957-05-31
Filing date: 1957-05-31
Publication date: 1962-05-29
Anticipated expiration: 1979-05-29

Description

May 29, 1962 R. J. FINDLETON JOIST HANGER Filed May 51, 1957 4 Sheets-Sheet l INVEN TOR.

ROLAND JAMES F/NDLE TON ATTORNEY May 29, 1962 R. J. FINDLETON JOIST HANGER 4 Sheets-Sheet 2 Filed May 51, .1957

||||| Ill/ INVENTO ROLAND JAMES F/NDLE ATTORNEY May 29, 1962 R. J. FINDLETON I 3,036,347.

JOIST HANGER 4 Sheets-Sheet 3 Filed May 31, 1957 INVRNTOR' RONALD JAMES F/NDLETO/V BY 60 a ATTORNEY May 29, 1962 R. J. FINDLETON 3,035,347

' JOISTHANGER Fiied May 51, 1957 4 Sheets-Sheet 4 INVENTOR.

A T TORIVEY- RONALD JAME FIND E7'0/V BY 6 I United States Patent 3,636,347 JOIST HANGER Ronald James Findleton, Lafayette, Calif., assignor t0 Easybow Engineering 8: Research (30., Oakland, Calif., a corporation of California Filed May 31, 1957, Ser. No. 663,331 3 Claims. (Cl. 20--94) :This invention relates to an improved structure for connecting joists to beams. It also relates to an improve-d joist hanger for connecting one or a pair of generally horizontal joists to a generally horizontal beam, with the joists running perpendicularly to the beam. This application is a continuation-in-part of my earlier-filed copending application, Serial No. 442,799, filed July 12, 1954, now abandoned.

By means of a novel structural configuration the present invention obtains an extraordinary strength-per-weight factor. Actual tests have shown my new joist hanger capable of handling loads up to twice as great as comparable, high-quality prior-art hangers weighing three times as muchin other words, this new joist hanger has about six times as much strength per weight as standard hangers on the market heretofore.

.By providing a new shape incorporating a channel enclosed by metal on three sides and an integral seat closing the lower end of the channel, my new joist hanger gives greatly improved performance at greatly reduced costs. My new joist hanger is a one-piece, die-stamped sheet sheel member. It is as strong as castings many times as heavy and is much stronger than other hangers made from much heavier gauge sheet steel. As a result, and since steel is sold by weight, my new hanger is much less expensive in material cost as well as being cheaper to ship and easier to handle.

Another unusual feature of my invention is its nearly perfect dimensional stability. Where other hangers have lines that are not parallel to start with or, if they are, some get out of parallel, the side walls of the channel of my hanger stay parallel even when subjected to considerable abuse. Where other hangers get out of shape, my joist hanger holds its shape. In some hangers, the joist can rattle at the top after installation, but not in mine. As a result, this hanger provides a reliable mass-produced article.

Another outstanding feature of my invention is its adaptability to both wooden and metal beams. In its preferred form it has a portion resting on the beam and secured to it solely to prevent lateral slipping, either by nailing it to a wooden beam or by welding it to a metal beam.

In most of the joist hangers and joist connections heretofore in use with wooden beams, great reliance has been placed on the shear-strength of nails to support the joists, and the result has been relatively weak construction that has frequently failed. The present invention has solved this problem by providing a joist hanger that extends over and rests upon the beam and has a pair of pockets at each side in which the joists fit, so that practically no reliance is placed on the shear strength of nails. With metal beams, no reliance is placed on the shear strength of the weld, which can be direct to the beam.

Another problem presented by joist hangers of the past has been that presented by the twisting or rotation of the joist after it was put in place. There are many factors that may cause rotation. One factor is the natural tendency of unseasoned wood to twist as it dries out. Another factor is that many joists are already bowed when they are installed, usually caused by faulty drying. Such bowed joists are already eccentric and when weight is applied, naturally tend to rotate. Whatever the cause may be, once rotation begins, the weight on the joist ag- 3,036,347 Patented May 29, 1962 gravates the torsional moment and in many cases causes the joist to give way. Although a straight, unbowed, wellseasoned joist will not rotate if it is placed perfectly vertically, it is rare to find such a joist. Therefore, in a preferred form of my invention -1 have provided means for preventing joist rotation.

In the past there have been a number of attempts to solve this problem of joist rotation but none of them have been satisfactory. One prior-art method for preventing rotation was called blocking because wooden blocks were nailed into the beam on either side of the joist. This involved a great deal of carpenters time and meant that there was no protection against rotation until after the blocks were in place.

Another method of meeting the problem was called toe-nailing, because a nail Was hammered down through the top of the joist and into the beam at approximately a 45 angle. This meant that the strength of that nail was all that prevented rotation, and while it might prevent rotation for a short time, over a longer period it has been proved that this toenailing was not reliable. When the torsional moment became very great, the toenail gave way. Another disadvantage of toenailing was that it took considerable skill on the part of the carpenter. An unskilled carpenter attempting to put in such a toenail oftentimes would split the joist or put the nail in at such an angle that it would be almost useless.

Without examining the other prior-art methods used in an attempt to meet the natural twisting tendency of the joist and the rotation of a bowed joist caused by the improper bearing or relationship between the top and bottom of the joist, it will be noted that they generally involved a separate operation from that of placing the joist itself in position. In all cases much time and labor was wasted.

With the tabs which are incorporated in the preferred embodiment of my invention, the bearing of the upper portion of the joist with the seat of the hanger is established immediately upon the installation of the joist into the hanger. A load can be placed immediately upon the joist, and there is no possibility of rotation even though an imperfect joist of the unseasoned or bowed variety is used.

Another problem, which has been solved by my invention, was also caused by the shrinkage of joists. Almost all wood shrinks as it dries, especially when green lumber is used. Here again, no problem would be presented if all the Wood were properly seasoned, but unformtunately most woods used in construction today are not.

For example, take Douglas fir. It shrinks approximately 4% of its depth, or /s of an inch in a joist which is 10 inches deep. If such a Douglas fir joist were set on a joist hanger and toenailed in, the joist would be lifted up off its vertical supporting member as it shrank. Then the joist would no longer be resting upon a block or a seat but would be held by the toenail alone. Once the toenail failed, the joist would drop down on the block or other holding means. When that happened, there would be vertical support again, but no means of preventing the joist from twisting. My invention also solves this problem. Shrinkage merely causes the joist to shrink down into the seat, where it is held firmly at all times against rotation and also is always supported by my joist hanger.

Heretofore, the erection of joists has been :a relatively slow operation, but the present invention speeds up the construction work, because the joist hanger is quickly put into position on the beam, and it is provided with a twisted side flange that helps to guide the joists into their seat or pocket. In a preferred form of the invention, there are offset tabs which also help to guide the joist into a truly vertical position. Only a small numtion, extending down on the face of the beam. This depending side portion is provided with a channeled seat her of nails are used, and these merely for holdingthe hanger in place and not to support the joist. These nails are easily hammered in because their proper locations are indicated by openings punched out through the hanger.

This invention reduces the cost of construction in at least three ways. First, by reducing the time to erect the joists, it reduces the labor costs, especially in the form of the invention Where each hanger supports two joists. Second, time is saved by eliminating a separate operation required in the prior art, where the workman either had to nail blocks in place or place a toenail to give lateral support to the joists and prevent rotation or twisting of the joist. The present invention includes means giving this lateral support from the moment the joist is installed. Third, the material cost of the hanger itself is between one-half and one-quarter that of comparable joist hangers heretofore in use. My new hanger can be constructed from a single strip of galvanized sheet iron (or other sheet metal), bent and spot welded, or bent and drawn into shape. The use of this inexpensive material also makes it possible to shape the hanger with light machine dies instead of the heavy presses that have been required to manufacture the joist hangers heretofore known.

The joist hanger of this invention is also unusually strong, both relatively as to its cost and weight .and absolutely. Its back reinforces and stiffens the joist seat or pocket so that in actual tests the hanger did not fail until subjected to pressures five times the design load. My new joist hanger comprises a single unitary sheet metal strip punched for naiLreceiving openings, and in most forms the strip is bent to provide a top portion that fits over the beam and a depending .vertical poror pocket at its lower end and with a curved twisted side margin that aids'in guiding the joist into its seat.

- In a preferred form of the invention, there arealso two tabs parallel with the channel and slightly below the top horizontalportion, one tab being slightly lower than the other. In addition to the advantages of these tabs that have alreadybeen discussed, they give protection against earthquake, wind, and other forces acting in shear between the beam and the joist, for they act as transfer bearings for shear parallel to the beam.

Other objects and advantages of the invention will appear from the following description of preferred embodiments thereof in accordance with 35 U.S.C. 112.

In the drawings:

FIG. 1 is a view in perspective of a joist hanger embodying some of the principles of this invention,

FIG. 2' is a view in perspective of the joist hanger of vFIG. 1 installed on a beam' and with the joist in place.

Both the beam and the joists have been cut off in order to conserve space.

FIG. 3 is a view in elevation and in Section of the installed connection, taken perpendicular to the beam and parallel to the joists.

FIG. 4 is a View in elevation and in section taken parallel to the beam and perpendicular to the joists.

FIG. '5 is a view in perspective of a modified form of joist hanger embodying the principles of this invention.

FIG. 6 is a view'in perspective of the joist hanger'of FIG. installed on a beam and with two joists in place.

Both the beam and the joists have been cut oifin order to conserve space. V 7

FIG. 7 is a view in perspective of another modified form of joist hanger of this invention, similar to that of FIG. 5 except that it supports only one joist.

.7 FIG. 8 is a view in perspective of the joist .hangerof 7 Both the beam and the joist have been cut on? FIG. 7 installed on abeam and with the single joist in" place. in order to conserve space.

FIG. 9 is a view in elevation and in section of the in stallation of FIG. 8 taken parallel to the beam and perpendicular to the joist. The beam has been cut off in order to conserve space.

FIG. 10 is a view in elevation of a blank from which the joist hanger of FIG. 7 is made.

FIG. 11 is a view in perspective of another modified form of joist hanger that can be made from the blank of FIG. 10, for use where installation over the beam is impractical.

FIG. 12 is a perspective view of the hanger of FIG. 7, shown installed on a metal I-bearn.

FIG. 13 is a view similar to FIG. 12 showing the hanger of FIG. 5 installed on a metal I-beam.

The joist hanger 10 shown in FIGS. 1-4 is secured to a generally horizontal beam 7 to provide a connec tion for a pair of generally

horizontal joists

8 and 9. The beam 7 may be slightly curved and need not be exactly horizontal, for the hanger 10 can be used to connect the

joists

8 and 9 that extend between the curved upper chords of a bowstring truss, the joists then being horizontal but tilted slightly from the vertical.

The joist hanger 10 shown in the drawings may be and preferably is made from a single piece of sheet metal, such as galvanized sheet iron, and may be formed into shape by light machine dies. Each hanger 10 is adapted to support two

joists

8 and 9; where only one joist is to be connected, as on an end of a building, the other side of the hanger 10 need not be used; it can be left there or it can be removed wholly or partly, as by cutting it off or by making it single in the first place. This will be described in connection with FIGS. 6-10.

In general, the hanger 10 includes a horizontal top plate or central portion 11 and a pair of depending vertical side plates or

portions

12 and 13, one at each end of the central portion 11 and perpendicular thereto at the

corners

14 and 15. The top plate 11 is planar and rests hori zontally on the top face 16 of the beam 7 as shown in the drawings. It does not need to be provided with nail holes or other openings, though it may be, if desired (of. FIG. 7).

Each

side plate

12 or 13 abuts a

side face

17 or 18 of the beam 7 and has four zones or portions. The uppermost of these is a generally planar vertical portion 20 that extends down about /3 or A of the height of the plate 12 or 1-3. The planar portion 20 adjoins and blends into an intermediate twist portion 21 immediately beneath it, which in turn leads, into a channeled portion 22 that terminates in the joist seat or pocket 23 at the bottom of the

plate

12 or 13. V

, The channel portion 22 may be provided by bending the

outer margins

24 and 25 of the

plate

12 or 13 outwardly so that they are perpendicular to the middle portion 26 thereof. In between the channel portion 22 and the upper planar portion 20, the

side margins

27, 28 of the intermediate portion 21 curve out in a kind of twist, so that their upper ends are co-plan-ar with the portion 20, and their lower ends blend into the perpendicular channel sides 24 and 25. This curved or twist portion 21 greatly strengthens the hanger and also serves to aid in locating the joist 8 or9 in position by guiding it into the lower pocket portions-23. j

'The pocket or joist seat 23'is at the lowermost end of each

side plate

12 or 13 and is provided with a bentout floor or horizontal seat 30 that is perpendicular to the remainder of the

side plate

12 or 13. Thus, the seat 30 is generally parallel to the top plate 11 of the hanger 10, and its

side margins

31, 32 are bent perpendicular upwardly to form a channel, as shown. The

margins

31, 32 can be spot welded at 33, 34 to the channel sides 24, 25, respectively. However, instead of spot welding, the pocket'23 may be formed (of. FIG. 5) or drawn; in many instances forming may be preferred, whereas in other instances the spot-weld construction has advantages.

The pocket 23 serves to hold the

joist

8 or 9 in position and support it. The main resolution of the downward force of the

joist

8 or 9 is through the joist hanger 10 to the top plate 11 and thus to the beam 7. The entire thickness of the beam 7 is utilized, since the joist-hanger face 11 rests on top of the beam 7, and no reliance there is made on nails, which are used at the most simply to hold the hanger 10 in position on the beam 7 and to hold the

joists

8 and 9 in position on the hanger 10 with respect to the beam 7.

Nailing is made possible by punching out openings in the

side plates

12 and 13. The upper portion of each

plate

12 or 13 may have a pair of nail openings and 41, one in each side margin so that they are beyond the area covered by the

joist

8 or 9. Through these, nails 42 and 43 may be driven into the beam 7. Since reliance is not being made on the shear strength of the nails, it is not necessary to use large nails. Usually short nails having a diameter about the same as 8d nails are used, and in many installations one nail may be suflicient here.

The upper plate portion 20 also has a centrally located, preferably oval-shaped opening 44 much larger than the other nail openings, so that a toenail 45 may be driven through the

joist

8 or 9 into the beam 7, thereby providing a direct nailed connection between the beam 7 and each

joist

8, 9. Many carpenters may prefer this toenailing as a means of preventing rotation of the joist, but others will prefer the modified form shown in FIGS. 5-11 and de scribed later.

In the channel portion 22 of the

plates

12, 13, a nail hole 46 is preferably provided in the middle area 26, and through this a third short nail 47 may be driven into the beam 7. The nail 47, if used, must, of course, be driven in before the

joist

8 or 9 is set in place; in fact all three of the nails '42, 43, and 47 that are used are usually driven in as soon as the hanger 10 is located on the beam 7, so that the joist hanger 10 will not move while the

joist

8 or 9 is being put in place.

After the joist hanger 10 has been placed over the beam 7 and the three

nails

42, 43, and 47 hammered in through each

side plate

12 and 13, the

joists

8 and 9 are put in position. In each instance this is done by lifting the end of the

joist

8 or 9. above the twist portion 21 and then utilizing the

curved shoulders

27 and 28 to guide the joist down into the pocket 23. Then a pair of

nails

50, 51 may be driven into the

joist

8 or 9 through

openings

52, 53 in the

outer flanges

24, 25. v

To summarize the installation of joists utilizing the structure shown in FIGS. 1-4, the joist hanger 10 is first placed over the beam 7, with its top plate 11 resting on the beams top face 16 and its

side plates

12 and 13 resting against the beams side faces 17 and 18. When the hanger 10 is located in the exact position desired, it is secured there by the

nails

42, 43, and 47. Then each

joist

8 and 9 is guided into its pocket 23 on its

side portion

12 or 13, by means of the

curved shoulders

27, 28 of the twist portion 21, until the

joist

8 or 9 rests on the floor 30 of the pocket 23 and its vertical inner end abuts the middle portion 26. The

nails

50 and 51 are then driven in through the openings 52, 53', securing the joist to the hanger 10. Finally, the toenail 45 is driven in through the

joist

8 or 9, through the oval opening 44 and into the beam '7.

Obviously, joist installation can be very rapid with this invention. The joist hanger 10 is quickly positioned, and once set in place it determines the position of the

joists

8 and 9. The joists are easily set in place, due to the guiding portion 21, and few nails are required. No reliance is made on the shear-strength of the nails, but instead the whole body of the hinge 10 transmits the stresses of the upper face of the beam 7. It is also apparent that the sheet metal hanger 10 can be formed by light machine dies and can be made quickly and in quality, because no tricky types of die work are needed.

The

channels

24, 25, 31, and 32 of the bottom pocket 23 give the hanger 10 great strength. The rigidity of the 6 light sheet metal is more than suflicient to transmit the stresses of the

joist

8 or 9 directly to the beam 7. In fact, my sheet metal hanger 10 is stronger than many hangers made from heavier material.

Except for certain very important differences, the joist hanger 60 shown in FIG. 5 of the drawings is essentially the same as the hanger 10 shown in FIG. 1 and identical reference numerals are used to refer to those parts that are the same.

The main difference between the hanger 60 shown in FIGS. 5 through 11 and the hanger 10 shown in FIGS. 1 through 4 is the elimination of toenailing and the direct and positive holding of the

joists

8, 9 against rotation. By eliminating toenailing, this form of the invention also solves the shrinkage problem discussed above. These important results are obtained by replacement of the toenail opening 44 with a pair of aligning members or

tabs

61, 62 in the upper planar portion 20 of the hanger 60. Preferably, one tab 62 is higher than the other tab 61. This not only strengthens the hanger 60 but helps when inserting the

joist

8 or 9 into the hanger 60 by guiding it first against the upper tab 62 above the tab 61 and then lowering it between the

tabs

61, 62. Preferably, the

tabs

61, 62 are formed as an integral part of the hanger 60 by cutting along four lines and bending the metal out of the planar vertical portion 20 to a 90 angle, thus making the

tabs

61 and 62 extend out parallel to channel

sides

24, 25. The five-sided shape shown has the advantage of providing relatively wide tabs tapering down and also enables their areas to overlap somewhat without cutting out the supporting portion 63 between them.

The hanger 60 with the

tabs

61, 62 provides much greater torsional rigidity for the

joists

8, 9 than has been the case with prior-art hangers. When the

joists

8 and 9 are installed, they immediately have the advantage of the torsional support of the

tabs

61, 62, without having to wait for a carpenter to block them in. Also, the

tabs

61, 62 give torsional support to the

joists

8, 9 while and after they shrink. As was pointed out earlier, a great many woods tend to shrink unless they are properly dried. This shrinkage causes a toenailed joist to rise out of the seat support and to lose its vertical support until the failure of the toenail, at which time the joist is again supported vertically at the cost of being deprived of its lateral support. The joist hanger 60, by providing the lateral support without any reliance on a toenail, provides lateral support at all times without ever losing the vertical sup port. To compensate for shrinkage the top of the joist should extend above the top of the beam at the initial installation, so that on shrinkage it will not sink below the top of the beam.

Joist hanger 70, shown in FIGS. 7, 8, and 9, is similar to the hanger 60 shown in FIGS. 5 and 6 except that it has only one depending vertical side plate 12. The hanger 70 is used where there is no need or room for a joist to extend over the other side of the beam, for example, on the outside wall of the building where the joists come to an end against the wall.

Another modified form of joist hanger 80, shown in FIG. 11, may be used where the top plate 11 is not able to fit over the beam or wall support. While the top plate 11 is missing, joist hanger has the other advantages of my invention, such as the strength and rigidity of single-piece construction, torsional strength given by the

tabs

61, 62, etc. Joist hanger 80 has two additional nail holes, 81, 82, to give it added vertical strength, since the nails do have to support this particular form of hanger.

While the hanger 80 is the only one described that requires nailing, it is advisalble to secure

hangers

10, 60, and 70' in place with at least one

nail

42 or 53 so that the hanger will not be moved during insertion of the joist end. Such movement might cause a misalignment of the joist and thereby weaken the structure.

FIG. 10 shows a blank suitable for making either joist hanger 70 01 80 by forming. (The joist hanger 60 is also made from one piece, but illustration of its blank is not believed to be necessary.) I will describe, though not in actual order as when manufactured, how the hanger is formed from this fiat metal piece. Along the dotted line 71 the top plate portion 11, which rests on the beam 7 when installed, is folded to form a 90 angle With the depending vertical side portion 12. The tabsfil, 62 are bent out along the dotted lines 72 until they are at right angles with the planar portion 20. The twist portion 21 is formed by twisting the

edges

27, 28 along dotted lines 73. Thus the upper portion of the twist is practically planar with the flat section 20, while the lowest portion of the twist ends up perpendicular to the channel portion 26. The bottom piece '30 of the hanger, which forms the pocket or seat 23, is bent along lines 74 to a 90 angle with the channel portion 26. The

side portions

31, 32 of the bottom piece 30 are bent up while working

portions

75, 76 through the

openings

77, 78. The

portions

75, 76 are bent to a position parallel to and flush with side portions 24. 25. This single-piece construction just described makes my hanger stronger, yet cheaper, than joist hangers known heretofore.

The formed metal type of pocket 23 is illustrated in FIGS. -11, and may he used if preferred over the spot welding form which is shown in FIGS. 14. Or drawn metal may be used, though it is not as trim looking.

While the

joist hangers

60, 70, 80 are used in the same way as joist hanger (of FIGS. l-4), theinstallation varies a'little. I will use hanger 70 to describe the operation. The joist hanger 70 is placed over the beam 7 and at least one or two of the three

nails

42, 43, and 47 are hammered in through side plate 12. The joist -8 is put in position by lifting the end of the joist 8 above the-

tabs

61, 62 and angling the joist slightly in between the

tabs

61, 62 and then straightening the joist '8, using the tabs to bring the joist 8 to a generally vertical position and then utilizing the

curved shoulders

27 and 28 to guide the joist 8 down into the pocket '23-. Then at least one of the pair of nail's50, 51 maybe driven into the joist 8 through

openings

52, 53 in the

outer flanges

24, 25. a V

The only variation when using joist hanger 80 is that r all nails 42, 43, 50, 51 must be placed in order to give the hanger its full vertical strength. I V

7 Obviously, construction can be very rapid when using this device. 'The .joisthangers 60, 70, 80 are quickly positioned and, once set in place, determine the position of the joists. The joists are easily installeddueto the

tabs

61, 62, the guiding

portion

27, 28 and the few nails required. No reliance is made on the shear strength of the nails except in the case of joist hanger 80, buteven in this case the body of the joist hanger is extremely V strong. There is, with my invention, no necessity for the separate operation of blocking. Toenailing is also done away with in one form of my invention.

' Tests have been performed to determine'the actual effectiveness of hangers madevaccording to the present invention, and in every instance they haveexceeded design expectations and calculations, showing that the combination gives unexpected results, Comparisons have been Qmade with the better'joist hangers heretofore known in 7 the prior art, and in every instance the hangers of the present invention have given highly superior results.

For example, vertical load capacity testsand torsional moment capacity tests have been run. For the sake of comparison the same tests were done on a prior-art hanger generaly like that in FIG. 5 of Seipp in Patent No. 829,- 2134, but with the upper ends fashioned to provide vertical nailing'to the top of a beam. The hanger is considered one of thebe'st on the market. The most nearly comparable embodiment of applicants invention, the v hanger 70 of FIG. 7 was similarly tested. V

Vertical load capacity was tested each time by nailing two identical hangers to 3 x 123. headers and supporting a 2'; 10' joist between them. In all instances eight- Prior-Art Hangers, Hangers of the Load in Pounds 0.119 steel Present Iuventiom.

' r g I r 18 gauge steel G H I .T K L N o'rs deflection occurred as follows: Lb

- s. 53 H J 53 I... 53 J 128 125 penny nails 1%" long were used. Load was applied through the center of the joist through a spherical bearing block 7" in diameter, and deflection was measured with dial gauges reading to 0.001" and mounted at each end of the joist. Conditions were identical except that the prior-art hanger was tested with joists 18" long, while the tests on the hanged 70 of the present invention were made on joists 24 long. A prime point to note is that the prior-art hanger was made of Ms steel and Weighed 1.74 lbs. each, while the hangers 70 were made of much thinner 18-gauge steel plate and weighed only about 0.65 lb. eachabout one-third as much. Yet, the present invention gave far superior results, as shown in the following table.

'TABLEI Deflections Under Vertical Loads of Joist Ends No readings were taken at the places left blank.

While the results tabulated in Table I are impressive, the results of the torsional load tests are even more so.

Two sets of tests were run, one Where the hangers were fastened to a metal beam by welding, as in FIG. 12, and one where they were fastened to a wooden beam, as in FIG. 8.- The former results are shown in Table II and the 'latterresultsin Table III. In all instances the torsional force was applied by twisting the outer end of a /2 from the bottom. I

TABLE II Torsional Moment Capacity Tests of Joist Hangers. De-

flection Measured /z" from Bottom. Hanger Welded to A" Steel Headers 9 TABLE III Torsional Moment Capacity Tests of Joist Hangers. De-

flection Measured /2 from Bottom. Hanger Nailed to 3" x 12" Beam. N Nails Between Hanger and J oist Prior-Art Hangers, Hangers of the 0.119 steel Present Invention, Load in Pounds 18 gauge steel M N O P Q R FIGS. 12 and 13 illustrate the use of the

hangers

60 and 70 with metal I-beams 90 instead of Wooden beams. In place of using nails to retain the hangers in position, welds 91 and 92 are shown. Since no reliance is made on the strength of the welds to support the joists and since these welds are only for holding the hangers in position, there is no problem of welding technique involved. As shown heretofore in Table II, the welded hangers are very effective.

To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will sug gest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

I claim:

1. A one-piece joist hanger for supporting a horizontal joist perpendicular to a horizontal beam, comprising a single sheet-metal member having means for securing it to a said beam and formed to provide a vertical plate having an upper planar portion and a lower channel portion with sides perpendicular to said plate, said sides comprising marginal portions of said plate bent out therefrom, said plate having a portion intermediate said upper and lower portions with the side marginal portions curved along a twist from co-planar with said plate to perpendicular thereto, a lower end portion of said channel portion extending out horizontally and providing an imperforate bottom seat with sides connected thereto by an imperforate bend, said seat sides being secured directly to said channel sides to form a joist-receiving pocket at the lower end, said upper planar portion having a pair of tabs cut and bent out therefrom perpendicular to said upper planar portion, said tabs providing a space between them substantially the same as that provided between the sides of said channel and serving to give lateral support to a said joist from the time of installation therein without blocking or toenailing, whereby a joist of substantially the width of said channel can be supported by said pocket with its sides given support by the sides of said channel and said tabs, said plate providing a metal bearing between said joist and said beam, said tabs being positioned with the upper edge of one substantially above the upper edge of the other and the upper edge of said other substantially above the lower edge of said one and with a supporting portion between them running diagonally along one of the cut edges of each said tab so that considerable portions of said tabs are wider than half the distance between them, whereby during installation a joist is lifted just above the upper edge of said other tab and place against said one tab and then lowered into place, guided between said tabs, whereby said tabs have portions horizontally opposite each other to give a high point of opposite lateral support and whereby said tabs are of substantial width so that as a joist shrinks it will not shrink out from be tween said tabs and is held between them for lateral stability while vertical support continues to be given by said pocket.

2. A building structure, including in combination a generally horizontal beam; a joist hanger fastened to said beam and having a horizontal planar central plate overlying the top of said beam and a pair of depending vertical side plates, bearing against the vertical sides of said beam, one at each end of said central plate, each said side plate having an upper planar portion, a lower channel portion formed by side margins of said side plate extending out perpendicular thereto, a strengthening portion intermediate said upper and lower portion where said side margins twist out from co-planar with said side plate to perpendicular thereto, and a joist seat at the lower end, formed by a horizontally bent-out lower end of said side plate secured to said channel portion, said upper planar portion having a pair of tabs out and bent out perpendicularly therefrom, said tabs when bent out providing a space between them substantially the same as that provided between the sides of said channel and serving to give lateral support to a said joist from the time of installation therein without blocking or toenailing; and a pair of joists, each having one end supported in said seats and fastened to said hanger whereby the weight of said joists is borne by the hanger and transmitted to said beam therethrough, said tabs being positioned with the upper edge of one substantially above the upper edge of the other and the upper edge of said other substantially above the lower edge of said one and with a supporting portion between them running diagonally along one of the cut edges of each said tab so that considerable portions of said tabs are wider than half the distance between them, whereby during installation a joist is lifted just above the upper edge of said other tab and placed against said one tab and then lowered into place, guided between said tabs, whereby said tabs have portions horizontally opposite each other to give a high point of opposite lateral support and whereby said tabs are of substantial width so that as a joist shrinks it will not shrink out from between said tabs and is held between them for lateral stability while vertical support continues to be given by said pocket.

3. A joist hanger for holding a pair of horizontal joists perpendicular to a horizontal beam, .comprising a single sheet-metal member formed to provide a horizontal top plate adapted to rest on said beam and to transmit the full load of said hanger to the full thickness of said beam, and a pair of depending vertical Side plates, one at each end of said top plate, each said side plate having an upper planar portion and a lower channel portion formed by side margins of said side plate being bent out perpendicular thereto to confine the sides of a joist therebetween, each said side plate also having a pair of integral tabs cut and bent out from the central portion of said upper planar portion perpendicular thereto and spaced apart substantially the same distance as the channel sides, for giving lateral support and alignment to a said joist, the lower end of each said side plate extending out horizontally to provide a joist-receiving pocket upon which a said joist may sit and providing the vertical support therefor, the forces thereagainst being resolved through said vertical plates to said top plate, said tabs being positioned with the upper tab and then lowered into place, guided between said tabs, whereby said tabs have portions horizontally oppositeeach other to give a high point of opposite lateral support and whereby said tabs are of substantial width so that as a joist shrinks it will not shrink out from between said tabs and is held between them for lateral stability while vertical support continues to be given by said 15 pocket. 7

References Cited in thefile of this patent UNITED STATES PATENTS Tuteur -s. July 30, Eberhardt Feb. 23, Heughes Apr. 24-, Lanz Aug. 14, Lindow Dec. 24, Taylor July 9, Murphy May 5, Isakson Mar. 14, Hagedorn Jan. 19, Neil Sept. 13,

FOREIGN PATENTS Great Britain Feb. 15,

Austria May 10,