United States Patent
`
`(72)
`
`Inventor Tyrtll T. Glib
`Berkdty, Calif.
`[21] Appl. No. 884,170
`(22) Filed
`Dec. 11, 1969
`(45] Patented Aug. 24, 1971
`(73) Assignee Simpson Company
`
`[54 I PRONGED JOIST HANGER
`3 Claims, 4 Dnwbag Figs.
`(52) U.S. Cl ........................................................ 287/20.94,
`s2no2
`( 51 J Int. Cl.......................................................... Fl6b 3/00
`[50) FieldofSearcb ............................................ 287/20.92
`L, 20.94, 20.95; s2no2. 289
`
`I I I I 3,601 ,428
`
`287/20.92 L
`
`[56]
`
`683.104
`
`Re(ertnces Cited
`FOREIGN PATENTS
`3/1964 Canada ........................
`OTHER REFERENCES
`Popular Mechanics Magazine article " Engineered Nailing
`Simplifies Framing." Aug. 1964 issue, pages 137. 138, 140,
`139 cited. Copy available in the Examiner' s Files, Class 287,
`Subclass 20.94
`Primary Examiner-David J. Williamowsky
`Assistant Examiner- Wayne L. Shedd
`A//orney-Milmore & Cypher
`
`ABSTRACT: A joist hanger formed with integral prongs
`which can be driven into a wood joist by a hammer blow
`thereby eliminating or reducing the number of nails required
`to fasten the hanger to the joist. Other integral prongs increase
`the holding power of the hange.r to the header.
`
`0001
`
`Simpson Strong-Tie Company Inc. EX1022
`Simpson Strong-Tie Co. v. Columbia Insurance Co.
`U.S. Patent No. 11,649,626
`
`

`

`PATENTED AUG241971
`
`3,601.428
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`37
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`4TTOR.NEY
`
`0002
`
`

`

`3,601,428
`
`1
`
`PRONGED JOIST HANGER
`
`SUMMARY OF THE INVENTION
`
`Joist hangers have been in use for several years. These han(cid:173)
`gers were formed with openings for nails which secured the
`joisf to the hanger. The gist of this invention is the discovery
`that prongs formed integrally with the hanger can secure a
`joist to a hanger and the hanger to a header.
`An object of the invention is to provide a joist hanger which
`eliminates or reduces the use of nails in securing the hanger to
`the joist and the hanger to the header thereby effecting a
`savings in time and materials.
`Another objecth,e is· to position the prongs so as to max(cid:173)
`imize the holding power of each prong.
`Another objective is to increase the holding capacity of the
`hanger to the header.
`Still another objective is to construct a hanger·having max(cid:173)
`imum holding capacity and minimum weight.
`
`2
`Further, since the prongs are a part of the hanger itself,
`uniform gripping of all of the prongs and the base of the
`hanger with the joist is achieved.
`There is an overall savings in material since nails are
`5 eliminated between the joist and the hanger, but the primary
`advantage is the labor savings in securing the joist to the
`hanger. The carpenter can hold the joist and hanger with one
`hand and drive the prongs into the joist with a hammer in the
`other hand. Usually, one sharp blow with the hammer is all
`IO that is required to set the prong in the joist.
`To. give the prongs rigidity so that they will be able to
`withstand a hammer blow and will be driven into the joist
`without buckling, they are formed with a lateral curvature.
`It has been found that the angle at which the prongs are
`I 5 formed in the hangers is extremely important. Since the load
`transferred from the end of the joist to the header is in almost
`all cases nearly vertical, it has been found that the gripping
`capacity of each prong is substantially increased by placing
`the prongs in an angular relation to the direction of the load
`20 indicated by arrow 18. Thus inste.id of the force of the loading
`tending to bend or unbend the prong, the load is transferred to
`the prong at an angle and a twisting force is translated to the
`prong. This twisting force is transmitted to the root of the
`prong which is much more effective in resisting a twisting
`force than a bending force. Further, the slight lateral bending
`of the prong tends to increase the prong's ability to transmit
`shear and bending forces from the joist to the joist hanger. It
`has been found that a prong angle of 45° to the. load has a
`30 holding capacity two to three times as much as a prong paral(cid:173)
`lel or at 90° to the direction of load.
`It is common to provide joist hangers with a base which is
`longer than the average width of the joist sides of the hanger.
`Thus ·side portions 19 and 20 connecting the base and joist
`35 sides form edges 22 and 23 angularly related to the base. It has
`been found that by positioning the prongs 26 and 27 parallel
`to the edges 22 and 23, greater gripping capacity between the
`joist and the hanger can be obtained. It has been calculated
`that prongs 26 and 27 individually carry a greater proportion
`40 of the joist load than the prongs 9. The reason for this unex(cid:173)
`pected holding capacity is not fully understood. One explana(cid:173)
`tion for the fact that an angular relationship of the prongs to
`the load will transfer more load from the joist to the hanger is
`the fact that as the load comes on the joist, it moves
`45 downwardly, causing the sides of the prongs, as for example at
`point 31 to come in contact with the sides of the slot at point
`32. Thus force is transmitted to the side of the slot formed by
`creation of the prong as well as to the root of the prong. This
`does not explain the reason for prongs 26 and 27 taking a
`50 greater share of the load except that there may be some distor(cid:173)
`tion of the side portion 19 and 20 near the base which may
`cause more contact between the prong side and the edge of
`the slot 35.
`Referring now to the side of the hanger in contact with the
`header, the present invention consists of a plurality of prongs
`37 located on each side. Since the holding power of a prong is
`about one-eighth of a nail holding value parallel to the load
`and one-third a nail value when at a 45° angle it is necessary to
`continue to use nails in the header side and nail openings 38
`are provided. The prongs in the header side are of the same
`shape as the previously described prongs and are not further
`described here. The header prongs are used primarily to hold
`the hanger in place until the nails can be driven ,although they
`are used for their added holding capacity. As may be seen in
`65 the drawings, the prongs in the header side and in the joist
`sides are interspaced so as to permit hammering a single prong
`without interference with another prong. Note also that the
`prongs on the joist sides are not directly opposite one another
`so that the beam is not weakened by driving the prongs at the
`70 same elevation.
`In order to lighten the hanger, scallops 39 may be cut in the
`header sides. Similar cut outs 41 may be cut in the joist sides,
`leaving protrusions 42 to provide sufficient clearance between
`the prong slots and the edge of the material. Some codes
`75 require seven-eighths inches to three-fourths inches edge
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a perspective view of a hanger constructed in ac(cid:173)
`cordance with the present invention.
`FIG. 2 is a perspective view of a hanger as shown in FIG. 1;
`the broken lines indicating a joist and a header.
`FIG. 3 is a side view ofa hanger shown in FIG. 1.
`FIG. 4 is a front elevation view of the hanger shown in FIG.
`I.
`
`DESCRIPTION OF THE PREFERRED EMBODIMENTS .
`
`25
`
`The joist hanger of the present invention consists briefly of a
`base 1; joist sides 2 and 3 supporting the base adapted for
`receiving the sides of a joist 4 and connected to header sides 6
`and 7 for connection to a header 8; prong means 9 integrally
`formed in the joist sides and being bendable to a position
`wherein a portion 11 of the prongs are bendable to a position
`in interlocking engagement with the joist.
`The basic form of the hanger is standard, being made from a
`single .sheet of metal .and is formed as shown in the drawings
`and as herein described. The base is formed at right angles to
`the joist sides and has varying widths depending upon the
`width of the joist to be carried. The length of the base is deter(cid:173)
`mined by the load to be carried. The joist sides are generally
`parallel and of a length equal to or less than the height of the
`joist. The header sides are bent at right angles to the joist sides
`and are preferably equal in length to the joist sides.
`There is little need in most cases for securing a joist to a joist
`hanger since there is no live load vertically upward and the
`holding power of nails provides far more holding power than is
`required for wind or earth quake uplift design loads. Further,
`the greatest force on the end of a beam is shear force and nail-
`ing of the ends can decrease the ability of the beam to
`withstand shear stress by inducing splitting of the ends of the 55
`joist or by the inability to create uniform holding at the nailing
`points and the base of the hanger. The latter problem results
`from the possible use of smaller nails in the nail holes pro(cid:173)
`vided. Thus some nai ls would not transfer any shear load to
`the sides of the joist hanger, whereas others might transfer 60
`shear loads before the load is transfered to the base.
`This invention eliminates the need for securing the joist to
`the joist hanger with nails by forming prongs integrally with
`the sides of the hanger. These prongs are formed by dies which
`create an elongated member 12 from the sides of the hanger,
`having a tapered portion 13 coming to a sharp point 14 .. An
`approximately right angled bend 16 is formed at a point
`between one half and three fourths the distance of the prong
`from its root 17 so that a sharp blow of a hammer on or near
`the bend area will drive the free, pointed end into the outer
`surface of the side of the joist.
`Since the prong does not penetrate as far into the joist as the
`nails normally used, there is less tendency of the end of the
`joist to split. The entire prong length is about an inch with less
`than half of the length penetrating the joist.
`
`0003
`
`

`

`3,601,428
`
`4
`lated to the direction of load placed on said hanger and sub(cid:173)
`stantially angularly related to a direction perpendicular to the
`direction of said load, and said penetrating portion of said
`prongs being located to cross the grain of said wood joist;
`c. each of said prong means being tapered to a point at its
`free end and bent to approximately a right angle near said
`tapered end.
`2. A joist hanger as described in claim 1 wherein:
`a. said prongs are laterally curved to provide rigidity so that
`IO they may be hammered into the joists.
`3. A joist hanger as described in claim 1 wherein:
`a. at least a pair of said prongs are located at an angle of 45°
`to the direction of the joist load.
`
`3
`clearance. Holes 42 and 43 are for tooling purposes and are
`purposely enlarged to distinguish them from nailing holes.
`I claim:
`1. A joist hanger for supporting a wood joist said hanger
`having a seat base, a pair of laterally spaced and parallel side 5
`members connected to the seat base adapted for receiving the
`sides of said wood joist there between, header engaging flanges
`extending laterally from each of said side members, the im(cid:173)
`provement comprising:
`a . prong means consisting of an elongated portion and an
`angularly related penetrating portion integrally formed in said
`hanger side member and being bendable to a position in inter(cid:173)
`locking engagement with said joist;
`b. the axis of said prongs being substantially angularly re-
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`15
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`20
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`25
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`30
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`35
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`40
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`45
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`50
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`55
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`60
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`65
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`70
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`75
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`0004
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