US2521643A - Load transfer assembly - Google Patents

Description

p 1950 I E. s. MATHERS 2,521,643

LOAD TRANSFER ASSEMBLY Filed June 24, 1947 2 Sheets-Sheet 1 Sept. 5, 1950 E. s. MATHERS LOAD TRANSFER ASSEMBLY 2 Sheets-Sheet 2 'Filed June 24, 1947 Patented Sept. 1950 oFr-ice LOAD TRANSFER-ASSEMBLY Edward s. Mathers, salami-; Ma, assignor a; Atlas MaterialsIncorporated, Baltimore, Md,

a corporation of Maryland Application June 24, ieimfsr ai Newest":

9 Claims.

1 Y This invention relates to. load transfer assemblies and more particularly to devices of this class which are adapted to reinforce concrete structures, such as roads, pavements, and flooring, and to transfer load stresses from one portion of such a structure to an adjacent one. These devices may be utilized in a variety of diiferent associations in the concrete art, but they are usually related to and used in conjunction with joints between adjacent slabs or other units of the structure, more especially in connection with expansion joints which embody strips of mat rial which are designed to allow for contraction and expansion of the slabs under changing conditions of temperature and moisture content both during setting and. subsequent thereto.

This application is a continuation-in-part of' my copending application Serial No. 581,? 65, filed March 9, 1945, since abandoned, The general object of the invention is to provide a novel and improved load transfer device of the class described, which is of simple and light-weight construction, easy and economical to manufacture, transport, and install, while at the same time sufficiently sturdy to afford the necessary rigidity transversely of the roadway during pouring and setting of the concrete, and totransfer th load efiiciently from one portion to the other during subsequentuse.

When used at joints between separate unitsof. concrete construction, the chief function of structures of this'type is to transfer the superposedload between the units during use so that the strength and rigidity of the support at the joint approachesthat of the intermediate portions. of.

the thus affording a substantially continuous beam longitudinally of the roadway or other construction. The assembly also serves to sup port the joint strip or filler when such strips are used.

To effectuate these purposes, the invention in its preferred embodiment contemplates the provision of a pair of structural shapes, for example, angle irons, supported in spaced parallel relationship at a level intermediate the thickness of the concrete, by means of a plurality of chairs or pedestals which are suitably anchored in-place upon the sub-grade.

At suitable intervals along the frame thus provided arerlgidly secured a series of dowels having outwardly projecting ends I fitted with slip sleeves of conventional construction. In an expansion joint arrangement, the dowels pass through openings provided in a vertically disposed strip or plate of suitable joint material such as asphalt-impregnated felt or the like.

The joint plate or strip is preferably disposed againstthe forward legs of the supporting chairs and retainedin position by means of bendable or frangible clips during transportation, assembly, a rq ne. 1 v

Other objects'and featuresfof no-veltywill be apparentfro ni thefollowing specification when readin connection with the accompanying drawings in which one embodiment'of the invention is illustrated byway of example.

In'the drawings,

Figure 1 is a transverse vertical sectional View through a joint construction in 'a concrete roadway, embodying the principles of the invention;

Figure Zis a fragmentary plan view of the joint construction and load transfer assembly itself before installation in the roadway, this figure being upon a somewhat smaller scale a Figure 31s a perspective view of an intermediate portion of the joint construction;

' Figure l is'a'vertical sectional View similar to Figure 1 in which is illustrated an alternative embodiment of the invention;

- Figure 5 is a transverse vertical sectional view of the loadtransfer' and reinforcing structure,

taken on line 5-5 of Figure 4; and.

Figure 6 is a fragmentary view n perspective of certain essential elements of the modified joint. In Figure 1 of the drawings, a joint between two concrete slabs designated A and B is shown, these slabs being apart of a roadway or pavement rest.

ing upon the sub-grade C. Asa partition betweenthe slabs, there may be provideda vertically disposed elongated plate or strip l2, this strip servingprimarily as means for allowing contraction and expansion longitudinally of the roadway between the slabs A and B, and also serving-during pouring of the slabs as part of the form. The expansionstrip I2 is preferably surmounted by a protective cap [4 which may be made of sheet metal, plastic, 7, or other suitable material. The'height of the joint strip 42 is ordinarily somewhat" less than the thickness of theslabs, and-ultimately the space remaining at the top of the strip may be filled in with cementitious, flexible, or other material I5 if desired.

'As asuppolting means for the joint strip l2 and the other operative parts of the load transfer structure, there ar provided two parallel angle irons l5 and ll of standard shapeand dimensions, the vertically disposed flanges of the angle irons being. atremote sides thereof, with the horizontal flanges directed toward each other. The verticalflange ll of the angle iron I! is disposed againstone side wall of the strip [2.

In this embodiment, the angle irons are supported in spaced position by a plurality of chairs or pedestals disposed at intervals across the roadway. These chairs are formed of strip metal and are bent so as to provide a horizontal body portion 2|, two spaced vertical legs 22 and '23, and rearwardly directed horizontal feet 24 and 25 which are adapted to rest upon the sub-surface or road bed C. The angle irons l6 and I1 are secured to the corners of the chairs at the junction of the body portion 2| with the legs 22 and 23, this attachment being preferably made by welding. The feet 24 and 25 are each provided with openings 2! and 28, and the body portion 2| is provided with a similar opening 29 for the reception of the pins or spikes 3B and 3|, the pin 30 passing through the opening 21 only, but the preferably longer pin 3| passing through the'aligned openings 28 and 29.

At intervals along the supporting structure provided by the strips I8 and I! and the chairs 20, are secured the dowel pins 32, preferably by welding as indicated at the points 33 in Figure 3. These dowels are of regulation size, figured to the particular load to be sustained, and are provided at their outwardly projecting ends with slip sleeves 35, the ends of these sleeves being crimped as at 38 to seal off the interior. Beyond the end of the dowels within the sleeves are the air spaces 31 which provide for expansion and contraction of the slabs adjacent the dowels. In order to further provide for relative movement between the slab B and the dowels 32 which are anchored in the slab A, the intermediate exposed portions 28 of the dowels are preferably painted.

The joint strip or plate l2, when such elements are to be used, is preferably not rigidly secured to the supporting structure and for this purpose temporary bendable or frangible clips are provided. A series of such clips 40 comprise strips of sheet metal passing through slits 4| in the plate 2 and having one end bent around the horizontal flange of the angle iron I1 and the other turned downwardly on the outer face of the plate I2. Preferably, the forward legs 23 of each of the chairs are also clipped to the plate or strip |.2 by means of the nail-like fastening elements which pass through openings in the legs 23 and in the plate l2 and have their outer ends 46 bent back against the face of the strip |2.

In Figures 4, 5, and 6 of the drawingsthere is illustrated a modification of the load transfer structure which is of somewhat simpler construction and which effects certain economies of manufacture, in that certain standardized elements may be used for supporting the dowels or load transfer elements.

In illustrating and describing this embodiment of the invention, the same reference characters are employed in designating the principal parts of the structure including the dowels, with comparable parts of the supporting structure designated with the same reference characters with the addition of the letter A, while the distinctive elements and portions of the modified form of support are given new reference characters.

The dowels 32, as in the earlier described embodiment may pass through openings in the optional expansion strip |2, at intervals across the road bed, and are ultimately embedded in the slabs A and B. The dowels 32 are welded as at 33A to the upper horizontal flanges of the angle irons "SA and HA.

Instead of the two-legged chairsor pedestals 20 employed in the earlier described embodiment, two identical pedestals 50 and 5| are employed which correspond in purpose and function to the respective forward and rear legs 23 and 22 of the first described device. The upper ends of each of the pedestals 50 and 5| lie flat against the inner surfaces of the vertical flanges of the angle pieces ISA and HA, and their ends abut the lower surface of the horizontal flanges of these angle pieces. Each of the pedestals 50 and 5| have horizontal feet 52 and 53 formed thereon, the feet 52 of the forward pedestals resting on the subgrade C and extending forwardly beneath the joint strip or plate l2. The feet 53 of the rearward pedestals 5| are rearwardly directed and also rest upon the sub-surface C. The feet are provided with openings 54 and 55 through which the spikes or pins 30A pass into the sub-grade.

The vertical portions of the pedestals 50 and 5| are offset at their intermediate points as at 56 and 57. This insures that the lower portion of the forward pedestal lies snugly against the rear face of the expansion strip l2 directly beneath the vertical flange of the angle iron HA. The lower portions of the vertical parts of the pedestals 50 and 5| are provided with openings 58 and 59. "This is to accommodate the cap nail 6B which passes through a registering opening in the expansion strip |2 andthe opening 58 in the forward pedestal. The head 6| of the cap nail lies against the forward face of the expansion joint strip and the joint62 of the nail is clenched against the rear face of the pedestal. The angle iron HA is secured tothe strip |2 in similar fashion by the cap nail 65 passing through an opening in thestrip |2 and having its point bent over the horizontal flange of thebar, |1A as at 65. The head 6'! of the cap nail 65 is disposed against the forwardface of the-expansion strip I2. 3

One advantage of the latter embodiment lies in the fact that the pedestals used as forward supports 50 or rearward supports 5| are identical and interchangeable, and may be manufactured in quantity regardless of the position in which they are to be used in the joint support. a

It will be seen that by means of the devices described, load transfer structures have been provided which are sturdyand rigid enough to provide adequate support for the dowels, but are of light construction renderingthem readily transportable and economical to manufacture. It will also be perceived that these assemblies may be used in a wide variety of installation, whether F or not a joint iscontemplated at the point of use,

but they are of particular utility when such joints are provided, especially in connection with the provision of means allowing expansion and contraction between slabs.

Various changes and modifications may be made in the embodiments illustrated and described without departing from the scope of the invention as defined in the sub-joined claims.-

Having thus described the, invention, what is claimed as. new and desired to be secured by Letters Patent is:

1. An expansion joint and, load transfer con-- struction for concrete roadways or the like comprising, in combination, a vertically disposed joint forming strip adapted to extend across the roadway between adjacent slabs, openings in said ing their opposite ends projecting upon the 1'87 spective sides of the strip, a pair of parallel elongatedxmembers of standard rolled structural shape spaced apart horizontally, extending along said strip on one side thereof and transversely of said:dowelpins, one of said members being disposed closely adjacent said strip, means securing said dowel pins to said members; a plurality of leg elements disposed beneath said elongated members at intervals therealong and adapted to rest upon the sub-grade, and a foot on eachof said leg elements, the feet on the leg elements supporting the member adjacent the strip extendingbeneath said strip and directed so as toextend along the sub-grade. I I

2.- An expansion joint and load transfer construction-for concrete roadways or the like comprising, in combination, a -vertically disposed joint formingstri'p' adapted to extend across the road-- waybetweenadjacent slabs, openings in said strip'at intervals therealong, a plurality of dowel pinsextending through saidopenings and having theiroppositeends projecting upon the respective sides of the strip, a pair of parallel elongated' members of standard rolled structural shape' spaced apart horizontally, extending along said strip on one side thereof and transversely of said dowel pins, one of said-members being dis'-:' posed'closely adjacent said strip, means securing said dowel pins to said members, a plurality of supporting leg elements disposed beneath said elongated members at intervals therealong, each of said le 'elernents being generally L shaped in configuration havingfeet adapted to rest upon of the strip, a pair of parallel elongated members or" standardr'olled structural shape spaced apart horizontally, extending along said strip on one side thereof and transversely of said dowel pins,

one of said members being disposed closely adjacent said strip, means securing said dowel pins to said members, a plurality of supporting leg elements disposed beneath said elongated members at intervals therealong, each of said leg elements being generally L-shaped in configuration having feet adapted to rest upon the sub-grade, the feet of the leg elements which support the elongated member adjacent the strip extending beneath the strip, and the feet of the leg elements supporting the other elongated member extending in the opposite direction, and clip elements tying said strip element to parallel member and leg element assembly.

4. An expansion joint and load transfer construction for concrete roadways or the like comprising, in combination, a vertically disposed joint forming strip adapted to extend across the roadway between adjacent slabs, openings in said strip at intervals therealong, a plurality of dowel pins extending through said openings and having their opposite ends projecting upon the respective sides of the strip, a pair of parallel elongated angle members spaced apart horizontally, extending along said strip on one side thereof and transversely of said dowel pins, one of said members being disposed closely'adjacent, said-strip; with a horizontal flange and a depending flange;

. the latter lying snugly against saidstrip,-means securing saiddowelpins to said membera-raplurality of supporting leg elements disposedibe-..-1-=

L-shaped in configuration having. feet adapted to rest uponthe. sub-gradeythe'feetof the leg: s

- other elongated membereextending in the oppo site direction, the upper: ends of the leg elements abutting the'horizont'al flanges of the angle mem- ,l bers and lying against the inner faces ofiithe Tde--'--* pending flanges, the'upper and.lowerportionsof"w the-vertical part of each of said'leg elements beelements which support-the elongated member adjacentthe strip extending beneath the 'str-ip;. 1 and the feet of theileg elements supporting the lngloffsetv from each other, whereby the lowerportions are coplanar with-the depending'flanges and may also lie snuglyagainst the joint forming strip, and means tying -said-strip element to parallel member and -leg elementiassembly v 5. A load transfer. construction for concret 5 roadways or the like comprising, in combinatio i a plurality of substantially parallel' horizontally standard rolled angle members'spaced 'apar't-hori zontally and extending transverselyof-said dowel pins, said parallel angle members having horizontal flanges extending toward each other'andthe angle members and lying against and welded to the inner faces of the depending flanges'there -f of. i

spaced parallel 'ch'a'irs,'-"said chairs being of an in 6; An expansionjoi'ntconstruction forconcrete roadways or the like comprising-in coli-'ribi-na'titifr, a supporting stru c'zt'ure inc'l'udingasries. 0f

verted rectangular U'-'shape,-having a-"horizontal body portion and two depending leg portions, a pair of elongated angle members extending transversely of said chairs and each secured at intervals along their lengths to said chairs, one at the junction of one leg with the body portion the body portion of each chair, the lower ends of said legs being bent in the same direction to provide horizontal feet adapted to rest on the subgrade, one of said feet underlying and extending parallel with said body portion, registering open ings in said last named foot and said body portion, an anchoring spike passing through said registering openings and adapted to enter the sub-grade, and an opening through the other of said feet through which another anchoring spike passes; a compressible joint-forming strip disposed alongside of one of said angle members and adjacent one of the legs of each of said chairs; and clips attaching said strip to said legs.

7. Aload transfer assembly for concrete roadways or the like comprising, in combination, a supporting structure including a series of spaced parallel chairs, said chairs being of an inverted rectangular U-shape, having a horizontal body 75 portion and two depending leg portions, a pair and one at the junction of the other leg with of elongated angle:- members extending trans- VBISEIYL'OI said chairs and secured at intervals along their lengths to said chairs, one at the junction of one leg with the-body portion and one-at the junction of theother leg with the body portion'of each chair, :thelower ends of said legs being bent-in the same direction to provide horizontalfeet adapted to rest upon the sub-grade, one-of said feetzunderlying and extending parallel withnsaid body portion, registering openings-in said last named foot and said body-portiOl'ly an anchoring-spike passing through said registering-openings and adapted to enter the subegrade,- andian opening through the other-of saidfeetthrough which another anchoring spike passes; and a series of dowel pins disposed trans-.

verselyof and secured to said parallel angle pieces at intervals along said' supporting structure, the ends of-said dowelpins upon one side of said structurejproj'ectingbeyond the angle piece upon thatside; the supporting structure proper adapted to be embedded within one slab of the paving material and the projecting ends of the dowel pins within the adjacent slab.

8. An expansion joint construction for concrete roadways or the like comprising, in combination, a supporting. structure including a series of chairs spaced, said chairs being of an inverted rectangular U-shape, having a-horizontal body portion and two depending leg portions, a pair of elongated angle membersjextending transversely of said-chairs and secured at intervals along their lengths to said chairs, one at the junction of one leg with the-body portion and one at the junction of th other leg with the body portion of each chair, the lower ends of said legs being bent in thehsame direction to provide horizontal feet adapted to rest on the-sub-grade, one of'said feet underlying and'extending parallel with said body'portion, registering openings in saidlast named foot and saidbody portion, an anchoring spike-passing throughsaid registering openings andadapted to'enter the sub-grade; and an opening through the other of said feet through which another anchoring spike passes; a com pressible joint-forming strip disposed alongside of one of said angle members and adajacent one of the legs of each of said chairs, clips for attaching said strip to said supporting structure;

and a; series'of dowel pins'dispo'sed transversely of and secured to said parallel angle pieces at intervals along said-supporting structure, the ends of said dowel pinsupon one side of said structure projecting through openings in the joint-forming strip and adapted to be embedded in a slab beyond the latter.

9. A load transfer construction for concretepins; said parallel angle members having hori-' zontal flanges extending toward each other and vertical flanges extending downwardly at remote edges of the two members, means securing said dowel pins to the upper surfaces of said horizontal flanges, a plurality of supporting leg elements disposed beneath said longitudinal members and secured thereto at intervals therealong, eachof said leg'elements being of identical constructionand being generally L-shaped in configuration having feet'adapted to rest upon the sub-grade and extend in opposite directions, the upper ends of the leg elements abutting the horizontal flanges of the angle members and lying againstand-secured 'to the inner faces of the depending flanges thereoflthe upper and lower portions of the vertical part of each of said leg elements-being ofifset'from each other whereby thelower portions-are co-planar with the depending flanges-of the angle members. 7

EDWARD S. MATHERS.

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

UNITED STATES PATENTS N'iunber Name Date 2,158,953 Wilcox May 16, 1939 2,164,590 Oates July 4, 1939 2,179,911 Wilmoth Nov. 14, 1939 2,187,428 Mier et a1. Jan. 16, 1940 2,245,972 Friberg June 17, 1941 2,301,865 Geyer et al. Nov.10, 1942 2,309,767 Heltzel Feb. 2, 1943

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