US2278917A

US2278917A - Dowel bar support

Info

Publication number: US2278917A
Application number: US323882A
Authority: US
Inventors: Joe G Curry
Original assignee: Reconstruction Finance Corp
Current assignee: Reconstruction Finance Corp
Priority date: 1940-03-14
Filing date: 1940-03-14
Publication date: 1942-04-07
Anticipated expiration: 1959-04-07

Description

April 7 1942- J. G. CURRY 2,278,917

DOWEL BAR SUPPORT Filed Marqh 14, 1940 IIIVVENTOR /5 JOE G. CUR/P Y BY ATTOfiYS Patented Apr. 7, 1942 I I DOWEL BAR SUPPORT Joe GaGurry, Indianapolis, Ind., assignor, -by

mesne assignments, to Reconstruction Finance Corporation, Boston, Mass, a corporation of the United States Application March 14, 1940, Serial No. 323,882

4 Claims. (01. 948) The present invention relates to reinforcing adapted to be imbedded in the end of one of the devices for use in the building of concrete roads concrete slabs and another part that is adapted and the like andembodies, more particularly, an to be imbedded in the adjacent end of the other improved mechanism by means of which the adslab, these parts being formed to support the jacent ends of two sections of concrete and like dowel bar in a desired position and being conmaterial may be connected in such fashion that nected in such fashion that relative -movement a desired relationship may be maintained there therebetween is' accommodated to provide for between under all conditions of service and reexpansion and contraction of the concrete slabs gardless of the spacing between the abutting and without tying the slab sections together. ends of the concrete sections, Further objects of the invention 'will be ap- In the construction of concrete roads, it is parent as it is described in greater detail in conir osrics common practice to pour the concrete in sections, nection with the accompanying drawing, wherebetween the adjacent ends of which a suitable .in: material is introduced to permit of relative moveg. 1 s a e in Vertical ct taken ment between the sections due to expansion and t ro a do pp COIlStrllcted in contraction thereof by reason of temperature accordance with the present invention and changes. The condition of the road remains showing the manner in which a dowel bar is more satisfactory by this sectional formation supported in position in proper relation to the and considerable attention has been directed to adja e t Conc ete Slab Sections.

the connecting structure by means of which the Fig. 2 is a perspective view of the Supp adjacent sections may be integrated. Shown in Fig. 1, the View being taken from be- The importance of maintaining the surface low and to one side of the supp I of the adjacent sections in the same plane will Fig. 3 is a view in section taken on line 3-3 be readily apparent and, to this end, dowel bars of g. 1 and ook n e di e tion of the arhave been inserted in the end structure of the OWS- concrete sections in order that the end sections 4 s a a e t p n V Showin the may be reinforced and maintained in the same r d s ce wi h h s ppor nd dowel bars in plane, the position which they assume during and after It has been extremely difficult to maintain these u Pouring a Se o t e ce ent. dowel bars effectively in a horizontal position Fig. 5 is a p n w Showing a od fied form during the pouring and setting of the cement of the invention.

and, to facilitate the proper positioning of these Fig. 6 is a view in section taken on the line dowel bars, various structures have heretofore 6-45 of F 5 and look in he direction of the been provided with this end in view. However, arrows. r

in these various structures, the supporting mech- 7 s a per pective view taken from the to? anism for the dowel bars has served as a nonand at one end of the dowel bar support shown yielding tie mechanism which tends to make the in s. 5 and coimection ri id, Fig.8 is a view in side elevation showing a fur- An object of the present invention is to proh mod fication Of the invention.

vide a dowel bar support by means of whichzthf?" Referring to the above drawing, the adjacent dowel bar may be effectively supported in a ends of two concrete slabs ofa road are shown position such that its axis lies parallel to the et la d being p d to eceive an exaxis .of the sections of the roadway, and mainpension joint 52 y a s of Which relative tained in such position during the pouring and movement of the slabs in respo o a es in setting of the cement, the structure being such temperature y e modated. In order as to avoid objectionable interconnection bet the D Surfaces 0f the djacent ends of tween the adjacent road sections after the con- Slabs i9 and ii y be maintained in the same crete has set. plane, a plurality of dowel bars I3 are provided,

A further object of the invention is to provide the dowel bars being D OIIed that their dowel bar support of. th above character axes lie parallel to the axis of the concrete slabs,

wherein the support structure is such as to perthus preserving the top surfaces of the adjacent mit of relative movement between the adjacent slabs l0 and H in the same plane regardless of sections of concrete after the joint has set. the extent of movement of the slabs under ten- The foregoing objects are attained by providsion or compression. The ends of the dowel bars ing a support structure having one part that is 55 I3 may be supported in the concrete slabs by expansion caps or sleeves l3a, in accordance with usual practice, to permit of movement of one or both ends of the bars in the respective slabs.

These dowel bars l3 are supported in the aforesaid position by means of a supporting structure consisting of cooperating sections 14 and I5 having respectively horizontal extensions l6 and H. The horizontal sections [6 and I1 are held together by means of a sleeve-like coupling I8 in such fashion as to permit relative movement between the sections l6 and IT, without destroying the connection which makes the supporting structure an integral unit.

In order that the supporting devices may be properly spaced and positioned across the roadway, tie bars H! are provided, these bars being welded or otherwise secured to the respective sections of the supports. At the top of the sections l4 and I5, notches 20 and 2| respectively are formed in order that the dowel bar may be received and supported in the position illustrated. If desired, the notches may be formed by pressing out

lugs

22 and 23, respectively, so that they will lie in a horizontal position. In order to align the bottom of the filler material interposed between the slabs l and II, a lug 24 is pressed out of the bottom of the supporting structure.

In the form of the invention shown in Figs. 5, 6 and 7, the dowel bars are supported by the transverse tie bars l9 which are welded or otherwise secured to respective bars of wire supports 25 and 26. These bars are of L-shape and have

horizontal portions

21 and 28 respectively, the ends of which are received within a sleeve-like coupling 29 having enlarged end portions 30 within which the

wires

21 and 28 are received. Wire sections 3| are welded to the horizontal wires 28 to serve in the supporting capacity served by the lug 24.

In the form of the invention shown in Fig. 8, the support of Figs. 1 and 2 is formed in such fashion that the sections thereof are initially secured in position by means of shear pins 32. After the concrete has been poured and has set, relative movement between the sections I4 and I of the dowel bar support is permitted in response either to expansion or contraction of the concrete slabs, by shearing of the pins 32, thus permitting the same relative movement between the support sections as is accommodated by the clamps l8 and 29 in the forms of the invention shown in Figs. 2 and 7, respectively.

From the foregoing, it will be apparent that a dowel bar support has been provided by means of which relative movement between the adjacent ends of concrete slabs may be accommodated regardless of whether the movement occurs by reason of the forces in compression or tension. The device is simple of construction and relatively inexpensive, yet it serves effectively to position the dowel bars in a desired position and maintain them therein during the pouring and setting of the cement. After the concrete slabs have set, relative movement therebetween is accommodated without the existence of restraining forces that have hereto-' fore been exerted where the support structure has provided a positive tie between the ends of the slabs.

The present invention may, of course, be used in a varied type of service and is not restricted either to the type of material to be reinforced or to the particular service in which such material is to be used.

While the invention has been described with specific reference to the modifications shown in the accompanying drawing, it is not to be limited save as defined in the appended claims.

I claim:

1. A dowel bar support comprising a plurality of L-shaped elements each adapted to be disposed with one portion vertical and the other portion horizontal, the vertical portion of each element being provided with means to receive a dowel bar, and a coupling having two opposed portions spaced apart to receive therebetween the horizontal portions of two of said elements to connect the same for relative movement there between, the opposed portions extending lengthwise of the horizontal portions of the L-shapedv elements a distance sufiicient to prevent the weight of said dowel bar from buckling same.

2. A dowel bar support comprising a pair of L-shaped straps each adapted to be disposed with one portion vertical and the other portion horizontal, the vertical portion of each strap being provided with a recess to receive a dowel bar, and a coupling having two opposed sides adapted to receive therebetween and in overlapping relation the horizontal portions of said straps to connect said straps for relative movement therebetween.

3. A dowel bar support comprising a pair of L-shaped straps each adapted to be disposed with one portion vertical and the other portion horizontal, the vertical portion of each strap being provided with a recess to receive a dowel bar. and a sleeve coupling adapted to receive the horizontal portions for relative movement lengthwise thereof, said coupling being provided with wall portions adapted to engage the sides and side edges of the horizontal portions of said straps for a distance lengthwise thereof sufficient to hold the L-shaped straps from buckling under the load of the dowel bar.

4. A dowel bar support comprising pairs of L-shaped bars, each bar being adapted to be disposed with one portion vertical and the other portion horizontal, means to connect the vertical portions of two pairs of said bars to form a support on which to receive a dowel bar, and means including opposed wall portions to receive therebetween and in side by side relation the horizontal portions of each pair of bars to connect the bars for relative movement lengthwise thereof.

JOE G. CURRY.