US2179911A - Expansion joint structure - Google Patents

Description

NOV. 14, 1939. w. F. WILMOTH 2,179,911

EXPANSION JINT STRUCTURE Filed March 5, 1939 Patented Nov. 14, 1939 UNITED STATES PATENT mm:

2 Claims.

The invention relates to expansion joints, particularly for use in concrete pavements and has as an objectthe provision of a pre-formed structure to be placed upon the subgrade and to act as a form against which the concrete for one section will be cast. a

It is a further object of the invention to provide a structure of the class described which will be assembled at the factory and which may be i installed by unskilled labor with a, minimum chance of faulty construction.

It is a further object of the invention to pro-, vide a structure of the class described wherein the dowel pins for connecting adjacent sections I of concrete will be preserved in correct alignment.

Further objects of the invention will appear from the following description showing an illustrative embodiment of the invention, and wherem:

Figure 1 is a perspective view of the structure partially installed; and

Figure 2 is a vertical transverse section on line 2-2 of Figure 1.

As shown the device comprises a plate Ill of a usual expansion joint material as asphalt-impregnated felt. To support the plate Hi there is shown a metallic plate It having a margin thereof as l2 bent at right angles, the plate I I being se cured to the plate III as by means of ears 25 struck out from the material of the plate and penetrating the plate Ill and clinched in the manner shown in Figure 2.

In accordance with accepted practice, the present invention is shown as embodying dowel pins l3, l4 penetrating the plates and desirably secured to the plate H as by electric welds ii.

To hold the plates in vertical position against the thrust of the first cast concrete block as l6, certain of the dowel pins as It are shown extended and bent downwardly as at l! and pro vided in their ends with perforations to receive pins ill to be driven into the sub-grade. These bent down portions may be provided upon as many of the dowel pins .as desired, but every fourth pin as shown is found to be a sumcient frequency for such supports.

To prevent the bottom of the structure from shifting, pins l9 are desirably passed through the angular portion l2 of the plate II. It is of great importance in structures of this character that -the dowel pins are maintained in a position parallel with the surface of the pavement and also parallel with vertical planes normal to the joint. When the structure is installed, the side of the structure presenting the downturned portion I1 is exposed while the block i6 is being cast.

In the installation of the structure with unskilled laborers working thereabout, it is almost certain that some one will step upon the exposed ends of the dowel l3 and unless supported the stepped upon dowel will be forced out of correct position. To hold the pins in correct position, there is shown a rod 20 placed along the ends of the dowel pins l3.and connected to each and to 10 the pins It as by electric welding indicated at 2|.

In accordance with usual practice sleeves 22 are shown placed upon the free ends of the dowels l3 which will be encased in the concrete and will preserve a space about the ends of the dowels to prevent their abutment against the concrete when set to permit of movement of the pavement in expansion and contraction. In accordance with usual practice the portion of the dowels which carry the sleeves 22, and from said sleeves up to the plate It, is provided with some type of coating which will prevent the bond of the concrete when set from locking the dowels in the concrete to prevent such movements'of the concrete relative to the dowels.

As is well understood the importance of maintaining of the dowels correctly parallel with the expected movements of the concrete in expansion' and contraction resides in the fact that if they are at an angle to such movement, the concrete will inevitably break when such movements occur.

The structure of the invention may be assembled at the factory and when shipped to the point of use all that is necessary to assure correct place- .35 ment is that it be dropped on the subgrade and the pins driven through the openings provided therefor. When this is done, the structure will inevitably stand in the proper position if placed at the point indicated by the engineer.

Minor changes may be made in the physical embodiment of the invention without departing from. the spirit thereof.

I claim: I

1. An expansion joint structure comprising, in combination: a plate of compressible material;

a metallic plate secured thereto, substantially coextensive therewith formed with a bottom marginal flange having anchoring-pin perforations; a plurality of dowel pins secured to said metallic plate, having straight portions extending in both directions from said plates normal thereto; certain of said pins beyond their straight portions and on the metallic plate side of said plates only downwardly deflected to con- 2 a,17o,o11

tact. a surface upon which said marginal flange rests at points spaced therefrom while said plates are perpendicular to the surface; the ends of said downwardly deflected portions having anchorpin receiving perforations whereby free ends of theustraight portions of said dowel pins at one side of the assembly are slidable'in enclosing concrete. v

2. The combination of claim 1 with a bar extending between and secured to the straight portions of said dowel pins in spaced relation to said plates adjacent the downwardly deflected portions of said certain pins.

WILLIAM F.

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