GB2138915A - Conduit - Google Patents

Abstract

The present invention relates to a built-up conduit made up of precast concrete products and is designed so as to obtain a conduit having a complete watertightness and which has walls that are not inclined outward by water pressure. The gist thereof lies in that notches (1a) and (2a) are provided in the facing surfaces of a bottom-board block 1 and L-shaped blocks (2) respectively, that anchor plates are fixed in said notches, that said anchor plates are tightened by bolts (5) and nuts (6), and that a mortar joint (8) is inserted therein to join the two kinds of blocks (1) and (2) to each other. The conduit thus prepared is best suited for use as an irrigation or drainage channel. <IMAGE>

Description

SPECIFICATION Precast built-up conduit The present invention relatestoaprecastbuilt-up conduit formed by connecting L-shaped right and left side wall blocks to a flat bottom board block, and more particularly it relates to a precast built-up conduit whose side-wall and bottom-board blocks are joined to each other through the intermediary of a mortar joint.

In a conventional built-up conduit consisting of L-shaped side wall blocks and a flat bottom board block, the blocks are connected to each other in such a mannerthatthe edge surfaces of each block is made to face each other directly and are joined together by, nuts and bolts, etc. However, in this conventional method wherein the blocks are made to face each other directly and are joined together, gaps inevitably form between said blocks owing to the presence of uneven spots on the surfaces ofthe blocks which are formed because of variations in the molding of the blocks.

Accordingly,the conventional method is imperfect in that it has disadvantages such that a sufficient watertightness can not be obtained, and that the top edges open outwhen said L-shaped blocks are tilted outward bywater pressure when these blocks are employed in the open onthe ground.

Therefore, an object of the present invention is to furnish a precast built-up conduitwherein blocks forming the conduit are surely connected to each other, and thereby high degree of water-tightness is attained.

Another object of the present invention is to furnish a precast built-up conduit enabling the preservation of the prescribed width of the conduit even when each block has some amount of constructional variation.

Athird object of the present invention is to furnish a precastbuilt-upconduitwhich is ableto withstand sufficiently external pressure such as water pressure or earth pressure.

A precast built-up conduit in the preferred form of the present invention has a bottom-board block and L-shaped blocks which are installed on both sides of said bottom-board block separately at a prescribed interval therefrom. A plurality of notches are formed in the facing edge surfaces of each block, and anchor plates each provided with a slit or a hole are fixed in thefrontofsaid notches, each gap between anchor plates is bridged by a bolt, a nut is fastened thereon, mortar is inserted in the gap between the two kinds of blocks, and thereby these blocks are joined to each other. In this way, two kinds of blocks are connected firmly and watertightly.

Figure 1 is a general perspective view showing a preferred embodiment of a precast built-up conduit constituted according to the present invention; Figure 2 is an analytical perspective view of a part of the embodiment; Figure 3 is a plan view of a detail showing the mutual connection of blocks; and Figure 4 is a section taken along the line I - I of Fig. 3.

The invention will be explained in detail hereunder with reference to the drawings. Numeral 1 denotes a bottom-board block, while numeral 2 denoting Lshaped blocks installed symmetrically on both sides of said bottom block, separated by a prescribed space S therefrom. In these two kinds of blocks 1 and 2, notches 1a and 2a are provided facing each other at several places on the joining edge surfaces thereof in the widthwise direction of the conduit, and an anchor plate 3 is provided monolithically in the front of each of said notches 1 a and 2a. Bent parts 3b at both ends of the anchor plate 3 and anchor rods 4welded thereto are buried in the blocks, while a slit 3a cut in the upper edge is provided in the front center of the plate.

Numeral 5 denotes a bolt which is dropped into said slit 3a and mounted between the anchor plates 3 of said blocks 1 and 2, and four nuts 6 are screwed onto the bolt so that they hold both the inner and outer surfaces of both anchor plates 3 between them. Of these nuts 6, each of the two nuts 6 positioned outside the anchor plates 3 arefirsttightened toward the outer surfaces of the anchor plates 3through the intermediary of washers 7.

Numeral 8 denotes a mortarjointwhich fills the spaces between said blocks 1 and 2 after the above two nuts 6 are tightened. The upper and lower surfaces of the joint are madeto be on the same planes as the upper and lower surfaces of the blocks 1 and 2.

After being constituted as described above, the conduit of the present invention is completed in the following manner. Afterthe setting of said mortar joints 8, the other nuts 6 within said notches 1 a and 2a are each tightened toward the corresponding inner surface ofthe anchor plates 3, and then mortar is poured into the notches 1 a and 2a. In this way, the bottom-board block 1 and the L-shaped blocks 2 are joined to each othermonolithicallythroughthe intermediary of the mortar joints 8.

According to the present invention, the bottomboard block 1 and the L-shaped blocks 2 are joined to each other, as described above, by inserting the morta rjoint 8 between them, and bytightening the nuts 6 in the notches 1 a and 2a afterthe setting of the mortar. Therefore, no gap is formed between the bottom-board block 1 and the L-shaped blocks 2.

Accordingly, perfect conduit properties can be obtained, and such a disadvantage, as described above, that the L-shaped blocks incline so thatthe top edges thereof separated, can be eliminated.

Generally, some variation in structure is usual when the bottom-board block 1 and the L-shaped blocks 2, etc., are molded. According to the present invention, the blocks are joined togetherthrough the intermedi aryofmortarjoints 8 as described above, and therefore, any error in the dimensions of the bottomboard block 1 or the L-shaped blocks 2 in the widthwise direction ofthe conduit can be compensated for simply by varying the width of the joint openings at the mortar joints 8.

In addition, the present invention has the effect that the junction ofthe blocks can completely withstand an external force, such as earth pressure, since two inner nuts 6 in contact the outer surfaces of the anchor plates 3, of the four nuts screwed onto the bolt 5, can be madeto perform the function of maintaining the spacing between the blocks.

The foregoing isa description of a preferred embodiment of the present invention, and itwill be easy for persons skilled in the artto understand that a number of alterations and modifications can be applied to the present invention without departing from thetrue spirit and coverage thereof.

Claims (4)

1. A precast built-up conduit characterized in that a plurality of notchesareformed facing each other in both the edges surfaces in the widthwise direction of theconduitofa bottom-board blockand in the edge surfaces of lower projecting parts of L-shaped blocks installed on both sides of said bottom-board block separately at a prescribed spacing therefrom, in that anchor plates provided each with a slit or a hole are fixed in the front of said notches, and in that said two L-shaped blocks and the bottom-board block are joined to each otherthroughtheintermediaryof mortarbytightening nutsand bolts bridging said anchor plates.

2. A precast built-up conduit substantially as herein before described with reference to and as shown in the accompanying drawings.

3. Any novel integer or step, or combination of integers or steps, as hereinbefore described, and/or shown in the accompanying drawings, irrespective of whetherthe present claim is within the scope of, or relates to the same or a different invention from that of, the preceding claims.

4. A precast built-up conduit formed by connect ingtwo-shaped side wall blocks to a board block.