A GRATING USING PRESS PROCESS AND METHOD

THEREOF

Technical Field

[1] The present invention relates, in general, to gratings and methods of manufacturing the same and, more particularly, to a grating in which a plurality of water drain slots is formed by deep-drawing a metal plate using a press machine without a welding process, and slot frame parts formed by deep-drawing serve to sustain load applied to the grating, thus having a structure capable of sustaining a relatively heavy load despite the simple manufacturing method thereof, and to a method of manufacturing the same through the pressing process.

Background Art

[2] Generally, sewers are formed at sides of roadways or streets, so that rainwater and the like flows into a sewer system through the sewers. A grating is disposed at upper ends of each sewer opening, such that a person or a vehicle can pass over the sewer but rainwater can flow into it.

[3] There are various methods of manufacturing such a grating. A method using a molding process is a representative example. However, in the case of a method using a molding process, an excessively large amount of steel material is required for a molding process, so that there are disadvantages in that the manufactured grating is too heavy, and the manufacturing cost thereof is increased. Therefore, recently, the method using the molding process is seldom used. Meanwhile, recently, gratings having lattice structures have been widely used.

[4] Fig. 1 is a perspective view showing the construction of a representative grating having a lattice structure.

[5] As shown in Fig. 1, in the conventional grating having the lattice structure, a plurality of I-bars 20, each of which has therein notches (not shown) at regular intervals, is longitudinally fastened to a rectangular main body 10 by welding. Bearing bars 30 are seated into the notches of the I-bars 20 in directions crossing over the I-bars 20. Each bearing bar 30 is fixed to the main body 10 and the I-bars 20 by welding.

[6] However, in the case of the conventional grating having the above-mentioned lattice structure, the main body 10, the I-bars 20 and the bearing bars 30 must be manufactured through separate processes before being assembled together. Therefore, there is a problem of a complex manufacturing process.

[7] Furthermore, the I-bars 20 and the bearing bars 30 are fixed to the main body 10 of the grating by welding, and the I-bars 20 and the bearing bars 30 are also fixed by

welding at junctions between them. Therefore, labor costs increase due to the increased number of welders, and the time required for manufacturing the grating is increased, so that there is a problem in that the unit cost of production is increased.

[8] To solve the above-mentioned problems, a method of manufacturing a grating through a pressing process has been proposed. However, because the bearing power of the conventional grating manufactured by this method is insufficient, it cannot be used in a sewer, over which vehicles pass, or to which a heavy load is applied. That is, this grating has been restrictively used in places over which vehicles seldom pass.

[9] Therefore, a grating, that makes it possible to overcome the problems of the conventional grating manufacturing method, that is manufactured through a simple process, and that can sustain a heavy load, is required. Disclosure of Invention Technical Problem

[10] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a grating, which can sustain a relatively heavy load, and a grating manufacturing method, which has a reduced number of steps thanks to the use of a press machine. Technical Solution

[11] In an aspect, the present invention provides a method of manufacturing a grating using a pressing process, comprising the steps of: bending opposite ends of a metal plate to form a main surface and supports, each having a predetermined height; drawing a plurality of water drain slot formation portions of the main surface to form slot frame parts, each having a predetermined depth; and perforating bottoms of the slot frame parts to form water drain slots.

[12] In another aspect, the present invention provides a method of manufacturing a grating using a pressing process, comprising the steps of: bending the opposite ends of a metal plate to form a main surface and supports, each of which has a height equal to the depth of a support seat of each sewer wall; cutting the metal plate along a longitudinal central line of each of a plurality of water drain slot formation portions to the length of each water drain slot to be formed; cutting the metal plate at each of opposite ends of the cut longitudinal central line of each water drain slot formation portion in lateral opposite directions of the cut longitudinal central line to lengths corresponding to the height of the support; and bending the cut water drain slot formation portions of the metal plate downwards and forming the slot frame parts.

[13] In a further aspect, the present invention provides a method of manufacturing a grating using a pressing process, comprising the steps of: bending opposite ends of a metal plate to form a main surface and supports, each having a predetermined height;

drawing a plurality of water drain slot formation portions of the main surface to form slot frame parts, each having a predetermined depth; perforating bottoms of the slot frame parts to form water drain slots; uniting front surface members to opposite ends of the supports; and charging a filling material into a space defined by the main surface, the supports and the front surface members.

[14] In yet another aspect, the present invention provides a method of manufacturing a grating using a pressing process, comprising the steps of: drawing a plurality of water drain slot formation portions of a main surface of a metal plate to form slot frame parts, each having a predetermined length; and perforating bottoms of the slot frame parts to form water drain slots.

[15] In still another aspect, the present invention provides a method of manufacturing a grating using a pressing process, comprising the steps of: bending opposite ends of a metal plate to form a main surface and supports, each having a predetermined height; drawing a plurality of first water drain slot formation portions of the main surface to form first slot frame parts, each having a predetermined depth; drawing parts between lower ends of the first slot frame parts to form a plurality of second slot frame parts; perforating bottoms of the second slot frame parts to form a plurality of water drain slots; uniting front surface members to opposite ends of the supports; and charging a filling material into a space defined by the main surface, the supports and the front surface members.

[16] Other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings.

Advantageous Effects

[17] The present invention provides a grating, which can sustain a relatively heavy load despite being manufactured through a simple pressing process, and a method of manufacturing the same through the pressing process.

[ 18] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Brief Description of the Drawings

[19] Fig. 1 is a perspective view showing the construction of a conventional grating;

[20] Fig. 2 is a perspective view showing the construction of a grating manufactured through a pressing process, according to a first embodiment of the present invention;

[21] Fig. 3 is a bottom perspective view of the grating of Fig. 2;

[22] Fig. 4 is a perspective view showing the construction of a grating manufactured

through a pressing process, according to a modification of the first embodiment of the present invention; [23] Fig. 5 is a front sectional view showing the grating placed on a support seat of a sewer wall according to the first embodiment of the present invention; [24] Fig. 6 is a front sectional view showing a grating according to the first embodiment placed on slope support seats of sewer walls; [25] Fig. 7 is a perspective view showing the construction of a grating manufactured through a pressing process, according to a second embodiment of the present invention;

[26] Figs. 8 and 9 are perspective views showing the construction of a grating manufactured through a pressing process, according to a third embodiment of the present invention; [27] Fig. 10 is a front sectional view showing the grating according to the third embodiment placed on support seats of sewer walls; [28] Fig. 11 is a front sectional view showing a modification of the fourth embodiment of the present invention; [29] Fig. 12 is a perspective view showing the construction of a grating manufactured through a pressing process, according to a fourth embodiment of the present invention; [30] Fig. 13 is a front sectional view showing the grating placed on the sewer walls according to the fourth embodiment of the present invention; [31] Fig. 14 is a front sectional view showing installation of a grating manufactured through a pressing process, according to a fifth embodiment of the present invention; [32] Fig. 15 is a front sectional view showing installation of a grating manufactured through a pressing process, according to a sixth embodiment of the present invention; and [33] Fig. 16 is a front sectional view showing installation of a grating manufactured through a pressing process, according to a sixth embodiment of the present invention.

Best Mode for Carrying Out the Invention [34] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. [35] Fig. 2 is a perspective view showing the construction of a grating 1 manufactured through a pressing process, according to a first embodiment of the present invention.

Fig. 3 is a bottom perspective view of the grating 1 of Fig. 2. [36] As shown in Figs. 2 and 3, the grating 1 according to the first embodiment includes two supports 4, which are formed by bending opposite ends of a metal plate. A plurality of water drain slots 2 is formed through a main surface 5. [37] The water drain slots 2 are defined in respective slot frame parts 4, which are

formed by pressing parts of the metal plate downwards, that is, by deep-drawing the main surface 5 using a machining means such as a press machine.

[38] Each slot frame part 4 is deep-drawn at an appropriate pressure such that it has the same height as the supports 4, and, thereafter, is perforated.

[39] Fig. 4 is a perspective view showing the construction of a grating manufactured through a pressing process, according to a modification of the first embodiment.

[40] In the case of a relatively wide water drain slot 2, a wheel of a cart or a heel of a shoe may be trapped in the water drain slot 2. To prevent this problem from occurring, the modification of the first embodiment of Fig. 4 has a structure in which the width of each water drain slot 2 is relatively narrow and a plurality of through holes 8 is formed in a part between adjacent water drain slots 2 to ensure smooth drainage.

[41] Fig. 5 is a front sectional view showing the grating 1 of the first embodiment placed on support seats 40 of sewer walls 30.

[42] As shown in Fig. 5, the height of the supports 4 is equal to the height (h) of the support seats 40 of the sewer wall, such that the grating 1 of the present invention does not interfere with a person or object passing over it after having been placed on the support seats 40 of the sewer wall.

[43] The length of each slot frame part 3 is greater than the width (t) of a sewer 20 but is less than the distance (T) between the support seats 40 of sewer walls. Therefore, opposite ends of the slot frame parts 3 are placed on bottoms 41 of the support seats 40 of sewer walls, so that the slot frame parts 3 can serve as support bodies along with the supports 4. Thus, even if a large load is applied to the main surface 5, the grating can sustain the load.

[44] Fig. 6 is a front sectional view showing a grating 1 according to the first embodiment placed on slope support seats 40 of sewer walls 30.

[45] In the case of the grating 1 of Fig. 5 having the support seat 40 with a perpendicular structure, noise may be generated by lateral movement of the grating 1. Therefore, preferably, the support seats 40 of the sewer walls 30 are slanted, and the support 4 is bent at an angle, at which the support seat 40 of the sewer wall 30 is slanted. Mode for the Invention

[46] Fig. 7 is a perspective view showing the construction of a grating 1 manufactured through a pressing process, according to a second embodiment of the present invention.

[47] In the grating 1 according to the second embodiment, the method of forming supports 4 by bending the opposite ends of a metal plate is the same as that of the first embodiment, but the method of forming both a water drain slot 2 and a slot frame part 3 differs from that of the first embodiment.

[48] In the second embodiment, after parts of a main surface 5 for formation of the water drain slots 2 are cut, they are bent downwards, so that the cut parts of the metal plate forms the slot frame parts 3.

[49] Furthermore, in the case of the second embodiment, the opposite ends of the slot frame parts 3 are placed on bottoms 41 of support seats 40 of sewer walls, so that the slot frame parts 3 can serve as support bodies along with the supports 4. Thus, even if a large load is applied to the main surface 5, the grating can sustain the load.

[50] Meanwhile, a method of manufacturing the grating 1 according to the second embodiment includes the step of bending the opposite ends of a metal plate to form the main surface 5 and the supports 4, each of which has a height equal to the depth (h) of the support seat 40 of each sewer wall 30. The method further includes the step of cutting the metal plate along a longitudinal central line of each of a plurality of water drain slot formation portions to the length of each water drain slot 2 to be formed. The method further includes the step of cutting the metal plate at each of opposite ends of the cut longitudinal central line of each water drain slot formation portion in lateral opposite directions of the cut longitudinal central line to lengths corresponding to the height of the support 4. The method further includes the step of bending the cut water drain slot formation portions of the metal plate downwards and forming the slot frame parts 3.

[51] Figs. 8 and 9 are perspective views showing the construction of a grating 1 manufactured through a pressing process, according to a third embodiment of the present invention.

[52] In the third embodiment, as shown in Fig. 8, a front surface member 6 is provided on each of open front and rear sides of the grating and fastened at opposite ends thereof to respective supports 4 by welding or the like. Thereafter, the grating 1 is turned upside down such that it has a box shape, which is open at an upper surface thereof. Subsequently, as shown in Fig. 9, the grating 1 is filled with filling material.

[53] Stone, synthetic resin, such as polyurethane, or rubber is used as filling material. In this embodiment, colored pebbles are charged into spaces in the grating other than water drain slots, thus providing a grating 1 that is solid and has a good appearance.

[54] Fig. 10 is a front sectional view showing the grating 1 according to the third embodiment placed on support seats 40 of sewer walls.

[55] As shown in Fig. 10, in the third embodiment, opposite ends of slot frame parts 3 are placed on respective bottoms of the support seats of the sewer walls, so that the slot frame parts 3 serve as support bodies along with the supports 4. Thus, even if a relatively heavy load is applied to the grating, the grating can sustain the load. Particularly, in the third embodiment, the filling material 7, which is charged into the space defined between the supports 4 and the slot frame parts 3, serves as another

support body, thus providing a stronger structure.

[56] A method of manufacturing the grating 1 according to the third embodiment includes the step of bending the opposite ends of a metal plate to form a main surface 5 and the supports 4, each of which has a height equal to the depth (h) of the support seat 40 of each sewer wall 30. The method further includes the step of deep-drawing a plurality of water drain slot formation portions on the main surface 5 such that the water drain slot formation portions of the metal plate are depressed by the height of the supports 4, thus forming the slot frame parts 3. The method further includes the step of perforating bottoms of the slot frame parts 3 to form water drain slots 2, and the step of uniting the opposite ends of the supports 4 to the related front surface member 6. The method further includes the step of charging the filling material 7 into a space defined by the main surface 5, the supports 4 and the front surface members 6.

[57] Fig. 11 is a front sectional view showing a modification of the third embodiment of the present invention.

[58] As shown in Fig. 11, in this modification, first slot frame parts 3 are formed by deep-drawing the surface of the grating by a predetermined depth less than the height (h) of the supports 4. Thereafter, second slot frame parts 9 are formed by deep-drawing the surface from the lower ends of the first slot frame parts 3 by the height of the supports 4 using a smaller press machine. Subsequently, a plurality of water drain slots 2 is perforated. The grating 1 is thereafter turned upside down, and filling material 7 is charged into a space defined in the grating 1.

[59] In detail, the method of manufacturing the grating 1 according to the modification of the third embodiment includes the step of bending the opposite ends of a metal plate to form a main surface 5 and the supports 4, each of which has a height equal to the depth (h) of the support seat 40 of each sewer wall 30. The method further includes the step of deep-drawing a plurality of first water drain slot formation portions on the main surface 5 such that the first water drain slot formation portions of the metal plate are depressed by a predetermined depth, thus forming the first slot frame parts 3. The method further includes the step of deep-drawing parts between the lower ends of the first slot frame parts 3 to form a plurality of second slot frame parts 9. The method further includes the step of perforating bottoms of the second slot frame parts 9 to form water drain slots 2, and the step of uniting the opposite ends of the supports 4 to the related front surface member 6. The method further includes the step of charging the filling material 7 into a space defined by the main surface 5, the supports 4 and the front surface members 6.

[60] Fig. 12 is a perspective view showing the construction of a grating 1 manufactured through a pressing process, according to a fourth embodiment of the present invention.

[61] The grating 1 according to the fourth embodiment has a structure suitable for a

"U"-shaped sewer 20 having no support seat 40 on a sewer wall 30. In a process of manufacturing the grating of this embodiment, because the support seat 40 does not exist in the sewer wall 30, the step of forming the supports 4 is eliminated, unlike the first embodiment.

[62] In detail, the method of manufacturing the grating 1 according to the fourth embodiment includes the step of deep-drawing a plurality of water drain slot formation portions on the upper surface of a metal plate such that the water drain slot formation portions of the metal plate are depressed by a predetermined depth, thus forming slot frame parts 3. The method further includes the step of perforating the bottoms of the slot frame parts 3 to form water drain slots 2.

[63] Fig. 13 is a front sectional view showing the grating placed on the sewer walls 30 according to the fourth embodiment of the present invention.

[64] As shown in Fig. 13, the slot frame parts 3 are disposed in the sewer 30, while the opposite ends of the main surface 5 are placed on the respective sewer walls 30.

[65] In the case of the fourth embodiment, the slot frame parts 3 have appropriate thicknesses and disperse load applied to the main surface 5, so that the grating can sustain a relatively heavy load.

[66] Figs. 14 through 16 illustrate modifications of the first through fourth embodiments adapted to the case in which the height of the support seat 40 differs from that of the grating.

[67] Fig. 14 is a front sectional view showing the installation of a grating 1 manufactured through a pressing process, according to a fifth embodiment of the present invention. The grating 1 of this embodiment includes a subsidiary height adjustment frame 50, which is welded both to the slot frame part 3 and each support 4 to adapt to the height of support seats 40 of the sewer walls 30, which is different from that of the grating. In other words, this embodiment can adapt to the height of various support seats 40.

[68] Fig. 15 is a front sectional view showing the installation of a grating 1 manufactured through a pressing process, according to a sixth embodiment of the present invention. In the case of Fig. 15, subsidiary height adjustment frames 50 are attached to the surface of a grating 1 which is turned upside down. In other words, the subsidiary height adjustment frames 50 are welded to a main surface 5. Furthermore, filling material 7 is charged into the grating 1 which is adjusted in height.

[69] Fig. 16 is a front sectional view showing installation of a grating 1 manufactured through a pressing process, according to a seventh embodiment of the present invention. Referring to Fig. 16, each support 4 is bent such that the height thereof is greater than the depth of a slot frame part 3 and, thereafter, the support 4 is bent several times at 90°, thus forming a multiply bent part 4a. Each of the opposite ends of

the slot frame parts 3 is in close contact with the related multiply bent part 4a, so that the slot frame parts 3 are supported on the multiply bent parts 4a. As such, the grating 1 of this embodiment has a structure such that the height thereof can be adjusted without a welding process for a separate subsidiary frame 50.

[70] Although the gratings for sewers have been explained in the preferred embodiment of the present invention, the present invention is not limited to this. The present invention can be applied to various kinds of gratings, such as a tree support grating, which is placed on the upper end of a tree protective unit, which is installed around a tree to protect it. Of course, these modifications fall within the bounds of the present invention.