Iron pallet, method of manufacturing the same, and intermediate support for the same

The present invention relates to an iron pallet which is essentially used to conveniently, quickly and correctly handle articles or products when producing, transporting and keeping the articles or products in an industrial field or in a distribution procedure, a method of manufacturing the same, and an intermediate support for the same.

So far, a pallet generally used for transporting and keeping products is manufactured by assembling timber having predetermined thickness or width in the shape of a lattice and driving fastening elements such as nails into the overlapped portions of the timber. The pallet manufactured in this way has a drawback in that it has a poor strength and a short lifetime. Specifically, when the pallet is used as a platform on which bricks, stones, etc. are stacked in the open air, the pallet is exposed to moisture or water. Therefore, moisture or water may soak into the timber to cause deformation of the timber, and the timber may be decomposed and gather mold, as a result of which an offensive odor can be produced and damage to the articles placed on the pallet can be caused. Further, when considering a situation that almost all of raw materials are imported, waste of foreign currency, unnecessary consumption of resources, environmental pollution may result. Accordingly, in order to cope with the problems related with the decomposition and poor strength as disadvantages of the timber, a pallet made of synthetic resin (plastic) has been utilized.

However, while the pallet made of synthetic resin is suitable for mass production, exhibits an excellent strength and has an extended lifetime when compared to the conventional wooden pallet, since the entire pallet is integrally formed by injection molding, the pallet has a substantial weight. Due to this fact, disadvantages are caused in that loading efficiency is degraded to serve as a cause for increasing a physical distribution cost, and it is difficult to recycle the pallet made of synthetic resin whereby environmental issues may be raised.

Recently, in order to solve these problems, a pallet made of iron has been disclosed in the art. Nevertheless, since the iron pallet has a number of parts, a manufacturing cost increases and the automated mass production of the iron pallet is difficult. Also, after the iron pallet is used for extended periods, since screws or bolts used for assembling the iron pallet may be easily loosened by vibration, inconvenience can be caused while using the iron pallet, and the lifetime of the iron pallet can be shortened. Under these circumstances, while another iron pallet which is integrally formed including leg parts has been suggested in the art, an excessive equipment cost is required, and various problems are caused to conduct a proper function as a pallet in relation with weight, manufacturing cost and in-use convenience in use.

As an invention solving these problems, the present applicant has filed several patent applications, in an example of which a reinforcing hole is defined in an upper plate and leg members are coupled to the lower part of the upper plate. Notwithstanding, an iron pallet which has improved in-use convenience and a simple construction is still required in view of economic efficiency. In particular, needs exist for an iron pallet which can maintain an excellent strength and can be easily assembled while being composed of an upper plate, a lower plate and an intermediate member as main component elements.

Meanwhile, the upper surface of an iron pallet which comes into contact with products placed on the pallet is likely to be abraded or broken due to exposure to corrosion and physical and chemical damages, and the products are apt to slip on the upper surface of the iron pallet. As methods for solving this problem, a pigment such as epoxy and paint is simply applied, or a galvanized iron sheet is used for forming the iron pallet. However, even in these methods, the problems related with the slip of the products and corrosion of the iron pallet are not thoroughly solved, and the galvanized iron sheet has a drawback in that it is expensive.

In the particular case of a pallet used for curing cement products, while a pallet made of stainless steel can be advantageously used, because the cost of the pallet made of stainless steel is expensive over six to ten times the cost of a hot-rolled iron sheet, the pallet made of stainless steel cannot be adequately used. In the case of the pallet made of the hot-rolled iron sheet which is relatively cheap, because it is used in a manner such that finished cement products are loaded on the pallet and the pallet is moved by a conveyor, a bogie or a forklift into a steam curing room to cure the cement products under a high temperature, the surface of the pallet made of the hot-rolled iron sheet is likely to be corroded. Particularly, the corner portions of the pallet are exposed to frequent contact with foreign objects, they are corroded to an increased degree.

Moreover, a conventional iron pallet comprises an upper plate, a lower plate and an intermediate plate. While these component elements are assembled with one another by means of screws, welding, riveting, etc., the assembling operations are proved labor and cost intensive, technical difficulties are accompanied with, defects are caused while using the pallet in situ after manufacture. That is to say, while the assembly using the screws provides a firm structure, the structure is likely to be adversely influenced by vibration, a labor cost is increased, and it is difficult to automatize the manufacturing procedure. In the case of assembling the pallet by welding, difficulties may be caused depending upon a working condition, and an initial equipment cost is excessively required when automatizing the manufacturing procedure. Even in the remaining method, satisfiable results cannot be obtained in terms of cost and quality.

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 an iron pallet which prevents slip of a product as occurred in the case of a conventional iron pallet, has excellent corrosion resistance when compared to the conventional iron pallet, and is coated on its side surface and upper and lower edges with a corrosion-resistant and abrasion-resistant material when being used for curing cement products, so that initial quality of the iron pallet can be maintained for extended periods and the iron pallet can be manufactured at a reasonable cost.

Another object of the present invention is to provide an iron pallet which can be easily assembled while maintaining the strength of a conventional iron pallet as it is.

A further object of the present invention is to provide an iron pallet which can be automatized in its manufacturing procedure to be quickly manufactured, has a light weight, can be conveniently assembled, and can be manufactured at a reasonable cost to accomplish competitiveness.

Yet another object of the present invention is to provide an iron pallet which is constructed in consideration of the fact that an intermediate support must have strength capable of standing the weight of a product placed on an upper plate and must be conveniently manufactured and that upper and lower plates must be quickly assembled with each other with sufficient strength at connection regions, and which has an intermediate support having a structure capable of standing the weight of a product placed on an upper plate and easily connecting upper and lower plates to each other with excellent strength.

The present invention is directed for an iron pallet (1) characterized in that a coating layer (5) is formed on an upper surface of the iron pallet (1) which will come into contact with a product to be placed on the iron pallet (1), by processing a solid material at a high temperature using one of plasma, arc and flame to produce fine particles (6) and by momentarily jetting the fine particles (6) to the upper surface of the iron pallet (1) such that fine particles (6) are formed on the upper surface of the iron pallet (1).

Also, since an iron pallet (7) for curing a cement product is used at a high temperature in a manner such that the produced cement product is loaded on the iron pallet (7) and the iron pallet (7) is moved into a steam curing room by a conveyor a bogie or a forklift to cure the cement product at the high temperature, the corner portions of the pallet (7) is likely to be severely corroded. In order to cope with this problem, the coating surface (8) of the iron patter (7) for curing a cement product is formed at the corner portions of the iron pallet (7) which are most likely to be corroded. The coating surface (8) is formed on the iron pallet (7) to extend over a distance of no greater than 50 mm when measured from respective edges of the iron pallet (7). The fine particles (6) are mainly formed from one selected from a group consisting of zinc, stainless steel, alloy of zinc and aluminum, and alloy of zinc and stainless steel. Alternatively, the fine particles (6) are formed from a mixture of stone, sand and iron powder, or various ceramic particles.

Further, the present invention is directed for a method for forming a coating surface (5, 8) on an iron pallet (1, 7), comprising the steps of forming a material such as metal, nonmetal and ceramic into wire or powder using one of plasma, arc and flame; melting and momentarily jetting the wire or fine particles (6) comprising the powder to a surface of the iron pallet (1, 7) using a thermal sprayer; and sealing the surface of the iron pallet (1, 7) to which the wire or fine particles are jetted, by applying liquid phase thermosetting resin such as epoxy resin, urethane resin and lacquer resin on the surface of the iron pallet (1, 7) using a sprayer, a brush or a roll.

Also, the present invention is directed for a method for forming a coating surface (5, 8) on an iron pallet (1, 7), comprising the steps of forming a material such as metal, nonmetal and ceramic into wire or powder using one of plasma, arc and flame; melting and momentarily jetting the wire or fine particles (6) comprising the powder to a surface of an iron plate using a thermal sprayer; sealing the surface of the iron plate to which the wire or fine particles are jetted, by applying liquid phase thermosetting resin such as epoxy resin, urethane resin and lacquer resin on the surface of the iron plate using a sprayer, a brush or a roll; and cutting the iron plate having undergone the jetting and sealing steps and fabricating a pallet (1, 7).

The present invention is illustrated in FIGS. 1(a) and 1(b), and 2(a) and 2(b). FIGS. 1(a) and 2(a) illustrate the iron pallet (1) and the iron pallet (7) for curing a cement product, respectively, which are entirely coated on their surfaces, and FIGS. 1(b) and 2(b) illustrate the iron pallet (1) and the iron pallet (7) for curing a cement product, respectively, which are partially coated on their surfaces.

The present invention is directed for an iron pallet (21) comprising an upper plate (22), a lower plate (23) and an intermediate member (24), wherein the intermediate member (24) has a substantially U-shaped cross-section, concaved reinforcing portions (29) are formed on respective walls of the intermediate member (24), and locking projections (28) for locking the upper plate (22) and the lower plate (23) are formed on upper and lower ends of the intermediate member (24) on which the concaved reinforcing portions (29) are not formed. The present invention is further directed for the iron pallet (21) wherein each locking projection (28) is divided into two parts which are bent in opposite directions.