1 A TRACK SHOE ASSEMBLY FIELD OF THE INVENTION [0001] The present invention relates generally to a track vehicle (crawler-type vehicle) but more particularly to a track shoe assembly for a track vehicle, heavy equipment such as bulldozers and the like where the parts subject to wear and tear thereof can easily be removed and replaced. BACKGROUND TO THE INVENTION [0002] Tracked vehicles (for example a continuous tracked tractor) such as bulldozers and the like have long been used in road constructions. This crawler type of vehicle is equipped with a substantial metal plate (known as a blade) used to push large quantities of soil, sand, rubble, or other such material during construction or conversion work and is typically equipped at the rear with a claw like device (known as a ripper) to: loosen densely compacted materials; assist with maneuvering; and even to be used in warfare scenarios. Various aspects of development of these vehicles have been attempted so as to improve their efficiency. [0003] Development of track shoes for these types of vehicles has also been attempted so as to improve mobility of the vehicle, reduce maintenance costs, etc. [0004] The track shoe consists of small parts, for example a shoe body, rubber pad, end connector, etc. According to an inventor's study, the service life of each of these parts is different. They are categorized into short-term, middle term and long-term service life. Parts with short-term service life are generally rubber parts such as the rubber pad. Parts with medium-term and long-term service life are metal parts such as the connector and metal shoe body. In the short-term category, the life cycle of the parts is extremely short. In order to 2 realize that the short-term life cycle of the rubber pad compares with the long term category, the life cycle of the metal shoe is not cost effective for production, rather it has to be replaced on the metal shoe body even if it is still in good condition because the rubber bushing is worn out. [0005] Generally, conventional track shoes are divided into two types. The first type is a whole-metal shoe body type which is widely used in the United States, Russia and European countries as shown in US 2,332,976 (Saurer et al.), US 3,357,750 (Reynold et al.), US 2,353,124 (Burgress) and US 4,262,972 (Falk). Their advantages are a replaceable rubber pad and long service life of the metal shoe body. The replaceable rubber pad provides long service life by replacing the rubber pad whenever the rubber wears out. However, there are many disadvantages such as high weight, shortened short-term service life of the rubber pad, less stability and more vibration during vehicle motion. Moreover, the whole-metal shoe body requires a grouser to hold the rubber pad. The grouser limits the life-span of the rubber pad because the height of the grouser is about half the thickness of the rubber pad so the rubber pad can be used at only half of its capacity. Further, its service life reduces to 50% according to the capacity of rubber. The rubber pad is consumed whenever it hits the grouser and is thus worn out. Moreover, the grouser always damages the road when the vehicle operates in an urban environment. In addition, the elongation of rubber is also limited by the grouser. One of the problems often encountered with the grouser is that, when the track laying vehicle operates at high speed and turns abruptly, the grouser will cut the rubber pad like a knife because of vehicle speed, load and the grouser's position. [0006] The second type is a rubber-block type track shoe as shown in US 4,765,694, US 4,765,695, US 4,840,438, US 4,871,216, US 5,069,510. The advantages are light weight, longer short-term service life of the rubber pad, more stability and less vibration during vehicle motion owing to absorption of vibration in the rubber block, as well as being economical in terms of production and fuel used. Moreover, rubber can be extended up to its full elongation and can be used up to its maximum capacity of life-span until it is thinned to a minimum 3 thickness of rubber at the shoe body without limitation to the grouser. However, its disadvantage is shortened service life of long-term service parts because the complete rubber block set has to be replaced. Even if one tried to replace only the rubber pad, this would be impossible due to the structure of metal parts. [0007] Another, similar, known type of track shoe has been used with light tanks such as the Scorpion tank of England. However, the major disadvantage of this type of track shoe is that the rubber pad is not replaceable. Once the rubber pad becomes worn or damaged, the entire track shoe needs to be replaced, resulting in higher maintenance costs. [0008] Therefore, there is the need for an improved track shoe assembly for tracked vehicles that enhances the mobility of the vehicle, increases the efficiency of the vehicle and makes it suitable for operation or maneuvering under various terrain types, offers high stability and vibrant absorption, provides longer service range and lifespan, easy and economical to maintain, and is cost effective between production and utilization. The ultimate goal is to increase the capability of the vehicle when it is operating in practice with cost effectiveness and reliability of maintenance. [0009] Due to the short life span of the rubber pads, manufacturers change these rubber pads to steel pads which are fixedly held on the track shoe body by bolts and the like. Steel pads make the life of the track shoe assembly stronger and longer. Furthermore, the bushings where connecting pins are inserted therethrough to connect one track shoe assembly to another shoe assembly are made to be removable and replaceable therefrom. This will save the track shoe body from being replaced when only the bushings had become defective. SUMMARY OF THE INVENTION [0010] It is desirable that the present invention provides a new and improved track shoe assembly that increases efficiency of the vehicle, improves mobility, 4 and is suitable for operation or maneuvering under wider terrain types, and easy and economical to maintain, using replaceable parts designed as short-term, medium-term and long-term life-span spare parts. [0011] The present invention desirably also provides a track shoe assembly having a track shoe body with a replaceable steel pad that provides strength when compared with a conventional track shoe body with rubber pads, or with one piece track shoe assembly with hardened steel pad. [0012] It is also desirable that the present invention provides a track shoe assembly having a plurality of opposed protruding connectors, each housing a replaceable bushing, thereby only the bushings are replaced whenever said bushing are already worn out instead of replacing the whole track shoe assembly. [0013] According to an aspect of the present invention, there is provided a track shoe assembly capable of being interconnected oppositely with a plurality of similar track shoe assemblies and being used in crawler-type vehicles, said track shoe assembly comprising: a track shoe body, a plurality of spaced apart protruding connectors extending the opposing sides of said track shoe body, and a drive lug pad welded on top of said track shoe body, wherein each of said protruding connectors being removably inserted with corresponding bushing such that said bushing can easily be removed and replaced when said bushings are worn-out. [0014] This invention advantageously provides a track shoe assembly that is very simple in construction and can be made using simple and ordinary equipment. [0015] These and other advantages will come to view and be understood upon a reading of the detailed description when taken in conjunction with the appended drawings.
5 [0016] Comprises/comprising and grammatical variations thereof when used in this specification are to be taken to specify the presence of stated features, integers, steps or components or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. BRIEF DESCRIPTION OF THE DRAWINGS [0017] Figure 1 is a perspective view of the present invention for a track shoe assembly; and [0018] Figure 2 is an exploded view of Figure 1. DESCRIPTION OF PREFERRED EMBODIMENT [0019] Referring now to the several views of the drawing in detail, wherein like reference numerals designate same parts throughout, there is shown a track shoe assembly generally designated as reference numeral 10. [0020] Said track shoe assembly 10 is capable of being interconnected oppositely with a plurality of similar track shoe assemblies and being used in crawler-type vehicles, armored vehicle, tanks, bulldozers and the like. Said track shoe assembly 10 comprises a generally rectangular track shoe body 11, and a drive lug pad 12 disposed on top of said track shoe body 11. [0021] Said track shoe body 11 as shown in Figure 2 is made of high tensile strength steel material and has a hollow portion 18 to reduce the weight therefore. Said track shoe body is further provided with a plurality of spaced apart protruding connectors 13 at the opposing sides of said track shoe body 11. Each of said protruding connectors 13 are provided with a bore 14 through which a removably inserted corresponding cylindrical bushing 14a is held. These protruding connectors 13 at the opposing sides of each track shoe body 11 are adapted to 6 be engaged with the protruding connectors of the adjacent track shoe body (not shown) by means of connector pins (not shown) inserted through the corresponding bushings 14a of said protruding connectors 13. [0022] The drive lug pad 12 is defined by a generally rectangular steel body 12a with higher hardness to be wear resistant, said steel body 12a having a rectangular protruding spoke 15 centrally thereof, and a pair of opposing slots 16 thereof. Said drive lug pad 12 is mounted on top of said rectangular track shoe body 11 and is fixed thereto by welding the peripheral side ends 17 thereof. The said drive lug pad 12 is further welded to said track shoe body 11 along the pair of slots 16. This will provide more strength to said track shoe assembly 10. [0023] It can be seen therefore that when the drive lug pad 12 is already worn out, it can easily be removed by unwelding the welded peripheral side end portion thereof and replace it with a new one by welding the peripheral side end portion anew. [0024] In the same manner, worn-out and defective bushings 14a can also be easily pulled out from the protruding connectors 13 and be replaced with new hardened and wear-resistant bushings 14a.