WO2004035332A1

WO2004035332A1 - Foldable snow chain for car tires

Info

Publication number: WO2004035332A1
Application number: PCT/KR2003/000222
Authority: WO
Inventors: Kyu-Han Park
Original assignee: Kyu-Han Park
Priority date: 2002-10-21
Filing date: 2003-01-30
Publication date: 2004-04-29
Also published as: AU2003206216A1

Abstract

The object of this invention is to provide a foldable snow chain for car tires. The chain has snow pads (60) that pass across the tread of a tire at regular intervals when the chain fully expands and is worn around the tire. A pad connector (21) is connected to each end of each snow pad (60), with a rim connector (22) coupled to the pad connector (21) by a ring-shaped coupler (23) to extend in a radial direction of the tire. At each side of the chain, rim pieces (11, 12) are hinged to the rim connector (22) of the snow pads (60) and are, at the same time, coupled to each other to form a support rim. The rim pieces (11, 12) are biased by springs (26) at junctions thereof not having the rim connectors (22). The chain is thus easily folded when not in use.

Description

FOLDABLE SNOW CHAIN FOR CAR TIRES

Technical Field

The present invention relates, in general, to a antiskid snow chain which is fixed around a tire of a motor vehicle when roads are frozen or snow piles up in the wintertime, to prevent degradation of braking efficiency, and, more particularly, to a foldable snow chain for a motor vehicle in which both ends of respective snow pads are connected by means of hinge pins with outer and inner rigid rim pieces capable of being folded, and each support rim formed by the outer and inner rim pieces alternately arranged includes a ratchet-type locking mechanism so that attachment and detachment of the snow chain to and from a tire of a motor vehicle can be performed in a quick, precise and easy manner and the outer and inner rim pieces can be brought into close contact with the tire so as to ensure functional stability of the snow chain.

Background Art

As well known to those skilled in the art, a snow chain fixed around a vehicle tire includes a plurality of snow pads each formed with antiskid protuberances or a plurality of wire chains, connecting sections for connecting both ends of respective snow pads with each other, inner wires for supporting the snow pads, inner and outer coupling sections each for coupling both ends of a cable, and springs or hook elements such as rubber ropes for combining cables to each other.

However, the conventional snow chain suffers from defects in that, since the connecting sections and the inner wires are configured to be hooked, it is difficult to adjust a wire length of the snow chain in conformity with a size and an air pressure of a vehicle tire, and a substantial amount of pulling force are needed to handle the separate hook elements. Also, because the snow chain is not brought into close contact with the tire, while the vehicle travels on the road, the snow chain may be unintentionally released from the tire, whereby functional reliability of the snow chain may be deteriorated and damage to the vehicle body may be caused. Further, when fixing the snow chain around the vehicle tire, since it is necessary to insert the hands between the tire and the snow chain and pull and hook both ends of the inner wire, clothes of a driver may be stained with soil or dirt existing on the tire, and a substantial degree of force and skill are required by the driver. When unfixing the snow chain from the vehicle tire, after unhooking the hook elements by the driver's own effort, the driver must again insert his hands between the tire and the snow chain to forcibly pull and disassemble both ends of the chains, whereby the same degree of force and skill are required as in the case of fixing the snow chain.

Moreover, when removing and receiving the snow chain in a casing to be kept in a trunk or a separate place, as the snow chain is resistant to folding due to elasticity of the steel wire, a storage space cannot but be increased.

Disclosure of the Invention

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 foldable snow chain for a motor vehicle which is configured to be brought into full close contact with a tire to thereby be functionally stabilized, to be quickly attached to and detached from the tire, and to be folded after detachment from the tire to thereby be minimized in its volume, be easily received in a case and occupy a minimum space in a trunk. In order to accomplish the above object, the present invention provides a snow chain for a motor vehicle, having a plurality of snow pads fixed around a circumferential outer surface of a tire with a predetermined separation angle, wherein a pad connector is connected to each end of each snow pad, with a rim connector coupled to the pad connector by a quadrangular ring-shaped coupler to extend in a radial direction of the tire; wherein, at each side of the snow chain, outer and inner rim pieces are coupled to the rim connectors by hinge means, the outer and inner rim pieces being alternately arranged and coupled to each other along a circumferential direction to form a support rim and being defined, adjacent to junctions thereof not having the rim connectors and on lower edges thereof, with spring grooves, respectively, to be biased by a first coiled torsion spring both ends of which are received in the spring grooves; wherein an inside locking box and a short ratcheted lever are respectively provided to both free ends of an inside combination of outer and inner rim pieces to complete an inside support rim when they are locked with each other, the inside locking box being fastened by screw means to the inner rim piece positioned at one free end of the inside combination and having a first lever insertion opening, a first roller, a first pawl and a rope insertion slot, the short ratcheted lever being coupled at one end thereof by a hinge shaft to an intervening rim piece which in turn is coupled to a connection rim piece and formed at the other end thereof with a first hook, in a manner such that the short ratcheted lever can be inserted through the first lever insertion opening; and wherein a mounting plate defined at upper and lower ends thereof with bolt holes is anchored by screw means to the inner rim piece positioned at one free end of an outside combination of outer and inner rim pieces, an outside locking box and a long ratcheted lever having a second roller are respectively provided to both free ends of the outside combination to complete an outside support rim when they are locked with each other, the outside locking box being fastened by a bolt and a nut to the mounting plate and having a second lever insertion opening, a second hook, a first release handle and a second pawl, the long ratcheted lever being coupled at one end thereof to the inner rim piece positioned at the other free end of the outside combination in a manner such that the long ratcheted lever can be inserted through the second lever insertion opening. By the feature of the present invention, only by changing a quadrangular ring-shaped coupler with others having a variety of lengths, the foldable snow chain according to the present invention can be widely applied irrespective of sizes of vehicle tires, such as circumference and width, whereby economic efficiency is improved. Also, it is possible to quickly and precisely fix the snow chain around the vehicle tire through simple manipulation while not causing clothes of a driver to be stained with soil or dirt existing on the tire. Further, since the snow chain occupies a reduced volume upon being folded, space utilization efficiency can be improved.

Brief Description of the Drawings

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a perspective view illustrating an assembled status of a foldable snow chain for a motor vehicle in accordance with an embodiment of the present invention;

Fig. 2 is a partially-enlarged perspective view illustrating a structure for connecting both ends of a snow pad with outer and inner rim pieces in the foldable snow chain according to the present invention;

Figs. 3a and 3b are partial front views respectively illustrating unfolded and folded statuses of a support rim formed by the outer and inner rim pieces alternately arranged;

Fig. 4 is a partially-enlarged exploded perspective view illustrating a structure of an inside locking mechanism in the foldable snow chain according to the present invention; Fig. 5 is an exploded perspective view illustrating a structure of an outside locking mechanism in the foldable snow chain according to the present invention;

Figs. 6a and 6b are schematic front views respectively illustrating operational statuses of the outside locking mechanism shown in FIG. 5;

Fig. 7a is a partially enlarged perspective view illustrating a locking rod;

Fig. 7b is a partially enlarged bottom view illustrating a state wherein a looped wire rope of the locking rod is hung on a hook formed at a free end of a ratcheted lever; and

Figs. 8a through 8e are views explaining a procedure for fixing the snow chain according to the present invention around a vehicle tire.

Best Mode for Carrying Out the Invention

Reference should now be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components.

A better understanding of the present invention may be obtained through the following example which is set forth to illustrate, but is not to be construed as the limit of the present invention. Fig. 1 is a perspective view illustrating an assembled status of a foldable snow chain for a motor vehicle in accordance with an embodiment of the present invention. The foldable snow chain according to the present invention is used in such a way that it is fixed around a vehicle tire. The foldable snow chain includes a plurality of snow pads 60. A pad connector 21, a quadrangular ring- shaped coupler 23 and a rim connector 22 are sequentially coupled to each of left and right ends of each snow pad 60 in a radial direction. At each side of the snow chain, a plurality of outer and inner rim pieces 11 and 12 each made of a rigid material are coupled to the rim connectors 22 by hinge means 25. The outer and inner rim pieces 11 and 12 are alternately arranged and coupled to each other along a circumferential direction to form a foldable support rim. An inside locking box 30 and a short ratcheted lever 312 are respectively provided to both free ends of an inside combination of outer and inner rim pieces 11 and 12 to complete an inside support rim when they are locked with each other. The inside locking box 30 and the short ratcheted lever 312 constitute an inside locking mechanism which can be locked and unlocked by ratchet-type operations. An outside locking box 40 and a long ratcheted lever 41 are respectively provided to both free ends of an outside combination of outer and inner rim pieces 11 and 12 to complete an outside support rim when they are locked with each other.

The outside locking box 40 and the long ratcheted lever 41 constitute an outside locking mechanism which can be locked and unlocked by ratchet-type operations. The short ratcheted lever 312 is rotatably coupled at one end thereof by a hinge shaft 313 to an intervening rim piece 31 which in turn is coupled to a connection rim piece 12'. The long ratcheted lever 41 is provided with a roller 422 to minimize friction loss when a rope hung on a hook and wound on the roller is pulled. A first release handle 402 is provided to unlock the outside locking box 40 and the long ratcheted lever 41 from each other. The hinge means 25 comprises a hinge bolt 251, washers 252 each interposed between two neighboring parts, and a nut 253 locked to a distal end of the hinge bolt 251 (see

FIG. 2).

Fig. 2 is a partially-enlarged perspective view illustrating a structure for connecting both ends of the snow pad 60 with the outer and inner rim pieces 11 and 12 in the foldable snow chain according to the present invention; and Figs. 3a and 3b are partial front views respectively illustrating unfolded and folded statuses of the support rim formed by the outer and inner rim pieces 11 and 12 alternately arranged. Each end of each snow pad 60 is formed with an ear portion 61 which is defined with a first rivet hole 62, and the pad connector 21 connected to the snow pad 60 is defined with an insertion cavity 213 and a second rivet hole 212 in a manner such that, after being inserted through the insertion cavity 213, the ear portion 61 can be riveted using a rivet 24 passing through the first and second rivet holes 62 and 212 and a washer 241.

The pad connector 21 is defined with an inward groove 211, and the rim connector 22 is defined with an outward groove 221. Free ends of the pad connector 21 and rim connector 22 which define the inward and outward grooves 211 and 221 are curved outward and inward, respectively, so that the pad connector 21 and rim connector 22 are connected with each other by the quadrangular ring-shaped coupler 23 in a radial direction. The outer and inner rim pieces 11 and 12 are connected to lower ends of the rim connectors 22 by the hinge means 25 so that the outer and inner rim pieces 11 and 12 are arranged along the circumferential direction. The quadrangular ring-shaped coupler 23 can be changed with another one depending upon a circumference and a width of a tire, whereby one snow chain can be applied to various kinds of motor vehicles. Due to the fact that the inward and outward grooves 211 and 221 have their entrances of a size which is less than a thickness of the quadrangular ring-shaped coupler 23 and the pad connector 21 and rim connector 22 respectively defining the inward and outward grooves 211 and 221 have a characteristic of a leaf spring material, the quadrangular ring-shaped coupler 23 can be introduced into the inward and outward grooves 211 and 221 while enlarging the entrances, as in the case of a snatch-type hook. Since the quadrangular ring-shaped coupler 23 is introduced into the inward and outward grooves 211 and 221 which are defined in opposite directions, even when severe impact force is applied to the tire, release of the quadrangular ring-shaped coupler 23 from the inward and outward grooves 211 and 221 is effectively prevented. The rim connector 22 is formed, at heightwise middle portions thereof, with a pair of projections 222 for preventing the outer and inner rim pieces 11 and 12 from being rotated upward.

Also, as described above, at each side of the snow chain, each pair of outer and inner rim pieces 11 and 12 are hinged at one ends thereof to the rim connector 22 in such a way as to be capable of being rotated downward. At this time, each pair of outer and inner rim pieces 11 and 12 are defined at the other ends thereof and on lower edges thereof with spring grooves 112 and 122, respectively, to be biased by a first coiled torsion spring 26, both ends of which are received in the spring grooves 112 and 122, in a direction of being rotated upward. Here, the other end of each inner rim piece 12, not having the rim connector 22, is formed adjacent to a lower edge thereof with a wing portion 121 for supporting an adjoining end of the outer rim piece 11, whereby downward rotation of the outer and inner rim pieces 11 and 12 is prevented.

Fig. 4 is a partially-enlarged exploded perspective view illustrating a structure of the inside locking mechanism used in the foldable snow chain according to the present invention, as roughly described with reference to Fig. 1. That is to say, Fig. 4 illustrates a construction in which the inside locking box 30 and the short ratcheted lever 312 respectively provided to both free ends of the inside combination of outer and inner rim pieces 11 and 12 are locked with each other.

In the snow chain according to the present invention, at one free end of the inside combination of outer and inner rim pieces 11 and 12, the inside locking box 30 is affixed to the rim connector 22 and the inner rim piece 12. The inside locking box 30 has arranged therein a first pawl 301. In a state wherein the first pawl 301 is raised upward, a countersunk head screw 351 passes through an inner wall of the inside locking box 30 so that a countersunk head of the screw 351 does not project out of a surface of the inner wall. The countersunk head screw 351 constitutes screw means 35 for fastening the inside locking box 30 to the inner rim piece 12. The inside locking box 30 has a first lever insertion opening 308, a first roller 304 and the first pawl 301. The inside locking box 30 further has a first support shaft 302, a second coiled torsion spring 303, a roller shaft 305, and a second release handle 307, which ensure a ratchet-type operation of the inside locking mechanism. An outer wall of the inside locking box 30 is defined adjacent to a lower end thereof with a rope insertion slot 306. The first pawl 301 is arranged in the inside locking box 30 so that it can be rotated about the first support shaft 302. The first pawl 301 is biased downward by elastic force of the second coiled torsion spring 303. As a consequence, in the case that the short ratcheted lever 312 is inserted into the inside locking box 30, the first pawl 301 is pushed upward by each tooth of the short ratcheted lever 312 in such a way as not to obstruct the insertion of the short ratcheted lever 312. However, in a direction where the short ratcheted lever 312 is removed out of the inside locking box 30, due to the fact that the first pawl 301 is held engaged with one of the teeth of the short ratcheted lever 312, unintentional removal of the short ratcheted lever 312 out of the inside locking box 30 is prevented. In this way, the ratchet- type operation is ensured. The screw means 35 comprises the countersunk head screw 351 which passes through the inner wall of the inside locking box 30 so that the countersunk head of the screw 351 does not project out of the surface of the inner wall. In a state wherein washers 352 are interposed between two neighboring parts, a nut 353 is locked to a distal end of the countersunk head screw 351. At this time, in order to prevent the inside locking box 30 from being rotated, a washer is not interposed between the countersunk head screw 351 and the inner wall of the inside locking box 30.

The short ratcheted lever 312 is formed at the other end thereof with a first hook 311, and is rotatably coupled at one end thereof by the hinge shaft 313 to the intervening rim piece 31 which in turn is coupled to the connection rim piece 12'. Therefore, the short ratcheted lever 312 is hingedly coupled to the rim connector 22 via the intervening rim piece 31 and the connection rim piece 12' so that it can be freely changed in its direction and inserted into the first lever insertion opening 308 to effect the ratchet-type operation. The connection rim piece 12' is connected at both ends thereof with the intervening rim piece 31 and the rim connector 22 by the hinge means 25. The first hook 311 is formed to be opened at a lower end thereof so that the rope is not released from the first hook 311 even when force is horizontally or downwardly applied to the rope. Fig. 5 is an exploded perspective view illustrating a structure of the outside locking mechanism in the foldable snow chain according to the present invention. The outside locking mechanism is constructed in a different way from the inside locking mechanism shown in FIG. 4. First describing the outside locking box 40, a mounting plate 404 defined at upper and lower ends thereof with bolt holes 406 is anchored by the screw means 35 to the inner rim piece 12 and the rim connector 22 positioned at one free end of the outside combination of outer and inner rim pieces 11 and 12. The outside locking box 40 and the long ratcheted lever 41 having a second roller 422 are respectively provided to both free ends of the outside combination to complete an outside support rim when they are locked with each other. The outside locking box 40 is fastened by a bolt 405 and a nut 407 to the mounting plate 404. The outside locking box 40 has a second lever insertion opening 408, a second hook 401 opened at a rear end thereof and a second pawl 403. A distal end of the outside locking box 40 extends toward the inner rim piece 12 to project as a free end. The long ratcheted lever 41 is coupled at one end thereof to the inner rim piece 12 positioned at the other free end of the outside combination in a manner such that the long ratcheted lever 41 can be inserted through the second lever insertion opening 408. The second roller 422 is provided on a surface of the long ratcheted lever 41. The second roller 422 is fitted around and supported by a long bolt 42, with a plurality of washers 421 and 423 interposed between two neighboring parts. At this time, a large-sized washer 423 is interposed between the second roller 422 and a nut 424 to prevent a rope from being unintentionally released from the second roller 422. Here, it is to be readily understood that, instead of the assembly including the second roller 422 of the long ratcheted lever 41, the long bolt 42 serving as a supported shaft of the second roller 422, the washers 421, the large-sized washer 423 and the nut 424, the same hook as the second hook 401 can be installed at the same position.

The long ratcheted lever 41 is connected with the inner rim piece 12 via the hinge means 25 and the first coiled torsion spring 26 so that it can be inserted into the second lever insertion opening 408.

The inside locking box 30 and the short ratcheted lever 312 which constitute the inside locking mechanism can be changed in their right and left positions as occasion demands. Similarly, the outside locking box 40 and the long ratcheted lever 41 which constitute the outside locking mechanism can be changed in their right and left positions as occasion demands. The inside locking mechanism or the outside locking mechanism can be commonly employed for the inside and outside support rims, and the inside locking mechanism and the outside locking mechanism can be changed in their inside and outside positions as occasion demands. Figs. 6a and 6b are schematic front views respectively illustrating operational statuses of the outside locking mechanism shown in FIG. 5, which adopts the ratchet-type operation. The outside locking box 40 is constructed in a manner such that, while the long ratcheted lever 41 having a plurality of ratchet teeth is inserted through the second lever insertion opening 408, the second pawl 403 for engagement with one of the ratchet teeth is biased downward by elastic force of a third coiled torsion spring 4032 while being supported by a support shaft 4031. The second pawl 403 functions to prevent unintentional removal of the long ratcheted lever 41 out of the outside locking box 40. The first release handle 402 provided on an outer surface of the outside locking box 40 is integrated with a cam-type operating rod 4022 via a second support shaft 4021.

Therefore, if the first release handle 402 is rotated, as the operating rod 4022 is rotated upward, the second pawl 403 is raised upward to be disengaged from the one of the ratchet teeth of the long ratcheted lever 41.

Fig. 7a is a partially enlarged perspective view illustrating a locking rod. A locking rod 50 for used locking the inside locking box 30 and the short ratcheted lever 312 with each other and the outside locking box 40 and the long ratcheted lever 41 with each other has a plurality of articulated segments 52 which are hingedly connected one with another by connection segments 53. One end of the locking rod 50 has a looped wire rope 51, and the other end of the locking rod 50 has a knob 54.

Fig. 7b is a partially enlarged bottom view illustrating a state wherein the looped wire rope 51 of the locking rod 50 is hung on the first hook 311 formed at the free end of the short ratcheted lever 312. Sequentially describing a locking procedure of the locking rod, after placing on the circumferential outer surface of the vehicle tire the short ratcheted lever 312 which is rotatably coupled by the vertical hinge 313 to the intervening rim piece 31 which in turn is coupled by the hinge means 25 to the connection rim piece 12', the looped rope 51 of the locking rod 50 is manually hung on the first hook 311, and is rotated toward the inside locking box 30. Then, by grasping the knob 54 and gradually pulling the locking rod 50 toward the right, the looped rope 51 approaches the inside locking box 30 and is introduced into the rope insertion slot 306 defined adjacent to the lower end of the outer wall of the inside locking box 30. Thereafter, when the short ratcheted lever 312 is inserted into the first lever insertion opening 308 of the inside locking box 30, by forcibly pulling the rope 51 wound on the first roller 304, the short ratcheted lever 312 is locked into the inside locking box 30.

Industrial Applicability

Hereafter, a procedure for fixing the snow chain according to the present invention around the vehicle tire will be described in detail with reference to Figs. 8a through 8e. First, as shown in Fig. 8 a, the foldable snow chain is placed on the vehicle tire, the short ratcheted lever 312 and the snow pad 60 positioned at one end of the snow chain are grasped together by the left hand, and the snow pad 60 positioned at the other end of the snow chain is grasped by the right hand. Then, by pulling downward both of the snow pads 60 on the circumferential outer surface of the tire, the outer and inner rim pieces 11 and 12 are fully deployed to surround the entire tire as shown in Fig. 8b. At this time, due to the presence of the projections 222 of the rim connectors 22 and the wing portions 121 of the inner rim pieces 12, the snow chain is supported on the tire while defining substantially a semi-circular sectional shape. Then, as shown in Fig. 8c, after bending the locking rod 50, with the knob 54 grasped by the right hand, the looped rope 51 is inserted toward the inside. Then, by hanging the looped rope 51 on the first hook 311 and gradually pulling the knob 54, the short ratcheted lever 312 is rotated about the hinge shaft 313 toward the inside. At this time, by grasping and stretching out a portion of the snow chain which is positioned adjacent to the inside locking box 30, the inside locking box 30 can be viewed from the outside. Therefore, by properly manipulating the knob 54, the rope 51 can be introduced into the rope insertion slot 306 (see Figs. 7b and 8d).

Thereupon, as shown in Fig. 8d illustrating the inside of the vehicle tire, by pulling the knob 54, the rope 51 is smoothly pulled on the first roller 304 which is rotated about the roller shaft 305, and the short ratcheted lever 312 is guided into the first lever insertion opening 308 of the inside locking box 30. At this time, the knob 54 is forcibly pulled, and the first pawl 301 is engaged with one of the ratchet teeth of the short ratcheted lever 312 to effect the ratchet-type operation, whereby unintentional removal of the short ratcheted lever 312 is prevented. In this case, while it can be envisaged that the short ratcheted lever 312 is not completely tightened, as the long ratcheted lever 41 is tightly locked into the outside locking box 40, the snow chain can be brought into close contact with the tire by tightening force of the entire snow chain, whereby functional reliability of the snow chain under the running condition of the vehicle is ensured.

Next, after removing the rope 51 from the first hook 311, in a state wherein an end of the long ratcheted lever 41 is slightly inserted into the second lever insertion opening 408 as shown in Fig. 8e, the rope 51 of the locking rod 50 is hung on the second hook 401 and wound on the roller 422. Then, by pulling rightward the knob 54 of the locking rod 50, a U-shaped contour of the rope 51 is defined. Then, by forcibly pulling the knob 54, the long ratcheted lever 41 is inserted into the outside locking box 40 to be completely tightened, whereby the ratchet-type operation is effected. In this way, the snow chain according to the present invention is brought into tight contact with the vehicle tire. Thereafter, by removing the rope 51 of the locking rod 50, the entire snow chain fixing procedure is finished.

The snow chain can be detached from the tire by performing necessary disassembling work based on the above-described procedure. First, in order to disassemble the outside locking box 40, the first release handle 402 is rotated, and then the second pawl 403 is disengaged from the tooth of the long ratcheted lever 41, whereby the long ratcheted lever 41 can be removed from the outside locking box 40. In the case that the second pawl 403 is engaged with the tooth of the long ratcheted lever 41 to the extent that it cannot be easily disengaged from the tooth, by rotating the first release handle 402 while pulling the locking rod 50 as in the case of performing the snow chain fixing procedure, the long ratcheted lever 41 can be easily disengaged from the tooth.

Then, by raising the second release handle 307 provided to the inside locking box 30, as the first pawl 301 is rotated about the support shaft 302 as in the case of the outside locking box 40, the first pawl 301 is disengaged from the tooth of the short ratcheted lever 312, whereby the short ratcheted lever 41 can be removed from the inside locking box 40.

Thereupon, while grasping and pulling upward left and right portions of the snow chain using both hands, the outer and inner rim pieces 11 and 12 are folded by restoring force of the first coiled torsion spring 26. After detaching the snow chain from the vehicle tire, by collapsing the outer and inner rim pieces 11 and 12 on the quadrangular ring-shaped coupler 23, a volume occupied by the snow chain can be significantly reduced. Then, the snow chain according to the present invention can be received in a separate case to be placed in a trunk compartment.

Claims

1. A snow chain for a motor vehicle, having a plurality of snow pads fixed around a circumferential outer surface of a tire with a predetermined separation angle, wherein a pad connector is connected to each end of each snow pad, with a rim connector coupled to the pad connector by a quadrangular ring-shaped coupler to extend in a radial direction of the tire; wherein, at each side of the snow chain, outer and inner rim pieces are coupled to the rim connectors by hinge means, the outer and inner rim pieces being alternately arranged and coupled to each other along a circumferential direction to form a support rim and being defined, adjacent to junctions thereof not having the rim connectors and on lower edges thereof, with spring grooves, respectively, to be biased by a first coiled torsion spring both ends of which are received in the spring grooves; wherein an inside locking box and a short ratcheted lever are respectively provided to both free ends of an inside combination of outer and inner rim pieces to complete an inside support rim when they are locked with each other, the inside locking box being fastened by screw means to the inner rim piece positioned at one free end of the inside combination and having a first lever insertion opening, a first roller, a first pawl and a rope insertion slot, the short ratcheted lever being coupled at one end thereof by a hinge shaft to an intervening rim piece which in turn is coupled to a connection rim piece and formed at the other end thereof with a first hook, in a manner such that the short ratcheted lever can be inserted through the first lever insertion opening; and wherein a mounting plate defined at upper and lower ends thereof with bolt holes is anchored by screw means to the inner rim piece positioned at one free end of an outside combination of outer and inner rim pieces, an outside locking box and a long ratcheted lever having a second roller are respectively provided to both free ends of the outside combination to complete an outside support rim when they are locked with each other, the outside locking box being fastened by a bolt and a nut to the mounting plate and having a second lever insertion opening, a second hook, a first release handle and a second pawl, the long ratcheted lever being coupled at one end thereof to the inner rim piece positioned at the other free end of the outside combination in a manner such that the long ratcheted lever can be inserted through the second lever insertion opening.

2. The snow chain according to claim 1, wherein each end of each snow pad is formed with an ear portion which is defined with a first rivet hole, and the pad connector is defined with an insertion cavity and a second rivet hole in a manner such that, after being inserted through the insertion cavity, the ear portion can be riveted using a rivet passing through the first and second rivet holes and a washer.

3. The snow chain according to claim 1 or 2, wherein the pad connector is defined with an inward groove, the rim connector is defined with an outward groove, free ends of the pad connector and rim connector which define the inward and outward grooves are curved outward and inward, respectively, to ensure that the quadrangular ring-shaped coupler can be easily introduced into the inward and outward grooves, and the quadrangular ring-shaped coupler can be changed with another one depending upon a circumference and a width of a tire.

4. The snow chain according to claim 1, wherein the rim connector is formed, at heightwise middle portions thereof, with a pair of projections, and one end of each inner rim piece, not having the rim connector, is formed adjacent to a lower edge thereof with a wing portion for supporting an adjoining end of the outer rim piece.

5. The snow chain according to claim 1, wherein the hinge means comprises a hinge bolt, washers each interposed between two neighboring parts, and a nut locked to a distal end of the hinge bolt.

6. The snow chain according to claim 1, wherein the screw means comprises a countersunk head screw passing through a wall of the inside locking box, washers each interposed between two neighboring parts, and a nut locked to a distal end of the countersunk head screw.

7. The snow chain according to claim 1, wherein the inside locking box constituting an inside locking mechanism further has a first support shaft, a second coiled torsion spring, a roller shaft, and a second release handle, which ensure a ratchet-type operation of the inside locking mechanism.

8. The snow chain according to claim 1, wherein the outside locking box constituting an outside locking mechanism further has a third coiled torsion spring, a second support shaft, a cam-type operating rod, and a handle shaft, which ensure a ratchet-type operation of the outside locking mechanism.

9. The snow chain according to claim 1, wherein the inside locking box and the short ratcheted lever which constitute the inside locking mechanism can be changed in their right and left positions as occasion demands, and the outside locking box and the long ratcheted lever which constitute the outside locking mechanism can be changed in their right and left positions as occasion demands.

10. The snow chain according to claim 1 or 9, wherein the inside locking mechanism or the outside locking mechanism can be commonly employed for the inside and outside support rims, and the inside locking mechanism and the outside locking mechanism can be changed in their inside and outside positions as occasion demands.

11. The snow chain according to claim 1, wherein a long bolt of greater than a predetermined length is fitted through the second roller of the long ratcheted lever to be locked with a nut, and each of washers is interposed between two neighboring parts, with a large-sized washer interposed between the second roller and the nut.

12. The snow chain according to claim 1 or 11, wherein the second roller, long bolt, washers, large-sized washer and nut of the long ratcheted lever can be replaced with the same hook as the second hook.

13. The snow chain according to claim 1, wherein a locking rod for locking the inside locking box and the short ratcheted lever with each other and the outside locking box and the long ratcheted lever with each other has a plurality of articulated segments which are hinged to connection segments, one end of the locking rod having a looped wire rope and the other end of the locking rod having a knob.