Background Art [2] The structure of a car tent, which is mounted on the roof of a car and of which in- stallation and packing up is made by using an electric power source of the car, is disclosed in Korean patent publication No. 2003-0011381. Such the conventional car tent is explained below in detail, referring to accompanied figures.

[3] Fig 1. is a perspective view showing the structure of a conventional car tent, Fig 2. is a perspective view enlarging'A'part of Fig 1, Fig 3. shows a conventional car tent when it is fully raised, Fig 4. shows a conventional car tent mounted on the roof of a car and Fig 5. is a sectional view of major parts when a conventional car tent is mounted on the roof of a car.

[4] A conventional car tent comprises a lower cover (10) which is combined with and separated from the roof of the car (l) ; a upper aDver (20) fastened with the lower cover (10) through fastening means (12) ; a tent cloth (30) sewed between the lower cover (10) and the upper cover (20); a key input means (78) for inputting instruction for automatic vertical movement of the upper cover (20); a vertical transporting means for vertically transporting the upper cover (20) automatically by the instruction from the key input means (78).

[5] In the above, the fastening means (12) consists of a connecting bar (12a) and a connecting arm (12b). The connecting bar (12a) is fixed at the upper over (20), and the connecting arm (12b) is pivotably installed at the lower aDver (l0). At least more than one fastening means (12) is installed at both longitudinal sides of the lower over (l0) and the upper cover (20).

[6] In addition, vertical transporting means comprises screw bars (22,24) fixed re- spectively at both longitudinal sides of the back of the lower cover (10) through fixing brackets (14, 16; 18,20). Sprockets (26,28 ; 30,32) are fitted into both ends of each screw bar (22,24). Idler gear (34) is fitted into one end of a screw bar (22). One end of the screw bar (22) passes through the lower aDver (l0) to protrude out, and a groove for insertion of lever (36) is formed at the protruded end of the screw bar (22).

[7] In addition, chains (38,40) are mounted on both lateral sides of the back of the lower aDver (l0), which are respectively meshed with sprockets (26,30) and sprockets (28,32). The chains (38,40) are installed laterally below the lower cover (l0), and fixing brackets (42,44), which prevents the chains from drooping or swinging, are installed at the center of lateral side where the chains are installed.

[8] In addition, cross bars (46,48 ; 50,52) are installed at both longitudinal sides of the lower aDver (l0) and the upper aDver (20). One end of the cross bars (46,48) is connected to one longitudinal side of the upper cover (20), hinged with hinge means (54,56). The other end of the cross bars moves along the screw bar (22) by the hinge-meshed means (62,64). By the movement of the other end, The two cross bars (46,48) are crossed with each other to move vertically and horizontally.

[9] And, one end of the cross bars (50,52) is connected to the other longitudinal side of the upper cover (20), hinged with hinge means (58,60). The other end of the cross bars moves along the screw bar (24) by the hinge-meshed means (66,68). By the movement of the other end, the two cross bars (50,52) are crossed with each other to move vertically and horizontally.

[10] Fixing brackets (70) are installed at the center of both longitudinal sides of the lower aDver (l0), and the screw bars (22,24) are installed, passing through the fixing brackets (70).

[11] One end of the hand-operated lever (72) is inserted into the insertion groove for lever (36). The hand-operated lever (72) inserted into the insertion groove for lever (36) is fixed by a pin (36a). The insertion groove for lever (36) can be made in a form which does not require the pin (36a).

[12] The drive gear (74) fitted into the axis of the motor (76) is meshed with the idler gear (34). The key input means (78) for instructing the clockwise and counterclockwise rotation of the motor (76) is installed at the outer surface of the lower aDver (l0). The key input means (78) is composed of an automatic ascending switch (78a) for in- struting the clockwise rotation of the motor (76) and an automatic descending switch (78b) for instructing the counterclockwise rotation of the motor (76).

[13] In the case that the user pushes down the automatic ascending switch (78a) or the automatic descending switch (78b), the motor (76) is operated to rotate the drive gear (74). In the case that the user rotates the screw bar (22) by using the hand-operated lever (72), the motor (76) becomes idle although the drive gear (74) on the axis of the motor is rotated by the idle gear (34).

[14] In addition, waterproof cloth (80) and mothproof net (82) are installed at the entrance of the tent cloth (30). The waterproof cloth (80) is installed at the outside of the mothproof net (82). The waterproof cloth (80) and the mothproof net (82) are raised or brought down respectively by the zipper (84) and (86).

[15] The waterproof cloth (80) can also act as a cloth for protection against wind. In addition, windows as ventilating openings can be formed in both lateral walls of the tent except the wall where the opening is located. The waterproof cloth (80) and the mothproof net (82) can be also installed at the above windows. The front of the upper cover (20) (that is, one of both longitudinal sides) is streamlined, and the rear thereof (that is, the other of both longitudinal sides) is angulated. A bicycle or other loads are carried on the upper cover (20). A guide bar (88) is installed along the edge of the upper cover (20) in order to carry loads safely.

[16] The protruded fastening means (90), on which the thread of screw is formed, is formed below the lower aDver (l0) in order to establish the car tent safely on frame (92) mounted on the roof of the car (l). Each fastening plate (94) having a hole is combined with or separated from the fastening means (90) by each nut (96).

[17] A couple of the fastening means (90) is installed at each corner below the lower cover (l0). A gap between one couple and another couple of the fastening means (90) is larger than the width of the frame (92).

[18] The fastening means (90), which is located below the lower cover (l0) of the car tent, is appropriately placed on the frame (92) of the roof (l) of the car in order to install the conventional car tent on the roof of the car (l). That is, the car tent is located above the frame to place the frame into the space between a couple of fastening means (90) installed at each corner on the back of the lower cover (l0).

[19] After that, a fastening plate (94) is inserted into the fastening means (90), and then a nut (96) is combined with the fastening means (90) by using a tool to install the car tent on the roof (l) of the car.

[20] In the case that the user wants to separate the car tent from the frame (92) on the roof (l) of the car, the user loosens the nut (96) combined with the fastening means (90) by using the tool and take off the fastening plate (94) to separate the car tent from the frame (92).

[21] The screw bars (22,24), the motor (76) and the accessory components thereof, which are installed at the side of the back of the lower aDver (l0), are protected by protecting means (98). In the top plane of the protecting means (98), a long hole (98a) is formed parallel with the longitudinal side of the lower cover (l0) to allow the cross bars (46,48 ; 50,52) to move.

[22] The back of the lower cover (l0) is composed of four (4) layers; a FRP layer (100) having a prescribed thickness is located at the bottom and a polyurethane layer is located thereon. A layer made of iron (104) is formed on the polyurethane layer (102) and a mattress is put thereon. In addition, the upper cover (20) is preferably made of FRP.

[23] The operation of the conventional car tent is explained below.

[24] The user drives to the camping place, mounting a car tent on the frame of the roof (1) of a car.

[25] Upon using the car tent, the user first releases the connection of the fastening means (12), which fastens between the lower cover (10) and the upper cover (20), and then raises the upper cover (20) vertically by using the hand-operated lever (72) or key input means (78).

[26] In the case of using the hand-operated lever (72), the user inserts the hand-operated lever (72) into the insertion groove for lever (36) formed at the end of the screw bar (22) (that is, protruded out of the lower cover (20) ), and then rotates the hand- operated lever (72) at firsthand in the ascending direction.

[27] At the initial stage, as illustrated in fig 1, each lower end of cross bars (46,48 ; 50, 52) is located respectively at both ends of the screw bars (22,24).

[28] By the rotation of the hand-operated lever (72), the screw bar (22) rotates in the same direction, and the sprockets (26,28) fitted into the both ends of the screw bar (22) also rotates in the same direction. Therefore, the chains (38,40) meshed with the sprockets (26,28) rotates in the same direction, the sprockets (30,32) meshed into both ends of the screw bar (24) at the opposite side also rotates in the same direction as that of the chains (38,40), and thus the screw bar (24) which the sprockets (30,32) is fitted into also rotates in the same direction.

[29] As described in the above, when the screw bars (22,24) rotates in the prescribed direction (that is ascending direction), the cross bars (46,48 ; 50,52), which are hinge- meshed with the screw bars (22,24), moves horizontally along the screw bars (22,24) to the center of the screw bars (22,24), as illustrated in fig 3.

[30] When the horizontal movement of the cross bars (46,48 ; 50,52) is completed, the upper aDver (20) is located above the lower cover at a distance therefrom, and the tent cloth (30) hidden between the lower aDver (10) and the upper aDver (20) is unfolded.

[31] In the case that the user rotates the screw bar (22) by using the hand-operated lever (92) as described in the above, the motor (76) becomes idle, although the drive gear (74) on the axis of the motor (76) is rotated by the idle gear (34).

[32] Upon installing the car tent in such a manner as described in the above, the user may come into the car tent through double or triple-folded ladder.

[33] Alternatively, the car tent can be installed on the ground of camping place, separated from the frame (92) on the roof (l) of the car.

[34] In the case of packing up the car tent installed by using the hand-operated lever (72), the user inserts the hand-operated lever (72) into the insertion groove for the lever (36), which is located at the one end of the screw bar (22) (that is, protruded out of the lower cover (10)), and then rotates the hand-operated lever (72) in the descending direction at firsthand.

[35] According to the above, the screw bar (22) rotates in the same direction (descending direction), and the sprockets (26,28) fitted into the both ends of the screw bar (22) also rotates in the same direction (descending direction). Therefore, the chains (38,40) meshed with the sprockets (26,28) rotates in the same direction (descending direction), the sprockets (30,32) meshed into both ends of the screw bar (24) at the opposite side also rotates in the same direction as the rotation of the chains (38,40), and thus the screw bar (24) which the sprockets (30,32) is fitted into also rotates in the same direction.

[36] As described in the above, when the screw bars (22,24) rotates in the prescribed direction (that is descending direction), the cross bars (46,48 ; 50,52), which are hinge- meshed with the screw bars (22,24), moves horizontally along the screw bars (22,24) to both ends of the screw bars (22,24), as illustrated in fig 1.

[37] When the cross bars (46,48 ; 50,52) are fully moved to both ends of the screw bars (22,24), the upper aDver (20) comes in contact with the lower cover (10), as il- lustrated in Fig 1, and thus the tent cloth (30) is hidden between the lower over (10) and the upper cover (20).

[38] After that, the lower cover (10) and the upper cover (20) are fastened with each other by the fastening means (12).

[39] As described in the above, in the case that the user rotates the screw bar (22) by using the hand-operated lever (92) as described in the above, the motor (76) becomes idle, although the drive gear (74) on the axis of the motor (76) is rotated by the idle gear (34).

[40] Next, it is explained below how the user raise the upper cover (20) vertically by using the key input means (78). At the initial stage, each lower end of the cross bars (46, 48; 50,52) is located at both ends of the screw bars (22,24), as illustrated in Fig 1.

[41] First, the user release the connection of the fastening means (12), which fastens between the lower cover (10) and the upper cover (20), and presses the automatic ascending switch (78a) on the key input means (78). According to the above, the motor (76) is operated to rotate the drive gear (74) on the axis in the prescribed direction, and thus the idle gear (74), which is fitted into the screw bar (22) and meshed with the drive gear (74), is rotated by the rotation of the drive gear (74) in the direction opposite to the rotation of the drive gear (74).

[42] According to the rotation of the idle gear (34), the screw bar (22) rotates in the same direction (ascending direction), and the sprockets (26,28) fitted into the both ends of the screw bar (22) also rotates in the same direction (ascending direction). Therefore, the chains (38,40) meshed with the sprockets (26,28) rotates in the same direction (ascending direction), the sprockets (30,32) meshed into both ends of the screw bar (24) at the opposite side also rotates in the same direction as the rotation of the chains (38,40), and thus the screw bar (24) which the sprockets (30,32) is fitted into also rotates in the same direction (ascending direction).

[43] As described in the above, when the screw bars (22,24) rotates in the prescribed direction (that is ascending direction), the cross bars (46,48 ; 50,52), which are hinge- meshed with the screw bars (22,24), moves horizontally along the screw bars (22,24) to the center of the screw bars (22,24), as illustrated in fig 3.

[44] When the cross bars (46,48 ; 50,52) are fully moved to the center of the screw bars (22,24), the upper aDver (20) is located above the lower cover at a distance therefrom, and the tent cloth (30) hidden between the lower aDver (l0) and the upper cover (20) is unfolded.

[45] Upon installing the car tent in such a manner as described in the above, the user may come into the car tent through double or triple-folded ladder.

[46] Alternatively, the car tent can be installed on the ground of camping place, separated from the frame (92) on the roof (l) of the car.

[47] In the case of packing up the car tent installed by using the key input means (78), the user presses the automatic descending switch (78b) on the key input means (78).

[48] According to the above, the motor (76) is operated to rotate the drive gear (74) on the axis in the direction opposite to the above-mentioned ascending case, and the idle gear (34) is rotated by the rotation of the drive gear (74) in the direction opposite to the rotation of the drive gear.

[49] By the rotation of the idle gear (34), the screw bar (22) rotates in the same direction (descending direction) as the rotation of the idle gear (34), and the sprockets (26,28) fitted into the both ends of the screw bar (22) also rotates in the same direction (descending direction). Therefore, the chains (38,40) meshed with the sprockets (26,28) rotates in the same direction (descending direction), the sprockets (30, 32) meshed into both ends of the screw bar (24) at the opposite side also rotates in the same direction as the rotation of the chains (38,40), and thus the screw bar (24) which the sprockets (30,32) is fitted into also rotates in the same direction (descending direction).

[50] As described in the above, when the screw bars (22,24) rotates in the prescribed direction (that is descending direction), the cross bars (46,48 ; 50,52), which are hinge- meshed with the screw bars (22,24), moves horizontally along the screw bars (22,24) to both ends of the screw bars (22,24), as illustrated in fig 1.

[51] When the cross bars (46,48 ; 50,52) are fully moved to both ends of the screw bars (22,24), the upper aDver (20) comes in contact with the lower cover (l0), as il- lustrated in Fig 1, and thus the tent cloth (30) is hidden between the lower over (l0) and the upper cover (20). After that, the lower aDver (l0) and the upper cover (20) are fastened with each other by the fastening means (12).

[52] However, the conventional car tent described in the above, lacks supporting means for the upper portion of the tent, which causes the problem that the structure of supporting the upper portion of the car tent is weak.

[53] In addition, because the car tent is carried on the roof of the car, the maximum length of the cross bar is the width of the roof of the car. Therefore, the maximum height of the car tent is the width of the roof of the car. Due to such the limitation of the height, the conventional car tent could not provide sufficient space for the user's action therein.

[54] In addition, upon installing or packing up the conventional car tent, the user should confirm the operation of the car tent with his eyes, in order to stop the installation or packing up of the car tent. Therefore, in the case that the user omits stopping the operation of the car tent after the installation or packing up has been completed, the motor is subject to be broken down due to the overload.

[55] In addition, the lower cover of the conventional car tent is composed of a FRP layer which produces glass fiber harmful to the user's health.

Disclosure of Invention Technical Problem [56] Considering the above disadvantages of the conventional car tent, the object of the present invention is to provide a car tent having stabilized connecting structure.

[57] Another object of the present invention is to provide a car tent having larger inner space than that of conventional ones.

[58] Still, another object of the present invention is to provide a car tent the operation of which can be stopped automatically without the user's additional instruction, after the installation or packing up thereof has been completed.

[59] In addition, another object of the present invention is to provide the lower cover of a car tent having no harm to the user's health.

Technical Solution [60] In order to achieve the above objects of the present invention, the present invention provides a car tent comprising a lower cover consisting of the floor of a tent, a motor, screw bars which rotate by the rotation of the motor, transporting parts which move along each screw bar by the rotation of the screw bars, cross bars of which lower ends are pivotably connected to the transporting parts and a upper cover consisting of the roof of the tent and transported upward and downward by the movement of the cross bars, characterized by further comprising : [61] upper supporting bars fixed by the attachment to a longitudinal part of the back of the upper cover ; [62] extension bars of which one end is pivotably connected to a connecting part located at a distance from the center of each upper supporting bar and of which the other end is pivotably connected to a upper end of each cross bar; and [63] several elastic fixing materials which connect respectively between the upper end of each cross bar and the longitudinal side of each upper supporting bar.

Advantageous Effects [64] The car tent of the present invention comprises the upper supporting bars for fully supporting the upper cover. In addition, the elastic fixing materials of the present invention fix more firmly between the cross bars and the upper supporting bars or between the lower cover and the upper cover. Moreover, the fixing springs of the present invention make the connecting parts much firmer. Such the constitutions improve the stability of the structure of the car tent.

[65] In addition, the car tent of the present invention further comprises the extension bars which are extended above the cross bars when the cross bars are unfolded. The extension bars increase the height of the car tent, and finally increase the inner space of the car tent.

[66] In addition, the car tent of the present invention comprises several stoppers. The stoppers determine when installation or packing up of the car tent should be stopped by sensing the location of the transporting parts which are connected to the cross bars and move along the screw bars. Therefore, installation or packing up of the car tent can be stopped automatically without the user's additional instruction after the installation or packing up thereof has been completed, which serves the user's convenience.

Description of Drawings [67] Fig 1. is a perspective view showing the structure of a conventional car tent.

[68] Fig 2. is a perspective view enlarging'A'part of Fig 1.

[69] Fig 3. shows a conventional car tent when it is fully raised.

[70] Fig 4. shows a conventional car tent mounted on the roof of a car.

[71] Fig 5. is a sectional view of major parts when a conventional car tent is mounted on the roof of a car.

[72] Fig 6. is a perspective view of the car tent of the present invention.

[73] Fig 7. is a perspective view of major parts which drive the car tent in Fig 6.

[74] Fig 8. shows the structure for extension and support of the car tent of the present invention.

[75] Fig 9. shows the structure of elastic fixing material of the present invention.

[76] <Explanation for symbols used in the figures> [77] 100: motor 110 : reduction gear [78] 120,130 : chain 140,150 : chain sprocket [79] 160,170 : screw bar 180,190 : supporting means [80] for screw bar [81] 210,220 : cross bar 230,240 : extension bar [82] 250,260 : upper supporting bar [83] 310-340 : transporting parts [84] 410-440 : elastic fixing material [85] 450 : vertical elastic fixing material [86] 500 : a first stopper 600: a second stopper [87] 700 : fixing spring Best Mode [88] The preferable example of the present invention is explained below in detail, referring to the accompanied figures.

[89] Fig 6. is the perspective view of the car tent according to the present invention.

[90] As illustrated in the figure, the car tent of the present invention comprises : [91] a motor (100) which employs the electric power source of the dgarjac installed in a car as a driving power source and which is controlled by a controller located in the car; [92] a reduction gear (l 10) increasing driving force by reducing turning force of the motor (100) ; [93] two chains (120, 130) transmitting the turning force of the reduction gear (l l0) ; [94] chain sprockets (140, 150) respectively connected to the chains (120, 130); [95] two screw bars (160, 170) in which the direction of the screw thread of one half from the center is different with that of the other half, of which one end is fixed by the chain sprockets (140, 150) and of which both ends is supported by screw supporting means (180, 190); [96] transporting parts (310,320) (330,340) moving to the center or to both ends of the screw bars (160, 170) along the screw bars (160, 170) by the rotation of the screw bars (160, 170); [97] cross bars (210) (220), of which one end is connected to the transporting part (310, 320) (330,340) and of which height is increased or decreased by their unfolding or folding according to the movement of the transporting parts (310,320) (330,340) ; [98] extension bars (230) (240), of which one end is connected to the other end of the cross bar (210) (220) and which are further unfolded above the cross bars (210) (220) when the cross bars (210) (220) are unfolded; [99] upper supporting bars (250) (260) for supporting the upper over (not illustrated), which are connected to the other end of the extension bars (230) (240); [100] fixing springs (700) which determine the unfolding extent of the extension bars (230) (240) according to the movement of the cross bars (210) (220), fixed at connecting parts between the extension bars (230) (240) and cross bars (210) (220) or between extension bars (230) (240) and the upper supporting bars (250) (260); [101] a first stopper which stops the rotation of the motor (100) upon recognizing that the packing up of the tent has been completed by sensing the location of the transporting parts; and [102] a second stopper which stops the rotation of the motor (100) upon recognizing that the installation of the tent has been completed by sensing the location of the transporting parts.

[103] Symbols 410-440 in the figure indicate the elastic fixing materials composed of elastic material such as rubber. They connects between both ends of the cross bars (210) (220) and those of the upper supporting bars (250) (260) to support or fix the upper supporting bars (250) (260) more firmly.

[104] In addition, symbol 450 indicates the vertical elastic fixing material composed of elastic material. It connects and fixes between the lower cover and the upper cover to make the structure of the car tent much firmer.

Mode for Invention [105] Hereinafter, one example of the car tent of the present invention is explained below in detail in the aspect of constitution, operation and effect thereof.

[106] First, according to the present invention, a car comprises the controller which drives the motor (100), although it is not illustrated in the accompanied figures.

[107] By using the controller, the user can install or pack up the car tent without getting out of the car.

[108] Such the constitution is practicable because the car tent of the present invention comprises a first and a second stopper (500) (600) to stop the operation of the car tent automatically.

[109] Figure 7 is the enlarged perspective view of the part for operating the car tent.

[110] Upon installing the car tent, the user manipulates the controller to drive the motor (lOO). The direction of the rotation of the motor (100) is predetermined by the shape of the screw thread formed at the screw bars (160, 170).

[111] The axis of rotation of the motor (100) is connected to the reduction gear (110). The reduction gear (110) reduces rapid velocity of the rotation of the axis to allow less rapid but more powerful rotatory power to be transmitted.

[112] And then, the rotatory power of the reduction gear (110) is transmitted through the chains (120, 130). The axis provided by the reduction gear (HO) has two chain sprockets, which have the same gear number and are connected to the same axis.

[113] Next, the rotatory power is transmitted to the screw bars (160, 170) through the chains (120, 130). Chain sprockets (140, 150) respectively connected to one end of the screw bars (160, 170) rotate in the same direction, which rotates the screw bars (160, 170).

[114] One half of the screw bars (160) (170) has different direction of the screw thread from the other half. That is, one half of the screw bars (160) (170), which is close to the motor (100), is a right-hand screw and the other half thereof, which is distant from the motor (100), is a left-hand screw.

[115] Therefore, according to the rotation of the screw bar (160), two transporting parts (310) (320) connected to one screw bar (160) move respectively in the different direction.

[116] The transporting parts (310) (320) is formed as a hexahedron having a hole which the screw bar (160) is inserted into. A screw groove and a screw thread corresponding to those of the screw bar (160) are formed in the hole.

[117] In addition, combining means is installed at one of the outer planes of the transporting parts (310,320), separated from the hole. Each lower ends of the cross bar (210) consisting of two bars the centers of which are hinged with each other is pivotably combined with each combining means of the transporting parts (310,320).

[118] The transporting parts (330,340) moving along the other screw bar (170) also have the same constitution as the above-described ones (310,320), and thus the lower ends of the cross bar (220) are connected to the transporting parts (330,340).

[119] As explained in the above, the transporting parts (310-340) move to each center of the screw bars (160) (170) by the rotation of the screw bars (160) (170). Accordingly, the cross bars (210) (220) are unfolded and the height thereof is increased.

[120] According as the cross bars (210) (220) are unfolded, the extension bars, of which one ends are pivotably connected to the upper ends of the cross bars (210) (220), are also unfolded.

[121] Because the other ends of the extension bars (230) (240) is pivotably connected to the prescribed position of the upper supporting bars (250) (260), when the cross bars (210) (230) are unfolded, the horizontal distance between both connecting parts, which are respectively located between the extension bars (230) (240) and the cross bars (210) (220) and between extension bars (230) (240) and the upper supporting bars (250) (260), is decreased. Accordingly, the extension bars (230) (240) is spon- taneously unfolded, maintaining the distance between each connecting part.

[122] At that time, fixing springs (700) are installed at each connecting part to make the connection much firmer.

[123] Fig 8 is the perspective view showing the connecting structure of the extension bars (230) (240).

[124] As illustrated in the figure, the fixing springs (700) are coiled around each connecting part which are respectively located between the extension bars (230) (240) and the cross bars (210) (220) and between extension bars (230) (240) and the upper supporting bars (250) (260).

[125] Both ends of the mil are cut and bent to be hooked respectively at the extension bars (230) (240), the cross bars (210) (220) and the upper supporting bars (250) (260).

[126] The extension bars (230) (240) described in the above, allow the height of the car tent to exceed the maximum height obtained by using the cross bar (210) (220). Ac- cordingly, the inner space of the car tent is increased.

[127] In addition, each connecting part between the cross bars (210) (220) and the extension bars (230) (240) is connected respectively to both ends of the upper supporting bars (250) (260) through elastic fixing materials (410-440).

[128] Fig 9 shows the structure of the elastic fixing materials (410-440). As illustrated in the figure, the elastic fixing materials (410-440) consist of two ring parts ringed re- spectively at cross bars (210) (220) and the upper supporting bars (250) (260), a first elastic material (412) connecting the two ring parts and a second elastic material (413) which is relatively shorter than a first elastic material (412).

[129] The elastic fixing materials (410-440) provide more stabilized structure by fixing both ends of the upper supporting bars (250) (260) and the upper ends of the cross bars (210) (220).

[130] A first elastic material (412) is supplementary, and a second elastic material (413) substantially acts as supporting and fixing means.

[131] In addition, the upper cover is supported more stably by using the upper supporting bars (250) (260).

[132] The upper supporting bars (250) (260) are located in the longitudinal direction of a car and thus, support the upper cover of the car tent in the longitudinal direction to prevent the car tent from being shaken by the wind.

[133] According to the above process, the cross bars (210) (220) are unfolded by the rotatory power provided by the motor (100) and thus, the car tent is installed.

[134] A second stopper (600), which converts physical contact to electric signal, is installed at the side of the center of the screw bar (160). When the transporting parts (320) contacts a second stopper (600), the operation of the motor (100) is stopped automatically by the signals from a second stopper (600).

[135] A contact-type stopper or other available stoppers are used as a second stopper (600).

[136] Therefore, the installation of the car tent can be stopped automatically without the user's additional instruction after the installation thereof has been completed, which serves the user's convenience.

[137] Meanwhile, the vertical elastic fixing material (450) connects between the lower cover and the upper cover. That is, one end thereof is connected to the side of the screw bar supporting means (180) (190) which allow the screw bars (160) (170) to rotate at a distance from the lower cover. In addition, the other end thereof is connected re- spectively to both ends of the upper supporting bars (250) (260). Such the connection can be in the form of crossing or contacting of two parts connected with each other.

[138] Such the vertical elastic fixing material (450) also stabilizes the car tent of the present invention.

[139] The vertical elastic fixing material (450) can be installed at every location that the upper cover and the lower cover are connected with each other.

[140] Next, when the user manipulates the controller in order to pack up the installed car tent, the motor (100) provides the rotatory power having the rotatory direction opposite to that for installing the car tent.

[141] Such the rotatory power is transmitted to the reduction sprockets (140) (150) through the reduction gear (HO) and the chains (120) (130). Accordingly, the screw bars (160) (170) rotates in the direction opposite to that for installing the car tent and thus, all transporting parts (310-340) move to both ends of the screw bars (160) (170) by the rotation of the screw bars (160) (170).

[142] In line with the above, the cross bars (210) (220) are folded, and the extension bars (210) (220), which are connected to the upper ends of the cross bars (210) (220), [143] are also folded. Finally, the cross bars (210) (220), the extension bars (230) (240) and the upper supporting bars (250) (260) are packed up at the outer side of the screw bars (160) (170).

[144] A first stopper (500) sensing the location of the transporting parts (310), determines when packing up of the car tent should be stopped.

[145] The action of a first stopper (500) is the same as that of a second stopper (600), and thus the explanation thereof is omitted.

[146] In addition, the lower cover according to the present invention is formed by injection molding, preferably with material selected from the group consisting of polypropylene, ABS (Acrylonitril-Butadiene-Styrene) resin, mixed resin of ABS resin and PC (Poly Carbonate) or PPF (Folypropyame Fiber). Therefore, it has no harm to the user's health. In addition, the injection molding provides more elegant appearance.

Industrial Applicability [147] The car tent of the present invention comprises the upper supporting bars for fully supporting the upper cover. In addition, the elastic fixing materials of the present invention fix more firmly between the cross bars and the upper supporting bars or between the lower cover and the upper cover. Moreover, the fixing springs of the present invention make the connecting parts much firmer. Such the constitutions improve the stability of the structure of the car tent.

[148] In addition, the car tent of the present invention further comprises the extension bars which are extended above the cross bars when the cross bars are unfolded. The extension bars increase the height of the car tent, and finally increase the inner space of the car tent.

[149] In addition, the car tent of the present invention comprises several stoppers. The stoppers determine when installation or packing up of the car tent should be stopped by sensing the location of the transporting parts which are connected to the cross bars and move along the screw bars. Therefore, installation or packing up of the car tent can be stopped automatically without the user's additional instruction after the installation or packing up thereof has been completed, which serves the user's convenience.