Apparatus for installing and withdrawing road sign

Abstract: Means (5) for conveying a group (A) of road signs (a), a pair of group of signs-conveying members (10) for conveying said group of road signs with supporting both sides of a bottom portion of the group of road signs, driving means for changing over the road sign to a support-releasing condition, a pair of sign-receiving means arranged at sign-separating positions (B), moving means for approaching and separating said pair of sign-receiving means, sign-ascending and descending means (46) for supporting and ascending and descending the road sign, means (58) for correcting a posture of the road sign, sign-holding means for releasably holding the road sign, position-changing means (59) for shifting said sign-holding means ranging from a position, where the sign is separated, to a position, where the sign is installed and withdrawn, and a holding means-ascending and descending mechanism for ascending and descending the sign-holding means at said position where the sign is installed and withdrawn, are carried on a loading platform (7,8) of said travelling car body. Not only the road signs can be installed in good order at the appointed positions without being tumbled and the automatically installed road signs can be automatically withdrawn but also an improvement of safety, the labor-saving and a remarkable improvement of working efficiency can be achieved.

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an apparatus and method for installing and withdrawing hollow road signs installed on for example boundaries between road repairing sites and roadways. Description of the Prior Art Aiming at an improvement of safety, a labor-saving and art improvement of working efficiency, an apparatus for automatically installing the above described road signs on road surfaces has been proposed (for example Japanese Patent Application Laid-Open No. Sho 63-241208). This apparatus for installing signs comprises conveyors provided swingably up and down and tilting on side portions of a travelling car body for conveying road signs, and wheels, which are provided in free end portions of the conveyor frames, and trailingly rotated during the travel of said car body, a turning force of said wheels being transmitted to driving shafts of said conveyors through reduction gears to drive the conveyors at a speed proprtional to a travelling speed of the travelling car body, and said road signs carried on the conveyors being dropped one by one on said road surfaces at desired intervals with said travelling of the travelling car body. However, art inclinedly descending inertia force acts upon the road signs conveyed by means of the conveyors, so that disadvantages have occurred in that they are apt to fall forward when engaged with the road surface at one side end of a bottom portion thereof and they are apt to irregularly tumble in a standing posture and to be shifted in position, when thrusted over the road surface at a corner portion of said bottom portion. In addition, the above described apparatus has aimed at merely the installation of the signs and thus they have been manually withdrawn as before That is to say, said improvement of safety and said labor-saving has not been sufficiently achieved and also said improvement of working efficiency was relatively small. Furthermore, a disadvantage has occurred also in that when positions of the signs to be installed are changed from the right side to the left side of the travelling car body, positions of the apparatus for install.ing the signs to be mounted on brackets on both sides of a loading platform must be changed, and thus not only a hard labor is required and a danger is apt to occur but also plenty of time is taken. EP-A-0 145 625 discloses an apparatus according to the preamble of claim 1 and methods according to the preambles of claims 4 and 6, with which it is possible to both install and withdraw the road signs automatically. This known apparatus comprises a carrousel-type conveyor for storing groups of road signs stacked one upon another on the travelling car body. A pair of retractable sign-receiving members are provided at a lateral side portion of the car body for supporting the bottom end of a stack which has been brought into a corresponding delivery position. These sign-receiving members are operated to release the road signs one by one from the lower end of the stack, and the released road signs are dropped through a chute to be installed on the road surface. When road signs are to be withdrawn from the road surface, they are caught, aligned and tilted by grip means provided on the lateral side of the car body, and when the presence of a road sign at the grip means has been detected, the tilted road sign is taken-over and lifted by means of a chain conveyor which has prongs projecting in the forward direction of travel and penetrating into the hollow interior of the road sign. At the top end of the chain conveyor, the road signs are dropped onto the top of one of the stacks in the carrousel-type conveyor. SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus and methods capable of automatically installing road signs smoothly in good order and at appointed positions and of automatically withdrawing the installed road signs and storing them in an appointed posture. According to the invention, this object is achieved by an apparatus specified in claim 1 and by methods indicated in claims 4 and 6. Optional features of the invention are specified in the dependent claims. The installation of road signs by means of the apparatus according to the invention is carried out during forward travelling of the travelling car body in the following manner. The group of a plurality of road signs stacked one upon another is conveyed to a separating position, where the lowermost road sign of the group of road signs is separated by a separating and approaching movement of group of signs-conveying members and sign-receiving means, and the sign is transferred to sign-ascending and descending means. The road sign taken out on the sign-ascending and descending means is supported by means of sign-holding means and is conveyed to the positions where the sign is installed and withdrawn. The sign-ascending and descending means is descended to release the road sign from the sign-holding means, thereby installing the road sign on the road surface. A withdrawal of the road sign is carried out during a rearward travel of the travelling car body in the following manner. The road sign installed on said road surface is supported by means of the sign-holding means and the sign-holding means is lifted up to convey the road sign to the separating position, where the road sign is released and put onto the sign-ascending and descending means. Here, the posture of the road sign is corrected by means of posture-correcting means, and then the sign-ascending and descending means is ascended and the sign-receiving means is positioned under the bottom portion of the road sign to include the road sign in the stack. The group of road signs is conveyed to the conveying means every time when an appointed number of road signs has been withdrawn With the apparatus according to a preferred embodiment, additionally the road signs can be installed and withdrawn on an optional one of the right and left sides of the travelling car body by changing the position where the road sign is installed and withdrawn by means of the sign-holding means. BRIEF DESCRIPTION OF THE DRAWINGS The first embodiment of the invention is shown in Figs. 1 to 20, in which Fig. 1 is a side view showing an apparatus for installing and withdrawing road signs; Fig. 2 is a plan view showing said apparatus for installing and withdrawing road signs; Fig. 3 is a back view showing the apparatus for installing and withdrawing road signs; Fig. 4 is a diagram showing an operation of installing and withdrawing road signs; Fig. 5 is a diagram showing a form of a driving system for a group of signs-conveying member; Fig. 6 is a side view showing said driving system for said group of signs-conveying member; Fig. 7 is a plan view showing the group of signs-conveying member; Fig. 8 is a detail drawing showing sign-receiving means; Fig. 9 is a plan view showing said sign-receiving means; Fig. 10 is a side view showing sign-ascending and descending means; Fig. 11 is a back view showing said sign-ascending and descending means; Fig. 12 is a plan view showing the sign-ascending and descending means; Fig. 13 is a detail drawing showing a holding means-ascending anti descending mechanism; Fig. 14 is a detail drawing fractioned in main parts showing sign-holding means; Fig. 15 is a plan view showing said sign-holding means; Fig. 16 is a plan view showing a trunk-supporting mechanism; Fig. 17 is a cycle diagram for installing road signs; Fig. 18 is a diagram showing an operation of installing road signs; Fig. 19 is a cycle diagram for withdrawing road signs; and Fig. 20 is a diagram showing an operation of withdrawing road signs. A second embodiment of the invention is shown in Figs. 21 to 41, in which Fig. 21 is a side view showing an apparatus for installing and withdrawing road signs; Fig. 22 is a plan view showing said apparatus for installing and withdrawing road signs; Fig. 23 is a back view showing the apparatus for installing and withdrawing road signs; Fig. 24 is a diagram showing an operation of installing and withdrawing road signs; Fig. 25 is a diagram showing a form of a driving system for a group of signs-conveying member; Fig. 26 is a plan view showing said group of signs-conveying member; Fig. 27 is a detail drawing showing sign-receiving means; Fig. 28 is a diagram describing a separation of road signs by means of said sign-receiving means; Fig. 29 is a plan view showing the sign-receiving means; Fig. 30 is a side view showing sign-ascending and descending means; Fig. 31 is a detail drawing showing posture-correcting means; Fig. 32 is a plan view showing said sign-ascending and descending means and said posture-correcting means; Fig. 33 is a rough plan view showing a, rear portion side of the apparatus for installing and withdrawing road signs; Fig. 34 is a rough back view showing the apparatus for installing and withdrawing road signs; Fig. 35 is a detail drawing showing a holding means-ascending and descending mechanism; Fig. 36 is a detail drawing showing sign-holding means; Fig. 37 is a plan view showing a sign-holding click; Fig. 38 is a plan view showing a holding member for holding a trunk portion of the road sign; Fig. 39 is a detail drawing showing position-changing means; Fig. 40 is a diagram showing an operation of installing road signs; and Fig. 41 is a diagram showing an operation of withdrawing road signs. Fig. 42 is a drawing showing another preferred embodiment of a road sign. DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be below described with reference to the drawings. Figs. 1 to 3 show an apparatus for installing and withdrawing road signs and Fig. 4 shows an operation of main parts. Referring to Figs. 1 to 4, reference numeral 1 designates conveying means for conveying a group (A) of a plurality of road signs (a) stacked one upon another. Jack-type supports 4 stand on a loading platform 3 of a travelling car body 2 at appointed intervals for regulating the height of the conveying means. A conveyor 5 extends over upper ends of said supports 4 for conveying said group (A) of road signs in the travelling direction of said travelling car body 2, and tumbling-preventing members 6 being arranged on both sides of said conveyor 5 for preventing the group (A) of road signs from tumbling. Said road signs (a) are composed of a hollow cone portion with a skirt expanded and a flange-like square base projected outward from said skirt of said cone portion and made of a synthetic resin material. Reference numeral 7 designates a first base arranged on the rear portion side of said loading platform, reference numeral 8 designates a second base projected from a rear lower portion of the loading platform 3 through a stay 9 hangingly connected with said first base 7, and reference numeral 10 designates a pair of group of signs-conveying members installed on the, first base 7 so as to be connected with said conveying means 1 for supporting both ends of a bottom portion of the group (A) of road signs to convey them. Speaking in more detail, as shown in Figs. 5, 6, a pair of brackets 11 stand on the first base 7, a driving shaft 12 provided with a ball spline groove (b) being laid over said pair of brackets 11, and two female spline members 14 connected with a sprocket 13 on the driving side in an outer side portion thereof, respectively, being engaged with said ball spline groove (b). On the other hand, driving means 15, for example a hydraulic motor, is carried on the first base 7 and a chain-type transmission mechanism 16 connects said driving means 15 to said driving shaft 12. A frame-fitting member 18 is supported by said respective female spline members 14 through a ball bearing 17, a frame 19 being connected with said frame-fitting member 18 under the condition that its idle end side is projected toward a rear portion of the loading platform 3, three pieces of trailing shaft 20 being installed on the idle end side and the base portion side of said frame 19 so as to be projected toward an inner surface side, respectively, and a sprocket 21 on the trailing side being provided in, a projecting end portion of the respective trailing shafts 20. In addition, an endless chain 22 for conveying the group (A) of road signs is wound round said sprocket 13 on, the driving side and said sprocket 21 on the trailing side, a guide member 23 supporting a straight course portion of said chain 22 being mounted on an inner side surface of the frame 19, and said group of signs-conveying members 10 supporting both sides of said bottom portion of the group (A) of road signs to convey them being adapted to be movable in a direction of axis shaft line of the driving shaft 12. Referring to Fig. 5, reference numeral 24 designates condition-changing over means for approaching said group of road signs-conveying members 10 to and separating them from each other to change over to a sign-supporting condition and a supporting-releasing condition, said condition-changing over means 24 being composed of an interlocking mechanism 25 for approaching the group of signs-conveying members 10 to and separating them from each other and a driving mechanism 26 for shifting one group of signs-conveying member 10 in said direction of axis shaft line of the driving shaft 12. Said interlocking mechanism 25, as shown also in Fig. 7, comprises a supporting shaft 27 standing midway of the pair of group of signs-conveying members 10 on the first base 7, a link 28 rotatably provided at an upper end of said supporting shaft 27 and a pivoted turnbuckle 29 ranging from an end portion of said link 28 to bottom plates of the respective frames 19, the pair of group of signs-conveying members 10 being adapted to approach to and separate from each other. Said driving mechanism 26 is composed of for example an oil pressure cylinder and a cylinder rod 26a connected with one of the frames 19. Referring to Figs. 1 to 3 again, reference numeral 30 designates a pair of sign-receiving means arranged at a sign-separating position (B) in a conveying end of the conveying members 10 for intervening between the bottom portions of the lower two signs of the group (A) of road signs to support the upper road sign (a) during the time when the signs are being installed and to support the road sign (a) which is withdrawn during the time when the signs are being withdrawn. Concretely stating, as shown in Figs. 8, 9, supports 31 stand on both sides of said sign-separating position (B) on said second base 8, a bracket 33 standing on a base plate 32 at an upper end of said support 31, said bracket 33 being provided with a guide cylinder 35 under the condition that a guide rod 34 is passed through the bracket 33, and said guide rod 34 being provided with a fitting member 37 on which a plate-like sign-receiving member 36 is pivoted swingably up and down so that said sign-receiving members 36 may be approached to and separated from each other in a direction same as the moving direction of the group of signs-conveying member 10. Energizing means (for example a coil spring) 38 is provided in a pivoting portion for swingably energizing the sign-receiving member 36 downward, and said fitting member 37 is provided with a stopper 39 for holding the sign-receiving member 36 in a horizontal posture against the force of said energizing means 38. On the other hand, said fitting member 37 is provided with moving means 40, for example an oil pressure cylinder, connected therewith so that the sign-receiving member 36 held in said horizontal posture may be changed over to a condition that it goes between the bottom portions of the lower two road signs (a) of the group (A) of road signs conveyed to the sign-separating position (B) and a condition that it retreated from there. Referring to Figs. 8, 9, reference numeral 41 designates a tumbling-preventing member for preventing the group (A) of road signs from tumbling. The tumbling-preventing member is mounted on said base plate 32 through a bracket 42, opposite plate portions 43 of said tumbling-preventing member 41 being provided with a retreating opening 44 for the sign-receiving member 36 and an optical sensor 45 for detecting the presence of the group (A) of road signs at the sign-separating position (B). Referring to Figs. 1, 2 again, reference numeral 46 designates sign-ascending and descending means for ascending and descending the road signs (a) at the sign-separating position (B), and the second base 8 is provided with a longitudinal bracket 47 on both sides of a sign-conveying center on the side facing the loading platform 3, said bracket 47 being provided with two pieces of shaft 48 laid thereabove and therebelow, respectively, the respective shafts 48 being provided with sprockets 49 mounted on both sides thereof, and an endless chain 50 being wound round the respective upper and lower sprockets 49. A sign-supporting member 51 positioned within a hollow inside of the road sign (a) to support the road sign (a) is provided with two arms 52 connected therewith, said arms 52 being connected with said chain 50, driving revolving means (for example an oil pressure motor) 53 being carried on the second base 8, and a chain-type transmission mechanism 54 being extended over said driving revolving means 53 and said two pieces of lower shaft 48. In addition, referring to Figs. 10 to 12, (c) to (h) designate approach switches, and the chain 50 is provided with actuating members 55 for said approach switches (c) to (h) so that said sign-supporting member 51 may be stopped at five positions in the up and down direction. Furthermore, referring to Fig 12, reference numeral 56 designates an opening formed in the sign-supporting member 51 for passing therethrough a bottom portion of a sign-supporting member 57, which will be mentioned later. Referring to Fig. 1 again, reference numeral 58 designates posture-correcting means for correcting the posture around a vertical axis shaft line of the road sign (a) supported by the sign-supporting member 51, and reference numeral 59 designates a car truck reciprocatable in the direction of width of the second base 8 composing position-changing means for changing the position, where the road sign is installed and withdrawn, from one longitudinal side L₁ to the other longitudinal side R₁ of the car body. And, said car truck 59 is provided with a post 61 driven and revolved around said longitudinal axis shaft line by means of revolving means (for example an oil pressure motor) 60, as shown in Fig. 13, and said post 61 is connected with sign-holding means 63 through a sign-holding means-ascending and descending mechanism 62, as shown also in Figs. 14 to 16. Said sign-holding means-ascending and descending mechanism 62 has a parallel four-series link structure and comprises a pair of links 64 (an upper link and a lower link) pivoted on the post 61 swingably up and down, a longitudinal link 65 pivoted to said upper and lower links 64, and ascending and descending means 66, for example an oil pressure cylinder, connected between said longitudinal link 65 and the post 61. In addition, reference numeral 67 designates a position-regulating stopper to be engaged with a triangular concave portion (j) formed in the lower link 64 for regulating a descending position of the sign-holding means 63 and preventing the sign-holding means 63 from being vibrated. The sign-holding means 63 is installed over idle end sides of the upper and lower links 64 in said sign-holding means-ascending and descending mechanism 62, in more detail a vertical member 68 is pivotably connected with said idle end sides of the upper and lower links 64 and provided with two pieces of click member 70 crossing each other so as to be rotatable around a vertical shaft 69 on an upper portion side thereof. And, said click members 70 are provided with an elastic member 71 on the respective idle end sides thereof to form two sets of sign-holding click 72, a shaft member 73 provided with a roller follower (m) at a lower end thereof being hangingly connected with a revolving base portion side of the respective click members 70, a bracket 75 connected with the vertical member 68 being provided with expanding and contracting means 74, for example an oil pressure cylinder, and a member 76 provided with a long hole (n), with which said roller follower (m) is to be engaged, being connected with said expanding and contracting means 74 so that said sign-holding clicks 72 may be changed over to a sign-holding condition and a holding-releasing condition by means of the expanding and contracting means 74. Referring to Fig. 14, reference numeral 57 designates a bottom portion of the sign-supporting member provided so as to be fixed and shiftable in the travelling direction of the travelling car body 2 for supporting one side of the bottom portion of the road sign (a) . As shown also in Fig. 16, reference numeral 77 designates two pieces of bracket connected with a lower portion side of the vertical member 68, a block 78 being provided over idle end sides of both brackets 77, respectively, and two sets of trunk-supporting mechanism 79 (merely one set is shown) on the lower portion side of the sign being provided on both a front side and a rear side in the travelling direction of the tarvelling car body 2 of the respective blocks 78. Said trunk-supporting mechanism 79 comprises two pieces of rod 80 provided slidably in the travelling direction of the travelling car body 2 on the blocks 78, plate-like members 81, 82 mounted over end portions of both rods 80, a bent support member 83 provided on said plate-like member 81 on an outer side for supporting a trunk portion on the lower portion side of the sign, and energizing means 84 for projectedly energizing said support member 83. The support member 83 is slightly moved against said energizing means 84 when engaged with the road sign (a) installed on the road surface. A sign-detecting sensor 85 is provided for detecting the presence of the road sign (a) on the basis of said movement of the support member 83. In addition, referring to Fig. 14, reference numeral 86 designates a locking member engageable with the plate-like member 81, with which the support member 83 is connected, under the condition that the support member 83 is shifted to a great extent against the energizing means 84 for holding the support member 83, which is unnecessary during the installation of the road sign (a), under the non-operating condition. Said posture-correcting means 58 for correcting the posture of the sign (a) when the withdrawn road sign (a) is inclined in posture comprises a member 87, which is engaged with a side edge of the bottom portion of the road sign (a) to correct said posture of the road sign (a), mounted on a L letter-shaped member 88, a cylinder rod 90 of driving means 89, for example a cylinder, connected with said L letter-shaped member 88 and a guide rod 92, which is guided by a guide cylinder 91, connected with the L letter-shaped member 88. An installing and withdrawing operation of road sign (a) by an apparatus for installing and withdrawing road signs having the above described construction will be below described with reference to cycle diagrams shown in Figs. 17, 19. At first, as to an installation of the road sign (a), said installation of the road sign (a) is carried out by a forward travel of the travelling car body 2 in the following manner, as shown in Fig. 18. In addition, the support member 83 is locked under the non-operating condition and said bottom portion of sign-supporting member 57 is projected at a bottom portion-receiving position to be fixed. Upon regularly driving the conveying means 1 and the group of signs-conveying members 10 (step S 1, S 2) to convey the first group (A) of road signs on the conveying means 1 to the side of the pair of group of signs-conveying members 10, the conveying means 1 is stopped to be driven by an action of a sensor 93 (refer to Fig. 2) and the group of signs-conveying members 10 are stopped to be driven by an action of a sensor 45 (refer to Fig. 9) at a point of time when the group (A) of road signs arrives at the sign-separating position (B). Here, as shown by a full line in Fig. 8, the sign-receiving members 36 of the pair of sign-receiving means 30 are changed over to the condition that they go between the bottom portions of the lower two pieces of the group (A) of road signs (step S 3) and the group of signs-conveying members 10 are separated from each other to be changed over to the condition that the holding of the signs is released (step S 4), thereby separating and dropping the lowermost sign (a). The fallen road sign (a) is, as shown in Figs. 10, 11, received by the sign-supporting member 51 of the sign-ascending and descending means 46 held at an upper position E₁ during the withdrawal of signs by means of the approach switch (e) and the sign-ascending and descending means 46 is descended until the approach switch (d) acts to stop the sign-supporting member 51 at a middle position D₁ (step S 5). Subsequently, the post 61 is regularly driven to change over the sign-holding means 63 from said installing·withdrawing position L₁ to the sign-separating position (B) (step S 6), the road sign (a) being held by the sign-holding clicks 72 of the sign-holding means 63 (step S 7), and the sign-ascending and descending means 46 being descended until the approach switch (c) acts to stop the sign-supporting member 51 at a lower position C₁ where it is drawn-off from said hollow inside of the road sign (a) (step S 8). Subsequently, the post 61 is reversely rotated to change over the sign-holding means 63 to the installing·withdrawing position L₁ (step S 9), the sign-holding means-ascending and descending mechanism 62 being descended midway of the rotation of the post 61 (step S 10), and the sign-holding clicks 72 of the sign-holding means 63 being changed over to the sign-holding-releasing condition (step S 11) followed by ascendingly driving the sign-holding means-ascending and descending mechanism 62 (step S 12) to complete the installation of a piece of road sign (a). And, the road sign (a) is first brought into contact with the ground on the rear side in the travelling direction of the travelling car body 2 under the condition that it is single-supported by means of the bottom portion of the sign-supporting member 57 and at almost the same time the bottom portion of the sign-supporting member 57 is drawn from the bottom of the sign to install the sign on the road surface. At this time, the road sign (a) has said inertia force in the travelling direction, so that it is not tumbled even though it is first brought into contact with the ground on the rear side in the travelling direction of the travelling car body 2 under the single-supported condition and the inertia force acts upon the road sign (a) in the drawing direction of the bottom portion of the sign-supporting member 57, whereby the road sign (a) is installed at an appointed position without being tumbled. During the above described steps S 6 to S 10, the pair of group of signs-conveying members 10 approach to each other to change over to the sign-receiving posture (step S 6'), the sign-receiving members 36 of the sign-receiving means 30 being once changed over to the retreating condition (step S 7') and soon to the going condition (step S 8'), and the sign-ascending and descending means 46 being ascendingly driven to change over the sign-supporting member 51 to said upper position E₁ (step S 10') to prepare for the following installation of the sign. Subsequently, the above described steps S 4 to S 12 are repeated and the conveying means 1 and the group of signs-conveying members 10 are driven during the steps S 6, S 7 midway the installation of the final road sign (a) to convey the following group (A) of road signs to the sign-separating position (B). The withdrawal of the road sign (a) will be below described. This withdrawal of the road sign (a) is carried out during rearward travelling of the travelling car body 2 in the following manner. In addition, the support member 83 is changed over to the operating condition, the bottom portion of the sign-supporting member 57 being changed over to the retreating condition, a pair of sign-receiving members 36 of the sign-receiving means 30 being changed over to the going condition, and a pair of group of signs-conveying members 10 being changed over to the supporting of the sign-releasing condition. At first, the post 61 Is reversely driven to change over the sign-holding means 63 from the sign-separating position (B) to the installing·withdrawing position L₁ (step S 1). As soon as the sensor 85 is actuated by engaging the support member 83 with the road sign (a) standing on the road surface, the sign-holding clicks 72 of the sign-holding means 63 are changed over to the holding condition (step S 2) to hold the road sign (a) by means of the sign-holding clicks 72. Then, the sign-holding means-ascending and descending mechanism 62 is ascendingly driven (step S 3), the post 61 being regularly driven to change over the sign-holding means 63 to the sign-separating position (B) (step S 4), the sign-supporting, member 51 of the sign-ascending and descening means 46 being lifted up to said middle position D₁ from said lower position C₁ (step S 5), and the sign-holding clicks 72 of the sign-holding means 63 being changed over to the holding-releasing condition (step S 6) to put the withdrawn road sign (a) in the sign-supporting member 51. Here, the posture-correcting means 58 is driven to correct the road sign (a) in disturbed posture (step S 7) and the sign-supporting member 51 of the sign-ascending and descending means 46 is lifted up to an upper position H₁ (a position above an operating surface of the group of signs-conveying members 10) in a step S 8, whereby the road sign (a) put in the sign-supporting member 51 once pushes up the sign-receiving members 36 to pass through. At the same time, the posture-correcting means 58 is reversely driven (step 8''). After passing through the sign-receiving members 36 the sign-supporting member 51 of the sign-ascending and descending means 46 is changed over to the lower position C₁ in an appointed timing (step S 9). Under such the condition, the sign-receiving member 36 of the sign-receiving means 30 is changed over to a horizontal posture, so that the road sign (a) is supported by means of the sign-receiving member 36. On the other hand, at the same time as the above described step S 7, the post 61 is reversely driven to change over the sign-holding means 63 to the installing· withdrawing position L₁ (step S 7') and the sign-holding means-ascending and descending mechanism 62 is descended (step S 8'), whereby the sign-holding means 63 prepares for the installation of the following road sign (a). Thereafter, the above described steps S 2 to S 9 including the above described steps S 7', S 8', S 8'' are repeated to withdraw the final road sign (a) to be withdrawn. Thereupon, the group of signs-conveying members 10 approach to each other so as to take the sign-receiving posture (step S 10) and the sign-receiving members 36 of the sign-receiving means 30 are separated from each other so as to take the sign-holding-releasing condition (step S 11), thereby supporting the group (A) of a plurality of withdrawn road signs (a) by means of the group of signs-conveying members 10. The group of signs-conveying members 10 supporting the group (A) of road signs and the conveying means 1 are reversely driven to take the group (A) of withdrawn road signs on the conveying means 1. In addition, although, the road sign (a) is single-supported by means of the bottom portion of the sign-supporting member 57 in the installation of the road sign (a), the bottom portion of the sign-supporting member 57 may be omitted to drop the road sign (a) onto the road surface in an upright posture. Furthermore, although the installation and withdrawal of the road signs (a) on one side (the left side in Fig. 3) of the travelling car body 2 was described in the above described preferred embodiment, the installation and withdrawal of the road signs (a) on the other side of the travelling car body 2 is carried out by moving the car truck 59 to the other side of the second base 8 under the condition that the post 61 is rotatably driven so that the sign-holding means 63 may be directed to the rear of the travelling car body 2 and using the other sign-holding click 72 of the sign-holding means 63. The car truck 59 rotatably and ascendably and descendably provided with the sign-holding means 63 comprises the position-changing means changing the installing·withdrawing position of the road signs (a) between one longitudinal side L₁ and the other longitudinal side R₁ of the car body. The second embodiment of the invention will be below described with reference to Figs. 21 to 41. Figs. 21 to 23 show an apparatus for installing and withdrawing road signs. Referring to Figs. 21 to 23, reference numeral 101 designates a base carried on a loading platform 102a of a travelling car body 102, said loading platform 102a being provided with a pair of longitudinal frames 103, that is a right longitudinal frame and a left longitudinal frame, so as to be projected to a rear portion of said loading platform 102a, and said base 101 being pivoted on a support 104 about a horizontal shaft on a driver side of the loading platform. Reference numeral 105 designates a jack for lifting up the rear side of the base 101, and reference numeral 106 designates receiving means supporting the base 101 lifted up by means of said jack 105 during the travel, said receiving means 106 being provided with base-receiving means 107 so that said base-receiving means 107 may be changed over to a receiving condition and a releasing condition. Reference numeral 108 designates conveying means for a group (A) of a plurality of road signs (a) stacked one upon another, said conveying means coprising three pieces of conveying chain 108a for conveying said group (A) of road signs while supporting the group (A) of road signs at three places that is, on both sides and the center. A tumbling-preventing member 109 is arranged on both sides of said conveying means 108. Said road signs (a) are composed of a hollow cone portion with a skirt expanded and a flange-like square base projected outward from said skirt of said cone portion and made of a synthetic resin material. Reference numeral 110 designates a pair of group of signs-conveying members for conveying the group (A) of signs while supporting both sides of a bottom portion thereof. As shown in Figs. 24 to 26, a pair of brackets 111 stand on a horizontal frame 131 extending over said pair of longitudinal frames 103, a driving shaft 112 provided with a ball spline groove (t) being laid over said pair of brackets 111, and two female spline members 114 connected with a sprocket 113 on the driving side in an outer side portion thereof, respectively, being engaged with said ball spline groove (t). On the other hand, driving means 115, for example a hydraulic motor, is carried on said horizontal frame 131, and a chain-type transmission mechanism is extended between said driving means 115 and said driving shaft 112. And, a frame-fitting member 118 is supportedly by said respective female spline members 114 through a ball bearing 117, a frame 119 being connected with said frame-fitting member 118 under the condition that its idle end side is projected toward a rear portion of the loading platform 103, three pieces of trailing shaft 120 being installed on the idle end side and the base portion side of said frame 119 so as to be projected toward an inner surface side, respectively, and a sprocket 121 on the trailing side being provided in a projecting end portion of the respective trailing shafts 120. In addition, an endless chain 122 for conveying the group (A) of road signs is wound round said sprocket 113 on the driving side and said sprocket 121 on the trailing side, a guide member 123 supporting a straight course portion of said chain 122 being mounted on an inner side surface of the frame 119, and said group of signs-conveying members 110 supporting both sides of said bottom portion of the group (A) of road signs to convey them and being adapted to be movable in a direction of axis shaft line of the driving shaft 113. Reference numeral 124 designates condition-changing over means for approaching the group of road sign-conveying members 110 to and separating them from each other to change over to a sign-supporting condition and a supporting-releasing condition, said condition-changing over means 124 being composed of an interlocking mechanism 125 for approaching the group of signs-conveying members 110 to and separating them from each other and a driving mechanism 126 for shifting one group of signs-conveying member 110 in said direction of axis shaft line of the driving shaft 113. Said interlocking mechanism 125 comprises a supporting shaft 127 standing between the brackets 111, 111 of said horizontal frame 131, a link 128 rotatably provided at an upper end of said supporting shaft 127 and a turnbuckle 129 pivoted between an end portion of said link 128 and bottom plates of the respective frames 119, the group of signs-conveying members 110 being adapted to approach to and separate from each other. Said driving mechanism 126 is composed of for example an oil pressure cylinder and a cylinder rod 126a connected with one of the frames 119. Referring to Figs. 22, 24 again, reference numeral 130 designates a pair of sign-receiving means arranged at a sign-separating position (B) in a conveying end of the conveying members 110 for intervening between the bottom portions of the lower two signs of the group (A) of road signs to support the upper road sign (a) during the time when the signs are being installed and supporting the road sign (a) which is withdrawn during the time when the signs are being withdarwn. Concretely stating, as shown in Figs. 27 to 29, horizontal brackets 132 on both sides of said sign-separating position (B) are provided with a pair of brackets 133 standing thereon with a horizontal guide cylinder 135 connected thereto, a support member 137 being provided over pointed ends of guide rods 134 held within said guide cylinder 135, a plate-like sign-receiving member 136 being pivoted on said support member 137 swingably up and down, and the support member 137 being provided with energizing means (for example a coil spring) 138 for swingably energizing the sign-receiving member 136 downward, and a stopper 139 for holding the sign-receiving member 136 in a horizontal posture against the force of said energizing means 138. In addition, a pivoting position of the sign-receiving member 136 is slightly upwardly biased relative to an axis shaft line of said guide rod 134 so that the sign-receiving member 136 may be swung upward when a load is applied to a pointed end of the sign-receiving member 136. Furthermore, the support member 137 is provided with moving means 140, for example a double-stage expansion and contraction-type oil pressure cylinder, connected therewith so that the sign-receiving member 136 held in said horizontal posture may be changed over to a condition that it goes between the bottom portions of the lower two road signs (a) of the group (A) of road signs conveyed to the sign-separating position (B) (refer to Fig. 27) and a condition that the sign-receiving member 136 is further extended to be swung up, thereby separating a lower road sign (a) from an upper road sign (a) and dropping said lower road sign (a) (refer to Fig. 28). Referring to Figs. 27, 29, reference numeral 141 designates a tumbling-preventing member for preventing the group (A) of road signs from tumbling. The tumbling-preventing member is mounted on said horizontal frame 131 through a bracket 142, and opposite plate portions 143 of said tumbling-preventing member 141 are provided with a retreating opening 144 for the sign-receiving member 136. Referring to Figs. 21, 22, 24 again, reference numeral 146 designates sign-ascending and descending means for ascending and descending the road signs (a) at the sign-separating position (B), a longitudinal bracket 147 being provided with a shaft 148 provided with a sprocket 149 laid thereabove and therebelow, an endless claim 150 being wound round the respective upper and lower sprocket 149, and driving revolving means (for example an oil pressure motor) 153 being interlockedly connected with said upper shaft 148. Arms 152 ascendable and descendable along guide rails 145 in the up and down direction are provided with a road sign-supporting member 151 connected therewith, a horizontal sliding member 154 being held by means of said arms 152, and pins (i) conneceted with said endless chain 150 being connected with said horizontal sliding member 154. That is to say, the horizontal sliding member 154 is transferred in the horizontal direction integrally with the chain 150 in a portion where the chain 150 is wound round the sprocket 149, thereby ascending arid descending the sign-supporting member 151. Referring to Figs. 21 to 24, reference numeral 156 designates posture-correcting means for correcting a posture around a vertical axis shaft line of the road sign (a) supported by the sign-supporting member 51. Reference numeral 157 designates means for installing and withdrawing road signs (a) composed of sign-holding means 158 releasably holding the road sign (a) therebetween, revolving means 159 for revolving said sign-holding means 158, said revolving means ranging from the road sign -separating position (B) midway of the car body to a road sign -installing· withdrawing position L₂ on one longitudinal side of the car body, a sign-holding means-ascending and descending mechanism 160 for ascending and descending the sign-holding means 158 at said road sign -installing· withdrawing position L₂, and position-changing means 161 changing the road sign -installing·withdrawing position L₂ of the sign-holding means 158 to the other longitudinal side R₂ of the travelling car body 102. As shown in Fig. 23, the right and left longitudinal frames 103 are provided with a pair of cylindrical frames, that is an upper cylindrical frame 162 and a lower cylindrical frame, 165 thereabove and therebelow, and, as shown in Figs. 30 to 32, said lower frame 165 is provided with said posture-correcting means 156. That is to say, the lower frame 165 is provided with a horizontal base 166 and a guide rail 167 connected therewith, said horizontal base 166 being provided with a rack 169 driven by a cylinder 168 and a pinion 170 engaged with said rack 169, and said pinion 170 being provided with an arm 171 connected therewith while a sliding member 172 is fitted slidably along said guide rail 167 and a pointed end of said sliding member 172 is connected with a pointed end of said arm 171 through a turnbuckle 173. A posture-correcting member 174, which is engaged with a side edge of the bottom portion of the withdrawn road sign (a) to correct its posture, is pivoted on the sliding member 172 so as to be rotatable around a horizontal axis, and a spring 175 and a stopper 176 are provided for holding said posture-correcting member 174 under an appointed posture-correcting condition. In addition, said upper frame 164 on the lower portion side is provided with a second stopper 177, with which the posture-correcting member 174 is engaged when the posture-correcting member 174 is changed over to a watching and waiting position (a position shown by a full line in Fig. 31), so that an idle end side of the posture-correcting member 174 may be swung downward at said watching and waiting position. This aims at that an engagement of a lower portion side of the road sign (a) with the posture-correcting member 174 is prevented when the lower portion side of the road sign (a) held by means of the sign-holding means 158 is brandished by a centrifugal force during the revolution of the sign-holding means 158 by said revolving means 159. Said means 161 for changing the sign -installing· withdrawing position L₂ to the other longitudinal side R₂ of the travelling car body 2 has the following structure. As shown in Figs. 23, 24, 33, 34, vertical shafts 178, 179 are pivoted at central positions in the direction of width of the travelling car body 2 over the respective upper and lower pairs of frames 162, 163, 164, 165 on the upper portion side and the lower portion side, and said upper and lower vertical shafts 178, 179 are provided with cylindrical arms 181, 182 rotatably provided with a support 180 of a sign-holding means-ascending and descending mechanism 160 which will be mentioned later. The upper vertical shaft 178 is provided with a pinion 183 fixedly mounted thereon, the upper frame 162 on the upper portion side being provided with a rack 184 to be engaged with said pinion 183 therewithin, a cylinder 185 being connected with said rack 184, and two sets of stopper means 186 being selectively engageable with a stopper concave portion (j) of said upper arm 181. Said sign-holding means-ascending and descending mechanism 160 has a parallel four-series link structure and comprises a pair of links 187 (an upper link and a lower link) pivoted on the support 180 swingably up and down, a longitudinal link 188 pivoted over said upper and lower links 187 and a cylinder 189 connected between said longitudinal link 188 and the support 180, as shown in Figs. 23, 24, 35. In addition, reference numeral 190 designates a position-regulating stopper receiving a triangular concave portion (m) formed in the lower link 187 for regulating a descending position of the sign-holding means 158 and preventing the sign-holding means 158 from being vibrated. The sign-holding means 158 is installed over idle end sides of the upper and lower links 187 in the sign-holding means-ascending and descending mechanism 160, in more detail, the upper link 187 is provided with a frame member 191 hangingly connected therewith on the idle end side thereof so as to be rotatable around a vertical axis shaft line, said frame member 191 being provided with a supporting shaft 192 hangingly connected therewith on a lower portion side thereof, a bearing 193 being mounted on said supporting member 192, and an idle end side of the lower link 187 being connected with said bearing 193 as indicated in Figs. 23, 24, 35 and 36. In addition, engaging holes (n) are formed in an upper member 194 of the bearing 193 at a differential phase of 180°, and the frame member 191 is provided with a stopper member 195 selectively engageable and disengageable with said engaging holes (n) so that the frame member 191 including the supporting shaft 192 may be revolved by 180°. As shown also in Fig. 37, two pieces of sign-holding click 197 provided with an elastic member 200 are pivoted on an upper portion side of the frame member 191 rotatably around a vertical shaft 196, and a link 199 with a cylinder' 198 conneceted thereto is connected with a base portion side of said sign-holding clicks 197 so that the sign-holding clicks 197 may be changed over to a sign-holding condition and a holding-releasing condition. On the other hand, as shown also in Fig. 38, a holding member 202 holding a trunk portion-holding member 201 for the road sign (a) movably in the back and forth direction is mounted on said lower portion side of the frame member 191, said holding member 202 being provided with a slide member 203, and a sensor 204 is provided for detecting the presence of the road sign (a) on the basis of a movement of said slide member 203. In addition, as shown in Fig. 36, a support member 205 supporting one side of the bottom portion of the road sign (a) merely when the road sign (a) is installed is provided on a lower portion side of the holding member 202 so as to be shiftable in the back and forth direction and fixed. Said revolving means 159 for the sign-holding means 158 has the following structure: As shown in Figs. 33, 34, 39, the support 180 is provided with a pinion 206 fixedly mounted on an upper end thereof, a rack 207 engaging with said pinion 206 being provided so as to be movable along a guide rail 208, and a cylinder 209 being connected with said rack 207. Said guide rail 208 and said cylinder 209 are provided on a unit base 211 swingable around a shaft 210 close to the vertical shaft 178, and said base 211 is provided with a cylinder 212 connected with an idle end side thereof so that an engagement of the rack 207 with the pinion 206 may be released. In addition, referring to Figs. 34, 35, reference numeral 213 designates stopper means which is engaged with concave portions (r) formed in a member 214 connected with the upper arm 181 at a differential phase of 180° to make a revolution of the holding means-ascending and descending mechanism 160 for the upper arm 181 around the support 180 impossible. An installation of the road sign (a) in the case where the road sign (a) is installed on one longitudinal side (left side) of the travelling car body 102 will be below described. This installation of the road signs (a) is carried out during a forward travel of the travelling car body 102, as shown in Fig. 40. At first, upon regularly driving the conveying means 108 arid the group of signs-conveying members 110 to convey the first group (A) of road signs on the conveying means 108 to the side of the group of signs-conveying members 110, the conveying means 108 is stopped and the group of signs-conveying members 110 are stopped at a point of time when the group (A) of road signs arrives at the sign-separating position (B). Here, as shown in Fig. 28, the sign-receiving members 136 of the sign-receiving means 130 are changed over to the condition that they go between the bottom portions of the lower two pieces of road sign in the group (A) of road signs to separate a lower road sign (a) from an upper road sign (a), thereby dropping the lower road sign (a). The fallen road sign (a) is, as shown in Fig. 30, received by the sign-supporting member 151 of the sign-ascending and descending means 146 watching and waiting at an upper position E₂, and the supporting member 151 is descendingly driven to be stopped at a middle position D₂. Subsequently, as shown in Figs. 24, 33, the support 180 is regularly driven to change over the sign-holding means 158 from the installing·withdrawing position L₂ to the sign-separating position (B) to hold the road sign (a) by means of the sign-holding click 197 of the sign-holding means 158. Then the sign-ascending and descending means 146 is descendingly driven to draw the sign-supporting member 151 out of a hollow inside of the road sign (a) and holding the sign-supporting member 151 at a lower position C₂. Subsequently, the support 180 is reversely rotated to change over the sign-holding means 158 to the installing·withdrawing position L₂ of the road sign (a), the sign-holding means-ascending and descending mechanism 160 being descendingly driven midway of the rotation of the support 180, and the sign-holding clicks 197 being changed over to the sign-holding-releasing condition at an appointed timing followed by ascendingly driving the sign-holding means-ascending and descending mechanism 160 to prepare the following installation of the road sign, thereby completing the installation of a piece of road sign (a). The road sign (a) is first brought into contact with the ground on the rear side in the travelling direction of the travelling car body 102 under the condition that it is single-supported by means of said bottom portion of the sign-supporting member 205 and at almost the same time the bottom portion of the sign-supporting member 205 is drawn out of the bottom portion of the sign to install the sign on the road surface, as shown in Fig. 40. At this time, the road sign (a) has said inertia force in the travelling direction, so that it is not tumbled even though it is first brought into contact with the ground on the rear side in the travelling direction of the travelling car body 102 under the single-supported condition, and the inertia force acts upon the road sign (a) in the drawing direction of the bottom portion of the sign-supporting member 205, whereby the road sign (a) is installed at an appointed position without being tumbled. During the above described sign-installing operation, the group of signs-conveying members 110 approach to each other to be changed over to the sign-receiving posture, the sign-receiving members 136 of the sign-receiving means 130 being once retreated from the bottom portion of the sign and soon changed over to the going condition, and the sign-ascending and descending means 146 being ascendingly driven to change over the sign-supporting member 151 to said upper position E₂. Subsequently, the above described operations are repeated and the conveying means 108 and the group of signs-conveying members 110 are driven during the installation of the final road sign (a) in the group (A) of road signs to convey the following group (A) of road signs to the sign-separating position (B). The road signs (a) can be safely and efficiently automatically installed by repeating the above described operation. The withdrawal of the road sign (a) will be below described. This withdrawal of the road sign (a) is carried out during the rearward travelling of the travelling car body 102 in the following manner, as shown in Fig. 41. At first, the support 180 is reversely driven to change over the sign-holding means 158 from the sign-separating position (B) to the installing·withdrawing position L₂. As soon as the sensor 204 is actuated by engaging the slide member 203 with the road sign (a) standing on the road surface, the sign-holding clicks 197 of the sign-holding means 158 are changed over to the holding condition to hold the road sign (a) by means of the sign-holding clicks 197. Then, the sign-holding means-ascending and descending mechanism 160 is ascendingly driven, the support 180 being regularly driven to change over the sign-holding means 158 to the sign-separating position (B), the sign-supporting member 151 of the sign-ascending and descending means 146 being lifted up to said middle position D₂ from said lower position C₂, and the sign-holding clicks 197 of the sign-holding means 158 being changed over to the holding-releasing condition to put the withdrawn road sign (a) in the sign-supporting member 151. Here, the posture-correcting means 156 is reciprocately driven to correct the road sign (a) in disturbed posture and the sign-receiving member 136 of the sign-ascending and descending means 146 is lifted up to an upper position H₂ (a position above an operating surface of the group of signs-conveying members 110), whereby the sign-receiving members 136 are once pushed up to pass the road sign (a) and the posture-correcting means 156 is returned to the original watching and waiting position. After the sign has passed the sign-supporting member 151 the sign-ascending and descending means 146 is changed over to the lower position C₂ in an appointed timing. Under such the condition, the sign-receiving member 136 of the sign-receiving means 130 is changed over to a horizontal posture, so that the road sign (a) is supported by means of the sign-receiving member 136. On the other hand, at the same time as the above described return of the posture-correcting means 156, the support 180 is reversely driven to change over the sign-holding means 158 to the installing·withdrawing position L₂ and the sign-holding means-ascending and descending mechanism 160 is descended, whereby the sign-holding means 158 prepares for the installation of the following road sign (a). Thereafter, the above described operations are repeated to withdraw the final road sign (a) to be withdrawn. Thereupon, the group of signs-conveying members 110 approach to each other so as to take the sign-receiving posture, and the sign-receiving members 136 of the sign-receiving means 130 are changed over to the sign-holding-releasing condition to support the group (A) of a plurality of withdrawn road signs (a) by means of the group of signs-conveying members 110, and the group of signs-conveying members 110 and the conveying means 108 are reversely driven to take the group (A) of withdrawn road signs on the conveying means 108. The road signs (a) can be safely and efficiently automatically withdrawn by repeating this operation. The procedures for changing the installing·withdrawing position L₂ of the road sign (a) to the other longitudinal side R₂ (right side) of the travelling car body 102 will be below described. At first, the stopper means 213 shown in Fig. 34 is engaged with the concave portion (r) formed in the member 214 connected with the upper arm 181 to make a revolution of the holding means-ascending and descending mechanism 160 relative to the upper arm 181 impossible. Then, as shown in Fig. 39, the cylinder 212 is extended to release an engagement of the pinion 206 with the rack 207, and after extending the cylinder 209 of the revolving means 159 the cylinder 212 is contracted to engage the rack 207 with the pinion 206. Thus, the revolving phase of the holding means-ascending and descending mechanism 160 is changed by 180°. Here, a fixation of the holding means-ascending and descending mechanism 160 by the stopper means 213 and a fixation of the upper arm 181 on the upper frame 162 by the stopper means 186 is released, respectively, and the cylinder 185 is extended to rotate the whole holding means-ascending and descending mechanism 160 including the sign-holding means 158 around the vertical shafts 178, 179 by 180°, as shown in Figs. 23, 33, 34. Under such the condition, as shown by an imaginary line in Fig. 33, the sign-holding clicks 197 of the sign-holding means 158 face forward in the travelling direction of the travelling car body 102. And, here, said fixation of the sign-holding means 158 on the holding means-ascending and descending mechanism 160 by the stopper member 195 shown in Figs. 35, 36 is released to manually change the sign-holding means 158 in phase by 180°, thereby achieving the installation and withdrawal of the road signs (a) on the right side of the travelling car body 102. In addition, although the road sign (a) is single-supported by means of the bottom portion of the sign-supporting member 205 in the installation of the road sign (a), the bottom portion of the sign-supporting member 205 may be omitted, so that the road sign (a) falls onto the road surface in an upright posture. Furthermore, road signs (a) having various kinds of shape may be used. One example is shown in Fig. 42. [Effects of the Invention] As above described, with the apparatus for installing and withdrawing road signs according to the invention, not only the road signs can be installed in good order at the appointed positions without being tumbled, and the automatically installed road signs can be automatically withdrawn, but also the improvement of safety, the labor-saving and the remarkable improvement of working efficiency as compared with the conventional appratus can be achieved. In addition, according to the second invention, the road signs can be installed and withdrawn in an optional one of right and left directions of the travelling car body by changing the position where the road sign is installed and withdrawn by means of the sign-holding means, on any one of the longitudinal sides of the car body.

Claims: An apparatus carried on a travelling car body (2; 102) for installing and withdrawing road signs (a), comprising: conveying means (5; 108) for conveying a group (A) of a plurality of hollow road signs (a) stacked one upon another, a pair of sign-receiving means (30; 130) arranged at a sign separating position (B) and movable towards and away from one another for separating individual road signs (a) from said group (A) of road signs, sign-holding means (63; 158) for releasably holding a road sign, and a holding means ascending and descending mechanism (62; 160) for ascending and descending the sign-holding means at a position (L₁, R₁; L₂, R₂) on one longitudinal side of the car body, characterized in that a pair of group of signs-conveying members (10;110) are provided between said conveying means (5; 108) and said sign-separating position (B), said group of signs-conveying members being arranged to support both sides of a bottom portion of the group (A) of road signs and to be moved toward and away from one another in the same direction as said sign-receiving means (30; 130) for transferring the road signs (a) to said sign-receiving means in an installing operation and for taking-over the road signs from the sign-receiving means in a withdrawing operation, sign-ascending and descending means (46; 146) are disposed below said pair of sign-receiving means (30; 130) in said separating position (B) midway of the width of the car body (2) and comprise a sign-supporting member (51; 151) engageable in the hollow inside of the road sign (a) for supporting and ascending and descending the road sign, posture-correcting means (58; 174) are arranged to correct the posture of the road sign supported on said sign-supporting member, and revolving means (80; 159) are provided for revolving said sign-holding means (63; 158) between said separating position (B) and said position (L₁, R₁; L₂, R₂) on the longitudinal side of the car body were the sign is installed and withdrawn. An apparatus according to claim 1, comprising position-changing means (59; 161) for changing the position (L₁, R₁; L₂, R₂) where the sign (a) is installed and withdrawn by means of the sign-holding means (63; 158). An apparatus according to claim 1 or 2, wherein the components of said apparatus are carried on at least one loading platform (7, 8) of said travelling car body (2). A method of taking hollow road signs (a) from a travelling car body (2) and installing them on a road surface, comprising the steps of (a) conveying a group (A) of a plurality of said road signs (a) stacked one upon another to a separating position (B), (b) descending the lowermost of the road signs of said group (A) while holding the rest of the road signs of this group in position, so that the lowermost road sign is separated from the rest of the group, (c) installing the separated road sign on the road surface, (d) repeating the steps (b) and (c) until the last road sign of said group (A) has been installed and (e) repeating the steps (a) to (d), characterized in that the step (c) comprises the substeps of (c1) horizontally approaching grip means (70) toward the descended road sign for gripping the same, (c2) moving said grip means holding said road sign from the separating position (B) at the rear end of the travelling car body (2) to a lateral side of the car body and descending it further to a releasing position (L₁, R₁; L₂, R₂) closely above the road surface, the road sign being held by said grip means in the releasing position from the side facing in the travelling direction of the car body (2), and (c3) releasing said road sign for installing it on the road surface. A method according to claim 4, wherein the road sign (a) when released by said grip means in said releasing position is supported at its lower circumferential edge in a front portion in the direction of travel, so that it is tilted rearwardly and hits the road surface first with its rear lower edge portion and then slips off from the supporting means with its front lower edge portion. A method of withdrawing road signs (a) from a road surface and storing them on a travelling car body (2), comprising the steps of: (a) catching a road sign (a) installed on the road surface in a withdrawing position (L₁, R₁; L₂, R₂) laterally of said travelling car body (2) by means of grip means (70; 158) which are open in the forward direction of travel, (b) detecting whether a road sign is caught by said grip means, (c) moving the road sign that has been caught by said grip means upwardly and inwardly relative to said car body (2) and adding it to a stack (A) of road signs that may already be present in a stacking position, (d) repeating the steps (a) to (c) until a predetermined number of road signs has been stacked, (e) conveying said stack (A) to a storage position on said car body (2) and (f) repeating the steps (a) to (e), characterized in that the step (c) comprises the substeps of (c1) closing the grip means when it is detected that the road sign has been caught, (c2) moving said grip means holding said road sign upwardly and inwardly relative to said car body (2), (c3) releasing the road sign to place it on road sign-ascending means (46; 146). (c4) ascending said road sign so that it may enter into said stack (A), (c5) supporting the road sign that has been ascended and forms the lower-most road sign of the stack (A), and (c6) moving said grip means (70; 158) back to said withdrawing position (L₁, R₁; L₂, R₂), and in that, in the step (e), conveying members (10; 110) are approached to one another to take-over said stack (A). A method according to claim 6, wherein the substep (c2) comprises a step of correcting the posture of the road sign.

Inventors: AKITA SATOSHI, SUGII MASANORI, YONEMORI TOSHIYA, AKITA, SATOSHI, SUGII, MASANORI, YONEMORI, TOSHIYA
Applicants: SHINMEI IND CO LTD, SHINMEI INDUSTRY CO., LTD.
Application year: 1992
Main classification: E01F9
IPC codes: E01F9