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CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This patent application claims priority on U.S. Provisional Patent Application No. 60/945,602, filed on Jun. 22, 2007. 
     
    
     FIELD OF THE APPLICATION 
       [0002]    The present application relates to installation of roadside railing, and more particularly to an apparatus used in the installation of rails to posts. 
       BACKGROUND ART 
       [0003]    The installation of roadside railing is a labor-intensive operation, that involves operators supporting and handling rails so as to secure these rails to posts. There are ergonomic issues associated with this type of operation, as operators must show strength to be capable of repeatedly supporting the rails, while having to show dexterity in aligning rails to secure them to one another and fix them to posts. 
       SUMMARY 
       [0004]    It is therefore an aim of the present disclosure to provide a railing installation apparatus that addresses issues associated with the prior art. 
         [0005]    It is a further aim of the present disclosure to provide a method for installing railing that addresses issues associated with the prior art. 
         [0006]    Therefore, in accordance with the present invention, there is provided a railing installation apparatus comprising: a support platform adapted to be displaced alongside a road; an installation unit connected to the support platform, the installation unit comprising: a feed conveyor unit feeding rails to a carriage unit; and the carriage unit being actuated to orient rails to an installation position against posts, and to twist a series of rails connected at one end to said posts to an overlapping position with rails in the feed conveyor unit for end-to-end attachment of the rails. 
         [0007]    Further in accordance with the present invention, there is provided a method for installing rails on posts, comprising the steps of: providing a sequence of at least two rails secured end to end; fastening an end of one of the rails to a post; and twisting the sequence such that a free end is in position to be secured to an end of another rail. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0008]      FIG. 1  is a perspective view of a railing installation apparatus in accordance with an embodiment of the present disclosure; 
           [0009]      FIG. 2  is a side elevation view of the railing installation apparatus of  FIG. 1 ; 
           [0010]      FIG. 3  is a rear elevation view of the railing installation apparatus of  FIG. 1 ; 
           [0011]      FIG. 4  is a top plan view of the railing installation apparatus of  FIG. 1 ; 
           [0012]      FIG. 5  is a perspective view of the railing installation apparatus of  FIG. 1 , with an installation system extended horizontally and with a rail on a feed conveyor unit; 
           [0013]      FIG. 6  is a perspective view of the railing installation apparatus of  FIG. 5 , with the rail reaching a carriage unit; 
           [0014]      FIG. 7  is a perspective view of the railing installation apparatus of  FIG. 6 , with rails on the carriage unit and the feed conveyor unit; 
           [0015]      FIG. 8  is a perspective view of the railing installation apparatus of  FIG. 1 , during the installation of railing along a road; 
           [0016]      FIG. 9  is a perspective view of the railing apparatus of  FIG. 1 , having an optional loading system; and 
           [0017]      FIG. 10  is an enlarged perspective view of the loading system of  FIG. 9 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    Referring now to the drawings, and more particularly to  FIG. 1 , a railing installation apparatus is generally shown at  10 . The apparatus  10  has an installation system  11  and a trailer  12 . 
         [0019]    The installation system  11  is used to provide assistance to operators installing the rails, by supporting the weight of the rails to reduce the involvement of the operators in such tasks. 
         [0020]    The trailer  12  supports the installation system  11  and is displaceable alongside the road as the railing is being installed. The trailer  12  supports the stacks of rails A on platform  20  prior to their being installed. In the illustrated embodiment, the trailer  12  is a flat bed that is connected to a motorized vehicle (not shown), but may also be an integral platform of a vehicle (e.g., a truck). Wheels  21  are illustrated in  FIG. 1 . 
         [0021]    The installation system  11  has a feed conveyor unit  13 , a carriage unit  14  and an operator station  15  between the feed conveyor unit  13  and the carriage unit  14 . 
         [0022]    The feed conveyor unit  13  is used to supply rails from the stack of rails A to the carriage unit  14 . 
         [0023]    The carriage unit  14  relates the rails A (1) that are connected end to end and mounted to the vertical posts B ( FIG. 8 ) to (2) rails A being individually fed by the feed conveyor unit  13 . The carriage unit  14  orients the rails A toward their installation orientation against the posts B ( FIG. 8 ). 
         [0024]    The operator station  15  is positioned between the feed conveyor unit  13  and the carriage unit  14 , for an operator to secure rails in end-to-end fashion. Moreover, the operator station  15  features the controls by which the operator will actuate various movements of the installation system  11  and the carriage unit  14 . 
         [0025]    The installation system  11  is displaceable horizontally (i.e., along the X-axis) and vertically (i.e., along the Y-axis) with respect to the trailer  12 . More specifically, the installation system has a vertical displacement mechanism  16  and a horizontal displacement mechanism  17 , such that the feed conveyor unit  13 , the carriage unit  14  and the operator station  15  can all be displaced simultaneously. In the illustrated embodiment, the displacement mechanisms  16  and  17  involve telescopic members and hydraulic cylinders, but other similar systems may be used as well. In  FIG. 5 , the installation system  11  is shown in an extended position along the X-axis. 
         [0026]    Referring concurrently to  FIGS. 1 to 4 , the feed conveyor unit  13  is shown having a conveyor  30  having a series of inline rollers  31 . The rollers  31  are idler rollers (some of which are optionally actuated) that support rails, as is seen in  FIG. 5 . The rails are typically of the type having a sinusoidal section, with two valleys and a ridge, as is best seen in  FIG. 3 . When the rail A is on the conveyor  30 , the rollers  31  are accommodated in the underside of the ridge, whereby the rail A can simply be manually displaced along the conveyor  30  (i.e., in direction of the Z-axis). 
         [0027]    A stabilizing unit  33  is positioned at a downstream end of the conveyor  30 . The stabilizing unit  33  is a structure supporting additional rollers  34  that are above the rollers  31 . The rollers  34  are positioned so as to be accommodated in the valleys of the rails A, as is shown  FIG. 6 . By having rollers  31  and  34  in the valleys and ridge, the rail A in the stabilizing unit  33  will be prevented from moving in the X-axis and in the Y-axis. It is pointed out that the additional rollers  34  may be positionable to a set position to adjust the stabilizing unit  33  to different sizes of rails A. The stabilizing unit  22  has a telescopic support  33 A, by which the stabilizing unit  33  can be displaced vertically (along the Y-axis). 
         [0028]    Referring concurrently to  FIGS. 1 to 4 , the carriage unit  14  is in alignment with the conveyor  30  to allow rails A to be transferred from the conveyor  30  to the carriage unit  14 . The carriage unit  14  has a structure  40  that supports lower rollers  41  (in line with the rollers  31  of the conveyor  30 ), and upper rollers  42  (in line with the additional rollers  34  of the stabilizing unit  33 ). The rollers  42  are positioned so as to be accommodated in the valleys of the rails A, whereas the lower rollers  41  are in the underface of the ridge as is shown in  FIGS. 6 and 7 . Therefore, when a rail A is in the carriage unit  14 , it is prevented from moving in the directions of the X-axis and the Y-axis. 
         [0029]    The structure  40  of the carriage unit  14  is pivotally mounted to a remainder of the installation system  11 . More specifically, the structure  40  of the carriage unit  14  is mounted to a remainder of the installation system by a pivot joint  43 . Therefore, the structure  40  of the carriage unit  14  is pivotable to an installation position, as illustrated in  FIG. 8 . The degree of rotation of the structure  40  of the carriage unit  14  about the Z-axis is actuated by hydraulic cylinders or a motor (not shown). 
         [0030]    The structure  40  of the carriage unit  14  also has a telescopic support  44  ( FIG. 3 ), by which the structure  40  can be displaced vertically (along the Y-axis), independently of the feed conveyor unit  13 . The structure  40  can also be displaced horizontally (along the X-axis) to facilitate the installation of rails A. The horizontal displacement is independent from the horizontal displacement of a remainder of the installation system  11 . 
         [0031]    The operator station  15  has a seat  50 . When seated, an operator is between the stabilizing unit  33  and the carriage unit  14 . Although not shown, it is contemplated to provide a control unit for the operator to control the horizontal and vertical position of the installation system  11 , as well as the orientation of the structure  40  of the carriage unit  14 . 
         [0032]    Now that the components of the railing installation apparatus  10  have been described, an installation of rails to posts is explained. 
         [0033]    It has been noted that rails A can be twisted. More specifically, when two or three rails A are secured end to end, it has been tested that such an assembly of rails A can be twisted along the longitudinal axis by at least 90 degrees. Accordingly, referring to  FIG. 8 , while one end of a sequence of end-to-end rails A is secured to a post B 1  amongst posts B, the free end that is supported by the carriage unit  14  can be twisted to the position illustrated in  FIG. 7 . Therefore, the installation system  11  is used to interconnect rails A in end-to-end fashion. 
         [0034]    In an embodiment, the installation takes place in the following order. The apparatus  10  is positioned adjacent to posts B, and the vertical and horizontal displacement mechanisms  16  and  17  are actuated to position the installation system  11  close to posts B ( FIG. 8 ). 
         [0035]    Referring to  FIG. 5 , a rail A is positioned on the conveyor  30 , and is moved along the Z-axis, through the operator station  15  ( FIG. 6 ), and into the carriage unit  14 . When the rail A is out of the feed conveyor unit  13  and fully supported by the carriage unit  14 , the carriage unit  14  is pivoted to the position illustrated in  FIG. 8 . 
         [0036]    Simultaneously, another one of the rails A is positioned on the conveyor  30  and is moved along the Z-axis. As a portion of the rail A extends out of the stabilizing unit  33  of the feed conveyor unit  13 , it overlaps the end of the rail A that is supported by the carriage unit  14 , as is shown in  FIG. 7 . When a pair of rails A overlap as is illustrated in  FIG. 7 , the operator interconnects the rails A, using appropriate fasteners. 
         [0037]    The connected rails A are then displaced along the Z-axis, with the downstream rail A moving out of the carriage unit  14 , for the upstream rail A moving into the carriage unit  14  to be secured in end-to-end fashion with a subsequent rail A. 
         [0038]    When a sufficient number of rails A extend out of the carriage unit  14  toward the rear of the trailer  12 , another operator may start securing the rails A to the posts B. As is shown in  FIG. 8 , the carriage unit  14  is pivoted to the installation position, whereby the rails A extending out of the carriage unit  14  can be connected to posts using appropriate fasteners. The various degrees of freedom of the installation system  11  allow the rails A to be positioned properly with respect to the posts. 
         [0039]    When the rails A are fastened to the posts B, it is necessary that a suitable length of rails from the carriage unit  14  not yet be secured to posts. As is shown in  FIG. 8 , between post B 1  and the carriage unit  14 , the rails A are not fastened to the posts B. Accordingly, the carriage unit  14  is pivoted back to the position illustrated in  FIG. 7 , thereby twisting a series of rails A as described above, such that an additional rail A may be installed in end-to-end fashion with the sequence of rails A downstream of the operator station  15 . The trailer  12  is displaced along the road as the sequence of rails A is installed to the posts. 
         [0040]    Referring concurrently to  FIGS. 9 and 10 , the railing installation apparatus  10  is illustrated as being equipped with a loading system  60 . The loading system  60  is mounted to the horizontal displacement mechanism  17  and is positioned adjacent to the feed conveyor unit  13 . The loading system  60  feeds rails A from the stack to the feed conveyor unit  13 . 
         [0041]    The loading system  60  is in the form of a bridge crane that has a support beam  61  with fingers  62  projecting downwardly therefrom. The support beam  61  translates horizontally and vertically, thus along the X-axis and the Y-axis. These translations are actuated by horizontal actuator  63  (e.g., a rack and pinion assembly with motor  63 A) and vertical actuator  64  (e.g., a rack and pinion assembly with motor  64 A). Actuatable clamps  65  are provided at the bottom end of the fingers  62  to separate then grasp the uppermost rail A from the stack, then raise the rail A, move the rail A to alignment with the feed conveyor unit  13 , and lower the rail A onto the feed conveyor unit  13 .

Summary:
A railing installation apparatus comprises a support platform adapted to be displaced alongside a road. An installation unit is connected to the support platform. The installation unit comprises a feed conveyor unit feeding rails to a carriage unit. The carriage unit is actuated to orient rails to an installation position against posts, and to twist a series of rails connected at one end to the posts to an overlapping position with rails in the feed conveyor unit for end-to-end attachment of the rails.