Patent Publication Number: US-2017356202-A1

Title: Vertically raising safety rail

Description:
RELATED APPLICATION 
     The present patent application claims priority to U.S. Provisional Patent Application Ser. No. 62/085,147, filed Nov. 26, 2014, and entitled “Vertically Raising Safety Rail.” 
    
    
     TECHNICAL FIELD 
     The present invention relates to a vertically raising safety rail having a base, a moveable center rail assembly, and a moveable top rail with a pair of operably connected upper and lower linkage arms assemblies configured to move the center rail assembly relative to the base and the top rail relative to the center rail assembly. A motor provides a rotational force to a drive shaft that transmits a force to the lower linkage arm assemblies in order to move the center rail assembly and, in turn, the top rail. The invention is also capable of collapsing into a compact size. 
     BACKGROUND OF THE INVENTION 
     Safety rails are known and required as an OSHA requirement on industrial sites and a good safety tool. However, some applications where lifts are required to get to the work space make a traditional non moveable safety rail impractical or dangerous. A moveable safely rail system that vertically raises and lowers, depending on the application, is desirable and currently unknown. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is directed to a vertically raising safely rail having a moveable top rail, a base, and a moveable center rail assembly that is positioned above the base and below the top rail. A pair of lower linkage arm assemblies is operably connected to the base and the center rail assembly and configured to move the center rail assembly relative to the base. A corresponding pair of upper linkage arm assemblies is operably connected to the center rail assembly and the top rail and configured to move the top rail relative to the center rail assembly. Each individual lower linkage arm assembly and corresponding upper linkage arm assembly are operably connected. The invention further includes a motorized drive shaft that transmits a rotational force to the lower linkage arms assemblies in order to move the lower linkage arm assemblies between the base and center rail assembly, thereby raising or lowering the center rail assembly. The upper linkage arm assemblies, being operably connected to the lower linkage arm assemblies, also move the top rail relative to the center rail. When the rotational force is reversed, the safety rail collapses into a compact footprint. 
     These and other advantages are discussed and/or illustrated in more detail in the DRAWINGS, the CLAIMS, and the DETAILED DESCRIPTION OF THE INVENTION. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying figures, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments. 
         FIG. 1  is a rear isometric view of a vertically raising safety rail system of the present invention in the raised position; the safety rail system illustrating a top rail; a center rail assembly having a center rail, one or more optional slidable rail guide tube that receives and supports the center rail, and one or more optional rail stops; a base support; at least one drive shaft; and a pair of upper and lower linkage arm assemblies; 
         FIG. 2  is a rear view of the safety rail system of  FIG. 1 ; 
         FIG. 3  is a front view of the safety rail system of  FIG. 1 ; 
         FIG. 4  is a top view of the safety rail system of  FIG. 1 ; 
         FIG. 5  is a bottom view of the safety rail system of  FIG. 1 ; 
         FIG. 6  is a left side view of the safety rail system of  FIG. 3 ; 
         FIG. 7  is a right side view of the safety rail system of  FIG. 1 ; 
         FIG. 8  is an enlarged rear view of a first embodiment lower linkage arm assembly in a raised position illustrating a worm gear in mating connection with a threaded shaft to obviate the need for a threaded nut and ball screw; 
         FIG. 9  is the same as  FIG. 8  except illustrating the lower linkage arm assembly in the fully collapsed position; 
         FIG. 10  is an enlarged rear perspective view of the worm gear; 
         FIG. 11  is an enlarged rear view of a second embodiment lower linkage arm assembly in a raided position with an arm plate and fork bracket connected to a threaded nut/ball screw assembly; 
         FIG. 12  is a rear perspective view of a third embodiment lower linkage arm assembly in a partially raised position illustrated with a drag linkage arm attached to the threaded nut/ball screw assembly; 
         FIG. 13  is an exploded rear perspective view of the safety rail better illustrating the mesh gear assembly: 
         FIG. 14  is a side view of the exploded safety rail of  FIG. 13 ; 
         FIG. 15  is a rear view of the safety rail in the fully collapsed position; 
         FIG. 16  is a rear perspective view of the safety rail in a slightly raised position; 
         FIG. 17  is a rear view of the safety rail in a partially raised position; 
         FIG. 18  is a rear view of the safety rail in the fully raised position; 
         FIG. 19  is rear view of a fourth embodiment lower linkage arm assembly in a raised position with an arm plate and telescoping member and solid fork bracket connected to the threaded nut/ball screw assembly; 
         FIG. 20  is a rear isometric view like  FIG. 1  except illustrating optional springs between the optional slidable guide rails and optional rail stops and illustrating a fifth embodiment lower linkage arm assembly in raised position with rail bearing assembly, linkage arm, and threaded nut/ball screw assembly; 
         FIG. 21  is a rear view of  FIG. 20 ; 
         FIG. 22  is an enlarged rear view of the fifth embodiment lower linkage arm assembly in the nearly collapsed position; 
         FIG. 23  is an enlarged rear view of the fifth embodiment lower linkage arm assembly in the nearly fully raised position; 
         FIG. 24  is a front view of the safety rail of  FIG. 20 ; and 
         FIG. 25  is a is a side view illustrating an optional kick plate operably connected to the base and an optional curtain that is operably connected to a portion of the base and the top rail and raises and lowers when the safety rail is raised or lowered. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1-7 , a collapsible safety rail  10  has a moveable top rail  12 , a moveable center rail  14 , a base  16  supporting a drive shaft  18  positioned between two threaded shafts  20 , a pair of spaced apart rotating upper linkage assemblies  22 , and a pair of spaced apart rotating lower linkage arm assemblies  24 . Each upper linkage assembly  22  is operably connected to its corresponding lower linkage arm assembly  24  at a midpoint and is further connected to a slidable rail guide tube  28  that receives the center rail  14 . 
     Referring now to  FIGS. 8, 9, and 10 , a first embodiment lower linkage assembly includes a lower linkage arm  30  that is connected to a worm gear  32 . The worm gear travels along its corresponding threaded shaft that is bordered by a drive shaft coupling  36  and a pillow support bracket  38 . Rotational force is transferred to linear motion via the threaded shaft and the worm gear attached to the lower linkage arm. 
     Referring now to  FIG. 11 , a second embodiment lower linkage assembly includes an arm plate  40  that is connected to a fork bracket  44  that allows the shortened link arm to travel along the length of a slot  46  within the fork bracket  44 . The fork bracket is connected to a ball screw and threaded nut assembly  48  that is capable of travelling the length of the unbounded threaded shaft  20 . Each ball screw and threaded nut assembly  48  can travel up to 16 inches along the threaded shaft  20  with a preferred travel span of 12 inches. Here, rotational force is transferred to linear motion via the threaded shaft to the ball screw/threaded nut assembly to the fork bracket, arm plate and connected lower linkage arm. 
     Referring now to  FIG. 12 , a third embodiment lower linkage assembly includes the arm plate  40  and linkage arm  30  as discussed above, but also includes a short drag linkage arm  42  that is connected to the ball screw/threaded nut assembly  48 , also as discussed above. Here, rotational force is transferred to linear motion via the threaded shaft to the ball screw/threaded nut assembly to the short drag linkage arm to the arm plate and connected lower linkage arm. 
     Referring now to  FIG. 19 , a fourth embodiment lower linkage arm assembly includes an arm plate  40  connected to a linkage arm  30  as discussed above. But instead of a short drag linkage arm  42  or slotted fork bracket  44  of  FIGS. 12 and 11 , respectively, the arm plate is connected to a short telescoping member  66  attached to a solid fork bracket  68  that is attached to the ball screw/threaded nut assembly  48 . 
     Referring now to  FIGS. 20-24 , a fifth embodiment lower linkage arm assembly includes an arm plate  40  connected to a linkage arm  30  as discussed above and also includes a short drag linkage arm  42  that is attached the ball screw/threaded nut assembly  48 . Here, though, the rotation function is effectuated though a double tapered bearing  41  that is integrated into lower linkage arm assembly. 
     Referring again to  FIGS. 1-7 , as well as  FIGS. 13, 14, 20, 21, and 24 , each lower linkage arm  30  is attached to its corresponding upper linkage assembly through a midpoint mesh gear assembly  50 , which includes two meshed gears: a lower mesh gear  52 , and an upper mesh gear  54 , as well as a gear plate  55 . As best illustrated in  FIG. 14 , each set of two gears  52 ,  54  and corresponding gear plate  55  is positioned about and connected to a corresponding rail guide tube  28  in which the center rail  14  is support and lifted when the linkages arms rotate. 
     Referring also to  FIGS. 15-18 , each upper linkage arm  22  includes an upper linkage arm  58  that is connected to upper mesh gear  54  at a lower end of the upper linkage arm. An upper end of the linkage arm  58  is connected to top rail  12 . In use, the mesh gear assembly  50  functions like an elbow respective to upper linkage arm  58  and lower linkage arm  30  that allows the upper and lower linkage arms to form an angle α that ranges from 0 degrees (fully collapsed position) to 150 degrees (fully raised position) or any position therebetween. The mesh gear assembly maintains chocking of the upper and lower linkage arms and the level nature of the top and center rail. 
     Any rotational force in one direction (e.g., clockwise) may be applied to the drive shaft, which will transfer torque to the threaded shaft, and thereby to the threaded screw. In this manner, the ball screw turns rotational motion to linear motion via the threaded nut. The threaded screw will rotate the nut to move in a linear direction. The nut moves the short linkage arm which rotates (and raises) the lower linkage arm  30 . This raising of the lower linkage arm will also simultaneously turn lower mesh gear  52 , which is joined and attached to upper mesh gear  54 . This will force angle α between the linkage arms to increase. The movement of the mesh gear assembly, which is connected to slidable rail guide tube  28 , forces the rail guide lube to move inwardly along center rail  14 . Rail stops  56  are positioned along center rail to stop the rail guide tube from moving too far and causing rail instability. Upper linkage arm  50  rotates upwardly as upper mesh gear  54  is turned, which raises upper rail  12  as the outer end of the upper linkage arm Is attached to upper rail  12  via pins or other fasteners. 
     As illustrated in  FIGS. 20, 21, and 24  optional rail springs  51  may be positioned between the rail guide tube and the rail stop to put tension on the rail guide tube and upper and lower linkage arm assemblies to better hold a vertically upright position. The rail springs keep the center rail aligned with the top rail to prevent “walking” back and forth during motion. 
     A rotational force in the other direction (e.g., counter clockwise) will rotate the threaded shaft and, therefore the ball screw and threaded nut and all connected linkages, in the reverse direction. The ball screw and threaded nut will move the worm gear and move the short linkage arm  42 , and rotate the lower linkage arm  30  so that the lower mesh gear moves in the reverse direction with the upper mesh gear. This action decreases angle a so that the top rail and center rail lower as much as desired. When the rotational force stops, the safely rail maintains its position as of that time. When the safety rail is fully collapsed, the center rail is tucked under the top rail, such as illustrated in  FIG. 16 , for storage purposes. 
     In one form of the invention, a motor  60  is added to drive shaft  18 . Drive shaft  18  may be in two pieces as illustrated in  FIGS. 1-7  with the motor being placed therebetween to rotate each drive shaft. The motor may be pneumatic (e.g., an air motor), electrical, hydraulic, or magnetic. 
     The invention is adaptable for explosion proof applications, such as painting in a large manufacturing facility. Air motors, (such as explosion proof C1D1 air motors) are particularly suited for explosion proof applications, such as painting airplane parts. An operator with a manual pneumatic valve delivers air pressure to two inputs (orifices) on the air motor. Air pressure to the first input raises the safety rail as described above. Air pressure to the second input lowers the safety rail as described above. In such an air motor application, a rotating air motor shaft transfers rotational force to a drive belt through two cogged pulleys and a cogged belt (not illustrated). Rotational force is transferred  10  the drive shaft (or drive shafts) via a second cogged pulley (also not illustrated). 
     An optional speed reducer  62  may be added. A pair of reducer couplers  64  may be positioned between the speed reducer  62  and the two drive shafts (as illustrated in  FIGS. 1 and 2 ). 
     Referring to  FIG. 25  an optional kick plate  66  make be added to the base. The kick plate will rotate or slide vertically during employment. Further, an optional raisable safety curtain  68  may be interconnected to base  16 , such as through a box  70  attached to base  16 . The safety rail is curled up in the box and unrolls out through a slot and is attached to the top rail. The safety curtain raises when the safety rail is raised and curls back in its box when the safety rail is collapsed and can be attached on either side. 
     The safety rail system can be adapted for industrial use, commercial use, and residential use (both indoors and outdoors). Indoor residential applications can be made from lightweight materials and made in a smaller configuration to function as a pet or child gate.