Yoke assembly for use in a collapsible handrail assembly and a handrail assembly incorporating the same

Abstract

A handrail assembly for a tank trailer and a yoke assembly forming a part thereof. Handrail assembly provides a safety device for an operator walking along a top wall of the tank trailer. The handrail assembly includes a top rail, a plurality of vertical members, a safety wire and, in most instances, a bottom rail. Each yoke assembly secures one of the top and bottom ends of the vertical members to either of the top and bottom rails or to a mounting bracket on the tank. Each yoke assembly includes a base member engaged partially in a bore of the vertical member, and a cradle member engaged with an exterior all of the top or bottom rails or mounting bracket. Base and cradle members are secured together by a pivot pin. Fluid-actuated cylinders extending between the vertical members and the tank move the handrail assembly between collapsed and expanded positions.

1 . A yoke assembly for securing a vertical rail to a horizontal rail in a collapsible handrail assembly, said yoke assembly comprising:
 a base member having a first end, a second end and a peripheral wall extending therebetween, said base member having a longitudinal axis extending between said first and second ends,   a first aperture defined in the peripheral wall and substantially at right angles to the longitudinal axis of the base member; and wherein said base member is adapted to be at least partially received within a bore of the vertical rail;   a cradle member having a first end, a second end and sidewall extending therebetween; said cradle member further having a longitudinal axis that extends between the first and second ends thereof; and wherein the second end of the cradle member is adapted to engage an exterior region of a sidewall of the horizontal rail;   a hole defined in the cradle member and being disposed substantially at right angles to the longitudinal axis thereof, said cradle member being selectively engageable with the base member such that the hole and the first aperture are aligned; and   a pivot pin extending through the aligned first aperture and hole; said pivot pin securing the base and cradle members together and permitting them to pivot relative to each other about an axis disposed at right angles to the longitudinal axes of the base and cradle members.   
     
     
         2 . The yoke assembly as defined in  claim 1 , further comprising:
 a locking member selectively engageable with the pivot pin once inserted through the aligned first aperture and hole to prevent withdrawal of the pivot pin therefrom.   
     
     
         3 . The yoke assembly as defined in  claim 1 , wherein the base member further comprises:
 a first region having a first diameter and being adapted to be received within the bore of the vertical rail; and   a second region continuous with the first region and having a second diameter greater than the first diameter of the first region, and wherein said second diameter is adapted to be greater than a diameter of the bore in the vertical rail.   
     
     
         4 . The yoke assembly as defined in  claim 3 , wherein the base member further comprises:
 a third region continuous with the second region and extending longitudinally outwardly therefrom, said third region being of a width that is smaller than the second diameter, and wherein the first aperture is defined in the third region.   
     
     
         5 . The yoke assembly as defined in  claim 4 , wherein the third region comprises:
 a first arm extending longitudinally outwardly from the second region of the base member;   a second arm extending longitudinally outwardly from the second region of the base member; and   a gap defined between the first arm and the second arm; and wherein the width of the third region is measured from an exterior longitudinal surface of the first arm to an exterior longitudinal surface of the second arm.   
     
     
         6 . The yoke assembly as defined in  claim 5 , wherein
 a first section of the first aperture is defined in the first arm and is disposed substantially at right angles to the longitudinal axis of the base member; and   a second section of the first aperture is defined in the second arm and is disposed substantially at right angles to the longitudinal axis of the base member and aligned with the first section of the first aperture;   
     
     
         7 . The yoke assembly as defined in  claim 1 , wherein the cradle member comprises:
 a stem that is selectively engageable with the base member; and wherein the hole is defined in the stem; and   a rest that extends outwardly from the stem and is adapted to engage the horizontal rail.   
     
     
         8 . The yoke assembly as defined in  claim 7 , wherein the rest includes a face that is complementary in shape to the exterior region of the sidewall of the horizontal rail. 
     
     
         9 . The yoke assembly as defined in  claim 8 , wherein the longitudinal axis of the base member is substantially aligned with the longitudinal axis of the cradle member. 
     
     
         10 . The yoke assembly as defined in  claim 8 , wherein the longitudinal axis of the base member is substantially parallel to and offset from the longitudinal axis of the cradle member. 
     
     
         11 . A collapsible handrail assembly for use on a top region of a tank trailer, said handrail assembly comprising:
 a first horizontal rail having a first end, a second end and a first exterior wall therein between, said first horizontal rail having a first longitudinal axis that extends between the first and second ends thereof;   a second horizontal rail having a first end, a second end and a second exterior wall thereinbetween, said second horizontal rail having a second longitudinal axis that extends between the first and second ends thereof;   a vertical rail having a first end, a second end and a sidewall extending therebetween, said vertical rail having a third longitudinal axis that extends between the first and second ends thereof, and wherein a longitudinal bore is defined in the vertical rail;   a first yoke assembly engaged with the first end of the vertical rail and a portion of the first exterior wall of the first horizontal rail such that the vertical rail is able to pivot relative to the first horizontal rail about a first axis disposed at right angles to the third longitudinal axis; and   a second yoke assembly engaged with the second end of the vertical rail and a portion of the second exterior wall of the second horizontal rail such that the vertical rail is able to pivot relative to the second horizontal rail and about a second axis disposed at right angles to the third longitudinal axis.   
     
     
         12 . The handrail assembly as defined in  claim 11 , wherein each of the first and second yoke assemblies comprises:
 a base member at least partially receivable in the bore of the vertical rail, said base member including a first end, a second end and a peripheral wall extending therebetween, said base member having a longitudinal axis extending between the first and second ends thereof,   a first aperture defined in the peripheral wall and substantially at right angles to the longitudinal axis of the base member;   a cradle member having a first end, a second end and sidewall extending therebetween; said cradle member further having a longitudinal axis that extends between the first and second ends thereof; and wherein the second end of the cradle member is configured to engage a region of one of the first and second exterior sidewalls of the first and second horizontal rails;   a hole defined in the cradle member and disposed substantially at right angles to the longitudinal axis thereof, said cradle member being selectively engageable with the base member such that the hole and the first aperture are aligned; and   a pivot pin extending through the aligned first aperture and hole, said pivot pin securing the base and cradle members together and permitting them to pivot relative to each other about an axis disposed at right angles to the longitudinal axes of the base and cradle members.   
     
     
         13 . The handrail assembly as defined in  claim 12 , further comprising:
 a locking member engageable with the pivot pin once inserted through the aligned first aperture and hole to prevent withdrawal of the pivot pin therefrom.   
     
     
         14 . The handrail assembly as defined in  claim 12 , wherein the base member further comprises:
 a first region having a first diameter that is complementary to the bore of the vertical rail, and wherein the first region is received within the bore;   a second region having a second diameter that is greater than the first diameter, wherein the second region abuts one of a top edge at the first end of the vertical rail and a bottom edge at the second end of the vertical rail, and extends laterally outwardly for a distance beyond the sidewall of the vertical rail.   
     
     
         15 . The handrail assembly as defined in  claim 14 , wherein the base member further comprises:
 a first arm extending outwardly from the second region, said first arm being generally parallel to the longitudinal axis of the base member and to the third longitudinal axis of the vertical rail; and wherein the first aperture is defined in the first arm.   
     
     
         16 . The handrail assembly as defined in  claim 15 , said cradle member comprising:
 a stem having a first end and a second end and having a longitudinal axis extending therebetween; and wherein the hole is defined in the stem and is oriented substantially at right angles to the stem's longitudinal axis; and   a rest extending outwardly from the stem, said rest defining a face that is complementary to a portion of one of the first and second exterior walls of the first and second horizontal rails.   
     
     
         17 . The handrail assembly as defined in  claim 16 , wherein the base member further comprises:
 a second arm extending outwardly from the second region of the base member, said second arm being generally parallel to the first arm;   a gap defined between the first and second arms;   a second aperture defined in the second arm and extending substantially at right angles to the longitudinal axis of the base member, and wherein the second aperture is aligned with the first aperture; and wherein the stem of the cradle member is received in the gap between the first and second arms, such that the hole in the stem member is aligned with the first and second apertures and the pivot pin is received through the aligned hole and first and second apertures.   
     
     
         18 . The handrail assembly as defined in  claim 17 , wherein the cradle member further comprises:
 a leg extending outwardly from the rest and substantially parallel to the stem;   a slot defined between the stem and the leg, and wherein one of the first and second arms of the base member is received within the slot;   a second hole defined in the leg, said second hole being oriented substantially at right angles to the stem's longitudinal axis and is aligned with the hole in the stem, and wherein the pivot pin extends through the aligned hole, second hole, and first and second apertures.   
     
     
         19 . The handrail assembly as defined in  claim 18 , wherein the face of the cradle member is fixedly secured to the portion of the one of the first and second exterior walls of one of the first and second horizontal rails. 
     
     
         20 . The handrail assembly as defined in  claim 11 , wherein the first and second horizontal rails are disposed substantially parallel to each other and a longitudinal axis of each of the first and second yoke assemblies is disposed substantially parallel to the first and second longitudinal axes of the first and second horizontal rails, and wherein the pivotal motion of the vertical rail enabled by the first and second yoke assemblies occurs about axes that are disposed at right angles to the longitudinal axes of the first and second yoke assemblies. 
     
     
         21 . The handrail assembly as defined in  claim 20 , wherein the first and second horizontal rails are substantially aligned with each other and with the vertical rail in the same vertical plane. 
     
     
         22 . The handrail assembly as defined in  claim 20 , wherein the first and second horizontal rails are offset a horizontal distance relative to each other, and wherein at least one of the first and second yoke assemblies includes an extension piece that is of a length sufficient to make up the horizontal distance between the first and second horizontal rails.