Roller side bearing mounting system and method

A mechanical fastening system for fixedly securing the bottom wall of a side roller bearing cage to a top surface portion of a rail car truck for accommodating swivel movement between said truck and an associated rail type car wherein said bottom wall and top surface portion each have at least one opening which may be placed in registry with each other, said fastening system comprising:

• an elongated threaded fastener extending through the registered openings in said bottom wall and top surface portion, said fastener having a head and an elongated shank threaded along at least the outermost end section thereof wherein said head and shank interface with each other at a distinct fillet area, said head being cooperable with said bottom wall with said shank having a length sufficient to extend through the registered openings in said bottom wall and top surface portion so that said threaded outermost end is disposed in threaded engagement with a retaining means disposed on the underside of said top surface portion, said threaded fastener being placed in some desired clampload condition within predetermined upper and lower limits by rotating said fastener into threaded advancement with said retaining means, wherein said desired clampload is less than an amount which would cause failure in said bearing cage and greater than an amount which increases the potential for failure in said fastener when it is subjected to tensile and bending loads resulting from loading of said side roller bearing cage during rolling travel of said rail car, said fastener further including means for limiting the torque applied thereto during fastener rotation into threaded advancement with said retaining means whereby the resultant fastener clampload may not exceed said upper limit;
• and, bearing means associated with said fastener and interposed between said fastener head and bearing cage bottom wall to facilitate control of frictional forces occurring at said head as said fastener is rotated into threaded engagement with said retaining means, said bearing means further protecting the fillet area of said fastener from being imbedded by the edges of said bearing cage bottom wall opening at least when said fastener is subjected to tensile and bending loads.

A method for fixedly securing the bottom wall of a roller side bearing cage to the top surface portion of a rail car truck assembly, said method comprising the steps of:

• passing the elongated shank of at least one mechanical fastener having a threaded section at least along the outermost end thereof through registered openings in said bottom wall and top surface portion such that an enlarged head on said fastener is cooperable with said bottom wall;
• interposing a bearing member between said fastener head and bottom wall for controlling frictional forces occurring therebetween and for protecting a distinct fillet area on said fastener at the interface between said head and shank when bending loads are applied to said fastener in response to normal movement of a rail car with which said truck assembly is associated;
• rotating said fastener at said head to threadedly advance said shank threaded section into retaining means disposed on the underside of said top surface portion;
• continuing said step of rotating until a clampload within predetermined upper and lower limits is obtained in said fastener;
• and,
• providing means associated with said fastener head for limiting the amount of torque which may be applied thereto during said step of continuing whereby the resultant clampload will not exceed said upper limit.

An arrangement for fixedly mounting a first member to a second member, said arrangement comprising in combination:

• a first member including a mounting surface portion having at least one first opening extending therethrough;
• a second member including a wall having at least one second opening extending therethrough in registry with said first opening;
• an elongated threaded fastener extending through said registered first and second openings, said fastener having a head and an elongated shank threaded along at least the outermost end section thereof wherein said head and shank interface with each other at a distinct fillet area, said head cooperating with said second member wall and said shank extending through said registered first and second openings with said threaded outermost end disposed in threaded engagement with retaining means disposed on the underside of said first member mounting surface portion, said threaded fastener being placed in some desired clampload condition within predetermined upper and lower limits as a function of rotating said fastener to secure threaded advancement thereof into said retaining means, said desired clampload being less than an amount which would cause failure in said second member and greater than an amount which increases the potential for failure in said fastener when said fastener is subjected to tensile and bending loads resulting from relative loading between said first and second members, said fastener further including means for limiting the torque applied thereto during fastener rotation into threaded advancement with said retaining means whereby the resultant fastener clampload may not exceed said upper limit;
• and,
• bearing means interposed between the head of said fastener and said second member wall to facilitate control of frictional forces occurring at said fastener head during rotation thereof into threaded engagement with said retaining means, said bearing means further protecting the fillet area of said fastener from being imbedded by said second member wall at said second opening at least when said fastener is subjected to tensile and bending loads.

A mechanical fastening system for fixedly securing a first member to a mounting surface portion of a second member wherein said first and second members each have at least one opening therethrough which may be placed in register with each other, said fastening system comprising:

• an elongated threaded fastener extending through the registered openings in said first and second members, said fastener having a head and an elongated shank threaded along at least the outermost end section thereof wherein said head and shank interface with each other at a distinct fillet area, said head being cooperable with said first member with said shank having a length sufficient to extend through the registered openings in said first and second members so that said threaded outermost end is disposed in threaded engagement with retaining means disposed on the underside of said second member mounting surface portion, said threaded fastener being placed in some desired clampload condition within predetermined upper and lower limits by rotating said fastener into threaded advancement with said retaining means, wherein said desired clampload is less than an amount which would cause failure in said first member and greater than an amount which increases the potential for failure in said fastener when it is subjected to bending and tensile loads resulting from relative loading of said first and second members, said fastener further including means for limiting the torque applied thereto during fastener rotation into threaded advancement with said retaining means whereby the resultant fastener clampload may not exceed said upper limit;
• and, bearing means associated with said fastener and interposed between said fastener head and said first member to facilitate control of frictional forces occurring at said head as said fastener is rotated into threaded engagement with said retaining means, said bearing means further protecting the fillet area of said fastener from being imbedded by the edges of said first member opening at least when said fastener is subjected to bending and tensile loads.