Patent Application
20100019056
The present invention relates to an isolator for use with a rail anchor and, more particularly, to an isolator for use with a concrete railroad tie.
In the installation and operation of railroad rail, the standard rail fastener is a spike driven into a wood tie on either side of the rail. Such arrangement is designed to keep the lateral spacing between rails to maintain gauge distance. Tie plates are also utilized as bearing pads against lateral and vertical forces.
Special problems have arisen due to the use of concrete ties in certain railroad rail installations. Certain approaches to restricting and restraining rail used with concrete ties are shown in U.S. Pat. Nos. 5,016,816, 7,147,169 and 7,374,110.
The particular problem with railroad rail mounted on concrete ties is longitudinal rail movement when holding is provided with resilient fasteners. Rail anchors can be used to restrict such longitudinal rail movement, which typically occurs during the acceleration and deceleration of trains or the expansion and contraction due to temperature changes. However, abrasions from the steel rail anchor against the concrete tie tend to erode and eventually damage the concrete tie.
Accordingly, it is an object of the present invention to provide an improved isolator for use with a rail anchor, particularly adapted for use with concrete ties.
The present invention provides an isolator particularly adapted for use with a rail anchor utilized in an application where railroad rail is installed on concrete ties. The isolator protects the concrete tie from longitudinal movement of the rail due to expansion and contraction due to changing temperatures, and the acceleration and deceleration of trains.
In one embodiment, the isolator is comprised of a structural plastic material and includes a front face section and a rear face section. The front face section and rear face section each comprise a generally rectangular structure, having a top edge, bottom edge, and side edges. A top and a bottom section join the front face section and rear face. A support section extends from an intersection of the rear face section and the bottom section. The rail isolator is designed to be embedded in a concrete railroad tie.
In the drawings,
Referring now to
Rail anchor isolator 10 also includes two side faces 33 and 35.
Rear face section 23 is seen to be a generally elongated, rectangular structure having a top edge intersecting with top section 20. Rear face section 23 also includes a lower portion which forms part of support section 24. Support section 24 is seen to extend outwardly from rear face section 23, and includes a rounded corner 25. Support section 24 also extends downwardly from bottom section 13. Corner 25 is preferably rounded, but may be of an angular shape as well.
As installed, rail isolator 10 is placed within a top corner of concrete railroad tie 40, which is a generally elongated rectangular structure, having edges 44 and 45, and top surface 46. A railroad rail is shown at 42 which includes a bottom edge or surface 43. A spacer 47 is provided on top 46 of concrete tie 40 to provide a space and support for rail 42.
A rail anchor 50 is shown as comprising a bent, steel structure having a top end 52 extending to a lower end 54. Rail 42 is seen to be received in rail anchor 50 in a usual fashion. Further, rail anchor 50 includes a lower edge 56 with an upper surface 57 which is spaced below and around rail anchor isolator 10; upper surface 57 contacts or abuts center section 20. It is seen that rear face section 23 provides insulation and spacing between concrete tie side 44 and rail anchor 50. Further, rear face rib section 24 is seen to include angle section 26 which is adjacent a similarly angled section 49 of concrete tie 40.
Rail anchor 50 is seen to have intermediate sections 62 and 64 to keep rail anchor 50 in place on rail 42.
It should be understood that rail anchor isolator 10 is a unitary device, usually made in an injection molding operation. The preferred material for rail anchor isolator 10 is a structural plastic, usually comprising about half a high density polyethylene, and about half a low density polyethylene component mix. Rail anchor isolator 10 is typically placed in a mold when concrete tie 40 is being formed by pouring concrete into a mold. Rail anchor isolator 10 is held in concrete railroad tie 40 by the forming of concrete adjacent rear face section 23, bottom section 13, and round support section 24. Support section 24, by extending either beyond rear face section 23 or bottom section 13, or both, is held within concrete railroad tie 40.
Support section 24 itself is comprised of an upper surface 27 that extends at an acute angle downwardly from rear face section 23. Main section 29 extends generally downwardly from upper section 27. Rounded corner 25 forms the intersection between inner section 29 and lower section 31. Lower surface 31 extends from bottom section 13 at an acute angle.
