Patent Application
20080251595
The present invention relates to an isolator for use with a rail anchor and, more particularly, to an isolator for use with a rail anchor applied to railroad rail mounted on concrete ties.
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. One approach to restricting and restraining rail used with concrete ties is shown in U.S. Pat. No. 5,016,816.
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.
It is another object of the present invention to provide a rail anchor isolator with improved positioning capabilities.
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 center section joins the front face section and rear face section and forms part of the top of the isolator. In another embodiment, the front face section includes a top section and bottom section, with the top section having a lower edge projecting laterally at an acute angle from the bottom section. Similarly, the rear face section includes a top section and a bottom section, with the top section having a lower edge projecting laterally at an acute angle from the bottom section. Both the front face section and rear face section include a positioning rib or positioning tabs on inner surfaces thereof.
The isolator is adapted to receive a rail anchor such that either the front face section or the rear face section of the isolator would contact the concrete tie and thereby isolate the steel rail anchor from the concrete tie.
In the drawings,
Referring now to
Front face section 12 is seen to be a generally elongated, rectangular structure having a top edge, a bottom edge 13, and two side edges 33 and 35. Front face section 12 also includes rib section 14 which extends laterally and includes an angle section 16 that extends from front face section depending lower section 18. Front face section depending lower section 18 is seen to taper to a decreasing thickness toward bottom edge 13.
Similarly, rear face section 23 is seen to be a generally elongated, rectangular structure having a top edge, a bottom edge 31, and two side edges 37 and 39. Rear face section 23 also includes rib section 24 which extends laterally and includes an angle section 26 that extends from front face section depending lower section 28. Rear face section depending lower section 28 is seen to taper to a decreasing thickness toward bottom edge 31.
Front face section 12 inner surface 19 is seen to have a rib 53 extending along its length adjacent bottom edge 13.
Rear face section 23 inner surface 29 is seen to have a rib 51 extending along its length adjacent bottom edge 31.
Front face section 12 is seen to have inner surface 19 and rear face section 23 is seen to have inner surface 29. These surfaces are spaced laterally by a distance A, which is seen to be less than the height of front face section 12, shown as H in
Center section 20 is seen to have longitudinal edges 32 and 34. These edges are inlet a distance B from the longitudinal edge 33 of front face section 12 and the longitudinal edge 37 of rear face section 23.
Referring now to
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 which fit through a spacing A between inner surface 19 of front face section 12 and inner surface 29 of rear face section 23. This fitting arrangement tends to keep rail isolator 10 in place between rail anchor 50 and concrete tie 40. Front face section 12 rib 53 and rear face section 23 rib 51 are seen to fit around and hold rail anchor 50 lower edge 56.
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.
Referring now to
Front face section 112 is seen to be a generally elongated, rectangular structure having a top edge, a bottom edge 113, and two side edges 133 and 135. Front face section 112 also includes rib section 114 which extends laterally and includes an angle section 116 that extends from front face section depending lower section 118. Front face section depending lower section 118 is seen to taper to a decreasing thickness toward bottom edge 113.
Similarly, rear face section 123 is seen to be a generally elongated, rectangular structure having a top edge, a bottom edge 131, and two side edges 137 and 139. Rear face section 123 also includes rib section 124 which extends laterally and includes an angle section 126 that extends from front face section depending lower section 128. Rear face section depending lower section 128 is seen to taper to a decreasing thickness toward bottom edge 131.
Front face section 112 is seen to have inner surface 119 and rear face section 123 is seen to have inner surface 129. These surfaces are spaced laterally by a distance A′, which is seen to be less than the height of front face section 112, shown as H′ in
A certain support 170 is seen to extend perpendicularly between inner surface 119 and inner surface 129.
Front face section 112 inner surface 119 is seen to have two elongated positioning tabs 163 extending from lower surface 121 of center section 120 to almost halfway down along inner surface 119.
Inner surface 119 also includes two angled positioning tabs 165 located near edges 137 and 139. Positioning tabs 165 are elongated raised structures on inner surface 119 and extend at an acute angle to top surface 122.
Inner surface 129 also includes two angled positioning tabs 166 located near edges 133 and 135. Positioning tabs 166 are elongated raised structures on inner surface 129 and extend at an acute angle to top surface 122.
Rear face section 123 inner surface 129 is seen to have two elongated positioning tabs 161 extending from lower surface 121 of center section 120 to almost halfway down along inner surface 129.
Center section 120 is seen to have longitudinal edges 132 and 134. These edges are inset from inlet a distance B′ from the longitudinal edge 133 of front face section 112 and the longitudinal edge 137 of rear face section 123.
Referring now to
A rail anchor 150 is shown as comprising a bent, steel structure having a top end 152 extending to a lower end 154. Rail 142 is seen to be received in rail anchor 150 in a usual fashion. Further, rail anchor 150 includes a lower edge 156 with an upper surface 157 which is spaced below and around rail anchor isolator 110; upper surface 157 contacts or abuts center section 120. It is seen that rear face section 123 provides insulation and spacing between concrete tie side 144 and rail anchor 150. Further, rear face rib section 124 is seen to include angle section 126 which is adjacent a similarly angled section 149 of concrete tie 140.
Rail anchor 150 is seen to have intermediate sections 162 and 164 which fit through a spacing A′ between inner surface 119 of front face section 112 and inner surface 129 of rear face section 123. This fitting arrangement tends to keep rail isolator 110 in place between rail anchor 150 and concrete tie 140. Front face section 112 tabs 163 and rear face section 123 tabs (not shown) are seen to fit around end hold rail anchor 150 lower edge 156, upper surface 157.
Angled positioning tabs 165 are seen to fit and position against an outer edge of rail anchor 150. Similarly, though not shown, angled positioning tabs 166 fit and position against an opposite outer edge of rail anchor 150.
