GB2193778A

GB2193778A - Securing rail spikes in sleepers

Info

Publication number: GB2193778A
Application number: GB08619275A
Authority: GB
Inventors: Reginald Frederick Morton
Original assignee: Multiclip Co Ltd
Current assignee: Multiclip Co Ltd
Priority date: 1986-08-07
Filing date: 1986-08-07
Publication date: 1988-02-17
Also published as: GB8619275D0

Abstract

An elastic rail spike 10 is secured in a rail sleeper 16 by inserting an insert 22 having a set of evenly spaced ratchet-like lugs 26 thereon, into a worn receiving hole in the sleeper 16, then driving into the hole the elastic rail spike 10 which is provided with complementary ratchet-like lugs 32 such that the lugs 26,32 on the insert 22 and spike 10 ride over each other but resist removal of the spike from the hole. Protusions 24 on the insert 22 bite into the sleeper 16 to hold the insert 22 in place. <IMAGE>

Description

SPECIFICATION Securing devices This invention relates to securing devices and more particularly to a securing device for taking up wear in rail spikes of the type known as elastic rail spikes.

The forces imposed on the rails of a railway line will gradually cause such elastic rail spikes which secure the rails to the sleepers to wear loose. The wear takes the form of an enlargement of the hole in the sleeper in which the elastic rail spike is located. Commonly, the enlargement is greatest on the rail-side of the hole. This uneven wear is due to the moment created in the spike about the top of the hole which moment causes the spike to abrade the rail side of the hole more than the side away from the rail.

Securing inserts for elastic rails are known which consist of a sleeve which is driven into the receiving hole. On the inner wall of the sleeve are formed a number of tangs which are intended to bite on an elastic rail spike inserted into the sleeve. However, the movement of the spike past the tangs forces them into the wall of the sleeve, reducing their ability to bite on the material of the spike.

According to the present invention there is provided a method of securing an elastic rail spike in a rail sleeper, the method comprising: inserting an insert, having a set of evenly spaced ratchet-like lugs thereon, in a receiving hole in the sleeper; providing an elastic rail spike, having complementary ratchet-like lugs, such that the corresponding lugs on the insert and spike are adapted to permit the elastic rail spike to ride down into the hole while mutually engaging so as to resist removal of the spike from the hole, and driving the said spike down into the hole with its lugs riding down over the lugs on the insert and engaging therewith.

Preferably the method is applied to resecuring an elastic rail spike in a worn rail sleeper and includes cutting the said complementary ratchet-like lugs in the said elastic rail spike.

Preferably, the insert comprises a flat metal body and a set of evenly spaced ratchet-like lugs is formed on one major face thereof.

Preferably, the insert has locating protrusions formed on the opposite major face of the insert to the lugs.

The present invention may be put into practice in various ways and one specific embodiment will now be described to illustrate the invention and by way of example with reference to the accompanying drawings in which: Figure 1 is a diagrammatic section through a sleeper and insert and spike assembly in accordance with the present invention; Figure 2 is a section through the insert along the arrow A in Fig. 1; and Figure 3 is a scrap section giving details of cooperating lugs on the insert and spike in Fig. 1.

Referring to Figs. 1 and 2, an elastic rail spike 10 having a square section is formed of a pair of leaves 12 and 13 of metal both of which are flat in the plane of the illustration.

The leaves 12 and 13 are joined at one end to form a nose 14 which is driven into a normally round hole in a sleeper 16 as an interference fit. The upper end of the spike left outside the hole secures a rail by means of a tongue 18 extending to one side of a shank portion 20 of the spike. The rail is located with its flange 19 seated in a chair 21.

The tongue 18 bears on a flange 19 of the rail (a small part of which is shown in Fig. 1) to hold it in place while allowing flexure in the length of the tongue 18 in the manner of a leaf spring.

According to the invention, a worn, generally square, receiving hole in a sleeper 16 has inserted into it an insert or shim 22. One face of the shim 22 has protrusions 24, typically spaced about 12 millimetres apart and 4 millimetres deep, for biting into the material of the sleeper 16 to hold the shim 22 in place. Each protrusion has an included angle of preferably 60C and is radiused to 1 millimetre at the tip.

The opposite wall of the shim 22 is formed with a series of regular ratchet-like lugs 26 typically spaced about 6 millimetres apart.

Each lug 26 has one face 28 inclined with respect to the axis of the hole and a corresponding face 30 which is substantially perpendicular to the axis of the hole. The outer and inner surfaces between the faces of the lugs 26 are flat and the depth of each lug is typically 2 millimetres.

A surface of the spike which faces the rail in use is also formed with a series of lugs 32, generally complementary to those on the shim 22 except that the opposing faces on each lug are farther apart than those on the shim 22 to allow the inclined surfaces on corresponding lugs to clear. This minimises the risk of inadequate engagement between the lugs 26 and 32 due to dirt on the inclined surfaces.

The clearance is illustrated in detail in Fig.

3. When an old elastic rail spike is being refitted it will have the lugs formed by grooving or milling across its appropriate face.

As the spike is forced into the hole, the protrusions 24 on the shim 22 are forced into the material of the sleeper. The inclined faces of the ridges on both the shim 22 and spike allow the spike to pass into the hole. However, the lugs will not not allow the spike to retreat out of the hole past the point of contact between adjacent corresponding abutting faces 30.

The shim is preferably made of a hardened aluminium. Alternatively cast iron or mild steel could also be used.

The grade of aluminium is preferably one having a shear strength of 15 tons or more e.g. 16 tons.

The material used for the shim or insert must be such that the elastic rail spike with the lugs in it can ride down over the lugs on the insert without shearing them off.

Claims

1. A method of securing an elastic rail spike in a rail sleeper, the method comprising: inserting an insert, having a set of evenly spaced ratchet-like lugs thereon, in a receiving hole in the sleeper; providing an elastic rail spike, having complementary ratchet-like lugs, such that the corresponding lugs on the insert and spike are adapted to permit the elastic rail to ride down into the hole while mutually engaging so as to resist removal of the spike from the hole; and driving the said spike down into the hole with its lugs riding down over the lugs on the insert and engaging therewith.

2. A method as claimed in Claim 1 applied to resecuring an elastic rail spike in a worn rail sleeper which includes cutting the said complementary ratchet-like lugs in the said elastic rail spike.

3. An insert for use on the method of Claim 1 or Claim 2 comprising a flat metal body and a set evenly spaced ratchet-like lugs formed on one major face thereof.

4. An insert as claimed in Claim 3, in which the locating protrusions are formed on the opposite major face of the insert to the lugs.

5. An insert for securing an elastic rail spike as claimed in Claim 3 substantially as described herein with reference to the accompanying drawings.

6. A method of securing an elastic rail spike in a rail sleeper as claimed in Claim 1 or Claim 2 substantially as described with reference to the accompanying drawings.