Improvements in and relating to rail fastening devices

Abstract

 A rail fastening device for flat bottom rails laid on a concrete slab-type track comprises a pair of identical gauge adjustment collars (4, 5) each having an aperture (6) such as to pass over a respective one of a pair of mounting blocks (1, 2) embedded in or secured to the track on either side of a rail (3) the aperture (6) being eccentric to provide at least two walls (e.g. a, d) of different thickness for lateral adjustment of the position of the rail (3) with respect to the mounting blocks (1, 2). A further pair of collars (12, 13) each with a concentric aperture (14) are in one embodiment of the invention located over the respective lateral adjustment collars (4, 5). A securing device (15) such as a spring clip is located between each mounting block (4, 5) and the respective height adjustment collar (12, 13) to exert clamping pressure on the rail.

Description

[0001] This invention relates to a rail fastening device for flat bottom rails laid on a concrete slab type track, and the invention particularly relates to an adjustable rail fastening device whereby a length of flat bottom rail may be adjusted laterally and/or vertically to allow for variations in rail dimensions, for errors in initial positioning of a rail, and for movement due to track settlement in addition to compensation for wear on the rail or to enable a worn rail to be jointed to a new rail when the track is completely or partially renewed.

[0002] In prior U.K. Patent Specification No. 1,336,999 there is described a rail fastening arrangement for securing a flat bottom rail on a foundation having preformed holes therein comprising in combination a baseplate on which the flat bottom of the rail is adapted to rest and means for securing the baseplate to the preformed holes in the foundation; a pair of rail clips one on each side of the rail; bolt means passing through a bolt aperture in each clip and engaging in a preformed bolt hole in the baseplate; each clip having symmetrically spaced about its bolt aperture at least two pairs of projecting heel lugs and the baseplate having symmetrically spaced about its bolt hole a complementary number of recesses adapted to receive and locate the clip heel lugs; each clip being engageable with the baseplate with the lugs received and located in the baseplate recesses, in at least two alternative dispositions; and each clip having for each lug a respective rail foot abutting and clamping shoulder, one of which rail foot abutting and clamping shoulders faces inwardly towards the rail foot for each alternative disposition of engagement of the clip with the baseplate; and wherein for each clip, each respective rail foot abutting and clamping shoulder is differentially spaced from the centre of the bolt aperture of the clip; and wherein each clip has upper and lower oppositely facing sides, there being on each of said sides at least one pair of projecting heel lugs symmetrically spaced about the bolt aperture of the clip, and for each lug a respective rail foot abutting and clamping shoulder, each respective such shoulder being differentially spaced from the centre of the bolt aperture of the clip.

[0003] In the rail adjustment device of the present invention, the vertical and lateral adjustment means are independent of one another and the device of the present invention allows a rail to be installed either before or after installation of the lateral adjustment collars.

[0004] An object of the invention is to provide an adjustable rail fastening device whereby a flat bottom rail may be adjusted vertically and/or laterally by comparatively unskilled labour by use of components inherently already available and forming part of the fastening device.

[0005] According to one aspect of the invention there is provided a rail fastening device for flat bottom rails comprising a pair of identical collars, each having an aperture dimensioned and shaped such as to pass over and be located around a respective one of a pair of mounting blocks shaped to match the respective collar and of similar section arranged to be embedded in or otherwise secured to the track on either side of a rail and in spaced relation therewith, the aperture of each collar being eccentric with respect to at least one axis thereof to provide at least two walls of different thickness such as to allow for lateral adjustment of the position of the rail according to tne particular wall of each collar located intermediate the respective mounting block and the foot of the rail, and securing means for holding the rail in the adjusted position with respect to said mounting blocks.

[0006] According to a furtner aspect of the invention there is provided a rail fastening device for flat bottom rails comprising a pair of identical collars each having a concentric aperture dimensioned and shaped such as to pass over and be located around a respective one of a pair of mounting blocks shaped to match the respective collar and arranged to be embedded or otherwise secured to the track on either side of a rail, adjacent walls of the collars having identical thickness but of different height such as to allow for vertical adjustment of the rail, each collar resting on a respective base flange of the rail and the securing means being clamped between the respective mounting block and associated collar.

[0007] The invention will now be described by way of example only with particular reference to the accompanying drawings wherein:

Figure 1 is a sectional view showing part of the device of the present invention for lateral and vertical adjustment of a rail showing the maximum rail adjustment for maximum rail wear;

Figure 2 is a sectional view showing the whole device of the present invention for lateral and vertical adjustment of a rail but with the rail laterally adjusted from the position shown in Figure 1;

Figure 3 is a plan view of part of the device shown in Figure 2.

[0008] The rail fastening and adjusting device of the invention is for flat bottom rails and particularly those laid on a concrete slab type track. Two mounting blocks 1, 2, are embedded in the concrete blocks or sleepers of the track on either side of a flat bottom running rail 3. The mounting clocks 1, 2, in the particular embodiment illustrated are square in plan for a purpose hereinafter described. A pair of gauge adjustment collars 4, 5, are located around the respective mounting blocks 1, 2, the two collars being identical (i.e. not handed) and each has a square section when viewed in plan (see Figure 3). Each collar 4, 5, is provided with a square aperture 6 which is a clearance fit when placed over the respective mounting block 1, 2, and the square aperture 6 is located eccentrically with respect to both axes of the collar thus providing four walls a, b, c, d each of different thickness. This difference in wall thickness is used to provide for lateral adjustment of the position of the rail 3 with respect to the fixed mounting blocks 1, 2.

[0009] As shown in Figure 2, the two adjustment collars 4, 5, are located over the respective mounting blocks 1, 2, such that the thin wall a of one collar 4 is located adjacent the base of the rail 3 intermediate the flange 7 of the rail 3 and the mounting block 1 whilst the thick wall d of the other collar 5 is located adjacent the base of rail 3 intermediate the flange 8 and the mounting block 2. This combination of wall thicknesses provides one extreme limit of the lateral adjustment range whilst the other extreme limit of the range is achieved by a combination of thick wall d between mounting block 1 and flange 7 and thin wall a between mounting block 2 and flange 8. The dimension between the two collars 4, 5, is maintained constant, to locate the rail therebetween, by ensuring that the correct pair of wall thicknesses are chosen. Thus, four different combination are provided with three adjustable steps from the initial lateral position of the rail.

[0010] The outer peripheral edge of each lateral adjustment collar 4, 5, is chamfered as shown at 9, 10, (Figure 1) to provide a lead-in for the rail to assist with the insertion and location of the rail 3 between the two collars 4, 5.

[0011] A plurality of pads 11 are located beneath the flanges 7, 8, of the rail 3 to allow for adjustment of the height of the rail. Each pad has ears (not shown) to engage around the peripheral wall of each collar 4, 5, to locate the pads 11 and prevent creep thereof under load. A single thickness pad 11 may be used or alternatively a plurality of thin pads as shown in Figure 1.

[0012] The rail adjustment device of the present invention includes a pair of height adjustment collars 12,.13 (Figure 2), each collar 12, 13, being of square shape in plan with a concentric square aperture 14 thus giving equal wall widths surrounding the aperture 14. In the drawing the corners have been chamfered to provide an aesthetic design feature. The aperture 14 is dimensioned to be a clearance fit over the respective lateral adjustment collar 4, 5, (Figure 2). The wall thicknesses of each height adjusting collar are different as shown for walls 12a, 12b; 13a, 13b, Figure 2 for a purpose hereinafter described.

[0013] When a new rail is installed, the thickest facet 12a, 13a is arranged adjacent the rail as shown in Figure 2. When the rail subsequently wears, the height of the rail is adjusted by the insertion of one or more packing pads 11 beneath the base of the rail following lifting of the rail. To compensate for the raising of the level of the rail, the height adjustment collars 12, 13, are re-located on the lateral adjustment collars, to bring a thinner facet into position on the respective base flange of the rail 3. To retain the rail in the adjusted position a spring clip such as that shown in 15 in Figure 1 and known as a Pandrol clip is located between mounting blocks 1, 2 and the respective height adjustment collars 12, 13 to exert clamping pressure on the foot of the rail. The clip 15 is a proprietory product of Pandrol Ltd. and no claim is made to any components covered by patents of Pandrol Ltd.

[0014] The top of each height adjustment collar must be maintained constant irrespective of the rail height in order that a consistent toe load can be maintained on the rail by the spring clip. Although a spring clip of conventional form has been shown, any suitable clamping means, such as bolts may be provided to retain the rail in the adjusted position.

[0015] The components of the rail fastening device may be formed of any suitable materials. For instance, the mounting blocks are normally manufactured in a malleable or spheroidal graphite cast iron. The lateral adjustment collars may be of high density polyethylene, Nylon (Registered Trade Mark) or glass filled Nylon. Similarly the latter material may be used for the height adjustment collars. The height adjustment pads may be of rubber bonded cork, ethylene vinyl acetate (EVA) or high density polyethylene (HDP). Although the invention has been particularly described and illustrated with reference to collars of square section and matching mounting blocks which are square in plan it will be appreciated that any regular shape may be used for the collars with three or more sides and matching mounting blocks. Similarly, the height adjustment collars may be used independently of the lateral adjustment collars and vice-versa.

Claims

1. A rail fastening device for flat bottom rails comprising a pair of mounting blocks (1, 2) arranged to be embedded in or otherwise secured to the track on either side of a rail (3) and in spaced relation therewith, and securing means (15) for holding the rail (3) in position with respect to said mounting blocks (1, 2) characterised in that there is provided a pair of identical collars (4, 5), each having an aperture (6) dimensioned and shaped such as to pass over and be located around a respective one of said mounting blocks (1,2), the aperture (6) of each collar being eccentric with respect to at least one axis thereof to provide at least two walls (e.g. a, d) of different thickness such as to allow for lateral adjustment of the position of the rail (3) according to the particular wall of each collar (4,5) located intermediate the respective mounting block (1, 2) and the foot of the rail (3), the securing means (15) being arranged to hold the rail (3) in the adjusted position with respect to said mounting blocks (1, 2).

2. A rail fastening device for flat bottom rails comprising a pair of mounting blocks (1, 2) arranged to be embedded or otherwise secured to the track on either side of a rail (3), and securing means (15) for holding the rail (3) in position with respect to said mounting blocks (1, 2) characterised in that there is provided a pair of identical collars (12, 13) each having a concentric aperture (14) dimensioned and shaped such as to pass over and be located around a respective one of the pair of mounting blocks (1, 2) which are shaped to match the respective collar (12,13) and arranged to be embedded or otherwise secured to the track on either side of the rail (3), adjacent walls of the collars (12,13) having identical thickness but of different height such as to allow for vertical adjustment of the rail (3), each collar (12,13) resting on a respective base flange of the rail (3) and the securing means (15) being clamped between the respective mounting block (1, 2) and associated collar (12,13).

3. A rail fastening device as claimed in Claim 1 and including a further pair of collars (12, 13) each having a concentric aperture (14) to provide adjacent walls of identical thickness but of different height, said further pair of collars (12, 13) each being arranged to pass over and surround a part of a respective one of said first mentioned collars (4, 5) such as to allow for vertical adjustment of the rail, each further collar (12,13) resting on a respective base flange of the rail (3) and the securing means (15) being clamped between the respective mounting block (1,2) and further collar (12,13).

4. A rail fastening device as claimed in Claim 1 or 2 wherein said pair of collars (4, 5: 12, 13) are each of square section in plan, each having a square aperture (6,14) dimensioned such as to pass over and be located around a respective one of said pair of mounting blocks (1,2) which are of similar section.

5. A rail fastening device as claimed in Claim 1 wherein the outer peripheral edge (9, 10) of each collar (4,5) is chamfered to provide a lead-in for the rail (3) to assist with the insertion and location of a rail (3) between the two collars (4,5).

6. A rail fastening device as claimed in any preceding claim including at least one pad (11) arranged to be located beneath the rail flange (7,8) for adjustment of the height of a rail (3).

7. A rail fastening device as claimed in Claim 6 wherein said at least one pad (11) has projections extending therefrom to engage in complementary shaped recesses around the peripheral wall of each collar (4,5) to locate the pad(s) 11 in position and prevent creep thereof under load conditions.

8. A rail fastening device as claimed in Claim 3 wherein each of said further pair of collars (12,13) are of square shape in plan with a concentric square aperture (14).

9. A rail fastening device as claimed in Claim 1 or 2 wherein said securing means (15) comprises a pair of spring clips, each located between a mounting block (1,2) and a respective one of said pair of collars (4,5; 12,13) such as to exert clamping pressure on the foot of the rail (3) when the fastening device is positioned adjacent a rail.

10. A rail fastening device as claimed in Claim 1 or 2 wherein said securing means (15) comprises a pair of bolts coupling a mounting block (1,2) to a respective one of said pair of collars (4,5; 12,13).

Drawing