GB2442850A

GB2442850A - Device for throwing a points blade

Info

Publication number: GB2442850A
Application number: GB0719446A
Authority: GB
Inventors: Frank Meyer
Original assignee: Schwihag AG
Current assignee: Schwihag AG
Priority date: 2006-10-13
Filing date: 2007-10-04
Publication date: 2008-04-16
Anticipated expiration: 2027-10-04
Also published as: DE102007038653B4; MY141176A; CA2607787A1; US20080087773A1; KR20080033849A; GB2442850B; GB0719446D0; JP2008095494A; DE102007038653A1; JP5100296B2; CN101161934A

Abstract

A device for throwing a points blade is intended for incorporation in a rail assembly comprising a rail support (9) which has an upwardly directed generally planar slide face, a longitudinally extending running rail (2) secured to the support and a longitudinally extending points blade (3) adjacent the running rail (2), the blade being displaceable between an inner position adjacent to and an outer position spaced from the running rail. The device comprises a slide (8) carrying an outer roller (11 b), a middle roller (12) and an inner roller (11 a) respectively rotatable about three parallel axes at different spacings from the running rail (2). The middle roller (12) is axially offset from the inner and outer rollers (11b, 11a) and is of such a diameter that its circumference radially overlaps the circumferences of the inner and outer rollers as seen in the axial direction of the rollers.

Description

1 2442850

DEVICE FOR THROWING A POINTS BLADE

The present invention relates to a device for throwing a points blade, especially points where the points blade rides on a carnage supported on rollers.

Throwabte blade devices in points can have different geometries depending on the country. In most European countries, usually blade devices with low blade profiles, so-called shallow depth rail profile, are used. These have the advantage that an open space is provided under the blades that can accommodate a clip for a running rail and in particular, the blade foot, even after final machining, still has a significant width as a support surface on a slide frame.

In another main group of blade devices for points a symmetrical rail cross-section is used for the blade profile, which usually corresponds to the regular rail profile that is used for track rails as well. The height of the blades thus approximately corresponds to the height of the running rail, so-called full depth rail profile.

For example, this group includes the blade profiles manufactured in accordance with the AREMA standard (United States standard). Part of the blade foot in the inner region of the blade device is significantly narrower than in the blade devices described above and than in BS (British standard) blade profiles, for example.

The sliding action of the blade profiles inside the points usually occurs with the aid of roller devices that support the blades. The typical roller device for this purpose entails inner and outer rollers rotatable about parallel axes and transversely aligned with each other, and a slide frame or chair in which they are joumalled. This slide frame is typically biased upward to support the blade above a so-called slide plane formed by or carried on the underlying sleeper. When a substantial force is exerted downward on the points blade, the rollers and carnage plate move downward and the foot of the blade comes to rest on this slide plane. Such systems are described in DE 44 34 143 and US 5,622,340, 5,628,480, 6,189,840 and 6,464177.

In such devices the foot of the points blade is quite narrow since it must fit with the running rail. As a result continuous and uniform rolling is either only possible to a limited degree or is not possible at all because the distance between the rollers is too great. The roller diameters cannot be reduced too much without reducing their effectiveness. The blade foot in this instance travels onto the inner roller and then tilts with the inner edge of its blade foot into the gap between the inner and outer rollers before it is lifted up again by the circumference surface of the outer roller and transported further. This bumpy rolling process can cause damage to the roller assembly, caused by the possible impact of the blade with the roller frame between the rollers, even though the blade is typically not loaded during the adjustment movement between its inner and outer positions.

Furthermore, this discontinuity can significantly increase the blade throwing force and can consequently cause the switch to move sluggishly.

It is therefore an object of the present invention to provide an improved device for throwing a points blade.

Another object is the provision of an improved device for throwing points blades that overcomes the above-given disadvantages, in particular permits an easy, smooth movement, even of a points blade with a narrow blade foot.

The instant invention is used in combination with a rail support forming an upwardly directed generally planar slide face, a longitudinally extending running rail secured to the support and having a foot with a predetermined transverse width, and a longitudinally extending switch blade adjacent the rail and shiftable above the slide face between an inner position closely transversely juxtaposed with the running rail and an outer position transversely spaced from the running rail. The device has according to the invention a frame defining a longitudinal outer axis spaced transversely along the slide face from the running rail, a longitudinal middle axis between the outer axis and the running rail, and an inner axis between the middle axis and the running rail. Respective outer, middle and inner rollers are carried on the frame and rotatable about the respective axes. The middle roller is axially offset from the inner and outer rollers and is of a such a diameter that it radially overlaps the inner and outer rollers.

Thus, axially offset from the inner and outer rollers and approximately in the middle between them there is a middle roller, so that as the blade rides on moving from the inner roller to the outer roller it rides on the middle roller. In a rolling points blade throwing process, this design permits the narrow lower face of the points blade to always roll in a definite, preferably stable fashion on at least two rollers of the triple roller arrangement.

More precisely stated, it is possible for the maximum distance between the roller axes of the middle and inner rollers or between the middle and outer rollers to be defined so that, when the blade foot is situated approximately in the middle between two rollers, the edges of the blade foot still rest on or contact two rollers. Thus, roller diameters and axis spacing are such that the outer peripheries of adjacent rollers are spaced apart at the slide plane by a distance shorter than a transverse width of the lower face of the points blade foot.

In an advantageous embodiment of the invention, the roller circumferences of the rollers of the roller paid and of the laterally offset roller overlap one another. Because the roller circumferences of two successive rollers -one of which is always the laterally offset roller -overlap each other, this securely closes or bridges over the empty space between the inner and outer rollers of the roller paid. This can also be guaranteed even if the empty space between these rollers is slightly larger than the width of the narrowest blade foot in use.

According to one embodiment of the invention, the middle, laterally offset roller is preferably embodied so that its vertical position or height can be adjusted. This makes it possible to achieve a definite presetting so that the middle roller is at least the same height as the adjacent surface of the support or, better still, projects slightly above it. The height of the roller here can be adjusted by means of an eccentric adjusting mechanism or by means of an eccentric roller bearing so that the height of the roller can be easily and smoothly adapted to the height of the roller pair and/or of the slide frame and locked in the set position.

The rolling process can be further improved if the inner roller onto which the blade first rolls is set lower than the outer roller.

Primarily if the laterally offset roller is not height-adjustable, in an advantageous embodiment of the invention the rollers are set and/or positioned so that the height of the laterally offset roller is between that of the inner and outer rollers. As all of the rollers co-operate, this results in a inwardly inclined roller plane, which slopes downward toward the running rail.

According to another embodiment of the invention, the middle roller and the parallel, adjacent roller pair are situated on a common plate of the slide frame. The plate or ribbed plate is preferably a component of a slide frame that accommodates the rollers together with their, for example, eccentric adjusting mechanism. The slide frame, which is slidingly integrated into the support, makes it possible, when adjusting the roller arrangement, to shift the outer roller as far as possible toward the blade foot so that when the blade is thrown the rolling movement begins as early as possible.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a device for throwing railway points blades, having a running rail which is clipped to a support, and a switch blade, which is depicted both in a position resting against this running rail and in a position spaced from it and is supported on rollers of a roller assembly likewise accommodated in the support, which assembly is contained within a slide frame; Fig. 2 is a side view of the points blade throwing device according to Fig. 1; Fig. 3 is a perspective top view of a detail of the points blade throwing device, showing the roller assembly comprised of two rollers situated one behind another and in line with each other and a middle roller laterally offset from them; and Fig. 4 shows the subject of Fig. 3 from the right, the adjusting side.

As seen in Fig. 1 a points blade throwing device I is carried on a support 9 with a running rail 2 also clipped to the support 9. The blade tip 4 of a points blade 3 rests against the running rail 2 (see Fig. 2) in an inner position shown in solid lines and is spaced transversely from it in an outer position shown in broken lines. The blade 3 has a narrow foot 7 that supports the switch blade 5 and rests and rolls during adjusting movements on a roller plane of a plate-like slide frame 8, which for positioning purposes, is situated so that it can move linearly on a support 9 of the points blade throwing device 1.

In the illustrated embodiment, a slide frame 8, which functions as a base support element and is equipped with a ribbed plate 13, in co-operation with a top plate (see Fig. 4), on the one hand provides a height-adjustable support for inner and outer rollers 11 a and lib that are centred on respective axes 14a and 14b. In addition there is a middle roller 12 that is spaced axially offset from the rollers 11 a and II b, with its axis 1 2a (Fig. 1) parallel to and approximately midway between the axes 14a and 14b of the rollers I la and lib. This roller 12 is also height-adjustable so that the points blade 3, when moved from its contacting position 5 to the spaced-apart position 6 and vice versa is always supported by either the inner or outer roller I Ia or 1 lb or the laterally offset roller 12. The rollers 1 Ia, 1 lb and 12 are here all of the same diameter, which is such that their outer peripheries radially overlap, that is the inner portion of the roller 12 overlaps the outer portion of the roller 11 a and the outer portion of the roller 12 overlaps the inner portion of the roller 11 b.

These diameters and the transverse spacing of the axes 14a, 14b and I 2a are such that a spacing between the outer peripheries at a slide plane P of the support 9 is smaller than the transverse width of the bottom face of the rail foot 7. This ensures that when the blade foot 7 is situated in the middle between two rollers 11 a and 12 as shown in Fig. 2 for the spaced-apart blade 3 (position 6), its edges continue to rest on and contact both rollers ha and 12.

Despite the lateral offset, the middle roller 12 bridges the gap between the rollers 11 a and I Ib, thus making it possible, even during the points blade throwing process as it rolls from the inner contacting position 5 into the outer position 6, for the narrow blade foot 7 to always rest on two rollers, i.e. roller 11 a and roller 12 or roller 11 b and roller 12. This ensures a smooth, continuous rolling process of the blade 3, thus significantly reducing the blade-throwing force of the unhllustrated actuator that shifts the blade 6 transversely.

As is clear from Figs. I and 2, the rollers 11 a, lib and 12 project upward and downward from the shaped ribbed plate 13 of the slide frame 8 situated in the support 9. The entire subassembly formed by the frame 8 and rollers 11 a, 1 lb and 12 can travel transversely between the illustrated inner position close to the running rail 2 with the blade 3 resting against this running rail 2 to an unillustrated outer position. In the inner position the inner roller 11 a almost comes into contact with the blade foot 7 and as a result, when the switch blade is being thrown, a rolling motion begins as early as possible, as soon as the blade 3 pulls away from the rail 2 and lifts up slightly from a support face or the plane P of the support 9.

If an eccentric adjusting device 14 shown here only for the rollers I Ia and I Ib, but also supplied for the roller 12, sets the inner roller 11 a and the middle roller 12 lower than the outer roller 11 b, then the blade foot 7 can roll even more easily and in an almost infinitely variable fashion onto the inner roller 1 la and the laterally offset roller 12 and can also roll smoothly onto the outer roller 11 b. The height of the middle, laterally offset roller 12, however, should be preset so that it does not lie beneath the surface of the support 9. The devices 14 each have an eccentric core shaft 15 on which the respective roller 11 a, lib or 12 is joumalled and centred. Different settings are denoted by "-1", "1.5", "4" and 6".

Claims

CLAIMS: 1. A device for throwing a points blade, comprising a slide

provided with a plurality of rollers for supporting a foot of the blade in a plane defined by the rollers, the rollers comprising a pair of rollers for successively supporting the blade foot during throwing of the blade and an intermediate roller so arranged laterally of and adjacent to the rollers of the pair that during transition of the blade between the rollers of the pair the blade foot is supported by the further roller and one of the rollers of the pair and then by the further roller and the other roller of the pair.
2. A device as claimed in claim I, wherein the circumference of the further roller overlaps the circumference of each of the rollers of the pair as seen in the axial direction of the rollers.
3. A device as claimed in claim I or claim 2, wherein the third roller is adjustable in height relative to the plane.
4. A device as claimed in claim 4, wherein the slide comprises a mounting plate and the rollers are mounted in common on the plate.
5. A device as claimed in claim 4, whereIn the plate is a fixing frame mountable to be transversely displaceable relative to such a points blade.
6. A device as claimed in any one of the preceding claims, wherein one of the rollers of the pair is intended, in the use state of the device, to be disposed closer than the other roller of the pair to a running rail CO-operable with the points blade and to be lower in height than that other roller.
7. A device as claimed in daim 6, wherein the height of the further roller in the use state of the device is intermediate the heights of the rollers of the pair.
8. A rail points assembly comprising a rail support forming an upwardly directed generally planar slide face, a lOngitudinally extending running rail secured to the support and having a foot with a predetermined transverse width, a longitudinally extending points blade adjacent the rail and shiftable above the slide face between an inner position closely transversely juxtaposed with the running rail and an outer position transversely spaced from the running rail, and a device for throwing the points blade, the device comprising a frame defining a longitudinal outer axis spaced transversely along the slide face from the running rail, a longitudinal middle axis between the outer axis and the running rail and an inner axis between the middle axis and the running rail, and respective outer, middle and inner rollers carried on the frame and rotatable about the respective axes, the middle roller being axially offset from the inner and outer rollers and being of such a diameter that it radially overlaps the inner and outer rollers.
9. An assembly as claimed in claim 8, wherein the axes are transversely spaced and the rollers have outer peripheries of such diameter that a spacing between the outer periphery of the middle roller and the outer periphery of each of the inner and outer rollers on a plane of the slide face is less than the transverse width of the foot of the points blade.
10. An assembly as claimed in claim 8 or claim 9, further comprising means for vertically shifting the middle axis and roller relative to the slide face.
II. An assembly as claimed in any one of claims 8 to 10; wherein the frame is a single plate supporting the inner, middle and outer rollers.
12. A device as claimed in any one of claims 8 to 11, wherein the frame is shiftable transversely of the running rail.
13. An assembly as claimed in any one of claims 8 to 12, wherein the uppermost extent of the outer periphery of the inner roller is below the uppermost extent of the outer periphery of the outer roller.
14. An assembly as claimed in 13, wherein the uppermost extent of the outer periphery of the middle roller is above that of the inner roller and below that of the outer roller.
15. An assembly as claimed in claim 14, wherein the outer peripheries of the rollers define a plane on which the foot of the points blade sits and which is inclined at an acute,.

angle downwardly towards the running rail.
16. An assembly as claimed in any one of daims 8 to I 5, wherein the frame is also displaceable on the support between an innermost position adjacent to the running rail and an outermost position spaced from the running rail, the foot of the points blade being between the inner roller and the running rail and resting on the slide face in the innermost position of the frame.