WO1997047814A1

WO1997047814A1 - Heating system for box-type sleepers

Info

Publication number: WO1997047814A1
Application number: PCT/EP1997/003004
Authority: WO
Inventors: Armin Heim
Original assignee: SCHWIHAG GESELLSCHAFT FüR EISENBAHNOBERBAU MBH
Priority date: 1996-06-11
Filing date: 1997-06-10
Publication date: 1997-12-18
Also published as: EP0904460A1; AU3094497A; DE59701184D1; EP0904460B1; ATE190099T1

Abstract

The invention concerns a box-type sleeper for points fitted with heating elements (14, 17). The heating system can be accommodated better, in particular the reliability can be increased, by virtue of the fact that the box-type sleeper is closed and has at least one inlet aperture for several heating-element leads (12, 13).

Description

Box threshold heating

The invention relates to box sleepers for switch devices in which electric heating elements are arranged.

In recent years, box or trough sleepers have been increasingly used to accommodate and arrange complete clamp locks, latch locks, vertical clamp locks, as well as tongue testers and spring rockers for movable tongues and / or movable centerpiece tips. Their use results in a variety of advantages, e.g. a low-lubrication and low-maintenance point setting system, less maintenance and the possibility of automatically tying the box sleepers without destroying the ballast. This significantly increases the availability of the point setting systems.

The previously used box sleepers - which have the same box cross-sections as wooden or concrete sleepers for better tamping using switch tamping machines and improved settlement behavior - are formed from relatively thin folded sheets into U-profiles, on both flanges of which the upper straps are used, to reduce production costs be welded on. In order to keep the costs deliberately low, the entire cross section of the box tie after the welding process is stress-relieved, which, however, entails increased cracking and corrosion.

Furthermore, the bending of the approximately 10 mm thick sleeper plates has the disadvantage that the transitions from the horizontal bottom region of the sleeper to their vertical flange regions have a large bending radius. When darning the box sleepers is due to the big ones Bending radii cannot be optimally sealed because the ballast swells upwards. This problem of tamping can be countered more or less successfully, on the one hand, by hand tamping and, on the other hand, by angles welded to the longitudinal edges of the box sleeper feet over the entire length.

To e.g. To prevent ice formation in the box sleepers, which are usually open at the top, these electric box tie heaters - in the form of heating rods - are installed. There is no prescribed or defined installation position for the heating elements, so that they are installed in the box sleepers differently by each installation company or the installation teams of the state railways and mostly with major disadvantages. On the one hand, the heat transfer from the heating elements to the entire box sleeper is very bad, because the heating element is mounted with only two fastening clamps on the floor plate, which is bulged and therefore wavy due to the ballast. On the other hand, the heating rod cross section is often in a water accumulation area, so that premature corrosion and thereby a possible defect, e.g. a short circuit is preprogrammed.

Mostly, no or only a few water drainage holes are provided in the floor area of the box sleepers, so that puddles of water form on the uneven floor, which remain until evaporation and lead to a water sump in particular in connection with dirt and waste accumulations in the box tie.

Furthermore, after the installation of a tip closure, the fastening clamps of the screw connections for the heating rods are often no longer detachable, so that the tip closure must be partially or completely dismantled before one can get to the heating rods. In addition, the replacement of a defective heating element takes far too long, which significantly reduces the availability of the switch.

The invention is based on the object of arranging or accommodating the box threshold heating in a generic box sill improve, in particular to increase the availability of the switch and operational safety.

This object is achieved in that the box threshold is closed and at least one input opening for heating rod leads is formed. The entrance opening is preferably located in one of the two longitudinal walls of the box sleeper and is inclined by 60 ° in the direction of the end wall of the box sleeper. As a result, the heating element feed lines - usually two heating elements are provided for one box tie - can be inserted together through the entry opening into the box tie with a relatively small kink dimension.

It is preferably provided in the invention that inlet openings are formed at all four ends of the longitudinal sides of the box sleeper. It is possible, depending on which side and at what distance from the box tie an electrical connection box is arranged, to feed the supply cables in the shortest way and, if necessary, without having to lay them in the ground, one of the four entry openings. A hole closure lid is pressed into the unneeded inlet openings and is held in the respective inlet opening by a clip spring arranged on it, so that no ballast can get into the box sleeper when tamping.

The entry openings are chosen so large that an angled cable protection tube, which preferably contains plastic, can be inserted into the inside of the box threshold. The supply cables are thus effectively protected against damage on the one hand in the area of the entrance opening and on the other hand outside the box threshold in the area of the ballast.

According to one embodiment of the invention, a cable protection tube is arranged inside the box threshold. A supply cable is fed directly to the heating element closest to the selected inlet opening, while the other supply cable through the inner protective tube to the heating rod removed from the inlet opening.

Another embodiment of the invention provides that the cable protection tube rests on base webs and is held by means of clamping springs. The plinths are arranged in the right-angled transition area between the longitudinal wall and the floor of the box sleeper. Over the entire length of the box sleeper tension springs are arranged between two base webs, which protrude into openings formed in the box sleeper floor and are fixed to a web of the box sleeper floor delimiting the opening. On the one hand, the cable protection tube is locked securely by simply pressing it between the clamping spring and base bars, on the other hand, the clamped cable protection tube rests on the skirting boards, so that any water standing on the sleeper floor cannot penetrate the protection tube.

Furthermore, end stops are advantageously assigned to the cable protection tube, between which the cable protection tube is embedded axially immovably; this effectively prevents the cable from being squeezed between the end faces of the box tie and the cable protection tube.

A preferred embodiment of the invention provides that the heating elements are arranged on a spacer bar and locked there by means of tension springs. The spacer bar is arranged in the longitudinal axis of the box sleeper on the box sleeper floor; the two heating elements arranged one behind the other lie on it. The preferably S-shaped tension springs each rest on a raised base. The upper clamps overlap the heating rods and fix them on the spacer bar. The lower tensioning bracket of the tension spring projects into an opening, which is also formed in the box sleeper floor, and is fixed to a web of the raised base and the box sleeper floor delimiting the movement in a manner that prevents movement. So that the heating rods cannot be pushed over the spacer bar when they are inserted laterally into the preassembled tension springs and, on the other hand, are aligned in the axial direction, the heating rods are assigned several stops arranged on the base bar.

Another embodiment of the invention provides that the heating rod heads rest on a baseboard and are each fastened with a spring clip. The skirting board is arranged between the vertical longitudinal walls of the box sleeper on the box sleeper floor. The heating rod heads are resiliently screwed to the skirting board with a double-lobed clamp overlapping them or a band made of spring steel. The resilient screw connection of the heating rod heads ensures safe earthing, if the heating rod insulation is no longer intact. A lateral stop is also assigned to the heating rod heads in order to prevent the heating rod head from slipping when the double-lobed clamp or spring band is screwed on.

The increased arrangement of the heating elements or the heating element heads on the box sleeper floor and the associated full-surface support on the one hand result in good heat transfer to the floor area of the box sleeper. On the other hand, it is possible to replace the previously used heating rods with an individual heating output of 2x450W with heating rods with an individual heating output of 200-300W in connection with the box threshold, which has a very great economic advantage. Furthermore, the heating rods are not - as is customary in known arrangements - in the water accumulation area of the box threshold, which effectively prevents corrosion of the heating rods.

In order to prevent water accumulation in the box sleepers from the outset, according to one embodiment of the invention, the box sleeper floor is channel-shaped and provided with at least one water drain opening. Under channel-like formation of the floor are both in the longitudinal and in the transverse direction To understand floor surfaces inclined towards the water drain opening, which direct the water to the drain at the lowest point. Preferably, several water drainage openings are provided, namely on the one hand the openings provided anyway for the tension springs of the heating rods in the longitudinal axis of the box sleeper floor and on the other hand drainage openings are additionally formed in the center of the box sleeper floor. This makes it possible for condensate or rainwater that occurs in the box sleeper to drain off completely and that no water can accumulate inside the box sleeper, for example when the points are too high. To further increase the drainage effect, the edges of the water drainage openings can be chamfered.

Further details and advantages of the invention emerge from the claims and the following description, in which exemplary embodiments of the invention illustrated in the drawings are explained in more detail. Show it:

Figure 1 shows a box threshold with heating elements arranged therein, shown in plan view;

FIG. 2 shows the box sleeper according to FIG. 1 with two inlet openings for heating rod feed lines, seen from the side and shown in longitudinal section;

Figure 3 shows as a detail an entrance opening of the box tie according to Figure 2 with a cable protection tube, in plan view and in section.

FIG. 4a shows a detail of an entrance opening of the box sleeper with a closure cover, shown in plan view and in partial longitudinal section;

Figure 4b shows a section along the line IV-IV of Fig. 4a;

Figure 5a as a detail a partial view of a heating element according to FIG. 1, in the Top view and shown in longitudinal section;

Figure 5b shows a section along the line V-V of Fig. 5a;

6a, 6b show in detail the fastening of a heating rod head, in a top view (FIG. 6a) and in a front view (FIG. 6b);

7a shows as a detail a partial view of a cable protection tube arranged in the box sleeper according to FIG. 2, shown in plan view and in longitudinal section; and

Figure 7b shows a section along the line VII - VII of Fig. 7a.

FIG. 1 shows an open box tie 1 cast from spheroidal cast iron. At the four corners 2a, 2b, 2c, 2d of the longitudinal walls 3a, 3b of the box tie 1 there is an entry opening 4a, 4b, 4c, 4d (see FIG. 2) provided for inserting a Kabeischutz¬ tube 5. The inlet openings 4a, 4b, 4c, 4d are each inclined by approximately 60 ° to the two end faces 6a, 6b (cf. FIGS. 2 and 3). This makes it possible for the cable protection tube 5 to be inserted into the entry opening 4a in a relatively soft curve and to run outside the entry opening 4a at a short distance parallel to the longitudinal wall 3a of the box sleeper 1 (see FIG. 3). The inlet openings 4b, 4c, 4d which are not required in the exemplary embodiment are protected by a sealing cover 7 against the ingress of ballast, water and dirt.

The closure cover 7 is formed on its rear side 8 with two spring clips 9a, 9b, which spread apart after the closure cover 7 has been pressed into the inlet openings 4b, 4c, 4d and frictionally fit against the opening walls 10a, 10b, whereby the cover 7 firmly in the Entrance openings 4b, 4c, 4d is held (see FIGS. 4a, 4b). In addition, the closure cover 7 has two fixing pins 11a, 11b, one of which is axial Prevent displacement of the cover 7 in the inlet openings 4b, 4c, 4d.

According to FIG. 1, two heating rod supply cables 12, 13 are led through the cable protection tube 5. The supply cable 12 is fed directly to the heating element 14 facing the input opening 4a and connected to the heating element head 15 thereof, while the supply cable 13 is passed through an additional, protective-cable-side conduit 16 associated with it to the heating element 17 removed from the input opening 4a, where it leads to the heating rod head 18 is connected there (see FIG. 2). The cable protection tube 16 lies on paired base webs

19 on. The base webs 19 are cast in the area of the right angle between the longitudinal wall 3a to the box sleeper floor 20. As shown in Fig. 7a and 7b, pair 19 is in each case between a base web in the sleeper floor

20 a molded opening 21 is formed. The lower bracket 23 of a clamping spring 24 is fixed on the web of the sleeper base 20 projecting into the opening 21. The upper bracket 25 of the clamping spring 24 defines the cable protection tube 16 against movement against the base webs 19. The spreading of the upper tensioning bracket 25 - when the cable protection tube 16 is pressed in between the base webs 19 and the clamping springs 24 - is limited by a fin 26 cast onto the box sleeper base 20. In order to prevent an axial displacement of the cable protection tube 16 within the box threshold 1, 16 end stops 27 and 28 are assigned to the cable protection tube (cf. FIGS. 1 and 2).

The heating rods 14, 17 shown in FIG. 1 lie on a spacer bar 29 which extends in the longitudinal axis of the box sleeper 1 on the box sleeper floor 20 (cf. FIG. 5b). The heating rods 14, 17 are each assigned three S-shaped tension springs 30. The tension springs 30 are arranged on base-like elevations 31 of the sleeper base 20 and are fixed via a lower U-shaped bracket 32 to a web 34 of the sleeper base 20 and the elevation 31 projecting into an opening 33 provided in the sleeper base 20. The upper tensioning bracket 35 of the S-shaped tensioning spring 30 overlap the heating rods 14, 17 and fix them on the spacer bar 29 in a movement-safe manner via a complementary recess 36 formed in the upper clamping bracket 35. In order to prevent the tension spring 30 from being pushed away when the heating rods 14, 17 are pushed in laterally, as shown schematically in FIG. 5b, the lower bracket 32 is fixed by means of a bulge 38 of the base-like elevation 31 arranged in a recess 37. In addition, a lateral slipping of the tension spring 30 is prevented by limiting webs 39, 40 formed on the base-like elevation 31. So that the heating elements 14, 17 cannot be pushed laterally beyond the spacing element 29 when inserted between the spacer strip 29 and the upper bracket 35, stops 42 are assigned to the heating elements 14, 17 opposite the insertion side.

As shown in FIGS. 6a, 6b, the heads 15, 18 of the heating rods 14, 17 lie, for reasons of corrosion technology, just like the heating rods 14, 17 themselves on skirting boards 43 cast transversely on the sleeper floor 20. The heating element heads 15, 18 are fixed on the skirting 43 via a spring clip 44 screwed to the skirting 43. So that the heating element heads 15, 18 do not push away in the direction of the arrow 46 when the spring clip 44 is screwed together by means of the screws 45 and the associated tensioning, stops 47 are assigned to them. The resilient screw connection of the heating rod heads 15, 18 ensures - in the case of insulation that is no longer intact - that the heating rod heads 15, 18 are securely grounded (cf. FIG. 1). The necessary earthing of the box weld 1 takes place via an earthing cable, not shown here. For fastening the earth cable, e.g. by means of a screw / nut combination, a bore 48 is provided in the longitudinal walls 3a, 3b in each case next to the inlet openings 4a, 4b, 4c, 4d (cf. FIGS. 1 and 2).

Both the openings 33 formed in the longitudinal axis of the box sleeper floor 20 and the openings 49 in the middle of the box sleeper floor 20 next to the heating rods 14, 17 serve as water outflow. The sleeper floor 20 is - as shown schematically in FIG. 5a - towards the water drainage openings 33, 49 (cf. also FIG. 1) both in the longitudinal direction (cf. the arrow 50) as well as in the transverse direction (cf. arrow 51), so that condensate or rainwater occurring in the sleeper floor can drain off easily.

Claims

claims

1. box sleepers for switch devices in which electric heating elements are arranged, characterized in that the box threshold (1) is closed and with at least one input opening (4a, 4b, 4c, 4d) is formed for heating element supply lines (12, 13).

2. box tie according to claim 1, characterized in that at all four ends (2a, 2b, 2c, 2d) of the box tie longitudinal sides (3a, 3b) input openings (4a, 4b, 4c, 4d) are formed.

3. box sleeper according to claim 1 to 2, characterized by an inside the box sleeper (1) arranged cable protection tube (16).

4. box sleeper according to claim 3, characterized in that the cable protection tube (16) rests on base webs (19) and is held by means of clamping springs (24).

5. box sleeper according to one of claims 1 to 5, characterized in that the heating rods (14, 17) are arranged on a spacer bar (29) and locked with tension springs (30).

6. box sleeper according to one of claims 1 to 5, characterized in that the heating rod leads (12, 13) with heating rod heads (15, 18) rest on a skirting board (43) and are each fastened with a spring clip (44).

7. box sleeper according to one of claims 1 to 6, characterized in that the box sleeper floor (20) is channel-shaped and is provided with at least one water drain opening (49).

8. box sleeper according to one of claims 1 to 7, characterized in that the heating rods (14, 17) and the heating rod heads (15, 18) side stops (42, 47) and the cable protection tube (16) assigned end stops (27, 28) are.