EP0021248B1 - Flexible track section for model railways and method for manufacturing it - Google Patents

Abstract

Improved curvable track for model railroads in which a track bed of simulated crossties is formed as an integral flexible structure by linking the ties with a continuous web underlying the rail on one side of the track. Opposite the continuous web and underlying the other rail of the track, the ties are linked in alternate pairs. The rail of the track overlying the continuous web of the crosstie bed is secured thereto by simulated spikes against both lateral and longitudinal movement while the opposite rail overlying the alternately linked tie pairs is secured by simulated spike heads only against lateral movement and is free to move longitudinally with respect to the tie bed.

Description

The invention relates to a flexible track piece for model trains according to the preamble of claim 1 and a method for producing a flexible track piece using a two-part injection mold according to the preamble of claim 5.

DE-C-635110 discloses a flexible track piece for model trains of the type outlined in the preamble. In the case of this flexible track piece, a first rail track is fixed against transverse and longitudinal movements on the cross sleepers and, parallel to this, a second rail track is fixed at a distance against transverse movement on the cross sleepers and is freely displaceable in the longitudinal direction. The cross sleepers are designed individually to prevent the sleepers from falling off the rails. The cross sleepers, which are designed as individual parts, are held together by the rail tracks.

From DE-A-2 045 036 and GB-A-542 521 it is known to connect the cross sleepers via flexible connecting elements to form a one-piece flexible cross tie grid.

From CH-A-310 527 a manufacturing method for flexible track pieces of the kind outlined in the preamble of claim 5 is known. Here, a two-part injection mold is used, which has track sections with panel flaps, which are guided in recesses in one half of the mold and which penetrate a coherent cavity, gaps remaining after the casting, which are located below the rail foot.

DE-A-2 248 727 describes a bendable track for model railways, which consists of sleepers with cramps formed on the surface, which hold or guide the foot of the respective rail between them, the sleepers and a longitudinal belt in one piece are manufactured by injection molding and the staples have a particularly wide manufacturing tolerance in order to improve the mobility of the rails.

The invention is therefore based on the object of designing a flexible track piece for model railways in such a way that, while maintaining the correct track width of the track strands, easy flexibility of the flexible track piece is ensured in such a way that not only easy handling of the flexible track piece, but also easy repair receives, as well as to provide a method for producing such a flexible track piece, which allows a significantly simplified method of manufacture.

According to the invention, this object is achieved with regard to the flexible track piece of the type outlined in the preamble of claim 1 in connection with the combination of the features of the characterizing part of claim 1.

In the case of the flexible track section according to the invention, not only are the cross ties connected via flexible connecting elements to form a one-piece flexible cross-tie grate, but the connection is also designed such that the connecting elements under the first rail track, which is fixed against transverse and longitudinal movements, extend over the entire length of the track section form a continuous spar, while the connecting elements on the opposite side are webs that connect the transverse sleepers on this side in groups, preferably in pairs. This combinatorial connection ensures that when the flexible track section is bent, the track width, i.e. the distance between the two tracks is reliably maintained, since the continuous spar formed by the connecting elements with the rail track fixed thereon against longitudinal and transverse movements forms a more rigid part than the other part with the transverse sleepers connected in groups with the aid of webs, so that when Bending there is a firmer or more rigid reference part for compliance with the track. Nevertheless, the flexible track piece is easy to handle and deform, so that almost any desired radius of curvature can be achieved by bending.

Surprisingly, this has the advantage that the flexible track piece can also be easily repaired using pass gauges if, for example, the rail track set only in the transverse direction but freely movable in the longitudinal direction jumps out of the assigned brackets and the cross ties when bending is. The more rigid part, which is formed by the crossbar grate with the continuous spar as a connecting element together with the rail track fixed thereon against a longitudinal and a transverse movement, also serves as a reference point for this repair. This eliminates the need for a fitting gauge, since this rail track reliably ensures that the track gauge is maintained, which is due to the fact that this rail track is rigidly and firmly connected to the cross sleepers and the cross sleep rust.

Appropriate developments of the flexible track section are given in claims 2 to 4.

The task with regard to the manufacturing process is solved with claim 5. To simplify the method of manufacture, the cross-sleeper grate is formed as a coherent structure with the rail track fixed against transverse and longitudinal movements, with the brackets in the form of nail-head-like parts being formed on the connected structure both for the fixed rail track and for the longitudinally displaceable rail track . This means that the basic structure of the flexible track section, consisting of the cross-sleeper grating and the one permanently attached to it, can be fixed against longitudinal and transverse movement Produce the rail track inexpensively in one work step and the second rail track only needs to be inserted into the already prepared and provided brackets in order to complete the flexible track piece as a whole.

• Fig. 1 in Draufsicht ein flexibles Gleisstück für Modelleisenbahnen,
• Fig. 2, 3 und 4 Unteransichten von verschiedenen bekannten Querschwellenrosten mit verschiedenen Mitteln zum Verbinden der Schwellen zu einem einstückigen, aber biegsamen Gebilde,
• Fig. 5 eine Querschnittsansicht eines bekannten biegsamen Gleises mit zwei längsbeweglichen Schienen,
• Fig. 6 im Querschnitt ein bekanntes biegsames Gleis mit zwei am Querschwellenrost befestigten Schienen,
• Fig. 7 in Draufsicht zwei miteinander verbundene bekannte Gleisstücke mit einander gegenüberliegenden Schienenstössen,
• Fig. 8 in Draufsicht eine der Fig. 7 ähnliche Anordnung, aber mit gegeneinander versetzten Schienenstössen,
• Fig. 9 im Querschnitt eine zweiteilige Form zum Anformen des Querschwellenrostes an eine einzelne Schiene,
• Fig. 10 eine Untersicht des Gleises gemäss der Erfindung und
• Fig. 11 im Querschnitt das Gleis gemäss der Erfindung.

Embodiments of the invention and the prior art are explained below with reference to the drawing. It shows:

• 1 is a plan view of a flexible track piece for model trains,
• 2, 3 and 4 bottom views of various known cross-sleeper gratings with different means for connecting the sleepers to form a one-piece but flexible structure,
• 5 is a cross-sectional view of a known flexible track with two longitudinally movable rails,
• 6 shows in cross section a known flexible track with two rails fastened to the crossbar grate,
• 7 is a top view of two known track pieces connected to one another with mutually opposite rail joints,
• 8 is a top view of an arrangement similar to FIG. 7, but with mutually offset rail joints,
• 9 in cross section a two-part form for molding the cross-tie grate onto a single rail,
• Fig. 10 is a bottom view of the track according to the invention and
• Fig. 11 in cross section the track according to the invention.

The preformed track section 20 shown in FIG. 1 has a one-piece grate of cross sleepers 22 and rails 28 attached to it. Such a preformed track section with rails fastened to the cross sleeper grate can be used to advantage when building a smooth, perfectly aligned track system for a model railroad. It is similar in appearance to a real railway track, in which each rail is attached to each individual sleeper with nails. It is not easy to see that the cross-sleeper grate in the track according to FIG. 1 is in one piece, because the elements connecting the sleepers lie under the rails and are not visible under normal observation. The track section shown in FIG. 1 can either be a rigid straight track section or a flexible track section according to the prior art or according to the invention, because the differences between the prior art and the invention do not affect the appearance of the track. In order to produce the track section, the plastic cross-tie grate consisting of sections 24 made of cross-ties connected to one another is molded onto two rails made of spring brass and approximately 60 cm long. The connecting elements between the cross sleepers can be designed in various ways, as will be explained below.

In FIGS. 2, 3 and 4, parts of one-piece cross-sleeper gratings are shown from below, as can be used in known flexible tracks. Each of these grates can also be used in the track material according to the invention. For the reasons given below, however, the arrangement according to FIG. 4 is preferred. When forming each curve, the track width, ie the distance between the rails from one another, should be kept as unchanged as possible at the prescribed value. This means that the rails have a common center of curvature at every point on the curve and the difference between the radii of curvature of the two rails corresponds to the track width. The transverse sleepers then lie on radii which intersect one another at the center of the curvature, and the threshold spacings are identical to one another on the inner rail and likewise identical to one another on the outer rail, but larger than on the inner rail. So that the sleepers can be deformed into the required fan-like arrangement, both rails would have to be displaceable and pivotable relative to each sleeper. In practice, this ideal can only be achieved approximately. According to FIG. 2, successive threshold ends can be connected to one another alternately on one and the other side of the track section. According to FIG. 3, the sleepers can be connected to one another in pairs on both sides by means of webs 26 'and the successive pairs of sleepers thus obtained can be alternately connected to one another by means of webs 26 on one and the other side of the track section. In the arrangement shown in FIG. 4, the sleepers are provided on one side by a continuous spar 26 "and on the other side are only connected in pairs by webs 26. In all the arrangements shown in FIGS. 2 to 4, the molded sleepers and connecting elements consist a plastic that is so flexible that the sleepers at the connection points of the connecting elements can be deflected somewhat in a hinge-like manner In a track curve with the threshold grate according to Figure 3, the distances between the interconnected threshold ends remain essentially unchanged and the distances between the unconnected threshold ends on the inner rail move closer to one another and those on the outer rail The ends of the rails are smaller on the inner rail and larger on the outer rail, on every side at every fourth threshold. Unconnected sleeper ends are present on each side of the track at intervals of four sleeper intervals and offset from each other by two sleeper distances. In a track curve with the sleeper grate according to FIG. 4, the distances between the unconnected sleeper ends only take one Side of the curve in such a way that the thresholds come to lie approximately along the radii of the curve and an arrangement is obtained with essentially the same accuracy as in FIG. 3.

When producing a known track section with one of the threshold gratings according to FIGS. 2, 3 and 4, it is customary to preform the threshold gratings without rails or to mold the threshold gratings onto both rails. In this way, the tracks shown in cross section in Figures 5 and 6 can be obtained.

The threshold grate shown in FIG. 5 is preformed without rails. Sufficient space is left between the upper surface of the threshold 22 and the inward and downward facing surface of each nail head 30A so that both rails 28 can be inserted by means of a holding device which ensures that when the rails are inserted, the thresholds are perpendicular to the path of movement of the Rails are held and properly aligned with them. After the rails have been attached, there is still a small distance between the foot 32 of each rail and the inwardly and downwardly facing surface of each nail head, so that both rails are freely displaceable relative to the sleepers. However, when the track piece is held by the user for cutting or bending or for installation, it often happens that one or both rails detach from the sill grate. It is then very tedious to reconnect the rails to the sleepers, because they deflect sideways and, due to the limited displaceability and pivotability of the sleepers relative to the rails, it can even happen that the sleeper grate is compressed or pulled apart like an accordion in the longitudinal direction of the track piece.

In the manufacture of the track piece according to FIG. 6, the threshold grate is molded onto both rails, so that there is no space between the rail feet 32 and the inwardly and downwardly facing surface of each nail head 30B. As a result, considerable frictional forces act between the sleeper grate and the rails, which prevent the individual rails from moving relative to the sleeper grate. Such a shift is necessary to curve the track. Therefore, the track is very stiff and it cannot be bent into a curve as tight as the more flexible track according to FIG. 5 and the track according to the invention. In the case of the track according to FIG. 6, it is not easy for the rails to unintentionally detach from the sleepers, but it is practically impossible to reattach the rails to the sleepers once the rails have detached from the sleepers. The fact that the rails are so difficult to move along the threshold grate makes it difficult to set up a track system that can be driven without problems, as will be described below with reference to FIGS. 7 and 8.

The rails of a flexible track section, which are made of resilient material, seek to spring back to a straight course after the track section has been bent. Therefore, if the curved track piece is connected to a straight track piece tangent to the curve or to a curved track piece continuing the curve, the rails will spring back somewhat so that a gap is formed on the outer rail joint of a curve, as shown in FIG 7 is shown at 34. To connect track pieces, rail connectors in the form of slotted clips are usually used, which grip parts of the feet of the rails to be connected in a friction-locking manner and thereby make it difficult to pull the rails apart. In contrast, these rail connectors only offer insufficient resistance to transverse forces, so that gaps and kinks can occur, as shown in FIG. 7. When driving on the curve, gaps and kinks are exerted on the railway vehicles at such gaps and kinks, which can often also result in rail vehicles derailing or tipping over. Furthermore, it often happens that even with tracks that are not too large gaps on the rail joints, the condition of the rail joints deteriorates until the track is unusable because the wheels of the train hit the rail joint and thereby the rails in the sense of a Relocate widening of gap.

The model railroaders have known for a long time that the rail joints are expediently offset from one another in a track curve, as indicated at 36 in FIG. This is especially true for flexible tracks. In this case, the uninterrupted rail part opposite each rail joint and the forces which are attributable to the tensioning of the uninterrupted rail part and the sleepers connected to it and which are transmitted via the sleepers to the rail ends forming the rail joint, ensure that they are aligned at the rail joint Able to be held. A train can run smoothly on such a track curve because there are no gaps or kinks that could cause impacts on the railway vehicles or derail them.

For tracks with mutually offset rail joints, track sections are used in which one rail is pulled a little out of the threshold grate and the other rail is pulled a bit into the rail grate and which are laid so that each rail joint is pulled out by one rail from its threshold grate and one is formed in their threshold rust retracted rail. The rail that has been pulled out of its sleeper grate extends in the sleeper grate of the other track section to the rail drawn into it.

In the known track piece according to FIG. 5, in which both rails can be freely moved along the threshold grate, the rails can be easily be drawn in and out. With this track, the rail part of the one track piece opposite the rail joint to be formed cannot hold the threshold grate of the same so reliably that it is perfectly aligned with the rail of the other track piece to be inserted. Therefore, it is very difficult to push the advanced rail of each track piece in the sill grate of the other track piece exactly into the position that previously occupied a part of the now retracted rail. If, on the other hand, the track pieces are completely connected to one another, the mutually offset rail joints are reliably fixed, so that no kinks and gaps can occur.

Tracks according to Figure 6, in which both rails are rigidly attached to the sleepers rust, are rarely laid with mutually offset rail joints. Since no rails can be pulled forward or retracted, one would have to cut off a rail section from the two track sections to be connected on opposite sides of the two track sections to be connected, the length of which corresponds to the dimension by which the rail joints are to be offset against one another. Furthermore, in one piece of track, the sleepers are completely removed from the unshortened rail, while in the other piece of track the sleepers are left on the unshortened sleeper. Before the connection is made, therefore, a rail section that is free of all sleepers protrudes from the cross-sleeper grate in one track section, while all sleepers are still connected to the longer track of the other track section. This longer rail comes to lie on the other side of the track than the freely protruding rail. When connecting these two pieces of track, the rail joints are offset from one another, but the threshold grille cannot fix the freely projecting rail against transverse movement, and the rail joint formed by the freely projecting rail is very likely to form a kink or gap, depending on whether the rail joint lies on the inside or outside of the curve.

A part of a track piece according to the invention is shown in Figures 10 and 11. As can best be seen from the bottom view in FIG. 10, the one-piece, flexible threshold grille consists of the thresholds 24, the continuous bar 42A connecting them on one side and the webs 42B connecting the thresholds on the other side in pairs. The webs 42B and the spar 42A lie under the rails 44A and 44B and are covered by these rails in the use position of the track and are therefore invisible. The rail 44A lying above the spar 42A is fixed to the rail grate against transverse and longitudinal movement relative to the sleeper grate, namely with nail head-like parts 48A (FIG. 11), each of which is integral with a sleeper 24 and molded onto the rail foot 46. The rail overlying the webs 42B and the free end portions of the sleepers is inserted with its foot 46 into the free spaces that exist between the upper surfaces of the sleepers and the inward and downward faces of nail head-like parts 48B. Since the rail 44B is fixed against transverse movement, the track maintains the correct track width when bending into a curve. The rail 44B is, however, freely longitudinally movable in the longitudinal direction of the threshold grate, so that when the track is bent, the distances between the unconnected ends of the threshold under this rail can increase or decrease such that the thresholds extend essentially along radii of the curve.

A two-part mold, as shown in cross section in FIG. 9, is used for compression molding the track according to the invention. A cavity 60 is formed in the molded part 52, which receives the rail 44A in the reverse position, the rail foot 46 sealingly closing the cavity 60. The parting line 54 of the mold is formed by the upper surface of the molded part 52. Flat cavities 58 and 58 'extend from this surface to form nail head-like parts 48A and 48B. In the molded part 50, which fits snugly against the molded part 52, a plurality of cavities 56 are formed which are arranged at a distance from one another and which are perpendicular to the cavity receiving the rail 44A and. serve to form the thresholds. Also formed in the molded part 50 is a cavity (not shown) which is continuous in the longitudinal direction and which is parallel to the cavity 60 for the rail 44A and, when the mold is closed, lies above it. The longitudinal cavity of the molded part 50 communicates with all the cavities 56 for the sleepers and is used to shape the spar 42A. Interrupted cavities (not shown) are also formed in the molded part 50, through which the cavities 56 for the sleepers are connected in pairs and which serve to form the webs 42B. A number of hold-down pins 62 carried by the molded part 50 are provided along the longitudinal cavity in the longitudinal direction, the spacing of which is a multiple of the distance between the cavities for the sleepers. The molded part 50 carries core pins 66 which extend downwards through one of the cavities 56 for the sleepers. The end parts 68 of the core pins 66 are rectangular in cross-section and engage directly on the upper surface of the molded part 52 at such a depth that after the later insertion of the rail 44B between its foot, the upper surfaces of the sleepers and formed along the parting line 54 There is so much play in the surfaces 70 of the nail head-like parts 48B facing the rail base that the rail 44B can be moved along the threshold grate.

To produce the track according to the invention, the rail 44A is inserted into the cavity 60 and the mold is closed so that the pins 62 hold the rail 44A and the latter in place closes the cavity 60 tightly. Plastic P is then injected into the mold to produce the cross-sleeper grate. The crossbar grate with the rail 44A connected to it is then pulled out of the mold and the rail 44B is pushed in.

The track according to the invention can easily be bent into a curve in which a model train can travel within the limits given by the car spacing etc. The track sections can be easily connected to one another in such a way that the rail joints are offset from one another and both rails are fixed by the threshold grille in such a way that no kinks or gaps are formed at the rail joints. Since the rail, which is firmly connected to the cross-sleeper grate, ensures its perfect alignment, you can easily pull out the sliding rail and slide it back in again.

Within the scope of the inventive concept, the person skilled in the art can modify the exemplary embodiments of the invention described and illustrated above and create other embodiments of the invention.

Claims (5)

1. A flexible track section for model railways, comprising a plurality of transverse sleepers (24), a first rail (44A), which is held on said sleepers against transverse and longitudinal movements, and a second rail (44B), which is parallel to the first rail and held on said sleepers against a transverse movement but is freely displaceable in its longitudinal direction, characterized in that the transverse sleepers (24) are joined in a manner known per se by flexible connecting elements (42A and 42B) to form an integral flexible sleeper grate (42A), and the connecting elements (42A) disposed under the first rail (44A), which is held against transverse and longitudinal movements, constitute a bar, which extends throughout the length of the track section, whereas the connect ing elements disposed on the opposite side consist of webs (42B), which are disposed under the second rail (44B) and connect the transverse sleepers (24) in groups, preferably in pairs.

2. A flexible track section according to claim 1, characterized in that the sleeper grate consists of molded synthetic plastics.

3. A flexible track section according to claim 2, characterized in that the sleeper grate is integrally formed with nailheadlike portions (48A), which serve to retain the first rail (44A) on the sleeper grate and overlie the foot (46) of the first rail in frictional engagement therewith.

4. A flexible track section according to claim 3, characterized in that the sleeper grate is integrally formed with nailheadfike portions (47E), which overlie the foot of the second rail (44B) with a slight clearance.

5. Apparatus for manufacturing a flexible track section in accordance with claim 4 with the aid of a bipartite injection mould (50, 52), which comprises sliders (62, 66), which are guided in recesses of one mould half and extend through a continuous cavity below the foot of the rail, characterized in that the sliders are pins (66), which in the closed mold (50, 52) extend through respective cavities (56) for the transverse sleepers (24) in such a manner that spaces for receiving the second rail (44B) serving to hold the second rail (44B) and the adjacent portions of the transverse sleepers (24), and the first rail (44A) is placed before the injection moulding into a cavity (60) of the mould (50, 52), and is removed from the mould together with the sleeper grate so as to form a coherent structure therewith.

Images