AU632828B2 - Apparatus for fastening rails - Google Patents

Description

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AUSTRALIA

PATENTS ACT 1952 Form I ii

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COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: Complete Specification Lodged: Accepted: Lapsed: Published: Priority: Related Art: TO BE COMPLETED BY APPLICANT Name of Applicant: Address of Applicant: Actual Inventors: Addre~ss for Service: VEOEST-ALPfiNED1 ZelffwegGslshftt...6

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CoA iSE -T Au:fl1"9 4 A- 14o ie I-OR3 11O4.

H-ermann Orashe, Johann CALLINAN LAWRIE, Patent Trade Mark Attorney, 278 High Street, Kew, Victoria 3101, Australia.

Complete Specification for the invention entitled: 4 '~Pk7&m f=09 FA ST-PJj Aq-qt- The following statement is a full description of this invention, including the best method of performing it known to me:- 7 0 t~S

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ORIGINAL

Equipment for Fastening Rails The invention relates to equipment for fastening of rails and/or switch parts to railroad ties, using tie plates and/or ribbed plates, in which the tie plates and/or ribbed plates are connected to the ties, particularly steel ties, with intermediate connection of electrical insulation, and insulating layers are provided in the fastening area of the ribbed and/or tie plates, whereby between the tie and the ribbed and/or tie plate at least two layers of electrically insulating material are mounted.

A rail fastening is already known from DE-OS 25 27 494, in which an UfI elastic fastening of the rail to the ties is provided. The rails themselves were screwed to a ribbed and/or tie plate with intermediate connection of an intermediate 0 layer of elastic material and the ribbed plate was screwed to the tie with intermediate connection of an additional elastic layer which was applied as a coating on the underside of the tie plate and/or ribbed plate. Also from DE-OS 37 08 752, an elastic and simultaneously adjustable rail fastening of this type can be o" found, whereby here again the ribbed and/or tie plate is connected to the tie with o.o" intermediate connection of vibration and structure-bome noise damping, as well as electrically insulating, intermediate plate. The main task of these known constructions is clearly the elastic fastening of ties, whereby particularly in the case o 2 of DE-OS 37 08 752 there was also the purpose of creating an electrically insulating connection.

With modern electronic signal towers, a large number of signals are scanned and transmitted and the occurrence of surface leakage current must be reliably prevented. Particularly in poor weather, it has been shown that the known simple types of electrical insulation are nc- able to dependably prevent this type of surface leakage current. Particularly in connection with image signal towers, in which high frequency signals must also be reliably insulated, the' known versions are subject to malfunction during bad weather. Particularly when the selection of plastics is made with respect to their elastic damping characteristics, optimum insulation values cannot always be achieved in the same way.

I 5 An electrically insulating spacer for railroad tracks has become known from DE-OS 14 55 354 whereby between two insulating layers below the railfoot, an electrically conductive intermediate layer is provided in order to be able to determine by measurement the insulation status of each individual spacer. Thus for this purpose an additional conducting and/or measuring system must be 1 tQ0, attached to each individual spacer, whereby the number of data to be processed is further increased and because of the presence of additional conductive layers within *t the insulation, the formation of undesirable signals and surface leakage currents is increased.

The goal of the invention is now to create a device of the type mentioned at the beginning with which electrical insulation can be maintained even under unfavourable weather conditions and which additionally permits the damping I l behaviour of the rail fastening to be appropriately optimized if necessary. To solve I this task, the device according to the invention basically consists of the fact that the I 1" electrically insulating layers lying over each other are formed as plates with surface 1 20 areas different from each other and that the upper insulating plate turned towards |I the railroad tie projects over the circumference of the insulating plate lying below it, preferably on all sides. Since between ribbed and tie plate and tie, at least two electrically insulating layers lying over each other are mounted, there is for one thing the possibility of selecting at least one of these plates independently of the desired damping, corresponding to the required iasulation capability of the material. Because of the fact that now two plates lying over each other can be 3 used, the construction can reliably prevent undesirable surface'leakage currents during damp weather conditions, in that at least one of the plates has a surface area different from the other plate. In this way, a step-like edge profile is achieved which counteracts the formation of a continuous film of fluid which in turn would exhibit conductivity. A particularly effective insulation can be achieved in this way because of the fact that the upper insulating plate turned towards the tie projects over the circumference of the insulating plate lying above it, preferably on all sides.

In this way, a shoulder edge turned towards the inside between the upper plate and the lower plate is formed, which already prevents the formation of a continuous fluid film during heavy rain showers by gravity. The construction can preferably be made in such a way that the circumference of the flat larger S' insulating plate is designed as a draining edge, whereby the lower plate side wall running in the peripheral direction that is next to the tie can be kept free of the direct effect of rain water.

The embodiment according to the invention thus has the advantage that it can be used not only in connection with steel ties in the superstructure, but that °o the same construction elements can be used for different tie designs. In particular the same fastening elements are also useful for concrete ties, which naturally do not have the same insulation capability requirements as in steel ties.

A uniform system of ribbed plates with damping plates or tension plates and a corresponding fastening by spring elements, like for example pandrol fastening or the like, for ties of different material with simultaneous achievement of the most practical insulation values in steel ties, is particularly favourable for efficient rail superstructure.

The position setting of the plate is generally only done in the last phase of construction with this type of moe or less elastic rail fastenings and as a rule 4 it is necessary to later align the already tightly fastened rails. In order to be able to safely maintain the insulation characteristics, particularly when steel ties are used, even during this type of position correction during the final fastening, the embodiment is constructed advantageously in that on at least one narrow side of the tie plate the ties have support elements and/or carriers and that insulating strips are mounted between the support elements and the adjacent narrow sides of the tie plate and/or ribbed plate. Mo,,nting this type of additional, insulating strips between the ribbed plates and the support elements and/or carriers insures that even with subsequent lateral displacement for purposes of alignment of the rails, the ribbed plates cannot come directly in contact with the support elements and/or carriers that are rigidly fastened on the steel rails, for example by welding. A particularly stable and dependable insulation in this lateral area of the tie and/or ribbed plate can be achieved in that the support elements and/or carriers are a a formed of support strips rigidly connected to the tie, particularly welded, forming an open oblique angle to each other at the narrow side of the tie plate and/or I ribbed plate, and that the insulating strips are designed as plates that are wedge- I shaped when viewed form the top, the wedge angle of which corresponds to the oblique angle between the support strips. With this type of embodiment, even a high adjusting forces cannot lead to a disruption of the insulation.

20. Finally, in a known way, the insulation in the area of the bolts that connect the tie plates to the tie can be made in such a wvay that the bolts connecting the tie plates and/or ribbed plates to the tie can be connected to the tie with intermediate connection of insulating bushings and covered on their head side with insulating caps, whereby this type of insulating bushings must prevent direct contact of the bolts to the inner edge of the corresponding opening of the tie plate and/or ribbed plate as well as the upper and lower edge of this opening. In the area of the lower edge., however, the insulation consisting of at least two plates is located, whereby in this area the danger of forming a conductive bridge is prevented. Also in the area of these recesses, the structure can be made for prevention of surface leakage currents in s.ch a way that the upper plate extends over the edge of the recess of the insulating plate lying below it. Finally, additional protection can be achieved by placing an insulating cap on the outside of the head.

The invention will be explained in more detail using example embodiments shown schematically in the drawing. In these, Fig. 1 shows a view 1 of equipment according to the invention for fastening rails and/or switch parts fo o: ties, partially in cross section; Fig. 2 a top view in the direction of arrow II on the j design according to Fig. 1, whereby Fig. 1 represents a view in the direction of I arrow I of Fig. 2; and Fig. 3 an enlarged, partial section through a modified embodiment.

In the design according to Fig. 1, a ribbed plate 4 is fastened to a steel tie 1, electrically insulated from the tie, by means of threaded connections 5 with intermediate connection of two plastic intermediate layers 2 and 3, which have electrical insulation characteristics and damping characteristics. A rail 6 is fastened \to the ribbed plate and/or tie plate 4 by means of clamping plates 7, hooked bolts t 20 8 and doubled spring washers 9 with intermediate connection of an elastic plastic intermediate layer The layers 2, 3 of electrically insulating material provided between tie 1 and the ribbed and/or tie plate 4 have different surface areas, whereby the upper insulating plate 3 next to the ribbed plate 4 extends beyond the circumference of the plate 2 lying below it on all sides and is formed as a draining edge in order to achieve reliable drainage of a liquid film directly from the insulating layer 3 to the

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6 tie 1 without formation of a continuous liquid film between the ribbed plate 4 and the tie 1. Also the threaded connector 5 must be designed in such a way as to maintain the insulation between the tie 1 and the ribbed plate and/or tie plate 4, whereby a bushing 11 is provided which is installed in the appropriate recess of the .ribbed plate 12 and which prevents contact of the threaded connection formed, for example, as a hooked bolt 13, to the ribbed plate and/or tie plate with intermediate connection of a spring washer 14. Through the appropriate design of bushing 11, the screw 13 as well as the spring washer 14 are thus electrically insulated from the ribbed and/or tie plate 4. In order to prevent entry of dampness and/or 1 contamination into the area of the threaded connection even during bad weather n conditions, the screw 13 is covered, after it is tightened, by an insulating cap The spring washers that are again formed as doubled spring washers 14 have a significantly greater spring excursion than the plastic layers 2 and 3, whereby a satisfactory position-stable mounting is assured even under dynamic load when the tie is passed over.

The support elements and/or carriers 16 that are rigidly connected, particularly welded, to the tie 1 are provided on one side of the ribbed and/or tie plate 4, whereby insulating strips and/or inserts 17 are provided to maintain the insulation between the tie plate and/or ribbed plate 4 and the tie 1. The support I* 20 elements and/or carriers form an obtuse angle to each other, as can particularly be seen from Fig. 2, whereby for safe maintenance of the insulation, the insulating strips and/or insulating inserts 17 in the top view are formed as basically wedgeshaped plates, the wedge angle of which corresponds to the obtuse angle cbetween the support strips and/or carriers 16.

The additional support elements and/or carriers 16 are used to absorb sudden forces, as can sometimes occur with mechanical adjusting, via the insulating a r. I i l i 7 support elements 17. In addition, by appropriate selection of the dimensions of the insulating strips and/or the insulating elements 17, uniform components can be used since the adjustment ability of the fastening position of the ribbed and/or tie plate 4 to the tie 1 is made possible. For orderly mounting, the insulating strip 17 can be designed to be slotted in the area of the larger insulating layer 3 so that the insulating layer 3 partially engages in the insulating strip 17 as indicated in Fig. 1.

In the modified embodiment shown in Fig. 3, a collar-shaped insulating bushing 11 is used, into which the spring washer 14 partially dips. The threaded connection is thus provided for fastening the ribbed and/or tie plate 4 to a concrete 10 tie 18 and the lower electrically insulating layer 2 is formed in a modified way. The I electrically insulating layer 3 next to the ribbed and/or tie plate again exhibits a larger surface in order to counteract the formation of liquid films and thus of surface leakage currents. Again, a plastic cap can be provided over bolt 14.

The fastening of the rail 6 to the ribbed and/or tie plate 4 can also, instead of the embodiment shown in Fig. 1, be designed using tension damps and hooked bolts, with spring clips or with pandrol damps, whereby the dimension and the number of the plate threaded connections and the damping values of the electrically insulating plastic intermediate layers 2, 3 can be adapted to the I respective requirements.

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Claims (9)

1. Apparatus for fastening rails and/or switch parts to ties, using tie plates and/or ribbed plates, wherein said tie and/or ribbed plates are connected to said ties, with intermediate connection of electrical insulation and insulating layers are provided in the area of said ribbed and/or tie plate fastening, whereby between said tie and said ribbed and/or tie plate at least two layers of electrically insulating material are mounted, said electrically insulating layers lying on top of each other and formed as plates with surface areas that are different from each other and wherein the upper insulating plate turned towards said tie projects beyond the 1 circumference of said insulating plate lying below it.

2. Apparatus according to claim 1, wherein the circumference of said i insulating plate with the larger surface area is formed as a draining edge.

3. Apparatus according to claim 1 or claim 2, wherein said ties have support elements and/or carriers on at least one narrow side of said tie plate and 15 wherein insulating strips are mounted between said support elements and adjacent narrow sides of said tie and/or ribbed plate.

4. Apparatus according to claim 3, wherein said support elements and/or carriers are designed as support strips forming an open obtuse angle to each other at the narrow side of said tie and/or ribbed plate and are rigidly connected 20 to said tie, and wherein said insulating strips are formed as wedge shaped plates in the top view, the wedge angle of which basically corresponds to said obtuse angle between said support strips.

Apparatus as claimed in claim 4, wherein said support elements are connected to said tie as by welding.

6. Apparatus according to any one of claims 1 to 5, wherein bolts connecting said tie and/or ribbed plates to said tie are connected to said tie with intern insula

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8. upper lying

9. as des DATE: VOEST 1. by the SCALLI e l -f i ip r 1 I'! i i3 itt II rt intermediate connection of insulating bushings and their head side is covered by insulating caps. 7. Apparatus as claimed in any one of the preceding claims, wherein said ties are constructed of steel or the like material. Apparatus as claimed in any one of the preceding claims, wherein said upper insulating plate projects beyond the circumference of said insulating plate lying below it on all sides. 9. Apparatus for fastening rails and/or switch parts to ties, substantially as described herein with reference to the accompanying drawings. DATED the 5th day of July, 1990 VOEST-ALPINE Zei-Je gE ,sf.-IWl 1.L.II. OC PSr-AL-piwNe eIS ehtr v s8AsHVT/s7 rESEuj r scH .h. by their Patent Attorneys S CALLINAN LAWRE t C. *i: