IE63432B1

IE63432B1 - Device for wedging a plate spring in position on a railway tie

Info

Publication number: IE63432B1
Application number: IE314489A
Authority: IE
Inventors: Philippe Duval; Rene Duconseil
Original assignee: Allevard Ind Sa
Priority date: 1988-10-19
Filing date: 1989-10-02
Publication date: 1995-04-19
Also published as: IE893144L; MA21639A1; JPH04501149A; NO911471L; OA09099A; PT91935A; BR8907730A; FI911869A0; TNSN89113A1; DK70591D0; FR2627519B1; DK70591A; MY104212A; GR890100616A; NO176063B; FR2627519A1; KR900702140A; NO911471D0; DK164515B; EP0439485A1

Abstract

In a device for wedging a spring plate 1 on a railway sleeper 2, the spring plate 1 constitutes a part of a system for fastening the rail to a sleeper of the type that comprises a clamping device 3, which extends through an opening 4, which is provided in the spring plate by removing material off-cuts 5, and which by locking in the sleeper allows the spring plate 1 to bear against the foot 6 of the rail R and a locking and pressing device between the rear end part 1R of the spring plate 1 and the sleeper 2. The locking and pressing device comprises vertical projections 2D, 2G, which are formed in the sleeper block 2 and define a space 7 for receiving the off-cut 5 vertically, and against which off-cut 5 the rear end part 1R of the spring plate has bearing contact.

Description

The present invention relates to a device for wedging a plate spring in position on a railway tie.

The systems for fastening a railway rail on a tie, such as those described in patent application FR 88/10759 or in patents FR-A-1 228 126 and FR-A-2 287 551 comprise, as fastening elements, a plate spring, an insulating stop positioned between the spring and the rail pad, and means for fastening and clamping the spring on the tie.

Such systems provide the possiblity for the back of the plate spring to bear against a pressure distributing insert which is in contact with the back heel portion of the spring. Seid insert is generally provided with a groove for receiving and positioning the back heel portion of the spring in order to prevent the latter from rotating.

One example of this is the embodiment described in patent CH-A-301375 (SIDERVIA) which comprises an elastic plate of which the rear end forms a rectilinear projection mounted in a groove formed on a metallic insert fixed on and embedded in the tie.

In the conventional devices, the bearing insert is produced by cutting a small flat piece in ordinary rolled steel. It can also be produced by molding a plastic material in order to avoid damaging the concrete tie .

In fact the insert may be either pre-mounted on the tie during manufacture of the latter, or post-mounted thereon on the railway site.

The dimensions of such insert are dependent on the distribution of the pressure which should be exerted over a wide surface in order to prevent the problems linked to the resistance of the material constituting the tie (wood or concrete).

The disadvantage with this system resides mainly in its cost price, indeed, the small flat piece of rolled steel is relatively expensive particularly due to the fact that it comprises a groove which is milled therein with a special roller, and that, since it is destined for a specific type of spring, it is never produced in sufficient quantity to make its price advantageous. Furthermore, in this device, it is the fixed metallic insert which forms the means for pressing in lateral abutment for the back heel portion of the plate rather than the actual tie.

In Patent Application FR 88/10759, the ties are in concrete and the aim is precisely to find the simplest and cheapest fixing method.

It is the object of the present invention to solve this new technical problem satisfactorily by providing a device for wedging a plate spring in position on a railway tie, said plate spring forming part of a system for fastening a rail on a tie, of the type comprising: clamping means passing through an opening formed in » the plate spring which, when locked in position on the tie enable said spring to press against the rail pad, and means for locking and pressing the back heel portion of the plate spring on the tie, characterized in that seid locking and pressing means comprise vertical projections formed in the tie block and defining a housing for receiving a horizontal swarf, obtained by removing material from the plate spring when forming the opening, so that the back heel portion of the plate spring bears perpendicularly on said swarf and in lateral abutment on said projections.

Another object of the invention is a method for manufacturing 8 device for wedging a plate spring in position on a railway tie, said plate spring forming part of a system for fastening a rail on a tie, consisting in removing a swarf of material from the blade spring in order to produce an opening through which a clamping means passes, the locking in the tie of which clamping means enables said spring to press against the rail pad and the locking and the pressing of the back heel portion of the plate spring on the tie, characterized in that the locking and pressing of the back heel portion of the plate are achieved by inserting said swarf horizontally in a housing defined between vertical projections formed in the tie block and by placing the heel portion in resting corLact against the swarf.

The opening in the plate spring is generally formed by cold punching. The dimensions of said opening (25 x 30 mm) and therefore the dimensions of the swarf, namely of the piece of material removed for producing said opening, are calculated so as to distribute adequately the pressure exerted by the back heel portion of the plate spring on the concrete tie. The shape of the swarf is substantially that of two joined-up half-circles whose centers are spaced apart.

Heretofore, such a swarf was scraped, as of now it will be used as a bearing plate and will eliminate the need of producing or buying the special inserts. Also with this solution, the plate springs produced are all the same, whether they are destined to be used with wooden ties as descibed in French Patent 2 287 551, or with concrete ties as descibed in French Patent Application 88/10759. With the wooden ties, the small rectangle of flat grooved steel can still be used, whereas with the concrete ties, the swarf resulting from the forming of the opening in the spring, will now be used.

The invention will be more readily understood on reading the following description with reference to the accompanying drawings, in which: - Figure 1 is a plan view of a plate spring according to the prior art.

- Figure 2 is a perspective view of a swarf removed from the plate spring according to Figure 1.

- Figure 3 is a plan view of a system for fastening a railway rail on a tie with the wedging device according to the invention.

- Figure 4 is a side view of the fastening system illustrated in Figure 3.

Figure 1 illustrates a plate spring 1 of substantially trapezoidal shape in which an opening 4 has been formed by removal of material (such as for example by cold-punching). The piece resulting from this operation is a swarf 5 illustrated in Figure 2 which has the same dimensions as the opening 4. Usually, such swarf 5 would be scrapped, but its dimensions are such that its surface is large enough for it to be used as a bearing plate for the plate spring 1, when said plate spring is locked in the rail-fastening position.

Thus, according to the invention, said swarf 5 is kept and used as a bearing plate.

Figure 3 illustrates a fastening system such as that described in Application 88 10759 but which is equipped with the wedging device according to the invention.

The fastening system comprises, in particular, clamping means 3 passing through the opening 4 formed in the plate spring 1 by removing the swarf of material 5.

The locking operation, for example by screwing the clamping means 3 in the tie 2 through the spring 1 presses the plate spring 1 against the pad 6 of the rail R.

The front end IA of the plate spring is thus brought in bearing contact on an insulating stop 9 interposed between the rail and the spring 1.

In order to prevent the plate spring 1 from rotating about the axis of the clamping means 3, it is necessary to wedge said spring in position.

Such wedging is achieved with means for locking and pressing the back heel portion IR of the plate spring 1 on the tie 2.

According to the invention said locking and pressing means comprise vertical projections 2D, 2G formed in the block of the tie 2. Projections 2D, 2G define a housing 7 for horizontally receiving the swarf 5, on which the back heel portion IR of the plate spring 1 comes in bearing contact. Projections 2D, 2G are produced on the tie 2 in parallel to the rail R and form a raised border against which the external edge 8 of the back heel portion IR of spring 1 abuts and bears laterally.

The largest dimension of the swarf 5 (formed of two joined-up half-circles of 25 mm diameter whose centers are spaced apart by 5 mm, thereby making a surface of about 6 cm2) is smaller than the width of the back heel portion IR of the plate spring 1, which is about 70 mm. The back heel portion IR is arched and therefore rests only by its central part and by its edge on the swarf 5 which acts both as a bearing plate for distributing the pressure and as a protective plate for the material constituting the tie 2.

Plate spring 1 exerts on the swarf 5 a force of approximately 630 kg, which corresponds to a pressure of about 105 kg/cm2 and is quite acceptable for the concrete tie, knowing that the thickness of the swarf 5 is about 4 mm and its breaking strength about 70 kg/mm2.

The back bearing pressure of the plate spring 1 on the tie 2 is virtually perpendicular to the swarf 5.

As a result, projections 2D, 2G are subjected to only very little stress, and do not risk being damaged.

The swarf therefore presents all the qualities necessary to fulfill its function. The housing 7 with the swarf 5 is situated inside the plane of symmetry of the plate spring 1.

Projections 2D, 2G permit the transverse positioning of plate spring 1 with respect to the rail in combination with the clamping means 3, and prevent any rotation of the spring 1 about the axis of said clamping means.

Claims

1. Device for wedging in position a plate spring (1) on e railway tie (2), said plate spring (1) forming part of a system for fastening a rail on a tie, of the type comprising: - clamping means (3) passing through an opening (4) formed in the plate spring (1) and which, when locked in position on the tie (2) enable said spring to press against the pad (6) of the rail (R), and - means for locking and pressing the back heel portion (IR) of the plate spring (1) of the tie (2), characterized in that said locking and pressing means comprise vertical projections (2D, 2G) formed in the tie block , (2) and defining a housing (7) for horizontally receiving a swarf (5) obtained by removing material from the plate spring when forming the opening, so that the back heel portion (IR) of the plate spring bears perpendicularly on said swarf and in lateral abutment on said projections.

2. Wedging device according to claim 1, characterized in that the largest dimension of the swarf (5) is smaller than the width of the back heel portion (IR) of the plate spring (1).

3. Wedging device according to claim 2, characterized in that the housing (7) with the swarf (5) is situated in the plane of symmetry of the plate spring (1) ·

4. Method for manufacturing a device for wedging a plate spring (1) in position on a railway tie (2), said plate spring (1) forming part of a system for fastening a rail on a tie, consisting in removing from the blade spring a swarf (5) of material in order to produce an opening (4) through which a clamping means (3) passes, the locking in the tie (2) of which clamping means (3) enables said plate spring to press against the pad (6) of the rail (R) and the locking and the pressing of the back heel portion (IR) of the plate spring (1) on the tie (2) , characterized in that the locking and pressing of the back heel portion (IR) of the plate spring (1) 05 are achieved by inserting said swarf (5) horizontally in a housing (7) defined between vertical projections (2D, 2G) formed in the tie block and by placing the heel (IR) in resting contact against the swarf (5).

5. Method according to claim 4, characterized in 10 that the external edge (8) of the back heel portion (IR) of the plate spring (1) comes in lateral bearing abutment on said projections (2D, 2G).

6. Method according to claim 4 or 5, characterized in that the largest dimension of the swarf 15 (5) is smaller than the width of the back heel portion (IR) of the plate spring (1).

7. A device according to claim 1, substantially as hereinbefore described with particular reference to and as illustrated in the accompanying drawings.