RAIL FASTENING CLAMP
The rail fastening clamp with a two-radii loop-shaped section and straight clamping design addresses issues of wear and stress concentration, enhancing durability and reliability by evenly distributing loads and reducing insulator wear.
Patent Information
- Authority / Receiving Office
- RU · RU
- Patent Type
- Utility models
- Current Assignee / Owner
- ПОТАПОВИЧ АНДРЕЙ НИКОЛАЕВИЧ
- Filing Date
- 2026-03-17
- Publication Date
- 2026-07-10
AI Technical Summary
Existing rail fastening clamps suffer from reduced service life due to dynamic loads causing wear at contact points, complex configurations leading to increased metal consumption, and localized stress concentration on insulators resulting in abrasive wear and reduced clamping force.
A rail fastening clamp designed with a steel rod structure featuring a loop-shaped section formed by two radii of curvature and a straight clamping section, ensuring stable contact with the insulator, reducing localized stresses and abrasive wear, and maintaining a uniform distribution of operational loads.
The design enhances durability and operational reliability by distributing loads evenly, reducing insulator wear, and maintaining stable clamping force without excessive plastic deformation.
Smart Images
Figure 00000001_ABST
Abstract
Description
[0001] The utility model relates to the superstructure of a railway track, in particular to the structures of rail fastening of the superstructure of a railway track, in which the fastening of rails to reinforced concrete, polymer concrete or composite sub-rail bases, such as sleepers, half-sleepers, beams, slabs, blocks, sleepers, etc., is carried out using elastic clamps that press the soles of the rails to the sub-rail bases, ensuring the fastening of the rails to the sub-rail base by means of rail fastening and is intended for use in the track facilities of subways, trams, mainline and industrial transport.
[0002] The following solutions are known from the prior art.
[0003] A rail fastening clamp (RU Patent No. 2137874, publication date: September 20, 1999) is known. It is made of a steel rod and comprises an inner and outer part. The outer part is formed by free branches oriented parallel to each other, each of which transitions into an arc before the bend and into parallel lateral branches of the inner clamping part. The inner branches are connected to each other, forming a straight section, the length of which is equal to the distance between the two free ends of the branches of the outer part of the clamp.
[0004] The anchor is secured to a reinforced concrete support, and the free ends of the clamp are located in its eyes. The ends of the clamp protrude from the anchor eyes above the rail base.
[0005] A disadvantage of the known clamp is that the ends of the clamp protrude from the anchor eyes above the rail base and are in contact with it. Due to dynamic loads generated during the movement of the rolling stock, the ends of the clamp and the rail base wear at the contact point, which reduces the clamp's service life.
[0006] A rail fastening clamp is known, Russian Federation patent No. RU196421U1, publication date 2020.02.28, made of a steel rod and containing an internal, intermediate and external branches, wherein the external branch is rectilinear and is formed in the section from the free ends to the first bend, and in the section after the first bend, an intermediate branch is formed, having the shape of an arc with a first radius of curvature, the parts of the rod of which expand in the direction of the second bend, after the second bend, an internal branch is formed having the shape of an arc with a second radius of curvature, the sections of the rod of which are connected to each other on one side to form an arc-shaped section, and on the other - are made parallel, the distance between them is equal to the distance between the rods in the region of the second bend and exceeds the distance between the free ends of the rod of the external branch, while the clamping surface of the internal branch of the clamp is made flat.
[0007] The disadvantage of the well-known terminal is that this terminal has a complex configuration, which in turn requires the use of a longer rod in its production, which increases the metal consumption of the terminal.
[0008] A known elastic clamp for intermediate rail fastening (RU Patent No. 166829, publication date: 06 / 29 / 2016) is made of a steel rod bent to form a middle loop, two lateral branches and two end rectilinear sections located under the lateral branches, symmetrical relative to the longitudinal and vertical axes of the clamp, wherein the middle loop is formed by bending the middle section of the clamp rod towards the end rectilinear sections of the clamp and is made with a rectilinear section in its central part, the lateral branches are formed by bending the clamp rod in sections connecting the middle loop with the end rectilinear sections, wherein the lateral branches are made with a symmetrical inclination relative to a plane passing through the longitudinal and vertical axes of the elastic clamp, with the angle of inclination opening in the direction from the middle loop, and the length of the rectilinear section in the central part of the middle loops are less than the distance between the end straight sections.
[0009] The closest analogue of the patented utility model is a rail fastening clamp (patent RU 235311, publication date: 30.06.2025), made from a steel rod and containing an internal, intermediate and external part, wherein the external part is rectilinear and is formed in the section from the free ends to the first bend, and in the section after the first bend an intermediate branch is formed, having the shape of an arc with the first radius of curvature, the lateral parts of which are parallel relative to the plane passing through the longitudinal and vertical axes of the terminal, after the second bend an internal part is formed, having the shape of an arc with the second radius of curvature, the sections of the rod of which on one side are connected to each other to form an arc-shaped section, and on the other side are made parallel, the distance between them is equal to the distance between the free ends of the rod of the external branch, wherein the clamping surface of the internal branch of the terminal is made round, corresponding to the seat in the insulator of the rail fastening.
[0010] A disadvantage of the known terminal is that the loop-shaped section of the terminal's outer part has a single radius of curvature. This design feature of the terminal results in a small contact patch area with the polymer insulating liner (insulator). This can cause increased stress concentration on the insulator and abrasive wear of the insulator at the point of contact with the terminal due to dynamic loads in the "insulator-terminal" system that occur during the passage of rolling stock. This, in turn, leads to increased wear and failure of the insulating liner during operation. Due to abrasive wear in the insulator, the polymer material of the insulator wears out, causing a decrease in the height of the insulator's clamping portion above the top of the rail base. This, in turn, reduces the height of the clamping surface of the loop-shaped section of the terminal's outer part above the top of the rail base, thereby weakening the clamping force of the fastening assembly as a whole.
[0011] The technical problem is in the formation of the terminal configuration with
[0012] - shortened free ends that do not protrude from the anchor eyes to prevent their contact with the rail base;
[0013] - lateral branches made parallel to the plane passing through the longitudinal and vertical axes of the elastic clamp;
[0014] - lateral branches that do not have extensions relative to the plane passing through the longitudinal and vertical axes of the elastic clamp;
[0015] - a round pressure surface of the inner branch of the terminal, corresponding to the seat in the insulator of the rail fastening (patent of the Russian Federation RU 199291);
[0016] - a straight pressure section of the loop-shaped section of the outer part of the terminal, formed between two radii at the transition point of the side branches of the terminal into the outer part of the terminal with such a configuration of the loop-shaped section of the outer part of the terminal that would ensure an increase and stabilization of the contact area of the terminal with the insulator in the pressure zone, a decrease in local concentration stresses and a decrease in abrasive wear of the insulator while maintaining the required elastic properties of the terminal.
[0017] The problem is solved by using a rail fastening clamp made from a steel rod. The loop-shaped section of the outer part is formed not by a single continuous arc, but by two radii of curvature, between which a straight clamping section is formed, designed to engage with a corresponding recess in the rail fastening insulator. This design ensures a longer and more stable contact between the clamp and the insulator compared to a curved section formed by a single radius.
[0018] The technical result of the claimed utility model is to increase the durability and operational reliability of the rail fastening unit by reducing localized concentration stresses in the terminal and insulator, more uniformly distributing operational loads, reducing abrasive wear of the insulator in the contact zone with the terminal and ensuring a stable rail pressing force.
[0019] The stated technical result is achieved due to the design of a spring terminal made of a steel rod and containing an internal, intermediate and external part, while
[0020] - the outer part is formed by two straight free ends from their beginning to the first bend with a formed straight pressure section of the loop-shaped section of the outer part of the terminal, formed between two radii at the transition point of the side branches of the terminal to the outer part of the terminal
[0021] - the intermediate part is formed by two lateral branches having the shape of an arc with the first radius of curvature and located parallel to the plane passing through the longitudinal and vertical axes of the elastic clamp;
[0022] - the outer part is formed by an arcuate section with a second radius of curvature connecting the side branches, while the distance between the sections of the rod of the outer part is equal to the distance between the free ends;
[0023] in this case, the clamping surface of the outer part of the terminal is made round, corresponding to the seat in the insulator of the rail fastening.
[0024] In particular cases of the implementation of the utility model, the thickness of the rod is 16±1 mm; the height of the terminal in the working position: 82±2 mm; the length of the terminal in the working position: 102±2 mm; the length of the straight section of the free ends: 45±2 mm; the distance between the free ends: 34±2 mm; the first radius of curvature of the intermediate part: 25±2 mm; the second radius of curvature of the outer part: 45±2 mm; the radius of the arcuate section (9): 17±2 mm.
[0025] In particular cases of the implementation of the utility model, the side branches of the intermediate part do not have extensions relative to the plane passing through the longitudinal and vertical axes of the terminal, which ensures uniform distribution of loads.
[0026] In particular cases of the implementation of the utility model, the terminal is made with a straight clamping section of the loop-shaped section of the outer part of the terminal, formed between two radii at the transition point of the side branches of the terminal into the outer part of the terminal.
[0027] The claimed technical result is achieved through the following features of the utility model. The clamp, constructed from a steel rod, enables repeated elastic deformation and supports operational loads without loss of functionality, which is necessary to maintain a stable rail clamping force. The clamp's design, consisting of an internal, intermediate, and external section, creates a spatial elastic clamp structure in which the load is supported and redistributed across several working areas, reducing local stress and increasing the durability of the structure.
[0028] The straight-lined section from the free ends to the first bend ensures stable placement of the clamp in the anchor zone and load transfer to the working curved sections without excessive localized deflections. The arc-shaped intermediate section with the first radius of curvature creates a flexible working section that absorbs some of the bending loads and ensures smooth stress redistribution. The parallel arrangement of the lateral sections of the intermediate section relative to the plane passing through the clamp's longitudinal and vertical axes ensures symmetrical clamp operation under load, reduces distortion, and promotes a more even distribution of forces.
[0029] The arc-shaped inner section with a second curvature radius creates an additional elastic working area, ensuring the required operating stroke of the terminal and reducing the likelihood of peak stresses in the bending zones. The design of the rod sections, on one side connected to form a loop-shaped section and on the other side parallel, with the distance between them equal to the distance between the free ends of the rod, ensures the geometric symmetry of the terminal and stable force transmission to the insulator without uneven loading of individual sections of the structure.
[0030] The circular clamping surface of the inner leg, designed to fit the mounting surface in the rail fastening insulator, ensures a more complete fit with the insulator, reduces point contact, and thereby reduces stress concentration and insulator wear. The loop-shaped section, formed with two radii of curvature where the loop and side legs of the terminal transition to the outer section, ensures a smoother transition of the terminal's shape in the loaded zone, reduces local stresses in the terminal material, and creates conditions for the formation of a stable contact zone with the insulator. The presence of a straight clamping section in the loop-shaped section, designed for mounting in a corresponding recess in the insulator, increases the contact area between the terminal and the insulator, more evenly distributes contact pressure, reduces abrasive wear of the insulator, and stabilizes the clamping force during operation.
[0031] Thus, it is the combination of the above mentioned features that ensures increased durability and operational reliability of the rail fastening unit.
[0032] The solution is further explained by references to figures, which show the following.
[0033] Fig. 1 – general view of the rail fastening terminal.
[0034] Fig. 2 – general view of the rail fastening terminal.
[0035] Fig. 3 – Front view of rail fastening terminal.
[0036] Fig. 4 – top view of rail fastening terminal.
[0037] Fig. 5 – side view of rail fastening terminal.
[0038] Fig. 6 – side view of the rail fastening terminal in section A-A from Fig. 1.
[0039] Fig. 7 – view of rail fastening with the proposed clamp.
[0040] Fig. 8 – view of the rail fastening insulator.
[0041] Spring terminal, made from a steel rod, by bending it in a heated state, followed by hardening and tempering in order to obtain an internal structure of the metal that has the properties of a spring.
[0042] As a result of bending, the inner part 1, intermediate part 2, and outer part 3 are formed. The inner part 1 is straight and is formed in the section from the free ends 4 to the first bend 5.
[0043] In the section after the first bend 5, an intermediate part 2 is formed, having the shape of an arc with a first radius of curvature 15. The lateral branches 6 of the intermediate part 2 are parallel relative to the plane passing through the longitudinal and vertical axis of the elastic clamp.
[0044] After the second bend 7, the outer part 3 is formed, which has the shape of an arc with a second radius of curvature 8. The sections of the rod of the inner branch are connected to each other on one side to form a loop-shaped section 9, and on the other side they are made parallel, the distance between them is equal to the distance between the free ends 11. The clamping surface 12 of the outer part of the terminal 3 has a circular shape. The loop-shaped section 9 of the outer part of the terminal is made composite in shape and is formed by two conjugate radii of curvature 16, between which a rectilinear clamping section 17 is located. The rectilinear clamping section 17 is designed with the possibility of placement in a corresponding recess 18 of the insulator and serves as the main contact area of the terminal with the insulator. The loop-shaped section 9 of the outer part of the terminal is made composite in shape and is formed by two conjugate radii of curvature 16, between which a rectilinear pressure section 17 is located.The straight clamping section 17 is designed to fit into the corresponding recess 18 of the insulator and serves as the primary contact area between the terminal and the insulator. Unlike a curved contact section, a straight clamping section ensures a more uniform load distribution across the surface of the insulator recess, reduces local contact stresses, and decreases insulator wear.
[0045] Parameters of the proposed terminal:
[0046] - rod thickness - 16±1 mm,
[0047] - terminal height in working position - 82±2 mm,
[0048] - terminal length in working position - 102±2 mm,
[0049] - length of straight section - 45±2 mm,
[0050] - distance between free ends - 34±2 mm,
[0051] - first 5 radius - 25±2 mm,
[0052] - second 8 radius - 45±2 mm,
[0053] - radius 13 of the arcuate section 9 - 17±2 mm.
[0054] The utility model is used as follows.
[0055] The spring rod clamp of the rail fastening 10 without the use of threaded connections, as well as without soldering and welding, is fixed in the corresponding seats of the anchor 14, mounted in the reinforced concrete sleeper, which simplifies the design of the fastening, facilitates its installation and reduces the costs of ongoing maintenance and production.
[0056] The straight sections 11 of the inner 1 part of the spring clamp 10 are inserted into the pre-made fixing holes of the anchor 14 of the intermediate rail fastening of the SB or KPP type, the free ends 11 of the clamp rest against the insulator 13, do not protrude from the eyes of the anchor 14 above the rail foot and do not have contact with it, and the outer 3 closed part of the spring clamp presses the rail to the sleeper through the insulator 13. In this case, the clamping surface of the inner branch of the clamp is made round 12 and corresponds to the seat in the insulator 13 of the rail fastening of the SB and / or KPP type. The parallelism of the side branches 6 and the round pressure surface 12 in combination with the formed straight pressure section of the loop-shaped section of the outer part of the terminal, formed between two radii at the transition point of the side branches of the terminal into the outer part of the terminal, eliminate concentration stresses and abrasive wear of the insulator.
[0057] The proposed terminal shape provides the following advantages:
[0058] - Optimal elastic clamp travel (up to 14 mm) is achieved by flexing its working sections. With a vertical rail travel of up to 14 mm, there is no plastic deformation of the clamp's working sections. As a result, the spring rod clamp maintains its functionality and provides the force necessary to press the rail against the reinforced concrete sleeper.
[0059] - low labor intensity of current maintenance on the track due to the clamp's perception of compressive and bending loads during operation, there is no reduction in the clamp's pressing force on the rail to the sleeper, which in turn contributes to the durability of the clamp.
[0060] - simplified bending technology during its production - one technological operation is required to give the terminal its spatial shape.
[0061] - reduction of abrasive wear of the insulator at the point of contact with the clamping section of the loop-shaped section of the outer part of the terminal due to an increase in the contact patch area.
Claims
1. A rail fastening terminal made from a steel rod and comprising an internal, intermediate and external portion, wherein the internal portion is rectilinear and is formed in the section from the free ends to the first bend, and in the section after the first bend an intermediate portion is formed, which has the shape of an arc with a first radius of curvature, the lateral branches of which are parallel relative to a plane passing through the longitudinal and vertical axes of the terminal, after the second bend an external portion is formed, which has the shape of an arc with a second radius of curvature, the sections of the rod of which are connected to each other on one side to form a loop-shaped section, and on the other side are made parallel, the distance between them is equal to the distance between the free ends of the rod of the internal portion, wherein the clamping surface of the external portion of the terminal is made round, corresponding to the seat in the insulator of the rail fastening, and the loop-shaped section of the external portion is formed by two radii of curvature,between which there is a rectilinear pressure section, designed with the possibility of placement in the corresponding recess of the rail fastening insulator.
2. The terminal according to paragraph 1, characterized in that the free ends of the terminal rest against the insulator, do not protrude from the anchor eyes above the rail base and do not have contact with the rail base.
3. The terminal according to claim 1, characterized in that the side branches, having the shape of an arc with a first radius of curvature, do not expand in the direction of the second bend, but remain parallel.
4. The terminal according to item 1, characterized in that the clamping surface of the outer part of the terminal is made round, corresponding to the seat in the insulator of the rail fastening of the SB and / or KPP type.