A RAILWAY WAGON BUFFER AND A METHOD FOR MANUFACTURING THEREOF

A RAILWAY WAGON BUFFER AND A METHOD FOR MANUFACTURING

THEREOF

DESCRIPTION

TECHNICAL FIELD

The present invention relates to railway wagon buffers and methods for manufacturing thereof.

BACKGROUND ART

Various types of railway buffers are known, such as buffers with metal springs, with rubber springs, with combined metal and rubber springs, with fluid springs or shock-absorbers. The shock-absorbing constructions may utilize mechanical friction action or permanent deformation of buffer element. Various attempts are made to improve the shock-absorbing properties of the buffer in order to dissipate the energy of shock in an efficient way.

A US patent application US20070007780 describes a kinetic energy absorber for connecting to a bumper of a car and comprising a rotatable energy absorber with a rotor connected with the bumper via a toothed bar and a multiplying gear. Upon impact directed to the bumper, the translational motion of the bumper induces translational motion of the toothed bar, which induces rotation of the rotor. The absorber is designed for a single use during a car crash and is not adapted for receiving repeated impacts. Moreover, it is not designed for vehicles of a large size and weight, such as railway wagons.

DISCLOSURE OF THE INVENTION The aim of the invention is to provide a railway buffer allowing efficient absorption of impact energy.

The object of the invention is a railway wagon buffer comprising an impact plate coupled via a movable spacer with impact-absorbing means for absorbing the impact energy imparted to the impact plate, wherein the impact-absorbing means comprise a plurality of rotatable energy absorbers arranged along the pathway of the movable spacer to engage with the movable spacer during its movement along the pathway, each rotatable energy absorber comprising a rotor for absorbing in rotational movement at least part of the kinetic energy of the movable spacer.

The movable spacer may comprise a toothed bar for engaging with toothed wheels of the rotatable energy absorbers mounted on a shaft of the rotor.

The toothed bar may comprise sections joined with elastic elements, wherein each section is configured to engage with a toothed wheel of a distinct rotatable energy absorber.

The movable spacer may comprise an elastic element between the impact plate and the toothed bar.

The rotatable energy absorbers may have the same energy storage capacity.

The rotatable energy absorbers may have energy storage capacity increasing along the direction of impact receivable by the impact plate.

The rotors can be freewheels.

The buffer may further comprise a biasing element for biasing the movable spacer in a direction opposite to the direction of the impact force to be absorbed.

The biasing element can be a telescopic rod with a spring mounted between a stationary portion and a movable portion of the buffer.

The movable spacer can be configured to engage with at least two neighbouring rotatable energy absorbers at a time.

The rotatable energy absorbers can be arranged in two sets, wherein each of the rotatable energy absorbers of a first set comprises a rotor for absorbing in rotational movement at least part of the kinetic energy of the movable spacer during its movement in the direction of the impact force, and each of the rotatable energy absorbers of a second set comprises a rotor for absorbing in rotational movement at least part of the kinetic energy of the movable spacer during its movement in the direction opposite to the impact force.

The object of the invention is also a method for manufacturing of a railway wagon buffer comprising an impact plate coupled via a movable spacer with impact-absorbing means for absorbing the impact energy imparted to the impact plate, wherein the impact-absorbing means comprise a plurality of rotatable energy absorbers arranged along the pathway of the movable spacer to engage with the movable spacer during its movement along the pathway, each rotatable energy absorber comprising a rotor for absorbing in rotational movement at least part of the kinetic energy of the movable spacer, wherein the movable spacer comprises a toothed bar for engaging with toothed wheels of the rotatable energy absorbers, the method comprising the steps of forming and balancing of the rotors, forming and hardening of the toothed wheels of the rotatable energy absorbers and forming of the movable spacer, the impact plate and assembling the elements to make the railway wagon buffer.

BRIEF DECRIPTION OF DRAWINGS The invention is shown by means of an exemplary embodiments on a drawing, in which:

Fig. 1 shows an exemplary configuration of a railway wagon,

Fig. 2 shows a railway wagon buffer according to a first embodiment of the invention in a side view,

Fig. 3 shows a railway wagon buffer according to a first embodiment of the invention in a perspective view,

Fig. 4 shows a railway wagon buffer according to a second embodiment of the invention in a side view,

Fig. 5 shows a railway wagon buffer according to a third embodiment of the invention in a side view,

Fig. 6 shows a railway wagon buffer according to a fourth embodiment of the invention in a perspective view,

Fig. 7 shows a railway wagon buffer according to a fifth embodiment of the invention in a perspective view,

Fig. 8 shows the process of manufacturing of the railway wagon buffer according to the invention. Fig. 1 shows an exemplary configuration of a railway wagon 190. The wagon 190 has a body 191 with at least one buffer 192 at its ends for contacting with a buffer of a neighbouring wagon. The buffer 192 has a stationary portion 193 fixed to the body 191 of the wagon and a movable portion 194 which moves into the stationary portion 193 upon impact, for example when a line of railway wagons brakes. The neighbouring wagons can be connected via a buffers-and-chain system, wherein a chain joins the wagons to allow pulling of the wagons and the buffers limit the slack and lessen the shocks. The wagons can be connected via other means, such as multi-function couplers, wherein the buffers of neighbouring wagons are joined together. The present invention is applicable to both types of coupling. Although the present invention is called a railway wagon buffer, it will be evident for a skilled person that it can be applied to other railway vehicles, such as locomotives.

Figs. 2 and 3 show a railway wagon buffer according to a first embodiment of the invention in a side view and a perspective view, respectively. The buffer comprises an impact plate 101 , which is coupled via a movable spacer 1 10 with impact-absorbing means for absorbing the impact energy imparted to the impact plate 101 . The movable spacer 1 10 can be housed within the movable portion 194 of the buffer ended with the impact plate 101 and the impact-absorbing means can be housed within the stationary portion 193 of the buffer. The impact-absorbing means comprise a plurality of rotatable energy absorbers 120, 130, 140 arranged along the pathway 1 15 of the movable spacer 1 10. The pathway 1 15 can be defined by a longitudinal support 1 15 fixed to the stationary portion 193 of the buffer. The rotatable energy absorbers 120, 130, 140 are arranged such as to be able to engage with the movable spacer 1 10 during its movement along the pathway 1 15. Each rotatable energy absorber 120, 130, 140 comprises a rotor 121 , 131 , 141 for absorbing in rotational movement at least part of the kinetic energy of the movable spacer 1 10.

The rotors 121 , 131 , 141 may have a form of flywheels, which are induced into rotation by the movement of the spacer 1 10. Therefore, a part of the impact energy imparted to the impact plate 101 is accumulated in the rotors 121 , 131 , 141 . The amount of energy accumulated in the rotors, in other words rotatable masses, depends on the weight of the rotors, their diameter and rotational speed, which in turn depends on the coupling between the movable spacer 1 10 and the rotatable energy absorbers 120, 130, 140. The energy accumulated in the rotors 121 , 131 , 141 can transmitted to an energy accumulator (for example, a converter of mechanical to electric energy), or simply dissipated by friction of internal components or external brake used to stop the rotors 121 , 131 , 141 after it is no longer induced into rotation.

The movable spacer 1 10 may comprise a toothed bar 1 1 1 for engaging with toothed wheels 122, 132, 142 of the rotatable energy absorbers 120, 130, 140, the toothed wheels 122, 132, 142 being mounted on a shafts 123, 133, 143 of the rotors 121 , 131 , 141 .

An elastic element 1 12, such as a spring, is mounted within the body of the spacer 1 10 between the impact plate 101 and the toothed bar 1 1 1 to dampen the energy of impact and facilitate inducing the rotatable energy absorber 120, 130, 140 into rotation.

A biasing element 1 14, is mounted inside the housing of the buffer 192 between the stationary portion 193 and the movable portion 194. The biasing element 1 14 biases the movable spacer 1 10 in a direction opposite to the direction of the impact force to be absorbed. For example, the biasing element 1 14 can be a telescopic rod with a spring acting to expand the rod. Therefore, after the impact, it causes the movable spacer 1 10 to return to its pre-impact position, in order to allow absorbing the following impacts.

The buffer of the first embodiment operates as follows. When impact is received by the impact plate 101 , the movable spacer 1 10 starts to move and the elastic element 1 12 is compressed. When the impact force is small, the elastic element 1 12 may absorb the whole impact energy and after the impact is absorbed, it causes the movable spacer 1 10 to return to its pre-impact position. When the impact force is larger than the energy-absorbing capabilities of the elastic element 1 12, the toothed bar 1 1 1 induces the rotor 121 of the first rotatable energy absorber 120 into rotation, thereby absorbing in rotational movement at least part of the kinetic energy of the movable spacer 1 10. In case the whole impact energy is absorbed by the first rotatable energy absorber 120, the biasing element 1 14 and the elastic element 1 12 cause the movable spacer 1 10 to return to its pre-impact position, wherein the return movement is not restricted by the first rotatable energy absorber 120 as it is a freewheel acting only in the direction of impact. When the impact force is larger than the energy-absorbing capabilities of the elastic element 1 12 and the first rotatable energy absorber 120, the movable spacer continues to move towards the second rotatable energy absorber 130. During the movement of the toothed bar 1 1 1 between the engagement means 122, 132 of the rotatable energy absorbers 120, 130, the elastic element 1 12 decompresses such as to absorb at least part of the impact energy between the toothed bar 1 1 1 and the toothed wheel 132 of the second energy absorber 130. The remaining at least part of the kinetic energy of the movable spacer 1 10 is absorbed in rotational movement of the second rotational energy absorber 130. In case the whole remaining impact energy is absorbed by the second rotatable energy absorber 130, the biasing element 1 14 and the elastic element 1 12 cause the movable spacer 1 10 to return to its pre-impact position, wherein the return movement is not restricted by the rotatable energy absorbers 120, 130 as they are freewheels acting only in the direction of impact. When the impact force is larger than the energy-absorbing capabilities of the elastic element 1 12, the first rotatable energy absorber 120 and the second rotatable energy absorber 130, the movable spacer continues to move towards the third rotatable energy absorber 140. Only when the impact force is larger than the energy-absorbing capabilities of all rotatable energy absorbers 120, 130, 140 of the impact absorbing means, the remaining energy of impact is imparted to the end wall of the buffer, i.e. the wall of the wagon to which the buffer is fixed.

Fig. 4 shows a railway wagon buffer according to a second embodiment of the invention in a side view, which differs from the first embodiment shown in Figs. 2 and 3 by the configuration of the rotatable energy absorbers 120, 130, 140. The rotatable energy absorbers 120, 130, 140 of the first embodiment of Fig. 2 and 3 have the same energy storage capacity, while the rotatable energy absorbers 120, 130, 140 of the second embodiment of Fig. 4 have energy storage capacity increasing along the direction of impact receivable by the impact plate 101 . The energy storage capacity may depend on factors such as the mass of the rotors, their internal structure or the transmission ratio between movable spacer 1 10 and the rotor 121 , 131 , 141 . The energy storage-capacity of the rotors may be configured depending on the types of impacts to be absorbed. For example, the first rotatable energy absorber 120 may be configured to absorb energy of impact of an unloaded wagon, the second energy absorber 130 may be configured to absorb energy of impact of a loaded wagon and the third energy absorber 140 may be configured to absorb energy of impact during a crash accident.

Fig. 5 shows a railway wagon buffer according to a third embodiment of the invention, which differs from the first embodiment shown in Figs. 2 and 3 by the configuration of the toothed bar 1 1 1 and the number and configuration of the rotatable energy absorbers 120, 130, 140 (not all energy absorbers have been assigned reference numerals for clarity purposes). The toothed bar 1 1 1 , by having appropriate length, is configured to engage with two neighbouring rotatable energy absorbers at a time, in order to provide more uniform conversion of translational movement energy of the movable spacer 1 10 into rotational energy of the rotors 121 , 131 , 141 .

Fig. 6 shows a railway wagon buffer according to a fourth embodiment of the invention, which differs from the first embodiment shown in Figs. 2 and 3 in that the rotatable energy absorbers are arranged in two sets. Each of the rotatable energy absorbers 120A, 130A, 140A of a first set comprises a rotor 121A, 131A, 141 A for absorbing in rotational movement at least part of the kinetic energy of the movable spacer during its movement in the direction of the impact energy. In turn, each of the rotatable energy absorbers 120B, 130B, 140B of a second set comprises a rotor 121 B, 131 B, 141 B for absorbing in rotational movement at least part of the kinetic energy of the movable spacer during its movement in the direction opposite to the impact force. In other words, the second set replaces the biasing element 1 14 of the first embodiment. Such construction can be utilized in multi-function couplers, wherein the buffers of neighbouring wagons are joined together and the energy should be absorbed both during the impact phase when the wagons move towards each other and during the pulling phase, when the wagons move away from each other.

Fig. 7 shows a railway wagon buffer according to a fifth embodiment of the invention, which differs from the first embodiment shown in Figs. 2 and 3 by the configuration of the movable spacer 1 10. The movable spacer comprises a plurality of sections of toothed bars 1 1 1 A, 1 1 1 B, 1 1 1 C, each coupled with a toothed wheel 122, 132, 142 of the rotatable energy absorbers 120, 130, 140 and joined with a neighbouring toothed bar with an elastic element 1 16AB, 1 16BC such as a spring. The toothed bars 1 1 1 A, 1 1 1 B, 1 1 1 C may have an increasing height along the direction of impact, as well as the shafts 123, 133, 143 of the rotatable energy absorbers can be mounted above the pathway 1 15 on increasing heights, so that each toothed bar 1 1 1 A, 1 1 1 B, 1 1 1 C engages with a single toothed wheel 122, 132, 142 only.

The buffer of the fifth embodiment operates as follows. When impact is received by the impact plate 101 , the movable spacer 1 10 starts to move and the elastic element 1 12 is compressed. When the impact force is small, the elastic element 1 12 may absorb the whole impact force and after the impact is absorbed, it causes the movable spacer 1 10 to return to its pre-impact position. When the impact force is larger than the energy-absorbing capabilities of the elastic element 1 12, the first toothed bar 1 1 1 A induces the rotor 121 of the first rotatable energy absorber 120 into rotation, thereby absorbing in rotational movement at least part of the kinetic energy of the movable spacer 1 10. Simultaneously, the elastic element 1 16AB between the first toothed bar 1 1 1 A and the second toothed bar 1 1 1 B is partially compressed. In case the whole impact energy is absorbed by the first rotatable energy absorber 120, the biasing element 1 14 and the elastic element 1 12 cause the movable spacer 1 10 to return to its pre-impact position, wherein the return movement is not restricted by the first rotatable energy absorber 120 as it is a freewheel acting only in the direction of impact. When the impact force is larger than the energy-absorbing capabilities of the elastic element 1 12 and the first rotatable energy absorber 120, the movable spacer continues to move towards the second rotatable energy absorber 130. The next elastic element 1 16AB is totally compressed and the second toothed bar 1 1 1 B starts to induce rotation of the second rotatable energy absorber 130, further causing partial compression of the following elastic element 1 16BC. The operation may continue until all rotatable energy absorbers 120, 130, 140 absorb the impact energy imparted to the impact plate 101 . In the buffer of the fifth embodiment the rotatable energy absorbers 120, 130, 140 can operate simultaneously and their progressive induction into rotation occurs smoothly due to the presence of elastic elements between the toothed bars. Fig. 8 shows the process of manufacturing of the railway wagon buffer according to the invention. In steps 301 -306 the elements via which the impact energy is transmitted to the rotatable energy absorbers are formed, including the rotors formed in step 301 , the toothed bar formed in step 303 and the toothed wheels formed in step 305. The elements are manufactured with high degree of precision, such as to allow efficient movement of the elements with limited friction upon impact of forces of large magnitude. The rotor is balanced in step 302 by precise profiling such that it can rotate with high rotational speeds. The teeth of the toothed bar and toothed wheels are hardened in steps 304, 306 such as to withstand large forces and limit the friction between them. The other elements of the buffer, such as the springs and the elements of the housing are formed in step 307 and assembled in step 308. In order to provide high precision of manufacture of the rotatable energy absorbers and the other components of the buffer of the invention, the following tools can be used: a water jet cutter, a band saw, welding machines, a standard lathe, a precision lathe, a standard miller, a precision miller, a surface grinder, an external grinder, an internal grinder, a standard drill, a pillar drill, a hydraulic press, a brake press, a bending machine for tubes and sections, a hydraulic bending machine, a belt grinder, a fitter's vice, a compressor, an electro- erosion machine, a hobber, a threader, a welder, cleaning tanks, measurement and control apparatus, a hardening furnace, an electronic balancer, a marking-off table and marking-off tools.