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Title:
SHOCK ABSORBING SPRING
Document Type and Number:
WIPO Patent Application WO/2003/067116
Kind Code:
A2
Abstract:
The invention refers to a spring shock absorber destined especially for buffers and traction devices of the rail vehicles; while it may have other applications as well, in others technical domains where it is necessary to absorb shocks. The shock absorbing spring, according to present invention, is composed by a tubular cylinder (1), or ring-shaped cylinder Z sealed at one end and divided by a diaphragm a with central guiding and sealing system (b), into two coabal rooms (c) and (d), in room (d) being mounted a piston (3) or several concentric pistons (4, 6) respective (6, 7), piston having its head (e) set at certain distances to the ends of the piston's rod, a rod f from one end of the piston's head (e) being mounted into the guiding and sealing system (b), while the other rod (g) from the other end of the piston's head being mounted into the guiding and sealing system (h) made of a cap (8) that closes the room d of the cylinder. Room (c) is filled with gas or compressible crude rubber (9) at a certain pressure level, and the room (d) is filled with hydraulic oil (10) at atmospheric pressure. The rooms (c) of the cylinders of the shock absorbing springs mounted into the shock or traction devices of the railcars can be interconnected in various configurations, ensuring the adaptation of the force - travel characteristic depending on the railcar situation (whether it is passing through curves, applying shocks to an isolated railcar or to a railcar in a convoy).

Inventors:
OTLACAN DIMITRIE DANUT (RO)
Application Number:
PCT/RO2002/000023
Publication Date:
August 14, 2003
Filing Date:
October 22, 2002
Export Citation:
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Assignee:
OTLACAN DIMITRIE DANUT (RO)
International Classes:
F16F9/00; F16F9/06; F16F9/18; F16F9/20; F16F9/22; F16F13/06; (IPC1-7): F16F/
Foreign References:
RO113229B1998-05-29
US3913495A1975-10-21
US3817506A1974-06-18
US3614931A1971-10-26
US2873963A1959-02-17
US2029829A1936-02-04
FR1216426A1960-04-25
FR353087A1905-09-01
DE2410166A11975-09-11
FR1120705A1956-07-11
GB1531565A1978-11-08
US3328019A1967-06-27
FR2146814A51973-03-02
DE2020930A11971-11-25
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Claims:
SHOCK ABSORBING SPRING CLAIMS
1. The shock absorbing spring is composed by a tubular cylinder, 1, or ringshaped spring, 2, and a piston, 3, or system of concentric pistons 4 and 5, respective 6 and 7, is characterized by the fact that the tubular cylinder 1, or ringshaped, 2, is sealed at one end and divided in two coaxial rooms, c and d, through a diaphragm a, with central guidance and sealing system, b.
2. The shock absorbing spring, according to claim no. 1, is characterized by the fact that into the room d there is mounted a piston, 3, or several concentric pistons 4, 5 respective 6, 7, piston that has its head e set at certain distances to the ends of the piston's rods, one rod f from one side of the head of piston e being mounted in the guidance and sealing system b while the rod g from the other side of the head of the piston e being mounted in the guidance and sealing system h made by the cap 8 that closes the room d of the cylinder.
3. The shock absorbing spring, according to claim no. 1 and 2, is characterized by the fact that the room c is filled with gas or compressible crude rubber 9 at a certain pressure level, and room d is filled with hydraulic oil 10 at atmospheric pressure.
4. The shock absorbing spring, according to claims 1,2 and 3, is characterized by the fact that the inner diameter j of the room d may vary along its a) de, while making, with the cylindrical surface e of the piston 3, the slot 1 with variable size during the compression/decompression of the shock absorbing spring.
5. The shock absorbing spring, according to claims 1,2, 3 and 4, is characterized by the fact that in the case of utilizing concentric pistons 4 and 5, when first the rod with smaller diameter is pressed, the head e of the piston 3 would not travel until the travel k is consumed, thus no hydraulic resistance appears in the shock absorber during the travel.
6. The shock absorbing spring, according to claims 1,2, 3,4 and 5, is characterized by the fact that in the case of utilizing concentric pistons 6 and 7, the inner piston rod is held pressed by a retaining system 11 in which case first the bigger diameter rod is pressed, thus there is hydraulic resistance within the shock absorber during the consumption of travel k.
7. The shock absorbing spring, according to claims 1, 2, 3,4, 5 and 6, is characterized by the fact that in the case of having the spring mounted on buffers from the same end of the railcar, the rooms c of the cylinders can be interconnected through a pipe, thus obtaining a reduction to half of the force between buffers when passing a curve.
8. The shock absorbing spring, according to claims 1,2, 3,4, 5, 6 and 7, is characterized by the fact that in the case of the spring mounted in the buffers, the rooms c of all four cylinders can be interconnected through a pipe, thus obtaining a reduction to half of the force between buffers when passing a curve together with a convenient variation of the parameters (force, acceleration) appearing at shocks, depending on the railcar's rolling condition (in a convoy or isolated).
9. The shock absorbing spring, according to claims 1, 2, 3,4, 5 and 6, is characterized by the fact that in the case of the spring mounted within the coupling device or draw gear, the rooms c of the cylinders can be interconnected through a pipe, thus the railcars begin to move after a longer travel of the shock absorbers, therefore a smaller locomotive power would be needed for moving a specific train mass.
Description:
SHOCK ABSORBING SPRING The invention refers to a shock absorbing spring destined especially for buffers and traction devices of the rail vehicles ; while it may have other applications as well, in others technical domains where it is necessary to absorb shocks.

There are known hydrodynamic and hydrostatic devices designed to prevent shocks and vibrations, see patent R0113229 C, which combines the fore-mentioned two types of devices but they have the disadvantage of an expensive and highly demanding construction or the disadvantage of low functional characteristics, since all constructive variants have high-pressured rooms close to the exterior. Moreover, none of the existing constructive solutions of the spring absorbers is able to adapt its characteristics to the requirements of the railcar at a specific moment The technical issue this invention is going to resolve is to produce a spring shock absorber that combines the qualities of the hydrodynamic absorbers with the simple construction of the hydrostatic absorbers without having pressure in the room next to the exterior ; additionally the spring absorber fixed within the railcar's buffers would be able to change its static characteristics depending on the railcar'situation, meaning itwould detectwhether the railcar is in shunting process or in convoy rolling, marching in line or in curves.

The spring absorber, according to the invention, is composed by a tube cylinder, or ring-shaped cylinder sealed at, one end and divided by a diaphragm with central guiding and a sealing system, into two co-axial rooms, in one of the rooms would be mounted a piston or several concentric pistons having one of its heads set at certain distances to the ends of the piston's rod, while the rod from the other side of the piston's head is mounted within a guiding device with sealing system made of a cap that closes the room of the tube cylinder. The room in which the piston's head is fixed, would be filled with hydraulic oil at atmospheric pressure, while the others room is filled with gas or compressible crude rubber under a certain pressure level.

Exterior piston rod once being pressed, the inside rod enters the room with compressible fluid and the system would act as a spring; the travel of the piston's rod with a certain speed makes the system act as a shock absorber, therefore leading to an increase of the pressure between the piston's head and the diaphragm, due to the hydraulic resistance that appears when the hydraulic oil passes the ring slot between the cylindrical surface of the piston's head and the inside surface of the room, the slot'size may vary according to the desired characteristic by varying the inner diameter of the room.

The shock absorbing springs mounted within the buffers of the same railcar end, can have their compressive fluid rooms connected through a pipe, in which case it is obtained a 50% decrease of the tension between buffers when passing through curves; supplementary, if the compressible fluid rooms of all four buffers of a railcar are connected, then we obtain a convenient variation of the parameters (force, acceleration) appearing at shocks, depending on the railcars rolling condition (in a convoy or isolated).

The shock absorbing springs mounted within the coupling devices or draw gears may have their compressible fluid rooms connected, in which case the railcars begin to move after a longer travel of the shock absorbers, therefore a smaller locomotive power would be needed for moving a specific train mass.

The following advantages can be obtained by using this invention: -simple construction at low costs; -reduced overall dimensions and mass; - reduced wearing of the buffer's plate, of the wheels and of the rai) way when passing through curves; reduced curve radius necessary for the railcar to roll in safe conditions ; - increased safety when rolling through a curve; -reduced power of the locomotive required to move the train.

The following section is describing an example of how the invention can be realized, example that will use drawings 1 to 6, described above: -drawing 1 (Fig. 1), view of longitudinal section through the shock absorbing spring in the variant with a single piston and two cylindrical pressure rooms; drawing 2 (Fig. 2), view of longitudinal section through the shock absorber spring with two cylindrical pressure rooms and two concentric pistons so that, at shocks, the hydraulic absorption during the first part of the spring travel does not contribute to increase the force; -drawing 3 (Fig. 3), view of longitudinal section through the shock absorber spring with two cylindrical pressure rooms and two concentric pistons so that, at shocks, the hydraulic absorption during the first part of the spring travel does contribute to increase the force; - drawing 4 (Fig. 4), view of longitudinal section through the shock absorbing spring with two ring-shaped pressure rooms, in variant with a single piston; - drawing 5 (Fig. 5), view of longitudinal section through the shock absorbing spring with two ring-shaped pressure rooms, in variant with two concentric pistons so that, at shocks, the hydraulic absorption during the first part of the spring travel does not contribute to increase the force; -drawing 6 (Fig. 6), view of longitudinal section through the shock absorbing spring with two ring-shaped pressure rooms, in variant with two concentric pistons so that, at shocks, the hydraulic absorption during the first part of the spring travel does contribute to increase the force.

The shock absorbing spring, according to present invention, is composed by a tubular cylinder 1, or ring- shaped cylinder 2 sealed at one end and divided by a diaphragm a with central guiding and sealing system b, into two co-axal rooms c and d, in room d being mounted a piston 3 or several concentric pistons 4,6 respective 6,7, piston having its head e set at certain distances to the ends of the piston's rod, a rod f from one end of the piston's head e being mounted into the guiding and sealing system b, white the other rod g from the other end of the piston's head being mounted into the guiding and sealing system h made of a cap 8 that closes the room d of the cylinder. Room c is filled with gas or compressible crude rubber 9 at a certain pressure level, and the room d is filled with hydraulic oil 10 at atmospheric pressure.

Exterior rod g of the piston 3 being pressed, the rod f of the same cylinder enters the room c and due to the compressibility of the fluid 9, the system act as a spring; while the travel with a certain speed of the head e of the piston 3 makes the system act as a shock absorber and therefore leading to an increase of the pressure between the head of the piston e and the diaphragm a due to the hydraulic resistance that appears when the hydraulic oil 10 passes through the slot I situated between the cylindrical surface of the room d, slot'see may vary according to the desired characteristic by varying the inner diameter j of the room d.

In the case of using concentric pistons 4 and 5, when first the rod with the smaller diameter is pressed, there is no hydraulic resistance determined within the system until the whole travel k is consumed; when using concentric pistons 6 and 7, case in which first the exterior rod 6 is pressed and the inner piston 7 is held pressed by a retaining system 11, there is hydraulic resistance determined within the system right from the beginning of the travel of the exterior piston I in both cases there is a step variation of the force in static regime after consuming the travel k.

The shock absorbing springs mounted within the buffers of the same end of the railcar can have the rooms c connected through a pipe, in which case it is obtained a 50% decrease of the tension between buffers when passing through curves, and, in addition, if rooms c of all four buffers of a railcar are connected, then we obtain a convenient variation of the parameters (force, acceleration) appearing at shocks, depending on the railcar's rolling condition (in a convoy or isolated) The shock absorbing springs mounted within the coupling devices or draw gears may have their rooms c connected, in which case the railcars begin to move after a longer travel of the shock absorbers, therefore a smaller locomotive power would be needed for moving a specific train mass.