The invention relates to the field of transport mechanical engineering and concerns primarily shock-absorbing devices for automatic couplers of cars of a railway train.

A prior art friction shock absorber is known, [1, Patent U.S. Pat. No. 6,478,173, IPC B61G9/10; B61G11/14; B61G9/18; B61G9/06, priority date Feb. 13, 2001, publication date Nov. 11, 2002], which comprises a housing with a bottom, whose walls form a hexagonal orifice, in which a friction assembly is located, such friction assembly consisting of a pressure wedge and stay wedges, which are in contact with said pressure wedge and the internal walls of the orifice, wherein a return-and-retaining device with a supporting plate is located between the friction assembly and the bottom. A centering bar goes through the return-and-retaining device and the pressure wedge of the friction assembly along the main axis.

This design of the friction shock absorber has sufficient power capacity, but tends to deteriorate during operation. This is due to the conditions under which the friction shock absorber operates with its main axis oriented horizontally, and with the shape of the orifice, the inner surfaces whereof form a regular hexagon in any section parallel to the bottom.

When the orifice has such a form, its walls have an equal thickness. When the shock absorber operates in horizontal position, it is additionally affected by the gravity force, which tends to shift the pressure wedge and the stay wedges away from the main axis towards the wall, on which the friction shock absorber, installed in the automatic coupling device of the car, rests. Due to this reason, some of the walls deteriorate more intensively than the other, and this not only leads to the rejection of the housing before expiration of than the required maintenance-free service life period according to the criteria of the residual wall thickness, but also affects its mechanical strength, since significant separating forces that occur during the operation of the shock absorber can break the orifice of the housing in points of excessive wear of some of its walls due to their thinning and concentration of stresses in these points.

These factors cause premature deterioration in performance and reduce the reliability of the prior art device. An increase in the thickness of all walls of the housing in order to compensate for such deterioration would lead to a decrease of the internal volume of the housing, which would prevent installation of a return-and-retaining device with sufficient power capacity.

Therefore, the object of the invention is to improve the operational life, performance and reliability of the friction shock absorber by achieving a technical goal that involves increase in the transmission coefficient of the friction shock absorber and compensation of uneven deterioration of the housing walls due the negative impact of gravity forces.

Said object is achieved by a friction shock absorber, comprising a housing with a bottom and with an orifice formed by walls, the internal surfaces whereof form alternating working beds and connecting beds, and further comprising a friction assembly consisting of a pressure wedge and stay wedges in contact with same, said stay wedges being provided with friction surfaces, adjacent to the internal surfaces of the walls of the orifice, while a return-and-retaining device is located between the bottom and the friction assembly, and having a characteristic feature: the area of contact between the friction surfaces of the stay wedges and the internal surfaces of the walls of the orifice in the working beds exceeds the corresponding area of contact in the connecting beds.

This characteristic feature allows increase of the transmission coefficient of the friction shock absorber and, accordingly, its power capacity, as well as redistribution of the separating forces along with the gravity forces in such a way that their impact on the housing orifice becomes uneven and directed towards their thicker zones formed by different shapes of working and connecting beds that are not uniform in shape. It allows effective compensation of the negative influence of gravity forces and to increase the reliability and service life of both the housing and the friction shock absorber as a whole.

Additional Characteristic Features of the Utility Model:

the internal surfaces of the walls, which form the working beds and the connecting beds, are straight and are located at an angle to each other.

the values of angles between adjacent internal surfaces, which form working beds, are lower than the values of angles between adjacent internal surfaces, which form the connecting beds;

the thickness of walls of the orifice is variable with an increase in the direction from the working bed to the connecting bed;

the return-and-retaining device is provided with a supporting plate in contact with the stay wedges;

hard lubricant inserts are available between the stay wedges and the walls of the orifice;

hitches are provided in the walls of the orifice on the connecting beds;

the contact between the pressure wedge and the stay wedges is provided along linked curved surfaces.

