GB2281114A

GB2281114A - Buffer

Info

Publication number: GB2281114A
Application number: GB9403113A
Authority: GB
Inventors: Stanislaw Bak; Marek Bruski; Andrzej Chmielewski; Jozef Kedzior; Antoni Kubicki; Kazimierz Milczarski; Wojciech Poplawski; Eugeniusz Strzyz; Marian Wojturski
Original assignee: Fabryka Urzadzen Mechanicznych Kamax SA
Current assignee: Axtone SA
Priority date: 1993-08-16
Filing date: 1994-02-18
Publication date: 1995-02-22
Anticipated expiration: 2014-02-18
Also published as: GB2281114B; FR2709107A1; PL172461B1; FR2709107B1; DE4419042C2; PL300097A1; GB9403113D0; DE4419042A1

Description

2281114 1 BUFFER The present invention relates to arrangement, in

particular for railway cars.

a buf fer The hitherto known sleeve buffer in particular for railway cars disclosed in the Polish patent description No. P298759 includes a buffer box provided with a pocket, which is located at the end of the said box opposite to a buffer disk; the said pocket holding stop means attached to the buffer box. The stop means comprises at least one element chosen from known annular securing elements i.e. whole ring, segmented ring, threaded ring, spring ring. The mentioned elements may be used alone or as a combination.

Moreover inside a buffer box at least one longitudinal groove is provided. On the periphery of the buffer sleeve a tongue is made, which together with the stop means constitute a stop block restricting the longitudinal movement of the buffer box relative to the buffer sleeve.

Moreover on the side surface of the buffer box at least one key is provided; the said key being located in the pocket and together with the longitudinal groove holding the buffer box and the buffer sleeve against 2 rotation. Moreover the above mentioned description discloses that inside the buf fer sleeve and partially inside the buffer box a damper spring unit is located.

Polish utility design application No. 93155 describes a buffer arrangement for passenger and freight cars which is provided with a buffer disk having a pocket located in the centre of the inner surface of the said disk. In the pocket a flange is mounted which constitutes the ending of the buffer housing. Between the outer edge of the flange and the inner edge of the pocket a peripheral weld is located. Moreover the description of the embodiments of the mentioned utility design discloses that the railway buffer is equipped with elastomeric shock absorbers and guide means.

The main disadvantage of the above designs relies in unsatisfactory durability of the buffer arrangements.

It is one important object of the present invention to mitigate the above identified problem associated with known buffer arrangements.

The buf fer arrangement according to the invention comprises at least one spring damper and an elastomeric shock absorber; the perimeter of the casing of the said elastomeric shock absorber, at the end facing the spring 3 damper, being smaller than the perimeter of the bore of the spring damper.

Under operating conditions, when the impact forces have been exerted against the buffer, the above design enables the narrowed portion of the elastomeric shock absorber casing to move inwardly in the bore of the spring damper. The above construction enhances the durability of the buffer arrangement while maintaining the desired force and energy parameters and meeting the requirements of limited space available inside the housing of the buffer arrangement.

As the perimeter of the casing of the shock absorber is smaller than the perimeter of the bore of the spring damper, so (if the items are circular in cross section) will the diameter of the f irst be smaller than the diameter of the second.

According to the present invention it is advantageous to provide an elastomeric shock absorber whose casing is narrowed at the end of the piston rod.

It is also advantageous if the casing is narrowed at the end of the closure member.

Further improvement may be achieved if the casing of the elastomeric shock absorber is narrowed at both ends:

4 at the end of the piston rod and at the end of the closure member.

1 The elastomeric shock absorber may therefore be mounted between two spring dampers and plunges bilaterally in the bores of the mentioned spring dampers.

It is also advantageous if the elastomeric shock absorber includes a casing whose perimeter along the whole length is smaller than the perimeter of the bore of the spring damper. In this case, the casing of the elastomeric shock absorber may then be mounted in a housing on guide means.

Embodiments of the present invention will be described with reference to the following drawings, where:

Fig. 1 depicts a buffer arrangement which utilizes a spring damper and an elastomeric shock absorber, whose casing is narrowed at the end of the piston rod; Fig. 2 depicts a contracted buffer arrangement comprising a shock absorber whose casing is narrowed at the end of piston rod; Fig. 3 depicts a buffer arrangement which utilizes a spring damper and an elastomeric shock absorber whose casing is narrowed at the end of the closure member; Fig. 4 depicts a contracted buf fer arrangement which utilizes an elastomeric shock absorber narrowed at the end of the closure member; Fig. 5 depicts a buffer arrangement which utilizes two spring dampers and, located in between, an 5 elastomeric shock absorber; Fig. 6 depicts a contracted buf fer arrangement which utilizes an elastomeric shock absorber and two spring dampers; and Fig. 7 depicts a buf fer arrangement in which the perimeter of the elastomeric shock absorber along the whole casing is smaller than the perimeter of the bore of the spring damper.

1 In the embodiment of Fig. 1 a buf fer arrangement encompasses a buffer sleeve 1 telescopically mounted in a buffer box 2. Inside the buffer sleeve, abutting its bottom, there is located an elastomeric shock absorber 3 whose piston rod 4, having a pitch a, abuts a mobile pin 5 of the spring damper 6. The spring damper is fixedly attached to the bottom of the buffer box and on the side facing the mobile pin and it is provided with a bore 7 having a perimeter D. The elastomeric shock absorber at the end f acing the spring damper is provided with a contraction 8 having a perimeter d and length b. Moreover in between the buffer sleeve and the buffer box stop means is located, which restricts the maximum pitch s of the above mentioned elements. The buffer 6 arrangement according to the present invention is preferably designed so that the following relationships are operative: D>d and b>S-a.

Figure 2 shows the arrangement of Figure 1 in a 5 compressed condition.

1 In another variant of the invention (shown in Fig. 3) inside the buffer sleeve 1 an elastomeric shock absorber 10 is slidably mounted; the piston rod 4 of the said elastomeric shock absorber, having a pitch a, abutting the bottom of the said buffer sleeve. The end of the casing of the elastomeric shock absorber facing the spring damper 6 is provided with a contraction 8 having a length b and a perimeter d; the said perimeter being smaller than the perimeter D of the bore 7 of the spring damper 6 fastened to the bottom of the buffer box 2. Also in this case the following relationship is operative b>S-a.

Figure 4 shows the arrangement of Figure 3 in a compressed condition.

In another embodiment of the present invention illustrated in Fig. 5 one of the spring dampers 6 abuts the bottom of the buffer sleeve 1; the said spring damper being equipped with a bore 7 having a perimeter D, while 7 1 inside the said bore a mobile pin 5 is positioned. The casing of the elastomeric shock absorber 11 abuts the mobile pin 5. The said casing is provided with a contraction 8 having a perimeter d and length b. The elastomeric shock absorber is slidably mounted in a buffer sleeve and its opposite end is provided with contraction 81 having a perimeter d' and length b'. Moreover the elastomeric shock absorber includes a piston rod 4 having a pitch a. The said piston rod abuts the mobile pin 51 positioned inside the bore 7' having a perimeter D' and belonging to the second spring damper 6', which is attached to the bottom of the buffer sleeve 2. Stop means 9, located between the buffer sleeve 1 and a buffer box, restricts the maximum pitch S of the above mentioned elements. Moreover the following relationships are operative: D> d, D'>d', S<a+b+b'.

Figure 6 shows the arrangement of Figure 5 in a compressed condition.

Another variant of the present invention (illustrated in Figure 7) includes a spring damper 6 located inside a buffer box 2 and abutting its bottom. The piston rod 4 of the elastomeric shock absorber.12 abuts the mobile pin 5 of the spring damper 6; the said piston rod 4 having a pitch a and the said pin being located in a bore 7 having a perimeter D. The outer 8 perimeter d of the elastomeric shock absorber utilized in this design is, along the whole casing, smaller than the perimeter of the bore (7). The bottom of the said shock absorber abuts the bottom of the buffer sleeve 1 and is 5 mounted therein on the guide means 13.

1 While certain preferred embodiments of the invention have been illustrated for the purpose of the present disclosure other constructions are also possible including an elastomeric shock absorber having a constant perimeter along the whole casing and being located in between two spring dampers, while the said spring dampers have the same perimeter of the bore.

The buffer arrangement according to the invention mounted for example on a railway car transfers longitudinal impact forces and after exceeding the initial tension of one of the damper spring units, for example the spring damper 6, 6 1, the buf fer sleeve 1 moves inwardly in the buf f er box 2. With the further increase of the impact f orce the initial tension of another damper spring unit is exceeded, the damper spring unit being an elastomeric shock absorber 3, 10, 11, 12. The casing of the elastomeric shock absorber can plunge in the bore 7, 7' of the spring damper. The above described design enables to take full advantage of the working space of the buffer arrangement and achieve the 9 performance characteristics which assures high durability and reliability of the design. Af ter the impact force is dissipated the damper spring units utilized in the disclosed buf fer arrangement expand and protrude the buffer sleeve from the buffer box.

1

Claims

CLAIMS:

1. A buffer including: a buffer sleeve telescopically mounted in a buffer box, at least one spring damper and an elastomeric shock absorber (2, 10,. 11,.12,) for damping relative movement between the buffer sleeve and buffer box; wherein the perimeter of the shock absorber at the end f acing the spring damper is smaller than perimeter of a bore of the spring damper, so that a portion of the shock absorber is receivable in said bore.

2. A buffer according to claim 1 wherein the casing of the elastomeric shock absorber is of reduced perimeter at the end nearest to a piston rod of the shock absorber.

3. A buffer according to claim 1 wherein the casing of the elastomeric shock absorber is of reduced perimeter at the end nearest to a closure member of the shock absorber.

4. A buffer according to claim 1 wherein the casing of the elastomeric shock absorber is of reduced perimeter at the end of a piston rod nearest the end of a closure member of the shock absorber.

5. A buffer according to claim 1 wherein the perimeter of the casing of the elastomeric shock absorber is along the whole casing smaller than the perimeter of the bore of the spring damper; the said casing being positioned in the buffer sleeve on guide means.

6. A buffer according to any of the above claims 5 including stop means restricting the relative movement of 1 the buffer sleeve and buffer casing.

7. A buffer substantially as any one embodiment herein described with reference to the accompanying drawings.