GB2201708A

GB2201708A - A tamping tine for a track tamping machine

Info

Publication number: GB2201708A
Application number: GB08801925A
Authority: GB
Inventors: Josef Theurer; Johann Hansmann
Original assignee: Franz Plasser Bahnbaumaschinen Industrie GmbH
Current assignee: Franz Plasser Bahnbaumaschinen Industrie GmbH
Priority date: 1987-03-05
Filing date: 1988-01-28
Publication date: 1988-09-07
Also published as: DE3737276A1; AT389335B; ATA50587A; GB8801925D0

Description

4 1 A TAMPING TINE FOR A TRACK TAMPING MACHINE 1 2201708 This invention

relates to a tamping tine for a track tamping machine consisting of a tine shaft form-lockingly connected to the tamping drive at the upper end of the tine and of a tine plate formed integrally on the tamping tine at the lower end thereof, the tine shaft and the tine plate being designed as separate parts interconnectible by a formlocking plug connection consisting of a spigot extending longitudinally of the shaft and a receiving part with a recess or opening and the spigot and the receiving part connected to the tine plate each being formed with an opening extending through transversely of the shaft to receive a connecting element.

The tamping tines designed to be fitted in the tamping units of track tamping machines are adapted for vibration and for penetration into the ballast between the individual sleepers under the power of their drives and are squeezed together in pairs to tamp the ballast beneath the sleepers. As a result, powerful forces are transmitted to the tamping tines. During penetration into,the ballast bed in particular, a very high penetration resistance often has to be overcome, in addition to which the tamping tine is subjected to particularly severe stressing by the pressure applied during the compression of the ballast beneath the sleeper. Through the constant and deep penetration into the track ballast under powerful forces, the actual plates of the tampingtines are subjected to very heavy wear. Accordingly, to correct such wear, the tamping tines are removed from the holders on the tamping unit after a certain period of use to enable the worn areas of the plates to be repaired by build-up welding. These tamping tines which consist of solid metal have a considerable weight so that the replacement of a tamping tine and, more particularly, a relatively large number of tamping tines is a laborious and time-consuming operation. A typical tamping unit per rail comprises four to eight such tamping tines for each rail/sleeper crossing f 1 and hence eight to sixteen tamping tines for both rails. A two-sleeper tamping machine for example may even be provided with a -total of thirty- two tamping tines. Apart from this laborious and relatively time- consuming operation, during which the machine is stationary and cannot be used, the build-up welding process itself is very expensive and laborious and can only be repeated a few times because, thereafter, the quality of. material is no longer sufficient for use. For these reasons, therefore, so-called tamping tines comprising a separate tine shaft and tine plate of the type described at the beginning have already been pro posed to enable above all the actual tine plate to be re moved and refitted quickly and easily with minimum effort.

DE-PS 2 723 551 describes a tamping tine for a track tamping machine of which the tine shaft and tine plate with an integrally formed fastening stub are in the form of separate parts interconnectible by a form-locking plug connection. The plug connection consists of a spigot and recess designed to fit into one another longitudinally of the tine shaft and each comprising a bore extending transversely of the shaft to receive a radially elastic connecting element. The embodiments shown in this literature reference comprise cotter-like spigots formed on the. fastening stub and correspondingly shaped recesses, although in both cases the fast- ening s tub with the recess and the spigot extends far beyond the upper edge of the tine plate, resulting in an unfavourable arrangement of the shaft cross-section weakened by this recess, particularly in regard to the transmission of forces. In use, therefore, this connection is overly stressed, particularly by the forces occurring during the squeezing or tamping movement, and is thus prone to breakage. For these reasons, the same patentee further developed this tamping tine (cf. DE-OS 2 849 951) because these interengaging elements are not capable, particularly under very severe stressing, of reliably keeping the reaction forces 4 1 - 3 1 away. This futther development of the tamping tine consists of further interengaging form-locking elements, more especially with a protuberance reaching almost to the middle of the tine shaft, with the result that the tamping tine as a whole is very expensive, uneconomical and also very difficult to make. Apart from this, the radially elastic clamping sleeve or a setscrew serving as connecting element often jams during assembly and dismantling so that assembly is again impeded.

US-PS 3,729,055 describes a tamping tine for a track tamping machine in which the tine plate comprises a frustoconical projection above its upper edge and the lower end of the tine shaft is formed with a corresponding conical bore. The two separate parts are designed to interengage and are held by a setscrew and pin to stop them from turning and dropping out. Although this form is very simple, it is certainly not capable of taking up the very powerful forces or, in particular, of preventing the the tine plate from turning in relation to the shaft. In addition, the frustoconical projection directly above the edge of the tine plate is too small in diameter so that, in work involving powerful tamping forces, breakage cannot be prevented at this very place.

Finally, GB-OS 2134 576A describes an embodiment of a tamping tine with a separate tine shaft and tine plate in which the end of the shaft has a substantially trapezoidal cross-section and the corresponding opening in the tine plate is formed by two flanges formed integrally on the back of the tine plate and inclined at an angle to one another.

This plug connection of substantially trapezoidal crosssection is intended to hold the two parts by establishing a force-locking connection when they are fitted together because no other means of holding the two parts, for example a connecting element, is provided. With this tamping tine, which has already been used in practice, the tine plates 1 often remain in the ballast in operation or drop down on lifting. In addition, this opening which is open on three sides and which is formed solely by the two projecting flanges and also the shaft of the tamping tine in the special trapezoidal cross-section, which is combined with a special surface configuration to avoid sudden transitions, are very complicated and hence also very uneconomical to make. US-PS 376,565 describeg another, albeit simpler tamping tine of this type with a substantially trapezoidal cross-section of the shaft end and a correspondingly shaped tine plate. With this opening, the two flanges which delimit the opening in the tine plate.extend to the side edges of the tine plate. In this embodiment, too, the end of the shaft is intended to be inserted into and held in the trapezoidal opening of the tine plate through the establishment of a force-locking connection.

Now, the object of the present invention is to improve a tamping tine of the type described at the beginning in such a way that the tine plate-can be dismantled and re- fitted quickly and easily with minimal effort and, despite the separate construction, the tamping tine as a whole is capable of taking up even powerful forces and the tine plate is also prevented from dropping out.

According to the invention, this object is achieved with a tamping tine of the type described at the beginning in that the receiving part connected to the tine plate comprises only a single, substantially frustoconical or frustopyramidal recess or opening and in that only a single, substantially frustoconical or frustopyramidal spigot arranged at the lower end of the tine shaft is provided, the spigot and the opening or recess being desiged to be connected and released by a connecting element, more especially in the form of a cotter, which is designed to be inserted at least partly through the openings. Through the provision of only one recess or opening in the receiving part connected to the 1 1 tine plate and only one spigot on the tine shaft, it is possible quickly and easily to establish a plug connection by which the tamping and vibration forces can be fully transmitted, even after prolonged use, despite the divided construction of the tamping tine. These advantages are attributable in particular to the largest possible crosssection in relation to the shaft diameter and, above all, to the fact that, through the central arrangement of a nsingle" spigot and a "single" frustoconical or frusto- pyramidal recess or opening in the tine plate, the spigot can be uniformly surrounded. In this way, the forces can be uniformly transmitted, avoiding local peak stressing of the receiving part or spigot. The effect of the connecting element joining the tine plate and tine shaft to one another is that, during assembly, the spigot and receiving part are pushed into one another as far as possible with establishment of a powerful wedging effect and are safely held in this favourable position, even after prolonged use.

In one preferred embodiment of the invention, the single, substantially frustoconical recess is substantially circular in cross- section and is intended'to receive a similarly shaped spigot in a fastening stub of the receiving part which projects beyond the upper edge of the tine plate, the lower end of the recess preferably conical in shape with a cone angle of approximately 20 extending to near the upper edge of the tine plate. In this embodiment of the invention, the receiving part is in the form of a cup-shaped extension of the tine plate so that the point of connection is situated in that part of the tine shaft which is of even wider cross-section. The receiving part can thus be made thicker without weakening the spigot for the establishment of a robust and permanent connection.

In another advantageous embodiment of the invention, the spigot and the receiving part connected to the tine plate or rather the fastening stub are each formed with an opening a 1 1 to receive the cotter which extends transversely of the shaft and in the squeezing direction of the tamping tine. The connection of the tine plate and tine shaft by a cotter produces a particularly intense wedging effect which with- stands even the severe impact-like stressing caused by the rapid penetration of the tamping tine into the ballast and also the vibration of the tamping tine. Because the cotter is arranged to extend in the squeezing direction of the tamping tine, the tamping pressures advantageously act in the direction in which the cotter is driven in, thus counteracting any loosening of the cotter.

In another advantageous embodiment of the invention, the spigot and the receiving part connected to the tine plate or rather the fastening stub are each formed with an opening to receive the cotter which extends transversely of the shaft and in a position offset through 900 in relation to the squeezing direction. This arrangement of the cotter in relation to the tine plate is particularly suitable for one-sleeper tamping units, ensuring unimpeded and rapid insertion and removal of the cotter.

In another advantageous embodiment of the invention, the opening has a consid:erably larger slot-like crosssection lo ngitudinally of the shaft to receive a cotter connecting element in the form of an elevated cotter. Taking into account the fact that relatively little material is available transversely of the longitudinal axis of the shaft, the design of the cotter as an elevated cotter has the advantage of avoiding asignificant reduction in the cross-section of the spigot.

In another simple embodiment of the invention, the slotlike opening in the frustoconica I or frustopyramidal spigot and the cotter each have an inclination of approximately 1:25 solely in the region of a lower contact surface, the openings of the receiving part or rather the fastening stub in the position in which it is pushed onto the spigot being t 1 situated slightly lower than the opening of the spigot. without wedging the cotter and having a cross-section corresponding at-least to the largest cross-section of the cotter. The confinement of the inclined contact surface to the lower contact surfaces of the spigot and cotter provides advantageously for wedging forces which solely act longitudinally of the shaft, reliably precluding overstressing of the narrow webs of material situated laterally of the opening. The vertically offset arrangement of the openings provides for full contact between the contacting frustoconical or frustopyramidal surfaces which in turn provides for a stable and strong plug connection.

In another embodiment of the invention, the spigot is designed to be connected to and released from the receiving part or rather the fastening stub by a cotter in the,form of a connecting element which is arranged with its larger cross-section facing the tine plate. By virtue of this arrangement of the cotter in relation to the tine plate, the tamping pressure is with advantage partially transmitted to the cotter during each squeezing movement. The cotter is thus reliably prevented from loosening and from dropping out.

Another simple embodiment-of the invention is characterized in that, in the connected position, the cotter acting as connecting element projects only slightly at both ends from the opening in the receiving part or rather the fastening stub,'preferably with a convex surface. The effect of the only slightly projecting convex surface is that the cotter does not offer any increased resistance to the penetration of the tamping tine and is only subjected to very little wear.

Another preferred embodimen t of the invention is characterized in that the single frustopyramidal opening of trapezoidal cross-section is connected as a U-shaped holder to the rear of the tine plate, that surface of the holder which 1 9 faces the tine plate having a trapezoidal cross-section and being arranged at an angle of inclination of approximately 200 to the tine plate to receive a similarly shaped, frustopyramidal spigot. This positioning of the plug con- nection immediately behind the tine plate provides for the particularly favourable direct transmission of the squeezing or tamping forces from the spigot to the tine plate. The inclined arranged of the surface opposite the tine plate provides for an advantageous V-shaped configuration of the receiving part with relatively little penetration resistance. The frustoconical opeping, above all in conjunction with a cotter, makes it possible to produce intense wedging forces which press the opening together with the tine plate onto the matchingly shaped spigot with establishment of a firm, play- free-connection. In addition, the U-shaped holder which can be made in a die shows high resistance to wear and may be economically welded onto the back of the tine plate.

Another advantageous embodiment of the invention is characterized in that, at its upper end, the U-shaped holder f orming the opening is flush with the upper edge of the tine plate and in that the holder corresponds'in height to only about two thirds of the height of the tine plate. By virtue of this arrangement of the holderaccommodating the spigot, very little penetration resistance is offered to the penetration of the tamping tine. On the other hand, the height of the holder is sufficient for the spigot to be tightly and durably surrounded for transmission of the tamping and vibration forces.

Finally, in another advantageous embodiment of the in- vention, the fourth side wall of the substantially frustopyramidal spigot of substantially trapezoidal cross-section extends parallel to the tine plate and preferably up to a step-like shoulder of the tine shaft which projects beyond the upper edge of the tine plate. The stepping of the tine shaft in the transitional zone of the spigot enables the width of the spigot, holder and tine plate to be reduced which reduces 1 the penetration resistance without weakening the tine shaft.

Three examples of embodiment of the invention are described in detail in the following with reference to the" accompanying drawings, wherein:

Figure 1 is a front elevation of a tamping tine according to the invention.

Figure 2 is a side elevation, partly in cross-section, of the tamping tine shown in Figure 1.

Figure 3 is a rear view of part of the same tamping tine.

Figure 4 shows two separate tamping tines according to the invention for a two-sleeper tamping unit in the working position.

Figure 5 is a side elevation of part of another example of embodiment of a tamping tine according to the invention.

Figure 6 is a front elevation of another example of embodiment of a tamping tine according to the invention.

Figure 7 is a side elevation, partly in cross-section, of the same tamping tine.

Figure 8 is a rear view of the tamping tine shown in Figures 6 and 7.

Figure 9 is a view of the lower end of a tamping tine in the direction of arrow IX in Figure 6.

Figure 10 is a cross-section through the tine shaft on the line X-X in Figure 8.

The tamping tine 1 shown in Figures 1 to 3 consists essentially of a tine shaft 2 connected to a tamping unit and of a tine plate 3 fixed to the lower end of the shaft 2 for penetration into the ballast. The tine shaft 2 and the tine plate 3 are designed as separate parts, being connect- ible to the one another by a form-locking plug connection 7 consisting of a spigot 4 extending longitudinally of the shaf t and of a receiving part 6 in a recess or opening 5. The spigot 4 and the receiving part 6 connected to the tine plate 3 are each formed with an opening 8,9 extending through transversely of the longitudinal axis of the shaft to receive a connecting element 10. The receiving part 6 joined to the tine plate 3 com- 1 prises only a single recess 5 frustoconical in shape. Provided at the lower end of the tine shaft 2 is only a single, frustoconical spigot 4 which is designed to be connected to and released from the receiving part 6 by the connecting element 10 in the form of' a cotter 11 designed for insertion through the openings 8,9.

As can be seen from Figure 2 in particular, the single frustoconical recess 5 has a circular cross-section and is intended to receive the matchingly shaped spigot 4 in a fastening stub 13 of the receiving part 6 projecting beyond the upper edge 12 of the tine plate. The lower end of the recess 5, which includes an angle of approximately 200 with the longitudinal axis 14 of the tine shaft, extends to near the upper edge 12 of the tine plate. The two openings 8,9 in the receiving part 6 and the spigot 4 are arranged in such a way that the longitudinal axis of the cotter 11 extends transversely of the longitudinal axis 14 of the tine shaft and in the squeezing direction of the tamping tine. The slot-like openings 9 in the f rustoconical spigot 4 and the cotter 11 each have an inclination of around 1:25 solely in the region of a lower contact surface 15. The openings 8 of the receiving part 6,' in the position in which it is pushed onto the spigot 4, are situated slightly lower than the opening 9 of the spigot 4 without wedging the cotter 11.

In addition, the two openings 8,9 have a cross-section corresponding at least to the largest cross-section of the cotter 11.

At its upper end, the tine shaf t 2 is designed to be releasably connected by a setscrew 16 to the lower end of a tamping drive 17 shown in dash-dot lines.

As shown in Figure 3, the lower part of the fastening stub 13 or rather the receiving part 6 has two inclined side walls 18 which are welded onto the back of the tine plate 3. The opening 8 for receiving a connecting element 10 in the form of an elevated cotter 19 has a slot-like cross-section 1 1 11 - 1 which is considerably larger in the longitudinal direction 14 of the tine shaft.

The two tamping tines 1 shown in Figure 4 are each fixed to their own tamping drive,by which they are moved towards a sleeper 20 of a track 21 to make the tamping or squeezing movement. Another tamping tine is arranged opposite the two illustrated tamping tines 1 (arranged centrally in relation to the tamping unit) transversely of the longitudinal axis of the sleeper.

The tamping tine 22 shown in Figure 5 with a tine shaft 23 and a frustoconical spigot 24 is designed to be connected to a tine plate 26 comprising a receiving part 25. For this releasable connection, the spigot 24 and the receiving part joined to the tine plate 26 are each formed with an open- ing 28,29 to receive a cotter 27. These openings 28,29 extend transversely of the longitudinal axis of the shaft and in a position offset through 900 in relation to the squeezing or tamping direction extending in the plane of the drawing. A tamping tine 30 shown in Figure 6 likewise comprises a tine plate.32 separate from the tine shaft 31. The lower end of the tine shaft 31 is in the form of a frustopyramidal spigot 33 which is designed for insertion into a single, similarly f rustopyramidal opening. 34 to form a plug connection 35.

As-can be seen in particular from Figure 7, this single frustopyramidal opening 34 of trapezoidal cross-section is connected as a U-shaped holder 36 to the rear of the tine plate 32. That surface 37 of the holder 36 which faces the tine plate 32 has a trapezoidal cross-section and is arranged at an angle of approximately 20 to the tine plate 32. In the connected position, a.cotter 38 acting as connecting element projects slightly at either'end from he opening 39 of the receiving part 40 formed by the holder 36 in the form of a convex surf ace 41. In addition, the cotter 3&. f aces- the tamping plate 32 with its larger cross-section.

J A slot-like opening 42 in the frustopyramidal spigot 33 and in the cotter. 38 has an inclination of around 1:25 solely in the region rif a lower contact surface 43. The openings 39 of the receiving part 40, in the position in which it is pushed onto the spigot 33, are situated slightly lower than the opening 42 of the spigot 33 without wedging the cotter 33. At its upper end, the U-shaped holder 36 which forms the opening 34 is flush with the upper edge 44 of the tine plate. The holder 36 corresponds in height to only about two thirds of the height of the tine plate. The fourth side wall 45 of the frustopyramidal spigot 33 extends parallel to the tine plate 32 up to a step-like shoulder of the tine shaft 31 is which projects beyond the upper edge 44 of the tine plate.

It can be seen from the rear view in Figure 8 that the U-shaped holder 36 is welded onto the back of the tine plate 32. The view of the tamping tine 30 in Figure 9 shows the frustopyramidal shape of the receiving part 40 attached to the back of the tine plate 32. The spigot 33 which is surrounded by the receiving,part 40 and by part of the tine plate 32 is also frustopyramidal in shape to accorhmodate the receiving part 40. At one end, the cotter 38 projects slightly beyond the front side of the tine plate 32 and, at its other end, beyond the surface 37 of the holder 36. Figure 10 shows the trapezoidal cross-section - perpendicular to the tine plate 32 - both of the spigot 33 and of the holder 36 surrounding it. The cross-section of the tine shaft 31 where it adjoins the spigot 33 is circular.

The assembly and dismantling of the tine plate 3,32 are described in detail in the following:

While the tine shaft 2,31 is secured in the holder of the tamping drive 17 through its free-standing spigot 4,33, a tine plate 3,32 is pushed with"its receiving part 6,40 onto the spigot 4,33. The cotter 11,38 is then inserted into the openings 8 and 9; 39 and 42 from the front side of the tine plate 3,32.For permanent fixing, the cotter 1 k.

1 1 11,38 is driven in by hammering or by means of a tool resembling a screw clamp. The contact of the lower contact surface 15,43 with the lower end region of the spigot opening 9,39 results in vertical displacement of the receiving part 6,40 which, at the upper ends of its openings 8,39, bears on an upper contact surface of the cotter 11,38. The vertical displacement of the receiving part 6,40 ensures full and permanent contact between the equally inclined contact surfaces of the spigot 4,33 and the fastening stub 13 or rather the holder 36. The dismantling of worn tine plates 3,32 may be carried out just as quickly and easily by knocking out the cotter 11, 38 against the direction in which it was driven in, i.e. in the direction of the larger cross-section of the cotter.

Claims

1. A tamping tine for a track tamping machine consisting of a tine shaft form-lockingly connected to the tapping drive at the upper end of the tine and of a tine plate formed integrally on the tamping tine at the lower end thereof, the tine shaft and the tine plate being designed as separate parts interconnectible by a form-locking plug connection consisting of a spigot extending longitudinally of the shaft and a receiving part with a recess or opening and the spigot and the receiving part connected to the tine plate each being formed with an opening extending through transversely of the shaft to receive a connecting element, characterized in that the receiving part connected to the tine plate comprises only a single, sub stantially frustoconical or frustopyramidal recess or opening and in that only a single, substantially frustoconical or frustopyramidal spigot arranged at the lower end of the tine shaft is provided, the spigot and the opening or recess (5) being designed to be connected and released by a connecting element, more esp ecial ly in the f orm of a cotter; 7'; A), which is designed to be inserted at least partly through the openings

2. A tamping tine as claimed in claim 1, characterized in that the single, substantially frustoconical recess (X) is substantially circular in cross-section and is intended to receive a similarly shaped spigot '" in a fastening stub YN of the receiving part ' ()4 which projects beyond the upper edge (P!K) of the tine plate, the lower end of the recess .,N preferably conical in shape with a cone angle of approximately 20 extending to near the upper edge (X) of the tine plate (Figures 1 to 5). '

3. A tamping tine as claimed in claim 1 or 2, characterized in that the spigot (Xl and the receiving part X connected to the tine plate or rather the fastening stub X) are each i L - formed with an opening (" to receive the cotter (.<) which extends transversely of the shaft and in the squeezing direction of the tamping tine.

4. A tamping tine as claimed in claim 1 or 2, characterized in that the spigot and the receiving part ( connected to the tine plate or rather the fastening stub are each formed with an opening to receive the cotter which extends transversely of the shaft and in a position offset through 90 in relation to the squeezing direction (Figure 5).

5. A tamping tine as claimed in any of claims 1 to 4, characterized in that the opening has a considerably larger slot-like cross-section longitudinally of the shaft to receive a cotter connecting element in the form of an elevated cotter

6. A tamping tine as claimed in claim 5, characterized in that the slot-like opening in the frustoconical or frustopyramidal spigot and the cotter each have an inclination of about 1:25 solely in the region of a the openings lower contact surface of the receiving part or rather the fastening stub (NY' in the position in whiqh it is pushed onto the spigot being situated slightly lower than the opening CV;:M;0) of the spigot without wedging the cotter and having a cross-section corresponding at least to the largest cross-section of the cotter

7. A tamping tine as claimed in any of claims 1 to 6, char acterized in that the spigot is designed to be connected to and released from the receiving part or rather the fastening stub (,&j by a cotter in the form of a connecting element which is arranged with its larger cross-section facing the tine plate PK;,k;3;K)

8. A tamping tine as claimed in any of claims 1 to 7, characterized in that, in the connected position, the cotter C^;X6.>C acting as connecting element Projects only 11 slightly at both ends from the opening Qfo) in the receiving part or rather the fastening stub (Rj, preferably with a convex surface

9. A tamping tine as claimed in claim 1 and any of claims 3 to 8, characterized in that the single frustopyramidal opening (,W of trapezoidal cross-section is connected as a U-shaped holder (><) to the rear of the tine plate (X, that surface (X) of the holder (>I which faces the tine plate having a trapezoidal cross-section and being arranged at an angle of inclination of approximately 20 to the tine plate (>:r) to receive a similarly shaped, frusto pyramidal spig ot (PJ (Figures 6 to 10).

10. A tamping tine as claimed in claim 9, characterized in that, at its upper end, the U-shaped holder ()<) forming the opening () is flush with the upper edge (""' of the tine plate and in that the holder (11 corresponds in height to only about two thirds of the height of the tine plate.

11. A tamping tine as claimed in claim 9 or 10, character ized in that the fourth side wall (A of the substantially frustopyramidal spigot ("" of substantially trapezoidal cross-section extends parallel to the tine plate 0"(1 and preferably up to a step-like shoulder of the tine shaft C which projects beyond the upper edge (K) of the tine plate.

12. A tamping tine for a railway track tamping machine, substantially as herein describe with reference to Figures 1 to 4, Figure 5,.or Figures 6 to 10 of the accompanying drawings.

Published 1988 at The Patent Office, State House, 68171 High Holborn, London WC1R 4TP. Further copies may be obtained from The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques Itd, St Mary Cray, Kent. Con- 1/87.