US2876709A - Track packing or tamping machine - Google Patents

Description

March 10, 1959 Filed Oct. 13, 1954 F. PLASSER ETAL I TRACK PACKING OR TAMPING MACHINE 5 Sheets-Sheet 1 INVENTOR. Franz flasserwosef Freq/er 4 TTOQNEY March 10, 1959 F. PLASSER El'AL 7 2,876,709

TRACK PACKING OR TAMPING MACHINE Filed Oct. 13, 1954 s Sheets-Shget 2 III 5 lllllI/lilliliIl/II/l/Il 57 INVENTOR.

' 30 24a 24 Franz P/asser wosef T/weure'r BY 04, J04 @0411,

ATTORNEY March 10, 1959 F. PLASSER ETAL 2,876,709

TRACK PACKING OR TAMPING MACHINE 3 Sheets-Sheet 3 Filed Oct. 1s. 1954 llfi ENTOR.

561V: YNFF FAWN/Q BYMMM 72 30 ,4? If 2,876,709 TRACK PACKING R TAMPING MACHINE in: Franz Plasser and Josef Theurer, Vienna, Austria Application October 13, 1954, Serial No. 462,086

1 claim. (Cl. 104-12) upper end, an eccenter shaft operatively connected to the mounting device for imparting a vibratory movement to the mounting device and the tamping tools linked thereto, and means for varying the distance between the tamping tools of each pair. The ballast is packed under a tie by placing a pair of tamping tools over the tie and forcing the tamping tools together while they are simultaneously vibrated.

It is known to effect the spacing adjustment for each pair of'cooperating tamping tools, i. e. their approachment or closing as well as their opening, by hydraulic means.

Known hydraulically-operated track tamping machines include a large number of movable parts which require-constant service, lubrication, etc., as well as a considerable number of control valves, slides, etc. in the numerous pressure fluid conduits. This makes the operation of such machines excessively difiicult, breakdowns are frequent and the manufacture of the machines is very expensive. In addition, there are structural xdifliculties in building the machines and they are extremely bulky.

It is the principal object of the present invention to provide a track tamping machine of the above type with a considerably simplified operating mechanism and greatly improved operational efiectiveness.

' It is a concomitant object of this invention to provide such a machine with a minimum of movable parts, thus reducing operational break-downs.

It is a more specific object of the invention to provide an improved spacing adjustment mechanism for each pair of tamping tools. In accordance with the invention, the spacing adjustment mechanism for each pair of cooperating tamping tools comprises at least one cylinder closed at both ends, at least one piston in each cylinder and pressure means for shifting either the cylinder or the piston, the movable element (cylinder or piston) being linked with the cone sponding tamping tool intermediate its ends and the other element (cylinder or piston) being fixedly mounted on the tamping tool carrier.

The above and other objects, features and advantages of the present invention will be more fully explained in the following description of some now preferred embodiments thereof taken in conjunction with the accompanying drawing wherein Fig. 3 shows the operating arrangement of the mechanism of Fig. 2;

Fig. 4 shows the operating arrangement of another modification;

Fig. 5 is a sectional view of a detail of Fig. 4; and

Fig. 6 is a perspective view of the tamping tool carrier.

Referring now to the drawing, the same reference numerals are applied to like parts in all figures.

Fig. 1 shows a track tamping machine incorporating a tamping tool spacing adjustment mechanism which comprises a closed cylinder cooperating with each tamping tool, each cylinder being glidably mounted with its two closed end walls on a longitudinal piston which is fixedly mounted in the vertically adjustable tamping tool carrier, the piston dividing the cylinder into two chambers. In this embodiment, hydraulic or pneumatic pressure means may be applied to the cylinder chambers, or to one chamber only. As shown, tamping tool carrier 2 is slidably supported on posts 3 and 3' which are mounted in carriage frame 1. Eccenter shaft 4 is supported on carrier 2, the shaft axis being parallel to ties 9 supporting track 9 upon which the carriage travels. Upon rotation, shaft 4 imparts a reciprocating motion to tamping tool mounting arms 5, the pair of tamping tools 6 and 6 being pivotably connected at their upper ends to the ends of mounting arms 5. Intermediate their ends, the tamping tools are linked to a pivot element 7 which enables the spacing of the tamping tools to be adjusted in a manner described hereinafter. The lower ends of the tamping tools reach into the ballast 10 at either side of ties 9. The ballast is packed under tie 9 when the two tamping tools are moved toward each other, thus exerting pressure on the rocks and pebbles therebetween, while the tools are simultaneously vibrated by rotation of eccenter shaft 4. The tamping tool carrier 2 is vertically movable by adjustable support means 8 (not illustrated in detail), whereby the depth of the tamping tools in the ballast may be changed. When the tamping at one tie is completed, the entire carrier is raised on standards 3, 3', the carriage is moved along tracks 9' to the next tie and the operation is repeated there.

Intermediate its ends, each tamping tool is connected to cylinder 21 by means of pivot 7. The cylinder is closed at both ends and is adapted to glide along fixed piston rod 22 which is mounted in the tamping tool carrier parallel with the tracks. Piston 24, which is fixedly mounted upon or integral with the piston rod, divides the movable closed cylinder into chambers 30 and 31, pressure fluid conduit 23 opening into outer chamber 30 while pressure fluid conduit 25 leads into chamber 31. The conduits for the pressure fluid, i. e. oil, are partially constituted by bores in rod 22, as shown.

Fig. l is a side view of a ballast tamping machine ina In operation, when fluid is fed toouter cylinder chamber 30, pressure will be exerted upon the outer wall of the cylinder, thereby moving the cylinder to the right, as seen in the drawing, and imparting an outward or opening movement to the tamping tools. Contrariwi'se, when fluid is fed to chamber 31, the tamping tools will move toward each other. The closing movement, which should always be effected very slowly and requires cons'iderable power to assure good tamping of the ballast, is best actuated by hydraulic means. However, for opening the tamping tools or moving them apart from each other at the end of the tamping operation, it is advantageous to use means which work faster and thus save time.

One preferred means for moving the tamping tools apart is a helical spring mounted in the outer cylinder chamber to return the movable cylinder (and thereby the tamping tool) to its original position when the hydraulic pressure in the insidechamber is released. .It

Patented Mai-.10, 1959 may be desirable to control the extent of the closest and widest distance of the cooperating tamping tools by adjustable stops placed in the path of their movement, the adjustment of the stops resulting in a predetermined maximum or minimum spacing of the tools. The practically instantaneous action of the spring means will save considerable time in opening the tamping tools because hydraulic operation involves a relatively long time. Since the tamping tools can be moved apart without the use of much power and should be opened as quickly as possible to assure etficient operationof the machine, the use of the hydraulic pressure for opening the tamping tools is wasteful and undesirable.

Figs. 2 and 3 illustrate the use of springs used for moving the tamping tools apart after the tamping operation. Instead of a pressure fluid conduit leading into outer cylinder chamber 30, the chamber is provided with pressure spring 26 held between the wall of cylinder 21 and piston 24. Otherwise, the spacing adjustment mechanism of Fig. 2 is the same as that shown in Fig. 1, except for the provision of stops 27, which limit the reciprocating movement of each tamping tool.

The operation of the apparatus shown in Fig. 2 is further illustrated in Fig. 3. The pressure fluid supply to chamber 31 of each cylinder is regulated by control member 33. In the rest position, when no pressure fluid is to be fed to chamber 31, the piston in the control membet is pressed upwardly by spring 34 acting upon actuating lever 35 of the control member (position shown in dotted lines). In this position of the control member, pressure fluid supply from pump 12 is cut off from conduits 25. When lever 35 is actuated against the pressure of spring 34, the pressure fluid delivered from pump 12 is free to enter conduits 25 through the cylinder of control member 33 (position shown in full lines), entering chambers 31 and thus effecting the approachment of the tamping tools and tamping of the ballast therebetween. The tamping tools will move toward each other until they hit inside stops 27. The stops are so positioned as to avoid damageto tie 9 by the tamping tools which are located at each side thereof to tamp the ballast under the tie. The increased pressure thus created in conduits 25 is released by means of highpressure relief valve 32 which is arranged in the return conduit 25b. When lever 35 is no longer actuated, pressure fluid supply to chambers 31 is cut ofi and the tamping tools return to their original (open) position under pressure of springs 26 in cylinder chambers 30. The opening under spring pressure is, of course, effectuated much quicker than the closing with hydraulic means.

In the rest position of control member 33, when no pressure fluid is supplied to chambers 31, the pressure fluid constantly delivered by pump 12 returns to storage tank 33 by means of return conduit 25b. if desired, throttle or butterfly valve 29 may be arranged in return conduit 25a to regulate the return speed of movable cylinders 21, i. e. the speed of opening the tamping tools. The return stroke of cylinders 21 may also be controlled by adjustable limiting stops 27 to adapt the tarnping operation to various tie distances.

High-pressure relief valve 32 in return conduit 25b serves to adjust the desired pressure and permits variations of the pressure during operation. If it is desired,

.for instance, to adjust the pressure applied to each pair of tamping tools separately, each pair of tools is provided with a separate conduit system having its own pressure control valve. This makes it possible, for in stance, to tamp the ballast outside the tracks more densely than therewithin, thus preventing so-called riding of the tie,

n the other hand, equal pressure upon all pairs of tamping tools may best be obtained by building fluid supply meters 28 into feed lines 25. This also permits regulation of theapproachment or closing speed of the 4 tamping tools by varying the amount of pressure .fluid supplied to the cylinders.

Instead of using the time-saving return springs for opening the tamping tools, it is also possible to use pneumatic means for this purpose, applying hydraulic pressure for moving the tamping tools together but pneumatic pressure for moving them apart. In this instance, too, valuable operating time is saved and, in addition, it simplifies the construction of the machine considerably. The necessary compressed air for the pneumatic operation will be readily available in any conventional ballast tamping machine since it is used for other operational purposes, such as the vertical adjustment of the tamping tool carrier.

A practical embodiment of this variant of the invention is illustrated in Figs. 4 and 5. In this case, the return stroke of the tamping tools is expedited by supplying compressed air to cylinder chambers 31 instead of hydraulic fluid which is used only for closing thetamping tools.

As shown in Fig. 4, when actuating lever 36 is in position I (full lines), control member 37 will permit by? draulic fluid, i. e. oil, to be supplied from storage tank 38 by means of pump 12 to conduit and cylinder chambers 31. As hereinabove described, the hydraulic pressure will close the tamping tools and effect the tamping operation. At the end of this operation, i. c. when the ballast has been .sufliciently tamped and/or the temp ing tools are limited by stops 27, the pressure fiuid delivered by pump 12 will be released by high-pressure relief valve 39 and enter return conduit 49 back into storage tank 38.

When hydraulic fluid is supplied to chamber .31, thus moving the cylinder to the right, as seen in the drawing, the air in cylinder chamber is displaced and flows out into the atmosphere by way of blow-0d valve 43 because back-pressure valve 44 is provided in the pneumatic air conduit 23. The back-pressure valve prevents the air from being led back to compressor 46.

The tamping tools are moved apart after tamping by moving lever 36 into position 11 (indicated in dotted lines in Fig. 4). In this position of control piston 37, the hydraulic fluid will be returned without pressure to storage tank 38 by way of conduit 40. On the other hand, the continuously working compressor 46 will constantly supply compressed air to cylinder chamber 30 by way of pressure reducing valve 45, back-pressure valve 44, pressure-relief valve 43 and conduit 23. The compressed air supplied to chamber 30 will move cylinder 21 leftward (as seen in the drawing) and thus move the tamping tools apart. The pressure-reducing valve 45 serves to adjust the air pressure so as to eliminate any vibration of cylinder 21 and may also be used to influence the velocity of the return stroke, i. .e. the opening, of the pair of tarnping tools.

The hydraulic fluid in cylinder chamber 31 is displaced when compressed air is supplied to chamber 30, and flows back into storage tank 38 by way of conduits 25, control member 37 and conduit 46 where it combines with the fluid coming from pump 12.

Fig. 5 shows the sealing of cylinder chambers 30 and 31 by means of scaling rings 24a on piston 24. Any air which may have penetrated through the sealing ring from chamber 30, or hydraulic fluid seeping through from chamber 31, will reach the circumferential groove 42 of piston 24 which is located intermediate the sealing rings. The pressure fluid will then be conducted from groove 42 through bore 41 in the piston rod back to storage tank 38 where-the hydraulic fluid remains stored while the air may be permitted to dissipate.-

While some preferred embodiments of the tamping tool spacing adjustment mechanism have been described and illustrated in detail, it will be understood that various "variants of the described principles may occur to the skilled in the art, particularly after they have had the benefit of the present disclosure, without departing from the spirit and scope of the present invention as defined in the appended claim.

What is claimed is:

In a track tamping machine of the type comprising a carriage to travel on the track, a vertically movable carrier mounted on the carriage, at least one pair of opposing tamping tools carried by the carrier to reciprocate in a direction substantially parallel to the track, and eccenter shaft means operatively connected to the upper ends of the tamping tools for imparting a vibratory movement to the tools: a pressure-operated mechanism for varying the relative distance between the two tamping tools of each pair of opposing tools, said mechanism including a piston rod fixedly mounted on the tamping tool carrier substantially parallel to the track, two pistons fixedly arranged on said rod, said pistons being arranged substantially symmetrically with respect to the center point of the piston rod, two cylinders closed at both of their ends movably mounted on said piston rod with each of said pistons dividing a respective one of said cylinders into an outside chamber and an inside chamber,

pivot means connecting each tamping tool of a pair of cooperating tools intermediate its ends to a respective one of said cylinders, and pressure means for applying pressure to each chamber of said closed cylinders, the pressure means connected to the inside chambers being hydraulic fluid.

References Cited in the file of this patent UNITED STATES PATENTS 1,980,704 Scheuchzer Nov. 13, 1934 2,052,943 Scheuchzer Sept. 1, 1936 2,399,505 Phillips Apr. 30, 1946 2,404,639 Lane July 23, 1946 2,550,925 Weimar May 1, 1951 2,712,287 Zurrnuhle July 5, 1955 FOREIGN PATENTS 182,113 Austria June 15, 1954 680,644 Great Britain Oct. 8, 1952 683,453 Great Britain Nov. 26, 1952 703,011 Great Britain Jan. 27, 1954

Images