US3793960A

US3793960A - Tamper foot

Info

Publication number: US3793960A
Application number: US00288395A
Authority: US
Inventors: R Mckenry
Original assignee: Kennametal Inc
Current assignee: Kennametal Inc
Priority date: 1972-09-12
Filing date: 1972-09-12
Publication date: 1974-02-26
Anticipated expiration: 1991-02-26
Also published as: AU472696B2; DE2345967B2; DE2345967A1; GB1418964A; DE2345967C3; JPS5614803B2; AU6024973A; JPS4992803A

Abstract

A plate adapted for being fixed to the end of a tamper arm and having a groove extending across the leading edge and up the side edges and in which blocks of a hard wear resistant material, such as a cemented hard metal carbide, are mounted and secured in place as by brazing.

Description

D United States Patent 1 1 1111 3,793,960

McKenry Feb. 26, 1974 [5 TAMPER FOOT 2,693,938 11/1954 Roberts 175/410 2,617,631 11/1952 Shepherd 175/410 [751 Invenwr- Rbert McKenrY, wmdbe" 107,314 9/1870 Wentworth 294/56 [73] Assignee: Kennametal Inc., Latrobe, Pa. [22] Filed: Sept. 12, 1972 Primary Examiner-Gerald M. Forlenza Assistant Examiner-Richard A. Bertsch [2]] Appl- 288,395 Attorney, Agent, or FirmMelvin A. Crosby [52] US. Cl 104/10, 37/141 R, 173/90,

175/410, 294/56, 404/113 ABSTRACT A plate adapted for being fixed to the end of a tamper 175/410, 4}' 14 81/523f arm and having a groove extending across the leading 4 edge and up the side edges and in which blocks of a hard wear resistant material, such as a cemented hard I 56] References Cited metal carbide, are mounted and secured in place as by b 'n UNITED STATES PATENTS g 2,201,023 5/1940 Brown 104/13 8 Claims, 3 Drawing Figures TAMPER FOOT The present invention relates to a tamper foot and is particularly concerned with a tamper foot so constructed and arranged as to have especially long life.

Tamping machines of the nature with which the present invention is concerned are widely used, especially in connection with railroads for tamping the ballast around railroad ties and squeezing it into a solid formation around and beneath the ties whereby rails mounted on the ties are firmly and solidly supported.

Such ballast material is quite often an abrasive nature, containing sand and ballast rocks and cinders and the like, and the tamping feet mounted on the lower ends of the tamping arms of such devices wear away extremely rapidly, and when partly worn, are deficient for carrying out the tamping and squeezing operations efficiently.

With the foregoing in mind, a primary objective of the present invention is the provision of a tamping foot of the nature referred to which has long life and which operates with a high degree of efficiency throughout the life thereof.

Still another object is the provision of a tamping foot of the nature referred to which is relatively inexpensive but which has a life expectancy many times that of a conventional tamping foot.

These and other objects and advantages of the present invention will become more apparent upon reference to the following detailed description taken in connection with the accompanying drawings in which:

FIG. 1 is a fragmentary schematic view showing a typical tamping operation.

FIG. 2 is a front view looking in at the front of a tamping foot according to the present invention.

FIG. 3 is a fragmentary sectional view drawn at increased scale and indicated by line IIIIII on FIG. 2.

BRIEF SUMMARY OF THE INVENTION According to the present invention, a substantially conventional tamping foot, which is in the form of a rectangular steel plate and adapted for being mounted on the end of a tamping arm, as by welding, or by any other suitable method has a leading edge perpendicular to the tamping arm and side edges parallel thereto, and is grooved along the side edges and the leading edge and blocks of hard wear resistant material, such as a cemented hard metal carbide, are fixedly mounted in the groove, thereby providing resistance to wear in those portions of the tamping foot which deteriorate most rapidly.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings somewhat more in detail, FIG. 1 shows a tie which is surrounded by ballast 12. The tie 10 carries rail plates 14 to which a rail 16 is secured in a conventional manner. The ballast 12 is preferably tamped in place around the tie and squeezed so as to provide a solid foundation for the tie and, to this end, a machine is provided, preferably running on the rails, and having a plurality of tamper arms 18 which are adapted for reciprocation and also for lateral movement to tamp the ballast and on the lower end of each of which is a tamping foot 20.

As will be seen in FIG. 2, each tamping foot 20 is mounted on the lower end of the respective tamper arm 18 and is in the form of a substantially rectangular steel plate. According to the present invention, the side and leading edges of plate 20 are grooved with all of the grooves in the several edges in coplanar axial alignment. The grooves are preferably all of the same cross sectional size and shape.

Thus, the side edges of the plate 20 are provided with grooves 22 and the leading edge is provided with groove 24. Mounted in the several grooves are blocks 26 of a hard wear resistant material, such as a cemented metal carbide, which may be tungsten carbide. The blocks are so dimensioned that a certain number thereof mounted in groove portion 24 will extend from side to side of the plate and project outwardly a short distance from the sides, while in the side edges of the plate, a plurality of blocks are disposed, extending from about the bottom of groove 24 to the opposite edge of the plate. The end blocks in the groove at the leading edge of the plate thus overly the blocks in the grooves in the side edges of the plate in a protective manner.

Brazing material indicated at 28 may be employed for securing the blocks in place in the groove and to each other. This brazing material may include a layer of brazing material 30 between the backs of the outermost end portions of the blocks in groove portion 24 and adjacent ends of the blocks in the groove portions 22.

As will be seen in FIG. 3, brazing material 28 preferably extends about all three sides of each block which is disposed in a respective groove and may, if desired, extend between each adjacent pair of blocks. FIG. 3 will also show that the grooves in the plate are substantially rectangular and that the blocks have a substantially rectangular portion fitting in the groove with sufficient clearance to accommodate the brazing material 28, while a roof shaped portion 32 of the block projects outwardly from the mouth of the groove at least a short predetermined distance.

The arrangement is such that those portions of the tamper foot which are subjected to the greatest degree of abrasion and wear are protected by the hard wear resistant blocks in the grooves so that the life of the tamper foot is greatly prolonged while at the same time the tamper foot tends to maintain the original shape thereof and is thus highly efficient in both tamping and squeezing operations.

The edged tamping foot according to the present invention will even break up rocks that might interfere with proper compaction of the ballast whereby the ballast is more firmly tamped in place.

The tamping foot, when worn to the point that it should be replaced, is cut off the lower end of the tamper support arm 18 and a new plate having the hard edging thereon is fixed in place on the tamper arm, as, for example, by welding.

A typical tamping machine of the type with which the present invention is used may have 16 tamper arms with corresponding tamper feet and, when the tamper feet are formed of steel, a considerable amount of maintenance is required to maintain the tamper in good operation condition because of the high wear rate of the tamper feet. When tamper feet according to the present invention are provided, however, the tamper can remain in operation for a prolonged period of time before it is necessary to renew the tamper feet.

By way of example, the tampers may be driven at up to 3,000 strokes per minute, or more, by a motor having up to a three inch stroke.

Modifications may be made within the scope of the appended claims.

What is claimed is:

l. A flat substantially rectangular plate adapted for mounting on the end of a tamper arm by welding, said plate having a leading edge perpendicular to and facing away from the tamper arm when the plate is mounted on the arm, said plate also having side edges, a groove formed in said leading edge and side edges, and block means of hard wear resistant material fixedly mounted in said groove and extending from side to side and end to end of the said groove, and projecting at least a short distance outwardly from the mouth of said groove.

2. A plate according to claim 1 in which the block means in the portion of the groove in said leading edge extends the full width of said plate and the block means in the portions of said groove in said side edges extend from the bottom of the portion of the groove in said leading edge to the opposite edge of the plate.

3. A plate according to claim 1 in which said groove is rectangular in cross section and said block means has a rectangular portion fitting said groove and a roof shaped portion projecting outwardly from the mouth of said groove.

4. A plate according to claim 1 in which said block means comprise cemented hard metal carbide.

5. A plate according to claim 1 in which said block means are fixed in said groove by brazing.

6. A plate according to claim 1 in which said groove comprises a portion in each said edge, all of said groove portions being in coplanar axial alignment, and the said block means comprising a plurality of blocks in each groove portion.

7. A plate according to claim 6 in which each block is substantially longer than the depth of said groove portions and the end ones of the blocks in the said groove portion in the leading edge of said plate extending laterally over the ends of the blocks in the said groove portions in the side edges of said plate.

8. A plate according to claim 7 in which all of said groove portions have the same cross sectional dimensions.

Claims

1. A flat substantially rectangular plate adapted for mounting on the end of a tamper arm by welding, said plate having a leading edge perpendicular to and facing away from the tamper arm when the plate is mounted on the arm, said plate also having side edges, a groove formed in said leading edge and side edges, and block means of hard wear resistant material fixedly mounted in said groove and extending from side to side and end to end of the saiD groove, and projecting at least a short distance outwardly from the mouth of said groove.