WO1990013710A1

WO1990013710A1 - Tool for tamping ballast and the like

Info

Publication number: WO1990013710A1
Application number: PCT/US1990/002370
Authority: WO
Inventors: James E. Crowell
Original assignee: Crowell James E
Priority date: 1989-05-12
Filing date: 1990-05-03
Publication date: 1990-11-15
Also published as: AU5679290A

Abstract

Tool (10) for tamping or crushing ballast or other stony material comprising a shank (11) attachable at its upper end (13) to a machine for operating the tool, said shank having a lower end (14) with a vertical front face (27) and a rear face (19) which slopes downwardly toward the front face and forms a tip (20) with the front face (27), such tool also comprising a paddle (12) having a front face (30) and a rear face (29) and welded at its rear face (29) to the front face of the shank, such paddle having a groove at its lower end in which are secured a plurality of wear bits of abrasion resistant material; the rear face of the shank and the exposed faces of the paddle being coated with abrasion resistant material such as tungsten carbide applied by the plasma transferred arc process.

Description

TOOL FOR TAMPING BALLAST AND THE LIKE

FIELD OF THE INVENTION

This invention relates to a tamping tool to be used f tamping ballast on railway lines and for other simil material.

BACKGROUND OF THE INVENTION

in Kruse U.S. Patent No. 3,581,664 a tool is described whi is of the type with which this invention is concerned. comprises a shank, a number of which are attached to a fra on flanged wheels which travel along the rails of a railro and to each of which is attached a paddle which is made hardened material such as tool steel.

Such tools have been provided at their lower edges with harder material such as tungsten carbide which is extreme abrasion resistant. However, the steel paddle in which t carbide bits are mounted undergoes abrasion and undercutti such that the carbide bits fall out.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide tamping tool of the general character described above and U.S. Patent No. 3,581,664 which overcomes or diminish these and other difficulties. BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments of the invention are illustrated by of example in the accompanying drawings, in which:

Figure 1 is a view in front elevation of a tool includin shank, a paddle and wear bits;

Figure 2 is a side elevation of the same tool shown o larger scale and with the upper part of the shank omitted

Figure 3 is a rear view of the same tool;

Figure 4 is an end view along the line 4 - 4 of Figure 2;

Figures 5, 6, 7 and 8 are perspective views of wear bits the invention which illustrate different shapes;

Figure 9A is a rear view of the paddle detached from shank, showing a right hand orientation of the paddle; an

Figures 9B and 9C are views similar to Figure 9A but sho a centered paddle and a left hand paddle, respectively.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Referring now to Figures 1, 2, and 3 and also to Figure the tool in its entirety is designated by the refer numeral 10 and it comprises a shank 11 and a paddle 12 f to the lower end of the shank. The upper end of the s 11 is tapped at 13 to receive a screw or bolt by whic may be fastened to a tamping machine such as that descr in U.S. Patent No. 3,581,664.

The lower end 14 of the shank onto which the paddle 12 fixed has outwardly flaring, downwardly sloping shoulder 16 and 17 and has a downwardly tapering portion presenting a slanting face 19 terminating in a tip 20. lower end 14 also has a flange portion 25 project outwardly and forming a horizontal abutment surface 26 wh together with a vertical abutment surface 27 forms a rec into which the paddle 12 fits.

The paddle 12 has an upper horizontal surface 28 abutt surface 26 and a vertical surface 29 abutting surface 2 The lower end of the paddle is shaped to form an inverted shaped groove 31 into which hardened tips 32 are inser and are held. The paddle 12 also has a front face 30.

An important feature of the invention is an abras resistant rear wear surface 33 applied to the slanting f 19 of the shank. Preferably this wear surface is formed spraying granules of tungsten carbide onto the surface 19 for example by a technique known as plasma transferred which is described by Gillert A. Saltzman in an arti entitled "Carbides Add Muscle to PTA Antiwear Coatings" the February, 1986 issue of Metal Progress, at pages 25 30, which also describes a tungsten carbide alloy suitab for purposes of the present invention. However, a prefor plate 33 of suitably hard, abrasion resistant material s as tungsten carbide or hardened steel may be used which be affixed to the surface 19 by welding, brazing or epo resin or other suitable means. A tungsten carbide pla applied by PTA is preferred.

The paddle 12 has a core 35 which accounts for the bulk its thickness and on each face it has a highly abrasi resistant coating 36 of tungsten carbide which preferably applied by the plasma transferred arc (PT process referred to above, one on each face except for welding pad 37 on the inside of the paddle described bel with reference to Figures 9A, 9B and 9C. The core 35 m be any plain carbon steel such as AISI 1010 through AI 1040 or an alloy steel such as AISI 8620 or AISI 4180 some other similar steel alloy. In constructing the tamping tool 10, the paddle 12 may coated on both sides at 36 except for a welding pad 37 it is then welded as shown at 38 to the part 14 of the s 11. Preferably, however, the paddle is first welded place and the coating 36 is then applied.

An additional important benefit of the rear wear surfac is that it overlaps the weld 38 at the lower end of shank and in this way it protects the weld from b abraded and ensures that the paddle will remain attache the shank. This feature is shown in Figures 1, 2 and 4.

The bit 32 is preferably made in separate segments as s in Figures 1, 3 and 4 which are shaped and of a size to into the groove 31 and are fixed in the groove by suitable means such brazing, welding or press fitting o means of an epoxy resin.

Referring now to Figures 5 through 8, bits 32 of diffe shapes are shown. The bits are shown inverted with a 40, sloping sides 41, flat segments 42, side portions 43 bottom portion 44. The angle between the side portion is preferably 90° as in Figures 5 and 6 or 120° as Figures 7 and 8. Such angles provide a good distributio mechanical loads and good surfaces for bonding in the gr 31.

The bits 32 are preferably made of a very hard and abrasion resistant material such as tungsten car particles bonded together by a cobalt or steel binder.

As will be seen in Figure 2 the coatings 36 extend from top of paddle 12 to the flat segments 42 of the wear bit

By these means the problem of undercutting of the paddl which the bits are attached is alleviated. Also the surface 33, especially where it is applied by pl transferred arc as tungsten carbide as described abov resists wear and loosening of the bits of the paddle on t shank.

In effect all primary wear surfaces, that is the leadi edge, front face and rear face of the paddle, are eith protected by carbide or by a carbide coating or el protected by some other surface like the rear of the sha lower end which itself will be protected by carbide or carbide coating. In effect, the paddle will be encased either carbide or a carbide coating making it almo impervious to wear on all primary wear surfaces.

It will therefore be apparent that a novel and advantageo tamping tool is provided.

Claims

I CLAIM:

1. A tool for impacting particulate material comprising:

(a) a shank having an upper end attachable to machine for moving the shank up and down, said shank al having a lower end

(b) said lower end having a substantially vertic front face and a flange overlying the front face to for with the face, a recess or cut-out

(c) said lower end also having a rear face slopi downwardly and toward the front face and forming with t front face a tip

(d) a paddle separate from but secured to the fro face of the lower end of the shank, said paddle having upper end abutting said flange, a front face, a rear f abutting the front face of the lower end of the shank secured thereto and two side faces joining the front rear faces of- the paddle, said paddle being of st construction and

(e) a wear resistant tip secured to the lower end the paddle

(f) the front face and any exposed portion of the r face of the paddle being coated with a wear resist coating applied by the transfer plasma arc process.

2. The tool of Claim 1 wherein the sloping rear face of lower end of the shank is covered with a wear resist coating applied by the transfer plasma arc process.

3. The tool of either of Claims 1 and 2 wherein the w resistant coatings are tungsten carbide coatings.