US2608111A

US2608111A - Repointer bar and method of repointing teeth

Info

Publication number: US2608111A
Application number: US755110A
Authority: US
Inventors: Ratkowski Thomas Anthony
Original assignee: American Brake Shoe Co
Current assignee: American Brake Shoe Co
Priority date: 1947-06-17
Filing date: 1947-06-17
Publication date: 1952-08-26
Anticipated expiration: 1969-08-26

Description

. A m W INVE 27 HMO/106% I daj 444l- 3 width of that apex, the grooves gradually decreasing in depth as they extend toward the surfaces and 22.

As shown in Fig. 2, when it is desired to renovate the worn excavating implement tooth 28, having the rounded forward end 30, a suitable section of repointer bar having a width equal to the width of the tooth is cut from the repointer bar. The point so cut from the bar is then properly aligned with the worn tooth 28 so that it forms an extension thereof adjacent the end 30 and is welded into place, as shown in Fig. 2, so that the welding material 34 fills in the V- shaped areas formed by the flat surfaces l4 and I6 and the end 30 of the tooth 28.

It is common practice when securing a new point to worn teeth to hard-surface the new point after it is welded to the tooth. The most generally used method of hard-surfacing it is to apply the surfacing material along the entire cutting edge of the new point, which would correspond to the apex H of the point shown in Fig. 2, and also to apply several beads or strips of surfacing material on each side of the renovated tooth at right angles to the cutting edge and extending from the cutting edge to the base of the tooth. As shown in Fig. 3, a new point out from a repointer bar of the type shown in Fig. 1 lends itself readily to the hard-surfacing process. The grooves I8 are particularly adapted to receive hard-surfacing material, such as the material 36. If the new points are cut from the repointer bar along the longitudinal center line of the bases of the grooves l8, the lateral edges of the new, point will have the L- shaped indentations 38 therein. These indentations 38 may also be filled with the hard-surfacing material 36, as shown in Fig. 3, so that the lateral edges are made more. resistant to wear.

It has been found that the resistance to wear by the hard-surfacing in the grooves l8 does not start to function until the overall. thickness of the point has been reduced, and a sharper cutting edge is therefore maintained for the remaining life of the point because of the presence of the hard-surfacing. In addition, the groove construction of the repointer bar provides agreater surface area in the points out therefrom so that heat generated by the process of hard-facing is more readily dissipated than in the case of the repointer bars in common use today. This dissipation of heat results in a more satisfactory job of hard-surfacing so that the wear resistance of the new point is substantially improved.

An alternative form of the grooves which may be provided in the repointer bar is shown-in Fig. 4.

In this type of bar the grooves 40 on the two surfaces forming the sides of the wedge are not.ver-

tically aligned but are laterally displaced on one of the sides so that the grooves 40 and the ribs 42 are vertically aligned. This type of construction might be found desirable in cases where a greater; resistance to bending is sought; As shown in Fig. 4, the hard-surfacing material 44 can be applied; in the grooves 40 in the same fashion as previ-- ously described in connection with the form of repointer bar shown in Fig.3;

The form of repointer bar shown Fig; 5,; which bar is designated generallylby the numeral; 46, has substantially the same cross-sectional shape as the repointer bar shown'in Fig.1?" Thegrooves 48 are provided in thesides 50 and 52 'of the repointer bar and are marginally defined in a lateral direction by the relatively narrow ribs 54. However, these grooves extend from points adjacent the angularly disposed

flat surfaces

56 and 58 which form the base of the wedge and may be distinguished from the grooves I8 in the form of repointer bar shown in Fig. 1 in that they do not terminate at the apex 60 of the repointer bar but extend continuously around that apex from one side of the bar to the other, as shown in Fig. 6.

As shown in Fig. 7, hard-surfacing material 62 may be applied to the points out from the type of bar shown in Fig. 5 in the grooves 48. Here again the hard-surfacing material may also be applied to the lateral edges of the new points if the points are cut from the repointed bar along the bases of the grooves 48.

Although it is not shown in the drawing, obviously it would be possible to provide the repointer of the general form shown in Fig. l with ribs and grooves of the same general shape as those shown in Fig. '7. No attempt has been made to illustrate all the various configurations which the ribs and grooves might be given since the mere existence of ribs and grooves, regardless of their particular shape, is what is contemplated as being within the scope of this invention.

Although it has been stated above that the hard-surfacing material may be applied to the new points out from a repointer bar embodying this invention, applicant does not wish to limit his invention to a repointer bar in which this hard-surfacing material has been incorporated, since its use may or may not be desirable depending upon the type of work in which the implement F carrying the tooth is employed. Furthermore, if

it is the primary desire of the user to obtain the benefits or" the serrated or fluted construction of the points out from such a repointer bar, it may not be desirable to employ the hard-surfacing -material at all. The operation of this fluted construction in teeth for excavating implements and the like has been carefully set out in the applicants previously issued patent referred to above. The determination as to the desirability of employing hard-surfacing material as described will rest with the individual employing the repointer bar. It might even be desirable in some instances to place the hard-surfacing material on the ribs in the new points rather than in the grooves.

In any event, applicant has provided a novel repointer bar for renovating teeth for excavating implements and thelike, from which new points for worn teeth may be cut and which points have a construction which particularly adapts them to retain their sharpness and to greatly resist bend ing when in service.

The drawing and the above description are not 'intended to represent the only possible form of this invention, inregard to details of construction. Changesin form and in the proportion of parts,

from in the "form of .repointers for renovating teeth for use in. excavating implements and thej like' comprising a bar having. Substantially wedge-shaped transverseflcross section; the sideof said barforming the base of, said-wedge-shaped. cross section being divided along the'longiudinal axisof said side into two angularly'disposed faces,. and the sides of -.said'. bar forming the wedge.

surfaces thereof having a plurality of converging transversely disposed grooves therein, said grooves extending along one of said wedge surfaces, across the apex of said bar and thence along the other of said wedge surfaces.

2. The process of repointing teeth for excavating implements and the like which comprises cutting a relatively narrow section of substantially the same width as one of said teeth from an elongated metallic bar of stock of substantially wedgeshaped transverse cross-section having a plurality of transverse grooves in at least one of the surfaces thereof, said section being cut so that at least each upper lateral edge of said section is substantially coincident with the longitudinal axis 5 of one of said grooves, welding said section to said tooth so as to form a new point for said tooth, and subsequently depositing a hard-surfacing material in said grooves.

THOMAS ANTHONY RATKOWSKI.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number UNITED STATES PATENTS Name Date Rowe Apr. 23, 1872 Edmunds Dec. 8, 1931 Ratkowski June 24, 1941 Rea Nov. 30, 1943 Daniels et a1. Feb. 13, 1945' Dickenson Oct. 30, 1945 Daniels et al Apr. 29, 1947 FOREIGN PATENTS Country Date Great Britain Jan. 2, 1935