US2689419A - Excavating bucket adapter for replaceable tooth points - Google Patents

Description

P 21, 1954 A. w. DANIELS ETAL ,689,419

EXCAVATING BUCKET ADAPTER FOR REPLACEABLE TOOTH POINTS Filed Jan. 12, 1950 3 Sheets-Sheet l p 21, 1954 A. w. DANIELS ETAL 2,689,419

EXCAVATING BUCKET ADAPTER FOR REPLACEABLE TOOTH POINTS Filed Jan. 12, 1950 3 Sheets-Sheet 2 P 1954 A. w. DANIELS ET AL 2,689,419

EXCAVATING BUCKET ADAPTER FOR REPLACEABLE TOOTH POINTS Filed Jan. 12, 1950 3 Sheets-Sheet 3 IN V EN T 0R6 (Z'Zkar W 2762124625, Masgo/zP/Varlzzg/Z,

Patented Sept. 21, 1954 UNITED STATES PATENT OFFICE EXCAVATING BUCKET ADAPTER FOR REPLACEABLE 'roorn POINTS Arthur W. Daniels, Wilmette,

Murtaugh, Pacific Palisades, Calif., to American Brake Shoe Company,

111., and Joseph P.

assignors New York,

N. Y., a corporation of Delaware Application January 12, 1950, Serial No. 138,238 4 Claims. (01. 37-142) Many types and designs of two-part teeth for use on excavating implements have been developed over the last several years. More recently the trend has been toward a small, low cost, renewable point combining the features of economy with digging efliciency and which will provide a thin cutting edge for easy penetration into the material to be excavated. From an engineering and design standpoint there are two important features which have militated against arriving at the ultimate in perfection where a replaceable point is desired, the first being the inherent weakness of the nose portion of the adapter which necessarily has .to be correspondingly small to accommodate the point, the second being the necessity of using high alloy steels difierentially and specially heat treated to provide the hardness necessary and the stifiness required to avoid bending and deformation.

Accordingly, it is an object of the invention to provide a two-part excavating tooth which will be economical to manufacture although durable and rugged in service, and which will essentially consist of an adapter providing a nose portion of novel design and a replaceable point having a cavity of complementary shape for interfitting relation with the nose portion. In the excavating tooth of the invention the weight of the man ganese steel employed in the parts is kept to a minimum although adequate metal section is provided of the proper contour and shape to take advantage of all the good qualities of the metal and at the same time strengthen the parts against bending or deformation of any kind.

Another object of the invention is to provide a replacable point for an excavating tooth which is reversible on the nose portion of its adapter and wherein the design of said point and nose portion is such as to locate the greater portion of the metal where it is available for wear and to employ the minimum amount of metal for holding purposes.

Another object resides in the provision of a box-like replaceable point for excavating teeth which will have slotted openings in the top and bottom walls thereof to permit interlocking of all four inside corners of the point with overlapping ribs onthe adapter, and wherein an increasingly tight fit of the point on the adapter is obtained as pressure is applied in digging as a result of the tapering fit between the point and the adapter for the full length of the nose portion thereof.

A further object is to provide a composite excavating tooth wherein the adapter or base mem-' ber has a nose portion of novel and. improved design with the metal being so distributed and proportioned that advantage is taken of the total depth and most of the width of the nose portion at the point of greatest stress and leverage whereby to efiectively resist shock loads imposed from all directions.

A further object is to provide a replaceable 'point for an excavating tooth for interfitting relation with the nose portion of an adapter or base member and which is symmetrical about horizontal and vertical center lines, whereby the metal section at the top and bottom is equal for maximum strength of the point and for protection of the nose portion, and wherein the said point is so shaped and located on the nose portion as to automatically sharpen itself as a result of normal digging operations.

Another object of the invention is to provide a composite tooth characterized by the nose portion of the adapter being disposed at an angle in a downward direction with respect to the lon gitudinal center line of the composite tooth,

whereby the practicability of the self-sharpening feature of the replaceable point is improved, and' clearance is maintained at all times on the underside of the tooth to prevent any tendency of the adapter to force the digging point out of the work.

A further object resides in the provision of a replaceable digging point for a composite tooth which will have side edges of greater thickness than the center portion with no fiat surfaces top or bottom, and wherein the outside corners are extended beyond the center portion to compensate for the increased wear on the metal at the outside corners. When said outside corners are worn as a result of initial digging operations to provide a straight cutting edge, the entire cutting edge of the replaceable point will be workhardened under impact to approximately twice its original hardness and the cutting edge will continue to wear sharp for the entire life of the point.

With these and various other objects in view, the invention may consist of certain novel features of construction and operation as will be more fully described and particularly pointed out in the specification, drawings and claims appended hereto.

In the drawings which illustrate an embodiment of the invention, and wherein like reference characters are used to designate like parts- Figure l is an exploded view illustrating in perspective the parts of the present composite tooth comprising the adapter, the replaceable digging point and the locking key;

Figure 2 is a top plan view of the composite tooth with the parts in assembled relation;

Figure 3 is a fragmentary side elevational view of the nose portion of the adapter in assembled relation with the replaceable point as shown in Figure 2;

Figure 4 is a top plan viewof the replaceable point;

Figure 5 is a vertical sectional view of the replaceable point taken longitudinally along line 55 of Figure 4;

Figure 6 is a horizontal .sectional View of the replaceable point taken along line 6-6 of Figure 5;

Figure 7 is a vertical, transverse sectional view along line il of Figure 3 illustrating the interfitting relation of the replaceable point with the nose portion of the adapter;

Figure 8 is a vertical, transverse sectional view taken along line 88 of Figure 3;

Figure 9 is a vertical, transverse sectional view taken along line 9-9 of Figure 3;

Figure 10 is a perspective view showing a modified form of replaceable point characterized by edge portions of increased thickness with the outside corners being extended beyond the center portion; and

Figure 11 is a' transverse sectional view, somewhat enlarged, taken along line ll-H of Figure In the illustrated embodiment of the composite tooth selected for illustrating the present invention the adapter or base portion indicated by numeral 29 is provided with a rearwardly extending tang 2! having a verticalkeyway slot or opening 22 of conventional design and construction whereby the adapter may be detachably mounted on the forward digging lip of excavating buckets, shovels, dippers and the like as will be well understood by those skilledin the art. In accordance with the invention theadapter 20 has a nose portion 23 of special shape andwhichnose portion has interntting relation with the replaceable digging point 2 it being understood that the parts are assembled by relative longitudinal movement, the nose portion 23. fitting into a cavity located in the rear of the replaceable point.

The cavity in said replaceable. point is also of special design, having inwardly protruding lugs and recesses whereby the cavityis complementary in shape to that of the nose portion.

As illustrated in Figures 1 and 3, the nose portion is disposed on the adapter. 20 at a slight angle in a downward directionwithrespect to the longitudinal center line of the composite tooth, the angle being indicated by A in Figure 3. The purpose of this construction is to provide clearance on the underside of the cutting point. This is an important feature of the present design of composite tooth since it results in a greatly improved digging point and at the same time it enhances the practicabilit of the self-sharpening feature of the point. Also the box-like construction of the replaceable point makes it possible to-reverse the position of the sure is applied to the point.

The self-sharpening feature of the cutting point,

together with the clearance which is maintained on the underside of the point eliminates any tendency of the base member or adapter to force the digging tip out of the work digging operations.

Referring more particularly to Figures 1, 2 and 3, the nose portion 23 of the adapter is characterized by a web 26 which extends forwardly of theadapter, being nose-shaped in side elevation and disposed centrally on the vertical center line. The web 26 gradually merges into the top and bottom surfaces El and 29 of the adapter. However, at these points the web widens out to provide overlapping ribs 28 of arcuate shape as regards their periphery and which taper at their base. where they join the adapter to a substantially thin edge at the forward extremity where the ribs merge with the web. Four overlapping. ribs 2.8 are provided, two on each side of the web,

one at the top and one at the bottom. It will.

characterized by laterally projecting lugs 39, having location on eachside of the web 25, and being centrally positioned with respect to the longitudinal center line of the nose portion. At their base 35, where the lugs. join-the adapter, they have considerable width and'it will be observed that the lugs on each side of the web. are.

similar in shape and that they taper. rather abruptly in a. direction forwardly of the nose. portion, In fact, the lugs extend beyond the for-.

ward edge of the nose portion where they join.- to form the tongue 32.. The top and bottom surfaces 33 and 34,.respectively, of each lug 3U slope in a direction inwardly toward the web 26. Each lug therefore has its greatest thickness along its outer extremity. In other. words, the thickness of the lug at its outer extremity is greater than the thickness of the. lug at a comparative point adjacent the web. This constructional ,fea-- ture is perhaps best shown in Figures 7, 8 and'9, and an important advantage'thereof is to improve the interfitting relationwhich the replaceable point has'on the nose portion, which becomes increasingly tight as greater digging pres- The transverse opening 35 provides a keyway for receivingthe key 36. by means of which the'replaceable point is releasably locked in assembled relation on the nose portion of the adapter.

The replaceable point 2 5 is of box-like formation. having top and bottom walls 49 and M and side- walls 42 and 43. Each side Wall is provided' with a central boss portion 44 projecting laterally on the outside surface-thereof and having location so as to extend slightly beyond.

the rear edge 65 of the replaceable point; The

boss-like portion has the effect of thickening each wall at its location and the same is apertured to provide the keyway slot 46. The key.-

way slots in the side walls 42 and 43 are of course ing key 36. The key is slottedlongitudinally,to.

The replaceable point 24 is locked on the nose portion 23 by the taper-= provide the spaced prongs 41 and 48, there being located between the prongs a resilient insert 50 of rubber or other suitable material to apply tension to the prongs when compressed. Prong 41 at its terminal end is notched as at 5| so that the key 36 upon being inserted through the aligned keyways to its full extent will have locking relation with a side wall of the nose portion as a result of the resilient tension exerted by the prongs of the key. The full taper of the key 36 is applied to prong 48 and the transverse keyway I5 is similarly tapered so that it is impossible for the operator to insert the key in an improper manner.

The cavity in the rear wall of the replaceable point is best illustrated by Figures 1, 5 and 6. As previously explained, said cavity has a shape which is complementary to that of the nose portion. The cavity is characterized by longitudinal slots 52 in the top and bottom walls 40 and 4|, the slotted openings receiving the web 26. It will be observed that the entrance to each slotted opening is formed by spaced walls 53, which diverge in a direction toward the rear, each wall being slightly dished to provide an arcuate contour for receiving an overlapping rib 28. This structual feature permits interlocking of all four inside corners of the replaceable point with the overlapping ribs on the adapter. Each side wall within the cavity is recessed as at 55 and 56, each recess extending from the rear wall 45 in a forward direction and terminating in the transverse groove 51. The recesses 55 and '56 taper in a forward direction from the rear Wall 45 toward the cutting edge of the point, each recess terminating in the groove 51, which in effect connects the recesses in a manner similar to the connection of the lugs 30 by tongue 32. In fact, the recesses are designed to receive the lugs 30 and accordingly they have a shape complementary to the lugs with the groove 51 receiving the tongue 32. The top and bottom surfaces 58 and 59 of each recess slope in a direction outwardly toward their side walls, and it will be seen from Figures '1, 8 and 9 that the slope is such as to accommodate the lugs 30 to provide a close and tight fit between the coacting surfaces of the respective parts.

The recess formed in each side wall of the replaceable point in combination with the slottedopening in the top and bottom walls produce lugs that protrude inwardly of the cavity. Said lugs extend on each side wall from the rear wall 45 to adjacent the groove 51. The lugs protruding inwardly from the side wall 42 and which form the recess 55 are indicated by numerals 60 and 61, constituting the top and bottom lugs respectively. In a similar manner the lugs protruding inwardly from the side wall 43 and which form the recess 56 have been indicated by numerals 62 and 63, comprising the top and bottom lugs, respectively. In Figures 8 and 9 it will be seen that each lug for a, part of its length has a substantially flat and horizontal outer surface although the inside surface of each lug slopes in a direction outwardly toward its side wall. The flat surface of each lug is provided for receiving an overlapping rib 28, the coacting surface of each overlapping rib likewise being flat and substantially horizontal for the purpose.

The modified form of replaceable point generally indicated by numeral 64, as shown in Figures 10 and 11, is characterized by side edges 65 of increased thickness which extend from approximately the center of the point forwardly to the cutting edge. Also the outside corners 66 of the cutting edge have been extended beyond the center section 61. It must be remembered that manganese steel work-hardens under impact and also that the outside corners of the cutting edge wear faster than the central section, Thisis due to the breakdown of the metal at the outside edges where there is no support and the condition is particularly true as regards manganese steel due to the ductility and surface softness of the metal. It is well known in actual practice that when the outside corners of the cutting edge wear away during initial stages of operation, a tooth results having a blunt, rounded cutting edge that exists for the entire life of the tooth. The purpose of th modified design of point is to provide more wear metal at the points of greatestwear and additionally to make the outside edges of the point, both top and bottom, as well as the forward cutting edge take the initial wear and impact and work-harden to the extent that when the cutting edge is approxi- 'm=ately straight across the same will be workhardened under impact. From there on the point will have a sharp cutting edge which will be straight for its entire width with no rounded corners and which cutting edge will have about "twice the hardness of a new point and which will continue to wear sharp for the entire life of the same.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawings as various other forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. A tooth for excavating implements or the like including an adapter consisting of the conventional base portion and a nose portion of special shape and design for receiving a replaceable point, said nose portion including a forwardly projecting nose-shaped web disposed'vertically on the center line of the base portion, an integral lug on each side of the web protruding laterally of the web and tapering in a forward direction from the base portion to beyond. the web where the lugs join to form a tongue, said tongue being disposed substantially normal to the web, each lug being disposed centrally of the web and being symmetrical with respect to the longitudinal center line of the nose portion, the top and bottom surfaces of the lugs sloping laterally inward in a direction toward the web whereby said lugs have their greatest vertical dimensions along the outer surface thereof, an integral rib on each side of the web above and below the lugs adapted to have overlapping relation with a portion. of said replaceable point when the parts are assembled, said overlapping ribs each having location at the junction of the web with the base portion, each rib projecting laterally to one side of the web and forwardly of the base portion, and said replaceable point having a rear cavity of complementary shape for interfitting with the nose portion, said cavity including a forward recess for receiving the tongue of the nose portion.

2. A tooth for excavating implements and the like as defined by claim 1, wherein said overlapping ribs have a periphery substantially arcuate in contour, and wherein each said rib has its greatest thickness adjacent its connection with the base portion and tapers in a forward direc- 7 tion:to;.-a:relatively:thim edge at its extreme, for- Ward end where'=:the rib-merges with the web.

r13. A-.tooth1for excavatingdmplements and the like .as=:defined by claim I 1, wherein said overlapping ribsihaveza periphery substantially arcuate .:in;contour, 'wherein each rib has its greatest thickness adjaeentits :connection with the base portiontandtapers imaforward direction to a relatively thin edge .at its--extreme forward ,end "where :the ,rib {merges with a the web, and additionally vincluding a :transverse keyway for receiving a ekey whereby to lock the replaceable .pointin -assembledrrelationeon the nose portion, said :transversekeyway including .a passage gexytending-flthrough.theilugsgand.the web: on the longitudinal centerlineofthenose portion.

.1sl.-.-A.;to.oth for excavating implements and the likelincludingganradapter consisting of the conventionallbase portion and ,awnose portion, of spe- .point, said nose portion including a, forwardly projecting nose-shapedwebdisposed vertically on the reenter line of thebaseportion, an integral lug on each-side of 'the web protruding laterally of the shape inside elevation simulating, a triangle with the base of the same being located adjacent the cial shape-and designv forreceiving a replaceable 2O -baSe;portionlanditheItohgueformingtheapex 1th,e

top andi-bottomsurfaces of the lugs slopingulaterally inwardina. direction toward the web whereby the lugs have their-greatest Vertical dimensions along their outer surface; an integral. riboneach side of the web above and below the'lug on that side and adapted tohave overlapping relation with a portion of said replaceable point When the parts are assembled, said overlapping "ribs each occupying the angular space formed by the junction of the web with the base portion, andsaid ribs eachtapering .in -a forward direction whereby to provide a relatively thin edge at the extreme forward end of the rib where the rib mer es-with the web.

References Cited 4. in t thev file of this patent UNITED STATES v'PATlilN'IS Number Name 1,Date

821,215 Cantlebery et'al. May,22,'1'90.6 1,202,806 Clark, (Jr. 2 Oct. 31,1916 1,205,969 Brinton Nov. 28,1916 1,330,143 Seal Feb. 10,1920 1,548,374- Mullally 'Aug. 4, 1925 1,845,677 'Mekeel Feb. 16, 1932 2,256,488 Murtaugh Sept.23, 194.1 2,279,960 Terry Apr.'14, 1942 "2,435,847 Robertson Feb. 10, 1948

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