US2852874A - Digger point and locking mechanism therefor - Google Patents

Description

Sept. 23, 1958 GRUBB 2,852,874.-

DIGGER POINT AND LOCKING MECHANISM THEREFOR Filed June 15, 1954 IN V EN TOR.

ATTO]? E Y5.

United rates Patent BIGGER POINT AND LGCKING MECHANISlVI THEREFOR Norval Townley Grnbb, Portland, Oreg., assignor, by mesne assignments, to Electric Steel Foundry Company, a corporation of Gregon Application June 15, 1954, Serial No. 436,756 11 Claims. (Cl. 37142) This invention relates to a tooth structure and mount ing means therefor useful in digging and earth handling equipment and more particularly to a digger or box point and locking mechanism therefor adapted for use, for ex ample, in trenchers and like equipment.

As is well known, trenchers and similar earth moving equipment are generally provided with teeth or points so that the teeth can be removed for reconditioning and replacement as they become worn or broken, etc. from use. Numerous tooth structures have been provided and many are now in use that afford removability of the tooth from the base or nose. These known tooth structures provide a relatively stable mounting for the tooth upon the base therefor. Such structures, however, do not provide complete solutions to the problems that confront tooth designs for equipment of this character.

It is accordingly, an object of this invention to provide a tooth structure and locking mechanism therefor, useful in trenchers and the like, that will overcome a number of the shortcomings in prior art structures of this character, some of the advantages being the elimination of unnecessary dead weight in the locking mechanism, the provision of a locking mechanism that permits the tooth or point to be mounted upon the base quickly and easily and with a minimum of effort and the provision of a locking mechanism that positively locks and accurately seats the point upon the base.

Another object is to provide a tooth having a central chamber that receives therein the nose or base member, pin means being arranged in a cooperative relationship with the nose and point to position and lock the same together. Still another object is to provide a point adapted for use in trenchers having a base adapted to receive the tooth thereon, the base having a transverse passage therethrough carrying a compressible pin and the point providing recesses alignable with the pin in one position of the point upon the base.

Yet another object is in the provision of a digger tooth having a central chamber equipped with aligned recesses therein, a base receivable wihin the chamber and having a bore therethrough enlarged centrally and alignable with the recesses and a resilient pin carried within the bore, compressible therethrough and with end portions that snap into the recesses to lock the base and tooth together. Additional objects and advantages will appear as the specification proceeds.

An embodiment in the invention is illustrated in the accompanying drawing, in which Figure 1 is a side view in elevation of a tooth in position upon its base; Fig. 2 is a vertical sectional view taken on the line 2-2 of Fig. 1; Fig. 3 is a broken trans verse sectional view taken on the line 33 of Fig. 1; Fig. 4 is a broken sectional view similar to that of Fig. 3, but showing the tooth released from the locking mechanism; Fig. 5 is a broken sectional view similar to that of Figs. 3 and 4, but showing the tooth in an intermediate position during the seating thereof upon its base; and

Fig. 6 is an enlarged cross-sectional view of a modified form of the pin presented in Fig. 4.

In the drawing the tooth or point is designated with the numeral 10 and the base or nose member is designated with the numeral 11. The point or tooth 10 as shown best in Figs. 1 and 2, has side walls 12 and 13, a top wall 14 and a bottom wall 15. All of the walls are rigidly secured together and may be formed integrally in a casting operation. The side walls 12 and 13 are spaced apart and define therebetween a cavity or chamber 16. The top Wall 14 is relatively fiat, while the bottom wall 15 is inclined upwardly and forwardly toward the tip 17 of the tooth. Thus, the top and bottom walls of the chamber 16 converge toward the tip 17 of the tooth. The top wall 14 is elongated and pro vides a shroud or flange 19 that extends rearwardly and over the top of the base member 11.

The spaced- apart side walls 12 and 13 of the tooth are equipped with aligned recesses or notches 20 and 21 and beveled channels 22 and 23, also .formed in the walls 12 and 13 of the tooth, communicate at their inner ends with the recesses 20 and 21, respectively, and from there diverge outwardly and rearwardly to the rear edges of the walls 12 and 13.

The base 11 has a forward end portion 24 that is adapted to be received within the cavity or chamber 16. The forward portion 24 has parallel side walls which are spaced slightly from the walls 12 and 13 of the tooth when the tooth is set upon the base, while the top wall 25 and bottom wall 26 of the nose provide a matching taper that is complementary with and corresponds to the taper provided between the walls 14 and 15 of the tooth. Thus, as is clear from Fig. 1, the tooth 10 is adapted to set firmly upon the forward end portion 24 of the base. i

The base 11 and more especially the forward end portion 24 thereof, is provided with a bore or passage 27 extending transversely therethrough and which is alignable with the recesses 20 and 21 of the tooth in one position of the tooth upon the base. The bore 27 intermediate the ends thereof and at substantially the midpoint, is enlarged to provide the central enlargement 28.

To lock the tooth in position upon the base, a resilient plug or pin 29 is provided which is adapted to be received within and carried within the bore 27 with its end portions 30 and 31 extending outwardly from the bore. The pin 29 is both resilient and compressible so that it can be compressed longitudinally to move the end portions 30 and 31 thereof susbtantially into the bore 27. The pin, however, must have the property of expanding freely when compressive forces are released from the ends thereof so that the end portions of the pin can expand into the recesses 20 and 21, as shown most clearly in Figs. 2 and 3. It has been found that molded rubber provides a suitable material for the pin 31..

Preferably, the end portions 30 and 31 of the pin have bonded thereto metal sheaths that enclose the ends of the pin, or if desired, the end portions may be metal and the metal ends bonded to the rubber central portion 32 of the pin.

In operation of the structure the tooth 10 is provided, as has been described, with a chamber 16 having aligned recesses 20 and 21 in spaced-apart wall portions thereof. The base member 11 is also provided, as indicated, with a bore 27 therethrough. The pin 29 is inserted into the bore 27 with the end portions 30 and 31 extending outwardly therefrom. The tooth 10 is then moved toward the base 11 and the forward end portion 24 of the base is received within the chamber 16 of the tooth, as shown in Fig. 4. i i

As the tooth 10 is pushed further rearwardly toward seating relation upon the base 11, the end portions 30 3 4 and 31 of the resilient pin engage the inclined channel operative to facilitate axial compression of said pin during membersv 22- and 23 and the pin 29-iscompressed, as the mountingof'said tooth upon said base. shown in Fig. 5. Free compression of the pin is afforded 5. The structure of claim 3 in which said pin is rubber because of the central enlargement 28 of the bore 27. and the end portions thereof are enclosed by metal This: enlargement permits the central portion 32 of" the 5 sheaths. pin to expand diametrically while'the length' thereof is 6. The structure of claim 3 in which said tooth is decreased throughthe axial compressive forces applied equipped along the top wall thereof with a rearwardly exto. theendsvof the pin. The-minirnum point of -comtending flange that provides a shroud for protection 'of pression is'illustrated in Fig. 5. said base.

When the tooth is-urged rearwardly andonto the 7. In a digger tooth and locking mechanism structure basell and 'past' the point ofmaximum compression of substantiaily as described, a tooth having an. enlarged rear the pin 29,- as shown in Fig. 5, the pinexpands and the end portion providing a central chamber therein, at least end-portions-30'and 31 thereof snap into' the recesses 20' one of the walls defining said chamber being inclined to and 21 0f the'tooth, as shown in Figs; 2' and 3. In this provide: a tapering chamber, two of the walls' of said position-the tooth isproperly seated upon the base-11 and chamber which are in facing relation being provided with the-: base and' tooth arefirmly'lockedtogether by th pin aligned recesses therein, the wall portions adjacent said 293 recesses being equipped with channels which diverge latsubstantiallynoplay is permitted-between the tooth orally and rearwardly from the recesses and toward the 10 andibase- 11 for the end portions of the passage 27 rear end portion of said chamber, a base member having are. not enlarged and substantially engage the walls of 2. tapered forward end receivable Within said chamber and h i 29; yet the enlarged central portion 28 of the being provided'with a bore therethrough alignable with passage 27 permits free expansion of the pin diametricalsaid recesses, a compressible, resilient pin carried in said ly'when the axial length thereof is reduced. This onebore and having end portions normally extending 011tpiece locking mechanism permits ready assembly of the wardly therefrom, Said bore having an enlarged central tooth and base and it is only necessary to push the tooth Portion P Cross-Sectional eXpahsioh of said P rearwardly and onto the base 11 and in such operation during aXial compression thereof, the end Portions of Said thepin is first compressed and then snaps into locking p being adaptedto Tide Within Said Channels during the position to securely anchor the tooth upon thebase when mounting 0f Said moth p Said base whereby the P th t th i ly d thereon, Th shroud 19, is compressed axially between inclined Walls of said chanhi h extends. along h top 11 25 of h base, h i 30 nels and thereafter expands into said'recesses to lockthe by protects thearea of thebase which is normally subtooth basetogethel; Said P having relatively high ject'to-the greatest amount of 'wear; It also adds to the Shear stl'ellgthrigidit f. the tooth mounting upon the base-by Provid. 8. The structure of claim 7 in which said tooth along, i a greater b i area, the top wall thereof is equipped with a rearwardly extend Whil i th fo i ifi ti an embodiment f ing flange that extends over said base when said tooth is the invention has been set out in considerable detail, for mounted thereon purposes of illustration, it will be apparent to those skilled' The structurecif'clalm 8 111 Whlch sa1d P 15 molded in the-art that numerous changes-may be'made in 'these rubber and hasmetalhc end portionsdetails without departingfromthe principles and the a Structure of Character descflbed; a tooth" irit f-th invention; 40 and a base'member, one having a chamber therein d'eclaim: fined inpart by-facing walls'having spaced-apartportions, 1. In" a structure of the characterdescribed, a tooth Said h Portions each y a reCeSS h h i a a i therein andavbasemember having v the other providing at least a portion thereof receivable tion receivable within the cavity, the walls of said cavity Wlthm sa1d chamber and havlhg a bore fherfathrough E having aligned recesses therein and said portionreceiv- 5 b YQ l i a l ongltudlhany p able\withintthecavity havingia, bore therethmugh align; sible, res lient pin receivable'wlthin sa1d bore and having able with said" recesses; and an elongated resilient pin P portlonsiextfmdmg gutwardly h fi i the ehdipori receivablewithin. said bore and having end portions .ex tions thereof beingreceivable Within sard'recesstistolockf tending outwardly therefrom and being receivablewitb sald'base and tooth together sa1d P belng an ilntegral in aidi h Said portion is Withinsaid cavity 0 member having substantial resistance to'transverse shear;

said pin being longitudinally Compressible to ff move- Said bore'being enlarged centrally to accommodate expana ment of said Portion into Said cavity and longitudinally sion-of said pin therein during axial compression thereofl resilient), lock Said tooth and base together. 11. In a structure of the character described, a tooth 2. The structure ofclaim 1, in which said pin is an imd'a base m one hailing chamber therein defined) integral member having metallic end portions whereby Part by facmg Walls havmg shaced'apart portlolls said said pin possesses substantial resistance to transverse F each hilvmg a recess therem the Shean other providing at least a portlon thereof receivable with- 3. In a tooth structure and locking mechanism therein sa1d chamber and having a bore. theirethmugh alignable for, a tooth having a central chamber therein defined in between t i lwshudmany Compressib1. partby Spaced apart side Walls, said side walls, having resil ent pin receivable within said bore and having end aligned-recesses therein, a base member equipped with portions extending outwardlytherefrom, the end portions forward end portion receivable within'said chamber and, thereof recewable P F F Q lock said being provided with a transversely extending bore there base tooth togeiher sflald :pm'bemg an mtegral through, alignable between said recesses. Said bore being her having substantial resistance to transverse shear, the enlarged throughout the centralportion'thereof and anin- W i f l f adlacenfi salfi recesses tegral, elongated resilient pinncarried within said bore and mg Provlded Wlth mclmed channels 'dlvergmg outwardly having end portions extending outwardly therefrom, said and l' f f sa1d l F Q Y PT pimbeingiaxiauy compressible to Permit movement tpress sa1d pmiaxially'when said portion 18 moved into aid" forwardgendportion of said base into said'chamber and chamber" thereafterexpansible so that the end portions thereof snap References Cited file Of this Patem intorsaid. recesses to lock:said. tooth and base together; UNITED STATES PATENTS saidintegral pin having substantial strength intransverse 1,003,663 1 Skelton Sept." 19, 1911 directions to withstand shearing forces thereon; 1,434,128 Leopold an Oct; 31, 1922" 4. The structurerof claim 3 whereinvsaid sideiwalls ada 2,546,457 Launder et-al. a Mar. 27, 1951 jacent said. recesses are provided with divergingchannels 2,568,075 Launder Sept; 18; 1951 i

Images