US2891333A - Digging teeth for excavating, dippers, etc. - Google Patents

Description

June 23, 1959 L. w. VAN BUSKIRK 2,

-DIGGING TEETH FOR EXCAVATING, DIPPERS, ETC

Filed Sept. 10, 1954 2 Sheets-Sheet 1 1 FIG. 2 4 5? 1V i l 7 k INVENTOR L. w.- v n Bus/ark fiizj h ATTORNEY United States Patent {Ofice 2,891,333 Patented June 23, 1959 DIGGING TEETH FOR EXCAVATING, DIPPERS, ETC.

7 Lesher W. Van Buskirk, Easton, Pa.

Application September 10, 1954, Serial No. 455,199

8 Claims. ((137-142) My invention relates to improvements in digging teeth of the replaceable digging point type such as are carried by the digging lip of power shovel dippers, drag buckets etc. Digging teeth as characterized comprise a base section which is secured to the digging lip of the dipper or bucket, and its forward end provides a seat to which is detachably secured the digging point, or tip, which latter requiresmore or less frequent replacement, depending upon the character of material being dug.

' In excavating operations involving rock or coal the digging points of these teeth are subjected to tremendous stresses along lines originating from points forwardly of their base sections and from both vertical and lateral directions with respect to the longitudinal axis of the tooth. This means that if the interfitted or seat-providing portions of the tooth base and tip do not provide for adequate stress transfer from the tip to the base from all directions forwardly of the latter there will be overloading of base-carried portions of the tip and the ultimate breaking loose of the latter. A broken 01f digging tooth tipmay become a dangerous piece of metal because if it subsequently gets into expensive rock or coal crushing machinery it can cause great damage thereto, necessitating a shut-down of operations for costly repairs.

Therefore manufacturers of excavating equipment and others have devoted much time and effort to achieve. satisfactory tooth base-provided digging tip support against the stresses mentioned, but without any considerable degree of success for various reasons. In some instances, the opposed stress transferring surfaces of the tip and base have been improperly located or are of insuflicient area, and in other cases the formation of such'surfaces has made it difiicult and expensive if not actually impossible to grind or machine them sufliciently to bring about adequate stress-transferring engagement.

Then too, those of the prior art teeth which may be somewhat better than others as regards stress transfer from tip to base are difiicult to assemble and separate especially in large sizes due to an over tight or jam fit of the parts in certain areas even though proper stress transfer is lacking in other areas.

It is therefore the primary object of my present invention. to overcome the objections aforenoted and to provide a digging tooth of the class indicated, which is of simple and durable construction providing adequate tipto-base stress transfer, is relatively inexpensive to manufacture in that it requires but a minimum of easily accomplished machining of opposed stress-sustaining portions, and wherein the digging tip can be readily applied to or removed from the tooth 'base even as to large sized teeth.

,A--further and more specific object of my present development is to provide a tooth base and its separable digging tip which have certain cooperating stress-transmitting portions, the outer ends of which are brought into engagement prior to the interengagemen-t of other stress-absorbing portions of the tip and base as the latter are assembled, and which ends are relieved in planes normal to one another in a manner to admit of an initial play when assembling and which play will facilitate both assembly and disassembly of the parts; and wherein the relieved terminal part of one of said tip and base portiotns subsequently functions as a cam in conjunction with another part of the companion portion to tend to promote stress-sustaining engagement of other cooperating portions of said tip and base when the latter are fully assembled Additionally, the invention contemplates the provision of a novel excavating tooth which is characterized by a base-provided seating nose for a removable V-form digging tip having vertically divergent rearwardly extend ing wings, and wherein opposed parallel rearwardly extending lugs which are wedge shaped in cross-section are carried by said wings and received in correspondingly shaped nose-provided seats, there being a removable and novelly positioned load-sustaining retainer element for maintaining the tip and base assembled.

Also, having reference to the base nose-provided seats for the wedge-form tip lugs, mentioned in the preceding paragraph, it is an aim of the invention to provide novel means whereby the slanted side Walls of said seats can be easily and quickly machined to make adequate stressreceiving engagement with the related sides of the wedgeform lugs of the digging tip.

Other objects and advantages of the invention will be developed hereinafter, or will be obvious to those versed in the art, reference being bad to the accompanying drawings which illustrate a now preferred example of my inventive concept. It is to be understood, however, that the disclosures herein are to be taken as illustrative rather than limitative, as the invention is susceptible of other mechanical expressions within the spirit and scope of the subject matter claimed hereinafter.

In the drawings, wherein the same reference characters have been used to designate the same parts wherever they appear throughout the several views- .Figure 1 is a side elevational view partly broken and partly in longitudinal section of a tooth embodying my invention;

Figure 2 is a fragmentary top plan view thereof;

Figure 3 is a rear perspective view of the digging tip removed and showing the rearwardly extending wedgeforrn lugs and intermediate boss;

Figure 4 is a fragmentary perspective showing the tipseating forward portion of the base section of the tooth;

Figure 5 is a view partly broken and showing the tip and adjacent base portion in central longitudinal section along line 5-5 of Fig. 2;

Figure 6 is a fragmentary perspective illustrating the commencement of assembly of the digging tip and base' section, the dotted lines indicating the permissable initial play between the parts which facilitates the assembly operation; and

Figure 7 is a cross-sectional view of the assembled tooth taken on the line 7-7 of Fig. 2.

Referring to the drawings by reference characters,

. numeral 10 indicates the base section of the tooth, the

' rounded end of nose 11 make contiguous engagementwith' the rounded inner end of the tip-provided seating recess 14 that is bounded top and bottom by the vertically diverging rearwardly extending wings 13 of tip 12. As indicated in Figure 2, these tip-provided wings 13 are coextensive in width with the tip 12 and the base 10, and Figure 1 shows how the opposed inner surfaces of the respective wings 13 incline outwardly as at 13a, adjacent to the rear ends thereof. Thus wing end surfaces 13a make contiguous outwardly camming engagement with the correspondingly curved top and bottom surfaces 11a of the base 10 at the rear end of the base-provided nose 11. The advantage of the coacting camming portions 11a, 13a will be explained hereinafter.

Referring now to Figures 3 and 5, it will be noted that the digging tip 12 provides, as an integral part thereof and between wings-13, the two vertically spaced and parallel rearwardly extending lugs 15 whose rear ends project beyond the rear ends of said wings 13 as best shown in Figure 3. These lugs 15 are wedge-form in cross-section and are of substantial width as shown in Figure 3, they being located adjacent the inner surfaces of the respective wings 13 at points approximately midway between the sides of the latter. It is particularly important to note that the wedge-form of the lugs 15 is achieved by substantially plane side surfaces 15a which slant inwardly in the direction of the adjacent wing 13. It is also important to note that said lugs 15 embody what might be termed wing-carried base portions 16 (see Fig. which are coextensive in width with the outer, or wing-adjacent, lug surfaces 150 and terminate short of the wing and lug ends in nose portion-sustained shoulders 16a (see Figs. 3 and 5) to which further reference will be made later on herein.

In further carrying out the invention, 1 provide the digging tip 12 with the integral boss 17 which is located at the curved inner end of the nose-receiving recess 14 approximately midway between the wing sides. This boss 17 is in bearing engagement, top and bottom, with the opposed surfaces of lugs 15 adjacent the inner ends of the latter (see Figures 3 and 5) so as to cooperate with the lug bases 16 in sustaining the wings 13, and for another purpose which will be presently understood.

Coming now to the digging tip seating and sustaining formations of the nose portion 11 of the tooth base 10, and turning to Figures 4, 5 and 6, it will be observed that the top and bottom surfaces of the nose 11 each provide a rearwardly extending and groove-form lugreceiving seat 18. These seats 18 are open at their forward ends and are defined by the undercut side walls 19 which substantially conform to the slant of the lug sides 15a and flare laterally outward (1%) at the entry ends of the sockets to facilitate insertion of lugs 15. This outward wall flare 19a also facilitates grinding of walls 19 and especially the inner ends thereof within the lug end receiving socket 18a to which reference will presently be made.

The rear end of each lug-receiving seat 18 terminates in 9. lug end-receiving and sustaining socket 18a. The inner or bottom defining wall of each socket 18a curves outwardly as at 18b in the directon of the adjacent top or bottom surfaces of said base section (see Figure 5) to conform to the similar curve of the opposed and contacting end surfaces b of the lugs. Thus the lug and socket surfaces 15b, 18b, cooperate with the aforementioned wing and nose surfaces 13a, 11a in tending, cam fashion, to draw the wedging sides 15a of the lugs 15 into tight engagement with the undercut walls 19 of the related lug-receiving seats 18 of nose 11.

Also, as indicated, the rounded outer end of the nose 11 has the cut-out-provided seat 20 which snugly receives the boss 17 of tip recess 14. This interengagement of boss 17 with nose seat 20 cooperates with the lugs 15 and their seats 18, 18a to prevent relative lateral movement of the base 10 and tip 12 in service after the parts have been assembled.

.In the illustrated embodiment of the invention, I employ the fiat sided heavy duty wedge 23 as the means for securing the tip 12 and base 10 in tight rigid assembly. The wedge 23 is projected through aligned and correspondingly shaped wing and nose holes 22, 21, respectively, as indicated in Figures 5 and 7. It is important to note that the wing holes 22 are located at the site of the respective lugs 15 and lug bases 16 inwardly of the sides and rear shouldered end 16a of the latter. This means that there is a maximum of digging tip-provided bearing surface and stock opposed to both of the broad and flat front and rear surfaces of wedge 23. The result is that the heavy duty wedge will absorb and counteract any digging service-induced stresses tending to rock the digging tip 12 vertically relatively of the base-provided nose 11, and thus tend to bend or break the socketed lug ends at the site of the shouldered outer ends of sockets 18a.

Referring again to the lugs 15 and to the groove-form nose-provided seats 18 therefor, one of the problems left unsolved by the prior art, but which is solved by my invention is to so form the interengaging stress-sustaining parts of a tooth base and digging tip as to readily admit of necessary grinding or machining of same to obtain a proper fit and avoid looseness. This I achieve by provision of the broad, unbroken and preferably plane wedging sides 15a of the lugs 15; and also by the drilled longitudinal bores 24 (see Figures 4 and 7) which open laterally to the wedge-receiving seats 18 at the junctions of side walls 19, 19a with the bottom walls thereof. These bores 24 preferably extend the full length of the respective seats 18 and related lug end-receiving sockets 18a, and as will be appreciated they enable a grinding tool to properly act upon the full width of the groove bottoms and adjacent wedging walls 19, 19a. Bores 24 also receive the side and bottom-defined edges of lugs 15 to avoid binding in case the width of the seat bottom is less than lug bottom width.

Figures 5 and 6 show that the nose 11 provides the transversely coextensive shoulders 25 between the lug receiving sockets 18a and the curved wing end-engaging surfaces 11a. When the wedge 23 is driven into place as in Figure 5 the lug base-provided shoulders 16a are drawn against these nose provided shoulders 25; and surfaces 11a, 13a as well as surfaces 15b, 18b are jammed into engagement, as the nose 11 is jammed into the seating recess 14 of tip 12. As previously mentioned, the jamming together of surfaces 11a, 13a and 15b, 18b tends to produce forces in outward vertical directions as seen in Figure 5 which accentuate the wedging fit of lugs 15 in the seats 18, 18a.

The outward flaring (19a) of the side walls 19 at the entry ends of the lug seats 18 and the bevelled ends 15b of the lugs is also important in that it facilitates assembly of the tip 12 and base 10 by admitting of limited initial rocking of the former in planes normal to each other, as indicated by dotted lines and arrows in Fig. 6. The formations noted also facilitate final separation of the tip and base as will be appreciated.

Having thus described my invention what I claim is:

1. A dipper tooth or the like providing a base section and a detachable digging tip carried thereby, the base section having a forwardly extending tip-seating nose providing top and bottom surfaces tapering inwardly to-- ward its forward end, the tip having rearwardly extending top and bottom wings providing a substantially longitudinally coextensive open sided recess therebetween re ceiving and mounting the tip on said nose, a pair of vertically spaced and parallel wing-carried lugs of wedgeform cross-section providing broad seat-bottom-engaging surfaces, said lugs extending from adjacent the forward end of said tip-provided recess and projecting beyond the rear ends of said wings, said lugs being located adacent different ones of said wings and each of said lugs providing longitudinally coextensive and substantially plane uniformly spaced sides tapering transversely of said lugs in the direction of the adacent wing, each of said lugs providing thickened wing-carried portions substantially coextensive in width with the wing-adjacent outer surfaces thereof and terminating in shoulders short of the rear ends of said wings, the top and bottom surfaces of said nose portion having rearwardly extending wedge-form seats having bottom walls and undercut uniformly spaced side walls, said seats being open at their forward ends and receiving the respective lugs, the rear end of each seat terminating in a socket receiving the rear end of one of said lugs, each of s'aidsockets having 'a shoulder-providing wall portion overlying the outer surface of the received lug portion, the wall-provided shoulders of said sockets bearing against said lug base-providing shoulders when the tip and base are assembled, the fully engaged lugs and seats drawing said wings against adjacent nose surfaces while preventing relative lateral movement of said base and tip, a rearwardly extending boss carried by said tip at the forward end only of said nose-receiving recess and bearing top and bottom against opposed surfaces of said lugs inwardly of the sides of the latter, the forward end of said nose having a seating recess snugly receiving said tip boss to cooperate with the interengaged lugs and seats to prevent relative lateral movement of the base and tip, said nose and tip wings having transverse and alignable securing element-receiving holes, the wing holes extending through the thickened portions of said lugs, and a removable fastener element extending through said aligned holes when the tip and base are assembled, said removable fastener element comprising a heavy duty wedge having broad and flat front and rear surfaces corresponding in width to and contiguously engaging the forward nose hole wall and the rear walls of said wing holes throughout the depth of the latter.

2. A dipper tooth or the like providing a base section and a detachable digging tip carried thereby, the base section having a forwardly extending tip-seating nose providing top and bottom surfaces tapering inwardly to ward its forward end, the tip having rearwardly extending top and bottom wings providing a substantially longitudinally coextensive open sided recess therebetween receiving and mounting the tip on said nose, a pair of vertically spaced and parallel wing-carried lugs of wedgeform cross-section providing broad seat-bottom-engaging surfaces, said lugs extending from adjacent the forward end of said tip-provided recess and projecting beyond the rear ends of said wings, said lugs being located adjacent different ones of said wings and each of said lugs providing longitudinally coextensive and substantially plane uniformly spaced sides tapering transversely of said lugs in the direction of the adjacent wing, each of said lugs providing thickened wing-carried portions substantially coextensive in width with the wing-adjacent outer surfaces thereof, the top and bottom surfaces of said nose portion having rearwardly extending wedgeform seats having bottom and undercut uniformly spaced side walls, said seats being open at their forward ends and receiving the respective lugs, the full engaged lugs and seats drawing said wings against adjacent nose surfaces while preventing relative lateral movement of said base and tip, a rearwardly extending boss carried by said tip at the forward end only of said nose-receiving recess and bearing top and bottom against opposed surfaces of said lugs inwardly of the sides of the latter, the forward end of said nose having a seating recess snugly receiving said tip boss to cooperate with the interengaged lugs and seats to prevent relative lateral movement of the base and tip, said nose and tip wings having transverse and alignable securing element-receiving holes, the wing holes extending through the thickened portions of said lugs, and a removable fastener element extending through said aligned holes when the tip and base are assembled, said removable fastener element comprising a heavy duty wedge having broad and flat front and rear surfaces corresponding in gaging the forward nose hole wall and the rear walls of said wing holes throughout the depth of the latter.

3. The combination set forth in claim 2, and the bottom wall surface of each lug seat at its inner end and the rear end of theseat bottom-engaging surface of each lug being inclined-outwardly toward the adjacent tip wing, and wherein the inner surfaces of'the wing ends and the underlying contiguous nose surfaces are also outwardly inclined, whereby two forces are provided adjacent each of the top and bottom of said nose tending to draw the lug 'sides in to tight engagement with the walls of the nose-provided seat.

4. The combination set forth in claim 2 and wherein the nose-provided lug seat walls flare outwardly from a point substantially inwardly of the entry end of said seats whereby to admit of initial lateral rocking of the tip when the latter is being assembled on the tooth base and to facilitate milling of the inner ends of the lug seat walls.

5. The combination set forth in claim 2 and wherein the nose-provided lug seat walls flare outwardly from a point substantially inwardly of the entry end of said seats and wherein the entire width of the rear ends of the lugs are reduced in thickness, whereby to admit of initial rocking of the tip both up and down and laterally to facilitate assembly of same on the nose.

6. The combination set forth in claim 2 and each of said nose-provided lug seats having at each side a laterally extending and longitudinally coextensive recess into which the bottom wall and related side wall open, whereby to admit the bottom and side wall-defined edges of said lugs to assure of proper seat and lug side wall engagement in case the seat bottom wall is slightly less than lug bottom width.

7. A dipper tooth or the like comprising a base section and a detachable V-form digging tip providing top and bottom wings, the base section having a nose providing separate top and bottom forwardly opening seats providing a flat bottom wall and plane undercut side walls, said side walls flaring outwardly at and adjacent the seat entries and being uniformly spaced inwardly thereof, the tip having a substantially longitudinally coextensive and open sided nose-receiving recess between said wings, a pair of rearwardly extending and vertically spaced lugs projecting beyond said tip recess and carried by the respective wings, said lugs providing uniformly spaced and plane undercut side surfaces and a flat bottom and being engageable in said respective nose seats, the outward side wall flare at the seat entries admitting of initial lateral play of the lugs when the tip and base are being assembled and also facilitating milling of the seat walls, and each seat at least inwardly of its laterally flared entry having at each side a laterally extending and longitudinally coextensive recess into which the bottom wall and related side wall open, whereby to admit the adjacent bottom and side surface-defined edges of said lugs and avoid binding of same in the seats in case the seat bottoms are underwidth as compared to the lugs.

8. A dipper tooth or the like comprising a base section and a detachable V-form digging tip providing top and bottom wings, the base section having a nose providing separate top and bottom forwardly opening seats providing a flat bottom wall and uniformly spaced and plane undercut side walls which flare outwardly at the seat entries and for a substantial distance inwardly therefrom, the tip having a substantially longitudinally coextensive and open sided nose-receiving recess between said wings, a pair of rearwardly extending and vertically spaced lugs projecting beyond said tip recess and carried by the respective wings, said lugs providing uniformly spaced and plane undercut, side surfaces and a flat bottom and being engageable in said respective nose seats, the free ends of said lugs being of reduced thickness throughout their entire width so as to admit of initial play of the width to and contiguously enlugs in their seats in the depthwise direction of the latter to facilitate assembly of the digging tip and base section, the outward side wall-provided seat entry flare further admitting of lateral lug play during such assembly, and each seat at least inwardly of its laterally flared outer portion having at each side a laterally extending and longitudinally coextensive recess into which the bottom wall and related side Wall open, whereby to admit the adjacent bottom and side surface-defined edges of said lugs and avoid binding of same in the seats in case the 0 seat bottoms are underwidth as compared to the lugs.

References Cited in the file of this patent UNITED STATES PATENTS 1,016,181 Snyder Jan. 30, 1912 15 8 Pemberton June 27, 1916 Nichols Oct. 9, 1917 Nichols et 31. Nov. 13, 1917 McMonegal July 12, 1921 Taylor June 26, 1928 McKee Jan. 6, 1931 Mekeel Aug. 30, 1932 Graham Mar. 3, 1936 Fellmeth Dec. 15, 1936 Bruton Feb. 4, 1941 Seal July 29, 1941 You'nie Ian. 11, 1944 FOREIGN PATENTS Great Britain Jan. 11, 1917

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