CA1037995A - Excavating tooth assembly - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

The specification relates to a socket member, of an excavating tooth assembly, adapted to be secured to an excavating bucket and receive a tooth member.

Description

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BACICCROUND AND ~SUt~l/\RY Ol; INVE!lTION ~

; This invention relates to an excavating tooth assembly and, more particularly, to an assembly including a socket member and a tooth me~ber. The tooth membcr - ~ may be either a single piece tooth or a two-part tooth but in any event provides a forward digging edge for ground engagement. Such excavating teeth are mounted on a variety of excavators, viz., drag line buckets, -shovel dippers, front end loaders, trenchers, etc. -~
- 10 Normally the teeth are connected to the excavating machine ~;
in one of two basic ways: the rear portion of the tooth (generally designated the "shank") can either (1) extend . ~. . .
-- - into the mounting lip or other surface or (2) can extend - - around it -- as in the case of a bifurcated shank. The - actual connection between the shank and the lip can be achieved through pins, bolts or welding. The primary requirement of a tooth mounting is strength, i.e., resistance to failure when encountering harsh shock loads. On the other hand, an almost as important 20 requirement is simplicity of dissassembly -- excavatin~
; people being realistic to realize that even the strongest ;~
tooth ~ay fail and require replacement. Thus, a dilemma ~ ~
has been presented over the years ~o the excavating people -- `
providing connections which are strong and rugged, yet connections that can be readily disassembled so as to require minimum down-tLme of very expensive e~uipment.
This dilemma has been approached in a number of ., . ways -- most generally by making "multi-part" teeth. For example, starting with the lip of an excavator, the Iip may ` ' - 2 - .
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~37~95 - be equipped with a recess into which a holder is welded.
The holder, in curn, may receive an adapter, i.e., a connective member which has a sh~n~ at one and received on or in the holder and a nose at the forward end for the receipt of a replaceable tip or point. The point may be pinned to ehe adapter nose and the adapter shank pinned or welded to the holder. Xowever, there usually was welding or extremely strong connections in the portion of the tooth im~ediately adjacent the excavating 10 machine. Tnis was all well and good when the machinery was employed well within its designed rating. However, difficulties have arisen when the excavating people recognized thae larger, stronger teeth should be used on a given machine. I~en this occurred, there had to be a virtual rebuilding of the lip to accommodate a larger size tooth.

Thus, the object of this invention is to provide a replaceable adapter which fits into a socket -- the socket either being cast, forged or welded in or on a lip to 20 provide an adapter holding device that will last the life - of the lip -- while providing rapid change capability on the machine in the field to suit a different type of digging applicaeion or to replace the adapter nose due to a failure developed by excessive service loads.
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We achieve this advantageous versatility by a unique arrangement of bearing surfaces between the socket member and the tooth member. The tooth member is equipped with a massive section intermediate its length, i.e., between the tapered forward end or nose and the rearwardly ! ' -. 30 extending, relatively elongated shank. The bottom wali ~ J of this massive section provides a bearing surface which is : ':

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,, , , ,,,, " . ,. - .. : ' ' ' 79~5 - ~ substantially inclined relative to the path of movement of the tooth member when it is being installed in the socket member. Cooperating with this external bearing surface is an internal bearing surface on the socket bottom wall which i5 complementarily arranged. These surfaces take the brunt of downward shock loads on the tooth assembly. The bottom wall of the socket member is relatively thicker in this area - to provide a pad-like part which also is advantageously ~-utilized for the securement of the socket to the beveled portion of an excavator lip.
Spaced considerably rearwardly of the first mentioned pair of cooperating bearing surfaces, i.e., those on the massive section of the socket member and the pad-like part of the socket member, are top and bottom bearing surfaces on the external walls of;the shank and the internal walls of the socket member. These surfaces coact with the first mentioned pair of surfaces, i.e., those, positioned more forwardly, to resist beam loading. Additionally, we provide forwardly extending ears on the side walls of the socket member which are received within complementarily shaped recesses in the side walls of the massive section and which cooperate with the rear bearing surfaces in resisting upward beam shock loadings.
Other details of construction, advantages of operation, and objectives of the invention may be seenin the details of the ensuing specification.
The assignee's copending Canadian Application Serial No. 233,746 filed August 19~ 1975, of which this is a division .

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1~375~95 is directed to the tooth member as well as the combination of the tooth member and socket member. The present invention is directed to the socket member.
hus, the present invention may be described as a socket member adapted to be mounted on an excavator lip for receiving an excavating tooth member comprising a unitary generally rectangular, hollow element having top, bottom, rear and side walls to provide a socket for the receipt of a shank of a tooth member when the shank is moved along a generally linear path into the socket, the top and bottom walls being rearwardly convergent and the side walls also being rearwardly convergent, the rear wall being apertured to receive a securing -bolt for maintaining the tooth member in assembled relation with the socket member, the top and bottom walls each having internal bearing surfaces for transmitting beam loads on the tooth member from the shank to the socket member, a portion of the bottom wall internal bearing surface being positioned adjacent the forward end of the socket member and being more steeply inclined to the path than the portion of the bottom wall internal bearing surface adjacent the rear wall, the tooth member having a massive section in the portion thereof immediately rearward of the tapered forward end to transmit a substantial portion of a downward beam load to the forward portion of the bottom wall bearing surface, the bottom wall being relatively thicker in the forward portion than the remainder thereof to receive the downward beam load, the side walls being equipped with forwardly projecting ears spaced above the bottom wall forward portion to receive a portion o~ an upward beam load applied to the tooth member.

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1~937~5 DETAILED DESCRIPTION:
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The invention is described in conjunction with the accompanying drawing, in which -~
FIG. 1 is a fragmentary perspective view of the ground ~ engaging portion of a front end loader and equipped with tooth 6 assemblies according to the instant invention;

- 4b -~L~3~5 IG. 2 is a fragmentary pers~ective view of a ~Ltcher wheel ~ui~p~d with tooth ~ssemblics according to - the instant invention;
FIG. 3 is a perspective view of the invencive tooth member and soclccc member :in t'ne proccss of being assembledl i.e., only partially assembled;

FIC. 4 is another perspective view of the elements of FIG. 3 in about the same stage of assembly but showing the par~s generally from below;

lO FIG. 5 is a side elevational view of the inventive l :
- tooth assembly, partially in section, and corresponding generally (but with parts assembled) of the showing in FIG. 3;

FIG; 6 is a top plan view, partially in section, o~
the assembly of FIG. 5; -FIG. 7 is a sectional view as would be seen along ;1 the sight line 7-7 of FIG. 5, . ;

FIG. 8 is another sectional veiw such as would be seen along the sight line 8-8 of FIG. 5; ~ :

. 20 FIG. 9 is a fragmentary top plan view of a ditcher ~: .
equipped with tooth holders according to the instant invention;

FIG. 10 is a fragmentary front elevational view of -the ditcher seen in FIG. 9;
FIG. 11 is a view taken along the line 11-ll of FIG.
10; and - -. FIG. 12 is a view taken along the line 12-12 of FIG. 9.
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1~37~
- ' Refcrring now ~o the drawing and, in particular, to FIG. 1, the numeral 10 designatcs generally an excavating machine whicll, in che specific illustration given, is a front end loader bucket. The buclcet has the usual side walls 11 which flànlc a botto~ wall 12. The bottom wall 12 terminaccs in a lip 13 which is beveled, i.e., having a tapered top surface to develop betcer digging efficiency. ~ plurality of tooth assemblies generally designated 14 project forwardly from the bottom wall 12, that is, in advance of the beveled lip 13.

- 10 In the specific illustration given, each tooth assembly 14 includes a socket member generally designated 15 which is weldably secured to the bucket 10 and which slidingly receives a tooth member generally designated 16.
- As can be appreciated from a brie~ consideration of FIG. 5, the tooth member 16 is secured within the socket member 15 by a rear nut and bolt assembly generally designated 17 tsee the extreme right hand end). This is not a tension fit, it only being necessary to prevent loss of assembly through gravity or other negative thrust.
In the version illustrated in FIGS. 1, 5 and 6, the tooth member 16 does not itself provide the digging edge but receives a tip or point 18 which is fastened to the tooth member 16 by a pin lock (designated only in FIG. 6). As indicated previously, it is possible in some operations to ;
combine the two parts 18 and 16 into a single piece tooth although, generally speaking, separate points have been preferred because their usa~e minimizes the amount of throw-away metal.
Ie will be ppreciaced that ~he princip-l wear occurs on the a-ex :
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3L~37~9~
20 of the polnt 18 and by suitably proportioning th~ point (as illuscrated most ~raphically in ~IG. 5) it is possible to wear the poillt 18 almost down to its sockct 21, thcreby reducing thc amount of throw-aw,3y metal to 50~O or less of the original point. Ilowever, inasmuch as the instant invention is concerne~ primarily with structures positioned more rear-wardly, we utilize the expression "tooth member" to comprehend both single piece and two-piece teeth, viz., teeth made up of ?oints and adapters 10 Referring now to FIGS. 3 and 4, the tooth member 16 . .
is seen to be partially received within the socket member .
15. The path of movement (for inserting a portion of the ...
tooth member 16 into the socket member 15) is designated P in ~: ~
FIG. 3. The tooth member 16 has a tapered nose 22 at its ~-.
forward end, a massive section 23 intermediate its length, ~-.
and a relàtively elongated shank 24 at its rear end.
The socket member 15, like the tooth member 16, is a unitary cast body of alloy sceel and is generally rectangular having a hollow interior to provide a socket or ;~
20 the receipt of the shank 24. As such, the socket member 15 has side walls as at 25 and 26 -- the latter being best seen ~.
in FIG. 3. The side walls 25 and 26 are connected by a bottom :
wall 27 and a top wall 28 (see FIG. 3). Also provided is a rear wall 29 which is not designated in FIGS. 3 and 4 but which can be seen clearly in FIG 6. The rear wall 29 is apertured as at 29a to receive the bolt shank of the assembly 17 while the shank 24 of the tooth member 16 is recessed as at 24a to receive the head of the bolt. ~
- Referring now to FIG. 5, the bottom wall 27 of ~he ~:
30 socket mcmber 15 is seen to have a relatively thicker portion 30 at the forward end thereof -- particularly in contras~t eo ~ ;

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`" 1037995 the rearw~rd portion 31 of the bo~tom wall 27. As can be appreciatcd from a comparison of FICS. 4 and 5, the bottom wall portions 30 and 31 are separated by an openin~ 32 which extends from ~he intcrior of one side wall to the other and thereby develops rail-like bottom surfaces on the side walls 25 and 26 -- see the element designated 33 in FIG. 8 -- relative to the side wall 25. This assists in achieving excellent weld - securement of ~he socket member 15 to the bucket 10, more particularly to the rock steel cutting edge thereof.

lo - Thc relatively ~hicker forward portion 30 can be considered an essentially pad-like part and serves as a primary bearing surface for a downward shock load such ~.
as is designated by the vector FD ~~ at the extreme left in ::
FIG. 5. It will be appreciated that the pad-like part 30 . is associated with massive section 23 of the tooth member, thereby achieving advantageous transmission of shock loads and this, irrespective of the size of the tooth, viz., the size of the nose 22 and hence the size of the point 18. For the purpose of receiving stress, the pad-like part 30 has an upper 20 bearing surface 34.
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Cooperating with the bearing surface 34 is a confront-ing complementarily contoured bearing surface 35 (designated ~.
only in FIG. 4) on the bottom wall of the massive section 23 of the tooth member 16. We have found it advantageous to ~ :
contour both of the surfaces 34 and 35 as surfaces of revolution generated about a vertical axis V at the rear of the assembly - (designated only in FIG. 5). Further details and advantages of the surfaces of revolution 34 and 35 in resistin~ loads . (particularly those having late~al components) can be appreciated 30 from a consideration of co-owned U. S. Patent No. 2,91g,506.
i In the specific illustration given, we contour the surface 35 - so that the same is inwardly concave. By inwardly concave, we -- 8 -- .

~C~37995 mean that thc sides of the surface of a male type mcmber eY.tend further out than the central portion -- as can be readily appreciated by a consideration o~ the top bearing surface 36 of the shank 24 as seen in FIG. 7.
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Cooperaeing with the surface 36 is a surface 37 - on the interior of the top wall 28 and whieh is complementarily contoured. These two surfaces, 36 and 37, are also surfaces of revolution generated about the vertical axis V. As seen in FIG. 5, the surface 36 (and hence the surEace 37) is seen to 10 extend a substantial distance along the length o~ the assembly, i.e., approximately one-half the length of the shank 24 insofar ,1 as the surface 36 is concerned and in the same proportion relative to the length of the socket member 15 insofar as the surface 37 is concerned.

Also cooperating in absorbing beam loading are ~
the bottom wall surfaces 38 on the socket member 15 and 39 on the tooth member 16 (see the lower portion of FIG. 7).
Again, these are surfaces of revolution generated about the I
vertical axis of revolution V. j~ -From a consideration of ~IG. 5, it will be seen that the inclination of the fo~ard bearing surface 34 (and hence the surface 35 also) is much steeper relative to the path of ' i`
movement P (for installing the shank 24 in the socket member 15) than the inclination of the surface 39 (and also 38) therewith.
In the illustration given, the surfaces 38 and 39 form an ~ -angle of about 10 degrees relative to the path of movement P.
In contrast, the surfaces 34 and 35 are at an inclination of ~ about 35 degrees.

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L037~g95 A11 o~ the sur~acus 3l~-39 are ~,enera~e~ ~rom the salne point of ~encration C (see ~hc ri~llt hand cnd o~ ~IC. 5). Tlle upper surEaccs 36 and 37 oE about 15 de~recs with the path of movement P. l`he paired surfaces 36 and 37 relacive to the top walls and 38 and 39 on the bottom walls are eEfective co resist both upward and do~nward shoclc loads, i.e., FU as ., well as FD (see the ~ft hand end of FIC. 5). -Further assisting in resistin~ upward shock loads is a pair of confronting bearing surfaces llO ancl 41 positioned 10 centrally Or the massive section 23, i.e., I,encrally centrally of FIG. 5. ~or the purpsoe of providing the surEaces 40, we extend the side walls 25 and 26 forwardly to provide ears 42. The bottom walls of the ears 42 provide the surfaces 40 l~-and the ears are received in complementarily concoured recesses 43 in the massive portion 23 of the cooth member 16. t Throu~h the arrangement of the four sets of bearing surfaces as just described, we transmit the other deleterious shock loads most effectively to the excavating lip or other support surface (for example, the ditcher wheel 110 o~ FIG. 2), and 20 substantially irrespective of the size of the tooth, viz., width and length of the point 18. Further, the surfaces 40 and 41 are particularly effective in resisting back slap, i.e., the use of the teeth 14 as tampers or compressive tools. -The upper and lower bearing surfaces 36-37 and -38-39, respectively, serve to transmit both upward and down-ward applied loads, being part of convergently related top and bottom walls on the shank 24 and the socket member 15. ~e also have the co-rresponding side walls of the shank 24 and th~
socket member 15 (more particularly the interior side wall : ~
30 surfaces thereof~ rearwardly convergent. Clearance is provided : . , : . . - . . . - :

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iO3791 95 ~
bc~ween thc si~c walls of tl~e shank and thc socl<et membcr 15 to pcrmi~ la~cral shifting o~ ehe tooth member relacive to the socket membcr and WittlOUt substantial loss of bearin~ area.
This also is a capered type clearance and affords side loading scabili~ation. Thus, as side loadinK develops (as at 44 in FIG. 6) thc shank 24 t~ill come into full contact with the interior sid~ wall o~ the holderl particularly ac the fronc as the shank rotates about the axis of revolution V. For example, the ~orce 44 is resisted as at 45 in FIG. 6.

We also find it advantageous to terminate the cop wall 28 of the socket member 15 in general vertical alignment with the rear of the pad-like part 30 -- as at 46 in FIG. 5.
This enables the top wall 47 of ~he massive portion 23 o~ the tooth membeL 16 to extend rearwardly into general alignmcnt ,0 with the pad 30 and overlie the ears 42.
Further advantageous transmission of shock loads is achieved through a further set o~ bearing surfaces as at 48 relacive to che rear portion of the pad 3~ and 49 on the bottom wall of the shanlc 24. The inclination of the 20 surfaces h8 and 49 relative to the path of movcment P is less than that of the surfaces 38 and 39. Ilowever, we also find it advantageous to construct the surfaces 48 and 49 . -as surfaces of revolution generated about the vertical axis ~
V.
By providing the socket and tooth member arrangement -described, it is now possible for the user o~ excavating equipment to convert to a lar~er size tooth, nose and poin~ :
~or heavy duty applications and even larger sized noses and - points for extreme service applications; ~ll of the noses are i 30 mounted on t'ne same size shank to fit interchangeably in the integral welded socket. This provides the user a ~eature ~or quickly cl~anging broken adapters or othcr toQth parts rather ~.'.

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~L0379~S
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than s~cll~in~, ~hc cxcra cin1e and money ~or shuctinp, the m.lclli~e down and wel~inr~ on a new adapter. This is particularly crucial ;' in front cnd loadcr buckets or li~he and standard duty hoe and drag lines whicll have weld on adapters wich an inte~ral nosè.
Throu~h che use of the invention, the user is provided the feature o~ considerably reducecl ~achine ~own time, improved machine availability for dut~ service as well as reducin~ the overall maintenance cost in terms of material and labor.
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Also, ic will be appreciated that thc socket member 10 15 can be cast integrally with che excavatin~ too~h -- in contrast to the embodiment of ~IGS. 1-8 where the lower wall 27 is welded to the top of the cu~ting edge 12 (see particularly FIG. 5). The teeth 114 on the ditcher 110 of FIG. 2 are supported by integrally cast holders and this is seen in greater - detail in FIGS. 9-12.
, , ~ portion of the ditcher 110 is seen in ~IGS. 9 and 10.
There the socket members 115 are cast as integral components of the cuttin~ edge 112. More precisely, the holder members 115 extend forward of the tapered edge 113 (see particuiarly ~IG. 9).
~s can be readily appreciaeed from a consideration of FIG. 11, the base or ed~e portion 112 of the ditcher is integrally connected to the socket member 115 midway of the hei~ht thereof -- this in contrast to the showin~ in FIG. 5 wherein the holder member 15 is positioned above the cutting edge 12. More particularly, the cutting edge 112 is essentially bracket~
by the ears 142 (see FIG. 11) and extends at a slight an~le to the path of movement P, i.e., about 5 upward.
Irrespective of the type of mountin~, the socket member 15 or 115, as ehe case may be, is substantially protected 30 by the tooth member 16 from wear. Thus, the holder can be made of ferritic low alloy steel for superior welding characteristics while the tooth member-can be made in a minimum hardness ran~e of 388-440 Brinell to yield hi~h seren~th and wear resistance. Thus, with the s~ructurc of the instant invention, it is possible noe _ i 7 .

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~ 9 ~37~5 only to achievc versatili.ey in tooth assemblies but also achicve an advantageous marriage oE the mosc cfEective alloys.

Furthcr, in operation, there is an advantageous wedging action developed between the ears 42 and the forward bearing surface or ramp 34. As wear occurs between the surEaces 34 and 35 (compare FIG~S. 5 and 4, respectively), the adapter or tooth member 16 moves back and.up-along the forward ramp surface 34 of the socket member or holder 15 until there is contact be~ween the ears 42 and the confronting bearing .
surface 41, i.e., contact between the confronting surfaces 40 and 41. Once this con~act is es~ablished, the overall assembly is further stabilized, becoming stronger and more resistant to wear.
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Claims (8)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A socket member adapted to be mounted on an excavator lip for receiving an excavating tooth member comprising a unitary generally rectangular, hollow element having top, bottom, rear and side walls to provide a socket for the receipt of a shank of a tooth member when said shank is moved along a generally linear path into said socket, said top and bottom walls being rearwardly convergent and said side walls also being rearwardly convergent, said rear wall being apertured to receive a securing bolt for maintaining said tooth member in assembled relation with said socket member, said top and bottom walls each having internal bearing surfaces for transmitting beam loads on said tooth member from said shank to said socket member, a portion of said bottom wall internal bearing surface being positioned adjacent the forward end of said socket member and being more steeply inclined to said path than the portion of said bottom wall internal bearing surface adjacent said rear wall, said tooth member having a massive section in the portion thereof immediately rearward of said tapered forward end to trans-mit a substantial portion of a downward beam load to said forward portion of said bottom wall bearing surface, said bottom wall being relatively thicker in said forward portion than the remainder thereof to receive said downward beam load, said side walls being equipped with forwardly projecting ears spaced above said bottom wall forward portion to receive a portion of an upward beam load applied to said tooth member.

2. The structure of claim 1 in which said bottom wall has a third internal bearing surface portion positioned immediately rearward of said forward portion on said pad-like part and disposed at less of an inclination to said path than the portion of said bottom wall bearing surface adjacent said rear wall.

3. The structure of claim 1 in which said socket member has a substantially flat external surface on said bottom wall rearward of said relatively thicker portion whereby said socket is adapted to be weldably secured to an excavator lip.

4. The structure of claim 3 in which said bottom wall is equipped with an opening extending therethrough between the internal surfaces of said side walls and extending longitudinally from said relatively thicker portion to said bearing surface portion adjacent said rear wall to provide rail-like bottom portions on said side walls for weldable securement to an excavator lip.

5. The structure of claim 1 in which the internal bearing surface of said top wall extends further forward than said bottom wall bearing surface portion adjacent said rear wall and approximately one-half the length of said socket member.

6. The structure of claim 1 in which each of said bearing surfaces is a surface of revolution generated about a generally vertical axis adjacent to but spaced rearwardly of said rear wall.

7. The structure of claim 6 in which each of said bearing surfaces in said socket member is inwardly convex.

8. The structure of claim 1 in which said top wall has its forward end generally in alignment with the rear end of said relatively thicker portion.