US 3012346 A
Description (OCR text may contain errors)
Dec. 12, 1961 P. v. LARsl-:N
EXCAVATING Toom AND BASE SUPPORT THEREFOR 2 Sheets-Sheet l Filed Sept. 15, 1958 Dec. 12, 1961 P. v. LARSEN 3,012,346
EXOAVATING TOOTH ANO BASE SUPPORT THEREFOR Filed sept. 15, 195s 2 sheets-sheet 2 VEA/TUR.' JQ/z Wdw,
United States Patent O 3,012,346 EXCAVATKNG TOOTH AND BASE SUPPORT THEREFOR Paul V. Larsen, Portland, Oreg., assignor to Esco Corporation, a corporation of Oregon Filed Sept. 15, 1958, Ser. No. 7 60,996 16 Claims. (Cl. 37-142) This invention relates to an excavating tooth and base support therefor, and, more particularly, to replacement teeth and points adapted -for use on power-driven excavating and loading buckets, dippers, scoops, scariers, and similar excavating tools.
This application is a continuation-in-part of my copending application, Serial No. 729,858, now Patent No. 2,919,506, led April 21, 1958.
In the excavating devices eld, the bucket, dipper, scoop, scarier, etc., provides a supporting nose on which is mounted a tooth point or an adapter for supporting a tooth point. The present invention is concerned primarily with the nose, the hollow point or socket element removably carried by the nose, and with means for uniting these elements. The nose may be the adapter nose, or it may be the nose formed integrally with a base member such as the lip of a bucket or dipper, etc., and the socket element may be the cap portion of an adapter received upon the nose of the base or it may be the tooth point carried by the nose of the adapter itself. For the purpose of simplicity in describing the invention, I will -refer mainly to the nose carried by the adapter and to the tooth point carried thereby. In the type of adapter nose and point commonly employed today, the nose has angularly-related iiat surfaces and these contact similar surfaces in the tooth point.
While tooth designers have hoped to develop a tooth which might be held so tightly by mechanical means upon the adapter nose that the point could not move sidewise, this result has not been achieved, and further, in the operation of the tooth, wear occurs which increases the movement of the tooth point upon the adapter nose. I have discovered that in the swinging movement of the tooth point upon the nose under impact with rocks, etc., the lateral swinging movement of the point, by reason of the flat angular contacting nose surfaces, pivots about one edge at the rear of the tooth. Two surfaces such as are presented by the top and bottom surfaces of the nose in contact with mating surfaces in a tooth point, cannot swing laterally without changing the lfull bearing area on the two surfaces to a point contact at the opposite rear end of the point and nose. In other words, any pivotal movement sidewise of the tooth changes it from a full bearing area to a point contact, the point contact being at one back corner of the point opposite to the direction in which the tooth is moved. This point contact, by directing the full force of the impact thereon, causes excessive wear and greatly shortens the life of the tooth point.
A further phenomenon affecting the point wear of the tooth is that when the point tilts upon the nose at one rear corner of the point, the tooth point moves forward along the nose so that we have not only a lateral movement but also a longitudinal movement of the point. The lateral and longitudinal movement is the result of a radial movement and the defined two-way movement of the tooth, which is equal to the radial movement and varies with the varying lengths and widths of the tooth. Such compound movements not only produce wear along the specic points on which the heavy frictional stress is exerted, but also place stress upon the key or other fastening means employed to anchor the point and nose elements together. As an illustration, it is found that when the tooth point has been swung sidewise over the ,tive to the other.
3,012,35 Patented Dec. 12, 1961 base approximately one-eighth of an inch, with the pivot point being at one lrear corner of the point, the longitudinal movement at the apex is doubled to a one-fourth inch clearance at the apex.
If it were possible to provide a base or adapter nose with a tooth point or socket element carried thereby so that in the lateral swinging movement of the sket element there is provided a full bearing area, thus obviating point contact, it would be possible to increase the life of the tooth greatly and it might be possible that the socket element would in some instances last the life of the bucket or other supporting base member.
An object of the present invention is to provide a nose support and socket element in the nature of a point or cap or sleeve mounted on said nose whereby under impact the element may swing to a limited extent laterally while providing full bearing or surface contact be tween the parts throughout such lateral movement. Another object is to provide an excavating device in which cooperating nose and socket elements have surfaces which remain in contact during lateral movement of one of the members with respect to the other, while at the same time providing a sturdy interlock between the members. A further object is to provide nose and point elements having surfaces which remain in substantial bearing contact during longitudinal movement of one member rela- A still further object is to provide a combination of nose and socket elements united by keys or other means whereby the parts may swing relative to each other to a limited extent while at the same time providing wide areas of contact between the members during each portion of such travel so that a large bearing surface is provided between the members under heavy load and irrespective of the relative position of the two members. Yet another object is to provide in excavating devices nose and socket elements wherein the nose is provided with a segmental spherical surface contacting a corresponding surface of thesocket element, thus enabling the parts to move in an arc relative to each other with the bearing surfaces of the two members substantially in full contact. Other speciiic objects and advantages will appear as the specification proceeds.
The invention is shown, in an illustrative embodiment, by the accompanying drawings, in which- FIGUREI l is a top plan view of a base, adapter, and tooth point structure embodying my invention; FIG. 2, a longitudinal sectional View, the section being taken as indicated at line 2 2 of FIG. l; FIG. 3, a detail sectional view, lthe section being taken as indicated at line 3 3 of FIG. 2; FIG. 4, a side View in elevation of a spherical element and tooth point element shown in engaging relation for illustrating the operation of the structure shown in FIGS. 1 3, inclusive; FIG. 5, a bottom plan view of the structure shown in FIG. 4; FIG. 6, a view similar to FIG. 4 but showing a nose and point each equipped with a single spherical surface; and FIG. 7, a perspective view of the nose and tooth point structure illustrated in FIG. 4, the nose and point elements bein'g shown spaced apart.
In FIGS. l-3, inclusive, a specific embodiment of the invention is set out by way of illustration. The base member A may be a part of a scarier or dipper or bucket, and may, of course, be formed in a variety of shapes or forms. In the illustration given, A represents a base extension having therein a central opening receiving the shank of an adapter B. The adapter B carries a tooth point C.
The base A is provided with a pair of spaced nose portions 10 which are enclosed within sockets 11 formed in the adapter B.
The adapter B has a rearwardly-extending shank portion 12 apertured to receive a key 13 which passes Vthrough a recess 14 in the upper portion Vof the base mem-ber A and a recess 1S in the lower portion of the base A. The key may be of any suitable form or shape. In the illustration given, the key is provided with a circular forward portion 16 and a circular rear portion 17, as shown best in FIG. l. Y
The adapter B is provided at its forward end with a nose 18 which is shown in the shape of a spherical segment having the arcuate top and bottom surfaces as indicated by the numerals 19 and 2G. Such spherical surfaces will be described in greater detail hereinafter. At the rear of the nose 13, the adapter B is provided with a guide pro- Vjection 21 having a at bottom guide surface 22 and a i Vthe projection 21, and normally urges the member 24 forwardly into engagement with a key member 27 which has a corrugated rear surface adapted to en-gage the corrugations or teeth of the locking member 24. The nose 1S is provided with a vertical slot therethrough for receiving the members 24, 26 and 27. Y
The key 27 has a plurality of corrugations which engage forwardly-extending corrugations Yon the locking member 24, and this structure has Ythe important advantage of permitting the key to be readily inserted and removed by driving the Ysame into and out of position, while at the Sametime remaining sturdily in position during the operation of the parts. The multiple corrugations provide interlocking surfaces which areV eiective in retaining the parts in interconnected relation during heavy usage but, at kthe same time, when the key is driven into position and when later it is driven out of position by a tool inserted through the openings in the lower portion of the point, the corrugated mating surfaces permit ready insertion andremoval.
The tooth point C may be of any suitable exterior form or shape. Inthe illustration given, the point comprises casing Walls which include a top heavy spike Vportion 28 and a lower web portion 29 conncctedrby side webs 30. The point or socket element C provides on its interior a socket 31 conforming in shape substantially to the shape of the nose 18. The forward end 32 of the socket is arcuate and conforms substantially in shape to the forward curved contour 33 of the nose 18.
VThe toothV point C is provided at its rear with spaced, rearwardly-extending tongues received within recesses in the adapter YB. The top tongue or strap 34 is received within a recess 35, shown best in FIG. 2, while the rearwardly-extending tongue 36 at the bottom of the member C is received within the recess 37 at the bottom of the adapter B. The vrear side wall edges of the tooth point are preferably recessed to form forwardly-extending concave edges, as indicated by dotted lines at 38 in FIG. 2.
While in the drawings the nose 1S is rather snugly received within the socket 31 of the point C, it will be Vunderstood that in actual practice there is play between tne parts and upon use of the tool and heavy wear, the spacing between the parts increases and the point C, when struck at one side near its forward end with rocks which are'wedging between the teeth, swings laterally. It is a purpose of the cooperating nose and socket structure shown herein to support fully the point upon the nose in such lateral swinging movements so that point contact or point wear is substantially obviated. It is also a purpose of the structure shown to support the point on the nose during longitudinal movement therebetween.
It is believed that the operationof the structure can be best described by referring to the illustrations set out in FIGS. 4-7, inclusive. In FIGS. 4, 5 and 7, a double spherical segment member 4t? is shown, with the forward surfaces of revolution. spherical surface isY formed by revolving an arc of a end of the nose received within a point C1. The sides of the member C1 are cut away. The socket 41 provided within the member C1 tits the spherical segmental contour of the member 4i) so that the member C1 can be lrotated around the member l4t) on an axis P which is at the vertical center line of thespherical segments 49a and 4Gb. From this illustration, it will be noted that the spherical surfaces 40a and 4017 and the cooperating or fitting surfaces of member C1 remain in full bearing contact as the member C1 is rotated about the member 40 or as the member 4t) is rotated within the socket 41 of member C1. In FIG. V7, an imaginary line 42 is drawn to indicate how the double spherical segment area would Vbe sectioned to provide the nose area 43 adapted for the vedge is aligned with the center of the member 40, the
member 43 could rotate within the socket 41 ofthe vmember C1, just as such rotation is accomplished in the Vstructure illustrated in FIG. 2 where the key 27 forms a verticalaxs at the rear center of the spherical segmented nose. With this structure, there is no point contact, but,
instead, the spherical surfaces of the portion 43 remain in full engagement with the bearing surfaces within member C1 -irrespective of the position to which the member C1 is swung. i
' In the structures described, both in FIGS. l-'3 and in'FIGS. 4, "5 and 7, rthe nose structure is in the shape of 'a double spherical segment, and one advantage of this structure is that the socket element or tooth point is reversible. Where reversi-bility Vis not required, a single spherical segment form of nose may be employed, and such a structure is illustrated in FIG. v6.Y The spherical segment member 44 has a straight side 45 engaging the straight upper surface 46 of the upper socket wall of point C2, while the lower spherical surface 47 engages a corresponding concave surface within the lower portion 48 ofthe point C2. r
While in the'illustra-tions given I have sho-wn spherical surfaces having the contour illustrated, it will be understood thattbe contour may be varied. To provide continuous and effective 'bearing relation between the nose and the tooth point, the mating surfaces are formed as In the illustration given, the
circle about a Vertical axis, providing, in effect, a zone of a sphere. In FIG. 4, the top and bottom zones are employed, while in FIG. 6 only the bottom zone is employed. This provides an area'adjacent the end of the axis that approaches a fiat surface parallel to the direction of movement of the nose and point when they move longitudinally relative to. each other. It is to be appreciated, therefore, that the mating surfaces of the nose and Vpoint may vary from a true spherical segment or zone. The curve or line employed to generate the surface of revolution may be complex, i.e., having straight portions providing in etect a truste-conical surface. The end of the curve or line adjacent the axis about which the surface of revolution is generated should be a spherical arc to permit the desired bearing engagement'upon longitudinal movement of the point and nose, as well as the desirable engagement between the two upon later-al movement therebetween. YThe lines Vor. curves employed to generate theV upper and lower bearing surfaces are angularly related to each other and may be considered to be intersecting lines or curves. In the illustration given, theline of intersection of the two spherical zones'is imaginary, since the central portion is beveled or rounded as at 46c in FIG. 4. The curvature of the line or curve employed for generating the surface of revolution about Vthe vertical axis should have a radius considerably larger iiat surface in the curve or line in the area adjacent the vertical axis.
The spherical segments are provided by rotating arcs that have the centers of their radii of curvature along the vertical axis of surface generation to provide the pole of the spherical zonal segment on the axis of generation. By locating these centers remote from the nose, a substantially flat spherical portion is provided in the bearing surface adjacent the axis or pole, but one that still permits sidewise rotation of the point relative to the nose. rIihe arcs providing these spherical surfaces may be extended until they intersect, or may be provided as just the terminal portions of the divergent end of the tapered outline (i.e., the longitudinal section profile of the tooth as seen in FIG. 2) which is employed to generate the surface of revolution.
The structure just described provides several heretofore unobtainable advantages. When rocks wedge between the previously-employed teeth in the normal operation of the excavating device, a bodily movement in translating laterally of the nose would tend to damage the teeth and other structure and further would be less effective in releasing the rocks, etc. With the tooth structure shown, the point is restrained from a body movement or translation laterally of the nose by the spherical surfaces, while at the same time these surfaces per-mit swinging movement of the point on the vertical axis of the nose. When rocks or other obstacles moved the point longitudinally outwardly of the nose in previous teeth, there was a complete loss of bearing. With the inventive structure, this is avoided by the substantially fiat surface about the axis of generation.
The nose structure 18 has been described in detail so as to illustrate the double or single segmental spherical sunface relationship of the adapter nose to the tooth point. l now wish to refer to the nose members carried by the base A and received within sockets 11 of the adapter B. The nose members 1t) are also preferably formed as a part of a continuous spherical surface with an inner Segment removed to receive the shank portion of the adapter B. By shaping the nose members 10 as portions of a continuous spherical surface of the type illustrated in FIGS. 4, 5 and 7 and by shaping the sockets 11 in the adapter B so as to provide contacting surfaces receiving these segments 1i), a swinging movement of the adapter B about t-he key 13 provides the same full bearing support heretofore described in connection with the nose 18. In the latter operation, since the key 13 has a circular rear edge portion 17, the center of rotation would be about the center 17a of the key portion 17 and the axis of generation of the segments 1t) is also located at the center 17a of the key portion. It will also be understood that the nose 18 may be provided directly by the base A and without any interposed adapter or like member.
Operation In the operation shown in the illustrative models in FIGS. 4-7, inclusive, the spherical segment member is firmly received within socket recesses in the point C1 or C2 and may rotate therein with the bearing surfaces of the two parts in full contact.
In the preferred structure shown in FIGS. l-3, inclusive, the nose is fully enclosed within a socket and sections of the two spherical surfaces form the nose. When the adapter B moves under stress imposed upon it laterally about the pivot point 17a, the spherical segment portions 10 of the base A remain in full contact with the corresponding concave socket portions 11 of the adapter B. When the point C is moved laterally by the wedging of rocks between it and the adjacent toot-h, the point swings along the spherical surfaces of the nose 18, with the bearing surfaces of the two members in full contact.
When the point is to be assembled with the adapter, as illustrated in FIG. 2, the key 27 is driven downwardly to the position shown in FIG. 2, with the corrugated rear surface thereof engaging the corrugated forward surface of the locking member 24, and in this action the member 24 slides rearwardly in guided relation with the projection 21 and compressing the resilient block 26. For removing -the key, a tool element may be placed against the bottom of the key 27 and the key driven upwardly and out of the position shown, so as to free the point C from the adapter nose.
Referring more particularly to the structure shown in FIG. l, Ithe curved forward edge 33 of the nose permits relative movement of the nose and point, with little wear along the sides of the point. With structures heretofore employed, in which square nose ends are provided, the swinging movement contemplated caused point `con-tact at the forward side edges of the nose, tending to cut through the side Walls of the point during heavy operations. In the present structure, the rounded or arc-like forward structure of the nose, in cooperation with the rounded pocket of the point C, enables relative movement of the parts to take place under heavy stress without injury to the points side walls.
While an important advantage of the presen-t application lies in the full spherical bearing area, so that in any position of the parts there is provided a substantially full bearing surface to carry the stress, it will be understood that much of the advantage of the present invention can also be utilized where all the bearing surfaces are not constantly in full contact but where a major portion of said surfaces are in contact for the bearing of loads.
While, in the foregoing specification, I have shown the spherical surface employed on the nose of a specific form of tooth, it wil-l be understood that the surface may be employed with any type or kind of a tooth or point where a nose is employed and a point or socket member is held upon the nose. The cooperative action of the nose and socket element prevents lateral shifting bodily of the element upon the nose in translating, but permits swinging movement of the element, as under wedging impact of rocks, etc., while the bearing surfaces of the two members remain in contact or in contact over the major portion of their working area. This structure avoids point contact and wear, and by maintaining the bearing surfaces in Contact over wide areas during the movements of the parts, a long Wearing point or socket element is provided.
As stated above, the spherical bearing surfaces permit pivotal movement but resist lateral movement regardless of whether or not there are confining side walls, and, therefore, the tit of the side walls, and whether the side walls fit tightly or loosely is relatively unimportant.
Through the provision of a tooth structure of the character described, a Wider and lower weight nose or adapter is made possible. By the same token, the point itself is strengthened by providing a correspondingly larger portion of the metal in the overall tooth. This is desirable, since it is the point that is subjected to the greatest wear. Also, by providing a nose and .point that cooperate to permit a lateral pivoting action, the key member 27 can be positioned more rearwardly in the nose and point than was heretofore 'thought possible. The closer the Akey member is to the rear or socket portion of the point and the lip-engaging portion of the adapter, the stronger the composite tooth.
While, in the foregoing specification, I have set forth a specic structure in considerable detail for the purpose of illustrating an embodiment of the invention, it will be understood that such details of structure may be varied widely by those skilled in the art Without departing from the spirit of my invention.
l. A supporting structure for an excavating tooth, and the like, comprising a 'tapered nose and a socket member, said Socket member having Ia pair of opposite interior auras-se bearing surfaces fitting a pair of corresponding opposite exterior bearing surfaces on said nose member, at least `one set of adjacent bearing surfaces on said nose member Vand said ysocket member being surfaces of revolution having a common vertical axis of generation, the said surfaces including spherical segments adjacent said axis, and
3. A supporting structure for an excavating tooth sub` Vject to stresses tending to produce movement in a given plane, comprising a tapered nose member and a socket member, said socket member having upper Vand lower i11- terior bearing surfaces Vfitting a pair of corresponding opposite exterior bearing surfaces on said nose member, said bearing lsurfaces being surfaces of revolution generated by revolving a tapered outline about an axis perpendicular to said plane and remote from the apex portion of said outline, said tapered outline including an arc on one side thereof adjacent said axis, and means interconnecting said members for limited relative rotation on said axis.
4. A supporting structure for an excavating tooth, comprising a tapered nose member and a socket member receiving said nose member, said socket member having confronting upper and lower interior bearing surfaces fitting corresponding upper and lower exterior bearing surfaces on said nose member, at least one set of said bearing surfaces-being surfaces of revolution having a common axis extending vertically of said nose, said set of bearing surfaces including spherical segments adjacent said axis and having centers of curvature lying on said axis, and means on said axis interconnecting said members for limited relative rotation in a sidewise directionabout said axis.
V5. In a supporting structure for an yexcavating tooth, a. tapered nose member and a socket member receiving said .nose member, said socket member having confronting upper and lower interior bearing surfaces fitting corresponding upper and lower exterior bearing surfaces on said nose member, one set of said bearing surfaces being segmental spherical surfaces of revolution having a common axis extending vertically of said nose, and means on said axis interconnecting said members for limited relative rotation about said axis.
6. The structure of claim 5, in which both sets of said bearing surfaces are segmental spherical surfaces of revolution having a common axis extending vertically of said nose.
7..In an excavating device, a supporting nose element and a socket element receiving said nose, a key member interconnecting said nose element to said socket element and providing a single vertical axis about which said elements may rotate relative to each other, said elements each having two angularly related bearing surfaces in contact throughout the major portion of their area, said surfaces being surfaces of revolution generated by revolving two imaginary lines about said axis, said lines being arranged for intersection and at least one of said lines including an arc portion adjacent said axis with the center of curvature thereof lying on said axis.
V8. The structure of claim 7, in which the said elements are connected by a key having its rear portion aligned generally with the axis of revolution.
9.1 A tooth point having a spike portion and web portions providing with said spike a socketV adapted to receive a Supporting nose, said socket being formed with a contour adapted to snugly receive a nose support, said point having vertically-aligned openings in the spike por-y tion and the web portion opposite thereto adapted to receive locking key means, at least one surface of said socket adjacent said aligned openings having a concave `spherical contour with the center of curvature thereof lying on an axis passing through said aligned openings.
10. The structure of claim 9, in which said socket is shaped to receive a nose equipped with a passage extending vertically therethrough and adapted to receive key means, said nose having its upper and lower faces equipped with spherical segments about the ends of said passage, the centers of curvature of said spherical segments lying on an axis extending through said passage.
11. A tooth point having opposite convergent upper and lower casing walls providing a generally wedgeshaped socket adapted to snugly receive a nose support, at least one of said walls having a longitudinally-extending face in said socket of concave spherical contour.
12. A tooth point having inclined upperv and lower casing'walls forming a point and providing a wedgeshaped socket adapted torreceive a support, said socket having at least one face equipped with a spherical segment, the said spherical segment being positioned in said face at least in the portion of said face remote from the socket apex, said casing Walls being equipped with aligned key receiving openings remote from the socket apex.
13. In combinationia tapered nose element and a socket wear element, said nose element having oppositely disposed upper and lower faces, at least one of which includes a spherical zonal segment with the axis thereof extending transversely of the length of the nose element considered in the direction of taper, a pivot member uniting said nose and socket elements to provide a pivot point at the pole of said spherical zonal segment, said wear l Velement having its socket'adapted to snugly receive the said spherical segment of the nose element to permit relative movement of one of said members to the other while said nose element and socket wear element remain in bearing engagement.
14. A tooth point for an excavating tooth subject to stresses tending to produce transverse movement in a horizontal plane,V comprising a point having a support portion adapted to tit a support member for movement in said plane and having oppositely-facing longitudinallyextending bearing surfaces generally convergent in a direction longitudinally of the tooth point, at least one of said bearing surfaces *being a spherical surface of revolution having an axis of generation perpendicular to said plane.
15. A tooth point for an excavating tooth subject to stresses tending to produce transverse movement in a horizontal plane, comprising a point having a support portion adapted toiit a'support member for movement in said plane and provided with a pair of converging and longitudinally-extending bearing surfaces, at leastrone of said bearing surfaces being a spherical surface of revolution having an axis of generation perpendicular to said plane, and opening means provided in said point for receiving a retaining pin, said opening means being positioned in said point for effecting limited movement of said point relative to an associated support member and about said axis.
16. A tooth point support, comprising a horizontally elongated member having a point mounting part at one end provided by convergent upper and lower, wedge-defining faces, one of said faces, at least in the portion thereof remote from the apex of the Wedge, having a spherical segmental surface, shank means integrally provided on said member at the other end of said member,
- and opening means in said member for receiving a tooth point retainer pin.
References Cited in the file of thisl patent UNITED STATES PATENTS