US 3305954 A
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Description (OCR text may contain errors)
8, 1967 w. M.TROEPPL ET AL 3,305,954
NOTCHED TOOTH AND RETAINER Filed Oct. 22, 1965 73c INVENTORS 43c 74 wllham M. Troeppl FE g 8 8 John G. Benetti Fig.1
United States Patent Ofiice 3,305,954 Patented Feb. 28, 1967 3,305,954 NOTCHED TOOTH AND RETAINER William M. Troeppl, Santa Clara, and John G. Benetti,
Cupertino, Califl, assignors, by mesne assignments, of
one-half to Gerald A. Petersen, Sunnyvale, Calif., and
one-half to Anita E. Petersen, Saratoga, Calif.
Filed Oct. 22, 1965, Ser. No. 501,492 9 Claims. (Cl. 37-142) This invention is a continuation-in-part of applicants co-pending applications, Serial No. 369,780 filed May 25, 1964, and Serial No. 390,443 filed August 18, 1964, and is an improvement on Petersen Patent No. 2,968,880. The invention relates to a new and improved earth-digging tooth and holder having notches in the tooth and cooperating means on the tooth and holder to resiliently fit into the notches to retain the tooth in the holder.
The tooth illustrated and described in Petersen Patent No. 2,968,880 provides a hard, unitary tooth for an earthdigging machine having a tapered distal portion which performs the digging function and a bifurcated proximal portion composed of two prongs separated from each other by a rectangular slot which extends forwardly from the proximal end of the tooth. In that patent there is further illustrated and described a tooth-holder formed with a pair of recesses extending rearwardly from the forward end so that the holder as viewed in front elevation is substantially H-shaped with a web dimensioned substantially to fill the slot in the proximal end of the tooth. To hold the tooth in the holder against unintentional dislodgement there is further provided a resilient insert which is compressed between surfaces of the tooth prongs and walls of the recesses. The resilient insert, being located within the tooth-holder, is protected from wear and abrasion and further its resilient nature accommodates minor variations in the construction of the tooth and holder, thereby making close tolerances unnecessary and further accommodating wear of the parts with the passage of time. Particular advantages of the tooth and holder are the facility with which the tooth may be installed and removed and the fact that no special tools are required for such purpose. The present invention affords many of these advantages.
. Although the teeth and holders in accordance with the above identified patent have enjoyed widespread commercial success, certain opearting conditions create an environment for' which the hereinafter described tooth and holder are particularly suitable. A typical example occurs when a lubricant is employed in the cutting operation or when the nature of the earth being cut is particularly slippery. Under such conditions the natural frictional engagement of the resilient insert with the side walls of the prong of the tooth and of the web of the holder is diminished, sometimes permitting the sliding of the tooth relative to the holder. Further, where severe operating conditions and intense vibration of the tooth are encountered there is also a tendency for the tooth to be dislodged from its holder. It is a principal purpose and object of the present invention to provide means on the tooth and holder to enhance the retention of the tooth and to prevent unintentional dislodgement of the tooth.
In one form of the invention hereinafter illustrated, the flanges of the H-shaped holder are partially closed off by transverse straps parallel to the web, the inward faces of the straps having protuberances. The contiguous outer surfaces of the prongs of the tooth are provided with notches which mate with the protuberances in the assembled position of the parts. Hence the resilient insert is either replaced or augmented in effect by the lodging of the protuberances in the notches on the sides of the prongs.
In another form of the invention the notches on the prongs are transversei.e., on the top and bottom surfaces similar to the notches shown in Petersen Patent No. 2,877,574. Transverse flexible pins fit through one or more holes in the web of the holder and lodge in the notches in the assembled position of the parts, thereby preventing unintentional withdrawal of the tooth from the holder. However, the holder is so constructed that the pin can flex under sufficient stress to intentionally drive the tooth from the holder, permitting extraction of the tooth without removal of the pins.
In one form of the invention of the type heretofore described, a single transverse pin is used. Another form hereinafter described uses a staple or hairpin-shaped pin passing through two holes in the web and engaging notches in both the tops and bottoms of the prongs.
In still another form of the invention, notches similar to those last described are formed in the top or bottom surfaces of the prongs. The cooperating wall of at least one of the flanges of the holder is formed with a protuberance which lodges in the notch in the assembled position of the tooth. Thus the tooth is restrained against unintentional dislodgement. In order to hold the tooth and protuberance in engagement, a spring is installed between the opposite face of the prong and the wall of the recess which biases the tooth into engagement with the protuberance. However, when it is desired to withdraw the tooth from its holder suflicient force is exerted to overcome the resilient means and permit the notch of the tooth to escape from the protuberance.
Still another feature of the invention is the provision of improved means for dislodging the tooth from its holder when it is worn and must be reversed or replaced. For such purposes, holes are formed in the top and bottom flanges of the tooth-holder in registry with the forward end of the slot of the tooth. By driving a tapered instrument through the aligned holes, the tooth may be forced forwardly away from the holder despite the retaining means, thus extracting the tooth. It will further be understood that openings may be formed behind the prongs through which an instrument may be inserted to drive the tooth forwardly relative to the holder.
Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings in which similar characters of reference represent corresponding parts in each of the several views.
In the drawings:
FIG. 1 is a top plan view, partly broken away in section, showing one form of tooth, holder and retaining means.
FIG. 2 is a sectional view taken substantially along the line 2-2 of FIG. 1.
FIG. 3 is a fragmentary side elevational view of a modified construction.
FIG. 4 is a transverse sectional view taken substantially along the line 44 of FIG. 3.
FIG. 5 is a view similar to FIG. 3, of still another modification.
FIG. 6 is a sectional view taken substantially along the line 6-6 of FIG. 5.
FIG. 7 is a fragmentary sectional view of another modification taken substantially along the line 7-7 of FIG. 8.
FIG. 8 is a fragmentary sectional view taken substantially along the line 8-8 of FIG. 7.
Tooth 11 is subject to variation in shape and as illustrated has forwardly convering top and bottom distal surfaces 12 extending across the width of the tooth and terminating in a truncated front edge 14. Side edges 18 of the distal portion are substantially vertical and parallel, although they may converge slightly rearward- 1y. As illustrated particularly in FIG. 1, tooth 11 may be reversed to reduce the requirement of sharpening of the tooth until the working portion of the tooth is exhausted. However, such reversability is not essential to the present invention. Proximal prongs 19, or roots, are separated fromeach other by slot 21 which extends forwardly from the proximal end of the tooth. In the form of the invention shown in FIG. 1, outer side walls 23 in prongs 19 converge rearwardly. Rearward ends 24 of prongs 19 slant outwardly-forwardly, providing abutting ends 26 which bear the rearward thrust against holder 31. The forward end 27 of slot 21 is rounded and is located forward of the front end 32 of holder 31. As herein illustrated, edges 23, 24, 26, 27 are shown vertical, but it will be understood that they may be formed beveled where convenience of manufacture so requires.
A feature of the form of the invention shown in FIG. 1 and 2, is the formation on the exterior or outward edges of each prong 19 of a notch 33, which in normal position of the tooth is substantially vertically disposed. The function of notch 33 is to cooperate in retaining tooth 11 in holder 31, as hereinafter described. A further feature of the form of the invention, as shown in FIGS. 1 and 2, is the formation of serrations 34 on the inward facing side edges of slot 21. Serrations 34 are in buttress shape, having substantially transverse forward'walls 36 and rearwardly-outwardly slanted supporting walls 37.
The holder 31 herein illustrated may be fastened to an excavating tool or, as shown in FIG. 1, may be a connector connected to a primary holder 41.
Holder 31 has a proximal end 32, which is essentially H-shaped in front elevation in the sense that it has top and bottom flanges 42, 43 extending outwardly in either direction from a vertical web 44. The crosssectional shape of web 44 is slightly less than slot 21, so that there is a slight clearance between the walls of web 44 and serrations 34 of slot 21. The spacing between the opposed top and bottom walls of the flanges 42, 43 is slightly greater than the space between the top and bottom surfaces of prongs 19. The recesses in holder 31 terminate in end walls 46 against which points 26 abut. Openings 47 in holder 31 behind prongs 19 provide a means for extracting tooth 11.
Extending transversely through Web 44 is a hole 51 which receives a resilient insert 52 formed of rubber, synthetic rubber such as neoprene, or the like, which is preferably circular in cross-section and of a diameter approximately equal to that of hole 51. The length of insert 52 is substantially greater than the width of web 44 and preferably is about equal to the width of holder 31. Web 44 is formed with grooves 53 rearwardly of hole 51,.but the spacing is such that insert 52 is squeezed between serrations 34 and the bottom of grooves 53. The buttress serrations 34 dig into resilient insert 52 and augment the normal resistance to the extraction of tooth which occurs by reason of friction.
Further, to secure tooth 11 in position in holder 31, straps 56 are formed extending between top and bottom flanges 42, 43cm either side of holder 31 immediately outside of the side edges 23 of tooth prongs 19 in the assembled position of the parts. Protuberances 57 are formed on the inner faces of straps 56, mating with notches 33 in side walls 23 of tooth prongs 19. It will be noted, as indicated by reference numeral 30, that forwardly of strap 56 the side of holder 31 is stepped inwardly.
When tooth 11 is to be installed, resilient insert 52 is placed in hole 51 with the ends of the insert extending into the recesses on either side of web 44. Tooth 11 is forced rearwardly, the ends 26 of prongs 19 bending the insert back into grooves 53 and deforming the insert to accommodate the clearances between the parts. When the tooth is full'y'installed, the'buttress teeth 34 grip into insert 52 and the insert itself is squeezed in grooves 53 and elongated so that there is frictional as well as mechanical resistance to withdrawal of tooth 11 from holder 31. Additionally, the prongs 19 deflect inwardly until protuberances 57 slip into notches 33 thereby additionally locking tooth 11 in place.
When it is necessary to extract the tooth from its holder when it must be reversed or replaced, the tooth is driven out by various means. Thus a tool may be inserted through openings 47 in the back of the recesses to engage the rearward ends 24 of prongs 19. Alternatively, semicircular cutouts 58 are formed in the front of the holder substantially in registry with forward end 27 of slot 21. Hence a tapered tool (not shown) similar to a drift pin may be inserted in the aligned openings 58, 27 to force the tooth to the left and as viewed in FIG. 1, and thus extract the tooth, despite the function of the retaining means heretofore described.
By reason of the fact that tooth 11 is formed of a unitary piece of hard, abrasive-resistant steel which, nevertheless, has a certain amount of malleability, materials which arequite abrasive may be dug and considerable shocks may be absorbed by the tooth during its digging action. Holder 31 is of a more resilient material which permits a certain amount of bending or flexure to absorb much of the stress of the digging action. Essentially, therefore, holder 31 is of a less abrasive resistant material than tooth 11.
Turning now to FIGS. 3 and 4, in this form of the invention resilient insert 52 may be eliminated and web 44a substantially fills slot 21a between prongs 19a. In this modification, transverse notches 61 may be formed in the top and bottom surfaces of prongs 19a, adjacent the rearward ends of prongs 19a. Notches 61 are approximately semi-circular. It will be understood that although notches 61 are shown in both top and bottom, one set of notches may be eliminated. Web 44a is formed with a transverse hole 51a in registry with top notches 61- and the walls of flanges 42a are cut away in corresponding notches 62. The size of notches 62 is greater than notches 61 for a purpose which hereinafter appears.
The retainer for the form of the invention shown in FIGS. 3 and 4 is a flexible pin 63 which fits through hole 51a in web 44a projecting to either side of the web and fitting into notches 61 to act as a key to restrain withdrawal of the tooth 11a from its holder 31a. Retainer 63 is sufficiently flexible so that it can be deformed into the enlarged notches 62 in holder 31a to permit the tooth to be driven into place or to be extracted, but when tooth 11a is seated in assembled position pin 63 is straight, fitting into notches 61 to hold the parts in place.
When it is necessary to extract tooth 11a, the tooth is driven forwardly and pin 63 deflects into the enlarged notches 62 to permit withdrawal. It will be understood that instead of being located only on the top of the tooth, as shown in FIGS. 3 and 4, pin 63 may be located on the bottom or, alternatively, one pin may be used on the top and another pin on the bottom. In many other respects the elements of the invention shown in FIGS. 3 and 4 resemble those in the modification of FIGS. 1 and 2, and the same reference numerals followed by the subscript a are employed.
FIGS. 5 and 6 show a modification of the form of the invention shown in FIGS. 3 and 4. In this form of the invention notches 61b are formed in both the top and bottom surfaces of each prong 19b and corresponding notches 62b are formed in the adjacent inward facing surfaces of the top and bottom flanges 42b, 4317. Also, a pair of holes 5111 is formed in web 44]) in alignment with notches 6112. As a further feature, a vertical groove 66 may be formed in side edge 23b of one prong 19b interconnecting notches 61b.
Retainer 67 is preferably a staple or U-shaped member. The parallel legs 68 of the staple fit through holes 52b and in notches 61b. The interconnecting portion 69 of staple 67 fits in side groove 66. In other respects, staple 67 flexes to permit installation and extraction of the tooth in the same manner as pins 63 of the preceding modification and further functions to hold the tooth in position against unintentional dislodgment.
In other respects the modification of FIGS. 5 and 6 resembles that of the preceding modifications and the same reference numerals are used followed by the subscript 17.
The modification of FIGS. 7 and 8 employs a tooth similar to that shown in FIGS. 3 and 4. The same reference numerals followed by the subscript c are used to designate corresponding parts. In this form of the invention, however, a protuberance 71 is formed in the downward-facing wall of top flange 42c mating with notch 61c in prong 190. The clearance between the top and bottom of prong 19c and the facing walls of flanges 42c, 43c is greater than in the preceding modifications. To hold tooth 110 in place, a spring 72 is installed in the space below prong 19c, biasing the prong so that notch 61c fits protuberance 71 to restrain unintentional withdrawal of the tooth. The forward end of spring 72 may be formed with a curl 73 which lodges in transverse groove '74 in bottom flange 43c to prevent displacement of spring 72. In this form of the invention, when the tooth is installed spring 72 flexes to permit prong 19c to move downwardly and allow protuberance '71 to slide on the top of prong 19c until it nests in notch 610, as shown in FIG. 7. Thereafter, spring 72 holds the parts in assembled position. When it is necessary to extract the tooth, the tooth may be removed by means hereinbefore described and during such removal the spring 72 again deflects to permit the protuberance 71 to clear the notch. It will further be understood that whereas the protuberance 71 is shown 'on the top of the holder 31c and the spring 72 on the bottom, the arrangement may be reversed.
What is claimed is:
1. In earth digging equipment, a tooth formed of hard material having a distal portion formed with a cutting edge and a proximal portion having top and bottom faces formed with a longitudinal slot extending forwardly from the proximal end of said tooth to divide said proximal portion into two prongs, said slot formed with substantially parallel, inward facing side Walls;
a tooth holder formed with a pair of recesses to receive said prongs, said holder having a web separating said recesses and dimensioned substantially to fill said slot;
and retaining means for retaining said tooth in said holder against unintentional dislodgement, said tooth formed with at least one notch, said holder formed with at least one protuberance fitting in said notch in assembled position of said tooth and holder, said tooth and protuberance being resiliently movable relative to each other to force said protuberance and notch out of engagement to permit intentional extraction of said tooth from said holder.
2. The combination of claim 1, in which said holder is generally H-shaped in front elevation having a web and top and bottom projecting flanges and which further comprises a strap interconnecting the outer edges of flanges of said holder, said protuberance on said strap, said notch on the outer side edge of said tooth.
3. The combination of claim 2, which further com prises a resilient retainer compressed between said side walls and said web, said resilient retainer flexing to permit relative movement of said tooth and said holder.
4. The combination of claim 3, in which said side walls are formed with tooth-like protuberances biting into said resilient retainer.
5. The combination of claim 2, in which the outer edges of said tooth taper inwardly-rearwardly, said notch formed in the inwardly-rearwardly tapering outer edges.
6. In earth digging equipment, a tooth formed of hard material having a distal portion formed with a cutting edge and a proximal portion having top and bottom faces formed with a longitudinal slot extending forwardly from the proximal end of said tooth to divide said proximal portion into two prongs, said slot formed with substantially parallel, inward facing side walls;
a tooth holder formed with a pair of recesses to receive said prongs, said holder having a web separating said recesses and dimensioned substantially to fill said slot; said web formed with at least one transverse hole, a notch formed in a surface of at least one said prong in alignment with said hole, and retaining means comprising a flexible pin through said hole normally fitting in said notch, said holder formed relieved to accommodate flexing of said pin away from said notch during extraction of said tooth.
7. The combination of claim 6, in which said web is formed with a pair of transverse holes, at least one said prong formed with notches on top and bottom surfaces in alignment with said holes, said retaining means having flexible legs fitting through said holes and normally fitting in said notches, said holder formed relieved to accommodating flexing of said legs away from said notches during extraction of said tooth.
8. The combination of claim 7, in which said retaining means has a connecting portion interconnectnig said legs, said tooth formed to accommodate said connecting portion.
9. The combination of claim ll, in which said notch is formed in a series of a prong transverse to said web, said protuberance in a wall of said recess facing said last mentioned surface, said retaining means further comprising a resilient member interposed between said prong and said holder biasing said protuberance and said notch into engagement.
No references cited.
ABRAHAM G. STONE, Primary Examiner. A. E. KOPECKI, Assistant Examiner,