US3323236A

US3323236A - Reversely bent retainer for pronged excavating tooth

Info

Publication number: US3323236A
Application number: US460000A
Authority: US
Inventors: Gerald A Petersen
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-06-01
Filing date: 1965-06-01
Publication date: 1967-06-06
Anticipated expiration: 1984-06-06
Also published as: GB1115835A

Description

June 6, 1967 G. A. PETERSEN 3,323,236

REVERSELY BENT RETAINER FOR PRONGED EXCAVATING TOOTH Filed June 1, 1965 2 Sheets-Sheet l INVENTOR. GERALD A. PETERSEN ATTORNEY REVERSELY BENT RETAINER FOR PRONGED EXCAVATING TOOTH Filed June 1, 1965 v 2 SheGtS-Sheet 0L FIG- 6 INVENTOR. GER/4L0 A. PETERSEN A 7' TOPNE V United States Patent 3,323,236 REVERSELY BENT RETAINER FOR PRONGED EXCAVATING TOOTH Gerald A. Petersen, Sunnyvale, Calif., assignor of one-half to Anita E. Petersen, Saratoga, Calif. Filed June 1, 1965, Ser. No. 460,000 7 Claims. (Cl. 37142) This invention relates to a new and improved reversely bent resilient retainer for pronged excavating tooth. This application comprises an improvement on Petersen Patent No. 2,968,880. The latter patent discloses an excavating tooth having a proximal portion formed with two longitudinal prongs defined by a slot extending from top to bottom forwardly of the end of the tooth. The tooth holder has forwardly-opening recesses to receive the prongs and resembles in front elevation the letter H turned on its side. The web between the top and bottom .flanges is complementary to the slot. In said patent, a

resilient retainer extends transversely through a hole in the web and is compressed between the side walls of the slot and the contiguous walls of the web. The present invention uses a resilient retainer which is located and positioned in a different manner from that heretofore used.

Accordingly, the present invention has particular application to earth augers, trenching machines, and the like, but is also adaptable to larger earth-digging machines such as graders, clippers, back hoes, harrows, scarifiers, cable plows, and similar equipment Where a blade is subjected to heavier stresses than encountered in angers and trenching machines. The present invention enhances the area of surface contact between the resilient retainer and the surfaces between which it is compressed and thus more securely holds the blade in its holder. Thus, the present invention holds the blade on its shank against unintentional dislodgment despite extreme stresses tending to separate the parts. On the other hand, the retainer will permit intentional dislodgment of the blade holder when it is necessary to replace the blade.

It is a principal purpose of the present invention to provide means for retaining a blade on a permanent portion of a machine in such manner that it may be removed and sharpened, replaced, or otherwise repaired, and yet to provide a secure enough retention to prevent unintentional separation.

A particular advantage of the present invention is the facility with which the blade may be installed and removed and the fact that no special tools or other equipment are required for such purpose.

Still another advantage of the invention is the fact that the resilient insert which secures the blade on its holder accommodates minor variations in the construction of the blade and holder and thereby makes close tolerances of dimensions of the mating parts unnecessary, and further accommodates wear of parts with passage of time.

As hereinafter described in detail, the resilient retainer is inserted in holes in the toothholder and the ends of the retainer extend into the recess in the holder and are positioned between the blade and the holder when the blade is forced into the holder. Grooves may be formed in the holder and the internal ends of the resilient retainer are compressed between the bottoms of the grooves and the adjacent wall of the blade. The cross-sectional shape of each groove is preferably substantially different from the initial unstressed shape of the resilient insert and hence there is a considerable deformation of the insert which increases the area of surface contact between the insert and the holder and the blade. Hence, the resistance to unidirectional dislodgment of the blades from the holder is increased. When there is sufiicient clearance between blade and holder, use of grooves may be eliminated.

Another principal feature of the present invention is the fact that neither bolts, metal keys, nor similar fasten ers, nor welding to secure the blade on the shank are used, thereby eliminating a considerable amount of the difficulty heretofore occasioned in securing blades to their holders and removing the blades from the holders when required.

A distinguishing feature of one form of the invention hereinafter described is the doubling over of the resilient retainer so that there are two ends, both of which are compressed so as to retard separation of the parts, thereby materially increasing the resistance to withdrawal of the blades from the recess in the holder. A single retainer is bent in a U-shape and both of the ends are inserted through holes in the toothholder wall, the metal between the holes serving to prevent the retainer from being pulled into the holder. The exterior wall of the holder may be recessed so that the bent over portion of the retainer is protected against abrasion by being located below the exposed surface of 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. Tis a top plan view partly broken away to conserve space of :a tooth and holder in accordance with this invention.

FIGS. 2, 3, 4, and 5 are, respectively, sectional views taken along corresponding section lines in FIG. 1.

FIG. 6 is a view similar to FIG. 1 of a modification.

FIGS. 7, 8, and 9 are, respectively, sectional views taken along corresponding section lines in FIG. 6.

Tooth 11 shown in the accompanying drawings is similar to that tooth shown in Petersen Patent No. 2,968,880. The distal end 12 has top and bottom downwardly-forwardly converging surfaces 13, 14, terminating in a truncated transverse end 16, and having generally parallel longitudinal vertical side edges 17. Said side edges 17 continue rearwardly to proximal side edges 18 of the proximal end 19 of said tooth. The rearward end 21 of the proximal portion has transverse vertical end 21 and substantially parallel longitudinal top and

bottom surfaces

22, 23. A rectangular slot is formed from top to bottom extending forwardly-centrally from end 21, dividing the tooth into two proximal prongs 24, each substantially rectangular in cross-section defined by side edges 18, top and

bottomsurfaces

22, 23, and the inwardly facing vertical walls 26 of the slot.

Toothholder 31 is attached by means forming no part of the present invention and not herein illustrated and described to a permanent or removable part of the digging equipment. At its forward end, holder 31 is shaped to receive the proximal prongs 24 of tooth 11 and for such purpose has top and

bottom flanges

32, 33, and an interconnecting web 34. Web 34 is dimensioned to fit within the slot of tooth 11 and thus has side wall 36 parallel to and in close proximity to walls 26 of the tooth. The top and

bottom surfaces

37, 38, of

flanges

32, 33, are spaced apart about the same distance as

surfaces

22, 23, and are parallel to and in close proximity to said surfaces. Thus, when no retainer is used, the tooth 11 fits into and may be withdrawn from holder 31. A resilient retainer 41 is used to restrain unintentional dislodgment of the tooth. Retainer 41 may be formed of neoprene synthetic rubber, natural rubber, or other resilient material, such as nylon cord, latex-dipped nylon cord, soft iron wire, and other resilient substances. In the accompanying drawings the cross-sectional shape of insert 41 in its initial dimension is circular but it will be understood that other shapes may be used. A distinguishing feature of the use of insert 41 is that it is initially bent into a substantially U-shaped form prior to insertion in the holder 31. To provide for such insertion, adjacent the forward end of holder 31 as in flange 32 a pair of downwardly-rearwardly directed holes 42 is formed communicating with the recesses into \vyhich prongs 24 fit. A transverse arcuate groove 43 may beiormed in the top surface of flange 32 so that insert 41 is recessed below the top surface and is protected againstabrasion. The inner ends 44 of insert 41 are compressed

lfetween surfaces

22 and 37. To accommodate such compression without the necessity of unnecessarily large clearances-between

surfaces

22 and 37, grooves 46 may be formed in -surfaces 37. Preferably, grooves 46 are thinner and broaderthan the corresponding dimensions of insert 41 in its unstressed condition, thus spreading the ends 44 to the distorted shape best shown in FIG. 5,

\,au gmenting the area of surface contact with surface 22,

andincrea'sing the resistance to withdrawal of the teeth from its hol-der Although in FlGS'. ;1.-5, holes 42and groove 43 are shown formed in top flange iiz, it will be understood that they could be formed in bottom flange 33, and whereas the grooves 46 are shown in surface 37, nevertheless, they could be formed in

surfaces

22 or 23.

In installing the tooth, insert 41 is bent into grmerally U-shape and the ends 44 are inserted through holes 42h [insert resists withdrawal of the tooth from its holder and in normal usage unintentional withdrawal is prevented. However, when it is necessary to remove the tooth for sharpening, reversal or replacement, a tool may be inserted through openings 47 in holder 31 and driven against end 21 to force the tooth forward against the resistance of the insert.

The modification of the invention shown in FIGS. 69 is similar to that in the preceding modification and corresponding parts are designated by the same reference numeral followed by the subscript a. However, in this form of the invention holes 42a are located more closely together and in fact are directly inwardly of walls 36 of web 34. Grooves 46a are formed in walls 36 and hence the ends 44a of insert 41a are compressed between the bottoms of grooves 46a and web 34, and the inwardly facing walls 26a of prongs 24a.

Here again, it will be understood that although the holes 42a are formed in top flange 32a, they might also be formed in flanges 33a.

Here again, it will be understood that although the holes 4211 are formed in top flange 32a, they might also be formed in flanges 33a.

Whereas, a single insert 41 is shown in FIGS. 1 and 6, nevertheless a plurality of inserts may be used. For example, one insert might be inserted from the top and the other from the bottom. The

inserts

41 and 41a might both be used simultaneously so that the prongs 24a are engaged both on a top or bottom surface and on an inwardly facing wall 26 simultaneously. These modifications 4 readily will occur to one skilled in the art where problems of dislodgment of the tooth from its holder during normal usage are unusually severe.

What is claimed is:

1. In earth digging equipment, a tooth having a distal portion and a proximal portion, said proximal portion divided into a pair of prongs by a slot extending forward from the proximal end of said tooth from top to bottom of said proximal portion, a tooth holder formed with forward opening recesses to receive said prongs, and a web to fit within said slot, said prongs having a pair of first surfaces, said recesses having a pair of second surfaces in close proximity to said first surfaces, said holder formed with a pair of holes extending from the exterior of said holder and communicating with said recesses, and a resilient insert doubled over and having a pair of ends extending through said holes into said recesses and each positioned between a first and second wall to restrain unintentional withdrawal of said tooth from said holder.

2. The combination of claim 1, in which said second surface is located removed from said web and said first surface is the contiguous surface of one of said prongs.

3. The combination of claim 1, in which said second surface is on said web and said first surfaceris-thewon tiguous surfac e of oneofsaid'prongs'. A

4;The" combination of claim 1, in which said holder is formed with an external groove connecting the outer ends of said holes and the connecting portion of said insert is received in said external groove. 7

5. The combination of claim 1, in which said second surfaces are formed with longitudinal grooves rearward of the inner ends of said holes and the inner ends of said insert are received in said longitudinal grooves.

6. The combination of claim 5, in which said longitudinal grooves are shallower and wider than the corresponding unstressed dimensions of said inner ends of said insert.

7. In earth digging equipment, a tooth having a distal portion and proximal portion, said proximal portion having an extended first surface, a tooth holder formed with a forward opening recess to receive said proximal portion, said recess having an extended second surface in close proximity to said first surface, said holder formed with a pair of holes extending from the exterior of said holder and communicating with said recess at said second surface, and a resilient insert doubled over and having a pair of ends extending through said holes into said recess, each said end squeezed between said first and second surfaces to restrain unintentional withdrawal of said tooth from said holder.

References Cited UNITED STATES PATENTS 2,968,880 1/1961 Petersen 37-142 3,057,091 10/1962 Petersen 37142 3,286,378 11/1966 Benetti 37-142 ABRAHAM G. STONE, Primary Examiner.

R. CARTER, Assistant Examiner,

Claims

7. IN EARTH DIGGING EQUIPMENT, A TOOTH HAVING A DISTAL PORTION AND PROXIMAL PORTION, SAID PROXIMAL PORTION HAVING AN EXTENDED FIRST SURFACE, A TOOTH HOLDER FORMED WITH A FORWARD OPENING RECESS TO RECEIVE SAID PROXIMAL PORTION, SAID RECESS HAVING AN EXTENDED SECOND SURFACE IN CLOSE PROXIMITY TO SAID FIRST SURFACE, SAID HOLDER FORMED WITH A PAIR OF HOLES EXTENDING FROM THE EXTERIOR OF SAID HOLDER AND COMMUNICATING WITH SAID RECESS AT SAID SECOND SURFACE, AND A RESILIET INSERT DOUBLED OVER AND HAVING A PAIR OF END EXTENDING THROUGH SAID HOLES INTO SAID RECESS EACH SAID END SQUEEZED BETWEEN SAID FIRST AND SECOND SURFACES TO RESTRAIN UNINTENTIONAL WITHDRAWAL OF SAID TOOTH FROM SAID HOLDER.