US3426459A - Tooth and holder for bucket - Google Patents

Description

Feb. 11, 1969 G. A. PETERSEN TOOTH AND HOLDER FOR BUCKET Filed Oct. 22, 1965 FIG--3- INVENTOR. F I E 4 GERALD A. PETER-551V ywzm Q/AV Arron/5v United States Patent 4 Claims ABSTRACT OF THE DISCLQSURE The blade edge of a front end loader bucket is formed with slots in the leading edge to receive tooth-holders, the bottom edge of the holder being coplanar'with the bottom of the bucket so that the bottom of the bucket contacts the ground. Replaceable teeth are detachably held in the holders. When desired, teeth may be removed and the holder sockets filled with plugs merging with the contour of the bucket edge. The tooth is formed with a distal and a proximal end, the bottom surfaces of which are at an obtuse angle. The bottom of the distal end is coplanar with the bottom of the bucket, the holder formed with a socket-like recess disposed at an angle to accommodate such relationship.

This application is a continuation-in-part of copending application Ser. No. 485,154, filed Sept. 7, 1965, now US. Patent No. 3,349,508, issued Oct. 31, 1967. The invention relates to a new and improved tooth and holder for a bucket, such as used on a front end loader. Uses of buckets of this type including loading loose material into a truck, or pushing loose material along a relatively flat surface, such as a pavement, from one location to another as in back-filling a hole. In such primary uses it it important that the lip or leading edge of the bucket be smooth and fiat on the bottom so that the amount of sweeping and hand-shoveling which must be used to clean up the job is reduced to a minimum. However, it is frequently desirable to provide the front edge of the bucket with teeth either to assist in prying heavy objects, or for certain digging operations. Accordingly, it is common practice to provide tooth-holders on the lip or leading edge of the bottom of the bucket for replaceable digging teeth. In accordance with prior practice tooth-holders are welded or bolted to the front edge and left in position even when no teeth are installed in the holders and such tooth-holders interfere with most effective primary use of the bucket.

Accordingly, the present invention has for its principal purpose and function the provision of a tooth-holder for cooperation with a digging tooth in such manner that the tooth may be removed and, when removed, the toothholder does not detrimentally affect other functions of the bucket.

A principal purpose of the present invention is to provide a tooth-holder which is inserted in a slot cut in the leading edge of the bucket, with the bottom surface of the holder coplanar with the bottom surface of the bucket, so that no bumps or obstructions are created on the .bottom and interference with the normal loading of the bucket is reduced to a minimum.

A further feature of the invention is the facility with which the tooth may be installed and removed, the time consumed for such operations be minimal and no special tools, skills or equipment being required.

Another feature of the invention is the provision of plugs which fit into the holders when the teeth are removed, the leading edges of the plugs merging with the contour of the front edge of the bucket so that a sub- 3,426,459 Patented eb. 11, 1969 stantially smooth and continuous front bucket edge is achieved when the teeth are not required. The teeth and plugs may be interchanged with a minimum of time and skill required and no special tools or equipment required.

A feature of the invention is the shape of the proximal portion of the tooth which is received in the tooth holder and the cooperating shape of the recess or socket of the tooth-holder which is complementary thereto. In cross section, the portion of the tooth received in the holder is T-shaped. In one form of the invention the leg of the T is received between overhanging lips of the socket and the crossarms of the T are received in laterally-diverging extensions of the socket. Such shape assures that the tooth will be securely held against misalignment despite considerable force encountered in the digging action. In a preferred form of the tooth, the rib or leg of the proximal end of the tooth is higher than the socket so that the rib extends exteriorly of the tooth-holder. Such shape facilitates driving the tooth out of its socket when the tooth must be replaced, in that a tool may be inserted behind the leg for such purpose.

The rib and laterally extending feet provide a T-shaped cross-section of the proximal portion of the tooth which considerably enhances the strength of the tooth, a feature of advantage under severe operating conditions. At the same time, the rib may project above the holder for at least a portion of its length so that the projecting portion may be struck with a hammer or other tool to dislodge the tooth from the holder.

Another feature of the invention is the fact that the bottom face of the tooth is preferably coplanar with the bottom surface of the tooth-holder and the bottom surface of the bucket. The top face of the tooth slants downwardly-forwardly to merge with the bottom surface of the tooth at a small angle of about 10. A truncated transverse cutting edge is provided just short of the intersection of the top and bottom faces, This relationship of the various surfaces, thus described, greatly reduces the amount of energy required to perform the digging function, since for practical purposes the tooth digs approximately straight into the earth or other material being excavated instead of at an angle. In other words, the bottom surface of the tooth advances in the direction of movement of the tooth and the top surface wedges the earth or other material excavated upwardly. A great deal less energy is required for such digging action than in other relationships of tooth surfaces. Abrasion occurs on both the top and bottom faces of the tooth so that the tooth remains in essentially its original conformation until it is almost worn out and digs effectively during its entire life.

The preferred retention means for retaining the tooth in its socket, as hereinafter described in detail, is a resilient insert which is doubled over to a substantial U-shape and both ends of the insert are then inserted through a propriate holes in the tooth-holder, extending into the tooth socket. When the tooth is forced into the socket, the ends of the insert are bent back and compressed between the tooth and the wall of the socket to restrain unintentional dislodgment of the tooth from its holder. To eliminate undue wear of the rubber insert, a groove may be formed in the exterior of the holder interconnecting the ends of the holes to recess the connecting portion of the rubber insert below the surface of the holder so that it is not abraded.

Use of a rubber retainer bent in U-shape has several advantages over a straight piece of resilient material. One advantage is that the rubber is less likely to fall out of the holder when the tooth is removed and prior to the time the tooth is inserted if it is bent in such shape. Bending in such fashion puts stress on the rubber which discourages its slipping out of place. This feature is of great convenience in locations where finding the dropped retainer or replacing with a new one would be difiicult.

Still another advantage of the reversely bent retainer is that it tends to locate the retainer in a more positive and definite maner. Where a single length of rubber is installed in a hole, it tends to be pulled along when the tooth is inserted, but the extent of movement longitudinally of the tooth is unpredictable. Hence the total area of the rubber compressed between tooth and holder tends to be variable and its retaining effect is somewhat uncertain. This uncertainty makes accurate engineer-computations impractical. When the rubber is doubled over, the forces tending to pull each leg are balanced and hence the rubber is elongated and compressed but not pulled out of position. Therefore, the effective length or area is not so uncertain and the retention effect considerably more predictable.

An important feature of the invention is the fact that the tooth seats against the front end of the tooth-holder rather than seating interiorly of the tooth-holder. This construction avoids undue strain on the tooth and the holder which might otherwise occur if the corner of the tooth were to strike a rock or other hard object with great force. The back portion of the tooth transmits thrust to the holder. Additionally, protuberances extending transversely immediately in front of the holder reduce wear of the holder, particularly since the tooth is relatively hard and is also replaceable.

The shape of the distal portion improves the digging characteristics of the tooth blade. Thus a central longitudinal rib or spine on one surface of the tooth increases in elevation rearwardly. Immediately forward of the holder are transverse protuberances which merge with the rearward end of the spine. Rounded fillets occur at the corners where spine and transverse protuberances coincide. Surfaces thus described tend to break up the soil through which the tooth moves, curving the soil outward and upward, breaking up the formation with an explosive action. Such action is particularly effective in digging highly compacted soils.

The plugs, as heretofore described, may be specially fabricated for their purpose or, alternatively, they may be fabricated by simple operations from worn out digging teeth.

A further feature of the use of plugs in holders is that they increase the life of the blade at the bottom of the bucket over the normal life, because the teeth or plugs absorb a considerable amount of the wear. These elements are usually hardened steel and are more abrasive resistant than the bucket itself and accordingly protect the bucket from excessive wear.

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 an exploded perspective view of a portion of a bucket furnished with teeth, one of the teeth shown removed.

FIG. 2 is a view similar to FIG. 1, showing plugs instead of teeth.

FIG. 3 is an enlarged top plan view of a tooth and holder and a portion of the bottom of a bucket.

FIG. 4 is an enlarged side elevational view taken as indicated by reference line 44 of FIG. 3.

FIG. 5 is a transverse sectional view taken substantially along the line 5-5 of FIG. 4.

The invention provides means for installing a plurality of teeth 11 in bucket 12. The construction of bucket 12 varies, depending upon the design of the manufacturer, but may be considered to have a bottom 13 of extended width and depth, an upstanding back 14 and sides 16. The front edge 17 is bevelled, usually at an angle of about 45, merging with bottom surface 18 of bottom 13.

In accordance with the present invention, slots which are rectangular in top plan are cut into the leading edge of bottom 13. Such slots have vertical longitudinal sides 20 and a vertical transverse back 21, extending from top to bottom of plate 13.

Tooth 11 has a distal portion 40 and a proximal portion 50, both hereinafter described in detail. Holder 60 is shaped to receive proximal portion 50, and also shaped to fit into the slot in the bucket heretofore described. Thus holder 60 has vertical longitudinally extending side edges 67 and a back edge 68 which, in assembled position, fit tightly in the slot and the abutting surfaces are welded to make a completed structure. The bottom surface 66 of holder 60 is positioned flush with bottom 18. Inasmuch as the thickness of the material of bottoms 13 vary with different manufacturers, the top surface 63 of holder 60 may vary in elevation with respect to the top surface of bottom 13, as is best shown in FIG. 5. Such variation in height is not of any considerable consequence in normal operation, but it should be emphasized that it is highly desirable that surfaces 66 and 18 be coplanar.

Holder 60 is formed with a socket complementary to proximal portion 50 at tooth 11, and for such purpose has a bottom 29 and sides 27. Lips 24 overhang sides 27 at the top and are separated from each other by a longitudinal vertical slot 26, so that viewed in crosssection the socket is in the shape of an inverted T. Below lips 24, the walls 27 are spaced relatively far apart.

For the purpose of providing entry for resilient retainers 33, hereinafter described, into the recess in the holder holes 34- are formed slanting from bottom 66 upwardly-rearwardly and opening into the corners where bottom 2Q and sides 27 intersect. The outer ends of holes 34 are joined by a transverse groove 37, having a depth about equal to the diameter of holes 34.

A preferred distal portion 40 for tooth 11 is shown in FIGS. 1 and 3 to 5. In a preferred form, the bottom surface 71 is relatively flat and is coplanar with the bottom surface 66 of holder 60 and, further, with bottom surface 18 of bucket bottom 13. On the other hand, the bottom surface 72 of the proximal portion of the tooth slants upwardly-rearwardly at an angle of approximately 5 with respect to surface 71. The top surface 73 of the distal portion converges toward surface 71 at an angle of about 5, but is divided by a medial longitudinal rib 74 which slants downwardly-forwardly toward top surface 73 and converges therewith at a terminus 76 spaced rearward from the blunt transverse perpendicular forward end 77 of the tooth. The top of rib 74 slants with respect to bottom surface 71 at an angle of about 20. The side edges 78 of distal portion 40 are vertical and parallel and are spaced about the same distance as the side 67 of holder 60.

Immediately forwardly of holder 61 are laterally extending protuberances 79 on either side of rib 74 which, in effect, comprise a transverse rib. Protuberances 79 have an elevation at least as high as the top edge of the proximal rib 51 to protect the same against abrasion. It Will also be noted that rib 74 originates at about the same elevation as the top of the holder for the same purpose. The corners 80 where rib 74 and protuberances 79 coincide are rounded and filletted to direct the dirt dug by the front cutting edge 77 sidewardly. Protuberances 79 limit inward movement of the tooth relative to holder 61 and insure that the tooth seats against the front end of the holder and not at the back of the holder. This avoids undue strain at the point where the front of the holder and the tooth coincide, which in the event of the corner of the tooth hitting a rock or other hard object with great force might cause a fracture or dislodgement of the tooth.

Proximal portion 50 of tooth 11 is T-shaped in crosssection complementary to the socket and has an outwardly extending rib 51 which fills the space between lips 24 and has laterally projecting legs 52 which substantially fill extensions 27 of the socket of the tooth-holder. The length of rib '51 is shown less than the corresponding dimension of the socket providing a space 49 at the back of the tooth through which an instrument may be inserted. to drive the tooth out of its socket when required for replacement. Legs 52 extend rearward in a rear xtension 55, behind the rearmost end of rib 51. Extension 55 enhances the stability of the tooth in its holder. It will be noted particularly in FIG. 4, that the upper edge of rib 51 may be elevated substantially above the level flip 24 and thus an instrument may be used to drive the back end of rib 51 forwardly to force the tooth out of its socket. This is particularly desirable if opening 49 is eliminated.The extended height of the rib protects the socket to some extent against abrasion.

The preferred retaining means for the tooth is a short section 33 of circular section resilient material, such as natural rubber, neoprene synthetic rubber or similar material. Where high temperatures are encountered as a result of the digging action, synthetic materials are particularly desirable. The cross-section of retainer 33 is approximately equal to that of holes 34 and groove 37. Insert 33 is bent into U-shape and the ends are inserted through holes 34 into the recess prior to the insertion of the tooth 11. As the tooth is forced into its socket, the ends 53 of retainer 33 are bent back and compresed in the corners between walls 27 and bottom 19. Insert 33 restrains unintentional withdrawal of the tooth from its socket and also accommodates variations in dimensions of the parts. Since the pull on each end 53 is substantailly the same, the insert 33 is not pulled out of position and does not move longitudinally in an unpredictable manner. Accordingly, the retention effect is substantially uniform. When it is necessary to remove the tooth, the tooth slips relative to insert ends 53 to permit such withdrawal.

In use, prior to insertion of tooth 11 in the socket in holder 60, insert 33 is doubled over into U-shape and the ends 53 inserted through holes 34. The proximal end 50 of tooth 11 is then inserted in the socket and as the back end of the tooth encounters ends 53 of the insert, they are bent back and into the corners as shown in FIGS. 4 and 5, and deformed to approximately the shape they are illustrated. The insert ends 53 restrain unintentional withdrawal of the tooth from its socket. However, when it is necessary to replace the tooth it may be driven out of its socket either by striking the back end of rib 51 or by inserting a prying tool in space 49. The distal portion 40 of the tooth performs the digging function. Longitudinal rib 54 reinforces the blade of the tooth and assists in fracturing the formation being dug. Protuberances 59 limit inward movement of the tooth relative to holder 60 and, also, assist in protecting the holder from abrasion. The digging action of the distal portion 40 is particularly effective in that rib 74 increases in elevation and fillets in front of the protuberances 79 tend to break up the soil sliced by the cutting edge 77, wedging it upward and outward and breaking the earth into relatively small particles or chips with an explosive action. The tooth thus works more effectively in difficult soils than prior teeth of this general type. The exploded earth is scooped up into bucket 12. The teeth 11 also assist in prying under objects, such as rocks and tree limbs, facilitating transfer into bucket 12.

When teeth 11 are worn, they may be replaced or sharpened. When such teeth are no longer needed in the operation of bucket 12 they are removed and replaced with plugs 11a. Plugs 112: have proximal portions 50, similar in all details to the proximal portions 50 of tooth 11. The distal portion 90, however, of plug 11a has a blunt forward edge 91 and a transverse upwardly-rearwardly slanted surface 92 which more or less merges with the bevelled edge 17 of bucket bottom 13, as is best shown in FIG. 2. It will be understood that the angle of surface 92 need not coincide identically with the angle of surface 17, although such relationship is desirable. When the plugs 11a are installed in holders 60, they are held in place by resilient inserts 33, as in the case of the teeth. They plug up the sockets in holder 60 and hence prevent material from jamming in the sockets and interfering with subsequent installation of teeth. On the other hand, by more or less filling out the contour of surface 17, they facilitate normal loading and unloading of the bucket. Further the hard plugs resist abrasive wear of edge 17. The plugs 11a may be specially fabricated, or they may be cut by means of a torch or other convenient means from a worn out tooth 11.

The teeth and plugs may be interchanged as the working conditions of the equipment require.

Although the foregoing invention has been described in some detail, by way of illustration and example for purposes of clarity and understanding, it is understood that certain changes and modifications may be practiced within the spirit of the invention and scope of the appended claims.

What is claimed is:

1. A bucket having a flat bottom surface, a holder formed with a recess, said, recess opening forward, said recess slanting upward-rearward, said holder having a fiat bottom surface coplanar with said flat bottom surface of said bucket, a tooth having a distal cutting end and a proximal end, said proximal end complementary to said recess and slanting upward-rearward and detachable retaining means for holding said tooth in said holder against unintentional dislodgemen't, said distal end having a transverse cutting edge and top and bottom surfaces converging toward said cutting edge, the bottom of said proximal end slanting upward-rearward relative to said bottom surface of said distal end, the bottom of said distal end coplanar with said bottom surfaces of said bucket and said holder. 1

2. The combination of claim 1 in which said distal end is formed with an upstanding longitudinal rib on said top surface slanting upward from adjacent said cutting edge and rising to at least the? elevation of said holder at its rearward end.

3. The combination of claim 2 which further comprises transverse protuberances 'on said top surface to either side of said rib bearing against the front end of said holder.

4. The combination of claim 1 in which said retaining means is at least partially located in said holder below said proximal end of said tooth.

References Cited UNITED STATES PATENTS 775,770 11/ 1904 Herrod. 1,807,632 6/1931 McKee. 1,992,591 2/1935 Whisler. 2,040,085 5/1936 Fykse et a1 37-142 2,824,392 2/1958 Reinhard. 3,057,091 10/ 1962 Petersen. 3,136,077 6/ 1964 Troeppl 37-142 2,253,245 8/1941 Noack 37-142 2,925,673 2/ 1960 Sennholtz 37-142 2,992,498 7/ 1961 Mork 37-142 ABRAHAM G. STONE, Primary Examiner.

ALAN E. KOPECKI, Assistant Examiner.

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