ROUTER BIT ASSEMBLY FOR AN EARTH WORKING APPARATUS

Abstract: In an earth working apparatus (10, 12), a separate router bit (32) and support (34) are removably secured along a generally vertically extending side member (22) of an earth-working blade (18). By forming them of separate elements, the router bit can be made of inexpensive plate metal while the support can be economically forged since it is in relatively protected position between the router bit and side member. The support is reversible and has a first lip (36) overlying the upper end (38) of the router bit and a second lip (40) underlying the lower end (30) of the side member whereby forces are transmitted directly from the router bit to the side member through the support instead of through the removable bolts (50).

Description: Description Router Bit Assembly For An Earth Working Apparatus Technical Field This invention relates to a router bit assembly for earth working apparatus as, for example, a tractor scraper, a bucket loader, a dozer, etc. - Background Art The most pertinent prior art known to the appli- cant is United States Letters Patent 2,831,275 issued April 22, 1958 to Kimsey et al. Other prior art of possible relevance includes the following United States Letters Patents: 3,032,901 issued May 8, 1962 to Dils; 3,088,232 issued May 7, 1963 to Gilbertson; 3,456,370 issued July 22, 1969 to Gilbertson; 3,465,833 issued September 9, 1969 to Lutz; and 3,643,357 issued Febru¬ ary 22, 1972 to Benning et al. In most earth working vehicles, there is pro¬ vided a transverse, or horizontally elongated cutting edge for the purpose of cutting into the underlying terrain. In addition to the transverse cutting edge, it is desirable to provide short cutting edges on opposite ends of the transverse edge to act as leading edges at the lower parts of vertically extending sides of the earth working implement. These cutting edges are commonly known as router bits and they are provided to slice through the earth as the implement is being moved forwardly to insure a clean cut and to protect lower leading edges of the side members. If not pro- vided, the lower extremities of the side members wear at excessive rates necessitating frequent time consuming and expensive repair. Thus, for a considerable period of time, the assignee of the present application has utilized router OMPI *xπ\i bits of the type disclosed in the above identified Kimsey et al patent in apparatus where their desira¬ bility is apparent as, for example, tractor scrapers. While such router bits have worked well for their in- tended purpose and, are relatively long lived because of their reversability, they are not altogether satis¬ factory from an economic point of view. The Kimsey et al router bits are formed of forgings which are rela¬ tively expensive to fabricate and which must be dis- carded when worn out. And, because one side of the Kim¬ sey et al router bit, which is configured with flanges to provide for reversability, is drawn through the eart during use, some wear to such flanges will inevitably • occur. When such wear is exce'ssive, it may become dif— ficult to reverse the router bit and remount it due to the wear on the flanges. Such wear can also result in a relatively loose fit with the consequence that verti¬ cal shear stresses are placed upon the means, i.e. bolts used by Kimsey et al to secure the router bits in place. Disclosure of Invention The present invention is directed to overcoming one of more of the above problems. According to the present invention, there is provided a router bit assembly for an earth working apparatus including earth working means having a generally horizontally elongated blade with a generally vertically extending side member at at least one end of the blade. A relatively tall router bit formed of plate metal extends along the side member and in proxi- ity to the blade. A relatively short support is pro¬ vided for the router bit and is interposed between the router bit and the side member. The supporthas a first li overlying and substantially abutting the upper extremity of the router bit and a second lip underlying the lower extremity of the side member. Removable means secure - XT O " aiV the router bit and the support to the side member. As a consequence of this construction, the router bit may be formed of inexpensive plate metal as opposed to expensive. forgings. The relative di- mensioning of the router bit and its support minimizes wear of the support to provide it with a long li e thereby making it economically feasible to form the support of a forging. Because the support is not sub¬ jected to wear, vertical shear stresses in the securing means are eliminated through direct transmission from the router bit to the side member via the support. Other objects and advantages will become ap¬ parent from the following specification taken in connec¬ tion with the accompanying drawings. Brief Description of Drawings Fig. 1 is a side elevation of an earth working apparatus, namely, a tractor scraper, employing an em¬ bodiment of the present invention; Fig. 2 is an enlarged, fragmentary, side eleva- tion of the router bit assembly; Fig. 3 is an enlarged, fragmentary sectional view taken approximately along the line 3-3 in Fig. 2; Fig. 4 is a plan view of a support employed in the assembly; ' Fig. 5 is a sectional view taken along the line 5-5 in Fig. 2. Best Mode For Carrying Out The Invention One embodiment of a router bit assembly made according to the invention is illustrated in Fig. 1 in the environment of a tractor scraper. However, it will be understood that the invention is not limited to use in such an environment but may be employed with efficacy in a variety of earth working apparatus as, for example, dozers, bucket loaders, etc. The earth working apparatus includes a tractor 10 and a trailing scraper bowl 12. The forward end 14 of the scraper bowl 12 may be closed by an apron 16 or opened as desired. The lower edge of the bowl 12 at the forward end 14 is provided with a horizontally elongated scraper blade 18 which can be engaged with the underlying terrain by lowering the bowl 12 about a pivot axis defined by the centers of it rear wheels 20 in" a conventional fashion. The bowl 12 has upstanding side walls 22 and, a is well known, the blade 18 extends between the walls 2 Referring to Figs. 2 and 3, each side wall 22, near the forward end 14 of the bowl, has a slightly up¬ wardly inclined, downwardly facing lower edge 30. Alon the length of the edge 30, on each of the side walls 22, a router bit 32 of any desired configuration is provide According:to the invention, the router bit 32 is formed of metal plate, such as steel plate, as opposed to bein a cast or forged member. Consequently, the router bit 32 is relatively inexpensive. A support, generally " designated 34, is employed to secure the router bit 32 'to the side wall 22 at the lower edge 30 and as can be seen in Figs. 2 and 3, the support 34 includes a first, elongated lip 36 which ove lies and abuts the upper extremity 38 of the router bi 32 along its length. A second -hip 40 extends along the length of the support 34 and projects oppositely from the lip 36 to underlie the edge 30 of the side wall 22. As seen in Fig. 3, the lips 36 and 40 are spaced from each other and are interconnected by a web 42 to result in a Z-shaped cross section. As seen in Figs. 2, 3 and 4, the web 42 is pro¬ vided with a series of bolt holes 44. Similarly aligne bolt holes 46 are provided in the router bit 32 while aligned bolt holes 48 are provided in the side wall 22. Suitable bolts or the like 50 extend through aligned ones of the bolt holes 44, 46, and 48 so that the route bit 32 can be joined to the side wall 22 via the suppor O member 34 . It will be observed from Fig. 3 that the sup¬ port 34 is relatively short while the router bit 32 is relatively tall. Thus, the support 34 is somewhat spaced from the working edges of the router bit 32 and accordingly, will not be subjected to the wear imparting forces that occur thereat through contact with the earth. As seen in Figs. 2, 3 and 4, the first lip 36, at its rearwardmost end, that is, the end in the direc- - tion away from the working edge of the blade 18, in¬ cludes a downturned portion or section 52 which extends behind the rearwardmost extremity of the router bit 32. The second lip 40 includes an upturned section 54 which is located forwardly of the forwardmost edge of the side wall 32. From a consideration of the orientation of the lips 36 and 40 with respect to the web 42, the apertures 44 therein, and the downturned portion 52 and the up¬ turned portion 54, it will be appreciated that each support 34 is completely reversable. By completely re- versable it is meant that by " rotating the support 34 180° about its longitudinal axis as well as rotating the same 180° about the axis of the centermost bolt hole 44, the second lip 40 can be made to perform the function of the first lip 36 and vice versa. At the ' same time, simply by rotating the support 34 180° about the axis of the centermost bolt hole 44, it can be applied to the opposite side wall 22 of the bowl 12. Returning to Fig. 2, the forward edge 14 of the side wall 22 may be provided with a narrow forwardly projecting retaining strip 60 (see also Fig. 5) secured in place as by welding 62. The upper end of the re¬ taining strip 60 includes two converging surfaces 64 and 66 which define a projection. An elongated wear member 70 is releasably se- cured to the strip 60 without the need for auxiliary fasteners. As seen in Fig. 5, the wear member 70 O PI /.* WIPO - includes,aforwardly facing nose 72 and an opposite, rearwardly opening groove 74 which receives the re¬ taining strip 60. At its upper end, the wear member 70 includes a rearwardly directed section 76 which, together with a part of the groove 74, defines a hook¬ like cavity 78. The lower end-of the wear member 7O includes a small, downwardly extending-tongue 80i The tongue 80 is received between a part 82 of the forward end of the side wall 22 and the upturned section 54 of the second lip 40. To install the wear member 70, the same is dis¬ posed on the retaining strip 60 such that the projection defined by the converging surfaces 64 and 66 enters the cavity 78. Thereafter, the support member 34 may be installed to capture the wear member 70 with the tab 80 behind the upturned section 54. Industrial Applicability The present invention allows the use of in- expensive material in forming the router bit 32. At the same time, the support 34, is subject to miiώπiiri w≥ar and, as wear does occur, it will not occur on the sup¬ porting surfaces of the support 34, that is, the sur¬ face intended to abut the edge 30 or the extremity 38 of the router bit 32. Consequently, all vertical loading imparted to the router bit 32 is directly transmitted to the side wall 22 via the support 34 and not through the bolts 50. The reversability of the support 34 provides for great flexibility in its use and the unique construction allows simple installation of a vertical wear member 70 without the ' .need for the use of bolts or the provision of bolt receiving aper¬ tures therefor during manufacturing operations. OMPI

Claims: Claims 1. A router bit assembly for an earth working apparatus (10,12) comprising: earthworking means including a generally (18) horizontally elongated blade with a generally vertical- ly extending side member (22) at at least one end of the blade; a router bit (32) formed of plate metal extending along said side member and in proximity to said blade; a support (34) for said router bit interposed between said router bit and said side member and having a first lip (36) overlying and substantially abutting the. upper extremity (38) of said router bit and a second lip (40) underlying the lower extremity (30) of said side member; and removable means (50) securing said router bit and said support to said side member. 2. The router bit assembly of claim 1 wherein - said support is Z-shaped in cross-section. 3. The router bit assembly of claim 2 wherein said first lip, at its end in a direction away from the blade, includes a down 'turned section (52) behind the corresponding extremity of said router bit and said second lip, at its end remote from said first lip end, includes an upturned section (54) in front of said side member. 4-. The router bit assembly of claim 3 wherein said removable means• comprise bolts (50) and there are a plurality of bolt holes (44) in said support member centered between said lips., said support means being reversible. 5. The router bit assembly of claim 3 wherein said front of said side member includes a narrowed, vertically extending retaining strip (60) terminating in a projection (64,66) and further including an elongated wear member (70) having a slot (74) receiving said strip, a hook (76,78) on one end disposed on said projection, and its opposite end (80) disposed between said side member and said upturned section of said second lip. _O " w

Inventors: MERKEL R
Applicants: CATERPILLAR TRACTOR CO, MERKEL R
Application year: 1979
Main classification: E02F3
IPC codes: E02F3, E02F9