US3028693A - Boom construction for ditching machine - Google Patents

Description

April 10, 1962 G. E. MALZAHN BOOM CONSTRUCTION FOR DITCHING MACHINE Filed April 14. 1960 2 Sheets-Sheet 1 WW I 605 E Ma/za/m IN VENTOR.

April 10, 1962 G. E. MALZAHN 3,028,693

BOOM CONSTRUCTION FOR DITCHING MACHINE Filed April 14, 1960 2 Sheets-Sheet 2 United States Patent 3,028,693 BOOM CONSTRUCTION FOR DITCHING MACHINE Gus E. Malzahn, P.O. Box 66, Perry, Okla. Filed Apr. 14, 1960, Ser. No. 22,317 Claims. (Cl. 37-86) This invention relates to portable ditch or trench digging machines having a boom assembly adjustably mounted thereon and extending therefrom for supporting continuously moving digging tools used for various earth moving purposes.

It is therefore a primary object of this invention, to provide a boom assembly which is of simple construction, and having readily replaceable parts capable of being easily disassembled for repair purposes.

It is a further object of this invention, to provide a boom construction which is both laterally and torsionally rigid but longitudinally yieldable as desired, less susceptible to damage and therefore has a wider and greater utility.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a side elevational view of the boom assembly as mounted on a ditch trencher machine.

FIGURE 2 is a perspective view of the front sprocket supporting assembly.

FIGURE 3 is a partial side elevational view of the boom assembly, with parts shown in section.

FIGURE 4 is a partial top plan view of the boom assembly.

FIGURE 5 is a transverse sectional view taken through a plane indicated by the section line 5-5 in FIGURE 1.

Referring to FIGURE 1, the boom assembly generally indicated by reference numeral is shown mounted on a ditch trencher machine indicated by reference numeral 12 as is generally known in the art. The boom assembly slidably supports at its front end a front sprocket assembly or work thrust engaging means generally indicated by reference numeral 14 while the main supporting assembly 16 supports intermediate its length a sprocket assembly 18 while a chain 21 carrying a plurality of spaced digging tools 22 is trained around the sprockets supported by the sprocket assemblies, and is driven by power means located on the machine 12. The main boom assembly 16 is adjustably pivoted to the machine 12, for downward movement into various digging positions and upwardly movable when retracted.

Referring now to FIGURE 2, the front bracket assembly 14 includes a sprocket carrying bracket 24 having ears 26 and 28 having aligned holes 36 and 32 for journaling a sprocket wheel therebetween. A shank 34 is secured to the bracket 24 and has an enlarged portion 36 at its inner end for reasons which will hereafter become apparent.

As more clearly seen in FIGURES 3 and 4, the main boom assembly portion 16 includes a tubular member 38 within an open end of which the front sprocket assembly is slidable, the tubular member having secured thereto by welding or other equivalent means the sprocket assembly 18 consisting of a supporting sprocket bracket 40 depending downwardly therefrom for rotatably supporting a sprocket or transmitting wheel 42. A sprocket or transmitting wheel 44 is also rotatably mounted by the cars 26 and 28 of bracket 24 and the endless chain 20 is trained about sprocket wheels 42 and 44. As more clearly seen in FIGURE 5, the tubular member 38 is of rectangular cross-section so as to better resist bending in both a vertical and horizontal plane.

As clearly seen in FIGURES 3, 4 and 5, the shank 34 of the front sprocket assembly is slidably disposed within the tubular member 38 and is biased outwardly therefrom by means of a coil spring 46 reacting between the enlarged end portion 36 of shank 34 and a pin 48 transversely disposed between opposite side walls of the tubular member 38 and secured thereto as by welding 50 as seen in FIGURE 4. In order to slidably guide the narrow portion of shank 34 and limit outward movement of the shank, plates 52 and 54 are provided within the outer end of the tubular member 38 against the inner walls thereof. The plates 52 and 54 are secured to the tubular member 38 by welding 56 as more clearly seen in FIGURES 3 and 4. The plates 52 and 54 accordingly limit outward movement of the shank 34 by abutting against the shoulders formed by enlarged portion 36 of the shank and furthermore seal the open end of the tubular member 38.

From the foregoing description, it is therefore ap parent that the boom assembly 10 is capable of'yielding inwardly when overloaded by the digging tools 22, by virtue of the spring 46 reacting between pin 48 in the tubular member and the end of the shank slidable therein. It is also apparent that the spring 46 is protected from damage by the earth being moved, since it is entirely enclosed within the tubular member 38 and sealed therein by the plates 52 and 54 at its open end which also slidably guide the shank 34 and limit its outward movement. Also, since the plates are secured to the tubular member 38 only at its outer exposed end by welding 56 which may be readily cut, the boom assembly may be easily disassembled for repair purposes.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In a ditch trencher machine, a digging boom assembly adjustably mounted on said machine extending outwardly and forwardly of said machine, said boom assembly comprising an elongated tubular member of rectangular cross-section, a sprocket supporting bracket having parallel ears for rotatably supporting a sprocket wheel therebetween, a shank secured to said bracket and slidably disposed within said tubular member at an outer end thereof, said shank having an enlarged cross-section at an inner end portion thereof slidable relative to inner walls of said tubular member and spaced from a pin mounted in said tubular member and extending transversely between said inner walls, spring means disposed within said tubular member and abutting between said pin and said inner end portion of said shank, separate plates disposed against the inner walls of said tubular member adjacent its outer end, for slidably guiding said shank and limiting its outward movement by engagement with the enlarged inner end portion, said plates being secured to said tubular member by welding at its outer end, a second bracket rigidly secured to said tubular member intermediate its length extending downwardly and perpendicular thereto for rotatably mounting a sprocket and an endless chain drivingly engaged with said sprocket wheel and sprocket, carrying a plurality of spaced digging tools.

2. In a ditching machine, a digging boom assembly mounted on said machine and extending outwardly therefrom, said boom assembly comprising an elongated tubular member, a bracket having a sprocket wheel rotatably mounted thereon, a shank secured to and support ing said bracket and slidably disposed within said tubular member at an outer end thereof, said shank having at an inner end thereof a portion of enlarged cross section slidably received within said tubular member, a pin mounted in said tubular member and extending transversely thereof in spaced relation to said enlarged portion of said shank, spring means disposed in said tubular member and operatively engaging and yieldingly separating said pin and said shank, separate plates constituting combined means for journalling and retaining said shank in said tubular member and disposed against the inner walls of said tubular member adjacent its outer end and against said shank, the inner ends of said plates being engageable with said enlarged portion for limiting outward movement of said shank in said tubular member, means securing the outer ends of said plates to the outer ends of said tubular member, an endless chain drivingly engaged with said sprocket wheel and spaced digging tools on said chain.

3. The combination of claim 2 including a second bracket rigidly secured to said tubular member intermediate the length of the latter and projecting perpendicularly therefrom, a sprocket rotatably mounted upon said second bracket and engaged by said chain.

4. The combination of claim 2 including a plane surface on said enlarged portion perpendicular to the axis of said shank and disposed perimetrically about the shank at the junction of the latter with said enlarged portion, said surface constituting an abutment engageable with the adjacent ends of said plates.

5. The combination of claim 2 wherein each of said plates comprises a fiat rectangular member, the adjacent walls of said tubular member and of said shank having flat plane surfaces each complementary to and engaging one of said plates.

References Cited in the file of this patent UNITED STATES PATENTS 405,511 Umstead June 18, 1889 2,247,825 Warner July 1, 1941 2,667,709 Askue Feb. 2, 1954 2,686,981 Vaughn Aug. 24, 1954 2,702,485 Nadherny Feb. 22, 1955 2,714,262 Malzahn Aug. 2, 1955 2,764,031 Nystrom Sept. 25, 1956

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