Excavator

Application filed November

To dll whom it may concern:

Be it known that I, George H. Greimann, a citizen of the United States, residing at Garner, in the county of Hancock and e State of Iowa, have invented certain new and useful Improvements in Excavators; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in 10 the art to which it appertains to make and use the same.

My present invention relates to excavators of the type that are especially adapted for digging, for example, drainage trenches oils ditches in which to lay sewer, drain or other pipes, and generally stated, the invention consists of the novel construction, and combinations of parts hereinafter described and defined in the claims.

In a sense, the present invention is in the nature of. an improvement on. the machine disclosed and claimed in my prior Patent #1,287,675, of date December 17, 1918, entitled “Excavator.”

Primarily, the present invention is directed to improvements in the endless excavating mechanism, and is directed particularly to an improved arrangement of excavator spades or segmental excavating plates 30 that are carried by an endless link belt or belts arranged to run over polygonal driving and guiding wheels and whereby an important function, hereinafter described, is obtained.

The invention is illustrated in the accompanying drawings, wherein like characters indicate like parts throughout the several views.

. Referring to the drawings:

Fig. 1 is a view chiefly in side elevation with some parts in diagram and with some parts sectioned, illustrating my present invention;

Fig. 2 is a fragmentary view illustrating 45 the novel action of one of the polygonal wheels on an excavating spade that is approximately in position to drop its load; and

Fig. 3 is a perspective illustrating the manner in which the spades are connected to i>0 the chain or endless carrier. _

In Fig. 1, the invention is illustrated as incorporated in a self-propelled excavator, the parts of which may be briefly noted as follows: The numeral 4 indicates a truck 55 frame supported by front wheels 5 and by

5, 1820. Serial No. 421,898.

rear wheels 6, over which tread chains 7 are arranged to run. Through suitable mechanism, not necessary here to consider, the wheels 6 are driven from an engine 8 carried by the truck 4. The numeral 9 indicates 60 a transversely movable conveyor belt, whicli runs, over suitable rollers driven from the engine 8 and adapted to deliver dirt at one side of the excavator in a well known manner. The numerals 10 and 11 indicate up- 65 right columns rigidly secured on and car- . ried by the frame .4 and between which, as shown, the conveyor belt 9 is arranged to work.

The numeral 12 indicates a vertically ad- 70 justable boom, which, at its front end, is pivoted on a transverse shaft 13 journaled in suitable bearings on a trussed rearwardly projected boom-supporting frame 14 that is rigidly secured on the main frame 4. . The 75 shaft 13 carries, a large sprocket or chain of the wheel 15 and a small polygonal wheel 16. A similar polygonal wheel 17 is· journaled to the free rear end of the boom 12. A sprocket or link chain 18 runs over the two polygonal 80 wheels 16 and 17. Said wheels 16 and 17, as. shown, are hexagonal. : .

For raising and lowering the boom 12, a cable 19 is attached thereto and extended over a guide sheave 20 on the frame 14 and is 85 attached to a suitable windlass indicated as an entirety,by the numeral 21. For rotating the sprocket or chain wheel 15, a chain or. belt 22 is run thereover and this chain or belt is driven from the engine through any suit- 00 able transmission mechanism indicated as an entirety by the numeral 23 and not necessary for the purposes of this case to further consider. The sprocket chain or link belt 18 carries a plurality of curved spades 24 95 formed, by flat sheet metal bent into segmental form. These spades are rigidly se cured to the flanged outer ends of arms 25.

Said arms 25, at their inner ends, are bifurcated or forked and their prongs are formed 100 integrally with or otherwise rigidly secured to laterally spaced link-forming elements 26, which latter are incorporated as certain of the links of the chain or belt 18. The linkforming elements 26 are adapted to be read- 105 ily coupled to the standard links of the chain by coupling pins 27 that are held in place by cotters 28 passed through perforations in the ends of said chains and held between guard ribs 29 on the outer surfaces of said link- 110

1.481.602 forming elements 26. The pins 27, at one end, (see particularly Fig. 2), have flattened heads 27^a that are held between the adjacent ribs 29. These ribs 29 also perform fl the additional function of preventing rotation or oscillation of the pins in respect to the link elements 26, and, hence, cause the wear to take place between the pins and the standard links of the chain and. thus save the 1: link elements 26 from wear. This is important because said elements 26 are a part of the cast arm 25, the replacement of which would be expensive.

A sharp edged tempered cutting blade 30 K is boiled, riveted or otherwise rigidly secured to the front edge of each spade and to the flanged outer end of the spade-supporting arm. This cutting blade 30, at its ends, projects slightly beyond the sides of the 2e Spade, and the sharp front edge is cut on the line of -a circle so that the central portion thereof will move in advance of the encl portions in the excavating action. This is. important because, in the first place, it 25 will cause roots and the like to work off at the ends of the cutting blade and, in the second place, will cut a ditch with a slightly rounded bottom oi· that is lower at its central portion than at its sides. It is now imse portant to note that each blade-supporting arm 25 projects outward from the rear ends of the link-forming elements 26 and that the spade projects rearward from said arm 25, directions being taken in respect to the 35 direction of travel of the chain 18, in the excavating action. This ’forward projection of the link-forming elements 26, from the spade-carrying arm 25, affords means for attaching said link elements into the chain ^4!! at a point in advance of the cutting edge of the blade 30 and gives a good leverage resistance in'the chain to the reaction from the cutting force.

Another important result is this: Just be⁴ -fore a particular ‘ spade reaches a. position for dumping its load, (see Fig. 2), one of the salient or 'projecting angles of the wheel 16 strikes the rear portions of the link elements 26, thereby producing a sort of a rap51’ ping action and outward movement of the arm 25 and spade 24, which serves to loosen the dirt or load from the spade so that it will more readily subsequently discharge the load; and moreover, under continued up•'^!Π ward movement, the spade and especially its rear portion will be-thrown radially outward or farther away from the axis of'the shaft 13 so that the discharge of the load from the spade will be made an easier matter and the spade will more readily throw its 60 load forward onto the transverse conveyor belt 9.

The excavating blades 26 are herein designated as “spades” because they have much the action of a spade, in that they cut the 65 dirt loose and then scrape as well as carry . the load to the point of discharge. As the so-called spades, as preferably constructed, have no side flanges, the dirt will not be packed or caused to adhere thereto to the 70 same extent as with the excavating device of the character generally designated as buckets. The statements above made are based on actual experience in running· of commercial excavators embodying the in- 75 vention.