US 2637917 A
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May l2, 1953 H. KLAucKE 2,637,917
ExcAvATrNc uscmnrsu Fon Tamm mesma MACHINES Filed June 10, 1947 2 Sheets-Sheet l @6:92. 20 44 ff i 71 [l /2 50 A9 ll l o` l 40 l il a4 l n? 40 l -0 a 44 l 34 o l '20 40 .Q 0 /l /l3 "IIN I Hermann Klauc,
H. KLAUCKE May 12, 1953 EXCAVATING MECHANISM FOR TRENCH DIGGING MACHINES Filed June 10, 1947 2 Sheets-Sheet 2 dwo'meg h. WM
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Patented May 12, 1953 EXCAVATING MECHANISM FOR TRENCH DIGGING MACHINES Herma-nn Klaucke, Worcester, Mass., assigner to Chain Belt Company, Milwaukee, Wis., a. corporation of Wisconsin Application June 10, 1947, Serial No. 753,775
5 Claims. 1
The invention relates to trench digging machines of the kind provided with a digger boom carrying an excavating mechanism of the endless chain type, which machines are now used quite extensively for the digging of relatively narrow but fairly deep trenches in the earth to enable the laying of telephone, telegraph and similar cables below the frost line.
One of the objects of the invention is to provide an improved chain-type excavating unit for such machines, whereby trenches of the charac ter described may be cut more eliiciently and expeditiously in practically any kind of earth, including hard stony ground, compact gravel, and rm clay, as well as in lighter and less compact formations.
A further object or" the invention is to provide a comparatively light weight single strand chain excavator which may be operated at relatively high speeds, thus increasing the rate at which the trenches may be advanced; and the construction is quite simple, whereby the costs of manufacture and maintenance are materially reduced.
The chain of the excavating mechanism hereinafter described as an illustrative example of a practical embodiment of the invention, is of approximately 3 inch pitch and is of the roller type, with its pin links being of a special construction and each having a hardened toothed cutter member rigidly but readily detachably mounted thereon. This excavator is intended to run at a lineal speed on the order of 1,200 feet per minute, and to cut a trench approximately six inches in width to depths of say from 3 to 5 i'eet; however these figures are given merely by way of illustration rather than limitation, and all of them may be varied either way without departing from the spirit of the invention.
The excavating unit referred to is shown in the accompanying drawings forming a part of this speciiication, in which:
Figure 1 is a side elevational View thereof, partly broken away; all portions of the trenching machine itself being omitted except for the sprocket which drives the cutter;
Fig. 2 is a horizontal sectional view on a some what larger scale, taken on the plane indicated by the line 2-2 of Fig, 1, looking downwardly;
Fig. 3 is an enlarged vertical sectional View, partly in elevation, taken approximately on the plane indicate-d by the line 3 3 of Fig. 1, looking in the direction of the arrows;
Fig. 4 is a side elevational view on a still larger scale, of a pair or adjacent cutter elements, the
2 View being partly broken away and in section, and showing in detail the construction of the chain and the mounting of the cutter members thereon;
Fig. 5 is a front elevational view of the parts shown in Fig. 4, as seen from the right thereof; and
Fig. 5 is an end elevational view, as seen from the bottom of Fig. 5.
The excavating machine proper (not shown) may be of any well known type having a driving sprocket lil and a boom or its equivalent to which the plate-like guide member I! of the present cutter assembly may be vertically adjustably attached by means of one or more bolts passing through the elongated slot l2. At its lower end the opposed faces of the guide member are rabbeted as at I3 to receive the upper end portions of plates i4 which are secured to the member Il by bolts l5, and the lower portions of which mount an antiiriction bearing i6 which journals a lower or footsprocket I1.
An endless chain lit is trained about the sprockets l0 and il, said chain being of the roller type comprising alternating roller links I9 and pin links 2d, connected by headed or riveted chain pins 2l As best shown in Fig. 4, the roller links la are of a more or less conventional construction, comprising spaced side bars 22 rigidly connected by tubular bushings 23 upon each of which is journalled a roller 2li. The bores 25 of the said bushings journal the intermediate portions of the chain pins 2l.
As above indicated, the pin links 20 of the chain are of a special construction and comprise U-shaped stampings the legs 2S of which constitute the link side bars which are provided adjacent their ends with apertures 21 for receiving the end portions of the chain pins 2 l. These pins are held against rotation in such apertures by complementary iats 28 formed on the pins and the aperture Walls, and thus wear which inevitably occurs in the articulating joints of the chain is caused to take place in the roller links, which are less expensive to replace than the pin links.
The bridge or cross member of the pin links 253 have plates 3! rigidly secured to their outer faces, as. by welding at 32. The plates 3| are oi a width slightly less than that of the trench to be cut, while their length is such that in the straight runs of the chain between the sprockets the adjacent plates provide a substantially continuous wall disposed outwardly of the chain and tending to protect it from the excavated matter. A bracket 34, comprising a base plate 35 having an angular extension 35, and side wings 3T, is removably secured against the forward face 33 of each plate member 3|, as by bolts 38 passing through the bridge member 30, plate 3| and bracket base 35, as will be clear from Figs. 4, 5 and 6.
The extension 36 of the bracket is disposed at an angle of approximately 45 to the face 33 of the plate 3|, and a cutter member 40 is removably secured to such extension, as by bolts si. The said cutter member comprises a quadrangular plate of hardened steel or the like, the base of which is of a width substantially equal to that of the plate 3l and is beveled as at 42 to fit tightly against the face 33 of such plate. The sides of the cutter plate flare laterally outward from said base, as indicated at 43, to the forward or cutting end of the member, which is provided with a plurality of transversely spaced teeth or picks @e of triangular cross section.
As will be clear from Fig. 5, alternate cutters 4B are provided respectively with an odd number and an even number oi' teeth or picks M, with those of one member being transversely staggered relative to those of the adjacent member, thereby traversing diierent longitudinal paths. The teeth may thus be made rugged enough to withstand repeated contact with stones or the like, while at the same time the teeth of any pair of adjajcent cutters will act to dislodge material throughout the width of the cut. The teeth are given a forward clearance angle o approximately 15, as indicated at l5 (Fig. 4); and their entire formation is such that they are self-sharpening in use.
As best seen in Figs. l and 2, the vertical edges of the guide member l are rabbeted as at 5t, providing a tongue 5i which extends between the side bars of the chain links 'Aliand 2i! for engagement by the chain rollers 24. The guide member thus not only backs up the chain and cutters to maintain the cutting run between the sprockets perfectly straight. but it also prevents lateral shifting of these elements in the out.
As each cutter Il@ reaches the bottom of the foot sprocket il its teeth IM engage the ground in much the manner of picks, loosening the earth and gravel and, due to the high velocity, breaking up lumps and stones of reasonable size. This action continues through the balance of the arcuate sweep of the cutters and through their upward travel to the ground surface, the disintegrated material sliding back on the now inclined body of the cutter plate 40 into the pockets formed by adjacent cutters, the plates 3l and the cutter supporting brackets 34. As the cutters reach the ground level most of the material will be discharged from the sides of the pockets, to either side of the trench, although because of the high speed, some of it may be carried up to the head sprocket l0, where it will be thrown out by centrifugal force as the cutters pass around such sprocket. The sprocket of course should be hooded or otherwise shielded to prevent injury to workmen or damage to other parts of the apparatus.
With each pin link of the chain provided with a cutting member All, in the illustrative example cited above of a 3 inch pitch chain, the distance between adjacent cutters will be six inches. If such an excavating unit be driven at say 1,200 feet per minute there will thus be 2.400 cuts per minute, and if the trenching machine be advanced over the ground at a rate of 30 feet per minute (approximately 2.75 miles per 8 hour day) the bite for each cutter will be only 0.15 inch. These relatively light cuts reduce strain and wear and tear on the apparatus, and permit the construction of the chain and cutters to be appreciably lighter than heretofore, which in turn is conducive of the higher chain speed.
Although the excavating unit has been illustrated in the drawings as operating in a vertical position, it will function in the same manner and vjust as eiciently if inclined to the vertical, as is sometimes done in the art.
What is claimed is:
1. A high speed excavating mechanism for nai'- rovv-trench digging machines, which machines are provided with a horizontally mounted driving sprocket and with means for supporting the excavating mechanism in operative position below such sprocket: said mechanism comprising an elongated upright guide plate attachable to said supporting means in alinement with said sprocket; a single endless strand of chain comprising a series of pintle connected links engageable with said sprocket, said chain having an ascending run traversable along and in engagement with the forward edge cf the guide plate whereby the latter may support the chain against deilection in such run; a protecting plate carried by each alternate link of the chain outwardly thereof and extending laterally beyond each side of the chain to substantially the full width of the cut, said protecting plates being oi a length to overlap the connecting links, whereby they may abut one another in said ascending chain run and provide a continuous protecting wall outwardly of the chain; and a platelike excavating and conveying member secured to and extending forwardly at an acute angle from each cf said alternate links, each such member being of a width equal to that of the trench to be cut, and overlapping the protecting plate of the preceding link to form therewith a material receiving and conveying pocket.
2. An excavating unit for trenching machines, comprising a single endless strand of sprocket chain composed of pivctally connected links, alternate ones of which are of U-shaped cross section; a plate member secured to the outer face of the cross member of each of said U- shaped links and extending laterally to each side thereof to substantially the full width of the cut to be made, the ends of adjacent plates substantially abutting one another in the straight cutting run of the chain to provide a wall forwardly of the latter which protects it to the full width of the cut against entry of excavated material into and around its links; and a flat cutter member secured to each of the U-shaped links and extending angularly forward from the plate thereof, and prcvided along its forward edge with a plurality of transversely spaced pick-like teeth.
3. A narrow-trench excavating unit for trenching machines, comprising a single endless strand of sprocket chain composed of pivotally connected links, alternate ones of which are of U-shaped cross section; a plate member rigidly secured to the outer face ci the cross member of each of said U-shaped links and extending laterally to either side thereof, said plates being of a length to substantially abut one another when the links are alined in the straight cutting run of the chain; a bracket member detachably secured to each U-shaped link outv'ardly of its plate and having an extension projecting forwardly from the latter at an acute angle thereto; and a flat cutter member detachably secured to and paralleling said angular extension of each of said brackets, the forward edge of each cutter member being provided with a plurality of transversely spaced pick-like teeth.
, member at an acute angle thereto; and a flat cutter member detachably secured to and paralleling said bracket extension, the forward edge of said cuter member being provided with a plurality of transversely spaced pick-like teeth.
5. A cutter element for a chain type excavating unit of a trenching machine, comprising a sprocket chain link of U-shaped cross-,section providing spaced side bars connected by a cross member, said side bars having pin-receiving apertures adjacent their ends; a plate member rigidly secured to the outer face of said cross member and extending laterally to either side thereof, said plate member being of a length substantially equal to that of the link; a bracket having a base detachably secured to said link cross member, and an extension projecting forwardly from the outer face of said plate at an angle of substantially 45, said bracket also having side wings connecting said base and extension; and a quadrangular plate-like cutter member detachably secured to and paralleling said bracket extension and having a bevelled heel abutting the face of said link plate member, the forward edge of said cutter member being provided with a plurality of transversely spaced digging teeth of triangular cross section.
References Cited in the le of this patent UNITED STATES PATENTS Number Name Date Re. 16,997 Barber June 19, 1928 468,517 Winkler Feb. 9, 1892 1,020,296 Lyback Mar. 12, 1912 1,397,679 Dunlap Nov. 22, 1921 1,708,132 Haiss Apr. 9, 1929 1,750,219 Fonnesbeck Mar. 11, 1930 1,987,928 Eckert Jan. 15, 1935 2,096,997 Pray Oct. 26, 1937 2,324,033 Simmons July 13, 1943 2,389,936 Rupp Nov. 27, 1945 FOREIGN PATENTS Number Country Date 552,121 Great Britain Mar. 24, 1943