US2440501A

US2440501A - Excavating apparatus

Info

Publication number: US2440501A
Application number: US607475A
Authority: US
Inventors: Carl A Erickson
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-07-27
Filing date: 1945-07-27
Publication date: 1948-04-27
Anticipated expiration: 1965-04-27

Description

April 27, 1 948.

C. A. ERICKSON EXCAVATING APPARATUS Filed July 27, 194's 4 Sheets-Sheet 1 Cam. HHEEICK5ON) April 27, 1948 c, ERICKSON 2,440,501 v I EXCAVATING APPARATUS Filed July 27, 1945 4 Sheets-Sheet 2 mm. H. filcxsom A ril 27, 1948. c, A. RICKSON 2,440,501

EXCAVATING APPARATUS Filed July 27, 1945 4 Sheets-Sheet 3 CARL. Pl. EEICKSON) .mrhm

April 27, 1948. c, A, ERICKSON 2,440,501

EXCAVAT ING APPARATUS 'Filed July 27, 1945 4 Shets-Sheet 4 CARI. H. fi'lcxsow,

Patented Apr. 27, 1948 STATES PAT 12 fila ims.

The invention 'i'elate's to improvements: in excava'ting apparatus.

An object of the present invention is to provide an excavating apparatus capable of rapid and economical excavation in shaft sinking "operations in "bIastinganci in the i'emov'al of the blasted material at the bottom of shafts.

A runner object ofthe invention isto provide an excavating apparatus capable of enabling shafts to be su'n'k 'in' fnining'and other operations in nrnchless tiirie and with much less labor than is possible the manual handling or shoveling of the blasted inaterial, whereloy "the 'cost of 'snch xoavatiofis he Q'laitlir red'u'ced and the speed vastly increased. 1

A further object of the invention is to provide an excavating aptarsrus edni'pped with conveniently located drillsfor boring holes to receive blasting charges and a hinged boom carrying a pivoted excavating dipper or scoop and mounted for movement transversely of the hole or shaft and capable of enabling theexcavating dipper or scoop to rempve the blasted inaterial from the entire area or the Bottom of the shaft or hole and deposit the "excavatedinatriai into elevat in'g Skips for "hoi'sti'iig the 'fdcavaltd'materi'al t the top of theshaftor hole.

Another object or the invention is 120 provide an excavating emanates or this character adapted to he progressively-lowered to excavate the shaft or hole to the iqifiiddepth and provided with 'aidjiis fiabl e means for feiiablir'ig it, by positively engaging on osite Walls of the shaft or hole, "to he 'secnrei y anchored'in each successive lowering operation.

Another object of the ih'ventidnfis to provide an 'eXCavatifig apparatus "dt'i'nipli'sir'ig a niain frame and a carriage 'sli'clflo'li'e "thereon forwardly and rearwardly and earning s'aid trans'verselir slidahle beam-winner the b'o' 'vvith its excavating dipper or scenes lie a;c :'n rate1y iios'iti'oned and crones siven adusted for complete removal of the blasted rial.

A {hither tbje't t; the invention is 'to enable the carriage to be adjusted and thehin'g'e'd tom and ext'en e section and the pivoted dipper or scoop to he attested and controlled hi cable's teased by mechanism {arranged on the carnage convenient position for operation by an attenda-nt.

reg mm the eerie or neither-1s any of the advantages or the inveinian.

In the drawings: Fig. '1 is aside elevation, partly section,

of an excavating apparatus constructed in accordance. with this inventionand shown arranged in a shaft or hole.

Fig. 2 is a plan view 10f the same, partly'in section. i V

Fig. 3 is anenlargfeddetai-l sectional view illustrating the construction 'of the hinged boom and the pivoted dipper or scoop andillustrating the arrangement "of the cables {for controlling the hinged and pivotal movements of the boom and dipper or scoop and for adjusting the 'ex'tensiiole telescopic section of, the. boom. I

Fig. l isa-n-enlarged detail elevation illustrating the arrangement of the *guide's'for the skips.

Fig. '5 is anenlarged detail sectionalview'showme one :of the skins and 'the 'means for guiding the same.

Fig. 6. is a detail view of a portion of one 'of the sectional skip guides. v

Fig. '7 is an enlarged detail {sectional View of a portion of. the carriage and illustrating the arrangement of the upper :and lower guides for slidably mounting the carriage "on the Ina-"in frame.

Fig. 8 is a detail sectional view-illustrating the manner of mounting the slidabie bracket and sheave of the boom hoisting cable.

Fig. 9 is an enlarged detail sectional view *i-ll'n'strating the manner of slidably mounting the longitudinal bars :of the extensible section of the main frame and :also the slidable connection of the longitudinal bars with the transverse connecting bars.

Fig. '10 is an enlarged detailsectional View takensubstantially on the line 10-40 of Fig. 3 and illustrating the construction of the boom, the extensible section, and the manner of mounting' the upper and lower "sheaves thereof.

Referring to the. drawings, in which is illustrated the preferred embodiment of the invention, the excavating apparatus comprises in its construction an open main frame 1 composed of vertical bars -2-and top' and "bottom longitudinal and transverse connecting liars 3 and '4 and pro"- vided at the bottom with a depending ffarnework 5 :on which are moimt'ed a; plurality "ii-{phenmatic drills .6 arranged in convenient position for ready removal and use for drilling holest'o receive explosive charges for blasting mater al at the bottomfof a shaft 'or hole 1. The phenmatic drills are designed to be of the erdm ry don"- struction customarily "employed for "drilling li'oles for explosive charges arid 'as any 'eanstrucndn of pneumat c er ether type or iidrtatieenii may be employed; illustration 151E the particular drill of this character is deemed nnnecessary.

The main name, which -is oBfifiotd-with-l'ioisting cables 8 to 'euanieitto be progressively lowered in excavating a shaft or hole and to be removed therefrom, is substantially rectangular in plan and elevation and is provided at one end with fixedwall engaging anchoring projections 9 and at the other end with'an adjustable section l9 having wall engaging anchoring projections H. The anchoring projections 9 and II are arranged in pairs at the top and bottom of the main frame and the adjustable section thereof and penetrate the opposite walls of the shaft or hole and securely anchor the main frame in each adjustment thereof. While two pairs of anchoring projections are shown in each end of the main frame, any number of such projections may of course be employed.-.

The adjustable section of the main frame is composed of verticalbars l2, transverse connecting bars 13, and-top and bottom longitudinal bars M to which are connected hydraulic jacks l5 arranged in pairs at the top and bottom of the'main frame and adapted to thrust the anchoring projections 9 and II firmly into engagement withthe opposite wallsof the shaft or hole [for anchoring the main frame.

The hydraulic jack may 'be supplied with fluid pressure by 'any suitable means for forcing the plunger portion '16 of the jack outwardly. The adjustable section. lfl 'of the main frame is slidable thereon audit is retracted to withdraw the anchoring projectidns" H from the engaged wall of the hole orishaft by means of spaced cables ll. connected at their outer ends with the slidable sectionv of the main fr'ame'and having their inner portions connected to and arranged to be wound on drums l8 having cranks l9 or other suitable means for rotating the same for winding the .cables l'l'on the drums. When the anchoring projections I I are withdrawn from the engaged'walLLthe anchoring projections 9 may be readily disengaged from the opposite wall and the cables I! and drums I8 will hold the slidable section of 'the'main frame in its retracted position while lowering the excavating apparatus from one position to another.

i The main frame is provided at the top and bottom with upper and 'lower horizontal guides Zila'ndrZl arranged in pairs and located at opposite sides of the main frame and provided with

grooves

22 and 23 for the reception of upper and

lower rollers

24 and 25 of a carriage 26 slidable longitudinally of the main frame. The carriage consists of a framework substantially rectangular in plan and elevation and having a platform 21 and provided (at the rear end with a transverse channel guide 28 which slidably receives a slide portion 29 of a bracket or hanger 38. The channel guide is provided at its open side with inwardly extending flanges 3| forming upper and lower grooves which receive upper and lower vertical flanges 32 of the slide portion 29 of the hanger or bracket 39, whereby the hanger or bracket is slidably interlocked with the horizontal'guide and is adapted to, slide in the guideythereof. Any suitable anti-friction means may of course. be provided for reducing to a minimum friction incident to the hanger or' bracket traversing the'guide 28. The hanger or bracket carries a depending'pivoted or hinged boom 33 depending from the hanger or bracket and from the carriage and connected to the hanger 'or bracket byv a pivotal connection which maybe in the formiof a-knuckle joint as shown and having a pivot 34.

. The'boom, which is constructed of suitable metal; is tubular and telescopically receives an extension section 35 which is adjustable by the means hereinafter described to vary the effective length of the boom. The boom, which is adapted to swing forwardly and rearwardly, is provided at the lower or outer end of the extension section with a dipper or scoop 36 which is .connected with said extension section 35' by a pin or pivot 31. The dipper or scoop is adapted to swing downwardly through gravity to an inclined, position as illustrated in Fig. 1 of the drawings for engaging loose material at the bottom of the shaft and the boom is adapted to be swung forwardly and upwardly for carrying the dipper or scoop into engagement with the material and for elevating the dipper or scoop to a point above one or the other of a pair of elevator skips 38 which conveys the excavated material to the top of the shaft. The boom is adapted to swing downwardly and'rearwardly by gravity from an elevated position to the depending vertical position illustrated in Fig. 1 of the drawings.

The dipper or scoop, which is provided at the bottom with a projecting lip 39 and which is gravity acting in one direction, is controlled by a cable 40 extending upwardly from the topof the dipper or scoop and secured at its lower end to an ear 4| of the scoop. The cable 49 extends upwardly along the boom 33 and is guided by upper and

lower sheaves

42 and 43 mounted in

suitable bearings

44 and 45 which may be formed integral with the tubular metal boom but the sheaves may be mounted in any other desired manner. I

'I'he'cable 40 extends from the upper sheave 42 to a sheave 46 of the hanger or bracket39 and then upwardly toan overhead pulley or sheave 4'! and then to a drum 48. The drum 48, which is mounted in suitable bearings on the platform 21, is disposed transversely thereof and it may be operated by an electric motor 49 or any other suitable means. The cable 451s wound around the drum for swinging the dipper or scoop upwardly for arranging it in proper position for scooping or dipping up the loose material at the bottom of the shaft and' when it is carried into an elevated position above one of the skips 38 it-is released by slackening the control cable 40, thereby permitting the scoop or dipper to swing downwardly and discharge its contents into said skip.

The boom is controlled by a hoisting cable 50 secured at its lower endto an ear 5!, preferably formed integral with the extensible section of the boom and located near the lower or outer end thereof. The cable 59 extends upwardly and forwardly from the lower or outer portion of the boom to a sheave or pulley 52 mounted in a bearing bracket 53 having a slide portion 54 slidably mounted in a guide 55 disposed transversely of the front end of the carriage-at a point adjacent the platform 21. The slidable bearing bracket 53 which may, if desired, be provided with any suitable anti-friction. devices, is arranged in alignment with the hanger" or bracket 39 and is adapted to slide transversely of the carriage simultaneously with the hanger 30 when the boom is shifted laterally in either direction. The cable 50 extends rearwardly between spaced centrally arranged guide pulleys or sheaves 56 located at the front end of the platform of the carriage and it extends from the centrally arranged pulleys 56 to, and passes between, a pair of spaced guide pulleys or sheaves 51 located in advance of a transversely disposed drum 58 located in transverse alignmentywithvthe drum 4T8 on which the-dipper orscoop -controlling-.cable is wound. The drum 58 is :actuated by :anelectric motor -59 or other suitablemeansand the-cable-Eil ,is wound around the 'drum 58 .for swinging the boom lupwardly andwhen the cable 150 --is slackened, the boom will swing downwardly through :gravity.

The (hanger or bracket 130 and the bearing bracketifi are simultaneously moved-in the same direction transversely of the carriage by means of cables -60, -6 l, -62, and .63 (arranged in, pairs as clearly illustrated in Fig. 2 of the drawings. The cables :60 landfill are-secured at one end to the hanger or bracket at DP osite sides thereof and they rextendilaterally from the :hanger or bracket to pulleys 'or sheaves 64 and -65 located at ppposite sides of the=carriage -Fhe 'said cables iii! and :61 then extend around the pulleys or-sheaves 64 :and -65 and then inwardly to spaced pulleys or sheaves B6 and :61, and" then forwardly to :a transversely =disposed drum 68 on which :the cables are reversely wound.

The other pair of cables =62 and 63 are secured to the hanger -or bracket 30 at opposite sides thereof adjacent the points of attachment of the said :cables 60 and-t8! and they extend laterally from the hanger or bracket "36 to pulleys or sheaves 6B and 'HJlocated'at-oppositersidesof the carriage. They then extend forwardly longitudinally-of the carriage to spaced pulleys H andiZ located at opposite sides -of the carriage at the front portion thereof. The cables -52 and, 63 then extend transversely of the carriage, crossing each other centrally thereof and passing around side pulleys or sheaves t3 and at and then to the bearing bracket 55 "to which they are connected. The transverse'drum 68 is controlled by means of an electric motor 15 and when rotated in one direction, the hanger or bracket =35 and the bearing bracket 55 are simultaneously moved in the same direction, and svhen th'e drum is rotated in the opposite -di-rection,*the direction of movement of the hangeror bracket -33 and the bearing bracket 55 is reversed.

The telescoping :sectionSE-of the boom ismoved inwardly or upwardly by means of a line or-cable 16 secured at one end to an car on the inner or upper end of the boom. This l-inefit extends downwardly or; outwardly along the interior of the telescoping section to and arounda pulley or sheave 18 mounted on theyouter or lower portion of the telescoping section and it then extends upwardly .or inwardly through the telescoping section and the boom to an overhead pulley or sheave 19 mounted on the vmain frame. A line or cable 80 is secured to the upper end of (the telescoping section at .81 and extends downwardly or outwardly to and around the lower pulley 82 and then upwardly through the telescoping section and the boom to an overhead pulley or sheave 83. The cables or lines 16 land 85) extend from the overhead pulleys 19 and fiflto a drumtd and are reversely wound around the same so that when the drum is rotated, one of the lines or cables will be wound on the drum and the other unwound therefrom. I

The telescoping section 35 with the pivoted dipper has sufficient weight to move downwardly or outwardly by gravity :action and this arrange ment of the lines or cables 1'6 and 80 affordsibet ter control oi? the telescoping section than a single line or cable. The drum is mounted on the platform 2'! and is actuated by an electric motor 85 or other suitable means.

The carriage is moved .for-wardly and rear- .6 I wardly along thermain frame 'by meansof babies or lines 86 and v81 extending longitudinally of the main frame from an intermediate point on the carriage to the :front and rear ends of the mainframe. The cable or line 86 i-s-secured at itsouteror-front end at=88 tothe extensible section-oi i-the'mainirame and the other-cable or line 81 is -:secured at its outer or rear end at 89 to the rear end of. theimain 'frame. The inner portions of the eables B6 and 8-1 are reversely wound around a drum 90 so that when the-drum is rotated'on'e of the .cables will be wound :around thedrumeil and the other'cable unwound therefrom and the carriage moved longitudinally of themainirame. The drum 90 which is mounted on the platform? of the .carriageis actuated by anielectricmotor 9| :or other suitable means.

Theskips 38, which are alternately raised and lowered by hoisting cables 82 to'convey the excavated material to the surface of the .ground and to --return the empty skips to the bottom-of the hole, are provided at the back and sides with short vertical slides es and -94 having outer flanged webs providing :portions substantially T- shaped in cross section to slide in and interlock with rear and side channel guides 55 and 96. El he rear and side channel guides have spaced transverse flanges 9i and 98 forming slots: which receive the web portionsof the

slides

93 and 94 of the skips '38. :Any other suitable form of slides-and-guides may be providedfor guiding the skips '38 in their vertical movement.

rA-s the hole deepens, it is designed to be timbered as shown at 99 but the walls may be coated or walled with cement or any other suitable material to provide a liningtor the hole and prevent caving in-of the walls thereof. The guides for the skips are designed to be constructed of sections and to be extended as the hole. deepens. The adiacent ends of the sections of the guides may be connected by suitable joint such as are illustrated at liiflrin Fig-60f the drawings. The sections of the guides are designed to be supported by the timbered portion of the hole and also by the framework of the main frame and when :moving the apparatus from a hole, sections of :the guides may be pinned to adjacent timbers as illustrated at till in Fig-6 of the drawings.

The boom -33 ls rectangular in-crosssection and the extensiblesection, which may be constructed in any desired manner, is preferably composed of spaced parallel side bars or members I02 and H33 which are connected together at their upper andlower terminals and which slidably fit the interior oi the boom. The upper pulley 18, around which the cable 15 passes, is mounted on the side bar "or member I02 within a-bear-ing bracket it! and when the cable 16 is wound around its the telescoping" section will be moved upwardly or inwardly.

The lower pulley 52, around which the cable 86 passes, is carried by the boom and is located adil icentthe other side bar or member l03of the telescoping section. The boom is provided with hearing brackets L235 in which the lower pulley 824s mounted. The bearing brackets are secured to the boom at opposite sides thereof and when the cable 813 is Wound around its drum, the telescoping section will be positively moved downwardly and outwardly.

In order to enable the longitudinal bars of the extensible section of the main frame to be adjusted independently of each other to position them properly to engage the irregular surface of a hole, the longitudinal bars M are slidably -con nected with the transverse bars l3 and are provided'with guides or ways I06 in Which slide approximately T-shaped terminal portions I01 of the transverse bars, whereby the transverse bars and thelongitudinal bars are slidably interlocked with each other. Any suitable means, such as a clamping'screw I08, may be provided for rigidly securing the longitudinal bars in any adjusted position to suit the character of the surface to be engaged by the projections ll.

What is claimed is:

1. An excavating machine including a main frame provided at opposite sides with longitudinal ways'and having means for engaging walls of an excavated hole for securing the main frame in different positions in said hole, hoisting means connected with the main frame for lowering it into said hole as the excavation of the same progresses and for removing it from the hole when the excavation thereof is completed, a carriage slidable in the ways of the main frame and provided with a transverse guide, a pivoted boom mounted for sliding movement backand forth along said transverse guide and provided with an extensible section, a dipper pivotally mounted on the extensible section of the boom at the outer end thereof, means for actuating and controlling the boom to swing the same and to slide the boom along said transverse guide, means for effecting adjustment of said extensible section to vary the effective length of the boom, and a dipper line connected with the dipper and guided on and carried by the boom in the sliding movement thereof. 7

2. An excavating machine including a main frame provided at one end with fixed projections for engaging a wall of an excavated hole and having at the other end an extensible section slidably mounted on the main frame and provided with projecting means for engaging the opposite wall of said hole, hydraulic jacks mounted on the main frame and connected with the extensible section for moving the sameoutwardly to engage said projections with said walls of the hole for adjustably securing the main frame in position for excavating, excavating means carried by and depending from the main frame for excavating the hole below the main frame, drums having lines wound thereon and connected with the extensible section, and means for rotating the drums for moving the extensible section in- Wardly.

3. An excavating machine including a main frame provided at opposite sides with longitudinal ways and having means for engaging walls of an excavated hole for adjustably securing the main frame in said hole, a carriage slidably mounted in the ways of the main frame and provided with front and rear transverse guides, front and rear brackets slidable in said guides, a boom pivoted to the rear bracket and depending therefrom, a dipper carried by the boom, a cable connected with the boom and guided on the front bracket for swinging the boom, and means mounted on the carriage and connected with the front and rear brackets for simultaneously sliding the same in the same direction along the transverse guides.

4. An excavating machine including a main frame provided at opposite sides with longitudinal ways and having means for engaging walls of an excavated hole for adjustably securing the main frame in said hole, a carriage slidably mounted in the ways of the main frame and provided with front and rear transverse guides, front and rear brackets slidable in said guides, a boom pivoted to the rear bracket and depending therefrom, a pivoted dipper carried by the boom, a cable connected with the boom and guidedonthe front bracket for swinging the boom, means mounted on the carriage and connected with the front and rear brackets for simultaneously sliding the same in the same direction along the transverse guides, and a dipper line connected to and controlling the pivoted dipper and extending along and guided by the boom and the rear bracket.

5. An excavating machine including a main frame, means for adjustably positioning the main frame in an excavated hole, excavating mechanism carried by the main frame and including a pivoted boom having a pivoted dipper, operating means connected with the boom and the dipper for swinging the boom and for permitting the dipper to discharge its contents, skips movable vertically through the main frame for conveying excavated material to the surface of the'ground and adapted to receive excavated material from the dipper when at the lower limit of their vertical movement, said skips being provided with vertical slides and extensible vertical sectional guides receiving the slides and extending from the top to the bottom of the hole, sections of the guides being mounted on the main frame, and hoisting cable connected with the skips for raising and lowering the same.

6. An excavating machine including a main frame, means for adjustably positioning the main frame in an excavated hole, excavating mechanism carried by the main frame and including a pivoted boom having a pivoted dipper, operating means connected with the boom and the dipper for swinging the boom and for permitting the dipper to discharge its contents, skips movable vertically through the main frame for conveying excavated material to the surface of the ground, said skips being provided at the sides and rear with vertical slides, extensive vertical sectional guides receiving said slides'and extending from the top to the bottom of the hole, and hoisting cables connected with the skips for raising and lowering the same.

7. An excavating machine including a main frame provided with longitudinal ways, a carriage slidably mounted in said ways and provided with front and rear transverse guides, front and rear brackets slidable in a transverse guide, a boom pivoted to and depending from the rear bracket, a dipper carried by said boom, a cable connected with the boom for swinging the boom upwardly, said cable extending to and guided on the front bracket and movable with the same when the front bracket slides along the front guide, a drum mounted on the carriage, cables reversely wound aroundthe drum and connected with the rear bracket and extending laterally in opposite directions therefrom, means for guiding said cables to said drum, front cables connected with and extending laterally from the front bracket and crossed intermediate of their ends and extending to opposite sides of the rear portion of the carriage and laterally therefrom to the rear bracket and connected therewith, and means for guiding the cables which are connected with the front bracket, said drums when rotated being adapted to move the front and rear brackets simultaneously in the same direction.

8. An excavating machine including a main frame provided with longitudinal ways, a carriage slidably mounted in said ways and provided with front and rear transverse guides, front and rear brackets slidable in a transverse guide, a boom pivoted to and depending from the rear bracket, a dipper carried by said boom, a cable connected with the boom for swinging the boom upwardly, said cable extending to and guided on the front bracket and movable with the same when the front bracket slides along the front guide, a drum mounted on the carriage, cables reversely wound around the drum and connected with the rear bracket and extending laterally in opposite directions therefrom, means for guiding said cables to said drum, front cables connected with and extending laterally from the front bracket and crossed intermediate of their ends and extending to opposite sides of the rear portion of the carriage and laterally therefrom to the rear bracket and connected therewith, means for guiding the cables which are connected with the front bracket, said drum when rotated being adapted to move the front and rear brackets simultaneously in the same direction, hoisting cables connected with the main frame, and means for adjustably positioning the main frame in an excavated hole.

An excavating machine including a main frame of approximately the size of the hole to be excavated provided at opposite sides with ways and having means for engaging walls of an excavated hole for securing the main frame in different positions in said hole, hoisting means connected with the main frame for lowering it into the hole as the excavation of the same progresses and for removing the main frame from the hole when the excavation thereof is completed, a carriage slidable in the ways of the main frame and extending across the same and provided with two separate spaced guiding means extending transversely of the carriage, a pivoted boom mounted for movement along one of said transverse guiding means, a dipper carried by said boom and means mounted for sliding movement in the other of said guiding means and connected with the boom controlling the pivotal movement thereof.

10. An excavating machine including a main frame of approximately the size of the hole to be excavated provided at opposite sides with ways and having mean-s for engaging walls of an excavated hole for securing the main frame in different positions in said hole, hoisting means connected with the main frame for lowering it into the hole as the excavation of the same progresses and for removing the main frame from the hole when the excavation thereof is completed, a carriage slidable in the ways of the main frame and extending across the same and provided with two separate spaced guiding means extending transversely of the carriage, a pivoted boom mounted for movement along one of said transverse guiding means, a dipper pivotally mounted in the boom at the outer end thereof, means mounted for sliding movement in the other of said transverse guiding means and connected with the boom for controlling the pivotal movement thereof, and separate means connected with the dipper and extending along the boom and carried with the same in the sliding movement thereof.

11. An excavating machine including a main frame of approximately the size of the hole to be excavated provided at opposite sides with ways and having means for engaging walls of an excavated hole for securing the main frame in different positions in said hole, hoisting means connected with the main frame for lowering it into the hole as the excavation of the same progresses and for removing the main frame-from the hole when the excavation thereof is completed, a carriage slidable in the ways of the main frame and extending across the same and provided with front and rear guiding means extending transversely of the carriage, a pivoted boom mounted for sliding movement in the rear guiding means and provided with an extensible section, a dipper carried by the extensible section of the boom, means mounted in the front guiding means for sliding movement transversely of the carriage and connected with the boom for controlling the pivotal movement thereof, and means connected with the extensible section of the boom and extending along the boom and carried by the same in its sliding movement and connected with the extensible section for effecting adjustment of the extensible section to vary the effective length of the boom.

12. An excavating machine including a main frame of approximately the size of the hole to be frame and 'slidably mounted in the ways thereof and provided with front and rear transverse guiding means, a bracket slidably mounted in the rear guiding means for movement back and forth in said guiding means, a boom pivoted to and depending from the bracket, a dipper pivoted to the outer end of the boom, means mounted in the front guiding means for sliding'movement transversely of the carriage and connected with the boom for controlling the pivotal movement thereof and separate means connected with the dipper and extending along the boom andcarried by the same in the sliding movement thereof for controlling the pivotal movement of the dipper.

CARL A. ERICKSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 265,592 Fox Oct. 101, 1882 564,727 Trainor July 28 1896 820,055 Libbe May 8, 1906 1,048,244 Ward Dec. 24, 1912 1,171,686 Zaitz Feb. 15, 1916 2,326,172 Riddell Aug. 10, 1943 2,358,543 Tofilemire Sept. 19, 1944 FOREIGN PATENTS Number Country Date 486,168 Germany 1929 1,682 Great Britain 1868 11,219 Great Britain 1896