US1250521A

US1250521A - Asphalt-cutter.

Info

Publication number: US1250521A
Application number: US15640617A
Authority: US
Inventors: Henry Schumacher
Original assignee: Individual
Current assignee: Individual
Priority date: 1917-03-21
Filing date: 1917-03-21
Publication date: 1917-12-18
Anticipated expiration: 1934-12-18

Description

H. scHuMAcHEn.

ASPHALT CUTIER. APPucATloN FILED HAR. 21. ISH'.

Patented Dec. 18. 191'?.

. 4 SHEETSSHEET l.

H. SCHUMACHERL ASPHALT CUTTER. Y APPLICATIN FILED MAR. 21. 19u.

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H. SCHUMACHER.

ASPHALT CUTTER.

APPLTCATION FILED MAR. 2l, 19|?.

PatentedDec. 18, 1917.`

w mwN H. SCHUMACHER.

ASPHALT CUTTER. APPLICATION FILED MAR. 2l, 9l7

Patented Dec. l8,'1917.

lnlll wmllmm llllnll vNlTED STMESr P.2r-If,.ENf-I*C OFFICE i HENRY scriuivinciiiiii, orriauiirnilo, NEWYORK.

y ASPHALT-CUTTER...

f Application fiied'MarCii 2i', iai?. seriaiNo. 156,406.

To all 'whom it may concern:

Be it known that I, HENRY a citizen of the United States, residing at Biiffalo,yin the county of Erie and VState of vNew York, have invented new anduseful .Improvements in Asphalt-Cutters, of which the following` is a specification.

This invention relates to an asphalt cutter Y which is more particularly designed for cut tinggrooves, channels, or furrows in asphalt At pavements for'the purpose of facilitating repairing of the same and also to expedite the ydigging of trenches lbelow the pavement in ywhich to lay sewer, gas, water or other pipes and conduits `for telegraph,ltelephone and electric light and 'power wires, Vand for v other purposes. f

VIt is the object of this invention -to provide a macliinefwhereby the work of cuttingV the asphalt pavement in this manner can be effected quickly, easily and economically and with a `minimum expenditure of manual labor.4 l A In the accompanying drawingsz' Figure 1 is a side elevation of an asphalt `cutting machine embodying my invention.

Fig. 2 is atopplan view ofthe saine. Y Fig. 3 is a vertical longitudinal sectiontliereof, taken on line 3 3, Fig. 2. Fig. .4 is a front elevation of the machine, partly in section. Fig. 5 is a vertical transverse section of the machine takenon" line 5 5, Fig. 2, looking forwardly. Fig. 6 is a fragmentary vertical transverse section, on an enlarged Scale, taken on line 6 6, Fig52. Fig.-7'is a vertical section taken on line 7 7, Fig. 6. Fig.

8 is a fragmentary vertical section taken on Fig. 9 is a detached ele-v of any suitable construction to supportthe different working parts of the machine, butV in the preferred form shown in the drawings, the same comprises two upright longitudinal side pieces, beams, sills or girders 1, 2,a central ylongitudinal gli-der or beam 3 arranged i midway between the side girde'rs, a cross piece l connecting the front upper parts of these gir-ders, a transverse'tierod 5 vconnecting the SGHUMAGHER,

Specification of Letters Patent. y Patented Deals, 1917.

front parts of these girders and'surrounded between the respective .girders spacing sleeves 6 and an intermediate transversetie rod 7 connectingv the intermediate partsfof the girders and surrounded between the ref` spective, girders by Vspacing 1 sleeves4 8, fas shown in Figs. 1, 2` 3 and 5. This'frame ineffectforms the body of :L -carriage which.`v

is providedv with y.wheels so that the VVsame may be readily transported asthe cutting ofthe asphalt progresses and also for shift-v ing they machine quickly from onejo-b to another and to and'vfrom the place where the same isV being stored. The'preferred' means for this purpose which are showninl the drawings comprise two pairs of traction or. driving wheels 9, 10 which are arrangedV l i axially in line transversely of the machine at the rear end thereof, a `pair Vofgthese wheels being preferably. arranged between the intermediate girder and each of therside girders, as shown in Figsj2, 4l and 5. The

front of the' machineis provided with pair of steering wheels 11 which are prefer-Y ably arranged in recesses 12A formed in the lower'front corner of the side girders-'of the main frame, as shown in Figs. `1-4. These steering wheels may be mounted in any suitable Vmanner. but preferably in theA manner now in common use in automobiles. As shown in the drawings, the mounting of these steering wheels comprises ahorizontal steering axle 13 arranged transversely below the front part of the intermediate girder' and connected with opposite sides of the latter by means of brackets 14 and also connected nearits opposite ends withthel front parts of the side girders by means of side brackets 15, two horizontally-swinging A steering knuckles 16 which are'pivoted to turn vertically in bearings arranged at opposite ends of the steering axle and pivotally supporting the steering wheels, respectively, a transverse equalizing rod 17connectingftwo rearwardly-projecting arms 18' on the steering knuckles, and an upright steering postor shaft 19 journaledin suitable bearings on the Vcentralv part vof the intermediate girder and provided at itsfupper end with a steering wheel or handle 20 while its lower end is provided with a rock arm 21 which is connected bymeans vof a sliift- V ing rod 22 with a shifting arm 2,3 arranged on one of the steering knuckles, as shown Although variousmeans may be provide ilo f in Figs 2, 3 andv 4."

yse

for propelling the carriage forwardly and backwardly, those which are shown in the drawings are preferred and constructed as follows:

24 represents a motor, preferably of the explosion type, mounted on the front part of the main frame or body of the carriage and having a horizontal transverse driving shaft 25 which is provided with a driving gear wheel-26. A speed changing shaft is journaled horizontally and transversely in suitable bearings on the main frame in rear of the driving shaft and has a driving section 27 and a driven sectionk 28 which are connected by speed changing device 29 of any suitable character so that the driving section 27 may turn continuously in the same direction while the driven section 28 may be either coupled with or uncoupledV from the driving section or turned in either direction relatively to the driving section. Inasmuch as any suitable speed changing mechanism may be employed, no details of the saine are shown. i The driving section 27 of the speed changing shaft is driven by Vmeans-of a. gear wheel 30 secured thereto and meshing with the driving wheel 26 of the motor shaft.

3l represents a countershaft which is journaled in suitable bearings on the girders of the main frame in rear of the speed changing shaft 27, 28. On the central part of this countershaft is loosely kmounted a gear wheel 32 which meshes with a gear wheel 33 secured to the driven section of the speed changing shaft. The gear wheel 32 may be connected with the countershaft so as to turn therewith or disconnected therefrom so as to turn independently of this shaft by means of a clutch which preferably comprises a clutch sleeve 34 slidable lengthwise upon the countershaft but compelled to turn therewith by means of a spline and provided with clutch teeth which engage with corresponding clutch teeth on the hub of the gear wheel 32. 'Vhen the teeth of the clutch sleeve 34 and the gear wheel 32 are coupled, then the power of the motor 24 is transmitted to the eountershaft providing the speed changing mechanism has been operated to connect the driving and driven shaft sections V27, 28, while upon withdrawing this clutch sleeve so as to disengage its teeth from those on the hub of the gear wheel 32, then the countershaft will be unaffected by the motor. The carriage is propelled at a relative high rate of speed b v means of two driving chain belts 35 each of which passes around a driving sprocket wheel 3G mounted loosely .o-n one end of the countershaft and a driven sprocket wheel 37 secured to the outer end of the outer member 9 of one pair of traction wheels, as shown in Figs. l, 2 and 5. Each driving sprocket wheel36 may be connected with or disconnected from the countershaft by means of a clutch which, in the example shown in Figs. 2 and G, comprises a clutch sleeve 38 connected by means of a spline with the countershaft and provided with clutch teeth which are adapted to be engaged with or disengaged from clutch teeth on the hub of the respective driving sprocket wheel 36.

The

clutch sleeves

34, 38, 38, may be shifted into and out of their operative positions in various ways, for instance, by means of forks 39, 40, 40 engaging annular grooves in these clutch sleeves, upright shafts 41, 42, 42 journaled in suitable bearings on the main frame and carrying these forks, respectively, at their lower ends, and handles 43, 44, 44 secured to the upper ends of these shafts and arranged within convenient reach :f the operator who has control of the machine. lVhen the

clutches

34, 38, 3S are in operation, the machine may be propelled at a comparatively rapid rate over the ground,

it being operated in this manner whenV trans-v ported to and from the plant to the job, and from one jobv to another. lVhen, however, the machine is engaged in cutting a groove or a furrow in an asphalt surface, the saine is either pushed forwardly by hand, or the same may be pushed forwardly by power derived from the motor 24. For this purpose the following mechanism is provided, )arts of which are also used for accomplishing other purposes:

45 represents an operating shaft ournaled horizontally and transversely in appropriateV bearings on the girders of the main frame. rllhis shaft is turned by power in the direction of the arrow 45?", Fig. 2, by means of gear pinions 4G, 46 and engaging with

gear wheels

47, 47 secured to the 4ends of the operating shaft, as shown in Fig. 2. Each of the driving pinions-4G is mounted on the countershaft so as to be compelled to turn forwardly with the same but incapable of turning backwardly therewith, this being accomplished for instance, as shown in Figs, 6 and 7, by means of a ratchet mechanism interposed between each driven gear wheel 46 and the countershaft, which ratchet device may consist of a pawl 48 pivoted on the respective driving gear wheel 46 and engaging with a shoulder 49 on the adjacent part of the countershaft, as shown in Fig. 7. y

V@n opposite sides of the intermediate girder of the main frame, the operating shaft is provided with two eccentrics 50 each of which is surrounded by an eccentric strap 5l. 52 represents a ratchet wheel secured to that end of each inner traction wheel l0 which faces the'intermediate girder and 53 represents a `atchet lever which is journaled on the hub of each ratchet wheel and provided with a dog or pawl 54which is pivoted thereto and engages with the teeth of the companion ratchet wheel, and a connecting rod-55 yprojecting rearwardly from veach of theeccentric straps and pivotally connected atzits rear end-to thepupper end of one of the ratchet levers, asshown in Figs. 2, 3 and 5. Vhen the pawls 54: are in kengagementA with the ratchet wheels and the'counten.

tion of the arrow 57 in Fig. 3. By this means alcomparatively slow forward movement is imparted to the carriage to suit the progress of the cutting tools which are at this time operating upon the asphalt sur-v face. ThileA the' machine is being thus propelled slowly, the quick propelling mechanism is rendered yinoperative and when the quick propelling mechanism is inl use, the

' pawls54 ofthe ratchet levers are thrown b-ackwardly out of engagement fromY the ratchet wheels and against stop pins 58 inl which position the pawls or dogs are inoperative` Vand the ratchet levers are merely oscillated idly at such time as themachine v is being propelled forwardly at a rapid rate by the motor. y, j J

The traction wheels ,9, 10 may bemounted on the frame in any suitable manner but in order to permit of taking up the slackv in the driving chains 35 due to wear, these wheels are :preferably mounted as follows:

59 represents a stationary arbor which is mounted horizontally and transversely on the lower rear parts of the :girders and upon .which the two pairs of inner and outer traction wheels turn. The central part of this arbor is reduced to form a 4neck 60 and two` inwardly-facing shoulders 61, 61.. 62, 62 representtwo sections of a clamping sleeve which is s )lit lengthwise and diametricall so that the same may be applied to the central reduced part of the arbor and lwhich is provided `with,outwardly-facing shoulders 63 in opposite ends of its bore which engage with the shoulders 6l of the arbor in the assembled' position of the parts, and thereby prevent this split sleeve from moving length wise on the arbor. This splitl clamping sleeve has the central part of its periphery made square and arranged ina horizontal longitudinal slot, 64 formed in the lowery ofV the arbor but lalso clamp this s leeveon the central girder, so as to securely attach the centralpart of the arbor to the central part of the frame. At each of its outer ends, the arbor passes through a `support-V ing sleeve which is adjustable lengthwise on the'adjacentpart of the respective side girder. This sleeve, asshown'in Figs. 1 and 5, preferably comprises a square hub 66 movable lengthwise' in a longitudinal slot 67 formed in the adjacent part of the respective side -fgirder and provided onits inner4 end with ail-integral flange 68 which engages with 'the inner side of the respective girder while the outer end of thisV hub is provided with a removable flange 69 which is detachably secured thereto by means of screws 70 and engages with the outer side of the respective side girder. rIhis adjusting sleeve maybe moved rearwardly and held in its Y adj ustedposition by means of the horizontal adjusting screw 7l, arranged 1n a' iiange 72 on the side girder adjacent to the frontend of its slot 67 and bearing with its rear end against the hub 66 ofy the vadjusting sleeveY and'y a clamping nut 73 ,applied'ito said adjusting screw and bearing against the respective flange 72 in which said screw is mounted. l s

By adjusting the central supporting sleeve 62 andthe side supporting sleeve 66 horizontally with reference to the frame, the

position of the arbor 59 may be shifted as required to suit the driving chains 35 and y permit of taking up wear whenever this is necessary. Outside of each of the outer guide sleeves 66a retaining pin74 passes transversely through the same so as to prevent the lower parts of the. side frames adj a* cent to the traction wheels fromr spreading thereby utilizing the arbor not only as a` means for supporting the tract-ion wheels on the mainframe, but also stiffening this part of the frame and enabling it to resist side strains eifectively rwithout requiring the machine to be made unduly heavy.

The means for cutting or chopping the. asphalt surface and forming the groove, channel or furrow therein in accordancek withmyl invention, is constructed as follows: y i

75, 75 represent two vertically-swinging helves or cutter arms which are preferably constructed of wood so as to secure the necesi sary resilience, although the same maybe A made ofother material. These helves arey pivotally mounted .at their inner oru front ends on the main frameand the tools or cut-V ters which operate Vupon the asphalt sur'- face are mounted on their outer or rear lends soV that upon-oscillating vthe same the as-a pair-and are so mounted in thema.- 'p

chine that they converge rearwardly from their front ends and their rear ends are arranged close together. The driving mechanism associated with these helves is so censtructed and operated that the same are raised and lowered alternately, whereby the two tools of the helves are caused to operate successively on the asphalt and form opposite sides of a groove or channel therein. During the operation of a pair of these cutters the saine remove that part of the asphalt surface which is arranged between the two cutting lines in a manner substantially like that in which this is now done by manually operated tools. in order to produce this effect7 the operative cutting bit 76 of the tool which at this time is on the underside of the helve has its lower sharpened or cutting edge 77 arranged obliquely or at an angle relative to the length of the helve, so that the cutting edges of the two bits which for the time being are in the operative or cutting position diverge forwardly to a greater extent than the forward divergence of the helves` as shown in Fig. 2. By this means each bit upon striking the asphalt produces not only a cutting action thereony but also a prying action toward the other bit, so that between the cutting and prying operation by both operative bits, the asphalt surface between the two cutting lines of these bits is quickly and effectively removed to form a groove or channel in the asphalt.

Each bit preferably has its cutting edge so arranged relatively to the respective helve so as to form two cutting corners 78, 7S at opposite ends of the cutting edge. 1n operation, the bit upon striking ythe asphalt surface digs with its rear corner into the asphalt, as shown in Figs. 1 and 3, so that this corner receives the greatest amount of wear. Means are therefore provided for permitting this bit to be reversed fore and aft on the helve, so as to bring the previously unworn cutting corner into the rearmost or operative position. In order to avoid interrupting the operation of the machine as little as possible, the tool of each helve is preferably made with two bits, one of which projects downwardly from the helve while in use while the other projects upwardly therefrom and is held in reserve, both bits being preferably formed integrally with and on opposite sides of a central socket., hub or sleeve 79 which is mounted on the rear end of the respective helve in a manner resembling an ordinary hand-operated pick axe. i/Vhen thus organized the edges of the bits on opposite sides of thehub incline in op-f posite directions relative to the axis of its hub, so that when the tool is reversed end for end to bring either bit into the lower operative position or the same is reversed fore and aft, so that either corner of the f bit is brought into the working position,=

then the lower cuttingv edge of each bit will be arranged at the proper angle relative to the asphalt to produce the combined cutting and prying action above referred to. Each of the helves preferably enlarges from its central part toward its front and rear ends and the bore of the hub of the tool is of forwardly-tapering form so that when the latter' is applied to the helve it will not permit rearward movement of the tool on the helve while cutting blows are delivered against the asphalt surface. The rear part of each helve and the bore of the Socket in the tool is also preferably of oval form, so that the tool will not turn on the helve while the same is in use.- The front end of each helve is preferably of smaller cross sectional dimensions than the rear end thereof, so that the hub of each cutting tool may be slipped forwardly o from the helve andY then turned end for end or reversed fore and aft for bringing the desired corner of the tool to the working position. By'this means a very simple and reliable connection is provided between the helve and the tool which holds the latter effectively in place and also permits of readily adjusting the tool for successively using different parts thereof.

The preferred means for pivotally mounting the helves at their front ends on the rear part of the main frame, as shown in the drawings, are constructed as follows:

SO, 80 represent two pivot sleeves each of which is arranged between one side of the intermediate girder and one of the outer girders and both of which turn on an arbor or pivot-rod 81 extending horizontally and transversely through the upper parts of the girdersand provided at their ends with screw nuts 82 bearing against the outer sides of the outer girders. Each of these pivot sleeves is provided with a socket in which the front end of one of the helves is secured. This socket consists preferably ofa relatively lixed lower section 83 which is formed integrally with the pivot sleeve and an upper section Si which is detachably connected to the lower section by means of clips 85, as shown in Fig. 5, or by any other suitable means. rThe socket of the pivot sleeve preferably tapers rearwardly and the front end of the helve seated therein is of correspondingly rearwardlyftapering form, so that the latter will not slip rearwardly out of this socket when the same is moved vertically and its tool is delivering blows against the asphalt. sleeve is also preferably of oval form in cross section, so that the helve is prevented from turning in the socket and thereby retains the cutting tool always in its proper position with reference to the asphalt surface. Vhen it is desired to reverse the tool The helve socketk of the pivot? yfore and aft on the helve,v orctnrn the same .upside down, for bringing diiferent corners 'thereof into working position, ,the front end of the helve is removed from the pivot socket and then V.replaced after the tool has been shifted, into thedesired position. Y

Each of the helves is preferably so operated that it is slowlyy raised bypower and then thrown downv quickly so as to deliver a hammer blow against the asphalt. The ,meansl whereby thisA is accomplished are shown invFigsrle, and are constructed as follows: Y

i S6 represents a shifting arm .projecting upwardly fromeaeh of the pivot sleeves 80. In front of each of these shifting armsis sarranged an upright shifting rod 87 `which llisuprovided at its upper end with a bifurcated head 88 which is pivotally secured to the upper end of one of the sliifting'armsby meansof a transverse pin S9. 90 represents twol cam bars arranged lengthwise A. in .the spaces between the central and side girders below the operating shaft and each pivotally and adjustably connected at its rear end with the lower end of one ofV theupright shifting rods which connection is preferably effected bymeans ofanz adjusting "sleeve Sil-provided with an -internalscrew thread engagingI with an external screwv thread on the lower-endof the respective shiftingl rod 8fzandga transverse pivot pin 92 vpassing horizontally. through the reary end of the cani bar, and-a pair. of lugs 93 on the frontside ofthe adjusting sleeve ,91, as best shown in Figs. 2 and 8c. .Atits-front end each of the cam-barsslides through the front v v and rear `cross bars 94, v95 of. ayoke which has its side bars 96,96 pivotally mounted by on the adjacent parts ofthe girders, as best shown. in Figs.1 and/1.` 99, 99-represent springs surrounding thecam bars within the yokes land each bearing at 'its'v front end against the front crossbar 94 of the. respective yoke andyat its rear end against a collar orshoulder 100 formed on the cam bar within this yoke.v At-its lrear end each ofthe cam barsis provided on its upper -sider'with a bearingsurface 101 whichis adapted to be engaged `by aVK roller 102 whichis carried by fthe wrist 103 of adouble-armed `crank-104 formed on the adjacent part of the operating V,shaft,so that Vthis roller in effect performs .the function of a.-l cam.` During-each rotation ofv the operating shaft, each,V of the camrollersengagesfwith the cam face of the cam bar and pushes the same downwardly and also forwardly whereby this cam A bar is v caused to slide lengthwise in the yoke and the latter to turn, on the girder, thereby I :causingthe shifting rod87 to pull forwardly yand downwardly on the companion shifting arm and: lift the rear end 0f the respective heleiogetherwth the teal mounted thereon.

i-he spring ,99 and thereby aids gravity in means of pins97 journaled in .bearings 98 pensate for such wear. D

`'accomplished by lengthening the connection The instant the cam roller .clears .the front end of thecbearing face ofthe cam bar, the latter is released and i immediately returned to its rearmost and uppermost position byv Y quickly returning the tool into its lowered position. t lThis quick return `or downward movement of each cutting tool is further hastened by means of a depressing spring which is strainedv during the upward motion of the helve and which operates tothrow the latter downwardly with a powerful stroke the instant that the cam roller clears `the .bearing face of "the cam bar vand 'thereby `arranged upon the pivot sleeve on opposite sides of its socket, pressure .arms '106 con-- neeted with eachother in the forni of a Vloop vand .with the inner ends of thesetwo coils and exerting'pressure-upon.'the upper side of the respective helve inrear. of .its pivot and twovretai'ning arms 107 'arranged at 'theouter endsof'these spring coils `and engaging withl the-adjacentpart of the mainframe, as shown in Figs.' 2KV and 5. A wearingY piece 1i orcushion 108 of leather .or similarmaterial is preferably interposed between the upper side of each'helve and thel loop arms ofthe depressing spring, as shown in Figs'. 1, 2aiid 3, for the purpose of deadening any noise by engagement ofthe depressing spring with the helve, and also tolrelieve the latter fromV unduewear. f z y As the Vbits of the-cutting tool become shorter by wear and repeated grindingror re-sharpening, it becomes necessary to lower the rear end yof each helve `in orderto coin- This is preferably between each caniv bar and its shifting; rod

87,'by removing the upperhead 88 of the .shifting rod from the companion shifting reconnecting the head with the shifting 'arm7 the rear `end ofthe helve will be lowered :sufficiently to permit the shortened bit to j Vproperly reach the asphaltsurface. 1

are raised and lowered alternately `and `at intervals of ahalfvrotationV of the Voperating shaft, thereby vnot only causingfthe tools to a-cut .the asphalt in imitaton of;` the manner in which this vis now 'doneby hand but also distributing; thel work of-ithemotor'inore VWhile the machine is arm8`6 and then unscrewingfthe lower end j lofthis shifting,v rod from the adjusting sleeve 91, the requisiteextentsofthat'upon ii5 l without cutting asphalt, the two'helves are preferably raised into an inoperative position in which the cam bars are lowered so that they are beyond the range of the cani rollers and are uninfluenced thereby. rllhis raising of the helves may be effected by manual' means of any suitable construction, ,those shown in the drawings as an example consisting oftwo lifting levers 109 pivoted on opposite sides of the upper rear part of the central girder and having their upper arms connected with each other while their rear arms are provided with laterally projecting fingers 110 Y extending underneath the helves respectively, as shown inrFigs. 1, E2', 3 and 5. During the operation of the machine, these lifting levers are so turned that their lingers are arranged below the lowermost position of the helves and do not interfere with the free` movement ofthe latter, but when the helves are to'be shifted into their inoperative positions, the lifting levers are turned so that their fingers raise these helves into their highest position where they remain. unatl'ected by the meehanism which ordinarily actuatcs them. The lifting levers are retained in eitherV one of these tworposi-tions by means yof a hook 111 connected with the upper arms of the lifting lever and adapted to engagel either with the rear seat 113 on theV main frame when the lifting levers are in an inoperative position, or with a front seat 112 on the main frame when the lifting levers raise the helves into their inoperative posi-tion.`

In the machine shown in the drawings, only two helves are shown which are provided with tools adapted to form a single groove orfurrow in the asphalt. If desired, however, a plurality of such pairs of rhelves and tools may be mounted side by side on thev same frame, so that two ormore grooves or channels may be cut simultaneously while the ina-chine is moving over the asphalt. F or instance, if this machine is organized for cutting asphalt preparatory to removing the saine in order' toy dig a narrow trench in which telephone, vtelegraph or electric light conduits are to be placed, two pairs of cutter arms andtools are arranged side :by side, the space between the `two pairs of tools being equal to the width of the trench which is to` be formed in the streetftoreceive thel conduits.

Owing .to the' ease' with whichv the powei' may be applied either to the cutting tools or tothe propelling `mechanism for moving the machine either'slowly orl rapidly, it is possible to effect the cutting of asphalt much more rapidly' and kat considerable less cost than has been possible lbyl the means heretofore employedv for this purpose; Moreover owing to the fact that the" transverse tie rods or members which support various working parts of the machine alsoserve to vthe main frame, thereby rendering the machine very strongy and rigid and capable of withstanding heavy strains while in use without necessitating making the same unduly heavy for this purpose.

1 claim as my invention:

`1. An asphalt cutter comprising a helve which en'lai'ges from its central part toward opposite ends, a tool having a tapering sockety which receives the outer end of said helve, and a rocking socket of tapering form which receives the inner end of said helve.

2. Ail-,asphalt cutter comprisinga helve which enlarges from its central part toward opposite ends, a tool having a tapering socket which receives the outer` end of said helve, and a rocking socket of tapering form which receives the inner end of said helve, the inner end of saidhelve being smalleihin cross section than the outer endthereof.

3. An asphalt cutter comprising aina'in frame, an arbor mounted on said frame,a pivot sleeve journaled on said arbor, ya socket' having a. relatively'fixed sect-ion connect-ed with said sleeve and a removable section detachably connected with said fixed section, a helve having its .inner end secured in said section, and a. ytool mounted on the outer end vof said helve.

4l. -An asphalt cutter comprising a-inain frame, a` helve vpivotally `mounted on said vframe to swing vertically, a tool mounted on said helve, aspring for depressing said helve' and means for liftinO' said helve coniprising a cam .barV movable lvertically land lengthwise, a shifting airm connected with the helve', a shifting rod` connecting.saidarm and. bar, a yspring operating to move -saidv bar upwardly and lengthwise and a rota-table cam engaging said bar and operating to move the same-r downwardly andl lengthwise.

An asphalt cutterl comprising a finain frame, a. helve pivotally mounted on saidV frame to swing vertically, a tool mounted oni said helve, a springfor depressing said helve, yand means for llifting said helve comprising a cam bar movable vertically and lengthwise, a shifting arm connected withy `the helve, a*` shift-ing rod connectiiigsaid arnr and bar, asp'ring yoperating to move said bar upwardly and lengthwise, a rotatalble cam engaging said bar and operating to ni'ove the saine downwardly and length-v wise, and a yoke which ispivota'lly mounted on said frame and in which said `cam bar is Y guided.

6. An asphalt cutter comprising `a main frame, a-lielve pivotallyV mounted on saidy frai'ne to swing' vertically, aytool` mounted ongsaid helve, a spring for depressing said helve, and means for' lifting s'aid helve conipiisi'ng a cam' bary movable vertically and lengthwise,- an upwardly projecting l'shifting arm connected with the helve, a coupling Sleeve pivoted on the cani bar and having an internal screw thread7 an upright Connecting rod having its lower threaded end eugaglng with sald Coupling sleeve and its upper end pivotally connected with Saidy Shifting arm, and a rotatable cam engaging with said cani bar.

7. An asphalt cutter comprising a main lengthwise, an upwardly projecting shifting arm connected with the helve, a coupling sleeve pivoted on the Cain bar and having an internal screw thread, an upright oon-V neoting rodvhaving its lower threaded end engaging with said coupling Sleeve and its upper end pivotally Connected with said shifting arm, a rotatable cam engaging With l said Cam bar, a yoke which is pivoted to turn vertically on said frame and Which is guided in said yoke, and a spring interposedbetween said yoke and a shoulder on said bar.

HENRY SCHUMACHER.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents.

Washington, D. C. i