US3539014A

US3539014A - Road grading machine

Info

Publication number: US3539014A
Application number: US744069A
Authority: US
Inventors: Karl-Erik Arnold Jonsson
Original assignee: Brundell and Jonsson AB
Current assignee: Brundell and Jonsson AB
Priority date: 1968-07-11
Filing date: 1968-07-11
Publication date: 1970-11-10
Anticipated expiration: 1987-11-10

Description

r -Tea a I I United States Patent ll 13,53,9,014

[72] Inventor Karl-Erik Arnold Jon-Ion 2,054,129 9/1936 Kelsey 172/96 Gavle, Sweden 2,670,551 3/1954 Keeler..... 172/796 [21] Appl. No. 744,069 3,221,619 12/1965 Erickson 172/110- [221 My Primary Examiner-Robert E. Bagwill [45 1 htfmgd 1970 Assistant Examiner-Stephen C. Pellegrino [73] am och Jonsso Anorney- Wenderoth, Lind and Ponack Guvle, Sweden [54] ABSTRACT: A terrain grading machine comprising a vehicle a which carries at least one cutter head assembly secured to the U n "2/111, end of a motor-driven shaft supported upon a fully 360 172/1 17, 172/666, 172/668; 94/45; 2 9/ horizontally rotatable and universally articulated tool-carrying .a arm and adapted to be moved onto an existing or proposed Aolb B019 1 work or road surface to be worked. At least one scraper blade [50] Field Search 172/786, extending subsmmiany radially in relation to Said h ft is 59, 99, 110, 96, 666,668, 796; 94/45; 299/4, 55 mounted on the under or outer end surface of a rotary cutter head with its workin ed e bein transversely normal to and [56] Rehmc cud axially remote from fhe s haft, asd a separate drive to rotate UNITED STATES PATENTS the cutter head, whereby a milling operation may be per- 1,81 2,771 6/1931 Blood et a] 299/41 formed on the terrain when the cutter head is rotated.

Fig.1 4

INVENTOR KARL- ER l K RNOLD JONSSON ATTORNEYS PatenteaL iNov. 10, 1970 I I 3,539,014

Sheet 2 of9 INVENTOR KARL-ERIK ARNOLD JONSSON kW/aw M ATTORNEYS Sheet INVENTOR KARL- ERIK ARNOLD JONSSON INVENTOR Sheet 1 of 9 KARL-ERIK ARNOLD JoNssoN ATTORNEYS waHl; v a M m 3 .LL. 8 v

8f am a y .Patiented Noi r i flo,

Pat'eiiiecl No 10, 197O 3,539,014

Sheet 5 of 9 I INVENTOR KARL-ERIK ARNOLD JONSSON ATTORNEYS Patented Nov. 10, 1970 Sheet Q 019 Fig.6

Fig. 7

INVENTOR KARL-ER] K ARNOLDJONSHN $1 i/gw //MWZZ ATTORNEYS P'atentecl v N O r. 1-0,' 1970 3,539,014 I Sheet 7- are INVENTOR KARL-ERIK ARNOLD JONSSON ATTORNEYS "Fam d Nbv.10,1970 3,539,014

I net E or 9 V Fig.

v INVENTOR KAR L- ERIK ARNOLD JONSSON ATTORNEYS f Patented Nov. 10, 1970 3,539,014

Sheet 3 01's Fig.12

INVENTOR KARI: ERIK ARNQD JCNSSON ATTORNEY S travel. Because of the teeth of the blade, the roadway becomes fluted longitudinally, though the flutes are generally slightly sinuous, as the canting blade subjects the scraper to-var'ying lateral forces. When the scraper must detour to make way for other traffic, the serpentine flutes will, of course, get a larger amplitude. Particularly. on winter roads, where the road surface rapidly freezesto ice, such flutes are an inconvenience, as

the wheels of the vehicle tend to follow the grooves and thus run unevenly which may cause skidding with fatal results. Socalled winter tires which have a deep pattern to give a better traction, are especially effectively guided in the flutes so that their function-becomes the opposite of the one intended. A long journey on such a road is very tiresome for the driver. The sanding of a fluted winter road does not eliminate the difficulties, asthe sand mostly collects at the bottom of the flutes.

"Also, road scrapers of the type mentioned above have difticulty in managing thick layers of snow or ice covering the road. When the resistance becomes great, the drive wheels begin to spin and the scraper blade must be elevated. To eliminate the ensuing difference in level the road scraper must then reverse and repeat the performance.

SUMMARY or THE INVENTION The object of-the inventioh is to provide an improved road grading machine which eliminates the inconveniences men- 'tioned.The new machine may have one or several scraper blades which, however, are adapted to smooth the road surface by milling instead of by planing. For this purpose, at least one scraper blade is mounted on the-under or end surface of at least one cutterhead which is operatively connected to one end of a motor driven shaft, the arrangementbeing such that areas or a central weal often formed on winter roads. Also, it is possible to treat a wider surface by causing the arm to pendulate during the travel, and if a vehicle wants to pass, the arm with the cutterhead may be moved aside without changing the position or course of the machine. Conveniently, the scraper blades are adjustable at different angles to render possible a guidance of thematerial out. For obtaining special functions described hereinafter thecutterhead may be mounted to be turned into different angular positions in relation to the carrymg arm.

A milling gives a considerably smoother road surface than planing, and flutes,- if any, will besubstantiallytransverse, so that the vehicle tires get better traction. Also, the grading becomes less influenced bya varying'thickness of the snow or ice covering. Whenthein'achine encounters alar'ge protubeusefulfor grading gravel roads, in that cavities are effectively filled. Forinstan'ce, the machine may be used for levelling the top layer when building roads, for dredging ditches and the like. ln'the wintertime the machine may be used for reducing walls of snow formed by snowplows'.

which show an embodiment having 2 BRIEF DESCRIPTION OF THE DRAWINGS The machine according to the invention will be described in more detail with reference to the accompanying drawings one single cutterhead carried by apivoted arm.

In the drawings:

FIG. 1 shows a perspective view of the machine.

FIG. 2 is a plane view, where different positions of the arm with the cutterhead are indicated by dash-and-dot lines. I

FIG. 3 shows a side view, where the arm is turned forward and the cutterhead is set for working a vertical surface.

FIG. 4 showsan axial vertical cross section through the cutterhead on a larger scale.

FIG. 5 shows a broken-away perspective view of the members located in the interior of the cutterhead.

FIG. 6 shows a mechanism for varying the angular setting of the scraper blades, as seen substantially on and in the direction of the arrows VI-VI in FIG..5.

FIG. 7 is a diagrammatic view of the setting mechanism and the scraper blades, as seen fromabove.

FIGS. 8 and 9 show two different embodiments of cutterheads, as seen from one side.

FIGS. 10l3 show front views of the machine in various positions of operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT As appears from FIGS. 1-3, the machine or vehicle has a longitudinal frame 20 supported by two wheel undercarriages, a rear one 21 and a fore one 22. Each wheel undercarriage may conveniently be composed of two pairs of

tandem wheels

23, 24 and 25, 26, respectively. The shafts of the wheels may in the known way be journaled in cradles (not shown) which are rockable on pivots directed in parallel to the wheel shafts. By such an arrangement the vehicle getsa smoother movement when driven over a bumpy surface. The rear wheel undercarriage 21 carries driving motor, compressor etc. under a hood 27 as well as a drivers cabin 28, from which the adjacent end of the frame 20 extends. The fore wheel undercarriage 22 is secured to I a large ring 29 which is rotatably journaled around a disk 30 in a manner not shown. Said disk 30 is, in turn, secured to the foremost part of the frame 20 by means of a vertical shaft 31. A steering mechanism, not shown, may be mounted below the disk 30 to turn the wheel. undercarriage by means of a gear engaging an internal gear rim on the ring 29. The structural details hitherto mentioned do not constitute part of the invention and therefore need not be described in detail.

Between the frame 20 and the disk 30 the shaft 31 is sur rounded by a rotatable sleeve 32, and a gear rim 33 provided at the upper end of the sleeve 32 meshes with a pinion 34 which is driven by a hydraulic motor 35 mounted within the frame 20. A tubular member 36 welded to the sleeve 32 extends horizontally to constitute a primary arm part of the rotatable tool-carrying arm' of the machine. A rotatable roller 37 mounted on the lower side of the member 36 is adapted to roll on the upper end surface of the ring 29. A shaft 38 is journaled in the tube 36, and a projecting portion of said shaft 38 carries a gear 39 secured to it immediately outside the tube 36. A hydraulic motor 40 mounted on the tube 36 has a drive gear 41 which meshes with the gear 39 whereby the shaft 38 may be rotatedinto any desired angular position. The outer end of the shaft 38 is formed with an car 42 which carries a pivot 43 projecting on both sides and intersecting the axis of the shaft 38. A secondary tool-carrying arm 44 pivotably 45 linkedto theear 42 have their piston rods linked to lugs 46 on the inner sides of the fork legs. It is apparent that the foregoing means provides a universal type connection betweenthe primary and secondary tool-carrying arms.

The fork arm 44 carries at its outer end a cutterhead generally designated by 47. As apparent particularly from FIG. 4, the cutterhead includes a substantially disk-shaped supporting member 48 to which two upright brackets (only one bracket 49 is visible in FIG. 4) are screwed one on each side of a central cylindrical projection 50. A pivot 51 directed radially outwards is secured to each of the brackets 49. The two pivots 51 are arranged axially in alignment to each other and are journaled in the outer ends of the fork legs 44. At least one pivot 51 has a projecting end portion on which a worm wheel 52 is mounted. A worm screw 53 meshing with the worm wheel is by means of a linked shaft 54 (FIG. 1) connected to a hydraulic motor 55 on the outside of the fork arm 44. On supply of pressurized liquid to the motors 55 the cutterhead 47 may be turned from the horizontal position shown in FIG. 1 into different angular positions, such as the vertical position shown in FIG. 3, for instance. In FIGS. 1 and 4, the worm transmission has been shown without a surrounding housing, but of course a housing is required, inter alia to keep the screw 53 in engagement with the worm wheel 52.

The holder 48 of the cutterhead is surrounded by a ring 56 (FIG. 1) composed of several ring elements and carrying the scraper blades described below. The ring is rotatably journaled by means of a wire ball bearing 57 mounted around the periphery of the holder 48. Thus, two

ring elements

58, 59 are connected to form the outer runway of the wire ball bearing 57, and the ring element 59 is, in turn, connected to a lower ring 60 internally formed with a gear rim 61. Two motors 62 (FIG. 1) are mounted diametrically opposed on top of the holder 48. The motor shafts 63 (FIG. extend through apertures in the holder 48 and carry gears 64 meshing with the gear rim 61. At the operation of the motors 62 the ring 56 may be caused to rotate at a speed required for carrying out the work, say from and up to about 200 rpm.

The ring element 59 connected to the gear ring 60 carries a lower ring element 65 by means of a clamping ring member 66 C-shaped in cross section. The

rings

59 and 65 serve as supports for

bearings

67, 68 in which vertical shafts 69 carrying scraper tools are journaled. Further, the lower ring element 65 has its inner periphery connected by screws to a bottom disk 70 covering the'aperture and thus forming, together with the

ring elements

58, 59, 65, 66, a substantially cup-shaped unit rotatable around the holder 48.

In the embodiment shown, three scraper tools are uniformly spaced around the periphery of the cutterhead (FIGS. 2 and 7). As seen in FIG. 4, each shaft 69 has a threaded lower end portion screwed into a correspondingly threaded bore in the middle ofa heavy elongated member 71 serving as holder for a scraper blade 72 of equal length. The scraper blade 72 which is of high-grade steel, is secured by screws in a longitudinal groove 74 in the bottom surface of the member 71. A liner 33 of rubber in the groove 74 permits the blade 72 to give way slightly in case of great stress. Owing to the rotatable shafts 69, the scraper blades 72 may be adjusted in varying angular positions in dependence on the requirements arising when carrying out an operation, and below an adjusting mechanism rendering possible an adjustment of the blade angles during the operations will be described with reference to FIGS. 47.

A vertical shaft 76 is by means of roller bearings 77, 78 rotatably supported in an axial bore 75 in the holder 48. At a level below the gear ring 60 the lower end of the shaft 76 is secured to an approximately T-shaped plate 79 perpendicular to the axis of the shaft. A vertical dowel 80 coaxial to the shaft 76 projects from the underside of the plate 79 and carries a guide plate 81 (FIG. 6) parallel to the plate 79. On its upper side said plate 81 has two parallel riblike projections 82 serving as guide members. A cam disk 83 disposed between the

plates

79, 81 has two grooves to receive the guide ribs 82, and between said grooves the cam disk has an aperture 84, through which the dowel 80 passes. As seen in FIG. 7, said aperture 84 is elongated in the longitudinal direction of the ribs 82. Thus. the cam disk 83 is movable radially along the guide rlhs 82. the nmxlmum length of the movement being determined by the length of the central aperture 84. To move the cam disk two hydraulic cylinders 85 are mounted in parallel to the guide ribs 82 between lugs 86 projecting from the top side of the plate 79. The piston rods 87 of the cylinders are connected to brackets 88 secured to the top side of the cam disk 83 on either side of the middle portion of the T-shaped plate 79. The ends of the cylinders 85 are by means of

pressure hoses

89 and 90, respectively, connected to passages 91 and 92, respectively, which extend through the shaft 76 up to a sleeve 93 surrounding said shaft. Within the sleeve 93 the passages 91, 92 communicate with peripheral grooves 94, 95 provided in the inner wall of the sleeve. The two grooves 94, 95 are connected to a source of pressurized liquid, not shown, by means of

conduits

96 and 97.

Above the sleeve 93, a worm wheel 98 keyed to the shaft 76 meshes with a worm screw 99 connected to the shaft of a hydraulic motor 100. The worm wheel 98 is surrounded by a housing 101 mounted on the cylinder portion 50 and open towards a casing 102 (FIG. 1) enclosing the worm screw 99.

Fork-shaped arms 103 directed radially are keyed to the shafts 69 (FIGS. 4 and 5) between the

ring elements

59, 65 which support the bearings for the shafts 69 of the scraper tools. Rollers 104 are journaled on pivots 105 mounted at the outer ends of the arms 103 in parallel to the shafts 69. The rollers 104 are held in contact with the outer periphery of the cam disk 83 by means of tension springs (only one spring 106 is shown in FIG. 5) extending from attachments 107 on the underside of the gear ring 60.

In FIG. 7, the cam disk 83 is shown circular, but it may also be unsymmetrical. The shape may be varied in dependence on the requirements with regard to the function of the scraper blades. When a circular disk 83 is in its initial position, i.e. coaxial to the shaft 76, the scraper blades 72 have equal angular positions, as the cam follower rollers 104 of the arms 103 are disposed symmetrically around the center, and the blades are then preferably adjusted such that they perform an effective milling operation during the entire revolution. On supplying pressurized liquid to the rear ends of the cylinders 85, the cam disk is moved by the piston rods 87 into an eccentrical position, as shown in FIGS. 5 and 7, for instance, and the arms 103 are then caused to turn the scraper blades 72 into different angular positions against the action of the springs 106. To render possible the outward movement of the rollers 104 at a great displacement of the cam disk 83, the casing ring 66 of the cutterhead may be designed with bulges, as shown particularly at 108 in FIG. 2. If the central shaft 76 of the cutterhead 47 is not turned during the rotation of the cutterhead, the rollers 104 will of course move around the periphery of the cam disk 83, and during each such revolution the scraper blades 72 will successively pass through the different angular positions indicated in FIG. 7. The adjustment may then be such that in a certain angular position the blades tip off the material collected during the remainder of the revolution. By turning the shaft 76 by means of the motor 100 of the

worm gear

98, 99, the eccentricity of the cam disk 83 may be adjusted such that the tipping takes place in a predetermined direction, e.g. onto the roadside.

For some operations it may be sufficient to use a cutterhead with fixed scraper blades. FIG. 8 shows such a simple structure. In the same way as in FIG. 4, the blades 72 are attached in holders 71', but the holders are here screwed or welded to a head 47' having a central shaft 109 connected to driving means.

The cutterhead in FIG. 9 is of the same construction as that in FIG. 4, the only difference being that the lower end of a rod 110 directed downwards from the center of the bottom plate 70 carries asliding member 111 serving to limit the cutting depth of the scraper blades. If desired, the rod 110 may be resiliently telescoped in a sleeve 112.

Owing to its link connections and the hydraulic motors or cylinders, the

rotatable arm

36, 44 may be adjusted to carry the cutterhead in a great number of operative positions. As intllcuted by (illNiHllIlI-(IOI lines In FIG. 2. the cutterhead mny thus be swung to either side or forward from its position under the vehicle, and the head-proper may be set in different angular positions relative to the arm. FIGS. -13 show examples of some specific operations that may be carried out with the machine. in FIG. 10, the

arm

36, 44 is swung laterally, and the cutterhead is set in an inclined position to work a snow wall 113 at the roadside. in FIG. 11, the outer portion 44 of the arm has been swung upwards so that the cutterhead can assume a substantially horizontal position considerably above ground level to enable the scraper blades to smooth down the top of the snow wall. in FIG. 12, the machine is used for smoothing a slope atthe side of the road, and in FIG 13 an opposite sloping surface is workedto obtain a ditch. A number of other applications are also possible.

The machine described may be modified in various respects. The cutterhead need not necessarily be carried by a rotatable arm, although this is to prefer. As mentioned, the machinemay be provided with several cutterheads, and a rotatable arm may, for instance, carry two heads mounted side by side or one after the other. Of course, the driving motors described may be replaced by other means having the same connected primary and secondary arm portions and including means'for pivotally mounting said primary arm portion upon said pivot shaft; said mounting means including further means to selectively impart a substantially full 360 horizontal movement about said pivot shaft; said tool-carrying arm having at least one cutterhead assembly pivotally mounted on the outer end of its said secondary arm comprising means rotatably mounting at least one cutting blade thereon having acutting edge for engaging a terrainsurfsce to be worked. and including drive means on said cutterhead assembly for operatively rotating said cutting blade so as to perform a milling-type cutting operation to the terrain.

2. A machine as defined in claim 1 further including means for universally mounting said secondary tool-carrying arm portion relative to said primary arm; said means including coaxial, relatively rotatable primary shaft portions.

3. A machine as-defined in claim 1 wherein said rotary cutterhead assembly includes a cutterhead support member and a rotatable tool-mounting ring rotatably mounted relative to the cutterhead supportmember; and further including a plurality of cutting blades and means for adjustably mounting said blades for varying angular disposition relative to each other.

4. A terrain-grading machine adapted to move generally forwardly and rearwardly over terrain to effect grading thereof, comprising in combination:

a. a mobile vehicle frame having a drive motor power source 27 and controlling cab 28.-generally at one end thereof, and an elongated frame section projecting in a a direction forwardly therefrom and spaced substantially above and generally parallel to a generally horizontal portion of given terrain; a

b. means including a vertically disposed fixed pivot shaft 31 depending from said elongated frame, section 20 at a predetermined distance from said first one end;

c. tool-carrying arm means including a primary tubular outer arm 36 disposed generally horizontally and having a transversely attached sleeve portion 32 for pivotally mounting said primary arm on said vertical shaft 31 for unlimited rotation in a generally horizontal plane therearound, and further including an inner shaft 38 journaled coaxially within said outer arm 36 and having one end 42 projecting therefrom;

d. interrelated drivemeans 33-35 on said sleeve 32 and elongated frame section 20 for imparting selective pivotal rotation to said primary arm 36;

c. said tool-carrying arm means further comprising an elon gated secondary tool-carrying arm 44 having inner and outer ends. and means including first means 43 for pivotally linking said secondary arm 44 to the primary arm 36 via said projecting end 42 of said inner shaft 38 so that said secondary arm 44 is capable of movement in a generally vertical plane about said pivotal linking means 43 so as tobe selectively moved toward and away from a surface to be worked;

f. fluid pressure means 42, 45, 46 operably interconnecting said inner shaft and the secondary arm 44 to selectively effect predetermined pivotal movement of the secondary arm 44 in said vertical plane;

g. rotary cutterhead means 47 comprising at least one cutterhead holder 48 having upper and under sides; means 49-52 pivotally linking its upper side to and near the outer end of said secondary arm 44 by at least one pivot pin 51 disposed transversely to the length of said secondary arm 44, at least one grading tool having an elongate scraper blade 72 and means operatively mounting it radially transverse to and normally depending from said holder 48; means 60-64 mounted in association therewith and operatively connected to said holder 48 for facilitating rotating milling action to said blade during use; and

h. said cutterhead means and scraper blade being selectively rotatively movable via the tool-carrying arm means in substantially a full 360 directive manner about said vertical pivot shaft 31 relative to the vehicle frame to thereby universally treat terrain surfaces adjoining all sides of said machine.

5. A machine as defined in claim 4 wherein the means of paragraph (c) for linking said primary and secondary arms are of a universal acting character, and further include second complemental means adjacent said first means on said outer primary arm 36 and on said coaxial inner shaft 38 for selectively imparting rotative movement to said inner shaft 38 relative to said primary outer arm 36 about their common axis.

'6. A machineas defined in claim 4 wherein the rotary cutterhead means 47 of paragraph (g) further include rotatable ring means 58-60 which constitute at least part of the said means thereof operatively connecting said tool-scraping blade 72 for facilitating its rotary milling action, and said rotatable ring means further comprises motor drive and drive shaft means 62, 63 and relatively rotatable, interengaging rotary drive means 60, 61, 64 including a relatively rotatable annular ring member 60 constituting a part of said latter motor drive and drive shaft means, and means operatively connecting each blade to said ring member 60. I

7. A machine as defined in claim.4 wherein each toolscraper blade 72 is detachably mounted in a holder 71 and includes a

resilient lining

73, 74, material to permit the blade to give way under and to absorb predetermined high load stress as applied to the blade in a lateral or crosswise direction.

8. A machine as defined in. claim 6 wherein each grading tool includes a generally medially attached mounting shaft 69 projecting upright from and generally coextensive with the major plane of said elongate blade; and said cutterhead means 47 includes additional means 76-107 operatively connected to and for selectively adjusting a relative angular position of each tool blade about its mounting shaft.

9. A machine as defined in claim 8 wherein said latter additional means 76-107 therein includes:

l. at least one fixed

planar plate member

79, 81 attached transversely toand for rotation with a lower end of a separate driveable shaft 76 rotatably journaled in said cutterhead holder 48, which latter shaft 76 is spaced laterally of said tool blade mounting shaft 69 and of said motor drive shaft means 63; j

2. a selectively shiftable, planar, camming plate 83 having an outer arcuate camming periphery, and means for mounting said camming plate closely adjacent and for sliding movement relative to said fixed

plate member

79, 81 along suitable cooperative guide means 82;

3. power source means including means complementally interconnected to said fixed and shiftable camming plates to impart selective eccentric shifting movement to said camming plate as desired; and

4. each depending blade-mounting shaft 69 having a transversely extended, pivot arm 103 fixed thereto and including a free end with means resiliently engaging it with and for following along said camming periphery.

10. A machine as defined in claim 9 further including means 98-100 for imparting rotative drive to said separate driveable shaft 76; and wherein said camming plate mounting and guide means enable a coaxial disposition of said camming plate relative to said separate shaft 76 and to said annular ring member 60 so that in a said coaxial disposition said tool-scraping blades rotate with said annular ring member 60 in a noneccentric manner responsive to rotation of said annular ring member 60 and regardless of rotation of said separate shaft 76; but when said camming plate is eccentrically disposed with said separate shaft 76 nonrotating and with said annular ring member 60 being rotated, said blades are rotated therewith in an eccentric or angularly changing manner according to the predetermined eccentric setting of said cam plate; and during said latter eccentric setting, said separate driveable shaft 76 is capable of imparting rotation to said camming plate and thereby further imparting continuously eccentric milling rotation to said working blades.

11. A machine as defined in claim 8 wherein said latter additional means 76l07 includes therein:

1. an upper planar plate 79 and a lower planar plate 81 fixed in spaced-apart relation on a lower end of a separate driveable shaft 76 rotatably journaled in said cutterhead holder 48, said separate shaft being spaced laterally of said tool-mounting blade shaft 69 and of said motor driving shaft means 63; said upper and lower plates disposed with their planar surfaces normally transverse to said separate shaft 7 6;

\2. a selectively reciprocably shiftable camming plate 83 having an arcuate outer camming periphery and being slidably interposed between said upper and lower plates along guiding means 82, and having a generally medially disposed elongate aperture 84 to permit clearance around said separate shaft 76;

. fluid pressure operating means 8597 cooperatively interconnected to said upper plate 79 and said camming plate 83 to selectively impart eccentric shifting movement to said camming plate;

4. each blade-mounting shaft 69 having a transversely extended pivot arm 103 with one end rigidly fixed thereto and an antifriction cam-plate-following part 104 on the freely projecting other end;

5. bearing means 67, 68 to journal said tool-mounting shaft 69 for operatively rotatable connection in said cutterhead means 47; and

6. yieldable resilient means 106 acting as return means connected between each pivot arm 103 and said relatively rotatable annular ring member 60, to cause said freely projecting end of said pivot arm 103 to follow the periphery of said camming plate 83.

12. A machine as defined in claim 9 wherein said guiding means of paragraph 2 includes fixed linear track means 82 and complemental groove means, respectively, on the said fixed lower plate (81) and camming plate 83, and whereby said fixed spaced plates and interposed camming plate 83 are together rotatable responsive to a drive rotation imparted to said separate driveable shaft 76, to thereby impart rotative adjustment via said camming plate and guiding means to in turn angularly adjust said tool baldes 72.