Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
  • E01C23/00—Auxiliary devices or arrangements for constructing, repairing, reconditioning, or taking-up road or like surfaces
  • E01C23/06—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road
  • E01C23/08—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road for roughening or patterning; for removing the surface down to a predetermined depth high spots or material bonded to the surface, e.g. markings; for maintaining earth roads, clay courts or like surfaces by means of surface working tools, e.g. scarifiers, levelling blades
  • E01C23/085—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road for roughening or patterning; for removing the surface down to a predetermined depth high spots or material bonded to the surface, e.g. markings; for maintaining earth roads, clay courts or like surfaces by means of surface working tools, e.g. scarifiers, levelling blades using power-driven tools, e.g. vibratory tools
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
  • E01C23/00—Auxiliary devices or arrangements for constructing, repairing, reconditioning, or taking-up road or like surfaces
  • E01C23/06—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road
  • E01C23/12—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road for taking-up, tearing-up, or full-depth breaking-up paving, e.g. sett extractor
  • E01C23/122—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road for taking-up, tearing-up, or full-depth breaking-up paving, e.g. sett extractor with power-driven tools, e.g. oscillated hammer apparatus
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F5/00—Dredgers or soil-shifting machines for special purposes
  • E02F5/30—Auxiliary apparatus, e.g. for thawing, cracking, blowing-up, or other preparatory treatment of the soil
  • E02F5/32—Rippers
  • E02F5/326—Rippers oscillating or vibrating
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21C—MINING OR QUARRYING
  • E21C27/00—Machines which completely free the mineral from the seam
  • E21C27/20—Mineral freed by means not involving slitting
  • E21C27/46—Mineral freed by means not involving slitting by percussed planing means

Definitions

• This invention relates to road working equipment and, . more particularly, to a method and apparatus for removing pavement from a road bed.
• One procedure is to soften the asphalt pavement with a radiant heater or flame burner, and then clean off the softened asphalt in layers with the mold board of a road grader.
• the thickness of each layer removed in this manner is limited by the depth of the asphalt that can be softened by the radiant heater or flame burner, which is very small.
• a third procedure is to mill off the pavement in layers with a rotating drum on which carbide tips or teeth are mounted.
• a great deal of downward force needs to be exerted on the drum, which resul in too many fine particles if the asphalt is to be recycled
• Still another procedure is to use sonic energy to cut into pavement.
• a sonic vibration generator is coupled to the upper end of an essentially vertical beam or bar having pavement-engaging teeth or serrations formed at its lower end.
• the vibration generator supplies energy to the beam at its resonant fre ⁇ quency, and the vibrating teeth at the lower end of the bea cut into the pavement.
• One aspect of the invention is a method for removing . asphalt or concrete pavement from a road bed.
• An elongated cutter blade that extends in a downward and forward directi along a cutting plane to a cutting edge is held in contact with the pavement such that the cutting plane forms an acut angle with the surface of the pavement.
• the cutter blade engages the pavement such that the cutting edge penetrates the pavement.
• the cutter blade is intermittently driven wi a force parallel to the cutting plane in the forward direc ⁇ tion while the cutting edge penetrates the pavement to driv the cutter blade incrementally in a forward direction and plane off the pavement in a chisel-like manner.
• pavement planing apparatus comprising a transversely elongated cutter blade mounted on a support frame to permit reciprocation approxi ⁇ mately in a cutting plane.
• the cutter blade is disposed at an acute angle between 45° and 55° to the surface of a pave ment, and extends in a downward and forward direction along the cutting plane to a cutting edge that lies in the cuttin plane.
• Plural spaced apart force transmitting beams having an input and an output are mounted on the support frame, a source of vibrations is connected to the input of the force transmitting beams, and the output thereof strikes the cutt
• _0MPI blade to apply a unidirectional force thereto parallel to the cutting plane in a forward direction.
• a vehicle continuously transports the support frame in the forward direction while the unidirectional force is being applied to the cutter blade.
• the cutter blade with the described apparatus engages and planes off pavement in a chisel-like manner as the apparatus is transported in the forward direction.
• a feature of the foregoing apparatus is a support frame comprising plural spaced apart upright support beams, plural spaced apart forwardly projecting support beams, and plural struts, all equal in number to the force transmitting beams.
• the top of the upright support beams is attached to the back of the respective forwardly projecting support beams.
• One end of the struts is attached to the front of the respective forwardly projecting support beams and the other end of the struts is attached to the bottom of the respective upright support beams.
• the force transmitting beams are mounted on the support frame so they are approximately parallel to the respective struts, with the input near the front of the respective forwardly projecting support beams and the output near the bottom of the respective upright support beams.
• the cutter blade lies in front of the output of the force transmitting beam approximately under the upright support beams.
• the upright support beams have a larger mass per unit length than the forwardly projecting support beams and the struts.
• the center of gravity of the support frame is located nearly directly over the cutter blade so its weight counteracts most effectively the reactive forces exerted on the cutter blade by the material being cut.
• sonic generator produces a reciprocating force that is transmitted to a tool by a resonant or nonresonant force transmitting member having an output that reciprocates about a neutral position responsive to the force of the sonic generator.
• a continuous unidirectional force is applied to the force transmitting member.
• the tool advances intermittently along a work path through a medium responsive to the continuous unidirectional force and the reciprocating force.
• a gap is held between the neutral output position of the force transmitting member and the tool when the tool is unable to advance through the medium responsive to the continuous unidirectional force and the reciprocating force. The gap protects the tool driving apparatus from destruction.
• the sonic generator and the force transmitting member are supported by a tool holder or carrier to which the continuous unidirectional force is- applied.
• the reciprocating force produced by the sonic generator is substantially larger than the continuous uni ⁇ directional force applied to the tool holder.
• the force of the sonic generator is sufficiently large relative to the unidirectional force to overcome the latter and to drive the tool holder back away from the tool when the tool is unable to advance along the work path, thereby establishing the protective gap.
• FIG. 1 is a side elevational view of tool driving apparatus embodying the present invention and especially arranged to cut or shear hard material such as asphalt or concrete;
• FIG. 2 is a top plan view of the front of the apparatus of FIG. 1;
• FIG. 3 ' is a fragmentary enlarged side view of the material cutting assembly of the apparatus with portions broken away to show interior details;
• FIG. 4 is a fragmentary cross-sectional view taken along line 4-4 of FIG. 3;
• FIGS. 5A-5C are diagrammatic views of the tool and its drive mechanism in different stages of operation
• FIG. 6 is a graph showing the relationship of time and displacement of the tool and drive mechanism in the various operational stages shown in FIGS. 5A-5C;
• FIG. 7 is a front elevation view of part of the apparatus of FIG. 1;
• FIG. 8 is a fragmentary cross-sectional view taken along line 8-8 of FIG. 3, omitting the structure between the resonant beams;'
• FIG. 9 is a side elevation view of the cutting assembly support frame of the apparatus of FIG. 1;
• FIG. 10 is a front elevation view of the support frame of FIG. 9; and FIG. 11 is a top plan view of the support frame of FIG. 9. Detailed Description of the Specific Embodiment
• a tool such as a cutter blade
• the tool can take the form of a cutter blade having an elongated cutting edge arranged to engage concrete or other material to be removed at a controlled angle and at- a controlled depth, and having a transverse disposition so that, upon energization, a swath of predeter width can be simultaneously removed.
• the cutter blade is mounted from a powered and steered mobile frame for recipro eating motion, which mounting preferably constitutes a pivo support for the cutter blade so that it moves arcuately fir in a forward cutting direction and then rearwardly.
• the po of pivotal support is in advance of the cutting edge in the direction of cutting so that such pivotal motion is directed angularly downward into the material which is to be cut or severed, and at an angle which will vary dependent on the hardness and other mechanical properties of the material, and which can be adjusted to optimize the operation.
• Force impulses are delivered cyclically to the pivotall supported cutter blade by reciprocating drive means, which on its forward stroke engages and drives the cutter blade into the material and thence withdraws preparatory to a subsequent driving stroke, forming a gap between the cutter blade and the drive means.
• Forward motion of a mobile supporting frame generates a tractive force which tends to close the gap in a fashion such that the reciprocating drive means is brought into contact with the cutter blade after the former's speed (and momentum) approaches a maximum in the forward or cutting direction.
• the driv means is in driving contact with the cutter blade itself for less than 180° of any given cycle.
• the drive means takes the form of a resonant force transmitting member powered by a sonic generator or oscillator incorporating the general principles embodied in the unit shown and described in the aforementioned patent.
• the resonant member constitutes a generally upright beam mounted by a resilient tire at its upper node position to accommodate "pseudo-nodes" generated during operation.
• An additional rigid member engages the beam at its lower node position to support and maintain the desired beam disposition.
• the sonic generator is connected to the resonant beam at its upper end and preferably includes multiple eccentric weights mounted in spaced relation with a multiplicity of bearings on a common shaft so that the requisite force may be generated while minimizing the shaft diameter, and the peripheral speed and wear of the bearings because of the distribution of the bearing loads.
• the lower end of the beam lies adjacent the cutter blade to deliver the force impulses in substantial alignment with the cutting direction.
• the input force generated by the sonic generator is greater than the described tractive force resultant from the forward motion of the powered mobile supporting frame, and as a consequence, there is no possibility for clamping of the beam end against the cutter blade (and the engaged material), which would stop the resonant actuation and permit the vibratory action of the sonic generator to be applied in a harmful fashion to itself and the supporting frame members.
• a material cutting assembly generally indicated at 10 is mounted at the front of a mobile carrier 11 which includes forward and rearward frame sections 12, 14, each supported by two rubber-tired wheels 16, 18, the two frame sections being connected by a vertical pivot pin 20 which enables articulation of the frame sections for purposes of steering.
• Material cutting assembly 10 is specifically designed to cut asphalt or concrete pavement as found on streets, roads, and highways.
• a steering wheel 22 is mounted forwardly of a driver's seat 24 on the front section 12 of the frame and is arranged to -energize, upon turning, a hydraulic ram 26 pivotally joining the frame sections 12, 14 so as to effect articulation thereof and consequent steering.
• a hydraulic pump 30 is mounted on the rear section 14 of the frame, and driven by an internal combustion engine 32. Fluid from a hydraulic reservoir 28 is driven by pump 30 through suitable hydraulic conduits (not shown) to hydraulic ram 26.
• the engine 32 also drives a second hydraulic pump 34 which is hydraulically connected to hydraulic motors 35 to drive the wheels 16 on the front frame section 12 and the wheels 18 on the rear frame section 14, thus to provide motive power for the entire mobile carrier 11 in a generally conventional fashion.
• the motive power delivered to the wheels will urge the front- mounted cutting assembly 10 against material being cut with a certain tractive force which, for cutting a six-foot swath of concrete or asphalt, should vary for example between 5,000 and 60,000 pounds, depending upon the material resistance and vehicle speed.
• the maximum tractive force i.e., motive power delivered to the wheels
• the maximum tractive force of the vehicle depends upon the friction between the wheels and the surface on which it moves.
• Material cutting assembly 10 is symmetrical about a center plane in the direction of movement, i.e., parallel to the plane of FIG. 1. Many of the elements on the right side of the center plane, as viewed from the front, i.e., the left in FIG. 1, which are identified by unprimed reference numerals, have counterparts on the left side of the center plane, which are identified by the same reference numerals primed.
• a pair of laterally-spaced parallelogram units 36, 36' extend forwardly from the forward frame section 12. More particularly, the parallelogram units 36, 36' include parallel upstanding legs 38, 38' pivotally connected at their lower extremities to the central portion of a fixed transverse shaft 40 on the front frame section 12 and pivotally joined at their upper extremities to the rear ends of forwardly projecting legs 42, 42' . These forwardly projecting legs 42, 42' are pivotally joined at laterally- spaced positions (see FIG. 2) to a generally triangular cutting assembly support frame 44. As shown in FIGS.
• cutting assembly frame 44 comprises spaced apart, upright support beams 46, 46', spaced apart, forwardly projecting support beams 47, 47', struts 45, 45', and cross beams 49, 51, and 53.
• Downwardly and forwardly angled stop mounts 57, 57' are formed near the bottom of upright support beams 46, 46'.
• cross beam 51 is attached, for example by welding, to the top of support beams 46, 46', and the back of support beams 47, 47'.
• At the front of support beams 47, 47' are formed vertically flared bracket mounts 59, 59'.
• Cross beam 53 is connected between flared bracket mounts 59, 59' and is attached thereto, for example, by welding.
• An upwardly and forwardly extending platform support beam 61 is attached, for example by welding, to the middle of the cross beam 53.
• a platform 65 having mounting blocks 89 is attached to the upper end of support beam 61, for example, by welding.
• Struts 45, 45' are connected between beams 47, 47' near the front, and beams 46, 46' near the bot and are attached thereto, for example, by welding.
• Cross beam 49 is connected between support beams 46, 46' near the bottom and is attached thereto, for example, by welding. Pairs of rectangular brackets 75, 75' are attached, for example, by welding to the sides of flared bracket mounts 59, 59'.
• Support beams 46, 46' and cross beams 49 and 51 are made of "solid steel so their mass per unit length is as large as possible.
• Support beams 47, 47' including brac mounts 59, 59', struts 45, 45', and cross beam 53 are hollow so their mass per unit length is as small as possible Consequently, the resultant center of gravity of cutting assembly frame 44 is rearwardly located near support beams 46, 46'.
• Support beams 46, 46' form the forward upright legs of the parallelogram units 36, 36*.
• Lower and outwardl curving legs 48, 48' are pivotally connected at their opposi extremities to the lower ends of the support beams 46, 46' and the previously described shaft 40, thus completing the two parallelogram units 36, 36'.
• Brackets 80, 80' are attached to crossbeam 51, for example, by welding.
• Forwardl projecting legs 42, 42' are connected to brackets 80, 80' by pivoting links 84, 84' (FIG. 1). Pairs of brackets 85, 85' are attached to upright support beams 46, 46', for example, by welding. Outwardly-curving legs 48, 48' are connected to bracket pairs 85, 85' by pivot pins 87, 87'.
• a powered hydraulic ram 50 is pivotally secured between the forward frame section 12 and the rear upright legs 38, 38' of the parallelogram units 36, 36' to enable powered variation of the parallelogram disposition and accordingly the angular disposition of the cutting assembly 10. Additional powered hydraulic rams 52, 52' pivotally joined to the top of the frame section 12 and the lower generally horizontal legs 48, 48' of the parallelogram units 36, 36' enable substantially vertical adjustment of the cutting assembly.
• the cutting assembly frame 44 supports a pair of
• resonant beams 54, 54' m the form of angularly upright parallel resonant beams composed of solid steel or other elastic material.
• Resonant beams 54, 54' are approximately parallel to struts 45, 45'.
• each resonant beam 10 is secured by bolts or the like to the upper extremity of each resonant beam and generally incorporates the principles of an orbiting mass oscillator of the type shown in either United States Patent No. 2,960,314 or United States Patent No. 3,217,551. (The disclosures
• Orbiting mass oscillators 56, 56' are driven by a suitable hydraulic motor 58, that is energized through suitable hydraulic conduits (not shown) from a third hydraulic pump 60 driven by the previously described engine 32.
• a suitable hydraulic motor 58 that is energized through suitable hydraulic conduits (not shown) from a third hydraulic pump 60 driven by the previously described engine 32.
• each orbiting mass oscillator 56, 56' includes a shaft 62 driven by the hydraulic motor 58 and supported at several axially spaced positions by bearings 64 in a generator housing
• a plurality of eccentric weights 68 and 79 are carried by the shaft 62 adjacent to the bearings 64 so that their load on the shaft and the bearing loads are distributed.
• the eccentric mass of the centrally located weight 68 is twice as large as peripherally located weights 0 79; thus, the load on each of bearings 64 is approximately the same.
• the shaft can be relatively small because of such load distribution, and the exterior diameter and thus peripheral speed of the bearings can be minimized for a given power level.
• the sonic generator housing and the beams could be cast as a single unit in a one-piece construction.
• a drive shaft 67 is coupled by pairs of tandemly connected universal joints 69, 69' to shafts 62, 62'.
• Drive shaft 67 is supported by bearings 63, 63' mounted in the sidewalls of a protective housing 73, through which drive shaft 67 passes.
• Power transmission means 71 such as a belt, chain, or gear train inside housing 73 couples hydraulic motor 58 to drive shaft 67.
• Lubricating oil is sprayed in housing 73 by means (not shown) onto power transmission means 71 and bearings 63, 63'. Seals (not show outside of bearings 63, 63' prevent the oil spray from leavin housing 73.
• Protective housing 73 is secured to mounting blocks 89 (FIGS. 9 through 11).
• Motor 58 is attached, for example by bolting, to the outside of housing 73.
• Fly wheels 72, 72' are mounted on shaft 67 outside housing 73 for the purpose of isolating motor 58 and power trans ⁇ mission means 71 from transient forces exerted by oscillators 56, 56'.
• Housing 73 is stationary so drive shaft 67 only rotates.
• Resonant beams 54, 54' reciprocate. Tandemly connected pairs of universal joints 69, 69' permit shafts 62, 62' to reciprocate with beams 54, 54' as they are rotatably driven by drive shaft 67.
• Energization of the exemplary embodiment illustrated provides a total peak energizing input force to the two resonant beams 54, 54' of 125,000 pounds in the form of sequential sonic oscillations at a frequency of approximately 100 cycles per second, i.e., at or near the resonant frequenc of resonant beams 54, 54'.
• the total peak force provide by oscillators 56, 56' is larger than the weight of the vehic and its load.
• These force oscillations, delivered to the upper end of the beam cause resonant vibration thereof through appropriate dimensional design of such beam at that frequency so that a corresponding cyclical reciprocal vibration at the lower end of the beam is derived, as shown 1 by the arrow A in FIG. 3, preferably with a total peak-to- peak displacement of approximately one inch.
• Pairs of weights 55, 55' are attached, for example by bolting, to the front and back of resonant beams 54, 54' at the
• Each resonant beam 54, 54' is designed and so driven that two vibration nodes are formed thereon inwardly from its opposite extremities, and its ends are free to vibrate, i.e., reciprocate, and in fact do vibrate.
• resonant beam 54, 54' is designed and so driven that two vibration nodes are formed thereon inwardly from its opposite extremities, and its ends are free to vibrate, i.e., reciprocate, and in fact do vibrate.
• 1° beams 54, 54' are driven to form standing wave vibrations in their fundamental free-form mode.
• Each beam is carried from the cutting assembly frame 44 at its upper node position.
• the connection is resilient to allow for node variations (pseudo-nodes) during actual operation.
• pairs of rectangular brackets 75, 75' are attached, for example by welding, to the sides of flared bracket mounts 59, 59'. Pairs of annular resilient members 74, 74' in the form of pneumatic rubber tires are located inside
• resonant beams 54, 54' are encompassed by rigid metal stop members 90, 90' at their rear, resilient rubber pads 91, 91' at their front, and pairs of resilient rubber pads 92, 92' at their sides.
• Pad pairs 92, 92' and pads 91, 91' comprise pieces of rubber vulcanized on metal mounting plates.' Members 90, 90', pads 91, 91', and pad pairs
• stop members 90, 90' are attached, for example by bolting, to mounts 57, 57'. Pairs of bracket 100, 100' are attached to opposite sides of support beams 46, 46', for example by bolting.
• Cross supports 93, 93' are connected between bracket pairs 100, 100', for example by bolting.
• Mounts 57, 57', bracket pairs 100, 100', and cross supports 93, 93' define rectangular openings through which the lower portions of resonant beams 54, 54' pass.
• Pads 91, 91' are secure to cross supports
• resonant beams 54, 54' are secured to the inside of bracket pairs 100, 100', for example by bolting.
• Pad pairs 92, 92' at the sides of resonant beams 54, 54' are spaced slightly therefrom and serve to guide the resonant beams as they pivot about their upper node support and reduce noise and wear.
• resonant beams 54, 54' When resonant beams 54, 54' are at rest, they lie on and are supported by pads 91, 91'.
• resonant beams 54, 54' are resonating during operation of the apparatus, their lower node is driven up against stop members 90, 90' by the reaction of the material being worked upon as shown in FIGS. 3 and 8, and remain in abutment with stop members 90, 90' during operation of the apparatus.
• stop members 90, 90' serve as rigid lower node supports for resonant beams 54, 54'.
• Stop members 90, 90" and pads 91, 91' are spaced sufficiently far apart to enable resonant beams 54, 54' to be shimmed to synchronize their transfer of force to the work tool.
• shims 76, 76' are inserted between stop members 90, 90' and stop mounts 57, 57' so the lower extremities of resonant beams 54, 54' in their neutral position are both spaced precisely the same distance from the lever arms and cutter blade described below.
• the material cutting assembly 10 includes a work tool which takes the form of an angularly- directed and transversely-extending cutter blade 94 held in a blade base 95.
• Cutter blade 94 and blade base 95 extend along the full width of the apparatus between beams 54, 54'.
• cutter blade 94 is transversely elongated and is disposed at an acute angle to the surface
• OMPI OMPI
• Cutter blade 94 is clamped to blade base 95 by a retaining bar 81 that is attached to blade base 95 by bolts 83.
• Lever arms 96, 96' are pivoted about substantially horizontal pivot pins 9 * 8, 98' on bracket pairs 100, 100'.
• Lever arms 96, 96' are attached for example by welding to the ends of blade base 95 near resonant beams 54, 54'. It is to be particularly observed, as clearly shown in FIG.
• the cutter blade assembly comprising cutter blade 94, blade base 95, retaining bar 81, and lever arms 96, 96' is pivotably supported by brackets 100, 100' so it is adjacent to the lower extremity of the resonant beams 54, 54'.
• the beams reciprocate, they drive the cutter blade assembly in a forward and downward direction or to the left, as shown in FIG. 3, and thereafter withdraw from contact with the cutter blade assembly in its cyclical displacement in the opposite or rearward direction.
• only unidirectional driving impulses are delivered to the cutter blade assembly in its forward direction, and in alignment with its cutting direction, so the cutter blade 94 advances with a chisel-like action.
• a conveyor 97 in the middle of the front of assembly 10 above blade base 95 carries materia broken up by cutter blade 94 away from the assembly, as for example in a windrow or pile between wheels or to a dump truck moving with the assembly.
• the driving and supporting means for conveyor 97 are not shown.
• Diverters 99, 99' which extend across the front of assembly 10 above blade base 95 on either side of conveyor 97, are attached to brackets 100, 100'. Diverters 99, 99' are positioned to direct all the broken up material to conveyor 97.
• cutter blade 94 comprises a work tool that moves along the road surface, which comprises the work path.
• Cutting assembly frame 44 functions as a tool holder or carrier. Continuous unidirectional force is applied thereto by mobile carrier 11 in a direction parallel to the work path.
• Oscil- lators 56, 56' generate a reciprocating force, at least one component of which acts parallel to the work path.
• Each resonant beam 54, 54' comprises a force transmitting member, its upper extremity comprising an input to which the recipro ⁇ cating oscillator force is applied, and its lower extremity comprising an output from which the reciprocating force is transferred to the tool.
• the tool advances intermittently along the work path responsive to the continuous unidirec ⁇ tional force applied by mobile carrier 11 and the recipro ⁇ cating force applied by oscillators 56 and 56'.
• reactive forces will be directed thereagainst, both in horizontal and vertical directions, and will be dependent upon the character of the material.
• An angle between 45° and 55° relative to the surface of the material has been found optimum for cutting pavement to maintain the
• OMPI ultimate cutting in a plane parallel to the material surface in the direction of machine travel In general, the harder the material the larger the angle. Thus, for ordinary asphalt the angle has been found to be between 48° and 52°, for soft asphalt the angle has been found to be be ⁇ tween 45° and 48°, and for concrete the angle has been found to be between 52° and 55°.
• the parallelogram units 36, 36' can be shifted by appropriate energization of the angular adjustment ram 50 to optimize the cutting action on the ° material encountered.
• the cutting depth of cutte blade 94 below the grade, i.e., surface of the pavement, can be automatically or manually controlled by appropriate energization of the vertical adjustment rams 52, 52'.
• cutting assembly frame 44, 5 which locates its center of gravity close to upright support beams 46, 46', i.e., nearly directly over cutter blade 94, permits the weight of cutting assembly frame 44 to counteract most effectively the reactive forces exerted on cutter blade 94 by the material being cut. This minimizes ° the forces and moments exerted on parallelogram units 36, 36' by cutting assembly frame 44 and discourages cutter blade 94 from moving out of engagement with the material being cut.
• the beams 54, 54' withdraw from contact with the cutter blade 94 during resonant vibration a momentary 5 gap is formed which will remain until a repeated forward motion of the beams 54, 54'.
• contact of the beams with the cutter blade preferably is made in the region where maximum forward velocity (and momentum) of the beams is approached in the forward (cutting) direction. Since the cutter blade 94 is in engagement with material to be cut, the adjacent beam is urged forwardly relative thereto, thus to close the momentary gap at the appropriate time of the resonant cycle.
• This action which is important to the effective cutting of concrete, asphalt, and other hard materials, can be explained more readily by reference to FIGS. 5A-5C wherein the various operational dispositions of the cutter blade 94 and the resonant beams 54, 54' are diagrammatically illustrated in somewhat exaggerated form for purposes of explanation.
• the abscissa N represents the neutral position of beams 54, 54'
• sinu ⁇ soidal waveform S represents the reciprocating displacement of the beam outputs about their neutral position as a func ⁇ tion of time
• the dashed line represents the position of the tool, i.e., cutter blade 94, relative to frame 44 as a function of time.
• the beams For maximum force transfer, it is desirable for the beams to strike the tool when the beam outputs are traveling at maximum forward velocity, i.e. , at the neutral position of the beam outputs.
• the neutral position of the beam outputs is their position when at rest, i.e., not resonating or being deflected, while the beam is in operating position, i.e.
• the beam 5 outputs contact the tool during a short interval approaching 90° of the beam cycle, which is represented in FIG. 6 by the distance along waveform S between points X and Y.
• the beam outputs are out of contact with the tool, which is represented 0 in FIG. 6 by the distance along line D between points B and X.
• the speed of mobile 5 carrier 11 is adjusted accordingly to the stroke of the beam outputs, i.e. , their peak to peak amplitude. The larger the stroke, the faster the speed of mobile carrier 11.
• the peak sonic force generated by oscillators 56, 56' is substan ⁇ tially greater than the maximum tractive force generated by mobile carrier 11, i.e., the weight of the vehicle and its load.
• the sonic force is sufficiently large relative to the tractive force to enable the sonic force to overcome the tractive force and to drive the entire machine, including material cutting assembly 10 and mobile carrier 11, backwards away from the tool when the tool is unable to advance along the work path.
• the protective gap is established in a different manner, namely, by a tool stop which prevents the beam output in its neutral position from contacting the tool when it encounters an immovable object.
• a tool stop which prevents the beam output in its neutral position from contacting the tool when it encounters an immovable object.
• cessation of resonance is prevented. It has been discovered that without such a protective gap, when the tool encounters an immovable object the beam output becomes clamped between the tool and the tool holder, thus terminating resonance and preventing transfer of the oscillator force to the tool.
• the gap protects the tool driving apparatus from destruction by an immovable object.
• immovable object as used in this specification is relative, not absolute; it is an object that hinders the advance of the machine sufficiently that, in the absence of the protective gap, the vehicle would drive the force transmitting member against the tool and would thus prevent the force transmitting member from transmitting the oscillations to the tool, with the result that the apparatus would destroy itself.
• a resonant force transmitting member or beam when the output of the beams is clamped against the tool, the end of the beam is no longer free and becomes a node. The nodes thus shift and the entire mode of vibration changes, the largest vibrations now occurring at the node supports, which destroys the node supports and/or the oscillator and beams.
• the invention is illustrated in a machine for cutting concrete or asphalt road surfaces, it could be incorporated into any number of material working machines such as a coal planar, timber shearer, a bulldozer, a front end loader, a rock ripper, or a shovel bucket.
• material working machines such as a coal planar, timber shearer, a bulldozer, a front end loader, a rock ripper, or a shovel bucket.
• an appropriate tool is employed.
• the continuous unidirectional force would be the closing force, i.e., line pull, of the bucket, which is con ⁇ tinuous over the intervals of time in which the bucket is closing and is interrupted while the bucket is carrying its load from place to place.
• the invention is applicable to any type of material working function wherein a tool is advanced through the material to perform the desired work.
• the invention can be practiced with other types of force transmitting members including resonant beams of other configurations, such as the angular configuration shown in my U.S. application Serial No. , , filed on 26 December 1978 (Attorney Docket Case 12300), or nonresonant members vibrating in a forced mode.
• the gap prevents the oscillator force from being transferred self-destructively back through the force transmitting member.
• the invention is also applicable to apparatus in which the tool is attached to the force transmitting member, e.g., the resonant beams, as in Bodine Patent 3,232,669.
• the described embodiment of the invention is only considered to be preferred and illustrative of the inventive concept; the scope of the invention is not to be restricted to such embodiment.
• Various and numerous other arragements may be devised by one skilled in the art without departing from the spirit and scope of this invention.
• the invention can be practiced with other types of force transmitting members, including resonant beams of other configurations, such as the angular configuration shown in my U.S. application, Serial No. , filed 26 December 1978 (Attorney Docket Case 12300), or non-resonant members.
• the described support frame could be used with other types of apparatus, such as, for example, an earth or rock ripper.

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Citations (8)

• 1979
  • 1979-01-29 DE DE7979900211T patent/DE2962660D1/de not_active Expired
  • 1979-01-29 WO PCT/US1979/000042 patent/WO1979000563A1/en unknown
  • 1979-01-29 DE DE792934904A patent/DE2934904A1/de not_active Withdrawn
  • 1979-01-29 JP JP54500416A patent/JPS6256281B2/ja not_active Expired
  • 1979-08-28 EP EP19790900211 patent/EP0010105B1/en not_active Expired

Patent Citations (8)

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