CA1141536A - Resonant work performing apparatus such as ripping tool driving apparatus - Google Patents
Resonant work performing apparatus such as ripping tool driving apparatusInfo
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- CA1141536A CA1141536A CA000397552A CA397552A CA1141536A CA 1141536 A CA1141536 A CA 1141536A CA 000397552 A CA000397552 A CA 000397552A CA 397552 A CA397552 A CA 397552A CA 1141536 A CA1141536 A CA 1141536A
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- tool
- resonant
- output
- vibratory
- neutral position
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Abstract
Abstract of the Disclosure A ripping tool positioned below the earth's surface is driven by the output of a vibrating, preferably, resonant, force transmitting beam which has lateral dimensions smaller than those of the ripping tool and is positioned below the earth's surface. The beam is configured to have a single resonant node when restrained from vibrating at such node and is supported so that the single node is above the earth's surface and restrained from vibrating.
The output of the beam is enlarged in thickness to form a hammer. A protective gap is maintained by a tool stop between the tool and the output of the force transmitting beam. The width of the tool stop is precisely controlled by shimming the tool stop and/or the supports for the force transmitting beam.
The output of the beam is enlarged in thickness to form a hammer. A protective gap is maintained by a tool stop between the tool and the output of the force transmitting beam. The width of the tool stop is precisely controlled by shimming the tool stop and/or the supports for the force transmitting beam.
Description
114~536 RESONANT WORK PERFORMING APPARATUS SUCH AS
RIPPING TOOL DRIVING APPAl~ATUS
Background of the Invention The present invention relates generally to resonant work performing apparatus such as power apparatus for driving a tool or the like, and more particularly to apparatus utilizing a vibratory member for driving a ripping tool into earth, rock, or other earthen material.
Apparatus is known in which a ripping tool is driven by a vibratory member. For example, Bodine Patent 3,336,082 discloses a rock ripping tooth that is integral with the lower end of a straight resonant beam. Cobb et al Patents 3,770,322 and 4,003,603 describe a ripping tool that is mounted for reciprocal motion;
a source of oscillatory force is coupled by a non-resonant force transmitting rod to a hammer that periodically strikes the tool.
Shatto Patent 3,633,683 discloses a pivotally mounted ripping tool that is driven by a hammer located above the earth's surface.
The hammer is attached to the lower end of a straight resonant beam to which a source of vibrations is coupled. The requirement that the support for the force transmitting beams be above ground and the ripping tool be below ground makes difficult the design of apparatus for efficiently driving the ripping tool, because of the restraints on the component location and space occupancy.
Summary of the Invention According to the present invention there is provided resonant work performing apparatus comprising:
a resonant system that is vibratory in resonance at an unloaded resonant frequency near which the resonant system has a vibratory input, an output vibratory in first and second opposite directions about a neutral position responsive to vibrations at the input, and at least one vibratory node;
a frame attached to the resonant system substantially at the node;
a load receiving periodic impulses from the vibratory ¦ 35 output as the output moves in said first direction;
~4~536 means for applying a vibrational force to the input of the resonant system at or near the unloaded resonant frequency to excite the resonant system to at least near resonance; and means for preventing cessation of resonance when the load is excessive to minimize the transmission of the applied vibrational force to the frame.
Thus, in preferred power apparatus of the invention a reciprocally mounted ripping tool is driven by a vibrating, preferably, resonant, force transmitting member, the ouput of which has smaller lateral dimensions than the ripping tool. The force transmitting member is supported so its output lies below the earth's surface in close proximity to the cutting surface of the ripping tool. The lateral thickness of the ripping tool serves to divert the earthen material outwardly away from the path of the output of the force transmitting member. Preferably, the shank of the ripping tool lying above its cutting surface has its centrally located vertical leading edge that helps cut through the earthen material and divert it outwardly away from the force transmitting member.
A feature of such apparatus is that a resonant force transmitting member has a single node. The force transmitting member is supported so that the single node is above the earth's surface while its output is located below the~earth's surface in proximity to the cutting surface of the ripping tool. The use of a resonant force transmitting member having a single node shrinks the longitudinal space requirements for the resonant member for a given tool driving stroke.
Another feature of such apparatus is a tool stop between the tool and the output of the force transmitting member that maintains a protective gap independent of the relative magnitude of the vibratory force and the tractive force. The tool stop limits the backward movement of the tool so it cannot reach the neutral position of the output. Preferably, the tool stop and/or the supports for the force transmitting member are shimmed to precisely set the protective gap width.
114~5~6 1 Brief Description of the Drawings The features of a specific embodiment of the best mode contemplated of carrying out the invention are illustrated in the drawings, in which:
FIG. 1 is a side elevational, partially cut away view of tool drtving apparatus embodying the invention, with portions broken away;
FIG. lA is an enlargement of a portion of FIG. lt FIG. 2 iS a top plan view of the left, operative 10 portion of the apparatus illustrated in FIG. l;
FIG. 3 is a fragmentary sectional view taken along line 3-3 of FIG. l;
FIG. 4 is a fragmentary sectional view taken along line 4-4 of FIG. l;
FIG. 5 is a graphical illustration of the operating characteristics of the described tool driving apparatus;
FIG. 6 is a fragmentary sectional view of a slightly modified version of the apparatus in FIG. 3; and FIG. 7 is a side view of an alternative version of 20 a portion of the apparatus of FIG. 1.
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114~536 1 Detailed Description of the Specific Embodiment Tool driving apparatus employing a vlbrating member in a fashion that such vibration of the beam or other force transmitting member will be maintained, regardless of various other forces applied during operation of the apparatus. To achieve such objective, a ripping tool is supported for pivotal motion ~rom a tool frame adjustably supported at the rear of a mobile carrier in the form of a more or less standard tractor, the pivotal support being essentially 10 transverse to the direction of motion of the tractor so that the tool, in turn, swings forwardly and rearwardly along the general direction of tractor motion. The tool frame, through its adjustable support, can be raised or lowered, and when lowered, the ripping tool can lie several 15 feet below the surface of the earth or other material being engaged thereby.
To impart earth-cutting reciprocal motion to the ripping tool, a resonant member is utilized, and, more particularly, takes the form of an angle beam having a pair 20 of legs supported in angular relationship from a pivotal support carried by the side plates of the tool frame so that one leg projects substantially vertically downward to lie adjacent the rear surface of the ripping tool wherças the other leg extends from the first leg at a divergent 25 included angle of approximately ninety degrees and t.hus subst.antially horizontally forward between the frame plates, to mount at it.s extremit.y a sonic generator, eccentric weight oscillator o~ other means for energizing resonant vibration of the angle beam. The pivotal support therefor 30 is at a central node position so that substantially no vibration is transmit.ted back t.o the supporting frame. The angle beam has lateral dimensions no greater than that of the ripping tool so that it. can lie beneath the surface of the earth or other material being cut by the ripping tool 35 without interfering with the operation.
1~4~536 1 A short. ear extends from the angle beam upwardly from its node position and lies adjacent a stop member disposed between the plates, thus to restrict. the pivokal motion of the angle beam about its pivot rod in one direction. Shims, or other means, can be used to provide for adjustment of the position of shim engagement o~ the ear, and thus define the neutral position of the resonant angle beam, and more particularly the lower tool engaging portion thereof. In turn, the tool is restricted by a stop with adjustment shims so that it cannot swing backward into contact with the adjacent portion o~ the angle beam when in its defined neutral position. Thus, regardless of forces on the ripping tool, the resonant beam is able ~o swing to and fro in its resonant vibration when appro-15 priately energized by the sonic generator, eccentric weightoscillator, or other means, and no possibility of clamping the beam exists.
With reference to FIGS. 1 and 2, the ripping tool assembly 10 is mounted at the rear of a more or less con-20 ventional tractor 12 supported on mobile support means inthe form of spaced endless tracks 14 for motion in a forward direction determined by a conventional steering mechanism 16 accessible to an operator seated on a driver's seat 18, wit.h suitable adjacent controls 20 to effect not only the 25 steering but the application of power to the endless tracks rom a convenkional engine 22, and also energization o hydraulic pumps 3~ and 74 connected to certain hydraulic elements of the ripping tool assembly 10, as will be described hereinafter.
A heavy plate is mounted at the rear of the tractor 12 to carry at laterally spaced and subst.antially parallel posit.ions a pair o~ parallelogram units 26, each including a rigid upstanding leg 28 at the rear of the tractor, the t.ops and bottoms of which carry pivot.ally supported legs 30, 35 32. Legs 30, 32 extend rearwardly, to in turn pivotally 1 support the upper and lower ends of a vertical rear leg 34 of each parallelogram unit 26 at their rear extremities.
A double-acting hydraulic ram 36 is pivotally connected between the lower end of the rear legs 34 and the middle 5 of the front legs 28 by a cross rod 31 and another cross rod, not shown, so as to effect a raising or lowering of the rear legs of the parallelogram unit upon application of hydraulic fluid from previously mentioned pump 38 when actuated by the machine operator.
Rigid cross members 40, 42 extend transversely between the rear extremities of the parallelogram units 26 at both top and bottom to mount centrally brackets 44, 46 with aligned substantially vertical pivot pins 48, 50. Pins 48, 50, extend through aligned holes in brackets 52, 54 which 15 are joined rigidly to side plates 56 of the ripping tool assembly 10. Thus, the ripping tool assembly 10 can pivot about the generally upright axis defined by the pins 48, 50 to accommodate turning of the tractor 12.
~he side plates 56 extend i~ spaced parallelism 20 rearwardly from the supporting parallelogram units 26 and carry therebetween several elements, including a horizontal pivot pin 58 which supports a ripping tool 60 therefrom for pivotal motion in forward and backward directions. The ripping tool 60 has a substantially conventional configura-25 tion, with a long shank 60a extending substant.iallyvertically downwardly from the supporting pivot pin 58 and a forwardly and angularly project.ing tooth 60b at its lower extremity. A retaining pin 60d holds tooth 60b in fixed posit.ion at the end of shank 60a. As illustrated in FIG.
30 4, the front surface of shank 60a converges to form a centrally locat.ed vertical leading wedge shaped edge 60c that helps t.o cut. through t.he eart.h. It may be mentioned at this point t.hat while but. a single ripping tool 60 is herein shown, a series of parallel tools can be suspended if desired, 35 each having a similar configuration. When the parallelogram 1 unit is lowered into an operative position, the tool 60 can extend as much as several feet into the underlying earth or other surface, as shown in ~IG. 1, to provide the rippi~g action upon appropriate actuation of the tool driving apparatus and forward motion of the tractor, as will be described in detail hereinafter.
The ripping tool 60 is completely free to pivot for-wardly into contact with the earth or other matérial to be worked upon, but, in accordance with the present invention, 10 a stop member 62 with removable shims 63 is disposed between the side plates 56 of the frame, to limit its backward motion to a particular position to be described hereinafter, which will not interfere with normal machine operation.
The tool driving apparatus includes a resonant force transmitting member 64 in the form of an angle beam composed of solid steel or other resilient material and having a pair of straight integral legs extending in divergent paths at or near approximately ninety degrees from their point of 20 juncture. The legs of angle beam 64 are preferably e~ual in length and the vertical end thereof is enlarged in thickness, as illustrated in FIG. 1, to form a hammer that increases the mass at the region of impact with ripping tool 60. Stop member 62 comprises a rigid bar fixed to 25 side plates 56 of ripping tool assembly 10 between ripping tool 60 and the rest position of the vertical end of resonant member 64.
To mount the resonant angle beam 64, an integral ear 76 projects outwardly from the juncture of the legs 30 of the angle beam so as t.o bisect the angle between the bea~n legs. As used herein the term ~integral" means that. the entire resonant member 64, i.e., the legs and ear 76, is cast or forged as a single unit in a one piece construction.
Parallel plates 65 are att.ached as by welding to opposit.e 35 sides of ear 76. Holes in the plates 65 aligned with the junct.ure of the beam receive ~tub shafts 66 welded or 114~.536 1 otherwise fixedly secured to the plates 65. The shafts 66 are pivotally supported in bushings 67, which are in turn mounted in hard rubber hubs 69 supported in the side plates 56. Thus, although a pivotal support is provided or the beam, it is somewhat flexible and in no way interfere~
with the resonant vibration of the resonant angle beam 64.
In operative disposition, the one ieg of resonant angle beam 64 extends substantially vertically so the portion of enlarged thickness at its lower extremityO lie~ closely adjacent the rear face of the ripping tool 60 at its lower extremity, to provide, upon beam ac~uation, a repeated cyclical serie~ of blows to the rear of the ripping tool, so as to drive tooth 60b repeatedly into the adjacent earth or other earthen material. The tool engaging portion of 15 angle beam 64 lies below the earth's surface near tooth 60b, to provide optimum force transfer thereto. As shown in FIG. 1, the tool engaging portion of angle beam 64 thus lies below tracks 14. As shown in FIG. 4, the lower end of the resonant angle beam 64 has a transverse, i.e., lateral, 20 dimension less than that of the adjacent ripping tool 60.
Therefore, when earth has been dislodged by the tool, sub-stantially no earth contact with the beam will occur. The earth is diverted outwardly by ripping tool 60 much as a mobile snow shovel pushes snow out of its path.
Means are provided to energize the resonant angle beam 64 to resonant vibration, and preferably takes the form of a sonic generator or eccentric weight oscillator 68. Oscillator 68 is connected to the end of the horizontal leg of the resonant angle beam for actuation by a hydraulic motor 70 through a belt drive 71. Motor 70 is attached to one of the side plates 56, and fluidically connected to hydraulic pump 79 for actuation under control of the machine operator. Oscillator 68 is driven by motor 70 such that the eccentric weights rotate at or near ~14~.536 _g_ 1 the resonant frequency of angle beam 64, which typically is of the order of 100 cycles per second.
It is to be particularly noted that this form of resonant angle beam 64 has but a single central node, namely, at the beam juncture and ear 76 alonq a line bisecting the angle of beam 64, when the beam is supported so it is restrained from vibrating at the juncture as shown. The legs of the beam resonate about this single node, with anti-nodes at the ends of the legs. A relatively long lever arm is provided ~o by each of the beam legs so that a considerable stroke, particularly of the lower end of the tool actuating leg, is produced withou~ the necessity of a resonant member or beam of excessive longitudinal dimensions. For example, the cyclical reciprocating stroke with an angle beam having a leg length of no more than five feet can have an output amplitude adjacent the ripping tool of one inch or more.
Further, the single node and the associated node support struc-ture are spaced far from the ends of the beam in comparison to a straight resonant beam having two nodes, as disclosed in my above referenced copending application. This is important in a ripper, where the node support must be above ground level and the ripping tool must be underground. In addition, since the ends of the beam are at an angle to each other, the sonic generator is located in a plane displaced a substantial distance rom the plan~ in which the tool is located, as illustrated in FIG. 1.
The weight of oscillator 68 urges resonant angle beam 64 to pivot or rotate about pin 58 in a clockwise direction, as viewed in FIG. 1. A stop member -/8 is attached to side plates 56 and extends therebetween adjacent to the end of ear 76 in the path of its clockwise rot.ation, as viewed in FIG. 1.
~emovable shims 80 are mounted on the surface of stop member 78 facing toward ear 76. Stop member 78 is shimmed so that the end of resonant angle beam 64 adjacent to t.ool 60 is located in a desired position, u~ually so the upright leg 114~53~ 1 -- 10 -- , thereof is vertical when the beam is in it~ neutral po5ition. me neutral l~si~on of the beam is its position when at rest, i.e., when not rescnatlng or being defle ~ d. mUs, stop m~r 78 rigidly supports resonant angle beam 64 with respect to ripping tcol assembly 10 during operation as bD all motion except resonant vibration.
When oscillator 68 is operating, ~t applies a reciprocating force to the end of the horizontal le9 at or near the'resonant frequency of angle beam 64. While resonant angle beam 64 resonates, the juncture of its legs, which is the single node, remains stationary and the end of its vertical leg reciprocates in forward and back-ward directions, striking tool 60 each time it moves forward in its reciprocating excursion. A changing gap-is formed between the end'of the vertical leg of resonant angle 15": beam 64 and tool 60 -- as the vertical leg reciprocates in a forward direction the gap tends to close and as the vertical leg reciprocates in a backward direction the gap tends to open, disregarding the continuous forward movement of the frame.
Rippin~ tool 60 comprises a work tool that moves along through the soil, which comprises the work path. Ripping tool assembly 10 functions as a tool holder or carrier.
Continuous unidirectional force is applied thereto by tractor 12 in a direction parallel to the work path~ Oscillator 68 generat.es a reciprocating force, at leas~ one component of which acts parallel to the work path. Resonant angle beam 64 comprises a ~orce transmitt.ing member, the end of its horizontal leg comprising an input to which the reciprocating oscillator orce is applied, and the end of its vertical leg comprising an output. f'rom which the reciprocating force is transferred to the tool. The tool advances intermittently along the work path responsive t.o the continuous uni-directional force applied by tractor 12 and the reciprocating force applied by oscillator 68.
A minimum pro~.ect.ive gap is established between the neutral posit.ion of resonant angle beam 64 and tool 60 by stop members 62 and 78.' ~8 a result, when tool 60 encounters 114~536 an immovab~e object, which prevents its further advance, tractor 12 continues to advance until tool 60 abuts stop member 62. In other words, stop member 62 limits the back-ward movement of tool 60 so it cannot reach the neutral position of the beam output. Thus, the end of the vertical beam leg cannot become clamped by tool 6~ when tool 60 encounters an isnmovable object, and destroy the components of the ripping tool assembly. A different way for establishing a protective gap between the output of the beam and the tool when the tool encounters an immovable object is the use of substantially more reciprocating oscillator force than the con-tinuous unidirectional force provided by the mobile carrier.
In a number of applications, however, requiring that the mobile carrier supply a very large continuous unidirectional lS force, such as a shovel bucket or a rock ripper, it is imprac-tical to furnish sufficient reciprocating oscillator force to establish the gap in this manner.
Recognizing that small variations in relative spatial position between components cannot be avoided in the manufac-ture and assembly' of the components of ripping tool assembly 10, the length of the minimum protective gap is adjusted from machine to machine by shims 63 on stop member 6~ and shims 80 on stop member 78. Instead of shimming both stop members 62 and 78, one or the other of these stop members alone could be shLmmed to establish the minimum protective gap. In a typical examp~e, the peak-to-peak excursion of the beam output might be 2 inches, and the minisnum protective gap might be 1/4 of an inch, so that t.he power stroke o~ the beam out.put would be 3/4 of an inch. The minimum protective gap should be no larger than necessary to prevent cessat.ion os~ resonance when the tool encounter~ an immovable object, because 'the larger thls gap, 'the smaller the power stroke, i.e., the portion of the beam out.put excursion in which it cont.acts the tool.
~.14~536 1 If resonant angle beam 64 is driven at or near its r~sonant frequ~ncy without restrainlng the beam juncture from vibrating as disclosed herein, it has two nodes near its ends, as in the case of a straight resonant beam. Under 5 some circumstances, it may be desirable to operate a resonant angle beam in this way, i.e., with two nodes, by supporting the beam at these two nodes, rather than at the beam juncture.
For an explanation of how stop members 62 and 78 protect ripping tool assembly lO, reference is made to FIG. 5, lO' wherein the central horizontal line N represents the neutral position of the resonant angle beam 64, and more particularly the output thereof, and the dashed horizontal line S spaced thereabove, represents the rearmost position attainable by the ripping tool 60 when in engagement with stop member 62. The distance between N and S represents the minimum protective gap. The normal resonant swing of the output of the resonant angle beam 64 is represented by the solid line sine wave indicated at R. When the tool encounters a very hard material and can no longer advance, it moves zo against stop membe~ 62, thereby limiting the excursions o the beam output to an amount equal to the minimum protective gap forward and backward of the neutral position, as represented by the dashed line sine wave R'. This limited excursion is enough to maintain angle beam 64 in resonance and accordingly prevent destruction of the assembly.
As shown in the described embodiment and particularly in FIG. 3, the short connection of the stub shafts 66 in the plates 65 provides a relatively weak support.
Consequently, a slightly modified stronger mounting arrangement as shown in ~IG. 6 can be utilized. As there shown, parallel side plat.es ~2 are welded to an outwardly projecting ear 84 formed at the juncture of the legs of the angle beam 85 and extend adjacent the sides of the resonant angle beam 85 beyond its inner edge to support a tube 86 in aligned holes. Tube 86 in turn, carries a single shaft 88, mounted . . .
114~536 by bushings 90, and rubber hubs 92 in t~e side plates 94 of the frame. Tube 86 and beam ~5 are fixed relative to shaft 88, which is rotatable in bushings 90 about side plates 94 of the frame.
While the tool driving apparatu~ has been described specifically in connection with a ri pping tool, it will be apparent that it can al~o be applied to a cutter ~lade, and also to a shovel bucket or other members of various types requir- l ing considerable force in their operative functions. Consequently,j the term "tool" is to be broadly construed.
The described embodiment of the invention is only con-sidered to be p,referred and illustrative of the,inventive concept the scope of the invention is not to be restricted to such embodiment. Various and numerous other arrangements lS may be devised by one skilled in the art without departing from the spirit and scope of this inventlon. For example, a non-resonant force transmitting member could be employed with advantage in some situations, although a resonant member is preferable. Furthermore, the advantages of having a resonant member with a single node located above the earth's surface can be achieved when the output of the b0am strikes the tool from a position above the earth's surface.
, !
RIPPING TOOL DRIVING APPAl~ATUS
Background of the Invention The present invention relates generally to resonant work performing apparatus such as power apparatus for driving a tool or the like, and more particularly to apparatus utilizing a vibratory member for driving a ripping tool into earth, rock, or other earthen material.
Apparatus is known in which a ripping tool is driven by a vibratory member. For example, Bodine Patent 3,336,082 discloses a rock ripping tooth that is integral with the lower end of a straight resonant beam. Cobb et al Patents 3,770,322 and 4,003,603 describe a ripping tool that is mounted for reciprocal motion;
a source of oscillatory force is coupled by a non-resonant force transmitting rod to a hammer that periodically strikes the tool.
Shatto Patent 3,633,683 discloses a pivotally mounted ripping tool that is driven by a hammer located above the earth's surface.
The hammer is attached to the lower end of a straight resonant beam to which a source of vibrations is coupled. The requirement that the support for the force transmitting beams be above ground and the ripping tool be below ground makes difficult the design of apparatus for efficiently driving the ripping tool, because of the restraints on the component location and space occupancy.
Summary of the Invention According to the present invention there is provided resonant work performing apparatus comprising:
a resonant system that is vibratory in resonance at an unloaded resonant frequency near which the resonant system has a vibratory input, an output vibratory in first and second opposite directions about a neutral position responsive to vibrations at the input, and at least one vibratory node;
a frame attached to the resonant system substantially at the node;
a load receiving periodic impulses from the vibratory ¦ 35 output as the output moves in said first direction;
~4~536 means for applying a vibrational force to the input of the resonant system at or near the unloaded resonant frequency to excite the resonant system to at least near resonance; and means for preventing cessation of resonance when the load is excessive to minimize the transmission of the applied vibrational force to the frame.
Thus, in preferred power apparatus of the invention a reciprocally mounted ripping tool is driven by a vibrating, preferably, resonant, force transmitting member, the ouput of which has smaller lateral dimensions than the ripping tool. The force transmitting member is supported so its output lies below the earth's surface in close proximity to the cutting surface of the ripping tool. The lateral thickness of the ripping tool serves to divert the earthen material outwardly away from the path of the output of the force transmitting member. Preferably, the shank of the ripping tool lying above its cutting surface has its centrally located vertical leading edge that helps cut through the earthen material and divert it outwardly away from the force transmitting member.
A feature of such apparatus is that a resonant force transmitting member has a single node. The force transmitting member is supported so that the single node is above the earth's surface while its output is located below the~earth's surface in proximity to the cutting surface of the ripping tool. The use of a resonant force transmitting member having a single node shrinks the longitudinal space requirements for the resonant member for a given tool driving stroke.
Another feature of such apparatus is a tool stop between the tool and the output of the force transmitting member that maintains a protective gap independent of the relative magnitude of the vibratory force and the tractive force. The tool stop limits the backward movement of the tool so it cannot reach the neutral position of the output. Preferably, the tool stop and/or the supports for the force transmitting member are shimmed to precisely set the protective gap width.
114~5~6 1 Brief Description of the Drawings The features of a specific embodiment of the best mode contemplated of carrying out the invention are illustrated in the drawings, in which:
FIG. 1 is a side elevational, partially cut away view of tool drtving apparatus embodying the invention, with portions broken away;
FIG. lA is an enlargement of a portion of FIG. lt FIG. 2 iS a top plan view of the left, operative 10 portion of the apparatus illustrated in FIG. l;
FIG. 3 is a fragmentary sectional view taken along line 3-3 of FIG. l;
FIG. 4 is a fragmentary sectional view taken along line 4-4 of FIG. l;
FIG. 5 is a graphical illustration of the operating characteristics of the described tool driving apparatus;
FIG. 6 is a fragmentary sectional view of a slightly modified version of the apparatus in FIG. 3; and FIG. 7 is a side view of an alternative version of 20 a portion of the apparatus of FIG. 1.
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114~536 1 Detailed Description of the Specific Embodiment Tool driving apparatus employing a vlbrating member in a fashion that such vibration of the beam or other force transmitting member will be maintained, regardless of various other forces applied during operation of the apparatus. To achieve such objective, a ripping tool is supported for pivotal motion ~rom a tool frame adjustably supported at the rear of a mobile carrier in the form of a more or less standard tractor, the pivotal support being essentially 10 transverse to the direction of motion of the tractor so that the tool, in turn, swings forwardly and rearwardly along the general direction of tractor motion. The tool frame, through its adjustable support, can be raised or lowered, and when lowered, the ripping tool can lie several 15 feet below the surface of the earth or other material being engaged thereby.
To impart earth-cutting reciprocal motion to the ripping tool, a resonant member is utilized, and, more particularly, takes the form of an angle beam having a pair 20 of legs supported in angular relationship from a pivotal support carried by the side plates of the tool frame so that one leg projects substantially vertically downward to lie adjacent the rear surface of the ripping tool wherças the other leg extends from the first leg at a divergent 25 included angle of approximately ninety degrees and t.hus subst.antially horizontally forward between the frame plates, to mount at it.s extremit.y a sonic generator, eccentric weight oscillator o~ other means for energizing resonant vibration of the angle beam. The pivotal support therefor 30 is at a central node position so that substantially no vibration is transmit.ted back t.o the supporting frame. The angle beam has lateral dimensions no greater than that of the ripping tool so that it. can lie beneath the surface of the earth or other material being cut by the ripping tool 35 without interfering with the operation.
1~4~536 1 A short. ear extends from the angle beam upwardly from its node position and lies adjacent a stop member disposed between the plates, thus to restrict. the pivokal motion of the angle beam about its pivot rod in one direction. Shims, or other means, can be used to provide for adjustment of the position of shim engagement o~ the ear, and thus define the neutral position of the resonant angle beam, and more particularly the lower tool engaging portion thereof. In turn, the tool is restricted by a stop with adjustment shims so that it cannot swing backward into contact with the adjacent portion o~ the angle beam when in its defined neutral position. Thus, regardless of forces on the ripping tool, the resonant beam is able ~o swing to and fro in its resonant vibration when appro-15 priately energized by the sonic generator, eccentric weightoscillator, or other means, and no possibility of clamping the beam exists.
With reference to FIGS. 1 and 2, the ripping tool assembly 10 is mounted at the rear of a more or less con-20 ventional tractor 12 supported on mobile support means inthe form of spaced endless tracks 14 for motion in a forward direction determined by a conventional steering mechanism 16 accessible to an operator seated on a driver's seat 18, wit.h suitable adjacent controls 20 to effect not only the 25 steering but the application of power to the endless tracks rom a convenkional engine 22, and also energization o hydraulic pumps 3~ and 74 connected to certain hydraulic elements of the ripping tool assembly 10, as will be described hereinafter.
A heavy plate is mounted at the rear of the tractor 12 to carry at laterally spaced and subst.antially parallel posit.ions a pair o~ parallelogram units 26, each including a rigid upstanding leg 28 at the rear of the tractor, the t.ops and bottoms of which carry pivot.ally supported legs 30, 35 32. Legs 30, 32 extend rearwardly, to in turn pivotally 1 support the upper and lower ends of a vertical rear leg 34 of each parallelogram unit 26 at their rear extremities.
A double-acting hydraulic ram 36 is pivotally connected between the lower end of the rear legs 34 and the middle 5 of the front legs 28 by a cross rod 31 and another cross rod, not shown, so as to effect a raising or lowering of the rear legs of the parallelogram unit upon application of hydraulic fluid from previously mentioned pump 38 when actuated by the machine operator.
Rigid cross members 40, 42 extend transversely between the rear extremities of the parallelogram units 26 at both top and bottom to mount centrally brackets 44, 46 with aligned substantially vertical pivot pins 48, 50. Pins 48, 50, extend through aligned holes in brackets 52, 54 which 15 are joined rigidly to side plates 56 of the ripping tool assembly 10. Thus, the ripping tool assembly 10 can pivot about the generally upright axis defined by the pins 48, 50 to accommodate turning of the tractor 12.
~he side plates 56 extend i~ spaced parallelism 20 rearwardly from the supporting parallelogram units 26 and carry therebetween several elements, including a horizontal pivot pin 58 which supports a ripping tool 60 therefrom for pivotal motion in forward and backward directions. The ripping tool 60 has a substantially conventional configura-25 tion, with a long shank 60a extending substant.iallyvertically downwardly from the supporting pivot pin 58 and a forwardly and angularly project.ing tooth 60b at its lower extremity. A retaining pin 60d holds tooth 60b in fixed posit.ion at the end of shank 60a. As illustrated in FIG.
30 4, the front surface of shank 60a converges to form a centrally locat.ed vertical leading wedge shaped edge 60c that helps t.o cut. through t.he eart.h. It may be mentioned at this point t.hat while but. a single ripping tool 60 is herein shown, a series of parallel tools can be suspended if desired, 35 each having a similar configuration. When the parallelogram 1 unit is lowered into an operative position, the tool 60 can extend as much as several feet into the underlying earth or other surface, as shown in ~IG. 1, to provide the rippi~g action upon appropriate actuation of the tool driving apparatus and forward motion of the tractor, as will be described in detail hereinafter.
The ripping tool 60 is completely free to pivot for-wardly into contact with the earth or other matérial to be worked upon, but, in accordance with the present invention, 10 a stop member 62 with removable shims 63 is disposed between the side plates 56 of the frame, to limit its backward motion to a particular position to be described hereinafter, which will not interfere with normal machine operation.
The tool driving apparatus includes a resonant force transmitting member 64 in the form of an angle beam composed of solid steel or other resilient material and having a pair of straight integral legs extending in divergent paths at or near approximately ninety degrees from their point of 20 juncture. The legs of angle beam 64 are preferably e~ual in length and the vertical end thereof is enlarged in thickness, as illustrated in FIG. 1, to form a hammer that increases the mass at the region of impact with ripping tool 60. Stop member 62 comprises a rigid bar fixed to 25 side plates 56 of ripping tool assembly 10 between ripping tool 60 and the rest position of the vertical end of resonant member 64.
To mount the resonant angle beam 64, an integral ear 76 projects outwardly from the juncture of the legs 30 of the angle beam so as t.o bisect the angle between the bea~n legs. As used herein the term ~integral" means that. the entire resonant member 64, i.e., the legs and ear 76, is cast or forged as a single unit in a one piece construction.
Parallel plates 65 are att.ached as by welding to opposit.e 35 sides of ear 76. Holes in the plates 65 aligned with the junct.ure of the beam receive ~tub shafts 66 welded or 114~.536 1 otherwise fixedly secured to the plates 65. The shafts 66 are pivotally supported in bushings 67, which are in turn mounted in hard rubber hubs 69 supported in the side plates 56. Thus, although a pivotal support is provided or the beam, it is somewhat flexible and in no way interfere~
with the resonant vibration of the resonant angle beam 64.
In operative disposition, the one ieg of resonant angle beam 64 extends substantially vertically so the portion of enlarged thickness at its lower extremityO lie~ closely adjacent the rear face of the ripping tool 60 at its lower extremity, to provide, upon beam ac~uation, a repeated cyclical serie~ of blows to the rear of the ripping tool, so as to drive tooth 60b repeatedly into the adjacent earth or other earthen material. The tool engaging portion of 15 angle beam 64 lies below the earth's surface near tooth 60b, to provide optimum force transfer thereto. As shown in FIG. 1, the tool engaging portion of angle beam 64 thus lies below tracks 14. As shown in FIG. 4, the lower end of the resonant angle beam 64 has a transverse, i.e., lateral, 20 dimension less than that of the adjacent ripping tool 60.
Therefore, when earth has been dislodged by the tool, sub-stantially no earth contact with the beam will occur. The earth is diverted outwardly by ripping tool 60 much as a mobile snow shovel pushes snow out of its path.
Means are provided to energize the resonant angle beam 64 to resonant vibration, and preferably takes the form of a sonic generator or eccentric weight oscillator 68. Oscillator 68 is connected to the end of the horizontal leg of the resonant angle beam for actuation by a hydraulic motor 70 through a belt drive 71. Motor 70 is attached to one of the side plates 56, and fluidically connected to hydraulic pump 79 for actuation under control of the machine operator. Oscillator 68 is driven by motor 70 such that the eccentric weights rotate at or near ~14~.536 _g_ 1 the resonant frequency of angle beam 64, which typically is of the order of 100 cycles per second.
It is to be particularly noted that this form of resonant angle beam 64 has but a single central node, namely, at the beam juncture and ear 76 alonq a line bisecting the angle of beam 64, when the beam is supported so it is restrained from vibrating at the juncture as shown. The legs of the beam resonate about this single node, with anti-nodes at the ends of the legs. A relatively long lever arm is provided ~o by each of the beam legs so that a considerable stroke, particularly of the lower end of the tool actuating leg, is produced withou~ the necessity of a resonant member or beam of excessive longitudinal dimensions. For example, the cyclical reciprocating stroke with an angle beam having a leg length of no more than five feet can have an output amplitude adjacent the ripping tool of one inch or more.
Further, the single node and the associated node support struc-ture are spaced far from the ends of the beam in comparison to a straight resonant beam having two nodes, as disclosed in my above referenced copending application. This is important in a ripper, where the node support must be above ground level and the ripping tool must be underground. In addition, since the ends of the beam are at an angle to each other, the sonic generator is located in a plane displaced a substantial distance rom the plan~ in which the tool is located, as illustrated in FIG. 1.
The weight of oscillator 68 urges resonant angle beam 64 to pivot or rotate about pin 58 in a clockwise direction, as viewed in FIG. 1. A stop member -/8 is attached to side plates 56 and extends therebetween adjacent to the end of ear 76 in the path of its clockwise rot.ation, as viewed in FIG. 1.
~emovable shims 80 are mounted on the surface of stop member 78 facing toward ear 76. Stop member 78 is shimmed so that the end of resonant angle beam 64 adjacent to t.ool 60 is located in a desired position, u~ually so the upright leg 114~53~ 1 -- 10 -- , thereof is vertical when the beam is in it~ neutral po5ition. me neutral l~si~on of the beam is its position when at rest, i.e., when not rescnatlng or being defle ~ d. mUs, stop m~r 78 rigidly supports resonant angle beam 64 with respect to ripping tcol assembly 10 during operation as bD all motion except resonant vibration.
When oscillator 68 is operating, ~t applies a reciprocating force to the end of the horizontal le9 at or near the'resonant frequency of angle beam 64. While resonant angle beam 64 resonates, the juncture of its legs, which is the single node, remains stationary and the end of its vertical leg reciprocates in forward and back-ward directions, striking tool 60 each time it moves forward in its reciprocating excursion. A changing gap-is formed between the end'of the vertical leg of resonant angle 15": beam 64 and tool 60 -- as the vertical leg reciprocates in a forward direction the gap tends to close and as the vertical leg reciprocates in a backward direction the gap tends to open, disregarding the continuous forward movement of the frame.
Rippin~ tool 60 comprises a work tool that moves along through the soil, which comprises the work path. Ripping tool assembly 10 functions as a tool holder or carrier.
Continuous unidirectional force is applied thereto by tractor 12 in a direction parallel to the work path~ Oscillator 68 generat.es a reciprocating force, at leas~ one component of which acts parallel to the work path. Resonant angle beam 64 comprises a ~orce transmitt.ing member, the end of its horizontal leg comprising an input to which the reciprocating oscillator orce is applied, and the end of its vertical leg comprising an output. f'rom which the reciprocating force is transferred to the tool. The tool advances intermittently along the work path responsive t.o the continuous uni-directional force applied by tractor 12 and the reciprocating force applied by oscillator 68.
A minimum pro~.ect.ive gap is established between the neutral posit.ion of resonant angle beam 64 and tool 60 by stop members 62 and 78.' ~8 a result, when tool 60 encounters 114~536 an immovab~e object, which prevents its further advance, tractor 12 continues to advance until tool 60 abuts stop member 62. In other words, stop member 62 limits the back-ward movement of tool 60 so it cannot reach the neutral position of the beam output. Thus, the end of the vertical beam leg cannot become clamped by tool 6~ when tool 60 encounters an isnmovable object, and destroy the components of the ripping tool assembly. A different way for establishing a protective gap between the output of the beam and the tool when the tool encounters an immovable object is the use of substantially more reciprocating oscillator force than the con-tinuous unidirectional force provided by the mobile carrier.
In a number of applications, however, requiring that the mobile carrier supply a very large continuous unidirectional lS force, such as a shovel bucket or a rock ripper, it is imprac-tical to furnish sufficient reciprocating oscillator force to establish the gap in this manner.
Recognizing that small variations in relative spatial position between components cannot be avoided in the manufac-ture and assembly' of the components of ripping tool assembly 10, the length of the minimum protective gap is adjusted from machine to machine by shims 63 on stop member 6~ and shims 80 on stop member 78. Instead of shimming both stop members 62 and 78, one or the other of these stop members alone could be shLmmed to establish the minimum protective gap. In a typical examp~e, the peak-to-peak excursion of the beam output might be 2 inches, and the minisnum protective gap might be 1/4 of an inch, so that t.he power stroke o~ the beam out.put would be 3/4 of an inch. The minimum protective gap should be no larger than necessary to prevent cessat.ion os~ resonance when the tool encounter~ an immovable object, because 'the larger thls gap, 'the smaller the power stroke, i.e., the portion of the beam out.put excursion in which it cont.acts the tool.
~.14~536 1 If resonant angle beam 64 is driven at or near its r~sonant frequ~ncy without restrainlng the beam juncture from vibrating as disclosed herein, it has two nodes near its ends, as in the case of a straight resonant beam. Under 5 some circumstances, it may be desirable to operate a resonant angle beam in this way, i.e., with two nodes, by supporting the beam at these two nodes, rather than at the beam juncture.
For an explanation of how stop members 62 and 78 protect ripping tool assembly lO, reference is made to FIG. 5, lO' wherein the central horizontal line N represents the neutral position of the resonant angle beam 64, and more particularly the output thereof, and the dashed horizontal line S spaced thereabove, represents the rearmost position attainable by the ripping tool 60 when in engagement with stop member 62. The distance between N and S represents the minimum protective gap. The normal resonant swing of the output of the resonant angle beam 64 is represented by the solid line sine wave indicated at R. When the tool encounters a very hard material and can no longer advance, it moves zo against stop membe~ 62, thereby limiting the excursions o the beam output to an amount equal to the minimum protective gap forward and backward of the neutral position, as represented by the dashed line sine wave R'. This limited excursion is enough to maintain angle beam 64 in resonance and accordingly prevent destruction of the assembly.
As shown in the described embodiment and particularly in FIG. 3, the short connection of the stub shafts 66 in the plates 65 provides a relatively weak support.
Consequently, a slightly modified stronger mounting arrangement as shown in ~IG. 6 can be utilized. As there shown, parallel side plat.es ~2 are welded to an outwardly projecting ear 84 formed at the juncture of the legs of the angle beam 85 and extend adjacent the sides of the resonant angle beam 85 beyond its inner edge to support a tube 86 in aligned holes. Tube 86 in turn, carries a single shaft 88, mounted . . .
114~536 by bushings 90, and rubber hubs 92 in t~e side plates 94 of the frame. Tube 86 and beam ~5 are fixed relative to shaft 88, which is rotatable in bushings 90 about side plates 94 of the frame.
While the tool driving apparatu~ has been described specifically in connection with a ri pping tool, it will be apparent that it can al~o be applied to a cutter ~lade, and also to a shovel bucket or other members of various types requir- l ing considerable force in their operative functions. Consequently,j the term "tool" is to be broadly construed.
The described embodiment of the invention is only con-sidered to be p,referred and illustrative of the,inventive concept the scope of the invention is not to be restricted to such embodiment. Various and numerous other arrangements lS may be devised by one skilled in the art without departing from the spirit and scope of this inventlon. For example, a non-resonant force transmitting member could be employed with advantage in some situations, although a resonant member is preferable. Furthermore, the advantages of having a resonant member with a single node located above the earth's surface can be achieved when the output of the b0am strikes the tool from a position above the earth's surface.
, !
Claims (9)
1. Resonant work performing apparatus comprising:
a resonant system that is vibratory in resonance at an unloaded resonant frequency near which the resonant system has a vibratory input, an output vibratory in first and second opposite directions about a neutral position responsive to vibrations at the input, and at least one vibratory node;
a frame attached to the resonant system substantially at the node;
a load receiving periodic impulses from the vibratory output as the output moves in said first direction;
means for applying a vibrational force to the input of the resonant system at or near the unloaded resonant frequency to excite the resonant system to at least near, resonance; and means for preventing cessation of resonance when the load is excessive to minimize the transmission of the applied vibrational force to the frame.
a resonant system that is vibratory in resonance at an unloaded resonant frequency near which the resonant system has a vibratory input, an output vibratory in first and second opposite directions about a neutral position responsive to vibrations at the input, and at least one vibratory node;
a frame attached to the resonant system substantially at the node;
a load receiving periodic impulses from the vibratory output as the output moves in said first direction;
means for applying a vibrational force to the input of the resonant system at or near the unloaded resonant frequency to excite the resonant system to at least near, resonance; and means for preventing cessation of resonance when the load is excessive to minimize the transmission of the applied vibrational force to the frame.
2. The apparatus of claim 1, wherein said preventing means comprises means for establishing and maintaining a gap between the neutral position of the vibratory output and the load.
3. The apparatus of claim 1, wherein the establishing means comprises a mechanical stop establishing and maintaining said gap between the neutral position of the vibratory output and the load.
4. The apparatus of claim 2, wherein the establishing means compris,es a mechanical stop establishing and maintaining said gap between the neutral position of the vibratory output and the load.
5. The apparatus of anyone of claims 1 to 3, wherein the load comprises a tool and means for mounting the tool on the frame for reciprocation in the first and second directions in the path of the output of the resonant system so that said output strikes the tool when moving in the first direction.
6. Resonant work performing apparatus as claimed in claim 1, comprising a material working machine having a tool holder, a tool movably attached to the tool holder and adapted to move forward and backward relative to the tool holder along a work path, the tool and tool holder constituting the said load, the said resonant system including a resonant member mounted on the tool holder, the resonant member having an output backwardly spaced from the tool and an input, means for rigidly supporting the resonant member with respect to the tool holder as to all motion except resonance, means remote from the supporting means for applying an oscillatory, resonance causing force to the input of the resonant member for a given period of time to cause the output to oscillate forward and backward relative to the tool holder about a neutral position and to strike the tool on forward oscillations, and means for applying an unidirectional force to the tool holder for the given period of time to advance the tool intermittently along the work path as the resonant member resonates, said preventing means comprising means for stopping the backward movement of the tool before the tool reaches the neutral position of the output of the resonant member when the tool encounters an immovable object during the given period of time.
7. The material working machine of claim 6, in which the stopping means comprises a stationary bar supported by the tool holder between the output of the resonant member and the tool.
8. The machine of claim 7, in which the bar is so located that the spacing between the bar and the neutral position of the output of the resonant member is approximately 1/8 of the total peak-to-peak amplitude of the oscillations of the output of the resonant member.
9. The machine of claim 7 or 8 additionally comprising a plurality of shims mounted on the bar facing toward the tool.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000397552A CA1141536A (en) | 1980-01-03 | 1982-03-03 | Resonant work performing apparatus such as ripping tool driving apparatus |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000342990A CA1135501A (en) | 1980-01-03 | 1980-01-03 | Resonant beam for tool driving apparatus |
| CA000397552A CA1141536A (en) | 1980-01-03 | 1982-03-03 | Resonant work performing apparatus such as ripping tool driving apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1141536A true CA1141536A (en) | 1983-02-22 |
Family
ID=25669023
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000397552A Expired CA1141536A (en) | 1980-01-03 | 1982-03-03 | Resonant work performing apparatus such as ripping tool driving apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1141536A (en) |
-
1982
- 1982-03-03 CA CA000397552A patent/CA1141536A/en not_active Expired
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