Patent Publication Number: US-2006000124-A1

Title: Resonant demolition tool

Description:
REFERENCE TO PENDING PRIOR PATENT APPLICATION  
      This patent application claims benefit of (1) pending prior U.S. Provisional Patent Application Ser. No. 60/556,177, filed Mar. 25, 2004 by Mark Nye for RESONANT DEMOLITION TOOL, and (2) pending prior U.S. Provisional Patent Application Ser. No. 60/662,034, filed Mar. 15, 2005 by Mark Nye for RESONANT DEMOLITION TOOL which patent applications are hereby incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION  
      This invention is related to demolition apparatus and methods in general and more particularly to apparatus and methods for pulverizing a material using a resonant demolition tool.  
     BACKGROUND OF THE INVENTION  
      For many demolition tasks, it is often desirable to apply a minimal amount of impact energy at a relatively high velocity. As an illustration, two examples are discussed below of an equal amount of impact energy applied to pulverize a standard clay brick lying on a grass surface.  
      In a first example, a 2600 lb lead weight is raised one foot above the brick and dropped. The brick is then driven down into the grass and may not even fracture. Most of the kinetic energy will be converted to heat as the sod is displaced and compressed.  
      In a second example, a .308 rifle is positioned over the brick and the rifle is fired directly down so as to shoot the brick at point-blank range. The brick will be completely shattered such that most of the energy of the bullet fired by the rifle is converted to kinetic energy in the flying bits of brick.  
      In both examples the impact energy is 2600 ft-lbs, but the energy transfer is quite different. High velocity impact is generally much more suited to pulverizing a material. Accordingly, it would be desirable to provide an impact tool which efficiently provides impact energy at a high velocity.  
     SUMMARY OF THE INVENTION  
      The high velocity impact tool of the present invention provides a demolition apparatus for pulverizing a material using resonant energy at a high velocity.  
      An object of the invention is to provide an impact tool for pulverizing concrete.  
      Another object of the invention is to provide an impact tool for compacting materials.  
      Another object of the invention is to provide an impact tool for driving piles.  
      Another object of the invention is to provide an impact tool for demolishing reinforced concrete structures.  
      Another object of the invention is to provide an impact tool for reducing oversized quarry rocks.  
      Another object of the invention is to provide an impact tool for freeing rock jammed in a rock crusher.  
      Another object of the invention is to provide an impact tool for rubblizing concrete roads and runways.  
      Another object of the invention is to provide an impact tool for curring asphalt.  
      Another object of the invention is to provide an impact tool for driving or pulling sheet pilings.  
      Another object of the invention is to provide an impact tool for excavating earth.  
      Another object of the invention is to provide an impact tool for mine sweeping.  
      Another object of the invention is to provide an impact tool for evaluating the strength of a structure.  
      A still further object is to provide a method for applying impact energy to a material with a tuning fork having an exciter component mounted thereto so as to pulverize material by actuating the exciter component at the first tine end of the tuning fork and applying resonant energy to the material using the second tine of the tuning fork.  
      A still further object is to provide a method for applying impact energy to a material with a tuning fork having an exciter component mounted thereto and configured for attachment to a vehicle.  
      A still further object is to provide a method for applying impact energy to a material with a tuning fork having an exciter component mounted thereto and configured for hand-held operation.  
      With the above and other objects in view, as will hereinafter appear, there is provided an impact tool for applying impact energy to a material, the impact tool comprising:  
      a fork portion having a first tine, a second tine, and a base portion, the first tine having a first end and a second end, the second tine having a third end and a fourth end, the first end of the first tine configured adjacent the base portion, and the third end of the second tine configured adjacent the base portion;  
      an exciter component disposed adjacent at least one of the second end of the first tine and the fourth end of the second tine, wherein the exciter component is configured to excite the first tine and the second tine to resonate sympathetically with one another at a given frequency; and  
      a striking surface disposed adjacent at least one of the second end of the first tine and the fourth end of the second tine, wherein the striking surface is configured to contact the material with the first tine and the second tine resonating sympathetically with one another so as to apply impact energy to the material.  
      In accordance with a further feature of the invention there is provided an impact tool for applying impact energy to a material, the impact tool comprising:  
      a resonating bar member having a single tine and a base portion, the single tine having a first end and a second end, the first end of the single tine configured on one side of the base portion, and the second end of the single tine configured on the other side of the base portion;  
      an exciter component disposed at one chosen from the group consisting of the first end of the single tine, the second end of the single tine, and an anti-node disposed between the first end and the second end, wherein the exciter component is configured to excite the single tine to resonate at a given frequency;  
      a striking surface disposed adjacent at least one of the first end of the single tine and the second end of the single tine, wherein the striking surface is configured to contact the material with the first end of the single tine and the second end of the single tine resonating sympathetically with one another so as to apply impact energy to the material; and  
      a frame member in connection with the resonating bar member, and the frame member selectively connectable with various carrier vehicles.  
      In accordance with a still further feature of the invention, there is provided a method for applying impact energy to a material, the method comprising:  
      providing an impact tool for applying impact energy to a material, the impact tool comprising: 
          a fork portion having a first tine, a second tine, and a base portion, the first tine having a first end and a second end, the second tine having a third end and a fourth end, the first end of the first tine configured adjacent the base portion, and the third end of the second tine configured adjacent the base portion;     an exciter component disposed adjacent at least one of the second end of the first tine and the fourth end of the second tine, wherein the exciter component is configured to excite the first tine and the second tine to resonate sympathetically with one another at a given frequency; and     a striking surface disposed adjacent at least one of the second end of the first tine and the fourth end of the second tine, wherein the striking surface is configured to contact the material with the first tine and the second tine resonating sympathetically with one another so as to apply impact energy to the material;        

      raising the second tine away from the material;  
      actuating the exciter component so as to cause the first tine and the second tine to resonate at a given frequency with increasing amplitude until a desired level of excitation is achieved and maintained; and  
      positioning first tine and second tine to cause the second tine to strike the material while the exciter component maintains the given frequency of resonation of the second tine so as to apply impact energy to the material.  
      The above and other features of the invention, including various novel details of construction and combinations of parts and method steps will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular devices and method steps embodying the invention are shown by way of illustration only and not as limitations of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which are to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein:  
       FIG. 1  is a schematic view of one form of a resonant demolition tool having a tuning fork configured for attachment to a thirty ton excavator, illustrative of a preferred embodiment of the present invention;  
       FIG. 2  is another schematic view of the tuning fork and rotatble connector component of the resonant demolition tool as shown in  FIG. 1 ;  
       FIG. 3  is a schematic view of another preferred embodiment of the present invention with a resonant demolition tool having a resonating bar member with a frame selectively attachable to a carrier vehicle;  
       FIGS. 4A-4G  are schematic views of various components disposed at the striking surface of a working tine or an impact tool;  
       FIG. 5  is a schematic view of another preferred embodiment of the present invention with a resonant demolition tool having a tuning fork with a pair of radically curved tines;  
       FIGS. 6-8  are diagrammatic illustrations of a model of an impact tool with a pneumatically driven exciter component mounted on an exciter tine;  
       FIGS. 9-11  are diagrammatic illustrations of an impact tool of the present invention having a handle mounted at the base of the tuning fork for hand-held operation by a single operator; and  
       FIGS. 12-18  are diagrammatic illustrations of an impact tool of a preferred embodiment of the present invention having a tuning fork as shown in  FIGS. 1 and 2 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Referring to  FIG. 1 , and in a preferred embodiment of the present invention, there is shown a resonant impact tool  5  for pulverizing concrete and performing other various tasks. Resonant impact tool  5  is referred to herein below as impact tool  5 .  
      Referring to  FIGS. 1 and 2 , and in a preferred embodiment of the present invention, impact tool  5  comprises a steel profile forming a very large tuning fork  10 . For a typical carrier  15 , such as a thirty ton excavator  15 , the overall length is preferably about 2000 mm to about 3500 mm and the thickness is preferably about 100 mm to about 250 mm. A base portion  12  of fork  10  is preferably pivotally mounted to an arm  20  of carrier apparatus  15  with a rotatable connector component  17 . Two existing bucket pins  25  are attached to rotatable connector component  17  such that tuning fork  10  can be angled up and down by the machine&#39;s bucket cylinder  30 . A turn-table  35  attached by pins  35 A to base  12  of fork  10  between fork  10  and carrier machine  15  allows the entire assembly to be rotated so a working tine  40 , having a striking surface  45 , can be used at any angle.  
      In one preferred embodiment of the present invention, a striking surface is located on each of tine  40  and  50 . In another preferred embodiment of the present invention, a striking surface is located on tine  50  instead of tine  40 .  
      A resonant tine  50  of fork  10  is excited by an exciter  55 , which is preferably a motor driven rotating eccentric weight  55 A mounted at an end  60  of tine  50 . Working tine  40  resonates sympathetically with resonant tine  50  as it is excited by exciter  55 . An enlarged striking surface  45  at an end  65  of working tine  40  is used to deliver blows to the material to be demolished.  
      As discussed herein below, and in other preferred embodiments of the present invention, working tine  40  may include other tools disposed thereon.  
      Preferably, the tine displacement or amplitude of working tine  40  is about 15 mm to about 30 mm. This amplitude is proportional to excitation strength provided by the motor driven weight  55 A, and can be varied by changing the mass and radius of rotating eccentric weight  55 A.  
      Preferably, the impact frequency is about 10 Hz to about 500 Hz, and, more preferably, the impact frequency is about 30 Hz to about 60 Hz, which is set by the length of tine  45 . Impact energy provided at enlarged striking surface  45  is a function of the amplitude, frequency and mass of tine  45 .  
      In a preferred embodiment of the present invention, fork  10  comprises one or more selected materials. For example, these materials may include, but are not limited to, at least one of steel, carbon fiber, aluminum, and monel, for non sparking applications.  
      In an alternative embodiment of the present invention, a fork portion is laminated vertically with multiple portions joined together at the locations of the nodes such that the fork portion has a construction similar to a transformer (not shown).  
      In an alternative embodiment of the present invention, a fork portion is laminated horizontally with multiple portions joined together at the locations of the nodes such that the fork portion has a construction similar to a leaf spring (not shown).  
      Referring now to  FIG. 3 , and in a preferred embodiment of the present invention, there is shown a resonating bar member  10 A. A frame  67  preferably connects resonating bar member  10 A to rotatable connector component  17  with a fixed node pin  69  and a suspension link  70  to a floating node pin  75 .  
      In an alternative embodiment of the present invention, a resonating bar member is laminated vertically with multiple portions joined together at the locations of the nodes such that the bar member has a construction similar to a transformer (not shown).  
      In an alternative embodiment of the present invention, a resonating bar member is laminated horizontally with multiple portions joined together at the locations of the nodes such that the bar member has a construction similar to a leaf spring (not shown).  
      Impact tool  5  may be used to drive a pick, chisel, plate packer, rotating drill, sheet pile driving clamp, replaceable impact hammer, blender, mixer or one or more other tools.  
      Referring now to  FIGS. 4A-4F , and in a preferred embodiment of the present invention, working tine  40  of impact tool  5  preferably includes, but is not limited to, one or more various components  45 A,  45 B,  45 C,  45 D,  45 E,  45 F, and  45 G disposed at striking surface  45  of working tine  40 .  
      Looking at  FIG. 4A , there is shown impact tool  5  with component  45 A configured for rapid demolition of steel reinforced concrete structures. For example, component  45 A preferably comprises a round or flat chisel point.  
      Looking at  FIG. 4B , there is shown impact tool  5  with component  45 B configured for compacting materials. For example, component  45 B preferably comprises a compactor foot.  
      Looking at  FIG. 4C , there is shown impact tool  5  with component  45 C configured for driving piles, demolishing reinforced or non-reinforced concrete structures, reducing oversized quarry rocks, freeing material jammed in rock crushers, or rubblizing concrete road beds or runways. For example, component  45 C preferably comprises an elephant foot.  
      Looking at  FIG. 4D , there is shown impact tool  5  with component  45 D configured for cutting asphalt. For example, component  45 D preferably comprises a cutter wheel.  
      Looking at  FIG. 4E , there is shown impact tool  5  with component  45 E configured for driving or pulling sheet pilings. For example, component  45 E preferably comprises a clamp.  
      Looking at  FIG. 4F , there is shown impact tool  5  with component  45 F configured for excavating earth. For example, component  45 F preferably comprises a spoon blade  45 F.  
      Looking at  FIG. 4G , there is shown impact tool  5  with component  45 G configured for mine sweeping. For example, component  45 G preferably comprises a multi-tined rake  45 G. Preferably, the multiple tines of multi-tine rake  45 G are configured to sift and travel through the dirt, raking, without plowing.  
      In a preferred embodiment of the present invention (not shown), impact tool  5  is configured for evaluating the strength of structures. For example, the impact frequency of working tine  40  of impact tool  5  is selectively adjusted to test concrete columns for seismic stability.  
      Referring to  FIG. 5 , and in a preferred embodiment of the present invention, there is shown an impact tool  5 B comprising an alternatively shaped tuning fork  10 B having a pair of radically curved tines  40 A and  50 A.  
      In another preferred embodiment of the present invention (not shown), variable length tines are preferably provided to allow resonant frequency adjustment so as to provide a matching frequency for optimized performance relative to various materials.  
      In a preferred embodiment of the present invention, impact tool  5  is configured to be mounted on various types of stationary or mobile equipment.  
      Looking at  FIGS. 6-8 , and in a preferred embodiment of the present invention, there is shown a table mounted impact tool  80  having a support portion  85  for holding base  12  of tine  40  and tine  50 . A pneumatic system  90  is provided to drive a pneumatic motor, which in turn drives weight  55 A ( FIG. 1 ).  
      Referring now to  FIGS. 9 and 10 , and in a preferred embodiment of the present invention, there is shown a resonant impact tool  105  having a handle  135  configured for hand-held operation by a single operator. Preferably, handle  135  includes a pair of hand grips  135 A and  135 B in attachment to base portion  115 .  
      Looking at  FIGS. 9-11 , and in a preferred embodiment of the present invention, there is shown exciter  55  with an electric motor  55 D to drive weight  55 A ( FIG. 1 ).  
      In another preferred embodiment of the present invention, the motor of exciter  55  preferably comprises a rotary hydraulic motor, a pneumatic motor, or an electric motor. In another preferred embodiment of the present invention, exciter  55  preferably comprises a linear actuator, a magnetic coil, a piezoelectric motor or an internal combustion engine.  
      Referring now to  FIGS. 12-15 , and in a preferred embodiment of the present invention, there is shown a resonant impact tool  5  with a hydraulic exciter component  200  and a machine mount  205  ( FIGS. 14-18 ) configured for attachment to a vehicle  210  ( FIGS. 14 and 17 ).  
     DESCRIPTION OF A PREFERRED METHOD OF OPERATION  
      In a preferred embodiment of the present invention, a method for operating impact tool  5  preferably comprises the following steps. First, tine  40  and tine  50  are raised away from the material. Second, exciter motor  55  is started. Third, tine  40  and tine  50  each begin to resonate with increasing amplitude until fully excited. Fourth, tine assembly  10  is rotated and positioned to cause one or both of excited tine  40  and excited tine  50  to strike the material to be pulverized.  
     ADVANTAGES OF THE PRESENT INVENTION  
      The impact tool of the present invention is scalable within a wide range of sizes and uses.  
      The impact tool of the present invention is configured for quiet operation due to a low amount of energy needed per impact.  
      The impact tool of the present invention has a relatively simple construction, with no precision parts.  
      The impact tool of the present invention does not require any special alloys or heat treated parts.  
      The impact tool of the present invention is able to produce smaller rubble due to high energy rate.  
      The impact tool of the present invention is able to process unsupported material as it does not require anything to hit against.  
      The impact tool of the present invention does not drive material down or away from striking surface.  
      The impact tool of the present invention is able to use the material&#39;s own inertia to shatter it at high velocity.  
      The impact tool of the present invention is able to demolish items of relatively low mass.  
      The impact tool of the present invention produces very little or no seismic disturbance. The impact tool of the present invention does not shake the surrounding ground or foundations. The impact tool of the present invention is configured for applications in connection with urban search and rescue inasmuch as it does not cause movement of structures and is distinct from a hydraulic hammer or breaker.  
      Some potential disadvantages of the impact tool of the present invention may include fatigue cracking of the tines and that careful control of application pressure may be required to avoid instances of stalling and loss of excitation when too much application pressure is applied to the working tine.  
      Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the embodiments shown herein are by way of example, and that various changes and modifications may be effected by one skilled in the art without departing from the scope or spirit of the invention as defined in the following claims.