Patent Publication Number: US-2006017313-A1

Title: Hydraulically actuated impact apparatus

Description:
FIELD OF THE INVENTION  
      The present invention relates to impact apparatuses, and more particularly, relates to such which include an impact actuator assembly.  
     DESCRIPTION OF THE PRIOR ART  
      Excavating buckets are well known in the art and are designed to excavate hard soils and the like. One such excavating bucket is shown in U.S. Pat. No. 6,574,891 wherein the bucket includes a bucket body, a moveable head, a moveable floor mounted between the moveable head and an impact actuator provided between and mounted to the bucket body and the moveable head.  
      Other arrangements are shown in the art and thus, one may have reference to U.S. Pat. No. 4,625,438 which teaches an excavating bucket having a leading edge provided with a row of individually pneumatically driven digging teeth. Each digging tooth is connected to a pneumatic hammer that that reciprocates the tooth at high speed. Since each tooth is connected to an individual pneumatic impact hammer, the total weight of the excavating bucket is much higher than the weight of a conventional bucket which is a disadvantage when the arm of the machine carrying the bucket is fully extended.  
     SUMMARY OF THE INVENTION  
      It is an object of the present invention to provide an impact actuator which is of relatively simple design with a stable floor and reciprocating teeth which are easily interchangeable.  
      According to the present invention, there is provided an impact actuator assembly comprising: 
          a housing having a front, a rear, two opposite sides, a top and a bottom, and defining an actuator receiving area;     a hydraulic actuator fixedly mounted in said actuator receiving area, said actuator being provided with an actuator head, at least a portion of said actuator head extending forwardly of said actuator receiving area;     a nosepiece fixedly attached to said front of said housing at a distance from said actuator receiving area, defining a space between said nosepiece and said actuator head;     said nosepiece being provided with at least one longitudinal hollow guide for receiving a tool pin, each of said tool pin having a rear and a front, said rear of said tool pin extending in said space between said nosepiece and said actuator head, said front of said tool pin extending beyond said front of said housing; and     a plurality of hydraulic connectors mounted on said housing and operatively connected to said actuator;     whereby, in use, when said actuator is actuated, said actuator head is engaged in reciprocating longitudinal movement to cyclically impact said tool pin.       

    
    
     DESCRIPTION OF THE DRAWINGS  
      Having thus generally described the invention, reference will be made to the accompanying drawings illustrating an embodiment thereof, in which:  
       FIG. 1  is a top plan view of an excavator bucket with one actuator assembly and fitted with abutments arrangement;  
       FIG. 2  is similar to  FIG. 1 , except the nosepiece has been cutted to see its internal components;  
       FIG. 3  is a cross-sectional side view of an excavator bucket with one actuator assembly and fitted with abutments arrangement;  
       FIG. 4  is an exploded perspective view of an excavation bucket;  
       FIG. 5  is an exploded rear perspective view of the bucket of  FIG. 1  and  FIG. 5   a  is a detail thereof;  
       FIG. 6  is a front perspective view of the bucket of  FIG. 1 , with some elements removed so to show internal components;  
       FIG. 7  is a rear perspective view of the bucket of  FIG. 1 , with some elements removed so to show the abutment members arrangement;  
       FIG. 8  is a rear perspective view of the bucket without abutment members, with some elements removed to facilitate the representation;  
       FIG. 9  is a top plan view of the bucket;  FIG. 9   a  being an enlarged view of the connectors at the rear of the bucket;  
       FIG. 10  is a front perspective view;  
       FIGS. 11 and 12  are perspective views of the bucket with the top cover removed;  
       FIGS. 13 and 14  are similar views as  FIGS. 11 and 12  showing a bucket with two impact actuator assemblies and two independent nosepieces;  
       FIG. 15  is an exploded perspective view of an excavation bucket with two impact actuator assemblies and two independent nosepieces;  
       FIGS. 16 and 17  are perspective views of buckets with two impact actuator assemblies, one common nosepiece and sharing the same dividing wall;  
       FIGS. 18 and 19  show two different options for removable wear bushings into the nosepiece;  
       FIG. 20  is a perspective view of an impact actuator assembly according a preferred embodiment of the invention;  
       FIG. 21  is a perspective view of the impact actuator assembly with the top portion removed;  
       FIG. 22   a  is a rear perspective view of a compaction roller;  
       FIG. 22   b  is a front perspective view of a compaction roller;  
       FIG. 23   a  is an exploded view of a 12-inch V-knife;  
       FIG. 23   b  is a perspective view of an assembled 12-inch V-knife;  
       FIG. 24   a  is an exploded view of a 24-inch V-knife;  
       FIG. 24   b  is a perspective view of an assembled 24-inch V-knife;  
       FIG. 25   a  is an exploded view of a 12-inch levelling knife;  
       FIG. 25   b  is an assembled view of a 12-inch levelling knife;  
       FIG. 26   a  is an exploded view of a 24-inch levelling knife;  
       FIG. 26   b  is an assembled perspective view of a 24-inch levelling knife;  
       FIG. 27   a  is an exploded view of a compacting plate;  
       FIG. 27   b  is an assembled view of the compacting plate; and  
       FIG. 28  shows a variety of configuration for the tool pins. 
    
    
     DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION  
      As mentioned in the summary of the invention, the present invention concerns an impact actuator assembly. Although the impact actuator assembly may be used on its own, in a preferred embodiment, this impact actuator assembly  26  is preferably incorporated into an excavating shovel.  
      Referring to the drawings in greater detail and by reference characters thereto, there is illustrated in  FIGS. 1, 2  and  3  a preferred embodiment of the invention where the impact actuator assembly is integrated in an excavating shovel which is generally designed by reference numeral  10 . In this respect, shovel  10  is similar to that shown in U.S. Pat. No. 6,574,891.  
      Shovel  10  has a floor  12 , a back wall  14 , side walls  16  with mounting brackets  18  having apertures  20  therein for securement purposes.  
      Depending upon its use and its width, each shovel  10  is fitted with one or more impact actuator assemblies  26  (refer to FIGS.  13  to  17  for multiple use of impact actuators). When used in series (more than one per shovel  10 ), each impact actuator assembly  26  is mounted side by side, separated by internal walls. Upon the specific design of the shovel, the multiple impact actuator assemblies may share the same dividing internal wall  24 .  
      Each one of the impact actuator assemblies  26  are provided with a pair of lateral walls  22 , positioning spacers  21  and a rear plate  39  to house an impact actuator assembly  26 . As may be seen in the drawings, impact actuator  26  is provided with a rear cushion  28 , center cushions  30  and front cushion  32 . A cover  34  is secured to the interior wall  22  to enclose the impact actuator assembly  26 . Cover  34  is secured to the lateral wall  22  by means of screws  36 . Similarly, a front wall  38  is secured to the lateral wall  22  by spacers  21 .  
      Each one of the impact actuator assemblies  26  also includes an actuator head  42  which functions as an anvil. One end of the anvil fits into its actuator while the other end (wider) hits the end of tool pins  48  (number of tool pins undetermined, min of 1, no max). Tools pins  48  are mounted in a nosepiece  44  which is secured to the bucket floor  12  and to the bucket side walls  16  or lateral walls  22 . To this end, nosepiece  44  may by welded thereto. In turn, tool pins  48  are moveable within slots or guides  45  formed in nosepiece  44 . Tool pins are retained in position by a backing rod  60 . In a multi actuator impact assembly&#39;s application, there is no specific rule for specifying the quantity of nosepieces  44 . Each one of the impact actuator assembly  26  within a shovel  10  may have its own nosepiece  44 , as well as one nosepiece  44  may guide tools pins  48  for more than one impact assembly  26 , with no limitation in size nor number of tools pins  48  being guided. Similarly, the tool locking mechanism may have one or more rod  60  to secure all of the tools pins  48 . Each rod  60  may serve one or many nosepiece  44 .  
      Referring to  FIGS. 6 and 9 , each one of the impact actuator  26  has 2 hydraulic connections  66  (inlet and outlet), one grease connection  68  for its anvil wear bushing, and one connection  70  for compressed air used for actuator seal in a underwater use. Every line connecting the actuators run from inside the bucket up to outside connectors  67 - 69 - 71 , therefore allowing the operation and basic maintenance of the impact actuator unit from the outside (no cover removal).  
      Each one of the impact actuator assemblies  26  could be totally independent of each other, in terms of operation and motion. In such a case, the actuators  26  are not interconnected. The tools pins  48  driven by one assembly are totally free from the other assemblies. The hydraulic connections are independent. However, actuators  26  of different assemblies may be hydraulically interconnected. In such a case, the tools work in phase. Similarly, actuator could share common gas chamber (to reduce space).  
      Application 1  
      Hard Soil, with Long Anvil  42  and Abutment Members  54 .  
      As may be best seen in  FIG. 5  and  7 , there are provided a plurality of recesses  56  within nosepiece  44 . Each recess  56  has a spring member  52  mounted therein. One end of spring  52  seats on end wall of recess  56  while the other end thereof seats against an abutment member  54 . The abutment member  52  is secured in place with a abutment screw  50 . As seen in  FIG. 7 , abutment member  54  extents slightly beyond the end wall  58  of the nosepiece  44 . During normal operation in hard soil, pressure is always applied against the tools pins, thus to the anvil  42 . The course of the anvil  42  is short and as long as the hard material is not broken, the pressure on the tools pins  48  will prevent the anvil  42  of hitting the inner wall surface  58  of the nosepiece  44 . However, when the hard material is broken, the pressure at the tip of the tools pins  48  is nil and the anvil  42  is pushed against the nosepiece  44 . With the abutment arrangement, we now control the impact force of the anvil  42  on the nosepiece  44  after a pressure release on the tools pins  48 . With the proper spring tension adjustment of the abutments  54 , the deceleration of the anvil  42  is controlled so that the impact is minimized and set as desired. The resistance of spring member  52  will also ensure that actuator head  42  is returned to its position for the next stroke.  
      Application 2  
      Hard Soil, with Long Anvil  42  only (No Abutment Members  54 ).  
      Refer to  FIG. 8 . In this option of impact actuator arrangement, they are no abutment members  52 , springs  52  and screws  50  secured into the nosepiece  44 . The normal operation in hard soil is similar to application 1 described above. The difference is when the hard material is broken and the pressure at the tip of the tool pins  48  is nil, the anvil  42  will directly hit the inner face of the nosepiece  58 . The impact force will not be controlled.  
      Application 3  
      Hard Soil, with Short Anvil  42 .  
      In this option of impact actuator arrangement, the design is such as even with the actuator piston in its full extended position (out of actuator  26 ), the anvil  42  will not be pushed against the nosepiece inner wall  58 . The anvil  42  free space is longer that the piston stroke. Consequently, when hard material is broken, the pressure release of the tips of the tools pins  48  will not make the anvil  42  to hit the inner wall of the nosepiece  58 . There are no damageable impacts on the nosepiece  44 . In the case of material removal with no pressure on the tools pins  48  (for example: clay), this application may not be suitable since less vibration is generated to the bucket walls.  
      Application 4  
      Clay, Impact Vibration.  
      This application refers to a situation where we have a bucket full of material (example: clay) sticking to the inner surfaces and therefore difficult to clean out. Any of the three applications described above could be used for clay removal. The vibration generated to the shovel  10  by the each one of the impact design will ease the extraction of clay out of the shovel  10 . Referring to application 1, the abutment arrangement  54  allows to operate the impact actuator  26  with not load on the tools pins  48 , and to control the impact of the anvil  42  onto the inner nosepiece wall  58 , such as generating enough vibration to force the clay (or other material) out of the bucket. Similarly, application 2 can also be used with no load on the tool pins  48  but without controlling the impact.  
      The direct impact of the anvil  42  with the nosepiece  44  will generate more vibration that application 1. The impact force will be absorbed by the welds of the nosepiece  44  to the shovel  10 . Application 3 will also generate vibration to the shovel  10  (less than the two previous applications). The impact will be absorbed by internal components of the impact actuator  26 .  
      Application 5  
      Clay, Vibrating Cover.  
      Without limitation to the previous application (no 4), the impact actuator assembly  26  may be fitted with a mechanical mechanism, making the actuator cover  34  (or part of it), to move longitudinally with the anvil  42 . The back and forth motion of the moveable cover (or part of it) will facilitate the disengaging of soil packed in the bucket body  10 .  
      Because of very abrasive applications, the nosepiece  44  and specially its guiding holes  45  will require the use of appropriated harden material. As other alternatives, removable wear bushings  64  may be used (refer to  FIGS. 18 and 19 ).  
      As mentioned also previously, the impact actuator assembly  26  can also be used on its own as illustrated in  FIGS. 20 and 21 . In that respect, the tool pin  48  may be connected to a variety of different tools in order to increase the versatility of the impact actuator assembly.  
      In one embodiment, the tool pins  48  are connected to a compaction roller of a construction which is well-known in the art. Thus, the cyclical impact of the anvil increases the efficiency of the compaction roller.  
       FIGS. 23   a ,  23   b ,  24   a  and  24   b  illustrate another tool which may be used, viz. a V-shaped knife which can come in sizes of 12 inches or 24 inches, or any other size that the client would desire. The tool pins  48  are secured to the knife with retaining pins  201  are secured within the knife with washer tool  3  and retaining clip tool  5 . Referring more specifically to  FIG. 24   a , the retaining pins  201  are adapted to retain tool pins  48  which are provided with retaining groove  207 .  
      Similarly, the tool could be a 12-inch levelling knife  230  or a 24-inch levelling knife  240 . The tool pins  48  are retained to the tool in the same manner as for the V-shaped knife.  
      Yet another tool which can be used with the present invention is a compacting plate which can be either 12 inches or 24 inches or in other sizes as a client may deem. Tool pins  48  are retained to the compacting plate with a retaining pin  251  which passes through bores  252  in the compacting plate and bores  253  in the tool pins  48 . Appropriate retaining members are used to secure the plate to the tool pins.  
      It will be understood that the above described embodiment is for purposes of illustration only and that changes and modifications may be made thereto without departing from the spirit and scope of the invention.