Patent Publication Number: US-2006010725-A1

Title: Excavating tooth and adapter

Description:
REFERENCE TO RELATED APPLICATION  
      This claims priority from Canadian patent application no. 2,367,860, the subject matter of which is incorporated herein by reference.  
     TECHNICAL FIELD  
      This invention pertains to an excavator tooth and adapter connection system for use on buckets for mass excavation equipment that are used to move earth and rock material.  
     BACKGROUND  
      For years construction and mining establishments have used teeth on mass excavation equipment such as front end loaders, back hoes, rippers and draglines. Initially teeth for mass excavation equipment were made of a single unitary piece. When the one piece tooth became dull or broken, a tremendous amount of time was required to remove the tooth. Replacing a single tooth was very expensive in time and material since 60%-80% of the old tooth was not damaged but was replaced along with the problematic part of the old tooth. If the tooth was not replaced, the tooth continued to get increasingly blunt and unproductive.  
      Some of the difficulties of the unitary tooth system have been minimized in a two part tooth system where a tooth is comprised of a point and an adapter. Early two piece teeth posed many problems. A shell type structure was prone to breakage. Many two piece teeth were of a design wherein the adapter nose and the point socket were predominantly triangular in shape, which when a digging force was exerted on the end of the tooth, an internal part of the tooth would walk off the mating surface, thereby exerting a shearing force on the locking mechanism. Locking mechanisms such as vertical pins would elongate and shear under these circumstances. The point would then break off or the nose of the adapter would shear at the pinhole.  
      Tooth breakage would often result in the mating surface of the adapter being destroyed through exposure to material flow. Shearing of the adapter nose resulted in adapter destruction due to breakage. In both cases, the adapter would have to be replaced and would result in significant loss of production. In many operations, such as mining operations, the breakage and loss of the tooth was secondary to the possible cost incurred if the lost tooth was not recovered and resulted in a breakage of more valuable processing equipment.  
      To reduce problems associated with tooth breakage, a number of two piece arrangements have been devised that include vertically driven locking devices. These devices have often been unsuccessful, struggling with pin shearing problems and resulting loses of the tooth.  
      Manufacturers have reduced breakage by designing massively oversized nose pieces of the edges and providing significantly larger pins in order to prevent breakage of either the tooth or nose piece. The oversized nose pieces and larger pins have led to ineffective digging. Further, if a larger pin was used on a smaller nose, nose breakage would usually occur. This was undesirable.  
      There exists a need for a successful mounting system for connecting a point and the nose of an adapter in a two or more piece excavating tooth system.  
     SUMMARY OF INVENTION  
      An aspect of the invention provides an excavating tooth comprising having an adapter, a point and a locking device. The adapter has a forwardly protruding nose, a channel and a base. The base of the adapter is configured to be secured to excavating equipment. The point has a rearwardly opening socket for receiving the adapter nose therein, a forward digging member, and an ear extending from a side wall of the point, the ear having a recess. The locking device has a rigid body and a depressible protrusion. The rigid body is configured for receipt in the channel of the point and the depressible protrusion is configured for receipt in the recess of the adapter. The protrusion resiliently engages the recess for tightening the point to the adapter.  
      An aspect of the invention provides that the nose of the adapter is configured in a general cone shape. The nose of the adapter has a plurality of tongues and the socket of the point has a plurality of grooves for receiving the plurality of tongues.  
      An aspect of the invention provides that a front portion of the adapter nose has a front stabilizer. A rear portion of the socket comprises a stablizer receiving depression for receiving the front stabilizer.  
      An aspect of the invention provides that a plurality of tongues on the adapter are configured in a rearwardly spiraling formation about the nose of the adapter. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
      In drawings that illustrate non-limiting embodiments of the invention:  
       FIG. 1  is a side perspective view of a tooth system having an adapter, point and locking device in accordance with an embodiment of the invention;  
       FIG. 2  is a side perspective view of an adapter according to an embodiment of the invention;  
       FIG. 3  is front end view of the adapter of  FIG. 2 ;  
       FIGS. 4A, 4B  and  4 C is are end views of adapters according to embodiments of the invention;  
       FIG. 5  is a side view of the adapter of  FIG. 2 ;  
       FIG. 6  is a second side view of the adapter of  FIG. 2 ;  
       FIG. 7  is third side view of the adapter of  FIG. 2 ;  
       FIG. 8  is a side view of a nose of the adapter of  FIG. 2 ;  
       FIG. 9  is an end perspective view of a first point embodiment in accordance with an embodiment of the invention;  
       FIG. 10  is a side perspective view of a socket of the point of  FIG. 9 ;  
       FIG. 11  is a side view of the point of  FIG. 9 ;  
       FIG. 12  is an end perspective view of a second point embodiment in accordance with an embodiment of the invention;  
       FIG. 13  is a side view of the point of  FIG. 12 ;  
       FIG. 14  is an end perspective view of a third point embodiment in accordance with an embodiment of the invention;  
       FIG. 15  is a side view of the point of  FIG. 12 ; and  
       FIG. 16  is a cross sectional view of a locking device embodiment engaged to an ear of a point embodiment in accordance with  FIG. 1 . 
    
    
     DESCRIPTION  
      Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense.  
       FIG. 1  shows a tooth system  100  having an adapter  105 , a point  110  and a locking device  115 . The adapter  105  has a body  120  having a channel  125  for receiving the locking device  115 . The body  120  of the adapter  105  is to be secured to an excavating machine, such as to the bucket of a front end loader (not shown), by conventional means such as welding. The adapter  105  has a forwardly protruding nose  130  for receipt in the socket  135  of the point  110 . The point  110  further has an ear  140  extending from a side wall  145  of the point  110 .  
      The nose of the adapter  105  has according to certain embodiments of the invention as shown in  FIGS. 2, 3 , and  5 - 8  is based on a modified rope design. A common rope is a 6/19 arrangement, which means that a core of 6 strands of straight rope is angularly encircled by 19 strands of roper that extend the length of the rope in an angular fashion around the core.  
      The nose has a conical shaped center core  155  with a plurality of angular tongues  150  around the core. In certain embodiments as shown in  FIGS. 2-8 , the plurality of angular tongues is three angular tongues  150 . At the forward end of the nose of the adapter, a stress (or stabilizer) beam  160  is incorporated. The stress beam  160  receives stress from the tooth when a digging force is applied to the digging end of the tooth (i.e. the point). The stress beam  160  is enhanced by the plurality of the tongues  150 . In embodiments having three tongues, at least two of the three tongues significantly share the stress from a digging force and thus enhance the stress beam.  
      The rope type concept for the nose of the adapter is illustrated in embodiments shown in  FIGS. 4A, 4B  and  4 C. In each embodiment tongues  150  encircle the center core  155 .  FIGS. 4A and 4B  show a generally circular shaped stress beam  162 .  FIG. 4C  shows an embodiment having a stress beam  160  that is non-circular in accordance with the adapter  105  embodiment of  FIG. 2 . The three tongues  150  together form a general triangular shape when viewed from the forward end as shown with triangle  165 . The triangular shaped formation has a narrow topside for penetration and has a doublewide base for bearing surface when the tooth is subjected to stress.  
      The channel  125  can be located on the body  120  of the adapter  105  near where the point  110  engages with the adapter  105 . It is to be understood that the channel  125  can be located on the top, bottom or either side of the 120 of the adapter  105 . The location of the channel  125  depends upon the desired location of the locking device  115  when the tooth system is in the locked position.  
      The tongues  150  and the stress beam  160  of adapter  105  shown in  FIGS. 2, 3  and  5 - 8  are configured in a manner that requires rotation of the adapter  105  or rotation of the point  110  when engaging or disengaging the adapter  105  and point  110 . The rotation of the point  110  during engagement insures that once the locking device  115  is in position and force is applied to the point  110 , the locking device  115  holds the point  110  firmly in place. The stress beam  160  and the tongues  150  are configured to require the same amount of rotation during engagement of the point  110  with the adapter  105 . The combination of the tongues  150 , the stress beam  160  and the locking device  115  provide a strong assembly and reduce the shear force on the locking device  115 . Further the arrangement of the locking device  115  in relation to the adapter  105  and point  110  results in angular compression when the locking device  115  is engaged, significantly reducing or eliminating pin shear and point  105  loss.  
      Certain dimensions of the embodiment of the adapter  105  shown in  FIGS. 6-8  are described herein with reference to a center line  170  that extends longitudinally through the center of adapter  105 . The angles upon which the tongues  150  and the stress beam  160  of adapter  105  are rotated in relation to the center line  170  are shown as angle  175  which is approximately 22.5°. The angle  240  that the outer edge of the center cone  155  forms with the center line is approximately 22°. The angle  245  formed from the inner edge  250  of the channel  125  to the center line  170  is approximately 17.2°. The examples provided will result in an angular rotation of the point  110  by 22.5° about the center line  170  relative to the adapter  105  for engagement or disengagement. It is to be understood that these dimensions and rotations are not meant to limit the claims of the invention but rather are provided by way of example and adapters with differing dimensions and rotation values may also be practiced in accordance with this invention.  
      The three tongues  150  are sloped at ⅛ of a revolution, or 22.5 degrees. The tongues  150  are tapered and slope from a location starting about half of the distance from the font tip of the nose. The tapered tongues  150  can be formed to extend in a gradual tapered fashion from the front end direction of the nose to the rear end direction. The tongues  150  can also be formed extending from left to right or right to left. In conjunction with the corresponding grooves  225  in the socket of the point, whether the tongues are formed left to right or right to left will result in the engagement connection requiring either a clockwise or counterclockwise rotation.  
      An adapter  105  according to this invention can be used with a point  110  of various shapes. Point embodiments  200 ,  205  and  210  are shown in  FIGS. 9-15  and are provided as examples. The shape of the point  110  for a given application can be chosen based on a variety of factors, including the type of earth or rock to be excavated.  
      Points  200 ,  205  and  210  (collectively point  110 ) have a recess  215  on the inside surface of the ear  140  for receiving the protrusion  220  of the locking device  115 . The recess  215  may optionally be located with a depression  265  on the inside surface of the ear  140 . Point  110  has grooves  225  for receiving the tongues  150  of adapter  105 .  
      The manner in which the locking device  115  engages the recess  215  is shown in  FIG. 16 . Locking device  115  has a rigid outer casing  235  and at least one protrusion  220 . Although not shown in the drawings, it is to be understood that additional embodiments of the locking device  115  may include multiple protrusion  220  as described in U.S. Pat. No. 5,469,648 which is incorporated herein by reference. The protrusion  220  may be made of polymer and is elastomeric and/or resilient.  
      The rigid outer casing  235  of the locking device  115  (or locking pin) can be made of steel construction. The protrusion  220  is located in a cavity in the outer casing  235 . The protrusion  220  can be made of a dual polymer. The inner section of the protrusion  220  can be made of a resilient material with air-bubbles such that when the protrusion  220  is driving into the locked position, the bubbles are compressed, creating an outward force. The outer section of the protrusion  220  can be made of a non-resilient polymer to make the outer section of the protrusion  220  rigid for contacting the recess  215  of the point  110 .  
      When the locking device  115  is driven into a position in which the protrusion  220  engages the recess  215  to engage and lock point  110  with adapter  105 , the protrusion  220  is securely held in the correct position in recess  215 . Embodiments of the locking device  115  are designed so that when stress is brought to bear on the point  110 , the locking device  115  does not become rigid in the adapter  105  but rather moves freely with the point  110 . This reduces the shearing or breakage of the protrusion  220  and locking device  115 .  
      As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.