Patent Publication Number: US-9840828-B2

Title: Container lip for excavating equipment providing improved material flow over lip

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/489,626, filed on May 24, 2011, the full disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Ground excavating equipment for moving/removing ground materials such as rock, sand, mineral deposits and the like (hereafter generally “ground”) typically has a bucket or container with an open front end that is forced into the ground to scoop up a load of ground. To facilitate digging into the ground, the sides and lower edge of the open bucket end are defined by a lip, suitably secured to the accompanying bucket, which mounts a variety of ground contacting components such as digging teeth and shrouds, for example. 
     To protect the lip from wear and tear while permitting the intermittent replacement of worn teeth, the latter are normally removably secured to an adapter, with wedges, bolts, etc., so that the worn teeth can be replaced. The adapters are in turn removably mounted to the lip of the bucket so that they can also be replaced when worn, or to secure a different component to the lip that requires its own adapter. In this manner, the costly bucket lip is protected against wear to the maximum extent possible. 
     In the past, reconnection of the adapter or component to the lip has been problematic because it is subjected to large forces, high loads, shock, vibration and contamination by abrasive materials, all of which have the tendency of inadvertently loosening or freezing the connection. Both are undesirable because they make it more difficult, time-consuming and costly to replace adapters, teeth and/or other components mounted to the lip at the front end of the bucket and/or cause equipment down-time. 
     An additional difficulty encountered with bucket lips is that the lip must be capable of receiving and holding components of widely differing shapes and/or sizes and at different positions over the length of the horizontal and upwardly extending sides of the lips. In some instances, the lips were provided with forwardly extending projections positioned and configured to place particular components at predetermined locations along the lip. Such lips were ill-adapted for placing the components at different locations where, for example, the needed projection to mount a given component is not available. Alternatively, the operator of the equipment can be provided with a supply of adapters which are configured so that they can be placed over the length, or part of the length, of the lip. A big disadvantage of such an arrangement is the need to store and keep track of a relatively large supply of parts, which is costly to acquire as well as to install. 
     Finally, conventional ground excavating equipment typically employed straight, oval, rounded and/or threaded wedge members which had to engage tightly fitting, overlapping bores in the adapter and the lip to keep the adapter firmly in place in the rough environment in which excavating equipment operates. Such wedge-like members are time-consuming to install and difficult to remove, which renders them costly and therefore undesirable. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides a releasable connection between components, such as adapters for teeth and shrouds, which must be attached to the lip at a forward end of the container for ground excavating equipment. The lip has regularly spaced projections at and along its front edge over which the components, e.g. an adapter, are slipped. The lip has a bulbous cross-section aft of the front edge of the lip which gives the lip a maximum thickness at a point aft of the front edge of the lip. As a result, the cross-section of the lip first increases from the lip edge in the aft direction and then again decreases. The resulting hump in the cross-section of the lip facilitates the secure, firm, stable and easily releasable connection between the adapter and the lip. 
     Thus, a lip constructed in accordance with the present invention is applied to the open front end of the bucket of excavating equipment for moving ground material and has a front edge that faces in the forward direction of the container. The lip defines a substantially horizontal bottom lip portion and side lip portions which extend upwardly from lateral ends of the bottom portion. A multiplicity of like projections extend forwardly relative to the lip from at least one, and typically from all, of these portions of the lip. Top and bottom surfaces of the lip extend in the aft direction from the front edges of the lip portions. First sections of the top and bottom surfaces which are contiguous with the front edge converge in a forward direction, and second sections of the top and bottom surfaces located aft of the first section diverge relative to each other in a forward direction towards the end of the first sections. A component releasably applied over the lip frequently is an adapter which has upper and lower legs in contact with the top and bottom surface sections of the lip. The relatively longer lower leg has an upwardly facing surface shaped complementary to and in contact with the first and second sections of the bottom surface of the lip. Bolts or like fasteners secure the ends of the adapter legs to the lip to keep it firmly in place. 
     Aside from providing a stable, secure connection between the lip and the adapter, the portions of the shroud, adapters and the like overlying the top surface of the lip are relatively smooth and do not obstruct ground material that is being scooped up by the teeth and the shrouds between the teeth and then flows over the teeth, adapters and the shrouds into the container. As a result, no ground material tends to build up at and just behind the components mounted to the front edge of the lip, which enhances the efficiency of the lip for moving ground materials. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a lip made in accordance with the present invention for a container of excavating equipment; 
         FIG. 2  is a view similar to  FIG. 1  and shows the lip only; 
         FIG. 3  is a plan view of the underside of the lip shown in  FIG. 1 ; 
         FIG. 4  is a partial, side elevational view which shows the cross-section of the lip; 
         FIG. 5  is a cross-section through the lip to which an adapter carrying a tooth is mounted; and 
         FIG. 6  is a cross-section similar to  FIG. 5  and shows a shroud mounted on the lip. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1-3 , a lip  2  constructed according to the present invention has a relatively flat bottom  4  with lip sides  6  extending upwardly from lateral ends  8  of the lip bottom. The lip has a front edge  10  that is defined by a multiplicity of projections  12  arranged along the length of the front edge extending in a forward direction. Teeth  14  mounted on adapters  16  (shown in  FIG. 5 ) and shrouds  18  are secured to the projections, as is further described below. The lip as such is secured, e.g. welded, to an open forward end of a container or bucket  20  of the excavating equipment. In use, the bucket is moved in a forward direction  22  and the front end  10  of the lip, including the teeth  14  thereon, digs into the ground as the bucket is driven forwardly. This causes ground to flow over the top surface of the teeth, shrouds and the lip into the container. Neither the teeth, the adapters nor the shrouds constitute an obstacle for the ground to smoothly move over them into the bucket without forming obstructions by compacted ground, stones, rocks and the like in the vicinity of the lip, because there is a substantially smooth, non-obstructing transition between the components on the front of the lip and the remainder of the lip and the container, as will be apparent from the following. 
     Referring to  FIG. 4 , lip  2  defines a top surface  24  and a bottom surface  26 , which, at their respective forward parts, form first upper and lower surface sections  28 ,  30  which diverge in the aft or rearward direction beginning at the front edge of the lip (defined in part by projections  12 ). The substantially flat, smooth bottom surface  26  of the lip begins where the outwardly inclined section  28  ends. The downwardly inclined lower section  30  becomes inclined outwardly at a location aft of the lip front edge  10  and approximately below where the upper section  28  and the top surface  24  intersect. As a result, the cross-section of the lip initially increases in the aft direction from the lip front edge  10  and then decreases because a second, lower section  32  of the bottom surface  26  is angularly inclined relative to and extends rearwardly towards the upper surface  24  as can be seen in  FIG. 4 . As a result, the lip forms a bulbous enlargement  34  of the cross-section of the lip some distance aft of the front edge of the lip. 
     Referring to  FIGS. 5 and 6 , a digging tooth  36  is conventionally detachably secured to a front end of adapter  16 . The adapter has a main, forward body  38  from which spaced-apart upper and lower legs  40 ,  42  extend in the aft direction. The upper leg has a surface  44  facing the lip which is shaped and oriented complementary to upper surface section  28  of the lip (defined by projections  12 ). Likewise, the lower leg  42  of the adapter has a surface  46  which is shaped and oriented complementary to lower surface section  30  of the lip. 
     In the area  48  generally below where inclined surface  28  and top surface  24  meet, and where the second lower surface section  32  begins, an aft portion  50  of the lower adapter leg is angled upwardly in the aft direction, and the surface of the lower leg opposite thereto is shaped and oriented complementary to the second lower section  32  of the lip. Bolts  52  or similar fasteners extend through appropriate holes  54  in the legs of the adapter, suitably, e.g. threadably, engage the lip, and releasably secure the legs to the lip adjacent the aft ends of the legs, as is shown in  FIG. 5 . Bolt configurations as shown and described, for example, in published U.S. patent application No. US-2010-0162594-A1, which is incorporated herein by reference, are well suited for this purpose. 
     Upper and lower adapter legs  40 ,  42  effectively cradle and embrace the bulbous enlargement  34  of the lip in a mechanically locking configuration. When the connecting bolts are tightened, they slightly deflect the legs and press them against the bulbous enlargement of the lip which provides enhanced stability for the connection and prevents its undesired loosening. At the same time, the adapter is readily and quickly removed from and installed on a projection of the lip by removing the bolts with a wrench or the like manually and/or with hand tools by sliding, wiggling and/or twisting the adapter legs generally sideways relative to the bulbous enlargement  34  to disengage the legs from the lip. 
     In a preferred embodiment, a flat cap  55  can be applied over the upper leg of the adapter. This protects the head of the screw during use of the excavator and forms a smooth, substantially continuous surface from the teeth to the top surface  24  of the lip, which further facilitates the flow of ground material over and past the lip into the container. 
       FIG. 6  is a view substantially identical to  FIG. 5  but shows a cross-section through the lip and a shroud  18  mounted on those lip projections  12  which do not receive an adapter. The shroud has upper and lower rearwardly extending legs  58 ,  60  which are in contact with the upper and lower, inclined lip front sections  28 ,  30  in the same manner in which the legs  40 ,  42  of adapter  16  shown in  FIG. 5  contact the lip, as was described above. A bolt  52  extends through a hole  54  in the upper leg of the shroud and removably secures the latter to the lip.