Patent Publication Number: US-6910290-B1

Title: Excavator bucket with retractable scarifier and improved actuator mounting

Description:
FIELD OF THE INVENTION 
   This invention relates to excavator buckets, more specifically, to an excavator bucket including a retractable scarifier useful in breaking-up and leveling ground when attached to a powered device such as skid steer loader or the like. 
   BACKGROUND OF THE INVENTION 
   All-wheel drive skid-steer loaders have gained in popularity due to their compact size and maneuverability. The conventional skid-steer loaders are configured so that a variety of separate attachments can be coupled thereto such as an excavator bucket, a scarifier, a dozer blade, etc. 
   Oftentimes when using a skid-steer loader with a bucket attachment, it is necessary to break-up hard ground. Thus, an operator is required to stop the operation of the loader and physically remove the bucket to put on a scarifier having teeth to break-up compacted or hard ground. Many operators find this to be a great loss in work time and often choose to just break-up the ground with the bucket, thus creating additional costs and loss of time to repair/replace the misused equipment. 
   There are conventional buckets having teeth that protrude from the lower front edge of the bucket. These buckets work well when digging and ground-breaking are needed but, because the teeth are permanently fixed to the front edge of the bucket, the teeth hinder the process of smoothing and packing soil because the points of the teeth leave lines in the ground during back-dragging of the bucket. 
   My U.S. Pat. No. 6,546,650 discloses a bucket including a retractable scarifier so that the bucket can be used without obstruction from the scarifier when the scarifier is not required, and so that the scarifier can be employed when needed to break-up hard ground. A hydraulic cylinder or actuator is mounted generally vertically with respect to the rear wall of the bucket to cause movement of the scarifier teeth. Although these type of bucket/scarifiers are effecting in operation, it has been determined that bucket/scarifiers with the vertically mounted cylinder may not be employed on certain skid steers having oversized tires since the cylinder may interfere with the tires. 
   There is a need to provide a bucket having a retractable scarifier with an improved actuator mounting so that the bucket can be used on any type of powered device without obstructing components of the device. 
   SUMMARY OF THE INVENTION 
   An object of the invention is to fulfill the need referred to above. In accordance with the principles of the present invention, this objective is obtained by providing a combined bucket and scarifier device including a bucket having a bottom wall, a rear wall, and two side walls coupled to the bottom wall and the rear wall to define an interior space. The bucket has an open front end and the rear wall is generally rectangular having a long axis. A scarifier is operatively associated with the bucket. The scarifier has a plurality of teeth constructed and arranged to be moved with respect to the bucket between a stored, inoperative position, and an operative position with portions of the teeth extending outwardly with respect to a portion of the bottom wall of the bucket. Actuating structure is mounted with respect to the bucket. The actuating structure includes a cylinder unit having a piston, and linkages coupled between the piston and teeth such that movement of the piston causes movement of the linkages thereby causing movement of the teeth between the inoperative and operative positions. The cylinder unit is mounted with respect to the rear wall such that the piston extends generally along the long axis of the rear wall. 
   Other objects, features and characteristics of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts and economics of manufacture will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form a part of this specification. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is rear perspective view of a device providing a combined bucket and scarifier in accordance with the principles of the present invention, shown with a piston of a cylinder unit retracted and thus scarifier teeth in an extended, operative position. 
       FIG. 2  is a side view, partially in section, of the apparatus of  FIG. 1  shown. 
       FIG. 3  is rear perspective view of a device providing a combined bucket and scarifier in accordance with the principles of the present invention, shown with the piston of a cylinder unit extended and thus scarifier teeth in a retracted, inoperative position. 
       FIG. 4  is a side view, partially in section, of the apparatus of  FIG. 3 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EXEMPLARY EMBODIMENT 
   With reference to  FIGS. 1 and 2 , a device providing a combined bucket and scarifier in accordance with the invention is shown generally indicated at  10 . The device  10  is constructed and arranged to be attached to, for example, a conventional skid-steer loader such as the type manufactured by the Melroe Company under the name Bobcat®. The device  10  can be employed on any suitable powered device such as skid steers having driving tracks or wheels, or compact utility loaders, such as, for example, the Toro® Dingo. 
   The device  10  includes a bucket, generally indicated at  12 , for use in loading trucks, smoothing the ground by back dragging, etc. The bucket  12  has a bottom wall including a generally planar horizontal portion  14  and a portion  15  extending upwardly at an angle with respect to the planar portion  14 , a rear wall  16 , a left side wall  17  and a right side wall  18  coupled to the bottom wall  14  and the rear wall  16  to define an interior space  20  for containing soil or the like. The rear wall  16  is generally rectangular defining a long axis A. The bucket  12  has open front end for access to the interior space  20 . The angled portion  15  of the bottom wall defines a space  19  at the underside of the bucket for containing a scarifier, generally indicated at  22 , as will be explained in more detail below. Mounting structure  23  is coupled to the rear wall  16  for removably coupling the device  10  to a loader such as a conventional compact utility loader or skid-steer loader. The mounting structure  23  can be integral with the rear wall  16  or attached thereto. 
   The scarifier  22  is operatively associated with the bucket  12 . The scarifier  22  includes a plurality of teeth  24  constructed and arranged to be movable with respect to the bucket  12  between a retracted, inoperative position ( FIGS. 3 and 4 ) substantially within space  19  so as not to obstruct the bottom wall portion  14  of the bucket  12 , and an extended, operative position ( FIGS. 1 and 2 ). In the operative position, at least a portion of the teeth  24  extend outwardly from the space  19  beyond an extent of the bottom wall portion  14 . As shown in  FIG. 2 , in the operative position thereof, the teeth  24  extend at an angle with respect to the wall portion  14  such that distal ends  26  of the teeth face rearward so that to use the teeth  28  in a ripping operation, the bucket  12  must be dragged backwardly. 
   The device  10  includes an actuating structure, generally indicated at  28 , mounted with respect to the bucket  12  and constructed and arranged to rotate the teeth  24  simultaneously to move the teeth between the inoperative and operative positions. In the embodiment, the actuating structure  28  includes at least one hydraulic cylinder unit  30  and linkages associated with the teeth  24  for moving the teeth  24 . In accordance with the invention, cylinder unit  30  is mounted so that a piston  31  thereof extends generally along the long axis A of the rear wall  16  so as not to create an obstruction at the rear of the device  10 . In the illustrated embodiment, the cylinder unit  30  is mounted to a top edge  32  of the rear wall  16 . The cylinder unit  30  is constructed and arranged to be fluidly coupled to the hydraulics of the conventional device to which it is attached (e.g., loader) via connectors  33 . 
   The teeth  24  are coupled to a common rotatable shaft  34 . The linkages include a first linkage  36  pivotally coupled at one end thereof to the piston  31 . A transfer linkage or shaft  38  is coupled to the first linkage  36 . A second linkage  40  is pivotally coupled to the transfer linkage  38 . One end  42  of a third linkage, in the form of a rod  44 , is pivotally coupled to the second linkage  42  and the other end  46  of the rod  44  is pivotally coupled to a rocker linkage  48  that pivots about pin  49 . The rocker linkage  48  is pivotally coupled to a fourth linkage  50  that is pivotally coupled with a portion of the common rotatable shaft  34 . 
   Thus, with reference to  FIGS. 1 and 2 , when the piston  31  is retracted into the cylinder unit  30 , the first and second linkages  36  and  40 , respectively, rotate causing the rod  44  to move generally upwardly (in the direction of arrow B) causing rocker linkage  48  and linkage  50  to rotate, which in turn rotates the common rotatable shaft  34  causing the teeth  24  to rotate to the extended, operative position. 
   With reference to  FIGS. 3 and 4 , to retract the teeth,  24 , the piston  31  is extended from the cylinder unit  30  causing the first and second linkages  36  and  40 , respectively, to rotate causing the rod  44  to move generally downwardly (in the direction opposite of arrow B) causing rocker linkage  48  and linkage  50  to rotate, which in turn rotates the common rotatable shaft causing the teeth  24  to rotate to the retracted, inoperative position. 
   Although one cylinder unit  30  and associated linkages are shown, it can be appreciated that a hydraulic cylinder unit and linkages can be provided near each end of the bucket  12  and operated by a common hydraulic line of the vehicle to which the bucket is attached. 
   The cylinder unit  30  and thus retraction and extension of the teeth  24  is controlled by a lever of the device to which it is attached (e.g., utility loader, skid-steer loader) that controls the application of hydraulic fluid to the hydraulic cylinder unit(s)  30 . When the teeth  24  are not in use, they are retracted or stored so as not to interfere with the normal use of the bucket  12 . When the teeth  24  are needed to break-up the hard, packed ground, the operator would only need to operate the lever to lower the teeth  24 . The depth of engagement of the teeth  24  with the ground is limited by the underside of the bucket (bottom wall  14 ). 
   Thus, with the cylinder unit  30  being mounted generally horizontally with respect to the bucket  12  so that a side  52  thereof is substantially flush with the rear wall  16 , the cylinder unit  30  advantageously does not become an obstruction at the rear of the bucket. The linkages between the piston  31  of the cylinder unit  30  ensure transfer of linear, generally horizontal movement of the piston, to rotational movement of the common rotatable shaft that carries the teeth  24 . Although particular linkages are illustrated, any linkages can be provided that transfer the linear motion of the piston  31  to rotational movement of the teeth  24 . 
   The foregoing preferred embodiments have been shown and described for the purposes of illustrating the structural and functional principles of the present invention, as well as illustrating the methods of employing the preferred embodiments and are subject to change without departing from such principles. Therefore, this invention includes all modifications encompassed within the spirit of the following claims.