Patent Publication Number: US-10774498-B2

Title: Robust multi-tool assembly for hydraulic excavators

Description:
PRIORITY 
     This application claims priority based upon GB provisional applications:
         GB-1604983.5, filed 23 Mar. 2016, and,   GB-1701204.8, filed 24 Jan. 2017,       

     FIELD OF THE INVENTION 
     This invention provides a multiple tool assembly relating to rotatable tools secured to the working distal boom end of hydraulic excavators for controlled relative rotation between a working tool and the assembly framework. 
     BACKGROUND 
     The overall form of a hydraulic excavator has been well known for decades. There are many examples of such excavators with a 2-boom stick hydraulically and rotationally secured to work within in a vertical plane, itself rotatable about a vertical axis coincident with a engine/cab combination mounted to a pair of tracks. The position and movement of the distal working end of the stick is controlled typically from a operator&#39;s cab mounted on the excavator. Although this general design profile is common, the range of sizes and shapes varies considerably due to the type and extent of work to be conducted. 
     The most common working tool used with a hydraulic excavator, among many, is a digging bucket rotatably secured to the distal end of the stick for rotation about a horizontal axis. The bucket is independently hydraulically driven in rotation about the horizontal axis by a cylinder positioned to apply hydraulic force between the stick and the bucket. The power of such machines and the amount of energy involved has and continues to increase with increasingly larger, heavier and more difficult materials and includes not only digging but also breaking and shearing, among others. Generally the bucket cylinder and its related hydraulic lines and connections are positioned on the outside of the stick well away from the working parts of the bucket and its various motions. The outside is that part of the operating range which lies outside of the work area between the stick/bucket and an engine/cab. 
     Necessarily, hydraulic excavators are designed to carry out a broad range of construction and demolition duties in extremely adverse and highly variable conditions, including high impact loading during initial contacts and continuing work, abrasive debris and severe vibration while working in all manner of solid, semi-solid and liquidy or mixed materials. Any tool failure or work failure is not only unacceptable but also very dangerous and must occur under tightly controlled conditions. Typically the operator is or prefers to concentrating on the machine interaction with the work area and not exclusively the moving parts of the excavator other than the actual working tool. As such, operational conditions, with or without error or failure, and with or without high energy events. 
     The variety of work types and conditions is exacerbated by location of the work which is often far beyond the reach of support or repair opportunities and even, on occasion, far beyond immediate accident support. 
     In many cases the work being done or which could be done would be facilitated by expanded flexibility in the form and use of the excavator as a whole and by an increase in the speed and continuity of operations. Thus, modern excavators are available with multiple working tools and with quick-connect mounting components adapted for rapid and operator-free changing of at least the primary working tool. 
     While convenient, these requirements bring about mechanical complexity as the bucket or other primary working tool is no longer a permanent fixture at the distal end of the stick. Consequently it is advantageous to secure as many moving parts, particularly relatively fragile and expensive hydraulic parts against the harsh environment in which they are called to operate. 
     To increase utility, in the past traditional bucket arrangements have been coupled with additional support tools such as thumb-like arrangements which operate to secure materials within and against the body of the bucket. Of these, there have been several common types, including:
         1. a fixed retractable thumb secured to the stick,   2. a hydraulic thumb secured between the stick and the bucket for rotation about a single horizontal axis on the stick. The bucket and thumb are in relative rotation and motion during working and carriage of a load.   3. a stick pivot thumb where the thumb rotates on the same pivot point as the original bucket pin, not a secondary weld-on pivot point. A hydraulic cylinder is also directly connected between the thumb and the stick, providing rotation in relation to the bucket. The thumb and the bucket pivot on the same axis providing for maintenance of a constant grip on the load with suitable hydraulic circuits. The pivot eliminates scraping and slippage and reduces risk of release during rotation, reducing complexity, and,   4. more recently a hydraulic thumb secured to the bucket for rotation about a horizontal bucket axis driven by a hydraulic cylinder operating between the thumb and the sick.       

     OBJECTS 
     It is an object of the invention to provide a more robust multi-tool assembly for use with heavy duty hydraulic excavators. 
     It is a further object to provide an excavator working tool assembly with expanded utility. 
     It is a another object to provide particularly, a rake or bucket tool assembly for secure mounting to an excavator stick which assembly includes a separately pivotable thumb, whereby the range of rotation of a thumb is greatly increased while maintaining operating components, particularly bearing surfaces and thumb components, in a protected position while within the work area under control of relative movement. 
     It is a further object to provide a method and procedure for improving the range of motion and utility of multi-use excavator tools while maintaining the robust character of the main working tool. 
     It is a still further object to provide for minimal extra components and minimal interference with bucket or machine operations while isolating thumb components from the full range of the harshest uses of the main working tool. 
     It is yet another object to provide a tool including a rotary hydraulic drive cylinder positioned securely within boundary walls. The exterior armor protects the moving hydraulic parts and flexible lines from the serve working environment to which excavators and their working tools are routinely subjected to. Manufacturing tolerances, and tool variety dictate that tool parts may be spaced apart by a significant and variable distance. 
     Exposure of hydraulic cylinders and lines to severe environments such as excavator operations is a condition to be avoided. Typical hydraulic cylinders completely expose their hydraulic seals and piston rods to these conditions and full protection is difficult to achieve and expensive to implement while making the attachment tool itself cumbersome and heavy, thereby interfering with the ongoing excavator work. 
     It is an object of the invention to reduce excavator tool complexity and cost, reduce size where possible, increase utility across a wider variety of excavator types and models and all the while maintaining rigorous protection protocols in respect of system hydraulics and providing simple controlled operations. 
     It is an object of the invention to provide an excavator tool capable operating in the most demanding conditions for long periods and far from maintenance and repair facilities as the slightest interruption of work schedules by failure or even simple tool switching can be extremely expensive and ruinous to production schedules in such conditions, or elsewhere. 
     THE INVENTION 
     The invention provides a hydraulic excavator tool adapted to be secured to the distal working end of an excavator boom comprising
         a main tool assembly including a tool framework, a spaced apart pair of connection flanges fast with said tool framework, and, a structural tubular casing integral with the tool framework extending across and through the tool framework and through the flanges, plus   a rotary hydraulic actuator within the tubular casing extending between the connection flanges and adapted to provide a rotational drive motion of a drive axle extending between the connection flanges adapted to provide a rotary drive motion of the axle adjacent the connection flanges, and   a working tool framework fast to the axle adjacent each of the connection flanges for rotation of the working tool framework about the drive axle between the tool framework and a working position.       

     The invention also provides a hydraulic excavator tool with the rotary actuator fast with the tubular casing adjacent both of the connection flanges to support the drive axle adjacent both of the connection flanges. 
     The invention also includes a working tool skeletal framework with a pair of working arms spaced apart along the direction of the axle by at least the length of the tubular casing, each fast to the axle, and a working tool remote from the axle spaced apart by the length of the tubular casing. 
     Further the invention provides the axle lying between the working tool and the distal working end of an excavator boom and controlled rotation of more that 45, 60 and 90 degrees relative between the working tool and tool framework. 
     The invention also provides an excavator bucket tool with a controlled rotation thumb tool for relative controlled rotation between the bucket the the thumb about an axle integral with the bucket and between the bucket mount to the distal working end of the bucket and the working teeth. 
     Similarly, controlled and protected rotation about such an tool mounted axle is provided for rake tools and tool couplers. 
    
    
     
       DRAWINGS 
         FIG. 01  is an elevation view of the bucket tool assembly embodiment of the invention in in-use conditions separately shown in sub- FIGS. 01A and 01B  depicting the thumb-bucket combination secured to the distal working end of the excavator boom in fully closed and fully open condition, respectively. 
         FIG. 02  is a perspective view of the working tool assembly of  FIG. 01  adapted in to a rake configuration. 
         FIGS. 03 and 04  are front and side elevations of a variation of the the rake tool assembly of  FIG. 02  shown the tool in fully closed, pinching, partially open and fully open condition in dotted relief in  FIG. 04 . 
         FIG. 05  is an end view of the structural tube and encased rotary hydraulic actuator of  FIGS. 01 through 04  the invention. 
         FIG. 06  is a cross-sectional view of the tube and actuator of  FIG. 05  taken along line A-A in  FIG. 05  and showing the spatial relationship with the secondary arm of a hydraulic excavator. 
         FIG. 07  is a partial perspective view of the rotary tool coupler embodiment of the invention. 
         FIG. 08  is a central cross-section of the coupler embodiment of  FIG. 07  shown an end view of the rotary hydraulic actuator and the range of relative controlled motion between the coupler and the working tool pin and the coupler framework. 
         FIG. 09  shows an internal elevation and an external elevation of the A through D sequence of operations of the coupler embodiment of  FIG. 07 . 
         FIG. 10  shows a partial perspective view of the coupler with the grabbing hook claw bolted to rotary actuator flanges and the rotary axle at each end of the axle adjacent the connection flanges. 
     
    
    
     THE PREFERRED EMBODIMENTS 
     The hydraulic excavator  2  tool  1  of the invention is shown in a side elevation view in  FIG. 01  configured as a bucket  12  plus a gripper thumb  13  connected for controlled relative rotation about axle  14  separate from the main bucket axes of work  10  and  11 .  FIG. 01 a    shows the thumb  13  in a fully closed position which  FIG. 01 b    shown the thumb in the full open position. 
     All of the operating requirements for the tool assembly  1  are within the working area A between the cab  3 , tracks  4 , the primary arm or stick  5  and the secondary arm or stick  6  of the excavator while none of these are in the external area B. Tool assembly  1  is operated hydraulically from the cab completely independently of the bucket  12  or the secondary arm  6  or their operating or connecting linkages and thus is under separate operator control. 
     As is commonly the case, rotation of stick  5  about stick  6  is driven and maintained by linear hydraulic cylinder  7 . Similarly, stick  6  includes a further secondary linear hydraulic cylinder  9  adapted to drive and maintain bucket  12  in rotation about stick  6 . Notably both cylinders and related bearings and linkages  7  and  9  are fully within external area B and are fully protected from work area A by the body of each of the sticks  5  and  9  respectively. 
     Main working tool  1  of the bucket embodiment is secured to secondary stick  6  for pivotal movement about horizontal working axis  10 . The angular position of bucket  1  in respect of stick  6  is driven and maintained by tool linkage  8  mounted between cylinder  9  and a bucket drive horizontal working axis  11  in a traditional and well-known manner which is very comfortable for use by the excavator operator. Axes  10  and  11  are parallel to each other and fitted with very robust bearings. 
     Thumb  13  is mounted to the bucket tool assembly about a 3 rd  parallel and horizontal axis of rotation  14 . Preferably, bucket axis  14  is between the mounting axes  10  and  11  and the distal working end of the bucket tool. Mounting the thumb  13  to the bucket  1  separates the thumb and its mechanisms from the harshest of the work activity carried out by the excavator and bucket combination as it may be independently rotated from a fully engaged position along line  15  in  FIG. 01A  to a fully open or disengaged position along line  16  as shown in FIG.  01 B. 
     The range to open is as shown at item  17  in  FIG. 01A  and as item  18  in  FIG. 01B  as a range to close. 
     The working tool assembly of the invention is shown in the rake tool  19  embodiment depicted in a partially open perspective view in  FIG. 02 . 
     The rake tool  19  includes a rake frame  20  and a plurality of extending rake tines  21  monolithic with the frame  20 , a pair of tool mount flanges  29  and  30  and a drive casing  34 . As with  FIG. 01 , tool mount flanges  29  and  30  provide for horizontal pivot axes  10  and  11  and for a quick tool change between a bucket tool of  FIG. 01  and the rake tool of  FIG. 02  without interference with thumb components. 
     Drive casing  34  is a hollow tubulal structural element tool of rake frame  20 , as by welding, and extends across a substantial proportion of the width of the rake tool  19  so as to include both mounting connecting flanges  29  and  30  and the rake frame  20 . 
     The rake tool  19  may include an inter-tine support framework  25  adjacent the working tips. 
     The thumb  22  is shown in partially open angular position depicted along line  26 . 
     Thumb  22  includes a pair of spaced apart arms  26  monolithic with a horizontal drive rotary hydraulic cylinder for pivotal motion in respect of tool  19  about transverse axis  14  central to the drive cylinder and the drive casing  34 . 
     Thumb may be driven closed along arc  27  towards a fully closed position depicted by line  15  or driven open along arc  28  towards a fully open position depicted at line  16  or even further in rotation. 
     Thumb  22  also includes a thumb framework  24  extending between arms  23 . 
     Thumb  22  encompasses a fully open relief spacing  48  between the arms  23 , the thumb framework  24  and the tool frame  20  as it is mounted to the rotary drive at points external to both the drive casing  34  and the tool framework  20 . 
       FIGS. 03 and 04  show a frontal and side elevation of a variant upon the rake tool of  FIG. 02  shown in fully closed position  31  and an open position in dotted relief in  FIG. 04 . 
     In the embodiment of  FIGS. 03 and 04  the structural casing  34  extends only to a width  35  just slightly less that the inter-arm spacing  36  of thumb arms  23 . 
     As can be seen, spacing  32  between flanges  29  and  30 , including mounting hardware  33 , is fully within the length  35  of casing  64  and also within the nominal width  45  of secondary stick  6 . 
     Since thumb arm width  35  is greater than stick width  45  the thumb  13  is able to rotate from the fully closed position of  FIGS. 03 and 04  to an open position shown in dotted relief if  FIG. 04  as line  26  rotates through arc  28  to a first open position  16   a  and further to open position  16   b  whereat the arms  23  have rotated to the fullest extent past the outer boundaries of stick  6  until rake framework  24  contacts stick  6 . As can be seen, the extent of rotation will vary depending upon the particular embodiment being designed as a smaller thumb frame  24  or longer arms  23  will provide for a larger inter-arm spacing  48   
       FIGS. 05 and 06  are an end elevation of the rotary actuator and a cross-section taken along line A-A of  FIG. 05  in  FIG. 06 . 
     Rotary actuator  40  is generally cylindrical and is mounted monolithically, as by welding, into structural casing tube  34  at least at its horizontal extremities  49  so that non-axially aligned stresses are transmitted through to casing  34  and then the more robust elements of the tool framework and the excavator. Arms  23  are secured to opposite ends of the rotary actuator for rotation on the actuator horizontal axis  14 . Actuator axle bearings  42  are thus in close proximity to extremities  49 . Arm spacing  36  is shown close coupled to casing length  35 . 
     Hydraulic drive lines may be fully engaged outside of work area B and connect through casing  34 . Engagement of hydraulic pressure drives the piston laterally in direction  44  and thus along a spline to rotate axle  41  in either direction through a broad arc as in  28  or larger. 
     The tool coupler embodiment of the invention is shown in  FIGS. 07 through 10  with independent numbering corresponding in element type or function to  FIGS. 01 through 06 . 
     Rotary hydraulic drive cylinder is welded into a protective cylindrical sleeve to form rotary cylinder arrangement RH as in  FIG. 07  preferably at weldment points  106 . Claw G 1  from  FIG. 07  is formed of an opposing pair of grapple claws  104  and  107  (see  FIG. 10 ) with engagement teeth  105 , one affixed at each end of the central x-y axis of arrangement RH for rotation about axis  103  which corresponds to axis  14  in  FIG. 01 through 06 . 
     As can be seen in  FIG. 07  the main working hydraulics of the rotary actuator and its hydraulic lines have been completely isolated from the rigors of the excavating environment with only exterior seals showing, if at all, and no moving (linear) internal parts. This provides for economies of space along the axis  103  and in the remaining body of the coupler C whose volume is now solely occupied by pawl or claw operations. 
       FIG. 08  shows a central vertical cross-section of the rotary cylinder RH of  FIG. 07 . 
     Central x-y axis  103  is provided by the central rotating drive shaft of cylinder RH (R in this view) and rotates about axis  103  preferably about 62 degrees from the fully open position to a fully locked position. In this transition pins  102   a  and  102   b  are placed and then driven from positions  102   aii  to position  102   ai  where it may be captured by pawl S. The rotation of claws G 1  secure pins  102   b  and drive them from positions  102   bii  to  102   bi.    
     Preferably rotary drive RH is only required to work in the range of about 0 to 62 degrees. In the present preferred embodiment the rotary cylinder may be quite short. 
     Once in position  102   bi  the operation of pawl S rotates pawl P into engagement with ratchet R for mechanical security. 
       FIG. 09  shows an internal elevation and an external elevation of the A through D sequence of operations of the coupler embodiment of  FIG. 7 .  FIG. 10  shows another perspective view of the rotary cylinder assembly RH of this embodiment of the invention. Outer tubular structural casing is fixed as by welding to cylinder body as at weldments  106 . Claws G 1  are shown as elements  104  and  107  at opposite ends of the tubular casing and connection flanges assembly and are fixed to the rotary axle for rotation about axis  103 . Between elements  104  and  107  are a pair of ratchet pawls  201  and  203  separated by spacers  202  and  204  and the whole affixed into a single rotating claw assembly supported on the end arms adjacent the connecting flanges and the rotary cylinder axle. 
     Once the coupler C is encased in its armor cover casing the isolation of the moving components from the work environment is complete and the user is provided with a robust and compact working coupler tool. 
     It should be understood that components and features provided in respect of one embodiment described herein can be interchanged with corresponding features in other embodiments, insofar as that is physically possible, unless otherwise stated. 
     The scope of the patent protection sought herein is defined by the accompanying claims. The apparatuses and procedures shown in the accompanying drawings and described herein are examples.