Patent Abstract:
An excavating machine, representatively a tracked excavator has a boom stick portion on which both an excavating bucket and a hydraulic breaker are mounted for hydraulically driven pivotal movement between first and second limit positions. The bucket may be operated independently of the breaker for digging operations. Similarly, the breaker may be operated independently of the bucket for refusal material-breaking operations. The same excavating machine may now use the bucket and breaker in a rapid and continuous exchange to permit frequent removal of small quantities of broken refuse material with the bucket, exposing the bucket and breaker to fresh refuse material. A lubricatable attachment system is disclosed for improved breaker system connectivity that permits quick installation and removal of the breaker. An alternative deployment system is disclosed having a rotary actuator for efficient and rapid deployment without the need for an additional hydraulic cylinder.

Full Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]    This application is a Continuation-in-part of co-pending U.S. application Ser. No. 10/150,057 filed May 17, 2002, now U.S. Pat. No. 6,751,896, which is a Continuation-in-part of copending U.S. application Ser. No. 09/624,099 filed Jul. 24, 2000, now U.S. Pat. No. 6,430,849 . 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Technical Field  
           [0003]    The present invention generally relates to a material handling apparatus and, in a preferred embodiment thereof, more particularly relates to an excavating apparatus, representatively a tracked excavator, having operatively attached to the stick portion of its boom a specially designed combination bucket and breaker structure which uniquely permits the excavator operator to selectively carry out either digging or refusal material breaking tasks without having to change out equipment on the stick.  
           [0004]    2. Description of Related Art  
           [0005]    Large scale earth excavation operations are typically performed using a powered excavating apparatus, such as a tracked excavator, having an articulated, hydraulically pivotable boom structure with an elongated, pivotal outer end portion commonly referred to as a “stick”. Secured to the outer end of the stick is an excavating bucket which is hydraulically pivotable relative to the stick between “closed” and “open” positions. By pivotally manipulating the stick, with the bucket swung to a selected operating position, the excavator operator uses the bucket to forcibly dig into the ground, scoop up a quantity of dirt, and move the scooped up dirt quantity to another location, such as into the bed of an appropriately positioned dump truck.  
           [0006]    A common occurrence during this conventional digging operation is that the bucket strikes refusal material (in excavation parlance, a material which “refuses” to be dug up) such as rock which simply cannot be broken and scooped up by the bucket. When this occurs it is typical practice to stop the digging operation, remove the bucket from the stick, and install a hydraulically operated “breaker” on the outer end of the stick in place of the removed bucket. The breaker has, on its outer end, an oscillating tool portion which rapidly hammers the refusal material in a manner breaking it up into portions which can be subsequently dug up. After the breaker has been utilized to break up the refusal material, the operator removes the breaker from the stick, replaces the breaker with the previously removed bucket, and resumes the digging operation with the bucket.  
           [0007]    While this procedure is easy to describe, it is a difficult, laborious and time-consuming task for the operator to actually carry out due to the great size and weight of both the bucket and breaker which must be attached to and then removed from the stick , and the necessity for the operator to climb into and out of the high cab area of the excavator (often in inclement weather) to effect each bucket and breaker changeout on the stick. This sequence of bucket/breaker/bucket changeout, of course, must be laboriously repeated each time a significant refusal area is encountered in the overall digging process.  
           [0008]    A previously utilized alternative to this single excavator sequence is to simply provide two excavators for each digging project—one excavator having a bucket attached to its boom stick, and the second excavator having a breaker attached to its boom stick. When the bucket-equipped excavator encounters refusal material during the digging process, it is simply moved away from the digging site, and the operator climbs down from the bucket-equipped excavator, walks over to and climbs up into the breaker-equipped excavator, drives the breaker-equipped excavator to the digging site, and breaks up the encountered refusal material. Reversing the process, the operator then switches to the bucket-equipped excavator and resumes the digging process to scoop up the now broken-up refusal material.  
           [0009]    While this digging/breaking technique is easier on the operator, it is necessary to dedicate two large and costly excavators to a given digging task, thereby substantially increasing the total cost of a given excavation task. A modification of this technique is to use two operators—one to operate the bucket-equipped excavator, and one to operate the breaker-equipped excavator. This, of course, undesirably increases both the manpower and equipment cost for a given excavation project.  
           [0010]    Another attempt to solve this problem is disclosed in U.S. Pat. No. 6,085,446 and U.S. Pat. No. 4,100,688 for an excavating machine having a motorized milling tool attached to the back of the bucket. A primary disadvantage of these devices is complexity, cost, and reliability. Another disadvantage is the weight that must be continuously carried by the bucket. The additional weight substantially reduces the carrying capacity and mobility of the bucket. Another disadvantage to the device of U.S. Pat. No. 6,085,446 is that the back of the bucket cannot be used to smooth or pad the soil, as is a well-known practice in the industry. Another disadvantage is that surface rock is not subject to an overburden pressure, so it generally fails faster under compression and impact forces than by the shearing forces of a scrapping and gouging rotary drilling tool.  
           [0011]    Another attempt to solve this problem is disclosed in U.S. Pat. No. 4,070,772 for an excavating machine having a hydraulic breaker housed inside, or on top of, the boom stick. A primary disadvantage of this device is that it is extremely complex and expensive. Another disadvantage of this device is that it cannot be retrofit to existing excavators. Another disadvantage of this device is that the size of the breaker is limited. Another disadvantage of this device is that the bucket must be fully stowed to access the breaker and vice versa, making simultaneous operation impractical.  
           [0012]    A more recent attempt to solve this problem is disclosed in U.S. Pat. No. 5,689,905 for another excavating machine having a hydraulic breaker housed inside, or on top of, the boom stick. In this device, the chisel portion of the breaker is removed when not in use. A primary disadvantage of this device is that it fails to permit immediate, unassisted switching from breaker to bucket, and thus simultaneous operation is impossible. Another disadvantage of this device is that it requires manual handling of the extremely heavy chisel tool each time the operator desires to convert to a breaker or bucket operation. Another disadvantage of this device is that it is extremely complex and expensive. Another disadvantage of this device is that it cannot be retrofit to existing excavators.  
           [0013]    As can be readily appreciated from the foregoing, a need exists for an improved technique for carrying out the requisite digging and refusal material-breaking portions of an overall excavation operation in a manner eliminating or at least substantially eliminating the above-mentioned problems, limitations and disadvantages commonly associated with conventional digging and breaking operations. It is to this need that the present invention is directed.  
         SUMMARY OF THE INVENTION  
         [0014]    In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, an excavating machine, representatively a tracked excavator, is provided with a specially designed pivotable boom stick assembly that includes a boom stick having first and second excavating tools secured thereto for movement relative to the boom stick. Illustratively, the first excavating tool is an excavating bucket secured to the boom stick for pivotal movement relative thereto between a first position and a second position, and the second tool is a breaker secured to the boom stick for pivotal movement relative thereto between a stowed position and an operative position.  
           [0015]    A hydraulically operable drive apparatus is interconnected between the boom stick and the bucket and breaker and is useable to pivotally move the bucket between its first and second positions, and to pivotally move the breaker between its stowed and operative positions. Representatively, the drive apparatus includes a plurality of hydraulic cylinder assemblies operatively interconnected between the boom stick and the bucket and breaker.  
           [0016]    The bucket, when the breaker is in its stowed position, is movable by the drive apparatus to the second bucket position and is useable in conjunction with the boom stick, and independently of the breaker, to perform a digging operation. The breaker, when the bucket is in its first position, is movable by the drive apparatus to the breaker&#39;s operative position and is useable in conjunction with the boom stick, and independently of the bucket, to perform a breaking operation. Accordingly, the excavating machine may be advantageously utilized to perform both digging and breaking operations without equipment changeout on the boom stick.  
           [0017]    Another advantage of the present invention is that the bucket can be operated without fully stowing the breaker. Likewise, the breaker may be operated without the necessity to fully extend the bucket. This increases the efficiency of the excavation process by providing immediate access to each of the tools, without delay. Another advantage of this capability is that it further increases the efficiency of the excavation process by rendering the bucket available to frequently scrape away the freshly generated cuttings so the breaker tool is always exposed to fresh refusal material, avoiding operation against previously generated cuttings. Another advantage of this capability is that by avoiding operation against previously generated cuttings, the breaker tool will last longer.  
           [0018]    In an illustrated preferred embodiment thereof, the excavating machine is also provided with control circuitry coupled to the drive apparatus and useable to operate it. Representatively, the control circuitry includes a hydraulic flow circuit in which the drive apparatus is interposed; a flow controller operative to electively reverse the direction of hydraulic fluid flow through a portion of the hydraulic flow circuit; a diverting valve apparatus interconnected in the hydraulic flow circuit and operable to selectively route hydraulic fluid through the hydraulic flow circuit to (1) a first portion of the drive apparatus associated with the bucket, or (2) a second portion of the drive apparatus associated with the breaker; and a switch structure useable to selectively operate the diverting valve apparatus.  
           [0019]    In another illustrated preferred embodiment of the present invention, a breaker and deployment system is disclosed, having a mounting bracket attached to the underside and lower end of the boom stick. A breaker is pivotally attached to a first pivot on the bracket. In the preferred embodiment, the first pivot is bifurcated. A hydraulic cylinder is pivotally attached at a second pivot on the bracket, in close proximity to the first pivot. The hydraulic cylinder is pivotally attached to the breaker at a third pivot. This embodiment has the advantage of requiring only one hydraulic cylinder. This embodiment has the additional advantage of using a much shorter hydraulic cylinder. This embodiment has the additional advantage of rapid deployment and retraction of the breaker. This embodiment has the additional advantage of a more stable and durable assembly during use. This embodiment has the additional advantage of being much easier and faster to install or remove. This embodiment has the additional advantages of being less expensive to manufacture, install, and service. This embodiment has the additional advantage of resulting in an increased range of motion of the deployed tool. This embodiment has the additional advantage of providing protection for the hydraulic cylinder when the tool is deployed and operational. This embodiment has the additional advantage of resulting in a less obstructive configuration of the hydraulic cylinder in relation to the boom stick when deployed.  
           [0020]    In another illustrated preferred embodiment of the present invention, a bracket is attached to the inside and lower end of the boom stick. A breaker is pivotally attached to a first pivot on the bracket. A latch-lock assembly is mounted to, and between, the boom stick and the breaker. This embodiment has the advantage of preventing undesired, partial deployment of the breaker from the vibration and impact forces encountered during operation of the bucket. In a preferred embodiment, the latch-lock assembly comprises a slide latch located in a guide box attached to the boom stick for latching engagement with a strike attached to the breaker assembly. In another preferred embodiment, the latch-lock assembly comprises a ball latch attached to the boom stick for latching engagement with a strike ball attached to the breaker assembly.  
           [0021]    In another illustrated preferred embodiment of the present invention, a shock absorbing retraction stop is attached to the boom stick. This prevents damage to the breaker and the boom stick when the breaker is in the stowed position, encountering vibration and impact forces during operation of the bucket.  
           [0022]    In another illustrated preferred embodiment of the present invention, a bracket is attached to the underside and lower end of the boom stick. A breaker is pivotally attached to a first pivot on the bracket. Deployment of the breaker is made by the force of gravity acting on the breaker, upon release of the latch-lock assembly. In this embodiment, a controllable hydraulic cylinder is unnecessary to forcibly move the breaker. The breaker may be stowed by retracting the bucket into the breaker, thus forcing it upwards and against the boom stick until the latch-lock assembly can be engaged to secure the breaker in place. This embodiment has the advantage of being easily retrofit onto excavating machines without modification of the hydraulic system. An additional advantage of this embodiment is the lower cost of materials and installation. Optional to this embodiment, an uncontrolled hydraulic or pneumatic cylinder may be used to prevent free fall of the breaker upon release of the latch-lock. An advantage of this embodiment is increased safety.  
           [0023]    In another illustrated preferred embodiment of the present invention, a bracket is attached to the underside and lower end of the boom stick. An extension stop is attached to the bracket, engageable with the breaker. One advantage of this embodiment is that it adds to the operator&#39;s control of the breaker tool. Another advantage of this embodiment is that the extension stop transmits a component of the impact force from the breaker directly to the boom stick, which reduces the reaction forces on the hydraulic cylinder, thus extending the life of the hydraulic cylinder. Another advantage of this embodiment is that the extension stop prevents over-extension of the breaker away from the boom stick, which has been shown to result in damage to the hydraulic cylinder used to deploy the breaker. Another advantage of this embodiment is that it is also useful in the gravity deployment embodiment disclosed above and elsewhere herein, to prevent excessive movement of the breaker during operation. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    [0024]FIGS. 1 and 2 are simplified, somewhat schematic side elevational views of a representative excavating machine illustrating the variable positioning available for a bucket and breaker simultaneously carried by the stick portion of its boom.  
         [0025]    [0025]FIGS. 3A and 3B are schematic diagrams of a specially designed hydraulic and electrical circuit used to control the pivotal orientations of the bucket and breaker relative to the boom stick.  
         [0026]    [0026]FIGS. 4, 5 and  6  are simplified, somewhat schematic side elevational views of a representative excavating machine, fitted with a preferred embodiment of a breaker and deployment system of the present invention. These figures illustrate the deployment of the breaker from the stowed position.  
         [0027]    [0027]FIG. 7 is an isometric view of a preferred embodiment of a breaker portion of the breaker and deployment system of the present invention.  
         [0028]    [0028]FIG. 8 is an exploded view of a preferred embodiment of a breaker portion of the breaker and deployment system of the present invention.  
         [0029]    [0029]FIG. 9 is a top view of a preferred embodiment of the bracket of the present invention.  
         [0030]    [0030]FIG. 10 is a side view of a preferred embodiment of the bracket of the present invention.  
         [0031]    [0031]FIG. 11 is an isometric view of a preferred embodiment of the bracket of the present invention.  
         [0032]    [0032]FIG. 12 is a side-sectional view of a preferred embodiment of the breaker and deployment system of the present invention.  
         [0033]    [0033]FIG. 13 is a side-sectional view of a preferred embodiment of the breaker and deployment system of FIG. 12, showing the breaker fully deployed.  
         [0034]    [0034]FIG. 14 is a bottom sectional view of a preferred embodiment of the breaker and deployment system of the present invention  
         [0035]    [0035]FIG. 15 is a side view of the preferred embodiment of the breaker and deployment system shown attached to the boom stick of an excavating machine, with a breaker assembly in the fully retracted and latched closed.  
         [0036]    [0036]FIG. 16 is a side view of the preferred embodiment of the breaker system of FIG. 15, with the breaker system unlatched and in a fully extended and stopped position.  
         [0037]    [0037]FIG. 17 is an isometric view of the preferred embodiment of the breaker system of FIGS. 15 and 16, with the breaker system shown in a fully extended and stopped position.  
         [0038]    [0038]FIG. 18 is an isometric view of the preferred embodiment of the breaker system of FIG. 17, disclosing an alternative latch-lock assembly.  
         [0039]    [0039]FIG. 19 is a side view of a preferred embodiment of a gravity deployment system of the present invention, showing the breaker on an excavating machine in the extended position.  
         [0040]    [0040]FIG. 20 is a side view of the preferred embodiment of the gravity deployment system of FIG. 19, showing the relationship between the bucket, the breaker, and the boom stick, as the bucket is retracted to retract the gravity deployed breaker.  
         [0041]    [0041]FIG. 21 is a side view of the preferred embodiment of the gravity deployment system of FIGS. 19 and 20, showing complete retraction and latching of the breaker by retraction of the bucket.  
         [0042]    [0042]FIG. 22 is a partial perspective view of an alternative embodiment of the present invention in which a hydraulic rotary actuator is employed to move the breaker assembly relative to the boom stick.  
         [0043]    [0043]FIG. 23 is an isometric section view of the rotary actuator of the embodiment of FIGS. 22, and  23  through  25 .  
         [0044]    [0044]FIG. 24 is an side view of the alternative embodiment of FIG. 22.  
         [0045]    [0045]FIG. 25 is a top view of the alternative embodiment of FIGS. 22 and 23.  
         [0046]    [0046]FIG. 26 is a partial section view of an alternative bracket assembly for securing the breaker assembly to the boom stick.  
         [0047]    [0047]FIG. 27 is a left-side view of a portion of the alternative bracket assembly of FIG. 26.  
         [0048]    [0048]FIG. 28 is an end section view of the portion of the alternative bracket assembly of FIGS. 26 and 27. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0049]    Illustrated in simplified form in FIGS. 1 and 2 is an earth excavating machine which is representatively in the form of a tracked excavator  10  having a body portion  12  supported atop a wheeled drive track section  14  and having an operator cab area  16  at its front or left end. While a tracked excavator has been illustrated, it will be readily appreciated by those of skill in this particular art that the principles of the present invention, as later described herein, are equally applicable to other types of earth excavating machines including, but not limited to, a wheeled excavator and a rubber-tired backhoe. It is further understood that the invention may assume various orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in appended claims. Hence specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.  
         [0050]    A conventional articulated boom structure  18  projects forwardly from excavator body portion  12  and includes an elongated base portion  20  and a stick portion  22 . The right or inner end of boom base portion  20  is pivotally secured to body portion  12 , adjacent the front end thereof, and boom base portion  20  is pivotable in a vertical plane, toward and away from the ground, by means of hydraulic cylinder assemblies  24  (only one of which is visible in FIGS. 1 and 2) disposed on opposite sides of boom base portion  20  and interconnected between a pivot location (not visible) on excavator body portion  12  and a pivot location  26  on boom base portion  20 .  
         [0051]    Upper end  22   a  of boom stick  22  is connected to the left or outer end of boom base portion  20 , at pivot location  28 , and is forcibly pivotable in a vertical plane about pivot location  28 , toward and away from the front end of the excavator body  12 , by means of a hydraulic cylinder assembly  30  operatively interconnected between a pivot location  32  on boom base portion  20  and a pivot location  34  on the upper end  22   a  of boom stick  22 .  
         [0052]    A conventional excavating bucket  36  is pivotally secured to lower end  22   b  of stick  22 , at pivot location  38 , and is further secured to the lower end of stick  22  by a conventional pivotal drive bar linkage  40 ,  42 . A hydraulic cylinder assembly  44  is pivotally interconnected between a pivot location  46  on upper end  22   a  of stick  22  and a pivot location  48  on drive bar linkage  40 ,  42 . The hydraulic cylinder assembly  44  may be utilized to pivot bucket  36  relative to lower end  22   b  of stick, in a vertical plane toward and away from the front end of excavator body  12 , between (1) a solid line, fully open position (see FIGS. 1 and 2) in which bucket  36  is disposed on the front side of stick  22  with its open side facing generally downwardly, and (2) a dotted line, fully closed position  36   b  (see FIG. 1) in which bucket  36  is disposed on the right side of stick  22  with its open side facing generally upwardly. And, of course, bucket  36  may be pivoted to a selected dotted line operating position  36   a  (see FIG. 1) somewhere between these two pivotal limit positions.  
         [0053]    According to a key aspect of the present invention, a breaker  50  is mounted on stick  22  in addition to excavating bucket  36 . In a manner subsequently described herein, this permits the same powered excavating apparatus  10  to uniquely perform both digging and breaking operations without the previous necessity of having to perform repeated tool changeouts on stick  22  or having to provide two separate powered excavating machines—one to dig and one to break.  
         [0054]    Breaker  50  has a body section  52  with inner and outer ends  52   a  and  52   b . Carried on the outer end  52   b  is an elongated, longitudinally reciprocable breaking tool  54  which is forcibly reciprocated in response to selective transmittal to breaker  50  of pressurized hydraulic fluid via suitable hydraulic lines (not shown). Inner breaker body end  52   a  is pivotally connected, at pivot location  56 , to a suitable bracket  58  anchored to lower stick end  22   b  and projecting outwardly from its rear side. Outer breaker body end  52   b  is pivotally connected, at pivot location  60 , to the rod ends of a pair of hydraulic cylinder assemblies  62  (only one of which is visible in FIGS. 1 and 2) pivotally connected at their opposite ends to upper stick end  22   a  at pivot location  64 .  
         [0055]    Hydraulic cylinder assemblies  62  are selectively operable, as later described herein, to forcibly pivot breaker  50  between (1) a solid line stowed or fully open position (see FIGS. 1 and 2) in which breaker body  52  extends upwardly along and generally parallel to the inner side of stick  22 , with reciprocable breaker tool  54  positioned adjacent upper stick end  22   a , and (2) a dotted line fully closed operational position  50   a  (see FIG. 2) in which the breaker body extends downwardly beyond lower stick end  22   b , at an obtuse angle to the length of stick  22 , with reciprocable breaker tool  54  pointing downwardly as viewed in FIG. 2. Of course, breaker  50  may also be positioned at any selected pivotal orientation between these two illustrated pivotal limit positions.  
         [0056]    As can be seen by comparing FIGS. 1 and 2, with breaker  50  in its solid line stowed orientation (see FIGS. 1 and 2), bucket  36  may be freely pivoted between its solid and dotted line limit positions  36  and  36   b  (see FIG. 1), and used in digging operations, without interference from stowed breaker  50 . Similarly, with bucket  36  in its fully open solid line pivotal orientation (see FIGS. 1 and 2), breaker  50  can be swung downwardly from its solid line stowed orientation (see FIGS. 1 and 2) to a selected dotted line operating orientation (see FIG. 2), and used to break up refusal material, without interference from bucket  36 . Thus, either bucket  36  or breaker  50  may be used independently of the other without the necessity of excavation equipment changeout on boom stick  22 .  
         [0057]    The present invention thus provides an excavating machine or apparatus having a uniquely operative boom stick assembly  66  (see FIGS. 1 and 2) which includes stick  22 , two independently operable excavation tools (representatively, excavating bucket  36  and breaker  50 ) each carried on the stick  22  for movement relative thereto between first and second limit positions, and drive apparatus (representatively the hydraulic cylinder assemblies  44 ,  62 ) interconnected between stick  22  and bucket  36  and breaker  50  and operable to variably position them relative to stick  22 .  
         [0058]    Using the representative excavating machine  10 , a typical digging and breaking operation can be carried out as follows. With breaker  50  in its solid line stowed orientation (see FIGS. 1 and 2), and bucket  36  pivoted to a suitable operational orientation (for example, the dotted line orientation  36   a  shown in FIG. 1), the operator carries out a digging operation in a conventional manner. When refusal material, such as rock, is encountered and cannot be scooped up with bucket  36 , the operator simply pivots bucket  36  back to its fully open, solid line position (see FIGS. 1 and 2), pivots breaker  50  away from its solid line stowed orientation (see FIGS. 1 and 2) to a selected operational orientation (for example, the dotted line orientation  50   a  shown in FIG. 2), and hydraulically operates breaker  50  to break up the refusal material.  
         [0059]    After this breaking task is completed, the operator simply pivots deployed breaker  50  back to its solid line, stowed orientation (see FIG. 2), pivots bucket  36  away from its solid line fully open orientation (see FIG. 1) to a selected dotted line orientation, scoops up the now broken refusal material, and resumes the digging operation using bucket  36 . Accordingly, both the digging and breaking portions of an overall excavation task may be performed by the machine operator without leaving cab area  16  or having to effect an equipment changeout on stick  22 .  
         [0060]    Schematically depicted in FIGS. 3A and 3B is a specially designed hydraulic/electric circuit  70  used to selectively pivot bucket  36  and breaker  50  between their previously described limit positions relative to stick  22 . Circuit  70  includes bucket hydraulic cylinder assembly  44 ; breaker hydraulic cylinder assemblies  62 ; a manually operable hydraulic bucket/breaker pivotal position controller  72 ; a pair of solenoid operated hydraulic diverter valves  74 ,  76 ; and an electrical bucket/breaker selector switch  78 .  
         [0061]    Hydraulic cylinder assemblies  44  and  62  are of conventional construction, with each of them having a hollow cylinder  80 , a piston  82  reciprocally mounted in the cylinder  80 , and a rod  84  drivably connected to piston  82  and extending outwardly through an end of cylinder  80 . Hydraulic bucket/breaker position controller  72  is appropriately positioned in cab area  16  and has a control member  86  that may be manually moved in the indicated “close” and “open” directions. Similarly, electrical bucket/breaker selector switch  78  is appropriately positioned in cab area  16  and has a switch member  88  that may be manually toggled to either a “breaker” position or a “bucket” position. Each of the hydraulic diverter valves  74 ,  76  has, from left to right as viewed in FIGS. 3A and 3B, a dead end port  90 , a through-flow passage  92 , an interconnected pair of turnaround ports  94 , and a dead end port  96 . Additionally, each valve  74 ,  76  has an electrical solenoid portion  98  operative as later described herein to shift the porting in its associated valve as schematically indicated by the arrows  100  in FIG. 3B.  
         [0062]    DC electrical power supply lines  102 ,  104  are connected to the input side of bucket/breaker selector switch  78 , and DC electrical control output lines  106 ,  108  are interconnected between the output side of switch  78  and valve solenoids  98 . With selector switch member  88  toggled to its “bucket” position, no electrical power is supplied to solenoids  98 , and ports and passages  90 ,  92 ,  94 ,  96  of hydraulic diverter valves  74 ,  76  are in their FIG. 3A orientations relative to the balance of schematically depicted circuit  70 . When selector switch member  88  is toggled to its “breaker” position, DC electrical power is transmitted to the solenoids  98  via electrical lines  106  and  108  to thereby shift the valve porting leftwardly relative to the balance of circuit  70  as schematically indicated by arrows  100  in FIG. 3B.  
         [0063]    With electrical switch member  88  in its “bucket” position, hydraulic cylinder assemblies  44  and  62 , hydraulic position control  72 , and hydraulic diverter valves  74  and  76  are hydraulically interconnected as follows as viewed in the schematic FIG. 3A circuit diagram.  
         [0064]    Main hydraulic power lines  110 ,  112  are connected to the bottom side of position controller  72 ; hydraulic line  114  is interconnected between the right end of position controller  72  and through-flow passage  92  of diverter valve  76 ; hydraulic line  116  is interconnected between through-flow passage  92  of diverter valve  76  and the upper end of cylinder portion  82  of bucket hydraulic cylinder assembly  44 ; hydraulic line  118  is interconnected between the lower end of cylinder portion  82  of bucket hydraulic cylinder assembly  44  and through-flow passage  92  of diverter valve  74 ; and hydraulic line  120  is interconnected between through-flow passage  92  of diverter valve  74  and the left end of position controller  72 . Hydraulic line  122  is interconnected between dead end port  90  of diverter valve  76  and the upper ends of cylinder portions  80  of breaker hydraulic cylinder assemblies  62 ; and hydraulic line  124  is interconnected between dead end port  90  of diverter valve  74  and the lower ends of cylinder portions  80  of breaker hydraulic cylinder assemblies  62 .  
         [0065]    Referring to FIG. 3A, with electrical selector switch member  88  toggled to its “bucket” position, position controller  72  is useable to control the pivotal orientation of bucket  36  relative to stick  22  (see FIG. 1) when breaker  50  is in its solid line stowed orientation. For example, when hydraulic control member  86  is moved toward the “open” position, hydraulic fluid is sequentially flowed (as indicated in the arrowed hydraulic portion of circuit  70  in FIG. 3A) through hydraulic lines  112  and  114 , through-flow passage  92  of diverter valve  76 , hydraulic line  116 , the interior of cylinder portion  80  of bucket hydraulic cylinder assembly  44 , hydraulic line  118 , through-flow passage  92  of diverter valve  74 , and hydraulic lines  120  and  110 . This hydraulic flow retracts rod  84  of bucket hydraulic cylinder assembly  44  to thereby pivot bucket  36  in a clockwise direction away from its fully closed orientation  36   b  in FIG. 1. Conversely, when position control member  86  is shifted in a “close” direction, the hydraulic flow through this arrowed hydraulic portion of circuit  70  is reversed, thereby forcibly extending rod  84  of bucket hydraulic cylinder assembly  44  and pivoting bucket  36  in a counterclockwise direction toward its fully closed dotted line orientation  36   b  shown in FIG. 1.  
         [0066]    Turning now to FIG. 3B, when it is desired to use breaker  50  instead of bucket  36 , bucket  36  is pivoted to its fully open solid line position shown in FIG. 1, and electrical bucket/breaker switch member  88  is toggled to its “breaker” position to thereby supply electrical power, via leads  106  and  108 , to solenoids  98  of hydraulic diverter valves  74 ,  76 . This, in turn, causes the porting of valves  74 ,  76  to shift leftwardly (as viewed in FIG. 3B) as schematically indicated by arrows  100 . After such port shifting (see FIG. 3B), hydraulic lines  120 ,  124  are coupled as shown to interconnected turnaround ports  94  in valve  74 , and hydraulic lines  114 ,  122  are coupled to the interconnected turnaround ports  94  in valve  76 .  
         [0067]    Next, hydraulic control member  86  is moved in its “close” direction. In response, hydraulic fluid is sequentially flowed (as indicated in the arrowed hydraulic portion of the circuit  70  in FIG. 3B) through hydraulic lines  110  and  120 , interconnected turnaround ports  94  in diverter valve  74 , hydraulic line  124 , the interiors of cylinder portions  80  of breaker hydraulic cylinder assemblies  62 , hydraulic line  122 , interconnected turnaround ports  94  in diverter valve  76 , and hydraulic lines  114  and  112 . This hydraulic flow forcibly extends rod portions  84  of breaker hydraulic cylinder assemblies  62  to thereby forcibly pivot the stowed breaker  50  (see FIG. 2) downwardly to a selected operating orientation such as dotted line position  50   a  in FIG. 2. The now operationally positioned breaker  50  may be hydraulically operated, to cause the reciprocation of its tool portion  54 , using a conventional hydraulic breaker control (not shown) suitably disposed in cab area  16  of representative excavating apparatus  10 . After breaker  50  has been used, the circuit  70  can be utilized to swing breaker  50  back up to its stowed orientation and then swing bucket  36  back down to a selected operational orientation thereof.  
         [0068]    As will be readily appreciated by those of skill in this particular art, excavation apparatus  10  may be easily retrofit to provide it with both digging and breaking capabilities as previously described herein by simply connecting breaker  50  and its associated hydraulic drive cylinder apparatus  62  to stick  22 , and modifying the existing bucket positional control circuitry (for example, as shown in FIGS. 3A and 3B) to add positional control capabilities for added breaker  50 . In this regard it should be noted that position controller  72  shown in the circuit diagrams of FIGS. 3A and 3B may be existing bucket position controller. With the simple addition of diverter valves  74  and  76 , bucket/breaker selector switch  78 , and additional hydraulic lines, the operator can select and independently control both bucket  36  and breaker  50 .  
         [0069]    A variety of modifications may be made to the illustrated embodiment of the present invention without departing from the principles of such invention. For example, as previously mentioned, aspects of the invention can be advantageously utilized on a variety of types of excavating machines other than the representatively illustrated tracked excavator  10 . Additionally, while hydraulic/electric circuit  70  permits the selected positional control of either bucket  36  or breaker  50 , other types of control circuitry may be alternatively utilized, if desired, including separate hydraulic circuits for bucket and breaker. Moreover, while the independently utilizable tools mounted on stick  22  are representatively an excavating bucket and a breaker, other independently utilizable excavating tools could be mounted on stick in place of the illustrated bucket and breaker. Also, while the illustrated bucket and breaker are shown as being pivotally mounted to stick, the particular independently operable tools selected for mounting on stick could have alternate positional movements, such as translation, relative to boom stick on which they are mounted.  
         [0070]    [0070]FIG. 4 discloses earth-excavating machine  10  of FIG. 1 and FIG. 2, fitted with a preferred embodiment of an alternative and preferred breaker and deployment system  200  which is unique, and has numerous advantages. In this embodiment, a hydraulic breaker assembly  201  is mounted on boom stick  22  in addition to excavating bucket  36 . A unitary bracket  202  is rigidly attached to stick  22  by welding or other means of secure attachment. Breaker assembly  201  is pivotally attached to bracket  202 . A single hydraulic cylinder assembly  204  is pivotally attached at one end to bracket  202 . Hydraulic cylinder assembly  204  is pivotally attached at its other end to breaker assembly  201 . Thus, bracket  202  supports the entire deployment system of breaker assembly  201 . The principle of the hydraulic operative control of breaker and deployment system  200  is identical to that disclosed above, except that single hydraulic cylinder  204  is operated for deployment and retraction of breaker assembly  201 .  
         [0071]    [0071]FIG. 5 illustrates earth excavating machine  10  fitted with breaker and deployment system  200  as in FIG. 4. In this figure, breaker assembly  201  is shown released and in a partially deployed position.  
         [0072]    [0072]FIG. 6 illustrates earth excavating machine  10  fitted with breaker and deployment system  200  as in FIG. 4. In this figure, breaker assembly  201  is shown released and in a fully extended position. In this embodiment, breaker assembly  201  may be selectively positioned in any orientation between (and including) the fully deployed and fully retracted positions.  
         [0073]    [0073]FIG. 7 is an isometric view of a preferred embodiment of breaker assembly  201  of the present invention. In this embodiment, breaker assembly  201  has a left body section  206  and an opposite right body section  208 . Breaker assembly  201  has an inner end  210  and an opposite outer end  212 . An optional cover plate  214  is attached between left body section  206  and right body section  208 , over outer end  212 . A conventional breaker tool  216  is secured between left body section  206  and right body section  208 . Cover plate  214  has an opening  218 , through which breaker tool  216  extends. Breaker tool  216  has an internal hydraulically operated cylinder  220  (not shown). A longitudinally reciprocating tool  222  is removably connectable to breaker tool  216 . Reciprocating tool  222  forcibly reciprocates in response to selective transmittal of pressurized hydraulic fluid via suitable hydraulic lines (not shown) to internal hydraulic cylinder  220  of breaker tool  216 .  
         [0074]    [0074]FIG. 8 is an exploded view of another preferred embodiment of breaker assembly  201 . In this embodiment, a gripping structure  224  is located on breaker tool  216 . A pair of lower lock plates  226  secures the outer end  212  of breaker tool  216  between left body section  206  and right body section  208 . In another preferred embodiment, each lower lock plate  226  has a surface structure  228  for secured engagement with gripping structure  224  of breaker tool  216 . Left body section  206 , right body section  208 , and lower lock plates  226 , have matching hole patterns  230  receivable of a plurality of mechanical fastener assemblies  232 .  
         [0075]    A pair of upper lock plates  236  secures the inner end  210  of breaker tool  216  between left body section  206  and right body section  208 . Left body section  206 , right body section  208 , and upper lock plates  236 , have matching hole patterns  230  receivable of a plurality of mechanical fastener assemblies  232 . In an alternative and equivalent embodiment (not shown) left body section  206  and right body section  208  are manufactured with the functional equivalent of lower lock plates  226  and upper lock plates  236  formed integrally on their inside surfaces.  
         [0076]    Still referring to FIG. 8, left body section  206  has a first socket  238  and right body section  208  has a matching first socket  240  located near inner end  210  of breaker assembly  201 . First sockets  238  and  240  are pivotally connectable to bracket  202 .  
         [0077]    Left body section  206  has a third socket  242  and right body section  208  has a matching third socket  244 . A third pivot bushing  246  is attached in and between third sockets  242  and  244 . Pivot bushing  246  is pivotally connectable to hydraulic cylinder assembly  204 .  
         [0078]    [0078]FIG. 9 is a top view of a preferred embodiment of bracket  202  of the present invention. FIG. 10 is a side view of bracket  202 , and FIG. 9 is an isometric view of bracket  202 . Referring to FIG. 9, bracket  202  has a low-end  250  and an opposite high-end  252 . Bracket  202  has a base  254 . In a preferred embodiment, a slotted portion  256  is located on base  254  at each of a low-end  250  and an opposite high-end  252 .  
         [0079]    As best seen in FIG. 11, a left bracket side  258  and a right bracket side  260  extend upward from base  254  in substantially parallel relation to each other. Referring to FIG. 9, left bracket side  258  and right bracket side  260  each have a first socket  262  in substantial centerline alignment with each other. First socket  262  is located on high-end  252  of bracket  202 . Left bracket side  258  and right bracket side  260  each have a second socket  264  in substantial centerline alignment with each other. Second socket  264  is located on low-end  250  of bracket  202 .  
         [0080]    In a preferred embodiment, bracket  202  has a bifurcated pivot means for pivotal attachment of breaker assembly  201  to bracket  202 . In the embodiment disclosed in FIGS. 9, 10, and  11 , the bifurcated pivot means comprises a left bushing  268  extending out of first socket  262  of left bracket side  258 , and a right bushing  270  extending out of first socket  262  of right bracket side  260 . It will be known by one of ordinary skill in the art, that there are other ways to achieve the disclosed configuration of bushings  268  and  270  extending from sides  258  and  260 , without the necessity for first sockets  262 , such as by external welding, casting of the bracket, and other means.  
         [0081]    In a preferred embodiment, best seen in FIG. 14, left bushing  268  and right bushing  270  are removably located in respective first sockets  262 . In this embodiment, an optional bushing stop  272  is attached to the inside wall of each of left bracket side  258  and right bracket side  260 . Also in this embodiment, each of left bushing  268  and right bushing  270  have an internal thread  271  to facilitate removal. Looking to FIG. 14, a removable bushing cap  273  may be attached, as by bolts or other means, to each of first socket  238  and  240  of left body section  206  and right body section  208  respectively. The removability of left bushing  268  and right bushing  270  permits easy removal of breaker assembly  201  without disassembly or removal of bracket  202 .  
         [0082]    In a less preferred embodiment, a first pivot bar  275  (not shown) extends through and between first socket  238  of left bracket side  258  and first socket  240  of right bracket side  260 . While simpler in design, this configuration lacks a significant advantage of the disclosed bifurcated pivot means. As shown in greater detail below, the use of non-bifurcated pivot bar  274  presents a potential interfering obstacle for hydraulic cylinder assembly  204  when breaker assembly  201  is retracted.  
         [0083]    Referring again to FIG. 9, a pivot bar  274  extends through and between second socket  264  of left bracket side  258  and second socket  264  of right bracket side  260 . Pivot bar  274  provides pivotal connection of hydraulic cylinder assembly  204  to bracket  202 .  
         [0084]    In the preferred embodiment, left bushing  268  and right bushing  270  are located in closer proximity to high-end  252  than is pivot bar  274 . Pivot bar  274  is located in closer proximity to base  254  than are left bushing  268  and right bushing  270 .  
         [0085]    In another preferred embodiment, an extension stop means limits the maximum extension of breaker assembly  201 . In a preferred embodiment, the extension stop means is a mechanical interference between breaker assembly  201  and mounting plate  202 . In FIGS. 9, 10, and  11 , the extension stop means disclosed comprises a pair of extension stops  276 , attached, one each, to left bracket side  258  and right bracket side  260 . In an equivalent alternative embodiment not shown, extension stops  276  are attached to base  254 . One of ordinary skill in the art will understand that a variety of modifications may be made to the illustrated embodiment of the present invention without departing from the principles of such invention. For example, a single extension stop may by used.  
         [0086]    [0086]FIG. 12 is a cross-sectional side view of a preferred embodiment of the breaker and deployment system  200  of the present invention. In this view it can be seen that breaker assembly  201  is pivotally attached to bracket  202 , hydraulic cylinder assembly  204  is pivotally attached at one end to bracket  202 , and hydraulic cylinder assembly  204  is pivotally attached at its other end to breaker assembly  201 . Thus configured, a triangular relationship is formed between bushing  270 , pivot bar  274 , and pivot bushing  246 . Operation (expansion) of hydraulic cylinder assembly  204  increases the length of one side of the triangle, causing angular rotation of breaker assembly  201  around bushing  270  (and bushing  268 , not shown) and coincident deployment of breaker assembly  201  into operative position.  
         [0087]    [0087]FIG. 13 is a side-sectional view of a preferred embodiment of the breaker and deployment system of FIG. 12, showing the breaker fully deployed. In FIG. 13, the benefit of the bifurcated pivot means is clearly shown. In FIG. 13, breaker assembly  201  has been deployed to a point by which hydraulic cylinder  204  is aligned between the inside of left bushing  268  (not shown) and the inside of right bushing  270 , as shown by the position of bushing stop  272 . This positions reciprocating tool  222  closer to the vertical position, allowing the operator of excavating machine  10  to operate the tool at greater subsurface depths, and thus dramatically enhance the value of the breaker and deployment system.  
         [0088]    In another embodiment of the present invention, a method of “Su per-deployment” is disclosed. By this method, breaker assembly  201  may be deployed past the deployment angle permitted by full extension of hydraulic cylinder  204 . To accomplish this, the operator takes the following steps:  
         [0089]    1. Fully extend hydraulic cylinder  204 ;  
         [0090]    2. momentarily disengages the power to hydraulic cylinder  204 ;  
         [0091]    3. allow gravity to urge rotation of breaker assembly  201  a few degrees further;  
         [0092]    4. initiate retraction of hydraulic cylinder  204 , further extending the angular deployment of breaker assembly  201 .  
         [0093]    In this manner, the maximum deployment angle achieved is only limited by eventual mechanical interference with boom stick  22 , or selective placement of extension stops  276 .  
         [0094]    [0094]FIG. 14 is a sectional view of breaker and deployment system  200  of a preferred embodiment with the section taken as shown in FIG. 12. In FIG. 14, the benefit of the bifurcated pivot means is again shown. In this figure, it is seen that left first socket  238  of left body section  206  is pivotally attached to left bushing  268  of mounting plate  202 . Right first socket  240  of right body section  208  is pivotally attached to right bushing  270  of mounting plate  202 . Thus attached, it can be seen that there is clearance between the inside of left bushing  268  and the inside of right bushing  270  such that hydraulic cylinder assembly  204  can rotate freely to a position between them without mechanical interference. This permits a greater angular deployment, and thus convenient utilization of breaker assembly  201 .  
         [0095]    [0095]FIG. 15 is a side view of a preferred embodiment of breaker and deployment system  200  attached to boom stick  22  of excavating machine  10 , with breaker assembly  201  in the fully retracted position. A shock absorbing retraction stop  280  is attached between boom stick  22  and breaker assembly  201 . Retraction stop  280  prevents damage to breaker assembly  201 , hydraulic cylinder  204 , and boom stick  22  when breaker  201  is in the stowed position, encountering vibration and impact forces during operation of bucket  36 . In the embodiment shown, retraction stop  280  is attached to boom stick  22 . In an alternative and equivalent embodiment, not shown, retraction stop  280  is attached to breaker assembly  201 .  
         [0096]    Also disclosed in FIG. 15, a latch-lock assembly  282  is mounted to, and between, boom stick  22  and breaker assembly  201 . Latch-lock assembly  282  secures breaker and deployment system  200  in the retracted position, preventing undesired partial deployment of breaker assembly  201  from the vibration and impact forces encountered during operation of bucket  36 . As shown, latch-lock assembly includes a strike  284  located on breaker assembly  201 . In the preferred embodiment, latch-lock  282  is operable from within cab  16  of excavating machine  10 . Operation of latch-lock assembly  282  may be electrically, manually, pneumatically, or hydraulically.  
         [0097]    [0097]FIG. 16 is a side view of a preferred embodiment of breaker and deployment system  200  attached to boom stick  22  of excavating machine  10 , with breaker assembly  201  in the fully extended and stopped position. In this view, extension stop  276  has engaged left body section  206 , preventing further angular rotation (extension) of breaker assembly  201 . In the preferred embodiment, a second extension stop  276  has simultaneously engaged right body section  208  on the opposite side, and not visible in this view.  
         [0098]    [0098]FIG. 17 is an isometric view of the preferred embodiment of breaker and deployment system  200  of FIG. 16, with breaker and deployment system  200  shown in a fully extended and stopped position. In this view, it can be seen there is clearance between the inside of left bushing  268  and the inside of right bushing  270  such that hydraulic cylinder assembly  204  can rotate freely to a position between them without mechanical interference. This permits a greater angular deployment, and thus convenient utilization of breaker assembly  201 .  
         [0099]    Also seen in FIG. 17, is further detail of a preferred embodiment of latch-lock assembly  282 . In this embodiment, latch assembly  282  has a guide box  286  attached to the underside of boom stick  22 . A slide latch  288  is slidably located within guide box  286 . A control piston  290  is electrically, manually, pneumatically, or hydraulically operated from within cab  16  of excavating machine  10  to alternately move slide latch  288  between an engagement and release position with strike  284 . In a preferred embodiment, strike  284  has a beveled face  292  for contact engagement with slide latch  288 . In another preferred embodiment, guide box  286  has a reinforcement plate  294  to prevent deformation of guide box  286  and undesired release of breaker assembly  201 .  
         [0100]    [0100]FIG. 18 is an isometric view of the preferred embodiment of the breaker system of FIGS. 15-17, with the breaker system shown in a fully extended and stopped position, and disclosing an alternative latch-lock assembly  300 . In this embodiment, a strike ball  302  is located on breaker assembly  201 . In a preferred embodiment, strike ball  302  is welded or otherwise attached to the end of hydraulic cylinder  204 . A ball latch  304  is attached to boom stick  22 . Ball latch  304  is releasably operated by arm  306 . Release  308  actuates arm  306  and is electrically, manually, pneumatically, or hydraulically operated from within cab  16  of excavating machine  10 . A spring  310  (not shown) located within ball latch  304  urges ball latch  304  closed, and receivable of strike ball  302  upon subsequent retraction of breaker assembly  201 .  
         [0101]    [0101]FIGS. 19, 20 and  21  are side views of a preferred embodiment of an alternative gravity deployment system, showing the relationship between bucket  36 , breaker assembly  201 , and boom stick  22 . In this embodiment, bucket  36  is retracted to retract the gravity deployed breaker assembly  201 . The advantage of this embodiment is that it can be incorporated onto excavating machine  10  without a requirement for hydraulic cylinder  204  or hydraulic/electric circuit  70  to selectively pivot bucket  36  and breaker assembly  201 . FIG. 21 is a side view of the preferred embodiment of the gravity deployment system of FIGS. 19 and 20, showing complete retraction and latching of breaker assembly  201  by retraction of bucket  36 .  
         [0102]    [0102]FIGS. 22, 23, and  24  are isometric, side, and top views, respectively, of an alternative embodiment of the present invention that replaces the hydraulic cylinder assembly  204  (illustrated in FIGS. 12 through 21) with a compact and more efficient rotary actuator assembly  400 . Rotary actuator assembly  400  comprises a hydraulically actuated rotary actuator  402  disposed between boom stick  22  and breaker assembly  201  to cause pivotal movement between the two. Rotary actuators of the helical, sliding spline variety are readily commercially available, such as those sold by Helac® Corporation, located at 225 Battersby Avenue, Enumclaw, Wash. 98022, U.S.A.  
         [0103]    Referring to FIG. 25, a section view of hydraulic rotary actuator  402  is illustrated. As seen in this view, a generally cylindrical housing  404  contains a piston  406  which translates longitudinally back-and-forth within housing  404  in response to the application of hydraulic pressure from one side of piston  406 . Piston  406  engages a first helically splined shaft  408  that rotates responsive to the translation of piston  406  in housing  404 . Helically splined shaft  408  in turn engages a second helically splined shaft  410  (with splines pitched in the opposite direction), on an output shaft  412  of actuator  402 .  
         [0104]    The angular position of output shaft  412  is fixed by stopping flow of fluid into and out of cylindrical housing  404 . This stops piston  406  from moving and prevents output shaft  412  from rotating. The direction of rotation of output shaft  412  can be changed by supplying hydraulic pressure to the opposite side of piston  406 , causing the piston and output shaft  412  to reverse direction.  
         [0105]    Referring back to FIG. 22, in the preferred embodiment, actuator  402  is welded to pillow blocks  414 , which are secured by bolts  418  or other mechanical fastening means to boom stick  22 . Thus, rotary actuator  402  is fixed relative to boom stick  22 . Output shaft  412  extending from the end of rotary actuator  402  may be secured by a generally symmetrical bolt pattern  418  to breaker assembly  201 . Thus, when hydraulic pressure is supplied through one or the other of ports  409 , the output shaft  412  (and breaker assembly  201 ) rotate relative to housing  404  (and boom stick  22 ).  
         [0106]    As shown, hydraulic pressure acting on piston  406  is converted into rotary motion of output shaft  412  capable of moving breaker assembly  201  relative to boom stick  22 . This provides a compact, yet high-torque, rotary actuator  402  capable of replacing either of hydraulic cylinder assemblies  62  or  204 , shown in other embodiments, while using a smaller volume of fluid.  
         [0107]    [0107]FIGS. 26 through 28 illustrate an alternative embodiment of bracket assembly  202  employed to secure breaker assembly  201  to boom stick  22  (not shown). In some respects, bracket assembly  202  is similar to that illustrated in FIGS. 9 through 11 and  14 , and corresponding reference numerals are used where the components are identical. Referring to FIGS. 26 and 27, in this embodiment, a pair of threaded bolts  501  (each having a flat portion  503  milled in its end) is received in corresponding threaded sockets  505  formed in each bracket side  258 ,  260 . A set screw  507  and corresponding bore  509  is positioned in each bracket side  258 ,  260  to intersect sockets  505 , thereby bearing on flat portions  503  of bolts  501  and preventing inadvertent rotation of bolts  501  and removal from sockets  505 .  
         [0108]    As seen in FIG. 26, breaker assembly  201  has a left body section  206  and an opposite right body section  208 . Left body section  206  has a first socket  238  and right body section  208  has a matching first socket  240  (not shown). First sockets  238  and  240  are pivotally connectable to bracket  202 . As best seen in FIG. 28, a circular reinforcing boss  511  is provided around each of first sockets  238  and  240 , through which bolts  501  extend. As best seen in FIG. 28, a zerk or grease fitting  513  is provided on each boss  511 . A bore  517  extends through each boss  511  through which grease is injected to lubricate bolts  501  and the surfaces around them. Inserting grease through zerk or grease fitting  513  reduces the friction between bracket  202  and breaker assembly  201 , reducing the hydraulic horsepower needed for deployment and retraction and improving overall operability of breaker and deployment system  200 .  
         [0109]    As shown in FIG. 28, bolts  501  extend through boss  511  and breaker sections  206 ,  208  (only one side of the assembly is illustrated) and into threaded socket  505  in bracket sides  258 ,  260 . In the preferred embodiment, a metallic washer  515  is placed around each bolt  501  between breaker sections  206 ,  208  and bracket sides  258 ,  260 . Bolts  501  are secured against unthreading rotation within threaded sockets  505  by set screws  507  in set screw sockets  509 . Set screw sockets  509  intersect threaded sockets  505  and allow set screws  507  to engage flats  503  of bolts  501 . The bracket assembly is otherwise similar to that shown above and serves to provide a pivoting joint between boom stick  22  and breaker assembly  201 . This alternative bracket assembly is more quickly and easily disassembled than that shown above, permitting faster interchange of breaker assemblies  201 , if necessary.  
         [0110]    In a less preferred embodiment, flats  503  are not included, and set screws  507  bear directly on the threaded portion of bolts  501  and achieve a similar, though less secure result. Again, zerk or grease fitting  513  and its associated bore  517  permit lubrication of the pivot joint formed by the assembly.  
         [0111]    The foregoing detailed description is to be clearly understood as being given by way of illustration and example, the spirit and scope of the present invention being limited solely by the appended claims.

Technology Classification (CPC): 8