Abstract:
A jackhammer positioner comprising a support structure displaceably or fixedly resting on the ground, a base pivotally mounted onto the support structure, and an articulated arm pivotally connected to the base carrying a jackhammer. The articulated arm comprises two pivotally interconnected arm portions. A yoke is pivotally installed at the end of the arm opposite its connection to the base. The yoke pivotally carries a jackhammer support mechanism for carrying a jackhammer, the mechanism providing the positioner with the ability to linearly translate the jackhammer. The positioner thus comprises five pivot joints and one translation joint, and can consequently be operated to take a large number of different conformations. The operative tip of a jackhammer suspended to the positioner can thereby be easily and rapidly juxtaposed to a surface which needs to be worked.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to tool positioners, and more particularly to a jackhammer positioner with enhanced versatility and manoeuvrability features.  
       BACKGROUND OF THE INVENTION  
       [0002]     A jackhammer is a very heavy tool used to break concrete structures apart for performing maintenance or repair tasks thereon. It is difficult, not to say impossible, to use jackhammers other than on the ground without mechanical assistance; for instance, it would be impossible for a construction worker to manually uplift a jackhammer and to maintain it in an uplifted position, in order to apply its operative tip on an overhanging upright wall and use the jackhammer thereon. Despite this fact, jackhammers must be sometimes used on surfaces other than ground surfaces. For example, the bottom concrete surface of bridges, outdoors concrete ceilings, upright concrete walls of a given structure, are all surfaces which may require maintenance or repair interventions with a jackhammer. In order to assist a construction worker in supporting over ground and positioning the jackhammer in a desired position, it known to use jackhammer positioners. However, existing jackhammer positioners are cumbersome, inefficient and their versatility tends to be limited.  
       SUMMARY OF THE INVENTION  
       [0003]     The invention relates to a jackhammer positioner for assisting a worker in the over ground handling of a jackhammer, comprising: 
        a ground support member;     a base mounted onto said support member and moveable relative thereto;     an articulated arm having first and second ends, moveably mounted onto said base at said first end, said arm comprising a number of displacement joints, said articulated arm further comprising a jackhammer support member at said second end for interconnecting said arm to the jackhammer;     power means for power biasing said articulated arm into a continuously erected posture; 
 
 wherein at least three of said displacement joints are pivot joints, and wherein one of said displacement joints is a translation joint. 
       
 
         [0009]     In one embodiment, said base is pivotally mounted onto said ground is support member.  
         [0010]     In one embodiment, the range of reach of said jackhammer support member sweeps a volume represented by a virtual half sphere with said base forming approximately the center of said half sphere.  
         [0011]     In one embodiment, said positioner further comprises control means operatively connected to and controlling said power means.  
         [0012]     The invention also relates to an articulated support member for assisting a worker in the over ground handling of a jackhammer having a main body and a hammering head at one end of the main body thereof, said support member comprising: 
        an articulated arm, movable between a retracted limit first position and an extended limit second position, said arm defining an inner end and an outer end;     base means, for supporting said articulated arm spacedly over ground;     first mounting means, mounting said arm inner end to said base means for free relative movement of said articulated arm relative to said base means;     power means, for power biasing said articulated arm into a continuously erected posture;     a command and control unit, for securing and operating the jackhammer in a continuously airborne fashion, said unit defining an elongated main frame having a first end portion with a jackhammer attachment assembly and a second end portion opposite said first end portion with a manual command and control template; and     second mounting means, interconnecting said jackhammer attachment assembly and said arm outer end for relative movement therebetween, for continuously maintaining the jackhammer spacedly over ground so that the weight load of the jackhammer be fully compensated; 
 
 wherein the range of reach of said jackhammer attachment assembly over ground sweeps a volume represented by a virtual half sphere with said base means forming approximately the center of said half sphere. 
       
 
         [0020]     In one embodiment, said second mounting means includes means for anchoring the jackhammer main body at the center of gravity thereof.  
         [0021]     In one embodiment, said manual command and control template includes means for remote control of said power means.  
         [0022]     In one embodiment, said articulated support member further includes translational motion means, integral to said main frame of said command and control unit for relative movement of said jackhammer attachment assembly relative to said manual command and control template.  
         [0023]     In one embodiment, said articulated support member further includes second power means, operatively connected to said manual command and control template for selectively powering the jackhammer head in a reciprocating motion.  
         [0024]     In one embodiment, said first mounting means includes a turntable rotatably supporting said arm inner end about an axis transverse to said turntable.  
         [0025]     In one embodiment, said base means includes a lift platform movable vertically over ground.  
         [0026]     In one embodiment, said first mounting means includes a turntable fixedly secured to said lift platform and rotatably supporting said arm inner end about an axis transverse to said turntable.  
         [0027]     In one embodiment, said first mounting means includes: 
        an elongated rail member, fixedly mounted to said lift platform,     a carriage rollingly mounted to said rail member for rolling displacement of said carriage therealong, said carriage having a transverse frame, and     a turntable, fixedly secured to said carriage transverse frame and rotatably supporting said arm inner end about an axis transverse to said turntable; 
 
 wherein said articulated arm and associated command and control unit are movable into a translational motion over said platform. 
       
 
         [0032]     In one embodiment, wherein said turntable includes a central axle with low-friction PTFE coating.  
         [0033]     The invention also relates to a jackhammer device comprising: 
        a jackhammer comprising a jackhammer operative tip;     an articulated arm supporting said jackhammer, said arm movable between a retracted limit first position and an extended limit second position, said arm defining an inner end and an outer end;     first mounting means, interconnecting said jackhammer and said arm outer end for relative movement therebetween;     base means, for supporting said articulated arm spacedly over ground;     second mounting means, mounting said arm inner end to said base means for free relative movement of said articulated arm relative to said base means;     power means, for power biasing said articulated arm into a continuously erected posture and for maintaining said jackhammer spacedly over ground; 
 
 wherein the range of reach of said jackhammer operative tip sweeps a volume represented by a virtual half sphere with said base means forming approximately the center of said half sphere. 
       
 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0041]     In the annexed drawings:  
         [0042]      FIG. 1  shows a perspective view of a workman maneuvering a jackhammer installed on a jackhammer positioner according to the present invention;  
         [0043]      FIG. 2  shows an enlarged perspective view of the support structure and one embodiment of the base of the positioner of  FIG. 1 ;  
         [0044]      FIG. 3  shows an enlarged cross sectional view of the support structure and the base of the positioner taken along lines III-III of  FIG. 3 ;  
         [0045]      FIG. 4  shows an enlarged partial perspective view of the positioner of  FIG. 1 ;  
         [0046]      FIG. 5  shows an enlarged perspective view of the jackhammer positioner of  FIG. 1 , including the jackhammer and support yoke, showing the jackhammer control mechanism;  
         [0047]      FIG. 6  is a view similar to that of  FIG. 4 , but further showing in phantom lines a half-sphere suggesting jackhammer&#39;s operative tip span of accessibility;  
         [0048]      FIG. 7  shows a perspective view of the support structure and the base of the positioner according to an alternate embodiment of the present invention, with arrow A symbolizing a force applied on the base; and  
         [0049]      FIG. 8  shows a cross sectional view at an enlarged scale of the support structure and the base of the positioner taken along lines VIII-VIII of  FIG. 7 .  
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0050]     In  FIG. 1 , there is shown a workman W maneuvering a jackhammer  5  installed on a jackhammer positioner  10  according to the present invention.  
         [0051]     Positioner  10  can be installed on a platform  1 . Platform  1  is for example attached to a lifting mechanism of a utility vehicle (not shown), and can thereby be vertically raised under the action of the lifting mechanism. In one embodiment, a rail  6  is fixedly attached to platform  1 , rail  6  comprising a horizontal sheet-like elongated track  6   a , and three brackets  6   b  lengthwisely spaced apart along and integrally attached to track  6   a . Brackets  6   b  are affixed to platform  1 , and rail  6  is thus attached to platform  1 , with plate  6   b  being in a spaced apart and overhanging parallel relationship with platform  1 .  
         [0052]     Jackhammer positioner  10  is slidably mounted onto rail  6  of platform  1 , as described hereinafter. As shown in  FIG. 1-3 , positioner  10  comprises a support structure  12  comprising for example two parallelely spaced-apart horizontal beams  13 , and two parallelely spaced-apart tubular beams  14  extending between beams  13  and integrally attached thereto. A transverse cylindrical bushing  18  extends vertically through each beam  14  at the vicinity of their middle and is integrally attached thereto. The top edge of bushing  18  is slightly upwardly offset from the top surface of beam  14 , and the internal wall of bushing  18  is covered with a bronze sleeve  21 . Moreover, an upright beam  15 ,  15 ′ extends transversely, for example at right angle, from one end of each one  20  of beams  13 , and is fixedly attached thereto. Two engagement wheels  16 ,  17  and  16 ′,  17 ′ are provided on each beam  15 ,  15 ′ respectively, and are rotatably attached thereto in a spaced-apart fashion. Upper wheels  16 ,  16 ′ of the two beams  15 ,  15 ′ form a virtual axis parallel to that extending between lower wheels  17 ,  17 ′.  
         [0053]     Support structure  12  is slidably mounted onto rail  6 . Indeed, wheels  16 ,  16 ′ slidably engage the top edge of track  6   a  of rail  6 , and wheels  17 ,  17 ′ slidably engage the lower edge of track  6   a  of rail  6 . Support structure  12  can thereby be linearly slid along track  6   a  of rail  6 .  
         [0054]     Jackhammer positioner  10  further comprises a base  20 , base  20  comprising a transverse axle  22  fixedly attached at the center thereof. Base  20  has a circular shape, and can be made of steel for example. Axle  22  engages bushing  18  of one beam  14  of support structure  12 , and base  20  is thereby pivotally mounted thereon. In the appended figures, base  20  engages the beam  14  which is the furthest from beams  15 ,  15 ′. However, base  20  can be interchangeably mounted on either one of beams  14 .  
         [0055]     An annular washer  23 , which can be coated with a friction reducing compound such as polytetrafluoroethylene (PTFE or Teflon(g), is fitted over the top edge of bushing  18  and beneath base  20 . When base  20  is pivoted about its pivotal engagement with beam  14 , the bottom surface of base  20  will slide with low friction onto PTFE washer  23 , and axle  22  will slide against bronze sleeve  21 . The pivotal movement of base  20  relative to bushing  18  is hence carried out without being excessively impeded by friction-borne forces.  
         [0056]     As shown in  FIGS. 1 and 4 , a foot  20 - 1  is fixedly mounted onto the top surface of base  20 . Positioner  10  further comprises an articulated arm  30  connected to foot  20 - 1 , arm  30  comprising a first arm portion  32  and a second arm portion  34 . Arm portions  32 ,  34  are tubular and are made of a material which can withstand high amounts of mechanical stress, like steel for example. Arm portion  32  is pivotally attached at one end  32 A to foot  20 - 1 , and is pivotally attached at the other end  32 B to one end of arm portion  34 .  
         [0057]     A pivot actuator  24  is pivotally connected at one end  24 A to foot  20 - 1 , and is pivotally connected at the other end  24 B to an intermediate section of arm portion  32 . Actuator  24  can be a hydraulic or pneumatic cylinder, and is operatively connected to and controlled manually by control handles, as described hereinafter. Upon activation of actuator  24 , arm  30  is pivoted about its pivotal joint with foot  20 - 1  between two limit positions: a first limit position, where arm portion  32  is substantially vertical and where actuator  24  is retracted, and a second limit position where arm portion  32  is pivoted downwardly into a substantially horizontal position, and where actuator  24  is extracted.  
         [0058]     Similarly, a pivot actuator  26  is pivotally connected at one end  26 A to an intermediate portion of arm portion  32 , and is pivotally connected at another end  26 B to an intermediate section of arm portion  34 . Pivotal mount  26 A is distally located compared to pivot mount  24 B relative to base  20 . Actuator  26  can be a hydraulic or pneumatic cylinder, and is operatively connected to and controlled by control handles, as described hereinafter. Upon activation of actuator  26 , arm portion  34  is pivoted at pivotal mount  32 B relative to arm portion  32  between two limit positions: a first limit position, where arm portion  34  is coaxially aligned with arm portion  32 , and where actuator  26  is extracted, and a second limit position where arm portion  34  forms a large acute angle with arm portion  32 , for example a 60° angle, and where actuator  26  is retracted.  
         [0059]     Arm portion  34  integrally comprises an inner portion  38 , and an attachment outer end portion  36  integrally extending from fore portion  38  in an elbowed fashion. Outer end portion  36  defines a pivot axis  37 , and further comprises a cross-sectionally circular pivot pin  39  integrally axially extending from elbowed portion  36 . Moreover, positioner  10  comprises a yoke  40  pivotally connected to end portion  36 . As illustrated in  FIG. 5 , yoke  40  comprises two parallel legs  42 ,  42 ′, a crossbar  43  integrally extending between one end of ribs  42 ,  42 ′, and a pivot hole  41  recessed at the middle of crossbar  43 . Pivot hole  41  is pivotally engaged by pivot pin  39  of arm portion  34 , and yoke  40  is thereby pivotally attached to arm portion  36 , and can therefore be pivoted about pivot axis  37 . Bearings (not shown) are preferably installed at the pivot joint formed by the interconnection between pivot pin  36  and hole  41 ; the pivotal displacement of yoke  40  about pivot axis  37  can therefore be smoothly and frictionlessly carried out.  
         [0060]     Yoke  40  pivotally carries a jackhammer control mechanism  50  defining a longitudinal axis  51 . Mechanism  50  comprises a planar grip plate  52  defining two opposite fingers  55 ,  55 ′ laterally extending from one end thereof transversely and away from axis  51 . Grip plate  52  defines a grip opening  53  recessed therethrough, whereby a workman using positioner  10  can insert his hand and hang on to displace grip plate  52 . Control bars  54 ,  54 ′ integrally and co-extensively extend from both faces of plate  52 , perpendicularly to planar plate  52  and parallel to longitudinal axis  51 . A control handle  56 ,  56 ′ is provided at the free end of each control bar  54 ,  54 ′ respectively. Handles  56 ,  56 ′ are operatively connected to and control the activation actuators  24  and  26 . Mechanism  50  further comprises a rod attachment plate  58  integrally attached to grip plate  52  perpendicularly thereto and to longitudinal axis  51 . Control mechanism  50  also comprises two elongated rods  60 ,  60 ′ fixedly attached at one end thereof to attachment plate  58 . Rods  60 ,  60 ′ are parallel, transversely spaced apart and symmetrically arranged relative to axis  51 .  
         [0061]     Rods  60 ,  60 ′ are slidably connected to a jackhammer attachment member  62 . Attachment member  62  comprises two cylindrical hollow guides  64 ,  64 ′, each guide  64 ,  64 ′ being engaged by a corresponding registering rod  60 ,  60 ′ respectively. Guides  64 ,  64 ′ are closed at one end. The engagement between rods  60 ,  60 ′ and guides  64 ,  64 ′ is a translation joint, and rods  60 ,  60 ′ can thereby be axially slid along guides  64 ,  64 ′. Anti-egress means (not shown) should be provided within guides  64 ,  64 ′, on rod  60 ,  60 ′, or both, to prevent rods  60 ,  60 ′ from accidentally egressing from guides  64 ,  64 ′ respectively. A pivot node  70 ,  70 ′ is provided on each guide  64 ,  64 ′ respectively, and a pivot axis  71  extending between pivot nodes  70 ,  70 ′ is defined. Each leg  42 ,  42 ′ of yoke  40  is pivotally attached to a corresponding pivot node  70 ,  70 ′, and mechanism  50  can thereby be pivoted about axis  71 .  
         [0062]     Pivot nodes  70 ,  70 ′ are suitably positioned on mechanism  50  in order for the weight of jackhammer control mechanism  50  to be evenly distributed half and half on opposite sides of pivot axis  71 . As a result, a workman can easily pivot mechanism  50  about axis  71 , and can easily maintain it in a desired position without excessive effort.  
         [0063]     Attachment member  62  also comprises a hollow cylindrical neck  66  coaxially carrying jackhammer  5 . The main body of jackhammer  5  is partially engaged by and secured to neck  66 , and the elongated operative free end tip  7  of jackhammer  5  is arranged coaxially with longitudinal axis  51 , opposite handles  56 ,  56 ′.  
         [0064]     Mechanism  50  is further provided with two actuators  68 ,  68 ′, which are operatively connected to and controlled by handles  56 . Actuators  68 ,  68 ′ are preferably hydraulic cylinders, and therefore possess a chamber end and a piston rod end. The chamber end of each actuator  68 ,  68 ′ is firmly connected to a finger  55 ,  55 ′ respectively of grip plate  52 , and the piston rod end is connected to a corresponding pivot node  70 ,  70 ′. Upon activation of actuators  68 ,  68 ′, guides  64 ,  64 ′ of jackhammer attachment member  62  are slid along rods  60 ,  60 ′. Jackhammer  5  being affixed to jackhammer attachment member  62 , as actuators  68 ,  68 ′ are activated, jackhammer  5  is translated away or towards rod attachment plate  58  between two limit positions: a first limit position where rods  60 ,  60 ′ are brought to their outward most extended limit position guides  64 ,  64 ′, and a second limit position where rods  60 ,  60 ′ are brought to their inward most retracted condition on the closed end portion of guides  64 ,  64 ′.  
         [0065]     Since pivot nodes  70 ,  70 ′ of attachment member  62  link mechanism  50  to the rest of positioner  10 , the displacement of attachment member  62  affects the conformation of positioner  10 . Indeed, as actuators  68 ,  68 ′ are activated for translational motion of attachment member  62 , base  20  and arm portions  32 ,  34  can be concurrently pivoted to follow the displacement of attachment member  62 .  
         [0066]     To use jackhammer positioner  10 , platform  1  must be positioned at the vicinity of a structure which needs to be worked. Thereafter, the positioner  10  must be manually operated by workman W to position jackhammer  5 , in order to juxtapose the operative tip  7  of jackhammer  5  in close proximity to the structure which needs to be worked.  
         [0067]     Base  20 , as well as arm  30  installed on base  20 , can be manually pivoted for a full turn (360°) about vertical axle  22 , to sweep a circular horizontal area overhanging horizontal platform  1 .  
         [0068]     Moreover, handles  56 ,  56 ′ can be manipulated by worker W to effortlessly control hydraulic actuators  24 ,  26 ; upon activation of actuators  24 ,  26 , arm portions  32 ,  34  can be pivotally articulated about their shoulder joint  24 A and elbow joint  32 B, to retract or extend arm  30  within a vertical plane.  
         [0069]     Furthermore, workman W can pivot yoke  40  about pivot axis  37 , to rotate for up to a full turn the jackhammer  5  about the lengthwise axis of the latter. Workman W can also grip plate  52  by grip opening  53  and manually pivot mechanism  50  about pivot axis  71 .  
         [0070]     Also, by appropriately maneuvering handles  56 ,  56 ′ and activating actuators  68 , jackhammer  5  can be moved in translation axially along longitudinal axis  51  between its first extended position and second retracted limit positions, as guides  64 ,  64 ′ of attachment member  62  are slidably driven back and forth along rods  60 ,  60 ′.  
         [0071]     Finally, support structure  12  can be slid along rail  6  of platform  1 , and the whole positioner  10  can thereby be linearly displaced over platform  1 .  
         [0072]     Jackhammer  5  is then conventionally activated, and the work can take place. An electric line  80  interconnects handles  56 ,  56 ′ to jackhammer  5 , and a pneumatic line  82  interconnects jackhammer  5  to a pressurized air source. When the workman manipulates handles  56 ,  56 ′ to selectively activate jackhammer  5 , handles  56 ,  56 ′ will send an electric activation signal to jackhammer  5 . As a result thereof, pressurized air is injected into jackhammer  5  through the instrumentality of pneumatic line  82  to enable repeated back and forth hammering action of jackhammer tip  7  against the surface to be treated.  
         [0073]     By providing a positioner with such relative displacement features, positioning the jackhammer in a desired position is effortless and easily accomplished. The positioner is versatile and can be operated to take numerous different conformations. Indeed, as illustrated in  FIG. 6 , the positioner can be manipulated to position operative tip  7  of jackhammer  5  at any point located within at least the volume of a half-sphere  100 . The center of half-sphere  100  corresponds to pivotal base  20 , and its radius corresponds approximately to the maximum distance which can separate the free extremity of operative tip  7  of jackhammer  5  and base  20  (when arm is fully extended pivotally about hinge  32 B).  
         [0074]     Jackhammer positioner  10 , as described herein, possesses additional advantageous features. In the prior art, when a workman W handles a jackhammer directly, the operative tip  7  thereof forcefully and repeatedly pounds onto a concrete structure in reciprocating fashion, and the hands of the workman W are consequently jarred. On the contrary, in positioner  10  of the present invention, jackhammer  5  is not directly in contact with the workman; jackhammer  5  is attached to support member  62 , which can recoil and slide along rods  60  every time operative tip 7 pounds on concrete.  20  The reciprocating motion of the jackhammer  5  is thus not transmitted to the workman using jackhammer  5  when it is installed on positioner  10 , and the workman&#39;s hands are hence less, or even not at all jarred.  
         [0075]     Alternative embodiments of the invention will now be described. As illustrated in  FIGS. 7-8 , there is shown a beam  114  of an alternate support structure  112 , provided with a transverse cylindrical channel  118  extending therethrough. A discoid pivot plate  119  having a pivot hole  11   9 a at its center is fixedly attached to the internal walls of channel  118 . A base  120 , comprising a transverse axle  122  fixedly extending from its center, is pivotally mounted on beam  114 . Indeed, axle  122  pivotally engages pivot hole  119 a, and base  120  abuts on a PTFE washer  123  fitted between the top edge of channel  118  and the bottom surface of base  120 .  
         [0076]     Channel  118  has a diameter which is equal or slightly inferior to that of base  120 .  
         [0077]     If base  120  is subjected to an off-centred force A, base  120  will tend to tilt laterally. Since channel  118  is slightly smaller in diameter than base  120 , the top peripheral edge of channel  118  will peripherally support base  120 . Such a tilting motion, which would be likely to provoke bending and permanent damage of axle  122 , is hence accounted for by inherent tilt compensation.  
         [0078]     In another alternate embodiment (not illustrated in the appended drawings), support structure  12  is not slidable about a rail. Rather, support structure  12  is fixedly anchored on platform  1 , and therefore can not be linearly displaced.  
         [0079]     Certain modifications and improvements will occur to those skilled in the art upon a reading of the foregoing description. It should be understood that all such modifications and improvements have been omitted herein for the sake of conciseness and readability but are properly within the scope of the following claims.