Abstract:
A portable driving device for permanently driving stakes, survey flags, posts, or the like, of varying sizes and shapes, into the ground. The invention provides for powering the device by a pressurized fluid with a single power cylinder, a valve control assembly including a self-exhausting spool valve controlled by a rod that runs through the spool valve, and safety switches in series for controlling delivery of pressurized fluid to the driving device.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. 61/575,883, filed Aug. 29, 2011, which is incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to portable driving devices and in particular portable driving devices adapted for permanently driving stakes, survey flags, or posts, or the like, of varying sizes and shapes, into the ground, that are powered by a pressurized fluid. This invention also relates to a valve control assembly adapted for a portable driving device wherein a spool valve is controlled by a rod that runs through the middle of the spool valve. The invention also relates to a handle assembly adapted for a portable driving device wherein safety switches in series control delivery of pressurized fluid to the driving device valve control assembly. 
     BACKGROUND 
     The invention may be related to subject matter disclosed in the following U.S. Pat. Nos. 2,703,479; 3,712,389; 4,665,994; 4,984,640; 5,819,857; 6,182,772; 6,571,885; 6,776,242; 6,889,777; 6,932,166; 7,152,694; and 7,252,158, and U.S. Patent Application Publication 2002/0195273, which are hereby expressly incorporated by reference in their entireties. 
     SUMMARY 
     The present invention provides a portable reciprocating driving device which may include a valve control assembly and a pressurized fluid control assembly. Understanding the driving device from the reading of this document, may be facilitated by reference to the “Parts List” toward the end of this document. The improved driving device preferably comprises an inner rectangular sleeve (IRS) open at its lower end and closed at its upper end adapted to receive, for example, the upper vertical end of a reflective roadside post, which enable vehicle operators to track the location of the road relative to the reflective post with intention, typically, to drive the post permanently into the ground in the vicinity of the road&#39;s shoulder or thereabout. The IRS lower end opening and inner sleeve cross-sectional shape are adapted to receive such a sign or post or similar objects, including signs or posts or similar objects that are reflective (hereinafter inclusively referred to as “post”) with a cross-sectional shape that is typically and in this case as well is preferably rectangular, which allows the post to be fully inserted into the IRS such that the top end of the post engages the inside top of the IRS. The device also includes an outer rectangular sleeve (ORS) open at its lower end and closed at its upper end adapted to receive and securely and slidably engage the IRS—ergo the rectangular cross-sectional shape. 
     Cross-sectional shapes of the inner and outer sleeves need to be compatible with each other and the inner sleeve has a cross-sectional shape compatible with the top end of the object to be driven by the device. Therefore, it must be understood that the shape of the sleeves could be of varying cross-sectional shape. As long as the inner sleeve can receive the top of the object to be driven such that it can be effectively driven by the outer sleeve impacting the inner sleeve and the portion of the respective sleeves that are slidably engaged—the subject invention, and its alternative embodiments, will be functional within the scope of this specification. 
     The device also includes: a fluid power cylinder (FPC) releasably affixed to the ORS; and a base block (BB) releasably affixed to the IRS with a valve control rod (VCR) releasably affixed thereto. The device also includes a fluid power cylinder connecting rod (FPCCR) releasably affixed to the BB at the lower end of the FPCCR and affixed to fluid power cylinder piston (FPCP) (not illustrated) at its upper end, wherein FPCP resides and reciprocates within the FPC. 
     The device also includes a valve box (VB) adapted to sealably permit the VCR and FPCCR to pass therethrough wherein the VCR controls a spool valve mechanism, and extends through the spool valve (which is disposed in the VB), which alternately directs pressurized fluid, from an external source into opposite sides of the FPCP (which is disposed in the FPC), thereby creating reciprocating motion between the ORS and IRS  30 . The VB is adapted to be self cleaning in that it expels the pressurized fluid, preferably air (or a functional equivalent thereof), from alternating sides of the VB cylindrical chamber which houses the spool valve mechanism therein without the need for a designated exit port or ports. The device also includes a nut, spring, and washer which are preferably respectively located at the upper end of the VCR and preferably a spring and washer are respectively located at the lower end of the VCR—intermediate to the VB and BB. 
     The device may also include, fixed to the lower end of the IRS, a handle assembly (HA). The upper end of the post, which is intended to be hammered so that the lower end of the post may be driven into the ground, is inserted into the open lower end of the IRS until it engages the upper inner closed end of the IRS, the HA may control the delivery of fluid to the VB, which is in effect an ON/OFF switch for the portable driving device. Each handle of the HA includes a switch which opens a valve which is biased closed when pressurized. When each handle switch is activated pressurized fluid is delivered from an external source to the VB. 
     The HA may also include a fluid actuated means for engaging and securing the IRS to the upper portion of the post (not shown in Figures). For example the second handle switch may deliver pressurized fluid to both the VB and a means for securing the IRS to the post, such means being known and which may include providing a pin which is biased in a retracted position and which, when pressurized, presses the top of the post to an inner surface of the IRS. However, alternatively the weight of the device, and the operator&#39;s ability to hold the device on the post, which in turn may stabilize the driving device IRS in relationship to the post (and the ORS during operation) and which may keep the inner closed end of the IRS sufficiently engaged with the top of the post during operation—that is, when the device is pounding the post into the earth as the reciprocating motion of the ORS relative to the IRS. 
     The present invention is accordingly adapted and calibrated to drive the post into the ground by generally keeping the inner closed end of the IRS engaged with the top of the post wherein the VB control of pressurized fluid creates reciprocating motion between the IRS and the ORS wherein the top closed end of the IRS receives repetitive reciprocating impact blows from the inner closed end of the ORS thereby driving the post into the earth. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top isometric view of a first embodiment of a driving device. 
         FIG. 2  is a bottom isometric view of the driving device of  FIG. 1 . 
         FIG. 3  is plan view of a preferred embodiment of a valve box portion of the driving device of  FIG. 1 . 
         FIG. 4  is a top sectional view of an alternative embodiment of the valve box portion of  FIG. 3  with a spool valve. 
         FIG. 5  is a top sectional view of a spool valve showing concave tracts for O-rings. 
         FIG. 6  is a top sectional view of the valve box portion of the driving device of  FIG. 1  with the spool valve of  FIG. 4 . 
         FIG. 7  is a top view of a portion of the driving device of  FIG. 1 , showing additional detail. 
         FIG. 8  is a top isometric exploded view of a handle and handle valve assembly of the driving device of  FIG. 1 . 
         FIG. 9  is a top isometric assembled view of the handle and handle valve assembly of  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     A preferred embodiment of a device for power driving objects will now be illustrated and disclosed. The following description will also include alternative embodiments of the preferred embodiment. The portable driving device  10  is illustrated in the Figures and Drawings (listed above) and is comprised of the parts listed in “Parts List.” The device is adapted to drive a post, or generally any elongated article, into the ground or other medium as desired. The preferred embodiment, however, is adapted to drive a post with substantially rectangular cross-sectional shape which substantially fits within such a rectangular space defined by the driving device—specifically IRS  30 . The preferred embodiment disclosed and illustrated is specifically adapted to drive road-side posts (which are typically used to support “road-signs”) common along the soft shoulders, or similar features, of rural roads. Notwithstanding, the inventive embodiments disclosed herein are equally applicable to a portable driving device adapted to drive a post or an object with a substantially round cross-sectional shape, square cross-sectional shape or for that matter may be adapted for any shape. IRS  30  and ORS  20  merely need to be adapted to this cross-sectional shape—the inventive embodiments disclosed herein as they pertain to the mechanisms that generate reciprocating movement between the ORS  20  and the IRS  30  may be applied to a variety of sizes and shapes of the post and the energy required to drive them into a medium such as soil. 
     The portable power portable power driving device  10  may utilize an innovative valve control mechanism which is particularly useful for reciprocating devices powered by fluids including pneumatic devices powered by compressed air. 
     The innovative portable power portable power driving device  10  may utilize an innovative switch control mechanism which when properly utilized may provide for a safe power driving device. 
     Referring to  FIGS. 1 and 2  showing a preferred embodiment of an improved portable power driving device  10  according to the invention, the device includes IRS  30  and ORS  20 . IRS  30  is open at a lower end  17  thereof (referencing “UP” in  FIG. 1 ), and closed at an upper end  18  thereof, adapted to receive the upper end of a post (not illustrated). The upper end of the post, which is opposite the end which is to be driven into the ground, is preferably slid into the lower (open) end  17  of IRS  30 , until the top of the post engages an inside surface of the upper end  18  of IRS  30  (see  FIG. 2 ). Reflective posts are common on roadsides throughout the world to visually aid drivers at night—they reflect electromagnetic radiation from, for example, a vehicle&#39;s headlights, or similar devices. Such reflective posts have varying cross-sectional shapes; however, many may be slid inside IRS  30  as illustrated herein, and may be effectively hammered thereby into the ground by portable power driving device  10 . 
     As noted above, ORS  20  includes an open lower end  17  and a closed upper end  18  wherein IRS  30  and ORS  20  are adapted to be slidably engaged. Such an engagement can be achieved by many means known in the art including matching the respective cross-sectional shapes, material specifications and dimensional tolerances, of IRS  30  and ORS  20  illustrated and described herein. 
     The elongated cylindrical FPC  41 , with a round cross-sectional shape, may be vertically aligned with ORS  20  and fixed to an upper end  11  (referencing “UP” in  FIG. 1 ) of the outside top of the ORS  20 , and preferably releasably fixed at the upper end and lower end of FPC  41  to provide adequate structural integrity and stability for typical use of the portable power driving device  10 . An upper end  22  of the FPC  41  includes structurally sound means to releasably affix FPC  41  to ORS  20  and includes means to deliver fluid to the interior volume of the upper end of FPC  41 —namely FPCUB  44 —which is releasably connected to the ORS  20 . As illustrated in the preferred embodiment pneumatic connector  55  (including a manual valve as shown in  FIG. 1 ) provides means to get compressed air from VB  54  to FPCUB  44 . That is, FPCUB  44  is connected to FPC  41  wherein compressed air from VB  54  is ultimately delivered to the upper inner portion  24  of FPC  41  through FCP  40 . 
     VB  54  is illustrated in detail in  FIG. 3 . VB  54  has a first chamber  56   a  and a second chamber  56   b . Reference should also be made to  FIG. 4 , which illustrates a cross-sectional side view of a spool valve  57  within a valve box body (not the preferred embodiment of the subject invention).  FIG. 5  illustrates a detailed cross-sectional view of a spool valve detailing a concave tract for O-rings as is well known in the art. With additional reference to  FIG. 6 , showing the spool valve  57  of  FIG. 4  in the VB  54  of  FIG. 3 , and  FIG. 7 , the first chamber  56   a  is adapted to receive the spool valve  57  wherein spool valve  57  is adapted to sealably reciprocate within the first chamber  56   a  and wherein the spool valve  57  is adapted to sealably allow VCR  51  to reciprocate therethrough. Second chamber  56   b  is adapted to allow FPCCR  42  to reciprocate therethrough. FPCCR  42  must be sealably allowed to reciprocate into and out of the lower end  23  of FPC  41 . In the preferred embodiment of the subject invention an extreme end portion  23   a  of the lower end  23  of FPC  41  is sealably and releasably affixed to VB  54 . FPCCR  42  passes through VB  54  (its body). The spool valve, which is not illustrated in its entirety (but see  FIG. 4 ), sealably articulates within the first chamber  56   a  of VB  54  and the range of the spool valve&#39;s upward and downward movement may be defined by threaded stop chambers (or slots)  501   a  and  501   b , left and right respectively as shown in  FIG. 4 , in the top of VB  54  wherein corresponding stops  503   a  and  503   b  may be screwed into the top of the VB  54  to limit, or stop, the upward and downward range of the spool valve&#39;s reciprocation within spool valve chamber  56   a  of VB  54 . The slots ( 501   a  and  501   b ) are shown disposed in the top of the spool valve  57  and extending, in an upward and downward directions, beyond a middle sealed portion  26  of the spool valve (see  FIG. 4 ). VCR  51  sealably articulates through the middle sealed portion  26  of the spool valve within the spool valve chamber  56   a.    
     VB  54  includes a fluid connector, preferably a pneumatic connector  55 , which can be sealably connected to a portable air, or fluid, source such as a small portable air compressor of the type that is well-known in the art. The lower end  23  of FPC  41  is fixed to the approximate middle of the outside top surface  20   a  of ORS  20  at VB  54 . VB  54  includes means for alternately directing, via the spool valve, fluid to the interior volume  24  of the upper end of FPC  41 . Fluid is directly delivered to the interior volume of the lower end  23  of FPC  41  from VB  54 . 
     VB  54  may also include four threaded chambers (or holes)  502  which provide means by which VB  54  may be releasably affixed to ORS  20 . One means therefore would be with four threaded bolts which may extend through the four chambers  502  ( FIG. 3 ) from the top of VB  54  wherein the bottom of the four bolts may be screwed into and aligned with matching threaded holes in ORS  20  as illustrated in part in  FIG. 1 . 
     FPCCR  42  is releasably affixed to FPCP  43 , the latter component illustrated in  FIG. 7 , at the upper end of FPCCR  42  (referencing “UP” in  FIGS. 1 and 7 ), and the FPCP  43  divides FPC  41  between the interior volume  24  of the upper end and the interior volume of the lower end  23 . The affixation is of a sealable and structural nature consistent with reciprocating pressurized fluid power devices well-known in the art. A lower end  42   a  of FPCCR  42  is affixed to the BB  52 . The BB  52  is releasably affixed to the approximate middle of an outside top surface  30   a  of IRS  30 , and projects through a corresponding slot  27  in ORS  20 . The lower ends of FPCCR  42  and VCR  51  are affixed to the BB  52 , preferably releasably affixed. 
     Both FPCCR  42  and the VCR  51  pass through the body of VB  54 . The means for sealing this interface is well-known in the art. 
     With reference to  FIG. 7 , VCR  51  controls the spool valve  57  in VB  54  thereby alternately delivering fluid to the two ends (i.e., the interior volume  24  of the upper end, and the interior volume of the lower end  23 ) of FPC  41 . With additional reference to  FIG. 1 , when fluid is delivered to the interior volume  24  of the upper end of FPC  41  (from VB  54  through FPCC  46 ), FPCP  43  (shown in  FIG. 7 ) is driven from being closer to an upper end  20   b  of ORS  20  (referencing “UP” in  FIGS. 1 and 7 ) to being generally closer to the middle of ORS  20 . Because FPCCR  42  is affixed to BB  52 , which is affixed to IRS  30  and therefore can translate within the slot  27  in ORS  20 , relative motion between IRS  30  and the ORS  20  is created. When the interior volume  24  of the upper end of FPC  41  is “filled” (based upon calibration of the driving device) preferably prior to the top (referencing “UP” in  FIG. 1 ) of the cover  21  of ORS  20  interfering with the BB  52 , and preferably prior to FPCP  43  bottoming in FPC  41  at the extreme lower end  23   a  thereof, VCR  51  engages the spool valve  57  internal to VB  54  and fluid is directed to the interior volume of the lower end  23  of FPC  41 , thereby pushing FPCP  43  back up toward the interior volume  24  of the upper end of FPC  41 . Next, as fluid is directed by VB  54  to the interior volume of the lower end  23  of FPC  41 , ORS  20  is driven down toward IRS  30  until an inner closed end  31  (see  FIG. 2 ) of ORS  20  engages the inside surface of the closed upper end  18  (see  FIG. 2 ) of the IRS  30  whereupon an impact load/force is produced between the IRS  30  and the ORS  20  and is thereby delivered to the post. As noted previously, preferably two stops are bolted into the top of VB  54  to limit the external travel of the spool vis-à-vis VB  54 . 
     The portable power driving device  10  is calibrated so that the impact load is delivered prior to FPCP  43  hitting the ceiling of the interior volume  24  of the upper end of FPC  41  and prior to VB  54  hitting BB  52 . The device is calibrated so the impact load is delivered whereupon VCR  51  engages the spool valve  57  in VB  54  and fluid is directed back to the interior volume  24  of the upper end of FPC  41  and the cycle is repeated. 
     When the portable power driving device  10  is vertically oriented and a vertically oriented post has been engaged at its upper end by the inner closed end of IRS  30 , and the vertically oriented post has been engaged into the soil or a similar medium at its lower end—then the post is driven downward into the soil or similar medium. 
     Notably, the portable power driving device  10  does not require IRS  30  to be fixed to the post. Although the driving device is small and light-weight, its weight, in combination with the strength of an average user, enable the secure installation of a post without the need for means for removable fixing IRS  30  to the post. In one embodiment of the subject invention components are made of aluminum, with the exception of impact surfaces or components, wherein the device will weigh approximately 12 pounds, whereas an all steel unit will weigh approximately 20 pounds. The portable driving device  10  economically allows for such low weights vis-à-vis the prior art. 
     Preferably, fixed to the lower end  17  of IRS  30  is a handle assembly HA  60 , shown in  FIG. 1 . The upper end of the post, which is to be driven into the ground, is inserted into the open lower end  17  of IRS  30  until the upper end of the post engages the inside surface of the closed upper end  18  of IRS  30  (see  FIG. 2 ). Then, the HA  60  may be activated with a switch control (switches  62   a ,  62   b  in  FIG. 1 ), providing fluid actuation means for securing IRS  30  to the post. 
     Preferably, the HA  60  includes two handle bars  61   a  and  61   b  to be gripped firmly by the user—a 0.75 inch O.D. is preferred. Sponge handle grips are also preferably provided on the handle bars, for ergonomically absorbing the shock associated with the reciprocating motion and impact loads delivered. For example, bicycle handle bar grips or handle bar tape, known in the art, are designed for such approximate handle O.D. sizing. At the upper ends of the handles are the switches  62   a  and  62   b , referred to herein as “hand switches,” which are easily thumb activated. Preferably the portable power driving device  10  is not activated, i.e. air is not delivered to VB  54 , until both hand switches are engaged. Thus when either hand switch is disengaged, air delivery to VB  54  is terminated. Means for providing for fluid communication between the hand switches and the supply of air to VB  54  are well-known in the art. 
     Alternatively, the hand switches of HA  60  may obtain the compressed air from an external source, in which case they function as simple pneumatic switches which are well-known in the art. Moderate pressure and volumes of air are necessary for such safety switch functions—and little if any pressurized fluid. 
     Alternatively, one of the HA hand switches  62   a  or  62   b  may activate a pneumatic clamp for releasably securing IRS  30  to a post. The necessary compressive force ultimately securing IRS  30  to the post will be commensurate with the forces necessary to drive the post. Only upon activation of both switches is air delivered to the FPC  41  and hammering of the post commenced. 
     As shown in  FIG. 1 , handle brace bar  67  connects handles  61   a  and  61   b  and may be welded or releasably affixed to IRS  30 . Alternative means known in the art may be utilized to connect handles  61   a  and  61   b  to IRS  30  in a structurally sound manner. 
     Alternatively, IRS  30  may be secured to the post by manual means known in the art such as a simple set screw and threaded aperture in the lower portion of the top of IRS  30 . Disengaging either switch, which is easily achieved by releasing a thumb, which the user may do voluntarily or involuntarily, serves a valuable safety purpose. It is critical and desirable that both hands remain on the HA hand grips as this insures safer operation of the portable driving device  10  as even a hand that slides down a hand grip may not have optimal control of the device. 
     The portable power driving device  10  utilizes approximately 5.5 inches to 7 inches of travel at 50 to 150 psi (compressed air). The overall length of the device is approximately 20 inches—notably shorter than, for example, prior art units employing dual power cylinders. The device is approximately 6 inches wide and 0.75 inches deep. The device requires approximately 2 cubic feet of air, which is notably less than prior art units, including those with dual power cylinders. As noted previously, if the device is formed of steel, the approximate weight is 20 pounds. The device delivers an impact load approximately every 0.75 seconds. However, the impact frequency may be affected by the source of fluid. For example, 50 psi (air pressure) will produce an impact frequency of approximately 60 impacts per minute, whereas 120 psi may produce an impact frequency of 130 impacts per minute. Regulators are well-known in the art as a means of controlling the pressure of fluid delivered to VB  54 . 
     The device  10  is scalable for different impact loads, different cross-sectional shapes of posts, and different fluids used to power the device. 
     The subject invention is versatile. It can be made proportionally larger, while still utilizing the innovative valve control box and hand switch valve control assembly disclosed herein even though the preferred embodiment is disclosed is for use with a relatively small post, having a rectangular sleeve design, with rectangular impact surfaces in the sleeves. 
     Preferably, each end of VCR  51  is threaded with a nut, and proximate the nuts are springs and washers. So, with reference to  FIG. 7 , VCR  51  has upper and lower nuts  33   a  and  33   b  threadably attached thereto, and carries upper and lower springs  34   a  and  34   b , and upper and lower washers  36   a  and  36   b , respectively. The washers tamp and therefore make contact with corresponding faces  38   a  and  38   b  of the spool valve  57 , which will protrude external to VB  54  when directing fluid to one or the other side of FPC  41 , and therefore which will be available for making contact with the corresponding one of the upper and lower washers. An example of such protrusion is shown in  FIG. 6 , showing particularly protrusion of the face  38   b.    
     With reference to  FIG. 7 , when fluid is directed to the interior volume  24  of the lower end of FPC  41 , the piston  43  and FPCCR  42  will be driven downwardly (referencing “UP” in  FIGS. 1 and 7 ), pulling VCR  51  along with it until the upper washer  36   a  engages the spool valve, causing the upper spring  34   a  to become compressed against the upper face  38   a  of the spool valve  57  and eventually force the spool valve downwardly with the result that the lower  38   b  will protrude from the bottom side of the VB  54  as shown in  FIG. 6 . The same principle of operation necessarily functions in reverse, where as a result of the aforedescribed change in position of the spool valve, fluid becomes directed to the interior volume of the lower end  23  of FPC  41 , eventually causing the lower washer  36   b  to make contact with the lower face  38   b  of the spool valve  57 . 
     Calibration of the drive stroke, that is when VB  54  directs fluid into the interior volume of the lower end  23  of FPC  41 , may be in part effectuated according to the spring rate of the lower spring  34   b  on the lower end of VCR  51 . The spring rate may be varied to absorb varying amounts of energy per unit of displacement to impact when fluid directed to the interior volume of the lower end  23  of FPC  41  is terminated. Higher source pressure results in greater impact as more energy is required to move the spool valve. 
     It should be noted that the innovative VB  54  allows air to exit the side of the spool valve  57 . This allows VB  54  to be closed to the external pressurized fluid source as opposed to requiring an exhaust port or ports. Specifically, when fluid is directed to the interior volume  24  of the upper end of the FPC  41 , through FPCC  46  ( FIG. 1 ), and ORS  20  is moving upwardly relative to IRS  30 , fluid is, and critically needs to be, exiting from the interior volume of the lower end  23  of FPC  41 . At such time fluid exits the interior volume of the lower end  23  of the FPC  41  directly into VB  54  and out one side of the spool valve chamber  56   a  (the side not occupied by the spool valve) in VB  54 . And when fluid is directed to the interior volume of the lower end  23  of FPC  41 , and ORS  20  is moving downwardly relative to IRS  30 , fluid is, and critically needs to be, exiting from the interior volume  24  of the upper end of FPC  41 , through FPCC  46 , into VB  54  and out the other side of the spool valve chamber  56   a.    
     It should be noted that suitable seals are well-known in the art to enable the portable driving device  10  to function properly and reliably even though there are moving parts therein, notably the VCR  51  and FPCCR  42 , which oscillate in and out of the pressurized VB  54 . 
     Preferably when the portable driving device  10  is at rest ORS  20  is down—that is, the interior volume of the lower end  23  of FPC  41  is filled with fluid and so the device is collapsed into a configuration of minimum length. 
     It should be noted that the portable driving device  10  allows for compactness with an economy of space and parts. All valve assembly components, and all means of control thereof, are within the footprint of the ORS  20  and the device  10  need not employ more than a single power cylinder. 
     The subject invention is preferably constructed of components which are bolted together although alternatively welded components are viable. It will become apparent that bolted components will allow the subject driving device to be modular wherein the power driving components can be disassembled and reassembled—namely, bolted to an alternative IRS  30  and compatible ORS  20  which are cooperatively adapted for a post of alternative cross-sectional dimensions. For example, ORS  20  may break down into five components: a top, a bottom, two side panels and a closed end. For example, the top and bottom may be used for a post that has a similar cross-sectional length but a greater width, which would require the side panels and closed end to have a greater height. For example, preferably for a reflective post ORS  20  has a length of approximately 20 inches and a width of approximately 5 inches and a depth or thickness of approximately 1.5 inches. 
     Alternatively, ORS  20  need not break down into fewer components. However, what is preferred, to provide modularity which will also ease service to individual components, is for the BB  52  to be releasably affixed to IRS  30 , and VB  54  and FPCUB  44  to be releasably affixed to ORS  20 . Accordingly, the fluid power assembly, which includes FPC  41 , FPCCR  42 , FPCP  43 , and FPCUB  44 , and the VCA  50 , which includes VCR  51 , BB  52 , and VB  54 , may be removed and affixed to an alternative ORS and compatible IRS. As illustrated in  FIG. 1 , four bolts releasably affix VB  54  to the ORS  20  and four other bolts releasably affix the FPCUB  44  to ORS  20 . Two other bolts, not illustrated, affix the BB  52  to IRS  30 ; preferably, these other two bolts have flat heads, with the corresponding bolt-holes being countersunk with chamfer angles to match the bolt heads, to keep the inside surface of IRS  30  flush and thereby eliminate any projections from this surface which could impede or block or scrape the post inserted into IRS  30  as a result of relative motion between the IRS  30  and the post. 
     Alternatively, the slot in ORS  20  may extend to its bottom end and a cover plate  21  ( FIG. 1 ) for the BB  52  may function as a stop for BB  52 . 
     The handle assembly HA  60 , and the hand switches  62   a ,  62   b , and the aforementioned means for providing fluid communication between the hand switches and the supply of air, which may be referred to as a hand switch valve control assembly, may be releasably affixed to IRS  30  at its lower end adding another, if necessary, modular component, since the handle assembly and hand switch valve assembly communicates solely with VB  54  with an appropriate fluid. 
     It should also be noted that the portable power driving device  10  allows for the handle to remain fixed in space during operation of the device—excluding the time the ORS  20  impacts the IRS  30  which in turn drives the post into the ground/soil/other. This makes for a portable driving device that is more user friendly and ergonomic. 
     The HA  60  with pressurized fluid control is depicted in part of  FIG. 1  and in detail in  FIGS. 8 and 9 . A bottom portion of one of the handles, which is shown as  61   a , includes source intake means  39  for connecting to an external source of pressurized fluid (see pneumatic connector  55 ). Also, the intake handle includes an aperture  63  for connection to means by which to divert pressurized fluid from the intake handle  61   a  to the other handle  61   b  as illustrated in  FIG. 1 , such means being shown in  FIG. 1  as handle conduit  68 .  FIG. 8  also illustrates a handle valve assembly  64  which is sealably affixed to and resides on a switch shaft  65  and is slid into the interior volume of the handle  61   a  along with the switch shaft  65  as can be seen by comparing  FIGS. 8 and 9 . The assembly, structure and function of the handle valve assemblies will be readily appreciated by persons of ordinary skill in the art in view of the disclosure herein. 
     The handle valve assembly  64  has an internal portion including a recessed core  70  with an aperture  71 . When switch  62   a  is not engaged, a pressure nut  69  presses an O-ring A against the handle valve assembly. Therefore when external fluid is supplied to the interior volume of the handle  61   a  through the source intake means  39 , the O-ring A prevents fluid from entering the handle valve assembly  64  along the switch shaft and into the internal portion thereof. When air is allowed to pass O-ring A, along the switch shaft and into the internal portion of the handle valve assembly, then O-ring B and O-ring C prevent air from escaping into the interior volume of the handle  61   a  and air is diverted out of the aperture  71 . 
     When switch  62   a  is engaged the handle valve assembly does not move—it remains aligned with the aperture  63 , however the switch shaft  65  moves (typically downwardly) the pressure nut  69  away from O-ring A, thereby allowing O-ring A to float, or flutter, thereby allowing compressed fluid to enter into the inner body of the handle valve assembly and exit the handle valve assembly aperture  71  and out the aligned aperture  63  in handle  61   a , which in turn provides pressurized fluid to handle  61   b  via the handle conduit  68 . 
     On the other hand, when hand switch  62   a  is not engaged, the pressure nut  39  seals O-ring A against the handle valve assembly. Only upon engaging switch  62   a  is the O-ring A allowed to float. 
     Manual switches  62   a  and  62   b  a will not be sealed so air exits after operation and both switches are released. 
     Handle  61   b  is essentially identical to handle  61   a  with the exception that there is no intake means  39 , and pressurized fluid exiting the aperture  63  in the handle  61   b  is delivered to a device which requires, or preferably includes, a two switch means by which to control the delivery of pressurized fluid. It is not illustrated in  FIG. 1  but in the preferred embodiment of the subject invention a means to deliver pressurized fluid from handle  61   b  to the intake connector  55  of VB  54  may include the appropriate sealed connections and a hose or a conduit similar to that utilized for directing pressurized fluid from VB  54  to FPCUB  44 . 
     While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that there are modifications and alterations that do not depart from the inventive concepts disclosed herein. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be afforded the full breadth of the disclosure and any and all equivalents thereof. For example, while the subject invention is directed to post driving devices the innovative driving mechanisms disclosed herein may be adapted for utilization with fracturing devices such as jack-hammers or other devices that can utilize reciprocating motion. 
     Moreover, while the disclosure herein focuses on embodiments which have FPC  41  releasably affixed to ORS  20 , and the BB  52  releasably affixed to IRS  30 , it is fully within the scope of the subject invention to have FPC  41  releasably affixed to IRS  30  and the BB  52  releasably affixed to ORS  20  with accompanying design modification, which would not require independent invention or undue experimentation from one skilled in the art. 
     Additionally, while embodiments of the subject invention are described as having components that are releasably affixed to other components, it should be appreciated that this is to improve the modularity of the subject invention and does not limit the invention to releasably affixed components, and so components may be affixed to other components within the scope of the invention by non-releasable means. 
     PARTS LIST 
       10  portable driving device 
       17  lower end of IRS  30   
       18  upper end of IRS  30   
       20  ORS—outer rectangular sleeve 
       20   a  outside top surface of ORS  20   
       20   b  upper end of ORS  20   
       21  cover plate 
       22  upper end of FPC  41   
       23  lower end of FPC  41   
       23   a  extreme end portion of  23   
       27  slot in ORS  20   
       30  IRS—inner rectangular sleeve 
       30   a  outside top surface of FRS  30   
       31  upper closed end of ORS  20   
       33   a  and  33   b  upper and lower nuts attached to VCR  51   
       34   a  and  34   b  upper and lower springs carried by VCR  51   
       36   a  and  36   b  upper and lower washers carried by VCR  51   
       38   a  and  38   b  faces of spool valve  57   
       39  source intake means for HA  50   
       40  fluid power assembly 
       41  FPC—fluid power cylinder 
       42  FPCCR—fluid power cylinder connecting rod 
       42   a  lower end of FPCCR  42   
       43  FPCP—fluid power cylinder piston 
       44  FPCUB—fluid power cylinder upper box 
       45  fluid power cylinder conduit safety valve 
       46  FPCC—fluid power cylinder conduit 
       50  VCA—valve control assembly 
       51  VCR—valve control rod 
       52  BB—base block 
       54  VB—valve box 
       55  pneumatic connector 
       56   a  and  56   b —chambers of VB  54   
       57  spool valve 
       501   a  and  501   b —slots in VB  54   
       503 —VB threaded chambers 
       503  stops in VB  54   
       60  HA—handle assembly 
       61   a  and  61   b  handle bars 
       62   a  and  62   b  hand switches 
       63  first and second handle apertures 
       64  first and second handle valve assemblies 
       65  switch shaft 
       67  handle brace bar 
       68  handle conduit 
       69  pressure nut 
       70  recessed core of handle valve assembly  64   
       71  aperture through recessed core  70   
     O-rings A, B, and C