Abstract:
The down hole motor is a self-contained radial drive unit that is driven by a linear input, which can be supplied from various sources. As linear motion is applied to the input of the tool, drive pins on a drive shaft follow a helical path, converting the linear motion into radial motion at the attached mandrel end. This may then be utilized in various activities such as drilling, boring and obstruction removal. This tool may also be used in conjunction with jarring mechanisms in order to create an impact drilling device, or a percussion motor.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to down hole fishing and drilling operations, or removing obstructions to a drilling line when such a line becomes lodged or otherwise stuck in the well bore. Conventional means of down hole retrieval are dubious, and usually involve attempting to actuate the entire work string in the hope of dislodging it or removing an obstruction. Often this is unsuccessful either because the work string cannot jar loose the obstructions, or adequate motion cannot be effected in the well bore. Consequences of this failure to remove the obstruction can be failure of the well to produce at all or in part, also, older methods of removing obstructions can result in line breakage, both of which result in having to relocate the drilling operation, which necessarily involves lost time and money. 
     The present invention is able to drive various tools in a well bore that require a radial input, and if so configured, deliver jarring forces simultaneously. The invention can also actuate a lodged object in the path of the drilling path without moving the work string, which results in reduced trauma and friction and prevents work hardening of the work string. The tool can also have various other applications, such as drilling, retrieving or driving other tools that may be attached to it, or in any application, down hole or otherwise, that may require such a jarring, oscillating, jarring or drilling action. 
     OBJECTS OF THE INVENTION 
     One objective of this invention is to provide a device capable of maintaining the bind on a drilling work line while dislodging an object, which may be interfering with the drilling operation. 
     Another objective of the invention is to provide a device which is more efficient at dislodging obstructions interfering with drilling operations. 
     Still another objective of this invention is to provide a tool that can be operated in a well bore or other confined space and supply a radial input for various needs, such as drilling, driving and jarring. 
     Other objects and advantages of this invention shall become apparent from the ensuing descriptions of the invention. 
     SUMMARY OF THE INVENTION 
     According to the present invention, the down hole motor is a self-contained radial drive unit that is driven by a linear input, which can be supplied from various sources. As linear motion is applied to the input of the tool, drive pins on a drive shaft follow a helical path, converting the linear motion into radial motion at the attached mandrel end. This may then be utilized in various activities such as drilling, boring and obstruction removal. This tool may also be used in conjunction with jarring mechanisms in order to create an impact drilling device, or a percussion motor. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings illustrate a preferred embodiment of this invention. However, it is to be understood that this embodiment is intended to be neither exhaustive, nor limiting of the invention. They are but examples of some of the forms in which the invention may be practiced. 
     FIGS. 1A-1D show diametrical longitudinal cross-sections of the down hole motor assembly. 
     FIG. 2 shows an end cross-sectional view of the gear teeth shown in FIGS. 1C and 1D. 
     FIG. 3 shows an end cross-sectional view of the drive pins shown in FIG.  1 B. 
     FIG. 4 shows an end cross-sectional view of the spline shown in FIG.  1 B. 
     FIG. 5 shows a side cross-sectional view of the continuous cam assembly shown in FIG.  1 B. 
     FIG. 6 shows a side cross-sectional view of a single stroke cam assembly. 
     FIG. 7 shows an exploded view of the motor assembly shown in FIGS. 1A-1D. 
     FIG. 8 shows a cutaway view of the spline groove and guide pins shown flat for illustration. 
     FIG. 9 shows a detailed end view of the drive pins in the helical grooves shown in FIG.  8 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Without any intent to limit the scope of this invention, reference is made to the figures in describing the preferred embodiments of the invention. Referring to FIGS. 1 through 9, outer mandrel  101  is used to house and protect the inner workings of down hole motor assembly  300 . Reciprocating drive shaft  302  lies within outer mandrel  101 , and is permitted to move longitudinally within. Reciprocating drive shaft  302  may be attached on one end to a driving input, such as a flow-activated valve assembly  100 , as discussed in more detail below, or any other linear input, while the opposite end of reciprocating drive shaft  302  is operatively connected with upper rotating mandrel  303  in order to convert the linear input into radial motion. Reciprocating drive shaft  302  may also be hollow if it is intended to be used with a hydraulic driving tool, which may require exhaust of hydraulic or other fluid through the center of the tool. To prevent or limit movement of upper rotating mandrel  303  and to contain the parts aft of upper rotating mandrel  303 , a shoulder  323  may be employed along the surface of the inner diameter of outer mandrel  101 . 
     Upper rotating mandrel  303  fits within outer mandrel  101 , but also around reciprocating drive shaft  302 . Upper rotating mandrel  303  engages reciprocating drive shaft  302 , which has radial grooves on the surface of its outer diameter, as pictured in FIG.  5  and in detail in FIG.  8 . Grooves  311  are radially cut in a fashion which, as linear input is provided, provides a continuous linear to radial conversion, discussed further below. 
     Reciprocating drive shaft  302  has a plurality of bores  304  drilled into it, whereby drive pins  305  may be inserted through both reciprocating drive shaft&#39;s  302  bores and into grooves  311  of reciprocating drive shaft  302 . Once pins  305  are inserted, assembly  300  is placed within, and drive pins  305  are held in place by, outer mandrel  101 . This coupling of drive pins  305  in grooves  311  provides the operative connection that converts linear to radial motion. Upper spline connection  316  may be employed on a portion of reciprocating drive shaft  302  to prevent the introduction of any unintended radial motion into the linear movement of reciprocating drive shaft  302 . Upper spline connection  316  is illustrated in greater detail in FIG.  4 . 
     Upper rotating mandrel  303  is operatively connected to upper gear  306 , either by a threadable connection, some other affixation, or may be cast as a single unit so that they maintain mechanical communication. On the end of upper gear  306  opposite this connection is a gear face  307  that faces a complimentary gear face  308  on lower gear  309 . Lower gear  309  is operatively connected to lower rotating mandrel  310 , either threadably or otherwise to maintain mechanical communication. Lower rotating mandrel  310  is then attached to whatever tool or device that is sought to be driven with radial energy. 
     Upper gear  306 , upper gear face  307 , lower gear  309  and lower gear face  308  serve to prevent reverse torque from being applied to upper rotating mandrel  303  and other parts on up through the tool. If a rotational motion opposite to that being driven is applied to lower rotating mandrel  310 , lower gear  309  will freely rotate without engaging upper gear  306 , since gear faces  307  and  308  are configured to drive in only one direction. 
     In an another embodiment, a different groove pattern can be employed on reciprocating drive shaft  302 , such as the one pictured in FIG.  6 . Upper rotating mandrel  303  engages reciprocating drive shaft  302  which has radial grooves  311  on the surface of its outer diameter, as pictured in FIG.  6 . Grooves  311  are radially cut in a fashion which, as linear input is provided, provides a linear to radial conversion on each down stroke, as discussed further below. On the return, or upstroke, however, the radial direction is reversed, thus a full up and down stroke yields an agitating action, such as that provided by an agitator of a typical clothes washer. This method can be coupled with an additional set of gears and rotating mandrel, such as middle gear  313  and middle rotating mandrel  314  to accomplish single-stroke, rather than constant radial motion. 
     Between upper gear  306  and upper rotating mandrel  303  lies a ratcheting assembly, comprising upper kinetic energy sleeve  317 , which serves to maintain downward force on upper gear  306 . This force keeps upper gear  306  in constant communication with middle gear  320  or with lower gear  309 , depending upon which embodiment of the invention is employed. Middle gear  320 , if employed, is operatively affixed to middle rotating mandrel  314  to maintain mechanical communication between the two. 
     In either embodiment, affixed to lower rotating mandrel  310  is lower gear  308 , which utilize a lower spline to prevent unwanted reverse rotation on lower rotating mandrel  310 . Between lower rotating mandrel  310  and or lower spline, if employed, and middle gear  320  is lower kinetic energy sleeve  319  that may be comprised of a mechanical kinetic energy store, such as a spring or other mechanical means, or a compressible gas or fluid. Lower kinetic energy sleeve  319  also assists in maintaining upward force on middle gear  320 , thus keeping upper gear  306  and middle gear  320  in constant communication and engagement with one another, thus preventing it from reversing rotational direction, since the gear faces permit travel in one direction only. These methods prevent reverse torque from being applied to the internal parts of the tool, and prevent lower rotating mandrel  310  from reversing rotational direction. 
     In any embodiment, o-rings  213  may be strategically placed throughout the tool to prevent fluid or other materials that may be passing through or around the tool from entering moving part areas of the tool. It is also important to note that many of these component parts may be cast in single units, if desired, thus reducing the number of discrete parts in the tool. Additionally, the multiple gears  306 ,  308  and  320  may be configured to generate higher or lower ratios per iteration of reciprocating drive shaft  302 , thus generating higher or lower revolutions per minute at the output end, as desired. 
     In operation, when linear input is applied to reciprocating drive shaft  302  it moves downward toward the end of down hole motor assembly  300 , and drive pins  305  move downward within grooves  311 . Since reciprocating drive shaft  302  is prevented from turning within outer mandrel  101  by upper spline  316 , as drive pins  305  move downward, pins  305  follow grooves  311  and the upper rotating mandrel  303  turns in response. As this radial motion occurs, upper gear  306  rotates by virtue of its operative connection. Upper gear face  307  engages lower gear face  315  which rotates in kind, thereby also turning lower rotating mandrel  310 , and thus whatever tool may be attached to same. 
     If the alternate embodiment identified above is utilized, the operation is similar, though radial motion is only delivered as reciprocating drive shaft  302  moves downward, and middle gear  313  and middle rotating mandrel  314  are employed as a ratcheting mechanism so that as reciprocating drive shaft  302  returns upward, middle gear  313  will not be engaged by upper gear  306 , thus the radial motion at lower rotating mandrel  310  will not be reversed, and diminish the radial progress of the tool. 
     The tool can be driven by any device generating a linear input, such as the one in co-pending application entitled “Flow-Activated Valve,” which is hereby incorporated by reference in its entirety. Such a tool would be attached as the driving force of down hole motor assembly  300  by being attached to reciprocating drive shaft  302 . The flow-activated valve is described below. 
     The “top” of tool assembly  100  starts at the top of FIG.  1 A. Shown is outer mandrel  101 , which in the embodiment of the above-mentioned Figures, is threadably separable into several parts to facilitate assembly and maintenance by way of several threaded joints  102 . The tool assembly  100  is shaped to permit connection to a hydraulic source and/or other threaded tool at joint  103 . Outer mandrel  101  also has hydraulic exhaust ports  104 . Located within outer mandrel  101  is the inner mandrel  105 , which, in this embodiment, is threadably attached to outer mandrel  101  and is separable into parts by way of threaded connections  106 . Inner mandrel  105  has hydraulic fore exhaust ports  107  and aft exhaust ports  108 . Hydraulic fluid is also able to exhaust at the lower end of inner mandrel  105  through mill slots  109 . These parts are all stationary while the tool is being operated. 
     Some of the parts of tool assembly  100  are moving while tool assembly  100  is operated, the first of which is reciprocating valve  110 . Like outer mandrel  101  and inner mandrel  105 , reciprocating valve  110  has, in the embodiment shown, been cast as separable pieces joined by threadable connections  111 . Reciprocating valve  110  has fore hydraulic exhaust ports  113  and aft hydraulic exhaust ports  114 . Various shoulders are along reciprocating valve  110  and its path of travel, such as aft hammer shoulder  119 , which engages fore inner shoulder  120  of outer mandrel  101  on the down stroke. There also exists a reciprocating sleeve closing shoulder  118 , and a reciprocating sleeve opening shoulder  121  which is used to actuate reciprocating sleeve  115  during operation. Outer mandrel  101  has a top shoulder  122  where outer mandrel  101  joins inner mandrel  105 . Another moving part, reciprocating sleeve  115  is mounted to engage the outer portion of inner mandrel  105 , and to slide back and forth along a small portion of inner mandrel  105 . As in reciprocating valve  110 , reciprocating sleeve  115  has fore hydraulic exhaust ports  116  and aft hydraulic exhaust ports  117 . 
     It should be recognized that various threadable connections  111 , while shown, are not essential for proper operation, and the invention can be practiced with or without threadable connections  111  on reciprocating valve  110 , outer mandrel  101 , or inner mandrel  105 . Parts may be cast in fewer or more pieces, depending upon need and adoption for a particular use. In any embodiment, o-rings  213  may be strategically placed throughout the tool to prevent fluid or other materials that may be passing through or around the tool from entering moving part areas of the tool. 
     During operation, driving fluid, such as hydraulic fluid, gas or similar, is pumped or otherwise introduced into tool assembly  100  at joint  103 . The fluid then passes within outer mandrel  101 , to inner mandrel  105 , and while tool assembly  100  is in the “up” position, the fluid will exit via aft hydraulic ports  108  of inner mandrel  105 , aft hydraulic ports  114  of reciprocating sleeve  115  and aft hydraulic ports  117  of reciprocating valve  110 , at which point the fluid will force reciprocating valve  110  to move away from the “top” of tool assembly  100 . Eventually, reciprocating valve  110  will engage aft hammer shoulder  119 , creating an impact in the downward direction, as well as marking the end of the downward stroke. 
     Simultaneously with the above action, reciprocating sleeve opening shoulder  121  of reciprocating valve  110 , as it slides, will cause reciprocating sleeve  115  to move down the inner mandrel  105  in the same direction, effectively closing aft hydraulic ports  108  of inner mandrel  105 , and opening fore hydraulic ports  107  of inner mandrel  105 . At this time, the fluid will be permitted to exit via the lower end of inner mandrel  105  through mill slots  109 , at which point it may exit from end  20   122 . This leaves tool assembly  100  in the “down” position. 
     At all times during operation, additional fluid is being pumped into joint  103 , but because inner mandrel  105  hydraulic aft exhaust ports  108  are now closed, the fluid exits through the inner mandrel  105  hydraulic fore exhaust ports  107 , which forces reciprocating valve  110  to move in the direction of joint  103  due to fluid pressure being applied to reciprocating valve  110 , that being the path of least resistance. This movement continues until reciprocating valve  110  reaches top shoulder  122 , at which point reciprocating valve  110  engages top shoulder  122  and creates an impact in an upward direction, marking the end of the upward stroke. At this point, reciprocating valve  110  will have traveled far enough to expose outer mandrel&#39;s  101  hydraulic exhaust ports  104  so that fluid will exit tool assembly  100 . When reciprocating valve  110  is in this position, reciprocating sleeve closing shoulder  118  will have moved reciprocating sleeve  115  to its original, or “up” position, thus restarting the cycle. 
     To assist in the down hole operation, accelerator  123  may be attached to bottom end of tool assembly  100  in order to exaggerate the vibratory motion created by tool assembly  100 . Accelerator  123  is constructed of extending mandrel  124 , which is shaped to fit within outer mandrel  101 , but also to permit a compressible kinetic energy sleeve  125  to fit between the walls of outer mandrel  101  and extending mandrel  124 , and further be connected to reciprocating valve. Kinetic energy sleeve  125  is retained in place by being situated between a fore accelerator shoulder  126  and an aft accelerator shoulder  127 . 
     In this manner, when reciprocating valve  110  is performing a downward stroke, it is energizing a compressible kinetic energy sleeve  125 , such as a spring, belleville washer assembly, stacked chevron washer assembly, risked washer springs, hydraulic fluid or other known similar devices. This is accomplished when fore accelerator shoulder  126  is moving downwardly and compresses kinetic energy sleeve  125 . When reciprocating valve  110  reverses direction, it is thrust forward with the contained kinetic energy stored in compressible kinetic energy sleeve  125 , thus creating a more powerful impact on the upstroke. Similarly, compressible kinetic energy sleeve  125  can be configured to have the reverse effect, or to amplify the downward stroke. This can be done by reversing compressibility of the spring to change the direction of the release of kinetic energy. 
     Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims.