Abstract:
The disclosure provides a method of oil delivery to a chainsaw chain blade using a gerotor pump in sequence with flow control valves to provide lubrication to the chain blade to reduce friction with the chainsaw bar guide and prevent overheating and damage to the chain blade or guide bar.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/196,682, filed Jul. 24, 2015 and entitled OIL DELIVERY SYSTEM FOR THE LUBRICATION OF A CHAINSAW, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Field 
         [0003]    The present disclosure relates to an oil delivery system for lubrication, and, more particularly, to an oil delivery system for the lubrication of chainsaw chain blade around a guide bar. 
         [0004]    2. Description of Related Art 
         [0005]    Chainsaws are commonly used to fell trees and harvest timber, both on an industrial scale and in private use. Chainsaws generally include a motor, typically either electric or gasoline powered, that drives a metal chain blade, comprising interlinked articulated saw teeth, around a guide bar at a high speed such that saw teeth along the chain may cut through timber or other materials. Chainsaws are used in handheld form and are also mounted onto machines as part of a larger timber processing systems, such as firewood processors, tree harvesters, or feller grapple heads. 
         [0006]    The surface between the chain blade and guide bar requires adequate lubrication to reduce the amount of heat generated by friction, and prevent deterioration of the chain blade and guide bar. To lubricate this surface, lubricating fluid is typically pulled from a reservoir through fluid conduits by a pump and delivered to the guide bar, where the fluid lubricates the interface between chain blade and guide bar. 
         [0007]    Currently, two different types of pumps are used to provide oil and lubrication to the interface between a chainsaw chain blade and guide bar. One type of pump, a syringe pump, is comprised of a piston that forces oil through a chamber and fluid lines to the guide bar. Another type of pump, a gasoline fuel injection pump, comprises a cylinder that rotates inside of a chamber of oil, thereby flows oil to the guide bar. As depicted in  FIG. 1 , a chainsaw lubrication system generally comprises an oil reservoir, a pump, and fluid flow lines to provide lubricating oil to the interface between the chainsaw chain blade and guide bar channel. 
         [0008]    The conventional syringe and fuel injection style pumps require frequent maintenance and fail to consistently deliver the optimal flow of oil to the guide bar necessary for maximum chain cutting efficiency. Therefore, there is a need in the industry for an improved oil pump mechanism for delivery of lubrication. 
       SUMMARY 
       [0009]    The following is a summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not intended to identify all key or critical elements of the invention or to delineate the entire scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later. 
         [0010]    Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of claimed subject matter. Thus, appearances of phrases such as “in one embodiment” or “an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in one or more embodiments. 
         [0011]    The present invention comprises a positive displacement gerotor pump, oil reservoir, gate valve, pressure relief valve, chainsaw guide bar, and fluid tubing feed lines that together deliver oil at a consistent rate to the chainsaw chain blade and guide bar. The gerotor pump is mounted in a housing and powered by a motor. The housing incorporates input and output ports to which fluid feed lines may be attached, as well as an inner and outer gerotor gears. 
         [0012]    The motor spins the gerotor gears to create suction that pulls oil from an oil reservoir through the fluid feed tubing lines. A gate valve (GV) is connected to the output of the gerotor pump, and a pressure relief valve (PRV) is also connected to output of the gerotor pump. 
         [0013]    The GV downregulates the oil flow and the PRV outlet returns surplus oil back to the oil reservoir if the oil pressure exceeds a set threshold in the fluid lines upstream of the GV. The outlet line from the GV is connected to an oil inlet port on the chainsaw guide bar and the oil passes through an oil feed line to the guide bar channel and is picked up by the underside of the chain blade as it rotates along the guide bar. 
         [0014]    On larger systems such as firewood processors or tree harvesters, some components of the oil lubrication system may be located outside of the chainsaw motor housing, and system components employed to deliver oil to the chain blade and guide bar may be mounted throughout the machinery. 
         [0015]    During use the motor powering the gerotor pump is activated, simultaneously when an operator starts the firewood processor, chainsaw or other machine, and spins the gerotor gears to pull oil through the fluid flow lines. Oil is pumped through the fluid lines continuously while the machine is in operation. Upon shutting off the machine, the motor stops powering the pump, ceasing the flow of oil. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Non-limiting and non-exhaustive features will be described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various figures. The figures below were not intended to be drawn to any precise scale with respect to size, angular relationship, or relative position. 
           [0017]      FIG. 1  depicts the general structure and major components of oil lubrication systems currently used on chainsaws. 
           [0018]      FIG. 2  depicts the general structure and major components of a chainsaw. 
           [0019]      FIG. 3  depicts the channel and rails of a chainsaw guide bar. 
           [0020]      FIG. 4  depicts the attachment structures and other aspects of a chainsaw guide bar. 
           [0021]      FIG. 5  depicts a schematic of the present invention, including the fluid reservoir, gerotor pump, pressure relief valve, gate valve and chainsaw guide bar mounting plate. 
           [0022]      FIG. 6  depicts the outer gerotor gear, the inner gerotor gear and inner gerotor gear pin. 
           [0023]      FIG. 7  depicts the internal structure of the gerotor pump, with the gerotor pump housing top portion removed. 
           [0024]      FIG. 8  depicts the internal structure of the gerotor pump, with the o-ring, inner gerotor gear pin, and gerotor pump housing top portion removed. 
           [0025]      FIG. 9  depicts the gerotor pump bottom portion with most of the gerotor gear components removed. 
           [0026]      FIG. 10  depicts the gerotor pump housing top portion. 
           [0027]      FIG. 11  is a schematic that depicts the gerotor housing top portion in three separate views: front, side and back. 
           [0028]      FIG. 12  is a schematic that depicts the gerotor housing bottom portion in three separate views: front, side and back. 
           [0029]      FIG. 13  depicts a side view of the pump motor and the motor mounting plate. 
           [0030]      FIG. 14  depicts a perspective top-side view of the pump motor and the motor mounting plate. 
           [0031]      FIG. 15  depicts an exemplary configuration of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    These, and other, aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof and the invention includes all such modifications, such as, but not limited to, the use of this lubrication system technology on masonry chainsaws and systems, or for the lubrication of circular saw blades. 
         [0033]    Chainsaws are commonly used in the forestry industry to gather timber for production into finished goods such as lumber, firewood, or woodchips. Chainsaws are also commonly sold for private use for smaller-scale tree felling. They may be hand-held for direct use by an individual operator, or may be incorporated into harvesting systems where the chainsaw is used to cut timber for a larger-scale tree felling or log-splitting operation. Specialized chainsaws are also used in the masonry industry to cut through stone. 
         [0034]    The present invention is an improvement to lubrication systems currently employed in, but not limited to, chainsaws as well as larger raw material harvesting systems such as tree harvesters and firewood processors. Unlike existing lubrication systems, the present invention uses a gerotor pump to pull oil from an oil reservoir and drive oil through the system. The gerotor pump is a simple and elegant positive displacement pump design that requires little to no maintenance—in contrast to conventional chainsaw and bar saw oil pumps. 
         [0035]    In the present invention, a lubricating fluid, e.g. oil, is held in a reservoir and is pulled from the reservoir through fluid feed line tubing into a gerotor pump through suction created by operation of the pump. Further, once inside the gerotor pump the fluid is compressed and pushed through fluid feed line tubing to the gate valve (GV), which downregulates the fluid flow and may cause an increase in pressure in the fluid lines between the gerotor pump and the GV. 
         [0036]    A pressure relief valve (PRV) is also connected to the fluid lines downstream of the gerotor pump, wherein the PRV allows surplus fluid to flow back into the reservoir to decrease the amount of fluid in the feed lines and keep the pressure in the fluid lines between the gerotor pump and GV below some set threshold. Beyond the GV, the fluid flows through additional system fluid lines, components and delivery mechanisms to the point of application. 
         [0037]    In one embodiment for application to a chainsaw, the fluid, e.g. oil, flows from the GV to a guide bar mount inlet port, through the guide bar mount oil conduit, out of the guide bar mount oil delivery port and into the guide bar mount oil feed channel. The guide bar is secured to the guide bar mount and the guide bar oil inlet port is aligned with the guide bar mount oil feed channel, to feed oil from the oil feed channel into the guide bar oil conduit, out of the guide bar channel oil delivery port and into to the guide bar channel, applying lubrication to the channel, rails and also to the underside of the chainsaw chain blade. 
         [0038]      FIG. 1  depicts the general structure and major components of an oil lubrication system for a chainsaw, known in the art, which comprises an oil reservoir  122 , a pump  101 , and fluid delivery lines  146  and  130 . Oil travels from the reservoir  122  through the delivery line  146 , into the pump  101 , through delivery line  130  and into guide bar mount oil delivery port  142  of the guide bar mount  140  (see  FIG. 5 ). From the guide bar mount delivery port  142 , the oil travels through the oil feed channel  136  and into the guide bar oil inlet port  120  in order to lubricate the interface between the chainsaw chain blade and the guide bar (respectively  104  &amp;  106  in  FIG. 2 ). In practice, when the guide bar  106  is secured to the guide bar mount  140  inside the motor housing  102  via the guide bar mounting bolts  138  and the guide bar mounting holes ( 112  in  FIGS. 3 &amp; 4 ), the oil feed channel  136  is sealed against the surface of the guide bar  102  surrounding the guide bar oil inlet port  120 . The motor housing  102  may also include a handle  105  for easy carrying and use of the machine. 
         [0039]      FIG. 2  depicts the general structure of a chainsaw, known in the art, which comprises the motor housing  102 , the chainsaw chain blade  104  and guide bar  106 . The motor housing contains a chainsaw motor drive  108  (also seen in  FIG. 1 ), which is employed to drive the chain blade around the guide bar, and a guide bar mount plate ( 140  in  FIGS. 1 &amp; 5 ) to which the guide bar  106  is affixed. The motor drive  108  may be powered by an electric, gasoline or hydraulic motor, without limitation. The motor housing  102  also usually contains a lubrication system designed to provide oil to the interface between the chainsaw chain blade  104  and guide bar  106 . 
         [0040]      FIG. 3  illustrates the portion of a chainsaw guide bar  106 , including the guide bar mounting slot  110  and guide bar mounting holes  112 , that is typically employed in securement to and alignment with the guide bar mount plate ( FIGS. 1 &amp; 5 ).  FIG. 3  also depicts the guide bar rails  114  and guide bar channel  116 , which serve to guide the chainsaw chain blade  104  as it is driven around the guide bar  106  by the chainsaw motor drive  108  ( FIGS. 1 &amp; 2 ). In addition,  FIG. 3  shows the guide bar oil inlet port  120 , comprising a small opening located on the side of the guide bar. 
         [0041]      FIG. 4  depicts a side view of the portion of the chainsaw guide bar  106  that is typically secured to the guide bar mount plate  140  ( FIGS. 1 &amp; 5 ). The guide bar oil inlet port  120  is aligned with the guide bar mount plate oil feed channel  136  ( FIGS. 1 &amp; 5 ) using the guide bar mounting slot  110  and guide bar mounting holes  112 . The guide bar oil inlet port  120  receives oil from the guide bar mount plate oil feed channel  136  ( FIGS. 1 &amp; 5 ) and the oil passes through the guide bar oil inlet port and into the guide bar oil conduit  118  and flows into the guide bar channel  116  where the oil provides lubrication to the interface between the chain blade  104  and the guide bar channel  116  and guide bar rails  114 . 
         [0042]      FIG. 5  depicts an embodiment of the present invention, as designed for a chainsaw or bar saw application, which comprises at least an oil reservoir  122 , a gerotor pump  144 , a pressure relief valve  126 , a gate valve  128  and oil feed lines  124 ,  130  and  146 . As shown in  FIG. 5 , the PRV  126  and GV  128  are connected downsteam from the gerotor pump. The GV is also connected to the guide bar mount plate oil feed port  132 , located on the guide bar mount plate  140 , via oil feed line  130 . The guide bar mount plate  140  may either be contained within the chainsaw motor housing  102  (as shown in  FIG. 1 ) or mounted independently on larger machinery. 
         [0043]    In operation, the gerotor pump  144  pulls oil from the oil reservoir  122  through the oil feed line  146  and sends oil to the GV  128  and PRV  126 . The GV  128  functions to downregulate the amount of oil that can flow from the gerotor pump  144  and into the guide bar mount plate oil feed port  132 , and may enable the user to entirely shut off the flow of oil through the oil feed line  130 . Downregulating the flow of oil from the GV  128  to the guide bar mount plate oil feed port  132  increases the pressure in the oil feed lines upstream of the GV. 
         [0044]    If the pressure in the fluid feed line upstream of the GV exceeds a set threshold, the PRV  126  allows surplus oil to flow back into the oil reservoir  122  through oil feed line  124 . The PRV thereby controls system pressure between the gerotor pump  144  and the GV  128  and ensures that the system will not experience a potential catastrophic build-up of pressure that could cause it to rupture or explode. The system may operate with a pressure threshold that is set between 0 and 21 PSI, but ideally the system is operated with a pressure threshold that is set between 1 and 5 PSI. 
         [0045]    From the GV  128 , oil flows through the oil feed line  130  into the guide bar mount plate oil inlet port  132 , located on the guide bar mount plate  140 , through the guide bar mount plate oil conduit  134 , out of the guide bar mount plate oil delivery port  142  and into the oil feed channel  136 . As described above with respect to chainsaw and bar saw oil lubrication systems known in the art, oil flows from the oil feed channel  136  into the guide bar oil inlet port  120 , through the guide bar oil conduit  118  and into the guide bar channel  116  to provide lubrication at the guide bar channel  116  and rails  114  and the underside of the chain blade  104 . The guide bar mount plate  140  attaches to the chainsaw guide bar via the guide bar mounting bolts  138  on the guide bar mount plate. 
         [0046]    As shown in  FIGS. 6-12 , the gerotor pump  144  comprises inner and outer gerotor gears, with an offset number of interlocking teeth and notches, which function to open and close void spaces, or fluid cavities, as the gears turn and thereby create suction and pressure to drive fluid, e.g. oil, through the system. 
         [0047]      FIG. 6  depicts the outer gerotor gear  148 , inner gerotor gear  152  and inner gerotor gear pin  158 . The inner gerotor gear  152  has inner gerotor gear teeth  156  and inner gerotor gear pin notches  154 , and the outer gerotor gear  148  has (n+1) number of outer gerotor gear notches  150 , where “n” is the number of inner gerotor gear teeth. In one embodiment, the inner gerotor gear has four (4) gear teeth and the outer gerotor gear has five (5) gear notches. 
         [0048]      FIG. 7  depicts the inner gerotor gear  152 , outer gerotor gear  148  and inner gerotor gear pin  158  secured within the gerotor pump housing bottom portion  164 . The inner gerotor gear pin  158  passes through the motor rod pin hole ( 192  in  FIG. 13 ) and rests in the inner gerotor gear pin notches  154  to secure the inner gerotor gear  152  in position around the motor rod  160 . The inner gerotor gear  152  is positioned within the outer gerotor gear  148 , such that at any one time an inner gerotor gear tooth  156  fits precisely into an outer gerotor gear notch  150  leaving the other inner gerotor gear teeth misaligned with the other outer gerotor gear notches. 
         [0049]    In operation, the spinning gerotor pump gears induce oil to enter a fluid cavity via suction created by opening and expanding a fluid cavity  170 . The fluid is then discharged from the cavity as the cavity contracts and closes. As the motor rod  160  spins, the inner gerotor gear  152 , being secured to the motor rod by the inner gerotor gear pin  158 , rotates within the outer gerotor gear  148  and transfers the spinning motion to the outer gerotor gear  148 . 
         [0050]    As the gerotor gears spin, a fluid enclosure or cavity  170  is created, opening and expanding to pull oil from the fluid inlet port ( 180  in  FIGS. 10 &amp; 11 ). As the gears spin, a fluid cavity  170  opens, pulling in oil; as it expands to fully open, it reaches a maximum enclosure volume and oil containment capacity. Subsequently, the cavity begins to contract, and the shrinking volume forces the enclosed oil to flow out through the fluid outlet port ( 176  in  FIGS. 10 &amp; 11 ). The cavity closes entirely as an inner gerotor gear tooth  156  slides into place to occupy the outer gerotor gear notch  150  in entirety. 
         [0051]    As seen in  FIG. 7 , the gerotor pump housing bottom portion  164 , in conjunction with the gerotor pump housing top portion  182  ( FIG. 10 ) holds the internal gerotor pump components in place. The gerotor pump housing bottom portion  164  attaches to the gerotor pump housing top portion  182  via large bolt holes  166  and small bolt holes  162 . The gerotor o-ring  168  creates a sealed fluid chamber around the outer gerotor gear  148 , inner gerotor gear  152 , inner gerotor gear pin  158  and motor rod  160  required to maintain suction during the creation of a fluid enclosure  170  and ensure that oil does not leak out of the gerotor pump.  FIG. 8  shows the gerotor o-ring groove  172 , which holds the gerotor o-ring  168  that creates a fluid-tight seal around the gerotor gears. 
         [0052]      FIG. 9  depicts the gerotor pump  144  with the gerotor pump housing top portion ( 182  in  FIG. 10 ), inner gerotor gear  152  and outer gerotor gear  148  removed. Oil pocket recesses  174  present in the gerotor pump bottom housing portion  164  are visible, which recesses serve to increase the amount of oil that can be taken into and held within a fluid enclosure  170 . The oil pocket recesses  174  also function to bring oil to the underside of the gerotor gears for lubrication. 
         [0053]      FIG. 10  shows gerotor pump housing top portion  182 . Two oil pocket recesses  174  serve to bring oil to the topside of the gerotor gears for lubrication, and also expand total fluid enclosure  170  size. Oil enters the gerotor pump through the oil inlet port  180 , fills the fluid cavity  170  created by the gap between an inner gerotor gear tooth  156  and outer gerotor gear notch  150 , and is discharged from the gerotor pump through the oil outlet port  176 , as the fluid cavity  170  closes. 
         [0054]    The motor rod hole  178  provides space for the top end of the motor rod  160  to be enclosed entirely within the gerotor pump housing. To secure the two halves of the gerotor pump housing together bolts may be threaded into one or more large bolt holes  166  and small bolt holes  162 , which align between the top and bottom gerotor pump housing portions ( 164  and  182 , respectively). 
         [0055]      FIG. 11  is a schematic of the gerotor pump housing top portion  172  where View  1  is of the inner face of the top portion, View  2  is a side view of the housing top portion and View  3  is of the outer face of the top portion. In View  1 , the oil pocket recesses  174  used to increase fluid enclosure  170  size are visible. 
         [0056]      FIG. 12  is a schematic of the gerotor pump housing bottom portion  164  where View  4  is of the inner face of the bottom portion, View  5  is a side view of the housing bottom portion and View  6  is the outer face of the bottom portion—which connects to the motor mounting plate ( 188  in  FIGS. 13 &amp; 14 ). View  4  reflects two oil pocket recesses  174  that expand fluid cavity size and provide lubrication to the underside of the inner and outer gerotor gears,  152  and  148  respectively. As visible in View  5 , the motor rod pass-through  184  allows the motor rod  160  to pass from the motor ( 186  in  FIG. 13 ) through the gerotor pump housing bottom portion  164 , through the gerotor gears and into the motor rod hole  178 . 
         [0057]      FIGS. 13 and 14  depict a motor  186  that may be used to drive the inner gerotor gear  152  which in turn spins the outer gerotor gear  148  and creates the fluid enclosures  170  necessary to move oil between the fluid inlet port  180  and fluid outlet port  176 . The inner gerotor gear pin  158  rests in the motor rod pin hole  192  and occupies the inner gerotor gear pin notches  154  to rotationally secure the inner gerotor gear  152  to the motor rod  160 . The gerotor housing may be mounted onto the motor mounting plate  188  by securing bolts threaded into the large bolt holes  166  to the motor mounting plate pump fixture points  190 . 
         [0058]    The pump motor may be powered by, but is not limited to, combustion, electric or hydraulic mechanisms. In a preferred embodiment the powered motor is hydraulic. The powered motor may also be in communication with the combustion, electric or hydraulic drive system of the machine, e.g. chainsaw or firewood processor, such that the pump motor is activated simultaneously when the device is in use. 
         [0059]    The embodiments of the present invention may be implemented on devices including, but not limited to, chainsaws, felling grapple hooks, firewood processors, and/or tree harvesters. It should be understood that claimed subject matter is not limited to use only within the forestry industry, but may also be used in other industries such as, but not limited to, the mining industry. 
         [0060]    While the embodiment just described includes the placement of a GV and PRV after a gerotor pump, it should be understood that claimed subject matter is not intended to be limited in scope to any particular arrangement or combination of valves, and valves may be placed before or after the gerotor pump in any particular order as desired by the user. Further, it should be understood that claimed subject matter need not include any valves, or only two valves, but may include any number of valves in combination with a gerotor pump and oil reservoir to provide lubrication to a chainsaw chain blade, such as seen in  FIG. 15 . 
         [0061]      FIG. 15  depicts a sample configuration of the present invention without a PRV or GV in place, wherein the gerotor pump  144  is in fluid communication with the oil reservoir  122  via an oil feed line  146  and with the guide bar mount plate oil inlet port  132  via an oil feed line  130 . 
         [0062]    While the embodiment just described includes the use of large and small bolts to secure the gerotor pump  144  housing portions ( 164  and  182 ) together and to the motor mounting plate  188  of the motor  186 , it should be understood that claimed subject matter is not intended to be limited in scope to the use of bolts to secure the housing portions to each other or to a motor mounting plate, and bolts not need be used as the specific mechanisms of securement, attachment or affixation. 
         [0063]    Further, it should be understood that claimed subject matter can involve any configuration of bolts of any size, and need not be specifically oriented as depicted in  FIGS. 11 and 12 . Additionally, it should be understood that claimed subject matter is not intended to be limited to a pump housing composed of two independent halves secured together. But instead, the invention may rather include, but not is limited to, a single housing portion created as a single independent unit or a single housing portion comprising a gerotor pump housing top portion and bottom portion having been welded together. 
         [0064]    It should be understood that claimed subject matter is not intended to be limited in scope wherein the inner gerotor gear  152  and outer gerotor gear  148  rotate clockwise, but that inner gerotor gear and outer gerotor gear may instead rotate counterclockwise, as desired by the user. 
         [0065]    While the embodiment just described includes the use of two large oil recess pockets  174  in the gerotor pump housing bottom portion  164  parallel to two smaller oil recess pockets  174  in the gerotor pump housing top portion  182 , it should be understood that claimed subject matter need not include oil recess pockets sized and oriented in this manner, but may have any number of oil recess pockets, i.e. one large pocket or three or more small pockets, oriented at any angle with respect to any other oil recess pockets inside of the gerotor pump housing. 
         [0066]    While the figures just described depict an inner gerotor gear  152  with four inner gerotor gear teeth  156  and an outer gerotor gear  148  with five outer gerotor gear notches  154 , it should be understood that claimed subject matter is not limited to this specific number of teeth and notches, but may include an inner gerotor gear with any number of inner gerotor gear teeth and outer gerotor gear with any number of outer gerotor gear notches, such that the number of outer gerotor gear notches exceeds the number of inner gerotor gear teeth by at least one notch. 
         [0067]    While the embodiments just described entail the use of oil as a lubricant for chainsaw chain blades, it should be understood that claimed subject matter is not intended to be limited in scope to only the use of oil as a lubricant, but that the lubrication system may be used to deliver any type of lubricating fluid, including but not limited to vegetable oil, motor oil, gasoline, or water. 
         [0068]    It should be understood that, although a specific embodiment has just been described, claimed subject matter is not intended to be limited in scope to any particular embodiment or implementation. In the preceding description, various aspects of claimed subject matter may have been described. For purposes of explanation, specific numbers, systems, or configurations may have been set forth to provide a thorough understanding of claimed subject matter. However, it should be apparent to one skilled in the art having the benefit of this disclosure that claimed subject matter may be practiced without those specific details. In other instances, features that would be understood by one of ordinary skill were omitted or simplified so as not to obscure claimed subject matter. While certain features have been illustrated or described herein, many modifications, substitutions, changes, or equivalents may not occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications or changes as fall within the true spirit of the claimed subject matter.