Abstract:
A power line puller control package facilitates the installation of conductor or high tension power lines by directing the conductor or high tension line removal from at least one supply reel at a substantially stable rate, while adjusting the speed of the drum to the amount of the rope or cable on the at least one holding drum, to facilitate manufacturing, installation or use of the high tension power line at a substantially constant speed and tension.

Description:
This invention relates to a power line puller control package and, more particularly, to a power line puller control package which permits installation of a power line in an efficient and safe manner, and at a substantially constant rate of speed and line tension. 
     BACKGROUND OF THE INVENTION 
     Many problems exist with the installation of electrical transmission, distribution, or underground lines. Electrical transmission, distribution, and underground lines are commonly referred to as “conductors.” Conductors transport electrical energy from a generation source to at least one distribution point, and from distribution points to end users. These types of conductors are heavy, have large diameters, and are difficult to handle. Conductors are typically composed of aluminum bands wound around a steel core. 
     Conductors can be damaged if they come in contact with the ground or other objects. Therefore, tension conductor stringing, as opposed to slack conductor stringing, is generally the only acceptable method of installing conductors. During tension stringing, conductors can be damaged if tension beyond the specified maximum is applied during installation. It is desirable to install conductors in a more efficient, controlled, and safe manner. In addition, it is critical that conductor tension specifications are not exceeded. 
     In addition to conductors, fiber optic systems are also installed on transmission lines and distribution systems. Types of fiber optic systems include optical ground wire (OPGW), all dielectric, self supporting (ADSS) cables and optical fiber installed in high-density polyethylene (HDPE) conduits. These types of cables are generally more susceptible to damage from excess tension. 
     Conductor installation using the tension stringing process involves the removal of conductor from a supply reel at a speed and tension within specified parameters. Prior to stringing operations, towers or poles (hereinafter referred to as “structures”) are installed. The structures have several arms to which insulator strings are attached. Stringing blocks, which are large wheels or “sheaves” attached to a housing, are connected to the insulator strings. Hard line cable is unwound from the hard line drum puller and placed in the stringing blocks for a section of structures. When installing a smaller diameter conductor, pulling rope may be used in place of hard line cable. 
     At the opposite end of the rope or hard line cable drum puller, reels of conductor are mounted on reel stands. After the hard line is installed, it is attached to the conductor. The hard line is then recoiled, pulling the conductor back through the stringing blocks. This is often referred as the “pulling” operation. When stringing or pulling is complete, the line is said to be “pulled in.” Once pulled in, the stringing blocks are removed and the conductor is attached or “clipped in” to the structures. 
     During the pulling operation, power to the drum must be continuously adjusted to maintain the speed of the conductor and to maintain constant tension on the conductor as it moves through the stringing blocks. Continuous adjustments to power are necessary because of the continuous change in the diameter of the pulling drum as the pulling line is retrieved thereby causing conductor to be removed from the conductor supply reel. Excessive tension during installation can damage the conductor. A damaged conductor can cause voltage drops, corona losses, reliability issues, and catastrophic failure. Therefore, it is essential to maintain a constant pulling tension within the design parameters. In addition, a conductor can jam in a stringing block. Without a mechanism to automatically sense the increase in tension and make adjustments, including shutting down the pull if necessary, structures and equipment can be severely damaged. 
     The delays to a project caused by a conductor jam in a stringing block can be excessive. A damaged conductor may have to be removed and replaced. If a structure is damaged, the structure may have to be replaced. This may entail time to order and manufacture a new section as well as the time needed to perform the replacement. 
     SUMMARY OF THE INVENTION 
     Among the many objectives of the present invention is the provision of a power line puller control package for a conductor to be mounted on a series of electrical transmission towers that can maintain constant conductor tension and speed during a pull. 
     A further objective of the present invention is the provision of a power line puller control package that automatically prevents maximum tension parameters from being exceeded. 
     Another objective of the present invention is the provision of a power line puller control package, which automatically adjusts to the diameter of the pulling line wrap on at least one pulling drum or at least one cable drum. 
     Yet another objective of the present invention is the provision of a power line puller control package, which adjusts to the weight of the pulling line on at least one pulling drum. 
     Still another objective of the present invention is the provision of a power line puller control package, which records the tension on the conductor as it is pulled. 
     Also an objective of the present invention is the provision of a power line puller control package, which controls pulling of conductor through stringing blocks. 
     A further objective of the present invention is the provision of a power line puller control package, which prevents undue stress on structures supporting the conductor. 
     Still another objective of the present invention is the provision of a power line puller control package that will automatically stop the pull when maximum tension parameters are reached. 
     These and other objectives of the invention (which other objectives become clear by consideration of the specifications, claims, and drawings as a whole) are met by controlling the rope or hard line cable retrieval to maintain a substantially constant rate and constant tension, by adjusting the speed of the reel or drum to the amount of the pulling line wrap on at least one pulling drum. This facilitates installation of conductors by automatically controlling the speed and tension on the conductor as it is being pulled through stringing blocks. This invention can also be used in cable manufacturing by adjusting the system to maintain constant conductor tension when manufactured cable is wound on to supply reels. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  depicts a block diagram of the power line puller control package  100  of this invention. 
         FIG. 2  depicts a perspective view of the power line puller control package  100  of this invention mounted on a flat bed trailer  102 . 
         FIG. 3  depicts a perspective view of the power line puller control package  100  of this invention isolated to first drum of cable holding drum  120 . 
         FIG. 4  depicts a perspective view of the control panel  160  for computer  150  used with the power line puller control package  100  of this invention. 
         FIG. 5  depicts a side, cut away view of first drum of cable holding drum  120  with sensor  122  for the power line puller control package  100  of this invention. 
         FIG. 6  depicts a computer screen view  210  for the power line puller control package  100  of this invention. 
         FIG. 7  depicts a computer set up method for the power line puller control package  100  with the first soft button  212  of this invention. 
         FIG. 8  depicts a computer set up method with second soft button  214  for the power line puller control package  100  of this invention. 
         FIG. 9   a  and  FIG. 9   b  combine to depict a computer set up method with third soft button  216  for the power line puller control package  100  of this invention. 
         FIG. 10  depicts a computer set up method with fourth soft button  218  for the power line puller control package  100  of this invention. 
     
    
    
     Throughout the figures of the drawings, where the same part appears in more than one figure of the drawings, the same number is applied thereto. 
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to several embodiments of the invention that are illustrated in accompanying drawings. Whenever possible, the same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale. For purposes of convenience and clarity only, directional terms such as top, bottom, left, right, up, down, over, above, below, beneath, rear, and front, may be used with respect to the drawings. These and similar directional terms are not to be construed to limit the scope of the invention in any manner. The words attach, connect, couple, and similar terms with their inflectional morphemes do not necessarily denote direct or intermediate connections, but may also include connections through mediate elements or devices. 
     The power line puller control package of this invention provides for a safer, faster, and more efficient installation of transmission, distribution, or underground electric power lines, (“conductors”), from one or more supply reels, whether a hard line cable is required for the heavier conductor, or rope is used for the lighter conductor. Unless otherwise specified, hard line cable and rope are used interchangeably herein. More particularly, the power line puller control package provides these and other benefits when used in the tension stringing installation process as set forth above. 
     The power line control package provides several benefits during the installation process. These include maintaining a constant conductor speed as it travels through the stringing blocks, maintaining a constant tension on the conductor as it travels through the stringing blocks, preventing excessive tension on the conductor, and providing an automatic system shut down if the conductor becomes stuck in one of the stringing blocks. In addition, the power line control system can be used to record the actual amount of tension placed on the conductor during the pulling process. 
     Information from various parts of the puller control package is used to continuously adjust the speed of the hard line cable drum by compensating for the diameter changes on the drum as the hard line is reeled in. Also, in a manufacturing setting, this power line control package can assist in the efficient placing of the conductor as manufactured onto the reels for distribution. 
     The power line puller control package is a single or multi drum power line puller. During operation, one drum is engaged at a time by an operator manually or automatically connecting the drum to a drive axle and releasing or setting the brake. The prime mover is a diesel engine driving a closed loop pump which, in turn operates a motor, preferably a hydraulic motor. The output of the motor is connected through gear reduction. The control program for the computer calculates line speed and line pull, limiting these values to a maximum line speed and a maximum line pull. 
     Turning now to  FIG. 1 , the power line puller control package  100  pulls the conductor  110  from conductor reel  116  onto tower  118 . Computer  150  receives readouts from various parts of the puller control package  100  to adjust the speed of the hard line cable or rope holding drum  120  in order to control the pull on the hard line cable  112  or rope  114  ( FIG. 3 ) and thus the conductor  110  is strung on tower  118  as hard line cable  112  recoils on the cable holding drum  120  at a substantially linear constant rate within desired parameters by compensating for the diameter and weight changes of the conductor  110 , by measuring the wrap of the hard line cable  112  on the cable holding drum  120 , pursuant to adjustments by computer  150 . A drum sensor  122  measures the diameter of the wrap of the hard line cable  112  on cable holding drum  120  and feeds the information to the computer  150 . In so doing the conductor reel  116  has conductor  110 . 
     An engine  128 , preferably a diesel engine, is connected to a closed loop pump  136 . The closed loop pump  136  is connected to a motor  124 . Then motor  124  is connected to a brake  126 . Between the brake  126  and the cable holding drum  120  is planetary gear assembly  130 . 
     Computer  150  directly receives and coordinates data from engine  128 , closed loop pump  136 , motor  124 , brake  126  and drum sensor  122 . This data is tabulated and the speed of the drum  120  is measured and adjusted by the data tabulation of the computer  150  according to predetermined parameters. Computer  150  compares the data from each source and appropriately applies the motor  124  as desired, to keep the speed of cable  112  recoiling on the hard line cable holding drum  120  substantially constant, for safer installation of the conductor  110 . 
     Turning now to  FIG. 2 , the axle  132  is connected to motor  124  through a chain drive, which selectively operates each one of the drums  120  for the multi reel power line puller control package  100 . The multi-drum power line puller control package  100  and other equipment may be mounted on a flat bed trailer  102  which has towing neck  106  to assist in transport. The rope or hard line cable holding drums  120  are mounted on the support bed  104  of trailer  102 , while the computer  150  is mounted above the drums  120  on the trailer  102 . During operation, one drum  120  is engaged at a time by an operator, who manually or automatically connects the drum  120  to the drive axle  132  and releasing or setting the brake  126 . The prime mover is a diesel engine  128  driving a closed loop pump  136 , which operates a motor  124 . The output of the motor  124  is connected through a planetary gear assembly  130 . The control program for computer  150  will calculate line speed and line pull or tension of cable  112  and conductor  110 , limiting these values to a maximum line speed and maximum line pull. 
     In  FIG. 4 , control panel  160  for computer  150 , illustrates how the power line puller control package  100  operates. Engine revolutions per minute  162  is to be controlled with display push buttons  164 . Communication values displaying engine parameters of miles per hour  166 , pounds per square inch  168 , line pull  170 , are situated in a control panel  160 . Additional inputs will be monitored for warning or shut down conditions of the hydraulic system. In  FIG. 6 , pressing third soft button  216  will display an information page which will provide real time values of the hydraulic system  176 . 
     To engage the motor  124  and spin the axle  132 , a run mode or enable switch  180  must be in the “on” position. A center lock, friction held joystick  182 , which has joystick output  186 , will be used to operate the motor  124  in a forward manner or a reverse manner, as desired or necessary. The joystick  182  has a neutral switch  184 . With no inputs in the fault condition, the adjustable max line pull and max speed will be limited by the readout comparisons. 
     In  FIG. 5  cable holding drum  120  has a sensor  122  for the power line puller control package  100  of this invention. Sensor  122  assists in the determination of how much cable or rope is left on drum  120 . 
     Turning to  FIG. 7 , a limp mode  280  is to be included to operate at  50  percent of the maximum power if readout inputs are in fault condition. Enablement of limp mode  280  is done in a setup screen  192  of computer  150  with password protection. 
     Turning now to  FIG. 6 , computer screen view  210  depicts a standard procedure for operating the power line puller control package  100 . First soft button  212  provides a drum selection function  270  for any of the cable holding drums  120  ( FIG. 2 ). Second soft button  214  operates and controls the diesel engine  128 . Third soft button  216  controls various readouts during the operation of power line puller control package  100 . Fourth soft button  218  provides access to the fault modes  230  of power line puller control package  100 . 
     Fifth soft button  220 , sixth soft button  222  as well as the first soft button  212 , second soft button  214 , third soft button  216 , fourth soft button  218 , seventh soft button  224 , and eighth soft button  226  provide for the insertion of protective passwords for using computer  150 . Seventh soft button  224  relates to maximum engine revolutions (RPM) per minute and RPM gage  240 , and cooperates with eighth soft button  226  which relates to idle engine  128 , especially in an idle mode. 
     Also within computer screen view  210  is operation button  242  situated below line pull gage  234 , and above RPM adjustment switch  244 . Line speed indicator  246  is adjacent to first soft button  212 . Drum indicator  248  indicates which of the drums  120  is being used, and is positioned between line speed indicator  246  and line pull gage  234 . Layer indicator  250  is also positioned between line speed indicator  246  and line pull gage  234 , and below drum indicator  248 . 
     Below the screen view indicators are, from left to right, the escape button  256 , the adjustment button  258 , and the direction buttons  260 . In this manner, minor adjustments can be made. While other arrangements for  FIG. 6  are possible, this arrangement has proven to be the most efficient. 
     With the addition of  FIG. 7 , first soft button  212  for the power line puller control package  100  is further defined. Drum selection function  270  feeds from first soft button  212  and into first soft line pull selection function  272 . Also extending from soft button  212 , is the password function  274 . Password function  274  controls the access to the max line pull function  276 , the max line miles per hour (M.P.H.) function  278 , and the limp mode function  280 . Once these three functions are set, a password is required to make any changes. 
     Adding  FIG. 8  to the consideration, computer  150  is set up with second soft button  214  for the power line puller control package  100 . More particularly, second soft button  214  activates engine temperature gauge  290 , engine oil pressure  292 , electrical voltage  294 , and engine revolutions per minute  296 , each of which preferably includes a flashing light indication upon deviation from the desired parameters. Computer  150  ( FIG. 1 ) compares the activated parameter to determine and confirm that preset guidelines are met within the desired parameters. As those parameters are constantly monitored, information is fed to engine fault  298 . Engine fault  298  becomes fault active  300  if the parameters of safe operation as programmed into the computer  150  are not met, so that the operation of power line puller control package  100  ends until the problem is corrected. Engine fault  298  becomes fault inactive  302  if the desired parameters at one time were not met, but problems were corrected (history of active codes). 
       FIG. 9   a  verifies a computer set up method for computer  150  with third soft button  216  for the power line puller control package  100  which adjusts the main screen of computer  150  ( FIG. 1 ). Third soft button  216  activates a series of screen functions, such as the limp mode function  280 , and provides a screen readout on the functioning thereof. Other features covered include the suction strainer switch  310 , the case filter switch  312 , the charge filter switch  314  and the auxiliary filter switch  316 . Such readouts verify the working functions of the switches. 
     In a like fashion, hydraulic temperature readout  318 , fluid level indicator  320 , hydraulic motor rpm gauge  322  and feet per minute cable on drum measurement  324  provide gauges or similar indicators to show readings and provide a comparison with the preset computer readout. 
     Turning to  FIG. 9   b  third soft button  216  also provides for a scrollable information source  326 , to provide screen readouts for various other factors with the program for computer  150  ( FIG. 1 ). There are readouts for drum one diameter  328 , drum two diameter  330 , drum three diameter  332 , drum four diameter  334 , drum five diameter  336 , and any other drum which may be present. With this information, the diameter of cable  112  ( FIG. 3 ) on any drum can be determined. This in turn leads to determination of the amount thereon, pursuant to the computer  150 . 
     With the hydraulic motor displacement readout  338  ( FIG. 9   b ), the information on amounts and rates of cable  112  ( FIG. 1 ), combined with the bare drum diameter  340  ( FIG. 9   b ) knowledge thereon or paid out can be determined. When the gear ratio  350  of the planetary gear assembly  130  ( FIG. 1 ), is considered further control is achieved. For the other measurements like rope diameter  352 , drive efficiency  354 , sensing length for drum sensors gage  356 , case pressure gage  358 , pressure payout gage  360 , and feet gage  362  similar actions are possible. 
     Turning back to  FIG. 9   a , third soft button  216  also accesses a pump case temperature readout  370 , a motor case temperature readout  372 , the actual psi charge  374 , and the low psi indicator  376 . With the proper preset parameters, computer  150  analyzes all of these factors and provides tremendous control for pulling conductor  110  ( FIG. 1 ), with a clear recording of the tension and speed of the conductor  110  as it is positioned. Thus, conductor  110  can be positioned for use with great efficiency. 
     In  FIG. 10 , fourth soft button  218  provides a diagnostic system for the power line puller control package  100  of this invention, with a fault system for functions thereof. A first fault page  382  can display up to 24 faults on the hydraulic system  176  ( FIG. 1 ) while the second fault page  384  can display up to 24 different faults for the hydraulic system  176 , thereby providing even more control for the installation of a conductor with a cable  112 . 
     When considering the figures together inputs required for calculating line pull and line speed are: 
     1) Drum  120  with the cable diameter measured by an ultrasonic drum sensor  122 ; 
     2) Motor  124  hydraulic pressure measured with a pressure transducer; and 
     3) Motor Speed measured with pulse pick up unit (hereinafter “PPU”) frequency input. 
     PPU is the method of measuring the rotation of the drive motor. An electromagnetic pulse pick-up unit, particularly for use in flow meters having small nominal width, has a pair of magnets arranged at opposite locations and with opposite polarity in a measuring gear of the flow meter. Concentrically arranged with the axis of rotation of the gear, there is provided a sensing unit assembled of a central pick-up cylinder, a sensing coil arranged around the portion of the cylinder facing the magnet, and a plurality of Wiegand wires distributed side by side in axial direction on the cylindrical outer surface of the pick-up cylinder in close proximity to the sensing coil. A pole ring of magnetically conductive material short circuits the ends of the Wiegand wires remote from the magnets. 
     Memory variables for the motor  124  include motor displacement, drive ratio, drum diameter, cable winding diameter, and PPU frequency. The efficiency multiplier may be checked, so that wear and tear on the power line puller control package  100  can be determined efficiently. The rope or cable layer calculation is to be made utilizing the calculated pull radius minus the drum radius divided by the rope diameter. Layer number will be displayed. 
     To assist engagement of a given drum  120  through a planetary gear assembly  130  and the drive axle  132  is a Bump input which will allow pump flow at an eeMemory selected value. By Bump is meant a feature written into the code enabling the turning the drum remotely without using the joystick. There will be a Bump FWD (forward) and Bump (reverse) REV. This will be allowed in the setup screen of computer  150  with a display push button input, which enables Bump control. 
     Limp mode function  280  is set at maximum output of fifty (50%) percent. The limp mode function  280  is a feature of the computer program operating this device, which allows the operator (under password protection) to retrieve cable  112  when a fault, (non catastrophic) has occurred. This is a safety feature only, and can be used until the proper fix is completed. 
     Operation will be open loop with no maximum speed and line pull with a proportional-integral-derivative (hereinafter “PID”) controller. A proportional-integral-derivative controller (PID controller) is a generic control loop feedback mechanism (controller) widely used in industrial control systems. A PID controller attempts to correct the error between a measured process variable and a desired set point by calculating and then outputting a corrective action that can adjust the process accordingly and rapidly, to keep the error minimal. Limp mode function  280  will be read from the setup screen. 
     The eeMemory setup values to be made with Service Tool parameter pages. Additional hydraulic power unit parameters for the closed loop pump  136  monitored and actions preferably are: 
     The hydraulic temperature which has a display value with a warning at 180 degrees Fahrenheit, and shut down at 200 degrees Fahrenheit; 
     The low fluid level which has a display condition and a shut down at low level after 10 second delay; 
     The charge pressure which has a display value, with warning at 200 pounds per square inch (hereinafter “psi”), with shutdown at  150  psi, while the engine  128  is at greater than 500 revolutions per minute (hereinafter “RPM”) for 30 seconds; 
     The motor RPM which has a display value; 
     The suction strainer indicator which has a display condition and a shut down if active and engine 500 RPM for 30 seconds. 
     The charge filter indicator which has a display condition and shut down if active. 
     The auxiliary return indicator, which has a display condition and shut down if active. 
     An ISO (International Organization for Standards) term for the way the different computer systems interface with each other is under the code J1939 (or CAN) available with the engine parameters controlled and monitored. Any standard diesel engine  128  may be used. A diesel engine from John Deere and Company of Moline, Ill. is useful with this system. 
     Typical useful readouts include: 
     RPM—Push button for full throttle or to minimum throttle. Push button for throttle up by 50 rpm or down by 50 rpm per button input; 
     Oil Pressure—Display value, shut down below customer specified value and engine greater than 500 RPM for 30 seconds; 
     Voltage—Display value, warning at voltage below customer specified value; 
     Coolant Temp—Display value, warning and shut down at customer specified values; 
     Fairlead or Level Wind System refers to an open center hydraulic system operated electronically, moving an arm to wind the cable  112  on the drum  120  evenly. 
     The drum  120  selection is made by an input at the display setup screen  192 . The corresponding structure enables the solenoid valve is to energize allowing fairlead control at the drum. A fairlead control joystick  188  ( FIG. 4 ) will be used to operate the fairlead left and right. The fairlead control joystick  188  neutral switch is to be interlocked with fairlead control joystick output  190 . Controller output for proportional left and output for proportional right control is based on the fairlead control joystick  188  position. 
     For the Display Detail, the following parameters are preferred: 
     The Operation, Information, and J1939 Engine screens will be allowed during operation. Throttle is to be controlled in these screens. The fault screen is to be allowed in neutral and when fault is active. A setup screen is to be allowed in neutral. 
     Operation Screen: 
     RPM: Dial showing revolutions per minute (RPM) with adjustment buttons, which are used to throttle up or down. Use the right arrow for bump 50 RPM UP and the left arrow bump 50 RPM DN down. 
     Line Speed Miles per hour (MPH): Dial showing current speed, with a maximum speed indicator on the dial. The maximum speed to be set with the up or down arrows—enabled when pushing a soft button, entering a password protection screen before making the max speed change. 
     Line Pull: Dial showing current line pull, with a max line pull indicator on the dial. The max line pull to be set with the up or down arrows—enabled when pushing a soft button  200 , entering a password protection screen before making max line pull change. 
     Text value displaying system hydraulic pressure preferably includes: 
     Buttons for screen navigation; 
     Blinking icon for fault, warning, or shutdown; 
     Drum rope layer; 
     Drum  120  selection; 
     Fault Screen Warning or shutdown condition—blink the icon by soft button in operation screen; 
     Display fault conditions of I/O (input/output) (text with check box); 
     Information Screen: Warning condition—blink the icon by soft button in operation screen; 
     Charge pressure pump; 
     Hydraulic oil temperature; 
     Fluid level or low oil switch; 
     Motor  124  RPM; 
     Suction Strainer indicator; 
     Charge Filter indicator; 
     Auxiliary Filter indicator; 
     Drum with cable diameter; 
     Set Up Screen with Drum Selection, Bump Control, Limp Mode Enable; 
     J1939 screen: Warning or shutdown condition—blink the icon by soft button in operation screen; 
     Voltage; 
     Coolant Temp; 
     Oil Pressure. 
     These readouts may all be coordinated by computer  150 , which then directs the appropriate function of the power line puller control package  100 . Through the proper algorithm, the function of cable  112  can then be used to install a conductor as a high tension line. 
     In the following examples, which are intended to illustrate without unduly limiting the scope of this invention, all parts and percentages are by unless otherwise indicated. 
     Example 1 
     A 50 mile transmission line is scheduled to be installed. The job consists of 25 separate pulls. On the tenth pull, the conductor becomes jammed in a stringing block. Using the prior art procedure, the linemen performing the work do not realize the problem until the conductor is severely damaged and the pole where the jam occurs becomes twisted by the excessive force. The pulling operation is shut down. The damaged cable is removed causing a delay of two days. A new pole top section is ordered from the pole manufacturer, causing a delay of 60 days, and being delivered to the site, causing a delay of ten days. The damage pole top section is removed and the new section is installed causing a delay of three days. A new conductor is reinstalled causing a delay of two days. In addition, the crews must move ahead to another pull to continue the line pulling operation and return to damaged location to perform the repairs causing an eight-day disruption delay. Total delay equals 85 days. In addition to the excessive delays, this incident causes catastrophic cost failure. 
     Example 2 
     A 50 mile transmission line is scheduled to be installed. The job consists of 25 separate pulls. On the tenth pull, the conductor becomes jammed in a stringing block. Using the power line control package  100  of this invention, the puller automatically shuts down when the tension setting is exceeded. A lineman inspects the line and finds the jammed stringing block, the jam is corrected and the pull is restarted. Total delay equals five hours. The costs of this incident are minimal. 
     This application—taken as a whole with the abstract, specification, claims, and drawings—provides sufficient information for a person having ordinary skill in the art to practice the invention disclosed and claimed herein. Any measures necessary to practice this invention are well within the skill of a person having ordinary skill in this art after that person has made a careful study of this disclosure. 
     Because of this disclosure and solely because of this disclosure, modification of this tool can become clear to a person having ordinary skill in this particular art. Such modifications are clearly covered by this disclosure.