CABLE STRINGING ASSEMBLY HAVING ELECTRIC AIR MOVING DEVICE AND METHODS THERETO

The disclosed technology includes an air moving system for a stringing apparatus. The air moving system can comprise an energy bank, an electric air moving device in electrical communication with the energy bank and configured to output a supply of air to cause a cable to move along a duct and at least one controller. The at least one controller can be configured to determine a speed of the cable moving along the duct and control the output of the supply of air of the electric air moving device to control the speed of the cable based at least in part on the determined speed of the cable.

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THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

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SEQUENCE LISTING

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BACKGROUND OF THE DISCLOSURE

1. Field of the Invention

The invention is in the field of cable stringing apparatuses and methods, and, more particularly, to underground cable stringing apparatuses and methods.

2. Description of Related Art

High voltage utility transmission lines can transmit power over hundreds of miles with minimal losses because of the very high voltages used. These high voltage utility transmission lines are installed in both overhead and underground systems. Stringing high-voltage conductor lines across significant distances requires the use of conductor stringing apparatuses. The installation of power transmission lines and communication lines, sometimes referred to as “pulling conductors”, or “tension stringing” utilizes a number of components spread over a wide area. A device called a conductor or cable puller-tensioner is used, although those of skill in the art know that other terms are used for this equipment. The equipment is typically termed by what it does.

For underground stringing applications, special stringing equipment is used to push a bird (also referred to as a torpedo, pig, mouse, etc.) connected to an end of a cable (or rope) through an underground duct using a supply of air. This operation is sometimes referred to as a “blowing” operation because the air is used to blow the cable through the duct to reach the other end of the duct. Once at the opposite end of the duct, the cable is attached to a conductor (such as utility lines, fiber optic cables, and the like) and pulled back through the duct to complete the installation of the conductor. Generally, a reel (spool, wheel, drum, etc.) is positioned at the opposite end of the duct and the conductor is pulled off the reel and into the duct.

Existing underground stringing equipment generally include an internal combustion engine configured to power hydraulic systems and the air compressor, which can limit the applications where the air compressor is used. Furthermore, the air compressors currently used are designed to only output air from the air compressor at a single, full-capacity, flow rate. Thus, when the bird becomes stuck in the duct, the cable and bird must be pulled back out or additional air pressure must be applied by a vacuum placed at the opposite end of the duct or by an additional or larger air compressor system. This requires additional equipment which increases cost and time required to complete the installation.

Accordingly, there is a need it the art for improved underground stringing apparatuses capable of controlling a delivery of air to the duct through a range of flow rates to complete the stringing installation in a more efficient and effective manner. Furthermore, it is desirable to augment power supplied conventionally only by internal combustion engines/generators if not remove completely the dependence upon internal combustion engines in underground stringing applications. Aspects of the disclosed technology address these and other issues.

BRIEF SUMMARY OF THE INVENTION

The disclosed technology includes an air moving system for a stringing apparatus. The air moving system can include an energy bank, an electric air moving device in electrical communication with the energy bank and configured to output a supply of air to cause a cable to move along a duct, and at least one controller. The at least one controller can be configured to determine a speed of the cable moving along the duct and control the output of the supply of air of the electric air moving device to control the speed of the cable based at least in part on the determined speed of the cable.

The disclosed technology can further include stringing apparatus comprising an energy bank, a driveline in electrical communication with the energy bank and configured to receive or to deliver a cable, an electric air moving device in electrical communication with the energy bank and configured to output a supply of air, and at least one controller. The at least one controller can be configured to determine a speed of a cable being delivered from the driveline and control the output of the supply of air of the electric air moving device to control the speed of the cable based at least in part on the determined speed of the cable.

These and other objects, features and advantages of the disclosed technology will become more apparent upon reading the following specification in conjunction with the accompanying drawing figures.

DETAILED DESCRIPTION OF THE INVENTION

To facilitate an understanding of the principles and features of the various examples of the invention, various illustrative embodiments are explained below. Although examples of the invention are explained in detail, it is to be understood that other examples are contemplated. Accordingly, it is not intended that the invention is limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other examples and of being practiced or carried out in various ways. Also, in describing the examples, specific terminology will be resorted to for the sake of clarity.

It must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. For example, reference to a component is intended also to include composition of a plurality of components. References to a composition containing “a” constituent is intended to include other constituents in addition to the one named.

Also, in describing the disclosed technology, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.

Ranges may be expressed herein as from “about” or “approximately” or “substantially” one particular value and/or to “about” or “approximately” or “substantially” another particular value. When such a range is expressed, other exemplary embodiments include from the one particular value and/or to the other particular value.

It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Furthermore, although the various methods may be shown and described herein as having a particular order, it will be appreciated by one of skill in the art that the method steps shown and described can be rearranged in various other orders without departing from the scope of this disclosure. Similarly, it is also to be understood that the mention of one or more components in a composition does not preclude the presence of additional components than those expressly identified.

Examples of the disclosed technology can include underground stringing equipment for stringing wires, pulling lines, ropes, cables, cords, and the like (collectively, “cables”) through underground ducts. The underground stringing equipment can include a battery bank, a capacitor bank, or both (“energy bank”) configured to provide power to a hydraulic system and to an air moving device. The air moving device can be configured to vary its output to affect the pressure and flowrate of the air to control a speed at which a cable is moved through a duct. The energy bank can further provide power to a levelwind and a reel configured to pull a cable back through the duct to install the cable. The underground stringing equipment can further comprise an engine coupled to a generator, which can charge the energy bank to ensure sufficient power is available to complete the installation.

Examples of the present disclosure may include additional energy sources and stores. For example, the system can be adapted to receive power from an external power source (e.g., by plugging into an external generator or the power grid). The external power can include additional energy banks that can be connected to the underground stringing equipment to charge the onboard energy bank or to provide additional power to the underground stringing equipment during a blowing or pulling operation.

For case of explanation, the system is discussed below with reference to stringing underground power and communications lines. One of skill in the art will recognize, however, that the system is not so limited. Indeed, the system could be used in any number of industries where ropes, cables, wires, and other similar products need to be efficiently installed through a duct, whether above or below ground. Thus, the description below is intended to be illustrative and not limiting.

FIGS.1and2depict an underground stringing apparatus100(sometimes referred to herein as “underground stringing equipment”), duct20, and reel200, in accordance with the disclosed technology. As shown inFIG.1, the underground stringing apparatus100can be positioned at one end of the duct20and the reel200, which has a conductor50disposed on it, can be positioned at the other end of the duct20. As shown, the duct20can extend beneath the ground10between various access points. Although the underground stringing apparatus100is described herein as being used for installing conductors50underground, it will be appreciated that the disclosed technology can be used for installing conductor50through ducts20whether above ground or underground. Thus, although the disclosed technology is described in the context of an underground stringing apparatus, it will be understood by one of skill in the art that various other applications of the disclosed technology are possible.

The underground stringing apparatus100, as will be described in greater detail herein, can include features and components that can be used to first blow a cable30(or rope) through the duct20from the side closest to the underground stringing apparatus100to the side closest to the reel200. The cable30can then be attached to a conductor50(such as utility lines, fiber optic cables, and the like) and the conductor50can be pulled with the cable30back through the duct20to install the conductor50in the duct20(as shown inFIG.2).

To first blow the cable30through the duct20, the underground stringing apparatus100can include an air moving device, as will be described in greater detail herein, attached to an air hose32. Air can be supplied through the air hose32to an adapter34that can connect the air hose32to the duct20. The adapter34can be further configured to permit the cable30to pass therethrough. A bird40(also sometimes referred to as a torpedo, pig, mouse, etc.) can be attached to a distal end of the cable30. The bird40can have an outer diameter that is slightly less than the inner diameter of the duct20. Alternatively, the bird40can be made from a flexible material and have an outer diameter that is slightly larger than the inner diameter of the duct20such that the bird40forms a seal with the duct20. In this way, as air is passed through the air hose32and the adapter34into the duct20, a difference in air pressure on opposing sides of the bird40will cause the bird40to pass through the duct20, thereby pulling the cable30through the duct20.

Once the cable30reaches the other side of the duct20, the cable30can be attached to the conductor50using a connector60such as a pulling grip or other similar device. The underground stringing apparatus100can include a driveline, as will be described in greater detail herein, that can be configured to pull the conductor50back through the duct20. Various sheave blocks70or other similar components can be used to help guide the conductor50to and from the duct20to ensure the conductor50does not become damaged. The driveline of the underground stringing apparatus100can be sized to pull large conductors50long distances, such as several miles depending on the application. For example, the underground stringing apparatus100can include a driveline that is capable of pulling with a force of approximately 1,000 lbs, 2,500 lbs, 5,000 lbs, 7,500 lbs, 10,000 lbs or greater to install high voltage conductors50over great distances.

FIG.3Ais a first perspective view of an underground stringing apparatus100,FIG.3Bis a second perspective view of the underground stringing apparatus100,FIG.3Cis a top view of the underground stringing apparatus100, andFIGS.3D and3Eare side views of the underground stringing apparatus100, in accordance with the disclosed technology. As shown inFIG.3A, the underground stringing apparatus100can be disposed on a trailer having a chassis102, wheels103, and a trailer hitch104that can be configured to support the underground stringing apparatus100. Although shown as being disposed on a trailer, it will be appreciated that the underground stringing apparatus100can be disposed on other vehicles or supports such as a truck, van, boat, or support frame. Thus, although shown and described in the context of being disposed on a trailer, it will be appreciated that the disclosure is not so limited.

The underground stringing apparatus100can further include a boom106that can extend outwardly from the chassis102and be configured to articulate or move using one or more actuators. For example,FIG.3Ashows a first actuator108that can be configured to move the boom106up and down whileFIG.3Bshows second actuators109that can be configured to move the boom106from side to side. The actuators108,109can be hydraulic cylinders, electromechanical actuators, pneumatic actuators, etc. The underground stringing apparatus100can further include an actuator control console110that can include levers or other control elements to control the actuator108,109. The boom106can further include a sheave107at its distal end that can be configured to rotate and guide the cable30(shown inFIGS.1and2) from the underground stringing apparatus100.

As shown inFIGS.3D and3E, the boom106can be extended and retracted to increase and decrease the length of the boom106. Furthermore, the boom106can be lifted and lowered between a high position (FIG.3D) and a low position (FIG.3E) by the actuator108. Furthermore, although not shown, the end of the boom106can rotate to change an angle of the sheave107to ensure the cable30is not damaged by rubbing on the sheave107or other components of the underground stringing apparatus100.

The cable30can be wound around a driveline114that can be configured to rotate in a first direction to pull the cable30onto the driveline114and in a second direction to deliver the cable30from the driveline114(payout the cable). The driveline114can be configured to rotate via an electric motor115(shown inFIG.3B) that is attached to the driveline114. As described previously, the electric motor115can be sized for pulling the cable30and high voltage conductors over several miles depending on the application (e.g., capable of pulling with a force of approximately 1,000 lbs, 2,500 lbs, 5,000 lbs, 7,500 lbs, 10,000 lbs or greater).

The underground stringing apparatus100can further include a levelwind116that can be configured to align the cable30on the driveline114(a drum, bull wheel, spool, reel, driveline or the like), to ensure the cable30does not become tangled or bound. As will be appreciated, the levelwind116can be synced with the driveline114to ensure the levelwind116moves at the appropriate speed to align the cable30onto the driveline114.

The underground stringing apparatus100can include a sheave assembly112to help guide the cable30from the driveline114to the sheave107on the boom106to ensure the cable30does not become damaged from contacting other components of the underground stringing apparatus100when being paid out or pulled onto the driveline114.

The underground stringing apparatus100can further include an energy bank120that can be configured to provide power to various components of the underground stringing apparatus100. The energy bank120can include a battery, a capacitor, a bank of batteries, and/or a bank of capacitors. The energy bank120can be sized to provide sufficient power to the driveline114and an air moving device140.

The underground stringing apparatus100can include a generator unit130such as a gas generator having an engine that can drive a generator. The generator unit130can be configured provide power to the energy bank120to charge the energy bank120as necessary. For example, if the underground stringing apparatus100is used for a conductor installation job that lasts several hours or days, the energy bank120may be capable of providing power for the length of the installation job and, therefore, the generator unit130can be used to periodically charge the energy bank120to ensure sufficient power is available to complete the installation job.

The underground stringing apparatus100can include one or more air moving devices140that can be configured to provide a supply of air through an air hose32(shown inFIG.1) and to the duct20through an adapter34as previously described. The air hose32can be stored on or otherwise wrapped around a hose reel142from which the air hose32can be pulled off of or wound onto. The air moving device140can be sized and configured to provide a supply of air having a high flow and low pressure as well as a low flow and high pressure. In other words, unlike existing systems which only provide air at a maximum output when turned on, the disclosed technology can be configured to provide a supply of air that is highly tunable to the current conditions and desired installation parameters. In some examples the air moving device140can be configured to output an air supply at a pressure ranging from approximately 2 psi to 100 psi and a flow rate of approximately 10 CFM to 1000 CFM. In other examples, the air moving device140can be configured to output an air supply at a pressure ranging from approximately 4 psi to 30 psi and approximately between 100 CFM and 220 CFM.

The air moving device140can be or include an air compressor and/or an air blower that can be powered by an electric motor141. Furthermore, although only a single air moving device140is shown inFIGS.3A-3E, it will be appreciated that more than one air moving device140can be included in the underground stringing apparatus100. If the air moving device140is a blower, the air moving device140can include a roots-type blower, a twin-screw blower, or a centrifugal blower. If the air moving device140is a compressor, the air moving device140can include a super charger, a rotary screw compressor, a reciprocating air compressor, an axial compressor, a centrifugal compressor, and/or an oilless air compressor. Furthermore, the air moving device140can include a combination of two or more different types of air moving devices depending on the particular application and desired performance characteristics.

In some examples, the underground stringing apparatus100can include one or more electric motors141configured to drive one or more air moving devices140in a parallel or a series configuration as controlled by a controller150(described further herein). As a non-limiting example, the air moving device140can include a first air moving device and a second are moving devices that can operate in parallel when an air supply having a high flow and low pressure is desired and can operate in series when a low flow and high pressure is desired. To illustrate, the first and second air moving devices can operate in parallel during an initial installation phase in which a high flow and low pressure is desired to move the bird40through the duct20at a relatively fast speed. If the bird40encounters an obstruction or is otherwise unable to move forward, the first and second air moving devices can operate in a series configuration to deliver a low flow and high-pressure air supply to drive the bird40through the duct20. In this way, the first and second air moving devices can be utilized together to effectively push the bird40and cable30through the duct.

Although described as being an electric air moving device140, the underground stringing apparatus100can include one or more combustion engine driven air moving devices (not shown). For example, the underground stringing apparatus100can include an electric air moving device140as well as a combustion-engine-driven air moving device and the controller150can be configured to operate the electric air moving device140until the energy bank120is depleted at which time the controller150can cause the combustion-engine-driven air moving device to operate to continue driving the bird40. In other examples, the underground stringing apparatus100can include multiple combustion-engine-driven air moving devices and be configured to operate the multiple combustion-engine-driven air moving devices in series or parallel as just described, or according to any of the methods described herein. The underground stringing apparatus100can further include at least one controller150that can be configured to receive data from various sensors and output control signals to various components of the underground stringing apparatus100.

The controller150can be or include one or more digital, analog, or mechanical control elements. The controller150can further include a user interface152which can display data to, and receive inputs from, an operator of the underground stringing apparatus100. As will be described in greater detail herein, the controller150can be configured to control the underground stringing apparatus100to ensure the cable30is effectively blown through the duct20and that the conductor50is effectively pulled back through the duct20.

As shown inFIGS.3B and3C, the underground stringing apparatus100can include an air reservoir160that can be configured to store a volume of compressed air. As described previously, sometimes when blowing the cable30through the duct20, the bird40can encounter an obstruction or otherwise be unable to continue moving through the duct based on the current air supply. The air reservoir160can be configured to deliver the volume of compressed air when the bird40is unable to continue moving through the duct20. The air reservoir160can be sized to deliver a sufficient volume of the compressed air multiple times to help move the bird40through the duct before the air reservoir160needs to be refilled with compressed air. A control valve162can be in fluid communication with the air reservoir160and configured to control an output of air from the air reservoir160. The control valve162can be configured for manual control (e.g., an operator can manually open and close the control valve162by actuating a handle or pressing a button) and/or be controlled by the controller150. For example, the control valve162can be an electronically-controlled valve configured to open or close based on an output from the controller150.

As shown inFIG.3C, the underground stringing apparatus100can further include an air intensifier163and/or an air multiplier164that can each be in fluid communication with the air moving device140. The air intensifier163can be configured to increase a pressure of the air delivered from the air moving device140and to the duct20while the air multiplier164can be configured to increase a flow of air delivered from the air moving device140and to the duct20. The air intensifier163and/or the air multiplier164can each be configured to increase the pressure and flow of the air, respectively, whether the air moving device140is currently operating in a parallel or series configuration as described herein. Alternatively, the air intensifier163can be configured to activate when the air moving device140is operating in series to help further increase the pressure while the air multiplier164can be configured to activate when the air moving device140is operating in parallel to help further increase the flowrate.

The air intensifier163, for example, can be an air-driven, air pressure booster configured to increase the pressure of the air delivered to the duct20. If the air intensifier163is an air-drive, air pressure booster, at least a portion of the air used to drive the air-driven, air pressure booster can be received from the air moving device140. Alternatively, or in addition, the air intensifier163can be an electrically-driven or a gas-powered air intensifier configured to increase the pressure of the air delivered to the duct20.

The air multiplier164can be an active or a passive system configured to increase the flow of the air delivered to the duct20. The air multiplier164, for example, can be configured to increase the air flow using the Coanda effect. Alternatively, or in addition, the air multiplier164can be a device configured to deliver additional air flow (e.g., an additional air compressor, supercharger, air reservoir, etc.) By delivering a greater volume of air to the duct20, the underground stringing apparatus100can be configured to provide a greater moving force to the bird40to cause the bird40to move through the duct20.

The air intensifier163and the air multiplier164can each be configured to turn on and off. In other words, the underground stringing apparatus100can activate the air intensifier163and/or the air multiplier164when a greater pressure or volume of air is needed to cause the bird40to move. For example, the air intensifier163and the air multiplier164can each be connected to the air moving device140via pipes and valves and air can be routed through the air intensifier163and/or the air multiplier164as desired. Or the air intensifier163and/or the air multiplier164can have one or more actuatable components to cause the air intensifier163and/or the air multiplier164to turn on and off as desired.

FIG.4Ais a block diagram of an example control system of an underground stringing apparatus100, in accordance with the disclosed technology. As shown inFIG.4A, the controller150can be in communication with various components of the underground stringing apparatus100. The controller150can receive power from the energy bank120. The controller150can further be configured to receive data from a temperature sensor422that is configured to detect a temperature of the energy bank120. If the energy bank120has begun to overheat, the controller150can output a warning to notify the operator that the energy bank120is overheating. The controller150can further be configured to determine if a temperature of the energy bank120is greater than a high temperature threshold and be configured to shut the underground stringing apparatus100to prevent the energy bank120from overheating and becoming damaged.

The controller150can also be configured to reduce an output of the underground stringing apparatus100if the temperature of the energy bank120is below a low-temperature threshold. For example, if the temperature of the energy bank120is less than the low-temperature threshold, it can be indicative of the energy bank120being unable to output power at a full output capacity. For example, if the energy bank120is at a temperature less than the low-temperature threshold, the energy bank120may be damaged if too great of a load is placed on it. In this instance, the controller150can reduce the output of the air moving device140and/or the driveline114to ensure the load on the energy bank120remains below the load wherein the energy bank120may be damaged.

As the temperature of the energy bank120rises, the controller150can determine that the temperature of the energy bank120is greater than or equal to the low-temperature threshold and permit the underground stringing apparatus100to perform the blower or pulling operation at the full capacity of the energy bank120.

The controller150can be further configured to determine a charge level of the energy bank120and determine if the charge level is less than or equal to a low charge threshold. If a charge level of the energy bank120is less than or equal to the low charge threshold, the controller150can be configured to output a control signal to cause the generator unit130to activate. By activating the generator unit130, the generator unit130can begin to provide power to the energy bank120to recharge the energy bank120.

As shown inFIG.4A, the energy bank120can be further configured to connect to a supplemental energy bank420that can provide additional charge to the energy bank120. For example, the supplemental energy bank420can be an external battery or bank of batteries disposed on a trailer that can be transported to worksite to serve as a backup or supplemental supply of power to the energy bank120. The energy bank120can be further configured to receive power from an external power connection480. The external power connection480can be a connection to the utility grid to receive grid power for charging the energy bank120.

Further still, the energy bank120can be further configured to provide power to an auxiliary power circuit490that can be configured to provide power to various auxiliary units. The auxiliary power circuit490can include, for example and not limitation, a 120-volt, a 48-volt, or a 12-volt circuit that is configured to provide power to various electrical equipment such as power tools, lights, computers, etc. In this way, the energy bank120can be used for providing power to tools or devices that are necessary for completing the underground stringing operation. Similarly, the 48-volt and 12-volt circuits can be configured to provide a charge to other connected batteries or energy banks of equipment used with the underground stringing apparatus100. As will be appreciated, this can be particularly helpful in locations where grid power or other power sources are unavailable.

The controller150can be further configured to control the operation of the electric motor115and, subsequently, the driveline114. For example, the controller150can be configured to control a speed of the cable30being paid out, or pulled onto, the driveline114. For instance, if the cable30is being blown through the duct20, the controller150can be configured to receive speed data from a speed sensor415configured to detect a speed of the driveline114and/or the cable30. For example, the speed sensor415can be disposed near the driveline114and configured to detect a speed at which the driveline114is rotating for the controller150to interpolate the speed of the bird40and cable30traveling through the duct. Alternatively, or in addition, the controller150can be configured to determine a speed or approximate speed of the bird40traveling through the duct20based on a detected speed of the cable30. In either case, the controller150can be configured to determine if the cable30is traveling at or below a low-speed threshold. If the cable30is traveling at or below the low-speed threshold, the controller150can be configured to increase a supply of air to the duct. For example, the controller150can be configured to increase an output of the air from the air moving device140, open the control valve162to release pressurized air from the air reservoir160, activate the air intensifier163, and/or activate the air multiplier164. By supplying an increased air supply or a high-pressure air supply, the bird40can be pushed through the duct20at a greater speed or be dislodged from a stuck position.

The controller150can be further configured to control the speed of the driveline114by controlling the output of the electric motor115. For example, the controller150can cause the driveline114to rotate via the electric motor115at a predetermined speed and can increase or decrease the speed of the driveline114to ensure the cable30does not become tangled or does not experience too great of a force from the bird40being pushed too quickly by the air moving device140. Further, the controller150can be configured to control a speed of the driveline114when the cable30is being pulled onto the driveline114when pulling the conductor50back through the duct.

The controller150can also be configured to control both the air moving device140and the driveline114to ensure the speed at which the cable30is paid out from the driveline114and the supply of air are synced to ensure the maximum efficiency is achieved when completing the blowing operation. For example, if the air moving device140is operating at a maximum air output but the driveline114is rotating at a speed slower than the cable30would normally be able to be paid out under the maximum air output conditions, there will be much wasted energy by operating the air moving device at the maximum air output. Therefore, to help conserve energy and ensure the life of the energy bank120is maximized, the controller150can be configured to operate the driveline114to pay out cable at a speed that corresponds to the speed at which the cable30could move under the current air supply conditions. For example, as air supply is increased the cable30can likely move more quickly through the duct20and the controller150will increase the speed at which the driveline114rotates to ensure the cable30is paid out at a speed corresponding to the speed at which the cable30is being moved by the air moving device140.

Another way of ensuring the energy from the energy bank120is being used efficiently is by detecting a tension of the cable30using a tension sensor417. The tension sensor417, for example, can be incorporated into the electric motor115, the driveline114, and/or be a separate sensor configured to detect a tension on the cable30. The controller150can receive tension data from the tension sensor417and determine whether a tension of the cable30is greater than or equal to a maximum tension threshold. If the tension of the cable30is greater than or equal to the maximum tension threshold, this is likely an indication that the driveline114is not paying out cable30quickly enough to keep up with the bird40moving through the duct20. In which case, the controller150can determine that the speed of the driveline114should be increased and/or the output of the air moving device140should be decreased to maintain a tension on the cable30that is less than the maximum tension threshold, thereby efficiently utilizing energy from the energy bank120to complete the blowing operation.

As shown inFIG.4A, the air moving device140can be or include an electric air compressor440and/or an electric blower441that can each be controlled by the controller150. As described previously, if the air moving device140is an electric air compressor440, the electric air compressor440can be a super charger, a rotary screw compressor, a reciprocating air compressor, an axial compressor, or a centrifugal compressor. Alternatively, if the air moving device140is an electric blower441, the electric blower441can be a roots-type blower, a twin-screw blower, or a centrifugal blower. In some examples, the air moving device140can be two or more electric air compressors440configured to be operated in series and parallel configurations. Similarly, the air moving device can be two or more electric blowers441configured to be operated in series and in parallel configurations. If more than one electric air compressor440is used and/or more than one electric blower441is used, a first compressor440(or first blower441) can be configured to output air at a first pressure and flowrate and a second compressor (or second blower441) can be configured to output air at a second pressure and flowrate different from the first pressure and flowrate. Furthermore, one or more combinations of the above-listed compressors and blowers can be used. No matter the configuration, the controller150can be configured to output a control signal to control the operation of the air moving device140to output the appropriate supply of air under the give circumstances.

To illustrate, if the air moving device140comprises an electric air compressor440and an electric blower441, the controller150can initially control just the electric blower441to output a first flow of air to drive the cable30through the duct20. If the controller150determines that the speed of the cable30is less than or equal to the low-speed threshold, the controller150can continue to increase the speed of the electric air blower441until the speed of the cable30is greater than the low-speed threshold. If, after reaching the maximum output of the electric air blower441, the cable30still is not traveling at a speed greater than the low-speed threshold, the controller150can activate the electric air compressor440to provide additional supply of air to the duct20. The controller150can continue to increase the output of the electric air compressor440to provide a supply of air having a greater pressure to cause the cable30to resume travel at a speed greater than or equal to the low-speed threshold.

Continuing with the example above, if the controller150increases the output of the electric blower441and the electric air compressor440to the maximum output of both air moving devices and the cable30is still not traveling at a speed greater than the low-speed threshold, the controller150can activate the control valve162to release a supply of high-pressure air from the air reservoir160, activate the air intensifier163, and/or activate the air multiplier164to deliver a greater supply of air to cause the speed of the cable30to increase. In this way, the controller150can be configured to operate as efficiently as possible to conserve battery power but also to ensure the cable30is pushed through the duct20at a speed greater than the low-speed threshold. The low-speed threshold, for example, can be a speed below which it is likely that the bird40has become stuck, is encountering greater drag, or the weight of the cable30is causing the cable30to move more slowly through the duct20.

The controller150can be further configured to determine if the cable30has remained stationary for a predetermined length of time. If the cable30remains stationary for a predetermined length of time, it is likely that the bird40has become stuck or the weight of the cable30is too great for the bird40to move the cable30with the current supply of air. If the cable30has remained stationary for the predetermined length of time, the controller150can be configured to increase the output of the air moving device140, activate the air intensifier163, activate the air multiplier164, and/or activate the control valve162to cause the bird40and cable30to continue moving through the duct.

The controller150can also be in communication with a pressure sensor442that can be configured to detect a pressure of the air in the duct20. The controller150can be configured to control an output of the air moving device140to ensure the pressure in the duct20does not exceed a maximum pressure of the duct20. As will be appreciated, if the air pressure in the duct reaches too high a pressure, the duct20can rupture or otherwise become damaged. Thus, by monitoring the air pressure in the duct20and then controlling the air moving device140to maintain the pressure below a maximum pressure threshold, the controller150can ensure the duct20does not become damaged.

The controller150can be further configured to determine if the pressure in the duct20is less than a predetermine pressure. The predetermined pressure can be indicative of a minimum pressure required to cause the bird40to move through the duct20. If the detected pressure is less than the predetermined pressure, the controller150can output a control signal to increase the output of the electric air moving device140, activate the air intensifier163, activate the air multiplier164, and/or actuate the control valve162to increase the flow of air through the duct20.

As shown inFIG.4A, the controller150can be further in communication with an actuator system110that can be configured to control the first actuator108and the second actuator109to move the boom106up, down, and/or side to side as necessary. As will be appreciated, the actuator system110can be configured to control the flow of hydraulic fluid to cause movement of the boom106.

Although the components shown and described inFIG.4Aare described as being part of the stringing apparatus100, it will be appreciated that the many of the components can be incorporated into a stand-alone unit300such as that shown inFIG.4B. In other words, the disclosed technology includes a stand-alone unit300that can include all of the same components as the stringing apparatus100without the driveline114, electric motor115to drive the driveline114, and the actuator system. In other words, the air moving device140and associated components (controller150, pressure sensor442, generator130, air intensifier163, energy bank120, temperature sensor422, air multiplier164, control valve162, and air reservoir160can each be mounted on a stand-alone unit300that can be portable (e.g., on a cart, trailer, container, etc.) and used in conjunction with a stringing apparatus100or for other applications. In this way, the features and methods described herein can be incorporated into a smaller system than the entire stringing apparatus100. In some examples, the stand-alone unit300does not include the energy bank120and the stand-alone unit300can be configured to draw energy from an energy bank that is separate from the stand-alone unit300(e.g., an energy bank on the stringing apparatus100or a separate energy bank).

FIG.5is a flowchart of an example method500of installing an underground cable, in accordance with the disclosed technology. The method500can include determining510initial operation parameters. Determining510initial operation parameters can include determining at what speed the cable30should be installed, what pressure the maximum output of the air moving device140should be, the length of cable30to be paid out through the duct20, the tension at which the conductor50can be pulled through the duct, etc. The method500can further include delivering520air with an electric air moving device (e.g., the electric air moving device140).

The method500can further include determining530if the actual speed of the cable30is less than the predetermined cable speed (i.e., the low-speed threshold). If the actual speed of the cable30is less than the predetermine cable speed, the method500can further include outputting540a control signal to increase the output from the electric air moving device140. Outputting540a control signal to increase the output from the electric air moving device140can include increasing the speed of the electric air moving device140and/or, if the underground stringing apparatus100includes a second air moving device140, outputting540a control signal to increase the output from the electric air moving device140can include activating the second electric air moving device140.

The method500can further include determining550if the output of the electric air moving device140is at a maximum output. If the output of the electric air moving device140is at a maximum output, the method500can include outputting560a control signal to activate the air multiplier164and/or open the control valve162to release pressurized air from the air reservoir160.

The method500can once again include determining530if the actual cable speed is matches a predetermined cable speed and, if not, repeating the above-describe processes. If the actual cable speed matches the predetermined cable speed, the method500can include controlling570the air moving device140output to maintain the cable speed.

FIG.6is a flowchart of an example method600of installing an underground cable, in accordance with the disclosed technology. The method600can include determining610initial operation parameters. Determining610initial operation parameters can include determining at what speed the cable30should be installed, what pressure the maximum output of the air moving device140should be, the length of cable30to be paid out through the duct20, the tension at which the conductor60can be pulled through the duct, etc. The method600can further include delivering620air with an electric air moving device (e.g., the electric air moving device140).

The method600can further include determining630if the actual air pressure in the duct20is less than the predetermined air pressure (i.e., a low air pressure threshold). If the air pressure in the duct is less than the predetermined air pressure, the method600can further include outputting640a control signal to increase the output from the electric air moving device140. Outputting640a control signal to increase the output from the electric air moving device140can include increasing the speed of the electric air moving device140and/or, if the underground stringing apparatus100includes a second air moving device140, outputting640a control signal to increase the output from the electric air moving device140can include activating the second electric air moving device140.

The method600can further include determining650if the output of the electric air moving device140is at a maximum output. If the output of the electric air moving device140is at a maximum output, the method600can include outputting660a control signal to activate the air multiplier164and/or open the control valve162to release pressurized air from the air reservoir160.

The method600can once again include determining630if the actual air pressure matches a predetermined cable speed and, if not, repeating the above-describe processes. If the actual air pressure matches the predetermined air pressure, the method600can include controlling670the air moving device140output to maintain the cable speed.

As will be appreciated, the methods500and600just described is offered for illustrative purposes. The methods500and600can include more or fewer features than those just described. Furthermore, although described in a particular order, one of skill in the art will appreciate that the methods500and600do not necessarily need to be implemented in the order presented herein. Therefore, the methods500and600should be construed as one example of operating the underground stringing apparatus100and other method of operating the underground stringing apparatus100according to the various other examples described herein can also be implemented.

The disclosed technology described herein can be further understood according to the following clauses:

Clause 1: An air moving system for a stringing apparatus, the air moving system comprising: an energy bank; an electric air moving device in electrical communication with the energy bank and configured to output a supply of air to cause a cable to move along a duct; and at least one controller configured to: determine a speed of the cable moving along the duct; and control the output of the supply of air of the electric air moving device to control the speed of the cable based at least in part on the determined speed of the cable.

Clause 2: The air moving system of Clause 1, wherein the electric air moving device comprises an air blower.

Clause 3: The air moving system of Clause 2, wherein the air blower is at least one of a roots-type blower, a twin-screw blower, or a centrifugal blower.

Clause 4: The air moving system of Clause 1, wherein the electric air moving device comprises an air compressor.

Clause 5: The air moving system of Clause 4, wherein the air compressor is at least one of a super charger, a rotary screw compressor, a reciprocating air compressor, an axial compressor, or a centrifugal compressor.

Clause 6: The air moving system of any of the preceding Clauses, wherein the air moving device is a first electric air moving device, the air moving system further comprising a second electric air moving device.

Clause 7: The air moving system of Clause 6, wherein the at least one controller is further configured to: determine whether the determined speed of the cable is less than a predetermined line speed; and in response to determining that the speed of the cable is less than the predetermined line speed, control the output of the supply of air of the first electric air moving device and the second electric air moving device to increase the speed of the cable.

Clause 8: The air moving system of Clause 7, wherein the at least one controller is further configured to: output instructions to operate the first electric air moving device and the second electric air moving device in at least a first mode and a second mode, wherein the first mode comprises operating the first electric air moving device and the second electric air moving device in a parallel configuration, and wherein the second mode comprises operating the first electric air moving device and the second electric air moving device in a series configuration.

Clause 9: The air moving system of Clause 8, wherein operating the first electric air moving device and the second electric air moving device in the parallel configuration provides a first air supply having a high flow rate and a low pressure, and wherein operating the first electric air moving device and the second electric air moving device in the series configuration provides a second electric air supply having a low flow rate and a high pressure.

Clause 10: The air moving system of any of the preceding Clauses further comprising an air multiplier, the air multiplier configured to increase a flow rate of air delivered by the electric air moving device.

Clause 11: The air moving system of Clause 10, wherein the at least one controller is further configured to: determine whether the speed of the cable is less than a predetermined line speed; and in response to determining that the speed of the cable is less than the predetermined line speed, output a control signal to the air multiplier to activate the air multiplier and increase the flow rate of air.

Clause 12: The air moving system of any of the preceding Clauses further comprising an air reservoir, the air reservoir configured to store a volume of compressed air.

Clause 13: The air moving system of Clause 12, wherein the at least one controller is further configured to: determine whether the speed of the cable is less than a predetermine line speed; and in response to determining that the speed of the cable is less than the predetermine line speed, output a control signal to open a control valve to release at least a portion of the volume of compressed air from the air reservoir.

Clause 14: The air moving system of Clause 13, wherein the control valve is configured to be manually opened or closed.

Clause 15: The air moving system of any of the preceding Clauses, wherein the at least one controller is further configured to: determine whether the cable has remained stationary for a predetermined length of time, and in response to determining that the cable has remained stationary for the predetermined length of time, output a control signal to increase the output of the supply of air of the electric air moving device.

Clause 16: The air moving system of Clause 15, wherein the at least one controller is further configured to: in response to determining that the cable has remained stationary for the predetermined length of time, output a control signal to activate the air multiplier.

Clause 17: The air moving system of Clause 16, wherein the at least one controller is further configured to: in response to determining that the cable has remained stationary for the predetermined length of time, output a control signal to open a control valve to release at least a portion of a volume of compressed air from an air reservoir.

Clause 18: The air moving system of any of the preceding Clauses, wherein the at least one controller is further configured to: receive a pressure value from a pressure sensor, the pressure value indicative of a pressure in a duct; and in response to determining that the pressure value is less than a minimum pressure value, output a control signal to increase the output of the supply of air of the electric air moving device.

Clause 19: The air moving system of any of the preceding Clauses, wherein the at least one controller is further configured to: receive a pressure value from a pressure sensor, the pressure value indicative of a pressure in a duct; and in response to determining that the pressure value is greater than a maximum pressure value, output a control signal to decrease the output of the supply of air of the electric air moving device.

Clause 20: A stringing apparatus comprising: an energy bank; a driveline in electrical communication with the energy bank and configured to receive or to deliver a cable; an electric air moving device in electrical communication with the energy bank and configured to output a supply of air; and at least one controller configured to: determine a speed of a cable being delivered from the driveline; and control the output of the supply of air of the electric air moving device to control the speed of the cable based at least in part on the determined speed of the cable.

Clause 21: The stringing apparatus of Clause 20, wherein the electric air moving device comprises an air blower.

Clause 22: The stringing apparatus of Clause 20, wherein the electric air moving device comprises an air compressor.

Clause 23: The stringing apparatus of any of Clauses 20-22, wherein the electric air moving device is configured to output (1) a first air supply having a high flow rate and low pressure, and (2) a second air supply having a low flow rate and high pressure.

Clause 24: The stringing apparatus of any of Clauses 20-23, wherein the air moving device is a first electric air moving device, the stringing apparatus further comprising a second electric air moving device.

Clause 25: The stringing apparatus of Clause 24, wherein the at least one controller is further configured to: determine whether the determined speed of the cable is less than a predetermined line speed; and in response to determining that the speed of the cable is less than the predetermined line speed, control the output of the supply of air of the first electric air moving device and the second electric air moving device to increase the speed of the cable.

Clause 26: The stringing apparatus of Clause 25, wherein the at least one controller is further configured to: output instructions to operate the first electric air moving device and the second electric air moving device in at least a first mode and a second mode, wherein the first mode comprises operating the first electric air moving device and the second electric air moving device in a parallel configuration, and wherein the second mode comprises operating the first electric air moving device and the second electric air moving device in a series configuration.

Clause 27: The stringing apparatus of Clause 26, wherein operating the first electric air moving device and the second electric air moving device in the parallel configuration provides a first air supply having a high flow rate and a low pressure, and wherein operating the first electric air moving device and the second electric air moving device in the series configuration provides a second air supply having a low flow rate and a high pressure.

Clause 28: The stringing apparatus of any of Clauses 20-27 further comprising an air multiplier, the air multiplier configured to increase a flow rate of air delivered by the electric air moving device.

Clause 29: The stringing apparatus of Clause 28, wherein the at least one controller is further configured to: determine whether the speed of the cable is less than a predetermined line speed; and in response to determining that the speed of the cable is less than the predetermined line speed, output a control signal to the air multiplier to activate the air multiplier and increase the flow rate of air.

Clause 30: The stringing apparatus of any of Clauses 20-29 further comprising an air reservoir, the air reservoir configured to store a volume of compressed air.

Clause 31: The stringing apparatus of Clause 30, wherein the at least one controller is further configured to: determine whether the speed of the cable is less than a predetermine line speed; and in response to determining that the speed of the cable is less than the predetermine line speed, output a control signal to open a control valve to release at least a portion of the volume of compressed air from the air reservoir.

Clause 32: The stringing apparatus of Clause 31, wherein the control valve is configured to be manually opened or closed.

Clause 33: The stringing apparatus of any of any of Clauses 20-32, wherein the at least one controller is further configured to: determine whether the cable has remained stationary for a predetermined length of time, and in response to determining that the cable has remained stationary for the predetermined length of time, output a control signal to increase the output of the supply of air of the electric air moving device.

Clause 34: The stringing apparatus of Clause 33, wherein the at least one controller is further configured to: in response to determining that the cable has remained stationary for the predetermined length of time, output a control signal to activate the air multiplier.

Clause 35: The stringing apparatus of Clause 34, wherein the at least one controller is further configured to: in response to determining that the cable has remained stationary for the predetermined length of time, output a control signal to open a control valve to release at least a portion of the volume of compressed air from the air reservoir.

Clause 36: The stringing apparatus of any of Clauses 20-35 further comprising a generator configured to charge the energy bank.

Clause 37: The stringing apparatus of Clause 36, wherein the at least one controller is further configured to: determine a charge level of the energy bank; and in response to determining that the energy bank charge level is less than a threshold charge level, output a control signal to activate the generator to begin charging the energy bank.

Clause 38: The stringing apparatus of any of Clauses 20-37, wherein the energy bank further comprises a temperature sensor configured to detect a temperature of the energy bank.

Clause 39: The stringing apparatus of Clause 38, wherein the at least one controller is further configured to: determine a temperature of the energy bank; and in response to determining that the energy bank temperature is greater than a threshold temperature, output a control signal to reduce the output of the supply of air of the electric air moving device.

Clause 40: The stringing apparatus of Clauses 38 or 39, wherein the at least one controller is further configured to: determine a temperature of the energy bank; and in response to determining that the energy bank temperature is greater than a threshold temperature, output a control signal to reduce an output of the driveline.

Clause 41: The stringing apparatus of any of Clauses 20-40, wherein the at least one controller is further configured to: receive a pressure value from a pressure sensor, the pressure value indicative of a pressure in a duct; and in response to determining that the pressure value is less than a minimum pressure value, output a control signal to increase the output of the supply of air of the electric air moving device.

Clause 42: The stringing apparatus of any of Clauses 20-41, wherein the at least one controller is further configured to: receive a pressure value from a pressure sensor, the pressure value indicative of a pressure in a duct; and in response to determining that the pressure value is greater than a maximum pressure value, output a control signal to decrease the output of the supply of air of the electric air moving device.

Clause 43: The stringing apparatus of any of Clauses 20-42, wherein the at least one controller is further configured to: determine a charge level of the energy bank; and control the output of the supply of air of the electric air moving device to extend a life of the energy bank based on the charge level.

Clause 44: The stringing apparatus of any of Clauses 20-43, wherein the at least one controller is further configured to: determine a charge level of the energy bank; and control an output of the driveline to extend a life of the energy bank based on the charge level.

Clause 45: The stringing apparatus of any of Clauses 20-44, wherein the stringing apparatus is configured to deliver a cable through an underground duct.

Clause 46: The stringing apparatus of any of Clauses 20-45 further comprising a boom configured to extend and rotate to align the cable with a duct.

Clause 47: The stringing apparatus of any of Clauses 20-46, wherein the electric air moving device comprises an oilless air compressor.

Clause 48: The stringing apparatus of any of Clauses 20-47 further comprising an expandable air hose in fluid communication with the electric air moving device.

Clause 49: An air moving system for a stringing apparatus, the air moving system comprising: an air moving device configured to output a supply of air to cause a cable to move along a duct; and at least one controller configured to: determine a speed of the cable moving along the duct; and control the output of the supply of air of the air moving device to control the speed of the cable based at least in part on the determined speed of the cable.

Clause 50: The air moving system of claim48, wherein the air moving device is electrically-driven.

Clause 51: The air moving system of claim48, wherein the air moving device is driven by a combustion engine.

Numerous characteristics and advantages have been set forth in the foregoing description, together with details of structure and function. While the invention has been disclosed in several forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions, especially in matters of shape, size, and arrangement of parts, can be made therein without departing from the spirit and scope of the invention and its equivalents as set forth in the following claims. Therefore, other modifications or embodiments as may be suggested by the teachings herein are particularly reserved as they fall within the breadth and scope of the claims here appended.