Patent Description:
Known operation units have embodiments which absolve the operating personnel from the responsibility of deciding whether the screwing process was performed properly. However, it is still required that the operating personnel first set the setting parameters in the prescribed manner so that the target parameters or values to be achieved can be achieved. The setting parameters thereby conform to a plurality of screw connection process parameters, which result for example from the operator, the application or screw connection, and the tool in use. Known sources of errors, which lead to a defective screw connection, are for example: incorrect selection of tools; incorrect use of calculation tables; basic calculation errors in the determination of setting parameters; incorrect assignment of screw parameters to the screw connection; incorrect bolt elongation; failure of the tool or its components; failure of measuring means; incorrect setting of the setting parameters; etc..

These types of issues have been addressed in drive units for driving fluid power operated tools for the generation of a screw pretensioning force, which include for example hydraulically operated torque or other wrenches or expanding cylinders. In <CIT>, Applicant provided a drive unit that eliminates the risk of an incorrect setting of the setting parameter. Other control and management units and systems for power operated tools have been disclosed by Applicant in <CIT>, <CIT> and <CIT>. A method according to the preamble of claim <NUM> is known from <CIT>.

What is needed is improved industrial bolting systems.

The present invention relates to a method for simultaneous tightening of industrial threaded fasteners according to claim <NUM>.

The method comprises the steps of measuring the relative distance between the two parts of the joint to be closed using the bolting application separation gap sensor or measuring the fastener tension value using the bolting application fastener load cell.

Innovations disclosed in this application advance such drive unit and control unit technology and solve the object through an operation parameter regulation unit for use with a bolting system having a plurality of networked electrically powered torque tools and/or drive portions of torque tools for simultaneous tightening of industrial threaded fasteners with the characteristics of claim <NUM>. Electrically powered torque tools including such operation parameter regulation unit are disclosed. Industrial bolting systems for simultaneous tightening of industrial threaded fasteners are also disclosed, including either: such operation parameter regulation units; a plurality of networked electrically powered torque tools controlled by such an electrically powered torque tool; a plurality of networked electrically powered drive portions of torque tools controlled by such electrically powered torque tool; or any combination thereof. Advantageous embodiments of the invention are listed in the dependent claims.

Advantageously, innovations disclosed in this application include operation parameter regulation units for bolting systems having a plurality of networked electrically powered torque tools and/or drive portions of torque tools for simultaneous tightening of industrial threaded fasteners. Indeed SIMULTORC® is achievable with a plurality of networked electrically powered torque tools and/or drive portions of torque tools, particularly those of the handheld and/or mobile variety. SIMULTORC® is a proprietary bolting method of Applicant, to ensure Parallel Joint Closure® and joint integrity, which minimizes risk of operator injury, property damage and/or production loss by joint leakage, joint failure and/or crushing a gasket buffering closure of a flange.

Characteristic of the operation parameter regulation unit that is used in the method of the invention is that it has a processing unit with an output unit as well as a data capturing unit connected and/or integrated with the processing unit, wherein the processing unit is designed for the output of the value to be set on the operation parameter regulation unit based on fastener connection process parameters determined with the data capturing unit. The data capturing unit of the operation parameter regulation unit makes it possible to automatically capture fastener connection process parameters without requiring input from the operating personnel. The fastener connection process parameters include for example data on the operating personnel, data on the tool to be used, e.g. the used electric torque wrench or other tool, data on the fastener connection to be established, information on the fastener connection means and data on the structural elements to be fastened together. The saving of the corresponding fastener connection process parameters in a form in which they can be automatically imported by the data capturing unit permits the error-free capturing of all fastener connection process parameters required for the determination of the setting parameters, based on which the processing unit determines the setting parameters, insofar as they are not saved or do not already result directly from the imported data. The specification, input and/or use of incorrect setting parameters, which could result from incorrect inputs by operating personnel, is prevented by automated data capturing. The setting parameters determined by the processing unit are specified without error via the output unit of the processing unit, so that only a transfer of the specified setting parameters is required. The work process can then be started via activation of the activation, or power, unit via the operation unit of the tool and/or drive portion of the tool and can be ended again after the target values have been reached.

An activation unit connected and/or integrated with the processing unit activates operation units of the plurality of networked electrically powered torque tools and/or drive portions of torque tools. A control unit controls operation parameters of each of the plurality of networked electrically powered torque tools and/or drive portions of torque tools to maintain a difference between the operation parameters within a predetermined value. Note that a plurality of activation units may be connected and/or integrated with the processing unit to activate operation units of the plurality of networked electrically powered torque tools and/or drive portions of torque tools.

The operation parameters according to the invention are defined in claim <NUM>, and can further include: tool electrical circuit parameters including current voltage and/or magnetic field; tool torque output values; fastener rotation speeds; fastener pretensioning force; fastener rotation angle; fastener elongation; fastener and/or tool torsion, whether axial or housing flex; reaction fixture side load; fastener frictional resistance; and/or any combination thereof. The operation parameters of the invention are measured as stated in claim <NUM>, and further operation parameters may be directly and/or indirectly measured or sensed by various types of sensor units: strain gauges; rotary encoders; torque sensors and transducers; hall effect and similar magnetic and ferromagnetic field sensing units; clutches; position meters/sensors; etc. Note that other components known in the art may be used.

During a SIMULTORC® operation if the difference in the operation parameters of the plurality of networked electrically powered torque tools and/or drive portions of torque tools exceeds the predetermined value the control unit regulates the operation parameters of each tool and/or drive portion until the difference in operation parameter(s) returns to within the predetermined value. The control unit either: ceases operation parameter(s) of tool(s) and/or drive portions with increased operation parameter(s); lowers operation parameter(s) of tool(s) and/or drive portions with increased operation parameter(s); raises operation parameter(s) of tool(s) and/or drive portions with decreased operation parameter(s); or performs any one or more of such actions to any one or more such tool(s) and/or drive portions either causally, simultaneously and/or in predetermined order. Note that automatic executing systems and/or computer programs, which are e.g. integrated into the processing unit and that independently start the bolting process and end it after the target values have been reached, can also be used cooperatively and/or separately to perform bolting process(es) of the present invention.

The balancing of the automatically captured specific process parameters to be performed by the processing unit can generally take place in any manner, wherein for example the data required for determining the setting parameters are already saved in the processing unit. However, in accordance with an advantageous further embodiment of the invention, the processing unit is designed for connection with a storage unit. This embodiment of the invention makes it possible to selectively provide the processing unit with the information necessary for determining the required setting parameters via the storage unit. In the case of this further embodiment of the invention, the saving of the relevant data required for determining the setting parameters in the processing unit can be omitted so that it can be designed particularly cost-effectively.

The connection to a storage unit also enables in a simple manner access to current data so that an otherwise potentially complicated updating of the processing unit can be omitted.

The connection option to the storage unit also makes it possible to save process-specific information, e.g. data on the performed bolting processes, on the storage unit. A manual, potentially defective and time- and cost-intensive documentation of the performed bolting processes can be omitted in this case. The establishment of a connection of the processing unit with the storage unit can thereby take place in any form, wherein for example a standardized connection arranged on the processing unit, e.g. a USB connection, enables in a simple manner the connection of the storage unit to the processing unit.

However, according to a particularly advantageous embodiment of the invention, the processing unit is designed for wireless connection with the storage unit. The wireless connection, which can in particular be established via standardized radio protocols, enables a particularly simple and comfortable connection of the processing unit with the storage unit. They can be equipped for example with a GSM module, a Bluetooth module or the like. Note that any suitable means of wireless connection between the processing unit and the storage unit may be used including: Satellite, WI-FI, WiMAX, Bluetooth, ZigBee, Microwave, Infrared, Radio, and/or proximity sensor. This embodiment of the invention also makes it possible to access a central storage unit, e.g. a central database, with correspondingly designed drive units, so that local storage units are not needed. The use of a central database facilitates data management in a special manner since updates only need to be made in one database. Moreover, the wireless connection to the central storage unit makes it possible to save information on the performed bolting processes centrally so that information can be queried from the central database by authorized persons, similar to the tracking of product shipments.

For the determination of setting parameters, it is required that the fastener connection process parameters are saved in a manner comprehendible by the data capturing unit at a suitable location, e.g. in the operation parameter regulation unit itself, in one or more of the plurality of networked electrically powered torque tools and/or drive portions of torque tools, or the fastener connection. The fastener connection process parameters may include, e.g. the operating personnel identification; information about one or more of the plurality of networked electrically powered torque tools and/or drive portions of torque tools which includes e.g. information on the manufacturer, type, size, serial number, characteristics; data on the fastener connection instances can be type, application, description of the fastener connection type, fastener connection parameters (e.g. torque, pretensioning force, rotation angle, elongation, torsion, side load, or frictional resistance, etc.); data on the equipment of the fastener connection which includes e.g. manufacturer, thread, dimensions and yield points); and data on the fastener connection instance, or bolting application; etc. Note that fastener connection process parameters may include other relevant characteristics, data and/or information. These fastener connection process parameters are saved in a manner comprehendible by the data capturing unit on the individual elements. The type of the data saving in a manner comprehendible by the data capturing unit is thereby generally freely selectable. Since e.g. barcodes or RFID units have particularly proven themselves as machine-readable codes, the data capturing unit is designed as a mobile code reader unit and/or RFID receiver and/or write unit according to a particularly advantageous embodiment of the invention. Such data capturing units are characterized by their high reliability and cost-effective design. If applicable, the respective information is saved in a form corresponding to the data capturing units, i.e. in accordance with this advantageous embodiment as machine-readable code or on an RFID unit, so that it can be captured immediately. Note that the data capturing unit may be designed as any suitable means, such as, for example, a mobile code reading device, RFID receiver and/or write unit, etc..

The use of RFID units is thereby characterized in particular in that the capturing can take place in wireless form and over a greater distance, wherein the use of RFID units also makes it possible to save supplementary data on the RFID unit after completion of the bolting processes. Machine-readable code is thereby understood in particular as barcodes or the like, wherein the read devices then have corresponding scanners. The barcodes can be arranged on stickers, which are e.g. attached to the tool and/or the fastener connection.

The connection of the data capturing unit with the processing unit can also generally take place in any manner. However, according to a particularly advantageous embodiment of the invention, the data capturing unit is designed for wireless connection with the processing unit. A corresponding design of the invention, in which the connection is established e.g. via standardized radio procedures, increases ease of use in a supplementary manner since there is no restriction for data capturing via data capturing units due to a cable-bound connection.

The design of the operation parameter regulation unit for determining the setting parameter(s) and/or the operation parameter(s) to be applied by the power unit(s) of each of the plurality of networked electrically powered torque tool(s) and/or drive portion(s) of torque tool(s), e.g. for the establishment of a uniform pretensioning force, to achieve SIMULTORC®, can generally take place in any manner. However, according to a particularly advantageous embodiment of the invention, the operation parameter regulation unit is designed as having e.g. a keypad panel, touch screen, mobile device, etc., for controlling or regulating the target values of the setting parameter(s) and/or the operation parameter(s). Recall that controlling or regulating of the operation parameters (e.g. tool electrical circuit parameters including current, voltage and/or magnetic field; tool torque output values; fastener rotation speeds; fastener pretensioning force; fastener rotation angle; fastener elongation; fastener and/or tool torsion, whether axial or housing flex; reaction fixture side load; fastener frictional resistance; bolting application separation gap distance; and/or any combination thereof. ) is required to ensure Parallel Joint Closure® and joint integrity for the fastener connection. The operation parameter regulation unit can thereby be set in any manner, in the easiest manner automatically or manually, to the target value(s) specified on the output unit. The start of the bolting process can then take place via activation of the activation unit of the operation parameter regulation unit for activating operation units of the plurality of networked electrically powered torque tools and/or drive portions of torque tools.

Note that the operation parameter regulation unit is designed for wireless connection with the plurality of networked electrically powered torque tools and/or drive portions of torque tools by any suitable means including Satellite, WI-FI, WiMAX, Bluetooth, ZigBee, Microwave, Infrared, Radio, and/or proximity sensor.

In addition to a purely optical output of the setting parameters via the output unit, it is provided according to a further embodiment of the invention, that the output unit is designed for assistance in control and/or regulation of the operation parameter regulation unit. In accordance with this embodiment of the invention, the setting parameter determined by the processing unit is automatically transferred to the operation parameter regulation unit, e.g. an electrically controllable operation parameter regulation unit, after determination of the process parameters via the data capturing unit. This embodiment of the invention guarantees in a supplementary manner that a misadjustment caused by operating personnel and thus a defective screw connection does not result. In a particularly advantageous manner, the output unit is also designed to assist the control unit to check the setting parameters and to make corrections. This ensures in a particularly reliable manner an error-free establishment of the required fastener connections.

The documentation of the performed work processes can generally take place in any manner, for example as listed above, by saving information on a storage unit. However, according to a particularly advantageous embodiment of the invention, the output unit has a printing apparatus, which makes it possible to make available to operating personnel immediately in printed form reports on the realized fastener connections. Alternatively or additionally, it can also be provided according to a further development of the invention that the processing unit is designed for the documentation of the realized fastener connections. Should it be required to procure information on the realized fastener connections, the processing unit can be accessed at a later time and the data saved there can be called.

In accordance with a particularly advantageous embodiment of the invention, the operation parameter regulation unit and/or the processing unit has a time and/or position capturing unit attached and/or integrated with each of the plurality of networked electrically powered torque tools and/or drive portions of torque tools. This data, wherein the position capturing unit can be formed e.g. by a GPS receiver, can also be saved as information on the realized processes so that the quality of the realized and callable documentation can be increased in a supplementary manner. Furthermore, automation enhancements applied to such position capturing units, operation parameter regulation units and/or each of the plurality of networked electrically powered torque tools and/or drive portions of torque tools having such regulation units, such as drone flight capabilities, allow for remote, unsupervised and/or automatic performance of bolting operations.

SIMULTORC® operations are further improved with such automation enhancements because each of the plurality of networked electrically powered torque tools and/or drive portions of torque tools are available to automatically move to locations exhibiting atypical bolting characteristics. Proximity sensors may be used for improved location guidance of tools to the fasteners. Additional fastener connection process parameters would be needed for such an automation enhancement, such as, for example: interactive moving maps; bolting route guidance; fastener approach guidance; dynamic route editing with wind correction, speed, distance, headings and power consumption computation; bolting application elevation and orientation profiles; surroundings/terrain awareness in 2D and 3D; support for internal gyros or external AHRS boxes; displays of speed, altitude, course, etc.; live flight tracking; weight and balance computations; automatic recordation of bolting connections logbook; tool and tool portion movement synchronization; etc..

Further disclosed inventions include: the use of an electrically powered torque tool according to claims <NUM> and <NUM>; and the use of an industrial bolting system according to claims <NUM> and <NUM>.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. Previous discussion applies to the drawings. For ease of explanation tool torque output value(s) is the operation parameter of choice, but any disclosed operation parameter and may be used including: tool electrical circuit parameters including current, voltage and/or magnetic field; tool torque output values; fastener rotation speeds; fastener pretensioning force; fastener rotation angle; fastener elongation; fastener and/or tool torsion, whether axial or housing flex; reaction fixture side load; fastener frictional resistance; and/or any combination thereof.

Referring to <FIG>, it shows a perspective representation as a sketch of an industrial bolting system <NUM> for simultaneous tightening of industrial threaded fasteners <NUM> including a plurality of networked electrically powered torque tools <NUM> controlled by an electrically powered torque tool <NUM> having an operation parameter regulation unit <NUM>. Tool <NUM> acts as the master and networked tools <NUM> act as the slaves in this embodiment. For ease of explanation, operation parameter regulation unit <NUM> is shown exterior to tool <NUM> enclosed within a cover <NUM>, however in practice the whole of unit <NUM> and/or parts thereof are formed within or adjacent tool <NUM>. Tool <NUM> receives power via an electrical power supply <NUM>, preferably in the form of an on-board lithium ion battery. Power supply <NUM> may include any suitable source (e.g., solar cell, fuel cell, electrical wall socket, generator, motor, etc.). Generally, operation parameter regulation unit <NUM>,activates an electronic power unit <NUM> of tool <NUM> and controls the torque output level (or other operation or setting parameter) set on an operation unit <NUM>. Electronic power unit <NUM> and operation unit <NUM> are shown separate from each other and external from operation parameter regulation unit <NUM>. Electronic power unit <NUM> and/or operation unit <NUM>, however, may be formed as a single unit and/or may be formed integral with or adjacent operation parameter regulation unit <NUM>.

Operation parameter regulation unit <NUM>, in this case, regulates/monitors/measures etc. torque output of tool <NUM> and tools <NUM>, as the target value. In order to set the target value required for a fastener connection, operation parameter regulation unit <NUM> has an input unit <NUM>. A data capturing unit <NUM>, in this case a mobile barcode scanner, captures fastener connection process parameters <NUM> from the operating personnel, tool <NUM> and/or tools <NUM>, a fastener connection instance, or bolting application, <NUM> and fastener connection equipment <NUM>. Bolting application <NUM> may include, for example, a flange to be closed. Fastener connection equipment <NUM> may include, for example, threaded studs, bolts and/or nuts, washers and/or any other suitable items.

Data capturing unit <NUM> is shown external to operation parameter regulation unit <NUM>, however the whole of unit <NUM> or parts thereof may be found within tool <NUM> or operation parameter regulation unit <NUM>. Fastener connection process parameters <NUM> are transferred wirelessly to a processing unit <NUM>. Processing unit <NUM> indicates the compression torque to be set via the display, or output, unit <NUM>, which may be formed as or part of an operating panel <NUM> on tool <NUM> after accessing the data, perhaps saved on a storage unit (not shown). After setting the shown compression torque on input unit <NUM> either manually, semi-manually or automatically, the fastening process can be started and stopped via an activation unit <NUM>, either manually, semi-manually or automatically. If manually, activation unit <NUM> may be formed as a trigger <NUM> of tool <NUM>, which the operator pulls to start the fastening process. Note that the compression torque or the screw pretensioning force is the force necessary to tighten and/or loosen the screw connection. Note that each of tool <NUM> and/or tools <NUM> may be structurally similar to each other containing similar components such that embedded software commands in operation parameter regulation unit <NUM> perform a minority, majority and/or all of the steps of the SIMULTORC® bolting operations disclosed.

Note that each of the plurality of networked electrically powered torque tool(s) <NUM> and/or <NUM> are arranged equally distantly from one another on threaded fasteners <NUM> around fastener connection instance, or bolting application, <NUM>. SIMULTORC® is the proprietary bolting method of Applicant to ensure Parallel Joint Closure® and joint integrity, which minimizes risk of operator injury, property damage and/or production loss by joint leakage, joint failure and/or crushing a gasket (not shown) buffering closure of bolting application <NUM>. Note that a sensing unit (not shown) may be included with operation parameter regulation unit <NUM> and/or tool <NUM> and/or tools <NUM> to determine when the plurality of networked electrically powered torque tools <NUM> and <NUM> are available to tighten and/or loosen threaded fasteners <NUM>. In other words, electronic power unit(s) <NUM>, operation unit(s) <NUM>, trigger(s) <NUM>, operation parameter regulation unit(s) <NUM>, and/or parts thereof, may not be activatable unless tool <NUM> and/or tools <NUM> are correctly positioned about and safely engaged with threaded fasteners <NUM> and bolting application <NUM>. Such a sensing unit acts as a safety mechanism to reduce and/or eliminate risk of operator injury and a quality mechanism to ensure Parallel Joint Closure® and joint integrity.

During a SIMULTORC® bolting operation, as shown, for example, in <FIG>, a control unit <NUM> controls operation parameter(s), in this case tool torque output value(s), of each of the plurality of networked electrically powered torque tools <NUM> and/or <NUM> to maintain a difference between the operation parameter(s) within a predetermined value. If the difference in the operation parameter(s) exceeds the predetermined value, control unit <NUM> regulates the operation parameter(s) of tools <NUM> and/or <NUM> until the difference in operation parameter(s) returns to within the predetermined value.

Another exemplary embodiment is explained in more detail below with reference to <FIG>. Previous general discussion and specific discussion related to <FIG> applies to embodiment shown in <FIG>. Referring to <FIG>, it shows a perspective representation as a sketch of an industrial bolting system <NUM> for simultaneous tightening of industrial threaded fasteners <NUM> including a plurality of networked drive portions of electrically powered torque tools <NUM> controlled by electrically powered torque tool <NUM> having operation parameter regulation unit <NUM>. Tool <NUM> acts as the master and networked drive portions <NUM> act as the slaves in this embodiment.

Another exemplary embodiment is explained in more detail below with reference to FIG. Previous general discussion and specific discussion related to <FIG> and <FIG> applies to embodiment shown in FIG. Referring to FIG. <NUM>, it shows a perspective representation as a sketch of an industrial bolting system <NUM> for simultaneous tightening of industrial threaded fasteners <NUM> including a plurality of networked drive portions of electrically powered torque tools <NUM> controlled by a mobile device <NUM> having operation parameter regulation unit <NUM>. Mobile device <NUM> acts as the master and networked drive portions <NUM> act as the slaves in this embodiment.

An exemplary embodiment according to a first alternative of the invention is explained in more detail below with reference to <FIG>. Previous general discussion and specific discussion related to <FIG>, <FIG> and <NUM> applies to embodiment shown in <FIG>. A fastener connection instance, or bolting application, <NUM> is usable with industrial bolting systems <NUM>, <NUM>, <NUM> and/or variants thereof. Bolting application separation gap sensors <NUM> are arranged equally distantly from one another near the corresponding threaded fasteners. Bolting application separation gap sensors <NUM> measure the relative distance between the two parts of the joint to be closed. During a SIMULTORC® bolting operation, as shown, for example, in <FIG>, control unit <NUM> controls operation parameter(s), in this case bolting application separation gap distance, of each of the bolting application separation gap sensors <NUM> to maintain a difference between the operation parameter(s) within a predetermined value. If the difference in the operation parameter(s) exceeds the predetermined value, control unit <NUM> regulates the operation parameter(s) of tools <NUM> and/or <NUM> (and/or <NUM>/<NUM>) until the difference in operation parameter(s) returns to within the predetermined value. As shown, gap sensors <NUM> are networked sensor wands. Note that any suitable gap (or displacement) sensor may be used including 1D or 2D, thrubeam/reflective, laser, eddy current, ultrasonic, contact-type, inductive, capacitive, magnetic, optical, fiber, spring, etc. sensors.

An exemplary embodiment according to a second alternative of the invention is explained in more detail below with reference to <FIG>. Previous general discussion and specific discussion related to <FIG>, <FIG>, <NUM> and <FIG> applies to embodiment shown in <FIG>. A fastener connection instance, or bolting application, <NUM> is usable with industrial bolting systems <NUM>, <NUM>, <NUM> and/or variants thereof. Bolting application fastener load cells <NUM> are arranged adjacent a plurality of threaded fasteners. Bolting application fastener load cells <NUM> are shown adjacent and measure the tension in each fastener. During a SIMULTORC® bolting operation, as shown, for example, in <FIG>, control unit <NUM> controls operation parameter(s), in this case fastener tension values, of each of then actively engaged fasteners and load cells <NUM> to maintain a difference between the operation parameter(s) within a predetermined value. If the difference in the operation parameter(s) exceeds the predetermined value, control unit <NUM> regulates the operation parameter(s) of tools <NUM> and/or <NUM> (and/or <NUM>/<NUM>) until the difference in operation parameter(s) returns to within the predetermined value. Note that any suitable load cell may be used including strain gauge, piezoelectric, hydraulic, pneumatic, vibratory, capacitive, etc. load cells.

In an alternative embodiment not shown in the drawings, monitoring and controlling of:.

Claim 1:
Method for simultaneous tightening of industrial threaded fasteners with an operation parameter regulation unit (<NUM>) for use with a bolting system (<NUM>, <NUM>, <NUM>) having a plurality of networked electrically powered torque tools (<NUM>) and/or drive portions of torque tools (<NUM>) for simultaneous tightening of industrial threaded fasteners, the operation parameter regulation unit (<NUM>) including:
a processing unit (<NUM>);
an output unit (<NUM>) connected and/or integrated with the processing unit (<NUM>);
an input unit (<NUM>) connected and/or integrated with the processing unit (<NUM>);
an activation unit (<NUM>) connected and/or integrated with the processing unit (<NUM>) for activating operation units of the plurality of networked electrically powered torque tools (<NUM>) and/or drive portions of torque tools (<NUM>); and
a control unit (<NUM>) for controlling operation parameters of each of the plurality of networked electrically powered torque tools (<NUM>) and/or drive portions of torque tools (<NUM>) to maintain a difference between the operation parameters within a predetermined value,
including two or more sensor units for direct and/or indirect measurement of the operation parameters of either: the plurality of parts of a joint to be closed; or the plurality of networked threaded fasteners, characterized in that
the two or more sensor units are bolting application separation gap sensors (<NUM>) arranged equally distantly from one another and the method comprises the step of
- measuring the relative distance between the two parts of the joint to be closed using the bolting application separation gap sensors (<NUM>) and
- maintaining a difference between bolting application separation gap distances measured by the two or more bolting application separation gap sensors (<NUM>) within a predetermined value by means of the control unit (<NUM>), or
the two or more sensor units are bolting application fastener load cells (<NUM>) arranged adjacent a plurality of threaded fasteners, and the method comprises the step of
- measuring the fastener tension value using the bolting application fastener load cell (<NUM>) and
- maintaining a difference between fastener tension values within a predetermined value by means of the control unit (<NUM>).