WO2017060777A2

WO2017060777A2 - Apparatus for tightening threaded fasteners

Info

Publication number: WO2017060777A2
Application number: PCT/IB2016/001861
Authority: WO
Inventors: Eric P. Junkers
Original assignee: HYTORC Division Unex Corporation
Priority date: 2015-10-05
Filing date: 2016-10-05
Publication date: 2017-04-13
Also published as: WO2017060777A3

Abstract

An hydraulic drive unit (100), for torque controlled tightening of threaded fasteners (200) for use with hydraulic torque tools (300) having double-acting hydraulic cylinders which provides for the fully automatic generation of and complete documentation of a conforming bolting connection, includes: an electronic processing unit of a control circuit (40) for editing, processing and/or storage of system/bolting process information (50) in response to internal drive unit (100) information (50); a human-machine interface; a seat valve for alternatingly switching the working pressure to the respective side of the working cylinder of the tool (300); a pressure limiting valve implemented in the form of a proportional valve having a pressure sensor (13); wherein a desired final torque necessary to perform the desired bolting process is to be entered by an operator using the human-machine-interface by means of direct value entry; and wherein the electronic processing unit of the control circuit (40) calculates the required pressure by using corresponding pressure-torque-conversion-charts of the tools (300) to apply the respective actuating value to the proportional valve having the pressure sensor (13) measuring an achieved system pressure and/or regulating the proportional valve.

Description

Reference, 012-102/PCT

Title: APPARATUS FOR TIGHTENING THREADED FASTENERS

Inventor: Eric P. JUNKERS (US)

Applicant: HYTORC Division UNEX Corporation (US)

CROSS REFERENCE TO RELATED APPLICATIONS

This Application either claims priority to and/or is either a continuation patent application or a continuation-in-part application of the following commonly owned and co-pending patent applications, entire copies of which are incorporated herein by reference: U.S. Application Serial No. 62/237,058, having Filing Date of 5 October 2015, entitled "FULLY AUTOMATIC HYDRAULIC DRIVE UNIT"; and U.S. Application Serial No. 63/302,260, having Filing Date of 2 March 2016, entitled "APPARATUS FOR TIGHTENING THREADED FASTENERS".

BACKGROUND OF INVENTION

Known hydraulic drive units for bolting systems are equipped with a manually adjustable pressure control valve. Today the operator has to use dedicated "torque conversion charts" per tool which shows the pressure related torque values in steps of, for example, 200 psi. The user has to calculate the correct pressure relating to the desired torque by linear interpolation and then adjust this pressure manually at the pressure control valve. The operator has to supervise the pressure at the gauge which changes during bolting process operations, due to variation of physical characteristics like temperature, viscosity, flow, friction, etc. These changing characteristics often go unnoticed by the operator, which leads to nonconforming bolting connections. Additionally current procedures often lead to inaccurate and nonconforming bolting connections due to manual calculation errors.

SUMMARY OF INVENTION

An hydraulic drive unit, for torque controlled tightening of threaded fasteners for use with hydraulic torque tools having double-acting hydraulic cylinders which provides for the fully automatic generation of and complete documentation of a conforming bolting connection, includes:

an electronic processing unit of a control circuit for editing, processing and/or storage of system/bolting process information in response to internal drive unit information;

a human-machine interface;

a seat valve for alternatingly switching the working pressure to the respective side of the working cylinder of the tool;

a pressure limiting valve implemented in the form of a proportional valve having a pressure sensor;

wherein a desired final torque necessary to perform the desired bolting process is to be entered by an operator using the human-machine-interface by means of direct value entry; and

wherein the electronic processing unit of the control circuit calculates the required pressure by using corresponding pressure-torque-conversion-charts of the tools to apply the respective actuating value to the proportional valve having the pressure sensor measuring an achieved system pressure and/or regulating the proportional valve.

The drive unit is equipped with a graphical user interface, integrated intuitive guidance for the operator and an intelligent pressure control mechanism to ensure conforming bolting connections. The proper hydraulic tool for the given bolting application is chosen by illustration and size via the graphical user interface and the integrated intuitive guidance to the operator. The operator enters the desired final torque value, and if required other bolting process related parameters like pre-torque, angle, etc. The drive unit calculates the correct operating pressure by integrated interpolation. The intelligent pressure control mechanism sets and calibrates the drive unit to reach and control the final torque value during the bolting process. The intelligent pressure control mechanism and the integrated control loop of the drive unit maintains the pressure in a certain range, even if the physical characteristics like temperature, viscosity, flow, friction, etc. are changing. This finally leads to a conforming bolting connection which is the target of every bolting application. Advantageously, this invention eliminates the weaknesses of known hydraulic drive units and creates a user friendly, safe and fully automatic hydraulic bolting system. BRIEF DESCRIPTION OF THE DRAWINGS

The invention(s) of the present application may be described, by way of example only, with reference to the accompanying drawings, of which: FIG. 1 shows a block diagram of the hydraulic drive unit and bolting system; FIG. 2 shows a hydraulic schematic of the hydraulic drive unit and bolting system; FIG. 3 shows a schematic of a hydraulic tool; FIGs. 4A-4C show side, internal component and top views of the hydraulic drive unit; and the attached HY-V-115- -F2 manual includes numerous views of internal component assemblies and parts listings of the hydraulic drive unit.

SPECIFICATION

a human-machine interface;

The drive unit is equipped with a graphical user interface, integrated intuitive guidance for the operator and an intelligent pressure control mechanism to ensure conforming bolting connections. The proper hydraulic tool for the given bolting application is chosen by illustration and size via the graphical user interface and the integrated intuitive guidance to the operator. The operator enters the desired final torque value, and if required other bolting process related parameters like pre-torque, angle, etc. The drive unit calculates the correct operating pressure by integrated interpolation. The intelligent pressure control mechanism sets and calibrates the drive unit to reach and control the final torque value during the bolting process. The intelligent pressure control mechanism and the integrated control loop of the drive unit maintains the pressure in a certain range, even if the physical characteristics like temperature, viscosity, flow, friction, etc. are changing. This finally leads to a conforming bolting connection which is the target of every bolting application. Advantageously, this invention eliminates the weaknesses of known hydraulic drive units and creates a user friendly, safe and fully automatic hydraulic bolting system.

An hydraulic drive unit 100 and bolting system 1000 of the present invention, by way of example, may include the components: described immediately above; found in FIGs. 1- 4; in the below description; and/or in the attached HY-V-115-M-F2 manual.

Abbreviations which may be used in the drawings, the below description and/or the attached HY-V-1 15-M-F2 manual include and mean: HMI l.n (Human-Machine- Interface); \AC (Electronic processing unit); 11..n (Flow sensor); S1..n (Pressure sensor); V1..n (Valve); ASl.n (Angular sensor); CM (Communication module); RW (Read-Write- Unit): SEC (Security module): SC (Sensor signal conditioning): AC (Actor signal conditioning); MS (Mass storage): DC (Data carrier); Com (Interface for service, PDA/SCADA, etc.); and others.

Referring to FIGs. 1-3, by ways of examples, operation of hydraulic drive unit 100 and bolting system 1000 of the present invention is as follows. Hydraulic fluid, or oil, 18 is located in a reservoir 17. Oil 18 is transferred by a low pressure pump 3.2 through suction filter 1. Oil 18 becomes compressed oil 18' and flows through filters 4.1 and 5.1. Compressed oil 18' is pressurized up to a set maximum low pressure level P_LOW, which is set by a low pressure control valve 6 and sent to a check valve 10. Simultaneously compressed oil 18' is fed into medium pressure pump 3.3 and high pressure pump 3.4. As soon as set maximum low pressure level P_Low has been reached, low pressure control valve 6 opens, and pressurized oil 18' is fed to an oil cooler 9. Pressurized oil 18' will again be compressed up to a set maximum medium pressure level P_{M ED} which is set by a medium pressure control valve 7.

As soon as set medium pressure level P_{M ED} has been reached a medium pressure control valve 7 opens and only high pressure pump 3.4 is operational. In both cases pressurized oil 18" flows to check valve 10. A maximum pressure of the system P_MAX will be set at a safety pressure control valve 8. All pumps 3.2-3.4 will be driven by an electric motor 3.1 or any other kind of power unit.

The operating pressure of the system P₀, which is calculated out of a final desired torque T_F and a tool size S_T, will be set and controlled at a proportional pressure control valve 1 1. Note that final desired torque T_F and a tool size S_T, is selected by the operator at a user interface (e.g. remote control) 30, 31 and/or 32. Operating pressure P₀ is observed at a pressure sensor 13. Optionally a conventional pressure gauge can be connected to auxiliary port 12. Operating pressure P₀, which is measured at sensor 13 will be used in a control circuit 40 to control actual pressure of the system P_s. Note that the operator may need only to work with torque values as information given by a pressure gauge connected to port 12 is no longer relevant, per known drive units.

Additionally control circuit 40 of drive unit 100 is able to calculate desired torque T_F values out of the signals from pressure sensor 13. Note that these could be displayed on user interface 30 and/or 31 and/or visual display 32. It's also possible that actual values are not shown at the user interface, but intuitive progress graphs or "OK" signals as soon as final desired torque T_F is achieved. In other cases "ERROR" messages may be displayed.

A directional valve 14, which is also controlled by control circuit 40, switches pistons of tools 300 from an advance position to a retract position, and vice versa. The position of directional valve 14 is depending on the signals from: the signals given by pressure sensor 13; flow sensors 16.1 to 16. n of tools 300.1 to 300. n which are connected to the hydraulic feed lines A and B; and possible other, perhaps optional, sensors like a position sensor 310 or an angle sensor 320. Piston retract pressure P_R is set and controlled by a retract pressure control valve 15. An oil cooler 9 is optionally needed to reduce oil temperature t₀. Note that proportional pressure control valve 1 1 may be operated by a proportional magnet to control the pressure, but may use other technologies to operate the pressure control valve and achieve the same functions.

Put another way, drive units 100 are disclosed for use with hydraulic torque tools 300 with double-acting hydraulic cylinders for controlled tightening of threaded fasteners 200. Note that drive unit 100, fasteners 200 and tools 300 make up bolting system 1000 of the present invention. Drive unit 100 includes an electronic processing unit (μθ) 41 for editing and/or processing and/or storage of system-and bolting-process-information 50 in response to internal drive unit information. Drive unit 100 includes at least one mass storage device (MS) 42 and at least one human-machine interface (HMI) 30, 31 and/or 32, such as for example a combined display-operating unit/remote control/scanner/visual/touchscreen display. Drive unit 100 includes a seat valve (V₂) 14 for alternatingly switching the working pressure to the respective side of the working cylinder of tool 300. Drive unit 100 further includes a pressure limiting valve implemented in the form of a proportional valve (\ ) 1 1 and a pressure sensor (Si) 13. A desired final torque T_F necessary to perform the desired bolting process is to be entered by the operator using human-machine-interface (HMI) 30, 31 and/or 32 by means of direct value entry. Electronic processing unit (μθ) 41 of control circuit 40 calculates the required pressure by using the corresponding pressure-torque- conversion-charts of tools 300 to apply the respective actuating value to proportional valve (Vi) 11 comprising pressure sensor (Si) 13 measuring the achieved pressure P_s and regulating proportional valve (Vi) 11 if necessary.

Drive units 100 of the present invention may include at least one flow sensor (li...l_n) 16 that measures the fluid flow of tools 300. In this case, electronic processing unit (μθ) 41 of control circuit 40 determines the position of the piston inside tools 300 and therefore implicitly the position of the bolt/nut 200. This feature assists in performance of the fully automated torque controlled bolting operation and signals completion thereof, visually and/or optically, via human-machine-interface (HMI) 30, 31 and/or 32. Automatic bolting operations performed with such drive units 100 and tools 300 may also be realized by torque-and angle-control and/or further advanced bolting techniques. Further, such drive units 100 may include at least one additional seat valve (V_{3 .} V_n) 20 attached in such a way that tool(s) 300 attached to such bolting system 1000 may be selectively isolated from the working pressure P_s of the system.

Drive units 100 of the present invention may include a signal treatment and/or signal conditioning and/or signal processing unit (SC) 43 integrated with and/or attached to bolting process monitoring sensors, such as for example flow sensors 16 and/or pressure sensor (Si) 13.

Drive units 100 of the present invention may include a communication interface (Com) 48 to attach to a computer 4 0 and/or a network/cloud 420 and/or an industrial fieldbus (such like DeviceNet, PROFIBUS, etc.) 430.

Drive units 100 of the present invention may include a characteristic such that one communication module/interface (CM) 47 is provided for wireless communication, such as for example, Bluetooth, GSM, GPRS and/or UMTS mobile units and/or WiFi. In this case, human-machine-interface (HMI) 30, 31 , and/or 32, additional sensors, such as for example, a position sensor 310 and/or an angle sensor 320 for monitoring the bolting process and/or control-and service-equipment can be connected to such drive units 100 and such bolting systems 1000 using this module.

Drive units 100 of the present invention may include a read, write or combined read- write unit (RW) 46 for a mobile data carrier (DC) 33 integrated and/or attached into the system.

Drive units 100 of the present invention, characterized in that the system documents bolting operations and/or reads and/or writes process-related data and/or reads additional tool characterizing data 51 and/or reads functional improvements and/or reads and/or writes service and maintenance-related data or system-and bolting- process-information.

Generally, the open architecture of hydraulic drive units 100 of the present invention allows for the implementation of various tools and also additional accessories, features and sensors. These may include, for example: wireless remote control, wired or wireless connection to additional sensors like angle and elongation; technologies like the identification of tools or fasteners with RFID tags; and/or integration into company, statewide, national and/or international networks and process control systems.

Note that the open architecture of hydraulic drive units 100 of the present invention allows for the implementation of various tools and also additional accessories, features and sensors found in the commonly owned and co-pending patent applications, entire copies of which are incorporated herein by reference: U.S. Application Serial No. 13/885,845, having Filing Date of 16 May 2013, entitled "DRIVE UNIT FOR A POWER OPERATED TOOL"; U.S. Application Serial No. 14/621 ,379, having Filing Date of 12 February 2015, entitled "MULTIFUNCTIONAL HYDRAULIC DRIVE UNIT".

These commonly owned and co-pending patent applications disclose, inter alia, an hydraulic drive unit for a hydraulic bolting system with an electric motor, at least one pump stage on a pump block, and an electronics assembly comprising: an operator interface connectable to at least one internal and/or external interface in communication with a data cloud and/or a data server wherein programs stored by the data cloud and/or data server are loaded into the electronics assembly and automatically executed by the electronics assembly; and wherein process data and/or system data can, by the electronics assembly for the purpose of storage and/or analysis of the data, be in an automated manner transmitted back to the data cloud and/or the data server. The electronics assembly may be connectable to an internal and/or external storage for bidirectional data exchange of programs, process data, process parameters and/or system data.

The operator interface may be a tablet PC and/or a head-mounted display, in particular a pair of glasses for the detection and specification of information and can in particular be combined to a further input device, such as a microphone, for inputting commands. The operator interface may be operable, attachable and/or removable from the hydraulic drive unit by use of a magnetic holder, bolt attachments, a hook-and-loop fastener and/or a strap fastener. An externally disposed ventilated auxiliary reservoir may be connectable in fluid-dynamic communication with a closure cap preferably configured to be ventilated when not in use and airtight when in use.

The hydraulic drive unit may be connectable to sensors for providing external sensor signals of any measured physical quantity, where physical actual values are provided by the sensor signals and serve as control variables, control quantities, actuating variables, control parameters and/or additional parameters in the electronics assembly for further processing and process control and hydraulic assembly control and process validation. The hydraulic drive unit may be connectable to an external code reader, where in particular application names are received with the code reader and internal and/or externally stored program selections are in turn performed by them, and/or documentation content for the process and/or maintenance intervals of the hydraulic drive assembly and/or accessories is recorded, visualized, stored and/or reported. The external code reader may be a mobile phone with camera functionality and that preferably application images and/or optically readable codes are transmitted to the hydraulic drive unit, the server and/or the cloud for documenting the case of application. An external printer may be connectable to the hydraulic drive unit and outputs process results, a process status, process quality, program information, system information, service information and/or maintenance information.

A method for controlling the hydraulic drive unit described herein may include the hydraulic drive unit receiving from the code reader application programs to be executed by the code reader and/or application names, by means of which an automated program start occurs in the hydraulic drive unit and/or user information, documentation data and/or process information can be scanned and/or stored locally. The external storage(s), by means of at least one specific service, may send bolting programs, software updates and/or notices to the hydraulic drive unit for execution by means of which an automated program start, program transmission and/or visualization for execution is performed. The hydraulic drive unit may send logs, system data and/or raw data to the external storages which are archived, analyzed, controlled, forwarded to authorized individuals, and/or visualized via a web browser by means of an online portal. Analysis programs, by comparing data, may verify and/or assess the quality of process results in the cloud and/or the external server, and/or analysis models may, by comparisons, be based on available data records improved which also allows statistical inspection of processes performed in terms of their quality.

At least one externally assignable access authorization may be provided for the data in the cloud by means of which a selected group of individuals is given external access to the data, is informed in an automated manner when error processes are present and/or is informed when new process data has arrived. Transmitted program data, process data and/or system data may contain at least one checksum or a higher-quality validity certificate by means of which manipulations and/or error transmissions of the transmitted program data, process data and/or system data are detected and/or reported by the recipient and are, in the event of error, automatically again requested from the sender. A sender of data, only after the successful transmission message, may release the program data, process data and/or system data from his own memory for deletion. Access to information regarding necessary service intervals, system status messages, operating conditions, error messages and/or security checks may be for authorized individuals ensured by means of a cloud online portal via an external web browser and/or one that is implemented in the hydraulic drive unit. Name data and bolting application data recorded in the assignment may be compared for plausibility and/or consistency. Evaluation of the bolting applications may occur stochastically, preferably in an automated stochastical manner.

A method for controlling the hydraulic drive unit may include the steps of: scanning a bolting application into the electronics assembly; verifying the bolting application in the electronics assembly; loading a bolting program into the electronics assembly; executing the bolting program with the hydraulic drive unit for a hydraulic bolting system. Other steps may include the following. Scanning the bolting application occurs by means of the tag reader or the scanner, in particular a bar code scanner, where the bolting application is determined directly or indirectly by information that is disposed preferably in the region of the bolting application or the object itself, respectively. Verifying the bolting application may occur by further information such as object data, a checksum, geometric data or information, GPS data, travel directions, icons, street name, house number and images, which are stored in a database for the bolting application. Loading the bolting program may occur either via an existing LAN or WLAN connection, a mobile network connection such as via a mobile phone and thereby provides a connection to a database preferably to a server and/or a cloud for transmitting data, in particular the bolting program. The bolting program may provide essential data, such as data regarding control factors, control variables, the bolting method to be applied, the bolting pattern, the lubricant, the connected hydraulic tool, the ambient conditions such as temperature, rain, etc., for the individual bolting application.

The operator may be informed prior to or at the start of the bolting process about all essential data and/or parameters, such as the specific bolting program, the bolting pattern etc. The electronic assembly, in particular the interface, during the bolting process or when performing the bolting program, may record and check all essential operating parameters and procedures, and possibly has automated or operator- performed repetitions performed. Proof of process capability may be recorded, created or provided preferably using at least one external sensor which detects at least one target value such as a preload force of a bolt connection. The operating parameters recorded preferably in said electronics assembly may, after completion of a work assignment in the database, be transmitted back preferably to a server and/ora cloud, and may be used in particular for generating an updated and/or separate bolting program.

The actually recorded operating parameters, including any possible changes performed, may be, after completion of a first work assignment of the bolting program, temporarily stored in the electronics assembly and made available as a data record or a new bolting program for further work assignments. A clone of a bolting program for the currently available hydraulic drive unit and/or further hydraulic drive units may be provided after completion of a first work assignment of the bolting program and the actually recorded operating parameters.

Use of the hydraulic drive unit for fluid supply, in particular with oil supply, may be for tools, such as lifting cylinders, hydraulic bolting tools, torque tools, yield-driven tools, angle-driven torque tools or the like.

Note that the open architecture of hydraulic drive units 100 of the present invention allows for the implementation of various tools and also additional accessories, features and sensors found in the commonly owned and co-pending patent application, an entire copy of which is incorporated herein by reference: U.S. Application Serial No. 63/302,260, having Filing Date of 2 March 2016, entitled "APPARATUS FOR TIGHTENING THREADED FASTENERS".

This commonly owned and co-pending patent application discloses, inter alia, 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. The operation parameter regulation unit, which may be used with a hydraulic bolting system having a plurality of networked hydraulically powered torque tools and/or drive portions of torque tools for simultaneous tightening of industrial threaded fasteners, includes: a processing unit; an output unit connected and/or integrated with the processing unit; an input unit connected and/or integrated with the processing unit; an activation unit connected and/or integrated with the processing unit for activating operation units of the plurality of networked hydraulically powered torque tools and/or drive portions of torque tools; and a control unit for controlling 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. The operation parameters may include either: 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; reaction fixture side load; fastener frictional resistance; and/or any combination thereof. During operation if the difference in the operation parameters of the plurality of networked hydraulically powered torque tools and/or drive portions of torque tools exceeds the predetermined value the control unit may regulate the operation parameters of each tool and/or drive portion until the difference in operation parameter(s) returns to within the predetermined value by either: ceasing operation parameter(s) of tool(s) and/or drive portions with increased operation parameter(s); lowering operation parameter(s) of tool(s) and/or drive portions with increased operation parameter(s); raising operation parameter(s) of tool(s) and/or drive portions with decreased operation parameter(s); and/or performing 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.

A data capturing unit may be 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 may be designed as a mobile code reading device, RFID receiver and/or write unit and/or for wireless connection with the processing unit.

The operation parameter regulation unit may: include a storage unit; be designed for wireless connection with the plurality of networked hydraulically powered torque tools and/or drive portions of torque tools by any suitable means including Satellite, WI-FI, WiMAX, Bluetooth, ZigBee, Microwave, Infrared, and/or Radio; may include a sensor unit for direct and/or indirect measurement of the operation parameters of the plurality of networked hydraulically powered torque tools and/or drive portions of torque tools; be designed for the documentation of realized bolting connections.

The fastener connection process parameters may be determined from an operating personnel, a power operated tool, a fastener connection instance and fastener connection equipment.

An hydraulically powered torque tool may include the operation parameter regulation unit. An industrial bolting system for simultaneous tightening of industrial threaded fasteners may include: the operation parameter regulation unit; a plurality of networked hydraulically powered torque tools and/or drive portions of torque tools controlled by the hydraulically powered torque tool; a plurality of networked drive portions of hydraulically powered torque tools controlled by the hydraulically powered torque tool; the operation parameter regulation unit formed within a mobile device, and either, a plurality of networked electrically powered torque tools, a plurality of networked electrically powered drive portions of torque tools, or any combination thereof; the operation parameter regulation unit, which automatically controls the plurality of networked hydraulically powered torque tools and/or drive portions of torque tools; the activation unit of at least one of the plurality of networked hydraulically powered torque tools and/or drive portions of torque tools is formed as a button which is manually controlled by an operator; achievement of SIMULTORC^®, a proprietary bolting method of HYTORC^® Division UNEX Corporation, to ensure Parallel Joint Closure^® and joint integrity which minimizes risk of crushing a gasket buffering closure of a flange; wherein each of the plurality of networked hydraulically powered torque tools and/or drive portions of torque tools may be arranged equally distantly from one another on threaded fasteners around a fastener connection instance; wherein the plurality of networked hydraulically powered torque tools and/or drive portions of torque tools may include time and/or position capturing unit(s); wherein the time and/or position capturing unit(s) may include automation enhancements such as drone flight capabilities, which allow for remote, unsupervised and/or automatic performance of bolting operations; a sensing unit which determines when the plurality of networked hydraulically powered torque tools and/or drive portions of torque tools are available to tighten and/or loosen the threaded fasteners thereby rendering the operation unit activatable.

A method of automatically controlling the industrial bolting system may include: maintaining a difference between operation parameters of each of the plurality of networked hydraulically powered torque tools and/or drive portions of torque tools within a predetermined value; arranging each of the plurality of networked hydraulically powered torque tools and/or drive portions of torque tools equally distantly from one another on threaded fasteners around the fastener connection instance.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above. The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilized for realizing the invention in diverse forms thereof. Note that there may be slight differences in descriptions of numbered components in the specification. While the invention has been illustrated and described as embodied in a fluid operated drive unit, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Wthout further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.

When used in this specification and claims, the terms "comprising", "including", "having" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

What is claimed is:

Claims

1. An hydraulic drive unit for torque controlled tightening of threaded fasteners for use with hydraulic torque tools having double-acting hydraulic cylinders which provides for the fully automatic generation of and complete documentation of a conforming bolting connection.

2. An hydraulic drive unit according to claim 1 including:

a human-machine interface;

3. An hydraulic drive unit according to any preceding claim wherein the human- machine interface (HMI) includes a combined display-operating unit including either a remote control, scanner, visual or touchscreen display.

4. An hydraulic drive unit according to any preceding claim including a flow sensor that measures the fluid flow of the tool such that the electronic processing unit of the control circuit determines the position of the piston inside the tool, and therefore the angular position of the threaded fastener.

5. An hydraulic drive unit according to claim 4 which signals completion of the fully automatic generation of the conforming bolting connection via the human-machine- interface either visually, audibly and/or optically.

6. An hydraulic drive unit according to claim 4 wherein the fully automatic generation of the conforming bolting connection is performed by torque- and angle- control.

7. An hydraulic drive unit according to any preceding claim including a plurality of seat valves able to selectively isolate a plurality of tools from the working pressure of the system.

8. An hydraulic drive unit according to any preceding claim including a signal treatment and/or signal conditioning and/or signal processing unit integrated with and/or attached to bolting process monitoring sensors, such as, for example, the flow sensor(s) and/or pressure sensor(s).

9. An hydraulic drive unit according to any preceding claim including a communication interface to attach to a computer, a network/cloud and/or an industrial fieldbus.

10. An hydraulic drive unit according to any preceding claim including a communication module/interface for monitoring the bolting process and/or wireless communication, such as, for example, Bluetooth, GSM, GPRS, UMTS mobile units and/or WiFi, between the human-machine-interface, position sensor(s), angle sensor(s) and/or other connected control- and/or service-equipment.

1 1. An hydraulic drive unit according to any preceding claim including a mass storage device.

12. An hydraulic drive unit according to any preceding claim including a read, write or combined read-write unit for an integrated and/or attached mobile data carrier.

13. An hydraulic drive unit according to any preceding claim which documents bolting operations, reads and/or writes process-related data, reads additional tool characterizing data, reads functional improvements, and/or reads and/or writes service- and maintenance-related data or system-and bolting-process-information.

14. An hydraulically driven torque tool for use with a drive unit according to any preceding claim.

15. A system for fastening objects including:

a threaded fastener; and

an hydraulically driven torque tool of claim 14.

16. Any novel feature or novel combination of features described herein.

17. Any novel feature or novel combination of features described herein with reference to and as shown in the accompanying drawings.