Atlas Copco Industrial Technique Ab

Atlas Copco Tools Ab

Erik Vilhelm Persson

Gunnar Christer Hansson

Carl-Gustaf Carlin

Ulf Roland Brändström

Jarl-Olof Huldén

Christer Gunnar Hansson

Björn Gustav Undén

Kristoffer Felix Wadman

Martin Hertsius

Erik George Baker

Kjell Thomas Martin Eriksson

Arne Torgny Roloff

John Berglind

Karl Johan Lars Elsmark

Thomas Kjell Martin Eriksson

A power tool for tightening a fastener includes: an angle measurement unit for measuring a rotational angle (&#x3b1;) of the fastener; a torque measurement unit for measuring a torque (T) delivered to the fastener during tightening; a motor connected to rotatable parts of the power tool for driving the tightening of the fastener; a processor for calculating a tightening energy (E) needed to complete tightening of the fastener from &#x3b1; to a predetermined target angle (&#x3b1;), wherein Eis calculated based on &#x3b1;, &#x3b1;and a stiffness (k) of a joint; and a regulator to regulate a rotational speed (&#x3c9;) of the motor to provide rotational energy (E) in the form of rotational inertia in the rotatable parts of the power tool to meet the needed E, wherein the power tool interrupts the tightening of the fastener at &#x3b1;, &#x3b1;defined from snug, at a snug angle (&#x3b1;).

Power tool for tightening a fastener and a method

A sensor unit for inducing and indicating ultra sonic sound waves in at least one threaded fastener by physical contact with an end surface thereof, wherein the sensor unit includes: a support casing, a sensor element with forward contact surface for engaging the fastener end surface and movable relative to the support casing between rest and active positions, and a bias spring between the support casing and the sensor element to urge the sensor element into the rest position as the sensor element is out of contact with the fastener end surface and to bias the contact surface of the sensor element into physical contact with the fastener end surface in the active position. The support casing includes a positioning socket, engaged by the sensor element in the rest position, having a non-cylindrical and non-circular cross sectional inner shape and congruent with an outer shape of the sensor element.

Sensor unit for ultra sonic sound wave communication

The invention relates to a method of measuring elongation of a fastener by means of minimum peak side lobe (MPS) coded ultrasonic signals, and a power tool configured to performing the method. MPS coded signals with different base frequencies are transmitted into the fastener and a corresponding set of reflected signals are received from the fastener. Each reflected signal is cross-correlated with the corresponding transmitted signal, and a quality attribute of each transmitted signal is determined from the cross-correlated signals. Based on the quality attributes at least one parameter of an ultrasonic measurement signal is determined and the measurement is performed by transmitting the ultrasonic measurement signal into the fastener, and receiving a reflected ultrasonic measurement signal.

Method of measuring elongation of a fastener with ultrasound, performed by a power tool, and a power tool

In an apparatus and a method of evaluating a clamp force (F) in a threaded joint between a bolt and a matching threaded piece during a tightening operation, a torque (T) provided to the joint is continuously measured and ultra-sonic pulses are simultaneously induced into the bolt such that a time of flight (TOF) of the pulses in the bolt is measured. In response to an increase of the measured torque (T) an increase rate (dT/d&#x3b1;) of the torque (T) is determined, from which an initial rotation angle (&#x3b1;) where the torque (T) starts to increase due to bolt deformation is determined. An increase rate (dTOF/d&#x3b1;) of the time of flight (TOF) is also determined. A total increase of the time of flight (&#x394;TOF) during the tightening operation is then determined based on the initial rotation angle (&#x3b1;) and the increase rate (dTOF/d&#x3b1;) of the time of flight (TOF).

Method and apparatus for evaluating clamp force in a bolt by means of ultra-sonic measurements

A power wrench with a torque sensing unit includes a housing, a motor, an output shaft, and a planetary reduction gearing connecting the motor to the output shaft and including a stationary ring gear supported in the housing, wherein the torque sensing unit includes a torque transferring element with a single radially extending reaction arm arranged to transfer reaction torque from the ring gear to the housing and carrying strain measuring sensors for generating signals in response to the transferred reaction torque. The torque transferring element includes an annular body with two weak portions to be elastically deformed during torque transfer and having flat surfaces for carrying the strain measuring sensors.

Power wrench with a torque sensing unit

A torque sensing unit for a power tool arranged to generate a torque responsive signal by sensing the reaction torque transferred from a ring gear of a planetary reduction gearing to the tool housing. The torque sensing unit includes an annular torque transferring element disposed perpendicularly to the geometric axis of the ring gear and being formed with a first pair of external engagement portions for connecting the torque transferring element to the housing, a second pair of external engagement portions for connecting the torque transferring element to the ring gear, and at least one pair of weak elastically deformable zones located between the engagement portions and provided with sensors for delivering signals in response to the transferred reaction torque.

Torque sensing unit for a power tool and a power tool comprising such a torque sensing unit

An electric power tool having a housing, a motor, a jack for receiving a connection plug of an electric cable, and a swivel unit mounted on the housing and carrying the jack, wherein the swivel unit includes a first head mounted on the housing for rotation about a first axis, and a second head mounted on the first head for rotation about a second axis. The first and second axes form an angle between them, and provide for freedom of rotation of the jack, thereby providing for positioning of the jack and routing of a connected cable in desired directions relative to the housing.

Growing community of inventors

Solna, Sweden

Erik Vilhelm Persson