Abstract: A portable pneumatic power wrench has a housing with a handle, a motor, a pressure air inlet passage, and an outlet passage for ducting exhaust air from the motor out of the housing. An outlet unit is connected to the outlet passage and has a first outlet opening section forming a main exhaust air flow path, a second outlet opening section forming an additional exhaust air flow path, and a manually operable valve arranged to control the additional exhaust air flow path by opening or closing the second outlet opening section. The total outlet flow area of the main exhaust air flow path and the additional exhaust air flow path gives an augmented torque output of the power wrench.

Abstract: A power tool having a housing divided into two parts which are interconnected by a thread joint. Internal threads are provided on the housing parts. A tubular connection element has two external axially spaced thread sections which are provided for engagement with the internal threads on the housing parts. The tubular connection element has a thin walled waist section located between the external thread sections to provide a certain elastic deformation as a tightening torque is applied on the thread joint to thereby increase the clamping length of the thread joint. A resilient ring is carried on the waist section and is arranged to be elastically deformed by squeezing between the housing parts and the connection element at tightening of the thread joint, thereby providing a rotation locking friction force on the thread joint.

Abstract: A portable pneumatic power wrench has a housing with a handle, a motor, a pressure air inlet passage, and an outlet passage for ducting exhaust air from the motor out of the housing. An outlet unit is connected to the outlet passage and has a first outlet opening section forming a main exhaust air flow path, a second outlet opening section forming an additional exhaust air flow path, and a manually operable valve arranged to control the additional exhaust air flow path by opening or closing the second outlet opening section. The total outlet flow area of the main exhaust air flow path and the additional exhaust air flow path gives an augmented torque output of the power wrench.

Abstract: A number of pre-production calibration tightenings are performed at a screw joint identical to a screw joint used in production and using the same impulse wrench as to be used in production tightening. The value of one or more tightening related parameters are registered at the attainment of the desired pre-tension level, and those parameter values are used to statistically form a basis for a reference set-up. The tightening parameter values registered during production tightening are compared to the reference set-up, and an indication is obtained as to discrepancies between the reference set-up and the actually registered parameter values to get an indication as to whether the impulse wrench is malfunctioning and/or the screw joint is faulty.

Abstract: An impact wrench includes a housing, a rotation motor, an output shaft, and an impact mechanism including an inertia drive member with an impact chamber, a drive socket coupling the drive member to the motor, and anvil formed integral with an output shaft and extending into the impact chamber, and a coupling member arranged to transfer kinetic energy from the drive member to the anvil, a lubricant provided in the impact chamber, and barrier forming cover element mounted on the drive member to seal off the impact chamber and prevent lubricant from being expelled from the impact chamber at rotation of the drive member.

Abstract: A power tool having a housing divided into two parts which are interconnected by a thread joint. Internal threads are provided on the housing parts. A tubular connection element has two external axially spaced thread sections which are provided for engagement with the internal threads on the housing parts. The tubular connection element has a thin walled waist section located between the external thread sections to provide a certain elastic deformation as a tightening torque is applied on the thread joint to thereby increase the clamping length of the thread joint. A resilient ring is carried on the waist section and is arranged to be elastically deformed by squeezing between the housing parts and the connection element at tightening of the thread joint, thereby providing a rotation locking friction force on the thread joint.

Abstract: An impact wrench comprises a housing, a rotation motor, an output shaft, and an impact mechanism including an inertia drive member with an impact chamber, a drive socket coupling the drive member to the motor, and anvil formed integral with an output shaft extends into the impact chamber, and a coupling means arranged to transfer kinetic energy from the drive member to the anvil, a lubricant provided in the impact chamber, and barrier forming cover element mounted on the drive member to seal off the impact chamber and prevent lubricant from being expelled from the impact chamber at rotation of the drive member.

Abstract: A method and a power tool system are provided for performing screw joint tightening using a pneumatic torque impulse power tool that is controlled by a control unit. A torque magnitude and a torque growth are calculated based on signals delivered by an angle sensor, and pressurized air is supplied to the power tool via a flow regulating valve which is successively adjustable between zero and full power flow. The flow regulating valve is controlled by the control unit to deliver a reduced power air flow to the power tool before and during a first delivered impulse, and then to deliver full power flow until a certain torque magnitude or a percentage of a target torque level is reached, whereafter the air supply flow is again reduced until the target torque level is reached, and when the target torque level is reached the air flow is shut off.

Abstract: A number of pre-production calibration tightenings are performed at a screw joint identical to a screw joint used in production and using the same impulse wrench as to be used in production tightening. The value of one or more tightening related parameters are registered at the attainment of the desired pre-tension level, and those parameter values are used to statistically form a basis for a reference set-up. The tightening parameter values registered during production tightening are compared to the reference set-up, and an indication is obtained as to discrepancies between the reference set-up and the actually registered parameter values to get an indication as to whether the impulse wrench is malfunctioning and/or the screw joint is faulty.

Abstract: A method and a device for determining the torque magnitude transferred to a threaded fastener at each one of a series of torque impulses delivered to the fastener, includes application of repeated torque impulses on the fastener by a power tool having a motor with a rotor and a pulse unit which intermittently couples the motor to an output shaft. The pulse unit includes an inertia drive member which is accelerated by the motor and transfers its kinetic energy to the output shaft at each torque impulse. A rotation detecting device indicates the instantaneous rotation movement of the inertia drive member. At each impulse generation, the inertia drive member is retarded, and the retardation magnitude as a function of time is calculated. The product of the retardation magnitude and the total inertia moment of the drive member and other rotating parts of the tool forming a rigid unit with the inertia drive member reflects the torque magnitude transferred to the fastener at each impulse.

Abstract: A method and a device for determining the torque magnitude transferred to a threaded fastener (25) at each one of a series of torque impulses delivered to the fastener (25), including application of repeated torque impulses on the fastener (25) by a power tool having a motor (20) with a rotor (21) and a pulse unit (23) intermittently coupling the pulse unit (23) to an output shaft (24). The pulse unit (23) comprises an inertia drive member (27) which is accelerated by the motor (20) and arranged to transfer its kinetic energy to the output shaft (24) at each torque impulse, and a rotation detecting device (35, 38) is provided to indicate the instantaneous rotation movement of the inertia drive member (27).

Abstract: A portable power tool having a housing with a pneumatic motor, an output shaft extending in a longitudinal direction of the housing and connected to the motor, and a pistol type handle which a power supply for connecting the motor to a power source and which is fixable relative to the housing in alternate longitudinal positions. The housing is provided with an outer cylindrical surface with a geometric axis extending in the longitudinal direction of the housing, and the handle comprises a tubular portion with an inner cylindrical surface for guiding support of the housing surface. Locking elements are provided for arresting the handle relative to the housing in any desired position, and interacting air communicating passages are provided in the contact surfaces of the housing and the handle for conducting air to and from the motor irrespective of the actual longitudinal position of the handle relative to the housing.

Abstract: A basic method is provided for determining the installed torque in a screw joint which is being tightened by a series of repeated torque impulses, wherein the rotational movement of the screw joint is detected during each impulse, the point in which the screw joint ceases to rotate is detected. And the actually applied torque is indicated at the very instant the screw joint ceases to rotate. In a tightening process control application of the above described basic method, the per impulse increasing value of the installed torque is compared to a predetermined target value in a way known per se, and the tightening process is interrupted as the target value is reached. In a tightening process quality check application of the above described basic method, the accomplished angular displacements of the joint at repeated impulses are indicated and added, and high and low limit values for the final installed torque and the total angle of rotation are provided and compared to the actually obtained values.

Abstract: A basic method is provided for determining the installed torque in a screw joint which is being tightened by a series of repeated torque impulses. The rotational movement of the screw joint is detected during each impulse. The point in which the screw joint ceases to rotate is detected. And the actually applied torque is indicated at the very instance the screw joint ceases to rotate. In a tightening process control application of the above described basic method, the per impulse increasing value of the installed torque is compared to a predetermined target value in a way known per se, and the tightening process is interrupted as the target value is reached. In a tightening process quality check application of the above described basic method, the accomplished angular displacements of the joint at repeated impulses are indicated and added, and high and low limit values for the final installed torque and the total angle of rotation are provided and compared to the actually obtained values.

Abstract: A pneumatic power wrench having a rotation motor supported in a housing (11), an output shaft (13) for connection to a screw joint to be tightened, a pressure air inlet passage (14) controlled by a throttle valve (18), and an exhaust air outlet passage (16) including an automatic outlet flow restricting valve (26,28,43), wherein the outlet flow restricting valve (26,28,43) comprises a valve seat (26), a freely movable valve element (28,43) co-operating with the seat (26), a first activation surface (45) on the valve element (28,43) communicating with the inlet passage (14) downstream of the throttle valve (18) for exerting a motor feed pressure responsive actuating force on the valve element (28,43) in a direction away from the seat (26), and a bias spring (49) and a second outlet flow responsive activation surface (33) for actuating the valve element (28,43) in a direction toward the seat (26).

Abstract: A hydraulic torque impulse generator (16) of the kind having a motor rotated drive member (18;50) formed with a fluid chamber (19;53), an impulse receiving output member (20;51) coaxial with the drive member (18;50) and extending into the fluid chamber (19;53), a hydraulic peak generating mechanism (24-27;54-59) in the fluid chamber (19;53) for producing torque impulses at relative rotation between the drive member (18;50) and the output member (20;51), and a variable volume accumulator chamber (32;64) located in the drive member (18;50) and connected to the fluid chamber (19;53) for compensating for occurring volume changes in the hydraulic fluid, wherein the accumulator chamber (32:64) is divided into a first compartment (40;71) and a second compartment (42;72) by an elastically deflectable membrane (39;73), a passage (43;65) connects the first compartment (40;71) to the fluid chamber (19;53), and the second compartment (42;72) comprises at least partly a yeildable means for biassing the membrane (39;73) to

Abstract: A pneumatic power wrench which comprises a rotation motor (11) lodged in a housing (10) having air inlet and outlet passages (16, 23) for communicating air to and from the motor (11), respectively, and a power transmission for connecting the motor (11) to an output shaft (14), wherein the air outlet passage (23) comprises an adjustable air flow restricting mechanism (24) in the form of a valve spindle (29) extending substantially longitudinally through the outlet passage (23), an annular valve seat (34), and a valve element (32) supported on the valve spindle (29) for flow restricting cooperation with the valve seat (34). The valve spindle (29) is axially adjustable relative to the valve seat (34) for varying the flow restriction through the outlet flow restricting mechanism (24).

Abstract: A cable connector for assembly and mounting on a front section of a housing of a power wrench is arranged to connect at least one operation parameter sensor of the power tool to a multi-core cable. The cable connector includes a multi-contact cable connector plug carried on the multi-core cable, and a one-piece mounting member which is made of an elastically resilient material and which is secured to the front section of the housing and supports a multi-contact jack. The multi-contact cable connector plug includes a coupling sleeve formed with an internal thread, and the mounting member includes an open ring portion to be mounted around the front section of the housing and a tubular coupling portion extending laterally from the ring portion.

Abstract: A suspension device for providing a universally movable support of a pneumatic power tool of the type having a housing (10) with a pistol grip handle (11), and comprises an arc-shaped yoke (31) with a slip member (38) movably guided thereon and connectable to an overhead balancing device. A first end (32) of the yoke (31) is connected to the tool housing (10) by a swivel connection (33, 35) at a location opposite the tool handle (11), and a second end (34) of the yoke (31) is rigidly secured to the rotatable inlet part (20) of a right angle air supply conduit swivel connection (17) to be mounted at the outer end of the tool handle (11), wherein the inlet part (20) of the swivel connection (17) is rotatable in a plane transverse to the longitudinal direction of the tool handle (11).

Abstract: A hydraulic torque impulse generator having a drive member (10) with a fluid chamber (12) and an output spindle (11) extending into the fluid chamber (12) and being provided with a movable seal element (19) and an axial seal ridge (22) for cooperation with oppositely disposed axial seal lands (13, 14) in the fluid chamber (12) to, thereby, divide the fluid chamber (12) into one high pressure compartment (H.P.) and one low pressure compartment (L.P.) during a limited angular interval of relative rotation between the drive member (10) and the output spindle (11), and a valve means comprising an elongate contact element (24, 44) which is supported in an axial groove (23, 43) in the seal ridge (22 ), which groove (23, 43) communicates with the high pressure compartment (H.P.) such that the contact element (24, 44) is urged into its sealing condition by the fluid pressure at pressure magnitudes above a certain level.