Abstract: The invention concerns a device for tightening threaded joints in two subsequent steps, namely a first step during which a joint is tightened to a predetermined torque snug level and a second step during which the joint is further tightened up to a final predetermined pretension level. During the second tightening step the angle speed of the power tool (10) is gradually increased at a predetermined rate. The power tool (10) comprises an electric brushless motor which is supplied with power from a variable frequency output inverter (11), and the gradual increase in angle speed of the power tool (10) is accomplished by a gradually increased output frequency and voltage from the power supply means (11).

Abstract: A pneumatic power tool includes a housing (10), a motor (14), an air inlet passage (23) in the housing (10) communicating with the motor (14), a pistol type handle (12) extending from the housing (10) perpendicularly to the application direction of the tool, and an air communication arrangement (16, 20, 23) for connecting the air inlet passage (23) to a pressure air supply conduit connected to the tool, wherein the air communication arrangement (16, 20, 23) is separated from the handle (12) and comprises an air supply passage forming member (16) connected to the rear part of the housing (10), and an exhaust air passage (25, 26) having an outlet portion (26) coaxially disposed relative to the air supply passage forming member (16).

Abstract: A method for tightening threaded joints by applying torque on the joint by means of a power tool until a predetermined pretension level in the joint is reached, whereupon a controller means connected to the power tool is arranged on one hand to initiate power shut-off and on the other hand to initiate continued successively decreasing power supply to the tool as the predetermined pretension level is passed.

Abstract: A method and a device for tightening threaded joints includes applying torque on the joint by means of a power tool until a predetermined pretension level in the joint is reached, whereupon a controller connected to the power tool is arranged on one hand to initiate power shut-off and on the other hand to initiate continued successively decreasing power supply to the tool as the predetermined pretension level is passed.

Abstract: Screw joint tightening power tool, comprising a rotation motor (13), a power control (34), and a torque responsive override clutch (15) coupling the motor (13) to an output shaft (16). A power control (34) actuating mechanism is associated with the clutch (15) and comprises a push rod (36) which in an ON-position rests axially against a transversely movable latch (41) and is released for axial displacement toward an OFF-position at relative rotation between the driving and driven halves (20, 22) of the clutch (15). The actuating mechanism further comprises balls (45) which are disposed in peripheral pockets (48) in one of the clutch halves, either of which balls (45) is arranged to cooperate with the latch (41) to shift the latter to a push rod (36) releasing position to, thereby, make the power control (34) shut off the power supply to the motor (13) as the clutch (15) overrides at a desired torque level.

Abstract: A power wrench with torque control means, comprising a spring biassed torque limiting mechanism, wherein mark means indicating the actual length of the biassing spring (22) are visible from outside the tool housing (10) through one or more apertures (30, 38), and a gauge element (40) movably supported on the tool housing (10) and carrying two interspaced marks (42, 43) adapted to be aligned with the spring length indicating mark means in a nominal output torque setting of the torque limiting mechanism.

Abstract: When using hand-held electrically or pneumatically driven tools, for instance angled nut tighteners, different socket wrenches or box spanners (6) are used for different work processes. In order to enable a socket to be fitted quickly to a tool, the tool is provided with a manouverable socket holder (9), which also enables the socket to be readily removed from the tool. The socket holder includes a radially movable device (10) which is connected to the tool and which can be moved to positions in which it is excentric with or concentrical with the output shaft of the tool. A spring means (13) is provided for activation of the locking device to its excentric position relative to the output shaft, such as to hold a socket firmly thereto.

Abstract: A vibration insulated power tool handle, comprising a tubular grip portion (10), a mounting means (11) for rigid mounting on a tool housing, and an elastic vibration insulating leaf spring membrane (12) interconnecting the grip portion (10) and the mounting means (11). The spring membrane (12) is formed with a central opening (19) for receiving a screw (21) of the mounting means (11) and is connected by its periphery to a socket portion (16) on the grip portion (10).

Abstract: A power wrench for two-step tightening of screw joints, has a housing (13), an electric motor (10) including a rotor (25), an output shaft (24) coupled to the rotor (25), and a power supply. The power supply includes a power converter (11) with a variable frequency and voltage output and a current responsive power shut-off device. A retardation responsive inertia device (28) is coupled to the motor rotor (25) via a spring (32) and a cam (29, 30) for corotation with the motor rotor (25) and for activation of a switch (12) as a certain predetermined retardation magnitude in the motor rotor (25) is exceeded. The latter is used for obtaining a fast torque interruption of the initial tightening step of the two-step tightening process, whereas the final tightening step is discontinued automatically as a predetermined current magnitude in the power supply is reached.

Abstract: A hydraulic torque impulse generator comprises a hollow drive member (21) connected to a rotation motor (16) and comprising a fluid chamber (24) with axially extending seal lands (35, 36) and seal ridges (40, 41) on its peripheral wall for sealing cooperation with radially movable seal elements (33, 34) and axially extending seal ridges (38, 39) on an output spindle (18, 22) to divide the fluid chamber (24) into high pressure compartments (H.P.) and low pressure compartments (L.P.) during short intervals of the relative rotating between the drive member (21) and the output spindle (18, 22). The fluid chamber (24) is defined also by two opposite end walls (25, 28), one (25) of which comprises an annular, nonresilient contact element (37) which is axially displaceable between an active seal position in which it is urged against the seal elements (33, 34) and shoulders (43, 30) on the spindle portion (22) and the fluid chamber wall (20), respectively, and a rest position.

Abstract: A screw tightening power tool, comprising a rotation motor, a power supply (27) connected to the motor, an output shaft (13), a torque responsive release clutch (14) including a driving half (16) and a driven half (17) and coupling the motor to the output shaft (13), an activating rod (26) coupled to the power supply (27), a latch means (24) associated with one of the clutch halves (16) and cooperating with the activating rod (26), and a cam (30) associated with the other of the clutch halves (17) and operatively connected to the latch (24) for making the latch shift from an activating rod (26) supporting position to an activating rod (26) releasing position as the transferred torque has reached the actual preset release torque level of the clutch. The cam (30) comprises a spindle (30) which is rotatively supported relative to the driven clutch half (17) for a limited rotational movement relative thereto.

Abstract: A vibration damped hand held rotary grinding machine comprising a housing (10) with at least one handle (17, 18), a rotation motor (11), an output shaft (13) drivingly coupled to the motor and having a mounting (14) for attachment of a grinding wheel (15), and a sector-shaped non-resilient safe guard (19) which is rigidly attached to the housing (10) and surrounding partially the grinding wheel (15) and which has an arc-shaped rim portion (20) encircling partially the grinding wheel circumference. A vibration damping inertia device (22; 22a, 22b) is rigidly associated with the safe guard (19) on or adjacent the rim portion (20), such that the center of gravity of substantially all axial plane cross sections through the inertia device (22 22a, 22b) is located at a radius (R.sub.1) of at least 90% of the rim portion (20) radius (R). Preferably, the safe guard (19) is semicircular and th einertia device (22; 22a, 22 b) extends from both ends of the safe guard rim portion (20).

Abstract: A two-speed power transmission for a power tool comprises a housing (10), an input shaft (20), an output shaft (15), a planetary gear (18) and a torque responsive gear shift mechanism (19) for directing torque through the planetary gear (18) in a high torque/low speed drive mode or past the planetary gear (18) in a low torque/high speed drive mode. The gear shift mechanism (19) comprises a driving member (26) connected to the sun wheel (21) of the planetary gear (18), a driven member (27) connected to the output shaft (15), and a number of axially movable coupling elements (30) arranged to intercouple in a first position the driving member (26) and the driven member (27) and intercouple in a second position the planet wheel carrier (24) of the planetary gear (18) and the driven member (27). The coupling elements (30) are continuously supported in the radial direction by an axially extending coupling sleeve (28) formed in one piece with the planet wheel carrier (24).

Abstract: A torque impulse delivering power tool having an automatic power shut-off (28) and comprises a drive unit (15) including a rotor (16), a power supply (24) connected to the drive unit (15), a power controller (23) included in the power supply (24), an output shaft (20), and a hydraulic impulse clutch (19) coupling intermittently the drive unit (15) to the output shaft (20), which impulse clutch (19) comprises a drive member (18) drivingly connected to the drive unit rotor (16). A retardation responsive trip device (28) includes an inertia influenced activation member (29) which is mounted on a pivot pin (30) on the drive member (18) for movement about an axis substantially parallel to the rotation axis of the drive member (18) and which is arranged to activate a latch (40-44) by which the power controller (23) is shiftable from an open position to a closed position as a certain retardation magnitude is reached in the drive member (18).

Abstract: A torque impulse power tool primarily intended for tightening threaded joints comprises a housing (10), a rotation motor (11), a torque impulse generating mechanism (13), and a reduction gearing (12) coupling the impulse mechanism (13) to the motor (11). A torsion spring (21) is associated with the reduction gearing (12) to reduce substantially the difference in deceleration between the motor (11) and the impulse mechanism (13) by yielding elastically to the driving and inertia forces of the motor (11) and the gearing (12) during each impulse generation. The torsion spring (21) is connected to absorb the reaction torque peaks developed in the gearing (12) or the driving torque peaks between the gearing (12) and the impulse mechanism (13).

Abstract: A vibration damped hand held rotary grinding machine comprising a housing (10), a rotation motor (11), an output shaft (13) drivingly coupled to the motor and having a mounting (14) for attachment of a grinding wheel (15), two handles (17, 18) rigidly mounted on the housing (10) and extending in right angles relative to the output shaft (13) as well as to each other, and a sector-shaped non-resilient safe guard (19) which is rigidly attached to the housing (10) and surrounding partially the grinding wheel (15) and which has an arc-shaped rim portion (20) encircling partially the grinding wheel circumference. Vibration damping inertia elements (22, 23, 24) are rigidly attached to the safe guard (19) rim portion (20) and to the outer extremities of the handles (17, 18) such that the moment of inertia of the machine is substantially increased as is the vibration force absorption.

Abstract: A rotary valve type quick coupling for interconnecting two pressure medium conduits comprises a coupling unit (10) including a casing (14) and a spherical rotary valve element (18) formed with a socket (27), and a tubular connector nipple (12) adapted to be guidingly received in the socket (27). An elongate aperture (32) is provided in the casing (14) which permits the connector nipple (12) to be introduced into the valve element socket (27) and to be rotated conjointly with the valve element (18) between a connect/disconnect position and a connected position. A transverse annular shoulder (46) on the nipple (12) is arranged to engage a guide surface (45) on the casing (14) to guide the nipple (12) and the valve element (18) as they occupy the connect/disconnect position.