EP 0403460 A1 19901219 - Power wrench for tightening screw joints.
Title (en)
Power wrench for tightening screw joints.
Title (de)
Motorschraubenschlüssel zum Anziehen von Schraubverbindungen.
Title (fr)
Outil de vissage à moteur pour serrer des connexions de vissage.
Publication
Application
Priority
SE 8902101 A 19890612
Abstract (en)
A power wrench for two-step tightening of screw joints, comprising a housing (13), an electric motor (10) including a rotor (25), an output shaft (24) coupled to the rotor (25), and a power supply means including a power converter (11) with a variable frequency and voltage output and a current responsive power shut-off means. A retardation responsive inertia means (28) is coupled to the motor rotor (25) via a spring (32) and a cam means (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.
IPC 1-7
IPC 8 full level
B25B 21/00 (2006.01); B25B 23/14 (2006.01); B25B 23/145 (2006.01); B25B 23/147 (2006.01); B25B 23/151 (2006.01)
CPC (source: EP)
B25B 21/008 (2013.01); B25B 23/147 (2013.01)
Citation (search report)
- [A] US 3696871 A 19721010 - STENBACKA JOHAN RUNAR
- [AD] US 2768546 A 19561030 - AMTSBERG LESTER A
- [A] DE 3740076 A1 19880601 - ATLAS COPCO AB [SE]
Designated contracting state (EPC)
DE FR SE
DOCDB simple family (publication)
EP 0403460 A1 19901219; EP 0403460 B1 19950816; DE 69021647 D1 19950921; DE 69021647 T2 19960502; JP 2824125 B2 19981111; JP H04176574 A 19920624; SE 8902101 D0 19890612; SE 8902101 L 19901213
DOCDB simple family (application)
EP 90850234 A 19900611; DE 69021647 T 19900611; JP 15175490 A 19900612; SE 8902101 A 19890612