Atlas Copco Tools Ab

Jan K Edling

Rolf A Jacobsson

A portable power tool for operating a wheel type grinding or cutting working implement comprises a housing (10), a rotating output spindle (11) with a working implement supporting flange (14), a safety guard (16) adjustably supported on a guide flange (15) on the housing (10), and a selectively operable arresting device (18) for positively engaging lock openings (20) on the safety guard (16) for locking the latter in alternative positions relative to the housing (10), wherein the support flange (14) is provided with a number of peripheral indentations (21), and the arresting device (18) comprises a lock bolt (19) which is longitudinally shiftable between a first position in which it engages either one of the lock openings (20) on the safety guard (16), a second position in which it engages either one of the lock openings (20) on the safety guard (16) as well as either one of the support flange (14) indentations (21), and a third position in which it neither engages anyone of the safety guard (16) lock openings (20) nor anyone of the support flange (14) indentations (21). A spring means (28, 29) is provided to bias the lock bolt (19) toward the first position.

Portable power tool

An oil seal for sealing off a fast rotating shaft (10) relative to a housing (11) comprises a first seal element (15) mounted on the shaft (10), a second seal element (18) resiliently mounted in the housing (11), both seal elements (15, 18) having cooperating contact surfaces (25, 26), and a spring (22) acting on the second seal element (18) to provide an axial contact pressure between the contact surfaces (25, 26). The contact surfaces (25, 26) of the seal elements (15, 18) are made of materials of different hardness, and the one consisting of the hardest material is formed with one or more circular ribs (27a-c) disposed concentrically with the shaft (10) and intended to cut mating circular grooves in the other seal element contact surface (25) during a running-in period.

Grooved run-in face seal

A portable power grinder comprises a housing (11), a rotation motor (10) with a rotor (13) having a rear end portion (27) extending out of the motor (10), an output shaft (22) which is drivingly coupled via a reduction gearing (23) to the rotor shaft (13) and intended to carry a grinding tool, and a speed governor (18) for providing a constant motor speed. The reduction gearing (23) comprises a gear (24) integral with the rotor shaft (13) and another gear (25) integral with the output shaft (22). Alternative rotor shafts (13) with gears (24) of different sizes may replace each other for obtaining different gear ratios and different output speed levels, and the length of the rear end portion (27) of the rotor shafts (13) varies with the size of the integral gear (24). The housing (11) has a detachable lid (15) carrying the speed marking (2) of the tool and having an internal projection (28) of a size directly related to the speed level readable on the speed marking (21). The rear rotor shaft end portion (27) has a shape directly related to the maximum speed level provided by the actually fitted rotor shaft (13), and the lid projection (28) matches such rotor shaft end portions (27) only that correspond to gear ratios providing output speeds equal to or lower than the speed marking level.

Growing community of inventors

Alvsjo, Sweden

Jan K Edling