Abstract: A marking device for automatic marking of threaded joints tightened by a pneumatic power wrench, wherein a marking liquid container (48), a metering pump (37), a pressure air supply valve (31) and a marking liquid outlet passage (55) form a unit detachably clamped onto the power wrench housing (10). Pressure air communication passages (24, 25) feed the marking device directly with pressure air from the air supply passage (13) of the power wrench. The marking liquid container (48) comprises a replaceable collapsible tube which is pressurized all around in a pressure air supplied chamber (28). The single stroke metering pump (37) delivers for each stroke a well defined quantity of marking liquid to the outlet passage (55) which is formed by a fine hose made of plastic material with non-adhesive properties relative to the marking liquid. A pressure air operated feed valve (62) is arranged to prevent back flow and other uncontrolled flow of marking liquid through the outlet hose (55) by compressing the latter.

Abstract: A hydraulic torque impulse generator comprising a drive member (10) drivingly connected to a rotation motor and formed with a fluid chamber (11), and an output spindle (12) extending into the fluid chamber (11). Two radially movable seal elements (14, 15) of cylindrical shape are supported in a through slot (13) in the output spindle (12) and are arranged to sealingly cooperate with two axially extending ridges (17, 18) in the fluid chamber (11). A first set of two diametrically opposed and helically extending seal ribs (19, 20) on the drive member (10) is arranged to sealingly cooperate with a second set of two diametrically opposed and helically extending seal ribs (21, 22) on the output spindle (12).

Abstract: A vibration insulating handle for a pneumatic power tool comprising an inner tube (15) and an outer tube (16) both rigidly but adjustably attached to the tool housing (10). The inner tube (15) forms an air exhaust passage (13) which communicates with a silencer (12) carried on the extreme end of the outer tube (16). The tubes (15, 16) are radially spaced relative to each other leaving an annular heat insulating gap therebetween. A weakened portion (30) on the outer tube (16) is located adjacent the tool housing end of the latter and comprises two axially spaced pairs of peripherally extending slots (27, 28). The weakened portion (30) enables the outer tube (16) to yield elastically in radial directions to bending and shearing vibration forces transmitted to the handle during operation of the tool.

Abstract: A pneumatic rotary grinding tool in which the motor unit (15) is displaceable between a rear, operative position and a forward, dislocated position. A safety guard (18) mounted on the tool housing (10) forms an axial support for the motor unit (15) to keep the latter in a rear, operative position, thereby maintaining a seal (23-25) in active position to prevent supplied pressure air from passing directly from the supply passage (12) to the exhaust passage (35) without energizing the motor unit (15). When the safety guard 18 is removed the motor unit (15) is dislocated by the air pressure to a forward position in which the seal (23-25) is rendered inactive and allows supplied pressure air to pass directly from the air supply passage (12) to the exhaust passage (35).

Abstract: A chisel retaining device for a power operated percussion tool comprises a one-piece lock shell (20) which surrounds the chisel stem (17) and is pivotably supported on the front end of the tool housing (10). By pivoting the shell (20) about an axis (X) transverse to the chisel axis a large dimension part (29) or a small dimension part (28) of a front opening (27) of the shell (20) are alternatively aligned with the chisel (15) to prevent or permit passage of a flange (18) on the chisel (15). A spring means (24) is provided to keep the shell (20) in closed position. An internal annular shoulder (21) of the shell (20) cooperates with a toroidal spring (22) received in a circumferential groove (23) on the housing (10) to form an axial abutting means for the shell (20), and an inwardly projecting heel (31) forms together with the shoulder (21) and the toroidal spring (22) a pivot means for the shell (20).

Abstract: A vibration damped portable impact tool comprising a pneumatically powered reciprocating mechanism to which a chisel is connected. In the disclosed tool the chisel is rigidly connected to the piston of the reciprocating mechanism so as to move conjointly therewith. The drive mechanism is arranged in a previously known manner to absorb its own acceleration forces whereby the only vibration forces acting on the tool derive from the chisel in its contact with the work piece. By adapting the spring constant relating to bending of the chisel to the entire mass of the tool such that the resonance frequency of that system is lower than the impact frequency, the vibration forces arising at the working end of the chisel are not transmitted to the tool housing.

Abstract: A pneumatically operated hoist includes a housing 10 provided with a suspension means 12,13 for suspension of the hoist from an overhead support, a pneumatically driven motor 15 provided with a first flow passage 75 arranged for serving as a pressurized air inlet during raising of a load and as an air exhaust passage during lowering of the load and a second flow passage 76 arranged for serving as an air exhaust passage during raising of the load and a pressurized air inlet during lowering of the load, a load engaging means 16,17 drivingly connected to the motor 15, and a control means 18 or regulating air flow to and from the motor 15. Known such hoists of this type are slow in lowering light loads or too fast in lowering heavy loads safely.

Abstract: In a pneumatically powered grinding machine provided with a flyweight operated speed governor there is incorporated an independently operating overspeed safety device which in case of malfunction of the speed governor is intended to obstruct further motive air supply to the motor of the machine. The overspeed safety device comprises an annular valve disk having two centrifugal weights which together with a suspender plate form a latch means by which the valve disk is kept in its open position at motor speeds not exceeding a predetermined level. In its open position, the valve disk is elastically bent about a diameter line as a result of the latch engagement between the centrifugal weights and the suspender plate. When the predetermined speed limit is reached, the valve disk is released from the suspender plate to occupy, while resuming its original flat shape, an air supply obstructing, closed position. The safety device is not resettable without dismantling the machine.