초록 ▼

The present invention relates to an impulse wrench for use in conjunction with a fastener engaging tool and a power supply to selectively rotate threaded fasteners. The wrench comprises a housing and an impulse manifold rotatably mounted within the housing. An impulse piston is mounted inside a impu

The present invention relates to an impulse wrench for use in conjunction with a fastener engaging tool and a power supply to selectively rotate threaded fasteners. The wrench comprises a housing and an impulse manifold rotatably mounted within the housing. An impulse piston is mounted inside a impulse piston receiving space for reciprocating movement and has an impulse delivering surface and a pressurizing surface. The piston and the piston receiving space are constructed and arranged such that the pressurizing surface and an outer end portion of the piston receiving space cooperate to define at least a portion of a high pressure chamber which is filled with a substantially incompressible fluid. An impulse receiving portion of an output spindle and the impulse delivering portion of the impulse piston are constructed and arranged with respect to one another such that the motor rotates the manifold relative to the spindle so as to engage the impulse delivering surface of the impulse piston with the impulse receiving portion of the spindle so that (a) an impulse is delivered to the spindle to turn the spindle and the fastener engaging tool and (b) the impulse receiving portion cams the impulse delivering surface so as to move the impulse piston outwardly to increase the fluid pressure inside the high pressure chamber to a level which is related to the torsional resistance offered by the fastener. A pressure responsive shut-off structure is communicated with the high pressure chamber and movable between (a) a power communicating position and (b) a power shut-off position. The shut-off structure moves from the power communicating position thereof to the power shut-off position thereof in response to fluid pressure in the high pressure chamber reaching a predetermined level, thereby preventing power from being communicated from the power supply to the motor when the torsional resistance of the fastener has reached a predetermined level.

대표청구항 ▼

[ What is claimed is:] [13.] An impulse wrench for use with a fastener engaging tool and a supply of pressurized fluid to selectively rotate threaded fasteners, the engaging tool being constructed and arranged to be engaged with a fastener such that rotation of the tool rotates the fastener, said wr

[ What is claimed is:] [13.] An impulse wrench for use with a fastener engaging tool and a supply of pressurized fluid to selectively rotate threaded fasteners, the engaging tool being constructed and arranged to be engaged with a fastener such that rotation of the tool rotates the fastener, said wrench comprising:a housing;an impulse transmitting mechanism mounted in said housing, said mechanism comprising a driven component, an output spindle, and surfaces defining a high pressure chamber filled with a substantially incompressible fluid;said output spindle being mounted for rotation with respect to said housing and being connectable with the fastener engaging tool such that rotation of said spindle rotates the fastener engaging tool;a fluid-driven motor operatively connected to said driven component, said motor being constructed and arranged to rotate said driven component using pressurized fluid from said supply;said driven component being rotatable with respect to said housing and said output spindle such that rotation of said driven component as a result of pressurized fluid being supplied to said motor rotates said spindle to affect a fastener tightening operation wherein the threaded fastener is tightened in such a manner that its torsional resistance to tightening increases throughout the operation;said impulse transmitting mechanism being constructed and arranged such that the pressure of the fluid in said chamber increases during said fastener tightening operation to a level that is related to the torsional resistance offered by the fastener during the fastener tightening operation;an actuator selectively movable between (a) an actuated position establishing fluid communication between the supply of pressurized fluid and said motor and (b) a non-actuated position preventing fluid communication between the supply of pressurized fluid and said motor; andan adjustable pressure responsive shut-off structure communicated with said high pressure chamber and having a shut-off valve that moves between (a) a power communicating position wherein said shutoff valve permits the pressurized fluid to flow from the supply thereof to said motor and (b) a power shut-off position wherein said shut-off valve prevents the pressurized fluid from flowing from the supply thereof to said motor, said shut-off valve being positioned between said motor and the supply of pressurized fluid such that the pressurized fluid flows against the valve so as to apply a biasing force that urges said valve towards said power shut-off position thereof;said shut-off structure being constructed and arranged to maintain said shut-off valve in said power communicating position thereof while the pressure of the fluid in said high pressure chamber is below a shut-off initiating level that is related to a selected maximum amount of torsional resistance to which the fastener is to be tightened and to thereafter allow said valve to move to said power shut-off position thereof under the biasing force applied by the pressurized fluid flowing from the supply thereof in response to the pressure of the fluid in said high pressure chamber reaching the shut-off initiating level, thereby preventing the pressurized fluid from being communicated from the supply thereof to the motor when the torsional resistance offered by the fastener has reached the aforesaid maximum level,said shut-off structure being constructed and arranged such that the shut-off initiating level of the fluid pressure in said high pressure fluid chamber at which said shut-off structure moves to the power shut-off position can be adjusted, thereby allowing for selective control of the maximum torsional resistance for the fastener.