Black Decker Inc.

David L Sutton

Thomas J Howard, Jr

Scott D Price

Mark E Snetting

Steven A Anderson

Ernst Staas

Rainer Herting

Stefan Blickhan

Reimund Beck

A hand-operated electric tool, especially a jigsaw, has a motor unit provided in the tool housing. The motor unit contains in a motor housing the stator and the rotor. One end of the rotor shaft projects from the motor housing and is mounted in two bearings fixed in the motor housing. A countershaft forms an extension of the rotor shaft and carries a toothed arrangement. The countershaft is coupled to the rotor shaft and is rotatably mounted in a bearing. The rotor shaft and countershaft engage axially with radial play and are coupled non-rotatably by co-operating radial projections and recesses receiving the projections. In the region of the overlapping portions of rotor shaft and countershaft, one of the shafts has an annular portion extending at least over a part of the circumference. The annular portion is substantially in line contact with an adjacent circumferential surface of the other shaft. The line contact permits misalignment of the rotor shaft and countershaft but reduces noise.

Hand operated electric tool, especially a jigsaw

An air directing baffle for a random orbit sander. The baffle includes a main body portion forming an annular opening, a pair of neck portions extending approximately circumferentially opposite from one another, and a pair of recessed portions formed in each of the neck portions. The neck portions extend into airflow registration with a plurality of exhaust slots formed in a shroud rotatably disposed at a lower portion of a housing of the sander. The annular opening is adapted to fit over a boss portion protruding from a lower face surface of the housing of the sander to thus permit the baffle to be rotated freely relative to the housing. The recessed portions in each of the neck portions of the baffle inwardly engage with a pair of inwardly protruding shoulder portions formed in an interior area of the shroud. The interengagement of the baffle with the shroud permits the neck portions of the baffle to be maintained in alignment with the exhaust slots in the shroud as the shroud is rotated by a user during operation of the sander. Thus, the baffle is free to rotate relative to the housing but not relative to the shroud itself. The baffle serves to more effectively direct a cooling airflow drawn in by a fan through inlet slots in a top member associated with the housing such that the airflow is more directly exhausted from the interior area of the shroud. The design of the baffle further does not complicate the assembly of the sander 10 or otherwise add significantly to the overall cost of the sander.

Random orbit sander having air directing baffle

A random orbit sander having a braking member for frictionally controlling the speed of a platen of the sander when the sander is removed from a workpiece during operation. The braking member includes a base portion, an outwardly flaring, relatively thin wall portion and an enlarged outermost edge portion adapted to frictionally engage an upper surface of the platen. The braking member is secured to the bottom of the shroud of the housing via a groove formed in its base portion. The braking member exerts a relatively constant spring force against the upper surface of the platen which limits the rotational speed of the platen to approximately 1200 rpm when the platen is lifted off of a work surface, without significantly degrading the performance of the sander under load. This prevents swirl marks and other undesirable scratches from being made in a workpiece when the platen is reapplied to the workpiece as a result of the platen having increased in speed to an unloaded, free-wheeling speed, and yet allows the platen to operate at or above the minimum desired working speed of about 800 rpm. The braking member is formed from polyester butylene terephthalate which is doped with approximately 2% silicon and approximately 15% teflon in the preferred embodiments. This material formulation, plus its geometry, allows the braking member to exert and maintain a relatively constant spring force of about 3.5 lbs. against the platen and to resist frictional wear once past an initial break-in period. The braking member also acts as a seal between the lower surface of the shroud and the upper surface of the platen.

Random orbit sander having braking member

An accessory for inflating and deflating inflatable articles comprises a conduit 13, an intake 17, an outtake 19 and an injector 35. In use, conduit 13 functions as a venturi tube for rapid inflation and deflation of inflatable articles, preferably, articles having a large, low pressure air volume. For inflation, outtake 19 is connected to the inflatable article. For deflation, intake 17 is connected to the inflated article. For inflation and deflation, a source of pressurized air, preferably, an electric air compressor is connected to injector 35.

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Forest Hill, MD, United States of America

David L Sutton