Black Decker Inc.

The Black and Decker Manufacturing Company

Thomas J Howard, Jr

Alvydas P Karasa

David L Sutton

Robert Bradus

John W Miller

Danny R Jinkins

Ralph James Secoura

Martin Omer Schrock

A power tool has a mechanism to reverse a motor. The mechanism includes a first member secured with the motor surrounding the motor commutator. A pair of electrical contacts are supported in the first member. A second member is rotatable on the fist member. The second member carries a pair of brush holders which include electrical contacts. As the second member is rotated in the first member, the electrical contacts of the brush holders, as well as the electrical contacts in the first member, electrically couple with one another from a first position to a second position which relates to a forward and reverse direction of the motor. A lever moves the second member between its first and second positions.

Reversing mechanism for electric motors

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

A portable, cordless, electrically energized grass trimming device is disclosed having a rotary cutter blade which is formed of a flexible strip of material and which is mounted for rotation over a predetermined course. A blade stabilizing means is provided for restraining the blade along a segment of its length for maintaining rotary motion of the blade in the predetermined course upon impact with other objects. The flexibility of the blade is enhanced by mounting the blade for rotation over a course described by a curved surface of revolution and blade durability is improved by providing a means for absorbing impact shock when the blade strikes an object. An improved blade is described having integrally formed resilient means for absorbing the shock of impact.

Grass trimmer device

A means is described for restraining axial movement of an output shaft of a prime mover which protects the prime mover from undesired axial impact loads applied thereto. The protective means comprises a first body mounted to a rotating output shaft for motion in an axial direction upon the application of a thrust force to the body and a second body which is stationary relative to the output shaft. Means bias the bodies apart and enables mutual engagement therebetween which restricts movement between the bodies in an axial direction when an impact force is applied to the first body.

Arrangement for protecting a rotary device from impact thrust forces

A portable, electrically energized, cordless grass trimmer device is disclosed having a rotatable hub which is adapted to alternatively mount, for substantially balanced rotation therewith, a flexible cutter strip and a line cutter and mechanical counterbalance.

Growing community of inventors

Whitehall, MD, United States of America

Thomas J Howard, Jr