Abstract: A breathing apparatus having a main body with a generally cylindrical inner cavity. The main body has a main aperture for the user to breath into and at least two sets of outer openings. An inner cylinder is coaxially disposed within the inner cavity of the main body and is adapted to move relative to the main body. The inner cylinder has an open end adjacent the main aperture, and at least two sets of inner openings selectively matable with the openings in the main body upon movement of the inner cylinder with respect to the main body. By selecting the appropriate alignment of openings, either resistive, percussive, or pulsing breathing exercises can be performed.

Abstract: A breathing apparatus having a main body with a generally cylindrical inner cavity. The main body has a main aperture for the user to breath into and at least two sets of outer openings. An inner cylinder is coaxially disposed within the inner cavity of the main body and is adapted to move relative to the main body. The inner cylinder has an open end adjacent the main aperture, and at least two sets of inner openings selectively matable with the openings in the main body upon movement of the inner cylinder with respect to the main body. By selecting the appropriate alignment of openings, either resistive, percussive, or pulsing breathing exercises can be performed.

Abstract: A breathing apparatus and method of using the apparatus for exercising the lungs of a user. The breathing apparatus has a main body with a generally cylindrical inner cavity. The main body has a main aperture for the user to breathe into and at least two sets of outer openings. An inner cylinder is coaxially disposed within the inner cavity of the main body and is adapted to move relative to the main body. The inner cylinder has an open end adjacent the main aperture, and at least two sets of inner openings selectively matable with the openings in the main body upon movement of the inner cylinder with respect to the main body. By selecting the appropriate alignment of openings, either resistive, percussive, or pulsing breathing exercises can be performed.

Abstract: A breathing apparatus having a main body with a generally cylindrical inner cavity. The main body has a main aperture for the user to breath into and at least two sets of outer openings. An inner cylinder is coaxially disposed within the inner cavity of the main body and is adapted to move relative to the main body. The inner cylinder has an open end adjacent the main aperture, and at least two sets of inner openings selectively matable with the openings in the main body upon movement of the inner cylinder with respect to the main body. By selecting the appropriate alignment of openings, varied amounts of resistance can be achieved.

Abstract: A breathing apparatus and method of using the apparatus for exercising the lungs of a user. The breathing apparatus has a main body with a generally cylindrical inner cavity. The main body has a main aperture for the user to breathe into and at least two sets of outer openings. An inner cylinder is coaxially disposed within the inner cavity of the main body and is adapted to move relative to the main body. The inner cylinder has an open end adjacent the main aperture, and at least two sets of inner openings selectively matable with the openings in the main body upon movement of the inner cylinder with respect to the main body. By selecting the appropriate alignment of openings, either resistive, percussive, or pulsing breathing exercises can be performed.

Abstract: An annular hole cutter wherein each tooth is formed with a radially outer cutting edge and at least alternate teeth are formed with radially extending, circumferentially staggered inner and outer cutting edges. The bottom face of each tooth is formed with oppositely radially inclined inner and outer back-off faces which intersect in a downwardly extending crest which in turn intersects the radially outer cutting edge. The outer back-off faces of alternate teeth are vertically relieved relative to the outer back-off faces of the intermediate teeth and the inner back-off faces of the intermediate teeth are vertically relieved relative to the inner back-off faces of the alternate teeth a distance greater than the chip load at which the cutter is operated. In the preferred form, the radially inner portion only of the unrelieved inner back-off face is relieved to a greater extent than the relieved inner back-off faces.

Abstract: A cutting tool and method for cutting multidirectional cuts in a workpiece. The cutting tool has a body portion having a generally cylindrical outer wall and inner periphery. A plurality of cutting teeth are spaced circumferentially around the lower end and a plurality of flutes extend upwardly around the outer periphery from the lower end. The cutting teeth include a plurality of generally radially extending cutting edges positioned about the face of the cutting tool, a plurality of inside diameter cutting edges formed at the line of intersection of the radially extending cutting edges and the inner periphery of the cylindrical wall, and a plurality of outside diameter cutting edges formed at the line of intersection of the radially extending cutting edges and the outer periphery of the cylindrical wall.

Abstract: An annular hole cutter wherein each tooth is formed with a radially outer cutting edge and at least alternate teeth are formed with radially extending, circumferentially staggered inner and outer cutting edges. The bottom face of each tooth is formed with oppositely radially inclined inner and outer back-off faces which intersect in a downwardly extending crest which in turn intersects the radially outer cutting edge. The outer back-off faces of alternate teeth are vertically relieved relative to the outer back-off faces of the intermediate teeth and the inner back-off faces of the intermediate teeth are vertically relieved relative to the inner back-off faces of the alternate teeth a distance greater than the chip load at which the cutter is operated. In the preferred form, the radially inner portion only of the unrelieved inner back-off face is relieved to a greater extent than the relieved inner back-off faces.

Abstract: The annular cutter of the present invention has a body portion with a plurality of teeth circumferentially spaced about the lower end thereof and a plurality of flutes extending upwardly around the outer periphery of the body portion between the teeth. Each of the teeth has at least two circumferentially stepped cutting edges with the trailing edge being the outermost cutting edge. These two cutting edges are separated by a shoulder which in the preferred embodiment is defined by the bottom wall of the flute. This shoulder has a radial clearance adjacent the outermost cutting edge to accommodate the growth of the outermost chip cut by the outermost cutting edge to facilitate discharge of the chips through the flute.

Abstract: An annular hole cutter wherein each tooth is formed with a radially outer cutting edge and at least alternate teeth are formed with radially extending, circumferentially staggered inner and outer cutting edges. The bottom face of each tooth is formed with oppositely radially inclined inner and outer back-off faces which intersect in a downwardly extending crest which in turn intersects the radially outer cutting edge. The outer back-off faces of alternate teeth are vertically relieved relative to the outer back-off faces of the intermediate teeth and the inner back-off faces of the intermediate teeth are vertically relieved relative to the inner back-off faces of the alternate teeth a distance greater than the chip load at which the cutter is operated. In the preferred form, the radially inner portion only of the unrelieved inner back-off face is relieved to a greater extent than the relieved inner back-off faces.

Abstract: An annular hole cutter wherein each tooth is formed with a radially outer cutting edge and at least alternate teeth are formed with radially extending, circumferentially staggered inner and outer cutting edges. The bottom face of each tooth is formed with oppositely radially inclined inner and outer back-off faces which intersect in a downwardly extending crest which in turn intersects the radially outer cutting edge. The outer back-off faces of alternate teeth are vertically relieved relative to the outer back-off faces of the intermediate teeth and the inner back-off faces of the intermediate teeth are vertically relieved relative to the inner back-off faces of the alternate teeth a distance greater than the chip load at which the cutter is operated. In the preferred form, the radially inner portion only of the unrelieved inner back-off face is relieved to a greater extent than the relieved inner back-off faces.

Abstract: A hole cutter has a fluted annular wall formed with a plurality of circumferentially spaced teeth around the lower end thereof, the successive teeth being connected by webs of reduced thickness. Between successive teeth each web is formed with a gullet, the upper end of which is defined by a wall which inclines upwardly in a radially outward direction. The upper end wall of the gullet comprises a radially inner section and a radially outer section. The radially inner section is inclined to the horizontal at a substantially less angle than the radially outer section. The two wall sections intersect in a shoulder which is spaced substantially closer to the radially inner face of the web that the radially outer face of the web.

Abstract: An annular cutter having a cylindrical side wall provided with cutting teeth spaced circumferentially around its lower end, the inner periphery of each tooth being radially relieved to provide a narrow margin at the inner side of each tooth directly behind the cutting edge thereof and simultaneously provide a large escape path for chips and an enlarged coolant passageway directly adjacent the cutting teeth.

Abstract: Holes are cut in a metal workpiece by means of an annular cutter. The chips formed are broken and prevented from wrapping and accumulating around the cutter and its arbor by means of a chip breaker in the form of a lug or plate positioned generally radially to the cutter and extending into close proximity with the outer periphery of the cutter.

Abstract: An annular hole cutter wherein each tooth is formed with at least three cutting edges, each of which is designed to cut a separate chip. The two radially innermost cutting edges are formed on the portion of each tooth which corresponds to the thickness of the web between successive teeth.

Abstract: An annular hole cutter having an inverted cup-shaped body provided with a plurality of circumferentially spaced teeth around its lower edge. Helical flutes extend upwardly between successive teeth and form around the outer periphery of the cutter a plurality of radially relieved lands, each having a circle ground narrow margin at the leading edge thereof. Each tooth has a plurality of radially and axially staggered cutting edges thereon.

Abstract: An annular cutter wherein the outer periphery of the cutter side wall is accurately concentric to the central rotary axis of the cutter and the inner periphery of the cutter side wall is eccentric to a predetermined amount with respect to the outer periphery of the side wall.

Abstract: A magnet base drill unit having a finger thereon frictionally engaging the surface of the workpiece to which the base of the drill unit is magnetically adherred. The finger is movable in response to lifting or sliding of the energized magnet base from the support base of the workpiece to actuate a switch for de-energizing the drill motor. The unit also includes a pointed punch adjacent the rear end of the magnet base which can be in one form of the invention impacted into the workpiece support surface either by a manually operated lever or automatically whenever the drill spindle is retracted from the work to a position near the upper end of its stroke. A second punch may be located on the drill unit rearwardly of the automatically actuated punch. The second punch is arranged to be embedded into the support surface of the workpiece by a manually applied hammer blow.

Abstract: A magnet base drill having a pair of plates formed of magnetic material removably mounted on either the side walls or the bottom face of the electromagnet forming the base of the drill and adjustable thereon to contact portions of a convex support surface spaced laterally outwardly from the central lonitudinal axis of the electromagnet when the latter is positioned on the support surface.

Abstract: An annular cutter having a cylindrical side wall provided with cutting teeth spaced circumferentially around its lower end, the inner periphery of .[.each tooth.]. .Iadd.a plurality of teeth .Iaddend.being radially relieved to provide a narrow margin at the inner side of .[.each tooth.]. .Iadd.the plurality of teeth .Iaddend.directly behind the cutting edge thereof and simultaneously provide a large escape path for chips and an enlarged coolant passageway directly adjacent the cutting teeth.