초록 ▼

An oscillating tool, particularly a cast cutter (40) having a support housing (46) with a cutting blade (70) interconnected to the housing (46) proximate one end thereof for oscillatory rotational movement about an axis (56) is disclosed. A torsion shaft (54) is fixedly interconnected at a first end

An oscillating tool, particularly a cast cutter (40) having a support housing (46) with a cutting blade (70) interconnected to the housing (46) proximate one end thereof for oscillatory rotational movement about an axis (56) is disclosed. A torsion shaft (54) is fixedly interconnected at a first end (102) to the housing (46) so as to prevent rotational oscillation at the first end of the torsion shaft (54). The torsion shaft (54) further has a free second end (100) enabling oscillatory rotational movement of the second end (100) generally about the axis (56) of the cast cutter blade (70). A hollow tubular rotor support member (58) substantially more rigid than the torsion shaft (54) is attached to the torsion shaft (54) proximate the second free end (100) of the torsion shaft (54). The hollow tubular rotor support member (58) is concentrically positioned about the torsion shaft (54) and extends from proximate the second end (100) of the torsion shaft (54) along a major portion of the torsion shaft (54) toward the first end (102) of the torsion shaft (54). The cutting blade (70) is interconnected to the hollow tubular rotor support member (58) and torsion shaft (54) arrangement proximate the second end (100) of the torsion shaft (54) for oscillatory rotational movement therewith. A magnetically interactive rotor (60) is fixedly attached to the hollow tubular rotor support member (58) at a location axially removed from the cutting blade (70) for oscillatory rotational movement therewith. A magnetically interactive stator (66) axially adjacent but radially removed from the rotor (60) induces rotational oscillation of the rotor (60) and consequently the tubular member (58). Accordingly a rotational oscillatory movement of the cutting blade (70) is provided.

대표청구항 ▼

1. A cast cutter, comprising: (a) a support housing having first and second ends; (b) an elongated torsion bar, having first and second ends, fixedly interconnected at said first end to said housing so as to prevent oscillatory rotation about a longitudinal axis of said torsion bar at said first

1. A cast cutter, comprising: (a) a support housing having first and second ends; (b) an elongated torsion bar, having first and second ends, fixedly interconnected at said first end to said housing so as to prevent oscillatory rotation about a longitudinal axis of said torsion bar at said first end; (c) a hollow tubular support member, having first and second ends and being inherently more resistant to twisting movement than said torsion bar, fixedly interconnected proximate said second end to said torsion bar proximate said second end of said torsion bar, said hollow tubular support member being concentrically positioned about said torsion bar and extending axially toward said first end of said torsion bar along a portion thereof, said hollow tubular rotor support member being rotatably mounted in said housing by suitable bearing means; (d) a magnetically interactive rotor fixedly interconnected to the said tubular member at a location axially displaced from said second end of said first tubular member for oscillatory rotational movement with said tubular member; (e) a magnetically interactive stator positioned longitudinally adjacent and radially outwardly of said rotor, said stator cooperating with said rotor for inducing oscillatory rotational movement of said hollow tubular member upon interconnection to a suitable power source; and (f) a cutting blade interconnected to said rotor by said tubular member, said torsion bar cooperating with said hollow tubular member to provide oscillatory rotational movement of said cutting blade. 2. A cast cutter in accordance with claim 1, wherein said cast cutter further includes mechanical stops cooperating with said hollow tubular member for limiting the rotational movement of said cutting blade. 3. A cast cutter in accordance with claim 1, wherein said support housing includes an inner housing and an outer housing spaced from one another so as to define an exhaust pathway extending from approximate said cutting blade to an exhaust port leading from said outer housing proximate said first end thereof, said exhaust port being adapted for interconnection to a vacuum source whereby particulate can be drawn away from the proximity of the cutting blade. 4. A cast cutter in accordance with claim 1, wherein the angular oscillation of said cutting blade has a total angular displacement of approximately five (5) degrees. 5. A cast cutter in accordance with claim 1, wherein oscillatory frequency of 200 to 300 cycles per second is provided to said cutting blade. 6. A cast cutter in accordance with claim 1, wherein said torsion bar is interconnected to said housing proximate said first end of said housing by a support member extending transversely of the torsion bar and providing for limited axial movement of said torsion bar. 7. A cast cutter in accordance with claim 3, wherein said inner housing is supported within said outer housing by a resilient mounting assembly mechanically isolating the inner housing from the outer housing so as to minimize the transfer of noise and vibration from the inner housing to the outer housing. 8. A cast cutter in accordance with claim 1, further including a secondary spring/mass means operatively interconnected to said support housing for minimizing vibration of said support housing. 9. A cast cutter, comprising: (a) a housing having a front end and a back end; (b) a cutting blade proximate said front end of said housing mounted for oscillatory rotational movement about an axis extending generally longitudinally of the housing; (c) a stator and rotor assembly displaced axially of said cutting blade, a rotor of said stator and stator assembly interconnected to said cutting blade by a hollow tubular member having front and back ends, said rotor being fixedly interconnected to said hollow tubular member for oscillatory rotational movement therewith, said rotor cooperating with a stator of said stator and rotor assembly to cause oscillatory rotational movement of said hollow tubular member and correspondingly said cutting blade upon interconnection to a suitable power source; (d) said hollow tubular member being concentrically positioned about an elongated torsion member, having front and back ends, fixedly interconnected proximate said front end to said hollow tubular member proximate said front end of said hollow tubular member for oscillatory rotational movement therewith and rigidly fixed against rotation at said back end, said elongated torsion member being more resilient than said hollow tubular member; and (e) said hollow tubular member and said torsion member cooperating to provide a torsion spring/mass system, having a front end and a back end, whose natural frequency is approximately that of the required cast cutter operating frequency, wherein damping is minimized to achieve a high "Q" so an adequate angle of oscillation is achieved to generate a rigid cast cutting action. 10. A cast cutter in accordance with claim 9, wherein said stator generates an alternating magnetic field in response to an impressed alternating current, said rotor being responsive to said alternating magnetic field for alternately accelerating in one direction and then in the opposite direction. 11. A cast cutter in accordance with claim 9, wherein said cast cutter further includes control circuitry means for varying the oscillatory rotational frequency and excursion angle under operator control. 12. A cast cutter in accordance with claim 9, wherein the outside surface of said hollow tubular member is covered by an insulation layer generally between said rotor and said front end of said hollow tubular member. 13. A cast cutter in accordance with claim 9, wherein additional mass is provided proximate said front end of said hollow tubular member, approximately three quarters of the total spring/mass system weight being adjacent said back end of said spring/mass system, and approximately one quarter of the total spring/mass system weight being adjacent said front end of said spring/mass system. 14. A cast cutter in accordance with claim 9, further including a secondary spring/mass means interconnected to said housing for minimizing vibration of said housing. 15. A cast cutter in accordance with claim 14, wherein said housing includes an inner housing and an outer housing, said inner housing enclosing said stator and rotor assembly, said secondary spring/mass means being interconnected to said back end of said inner housing. 16. A cast cutter, comprising: (a) a housing having a front end and a back end, said housing generally defining a motor housing portion proximate said back end, a cutting blade end portion proximate said front end, and a hand grip portion intermediate of said motor housing portion and said cutting blade end portion; (b) an electromagnetic motor being enclosed by said motor housing portion, said electromagnetic motor including a rotor assembly and a stator assembly, said rotor assembly and said stator assembly cooperating to provide oscillatory, rotational movement of said rotor assembly; (c) torsion means, having a front end and a back end, extending longitudinally of said housing between said motor housing portion and said cutting blade end portion, a first end of said torsion means being fixedly secured against rotational movement in said motor housing portion; (d) a hollow tubular shaft, having a front end and a back end, concentrically positioned about said torsion means and extending along a major portion thereof, said hollow tubular shaft being rotatably supported by suitable bearing means in said housing, said hollow tubular shaft being fixedly interconnected to said rotor assembly for oscillatory rotational movement therewith, said hollow tubular shaft being fixedly secured proximate said front end to proximate said front end of said torsion means to provide oscillatory rotational movement of said front end of said torsion means; and (e) said hollow tubular shaft and said torsion means interconnecting said electromagnetic motor to a cutting blade at the cutting blade end portion of the housing, said hollow tubular member being inherently more resistant to twisting movement than said torsion means, said hollow tubular shaft and said torsion means cooperating to provide a primary spring/mass system providing oscillatory rotational cutting blade motion, said primary spring/mass system having a natural frequency which is approximately that of the desired operating frequency. 17. A cast cutter in accordance with claim 16, further including a secondary spring/mass system mechanically interconnected to said housing proximate said back end, said secondary spring/mass system having a natural frequency approximately that of said primary spring/mass system, said secondary spring/mass system oscillating 180 degrees out of phase from the primary spring/mass system to minimize vibration.