1. An assembly comprised of:
a) a cutting insert having a central axis extending therethrough, wherein the insert is comprised of a body having:
1) a top surface and a bottom surface;
2) at least one side therebetween; and
3) a cutting edge at the intersection of the at least one side and the top surface; and
b) a toolholder upon which the cutting insert is mounted, wherein the toolholder is adapted to rotate the insert about the central axis at a predetermined rotational speed.
2. The assembly according to claim 1 further including a spindle attached to the toolholder, wherein the spindle rotates the toolholder which rotates the insert.
3. The assembly according to claim 2, wherein the spindle is adapted to be attached to a machine tool capable of rotating the spindle.
4. The assembly according to claim 2 further including a spindle driver and a controller associated therewith, wherein the controller has a closed loop feedback to monitor and control the spindle rotational speed.
5. The assembly according to claim 4, wherein the controller is adapted to monitor and control the rotation of the workpiece such that the speed of the workpiece may be directly related to the speed of the spindle.
6. The assembly according to claim 1, wherein the cutting insert is urged against the toolholder to create a friction coupling between the insert and the toolholder for transmitting rotation of the toolholder to the insert.
7. The assembly according to claim 1, wherein the bottom surface of the cutting insert has projections extending therefrom which are matable with recesses within the toolholder to provide a positive coupling between the insert and the toolholder when the cutting insert is urged against the rotatable toolholder for rotationally securing the cutting insert to the toolholder.
8. The assembly according to claim 7, wherein the insert further includes projections on the top surface that are identical to the projections on the bottom surface such that the insert is invertible and may be positively driven by the toolholder in either position.
9. The assembly according to claim 1 further including chip control projections extending from at least one of the top surface and the bottom surface of the cutting insert.
10. The assembly according to claim 1, wherein the insert has an elliptical shape for shaping the workpiece so that it has a non-circular cross-section.
11. The assembly according to claim 1, wherein the insert has a polygonal shape for shaping the workpiece.
12. The assembly according to claim 1, wherein the cutting insert has at least one notch interrupting the cutting edge about the periphery of the insert to provide an interrupted cut to the workpiece.
13. The assembly according to claim 1 further including a bore extending through the center of the insert, wherein a threaded screw extends therethrough and mates with a threaded bore in the toolholder to secure the insert to the toolholder.
14. The assembly according to claim 1 further including a collet extending from the toolholder and a bore extending through the center of the insert wherein the insert is secured to the toolholder by securing the collet within the bore extending through the insert.
15. The assembly according to claim 1, wherein the toolholder is made of a heat resistant material.
16. The assembly according to claim 1, wherein the cutting insert is integral with the rotatable shank.
17. The assembly according to claim 1, wherein the insert has a frusto-conical side matable with a bore extending through the toolholder.
18. The assembly according to claim 17, wherein the side of the insert forms a friction fit with the toolholder bore.
19. The assembly according to claim 17, wherein a bore extends through the length of the insert to form a coolant path.
20. The assembly according to claim 19, wherein the bore at the top of the insert has an upwardly expanding conical taper to disperse coolant to a workpiece.
21. The assembly according to claim 1, wherein a bore extends within the toolholder and is entirely closed and wherein fluid partially fills the bore such that motion of the toolholder agitates the fluid thereby distributing heat more evenly throughout the toolholder to enhance heat dissipation.
22. The assembly according to claim 1, wherein a collet is mounted within the toolholder and the insert is secured to the toolholder through the collet.
23. The assembly according to claim 22, wherein:
a) the cutting insert body has a bore which extends along the central axis to define an inner wall with an internal diameter;
b) the collet is aligned with the longitudinal axis, nonrotatably secured within and protrudes from the toolholder, wherein the collet has an internal threaded bore and a maximum external outer diameter less than the insert bore maximum internal diameter;
c) a mounting bolt is threadably securable within the collet internal threaded bore; and
d) wherein the cutting insert is mounted over the collet outer wall extending within insert bore inner wall and with the mounting bolt tightened to expand and to secure the collet outer wall against the cutting insert bore inner wall.
24. The assembly according to claim 23, wherein the collet has a constant outside diameter to define a circular shape.
25. The assembly according to claim 23, wherein the collet outer diameter varies to define a non-circular shape.
26. The assembly according to claim 25, wherein the collet outer diameter varies to define an elliptical shape.
27. The assembly according to claim 22, wherein the collet is removably secured within the toolholder.
28. The assembly according to claim 1, wherein the toolholder is nonrotatably mounted within a stationary spindle and the spindle has a rotary drive to rotate the toolholder.
29. With a cutting insert having a body with a top surface and a bottom surface, at least one side therebetween, a cutting edge at the intersection of the at least one side and the top surface, and a central axis extending through the top surface and the bottom surface, a method of machining comprising the step of:
a) aligning the insert such that the central axis forms an angle with the longitudinal axis of a rotating workpiece;
b) rotating the insert about the central axis of the insert at a predetermined speed; and
c) urging the insert against the workpiece to initiate the machining operation.
30. The method according to claim 29, wherein the insert is rotated at a speed that is greater than or equal to the rotational speed of the workpiece.
31. The method according to claim 29, wherein the insert is rotated at a speed that is less than the rotational speed of the workpiece.
32. The method according to claim 29, wherein the insert is rotated at a predetermined speed.
33. The method according to claim 32, wherein the predetermined speed is variable.
34. The method according to claim 32, wherein the predetermined speed is independent of the speed of the rotating workpiece.
35. The method according to claim 29, wherein the insert is rotated at a speed directly related to the speed of the rotating workpiece.
36. The method according to claim 35, wherein the insert rotates at a speed which is directly proportional to the speed of the rotating workpiece.
37. The method according to claim 29, wherein the insert central axis is oriented non-parallel to a tangent from the outer surface of the workpiece and wherein the insert is driven in a rotational direction opposite to the direction the rotating workpiece tends to rotate the insert.
38. The method according to claim 29, wherein the insert central axis is oriented non-parallel to a tangent from the outer surface of the workpiece and wherein the insert is driven in the same rotational direction as the rotating workpiece tends to rotate the insert.
39. The method according to claim 29, wherein the top surface of the insert is non-circular and further including the step of synchronizing the rotation of the cutting insert with the rotation of the workpiece to impart to the workpiece a non-circular cross-section.
40. A cutting insert comprised of a body with a central axis extending therethrough and having:
a) a top surface and a bottom surface;
b) at least one side therebetween;
c) a cutting edge at the intersection of the at least one side and the top surface; and
d) at least one projection extending from the top surface spaced inwardly from the cutting edge to act as chip breakers when the insert is used in a turning operation and is rotated about its central axis and applied against a rotating workpiece.
41. The cutting insert according to claim 40, wherein the at least one projection is comprised of at least two projections spaced at equal angles about the centerline of the insert.
42. The cutting insert according to claim 40, wherein the cutting edge is in the shape of a circle.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A gas sensor comprising a cup-shaped solid electrolytic body with one end closed and an inside space serving as a reference gas chamber, a sensing electrode provided on an outer surface of the solid electrolytic body so as to be exposed to measured gas, a reference electrode provided on an inner surface of the solid electrolytic body so as to be exposed to reference gas in the reference gas chamber, and a heater disposed in the reference gas chamber,
wherein the solid electrolytic body has a leg to be disposed in the measured gas,
the leg comprises a proximal portion and a distal portion, the distal portion being thinner than the proximal portion, and
the heater is brought into contact with a surface defining the reference gas chamber at least partly in the region of the distal portion.
2. The gas sensor in accordance with claim 1, wherein a length N and a thickness t of the distal portion satisfy the relationship N5 mm and t0.7 mm.
3. The gas sensor in accordance with claim 1, wherein a length L and a thickness T of the leg satisfy the relationship LT25 and L20 mm.
4. The gas sensor in accordance with claim 1, wherein the heater has a heat generating distribution having a peak temperature within a region corresponding to the distal region.
5. The gas sensor in accordance with claim 1, wherein a protective layer is provided to cover an outer surface of the sensing electrode, and a thickness of the protective layer is not larger than 300 m.
6. The gas sensor in accordance with claim 1, wherein a heat absorbing layer is provided as a wall of the reference gas chamber at least partly in a region corresponding to the distal portion.
7. The gas sensor in accordance with claim 1, wherein an electrode protective layer, a catalyst layer, and a catalyst protective layer are successively coated on the sensing electrode.
8. The gas sensor in accordance with claim 7, wherein the catalyst layer contains at least one catalytic metal selected from the group consisting of platinum, palladium, rhodium, and ruthenium.
9. The gas sensor in accordance with claim 7, wherein an average particle diameter of the catalytic metal contained in the catalyst layer is in a range of 0.3 m to 2.0 m.
10. The gas sensor in accordance with claim 7, wherein catalytic metal contained in the catalyst layer is 10 gcm2 to 200 gcm2 when projected on the sensing electrode.