Belt grinding machine and method for forming cutting edges on surgical instruments

Claim 2

A belt grinding machine for forming cutting edges of complex geometry on surgical instruments, said machine comprising: (a) a support frame; (b) a fixture mounted on said support frame for holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface at the predetermined site thereon; (c) a grinding assembly mounted on said support frame and including a movable grinding belt having a planar span for grinding the predetermined surface at the predetermined site on the instrument; (d) an oscillation producing mechanism mounted on said support frame and coupled to said fixture for oscillating said fixture and the instrument therewith relative to said grinding belt to reciprocally translate the predetermined site on the instrument substantially parallel and relative to said planar span of said grinding belt during said grinding of the predetermined surface at the predetermined site on the instrument by said movable grinding belt; and (e) a translation producing mechanism mounted on said support frame and supporting said grinding assembly and being operable to selectively translate said grinding assembly and thus said planar span of said grinding belt toward and away from the predetermined site on the instrument to permit receiving and setting up of the instrument in said fixture and to place the instrument in a position for said planar span of said grinding belt to grind the predetermined surface at the predetermined site on the instrument.

Claim 3

The machine of claim 1 wherein said oscillation producing mechanism includes: an auxiliary frame member supporting said fixture; a support member mounted to said support frame and supporting said auxiliary frame member and thus said fixture therewith for undergoing translatory movement relative to said support frame along an axis extending substantially parallel to said planar span of said grinding belt; and drive means mounted to said support member and engaged with said auxiliary frame member for selectively driving said auxiliary frame member to reciprocally translate said fixture and thereby the predetermined site of the instrument held in said fixture in an oscillatory manner substantially parallel and relative to said planar span of said grinding belt.

Claim 4

The machine of claim 1 further comprising: (f) a grinding angle setting mechanism mounted on said support frame and coupled to said grinding assembly and being operable to pivotally move said grinding assembly about a first pivot axis and thereby selectively change the angular relationship of said planar span of said grinding belt relative to the predetermined site on the instrument to grind another predetermined surface thereon.

Claim 5

The machine of claim 1 further comprising: (f) a grinding site setting mechanism mounted on said support frame and coupled to the instrument and being operable to rotate the instrument relative to said fixture and to said planar span of said grinding belt to selectively change the location of the predetermined site on the instrument.

Claim 6

A belt grinding machine for forming cutting edges of complex geometry on surgical instruments, said machine comprising: (a) a support frame; (b) a fixture mounted on said support frame for holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface at the predetermined site thereon; (c) a grinding assembly mounted on said support frame and including a movable grinding belt having a planar span for grinding the predetermined surface at the predetermined site on the instrument; and (d) a translation producing mechanism mounted on said support frame and supporting said grinding assembly and being operable to selectively translate said grinding assembly and thus said planar span of said grinding belt toward and away from the predetermined site on the instrument to permit receiving and setting up of the instrument in said fixture and to place the instrument in a position for said planar span of said grinding belt to grind the predetermined surface at the predetermined site on the instrument.

Claim 7

A belt grinding machine for forming cutting edges of complex geometry on surgical instruments, said machine comprising: (a) a support frame; (b) a fixture mounted on said support frame for holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface at the predetermined site thereon; (c) a grinding assembly mounted on said support frame and including a movable grinding belt having a planar span for grinding the predetermined surface at the predetermined site on the instrument; and (d) a translation producing mechanism mounted on said support frame and supporting said grinding assembly and being operable to selectively translate said grinding assembly and thus said planar span of said grinding belt toward and away from the predetermined site on the instrument to permit receiving and setting up of the instrument in said fixture and to place the instrument in a position for said planar span of said grinding belt to grind the predetermined surface at the predetermined site on the instrument.

Claim 8

The machine of claim 5 wherein said grinding assembly includes: a support member mounted for undergoing pivotal movement about a pivot axis aligned with the preset position; an auxiliary frame mounted to said support member and supporting said grinding belt for movement about an endless path; a belt support platen mounted to said auxiliary frame adjacent to said fixture and along said endless path underlying said grinding belt so as to support a short section thereof extending along said fixture and engaged by the instrument in a planar orientation defining said planar span of said grinding belt intersecting said first pivot axis of said support member and said preset position to grind the predetermined surface at the predetermined site on the instrument; and belt drive means mounted to said auxiliary frame and drivingly engaged with said grinding belt for driving said grinding belt about said endless path.

Claim 9

The machine of claim 6 wherein said translation producing mechanism includes: a first supplementary frame member supporting said support member of said grinding assembly for undergoing pivotal movement about said pivot axis aligned with the preset position; a second supplementary frame member mounted to said support frame and supporting said first supplementary frame member for undergoing translatory movement relative to said support frame along a translatory axis extending in orthogonal relation to said pivot axis; and translatory drive means mounted to said support frame and engaged with said first supplementary frame member and for selectively driving said first supplementary frame member along said translatory axis and thereby translating said grinding assembly and said planar span of said grinding belt therewith toward and away from the predetermined site on the instrument.

Claim 10

The machine of claim 5 further comprising: (e) a grinding angle setting mechanism mounted on said support frame and coupled to said grinding assembly and being operable to pivotally move said grinding assembly about a first pivot axis and thereby selectively change the angular relationship of said planar span of said grinding belt relative to the predetermined site on the instrument to grind another predetermined surface thereon.

Claim 11

The machine of claim 5 further comprising: (e) a grinding site setting mechanism mounted on said support frame and coupled to the instrument and being operable to rotate the instrument relative to said fixture and to said planar span of said grinding belt to selectively change the location of the predetermined site on the instrument.

Claim 12

A belt grinding machine for forming cutting edges of complex geometry on surgical instruments, said machine comprising: (a) a support frame; (b) a fixture mounted on said support frame for holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface at the predetermined site thereon; (c) a grinding assembly mounted on said support frame and including a movable grinding belt having a planar span for grinding the predetermined surface at the predetermined site on the instrument; and (d) a grinding angle setting mechanism mounted on said support frame and coupled to said grinding assembly and being operable to selectively pivotally move said grinding assembly about a first pivot axis and thereby change the angular relationship of said planar span of said grinding belt relative to the predetermined site on the instrument to grind another predetermined surface thereon, said grinding angle setting mechanism including (i) a first auxiliary support member supported by said support frame for undergoing pivotal movement relative thereto about a lower axis spaced from and aligned parallel with said first pivot axis, (ii) a second auxiliary support member connected to said grinding assembly for undergoing pivotal movement about an upper axis spaced from and aligned parallel with said lower and pivot axes, and (iii) drive means mounted to said first auxiliary support member and engaged with said second auxiliary support member for selectively driving said second auxiliary support member along a translation axis to thereby translate said second auxiliary support member toward and away from said first auxiliary .support member and thereby selectively change the angular relationship of said planar span of said grinding belt relative to the predetermined site on the instrument.

Claim 13

A belt grinding machine for forming cutting edges of complex geometry on surgical instruments, said machine comprising: (a) a support frame; (b) a fixture mounted on said support frame for holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface at the predetermined site thereon; (c) a grinding assembly mounted on said support frame and including a movable grinding belt having a planar span for grinding the predetermined surface at the predetermined site on the instrument; and (d) a grinding angle setting mechanism mounted on said support frame and coupled to said grinding assembly and being operable to selectively pivotally move said grinding assembly about a first pivot axis and thereby change the angular relationship of said planar span of said grinding belt relative to the predetermined site on the instrument to grind another predetermined surface thereon, said grinding angle setting mechanism including (i) a first auxiliary support member supported by said support frame for undergoing pivotal movement relative thereto about a lower axis spaced from and aligned parallel with said first pivot axis, (ii) a second auxiliary support member connected to said grinding assembly for undergoing pivotal movement about an upper axis spaced from and aligned parallel with said lower and pivot axes, and (iii) drive means mounted to said first auxiliary support member and engaged with said second auxiliary support member for selectively driving said second auxiliary support member along a translation axis to thereby translate said second auxiliary support member toward and away from said first auxiliary .support member and thereby selectively change the angular relationship of said planar span of said grinding belt relative to the predetermined site on the instrument.

Claim 14

The machine of claim 10 further comprising: (e) a grinding site setting mechanism mounted on said support frame and coupled to the instrument and being operable to rotate the instrument relative to said fixture and to said planar span of said grinding belt to selectively change the location of the predetermined site on the instrument.

Claim 15

The machine of claim 11 further comprising: (f) an oscillation producing mechanism mounted on said support frame and coupled to said fixture and being operable to oscillate said fixture and the instrument therewith relative to said grinding belt to reciprocally translate the predetermined site on the instrument substantially parallel and relative to said planar span of said grinding belt during said grinding of the predetermined surface at the predetermined site on the instrument by said movable grinding belt.

Claim 16

A belt grinding machine for forming cutting edges of complex geometry on surgical instruments, said machine comprising: (a) a support frame; (b) a fixture mounted on said support frame for holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface at the predetermined site thereon; (c) a grinding assembly mounted on said support frame and including a movable grinding belt having a planar span for grinding the predetermined surface at the predetermined site on the instrument; (d) a grinding angle setting mechanism mounted on said support frame and coupled to said grinding assembly and being operable to selectively pivotally move said grinding assembly about a first pivot axis and thereby change the angular relationship of said planar span of said grinding belt relative to the predetermined site on the instrument to grind another predetermined surface thereon; (e) a grinding site setting mechanism mounted on said support frame and coupled to the instrument and being operable to rotate the instrument relative to said fixture and to said planar span of said grinding belt to selectively change the location of the predetermined site on the instrument; and (f) a translation producing mechanism mounted on said support frame and supporting said grinding assembly and being operable to selectively translate said grinding assembly and thus said planar span of said grinding belt toward and away from the predetermined site on the instrument to permit receiving and setting up of the instrument in said fixture and to place the instrument in a position for said planar span of said grinding belt to grind the predetermined surface at the predetermined site on the instrument.

Claim 17

A belt grinding machine for forming cutting edges of complex geometry on surgical instruments, said machine comprising: (a) a support frame; (b) a fixture mounted on said support frame for holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface at the predetermined site thereon; (c) a grinding assembly mounted on said support frame and including a movable grinding belt having a planar span for grinding the predetermined surface at the predetermined site on the instrument; (d) a grinding angle setting mechanism mounted on said support frame and coupled to said grinding assembly and being operable to selectively pivotally move said grinding assembly about a first pivot axis and thereby change the angular relationship of said planar span of said grinding belt relative to the predetermined site on the instrument to grind another predetermined surface thereon; (e) a grinding site setting mechanism mounted on said support frame and coupled to the instrument and being operable to rotate the instrument relative to said fixture and to said planar span of said grinding belt to selectively change the location of the predetermined site on the instrument; and (f) a translation producing mechanism mounted on said support frame and supporting said grinding assembly and being operable to selectively translate said grinding assembly and thus said planar span of said grinding belt toward and away from the predetermined site on the instrument to permit receiving and setting up of the instrument in said fixture and to place the instrument in a position for said planar span of said grinding belt to grind the predetermined surface at the predetermined site on the instrument.

Claim 18

A belt grinding machine for forming cutting edges of complex geometry on surgical instruments, said machine comprising: (a) a support frame; (b) a fixture mounted on said support frame for holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface at the predetermined site thereon; (c) a grinding assembly mounted on said support frame and including a movable grinding belt having a planar span for grinding the predetermined surface at the predetermined site on the instrument; and (d) a grinding site setting mechanism mounted on said support frame and coupled to the instrument and being operable to rotate the instrument relative to said fixture and to said planar span of said grinding belt to selectively change the location of the predetermined site on the instrument, said grinding site setting mechanism including (i) a guide track supported by said support frame adjacent to said fixture, (ii) rotary drive means for generating rotary motion, and (iii) movable means supported by said guide track adjacent to said fixture and said instrument held by said fixture, said movable means interconnecting said rotary drive means with the instrument for selectively rotating the instrument relative to said fixture and said planar span of said grinding belt to thereby selectively change the predetermined site on the instrument for grinding a predetermined surface at the predetermined site thereon.

Claim 19

A belt grinding machine for forming cutting edges of complex geometry on surgical instruments, said machine comprising: (a) a support frame; (b) a fixture mounted on said support frame for holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface at the predetermined site thereon; (c) a grinding assembly mounted on said support frame and including a movable grinding belt having a planar span for grinding the predetermined surface at the predetermined site on the instrument; and (d) a grinding site setting mechanism mounted on said support frame and coupled to the instrument and being operable to rotate the instrument relative to said fixture and to said planar span of said grinding belt to selectively change the location of the predetermined site on the instrument, said grinding site setting mechanism including (i) a guide track supported by said support frame adjacent to said fixture, (ii) rotary drive means for generating rotary motion, and (iii) movable means supported by said guide track adjacent to said fixture and said instrument held by said fixture, said movable means interconnecting said rotary drive means with the instrument for selectively rotating the instrument relative to said fixture and said planar span of said grinding belt to thereby selectively change the predetermined site on the instrument for grinding a predetermined surface at the predetermined site thereon.

Claim 20

A belt grinding machine for forming cutting edges of complex geometry on surgical instruments, said machine comprising: (a) a support frame; (b) a fixture mounted on said support frame for holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface at the predetermined site thereon; (c) a grinding assembly mounted on said support frame and including a movable grinding belt having a planar span for grinding the predetermined surface at the predetermined site on the instrument; (d) an oscillation producing mechanism mounted on said support frame and coupled to said fixture and being operable to oscillate said fixture and the instrument therewith relative to said grinding belt to reciprocally translate the predetermined site on the instrument substantially parallel and relative to said planar span of said grinding belt during said grinding of the predetermined surface at the predetermined site on the instrument by said movable grinding belt; (e) a translation producing mechanism mounted on said support frame and supporting said grinding assembly and being operable to selectively translate said grinding assembly and thus said planar span of said grinding belt toward and away from the predetermined site on the instrument to permit receiving and setting up of the instrument in said fixture and to place the instrument in a position for said planar span of said grinding belt to grind the predetermined surface at the predetermined site on the instrument; (f) a grinding angle setting mechanism mounted on said support frame and coupled to said grinding assembly and being operable to pivotally move said grinding assembly about a first pivot axis and thereby selectively change the angular relationship of said planar span of said grinding belt relative to the predetermined site on the instrument to grind another predetermined surface thereon; and (g) a grinding site setting mechanism mounted on said support frame and coupled to the instrument and being operable to rotate the instrument relative to said fixture and to said planar span of said grinding belt to selectively change the location of the predetermined site on the instrument.

Claim 21

A belt grinding machine for forming cutting edges of complex geometry on surgical instruments, said machine comprising: (a) a support frame; (b) a fixture mounted on said support frame for holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface at the predetermined site thereon; (c) a grinding assembly mounted on said support frame and including a movable grinding belt having a planar span for grinding the predetermined surface at the predetermined site on the instrument; (d) an oscillation producing mechanism mounted on said support frame and coupled to said fixture and being operable to oscillate said fixture and the instrument therewith relative to said grinding belt to reciprocally translate the predetermined site on the instrument substantially parallel and relative to said planar span of said grinding belt during said grinding of the predetermined surface at the predetermined site on the instrument by said movable grinding belt; (e) a translation producing mechanism mounted on said support frame and supporting said grinding assembly and being operable to selectively translate said grinding assembly and thus said planar span of said grinding belt toward and away from the predetermined site on the instrument to permit receiving and setting up of the instrument in said fixture and to place the instrument in a position for said planar span of said grinding belt to grind the predetermined surface at the predetermined site on the instrument; (f) a grinding angle setting mechanism mounted on said support frame and coupled to said grinding assembly and being operable to pivotally move said grinding assembly about a first pivot axis and thereby selectively change the angular relationship of said planar span of said grinding belt relative to the predetermined site on the instrument to grind another predetermined surface thereon; and (g) a grinding site setting mechanism mounted on said support frame and coupled to the instrument and being operable to rotate the instrument relative to said fixture and to said planar span of said grinding belt to selectively change the location of the predetermined site on the instrument.

Claim 22

The machine of claim 15 wherein said oscillation producing mechanism includes: an auxiliary frame member supporting said fixture; a support member mounted to said support frame and supporting said auxiliary frame member and thus said fixture therewith for undergoing translatory movement relative to said support frame along an axis extending substantially parallel to said planar span of said grinding belt; and drive means mounted to said support member and engaged with said auxiliary frame member for selectively driving said auxiliary frame member to reciprocally translate said fixture and thereby the predetermined site of the instrument held in said fixture in an oscillatory manner substantially parallel and relative to said planar span of said grinding belt.

Claim 23

The machine of claim 16 wherein said grinding site setting mechanism includes: a guide track supported on said auxiliary frame member adjacent to said fixture also supported thereon; rotary drive means for generating rotary motion; and movable means supported by said guide track adjacent to said fixture and said instrument held by said fixture, said movable means interconnecting said rotary drive means with the instrument for selectively rotating the instrument relative to said fixture and said planar span of said grinding belt to thereby selectively change the predetermined site on the instrument for grinding a predetermined surface at the predetermined site thereon.

Claim 24

The machine of claim 15 wherein said grinding assembly includes: a support member mounted for undergoing pivotal movement about a first pivotal axis aligned with the preset position; an auxiliary frame mounted to said support member and supporting said grinding belt for movement about an endless path; a belt support platen mounted to said auxiliary frame adjacent to said fixture and along said endless path underlying said grinding belt so as to support a short section thereof extending along said fixture and engaged by the instrument in a planar orientation defining said planar span of said grinding belt intersecting said first pivotal axis of said support member and said preset position to grind the predetermined surface at the predetermined site on the instrument; and belt drive means mounted to said auxiliary frame and drivingly engaged with said grinding belt for driving said grinding belt about said endless path.

Claim 25

The machine of claim 18 wherein said translation producing mechanism includes: a first supplementary frame member supporting said support member of said grinding assembly for undergoing pivotal movement about said pivotal axis aligned with the preset position; a second supplementary frame member mounted to said support frame and supporting said first supplementary frame member for undergoing translatory movement relative to said support frame along a translatory axis extending in orthogonal relation to said pivotal axis; and translatory drive means mounted to said support frame and engaged with said first supplementary frame member for selectively driving said first supplementary frame member along said translatory axis and thereby translating said grinding assembly and said planar span of said grinding belt therewith toward and away from the predetermined site on the instrument.

Claim 26

The machine of claim 19 wherein said grinding angle setting mechanism includes: a first auxiliary support member connected to said first supplementary frame member of said translation producing mechanism for undergoing pivotal movement relative thereto about a lower axis spaced from and aligned parallel with said pivot axis; a second auxiliary support member connected to said first supplementary frame member for undergoing pivotal movement about an upper axis spaced from and aligned parallel with said lower and pivot axes; and drive means mounted to said first auxiliary support member and engaged with said second auxiliary support member for selectively driving said second auxiliary support member along a translation axis to thereby translate said second auxiliary support member toward and away from said first auxiliary support member and thereby selectively changing the angular relationship of said planar span of said grinding belt relative to the predetermined site on the instrument.

Claim 27

A belt grinding method for forming cutting edges of complex geometry on surgical instruments, said method comprising the steps of: (a) holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface thereon; (b) operating a grinding belt having a planar span to grind the predetermined surface at the predetermined site on the instrument; (c) oscillating the instrument and thus the predetermined site thereon substantially parallel and relative to the planar span of the grinding belt during the grinding of the predetermined surface at the predetermined site on the instrument by operating the grinding belt; and (d) selectively translating the grinding belt and thus the planar span therewith toward and away from the predetermined site on the instrument to permit receiving and setting up of the instrument in an instrument holding fixture and to place the instrument in a position for the planar span of the grinding belt to grind the predetermined surface at the predetermined site on the instrument.

Claim 28

A belt grinding method for forming cutting edges of complex geometry on surgical instruments, said method comprising the steps of: (a) holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface thereon; (b) operating a grinding belt having a planar span to grind the predetermined surface at the predetermined site on the instrument; (c) oscillating the instrument and thus the predetermined site thereon substantially parallel and relative to the planar span of the grinding belt during the grinding of the predetermined surface at the predetermined site on the instrument by operating the grinding belt; and (d) selectively translating the grinding belt and thus the planar span therewith toward and away from the predetermined site on the instrument to permit receiving and setting up of the instrument in an instrument holding fixture and to place the instrument in a position for the planar span of the grinding belt to grind the predetermined surface at the predetermined site on the instrument.

Claim 29

The method of claim 21 further comprising the step of: (e) selectively changing the angular relationship of the planar span of the grinding belt relative to the predetermined site on the instrument to grind another predetermined surface thereon.

Claim 30

The method of claim 21 further comprising: (e) rotating the instrument relative to the planar span of the grinding belt for selectively changing the location of the predetermined site on the instrument.

Claim 31

A belt grinding method for forming cutting edges of complex geometry on surgical instruments, said method comprising the steps of: (a) holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface thereon; (b) operating a grinding belt having a planar span to grind the predetermined surface at the predetermined site on the instrument; and (c) selectively translating the grinding belt and thus the planar span therewith toward and away from the predetermined site on the instrument to permit receiving and setting up of the instrument in an instrument holding fixture and to place the instrument in a position for the planar span of the grinding belt to grind the predetermined surface at the predetermined site on the instrument.

Claim 32

A belt grinding method for forming cutting edges of complex geometry on surgical instruments, said method comprising the steps of: (a) holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface thereon; (b) operating a grinding belt having a planar span to grind the predetermined surface at the predetermined site on the instrument; and (c) selectively translating the grinding belt and thus the planar span therewith toward and away from the predetermined site on the instrument to permit receiving and setting up of the instrument in an instrument holding fixture and to place the instrument in a position for the planar span of the grinding belt to grind the predetermined surface at the predetermined site on the instrument.

Claim 33

The method of claim 24 further comprising the step of: (d) selectively changing the angular relationship of the planar span of the grinding belt relative to the predetermined site on the instrument to grind another predetermined surface thereon.

Claim 34

The method of claim 24 further comprising: (d) rotating the instrument relative to the planar span of the grinding belt for selectively changing the location of the predetermined site on the instrument.

Claim 35

A belt grinding method for forming cutting edges of complex geometry on surgical instruments, said method comprising the steps of: (a) holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface thereon; (b) operating a grinding belt having a planar span to grind the predetermined surface at the predetermined site on the instrument; (c) selectively changing the angular relationship of the planar span of the grinding belt relative to the predetermined site on the instrument to grind another predetermined surface thereon; (d) rotating the instrument relative to the planar span of the grinding belt for selectively changing the location of the predetermined site on the instrument; and (e) selectively translating the grinding belt and thus the planar span therewith toward and away from the predetermined site on the instrument to permit receiving and setting up of the instrument in an instrument holding fixture and to place the instrument in a position for the planar span of the grinding belt to grind the predetermined surface at the predetermined site on the instrument.

Claim 36

A belt grinding method for forming cutting edges of complex geometry on surgical instruments, said method comprising the steps of: (a) holding at least one instrument with a predetermined site thereon in a preset position for grinding a predetermined surface thereon; (b) operating a grinding belt having a planar span to grind the predetermined surface at the predetermined site on the instrument; (c) selectively changing the angular relationship of the planar span of the grinding belt relative to the predetermined site on the instrument to grind another predetermined surface thereon; (d) rotating the instrument relative to the planar span of the grinding belt for selectively changing the location of the predetermined site on the instrument; and (e) selectively translating the grinding belt and thus the planar span therewith toward and away from the predetermined site on the instrument to permit receiving and setting up of the instrument in an instrument holding fixture and to place the instrument in a position for the planar span of the grinding belt to grind the predetermined surface at the predetermined site on the instrument.

Claim 37

The method of claim 27 further comprising the step of: (f) oscillating the instrument and thus the predetermined site thereon substantially parallel and relative to the planar span of the grinding belt concurrently with grinding of the predetermined surface at the predetermined site on the instrument.