US3690071A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Taper compensating method and apparatus
Assignee: Pratt and Whitney Co Inc
•
Filing: 1970-12-24
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Granted: 1972-09-12
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Expires: 1990-12-24
Abstract
Abstract Taper compensating apparatus and method for elastically deforming a work support supporting one end of a workpiece being ground in a cylindrical grinding machine controlled by at least two in-process gages engaging opposite end portions of the workpiece. The apparatus distorts and forces the work support and hence the axis of the workpiece away from the grinding wheel to intentionally grind a taper in the same direction. When one end portion of the tapered workpiece furthest away from the deformed work support is ground to a predetermined oversize diameter an in-process gage thereon stops the infeed and actuates reversing means to relieve and allow the deformed work support to spring back and feed, without lost motion, the workpiece into the grinding wheel at a controlled precision fine feed rate until the end portion of the workpiece nearest the deformed work support is ground to exactly the same amount oversize as is the one end portion. Thereafter, the in-process gage thereon resumes the grinding feed at a fine rate until at least the end portions are ground to the final diameter at which time the gages stop and reverse the feed mechanism.
Inventors
- 👤 Oiva E Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:12
CPC Classifications
B; B24; B24B; B24B5/00; B24B5/02; B24B5/14; B24B49/00; B24B49/02; B24B49/04
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
492 words
In combination with a cylindrical grinding machine having at least one rotatably driven grinding wheel with a grinding face rotating about an axis of rotation; work support means axially spaced along a common axis spaced from the axis of rotation for engaging opposite end portions of a workpiece and supporting the workpiece for rotation about the common axis; grinding wheel feed means for feeding the grinding face into and out of engagement with the workpiece; gaging means for continuously measuring at least each of the opposite end portions of the workpiece and determining when the common axis is substantially parallel to the grinding face during a grinding cycle; and control means actuated by the gaging means for stopping the grinding wheel feed when one end portion of the workpiece is ground to a predetermined oversize diameter, resuming the wheel feed when the other end portion reaches a predetermined oversize diameter and the common axis is parallel to the grinding face, and retracting the grinding wheel when at least both end portions of the workpiece are ground to final size; wherein the improvement comprises: a taper compensating mechanism mounted on the grinding machine adjacent one of the work support means for engaging and supporting one of the opposite end portions of the workpiece including: distorting means for elastically deforming one of the work support means and deflecting the common axis and the workpiece in one direction away from the grinding face a predetermined amount sufficient to compersate for lost motion and all movement continually occurring between components of the grinding machine during operation thereof that changes a preset parallel relationship between the grinding face and the common axis, and for deliberately grinding a taper on the workpiece so that the other end portion of the workpiece nearest the deformed work support means is always ground oversize a greater amount than the one end portion further away is ground oversize during the grinding cycle; reversing means, actuated by the gaging means after the one end portion has been ground to the predetermined oversize diameter and the grinding wheel feed has been stopped for reversing the distorting means, to relieve and allow the elastically deformed work support means to spring back and feed the workpiece toward the griNding face at a fine precision controlled rate without lost motion until the gaging means detects the diameter of the end portion engaged by the deformed work support means is oversize by the same amount as the one end portion, the common axis is substantially parallel to the grinding face, the workpiece is substantially without taper, the reversing means is stopped, the grinding wheel feed resumed by the gaging means until at least both end portions of the workpiece are ground to the final size, and the gaging means actuates the control means to retract the grinding wheel and reset the grinding wheel feed means, the control means and the taper compensating mechanism for a subsequent grinding cycle.
Claim 2
Dependent Claim
492 words
In combination with a cylindrical grinding machine having at least one rotatably driven grinding wheel with a grinding face rotating about an axis of rotation; work support means axially spaced along a common axis spaced from the axis of rotation for engaging opposite end portions of a workpiece and supporting the workpiece for rotation about the common axis; grinding wheel feed means for feeding the grinding face into and out of engagement with the workpiece; gaging means for continuously measuring at least each of the opposite end portions of the workpiece and determining when the common axis is substantially parallel to the grinding face during a grinding cycle; and control means actuated by the gaging means for stopping the grinding wheel feed when one end portion of the workpiece is ground to a predetermined oversize diameter, resuming the wheel feed when the other end portion reaches a predetermined oversize diameter and the common axis is parallel to the grinding face, and retracting the grinding wheel when at least both end portions of the workpiece are ground to final size; wherein the improvement comprises: a taper compensating mechanism mounted on the grinding machine adjacent one of the work support means for engaging and supporting one of the opposite end portions of the workpiece including: distorting means for elastically deforming one of the work support means and deflecting the common axis and the workpiece in one direction away from the grinding face a predetermined amount sufficient to compersate for lost motion and all movement continually occurring between components of the grinding machine during operation thereof that changes a preset parallel relationship between the grinding face and the common axis, and for deliberately grinding a taper on the workpiece so that the other end portion of the workpiece nearest the deformed work support means is always ground oversize a greater amount than the one end portion further away is ground oversize during the grinding cycle; reversing means, actuated by the gaging means after the one end portion has been ground to the predetermined oversize diameter and the grinding wheel feed has been stopped for reversing the distorting means, to relieve and allow the elastically deformed work support means to spring back and feed the workpiece toward the griNding face at a fine precision controlled rate without lost motion until the gaging means detects the diameter of the end portion engaged by the deformed work support means is oversize by the same amount as the one end portion, the common axis is substantially parallel to the grinding face, the workpiece is substantially without taper, the reversing means is stopped, the grinding wheel feed resumed by the gaging means until at least both end portions of the workpiece are ground to the final size, and the gaging means actuates the control means to retract the grinding wheel and reset the grinding wheel feed means, the control means and the taper compensating mechanism for a subsequent grinding cycle.
Claim 3
Dependent Claim
136 words
The combination according to claim 1 wherein the distorting means comprises: a base rigidly fixed relative to the work support means to be deformed having a bore therein; a distorting piston slidably mounted within the bore for movement relative to the base; a piston rod, extending from the piston and one end of the bore, operatively connected to the work support means to be deformed; and means for directing a source of fluid under pressure against the piston for shifting the distorting piston and piston rod, taking up the lost motion, and continually applying a distorting force to deform and maintain the work support means deformed while grinding the taper and for opposing the reversing means while the workpiece is fed toward the grinding face without lost motion to remove the taper during the grinding cycle.
Claim 4
Dependent Claim
241 words
The combination according to claim 1 wherein the distorting means comprises: a base rigidly fixed to the grinding machine and connected to the work support means to be deformed by a narrow elongated portion extending axially between the base and the work support means to be deformed at a predetermined radius from the common axis, there being a space between base and the work support means to be deformed extending from the narrow elongated portion to adjacent front portions of the base and the work support means to be deformed; a movable threaded nut fixed to and movable with a front portion of the work support means to be deformed; a fixed threaded nut fixed to the front portion of the base and having threads of different pitch than the movable nut; a differential screw rotatably supported in the front portion of the base and having a threaded end portion threaded into the movable nut, and an opposite threaded end portion threaded into and mating with the threads of different pitch in the fixed nut; and power means, operatively connected to and for rotating the screw in one direction to move the movable nut and the work support means toward the base and elastically deform the elongated narrow portion to deflect the common axis away from the grinding face on an arc whose radius originates from a center in the elongated narrow portion connecting the base to the work support means.
Claim 5
Dependent Claim
183 words
The combination according to claim 2 wherein the reversing means comprises: an axially movable nut slidably mounted within the bore adjacent the distorting piston for engaging an opposite end face of the distorting piston and having a threaded hole therein; a fixed nut, at an opposite end of the bore, fixed relative to the base and having a threaded hole therein; a differential screw having a threaded end portion threaded into and rotatably supported in the movable nut and an opposite threaded end portion with threads of different pitch thereon threaded into the fixed nut; and power means operatively connected to and for rotating the differential screw in one direction to overpower the distorting force and axially move the movable nut and the distorting piston against the distorting force to relieve the deformed work support means at the fine precision controlled rate and for rotating the differential screw in an opposite direction to return the movable nut to a predetermined reset position which determines a distorting stroke of the distorting piston and amount the support means is deformed away from the grinding face.
Claim 6
Dependent Claim
139 words
The combination according to claim 3 wherein the power means comprises: a first ratchet wheel with ratchet teeth thereon operatively connected to rotate the differential screw in the one direction which deforms and moves the work support means to be deformed and the common axis away from the grinding face; first ratchet means, slideably mounted in a first bore in the front portion of the base, adjacent the first ratchet wheel for intermittently engaging the ratchet teeth and rotating the first ratchet wheel and the differential screw in the one direction; means for directing fluid under pressure intermittently into one end of the first bore to actuate the first ratchet means; and means for biasing the first ratchet means toward the one end of the first bore and to ride idly over the ratchet teeth to a deactuated position.
Claim 7
Dependent Claim
83 words
The combination according to claim 4 wherein the power means comprises: a gear operatively connected to rotate the differential screw; a housing fixed relative to the base and having a second bore adjacent the gear; a reversible rack piston slideable in the second bore and having rack teeth meshing with the gear; and means for directing fluid under pressure into opposite ends of the second bore for shifting the rack piston, and rotating the gear and the differential screw, respectively, in opposite directions.
Claim 8
Dependent Claim
111 words
The combination according to claim 4 further comprising: an axially adjustable housing fixed against axial and rotational movement relative to the base and having a forward portion clamped within the bore in the base; a first bore in the forward portion in which the distorting piston, the movable nut, and the differential screw are located and which extends between one end of the housing through which the piston rod extends and the fixed nut fixed to the housing at an opposite end of the first bore; and a rear portion adjacent the opposite end and the fixed nut within which is situated the power means operatively connected to the differential screw.
Claim 9
Dependent Claim
49 words
The combination according to claim 4 wherein the reversing means further comprises: resilient means compressable between the axially movable nut and the distorting piston for biasing the distorting piston away from the movable nut and taking up lost motion between the differential screw and the movable and fixed nuts.
Claim 10
Dependent Claim
76 words
The combination according to claim 4 wherein the power means comprises: first ratchet and pawl means operatively connected to and for intermittently rotating the differential screw in one direction, overpowering the distorting means, and relieving the deformed work support means at the fine precision controlled rate; and second ratchet and pawl means operatively connected to and for intermittently rotating the differential screw in an opposite direction for returning the movable nut to the predetermined reset position.
Claim 11
Dependent Claim
44 words
The combination according to claim 4 wherein the distorting means further comprises: means for pivotally connecting the piston rod to the work support means to be deformed and allowing axial movement of a work support center thereon for supportingly engaging and disengaging the workpiece.
Claim 12
Dependent Claim
148 words
The combination according to claim 5 wherein the reversing means comprises: a second ratchet wheel with ratchet teeth thereon operatively connected to intermittently rotate the differential screw in an opposite direction to relieve and allow the elastically deformed work support means to spring back and move the common axis and the tapered workpiece toward the grinding face; second ratchet means slideably mounted in a second bore in the front portion of the base adjacent the second ratchet wheel for intermittently engaging and rotating the second ratchet wheel and the differential screw in the opposite direction; means for directing fluId under pressure intermittently into one end of the second bore to actuate the second ratchet means; and means for biasing the second ratchet means toward the one end of the second bore and to ride idly over the ratchet teeth of the second ratchet wheel to a deactuated position.
Claim 13
Dependent Claim
69 words
The combination according to claim 6 further comprising: adjustable means, on the housing at one end of the second bore, for engaging and varying a return and reset stroke of the reversible piston, whereby rotation of the gear and the differential screw can be varied to change the reset position of the movable nut, the stroke of the distorting piston, and the amount the work support means is deformed.
Claim 14
Dependent Claim
201 words
The combination according to claim 9 wherein the first and second ratchet and pawl means comprises: a first ratchet wheel with ratchet teeth thereon operatively connected to rotate the differential screw in one direction for overpowering the distorting means and to relieve the deformed work support means; a second ratchet wheel with ratchet teeth thereon operatively connected to rotate the differential screw in an opposite direction for returning the movable stop nut to the predetermined reset position; a housing fixed relative to the base and having a first bore adjacent the ratchet teeth of the first ratchet wheel, and a second bore adjacent the ratchet teeth on the second ratchet wheel; ratchet means including a ratchet piston, slideably mounted in each of the first and second bores, for engaging the ratchet teeth and intermittently rotating the ratchet wheels and the differential screw in opposite directions; means for directing fluid under pressure intermittently into one end of each of the first and second bores to actuate the ratchet means; and means for biasing each of the ratchet means toward the one end of each of the first and second bores and to ride idly over the ratchet teeth to a deactuated position.
Claim 15
Dependent Claim
51 words
The combination according to claim 10 wherein the means for pivotally connecting the piston rod to the work support center comprises: a clamp fixed to the work support center; and connected a yoke having one end pivotally connected to the clamp and an opposite end pivotally connected to the piston rod.
Claim 16
Dependent Claim
132 words
The combination according to claim 11 further comprising: a detent gear having, a plurality of equally spaced teeth and notches between the teeth, connected to rotate with the differential screw; a detent movable within the front portion of the base and having a beveled end portion adapted to protrude into the notches and engage the teeth on the detent gear and to be cammed out of the notches by the teeth upon rotation of the detent gear by the differential screw; and resilient means for biasing the detent and the beveled end portion into the notches and engagement with the teeth on the detent gear to prevent rotation of the detent gear and the differential screw during an idle movement of the ratchet means over the ratchet teeth toward the deactuated position.
Claim 17
Independent Claim
476 words
A method of grinding a workpiece substantially without taper and compensating for taper in a cylindrical grinding machine having at least one rotatably driven grinding wheel with a grinding face rotating about an axis of rotation; work support means axially spaced along a common axis spaced from the axis of rotation, for engaging opposite end portions of the workpiece and supporting the workpiece for rotation about the common axis; grinding wheel feed means for feeding the grinding face into and out of engagement with the workpiece; gaging means for continuously measuring at least each of the opposite end portions of the workpiece, determining when the common axis is substantially parallel to the grinding face, and to actuate control means when each of the end portions have been ground to a predetermined oversize diameter and to final size during a grinding cycle; and control means actuated by the gaging means for arresting the Grinding wheel feed when the gaging means detects one portion of the workpiece is ground to a predetermined oversize diameter, resuming the grinding wheel feed when the other end portion is ground to a predetermined oversize diameter and the common axis is substantially parallel to the grinding face, and retracting the grinding wheel when at least the end portions of the workpiece are ground to final size, the method comprising the steps of: elastically deforming one of the work support means and deflecting the common axis and the workpiece in one direction away from the grinding face a predetermined amount sufficient to compensate for lost motion and all movement continually occurring between components of the grinding machine during operation thereof that changes a preset parallel relationship between the grinding face and the common axis, and to deliberately grind a taper on the workpiece os that the other end portion of the workpiece nearest the deformed work support means is always ground oversize a greater amount than the one end portion furthest away is ground oversize during the grinding cycle; and relieving and allowing the elastically deformed work support means to spring back and feed the workpiece toward the grinding face at a fine precision controlled rate without lost motion, after the gaging means detects that the one end portion has been ground to the predetermined oversize diameter and actuated the control means to stop the grinding wheel feed, until the gaging means detects that the other portion engaged by the deformed work support means has been ground to a diameter that is oversize by the same amount as the one portion, the common axis is substantially parallel to the grinding face, the workpiece is substantially without taper and the gaging means actuates the control means to stop the relieving the deformed work support means and resumes the grinding wheel feed until at least both ends of the workpiece are ground to the final size.
Claim 18
Independent Claim
476 words
A method of grinding a workpiece substantially without taper and compensating for taper in a cylindrical grinding machine having at least one rotatably driven grinding wheel with a grinding face rotating about an axis of rotation; work support means axially spaced along a common axis spaced from the axis of rotation, for engaging opposite end portions of the workpiece and supporting the workpiece for rotation about the common axis; grinding wheel feed means for feeding the grinding face into and out of engagement with the workpiece; gaging means for continuously measuring at least each of the opposite end portions of the workpiece, determining when the common axis is substantially parallel to the grinding face, and to actuate control means when each of the end portions have been ground to a predetermined oversize diameter and to final size during a grinding cycle; and control means actuated by the gaging means for arresting the Grinding wheel feed when the gaging means detects one portion of the workpiece is ground to a predetermined oversize diameter, resuming the grinding wheel feed when the other end portion is ground to a predetermined oversize diameter and the common axis is substantially parallel to the grinding face, and retracting the grinding wheel when at least the end portions of the workpiece are ground to final size, the method comprising the steps of: elastically deforming one of the work support means and deflecting the common axis and the workpiece in one direction away from the grinding face a predetermined amount sufficient to compensate for lost motion and all movement continually occurring between components of the grinding machine during operation thereof that changes a preset parallel relationship between the grinding face and the common axis, and to deliberately grind a taper on the workpiece os that the other end portion of the workpiece nearest the deformed work support means is always ground oversize a greater amount than the one end portion furthest away is ground oversize during the grinding cycle; and relieving and allowing the elastically deformed work support means to spring back and feed the workpiece toward the grinding face at a fine precision controlled rate without lost motion, after the gaging means detects that the one end portion has been ground to the predetermined oversize diameter and actuated the control means to stop the grinding wheel feed, until the gaging means detects that the other portion engaged by the deformed work support means has been ground to a diameter that is oversize by the same amount as the one portion, the common axis is substantially parallel to the grinding face, the workpiece is substantially without taper and the gaging means actuates the control means to stop the relieving the deformed work support means and resumes the grinding wheel feed until at least both ends of the workpiece are ground to the final size.
Claim 19
Dependent Claim
80 words
The method according to claim 16 further comprising the steps of: continuously applying a distorting force sufficient to elastically deform the work support means to be deformed the predetermined sufficient amount during the grinding cycle; and applying an overpowering force, continually opposed by the distorting force, in an opposite direction at the predetermined fine precision controlled rate to relieve and allow the deformed work support means to spring back and feed the workpiece, without lost motion, into the grinding face.
Claim 20
Dependent Claim
138 words
The method according to claim 17 wherein the step of applying the distorting force further comprises: directing fluid under pressure against one side of a piston slideably mounted within a bore of a base fixed adjacent the work support means to be deformed which is connected to the piston and move the piston relative to the base to deform the work support means; and stopping and limiting the movement of the piston when the work support means has been deformed the predetermined sufficient amount by engaging the piston with an axially movable threaded nut, adjacent the piston in the bore, threaded onto one threaded end portion of a rotatable differential screw having an opposite threaded end portion with different pitch threads threaded into a fixed threaded nut fixed to the base at an opposite end of the bore.
Claim 21
Dependent Claim
49 words
The method according to claim 18 wherein the relieving step further comprises: rotating the differential screw in one direction at a rate and with sufficient force to overpower the opposing distorting force and shift the axially movable nut together with the distorting piston at the fine precision controlled rate.
Claim 22
Dependent Claim
64 words
The method according to claim 19 further comprising the step of: rotating the differential screw in the opposite direction sufficiently to shift the axially movable nut away from the distorting piston, to a reset position at the end of the grinding cycle, an amount which limits and provides sufficient movement of the dIstorting piston to deform the work support means the predetermined sufficient amount.
Claim 23
Dependent Claim
77 words
The method according to claim 20 wherein the relieving step further comprises: directing fluid under pressure into a second bore of a housing fixed relative to the base and against one side of a reversible rack piston therein engaging a gear operatively connected to rotate the differential screw, shift the axially movable nut, reverse and overpower the opposing distorting piston with an overpowering force to relieve the work support means at the predetermined fine precision controlled rate.
Claim 24
Dependent Claim
88 words
The method according to claim 16 wherein the deforming step further comprises: rotating a differential screw, having one end portion threaded into an axially movable threaded nut attached to and movable with the work support means to be deformed and an opposite threaded end portion of different pitch threads threaded into a fixed nut fixed relative to the grinding machine adjacent the work support means to be deformed, in one direction sufficient to elastically deform the work support means the predetermined sufficient amount away from the grinding face.
Claim 25
Dependent Claim
27 words
The method according to claim 22 wherein the relieving step further comprises: rotating the differential screw in an opposite direction at the predetermined fine precision controlled rate.
Claim 26
Dependent Claim
22 words
The method according to claim 23 wherein the rotating steps further comprises: intermittently rotating the differential screw in each of the directions.
Claim 27
Dependent Claim
175 words
The method according to claim 23 further comprising the steps of: mounting and connecting the work support means to be deformed onto a base fixed relative to the grinding machine so that it is connected to the base by an elongated narrow portion, extending axially between the base and the work support means, a predetermined radius from the common axis and the differential screw being connected to the movable nut fixed to a front portion of the work support means to be deformed and the fixed nut fixed to an adjacent front portion of the base; and pivoting the work support means and the common axis about a center of the radius at the narrow portion by rotating the differential screw in one direction with sufficient force to deform and deflect the work support means to be deformed and the common axis on an arc away from the grinding face the predetermined sufficient amount and in an opposite direction on the arc at the fine precision controlled rate to relieve the deformed work support means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-12 | 1976-03-13 | 1976-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-12 | 1980-03-13 | 1980-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-12 | 1984-03-13 | 1984-09-12 | $7700.00 | Window Closed / Lapsed |