US3893371A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and means for operating a spindle drive in a machine tool
Assignee: BURGMASTER - HOUDAILLE Inc A CORP OF
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Filing: 1972-03-27
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Granted: 1975-07-08
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Expires: 1992-03-27
Abstract
Abstract A machine tool includes a head which supports a vertically movable quill within which there is disposed a rotatable spindle to which various kinds of cutting tools may be attached. The spindle is driven through a mechanism which includes means for locking the spindle in a particular predetermined angular position, such locking means including a detent wheel engageable by a stop member that is operated by a fluid actuator that is partially under the control of a means that senses the angular position of the spindle. Within the quill there is provided a spring-biased annular piston for operating actuating means that are connected to clamping members for clamping onto and for releasing tooling from the spindle when it is in its locked position. When the spindle is to be stopped, power is removed from a spindle drive motor and is reversely applied to obtain dynamic braking, and when the motor is nearly stopped, that condition is sensed to terminate such dynamic braking. For each revolution of the spindle, a pulse is provided and also, a low level of power is reapplied to the drive motor to cause it to creep. The next signal pulse from the spindle is used to remove the low level power and to energize the spindle brake briefly after which the spindle locking means is energized to enable actuation of the annular piston.
Inventors
- 👤 James L Frazier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:12
CPC Classifications
B; B23; B23B; B23B31/00; B23B31/02; B23B31/24; B23B31/26; B23B31/261; B23B31/266; B23Q; B23Q5/00; B23Q5/02; B23Q5/04; B23Q5/20; Y; Y10; Y10T; Y10T408/00; Y10T408/94; Y10T408/95; Y10T409/00; Y10T409/30; Y10T409/303752; Y10T409/309352; Y10T409/309408; Y10T409/309464
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
211 words
A machine tool comprising in combination: a. a head; b. a quill non-rotatably slidably mounted on said head for axial movement with respect to said head during machining; c. a spindle rotatably carried by and within said non-rotatable quill for joint axial movement with said quill with respect to said head, and adapted to drivably carry a tool; d. a spindle motor drivably connected to said spindle to rotate it; e. a quill motor drivably connected to said quill to reciprocate said quill and said quill-supported spindle; f. a detent wheel connected at all times to be rotatably driven at a speed having a fixed ratio to the spindle speed, and having at least one peripheral detent; g. a movable stop member disposed to be driven into and retracted from said spindle detent for locking said spindle in a predetermined angular position after said spindle motor has been fully deenergized; h. means defining a pressurized air inlet port directed toward said spindle; i. a ring corotatably carried on said spindle and having a bulge rotatable past said inlet port to restrict air flow therefrom for producIng a change in static pressure; and j. a pressure switch responsive to said pressure change and connected to control locking movement of said stop member.
Claim 2
Dependent Claim
211 words
A machine tool comprising in combination: a. a head; b. a quill non-rotatably slidably mounted on said head for axial movement with respect to said head during machining; c. a spindle rotatably carried by and within said non-rotatable quill for joint axial movement with said quill with respect to said head, and adapted to drivably carry a tool; d. a spindle motor drivably connected to said spindle to rotate it; e. a quill motor drivably connected to said quill to reciprocate said quill and said quill-supported spindle; f. a detent wheel connected at all times to be rotatably driven at a speed having a fixed ratio to the spindle speed, and having at least one peripheral detent; g. a movable stop member disposed to be driven into and retracted from said spindle detent for locking said spindle in a predetermined angular position after said spindle motor has been fully deenergized; h. means defining a pressurized air inlet port directed toward said spindle; i. a ring corotatably carried on said spindle and having a bulge rotatable past said inlet port to restrict air flow therefrom for producIng a change in static pressure; and j. a pressure switch responsive to said pressure change and connected to control locking movement of said stop member.
Claim 3
Dependent Claim
31 words
A machine tool according to claim 1 including means by which the angular position of said detent wheel may be initially set for selecting said predetermined angular position of said spindle.
Claim 4
Dependent Claim
50 words
A machine tool according to claim 1 in which said detent wheel has a plurality of distinct equally spaced detents, and in which there are such plurality of said predetermined angular positions that said stop member aligns with one of said detents each time one of said positions is reached.
Claim 5
Dependent Claim
29 words
A machine tool according to claim 3 in which said stop member is arranged to lock said spindle at random in either of two predetermined angular positions 180* apart.
Claim 6
Independent Claim
128 words
A method of stopping a machine tool spindle at a predetermined angular position, the machine tool having a dc-spindle drive motor, a spindle brake and spindle locking means, comprising: a. removing power from the dc-spindle drive motor and reapplying power thereto with reversed polarity to obtain dynamic braking; b. obtaining a signal pulse when the motor is nearly stopped and using it to terminate dynamic braking; c. providing a signal pulse per revolution of the spindle; d. reapplying a low level of power to the drive motor to obtain creep rotation thereof; e. using the next signal pulse from the spindle to effect removing the low level power and to energize the spindle brake for a predetermined period of time; and f. thereafter energizing the spindle locking means.
Claim 7
Independent Claim
128 words
A method of stopping a machine tool spindle at a predetermined angular position, the machine tool having a dc-spindle drive motor, a spindle brake and spindle locking means, comprising: a. removing power from the dc-spindle drive motor and reapplying power thereto with reversed polarity to obtain dynamic braking; b. obtaining a signal pulse when the motor is nearly stopped and using it to terminate dynamic braking; c. providing a signal pulse per revolution of the spindle; d. reapplying a low level of power to the drive motor to obtain creep rotation thereof; e. using the next signal pulse from the spindle to effect removing the low level power and to energize the spindle brake for a predetermined period of time; and f. thereafter energizing the spindle locking means.
Claim 8
Dependent Claim
24 words
A method according to claim 5 in which the signal pulse from the motor is provided when the motor speed is under 30 rpm.
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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) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |