US3875848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spindle and draw bar assembly
Assignee: Ex-Cell-O Corp
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Filing: 1973-08-10
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Granted: 1975-04-08
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Expires: 1993-08-10
Abstract
Abstract A rotary spindle and draw bar assembly of the type including a hollow spindle having a tool holder seat defined at one end thereof, and a draw bar mounted in the spindle for axial movement with respect to the spindle between an active, tool holder retaining position for retaining a tool holder in non-rotatable engagement with the spindle, and an inactive, tool holder releasing position permitting the tool holder to be removed from the tool holder seat. Spring means biases the draw bar to its active position such that movement of the draw bar from its active position requires deflection of the spring means. In accordance with the invention, a lock-out means is provided which is operable to positively lock the draw bar in its active position and prevent deflection of the spring means in response to forces acting on the tool holder end of the draw bar so that forces on the draw bar during machining operations cannot cause accidental release of the tool holder, and the tool carried thereby, from the spindle. Actuation of an hydraulic cylinder or the like to move the draw bar from its active position to its inactive position sequentially actuates (1) the lock-out mechanism to an unlocked position and (2) the draw bar to its inactive, tool holder releasing position. When a tool holder is installed in the spindle with the draw bar held in its inactive position by the hydraulic cylinder, release of the draw bar by the hydraulic cylinder causes the draw bar to be biased to its active position, and the lock-out mechanism automatically assumes its locked position to lock out the springs and prevent accidental movement of the draw bar from its active to inactive position. The invention is particularly suitable for use with apparatus of the type disclosed in U.S. application Ser. No. 376,634, filed July 5, 1973 of Dale J. Bondie, the entire disclosure of which is incorporated herein by reference.
Inventors
- 👤 Thomas Alun Powell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:09
CPC Classifications
B; B23; B23B; B23B31/00; B23B31/02; B23B31/24; B23B31/26; B23B31/261; B23B31/265; Y; Y10; Y10T; Y10T409/00; Y10T409/30; Y10T409/309352; Y10T409/309408; Y10T409/309464
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
288 words
A tool holding assembly comprising: a hollow spindle; a draw bar mounted in said spindle for axial movement with respect thereto between an active position for retaining a tool holder or the like in said spindle, and an inactive position permitting a tool holder or the like to be removed from or installed on the spindle; draw bar biasing means biasing said draw bar to said active position; lock-out means on said draw bar and spindle operable automatically upon movement of said draw bar to its active position to lock said draw bar against movement from its active position in response to forces applied to said draw bar so that release of said lock-out means is required in order to subsequently move the draw bar to its inactive position; said lock-out means including means defining a tubular extension on said draw bar; at least one aperture in the wall of said tubular extension; means defining a locking shoulder on said spindle; a locking element carried by said tubular member movable between an extended position projecting through said aperture beyond the periphery of said tubular member to engage said locking shoulder and a retracted position retracted radially from said extended position in which it does not project beyond the periphery of said tubular extension; and a lock actuator slidably received in said tubular extension for movement between a locking position in which it actuates said locking element to its extended position and a released position in which said locking element is movable to its retracted position, whereby said draw bar can be moved to said inactive position from said active position against said draw bar biasing means only subsequent to movement of said lock actuator to said released position.
Claim 2
Dependent Claim
288 words
A tool holding assembly comprising: a hollow spindle; a draw bar mounted in said spindle for axial movement with respect thereto between an active position for retaining a tool holder or the like in said spindle, and an inactive position permitting a tool holder or the like to be removed from or installed on the spindle; draw bar biasing means biasing said draw bar to said active position; lock-out means on said draw bar and spindle operable automatically upon movement of said draw bar to its active position to lock said draw bar against movement from its active position in response to forces applied to said draw bar so that release of said lock-out means is required in order to subsequently move the draw bar to its inactive position; said lock-out means including means defining a tubular extension on said draw bar; at least one aperture in the wall of said tubular extension; means defining a locking shoulder on said spindle; a locking element carried by said tubular member movable between an extended position projecting through said aperture beyond the periphery of said tubular member to engage said locking shoulder and a retracted position retracted radially from said extended position in which it does not project beyond the periphery of said tubular extension; and a lock actuator slidably received in said tubular extension for movement between a locking position in which it actuates said locking element to its extended position and a released position in which said locking element is movable to its retracted position, whereby said draw bar can be moved to said inactive position from said active position against said draw bar biasing means only subsequent to movement of said lock actuator to said released position.
Claim 3
Dependent Claim
57 words
An assembly as claimed in claim 1 wherein a locking sleeve is carried by said spindle and having a recess formed in its inner wall; said sleeve slidably receiving said tubular extension such that said aperture communicates with said recess in the active position of said draw bar; said recess having a wall defining said locking shoulder.
Claim 4
Dependent Claim
48 words
An assembly as claimed in claim 2 wherein said lock actuator includes a wedging element engaging said locking element in the locking position of said lock actuator to extend said locking element into said recess to engage said shoulder when said draw bar is in its active position.
Claim 5
Dependent Claim
43 words
An assembly as claimed in claim 3 wherein said locking element comprises a ball held captive in said aperture by said wedging member, said wedging member having a tapered surface slidably engageable with said ball to cause said ball to extend and retract.
Claim 6
Dependent Claim
47 words
An assembly as claimed in claim 4 wherein said locking shoulder is inclined radially and axially inwardly in the direction of the active position of said draw bar, and said wedging member comprises a frusto-conical member tapered in the opposite direction to the inclination of said shoulder.
Claim 7
Dependent Claim
40 words
An assembly as claimed in claim 5 wherein said lock actuator further includes a lock-out biasing spring received in said tube and engaging the large end of said frusto-conical wedging element to bias said lock actuator toward its locking position.
Claim 8
Dependent Claim
43 words
An assembly as claimed in claim 6 wherein said lock actuator further includes an operating stem on the end thereof opposite said wedging member, said operating stem being biased by said lock-out biasing means to project from the end of said tubular member.
Claim 9
Dependent Claim
153 words
An assembly as claimed in claim 7 further including draw bar actuating means selectively operable when the draw bar is in its active position to sequentially (1) engage said operating stem and actuate said lock actuator to its released position against the bias of said lock-out biasing means to permit said ball to retract out of engagement with said locking shoulder, and (2) engage said end of said tubular member from which said operating stem projects and actuate said draw bar to its inactive position against said draw bar biasing means; said draw bar actuating means being selectively movable in the opposite direction when said draw bar is in its inactive position to sequentially (1) permit said draw bar biasing means to return said draw bar to its active position and (2) permit said lock-out spring to return said lock actuator to its locking position when the draw bar reaches its active position.
Claim 10
Dependent Claim
302 words
In a tool holding assembly for a machine tool wherein a tool holder or the like is releasably secured to a rotary, hollow spindle by a draw bar having a tool engaging end and mounted in the spindle for axial movement with respect to the spindle between an active position for holding the tool holder in the spindle and an inactive position for releasing the tool holder, the draw bar being resiliently urged by biasing means to its active position so that movement of the draw bar to its inactive position is against a biasing force, characterized by lock-out means interconnected between the spindle and draw bar for positively locking the draw bar in its active position so that the lock-out means must be deactivated before the draw bar can be actuated to its inactive position against the biasing force; said lock-out means comprising: a tubular portion on the end of said draw bar opposite the tool engaging end thereof; a lock actuator slidably mounted in said tubular portion for movement between a locking position and a released position; lock-out biasing means in said tubular portion biasing said lock actuator to its locking position; a plurality of angularly spaced apertures in the wall of said tubular member having the same axial location along said tubular member; means defining a locking groove on said spindle, said apertures communicating with said locking groove in the active position of said draw bar; a ball received in each of said apertures; and said lock actuator including a wedging member slidably engaging said balls and actuating said balls to project into said recess in the locking position of said lock actuator and the active position of said draw bar, and permitting said balls to retract from said locking groove in the released position of said lock actuator.
Claim 11
Dependent Claim
302 words
In a tool holding assembly for a machine tool wherein a tool holder or the like is releasably secured to a rotary, hollow spindle by a draw bar having a tool engaging end and mounted in the spindle for axial movement with respect to the spindle between an active position for holding the tool holder in the spindle and an inactive position for releasing the tool holder, the draw bar being resiliently urged by biasing means to its active position so that movement of the draw bar to its inactive position is against a biasing force, characterized by lock-out means interconnected between the spindle and draw bar for positively locking the draw bar in its active position so that the lock-out means must be deactivated before the draw bar can be actuated to its inactive position against the biasing force; said lock-out means comprising: a tubular portion on the end of said draw bar opposite the tool engaging end thereof; a lock actuator slidably mounted in said tubular portion for movement between a locking position and a released position; lock-out biasing means in said tubular portion biasing said lock actuator to its locking position; a plurality of angularly spaced apertures in the wall of said tubular member having the same axial location along said tubular member; means defining a locking groove on said spindle, said apertures communicating with said locking groove in the active position of said draw bar; a ball received in each of said apertures; and said lock actuator including a wedging member slidably engaging said balls and actuating said balls to project into said recess in the locking position of said lock actuator and the active position of said draw bar, and permitting said balls to retract from said locking groove in the released position of said lock actuator.
References Cited (Backward Citations)
US3466739A
Cited
US3762271A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |