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US3667580A Expired / Lapsed US ⏱️ 0.0 years remaining

Machine tool indexing system

Assignee: ZF Friedrichshafen AG
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Filing: 1970-05-01
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Granted: 1972-06-06
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Expires: 1990-05-01
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Abstract

Abstract In a machine tool a spindle is brought to a slow speed, e.g., for indexing to selective angular positions, by means of a clutch and a hydraulic pump, in a hydraulic control system, wherein the spindle is slowed down, or stopped, or reversed. The construction, and a number of modifications, envisages carrying a conventional indexing mechanism preferably on the spindle itself, together with the clutch, as well as the hydraulic pump in a compact assembly. The hydraulic system includes a pressure source and a throttle which controls differential pressures acting on the hydraulic pump to drive it as a motor by which the slow speed of the spindle is produced by rotation thereof through the clutch. Differential pressure in the system can be utilized in conjunction with a control device to which an indexing mechanism actuation is responsive. However, the invention has use in any installation where a compact mechanism for slow drive of a shaft is desired, or where it is desired to stop and momentarily reverse such shaft, the main power to the shaft being rendered ineffective in any suitable manner when the mechanism of the invention is operating.

Inventors

  • 👤 Willi Schacher
  • 👤 Heinz Marschner

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 09:25
CPC Classifications
B; B23; B23Q; B23Q11/00; B23Q11/0078; B23Q11/0092

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 135 words
A machine tool shaft speed control system comprising a pump, a clutch, means for engaging said clutch whereby said pump is driven by the shaft of a machine tool to effect a braking action for slowing of said shaft, and regulating means for regulating pump flow to control the slowed speed of said shaft, said pump being reversible and operable as a hydraulic motor, a machine tool shaft, means for engaging said clutch whereby said pump is driven by said shaft to affect the slowing of said shaft, said pump and clutch being coaxially mounted on said shaft, including a control device responsive to the differential pressures between inlet and outlet sides of said pump; and an automatically operable indexing device responsive to said control device to hold said shaft at a fixed angular position.
Claim 2
Dependent Claim 135 words
A machine tool shaft speed control system comprising a pump, a clutch, means for engaging said clutch whereby said pump is driven by the shaft of a machine tool to effect a braking action for slowing of said shaft, and regulating means for regulating pump flow to control the slowed speed of said shaft, said pump being reversible and operable as a hydraulic motor, a machine tool shaft, means for engaging said clutch whereby said pump is driven by said shaft to affect the slowing of said shaft, said pump and clutch being coaxially mounted on said shaft, including a control device responsive to the differential pressures between inlet and outlet sides of said pump; and an automatically operable indexing device responsive to said control device to hold said shaft at a fixed angular position.
Claim 3
Dependent Claim 137 words
A machine tool shaft speed control system comprising a pump, a clutch, means for engaging said clutch whereby said pump is driven by the shaft of a machine tool to effect a braking action for slowing of said shaft, and regulating means for regulating pump flow to control the slowed speed of said shaft; said pump being reversible so as to serve as a motor and an external source of pressure connected to one side of said pump for inlet feed thereto, a pressure accumulator connected to the other side of said pump and operative to store fluid under pressure when said Pump is operating to slow said shaft and to feed pressure fluid to said pump to operate said pump as a motor when said shaft stops rotating, whereby reverse rotation of said shaft is effected.
Claim 4
Dependent Claim 137 words
A machine tool shaft speed control system comprising a pump, a clutch, means for engaging said clutch whereby said pump is driven by the shaft of a machine tool to effect a braking action for slowing of said shaft, and regulating means for regulating pump flow to control the slowed speed of said shaft; said pump being reversible so as to serve as a motor and an external source of pressure connected to one side of said pump for inlet feed thereto, a pressure accumulator connected to the other side of said pump and operative to store fluid under pressure when said Pump is operating to slow said shaft and to feed pressure fluid to said pump to operate said pump as a motor when said shaft stops rotating, whereby reverse rotation of said shaft is effected.
Claim 5
Dependent Claim 210 words
A machine tool shaft speed control system comprising a pump, a clutch, means for engaging said clutch whereby said pump is driven by the shaft of a machine tool to effect a braking action for slowing of said shaft, and regulating means for regulating pump flow to control the slowed speed of said shaft; including a rotary shaft, wherein said pump comprises a reciprocal hollow piston between an inner and all outer collar; said inner collar being keyed to said shaft and said outer collar being keyed to one side of said clutch, the other side of said clutch being connected to a housing, including cam grooves in said piston and said collars in opposed relation and balls in opposed cam grooves between said piston and said collars whereby engagement of said clutch effects rotation of said inner collar by said shaft to reciprocate said piston by cam action; and an accumulator for receiving pressure fluid effected by reciprocation of said piston, whereby resistance of increasing pressure in said accumulator effects retardation of the speed of said shaft to a stopping point, at which time pressure fluid is forced from said accumulator to reverse the movement of said piston for reversing the rotation of said shaft by reversed cam action.
Claim 6
Dependent Claim 210 words
A machine tool shaft speed control system comprising a pump, a clutch, means for engaging said clutch whereby said pump is driven by the shaft of a machine tool to effect a braking action for slowing of said shaft, and regulating means for regulating pump flow to control the slowed speed of said shaft; including a rotary shaft, wherein said pump comprises a reciprocal hollow piston between an inner and all outer collar; said inner collar being keyed to said shaft and said outer collar being keyed to one side of said clutch, the other side of said clutch being connected to a housing, including cam grooves in said piston and said collars in opposed relation and balls in opposed cam grooves between said piston and said collars whereby engagement of said clutch effects rotation of said inner collar by said shaft to reciprocate said piston by cam action; and an accumulator for receiving pressure fluid effected by reciprocation of said piston, whereby resistance of increasing pressure in said accumulator effects retardation of the speed of said shaft to a stopping point, at which time pressure fluid is forced from said accumulator to reverse the movement of said piston for reversing the rotation of said shaft by reversed cam action.
Claim 7
Dependent Claim 153 words
A machine tool shaft speed control system comprising a pump, a clutch, means for engaging said clutch whereby said pump is driven by the shaft of a machine tool to effect a braking action for slowing of said shaft, and regulating means for regulating pump flow to control the allowed speed of said shaft, said pump being reversible so as to serve as a motor and an external source of pressure connected to one side of said pump for inlet feed thereto, a pressure accumulator connected to the other side of said pump and operative to store fluid under pressure when said pump is operating to slow said shaft and to feed pressure fluid to said pump to operate said pump as a motor when said shaft stops rotating, whereby reverse rotation of said shaft is effected, wherein said regulating means is connected to control flow to the inlet side of said pump.
Claim 8
Dependent Claim 153 words
A machine tool shaft speed control system comprising a pump, a clutch, means for engaging said clutch whereby said pump is driven by the shaft of a machine tool to effect a braking action for slowing of said shaft, and regulating means for regulating pump flow to control the allowed speed of said shaft, said pump being reversible so as to serve as a motor and an external source of pressure connected to one side of said pump for inlet feed thereto, a pressure accumulator connected to the other side of said pump and operative to store fluid under pressure when said pump is operating to slow said shaft and to feed pressure fluid to said pump to operate said pump as a motor when said shaft stops rotating, whereby reverse rotation of said shaft is effected, wherein said regulating means is connected to control flow to the inlet side of said pump.

References Cited (Backward Citations)

US2226801A Cited
US2484913A Cited
US2827133A Cited
US3159246A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-06-06 1975-12-06 1976-06-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-06-06 1979-12-06 1980-06-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-06-06 1983-12-06 1984-06-06 $7700.00 Window Closed / Lapsed

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