Patent US4021715A successfully refreshed from Google Patents.
US4021715A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor drive for the displacement of a section of an X-ray examination apparatus
Assignee: US Philips Corp
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Filing: 1975-01-09
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Granted: 1977-05-03
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Expires: 1995-01-09
Abstract
Abstract A motor drive for an X-ray examination apparatus, in particular for the displacement of an auxiliary apparatus (imaging section). The motor has coupled thereto a tachometer, the output signal of which is differentiated and fed back to the motor control system such that a positive loop gain < 1 arises. The drive system delivers a torque which is proportional to the force delivered by the operator when a linear relationship exists between the control quantity of the motor and the torque thereof. In the case of a collision with the patient, the force exerted by the imaging section on the patient substantially does not exceed the manual force exerted by the operator, not even if the motor force amounts to a multiple of the force delivered by the operator.
Inventors
- 👤 Reinhard Von Hacht
- 👤 Klaus Rennicke
- 👤 Walter Schmedemann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:44
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/44; A61B6/4476; A61B6/4482; Y; Y10; Y10S; Y10S388/00; Y10S388/923; Y10S388/93
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
134 words
A motor drive to be used in an X-ray examination apparatus for the displacement of a section of the apparatus, notably an imaging section, the speed and the direction of rotation of the motor being controllable in dependence of the value and the direction of a manual force acting on the section, a tachometer forming a signal proportional to the speed, the said signal also serving for the control of the motor, a further control signal being applied to the motor circuit in order to compensate for the weight of the section, characterized in that the output signal of the tachometer is applied to the motor drive via a differentiating member, the loop gain in the loop formed by the tachometer, the differentiating member and the motor drive being positive and smaller than 1.
Claim 2
Dependent Claim
134 words
A motor drive to be used in an X-ray examination apparatus for the displacement of a section of the apparatus, notably an imaging section, the speed and the direction of rotation of the motor being controllable in dependence of the value and the direction of a manual force acting on the section, a tachometer forming a signal proportional to the speed, the said signal also serving for the control of the motor, a further control signal being applied to the motor circuit in order to compensate for the weight of the section, characterized in that the output signal of the tachometer is applied to the motor drive via a differentiating member, the loop gain in the loop formed by the tachometer, the differentiating member and the motor drive being positive and smaller than 1.
Claim 3
Dependent Claim
24 words
A motor drive as claimed in claim 1, characterized in that the drive motor delivers a torque which is proportional to the control signal.
Claim 4
Dependent Claim
36 words
A motor drive as claimed in claim 2, characterized in that it comprises a direct current shunt motor, the armature current of which comprises a component which corresponds to the output signal of the differentiating member.
Claim 5
Dependent Claim
31 words
A motor drive as claimed in claim 3, chracterized in that an armature control system is provided for which the output signal of the differentiating member serves as a target value.
Claim 6
Dependent Claim
32 words
A motor drive as claimed in claim 2, characterized in that it comprises a torque control system for which, the target value is formed by the output signal of the differentiating member.
Claim 7
Dependent Claim
57 words
A motor drive as claimed in claim 1, characterized in that there is provided a transducer which supplies a signal which is dependent of the forces exerted on the section, the said signal being superimposed on the output signal of the differentiating member, the loop gain in the loop comprising the transducer and the motor being negative.
Claim 8
Dependent Claim
62 words
A motor drive as claimed in claim 1, characterized in that there is provided a threshold circuit which is controlled by the tachometer signal and which superimposes a signal on the output signal of the differentiating member when the tachometer output signal exceeds a predetermined amplitude, the said superimposed signal having a reducing effect on the output signal of the differentiating member.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-02 | 1980-11-01 | 1981-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-02 | 1984-11-01 | 1985-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-02 | 1988-11-01 | 1989-05-03 | $7700.00 | Window Closed / Lapsed |