Mechanical clutch for MRI

• US 9,568,571 B2
• Filed: 02/02/2015
• Issued: 02/14/2017
• Est. Priority Date: 03/10/2014
• Status: Active Grant

• Current Assignee: Aspect Imaging Ltd.
• Original Assignee: Aspect Imaging Ltd.
• Inventors: Rapoport, Uri
• Primary Examiner(s): Skroupa, Josh
• Application Number:
  US14/611,379
• Publication Number:
  US 20150253397A1
• Time in Patent Office: 743 Days
• Field of Search: 464/30, 464/37, 464/41, 294/28, 294/34
• US Class Current: 1/1
• CPC Class Codes: F16D 7/02 of the friction type
• CPC Class Codes: F16D 7/048 with parts moving radially between engagement and disengagement F16D7/10 takes precedence
• CPC Class Codes: G01R 33/34092 RF coils specially adapted for NMR spectrometers
• CPC Class Codes: G01R 33/3628 Tuning/matching of the transmit/receive coil
• CPC Class Codes: G01R 33/3642 Mutual coupling or decoupling of multiple coils, e.g. decoupling of a receive coil from a transmission coil, or intentional coupling of RF coils, e.g. for RF magnetic field amplification
• CPC Class Codes: G01R 33/385 using gradient magnetic field coils
• CPC Class Codes: Y10T 29/4984 Retaining clearance for motion between assembled parts

Abstract

A mechanical clutch for preventing damage to a capacitor of an MRI device. The clutch prevents the application of excessive torque via the tuning rods of the gradient coil of the MRI device. The mechanical clutch allows the tuning rods to slip (disengage) when the capacitor reaches the end of its adjustment range.

Claims

1. A mechanical clutch comprising:

an outer element having a first main longitudinal axis with distal and proximal ends, further having, in a plane perpendicular to said longitudinal axis on said distal end, a substantially cylindrical bore;

said outer element is configured to be connected, in said proximal end, with a first rotatable shaft;

said cylindrical bore comprises at least one semi-flexible member “

SFM”

comprising at least one aperture;

said SFM is configured to automatically reversibly transition from a relaxed configuration “

RC”

to a tensed configuration “

TC”

;

an inner element, having a second main longitudinal axis with distal and proximal ends;

said inner element is configured to be connected, in said proximal end, with a second rotatable shaft;

said inner element comprises, in said distal end, a cylindrical protrusion having a third main longitudinal axis;

said cylindrical protrusion is configured to rotatably accommodate within said cylindrical bore;

said protrusion comprises at least one bulge perpendicular to said third longitudinal axis bulging from said cylindrical protrusion shell;

said at least one bulge having a distal and a proximal end;

said distal end is in contact with said cylindrical protrusion;

wherein said SFM is in said RC when said proximal end of said bulge is reversibly accommodated within said aperture and in said TC when said proximal end of said bulge is located outside said aperture;

wherein said SFM is configured to temporarily collapse outwardly when in said TC;

wherein said clutch ceases to engage said rotation of said first and said second rotatable shafts when said SFM collapses outwardly.

2. The mechanical clutch of claim 1, wherein said inner element and said outer element are either (a) MRI safe materials;

(b) plastic;

(c) thermoplastic;

or (d) any combination thereof.

3. The mechanical clutch of claim 1, wherein said mechanical clutch is selected from a group of clutches consisting of:

ratcheting clutch, synchronous clutch, overload clutch, and any combination thereof.

4. The mechanical clutch of claim 1, wherein said semi-flexible member is in said relaxed configuration when the torque applied by said second shaft is below a predetermined value and in said tensed configuration when said torque equals or above said predetermined value.

5. The mechanical clutch of claim 4, wherein at least one of the following is being held true (a) said predetermined value is adjustable;

(b) said mechanical clutch automatically reengages when said torque returns to less than said predetermined value.

6. The mechanical clutch of claim 1, wherein at least one of the following is being held true (a) said mechanical clutch requires manual reengaging;

(b) said reengaging occurs by transitioning said bulge from said aperture;

(c) said clutch has backlash-free torque transmission;

(d) said first shaft is at least one capacitor and said second shaft is at least one tuning rod of a resonance coil of an MRI;

(e) and combination thereof.

7. The mechanical clutch of claim 1,

wherein said second shaft applies a torque “

Tx”

, and said proximal end of said bulge is accommodated within said aperture when said Tx equals or is lower than a predetermined torque value “

PTV” and

said proximal end of said bulge is located outside said aperture when said Tx is above said PTV.

8. The mechanical clutch of claim 7, wherein at least one of the following is being held true (a) said first shaft is at least one capacitor and said second shaft is at least one tuning rod of a resonance coil of an MRI;

(b) said PTV is adjustable;

(c) said mechanical clutch is selected from a group of clutches consisting of;

ratcheting clutch, synchronous clutch, overload clutch, and any combination thereof;

(d) said mechanical clutch automatically reengages when said Tx returns to less than said predetermined value;

(e) said mechanical clutch requires manual reengaging;

(f) said reengaging occurs by transitioning said bulge from said aperture;

(g) any combination thereof.

9. The mechanical clutch of claim 7, wherein at least one of the following is being held true (a) said first shaft is connected to said outer member through a Cardan joint configured to change the angle of said Tx applied by said second shaft;

(b) said clutch has backlash-free torque transmission;

(c) said Tx drops immediately when said mechanical clutch disengages;

(d) said first shaft is connected to said outer member through a Cardan joint configured to change the angle of said Tx applied by said TR; and

any combination thereof.

10. The mechanical clutch of claim 7, wherein said first rotating shaft has a limit of torque it can receive “

Ty”

.

11. The mechanical clutch of claim 10, wherein said Tx<

Ty.

12. A mechanical clutch comprising:

an outer element having a first main longitudinal axis with distal and proximal ends, further having, in a plane perpendicular to said longitudinal axis on said distal end, a substantially cylindrical bore, said outer element is configured to be connected, in said proximal end, with at least one capacitor;

said cylindrical bore comprises at least one semi-flexible member “

SFM”

comprising at least one aperture;

said SFM is configured to reversibly transition from a relaxed configuration “

RC”

to a tensed configuration “

TC”

;

an inner element, having a second main longitudinal axis with distal and proximal ends;

said inner element is configured to be connected, in said proximal end, with a tuning rod of a resonance coil of an MRI “

TR”

applying torque “

Tx”

;

said inner element comprises, in said distal end, a cylindrical protrusion having a third main longitudinal axis;

said cylindrical protrusion is configured to rotatably accommodate within said cylindrical bore;

said protrusion comprises at least one bulge perpendicular to said third longitudinal axis bulging from said cylindrical protrusion shell;

said at least one bulge having a distal and a proximal end;

said distal end is in contact with said cylindrical protrusion;

wherein said SFM is in said RC when said proximal end of said bulge is accommodated within said aperture and in said TC when said proximal end of said bulge is located outside said aperture;

wherein said SFM is configured to temporarily collapse outwardly when in said TC;

wherein said clutch ceases to disengage said at least one capacitor with said TR when said SFM collapses outwardly;

wherein said proximal end of said bulge is reversibly accommodated within said aperture when said Tx is above a predetermined torque value “

PTV” and

said proximal end of said bulge is located outside said aperture when said Tx equals or is lower than said PTV

wherein said mechanical clutch automatically reengages when said Tx returns to less than said predetermined value.

13. The mechanical clutch of claim 12, wherein said mechanical clutch is made of either (a) MRI safe materials;

(b) plastic;

(c) thermoplastic;

or (d) any combination thereof.

14. The mechanical clutch of claim 12, wherein at least one of the following is being held true (a) said PTV is adjustable;

(b) said mechanical clutch is selected from a group of clutches consisting of;

ratcheting clutch, synchronous clutch, overload clutch, and any combination thereof (c) reengaging occurs by transitioning said bulge from said aperture;

(d) said capacitor is connected to said outer member through a Cardan joint configured to change the angle of said Tx applied by said TR; and

any combination thereof.

15. The mechanical clutch of claim 12, wherein at least one of the following is being held true (a) said clutch has backlash-free torque transmission;

(b) said Tx drops immediately when said mechanical clutch disengages; and

any combination thereof.

16. The mechanical clutch of claim 12, wherein said at least one capacitor has a limit of torque it can receive “

Ty”

.

17. The mechanical clutch of claim 16, wherein said Tx<

Ty.