US4689449A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tremor suppressing hand controls
Assignee: Massachusetts Institute of Technology
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Filing: 1986-10-03
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Granted: 1987-08-25
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Expires: 2006-10-03
Abstract
Abstract A hand control capable of suppressing tremors and other unwanted vibrations is disclosed which incorporates viscous damping in two degrees of freedom to mechanically filter the forces applied by the user's hand. To suppress pathological intention tremors, the damping characteristics are chosen so as to selectively reduce the amplitude of movements at or above about 3 Hertz. The hand control includes a chamber filled with a viscous fluid, a position-sensing actuator assembly and a damping element connected to the actuator and disposed within the chamber to suppress involuntary movements of the actuator. The volume of the chamber, size of the damping element and viscosity of the fluid are chosen to achieve a damping constant of about 2 to 20 lbf-sec/ft., preferably from about 5 to about 15 lbf-sec/ft. The viscous fluid is preferably a silicone oil having a viscosity of about 300,000 to about 900,000 cstokes.
Inventors
- 👤 Michael J. Rosen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:33
CPC Classifications
G; G05; G05G; G05G9/00; G05G9/02; G05G9/04; G05G9/047; G05G9/04785; G05G9/04788; G05G9/04796; G05G25/00; G05G25/02; G05G2009/04703; G05G2009/04707; G05G2009/0474; G05G2009/04748; G05G2009/04774; H; H01; H01H; H01H25/00; H01H25/06; H01H3/00; H01H3/60
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
132 words
A hand control device capable of suppressing vibrations during operation by a user, the device comprising: a handle adapted to be held by the user; a chamber filled with a viscous fluid; a shaft connected to said handle at one end and disposed within the fluid of the chamber at the other end, the shaft further including a drag element which cooperates with the fluid to damp spurious motion; and position-sensing means disposed about the shaft for sensing the position of shaft relative to a reference point and for generating electrical signals indicative of said position; said position-sensing means including at least a first sensing element and a second sensing element which are activated by said shaft during operation to generate electrical signals when said shaft is displaced from said reference point.
Claim 2
Dependent Claim
132 words
A hand control device capable of suppressing vibrations during operation by a user, the device comprising: a handle adapted to be held by the user; a chamber filled with a viscous fluid; a shaft connected to said handle at one end and disposed within the fluid of the chamber at the other end, the shaft further including a drag element which cooperates with the fluid to damp spurious motion; and position-sensing means disposed about the shaft for sensing the position of shaft relative to a reference point and for generating electrical signals indicative of said position; said position-sensing means including at least a first sensing element and a second sensing element which are activated by said shaft during operation to generate electrical signals when said shaft is displaced from said reference point.
Claim 3
Dependent Claim
24 words
The device of claim 1 wherein drag element and the fluid cooperate to achieve a damping constant of about 2 to about 20 lbf-sec/ft.
Claim 4
Dependent Claim
24 words
The device of claim 1 wherein drag element and the fluid cooperate to achieve a damping constant of about 5 to about 15 lbf-sec/ft.
Claim 5
Dependent Claim
35 words
The device of claim 1 wherein the position sensing means further comprises first and second orthogonally positioned potentiometers coupled to the shaft such that displacement of the shaft rotates one or both of the potentiometers.
Claim 6
Dependent Claim
39 words
The device of claim 1 wherein the position sensing means further includes means for defining a dead zone in which displacement of the shaft relative to the reference point does not result in a change in the electrical signals.
Claim 7
Dependent Claim
67 words
The device of claim 1 wherein the device further comprises an activation switch connected to a motor-driven machine to control the operation of the motor and the position sensing means is also connected to said machine such that the electrical signals generated by said position sensing means control directional movement of said machine, said directional movement not occurring unless said activation switch is activated by the user.
Claim 8
Dependent Claim
13 words
The device of claim 6 wherein the motor driven machine is a vehicle.
Claim 9
Dependent Claim
11 words
The device of claim 7 wherein the vehicle is a wheelchair.
Claim 10
Dependent Claim
14 words
The device of claim 6 wherein the motor driven machine is a robot arm.
Claim 11
Dependent Claim
19 words
The device of claim 1 wherein the drag element disposed within the fluid filled chamber comprises a spherical ball.
Claim 12
Dependent Claim
23 words
The device of claim 1 wherein the viscous fluid comprises a silicone oil having viscosity ranging from about 100,000 to about 900,000 cstokes.
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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) | 1990-08-24 | 1991-02-23 | 1991-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-24 | 1995-02-23 | 1995-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-24 | 1999-02-23 | 1999-08-25 | $7700.00 | Window Closed / Lapsed |