Eddy current braking apparatus with adjustable braking force
An eddy current brake includes a diamagnetic member, a first support wall and a second support wall with the first and second linear arrays of permanent magnets disposed on the walls facing one another. Apparatus is provided for moving at least one of the walls in order to control eddy current induced in the member in the passage of the member therepast to adjust the braking force between the magnets and the member. Apparatus is also provided for causing the velocity of the member to change the braking force between the magnets and the member.
1 . An eddy current brake mechanism comprising:
a first array of permanent magnets;
a second array of permanent magnets disposed adjacent said fixed array of permanent magnets;
a diamagnetic or non-magnetic member disposed for travel between the first and second arrays of magnets; and
velocity sensitive magnet array moving apparatus connected to at least one of the first and second arrays of permanent magnets for adjusting braking force against the member as a function of member velocity between the magnet arrays.
2 . The brake mechanism according to claim 1 wherein the first and second arrays are linear and the array moving apparatus comprises a linear actuator causing array movement in a direction parallel to the member travel.
3 . The brake mechanism according to claim 1 wherein the first and second arrays are linear and the array moving apparatus comprises a linear actuator causing array movement in a direction transverse to the member travel.
4 . The brake mechanism according to claim 1 wherein the array moving apparatus comprises a spring.
5 . The brake mechanism according to claim 1 wherein at least one of the first and second arrays is rotatable about an axis and the array moving apparatus comprises an actuator for rotating at least one of arrays.
6 . The brake mechanism according to claim 1 wherein the at least one of the arrays is rotatable about an axis and the array moving apparatus comprises a spring for rotating at least one of the arrays.
7 . The brake mechanism according to claim 1 wherein the array moving apparatus comprises a linear actuator causing array movement in a direction perpendicular to a plane established by the magnet arrays.
8 . An eddy current brake mechanism comprising:
a first array of permanent magnets;
a second array of permanent magnets disposed adjacent said first array of permanent magnets;
a diamagnetic or non-magnetic member disposed for travel between the first and second arrays of magnets;
a member velocity sensor; and
velocity sensitive magnet array moving apparatus connected to at least one of the first and second arrays of permanent magnets and sensor for adjusting braking force against the member as a function of member velocity between the magnet arrays.
9 . The brake mechanism according to claim 8 wherein the first and second arrays are linear and the array moving apparatus comprises a linear actuator causing array movement in a direction parallel to the member travel.
10 . The brake mechanism according to claim 8 wherein the first and second arrays are linear and the array moving apparatus comprises a linear actuator causing array movement in a direction transverse to the member travel.
11 . The brake mechanism according to claim 8 wherein the at least one of the arrays is rotatable about an axis and the array moving apparatus comprises an actuator for rotating the rotatable array.
12 . The brake mechanism according to claim 8 wherein at least one of the arrays is rotatable about an axis and the array moving apparatus comprises a spring for rotatable the moveable array.
13 . An eddy current brake mechanism comprising:
a first array of permanent magnets;
a second array of permanent magnets disposed adjacent said fixed array of permanent magnets;
a diamagnetic or non-magnetic member disposed for travel between the first and second arrays of magnets; and
velocity sensitive member moving apparatus connected to the member for adjusting braking force against the member as a function of member velocity between the magnet arrays.
14 . The brake mechanism according to claim 13 wherein the first and second arrays are linear.
15 . The brake mechanism according to claim 13 wherein the first and second arrays are linear and the member moving apparatus comprises a linear actuator causing member movement in a direction transverse to the member travel.