Elevator speed sensor

Claim 2

An elevator system, comprising: an elevator car, means for moving said elevator car in a predetermined path, speed sensor means including an eddy current coupling having rotatable driving and driven elements, means translating movement of said elevator car into rotational movement of said driving element, said driven element including a shaft member mounted for rotation, a magnetic field producing element, and cam means, said magnetic field producing element and said cam means being mounted on said shaft member to provide at least a partial counterbalancing relationship therebetween, switch means disposed to be operated from a first condition to a second condition by said cam means at a first predetermined speed of the elevator car when the elevator car is accelerating, and back to its first predetermined condition at a second predetermined speed when the elevator car is decelerating, control means responsive to the condition of said switch means, said means for moving said elevator car in a predetermined path being responsive to said control means, and spring means associated with said driven elements to provide retarding and restoring forces thereon when the speed of the elevator car is increasing and decreasing, respectively, to reduce the difference between the first and second predetermined speeds of the elevator car at which the switch means operates.

Claim 3

The elevator system of claim 1 wherein the switch means includes first and second switches and the cam means includes a single member having first and second cam surfaces disposed to operate the first and second switches, respectively, when the elevator car is moving in first and second directions, respectively.

Claim 4

The elevator system of claim 1 wherein the magnetic field producing element is fixed to the shaft member by a first support member which extends perpendicularly outward from the shaft member, and the cam means is fixed to the shaft member by a second support member which extends perpendicularly outward from the shaft member in a direction from the shaft member which is opposite to the direction of the first support member.

Claim 5

The elevator system of claim 1 wherein the magnetic field producing element and cam means are spaced from their supporting shaft member on opposite sides thereof, with the spring means being disposed to apply its retarding and restoring forces to a predetermined point between the shaft member and the cam means.

Claim 6

The elevator system of claim 1 wherein the spring means includes first and second extension spring members connected to the driven element of the eddy current coupling such that the first extension spring member is effective when the driven element rotates in a first circumferential direction, and the second extension spring member is effective when the driven element rotates in a direction opposite to the first circumferential direction.

Claim 7

The elevator system of claim 1 wherein the switch means includes a predetermined plurality of pairs of switches, and the cam means includes a like plurality of cam members, each of said cam members being associated with a different pair of switches, with each cam member defining first and second cam surfaces for operatiNg a predetermined switch of the pair with one cam surface when the car is moving in one direction, and for operating the remaining switch of the pair with the other cam surface when the car is moving in the opposite direction.

Claim 8

A speed sensor, comprising: a supporting structure, an electroconductive driving element, a magnetic field producing driven element, said driving and driven elements being mounted for rotation on said supporting structure on first and second spaced, parallel shaft members, respectively, with the spacing being selected such that the driven element establishes a magnetic field which links said driving element, means translating a predetermined external movement to rotation of said driving element, with the rotation of said driving element producing an angular movement of said driven element due to the magnetic coupling, cam means mounted on the second shaft member to provide at least a partial counterbalancing relationship with the magnetic field producing driven element, switch means carried by said support structure and disposed to be operated by said cam means from a first to a second condition at a first predetermined rotational speed of the driving element, as the speed of the driving element is increasing, and back to its first condition at a second predetermined rotational speed of the driving element when the speed of the driving element is decreasing, and springs associated with the driven element to provide a retarding force on the driven element when the speed of the driving element is increasing, and a restoring force on the driven element when the speed of the driving element is decreasing, to reduce the difference between the first and second predetermined speeds of the driving element at which the switch means operates.

Claim 9

A speed sensor, comprising: a supporting structure, an electroconductive driving element, a magnetic field producing driven element, said driving and driven elements being mounted for rotation on said supporting structure on first and second spaced, parallel shaft members, respectively, with the spacing being selected such that the driven element establishes a magnetic field which links said driving element, means translating a predetermined external movement to rotation of said driving element, with the rotation of said driving element producing an angular movement of said driven element due to the magnetic coupling, cam means mounted on the second shaft member to provide at least a partial counterbalancing relationship with the magnetic field producing driven element, switch means carried by said support structure and disposed to be operated by said cam means from a first to a second condition at a first predetermined rotational speed of the driving element, as the speed of the driving element is increasing, and back to its first condition at a second predetermined rotational speed of the driving element when the speed of the driving element is decreasing, and springs associated with the driven element to provide a retarding force on the driven element when the speed of the driving element is increasing, and a restoring force on the driven element when the speed of the driving element is decreasing, to reduce the difference between the first and second predetermined speeds of the driving element at which the switch means operates.

Claim 10

The speed sensor of claim 7 wherein any unbalance between the cam means and the magnetic field producing driven element about the second shaft member favors the cam means to direct the field producing driven element to a predetermined angular location about the second shaft member when the driving element is at rest.

Claim 11

The speed sensor of claim 7 wherein the switch means includes first an second switches and the cam means includes a single member having first and second cam surfaces disposed to operate the first and second switches, respectively, when the elevator car is moving in first and second directions, respectively.

Claim 12

The speed sensor of claim 7 wherein the magnetic field producing element is fixed to the shaft member by a first support member which extends perpendicularly outward from the shaft member, and the cam means is fixed to the shaft member by a second support member which extends perpendicularly outward from the shaft member in a direction from the shaft member which is opposite to the direction of the first support member.

Claim 13

The speed sensor of claim 7 wherein the magnetic field producing element and cam means are spaced from their supporting shaft members on opposite sides thereof, with the spring means disposed to apply its retarding and restoring forces to a predetermined point between the shaft member and the cam means.

Claim 14

The speed sensor of claim 7 wherein the spring means includes first and second extension spring members connected to the driven element such that the first extension spring member is effective when the driven element rotates in a first cicumferential direction, and the second extension spring member is effective when the driven element rotates in a direction opposite the first circumferential direction.

Claim 15

the speed sensor of claim 7 wherein the switch means includes a predetermined plurality of pairs of switches, and the cam means includes a like plurality of cam members, each of said cam members being associated with a different pair of switches, with each cam member defining first and second cam surfaces for operating a predetermined switch of the pair with one cam surface when the driving element is rotating in one circumferential direction, and for operating the remaining switch of the pair with the other cam surface when the driving element is rotating in the opposite circumferential direction.