초록 ▼

A torque limiter comprises a first body, a second body, and a biasing mechanism. The second body is rotationally attached relative to the first body. The biasing mechanism comprises at least first and second compression springs and an adjustment device. The first spring has a maximum compression con

A torque limiter comprises a first body, a second body, and a biasing mechanism. The second body is rotationally attached relative to the first body. The biasing mechanism comprises at least first and second compression springs and an adjustment device. The first spring has a maximum compression condition. The first and second springs are configured and adapted to create a torque-threshold below which the second body cannot be rotated relative to the first body and above which it can. The torque-threshold is adjustable via the adjustment device throughout a first torque range and a non-overlapping second torque range. The biasing mechanism is configured and adapted such that the first spring progressively compresses as the torque-threshold increases throughout the first torque range, and such that throughout the second torque range the first spring is in its maximum compression condition and the second spring progressively compresses as the torque-threshold increases.

대표청구항 ▼

1. A torque limiter comprising: a first body;a second body, the second body being rotationally attached to the first body about an axis;a biasing mechanism, the biasing mechanism comprising at least first and second compression springs and an adjustment device, the first compression spring occupying

1. A torque limiter comprising: a first body;a second body, the second body being rotationally attached to the first body about an axis;a biasing mechanism, the biasing mechanism comprising at least first and second compression springs and an adjustment device, the first compression spring occupying space between two planes that are perpendicular to the axis and intersect the first compression spring, the second compression spring at least partially occupying space between the two planes, the first compression spring having a maximum compression condition, the first and second compression springs being configured and adapted to create a torque threshold below which the second body cannot be rotated about the axis relative to the first body and above which the second body can be rotated about the axis relative to the first body, the torque threshold being adjustable via the adjustment device throughout a first torque range and a non overlapping second torque range, the biasing mechanism being configured and adapted such that the first compression spring progressively compresses as the torque threshold increases throughout the first torque range, and such that the first compression spring is in its maximum compression condition and the second compression spring progressively compresses as the torque threshold increases throughout the second torque range. 2. A torque limiter in accordance with claim 1 wherein the biasing mechanism is configured and adapted such that the second compression spring progressively compresses as the torque threshold increases throughout the first torque range. 3. A torque limiter in accordance with claim 2 wherein the first torque range and the second torque range are conterminous. 4. A torque limiter in accordance with claim 1 wherein the biasing mechanism comprises a plurality of ball bearings and a plurality of detents, the biasing mechanism is configured and adapted such that the ball bearings are locked in engagement with the detents when an applied torque between the first and second bodies is less than the torque threshold, and such that the ball bearings disengage the detents when such an applied torque between the first and second bodies is greater than the torque threshold, and the ball bearings each at least partially occupy space between the two planes. 5. A torque limiter in accordance with claim 4 wherein the biasing mechanism is configured and adapted such that the second compression spring progressively compresses as the torque threshold increases throughout the first torque range. 6. A torque limiter in accordance with claim 5 wherein the first torque range and the second torque range are conterminous. 7. A torque limiter in accordance with claim 4 wherein the first compression spring is aligned with the axis and has an outer diameter, the second compression spring is aligned with the axis and has an inner diameter that is larger than the outer diameter of the first compression spring, and the second compression spring encircles at least a portion of the first compression spring. 8. A torque limiter in accordance with claim 7 wherein the first compression spring comprises a stack of small Bellville springs and the second compression spring comprises at least one larger Bellville spring, and the larger Bellville spring encircles at least some of the small Bellville springs of the stack of the small Bellville springs. 9. A torque limiter in accordance with claim 1 wherein the adjustment device comprises an adjustment screw that is threadably attached to the first body. 10. A torque limiter in accordance with claim 9 wherein the compression springs are arranged and configured such that a first change of biasing load results from a single complete revolution of the adjustment screw relative to the first body when the torque limiter is in the first torque range and a second change of biasing load results from a single complete revolution of the adjustment screw relative to the first body when the torque limiter is in the second torque range, and wherein the compression springs are arranged and configured such that the second change of biasing load is at least ten times larger than the first change of biasing load. 11. A torque limiter in accordance with claim 10 wherein the compression springs are arranged and configured such that the second change of biasing load is at least twenty times larger than the first change of biasing load. 12. A torque limiter in accordance with claim 1 wherein the first compression spring is aligned with the axis and has an outer diameter, the second compression spring is aligned with the axis and has an inner diameter that is larger than the outer diameter of the first compression spring, and the second compression spring encircles at least a portion of the first compression spring. 13. A torque limiter in accordance with claim 12 wherein the first compression spring comprises a stack of small Bellville springs and the second compression spring comprises at least one larger Bellville spring, and the larger Bellville spring encircles at least some of the small Bellville springs of the stack of the small Bellville springs. 14. A torque limiter comprising: a first body;a second body, the second body being rotationally attached to the first body about an axis;a biasing mechanism, the biasing mechanism comprising at least first and second compression springs, a plurality of ball bearings, a plurality of detents, and an adjustment device, the first compression spring occupying space between two planes that are perpendicular to the axis and that intersect the first compression spring, the first compression spring having a maximum compression condition, the ball bearings each at least partially occupy space between the two planes, the first and second compression springs being configured and adapted to create a torque threshold below which the second body cannot be rotated about the axis relative to the first body and above which the second body can be rotated about the axis relative to the first body, the torque threshold being adjustable via the adjustment device throughout a first torque range and a non overlapping second torque range, the biasing mechanism being configured and adapted such that the first compression spring progressively compresses as the torque threshold increases throughout the first torque range, and such that the first compression spring is in its maximum compression condition and the second compression spring progressively compresses as the torque threshold increases throughout the second torque range, the biasing mechanism being configured and adapted such that the ball bearings are locked in engagement with the detents when an applied torque between the first and second bodies is less than the torque threshold, and such that the ball bearings disengage the detents when such an applied torque between the first and second bodies is greater than the torque threshold. 15. A torque limiter in accordance with claim 14 wherein the biasing mechanism is configured and adapted such that the second compression spring progressively compresses as the torque threshold increases throughout the first torque range. 16. A torque limiter in accordance with claim 15 wherein the first torque range and the second torque range are conterminous. 17. A torque limiter in accordance with claim 14 wherein the adjustment device comprises an adjustment screw that is threadably attached to the first body. 18. A torque limiter in accordance with claim 17 wherein the compression springs are arranged and configured such that a first change of biasing load results from a single complete revolution of the adjustment screw relative to the first body when the torque limiter is in the first torque range and a second change of biasing load results from a single complete revolution of the adjustment screw relative to the first body when the torque limiter is in the second torque range, and wherein the compression springs are arranged and configured such that the second change of biasing load is at least ten times larger than the first change of biasing load. 19. A torque limiter in accordance with claim 18 wherein the compression springs are arranged and configured such that the second change of biasing load is at least twenty times larger than the first change of biasing load. 20. A torque limiter in accordance with claim 14 wherein the first compression spring is aligned with the axis and has an outer diameter, the second compression spring is aligned with the axis and has an inner diameter that is larger than the outer diameter of the first compression spring, and the second compression spring encircles at least a portion of the first compression spring. 21. A torque limiter in accordance with claim 20 wherein the first compression spring comprises a stack of small Bellville springs and the second compression spring comprises at least one larger Bellville spring, and the larger Bellville spring encircles at least some of the small Bellville springs of the stack of the small Bellville springs.