Flexure hinge assembly

Abstract

A flexure hinge assembly comprising a pair of fixed telescopes inner and outer tubular members separated into at least one driving portion, at least one gimbal portion and at least one driven portion and a plurality of flexure blades all formed by a plurality of slots and apertures through the walls of each tubular member. flexure blades are formed by pairs of adjacent apertures with the slots interconnecting apertures to separate the tubular members into the driving, gimbal, and driven portions. The four slots of each tubular member which divide that member into these three portions are axially coextensive with the slots in the other member and all extend in the same axial direction from the apertures which form the flexure blades. Such axially coextensive slots displace the driving and the driven portions of the tubular members in the same axial direction from the center of suspension, i.e., from the flexure axes of these portions.

Description

CROSS-REFERENCE TO A RELATED APPLICATION

This application is related to an application, Ser. No. 673,605, entitled "Flexure Hinge Assembly and Method of Manufacturing Therefore" filed this same day by Robert J. G. Craig, Clifton T. Council and Jack F. Jansen, and assigned to the same assignee. U.S. Pat. Nos. 2,995,938, 3,077,785, 3,301,073, 3,354,726, 3,427,828, 3,512,419, 3,527,062, 3,538,776, 3,585,866, 3,614,894, 3,678,764, 3,700,289, 3,700,290, 3,709,045, 3,811,172, 3,832,906 and 3,856,366. None of these patents appear to teach or show a flexure hinge assembly having a driving element and a driven element displaced in the same axial direction from the center of suspension of the flexure hinge assembly.

Claims

1. A flexure hinge assembly comprising:

a pair of inner and outer concentric tubular members secured to one another, each of said tubular members having a plurality of pairs of adjacent apertures extending through the wall thereof and each of said pairs of apertures forming a flexure blade defining a first plane of flexure including therein a radial flexure axis and a longitudinal axis perpendicular to said flexure axis the plane of flexure of each blade in said inner tubular member being oriented substantially perpendicular to the plane of flexure of a flexure blade in said outer tubular member, a pair of mutually adjacent flexure blades with substantially perpendicularly oriented flexure planes defining a common flexure axis to form a flexure hinge;

said inner tubular member having a driven element portion, a gimbal element portion, and a driven element portion, connected to a pair of inner flexure blades, said outer tubular member having a driving element portion, a gimbal element portion and a driven element portion, each said inner gimbal element portion connected to said driving element portion and to said inner driven element portion by a pair of juxtaposed flexure blades, respectively, each said outer gimbal element portion connected to said outer driving element portion and to said outer driven element portion by a pair of juxtaposed flexure blades, respectively; and

said inner driving element portion and said inner driven element portion being axially displaced in the same direction from their respective flexure axes, said outer driving element portion and said outer driven element portion being axially displaced in the same direction from their respective flexure axes.

2. The device as claimed in claim 1 wherein each of said tubular members has two four pair of adjacent apertures extending through the wall thereof to form flexure blades between each pair, wherein the flexure axes of four said flexure blades in said inner flexure blades tubular member and the flexure axes of four said flexure blades in said outer tubular member al intersect at a common pivot point, and wherein said driving element portion and said driven element portion of each said tubular member are displaced in the same axial direction from said common pivot point.

3. A flexure hinge assembly comprising:

a tubular member having two four pairs of adjacent aperatures apertures extending through the wall thereof and each of said pair pairs of apertures forming a flexure blade having a radial flexure axis, said flexure axes intersecting at a common pivot point;

said tubular member being divided into a driving element portion, a gimbal element portion and a driven element portion by a plurality of slots interconnecting said apertures, one pair of said flexure blades connecting said driving element portion to said gimbal element portion, another pair of said flexure blades connection said gimbal element portion to said driven element portion; and

said driving element portion and said driven element portion being displaced in the same axial direction from said common pivot point.

4. A flexure hinge assembly comprising:

a pair of inner and outer concentric tubular members secured to one another, each of said tubular members having two four pairs of adjacent apertures extending through the wall thereof and each of said pairs of apertures forming a flexure blade defining a plane of flexure having a radial flexure axis, the plane of flexure of each flexure blade in said inner tubular member being oriented substantially perpendicularly to the plane of flexure of a radially adjacent flexure blade in said outer tubular member, to form a pair of radially adjacent flexure blades having substantially perpendicularly oriented flexure planes and with a common flexure axis to form a flexure hinge, the flexure axes of all said flexure hinges intersecting at a common pivot point;

said inner tubular member having slots interconnecting said apertures to form an inner driving element portion, an inner gimbal element portion and an inner driven element portion, the flexure blades of pair of inner blades having a common first inner flexure axis and flexibly connecting said inner driving element portion to said inner gimbal element portion, the inner flexure blades of a second pair of inner blades having a common second inner flexure axis and connecting said inner gimbal element portion to said inner driven element portion;

said outer tubular member having slots interconnecting said apertures to form an outer driving element portion, an outer gimbal element portion and an outer driven element portion, the inner flexure blades of a first pair of outer blades having a common first outer flexure axis and flexibly connecting said outer driving element portion of said outer gimbal element portion, the outer flexure blades of a second pair of outer blades having a common second outer flexure axis and flexibly connecting said outer gimbal element portion to said outer driven element portion; and

said inner driving element portion and said inner driven element portion displaced in the same axial direction from said common pivot point, said outer driving element portion and said outer driven element portion displaced in the same axial direction from said common pivot point.

5. The device as claimed in claim 4 wherein said inner driving element portion of said tubular member includes a hub, said hub being connected to said first pair of inner flexure blades, said hub including means for connecting said inner tubular member to a drive shaft.

6. The device as claimed in claim 5 wherein said outer driving element portion of said outer tubular member is displaced from said common pivot point in the same axial direction as said inner driving element portion and is secured to said inner driving element portion of said inner tubular member and wherein said inner driven element portion of said inner tubular member is secured to said outer driven element portion of said outer tubular member.

7. The device as claimed in claim 6 wherein said inner gimbal element portion and said outer gimbal element portion are fixedly secured to one another to form a flexure hinge assembly effectively having a single gimbal element, said inner and outer tubular members positioned relative to one another to substantially colinearly align said first inner flexure axis with said first outer flexure axis.

8. The device as claimed in claim 6 wherein the outer diameter of said inner gimbal element portion is shorter than the inner diameter of said outer gimbal element portion to permit independent rotation of said inner and outer gimbal element portions through small angles.

9. The device as claimed in claim 4 wherein the inner driving element and the inner driven element portions of said inner tubular member ard are both displaced in the opposite axial direction from said common pivot point as the outer driving element and the outer driven element portions of said outer tubular member, said inner and outer gimbal element portions of said inner and outer tubular members being at least partially nested.

10. The device as claimed in claim 9 wherein said inner driving element portion includes a first hub for connecting said inner tubular member to a drive shaft and said outer driving element portion includes a second hub for connecting said outer tubular member to a drive shaft.

11. The device as claimed in claim 10 wherein said first hub is located at one end of said inner tubular member and is connected to said inner gimbal element portion by said first pair of inner flexure blades and wherein said first pair of inner flexure blades and wherein said second hub is located at one end of said outer tubular member and is connected to said outer gimbal element portion by said first pair of outer flexure blades.

12. The device as claimed in claim 11 further including a third tubular member, said third tubular member being positioned coaxially within said inner and outer tubular members, said third tubular member extending between said first and second hubs to limit the nesting of said inner and outer tubular members so that said flexure axes intersect at said common pivot point.

13. The device as claimed in claim 12 wherein the outer diameter of said inner gimbal element portion is substantially equal to the inner diameter of said outer gimbal element portion and said inner and outer gimbal element portions are fixedly connected to form a flexure hinge assembly effectively having a single gimbal element, said first inner flexure axis being substantially colinear with said first outer flexure axis.

14. The device as claimed in claim 12 wherein the outer diameter of said inner gimbal element portion is shorter than the inner diameter of said outer gimbal element portion to permit independent rotation of said inner and outer gimbal element portions through small angles.

15. The device as claimed in claim 14 4 wherein said inner tubular member is coaxially positioned one with respect to said outer tubular member with said first inner flexure axis substantially colinear with said first outer flexure axis.

16. The device as claimed in claim 15 4 wherein said inner tubular member is coaxially positioned with respect to said outer tubular member with said first inner flexure axis substantially orthogonal to said first outer flexure axis.

17. The device as recited in claim 15 wherein said second inner flexure axis is colinear with said second outer flexure axis and perpendicular to said first axes.

18. The device as recited in claim 16 wherein said second inner flexure axis is orthogonal to said second outer flexure axis.