Articulated cane

1. A cane to assist walking, comprising:

a shaft, a base and an articulated connection allowing the base to pivot relative to the shaft, with the articulated connection including a pivot connected to one of the shaft and base and a gripper connected to the other of shaft and base, for increasingly gripping the pivot in response to increasing downward loading on the shaft; and

with the articulation capability of the connection decreasing as downward loading on the shaft is increased, and articulation capability increasing as downward loading on the shaft is decreased.

2. The cane of claim 1 wherein the pivot comprises a ball.

3. The cane of claim 2 wherein the gripper comprises a socket in which the ball is received.

4. The cane of claim 3 wherein at least one of the ball and socket have a textured surface.

5. The cane of claim 2 wherein the gripper includes first and second parts, the first parts engaging the sides of the ball, and the second parts exerting force on the first parts tending to clamp the ball between them in response to increasing downward loading on the second parts.

6. The cane of claim 5 wherein the first parts define a socket in which the ball is received.

7. The cane of claim 5 including tension members interconnecting the first and second parts to transmit increasing lateral force components to the first parts as the second parts are displaced downwardly relative to the first parts, for reducing shaft articulation capability.

8. The cane of claim 7 wherein said tension members extend in generally lateral directions, and are supported to deflect or lock in response to downward movement of the second parts, to exert clamping force to the first parts.

9. The cane of claim 8 wherein said tension members are located below the level of a center defined by the ball.

10. The cane of claim 5 wherein the base comprises a platform having at least two protrusions.

11. The cane of claim 10 wherein said protrusions are outside a zone within which downward projections from said parts extend.

12. The cane of claim 1 including means restraining free pivoting of the base, relative to the shaft, when the base is lifted from the surface.

13. The cane of claim 1 wherein said connection defines a two-axis universal joint.

14. The cane of claim 13 wherein said universal joint includes a first pivoting member defining a first axis of pivoting, and a second pivoting member defining a second axis of pivoting, said members being interconnected.

15. The cane of claim 14 including a primary friction damper acting to damp shaft rotation about one of said axes, and a secondary friction damper acting to damp shaft rotation about the other of said axes.

16. A cane to assist walking, comprising:

a. a shaft, a base and an articulated connection allowing the base to pivot relative to the shaft; with the articulated connection including:

i. jaw means to controllably and grippingly engage the pivot,

ii. said shaft having a lower extension, and mechanism associated with said lower extension and jaw means to urge the jaw means toward the pivot as the extension is urged downwardly,

iii. a carrier for said jaw means located for movement relative to said extension, as the shaft is lowered and elevated; and

b. with the articulation capability of the connection decreasing as downward loading on the shaft is increased, and articulation capability increasing as downward loading on the shaft is decreased.

17. The cane of claim 16 including spring means acting to urge the jaw means toward the pivot, and a friction damper carried by said carrier to engage the pivot and resist relative pivoting between the pivot and shaft.

18. The cane of claim 16 wherein said jaw means includes four jaws spaced about the pivot, in the form of a ball, said mechanism including four anti-friction devices to transmit force to said respective four jaws.

19. A cane to assist walking, comprising:

a. a shaft, a base and an articulated connection including an expansible ball allowing the base to pivot relative to the shaft;

b. with the articulation capability of the connection decreasing as downward loading on the shaft is increased, and articulation capability increasing as downward loading on the shaft is decreased.

20. The cane of claim 19 wherein the connection includes fluid within the ball, and an actuator connected to the shaft to increase fluid pressure within the ball in response to down loading of the shaft.

21. The cane of claim 20 wherein the connection includes a receptacle about the ball to grip the ball as it expands, the receptacle connected to the base.

22. The cane of claim 21 wherein the actuator includes a cylinder that pivots with the ball, and a piston movable in the cylinder to pressurize the fluid.

23. The cane of claim 20 wherein the ball has interior webs between the sections, and outer arcuate walls connected to the webs, for expanding outwardly, individually, when ball liquid or fluid is pressurized.

24. A cane to assist walking, comprising:

a. a shaft, a base and an articulated connection allowing the base to pivot relative to the shaft;

b. with the articulation capability of the connection decreasing as downward loading on the shaft is increased, and with the articulation capability increasing as downward loading on the shaft is decreased, and with the articulation capability substantially independent of the orientation of the shaft to the base.

25. A cane to assist walking, comprising:

a. a shaft, a base and an articulated connection allowing the base to pivot relative to the shaft;

b. with the articulation capability of the connection decreasing as downward loading on the shaft is increased, and articulation capability increasing as downward loading on the shaft is decreased, and wherein the articulation connection provides resistance to movement of the shaft relative to the base via friction between two or more surfaces.

26. A cane to assist walking, comprising:

a. a shaft, a base and an articulated connection allowing the base to pivot relative to the shaft;

b. with the articulation capability of the connection decreasing as downward loading on the shaft is increased, and articulation capability increasing as downward loading on the shaft is decreased, with the articulation connection adjustable to provide more or less resistance to articulation movement between the shaft and the base, based on characteristics of an intended user of the cane.