Shock and torsion absorber for elevated vacuum suspension

The present invention teaches a shock and torsion absorber that includes a base member having an accommodation space and an exhaust opening, a cushion member joined to a bottom end of the base member, a limit member including a positioning element and a seal element, and a joint member having an intake element, a trough, and a axial channel. A piston is housed in the joint member. The axial channel allows a shaft to thread through via the positioning element and to join with the shaft limit element. A bottom end of the positioning element is connected to the cushion member. The piston is connected to a top end of the positioning element. An upper vacuum chamber is formed above the seal element in the joint member. A lower vacuum chamber is formed beneath the piston and the seal element.

BACKGROUND OF THE INVENTION

(a) Technical Field of the Invention

The present invention is generally related to a prosthetic device, and more particular to a shock and torsion absorber for use on a prosthetic limb.

(b) Description of the Prior Art

Shock absorption is commonly found on prosthetic limbs. To offer more comfortable experience to users, manufacturers continue to work on innovative improvements on the design of shock absorption.

For example, U.S. Pat. No. 7,744,653 teaches a vacuum pump having shock absorption and controlled rotation for use in an artificial limb. The pump includes a housing having a first accommodation space, and a shaft configured to be received by and to reciprocate within the first accommodation space. The housing and shaft form a pump accommodation space. A piston is coupled to the shaft and positioned within the pump accommodation space. When the piston is moved upward, air in the pump accommodation space is expelled through an exhaust port. When the piston moves downward, air is drawn from a connected cavity to achieve buffering. A rotational structure involves a pair of blocks within a trough to limit the blocks' moving range. The blocks are made of a flexible material. As a shaft is turned, the blocks are depressed and deformed to allow rotation.

However, even though multiple chambers are provided by the vacuum pump, only one is substantially involved in buffering. As to the rotational structure, the higher number of parts and the way the parts are put together are both complicated, causing difficulty in subsequent maintenance.

On the other hand, U.S. Pat. No. 6,645,253 teaches a vacuum pump and shock absorber where, according to pages 22-25 of the specification, a first chamber 240 is formed in a cylinder 220 above a piston 260, a second chamber 250 is formed above the cylinder 220. A third chamber 241 is formed beneath the piston 260. Initially, the second chamber 250 has the largest capacity, and a first valve device 270 is closed to seal a cavity 62. As a casing 210 moves downward, the second chamber 250 shrinks and air is expelled through a second valve device 280. The air in the third chamber 241 provides shock absorption. As the casing 210 continues to move downward, the first chamber 240 would have the largest capacity and the second chamber 250 would have the smallest capacity. Through this repeated cycle, air flows between chambers to achieve buffering and more comfortable walking experience.

However, the vacuum pump and shock absorber conducts air flow all through an intake/exhaust post 272. Additional complexity is involved so that a single channel is shared for both air intake and exhaust. The number of related chambers also cannot be reduced. Furthermore, as a user walks faster or slower, the fluidity of air flow would be affected, leading to inferior walking experience.

SUMMARY OF THE INVENTION

The present invention teaches a shock and torsion absorber that includes a base member having an accommodation space and an exhaust opening, a cushion member joined to a bottom end of the base member, a limit member including a positioning element and a seal element, and a joint member having an intake element, a trough, and a axial channel. A piston is housed in the joint member. The axial channel allows a shaft to thread through via the positioning element and to join with the shaft limit element so as to buffer the joint member's pressure. An upper vacuum chamber is formed above the seal element in the joint member. A bottom end of the positioning element is connected to the cushion member. The piston is connected to a top end of the positioning element.

When the joint member moves upward, the intake element draws air into the upper vacuum chamber and air in the lower vacuum chamber is expelled through the exhaust opening. When the joint member moves downward, air in the upper vacuum chamber flows to the lower vacuum chamber. Therefore, the joint member may steadily operate in the base member by drawing air alternately by the upper and lower vacuum chambers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown inFIGS. 1 to 5, a shock and torsion absorber according to an embodiment of the present invention includes a base member10. The base member has an accommodation space11and an exhaust opening101. A cushion member12is joined to a bottom end of the base member10, and the cushion member12includes a casing121, a shaft limit element122, an elastic element123, and an adjustment element124. The shaft limit element122and the elastic element123are sequentially received in the casing121, and a bottom end of the casing121is sealed by the adjustment element124. The elastic element123may be a spring, or other element of elastic property. The present invention does not impose specific limitation.

A limit member20includes a tubular positioning element21and a seal element22. A bottom end of the positioning element21is threaded through the base member10and coupled to the cushion member12. The seal element22is joined to a top end of the positioning element21. A joint member30includes an intake element301joined to an outer circumference of the joint member30to draw air F inside the joint member30. The joint member30has a trough31around an inner circumference of the joint member30, and an axial channel33. Through the trough31, a piston32is tightly housed in the joint member30. A shaft40runs through the axial channel33and the positioning element21, and joints to the shaft limit element122for buffering pressure exerted on the joint member30. An intake 1-way valve302is further configured inside the intake element301so that air F is prevented from escaping from the upper vacuum chamber50through the intake element301.

An upper vacuum chamber50is formed inside the joint member30above the seal element22, and a lower vacuum chamber60is formed inside the joint member30beneath the piston32and the seal element22. When the joint member30moves upward, the intake element301draws air F into upper vacuum chamber50and air in the lower vacuum chamber60is expelled through the exhaust opening101. When the joint member30moves downward, air F in the upper vacuum chamber50flows to the lower vacuum chamber60. The joint member30therefore operate steadily inside the base member10.

Within the accommodation space11, there are two torsion springs111and two strength adjustment screws112. The torsion springs111run through the accommodation space11. Each torsion spring111has a first end1111and a second end1112. A number of pins322are extended from a top side of the piston32. The pins322are for fixing the joint member30so as to adjust the strength adjustment screws112's elasticity against the first ends1111and second ends1112, and further to limit the joint member30's left and right rotational range. In the present embodiment, the joint member30has a rotational range that is 15 degrees both clockwise and counterclockwise. This range may be conveniently adjusted according to the elasticity provided by the torsion springs111.

A seal element 1-way valve221is configured in the seal element22besides the axial channel so that air F drawn through the intake element301into the upper vacuum chamber50may enter single-directionally the lower vacuum chamber60without backflow. A piston 1-way valve321is also configured in the piston32besides the axial channel so that air F in the lower vacuum chamber60may be expelled single-directionally through the exhaust opening101.

As shown inFIGS. 6 and 7, a shock and torsion absorber according to a second embodiment of the present invention has a ring-shaped torsion spring111. Together with the strength adjustment screws112, the swivel angle of the joint member30is as such limited. The rest of the second embodiment is identical to the previous first embodiment, and the details are omitted.

As described above, the shock and torsion absorber has upper vacuum chamber50and lower vacuum chamber60formed by the base member10and joint member30. Through the one-way flow design on the seal element22and piston32, air F enters single-directionally into the upper vacuum chamber50and lower vacuum chamber60, so that vacuum and exhaust is achieved. Further, through the mutual contact between the torsion springs111and strength adjustment screws112within the accommodation space11, rotational angle between the joint member30and base member10may be adjusted.