Prosthetic leg with weight responsive knee lock

Claim 2

A prosthetic leg comprising: a thigh portion having a cavity formed at the lower end thereof with opposing walls a shin portion having a well at the upper end within which well the lower end of the thigh portion is free to pivot a shaft fixed to said shin portion at the upper end thereof and across said wall, a rod passing through said opposing wall of said thigh portion, and a pair of links engaging said rod and said shaft at their respective ends, a brake band disposed within said cavity, around said shaft and affixed to said rod, and a lever member disposed within said cavity engaging said brake band and said thigh portion so that the brake band tightens around said shaft when the thigh portion bears down upon said lever member.

Claim 3

The leg of claim 1 wherein: said rod is disposed on one side of said shaft and parallel thereto, said brake band is U-shaped and has the upper side thereof fixed to said rod, a bolt passes through both sides of the band and is free with respect to the upper side and fixed to the underside, said lever member engages the upper end of said bolt, a fulcrum is on the upper side of said brake band on which said lever member pivots, said lever member bearing against the upper wall of said cavity at a point thereof disposed on the side of said shaft opposite said rod.

Claim 4

A prosthetic leg comprising: a thigh portion having a pair of opposing members depending from the lower end thereof, a shin portion having a well at the upper end for receiving said members, said pair of members having at least one pair of aligned holes, a rod disposed snugly within said pair of aligned holes, a shaft disposed at the upper end of said shin portion and across said well, a link connecting said rod to said shaft and being journaled on said shaft, a brake band disposed between said pair of members and around said shaft and having one end thereof engaging said rod, a bolt fixed to the other end of said band, which slides through an opening in said one end of said brake band, a fulcrum, a lever engaging said bolt and said thigh portion so that when weight is being supported by said leg said link rotates downward about such shaft, causing said thigh portions to drop slightly, pivoting said lever about said fulcrum to cause said bolt to slide with respect to said opening in said one end, causing the brake band to tighten around the shaft.

Claim 5

A prosthetic leg comprising: a thigh portion having a pair of opposing members depending from the lower end thereof, a shin portion having a well at the upper end for receiving said members, said pair of members having at least one pair of aligned holes, a rod disposed snugly within said pair of aligned holes, a shaft disposed at the upper end of said shin portion and across said well, a link connecting said rod to said shaft and being journaled on said shaft, a brake band disposed between said pair of members and around said shaft and having one end thereof engaging said rod, a bolt fixed to the other end of said band, which slides through an opening in said one end of said brake band, a fulcrum, a lever engaging said bolt and said thigh portion so that when weight is being supported by said leg said link rotates downward about such shaft, causing said thigh portions to drop slightly, pivoting said lever about said fulcrum to cause said bolt to slide with respect to said opening in said one end, causing the brake band to tighten around the shaft.

Claim 6

The leg of claim 3 wherein: another link is provided connecting said rod to said shaft with said brake band disposed between the levers, said other link is journalled on said shaft, said rod is substantially disposed in front of said shaft when the leg is in the straight portion, said lever is disposed so that one end extends rearward to engage said thigh portion so that weight is transmitted through the spaced areas to said shin portion.

Claim 7

The leg of claim 3 wherein: said one end of said brake band is disposed over the other end and has a bore through which said rod passes, said lever engages said bolt by the forward end of the lever, said fulcrum if formed on said brake band on the upper side thereof.

Claim 8

A pivotal mechanism for a prosthetic limb comprising: a first portion with a cavity formed at one end thereof, a second portion with a well formed at one end to allow said one end of said first portion to pivot freely therein, a shaft fixed to said second portion across said well, a rod passing through and in journaled relationship with the opposing walls of said cavity, means for allowing said rod to rotate about and parallel to said shaft, a brake band disposed around said shaft and within said cavity and having one end engaging said rod and the other end having contact with said first portion so that said brake band tightens around said shaft when said first portion bears toward said second portion.

Claim 9

A pivotal mechanism for a prosthetic limb comprising: a first portion with a cavity formed at one end thereof, a second portion with a well formed at one end to allow said one end of said first portion to pivot freely therein, a shaft fixed to said second portion across said well, a rod passing through and in journaled relationship with the opposing walls of said cavity, means for allowing said rod to rotate about and parallel to said shaft, a brake band disposed around said shaft and within said cavity and having one end engaging said rod and the other end having contact with said first portion so that said brake band tightens around said shaft when said first portion bears toward said second portion.

Claim 10

The mechanism of claim 6 wherein: said one end of said brake band has a hole formed therethrough, a link is disposed through said hole and is connected to said other end, a fulcrum is formed on said one end a lever is connected at one end to said pin and disposed to pivot about said fulcrom and has its other end in contact with said first portion.