Improvements in and relating to Artificial Legs.
Year: 1898

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Artificial Legs.
:
I, HENRY IRVIN WELLER, a Citizen of the United States of America, residing at
226, Wilber Avenue, in the City of Columbus, County of Franklin, and State of
Ohio, United States of America, Wagon Builder, do hereby declare the nature of this
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
This invention relates to an improvement in the construction of ankle-joints having
universal motion for artificial legs.
The object is to provide a joint having a lateral as well as a forward-and-backward
motion, from which is eliminated all extra or superfluous cords or springs-that is to
say, a joint which is simply constructed, being composed of few and elemental
parts.
It is also desired to produce a joint which operates easily and which possesses the
requisite of strength and durability.
The construction and operation of my invention will more fully appear from the
detailed description which follows.
Figure 1 is a central vertical section of the foot and leg, taken in the direction of
the length of the foot.
Figure 2 is a vertical section of the leg and foot transverse of the direction of the
foot.
Figure 3 is a horizontal section of the foot through the ball in the center.
Figure 4 is a view of the bottom of the foot, the felt sole being removed.
Figure 5 is a detail.
The leg A and the foot B are made of light willow wood or other equivalent
material possessing sufficient lightness and strength, and they are of a shape to
conform as nearly as possible to that of the natural leg and foot. The back portion
of the leg at a point just above the heel is cut in to form a shoulder, the cut extending
forward to that portion b corresponding to the tibia of the natural leg.
The lower end of the tibia extends into the foot and is somewhat enlarged, as shown
at e, and in the end of this enlarged portion there is provided a socket having a
bushing of raw-hide for the reception of the round hollow ball h. The foot is
provided with a similar socket and bushing f¹ and g¹ for the reception of the opposite
portion of the ball. In addition to the socket mentioned the lower end of the
Paise 11

page_text: extended tibia is provided near its front and rear edges with hollowed out spaces e¹ e¹
curved to the form of a half moon or crescent, and extending partly around the
socket f. The material around the socket in the foot is also slightly hollowed out, as
at h¹¹, in directions substantially parallel with the direction of the foot and at right
angles to the curved slots e¹ e¹ in the lower end of the extended tibia.
-
The hollow ball is of aluminium bronze and has a couple of substantially
rectangular slots and ¹, the first being in the upper and the latter in the lower
surface of the ball. The longer dimension of the first is in the direction of the
length of the foot; while the longer dimension of the latter-that is the lower slot―
is transverse of the foot. The ball his provided with trunnions jj, j¹ j¹, which are
situated equi-distant around the surface of the ball along the circumference of a
great circle whose plane is horizontal when the leg is vertical. The axes of the
trunnions lie in the plane of the circle just referred to and are at right angles to each
other meeting at a point about the center of the ball. One axis extends in the
direction of the length of the foot and. the other at right angles or transversely of
that direction. The trunnions j j, having the latter axis, are journaled in
bearings jj, provided in the bushing at the lower end of the extended tibia, while
the other trunnions j¹ j, having à direction at right angles to jj-that is, in a
direction coincident with that of the length of the bushing e in the foot―are
journaled in bearings j³ ³, provided in the foot. The trunnions jjjj¹ are not
confined closely to their bearings, but when the foot assumes the various angles
necessary in walking they project, respectively, into the slots or hollow spaces el el
and h¹ h¹.
In the bottom of the foot there is a socket k, situated about one-fourth of an inch in
front of the bushing g', (in-the upper portion of the foot). This socket / receives the
cylindrical rubber spring k', which is about one and one-fourth inches in diameter and
one and one-half inches in length and which is provided centrally with a hole k², which
receives one of the threaded ends of a steel rod C, which extends up through the foot,
passing through the slots i and in the ball h into the leg, where the other end passes
through a cylindrical rubber spring k, substantially similar to that just described. Each
of the threaded ends of the rod C receives nuts, and when the rod has been placed
in position and the nuts adjusted the leg and foot, as is evident, are securely joined
together. The object of placing the socket for the spring in front of the
bushing g is to secure a greater heel leverage without placing the leg too far forward
relatively to the foot.
The heel-cord d is made with a loop m at one end which fits over a lug or
projection m¹ in the bottom of the heel. The other end is threaded and extends up
through the heel into the hollow leg, where it passes through a cross-piece n and
receives a nut n¹, by means of which the cord may be secured in position and its
tension regulated.
The toe portion of the foot, which should have more or less flexibility, consists of
a somewhat thickened piece of felt material 0 and having the proper size and
shape and which is bent or folded at its center upon itself, so that the inner faces of
the two section's o¹ and o² are parallel to each other.
Inclosed within the fold of the felt-toe-piece just mentioned is a piece of leather 03,
which is bent at its center in the same manner as the felt material by which it is
inclosed. It is thickened at its center and tapers toward the edges of its two ends-
that is, toward the toe of the foot. The bent or curved portion of the felt toe-piece
fits into a concaved or hollowed space p in the forward end of the wooden foot B, to
which the toe-piece is attached by means of a T-bolt.pl, passing back through the
foot and receiving a nut p². An additional flexibility is given to the toe by means of
a-flat metallic spring q, which is fastened to the wooden foot and extends forward and
rests against the bottoin of the toe-piece O and against the top surface of the front
portion of a felted sole q', which extends along the entire length of the foot. The
felted sole prevents any unnecessary jarring sensation which might be occasioned by
walking or moving about.
it

page_text: As pointed out above, the lower end of the rod C is normally in a vertical plane in
advance of the vertical plane of the upper end of said rod; but it will be seen that
the rod C lies entirely within the vertical planes of the ball .
One of the great objections incident to these attempts heretofore made to
provide a ball-and-socket joint between the leg-section and the foot-section of an
artificial limb with which I am acquainted has been that as the connecting devices,
such as the rod C herein, were arranged outside of the ball they were constantly
subjected to friction and rapidly destroyed. By my construction, however; the rod C
is relieved of all wear; it having no contact directly with either the foot-section or the
leg-section..
As shown in the drawings; the nuts are made tapering in form and fit snugly
within correspondingly shaped passages formed in the spring-blocks ¹³. By
this arrangement it will be seen that whenever the leg-section is moved relatively
to the foot-section, the, spring-block k¹, for example, will be compressed both
longitudinally and laterally and will strongly assist in returning the parts to their
normal position. upon the cessation of the power which catised such movement of the
leg-section. By means of the nuts the tension of the springs k¹³ can be
readily controlled and varied and the rod C always held in proper position vertically
relative to the. leg-section and the foot-section.
As I have above described and as will be apparent from the drawings; I have
provided a ball-and-socket joint between the leg-section and the foot-section, and it
will also be noted that I have provided means whereby a positive limit is placed upon
lateral or horizontal moveinent of the foot-section relative to the leg-section; the
lack of, which has; as I believe; prevented the successful use of this style of joint
heretofore in articles of this nature.
. While the trunnions j j¹ do not at all interfere with the desired freedom of motion
of the ball h, they do prevent the foot-section from swinging laterally beyond a
certain limit.
I have above described that the tension of the heel-cord d may be varied. For
accomplishing this and maintaining the tension on such cord, I at present
prefer to employ the following means: The nut n which engages with the
externally threaded tube or sleeve R; is provided with a series of peripheral notches
or recesses n². The sleeve R extends some distance above the nut n¹, and the
filaments of the cord D are suitably expanded and secured above the upper end of
such sleeve to form à firm connection therewith.
S designates a locking-bar; which is provided at one end with an internally-
threaded passage adapted to engage with the threads on the sleeve R. Near the
outer end the bar S is provided with an apertures, adapted to align with the recesses
or sockets n2 in the nut n¹. By means of a screw T, passing through said aperture 8
and any one of the peripheral notches in the nut n¹, the latter is held from rotation
on the sleeve R and rigidly secured to the cross-piece n.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim, is:
1. In an artificial ankle-joint, the combination of a leg A provided in its lower end with
a socket and bushing;,à foot B provided with a socket and bushing, said sockets being
opposite each other and adapted to receive a hollow metallic ball having a substantially
rectangular slot in its upper surface and a similar slot in its lower surface, the longest
dimension of the first being in the direction of the length of the foot and that of the
latter being at right angles to that direction; a steel rod adapted to receive a nut at
each end, and extending from a point in the leg through the aforesaid slots and
through a rubber spring in the bottom of the foot-said spring being one-fourth of an
inch in front of the aforesaid bushing in the foot, substantially as set forth and
described.
2. In an artificial leg, the combination of a foot-section, a leg-section, a ball fitted
in sockets formed in said foot-section and leg-section, and a rod extending through said

page_text: ball and having one end connected to the leg member and its other end connected to
the foot member, substantially as set forth.
3. In an artificial leg, the combination of a foot-section, a leg-section, an elastic or
yielding connection between the rear portion of the foot-section and the leg-section, a
rod connecting said foot-section and leg-section, and a ball and socket joint connecting
said sections in advance of the said yielding connection, the ball of said joint being
fitted loosely about said rod, substantially as set forth.
4. In an artificial leg, the combination of a foot-section, a leg-section, a ball arranged
between said leg-section and foot-section, a stiff rod extending loosely through a
passage in said ball and having one end connected to the leg-section and its other end
connected to the foot-section, a yielding connection between the rear portion of the
foot-section and the leg-section; and means for positively limiting the motion of
the foot section laterally of the leg-section, substantially as set forth.
5. In an artificial leg, the combination of a foot-section, a leg-section, a bushing
secured in a socket in the foot-section, a bushing secured in a socket in the leg-
section, a ball provided with laterally-projecting trunnions engaging bearings formed
in both said bushings, a rod extending through said ball and having one end secured
in the leg-section and its other end secured in the foot-section, and a yielding
connection, supplemental to said rod, between the foot-section and the leg-section,
substantially as set forth.
6. In an artificial leg, the combination of a foot-section, a leg-section, connected
to the foot-section by a ball and socket joint, and a rod extending through said joint
and having one end connected to the leg section and its other end connected to the
foot-section, the point of connection of said rod with the foot-section being in a
vertical plane in advance of the vertical plane of the connection of said rod with
the leg-section when the parts are in their normal position, substantially as set
forth.
7. In an artificial leg, the combination of a foot-section, a leg-section, a ball-and-
socket joint connecting said sections, and a rod having one end secured in the leg
section and its other end secured in the foot-section, said rod extending forwardly
from its upper to its lower end, and both ends of said rod lying within the vertical
planes of the ball-and-socket joint connecting said foot-section and leg-section,
substantially as set forth.
8. In an artificial leg, the combination with a foot-section, of a yielding toe-section
formed of a piece of felt or similar material bent upon itself and having its closed end
inserted in a socket in the foot section, a bolt having an expanded head fitted between
the sections of said toe-piece and its body connected to the foot-section, and a
supplemental wearing strip placed between the head of said bolt and said toe-piece,
substantially as set forth.
9. In an artificial leg, the combination of a foot-section, a leg-section, a yielding
or flexible cord having its lower end connected to the foot-section and its upper
end connected to a sleeve-support within the leg-section, a nut for adjusting said
sleeve vertically, and a lock-arm for rigidly connecting said nut to the leg-section,
substantially as set forth.