Improvements in the Construction of Artificial Limbs.
Year: 1899

page_text: Date of Application, 21st Feb., 1899- Accepted, 22nd Apr.,
1899
COMPLETE SPECIFICATION.
Improvements in the Construction of Artificial Limbs.
I, PETER JENSEN, of 77, Chancery Lane, London, Chartered Faient Agent, do
hereby declare the nature of this invention, which has been communicated to
me from abroad by The Doerflinger Artificial Limb Company, located in the City
and County of Milwaukee, and State of Wisconsin, United States of America,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention has for its object to improve the construction of artificial limbs,
and more especially the leg-portions and ankle-joints thereof, whereby extreme
simplicity of mechanism is combined with the greatest durability and firmness of
attachments, producing a natural, easy and noiseless step, avoiding friction, and
ensuring comfort to the wearer, and to these ends the said invention consists
in certain peculiarities of construction and combination of parts, all as hereinafter
more specifically set forth and illustrated in the accompanying drawings.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a partly sectional side elevation of the leg-portion of the said im-
proved artificial limb.
Figure 2 is a plan view thereof.
Figure 3 is a front elevation thereof, drawn to a reduced scale, and
Figure 4 is a detail rear view of the socket, detached, also drawn to a reduced
scale.
Figure 5 is a longitudinal sectional view of the foot portion, showing the
improved ankle-joint.
Figures 6 and 7 are detail sections on the lines 6-6 and 7-7 respectively, of
Figure 5.
Figures 8 and 9 are detail plan views, the latter partly in section on the line 9-9
of Figure 5.
Referring to the drawings, A represents the lower leg-portion made hollow,
and preferably of willow-wood, and B B are metallic straps, pivotally hinged as
shown at a a and secured to and connecting the said leg-portion A with a thigh-
socket, not shown. C is the stump-socket, which receives the lower end of the
amputated member, and is made preferably of sole-leather, said socket being
vertically split at the rear, and provided with two vertical series of perforations,
so that the separated edges can be adjustably drawn together by a lacing-cord, b,
the joint thus laced together being covered and protected from contact with the
secured
stump of the wearer by a thin flap of leather, or other suitable material
to the inner surface of the said socket C, as by smooth-headed rivets d d along one
vertical edge of said flap. The front upper part of this socket C is much higher
than the rear part, back of the center thereof, as best shown in Figure 1, to afford
room for the ready bending of the knee of the wearer. The top of the leg-
portion A is recessed or cut out, at both front and rear, as shown at e e, and there
preferably reinforced by metal wear-plates f f of angular form, to receive horizon-
tally disposed rollers D D', which, in their preferred form illustrated in the draw-

page_text: ings, are longitudinally bored cylinders of metal revolving freely on journals g g¹,
the ends of said journals having bearings in perforations in the opposed inner
faces of the said angular wear-plates ff.
E E represent flexible straps, either of leather or thin flexible metal, secured
to the opposite front and rear outer sides of the socket C, as by rivets h h¹ h',
and which pass upward between the said socket and the inner surface of the
hollow leg-portion A; and out over the rollers D D, and down outside the log-
portion A, and at their ends are joined securely to strips of elastic webbing i, i¹,
the lower ends of said webbing, being suitably reinforced, as by leather bindings jj,
each formed with a horizontally disposed series of lacing holes k k k therethrough.
FF represent the opposed ends (preferably formed of doubled strips of leather)
having corresponding series of lacing holes k¹¹k, the lower edges of said lacing
..ends FF being secured, as by screws m m, passing into suitably tapped openings
in transverse metallic plates n n, let into and secured to the opposite sides of the ankle
portion of the said leg-portion A, and suitable lacing-cords G G adjustably con-
nect the lower strap ends j j' with the opposing lacing-ends FF through the
described two series of perforations kkk and, as shown in Figures 1 and 3.
The described strap E is single at its inner end where it is secured by rivet / to
the socket C, but the strap E' is forked, at its inner end, as shown ato o in
Figure 4, and each half of the fork is secured by a separate rivet h¹, so that the
two branches of said forked end may be secured on opposite sides of the vertical
separated rear edges of the socket C, to enable said edges_to be adjusted at the
proper distance apart, according to the size of the stump of the amputated member
supported within said socket.
By reason-of-supporting the stump-socket C-in-the manner described and
illustrated in the drawings, friction between the stump of the wearer's leg and
leg-portion A is obviated, thus rendering the said artificial limb much easier and
more comfortable. Further, by the described lacing systems, at G G¹, in case
the elastic webbing i should stretch and become slack, this slack can be instantly
taken up, and also, as already stated, the socket C, by its lacing-cord b, can be
quickly adjusted, so as to be either diminished or increased in diameter, as required
in any particular instance, as for example, should the stump of the amputated
member shrink or swell, as often happens.
In case the leg is amputated above the knee, the outer thigh socket would be
made of willow wood, and practically like the upper part of the leg-portion A
shown, with an inner thigh-socket like the stump-socket C shown, with the same
form of straps, webbing sections and other attachments just as already described,
and with any desired approved construction of knee-joint.
In Figure 5, there is shown the lower end of the improved artificial limb, the
leg-portion A having a plate H mortised in the same to be flush with its under
portion, and bolted or otherwise rigidly secured in place. The plate H is herein
shown as having its central portion provided with a
arranged transversely thereof and engaged by convex lugs
depending concave rib ol
plate I, bolted or otherwise rigidly secured to the upper portion J of an artificial
rising from another
foot. The lower portion J¹ of the foot is preferably felt or some other suitable
yielding material rigidly_secured to the part J, the latter being usually wood.
The lugs pon plate I are on opposite sides of a longitudinal slot 7 in said
plate, and the latter is provided with concave under side recesses engaged by a
pin K loose in an eye-end r of a bolt L extending up through said slot and an
aperture in the plate H aforesaid.
Within a hollow portions of leg A, the bolt L is surrounded by a rubber
block M, or other suitable spring, the tension of the latter being regulated by
adjustment of a nut N run on the intermediate threaded portion of said bolt against
a spring-opposing washer t. The free upper end of said bolt L is reduced in
diameter and threaded in the opposite direction from the described intermediate
portion, to receive a jam-nut O, which bears against the nut N, and guards against
the latter becoming loosened in use,

page_text: A rubber block 1' or other elastic cushion is interposed between the forward ends
of the plates H I, and a central longitudinal slot u in the former plate is shown
engaged by the eye-end of a bolt that extends down through a similar slot w
in the other plate. A pin R loose in the eye-end of bolt Q has bearing in concave
upper side recesses of plate H, and within a recess of the foot said bolt is sur-
rounded by a rubber block S, or other suitable spring, the tension of this spring
being regulated by adjustment of a nut T run on the free end of said bolt against
a spring opposing washer y...
That portion of the foot through which bolt Q passes has a bore z of sufficient
area to prevent cramp of said bolt, and it will be apparent that the weight of
a person provided with an artificial limb embodying said joint is alternately
resisted by the spring S and cushion P, the normal compression of said spring
and the spring M being obtained by adjustment of nuts T N, to regulate
the tension of the aforesaid joint.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is;-
1. In an artificial limb, the combination with a hollow outer portion having
horizontally disposed rollers journaled in the upper part thereof at both front
and rear, of a stump-socket practically parallel with and of less diameter than
that of said outer portion, extending above and adapted to project downward
within the upper part of the latter, but absolutely free from contact therewith;
and flexible straps secured at their inner and upper ends to said stump-socket
and adapted to pass over said rollers and be secured at their outer and lower ends
to the outer surface of said outer portion of said limb.
2. In an artificial limb, the combination with a hollow outer portion having
horizontally disposed rollers journaled in the upper part thereof at both front
and rear, of a rearwardly vertically divided stump-socket practically parallel
with and of less diameter than that of said outer portion, extending above and
adapted to project downward within the upper part of the latter, but everywhere
absolutely free from contact therewith; flexible and partly elastic straps secured
at their inner and upper ends to said stump-socket and adapted to pass over said
rollers and down outside said outer portion, the portions of said straps connecting
the stump-socket and outer portion being inelastic; adjustable fastening devices
for connecting together the separated rear edges of said stump-socket; and other
fastening devices for adjustably connecting the lower ends of said straps to the
said outer portion and for taking up the slack of said straps.
3. In an artificial limb, an artificial ankle-joint comprising a pair of plates one
of which has rocker-bearing with respect to the other, a bolt in yielding connec-
tion with one of the plates and extended through the other plate, a spring sur-
rounding the bolt against the latter plate, a nut on said bolt in position to regulate
tension of the spring, an elastic cushion between forward ends of said plates,
another bolt having yielding connection with the forward end of the upper plate
and engaged with a longitudinal slot in the lower plate, a spring surrounding the
lower portion of the latter bolt, and a nut on said latter bolt in position to regulate
tension of the latter spring against an opposing surface.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.