CERTAIN IMPROVEMENTS IN THE CON- STRUCTION OF ARTIFICIAL LEGS
Year: 1810

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
MANN, of Bradford, in the County of York, Stuff Merchant, send greeting.
WHEREAS His most Excellent Majesty King George the Third did, by
His Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Thirty-first day of
October, in the fifty-first year of His reign, give and grant unto me, the said
Thomas Mann, my exors, adññors, and assigns, His especial licence, full power,
sole privilege and authority, that I, the said Thomas Mann, my exors, adñors,
and assigns, during the term of years herein mentioned, should and lawfully
might make, use, exercise, and vend, within England, Wales, and the Town of
Berwick-upon-Tweed, my Invention of "CERTAIN IMPROVEMENTS IN THE CON-
STRUCTION OF ARTIFICIAL LEGS;" in which said Letters Patent there is contained
a proviso, that if I, the said Thomas Mann, shall not particularly describe and
ascertain the nature of my said Invention, and in what manner the same is
to be performed, by an instrument in writing under my hand and seal, and
cause the same to be enrolled in His Majesty's High Court of Chancery
within two calender months next and immediately after the date of the said
Letters Patent, that then the said Letters Patent, and all liberties and advan-
tages whatsoever thereby granted, shall utterly cease, determine, and become
void, as in and by the said recited Letters Patent, relation being thereunto
had, may more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, 1, the sand
Thomas Mann, do hereby declare that the nature of my said Invention of.
certain improvements in the construction of artificial legs for the purpose of
assisting the human body after the loss of the natural leg by amputation or
otherwise, which improvements are upon and in addition to a similar Inven-
tion invented by me, and for which I obtained His Majesty's Royal Letters
Patent bearing date at Westminster, on or about the Twentieth day of
January, in the thirtieth year of His reign, particular description of which
Invention I did cause to be enrolled in His, said Majesty's High Court of
Chancery within the time limitted in such letters Patent, and in what manner
the same are to be performed and carried into effect, are particularly described
and ascertained in and by the Drawings hereunto annexed, and the following
description thereof, that is to say:-
a
Figure 1 represents the complete limb, leg and. thigh; when covered with doe
leather, or other fit material, to which are annexed at letters A, A, A, straps
which pass over the shoulders and fix the limb to the body.
Figure 2 represents the external appearance of the same when divested of
the covering; letters B, B, B, three slender spiral springs connected with the
patella C, designed to preserve the knee in perfect shape in all positions;
D, centre pin of the knee joint; E, centre pin of the ancle joint; F, F, thick
spiral springs, the one a repeller and the other an attracter, designed to
preserve the ancle in shape in every attitude, and also to sustain the foot when
taken from the ground, so as to prevent it from tripping when in the act of
walking.
Figures 3, 4, 5, 6, represent the limb when disjointed.
Figures 7, 8, my two newly invented springs of great power, designed to
improve the action of the several joints in the knee, ancle, and toes; the former
(Fig. 7) being fixed by means of the pin G, G, which passes through the
circular part of it, in the inner part of the thigh case, above the centre of the
knee joint (Fig. 3), letter H, attaches to the lower or leg part (Fig. 4), in the
manner represented, Fig. 9, by a thong or string of gut (letter K), which acts
in a circular groove (letter M), and has the effect of assisting the wearer to
recover the leg to a straight position after the flexure of the knee occasioned
by the movement of the limb when in the act of walking, but by its near
approach to the centre pin, as the leg bends to a right angle, loses its effect so
far as to prevent the inconvience of the leg being forced forward when required
to remain in a sitting posture. The latter spring, Fig. 8, being fixed in a
similar manner in the hollow part of the foot, Fig. 5, connects with the lower
part of the leg below the centre of the ancle joint in the manner represented,

page_text: Fig. 9, by means of the two prongs N, P; the prong N, which is acted upon as
the pressure of the body comes upon the heel, prevents the foot from dropping
to the ground with too great rapidity; the other prong P counteracts and the
operation of the springs at the heel and instep, Fig. 2, F, F, so as to prevent
the foot from remaining too much elevated after it is taken from the ground.
Letters QQ, are two long prongs, connected with the same spring, which
extends to the toe part (Fig. 6), and act as levers to raise the point of the
toe when the foot is off the ground so as to prevent tripping, which effect is
counteracted when the pressure of the body returns upon the foot.
Figure 10 represents the leg and foot complete, as it is designed for a
below-knee amputation, to be fastened to the body by the straps R, R, which
passing through the loops of a leather bearer, Fig. 11, S, S, when laced upon
the limb, are tied or buckled to a drawn upon the thigh and supported by
braces over, the shoulders.
In witness whereof, I, the said Thomas Mann, have hereunto set my
hand and seal, this Eleventh day of December, in the year of our
Lord One thousand eight hundred and ten.