AN IMPROVEMENT INSTRUMENT FOR EXTRACTING TEETH IN A PERPENDICULAR DIRECTION
Year: 1799

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
SIMPSON, of the Parish of Saint John, Clerkenwell, in the County of Middle-
sex, Surgeon's Instrument Maker, send greeting.
WHEREAS His most Excellent Majesty King George the Third, did by
His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, 'the Twenty-third day of April, in the thirty-ninth year of His
reign, give and grant unto me, the said Robert Simpson, His especial licence
that I, the said Robert Simpson, during the term of years therein mentioned,
should and lawfully might, use, exercise, and vend, within England, Wales,
and Town of Berwick-upon-Tweed, my Invention of "AN IMPROVEMENT
INSTRUMENT FOR EXTRACTING TEETH IN A PERPENDICULAR DIRECTION;" in which
said Letters Patent there is contained a proviso, obliging me, the said
Robert. Simpson, by an instrument in writing under my hand and seal, to
cause a particular description of the nature of my said Invention, and in
what manner the same is to be performed, to be inrolled in His Majesty's
High Court of Chancery within one calendar month after the date of the
said recited Letters Patent.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Robert Simpson, do hereby declare that my said Invention is described in the
above Drawings, and the following description, that is to say:-

page_text: The Figures 1, 2, 3, represent claws of different sizes, made of steel, each
consisting of two levers connected by a strong joint, to which is adapted a
spring, approximating their lower extremities to each other by a lateral pressure.
After the gum has been scarified, so that the neck of the diseased tooth is bare,
one of these claws must be cliosen of an appropriate size, and be applied to
the tooth by means of the forceps, Fig. 4, which has a groove 6 on the inside
of each extremity. In these grooves the processes of the upper extremities of
the claws a, a, a, a, are lodged, so that when the handles of the forceps are
compressed, the claw cannot escape, and its lower extremities are kept asunder
until they are applied to the neck of the tooth on both sides; the forceps is
next to be opened and taken away, the claw by the action of its spring
remaining firmly fixed to the tooth, which then occupies the space d, in
Figures 1 and 2, or the space delineated by a diseased tooth in Fig. 3. The.
vacuity c, between the upper extremities of the claw, thus becomes fitted for
the reception of a lever. The instrument which performs the extraction is
represented in Fig. 5, and consists of a cylindrical piece of highly polished
steel, with a process shaped like a hook or circular wedge C, near the
extremity A. A strong transverse ivory handle is adapted to its other
extremity B, at á distance of one-third of its length from the ivory handle;
this cylinder has a neck between the letters K and L, where two blades of
steel I, K, and D, L, connected by screws, are lodged between two ornamental
projections of the cylinder, so that they cannot be taken away without
removing the screws, but will permit the cylinder freely to turn between them;-
these blades are flexible, and tend to approach each other by a moderate degree
of elasticity. The upper blade I, K, is shorter than the other; at its extremity
I it becomes wider, and by a curvature embraces the cylinder at a small
distance from the hóók-like process C, in order to prevent any lateral deviation
in the action of the cylinder. The lower blade D, L, is flat in its upper surface
from the angle near its junction with the other blade as far as Ę, where it
becomes wider by a projection towards the side nearest, and is rounded off on
both sides; this extremity forms the fulcrum, upon which the extremity A of
the lever A, B, is raised by turning the ivory handle, so that the hook C
becomes interposed between the line A, B, and the fulcrum D; on the inferior
surface of the fulcrum there is a dovetail groove, admitting several sliding plates,
to which leather cushions of different shapes and sizes are fixed, as appear in
Figures 6 and 7. F.shews the sliding plate as it is sewed upon the cushion; to
tlie inferior surface of the blade D, L, a flat steel handle H is adapted by the
screw M. This handle is a plate of steel, about one inch and a half in length,

page_text: with a circular extremity of one inch diameter, which is made rough on its
superior surface, in order to be less liable to slip between the fingers; it is
also moveable upon the screw M, and can be turned toward either side of the
instrument to any angle that may be required.
In witness whereof, I, the said Robert Simpson, have hereunto set my
hand and seal, this Twenty-third day of May, in the year of our Lord
One thousand seven hundred and ninety-nine