IMPROVEMENTS IN TREPANNING INSTRUMENTS
Year: 1862

page_text: LETTERS PATENT to Arthur Wormull, of Old Fish Street, in the City of
London, Surgical Instrument Maker, for the Invention of "IMPROVEMENTS
IN TREPANNING INSTRUMENTS."
Sealed the 4th November 1862, and dated the 13th May 1862.
PROVISIONAL SPECIFICATION left by the said Arthur Wormull at the
Office of the Commissioners of Patents, with his Petition, on the 13th
May 1862.
I, ARTHUR WORMULL, of Old Fish Street, in the City of London, Surgical
Instrument Maker, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN TREPANNING INSTRUMENTS," to be as follows:-
My Invention of improvements in trepanning instruments consists in con-
structing the instrument in such a manner that the cutting tool may have the
required rotary motion communicated to it by means of some convenient
mechanical arrangement of gearing, instead of this motion being given by the
wrist of the operator, as heretofore.
In carrying out my Invention, the rotary cutting tool (of which there may
be various sizes adapted to one iustrument) is adapted to the lower end of a
tubular shaft, which carries at its upper end a toothed wheel, which is driven
by a pinion on a spindle mounted in bearings in the stationary part of the
instrument. This spindle projects from the inside through the hollow case of
the instrument, and is provided with a winch handle or a universal joint aud

page_text: handle, whereby it may be turned by means of the right band of the operator,
while the left hand of the operator is employed to hold down the instrument
by pressing on a knob at the top. A central spindle or pivot provided with a
sharp point round which the cutting tool rotates, passes down the centre of the
instrument. This central spindle is adjustable in the line of its axis by means
of a rack and pinion inside, the latter of which is actuated by means of a
thumb nut or milled head outside.
It will be evident that other mechanical contrivances equivalent to those
above described may be employed to effect the required motions. I, however,
prefer those above mentioned as being the most convenient.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Arthur Wormull in the Great Seal Patent Office on the
13th November 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARTHUR
WORMULL, of Old Fish Street, in the City of London, Surgical Instrument
Maker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of May, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Arthur Wormull, Her special license that I, the said Arthur
Wormull, my executors, administrators, and assigns, or such others as I, the
said Arthur Wormull, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom' of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
IN TREPANNING INSTRUMENTS," upon the condition (amongst others)
that I, the said Arthur Wormull, by an instrument in writing under my
hand and seal, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Arthur Wormull, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the

page_text: following statement, reference being had to the Drawing hereunto annexed,
and to the letters and figures marked thereon (that is to say):-
:-
"
My Invention of "Improvements in Trepanning Instruments consists in
constructing these instruments in such a manner that the cutting tool may
have the required rotary motion communicated to it by means of some con-
venient mechanical arrangement of gearing, instead of this motion being given
by the wrist of the operator, as heretofore.
The several Figures in the accompanying Drawing represent various views
of one of my improved instruments. Fig. 1 is a side elevation; and Fig. 2, a
vertical section of the same.
The instrument is so constructed that cutting tools of various sizes may be
adapted to the same instrument, and are secured thereto by a temporary
fastening. a is the circular cutting tool, which is secured to the lower end of
a tubular shaft by means of a bayonet joint, as shewn in the detached
sectional view, Fig. 3, and plan view, Fig. 4. The tubular shaft carries at
its upper end a toothed wheel c, Fig. 2, which is driven by a pinion d, on a
spindle d', mounted in bearings in the stationary part of the instrument. This
spindle projects from the inside through the hollow case of the instrument, and
is provided with a winch handle or common crank e, Fig. 2, or a jointed rod
and handle in combination with a universal joint, as scen at c in Fig. 1. By
this arrangement of parts the spindle and its pinion may be turned by means
of the right hand of the operator, while his left hand is employed to hold down
the instrument by pressing on a knob f at the top of the fixed part 6*.or
tubular case of the instrument. A central spindle or pivot g, Fig. 2, provided
with a sharp point g, round which the cutting tool a rotates, passes down the
centre of the instrument, and is adjustable up or down in the instrument in the
line of its axis by means of a rack which is formed on its upper part. A pinion
h, inside the instrument, gears into this rack, and is actuated by.means of a
thumb nut or milled head h', Fig. 1, outside. The tubular shaft b, which
carries the cutting tool a, is secured to the fixed part 6* of the instrument by
means of a collar i, which is screwed on to a tubular prolongation of the
piece 6, and bears against a shoulder or recess cut in the lower end of the
tubular shaft b, as seen in the sectional views.
The mode of operating with the instrument is as follows:-The central
point y' is adjusted by means of the rack and pinion h, until its point projects
beyond the lower edge of the teeth of the cutting instrument just sufficiently
to form a firm central pivot, round which the cutting tool a may be rotated by
means of the winch handle and toothed gear c and d. In order to cause the
point g to rotate with the cutting tool a, part of the side of the spindle is
I

page_text: cut away, so as to form a flat side, which passes through a hole of a corre-
sponding shape formed in a disc j, which is secured to the lower end of the
tubular shaft b by means of screws, as seen in the sectional plan views, Figs. 5
and 6. It will therefore be understood that as the discj is secured to the
tubular shaft b and moves round with it, the spindle g must also be carried
round with it. The point 9' having been properly adjusted, the operator places
it firmly on the central part of the piece of bone that it is desired to cut out
or remove; then, while bearing firmly on the top f of the instrument with the
left hand, so as to keep it steady, he turns the winch or crank e, so as to causo
the teeth of the tool a to cut into the bone, and as this proceeds, the point g¹
will be lowered with the tool a further into. the bone by boring its own
central hole. By turning from time to time the milled head of the pinion,
the point may be adjusted with nicety.
It will be evident that other mechanical arrangements equivalent to those
above described may be employed to effect the required motions; I, however,
prefer those above mentioned as being the most convenient.
Having now described my Invention of "Improvements in Trepanning
Instruments," and having explained the manner of carrying the same into
effect, I claim as the Invention secured to me by Letters Patent as aforesaid,
arranging the cutting tools of trepanning instruments in such a manner that
motion may be communicated to them by means of toothed gearing, instead of
effecting this object by the wrist of the operator, as heretofore.
In witness whereof, I, the said Arthur Wormull, have hereunto set my
hand and seal, this Twelfth day of November, in the year of our Lord
One thousand eight hundred and sixty-two.
Witness, -
J. W. MOFFATT,
66, Chancery Lane.
ARTHUR WORMULL. (L.S.)