Improvements in Thermo-cauters and similar Instruments for Pyrographic and Surgical purposes.
Year: 1897

page_text: Improvements in Thermo-cauters and similar Instruments for
Pyrographic and Surgical purposes.
I, WILLIAM HENRY BEACH, of 25, East Castle, Bridgenorth, in the County of
Salop, Veterinary Surgeon, do hereby declare the nature of this invention to be
as follows:-
My invention relates to instruments of the kind known as thermo-cauters and
to thermo-cauter lancets or knives used for surgical purposes and to instruments
similar to thermo-cauters but intended to be used for pyrographic etching pur-
poses, and the invention has, first, for its object to render the working point or
cutting edge more durable and better adapted for severing or cutting organic
substances or for incising or etching hard substances such as glass.
The improvement consists in tipping the working point or making the cutting
edge or it may be the entire combustion chamber of the instrument with, or of,
iridium osmi-iridium or an alloy of iridium. The hardness and non-oxidability of
the iridium under the high temperature to which it is subjected enable a sharp
point or a keen cutting edge to be given and maintained whilst the ability to raise
the working point or cutting edge to a state of incandescence enables the instru-
ment to be thorouglily disinfected after the performance of a surgical operation
even if the high temperature thus obtainable is not required for the purposes of
the operation, whilst for pyrographic etching on glass; for which platinum is not
suited owing to its softness and liability to adhere to the fused particles of glass,
iridium osmi-iridium or iridium alloy is admirably adapted.
The improvements have further for object to more effectually prevent the trans-
mission of heat from the incandescent working. point to the hydrocarbon vapourizing
chamber which (according to a previous Patent granted to me dated the 22nd day
of December 1888 No. 18757) forms the handle of the instrument. It is usual
to insert between the said vapourizing chamber and the combustion chamber an
insulating block of ebonite or other poor conductor of heat through which passes
the metallic tube by which the mixture of air and combustible vapour is conveyed
to the combustion chamber. This conveying tube has heretofore been in actual
contact with the insulating block which has been liable to become charred by
the heat transmitted to it. With the object of avoiding this defect the bore of the
block is made sufficiently large to give passage to the tube with a clearance or
air space all round it whilst mica washers are interposed between the insulating
block and the flange or head of the tube at the one end and the nut and washer
at the other end so that there will be no metallic contact with the insulating block
and the transmission of heat thereto or to the vapourizing chamber will be pre-
vented. The insulating block may be enclosed with clearance by a metallic
sheath or ferrule screwed to the body portion of the handle.
The improvements relate further to means of dosing the proportion of air in
the mixture of combustible vapour and air and consists in the provision of a.
rotary collar, plug, or disc valve between the hydrocarbon vapourizing chamber

page_text: and the combustion chamber, and of a suitable bye-pass passage or passages under
the control of the valve whereby a portion of the air supplied may if required be
blown directly into the passage leading to the combustion chamber without first
passing through the vapourizing chamber so as to vary the proportion of air in
the mixture of air and hydrocarbon vapour or so that air alone may be injected
into the combustion chamber or be so caused to circulate between the combustion
and vapourizing chambers as to prevent the transmission of heat to the latter.
This improvement also comprises the direct connection of the flexible air tube
from the blowing bulb to a nipple on the collar or plug forming the valve and
situated at a point between the vapourizing chamber which forms, as above men-
tioned, the handle of the instrument and the working point, so that the air tube
will be situated in a position where it will be least liable to interfere with the
freedom of motion of the hand in manipulating the instrument. From the air
inlet port of the valve the air admission tube to the vapourizing chamber rises
within the said chamber from the lower end thereof to a sufficient height to pre-
vent the outflow of hydrocarbon therethrough, the air tube being either concentric
with, or laterally adjacent to, the outlet tube by which the mixture of air and
combustible vapour is conveyed to the combustion chamber and the outlet tube
being provided with a gauze cap to prevent liability of the combustible mixture
firing back into the chamber.
The improvements consist, further, in the provision at the exhaust orifice by
which the products of combustion are emitted from the combustion chamber of
an adjustable jet nozzle by which the blast products of combustion may be directed
away from the operator or may be so directed upon the work or point of application
of the instrument that, the fumes arising from the charring of the substance
operated on may be blown away and prevented from incommoding the visual or
respiratory organs of the operator.
In addition to the above described jet nozzle for the escape of the products of
combustion, I provide the exhaust orifice with a damper by which the orifice is
normally partially closed, the damper being operated by a finger-key so as to
regulate the rate of flow of the combustible vapour through the combustion cham-
ber and admit of a rapid rise or fall in the temperature of the working point being
obtained by the sudden opening or closing of the damper whilst the instrument
is being manipulated.
Dated thin 15th dan T 1007
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
Improvements in Thermo-Cauters and similar Instruments for
Pyrographic and Surgical purposes.
I, WILLIAM HENRY BEACH, of 25, East Castle, Bridgenorth, in the County of
Salop, Veterinary Surgeon, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
My invention relates to thermo-cauters, to thermo-cauter lancets or surgical
knives, and to instruments intended to be used for purposes such as pyrographic
etching, incising or even perforating glass, and other substances, and the improve-
ments have, first, for object to render the working point or cutting edge of the
instrument more durable and to adapt it for working on hard substances such as

page_text: glass, to better adapt it for severing or cutting organic tissues whilst enabling it
to be thoroughly disinfected by being raised to incandescence, or to be used in the
incandescent state both for cutting organic tissues and at same time searing
the blood vessels.
The first improvement consists in the combination with the combustion chamber
made of platinum, of a working point or cutting edge made of iridium, osmi-
iridium, or a platinum alloy of iridium welded to the platinum chamber, the
hardness and non-oxidability of the iridium enabling the working point or cutting
edge to receive and be maintained at a degree of sharpness which is not possible
in the case of platinum owing to its softness. The instrument is thus adapted.
for use as an ordinary lancet or knife without the aid of heat whilst the ability
to raise the working point or cutting edge to a state of incandescence not only
enables the instrument to be thoroughly disinfected after the performance of the
operation but permits of a combined cutting and cauterizing action being obtained.
For etching, incising, perforating, or otherwise working glass by fusion of the
glass, before the working point, a tip of iridium, osmi-iridium, or iridium alloy
is eminently adapted whereas platinum is not suitable owing to its softness and
liability to adhere to the fused particles of glass.
The improvements have further for object to more effectually prevent the
transmission of heat from the incandescent working point to the hydrocarbon
vapourizing chamber which forms the handle of the instrument, and the improve-
ment consists in the mode of connecting an insulating block to the metallic parts
between which it is interposed so as to prevent the transmission of heat to the
vapourizing chamber.
The improvements relate, further, to means of dosing the proportion of air in
the mixture of combustible vapour and air, and consists in the provision of a
rotary collar or plug valve between the hydrocarbon vapourizing chamber and the
combustion chamber, and in the direct connection of the air supply tube thereto
so that a portion of the air may be blown directly into the passage leading to the
combustion chamber without first passing through the vapourizing chamber so
as to enable the proportion of air in the mixture of air and hydrocarbon vapour to
be varied in order to enable the maximum heating effect to be at all times obtained..
The necessity for properly dosing the proportions arises from the fact that at start-
ing, when the benzoline receiver is fully charged, the proportion of benzoline
vapour taken up by the air passing through it will be in excess and the incan-
descence of the working point cannot then be maintained unless the proportion of
air be increased by the direct injection of air as above mentioned.
The improvements consist, lastly, in the provision at the exhaust orifice by
which the products of combustion are emitted from the combustion chamber, of
an adjustable jet nozzle by which the exhaust. products of combustion may be so
directed with regard to the work or point of application of the instrument that
the fumes arising from the charring of the substance operated on, may be carried
away by the induced current and prevented from incommoding the visual or
respiratory organs of the operator.
Reference is to be had to the accompanying drawings forming part of this
specification wherein Figure 1 is an enlarged vertical section of the instrument,
part of the reservoir handle being broken out. Figure 2 is an elevation, omitting
the handle, the valve being turned to another position.. Figure 3 is a correspond-
ing cross-section on line 3-3 Figure 2. Figure 4 is a longitudinal section shewing.
another form of valve. Figures 5 and 6 are sections of the valve on lines 5-5
and 6-6 Figure 4 respectively. Figures 7, 8, and 9 are details of a modified form
of working point.
is the combustion chamber made of platinum and either of the usual cylindro-
conical or tusk-like shape, as shewn in Figures. 1 and 2, or of any other suitable
form, for instance in the form of a lancet or surgical knife, as shewn in Figures 7, 8,
and 9, the chamber being in this case made of flattened form in cross-section so
as to present a cutting edge. The working point or the cutting edge of the

page_text: chamber, as the case may be, is tipped or cased with iridium, osmi-iridium, or a
platinum alloy of iridium made of ^-shaped section so as to embrace the said point
or edge of the chamber a to which it is united by welding in the usual way of
working such metals. This iridium tip is represented at 6 in Figures 1 and 2 as
applied to the point of an instrument for use in the incandescent condition as a
thermo-cauter or for pyrographic etching or otherwise working on glass and other
substances; and it is represented at b in Figures 7 to 9 as forming the keen cutting
edge of a lancet or surgical knife which may either be used cold for scarifying or
cutting organic tissues and be disinfected by being heated to incandescence,
or which may be used in the incandescent state to act with a combined cutting
and searing or burning action.
The combustion chamber a is secured in its holder by a bushing c and a ferrule d
which is screwed to a union piece e. The bush c is tubular to give passage to
the platinum tube f by which the combustible mixture is supplied to the com-
bustion chamber a, this tube projecting into the combustion chamber and its open
end terminating therein nearly at the point in the usual way the said tube being
fixed in position by a flange f¹ at its outer end being tightly clamped between
the screw-plug of e and the bushing c. The union piece e has a central bore to
coincide with the tube f and a screw socket at its base to receive the projecting
end of a screw-threaded tube g which passes centrally through an insulating block h
of ebony or other poor conductor of heat and is fixed therein by end pressure in
such a way as to prevent contact of the tube with the block and the consequent
charring of the latter by heat. The bore of the block is so much larger than the
external diameter of the tube g as to give clearance all round and the tube is
secured centrally therein by a flanged head g¹ at its rear end and a nut g² screwing
on its front end, washers i ¹ of mica being interposed between the ends of the
block 6 and the head and nut so that when the latter is tightened up the tube g
will be secured by end pressure against the block without any direct metallic con-
tact between it and the tube. The block h has an enlarged conical or shouldered
base and it is fixed tightly in a metal cup ; by being screwed therein, as in Figure 4,
or by an external ferrule k of corresponding form screwing on to the cup, as in
Figure 1, and which is prolonged towards the point of the instrument so as to form
a sheath k¹ enclosing the block g, with clearance for an intervening air space, the
only contact with the block being at the base. Between the base of the block g
and the cup j, a disc of wire gauze is interposed to prevent the mixture firing
back. The tubular neck of the cup screws into a chamber m¹ formed in a body
portion m provided with passages for air and for the combustible mixture, con-
trolled by a valve as hereafter described, the body portion being carried by a cap n
screwing on to the tubular vapourizing chamber o which forms the handle of
the instrument and is lined with cotton wick o¹ and partly filled with cotton or
other absorbent for the benzoline. Into this chamber project the tubes
and q,
the former for the admission of air, and the latter for conveying the combustible
mixture to the tube g.
P
For working glass the tool would be provided with a working point or cutting
edges, adapted to scrape the fused glass from the groove or hole as the penetration
of the instrument progresses.
In Figures 1, 2, and 3, the body portion m is in the form of a cone and forms
the seat for a rotary collar valve which is pressed thereon by a spring s confined
between the collar ŕ and the flange of the ferrule k. The collar valve r is provided
with a nipple t to connect with the rubber tube from the pneumatic bulb the bore
of the nipple when the valve is fully open for the admission of air to the vapour-
izing chamber, coinciding with a passage p¹ opening through the side of the plug
and in connection with the air inlet tube p. The outlet tube q is in connection
with a similar passage q¹ opening through the side of the plug, a second passage q²
leading inwards through the plug to the chamber m¹ the two thoroughfares q', q²,
being put into connection through a cavity formed in the collar valve when the
valve is turned to the open position. When the valve is turned to the closed

page_text: position the connections of the bore of the nipple t with the air inlet passage p¹
and of the cavity rl with the thoroughfare q¹ are entirely cut off and the vapour-
izing chamber is completely closed so that loss of fuel by evaporation is prevented.
In addition to the air inlet p¹ there is a second inlet passage u leading through
the body portion m direct to the chamber m³, the orifice u¹, of this passage being.
adjacent to that of the passage p' so that by mining the valve r slightly, the bore t
of the nipple t may connect with both orifices at once, the two orifices p¹ and u¹
being laterally extended by bevelling off towards each other, as shewn at p², u²,
so as to admit of the connection of the bore t¹ with the one being cut off gradually
whilst that with the other is gradually opened in order that the relative propor-
tions of the air admitted to the vapourizing chamber o and that admitted direct
to the chamber m² may be under complete control. The cavity r¹ in the valve is
of sufficient breadth in the circular direction to maintain the connection be-
tween g, q, so long as the bore t¹ remains open to the inlet passage p¹. An index v
on the valve and a corresponding scale on the cap n serve to denote the position
of the valve.
In Figures 4, 5, and 6, the relative forms and positions of the valve r and its
seat are reversed, the valve being a conical plug seated in a corresponding seat
in the body portion m into which it is pressed by a spring v forming the index.
The bore t of the nipple connects with the radial passages p₁ and u, the plug being
circularly grooved or chamfered as at p², u², to allow of simultaneous passage of
air to the inlet tube p and through an orifice u¹ in the valve seat to the chamber m¹
or permit of the passage being wholly or partially shut off in the one or other
direction according as the valve is turned in its seat. The thoroughfare through
the valve plug also terminates in circumferential chamfers or grooves, as shewn
in Figure 6, so as to maintain its connection with the orifices q¹, q³, of the seat so
long as the bore t¹ of the nipple is in connection with the inlet orifice p¹. wis
the usual outlet for the products of combustion, formed in the side of the cham-
ber a near the base, and y is a sheath of platinum fitting about the combustion
chamber a and its ferrule d, being retained in position thereon by an inwardly
projecting spring tongue y¹ formed in one with it, engaging in a circumferential
groove y2 turned in the ferrule so as to permit of the sheath being revolved freely.
The sheath is formed with a circumferential channel z covering the outlet w and
provided with a radial outlet nozzle 2¹ so as to direct the fumes away from the
operator, the rotation of the sheath enabling the outlet z¹ to be adjusted in any
radial direction desired. Where the sheath y is not used, the outlet w may be
formed, as in Figures 7 and 8, by a notch cut at an acute angle to the axis of the
combustion chamber, the direction of the exhaust on leaving the outlet being
determined by the outward bend given to the lip w¹ of the notch.
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 a thermo-instrument of the kind described the combination with the
combustion chamber made of platinum, of a working point or cutting edge com-
posed of iridium, osmi-iridium, or platinum iridium alloy welded to the platinum
chamber as and for the purpose specified.
2. In a thermo-instrument of the kind described the combination with the
combustion chamber made of platinum, of a working point or edge composed of
iridium, osmi-iridium, or platinum iridium alloy of substantially A-form in
section so as to embrace the point or edge of the platinum chamber to which it is
welded as specified.
3. In a thermo-instrument of the kind described the combination with the central
supply tube leading to the combustion chamber having a nut or head on one end
and a nut screwing on the other, of a tubular block of insulating material sur-
rounding the central supply tube the bore of the insulating block being large

page_text: enough to give passage with clearance or air space to the said tube, and of washers
of mica interposed between the ends of the block and the nut and head on the
tube, between which the block is thus secured by endwise pressure only and
without metallic contact substantially as specified.
4. In a thermo-instrument of the kind described the combination with the
insulating block secured about the central supply tube by end pressure and with-
out metallic contact, as specified, of the enclosing sheath adapted to embrace the
shouldered base of the insulating block and secure it by endwise pressure to the
body part of the instrument, the insulating block being interposed between
the central tube and the body part of the instrument so as to prevent transmis-
sion of heat thereto and the sheath being prolonged so as also to shield the block as
described.
5. In a thermo-instrument of the kind described the combination with the
tubular vapourizing chamber forming the handle of the instrument and having
inlet and exit tubes projecting longitudinally therein, of a rotary valve interposed
between the vapourizing chamber and combustion chamber and in direct connection
by a lateral nozzle with the air supply tube, the valve being adapted to control
both the inlet and exit thoroughfares to and from the vapourizing chamber and
likewise a bye-pass thoroughfare giving direct admission for air without passing
through the vapourizing chamber, so as to enable the proportion of air to be dosed
and the supply of mixture or air to the combustion chamber to be efficiently
controlled as specified.
6. The herein described thermo-instrument having interposed between the
vapourizing chamber forming the handle of the instrument and the combustion
chamber rigidly attached to the handle, a rotary collar or a rotary plug valve con-
structed substantially as described and illustrated in the drawings, the valve being
adapted to control both the inflow and outflow thoroughfares of the vapourizing
chamber, and likewise a direct air inlet bye-pass to the combustion chamber supply
tube as specified.
7. The herein described thermo-instrument provided with a rotary collar or
rotary plug valve constructed and operating as described and interposed between
the vapourizing chamber forming the handle of the instrument and the combustion
chamber, and rigidly attached to the said handle and having connected directly to
the collar or plug of the valve the flexible connecting tube from the insufflating
bulb as described.
8. In a thermo-instrument, of the kind described the combination with the
combustion chamber having a lateral orifice for the escape of the products of com-
bustion, of an enclosing sheath connected rotatably with the combustion chamber
and its ferrule and having a circumferential channel into which the discharge
orifice opens and a radial discharge nozzle for directing the gaseous products away
from the operator as described.
.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.