Improvements in Forceps or like Instruments.
Year: 1897

page_text: Date of Application, 12th Aug., 1897
Complete Specification Left, 18th Apr., 1898-Accepted, 11th June, 1898
Improvements in Forceps or like Instruments.
I, EUGÈNE LOUIS DOYEN, M.D., of 5, Rue Cotta, Reims (Marne), France, do hereby
declare the nature of this invention to be as follows :-
This invention relates to improvements in forceps, or like instruments, whereby I
am enabled to obtain a progressive pressure, and comprises an additional or
supplementary lever adapted to act on one of the handles, in connection with a
spring controlled movable hook, so as to multiply the pressure exerted on the jaws;
and by a movable rack adapted to be retained by a fixed catch or detent for prevent-
ing the jaws becoming unlocked when developing the pressure up to its maximum.
In carrying out my invention, I pivot to one of the handles of the forceps (or like
instrument), at a suitable point thereon, a loose or movable lever provided with a
bow for the insertion of the thumb or finger, and with a notch at its pivotted end
into which the movable hook enters. This pivotted lever is so arranged that it may
lie against the handle or leg to which it is pivotted, or be turned on its pivot when
to engage, by its notch, the movable hook on the other handle or leg of the
instrument.
Dated this 12th day of August 1897.
Improvements in Forceps or like Instruments.
1, EUGÈNE LOUIS DOYEN, M.D., of 5, Rue Cotta, Reims (Marne), France, do
hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying drawings and to the letters
and figures marked thereon, that is to say :-
This invention relates to improvements in forceps, or like instruments, whereby I
am enabled to obtain a progressive pressure, and comprises an additional or supple-
mentary lever adapted to act on one of the handles, in connection with a spring
controlled movable hook, so as to multiply the pressure exerted on the jaws; and
by a movable rack adapted to be retained by a fixed catch or detent for preventing"
the jaws becoming unlocked, when developing the pressure up to its maximum,

page_text: And in order that my invention may be readily understood, I will describe the
same fully with reference to the annexed drawings, in which :
:
Fig. 1 is an elevation of my improved instrument, and
Fig. 2 a section thereof taken on the line X Y of Figure 1.
My improved forceps is arranged like ordinary bow forceps used in surgery, but
it presents this peculiarity that one of its legs A is provided with a movable hook C
arranged to pivot in a slot about an axis 1, while the other leg B is provided with a
lever handle D terminating in a bow, and working in a slot about an axis 2.
On the bow of the lever D is fixed a stud 4 adapted to engage a catch 3, pivoted
on the leg B, whereby the lever handle D can be rendered immovable on the leg B.
As shewn in Fig. 2, this leg carries at its lower end a fixed catch E, while the leg A
carries a pivoted rack 5 having inwardly turned teeth. By bringing the rack into
the position against the stop 9, engagement is effected between it and the catch E,
so that the legs A and B are thereby connected and are unable to move further
outwards. It is however possible, on account of the head of the catch being
inclined, to bring the legs nearer together as may be necessary. During this
movement the catch E slides gradually over the teeth of the rack, which latter, for
this purpose, is made somewhat flexible.
The leg A is provided with a blade spring 6 which compels the nose of the
hook C to remain in contact with a cam head 8 on the pivoted ond of the lever D.
The manipulation of the instrument is as follows:-
On commencing, the lever D is brought against the leg B and is held fast by the
pivoted catch 3. The forceps can then be handled like ordinary ones, the legs of
which turn about the axis 7. When the vascular tissues are seized by the jaws, the
two legs are prevented from separation by engaging the rack 5. Then on releasing
the catch 3, so as to disengage the lever D, this latter is turned until the hook C
enters a notch in the cam head.
If the instrument be now held by the hand and the bows A and D brought
together, the new leverage coming into play for multiplying the power is such as to
produce the complete crushing of the tissues.
A peculiarity of this forceps is that the multiplication of the power increases
progressively up to its maximum. When the lever D is in its extreme angular
position, determined by its engagement with the hook C, the leverage (being
measured by its projection on the leg B) increases progressively in length at the
rate at which it is brought closer to the leg B. Further, in the same extreme
angular position the point of engagement between the hook and the cam-head is
about midway of the leg B; in proportion as pressure is exerted on the bow of the
lever D, the projection of this point of engagement, relatively to the leg B, decreases,
the result of which is that, with the increased pressure, the ratio existing between
the cam-head and the lever D increases, and consequently the pressure exerted is
progressive.
Besides this, the gradual closing of the jaws brings about the successive
engagement of the catch 3 with the teeth of the rack.
At each fresh engagement, the tightening strain is exerted on this catch so that
the hook C, lever D, and its cam-head sustain no strain. It is thus possible to
proceed by successive steps until the final operation is reached.
In the forceps
shown, by way of example, in the annexed drawing, the legs A and B are 16 c./m.
long, while the jaws are only 8 c./m. this gives at the extreme end of these latter
a leverage of 2 when using the instrument as an ordinary forceps.
Again, the axis 1 is at a distance of 8 c./m. from the axis 7 and the leverage
between the lever D and its camhead is 10. The result is that during the second
phase of the operation the tightening strain increases progressively up to its
maximum in which the gripping energy is twenty times greater than the power
exerted by the operator.
The jaws of this instrument may be arranged differently according to the use for
which they may be required, be it for surgery, for extemporaneous crushing of

page_text: vascular tissues, or for delicate mechanical purposes. Cutting nippers, scissors,
or shears, or analogous tools, may be arranged in this manner.
Care must be taken not to grip, between the flat jaws, bodies that cannot be
crushed, such as wood for example, as this may cause the instrument to break as
the power obtained is considerable.
The construction of this instrument is very strong, all shoulders or edges
necessitated by the junction of the legs, being carefully round off so as to avoid
any weak points in the construction. The instrument is easily taken to pieces; the
two axes,
and 2, are slightly tapered pins which can be readily removed. As
regards the legs, they are simply fitted one onto the other at their point of
articulation. The axis 7 is fixed to the leg B and enters a suitable mortice in the
other leg A.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A forceps, or like instrument, in which a progressive pressure is
obtained by means of a supplementary lever D, adapted to act on the leg A through
the intervention of a camhead and a hook C so as to multiply the power exerted
on the jaws, and by a movable rack having a fixed catch for enabling this power to
be developed up to its maximum without the jaws opening, substantially as
described.
2. The improved forceps substantially as herein before described and shown in
the annexed drawings.
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 5A, Market Street, Nottingham,
Agent for the Applicant.