IMPROVE- MENTS IN ADJUSTABLE WRENCHES
Year: 1868

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery
Lane, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN ADJUSTABLE WRENCHES."-A communication from abroad
by Pierre Augustin Samuel, Civil Engineer, of 29, Boulevart St.
Martin, Paris.
Sealed the 24th July 1868, and dated the 30th January 1868.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 30th January 1868.
I, ALEXANDER MELVILLE CLARK, of 33, Chancery Lane, in the
County of Middlesex, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN ADJUSTABLE WRENCHES," to be as follows:-
This Invention relates to improvements in adjustable or universal
screw wrenches especially applicable for screwing up pipes and other
cylindrical parts, while they may also be used for tightening uuts and
other parts of polygonal form.
The improvements consist in the employment of a double cam fixed
in the head of the wrench, and acting on the ends of levers exerting a
self-acting gripping action which increases in proportion to the tractive
force imparted to the handle of the wrench.
[PS1

page_text: I have above mentioned that the double cam acting on the ends of
the gripping levers is an independent part rigidly attached to the head
of the wrench, but it will be understood that said double cam may
be formed on the handle of the wrench. These improved adjustable
wrenches being capable of powerfully gripping cylindrical surfaces
without slipping will permit of the general employment of round nuts
with either smooth or roughened surfaces, which has hitherto been
practically unattainable. Another advantage of these improved wrenches
is that they act on a very small surface and may thus be used in very
limited spaces.
This Invention is illustrated in the accompanying Diawing, which
shows two arrangements of the improved adjustable wrench applicable
for screwing up pipes, nuts, and other cylindrical parts.
Figure 1 shows a front view of one arrangement of the wrench;
Figure 2 a side view of the same, Figure 3 shows separately one of
the lugs to which the adjustable jaws are jointed; Figure 4 shows a
section on a larger scale of the head of the wrench, showing the way
in which the gripping jaws are operated by the cams; lastly, Figure 5
shows a sectional face view of a wrench with the double can formed on
the handle instead or being separately attached thereto. The same
letters serve for the several Figures.
a, lever handle of the wrench having a knob at one end and provided
with a head b; c, double cam rigidly fixed to head 6 by means of
rivets d, on either side of which cam is pivotted a jointed lug f, seen
separately in Figure 3; g, gripping jaws jointed at h to lugs f; these
Jaws are serrated on the inside in a contiary direction to that of the
tightening motion, and are adjustable by the aid of the double cam c.
I should here observe that the double cam is provided with a recess on
either side for receiving the ends of the gripping jaws when in then
widest position apart in order to permit of the removal of the wrench
from the cylindrical part they embrace.
The Invention thus consists in improvements in adjustable wrenches
for screwing and unscrewing pipes, nuts, and other circular parts, the
chief features consisting in the adjustable gripping jaws acted on by
a double cam or eccentric, all as herein-before described and represented
in the Drawings.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal
Patent Office on the 25th July 1868.
filed by the said Alexander Melvine
Patent Office on the 25th July 1868.
Clark
LUC
VICAL
334
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of January, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alexander Melville Clark, Hei special
licence, that I, the said Alexander Melville Clark, my executors,
administrators, and assigns, or such others as I, the said Alexander
Melville Clark, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time, and at all
times thereafter during the term therem expressed, should and lawfully
might use, make, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN ADJUSTABLE WRENCHES," a communi-
cation to me from abroad by Pierre Augustin Samuel, Civil Engineer,
of 29, Boulevait St. Martin, Paris, upon the condition (amongst others)
that 1, the said Alexander Melville Clark, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of
their hands and seals, 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 Alexander Melville Clark, do
hereby declare the nature of the said 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 Sheet of
Diawings hereunto annexed, and to the letters and figures marked
thereon (that is to say):-
This Invention relates to improvements in adjustable or universal
screw wrenches especially applicable for screwing up and unscrewing

page_text: Pipes and other cylindrical parts, while they may also be used for
tightening bolts, nuts, and other parts of polygonal form.
The improvements consist in the employment of a double cam fixed
in the head of the wrench and acting on the ends of levers exerting a
self-acting gripping action which increases in proportion to the tractive
force applied to the handle of the wrench.
I have above mentioned that the double cam acting on the ends of
the gripping levers or jaws is an independent part rigidly attached to
the head of the wrench, but it will be understood that said double
cam may be also formed on the handle of the wrench. These improved
adjustable wrenches being capable of powerfully gripping cylindrical
surfaces without slipping will permut of the general employment of
1ound nuts with either smooth or roughened surfaces, which has hitherto
been practically unattainable. Another advantage of these improved
wrenches is that they act in the manner of a ratchet spanner on a
very small portion of the surface at a time, and may thus be used in
corners and limited spaces. This improved wrench may also be used
for holding and turning a dill or screw tap when drilling holes or
cutting screw threads.
This Invention is illustrated in the accompanying Drawings, which
show two arrangements of the improved adjustable wrench applicable
for screwing up pipes, nuts, and other parts of cylindrical or other form,
as also some modifications of the same.
Figure shows a front view of one arrangement of the wrench, and
Figure 2 a side view of same, Figure 3 shows separately one of the
lugs to which the adjustable jaws are jointed; Figure 4 shows a section
on a larger scale of the head of the wrench, showing the way in which
the gripping jaws are operated by the cams; lastly, Figure shows
a sectional face view of a wrench with the double cam formed on the
handle instead of being separately attached thereto. The same letters
serve for the several Figures.
a, lever handle of the wrench having a knob at one end and provided
with a head b; c, double cam rigidly fixed to head b by means of
ivets d, on either side of which cam is pivotted a jointed lug piece /,
seen separately in Figure 3; g, gripping jaws jointed at h to lugs f.
These joints are serrated on the inside in a contrary direction to that
of the tightening motion, and are adjustable by the aid of the
double cam c. I should here observe that the double cam is provided

page_text: with a recess on either side for receiving the ends of the gripping
jaws when in the widest position apart in order to permit of the removal
of the wrench from the cylindrical part they embrace.
I further modify the arrangement of the wrench with regard, 1st,
to the double cam c for operating the jaws.
In order to ensure the
proper and uniform action of said jaws I determine the curve of
the cam by describing a series of circles intersected by radial lines
of equal number to said circles, as shown by the Diagram Figure 9,
whereby the curve to be given to the cam is readily obtained.
2ndly. Instead of mounting the jointed lugs or ears f on the head
of the wrench in the manner before described I apply them on the
outside of the same.
3rdly. I fix the double cam c to the head b of the wrench by
means of two pins or rivets d.
4thly. I may modify the shape of the ends of the jaws g so that
when they are opened out to the full extent and embrace the cylindrical
surface to be operated on they shall not project beyond the axial line
of the same, as shown in Figure 9 This arrangement is intended to
facilitate the disconnection of the wrench after using, as it is evident
that as the jaws only embrace one half of the cylindrical surface the
slightest movement of the wrench in the backward direction is sufficient
to detach it therefrom, and its action is thereby much facilitated.
The abovo wrench, which is represented in Figures 6, 7, and 8, is
suited for screwing or unscrewing all cylindrical parts, the diameter or
axial line of which is equal to or of the same dimensions as the space
between the jaws when they are opened to the full extent, while it is
evident that they may be used to screw and unscrew cylindrical parts
of smaller diameter; in this case, however, the jaws would project
beyond the axial line.
Figure 6 shows a front view of the wrench having the improvements
above mentioned applied; Figure 7 is a horizontal section of same
with the upper jointed cheek plate removed so as to show the action
of the double cam on the gripping jaws; Figure 8 is a transverse
section of the wrench on line 1, 2, Figure 7, while Figure 9 shows
one of the jaws g detached as bearing on the extreme diameter of
the cylindrical part i; this Figure also shows a diagram of double
cam c

page_text: Having described the nature of this Invention, and the manner of
performing the same, 1 declare that what I claim as the Invention
to be protected by the herein-before in part recited Letters Patent
is,-
First. The improvements in adjustable wrenches for screwing and
unscrewing pipes, nuts, and other parts of circular, oval, or polygonal
form, the chief features consisting in the adjustable gripping jaws acted
on by a double cam or eccentric, all as herein-before described and
represented in the Diawings.
Secondly. I claim the modifications in the above wrenches described
and illustrated in Figures 6, 7, 8, and 9 of the Drawings annexed.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Twenty-fifth day of July,
in the year of our Lord One thousand eight hundred and sixty-
eight