IMPROVEMENTS IN THE CONSTRUCTION OF SCREW-KEYS OR SPANNERS, PARTLY APPLICABLE AS RATCHET BRACES OR RATCHET LEVERS FOR SCREW JACKS."
Year: 1880

page_text: LETTERS PATENT to William Thomson, of Glasgow, in the County of
Lanark, North Britain, Engineer, for an Invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF SCREW-KEYS OR SPANNERS, PARTLY APPLICABLE AS
RATCHET BRACES OR RATCHET LEVERS FOR SCREW JACKS."
PROVISIONAL SPECIFICATION left by the said William Thomson at the
Office of the Commissioners of Patents on the 18th November 1880.
WILLIAM THOMSON, of Glasgow, in the County of Lanark, North Britain,
Engineer. "IMPROVEMENTS IN THE CONSTRUCTION OF SCREW-KEYS OR SPANNERS,
PARTLY APPLICABLE AS RATCHET BRACES OR RATCHET LEVERS FOR SCREW JACKS."
This Invention has reference to certain improvements in the construction of
screw keys or spanners for tightening and slackening screw nuts and bolts and
such like screws, or as ratchet braces for the turning of drills or taps for screwing,
or as ratchet levers for screw jacks, whereby such tools are made much more
efficient and more universally applicable and suitable for working in confined
places, besides being stronger and inore durable than ordinary screw keys or tools
of this description.
And the nature and novelty of the Invention consist particularly in forming the
screw key or tool in two main parts, namely, first, the head gripping jaws or box
part which fits the nut or polygonal part of the screw to be turned; and, second,
the arm or lever which turns the former. Both parts are connected together by a
swivel joint near the back of the former or gab gripping part, or exactly over the
centre of the said gripping part or screw to be turned, and so as to be able to be
set and secured whilst acting at any angle in relation to its lever in the plane of
motion of the key. That is under one modification, in which the gab is jointed
to the lever at a short distance behind the gab or jaws by a joint pin through an
eye or boss in both the jaw and inner end of the lever, the gripping gab is capable
of being set in line with the lever, and worked as a straight screw key, or turned
one fourth of a circle to the right or the left with the jaws against the lever; or it
may be turned to any intermediate angle between these, and locked in any of these

page_text: positions by a semi-circular sector or segment formed on one side and back of the
jaw piece, with U shaped or other notches formed in it so as to oscillate on one
side of the lever, past or under a locking lever or bolt hinged or it might be sliding
on the lever, actuated to enter the notches by a spiral or other spring to lock the
head or gab part, and disengaged by the thumb acting on a plate or presser over
behind the locker against the power of the spring. This modification or improved
screw key may be formed to have various heads shipped on to the lever, with
different sized jaws to suit different sizes of nuts or screws; or otherwise one of
the jaws may be made movable and slide by a slot and feather in the back of the
head, turned and secured by a screw or nut or other equivalent as other movable
jaw screw keys arc.
A further improvement consists in forming the heads with the gab or socket
parts circular, as a swivelling boss turned on a centre exactly over or in the axis
of the nut or bolt to be turned, under and in an eye on the inner end or head of
the lever, having the locking notches formed all round the upper outer edge of this
boss so as to be locked by the hinged or sliding bolt in any angular position, and
turned completely round in either direction as a ratchet screw key, to work at any
desired angle to the largest or smallest extent at a time it is possible to get the
lever turned in the position. In this modification the centre of the turning boss
may be made hollow so as to allow the bolts or screws when long of the nuts
being tightened, to pass up through this and the eye of the lever.
In some cases the inner end of the head or eye of the lever may be fitted with
a loose revolving eye, and formed with a square inner socket to receive a square or
other polygonal stem formed on the upper end of the swivelling boss (preferably in
the axis of its jaws or sockets) for gripping the nuts, so that these bosses may be
made changeable, and of sizes to suit different sized nuts and screws, either open
at the one side or as close box keys, strenthened by a horizontal web on the top
and edge rim. And these changeable bosses may be formed with an annular recess
above the polygonal stem and the eye of the lever or other equivalent secured to
the lever by a small segmental catch or lever on its upper face turned or swivelled
into the groove of the boss stem.
Another modification or development of the last described improved screw key,
wrench, or spanner, for making it act also as a right and left turning ratchet brace
or lever, consists in forming the revolving boss (having the square or polygonal eye
or socket through it for receiving the stem of the screwing heads, or the drills or
screw taps to be turned) with nearly right angled notches, or double or reversible
acting notched teeth round the outer central part of its periphery, and fitting and
enclosing this ratchet boss within a proper fitting and bearing eye or recess in the
thick eye or head of the wrench or band lever. And instead of the single hinged
or sliding spring locker of the former arrangement, two (or right and left locking
or turning) small bell crank pawl levers are fitted in enclosing recesses with
oscillating eyes in the thick shank or wrist part of the hand lever close to the
ratchet toothed boss. All so that the longitudinal pawl arms of each bell crank
takes into the ratchet teeth of the boss on opposite sides of the centre line of the
hand lever by the pressure of a conoidal, spiral, or other simple spring between
them. While the lateral arms of these bell crank pawl levers are turned towards
each other, and rest at a little distance apart on a recessed segmental part of the
oscillating boss of a small engaging and disengaging cam thumb lever, the acting
or pressing arm of which passes out through a small slot below a thin plate screwed
down over all the said working ratchet and pawl parts, retaining and protecting
them within the head of the hand lever. When the cam thumb lever is placed
centrally in a line with the hand lever both pawls are in action, so as to lock the
ratchet socket boss in the hand lever, so that it must turn in either direction
therewith, as the screw keys or spanners of the former arrangements capable of
being set to any angular position in relation to the hand lever, and turned to any
desired distance with it; but when the cam thumb lever is turned a little to the
right or left respectively, it takes the one pawl lever out of the teeth of the ratchet

page_text: boss, and leaves the other in gear, so that it can act either as a right or left hand
turning screw key or spanner or as a boring or screwing ratchet brace. This
arrangement may be worked with one ratchet pawl and a locker, as in the former
modification. And it will be understood that the gripping jaws of the turning
socket heads or bosses might be formed with a movable contracting plate inside,
actuated and secured by a pinching screw or screw cutter, so as to contract the
space within the gripping jaws, and make each portable screw boss suitable for two
or three sizes of nuts.
For small and medium sized screw keys or ratchet braces and tools all the parts
would preferably be made of cast malleable steel; and for the larger sizes the
gripping bosses, joint heads, eyes, and all the locking, ratchet, and other working
parts subjected to wear would also preferably be made of cast or welded steel and
tempered; but these might be made also of malleable cast iron, or mild steel, or
of wrought iron, with the wearing parts case-hardened or tempered when faced
with steel.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Thomson in the Great Seal Patent Office on the 17th May
1881.
WILLIAM THOMSON, of Glasgow, in the County of Lanark, North Britain,
Engineer. "IMPROVEMENTS IN THE CONSTRUCTION OF SCREW KEYS OR SPANNERS,
PARTLY APPLICABLE AS RATCHET BRACES OR RATCHET LEVERS FOR SCREW JACKS."
My said Invention has reference to certain improvements in the construction of
screw keys or spanners for tightening and slackening screw nuts and bolts, and such
like screws, or as ratchet braces for the turning of drills or taps for screwing, or as
ratchet levers for screw jacks, whereby such tools are made much more efficient and
more universally applicable and suitable for working in confined places.
And in order that my said Invention, and the manner in which the same is to
formed may be properly understood, I have for that purpose hereunto appended a
Sheet of explanatory Drawings representing various modifications of my improved
tools, which I shall now proceed to describe. In these Drawings the same reference
letters are used to mark the same or like parts in the different Figures.
Figure 1 is a plan and Figure 2 is an edge view showing a modification of my
improved screw keys or spanners, in which the jointed or swivelling gripping jaw
is forked at the joint part, or formed with an eye to receive the handle or lever
which is jointed to it by a pin. Figures 2 and 3 are a plan and edge view showing
a modification in which the jointed gripping part of the screw key is fitted between
the forked ends or an eye formed on the end of the handle or lever. Figures 5
and 6 are a plan and edge view, partly in section, of a modified construction of the
improved screw key, in which the swivelling gripping part is formed with a boss
fitting into an eye or socket in the inner end of the hand lever.
Figures 7 and 8 are a side elevation and plan of another modification of my
improved screw keys in which the gripping head is formed with a hollow boss
entered in an eye in the inner end of the hand lever, so as to form the swivelling
centre for the gripping head. Figures 9 and 10 are a plan and side clevation,
with the handle partly broken away, showing a modified form of key, in which
the gripping jaws are fixed by a pin to a revolving or swivelling ratchet eye piece
fitted in the inner end of the hand lever, and so fitted that by the withdrawal of
the centre pin the gripping jaw or head piece can be replaced by another to suit
different sizes of nuts to be acted on. Figures 11 and 12 are an elevation and
inverted plan, showing a gripping head piece suitable for fitting in connection with
the screw key shown in Figures 9 and 10, and Figures 13 and 14 are a sectional
elevation and plan of a screw key or wrench similar to that shown in Figures 9
and 10, but fitted with a drill socket piece to act as a ratchet brace for turning
drills for boring holes.
Referring to these Drawings, the Invention consists particularly in forming the
screw key or tool in two main parts, namely, first, the head gripping jaws or box
part A, A, which fits the nut or polygonal part of the screw to be turned, and,
second, the arm or lever B, B1, which turns the former. Both parts are connected
together by a swivel joint a near the back of the former or gab gripping part A, as
in Figures 1 to 6, and 9, 10, or exactly over the centre of the said gripping part
or screw to be turned, as in Figures 7, 8, 11, and 12, and so as to be able to be set
and secured whilst acting at any angle in relation to its lever in the plane of
motion of the key. That is, under the modifications, Figures 1 to 6, in which the
gab A is jointed to the lever at a short distance behind the gab or jaws by a joint
pin a through an eye or boss A' or B¹ in both the jaw and inner end of the
lever B; the gripping gab A is capable of being set in line with the lever B and
worked as a straight screw key, or turned one fourth of a circle to the right or the

page_text: left with the jaws A against the lever B; or it may be turned to any intermediate
angle between these, as shown in these Figures 1 to 6, and locked in any of these
positions by a semi-circular sector or segment A' formed on one side and back of
the jaw piece A with U shaped or other notches A2 formed in it, so as to oscillate
on one side of the lever B, past or under a locking lever or bolt C, entered between
feathers formed on the lever, and hinged by a pin c passing through these; or it
might be sliding on the lever B, actuated to enter the notches A by a spiral or
other spring c to lock the head or gab part A, and disengaged by the thumb
acting on a plate or presser C' over behind the locker C against the power of the
spring c. This improved screw-key may be formed to have various heads A, A',
shipped onto the lever B, with different sized jaws A³ to suit different sizes of nuts
or screws; or otherwise one of the jaws may be made movable and slide by a slot
and feather in the back of the head, turned and secured by a screw, or nut, or
other equivalent, as other movable jaw screw keys are.
In the modification shown in Figures 5 and 6 the gripping jaws A are formed
with a central boss A fitting into an eye B2 at the inner end B' of the lever B,
and it is held therein by expanding the inner end of the boss after insertion, as
shown at a. The seginental part A' with the notches A for fixing the gripping
jaws at the desired angle are formed on this boss A', and fit in the socket part B
formed within the eye B¹. In the modification of screw-key shown in Figures 7
and 8 the gripping head A, A, is formed with the gab or socket parts circular, as
a swivelling boss or head turned on a centre, exactly over or in the axis of the nut
or bolt to be turned, under and in an eye B' on the inner end or head of the lever.
The locking notches A2 are formed all round the upper outer edge A' of this boss A
so as to be locked by the hinged or sliding bolt C in any angular position, and
turned completely round in either direction as a ratchet screw key, to work at any
desired angle to the largest or smallest extent at a time that it is possible to get
the lever B turned in the position. In this modification the centre of the turning
boss A may be made hollow at a² so as to allow the bolts or screws of the nuts
being tightened when long to pass up through this eye a² and the eye B' of the
lever B.
In some cases, as in the examples shown in Figures 9 to 14, the inner end of the
head or eye B' of the lever B may be fitted with a loose revolving eye D, as shown
particularly in Figure 14, and formed with a square inner socket d to receive a
square or other polygonal stem a³, Figure 11, formed on the upper end of the
swivelling boss A (preferably in the axis of its jaws or sockets) for gripping the
nuts, so that such bosses A, as those shown in Figures 9, 10, and 11, 12, may be
made changeable, and of sizes to suit different sized nuts and screws, and be either
open at the one side as shown, or formed as close box keys, strengthened if necessary
by a horizontul web A' on the top and edge rim. These changeable bosses may be
formed with an annular recess as above the polygonal stem a³ and the eye D of
the lever B or other equivalent secured by a small segmental catch on its upper
face, or by a pin d', as shown in Figures 11 and 12. In the modification of screw
key described in reference to Figures 9 to 12, the gripping jaws or head A, A¹, may
be held or secured in the desired angled position by means of a hinged or sliding
lever on the hand lever B, fitting into notches in the segmental part A¹ of the
gripping head, as in the modifications previously described, but as is particularly
shown in Figures 13 and 14, in this modification the locking arrangement is more
especially adapted for using the spanner as a ratchet brace, in which the gripping
hend is only locked for turning in the one direction, while in the return movement
the locking lever C slips over the ratchet teeth D' on the eye D. The locking
lever or bolt C is jointed on a pin or stud c in the inner end of the lever B, and the
bolt C is pressed against the ratchet teeth D¹ by means of a small spiral or other
spring c which yields when the ratchet teeth press back the bolt C, when the
lever B is turned in the one direction round the ratchet as a centre, but when the
action is reversed to turn the ratchet and drill round, one of the ratchet teeth bears
on the extreme end of the bolt C, and the ratchet eye D is thereby held so that it

page_text: turns with the lever B. A small thumb lever 3 is fitted on the pin c of the
bolt C, but outside the lover head B', by means of which the bolt C can be pressed
back against the spring e' to prevent it acting on the teeth of the ratchet and thus
enable the lever B or ratchet and drill to be turned freely round. This ratchet cye
pieco D is covered and secured in its socket B at the inner end of the lever B
by means of a cap or plato B3 secured to the lever head B' by a screw b' or
otherwise.
The ratchet screw key or spanner illustrated in Figures 13 and 14 is shown fitted
with a drill stock or socket E with an extending screw E and flutted centre nut E³,
the latter being turned by hand as usual to deepen the hole while drilling or
boring. A square or other shaped socket may be formed in the eye D, or in tho
central swivelling eyes or bosses of any of the modifications of screw keys or
spanners described to enable them to be fitted on screw taps and used as spanners,
wrenches, or dwangs in tapping holes.
In the Provisional Specification of my Invention described a modification of
double ratchet screw key with bell-crank levers taking into the ratchet teeth of a
boss in the end of the handle or lever to enable the screw key to be turned to act
in either direction, but it will be evident that the ratchet screw key shown and
described in reference to Figures 13 and 14 can be inverted to enable it to act
either in the one direction or the other, and that if desired the arrangement of
locking lever C, shown in Figure 14, could be duplicated to act on either side of
the ratchet. I do not therefore propose to use nor do I claim the said double
ratchet arrangement described in my Provisional Specification.
For small and medium sized screw keys or ratchet braces and tools all the parts
would preferably be made of cast malleable steel, and for the larger sizes the
gripping bosses, joint heads, eyes, and all the locking, ratchet, and other working
parts subjected to wear would also preferably be made of cast or welded steel and
tempered, but these might be made also of malleable cast-iron or mild steel, or
of wrought iron with the wearing parts case hardened or tempered when faced with
steel.
Having thus particularly described the nature of my said Invention, and the
manner of performing the same, I have to state that I do not confine myself to the
precise details herein described or delineated, but what I consider novel and original,
and therefore claim as the Invention secured to me by the herein-before in part
recited Letters Patent is,-
The construction and arrangement or combination of the parts of screw keys,
spanners, ratchet braces, and tapping wrenches, fitted with swivelling ratchet
gripping heads or jaws or retaining eyes, capable of being fixed by a locking lever
at different angular positions in relation to the actuating handle or lever, and of
being fitted with different heads or gripping jaws to suit various sizes of nuts to be
screwed or turned, substantially as herein described in reference to and shown in
the accompanying Drawings.
In witness whereof, the said William Thomson, have hereunto set my hand
and seal, this Sixteenth day of May, in the year of our Lord One
thousand eight hundred and eighty one.
Witness,
WALLACE FAIRWEATHER, C.E.,
96, Buchanan Street,
Glasgow.
WILLIAM THOMSON. (L.S.)