Improvements in Adjustable Screw-keys or Wrenches.
Year: 1898

page_text: Date of Application, 5th Nov., 1898-Accepted, 17th Dec., 1898
COMPLETE SPECIFICATION.
Improvements in Adjustable Screw-keys or Wrenches.
I, HEINRICH FRIEDRICH LOOS, of 3, Petzoldstrasse, Nuremberg, in the Empire
of Germany, Metal Goods Maker, 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: -
This invention has for its object an improved screw key or wrench for gripping
parallel-sided or similarly shaped articles such for instance as hexagonal or
square headed screw nuts or bolts for cycle constituents.
In the accompanying drawings
Figure 1 is a vertical section,
Figure 2 an elevation,
Figure 3 a cross section,
Figure 4 a top view, and
Figure 5 a detail of one form of construction, whilst
Figures 6 to 11 show another form of construction and
Figures 12 to 17 a third modification.
As may be seen in Figure 1 the essential constituent of the whole arrangement
consists of a pair of jaws 1 which are also peculiar to the two other forms of
construction. The two parts a a of this pair of jaws have a common pivot 3
(Figures 1 to 3) which is firmly connected with a sheath or casing 2 within
which the ends 6 of the jaws are located. In the first shown form of construction
of this key or wrench, this pivot has a spring 4 wound round it which bears
with both ends c and d against the two jaws and consequently causes them to
have a constant tendency to open.
Usually this tendency is counteracted by a tapering piece k being pressed
like a wedge between the ends b of the jaws. This piece k is held in its actual
position by a screwed spindle 5, the nut of which is located in an intermediate
wall w of the sheath 2. The head end e of this screw has a long slot in which
is engaged a pin 6 which is firmly connected with a cylindrical hollow body or
the like 7 and serves on the rotation of the latter by the wings f to produce the
rotation of the spindle 5. The hollow body 7 which is provided with an annular
groove is prevented by means of transverse pins 8 engaging therein from being
displaced in the sheath 2 but not from being rotated.
In Figure 1 the screw 5 is shown in its lowest position when the spring 4 is
compressed and the jaws entirely closed. Figure 5 shows another position in
which the ends of the jaws stand a certain distance apart.
As may easily be seen, the spring 4 has merely for its object to produce the
rough adjustment of the ends a of the jaws, whilst the finer adjustment and
more especially the clamping or gripping of the object to be gripped is effected
by means of the screw 5.
The handles serve for effecting the rotation of the article (screw nut or the
like) which is to be turned after having been gripped.
The second form of construction of this improved screw key, as may be seen

page_text: in Figures 6 to 11, differs from the one hereinbefore described by the movement
of the jaws taking place by means of two links k pivotally attached to the screw
spindle 5 and forming toggles. The hollow, body 7 which in a similar manner
to the one shown in Figure 1 is revoluble in the sheath 2 and prevented from
longitudinal displacement, here again serves for operating the finer adjustment
of the mouth of the screw key by means of the screw 5. The nut m of this
screw 5 (which latter has only a longitudinal movement and does not rotate) is
for this object temporarily connected with the body 7. This body 7 has two
notches opqrst, Figure 9 placed opposite one another and intended for
receiving two pins z on the nut m (Figures 10 and 11). "The nut m is adjustable
downwards inside the casing 8 when the pins z come to rest on the surfaces o Ρ
upon the cylindrical body 7 being turned to the left, but on the other hand is
prevented moving when these pins encounter the surfaces q r on the body 7 being
turned to the right. The longitudinal displacement of the nut m, so far as it is
rendered possible by the position of the body 7 is produced by pressure on the
cap 9, thus compressing the spring 10 and causing in the compressed position
of the spring shown in Figure 7, the opening of the mouth of the jaws. This
closes again as far as the object gripped allows, as soon as the pressure on the
cap 9 ceases.
By turning the body 7 to the right the nut m is screwed upwards sufficiently
to allow the pins z to encounter the surfaces p q and the surfaces gr to act on the
pins z, the nut m sharing in the rotation of the sheath and a second spring 11
being compressed which has for object simply to prevent the nut moving loosely.
The nut m is then firmly connected with the body 7 and moves the screw 5
upwards when further turned to the right, thus firmly closing the jaws by means
of the toggles k.
The third form of construction of this improved adjustable screw key or
wrench, shown in Figures 12 to 17 is merely a less complete form of the one
last described, the toggle movement of the mouth of the jaws being replaced by
a movement consisting of a displacement or adjustment in a straight line of
inclined surfaces x x and y y of the jaws pivoted at b on the screw 5, in combina-
tion with a sliding of a transverse pin 3. The cylindrical body 7, similarly to
the one shown in Figure 6, is also provided with notches o p q r s t in larger
number so as to allow of the closing of the mouth of the wrench with greater
rapidity than in the previous case.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. An adjustable screw key or wrench characterized by the combination of
tongs like jaws partially enclosed by a sheath, and a cylindrical body or the
like revolubly mounted at the other end of the first sheath but immovable
longitudinally, and adapted on being rotated to produce the opening or closing
of the jaws by means of a screwed spindle substantially as hereinbefore set forth.
2. A form of construction of the screw key or wrench hereinbefore described
characterized by the screwed spindle being adjustably connected at one end with
the revoluble cylindrical body or the like (7) by means of a longitudinal slot
and cross pin (6) and having at its other end a tapering projection (k) adapted
to engage between the inner ends (6) of the jaws for the purposes of closing the
mouth of the jaws, the inner ends of which are normally approached to one
another by means of a spring (4) substantially as described.
3. A modification of the screw key or wrench herein before described charac-
terized by the screwed spindle (5) being pivotally connected at one end by
toggles (k) to the inner ends (b) of the jaws and adapted to make a rough move-
ment for the purpose of opening the mouth of the jaws by a cap (7) on the other
end being pressed down against the action of a spring (10), whilst the finer adjust-

page_text: ment of the mouth of the jaws is effected by means of a screw nut (m) easily
brought into connection with the revoluble cylindrical body or the like (7) if
required by means of pins (z) and notches (op q r s t) and being prevented
moving longitudinally by this connection, substantially as described.
4. A modification of the screw key or wrench hereinbefore described charac-
terized by the combination of a tongs like pair of jaws adjustable in a straight
line, a screw (5) connected therewith, and a screw nut (m) adapted to be secured
against displacement by a locking device (o p q r s t) in such a way that when
the locking device is released, the jaws and the attached screw (5) may be
directly displaced in the cylindrical body or the like (7) and brought into a
suitable position for gripping the object to be clutched (i.e. the nut to be
tightened) after which the screw nut (m) is fixed by turning the cylindrical
body (7) so that when the said body is still further revolved a powerful gripping
or tightening of the wrench jaws is produced, substantially as described.
Dated this 4th day of November 1898
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.