Improvements in or relating to Wrenches.
Year: 1895

page_text: Date of Application, 8th Oct., 1895-Accepted, 12th Sept., 1896
Improvements in or relating to Wrenches.
A communication from S. LLOYD WIEGAND, of 146 South Sixth Street,
Philadelphia, State of Pennsylvania, United States of America, Mechanical
Engineer.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, 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 relates to wrenches for grasping and turning cylindric objects,
such as pipes, and screw rods, and has for its object the firm and secure holding of
such objects without injury to them, by crushing or by indenting or abrasion of the
surfaces thereof, the easy application and release of the wrenches from such objects,
better facility of changing for different sizes of pipes, the grasping segments from
engagement with the operating lever, and by reason of the improved construction
and form of parts, greater strength and durability, with less weight of material, a
less risk of defects in the production of parts by casting, usually attributable to
inequalities in thickness of metal, causing shrinkage cracks, the thicker parts
setting and contracting after the metal of the thinner parts has become set.
To accomplish these several desiderata this invention consists in a hollow lever
provided with fulcrums formed integrally therewith, all of practically uniform
thickness of metal throughout each cross section in different parts of its length, a
spring-bolt fitted therein to engage and control the position of the grasping
segments and several series of segments interchangeably fitted to the fulcrums in
the lever, and adapted to fit and evenly grasp the circumference of pipes or rods
of different diameter; such segments being also formed of practically uniform
thickness of material, and fitted to interlock with each other with pivotal or
hinge-like connections.
The construction of this invention and its operation is hereinafter fully described,
and shown in the accompanying drawings, in which,
Figure 1 shows a plan or top view,
Figure 2 a shortened inverted plan view on a larger scale.
Figures 2 and 2B respectively show enlarged perspective views of the fulcrum
end portion of the lever handle in erect and inverted positions,
Figure 3 a shortened central section on a larger scale,
Figure 4 shows a side view of a set of grasping segments with a modified form
of joint connection,
Figure 5 shows a modified form of joint between the lever and the segments of
the ring,
Figures 6, 7 and 8, are severally enlarged perspective views of each of the
separate jaws forming the grasping ring, showing a modified form of joint for
connecting the several segments.
Figure 9 shows in section the parts of one of the joints between the segments of
the grasping ring of the construction as shown in Figures 6, 7 and 8.
Referring to the drawing, 1 represents the lever handle, formed of nearly uniform
thickness of metal through each part of its cross section, in the form of an open
trough; the cylindric convex surface 2, of which receives the pressure of the hand

page_text: in using the wrench; the edges 3 are rounded, and the outer end 4 made of
rounded form.
The opposite end of the lever 1, has formed with it a hooked fulcrum 5 to which
a segment 6 is hooked by a correspondingly shaped hook 7, so as to form a hinge-
joint, cheeks or side plates 8, braces 81, and a cross bar 9, are formed with the
lever 1, so as to confine the hooks 7, of the segment 6, laterally on the hooked
fulcrum 5.
When in normal position, (as shown in the full line in Figure 3), the hook 7 is
held by the cross bar 9 from becoming disengaged from the fulcrum 5, but when
raised to the position indicated by the dotted portion of Figure 3, then the
segment 6 is easily detached by lifting the hook 7, through the space between the
bar 9, and the fulcrum 5.
To the opposite end of the segment 6, is hinged a second segment 10, and to this
third segment 11; the outer end of which is provided with a hooked lip 12, which
engages with a fulcrum 13, on the cross bar 9, of the lever 1; having its axis
parallel with that of the fulcrum 5.
When a cylindric body (such, for instance, as an iron pipe 14), of a diameter
adapted to fill the ring formed by the segments 6, 10 and 11, is placed within it,
and pressure applied to the convex side of the lever 1, the force transmitted from
the fulcrum 5 and 13, respectively to the hook 7, and the lip 12, contracts the ring
formed of the segment 6, 10 and 11, forcibly with such an equalized pressure upon
the enclosed pipe 14, that it is grasped without abrading or crushing it and turns
with the segment and lever.
When pressure is applied in an opposite direction to the lever 1; the grasp of
the segments 6, 10 and 11, is released from the pipe, and if, after the relief of the
grasp such motion is continued, the fulcrum becomes disengaged from the hook or
lip 12, the ring or segment is opened and may be detached from the pipe 14; in the
use of this wrench such prompt disengagement from the pipe is undesirable, because
there are many situations of limited space in which the wrench and pipe can not be
turned by a continuous rotary motion, but must be moved by a reciprocating
motion of the wrench.
To permit the reverse motion of the wrench when relaxed from the pipe without
disengaging the hook 7 from the fulcrum 5, a bolt 15, is fitted to slide in guides 16
and 17, formed in the lever 1; the end 18 of which bolt, presses, by reason of the
reaction of a spring 19 against a collar 20 and the guide 17, upon the segment 6 so
as to hold the hook 7 in engagement with a slight pressure on the fulcrum 5; by
retracting the bolt 15, by means of the handle 21, the hook 12 of the segment 11,
is released from the fulcrum 13, and the ring of segments is thus opened and the
pipe 14 released.
By further retracting the bolt 15, the segment 6 may be turned back into the
position shown in dotted lines in Figure 3, and the ring of segments 6, 10 and 11,
opened and detached from the handle 1, and another ring substituted.
The joints between segments 6 and 10, and 10 and 11, are shown in Figures 1, 2
and 3, as made with pivotal pins 22, fitted in perforations in knuckles 23.
As shown in Figure 4, this joint is made by pairs of interlocking hooks 24 and 25,
which from their form hold in engagement with each other whilst closed, and are so
held when opened by screws, pins or rivets 26 secured to one of the segments, and
overlapping the hook on the contiguous segment.
As shown in Figures 6, 8 and 9, the segments 6 and 11, are formed integrally
with webs or ribs 33 and short pivots 22', with spaces between them.
The hooks 30 on the segment 10, are braced by webs 28 and are formed integrally
therewith these hooks 30 engage the pivots 221 in the segments 6 and 11, with the
webs 28 in spaces 27, forming strong and compact joints.
In Figure 5, a modification of the joint between the fulcrum 5¹ and hooks 7¹ is
shown, the bar 9 which rests upon the hook 12, is attached to the fulerum 5' and
lever 1 without the intervening braces 8 and 8'.
For convenience in handling the several segments, as linked together when

page_text: applying them to a pipe or like object, the opening motion between the segments 10
and 11, is restricted so that the segment 11 may be easily pressed under and
upward behind a pipe by holding either the segment 6 or 10, in the hand.
The cavity, or grooved hollow of the lever 1, affords a good protection from
injury and support for the spring bolt, which, whilst it can be easily and instantly
retracted to disengage the gripping segments, is not liable whilst in use, to be
accidentally liberated.
These wrenches are from the form of their several parts most economically made
by casting and to ensure the requisite tenacity and strength demanded of them in
service, are made of steel castings, or malleable iron castings; both of these
materials at the time of casting are brittle, and only acquire their ductility and
tenacity by subsequent treatment, and when cast, to avoid cracks from local
contraction in cooling, should be of such forms as to present throughout each part
of their length, nearly the same thickness of metal in the cross sections, the
lengthwise contraction not being so important as affecting the strength and
soundness of the casting. For this reason, the hollow shell-shaped lever handle
avoiding all abrupt changes of thickness, and the segments having thin interlocking
hooks, instead of interlocking knuckles of greater thickness than the other portion
of the segments, are less liable to be defective, and from their structural form are
stronger than separate pivotal pins, which latter are liable to bend under stress and
thus impair the diametral dimensions of the ring of segments.
The form of the several parts as described and shown, furnishes the requisite
strength to resist the stresses to which the different portions are exposed when in
use, and comply with the above recited conditions demanded for their sound
production in casting.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondent & in what manner the
same is to be performed, I declare that what I claim is :-
1. In a pipe-wrench, the lever or handle 1, segments 6, 10 and 11, hinged to each
other, and fulcrums 5 and 13 formed on said handle engaging the segments 6 and 11,
in combination with the sliding bolt 15, and spring 19, arranged to operate as and
for the purpose set forth.
2. In a pipe wrench handle of the character described, the hollow shell 1,.
guide 16 and 17, fulcrums 5 and 13, cheeks 8, and cross-bar 9, formed integrally of
metal of substantially uniform thickness throughout each cross section at the
several parts of their length, as and for the purpose set forth.
3. In a pipe wrench of the character described and shown, segmental links
adapted to form when assembled, a contractible gripping ring, in combination with
interlocking hooks and pivots formed integrally therewith, and hooks 7 and 12
adapted to be contracted by a suitable lever with corresponding fulcrums,
substantially as set forth.
4. In a pipe wrench of the character described, and shown, segmental links
provided with interlocking hooks formed integrally therewith, adapted as assembled,
to form a contractible clamping ring in combination with rivets or equivalent
fastenings arranged to hold the hooks in interlocked position, substantially as set
forth and described.
BOULT & WADE,
Agents for the Applicant.