A NEW OR IMPROVED EXCAVATOR
Year: 1875

page_text: LETTERS PATENT to James Deas, of the City of Glasgow, in the
County of Lanark, North Britain, Civil Engineer, and Andrew
Nairn, of Crosshill, in the same County, Mechanical Engineer,
PROVISIONAL SPECIFICATION left by the said James Deas and
Andrew Nairn at the Office of the Commissioners of Patents, with
their Petition, on the 7th May 1875.
We, JAMES DEAS, of the City of Glasgow, in the County of Lanark,
North Britain, Civil Engineer, and ANDREW NAIRN, of Crosshill, in the
same County, Mechanical Engineer, do hereby declare the nature of
the said Invention for "A NEW OR IMPROVED EXCAVATOR," to be as
follows:-
.
The nature of this said Invention or improved construction and action
of this excavator consist in rivetting or otherwise fixing a long lever to

page_text: each section, spade, or digger forming the hollow bowl or pear-shaped
vessel or excavator, and projecting inwards and jointed or fulcrumed
near the top inside of each to the under side of a very heavy circular or
polygonal weight above, open in the centre (without a central stem or
spindle, as in most excavators) so as to allow all the levers to cross
each other, and having the lower end of a rod, link, or short chain linked
to the free end of each lever, and the upper end to the lower end of the
closing and lifting chain above by a common centre eye, link, or shackle,
while the other or lowering chain is attached by a similar shackle or
connecting link higher up to the top ends of three or more short chains,
having their lower ends attached to the heavy weight, all so that when
hung by the lowering chain the excavator opens by the sections turning
on their joints and by the weight of the material within, or by the
weight of the long levers and the rods and eye above them, until each
section or digger is nearly vertical with the outer rim of the weight
above, and so that the top edges of these rest up against the under side
or rim of the weight, so as when the excavator is lowered to force the
spades or diggers into the material to be excavated the weight acts
directly on the top of the diggers or sections and not through the joints
or working parts, as in other excavators. And when thus dug into the
material below the chain attached to the weight is slackened and the
chain attached to the levers is pulled upon, which turns the sections or
diggers on their joints so as to grapple in the material and close them;
then when the whole is lifted to the top or part where the material
is to be emptied or deposited, and on the lifting chain being slackened
and the evcavator hung by the weight and lowering chain the diggers
are thereby opened as before stated, and this chain might be attached
to the diggers instead of to the weight.
Although the excavator has been described as of a bowl or pear shape
it might be only of this shape in elevation, and either round or polygonal
in plan; namely, triangular, square, or pentagonal, according to the
number of sections or diggers of which the vessel is formed, as three,
four, or five respectively, and the outer perimeter of the weight would
or might be of a corresponding round or polygonal shape, and the weight
would be made sufficiently heavy to force the spades to the depth
required in the particular earth or material being excavated. The object
of this excavator is principally for excavating the earth from the inside

page_text: of cylinders or caissons, for sinking these or other foundations for docks
or quay walls, but it might be used for sinking wells or for other
excavating or dredging purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Deas and Andrew Nairn in the Great
Seal Patent Office on the 6th November 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, James
DEAS, of the City of Glasgow, in the County of Lanark, North,
Britain, Civil Engineer, and ANDREW NAIRN, of Crosshill, in the same
County, Mechanical Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of May, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said James Deas and Andrew Nairn,
Her special licence that we, the said James Deas and Andrew Nairn,
our executors, administrators, and assigns, or such others as we,
the said James Deas and Andrew Nairn, our executors, admini-
strators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "A NEW OR
IMPROVED EXCAVATOR," upon the condition (amongst others) that we, the
said James Deas and Andrew Nairn, our executors or administrators,
by an instrument in writing under our, 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.

page_text: manner the same is to be performed, to he particularly described and
ascertained in and by the following statement in writing, reference
being had to the several Figures and reference letters on the accom-
panying Sheet of Drawings which we have hereunto appended for the
purpose of showing the best modes and means we are at present aware
of for performing or carrying our said Invention into effect or practice,
the same reference letters indicating the same or like parts in all the
Figures where shown
ascertained in and by the following statement in writing, reference
being had to the several Figures and reference letters on the accom-
panying Sheet of Drawings which we have hereunto appended for the
purpose of showing the best modes and means we are at present aware
of for performing or carrying our said Invention into effect or practice,
the same reference letters indicating the same or like parts in all the
Figures where shown.
Figures 1 and 2 are respectively a vertical or side elevation and a
plan corresponding to each other of a modification of our
<< new or
improved excavator," or construction and arrangement of the parts
thereof, in accordance with our said Invention, with the ordinary
excavating sections, diggers, or scooping spades or blades B, B, B, B,
as closed; and Figure 3 is a sectional elevation of the same excavator,
corresponding to Figures 1 and 2, taken on the line 11, in Figure 2,
at right angles to Figure 1, with the said sections or spades B, B, B, B,
forming the shell of the excavator as open, and their connected and
moving parts in positions corresponding thereto.
Referring to these Figures 1, 2, and 3, the nature and mode of
performing our said Invention (that is, the improved construction and
action of our said excavator) consist all as follows:-In rivetting or
otherwise fixing the short arm A of the improved lever A, A', by an
angle iron, or flanges at A", to the inside of each section, spade, or
digger B, composing the hollow bowl or excavating vessel B, B, B, B, in
this case formed of four sections (but it might be of less or more as two,
three, or five) which, when put together, are circular in plan, and
conoidal, or pear, or heart shaped in elevation. The levers A, A¹, pro-
jecting inwards across each other in an improved manner in different
planes near the middle to the opposite side of the vessel, so as to give
great leverage, and jointed or fulcrumed by the deep eye A² near the
top or inside of each section B by the strong pin C to the snugs C' on
the inside of the heavy circular weight D above the sections B.
This weight may be cored out and hollow at D' (or made solid when
desired to be very heavy) but it must be open in the centre at D", D³,
(without the central stem or spindle used in most other excavators) so
as to allow all the long arms A¹ of the levers A, A¹, to cross each other

page_text: '
in different planes laterally, and one pair over the other horizontally.
The lower end of a rod a² (or it might be of a link or short chain) is
jointed to, the free end or arm A' of each lever A, A', and the upper
ends of all the four rods a¹ are jointed to the eye or shackle piece a¹¹ at
the lower end of the chain a above, indicated in red lines, by which the
sections B, B, B, B, are closed to excavate and grapple in the material
and be lifted closed, with the material inside, as indicated in Figures 1
and 2. While the other or lowering chain b, shown in black lines, is
attached by a similar shackle or connecting link piece 6" (higher up or
above that a¹¹) to the top ends of the four rods b', or it might be chains,
having their lower ends attached to the short arms A of the levers A, A',
near or close to the inside of the diggers B, so that the rods ¹ work
down through the openings D² outside the fulcra A², C, or these rods 6¹
might be attached to the top of the heavy weight D instead, when
desired, all so that when hung by the said lowering chain the
excavator opens by the sections turning on their joint pins C and by
the weight of the material within, assisted by the weight of the long
arms A¹ of the levers A, A¹, and their rods a¹ and coupling eye a¹¹ above
them, until all the sections or diggers B are nearly vertical, with the
outer circumference or rim of the weight D above them, and so that
the upper edges B¹ of all these rest up against the under side or rim of
the weight D, so that when the excavator is lowered by the chain b, all
as thus stated and shown in Figure 3 of the accompanying Drawings,
to force the spades or diggers B into the material Z to be excavated, the
weight D acts directly on the top of the diggers or sections B, and gives
great stability and durability instead of transmitting the force through
the joints A, C, or other working parts in digging, as in other excavators.
And when the excavator is thus lowered and the spades forced or dug
into the material Z below it to be excavated, as in Figure 3, the chain,
eye, and rods b,.b", b', attached to the short arms A of the levers A, A',
(or to the weight D) are slackened, as in Figure 1, and the chain and
links a, a, a, attached to the arms of the levers A, A', which turn the
sections or diggers on their joints C, are pulled upon by winding up the
chain a so as to grapple in the material and close the sections B slowly
and raise the excavator full of or with the material within it to the top
or place where the material is to be emptied or deposited; when the
lifting chain and links a, a¹, a", are slackened, and the excavator bung
by the lowering chain and links b, b', b", the diggers B being thereby

page_text: opened, as before stated, for the excavated material to be discharged into
a shoot or waggons, or otherwise for removal as desired.
Although this excavator has only been shown and described as of a
conoidal or heart shape in elevation in Figure 1, and round in plan,
Figure 2, it might be polygonal in plan; namely, triangular, square, or
hexagonal, according to the number of the sections or diggers B of
which the vessel is formed, as three, four, or six respectively, and the
outer perimeter of the weight D would preferably be of a corresponding
polygonal shape, and the weight would be made sufficiently heavy to
force the spades B to the depth required into the particular earth or
material being excavated. The object of this excavator is principally
for excavating. the earth from the inside of cylinders or caissons for
sinking these for the foundations of docks, quay walls, or other works,
but it is also applicable and might be used for sinking wells, or for
other excavating, dredging, or grappling purposes, and for the lifting,
removing, and depositing of such materials and substances as stones,
gravel, sand, grain, salt, dross, or coal required in the loading and
unloading of ships or other purposes.
Having thus described the nature of our said Invention, and the
manner in which the same is or may be performed, we have to state that
we do not restrict ourselves to the precise details herein described or
delineated, neither, on the other hand, do we desire to claim any of the
parts separately or by themselves of such sectional or bowl-shaped
excavators, as many of these parts may have been used heretofore, but
what we believe to be novel and original and therefore claim as the
Invention secured to us by the herein-before in part recited Letters
Patent is,―
First. The general construction or arrangement and combination of
the parts as a whole of an excavator, 'substantially as herein described in
reference to and shown in the accompanying Drawings.
Second. The constructing of hollow or bowl-shaped sectional exca-
vators, each section of which is fixed to the short arm of a lever with
(or having) the levers (A, A'), so formed and fulcrumed to the open
heavy weight (D, D'), above them that their long arms (A¹) cross each
other near the centre and pass to opposite sides in different planes, thus
working up through the opening (D", D³), of the weight with great

page_text: leverage in closing and opening the excavator, and when full open,
having the upper ends (B¹) of the sections (B) or short arms (A) of the
levers resting or abutting against the weight, all substantially as herein
described in reference to and shown in the accompanying Drawings.
In witness whereof, we, the said James Deas and Andrew Nairn,
have hereunto set our hands and seals, this Fourth day of
November, in the year of our Lord One thousand eight hundred
and seventy-five.
Witness,
W. R. M. THOMSON,
Patent Agent,
Glasgow.
JAMES DEAS.
(L.S.)
ANDREW NAIRN. (L.S.)