IMPROVEMENTS IN MECHANICAL EXCAVATORS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Alfred Julius Boult at the Office of
the Commissioners of Patents on the 13th December 1883. A communication
: from Gustave Kervern of St. Nicolas de Redon in the Republic of France.
ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Engineer, "IMPROVEMENTS IN MECHANICAL EXCAVATORS" [a communication from
Gustave Kervern of St. Nicolas de Redon in the Republic of France]
'
This machine has a framework of triangular shape. Each side of the triangle
consists of three beams so that there are two spaces in each of which may work
one chain of buckets. Suitable stays keep this framework together or the triangle
formed thereby is rectangular. The point where the rectangle is, is at the base of
the framing. At each corner there is placed a large roller facilitating the working
of the chain of buckets. One of these rollers is fast on its shaft and supported on
a toothed segment which is centred on the same shaft; said shaft carries the frame-
work and is borne by rollers upon the truck which carries the whole machine.
The object of making the framework movable in a vertical plane (vis: round the
shaft at the base) as is above set forth, is to enable the operating parts to
be adjusted to the incline of the cutting.&c upon which the machine may be
employed.
Suitable provision is also made for tightening the chain of buckets when required
A screw may be employed for this purpose and act upon rods so arranged as to
keep the chains taut without interfering with their movements upon their drums
or rollers.
There also other drums which actuate a link chain by which a "pick drum"
hereinafter described can be raised or lowered by the intervention of a rope
The bucket-chains may be of wrought iron and in each eye of the "male" links
a steel bush is inserted which can easily be replaced when worn. Each "female"
link has a roller, and these support the chain.
Between the female links the buckets are carried. Rails may be used in
connection with the framing to ensure easy working of the bucket chain.
ر

page_text: On the second set of drums above mentioned works another chain similar to that
above described. At one point of this chain is fixed a rope acting upon the "pick
drum" This chain may also be made taut by a screw acting upon one of the
drums.
Each bucket consists of a framework fixed on the bucket chain. Into framework
or basket is inserted the bucket properly so called, which may be made of sheet-
iron stayed by angle-irons. The bucket is movable either round its top or its
bottom and will open and close automatically at the proper moment, that is to say
its lid will be thrown upon or shut when its heel abuts against corresponding
heels on the frame work. The movement of the buckets is facilitated by rollers
and by a movable slide.
There are in the construction herein described two series of buckets but one
series only or several, may be used by diminishing or increasing the number of
beams according to requirement, when only one series of buckets is to be employed
there need be but two sets of beams in the bucket-frame whilst there will be four
if three sets of buckets are required.
As hereinbefore stated the drum at the base of the triangle is movable on its
centre, the movement of said drum is derived from an engine on the truck, power
being transmitted by toothed gearing arranged in the usual manner.
The raising and lowering of the "pick cylinder" being effected as already set
forth its rotation is caused as follows; a set of loose and fixed pullies are carried
by a fixed support and by hinged arms or levers connected therewith, one of said
pullies receives rotary motion from toothed gearing, this motion being thence
transmitted to the "pick-cylinder". A friction roller serves to protect the “ pick-
cylinder" against the effect of sudden shocks.
3
The "pick-cylinder" above mentioned consists of a drum, say of sheet iron, upon
which are arranged in suitable settings wooden handles or holders fixed in position
by screw collars, The holders may be arranged in pairs, they may be fitted
according to circumstances and the nature of the soil to be excavated, with picks
or spades or scrapers at one end and at the other with hammers or steel points.
These tools break down the soil or other material. This pick-cylinder is fixed on
an adjustable frame which moreover carries a slide or shoot for the loosened soil.
Smaller slides carry the earth or soil from the large slide to the buckets.
A suitable guide is provided for the slide to ensure its being at a proper position.
The slide is so constructed that it always bears against the side of the trench and
therefore receives all the material as it is broken down.
For the purpose of regulating the opening of the buckets there is fixed upon the
second framing a device which is formed by strips movable on their longer sides
and upon this rollers may travel. The strips overlap one another and may be fixed
in a vertical position. When so fixed they enable the buckets to open and assume
a vertical position so as to be emptied.
An upright is provided and suitably stayed and by it and a winch or axle upon
which a chain may be rolled up the position of the main frame is adjusted, whilst
another chain imparts greater stability.
Upon the main framing the second framing is movably supported and is
adjustable by means of rods and a chain.
This frame which carries the "pick-cylinder" can moreover by a bead chain be
so adjusted as to cause the tools to enter more or less deeply into the soil.
The whole machinery is carried on three trucks, one supporting the engine and
two the main framing. The three trucks are connected by I irons. On the engine
truck provision may be made for ballast allowing the balance the main framing, but
other means may be employed for this purpose, for instance a large roller may rest
on the top of the cutting and support the main frame.
Water tanks and coal-boxes may be provided on the two trucks carrying the
main framing.
A device for filling trucks or waggons with the soil that is broken down, consists
of a trough of suitable dimensions in and under which moves an endless chain or

page_text: the like fitted with discs of suitable form. The chain is run over drums receiving
motion from the engine or otherwise.
Underneath the trough are provided supports with rollers for the chain and the
trough has apertures with adjustable slides through which the soil is admitted
into the waggons or the like. The trough and chain may be fitted upon the
machine itself or otherwise.
As above described the machinery is constructed to operate upon soil that is on
a higher level than that upon which the machinery rests. If it is desired to
operate upon the soil below the base of the machinery suitable modifications are
made which will readily suggest themselves to those skilled in the art, no departure
is however made from the principles of this invention.
The whole of the machinery may if desired be carried by a single truck. For
very heavy work the bucket chains are omitted and the mainframe supported by
rollers resting on the top of the cutting. On the main frame are fixed one or
more slides on which moves a horizontal structure upon which is mounted the
pick cylinder" and an engine for driving it. The soil is carried to the shoot for
filling the waggons by a screw. On the truck is mounted an engine imparting
the required movement to the frame which carries the "pick cylinder."
"