IMPROVEMENTS IN SELF ACTING EXCAVATORS OR DREDGERS AND IN THE APPARATUS CONNECTED THEREWITH
Year: 1883

page_text: LETTERS PATENT to Thomas Whitaker, of Horsforth in the County of York,
Contractor, for an Invention of "IMPROVEMENTS IN SELF ACTING EXCAVATORS
OR DREDGERS AND IN THE APPARATUS CONNECTED THEREWITH
"
PROVISIONAL SPECIFICATION left by the said Thomas Whitaker at the
Office of the Commissioners of Patents on the 12th February 1883.
THOMAS WHITAKER, of Horsforth, in the County of York, Contractor, "IM-
PROVEMENTS IN SELF ACTING EXCAVATORS OR DREDGERS AND IN THE APPARATUS
CONNECTED THEREWITH
13
This Invention relates to the parts of the self acting excavators which operate in
opening and closing the same, and also to the crane or lifting apparatus used in
connection therewith.
By this invention any ordinary crane or travelling crane or lifting apparatus is
rendered available for operating the self acting excavator or grab by the addition
of a discharging frame or hook, suspended from the crane jib or gantry at any
suitable elevation above the wagon or barge into which the material dredged, is to
be deposited.
A chain or rod is attached to the discharging frame or hook and carried within
easy reach of the driver of the crane.
To the opening or closing bar of the excavator an iron rod is fixed having a
crosshead at its upper extremity, constructed so as to engage readily with the
discharging frame or hook.
Suitable catches are fixed on the frame of the excavator. These catches engage
with and support the opening bar of the excavator when suspended by the
hoisting chain, but release the opening bar when the chain is relieved from the
tension by the excavator resting on the ground.
The modus operandi is as follows:-Suppose the excavator to be suspended from
the crane, having the catches before described, supporting the opening bar and
retaining the jaws of the excavator or grab wide open. The crane is set in motion
and the excavator allowed to descend rapidly and without stopping, until it rests
upon and penetrates the clay or other material to be removed

page_text: The catches supporting the opening bar release themselves automatically. The
crane is set in motion to raise the excavator. The jaws are drawn together,
enclosing the material and the whole is raised to the height required. The iron
rod and crosshead before mentioned pass through the discharging frame. The
crane is then swung round or moved over the wagon or barge to be filled
The attendant having pulled or pushed the discharging frame so as to engage the
crosshead, the crane chain is lowered, the weight of the excavator is thrown on to
the discharging frame and by it on to the crosshead and iron rod, This action
allows the jaws of the grab to open and empty the contents into the wagon or
barge. When empty the excavator is again hoisted by the crane. The catches
attached to the frame engage with the opening bar. The discharging frame frees
itself from the crosshead and the excavator is again ready to be run down to repeat
the operation and to receive another load of material.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Whitaker in the Great Seal Patent Office on the
11th August 1883,
THOMAS WHITAKER, of Horsforth, in the County of York, Contractor.
" IM-
PROVEMENTS IN SELF ACTING EXCAVATORS OR DREDGERS AND IN THE APPARATUS
CONNECTED THEREWITH
"3
This Invention relates to the parts of self-acting excavators or dredgers which
operate in opening and closing the same, and also to the cranes or lifting apparatus
used in conjunction therewith.
By this Invention any ordinary crane or travelling crane or lifting apparatus is
rendered available for operating the self acting excavator or grab, by the addition
of a discharging frame or hook suspended from the crane jib or gantry, above the
wagon or barge into which the material dredged is to be deposited. Chains or rods
are attached to the discharging frame and carried within reach of the driver of the
crane. Thus the discharging frame can be raised or lowered, or brought into
contact with the apparatus attached to the excavator.
L
To the opening or closing bar of the excavator there is fixed a rod having at its
upper extremity a cross-head constructed so as to engage readily with the
discharging frame. Suitable catches are fixed on the frame of the excavator and
engage with and support the opening bar of the excavator, when suspended by the
hoisting chain, and so retain the jaws of the excavator wide open. The catches
release the opening bar as soon as the tension of the chain is relieved by the
excavator resting on the ground.
The modus operandi is as follows:-
Suppose the excavator to be suspended from the crane, having the catches before
mentioned supporting the opening bar, and retaining the jaws of the excavator or
grab wide open; the crane is set in motion, and the excavator allowed to descend
rapidly and without stopping, until it rests upon and penetrates the clay or other
material to be removed. Upon the tension of the hoisting chain being thus
relieved the catches automatically release the opening bar. The crane is then
set in motion to raise the excavator, and its jaws are thereby drawn together,
enclosing the material, and the whole is raised to the height required, the
rod and crosshead before mentioned passing through the discharging frame.
The crane is then swung round or moved over the wagon or barge to be filled.
The attendant baving pulled or pushed or raised or lowered the discharging
frame as or if required, so as to engage the crosshead, the crane chain is lowered
and the weight of the excavator is thrown on to the discharging frame by means of
the crosshead and rod. This action allows the jaws of the grab to fly open and
empty its contents into the wagon or barge or elsewhere. When empty, the
excavator is again hoisted a short distance by the crane; the catches attached to
the frame again engage with the opening bar; and the discharging frame frees
itself or is freed from the crosshead; when the excavator is again ready to be run
down to repeat the operation and to receive another load of material.
Such being the nature and object of the said Invention, I will now proceed to
describe more in detail the manner in which the same is to be or may be performed
or carried into practical effect, and in order that the said description may be fully
understood, I have hereunto annexed two sheets of drawings illustrative of the
present improvements, and have marked the same with Figures and letters of
reference corresponding with those in the following description.
Inasmuch as the Invention does not apply to the general construction of the

page_text: excavator or crane as a whole, one well known form of grab and crane is illustrated,
to which the application of the present improvements is shown. The accompanying
illustrations will be amply sufficient to explain the application of the present
improvements to other forms of excavators and cranes.
On the accompanying drawings, Fig 1 represents a side elevation, and Fig 2 is an
end elevation, of a crane and excavator, illustrating the application of one modi-
fication of the present improvements thereto.
Figs 3, and 4, are similar views of another mode of applying the present
improvements. In these figures the parts of the excavator and apparatus which
are similar to those illustrated in Figs 1, and 2, are omitted.
Fig 5, is an end view, and Fig 6 is a side view on an enlarged scale, of the form.
of discharging frame illustrated in Figs 1 and 2. and Fig 7, is a plan of parts of the
same.
Figs 8 show details of the catches which act on the opening bar.
And Fig 9. is a plan of the form of discharging frame, applied to the crane and
excavator as illustrated in Figs 3 and 4.
A is the jib, B the tie rod, and C the hoisting chain of the crane. D is the body
--of an excavator with its jaws, barrels, shafts and usual attachments. E is the rod,
and F the crosshead attached to the opening bar G, of the grab. E' E' are wings
on the rod E. H, H, are the catches which engage with the opening bar G. I, I,
are parts of the discharging frame shown in Figs 1, and 2, and in detail in Figa б,
6, and 7 having suitable chains J, J, by which it is suspended from the crane jib.
These chains J, J, pass over pulleys, and are carried down to a simple crane
barrel K, carried by the jib A, or by any other part of the crane or hoisting
apparatus, within reach of the attendant. L, L, are levers pivotted on the
shafts
levers ends the frame and
supporting the crosshead F. From the lovers L, Ls is suppended a circular weight N,
which causes the enlarged ends of the levers L, L, to fly upward when relieved
from the weight of the excavator acting through the crosshead F, The crosshead F..
can then freely descend-along-with the excavator D, through the discharging
frame I, I, to receive another load of material.. O, is a roller attached to the frame
of the grab to guide the chain C, on to the barrel of the excavator D. This barrel
operates in closing the jaws of the same. P, P, are levers which act as a counter-
poise to the catches H, H. The screw Q, serves for the purpose of adjusting the
parts to act in unison, by varying the relative positions of the catches H, H, and
wings E', E'.
As soon as the wings E¹, E', of the rod E, lift the levers P, P, the
catches H, H, are free to engage with the opening bar G. When the crosshead F,
is relieved from the weight of the excavator, the rod E, falls with the wings E¹, E¹,
and enables the catches H, H, to swing clear of the opening bar G, at the proper
moment.
The apparatus being in the position delineated in Figs 1 and 2, the attentant
sets the crane chain C, in motion, and raises the excavator D, along with the
crosshead F, The enlarged ends of the levers L, L, acted on by the weight N, turn
and open. The motion of the crane chain is then reversed, and the crosshead F, is
free to descend between and through the opened levers L, L, and along with the
excavator which is lowered until it rests upon the soil to be dredged. The rod E,
with the wings E¹, E', drop and rest on the head of the screw Q, enabling the
catches H, H, to swing clear of the opening bar G. The chain C, being set in
motion and drawn upward, closes the jaws of the grab, and at the same time the
opening bar G, falls along with the crosshead F, until the crosshead F, is nearer
relatively to the frame of the excavator D. When the excavator and its
attachments approach the full height, the frame of the excavator raises the circular
weight N, whereupon the levers L, L, turn so that their enlarged ends rest upon the
frame I, I, The crosshead F, can pass upward between the levers L, L, which
thereupon again close so that on the crane chain C, being lowered, the crosshead F,
engages again with the levers L, L, and the whole weight of the excavator is
upheld by the crosshead F. The crane being turned round so that the excavator

page_text: is over the receptacle for the soil, a further slight drop causes the jaws of the grab
to fly open, and the soil is precipitated into the wagon or barge. At the same time
the catches H, H, engage with the opening bar G, and hold it fast, until it is again
released after the excavator has descended for another load.
In the modification illustrated in Figs 3, and 4, instead of the discharging frame
engaging automatically as hereinbefore described; the frame is made of the
formation shown in Fig 9. A rod or chain S, is attached to the frame, and is
carried to within the reach of the attendant. The frame R, can thus be pulled or
pushed so that when the crane chain C, is lowered, the frame R, will engage with
the crosshead F, and produce like results as herein before described. It will be
readily seen that the frame R, can be arranged so as to engage the crosshead F, of
itself, either in ascending or in descending, so that the attendant would be required
to pull or push it as the case may be, only once for each load raised.
In Figs 1, to 4, the barrel K, and the chains J, can be used so as to regulate the
height of the discharging frame above the wagon, but the barrels K, and part of
the chains J, may be dispensed with altogether if desired, and the discharging
frame hung at a fixed distance below the crane jib.
The present improvements allow of any ordinary crane being used with a few
simple and inexpensive additions. The second hoisting chain with its gearing as
used heretofore is dispensed with, and the operations are rendered simpler, and
more rapid in action.
Having now particularly described the nature and application of my said
Invention, I desire it to be clearly understood that I do not claim as new, the
excavator itself, nor its usual parts, nor the crane, nor its usual parts, nor do I
confine myself to the precise details herein described, but what I consider to be
novel and claim as the Invention secured to me by the herein before in part recited
Letters Patent is :-
In self acting excavators or dredgers and apparatus connected therewith.
1. The combination of a crosshead and suspension rod, with automatic catches
and with a discharging frame whether automatically or otherwise operated, the
parts being arranged and operating substantially in the manner hereinbefore
described with reference to the accompanying drawings.
2. The use of a crosshead and suspension rod with an arrangement of automatic
catches, substantially in the manner and for the purposes herein before described.
3. The use of a discharging frame (whether automatically or otherwise operated)
capable of adjustment, vertically or otherwise, substantially in the manner and for
the purposes herein before described.
In Witness whereof, I, the said Thomas Whitaker have hereunto set my hand
and Seal this 6th day of August, in the year of our Lord one thousand eight
hundred and eighty three.
THOMAS WHITAKER (LS)