Improved Mechanical Erroder and Dredger.
Year: 1890

page_text: Date of Application, 17th Nov., 1890
Complete Specification Left, 17th Aug., 1891-Accepted, 26th Sept., 1891
PROVISIONAL SPECIFICATION.
Improved Mechanical Erroder and Dredger.
We, BENJAMIN HOWARTH THWAITE, of 37 Victoria Street, Liverpool, in the
County of Lancaster, Civil Engineer, and THE SPHINCTER GRIP ARMOURED
HOSE COMPANY, LIMITED, of 9 Moorfields, City of London, do hereby declare
the nature of this invention to be as follows :-
This invention relates to an improved apparatus for erroding or otherwise
disturbing the integrity of accumulations of silt, gravel and mud in the bed of
a river, entrances to harbours, and other places of like character under water
and which form impediments to the passage of vessels, or other marine or water
craft.
It consists of a carriage mounted on wheels. The wheels are formed of cast
steel discs heavily proportioned, and with broad rims on which and at the centre
project outwards, spikes uniformly and numerously so that the spikes have greater
adhesion to the surface.
The axle of the wheels is very heavily constructed and carries loosely two or
more hanging and strongly proportioned bearings, carrying a revolving shaft
having projecting radially numerous steel arms or spikes which dig into and rake
up the matter to be disturbed and floated away by the current.
The revolving shaft is set in motion by chain, belt, friction, or spur gearing by
the motion of the axle of the heavy disc wheels but it is speeded up so as to have
a high relative velocity in proportion to the speed of the disc wheels.
The motion of the wheels therefore produce a rapid revolving action of the
spikes, which dig into the surface and stir, or break it up.
The carriage is dragged or otherwise moved forward by any desired means.
Dated this 17th day of November 1890.
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said Benjamin Howarth Thwaite and The Sphincter Grip
Armoured Hose Company, Limited.
COMPLETE SPECIFICATION.
Improved Mechanical Erroder and Dredger.
We, BENJAMIN HOWARTH THWAITE, of 37 Victoria Street, Liverpool, in the
County of Lancaster, Civil Engineer, and THE SPHINCTER GRIP ARMOURED
HOSE COMPANY, LIMITED, of 9 Moorfields, City of London, 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 an improved apparatus for erroding or otherwise
disturbing the integrity of accumulatious of silt, gravel, and mud in the bed of
a river, entrances to harbours, and other places of like character under water,
and which form impediments to the passage of vessels, or other marine, or water
craft.
It consists of a carriage mounted on wheels. The wheels are formed of cast
steel discs heavily proportioned, and with broad rims on which and at the centre
project outwards spikes uniformly and numerously, so that the spikes have greater
adhesion to the surface.
The axle of the wheels is very heavily constructed and carries loosely two or
more hanging and strongly proportioned bearings, carrying a revolving shaft

page_text: having projecting radially numerous steel arms or spikes which dig into and rake
up the matter to be disturbed and floated away by the current.
The revolving shaft is set in motion by chain, belt, friction, or spur gearing by
the motion of the axle of the heavy disc wheels but it is speeded up so as to have
a high relative velocity in proportion to the speed of the disc wheels. The motion 5
of the wheels therefore produces a rapid revolving action of the spikes which dig
into the surface and stir, or break it up.
The carriage is dragged or otherwise moved forward by any desired means.
Before referring in detail to the accompanying sheet of drawings and which it is
intended shall forin part of this Specification we wish it to be clearly understood
that we do not intend to be confined to the use of the exact details as these may be
modified without involving a departure from the nature of this said invention.
Referring to the figures in the drawings
Figure 1 is a front elevation of the eroder with the large disc wheels shewn in
section.
Figure 2 is a side sectional view taken through axle.
Figure 3 is a section taken through gearing wheels, whilst
Figure 4 is a general plan of the eroder.
The following are the essential elements of this invention.
1
The heavy disc wheels A are formed preferably of steel and have spikes B 2
projecting from their treading surfaces.
In the centre of the disc wheels is the heavy boss C carrying the axle D which
is provided with chain wheel or spur gearing by which the motion of the axle is
transmitted and multiplied to a second axle G suspended by bearing links H that
freely swing in bearings I.
On the secondary axle there project the steel spikes J.
The weight of the second axle is adequate to maintain it in a useful striking
position but if its spikes or other projections come into contact with any hard and
resisting obstacle the axle simply flys out of striking distance.
2
The mechanical eroding carriage is drawn along by shackles K and as the heavy 3
disc wheels revolve, the suspended second axle G with its projecting steel arms
rapidly move round striking into the sand or debris to be removed. Instead of steel
prongs or spikes we may employ flexible steel projections of spring steel or wire.
The movement of the mechanical croder along even the hardest silted surfaces
effectually erodes it, breaking up the surface, distributing and disentegrating the
disturbed silt and driving it into suspension.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The mechanical eroder substantially as hercin shewn and for the purpose
described.
2. The suspended revolving axle arrangement with its steel spikes or other
projections substantially as herein shewn and described.
Dated this 17th day of August 1891.
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said B. H. Thwaite and The Sphincter Grip Armoured
Hose Company, Limited.