A New or Improved Method of Protecting Marine Propeller Shafts from being Clogged by Ropes or other Articles Liable to Coil on their Outer Exposed Parts.
Year: 1887

page_text: Date of Application, 10th Oct, 1887
Complete Left, 22nd Feb., 1888
Complete Accepted, 23rd Mar., 1888
A New or Improved Method of Protecting Marine Propeller Shafts
from being Clogged by Ropes or other Articles Liable to Coil
on their Outer Exposed Parts.
We ROBERT ARMSTRONG of 68 Dock Street Newport Mon. Consulting Engineer
and EMERY JOHN CAIGER 23 St. Mary Axe London E.C. Consulting Engineer &
Surveyor do hereby declare the nature of this invention to be as follows:-
This invention consists in fitting or placing over the outer exposed part or parts of
the propeller shaft a loose ferrule or collar. Said ferrule or collar having sufficient
clearance fore & aft to allow of the fore and aft play of the propeller due to thrust
& wear and sufficient play in its internal diameter to admit of the shaft working
freely within it. The collar or ferrule being loose will be free not to revolve with
the shaft when fouled by ropes or other articles liable to coil thereon & therefore
will protect such articles from being coiled or twisted on the shaft in such a way
as to clog or impair the propelling machinery. The collar or ferrule may be made
of brass or any suitable material. It may be made in one piece or in halves suitably
fastened together. It may be flanged or of any suitable form.
Dated this 6th day of October 1887.
ROBERT ARMSTRONG.
EMERY JOHN CAIGER.

page_text: COMPLETE SPECIFICATION.
A New or Improved Method of Protecting Marine Propeller Shafts
from being Clogged by Ropes or other Articles Liable to Coil
on their Outer Exposed Parts.
We, ROBERT ARMSTRONG, of No. 68, Dock Street, Newport, Monmouthshire, Con-
sulting Engineer, and EMERY JOHN CAIGER, of 23, St. Mary Axe, London, E.C.,
Consulting Engineer and Surveyor, 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:—
The object of this invention is to prevent the exposed part of a propeller shaft
from becoming clogged or fouled by ropes, or other materials, with which it may
come in contact while it is revolving; and which, from their flexible nature, are
liable to be seized by the rapid rotation of the shaft and coiled round it, or be
dragged around it by the propeller.
The invention itself consists in fitting a loose collar upon the exposed part of the
shaft, between the propeller and the stern post or stern bearing.
In order that the said invention, and the means by which the same is to be carried
into practical effect, may be thoroughly understood, we will now proceed to describe
the same in detail, referring in so doing to the accompanying drawings which are to
be taken as part of this specification and read therewith.
Fig. 1 is a side elevation, illustrating the application of our invention
Fig. 2 is a front elevation, partly in section, of one form of collar.
Fig. 3 is a plan corresponding with Fig. 2.
Fig. 4 is a front elevation of a collar made in one piece.
Fig. 5 is a transverse section, and
Fig. 6 a plan corresponding with Fig. 4.
Figs. 7 and 8 are, respectively, front elevation and plan, both partly in section, of a
further modified form of collar.
A is the stern post, and B the propeller.
C is the loose collar embracing that part of the propeller shaft which lies between
the stern post, or stern bearing, and the propeller. This collar is, for the sake of
convenience, in fixing it, made in two parts, both flanged, to facilitate their connec-
tion around the shaft by bolts and nuts. But any convenient method of adapting
it for fixation on the shaft may be adopted.
We always make the collar to fit easily upon the shaft, so that the latter can revolve
freely within it and provide sufficient clearance, fore and aft, to allow the fore and
aft play of the propeller due to thrust, wear, and the like.
Since the collar is loose upon the shaft, it follows that should a piece of rope, or
similar flexible material, get any hold of the collar, the latter would be held

page_text: stationary and the rope kept away from the shaft ; or, if the rope were to be coiled,
it would be coiled on the collar, and not on the shaft, which latter would therefore
continue to rotate.
A set pin, or equivalent device, may be used, it being fixed to any convenient
position for the purpose of preventing the collar remaining stationary, or partially
so, whilst the shaft revolves and thereby incurring useless wear; unless it be fouled
by rope, or other material, when the temporary slight resistance of the set pin or other
holding device would be overcome.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
A loose collar adapted to embrace that part of a propeller shaft which lies between
the stern post, or stern bearing, and the propeller; and to allow of the shaft
revolving therein; substantially as described with reference to the accompanying
drawings
Dated this 22nd day of February 1800.
PHILLIPS & LEIGH,
Patent Agents,
22, Southampton Buildings, Chancery Lane, W.C.,
Agents for the Applicants.