Year: 1888

page_text: [Communicated from abroad by Messrs. SOHAEFFER AND BUDENBERG, of Buckau,
Magdeburg, in the German Empire, Engineers.]
near
I, WILLIAM EDWIN HEYS of 70 Market Street Manchester in the County of
Lancaster, Patent Agent, 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 apparatus for indicating the speed of ships.
An apparatus constructed according to these Improvements is illustrated by the
accompanying drawings to which reference is hereafter made.
Figs. 1 and 2 represent respectively a side and front view of the general construction
and arrangement of the apparatus.
Fig. 3 is a side view of the mouthpiece; Figs. 4, 5, 6, and 7 are sectional views of
the mouthpiece; Fig. 8 is a side view of the air-vessels; Fig. 9 is a cross section and
Fig. 10 is a longitudinal section of the air vessels; and Figs. 11 and 12 are
respectively a front and a sectional view of the indicating part of the apparatus.
The apparatus.consists in the first place of the mouth piece M, which is fixed
externally to the ship in as low a position as possible so that it will never be out of
the water when the ship rolls or pitches and also as near to the front of the vessel as
practicable so that it may be exposed to the full current of the water before it is
disturbed by the motion of the vessel.
The apparatus consists in the second place, of the air vessel W which is fixed within
the ship at any convenient point below the water level.
The apparatus in the third place consists of the pressure gauge (or indicator) N,
fixed on the bridge or other position where it may readily be observed by the
Commander. There may be any convenient number of these indicators employed in
combination with the apparatus and they may be fixed in any desired positions such
as in the engine room, the saloon, and the Captain's cabin.
The mouthpiece M has openings d and s s pointing in two directions, that is to say,
the opening d pointing forwards and the openingsss pointing backwards or in a

page_text: backwards direction as shewn in Fig. 7. The opening or openings which point in a
forward direction are connected with an air chamber D by means of the pipe & whilst
the openings which are directed backwards communicate-by-a separate-pipe s-with
the air chamber S. As represented in the drawings, the air chambers are formed in
one casting but separate vessels may be used if desired.
The duplex air vessel is provided with water gauge glasses, blow off cocks, and
connecting pipes for the air and water, so that the water in the respective vessels may
be adjusted to the same level and be under control. Within each of the vessels there
is fitted a perforated diaphragm or partition such as p, Figs. 9 and 10, to prevent
excessive agitation of the water therein owing to the motion of the ship.
If the ship be stationary in still water, and if the water level in each of the air
chambers D and S be at the same height, the pressure in the two chambers is equal
and corresponds with the hydrostatic pressure due to the external water. If however
the ship moves forward, a relatively increased pressure arises in the chamber D and a
relatively diminished pressure in the chamber S owing to the action of the current of
water past the mouthpieces d and s.
The difference in the pressures respectively existing in the two vessels or chambers,
depends upon the velocity with which the mouthpiece is moving through the water,
and is indicated by the pressure gauge or indicator N, which is connected by two
separate pipes with the air chambers. One of these pipes opens into the gauge above
the diaphragm and communicates with either of the vessels D or S; whilst the other
pipe opens into the gauge below the diaphragm and communicates with the other
vessel S or D. The pressure gauge therefore continuously indicates the speed of the
ship irrespective of the depth of the same in the water and of the roughness of
he sea.
The front of the gauge N is hermetically closed against the atmosphere by means of
a strong glass; this arrangement permits the motion of the gauge diaphragm to be
transmitted to the finger or index without the use of a stuffing box.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed, as communicated to me from
abroad, I declare that what I claim is :—
In a speed indicator for ships; two air vessels in one of which the pressure is
determined through an open communicating pipe pointing under water in the
direction of the ship's motion, while in the othor the pressure is determined through ก
similar pipe pointing in a backward direction under water, in combination with a
gauge or device for indicating the difference of pressure in the two vessels and
consequently also the speed of the ship; substantially as hereinbefore described and as
illustrated by the accompanying drawings.
Dated this 13th day of December A.D. 1888.