with Feathering Screw Propellers, for the Purpose of Turning and Indicating the Angle of same.
Year: 1886

page_text: with Feathering Screw Propellers, for the Purpose of Turning
and Indicating the Angle of same.
We, ROBERT THOMAS BELLS of 42 Windsor Street, Birkenhead in the County
of Chester, Engineer and WILLIAM PHILLIPS THOMPSON of 6, Lord Street Liverpool
in the County of Lancaster, Patent Agent for the said Robert Thomas Bells 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 has for its principal object an apparatus for working the
feathering shaft of feathering screw propellers.
At the present time these are worked by a cotter in the shaft passing through a
slot on the main shaft and an enormous nut on the main shaft requiring great
power to turn it.
We propose to effect this feathering by the engines themselves and ascertain the
angle at which the screw blades are set at any moment in the following manner.
Referring to the drawings:-
Figure 1 is a longitudinal section.
Figure 2 plan partly in section of the apparatus.
Figure 3 end view.
Figure 4 sectional view through X Y Figure 1.
Figure 5 modification of apparatus, and Fig. 6 view of indicator.
In these A is the main shaft-B enlarged coupling on same.
C. fenthering
shaft D worm-wheel thereon. This is keyed to the shaft C, if as in the case
shown the shaft has to be rotated or a thread is cut in it and on the shaft C if it
is required to move the shaft longitudinally as shown in Figure 5.
E worm
gearing into D
e shaft carrying worm E and spur wheel F, which latter gears
into a spur wheel G cast in one with bevel wheel H and working on pin I. This
plate 1', screws i and nipple to B. Bevel wheel H
riding on B and secured thereto by indicator sleeve J
The bevel wheel and indicator sleeve being on opposite
b of coupling B mutually hold themselves on B while
pin is firmly secured by
gears into bevel wheel I
screwed to it by screws j.
sides of projecting collar
Price1=

page_text: free to revolve thereon. Bevel wheel I' carries brake wheel K, brake strap k
thereon is worked by lever L and support fixed to tunnel. M is a cover boxing
in the gearing, this is attached to a flange m on wheel K, which flange is cut away
opposite H to admit that wheel. are a series of podger holes round wheel K to
use for turning by hand if desired. Sleeve J is screwed at J. N is a sliding
sleeve on the shaft A having screw at J¹ fitting screw on J and having a
continuation n preferably lapping over J, the shaft can be graduated, if desired, so
as to show by the space covered by n the angle to which the screw is turned, but
we prefer to regulate this by a dial R as set forth in Figure 1, or as in Figure 6, in
each case sleeve n has two ring guides, T T in which work the end of a lever or a
bowl thereon, this bowl works a lever O pivotted at P, from the axis Pan arın Q
We may also arrange
projects, showing the angle to which the screw is turned.
an electric or other stop, so that the moment the indicator comes in contact with
this stop, or as the case may be passes a spring catch, a bell rings. We have not
thought it worth while to show such on the drawings, as there are many arrange-
ments well known for setting a catch, so that at a given advancement of any
object the bell rings and almost any of these could be used.
The apparatus is worked as follows, if the screw has to be altered in pitch, the
engines are put in motion (or reversed as the case may be) the attendant holds the
handle L hard down putting on the brake, this stops the rotation of wheels K
and 12 and causes the wheels H, G, and F as they rotate with the shaft to rotate
When the indicator shows the
on their axes and give motion to the shaft C.
required angle, the brake is let go and the friction will keep the screw stationary
at this angle. If however it be found that a screw shifts, any convenient locking
apparatus such as a pin screwed through J into a recess in the shaft will be
sufficient. This apparatus is to be used with Mr Bells' feathering propeller
covered by provisional protections Nos. 849385 and 13848% the complete speci-
fication of the first of which is filed the same day as this.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that
what we claim is:-
1st. The mode of working the feathering apparatus of screw propellers, which
consists in running the screw shaft containing part of the feathering mechanism
and stopping or impeding the rotation of a part of the mechanism connected
with the feathering apparatus, whereby the feathering apparatus is actuated by
the differential between the angular speed of the main shaft and that of the
impeded part.
2nd. The apparatus for turning the worm wheel D consisting of the transverse
shaft e worm E and gearing F. G. H and 12, together with a brake K or podger
holes, or their equivalent for causing a differential between the motion of the
shaft A and wheel 12, substantially as described.
3rd. The combination of the mechanism outside shaft A for actuating shaft C, a
permanent scale or dial and a permanent pointer or its equivalent for showing
exactly how many degrees or to what extent the screw may be turned at any
given moment, substantially as described.
4th. The mechanism for indicating the amount of obliquity given to the screw
and for connecting the same to the feathering shaft, substantially as set forth.
Dated this 12th day of April 1886
WP. THOMPSON & Co.,
Agents for the Applicants.