IMPROVEMENTS IN AND RELATING TO APPARATUS FOR INDICATING THE SPEED AND DIRECTION OF MOTION OF MACHINERY, A PART OF WHICH INVENTION IS APPLICABLE ALSO TO PNEUMATIC BELLS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by John Lindsay Pattullo at the Office
of the Commissioners of Patents on the 9th September 1881.
JOHN LINDSAY PATTULLO, of North Shields, in the County of Northumberland.
"IMPROVEMENTS IN AND RELATING TO APPARATUS FOR INDICATING THE SPEED
AND DIRECTION OF MOTION OF MACHINERY, A PART OF WHICH INVENTION IS
APPLICABLE ALSO TO PNEUMATIC BELLS.""
This Invention is designed chiefly as an apparatus for indicating the speed and
direction of motion of marine engine shafts, so as to be visible or audible, or both,
to the captain on the bridge or other part.
By means of a steel wire rope, metal band, or other conductor of motion, I cause
a spindle on the bridge or other required place to rotate at the same velocity and
in the same direction as the engine shaft, or if desired, by intermediate gearing
reduce the speed to any required ratio.
This spindle works the hand of a dial, or by a train of wheels or their
equivalent it can be made to work two or more hands, each on a separate dial.
The captain by watching the dial can at any time see if his commands to the
engineer are obeyed. He can further count the number of revolutions per minute.
In order to make the sounds audible also, I place a cam or cams on the aforesaid
spindle or other mechanism driven from the driving shaft, which cams actuate
tappets or levers in such manner as to ring a gong or bell once every revolution of
the spindle when going ahead, and twice close together for each revolution in going
astern; or instead, I can have the bell to only sound when going astern, but this
is very inferior to the other plan.
I do not however confine myself to this exact arrangement, as there might be a
light-toned bell for going astern, and a low one for going ahead, or any other
arrangement whereby a different sound is given out when going ahead than when
going astern. Again, sometimes it may be found desirable (in sinall vessels
especially) to indicate by sound only. In this case I place my cam
or its
equivalent on the engine shaft or on a spindle geared directly to it, and cause the
said cams to actuate by pneumatic, hydraulic, electric, or other conducting
apparatus one or more bells or their equivalent on the bridge or other required

page_text: place. One plan is to cause the tappets on the engine shaft or on a spindle geared
to it to press forward a piston in a cylinder connected by a tube to another
cylinder on the bridge; the piston of the cylinder strikes the bell. A spring, weight,
or pneumatic pressure brings back the pistons. In all these cases the bell can be
made moveable or be placed on a pivotted support or slide, so that it can be thrown
out of gear; in other cases it can be rigidly attached to the bridge rail or other
suitable supports.
The actual striking apparatus I at present employ in my experimental machine is
as follows A wheel has two parallel projecting rims, like a V pulley; each rim has a
projecting piece, one for a little in advance of the other; pivotted on a cross-bar is a
steel forging, having in front a projecting lever, two cams, and at one side a
projecting pivot. On this pivot is a second tappet cam with two jaws projecting
far enough to come in contact with the spindle of the forging.
If going one way, one projecting piece of the wheel presses the tappet cam till
the jaw comes against the pivot of the forging; this depresses the forging and with
it the lever forming a part of it. This depresses the hammer; the projecting piece at
last travelling on releases the tappet, the whole flies back by means of a spring,
and the hammer strikes the bell.
When the projecting piece on the other rim of the wheel strikes the cam in the
forging with a like result, this makes two rings of the bell. If the cam wheel is
going the other way, it knocks the forging up, and by means of a cam on the same
the projecting end of the hammer is raised, depressing the hammers on the other side
of the fulcrum, till travelling further the hammer is released and strikes the bell.
The other projection merely kicks up the smaller tappet cam without doing
anything to the hammer; there are thus two strokes of the hammer when the
wheel is travelling one way, but only one the other way.