Improvements in Apparatus for Transmitting and Indicating the Direction of Revolution of Engine Shafts and Registering or Recording the Number of Revolutions Made in Either Direction
Year: 1887

page_text: Date of Application, 21st Dec., 1887
Specification Accepted, 3rd Feb., 1888
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Improvements in Apparatus for Transmitting and Indicating the
Direction of Revolution of Engine Shafts and Registering or
Recording the Number of Revolutions Made in Either Direction.
I JOHN SACHEVERELL GISBORNE of 13 Rochester Square in the County of Middlesex
Civil and Electrical Engineer 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 object the transmitting, and exhibiting, or indicating,
particularly on board ship, say on the Bridge, in the wheelhouse, or other convenient
place, the direction in which the main shaft of the engines is moving, and also when
so desired the recording the number of revolutions made by the Engine shaft in either
direction, "Ahead" or "Astern."
According to my said invention I transmit the movements of the shaft electrically by
one or other of the forms of Transmitters hereinafter described to any suitable
Indicator but by preference to one or other of the special forms of Indicators hereinafter
described and illustrated by my drawings.
DESCRIPTION OF THE DRAWINGS.
The same letters of reference indicate corresponding parts in all the figures in the
two sheets of drawings respectively.
Figure 1 sheet 1 of my drawings is a side elevation of one form of Transmitter (the
case containing which can be fixed in any suitable position) and section of the Engine
shaft with an eccentric band or collar fitted thereon.
Figure 2 is a plan of the same.
Figure 3 is a sectional elevation of a double tablet Indicator or Receiving instrument
electrically connected with the Transmitter.
Figure 4 is a bottom plan view of one of the movements that bring one or other
of the indicating tablets into view at each revolution of the Engine shaft "Ahead" or
Astern."
And Figure 5 is the Battery

page_text: In Figures 1 and 2 A. is the framework of the Transmitter carrying on suitable
bearings basmall spindle c having two arms or levers d and d¹ which arms or levers
work loosely on the spindle. On each lever is fitted a smaller lever or trigger catch e.
These trigger catches are fitted in reverse positions on the two levers, and are each
armed with an anti-friction roller both of which engage with the eccentric gl fast on
the Engine shaft g. The Engine shaft g carrying the eccentric g¹ when revolving in
one direction, will carry with it that lever which is prevented from slipping by the
pin and when revolving in the other direction the trigger catch e will allow it to
slip without moving the corresponding lever. The contact levers d and d¹ are cach
furnished with an adjusting screw and land cause contact to be made between the
spring and the platinum contact piece k. These levers d and d' are either so weighted,
or fitted with springs on opposite sides of their fulcrum as to insure their always
regaining their normal position. It will be obvious from the foregoing explanation
that when the shaft g with eccentric g' attached revolves in one direction say "Ahead
the eccentric will operate one of the contact making levers and when revolving in the
opposite direction it will operate the other contact making lever and by so doing, will
record on the Indicator in the manner hereinafter explained, the direction in which the
shaft is moving, by bringing into view one or other of the recording tablets representing
"Ahead" or Astern as the case may be.
In figures 3 and 4 the Indicating tablet m is shown in view and the indicating
tablet m out of view. n is a pair of electro magnets mounted in a frame o of which two
pairs are secured to the Indicator case, respectively operating the two recording tablets.
P is an armature pivotted on centres and having an arm q rigidly secured thereto, the
free end of which arm engages with the shorter arm of a lover working on a fixed
centres the longer arm of which lever is slotted and connected by a pin with the lug
or projection on the side of the freely hung lever arm u carrying the indicating
tablet m.
v is a spring which presses against the lever and serves to assist the tablet
to disappear from view. The bringing into view of either of the tablets m or m¹ is
effected by the direct action of the electro magnets n and n' when excited by the
current passing through the contact springs and the contact pieces of the
Transmitter, the said magnets attracting the armature p which brings the lever into
action, thereby causing the indicating tablet to come into view.
Figure 5 represents the Battery with the connecting wires from the two poles, one
connecting with Terminal No. 2 in the Indicator case (Figure 3) and the other with
the contact making push e, and from thence to the Terminal No. 1.
The cable containing three insulated conducting wires is represented by the
black line connecting the Indicator Figure 3 with the Transmitter Figures 1 and 2.
One of these wires is connected to terminal No. 2 in the Indicator case the second to
No. 3 terminal, and the third to No. 4 terminal. From No. 3 terminal a wire is led
and joined to one end of the coils of the Electro magnets a and another wire is led
from No. 4 terminal and joined to one end of the coils of the Electro magnets n³.
From the opposite ends of each pair of coils of the Electro magnets n and n¹ a return
wire for completing circuit is connected and joined up with terminal No. 1. The
other ends of the three conducting wires of the cable are connected to terminals in
the Transmitter (Figures 1 and 2) having corresponding numbers to the terminals in
the Indicator case, viz 2, 3 and 4.
It will be seen that when the shaft g carrying the eccentric band or collar g' is in
revolution either "Ahead ог Astern," and the contact push in the Indicator case
is pressed, so as to complete circuit with the Battery, then whichever way the shaft
with its eccentric is revolving, either the tablet m or the tablet m¹ of the Indicator
or Receiving instrument must be brought into view once for every revolution
"Ahead" ог Astern" according to the direction in which the Engine shaft may. be
revolving.
I may explain that the object of my introducing a make and break contact switch
or push in the Indicator case is to admit of the Indicator being worked only when
required it not being absolutely necessary in practice that the Indicator should be
constantly in action which if such were the case it would have the effect. of

page_text: Counters.
Figure 6 sheet 2 is a side elevation of another form of Transmitter.
Figure 7 is a plan of the same.
This Transmitter is to be fitted in proximity to the main shafting of the Engines, and
connected therewith by an endless driving band as hereinafter described or if preferred
by toothed wheel gearing.
Figure 8 is a front elevation of a double needle tablet form of Indicator or receiving
Instrument.
Figure 9 is a sectional plan of the same, and Figure 10 is the Battery.
In Figures 6 and 7 A is a small shaft having a strap wheel a fixed thereon which
strap wheel should be of the same diameter as the Engine shaft and carry an endless
strap which is driven by the shaft of the engine. The said strap wheel a turns by
bevilled wheels b a countershaft c running in suitable bearings d on which counter-
shaft are keyed or otherwise fixed two arms e carrying pawls which pawls are placed
in reverse positions. Running loosely on this counter shaft are two ratchet wheels g
the teeth of which are also in reverse, and so placed that the arms e can engage these
ratchet wheels g one way only. On each ratchet wheel by means of a pin h a rod h¹
is attached by which a reciprocating motion is imparted to the blocks i running in
guide bars. These blocks each carry a contact spring adjustable by the screws k
which springs are in contact with the bars l. Half of each of these bars is covered
with Ivory, Ebonite or other non-conducting substance m so as to break the Electrical
circuit. To prevent the possibility when the Engine shaft is at rest of the spring
which was last in motion remaining in metallic contact on the bar which would
maintain the Electrical circuit, the ratchet wheel g is weighted on one side so as to
turn automatically, and the spiral spring n then forces the wheel round until the
spring would rest on the non-conducting substance m. The said bar is insulated
from the rest of the apparatus by means of Ebonite or other suitable non-conducting
material. The bar o which runs easily through the block i is fixed in the slide bars
to keep the spiral spring n in its place.
In figures
and 9 the indicating needle carrying the tablet s is shown in view and
the needle carrying the tablet s¹ out of view. t and are the coils which operate the
two needle recording tablets. u is a contact making push similar to that marked a in
Figure 3 sheet 1 of my drawings and already fully explained. It will be seen that
this double needle Indicator or Receiver is made on the same principle as the ordinary
double needle Telegraph which is well understood so that there is no necessity to further
explain its construction.
Figure 10 is the Battery, the two poles of which are connected as shown in
figure S.
The cable containing three insulated wires is represented by the black line connecting
the Indicator Figure 8 with the Transmitter Figure 7. These wires are connected
to the terminals of the Indicator and to the terminals of the Transmitter in the same
manner as explained in reference to the connections in Figures 3 and 2.
It will now
be seen that when the Engine shaft carrying an endless band or strap actuating the

page_text: strap wheel a of the Transmitter is in revolution it turns the small counter shaft c by
means of the bevilled wheels band causes the arms e to revolve with it carrying with
it that ratchet wheel 9.whose teeth engage with the pawl faccording to which way the
shaft is revolving. The ratchet wheel g carrying the rod moves the block i to
which is attached the spring and makes contact with the bar once for every
revolution of the Engine shaft, so that when the contact making push u of the indicator,
Figure 8 is pressed thereby completing circuit with the battery, every revolution of
the engine shaft either ahead or astern must be recorded or indicated by one or other
of the indicating needle tablets s and s.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. In apparatus for electrically transmitting and indicating the direction of revolution
of an engine shaft the combination of one or a pair of eccentrics or tappets on the
shaft with a pair of vibrating lever contact-makers in electrical connection with an
Indicator showing either intermittently or continuously the direction of revolution
of the shaft of the Engine as specified.
2. In apparatus for electrically transmitting and indicating the direction of revolu-
tion of an engine shaft the combination of a counter shaft driven from the shaft of the
engine and carrying a pair of reversed ratchet wheels and pawl levers with
reciprocating sliding blocks and contact springs in electrical connection with an
Indicator showing either intermittently or continuously the direction of revolution of
the shaft of the Engine as specified.
3. The combination of a make and break contact push or switch with the Indicator
herein before described and illustrated by Figures 3 and 4 in conjunction or not with
permanent recording counters as and for the purpose specified.
4. The combination of a make and break contact push or switch with the Indicator
herein before described and illustrated by Figures 8 and 9 in conjunction or not with
permanent recording counters as and for the purpose specified.
5. The combination of a pair of recording counters with either of the forms of
Transmitters herein before described and illustrated by Figures 1 2, 6 and 7 of my
drawings for recording the number of revolutions made by the engine shaft either
a-head or a-stern as the case may be as specified.
Dated the 20th day of December 1887.