IMPROVEMENTS IN APPARATUS FOR INDICATING THE SPEED AND DIRECTION OF ROTATION OF ENGINE AND OTHER SHAFTS WHICH APPARATUS COMPRISES A PUMP APPLICABLE ALSO TO OTHER PURPOSES."
Year: 1882

page_text: LETTERS PATENT to Lionel Swift, of Parliament Street, in the City of
Westminster, Engineer, for an Invention of "IMPROVEMENTS IN APPARATUS
FOR INDICATING THE SPEED AND DIRECTION OF ROTATION OF ENGINE AND
OTHER SHAFTS WHICH APPARATUS COMPRISES A PUMP APPLICABLE ALSO TO
OTHER PURPOSES."
PROVISIONAL SPECIFICATION left by the said Lionel Swift at the Office of
the Commissioners of Patents on the 12th January 1882.
LIONEL SWIFT of Parliament Street in the City of Westminster, Engineer.
"IMPROVEMENTS IN APPARATUS FOR INDICATING THE SPEED AND DIRECTION OF
ROTATION OF ENGINE AND OTHER SHAFTS WHICH APPARATUS COMPRISES A
PUMP APPLICABLE ALSO TO OTHER PURPOSES."
1
According to my Invention to show upon a gauge scale or indicator (or gauges
scales, or indicators) the speed and direction of a rotating shaft which may be
situated at a considerable distance from such gauges, scales or indicators or some of
them, I employ an arrangement of apparatus as follows-I provide a rotary pump
and in connection therewith two vessels or compartments each occupied partly by
water or other suitable liquid and partly by air and each connected by a pipe
communicating with its air space to a gauge capable of indicating when and to
what extent the pressure in one chamber or compartment differs from the pressure
in the other chamber or compartment. I provide the gauge or scale with divisions
or marks representing the number of revolutions of the shaft per unit of time that
correspond to given pressures in the chambers or compartments. Each aperture of
the pump will serve indifferently for suction or delivery according to the direction
of rotation of the shaft from which the pump is driven. When the shaft, to which
the apparatus is connected, commences to revolve, the pump draws liquid from one
of the above-mentioned vessels or compartments, thereby permitting the expansion
of the air in the said vessel or compartment, and forces the said liquid into the
other vessel or compartment, compressing the air therein. The direction of

page_text: י
rotation of the shaft determines in which vessel or compartment the exhaustion
shall take place and in which the compression shall take place. Provision is made
for the return of the water or other fluid to the suction side of the pump through
an adjustable orifice or past a weighted valve as the difference of pressures increases.
Instead of or in addition to the adjustable orifice or weighted valve the pump may
be such that its delivery varies in an inverse ratio to the difference of pressures at
its inlet and outlet ends. A rotary pump for this purpose is constructed with an
eccentric disc or cylinder serving as piston which is fixed eccentrically upon a
revolving shaft and surrounded by a loose strap or ring or collar; this disc or
cylinder revolves with the strap or ring or collar in frictional contact or nearly so
with the inner periphery of a cylinder or casing. The two apertures of the pump
may be divided by a reciprocating division piece or slide which constantly bears
upon the strap or ring of the eccentric, rising and falling during the rotation of the
eccentric to prevent all direct communication between the two chambers or com-
partments. This division piece or slide ends in a jointed shoe or block curved to
the circumference of the loose strap or ring or thereabouts. In place of this
reciprocating division plate or slide the apertures of the pump may form ports that
are covered and uncovered at suitable times by the eccentric disc or cylinder in its
revolution. I employ a gauge wherein two Bourdon or other tubes or diaphragms
or pistons, such as are ordinarily used in pressure or vacuum gauges are connected
to opposite sides of one pointer or indicator, while each is in communication with
one of the aforementioned chambers or compartments. When the apparatus is in
action the pressure in one tube or on one diaphragm or piston exceeds the
atmosphere and the pressure in the other tube or on the other diaphragm is below
the atmosphere. The two tubes or diaphragms or pistons cooperate to move the
pointer or indicator in one direction or the other according to the direction of
rotation of the pump, and by their combined action tend to give indications that
represent the mean of the variations of the pressures in the chambers or compart-
ments above or below the atmosphere. In place of the ordinary circular gear
wheels between the tubes or diaphragms and the indicator or pointer, I prefer to
use elliptical gear or other devices that will transmit or convert the motion of the
tube or diaphragm in such a way that equal increments of speed of the shaft will
always be represented by equal divisions of the scale.
In place of the gauge above described a gauge may be used with a diaphragm
the two sides of which communicate respectively with the aforesaid vessels or
compartments or two distinct gauges may be employed, placed near together, and
each capable of indicating pressures both above and below the atmosphere. One
such gauge connected to one of the vessels or compartments if accurately graduated
would furnish the necessary indications.
In a modified form of the apparatus I employ a reciprocating pump with its
inlet and outlet passages controlled by valves that are automatically reversed when
the shaft is reversed. A slide valve actuated by an eccentric capable of taking up
two distinct positions, according to the direction of rotation of the shaft upon
which it is, forms a convenient arrangement for the purpose. Or a centrifugal
pump may be constructed with two circumferential ports communicating
respectively with the two vessels or compartments, and acting alternately as inlet
or outlet according to the direction of motion of the pump. If it be found desirable
that the inlet to the pump casing should be at the centre, as is usual, valves may
be arranged in the communicating pipes to be operated by the flow of the water.
A safety valve on each vessel or compartment prevents the pressure rising to a
dangerous or excessive amount from any cause. The pump above described may
be used separately for other purposes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Lionel Swift in the Great Seal Patent Office on the 12th July
1882.
LIONEL SWIFT late of Parliament Street now of Millbank Street in the City of
Westminster, Engineer. IMPROVEMENTS IN APPARATUS FOR INDICATING THE
SPEED AND DIRECTION OF ROTATION OF ENGINE AND OTHER SHAFTS WHICH
APPARATUS COMPRISES A PUMP APPLICABLE ALSO TO OTHER PURPOSES.
According to my Invention to show upon a gauge scale dial or indicator
(or
gauges, scales dials or indicators) the speed and direction of a rotating shaft which
may be situated at a considerable distance from such gauges scales dials or indi-
cators or some of them-I employ an arrangement of apparatus as follows,-I
provide a rotary pump and in connection therewith two vessels or compartments
communicating severally with the pump barrel by separate apertures or ports.
Each compartment or vessel being partly occupied by some suitable liquid, and
partly by air. Each vessel or compartment is connected by a pipe communicating
with its air space to a gauge capable of indicating when and to what extent the
pressure in onė vessel or compartment attached to pump differs from that in the
other vessel or compartment attached to pump. I provide the gauge scale or dial
with divisions or marks representing the number of revolutions of the shaft for
unit of time that correspond or correlate with definite pressures in the vessels or
compartments. Each aperture or port of the pump will serve indifferently for
suction or delivery according to the direction of rotation of the shaft from which
the pump is driven. When the shaft which drives the pump commences to revolve,
the pump draws liquid from one of the above mentioned vessels or compartments,
thereby permitting the expansion of the air in the said vessel or compartment, and
forces the said liquid into the other vessel or compartment, compressing the air
therein. The direction of rotation of the driving shaft determines in which vessel
or compartment the exhaustion shall take place and in which the compression shall
take place. Provision is made for the return of the liquid-or a portion of it-to
the suction side of the pump, through an orifice, adjustable, definitely or varying
automatically with the pressure, as by a weighted valve or plug, with a sub-way
and secondary valve opening only to the pressure side and the main passage, from
vessel to vessel and which arrangement provides an escape or safety valve to open
or enlarge the orifice, in case the maximum or intended pressure is exceeded. The
rotary pump, which may be used otherwise than in conjunction with apparatus for
indicating the speed and direction of rotation of shafts, consists of a cylinder
provided with suitable and properly fitting covers, and central rotating shaft or
axis working through stuffing boxes, and bearings as usual in such cases. This shaft
or axis carries on it firmly fixed an eccentric filling longitudinally the space between
the cylinder covers, and on the eccentric and of same longitudinal length, is
provided a loose, concentric cylinder, with its part which is furthest removed from
the shaft, gently impinging on the internal periphery of cylinder, during its
rotation. The two apertures or ports before named, as opening into the cylinder
pump are separated by a movable rectangular division piece or slide working in a
close fitting case, and provided at its lower portion with a knuckle jointed piece
curved to fit the circumference of the loose concentric ring or cylinder on the
eccentric. By means of springs or hydrostatic pressure this piece or slide is made
to bear with its concave part on the circumference of the ring or cylinder, before
mentioned and thus obtain a reciprocating motion due to the eccentricity. The
breadth of this reciprocating piece also coincides with the internal distance from
cover to cover or should the cylinder only have one cover and a solid bottom,
from the internal face of such bottom. When the parts of the reciprocating piece

page_text: or knucklejoint, are made of proportions suitable for lap or cover to the ports, all
communication from one vessel or compartment to the other, by the ports is
intercepted, except when the pump is in rotation.
The liquid is then carried round by the rotary motion of the eccentric, which
draws the liquid from one chamber and projects it into the other chamber, pro-
ducing exhaustion and compression of the overlaying volume of air, as before
mentioned. When great uniformity in the discharge of liquid is required, so as
to preclude intermittent or irregular effects, I propose to use two or more separate
eccentrics, with their separate loose rings as before described. The eccentrics are
each fixed to and carried by the same axial shaft and are so arranged that their
full or projecting parts are separated by equal angular distances in their plane of
rotation.
I further provide in this case one or more smooth diaphragms of uniform
thickness to lie between adjoining eccentrics, and form them with tail pieces
projecting into the case containing the separating réciprocating pieces-which are
made to coincide in breadth with the respective eccentrics and rings on which
they respectively ride thus each separate eccentric has its individual reciprocating
knuckle jointed division piece or slide. In connection with the upper part of each
of the two vessels or compartments occupied by air I introduce, an expansion
chamber, which consists of a fixed plate, and a loose plate of similar size or shape,
connected at a determined distance from each other by a coiled or other spring.
Further, connecting these bottom and top plates, and enclosing the spring, I use a
pliable air tight material securely attached to both bottom and top plates and pro-
vided with rings attached round its circumference. Each bottom plate forms the
top of one of the hereinabove mentioned vessels or compartments connected to
pump. Perforations in each bottom plate afford communication between the
bellows like chamber and the corresponding vessel or compartment and consequently
the expansion and contraction of the said bellows like chambers adds to or
diminishes the volume or space occupied by the air in the apparatus.
I employ a gauge wherein two Bourdon or other tubes, or diaphragms such as
are ordinarily used in pressure or vacuum gauges one of which tubes or one side
of such diaphragm, is in communication with one of the aforesaid vessels or com-
partments of pump, while the other tube, or other side of diaphragm is in similar
connection with the other chamber or compartment of pump. When the apparatus
is in action the pressure in one tube or on one diaphragm is in excess of the
atmospheric pressure while in the other tube or on the other diaphragm it is below
the atmospheric pressure. The two tubes or diaphragms are connected to an axis
carrying a pointer moving over a graduated scale and by their co-operative action
move the pointer or indicator in one direction or the other, according to the
direction of rotation of the pump-and by their combined action on opposite sides
and at equal radial distances from centre of axis give an angular motion that
represents the resultant of the positive and negative pressures in the vessels or
compartments of pump which resultant is made to correlate with and indicate the
number of revolutions and the direction of rotation.
In place of the ordinary circular gear wheels between the tubes or diaphragms,
and the indicator or pointer, I prefer to use elliptical gear or other devices that
will transmit or convert the motion of the tube or diaphragm in such a way that
equal increments of speed of the shaft will always be represented by equal divisions
of the scale.
In place of the gauge above described a gauge may be used with a diaphragm,
the two sides of which communicate respectively with the aforesaid vessels or
compartments or two distinct gauges may be employed, placed near together, and
each capable of indicating pressures both above and below the atmosphere. One
such gauge connected to one of the vessels or compartments if accurately graduated
'would furnish the necessary indications.
Referring to the accompanying Sheet of Drawings
Fig 1 is a central vertical section partly in elevation of an apparatus according

page_text: to my Invention but without the gauge, scale, dial or indicator and the connecting
tubes.
Fig 2 is a plan of the same.
Fig 3 is a vertical central section of the same at right angles to Fig 1.
Fig 4 is a vertical section, similar to Fig 1, of a pump according to my
Invention.
Fig 5 is a plan of the same.
Fig 6 shews a gauge with two tubes, intended to communicate with the two
vessels or compartments in connection with the pump, and operating the same
index. A. Fig 1, is a shaft driven from the shaft whose direction and speed of
rotation is to be indicated. It carries two eccentric discs B B working between
two covers B¹ B₁ and separated by diaphragm or plate B³. It is evident that
more than two discs may be used when it is desired.to increase the regularity or
capacity of the pump. The central shaft is carried in bearings in the end covers.
As indicated by the dotted lines in Fig 1 the two eccentrics are placed with their
full or eccentric portions on opposite sides of the shaft. Upon each eccentric disc
there is a loose cylinder or ring B³ of the same width as the eccentric. The shaft,
disca and rings, rotate within a cylinder D of such diameter that the rings run in
contact with its inner periphery. The cylinder is divided by a diaphragm B² and
into each part there opens a chamber or case D³ containing a movable rectangular
division piece or slide D³, to which is pivotted a knuckle jointed piece E with a
face curved to fit the loose ring or cylinder. Each rectangular division piece is
pressed toward the corresponding disc by a spring E¹, and receives a reciprocatory
motion from it, while the knuckle jointed piece has a slight oscillating motion
about its joint. There are two ports for entrance and exit of fluid to each part of
the pump cylinder, one at either side of the division piece and these ports are
separated by the knuckle jointed piece, which serves to prevent a direct communi-
cation being formed between them at any time. In operation fluid enters the
pump by one port, according to the direction of rotation, and passes into the space
between the loose ring or cylinder and the main cylinder, when the rotation of the
disc forces the fluid out at the other port.
In Fig 1 a pump of this description is shewn in combination with apparatus for
indicating the direction and speed of rotation, while in Figs 4 and 5 there is shewn
a pump according to my Invention, intended for any use for which it may be
found to be adapted. Like letters of reference indicate similar parts in both
Figures.
G, H, Fig 1, are two compartments, one of which say H is, for a given direction
of rotation, in communication with the inlet or suction side of the pump, and the
other G with the outlet or delivery side of the pump. Connected to and forming
part of each compartment is an air vessel I, the communication between the air
vessel and the compartment taking place through the perforations i i. In addition
to the communication that takes place between the compartments Gand H through
the pump, a second or return communication is provided through the pipe J. The
size of the communicating passage may be adjusted by hand or may be set to vary
automatically according to the pressure at the delivery side of the pump. In the
arrangement illustrated in the Drawings the valve J' is lifted by the pressure
acting on its under side. This pressure is admitted to it by the small passage j¹,
which contains a double non return valve (not shewn). The office of this valve is
to shut off direct communication from one vessel or compartment to the other, and
yet always to allow the pressure to penetrate to the valve J' whether it comes
from one compartment or the other. When the pressure accumulates in either
compartment beyond a determined amount the plug J is raised and an increased
passage opened for the return of the fluid to the suction side of the pump.
Each air vessel I contains at its upper part an expansion chamber K consisting
of a fixed plate L and a similar loose plate L' connected by coiled spring L², and
by a bag or cylinder M of pliable air tight material provided with rings round its
circumference. The spring is set to hold the movable plate at a definite distance
4

page_text: from the fixed one; and to assist all movements tending to place the two plates
nearer together or further apart. The object of using the expansion chamber is to
cause the pressure in the air space to be an approximately exact measure of the
speed of rotation of the pump. This may be attained still more exactly by the use
of expansion chambers of other forms than cylindrical such for instance as conical.
Each air vessel has connections N for the attachment of pipes to convey the pressure
from the air vessel to gauges, dials or indicators, such as that illustrated in Fig 6.
O, P, Fig 6 are two tubes, each of which is in communication with one air vessel.
The two tubes are connected to the opposite sides of an axis Q carrying a pointer
R, moving over a scale S, and co-operate to move it. When a vacuum exists in
one tube there is pressure in the other and vice versa, and from the positions of the
two tubes it follows that they are never in opposition, but always tend to move the
pointer in the same direction.
The action of the apparatus is as follows;-Supposing the shaft to rotate in the
direction of the arrow the pump draws liquid from the compartment H and delivers
it to the compartment G, consequently the air in the right hand vessel I becomes
tarefied and that in the left hand vessel compressed and the pressures in these two
vessels are communicated to the tubes of the gauge Fig 6, and move the pointer to
one side or the other. As soon as there is an excess of pressure in G over H the
liquid commences to circulate through the pipe J. Should the pressure in G
increase beyond a certain amount the plug J' will rise and allow the liquid to
return to H at an increased rate. If the shaft from which the pump is driven be
reversed the opposite state will obtain and there will be an excess of pressure in
H over the pressure in G, and the pointer of the gauge will be moved in the
opposite direction.
Having thus described the nature of the said Invention and the manner in
which it is to be performed, I would have it understood that what I consider to be
novel and original and therefore claim as the Invention secured to me by the
Letters Patent hereinbefore in part recited is :-
1. The use for indicating the speed and direction of rotation of a shaft of a
rotary pump capable of reversal in connection with two vessels or compartments
each occupied partly by liquid such as water and partly by elastic fluid such as air
and each having its elastic fluid space connected by a pipe to one or more gauges,
scales, dials, or indicators, the arrangement being such that when the pump is in
operation the elastic fluid is compressed in one vessel or compartment, and expanded
in the other vessel or compartment substantially as described.
2. In an apparatus of the kind referred to in Claim 1 wherein one vessel or
compartment is subject during the operation of the pump, to a pressure greater
than the atmosphere and one to a pressure, less than the atmosphere providing
between the two vessels or compartments an adjustable communication whereby
to return to the suction side of the pump liquid in such quantity as will accord
with the difference of pressures in the two vessels or compartments substantially as
described.
3 In an apparatus of the kind hereinabove set forth for indicating the speed and
direction of rotation of a shaft the use of a gauge or indicator wherein the pointer
or index is moved by the co-operative action of two tubes or diaphragms whereof,
when the shaft rotates in one direction, one is subject to a pressure greater than
the atmosphere and the other to a pressure less than the atmosphere, and when
the shaft rotates in the other direction the above described action of pressure
'as respects each tube or diaphragm is reversed substantially as described.
4. The improved apparatus for indicating the speed and direction of rotation of
a shaft comprising a pump capable of reversal, two vessels or compartments from
one of which the pump draws and into the other of which it delivers according
to its direction of rotation and which vessels or compartments are occupied partly
by liquid and partly by elastic fluid, an adjustable channel connecting the two
(vessels or compartments, and a gauge, wherein two tubes or diaphragms co-operate

page_text: to move one pointer or index substantially as and for the purposes herein above set
forth.
5. In a pump the use in combination with an eccentric disc rotating within an
enclosing cylinder of a division piece or slide provided with a knuckle jointed piece
urged towards the said dise and serving to divide the inlet and outlet ports from
each other substantially as described,
6. In a pump of the kind referred to in the preceding claim the use in com-
bination with the rotating eccentric dise, enclosing cylinder, and knuckle jointed
piece of a loose ring or cylinder such as B³ that surrounds the eccentric disc and
runs in contact with the inner periphery of the enclosing cylinder and against
which the knuckle jointed piece bears as it operates to divide the inlet and outlet
ports from each other substantially as described.
7. The improved rotary pump constructed, arranged and operating as shewn in
and described with reference to Figs 4 and 5 of the Drawings.
In witness whereof I the said Lionel Swift have hereunto set my hand and
seal this Twelfth day of July in the year of our Lord One thousand eight
hundred and eighty two,
LIONEL SWIFT. (L.S.)