IMPROVEMENTS IN ROTARY PUMPS
Year: 1881

page_text: LETTERS PATENT to Chester Comstock, of New Canaan, Fairfield County,
State of Connecticut, in the United States of America, but at present residing
at Wolverhampton, in the County of Stafford, Manager of Works, for an
Invention of "IMPROVEMENTS IN ROTARY PUMPS."
PROVISIONAL SPECIFICATION left by the said Chester Comstock at the
Office of the Commissioners of Patents on the 11th August 1881.
CHESTER COMSTOCK, of New Canaan, Fairfield County, State of Connecticut,
in the United States of America, but at present residing at Wolverhampton, in the
County of Stafford, Manager of Works. "IMPROVEMENTS IN ROTARY PUMPS."
My Invention consists in the construction and arrangement herein after
described of the parts of a rotary pump, whereby simplicity in construction and
efficiency in action are secured.
The body or outer case of the pump consists of a hollow cylinder closed at its
ends and and having on its cylindrical surface two openings separated by a strong
partition.
These openings respectively constitute the ingress and egress passages of the
pump. In the axis of the body or outer case is a shaft turning water tight in
bearings in the ends of the cylinder. This shaft carries a cylinder concentric with
the body or case, the space between the said cylinder and the interior of the body
or case constituting an annular chamber. In the said cylinder, and nearly in the
direction of a diameter are two recesses, extending from the surface of the
cylinder nearly to the shaft on which the cylinder is mounted. The said cylinder
is of somewhat greater length than the interior of the marginal portions of the
body or case, and its ends work water tight in circular depressions in the ends of
the body or case. The recesses in the cylinder extend nearly from end to end of
the cylinder, or have the same length as the interior of the marginal portion of the
body or case.

page_text: In the recesses in the cylinder plates or valves are situated and are made to
protrude from the recesses and to retire into them at the required times by the
mechanism herein after described.
When the plates or valves are in their advanced position they cross the annular
chamber of the pump and divide it into two water tight divisions, and by the
rotation of the shaft. carrying the cylinder and the said plates or valves the
capacity of one of the divisions is made to increase, and at the same time
the capacity of the other division diminishes to a like extent. Into the former
division water is drawn, and from the latter it is forced on the turning of the
shaft.
In order to force and support the plates or valves in their advanced position,
and to withdrawn them when they have to pass the division between the ingress
and egress openings, I employ mechanism constructed as follows:-In the inner
face of one or both of the closing plates of the body or case is a slot or hollow cam.
This slot for about three fourths of its length is concentric with the shaft. The
remaining portion is eccentric, and the whole constitutes a closed heart shaped
slot. The cylinder has two levers jointed to it near the two plates or valves. The
long arm of each lever engages in a recess in the adjacent plate or valve, and the
short arm, which makes an obtuse angle with the long arm, carries a pin or
projection which takes into the heart shaped slot described. When the shaft of
the pump is turned the plates or valves are by the action of the levers and heart
shaped slot described forced outwards until they approach the division between
the ingress and egress openings, when they are withdrawn into the recesses in the
cylinder. When either of the plates or valves has passed the said division it is
again advanced. By this arrangement the annular space between the cylinder and
inner surface of the body or case is divided by one or other of the plates or valves,
and by the changing capacity of the said divided space water is drawn into the
enlarging compartment and forced out of the diminishing compartment.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Chester Comstock in the Great Seal Patent Office on the 30th
January 1882.
CHESTER COMSTOCK, of New Canaan, Fairfield County, State of Connecticut,
in the United States of America, but at present residing at Wolverhampton, in the
County of Stafford, Manager of Works. IMPROVEMENTS IN ROTARY PUMPS."
86
My Invention consists in the construction and arrangement hereinafter described
of the parts of a rotary pump, whereby simplicity in construction and efficiency in
action are secured.
The body or outer case of the pump consists of a hollow cylinder, closed at its
ends and having on its cylindrical surface two openings separated by a strong
partition.
These openings respectively constitute the ingress and egress passages of the
pump. In the axis of the body or outer case is a shaft turning water tight in
bearings in the ends of the cylinder. This shaft carries a cylinder concentric with
the body or case, the space between the said cylinder and the interior of the body
or case constituting an annular chamber. In the said cylinder, and nearly in the
direction of a diameter, are two recesses extending from the surface of the
cylinder nearly to the shaft on which the cylinder is mounted. The said cylinder
is of somewhat greater length than the interior of the marginal portions of the
body or case, and its ends work water tight in circular depressions in the ends of
the body or case. The recesses in the cylinder extend nearly from end to end of
the cylinder, or have the same length as the interior of the marginal portion of the
body or case.
In the recesses in the cylinder plates or valves are situated, and are made to
protrude from the recesses and to retire into them at the required times by the
mechanism hereinafter described.
When the plates or valves are in their advanced position they cross the annular
chamber of the pump and divide it into two water tight divisions and by the
rotation of the shaft carrying the cylinder and the said plates or valves the
capacity of one of the divisions is made to increase, and at the same time
the capacity of the other division diminishes to a like extent. Into the former
division water is drawn, and from the latter it is forced on the turning of the
shaft.
This
The
In order to force out and support the plates or valves in their advanced position
and to withdraw them when they have to pass the division between the ingress and
egress openings, I employ mechanism constructed as follows:-In the inner face of
one or both of the closing plates of the body or case is a slot or hollow cam.
slot for about three fourth of its length is concentric with the shaft.
remaining portion is eccentric, and the whole constitutes a closed heart shaped slot.
The cylinder bas two levers jointed to it near the two plates or valves. The long
arm of each lever engages in a recess in the adjacent plates or valves, and the short
arm which makes an obtuse angle with the long arm carries a pin or projection
which takes into the heart shaped slot described. When the shaft of the pump is
turned the plates or valves are by the action of the levers and heart shaped slot
described forced outwards until they approach the division between the ingress and
egress openings, when they are withdrawn into the recesses in the cylinder. When
either of the plates or valves has passed the said division it is again advanced. By
this arrangement the annular space between the cylinder and inner surface of the
body or case is divided by one or other of the plates or valves, and by the changing
capacity of the said divided space water is drawn into the enlarging compartment
and forced out of the diminishing compartment.
•

page_text: I will now describe with reference to the accompanying Drawings the manner in
which my Invention is to be performed.
Figures 1 and 2 represent vertical sections taken at right angles to one another
of a rotary pump containing my improvements; Figure 3 represents the face of the
rotary cylinder of the pump, and exhibits the construction of the lever mechanism
by which the valves or plates are worked; and Figure 4 represents the inner face
of the cover or lid of the fixed case or body of the pump, and exhibits the con-
figuration of the cam or slot in which the lever mechanism works, as hereinafter
particularly explained.
The same letters of reference indicate the same parts in the several Figures of
the Drawing.
A is the fixed body or case of the pump, consisting of a hollow cylinder closed
at both ends. One end is provided with a moveable lid or cover B; a is the
ingress passage, and 6 the egress passage of the pump; e is the rotary cylinder of
the pump working in and situated concentrically with the outer case or body A,
an annular space or chamber A* being formed between the case A and the
cylinder e (see Figure 1). The pump cylinder e is carried by the horizontal shaft d
worked by steam or other motive power, the said shaft working water tight in a
bearing in the closed end of the cylinder and in a stuffing box in the lid or
cover B of the said cylinder (see Figure 2). At the middle of the base of the fixed
case or body A is a strong partition c for separating the ingress and egress
passages a, b, in the said case or body. This partition is furnished with an elastic
metallic packing constructed as herein after described to ensure a water tight
joint between it and the rotating cylinder e. The manner in which the cylinder e
works water tight in the case A will be best understood by referring to Figure 2,
where it will be seen that the cylinder e is of somewhat greater length than the
marginal portions at k, k, of the body or case A, and the ends of the said cylinder
work water tight in circular depressions in the ends of the said body or case;
1, m, are the valves or radially sliding plates carried by the rotating cylinder e, the
said valves working in the recesses fig. These recesses extend in one direction
from the circumference of the cylinder e nearly to the shaft d (see Figure 1), and
in the other direction nearly from end to end of the cylinder (see Figure 2). The
valves l, m, on the rotation of the cylinder e are made to protrude from the
recesses f, g, and cross the annular chamber A² of the pump (as shewn with respect
to the valve ), or to retire into the said recesses (as shewn with respect to the
valve m) when they pass the fixed division c. The advancing and retiring motions
of the valves or sliding plates l, m, are effected and the said valves supported by the
following mechanism.
Each
In the inner face of the cover B of the case or body A is a slot or heart shaped
cam p, p, as best seen in the separate view of the said cam or slot in Figure 4.
The part p of the said cam or slot is for about three fourths of its length concentric
with the shaft d, and the remaining portion marked p³ is eccentric to the said
shaft. Near the valve l is a lever q, and near the other valvem is a similar lever 7.
These levers are jointed to and are carried by the rotating cylinder e.
lever q, r, has a long and a short arm, the long arm of each lever engaging with its
respective valve 1 or m, and the short arm carries a roller which works in the
heart shaped cam or slot p, p². The construction of the levers q, r, will be under-
stood by referring to the lever q represented in Figure 3, where the said lever
turns on the centre or axis q, and its two arms are marked respectively q and q³.
The long arm q which engages with the valve is fixed on one end of the said axis,
and is situated at the middle of the cylinder (see Figure 2), and the short arm q³ is
fixed on the other end of the said axis and is situated in a recess in the end of the
cylinder e, and is furnished with a pin or projection q³ having on it a roller q³
which works in the heart shaped cam or slot p, p².
When the cylinder e is turned in the direction of the arrow, Figure 1, the plates
or valves l, m, are by the action of the levers q, r, and heart shaped cam or slot p,p³,
forced outwards so as to cross the annular chamber A, the rollers on the short

page_text: arms of the levers working in the concentric portion p of the hollow cam or slot,
and when the said valves l, m, approach the division c between the ingress and
egress openings a, b, the said valves are withdrawn into the recesses in the
cylinder e, and after they pass the said division c. the valves are again forced
outwards. The withdrawal and forcing outwards of the valves as they approach
and after they have passed the division c are effected by the rollers on the short •
arms of the levers l, m, working in the eccentric parts p³, p³, of the heart shaped
cam or slot.
In large pumps two heart shaped cams or slots may be used, one at each end of
the pump case A. In this modification the axes on which the levers q, r, are fixed
are carried to the fixed end of the case A as well as to the cover end B, and on
each end of the axes is a short arm with a roller for working in the heart shaped
cam or slot at each end of the case A. In Figures 1 and 2, the valve 7 is represented
at its highest position and forced outwards so as to divide the annular chamber A³.
into two parts, and the other valve m is represented drawn inwards and in the act
of passing the fixed division c, the water in the annular space A³ on the egress side
of the valve being forced by the said valve from that space through the egress
opening b, while water is being drawn through the ingress opening a into the
annular space on the other side of the said valve . When the valve m has passed
the division c, it is forced outwards and acts like the other valve l. In this way
the annular space A' between the cylinder e and case A is divided by one or other
of the valves or m, and by the changing capacity of the said divided space water
is drawn into the enlarging compartment through the ingress passage a, and water
is forced out of the diminishing compartment through the egress passage b, as will
be understood by an examination of Figure 1.
I will now describe some of the details of construction of the pump. In order
to avoid leakage in the valves l, m, I make them with converging sides marked l², m³,
respectively in Figure 2, the sides of the case or body A being made of a corre-
sponding figure. By this construction the valves wear themselves into shape, thus.
avoiding leakage. This part of my Invention may be applied to the valves or
radially sliding plates of rotary pumps generally.
The edges of the valves l, m, or those parts which take a bearing against the
cylindrical surface of the case or body A, are provided with metallic packings 7³, m³.
Each of these packings consists of a stem working in a recess in the body of the
valve, and having a cross head which bears against the cylindrical surface of the
case A. The packings are pressed outwards by bow springs at , m*, under the
stems.
The action of the bow springs l, m, is limited by the slots s' and 8² on the
valve, and the rivets t, t, which pass through the valve and packing pieces 1³, m³.
In order to prevent the rivetting up of the rivets t, t, contracting the space in
which the packing pieces work and thereby impeding the action of the said packing
pieces, rings t, t, upon the rivets t, t, are used, by which the rivetting is prevented
from closing the spaces in which the packing pieces work.
A range of motion may be permitted to the packing pieces of one sixteenth of
an inch, and the valves will work watertight until they have shortened one sixteenth
of an inch by wear.
I construct the metallic packing for the division c in the manner represented.
The said packing for the division c is marked c³, and is pressed outwards by the
bow spring c³.
Among the advantages possessed by my Invention it will be observed that there
is only one stuffing box in the pump, namely, that through which the shaft & passes
and in which it works, and the valves, as already mentioned, have the advantage,
that during working they wear themselves into shape and thus avoid leakage.
Having now described the nature of my Invention, and the manner in which the
same is to be performed, I wish it to be understood that I claim as my Invention
of "Improvements in Rotary Pumps,"
First. The construction and combination of the parts of the mechanism herein

page_text: G
before described and illustrated in the accompanying Drawings, for working the
valves or radially sliding plates of rotary pumps, that is to say, the construction of
the levers q, r, and parts connected with them, and their combination with the
heart shaped cam or slot p, p³, (or cams or slots) in which the rollers on the short.
arms of the said levers work, substantially as described and illustrated.
Secondly. The construction of the valves or radially sliding plates of rotary pumps,
herein before described and illustrated in the accompanying Drawings, that is to
Bay, making the said valves or plates with converging sides, so that in use they
wear themselves into shape and thus avoid leakage, substantially as described and
illustrated.
Lastly. The combination with the valves of the rotary pump, described and
illustrated, and with the fixed division between the ingress and egross passages of
the said pump, of the elastic metallic packings described and illustrated in the
accompanying Drawings.
In witness whereof, I, the said Chester Comstock, have hereunto set my
hand and seal, this Thirteenth day of January, in the year of our Lord One
thousand eight hundred and eighty two.
Witness,
JOSEPH F. SILLIMAN,
New Canaan,
Conn., U.S.
CHESTER COMSTOCK. (L.S.)