Improvements in Packing-devices for Engines and Pumps.
Year: 1893

page_text: Date of Application, 3rd Oct., 1893
Complete Specification Left, 3rd July, 1894-Accepted, 11th Aug., 1894
PROVISIONAL SPECIFICATION.
Improvements in Packing-devices for Engines and Pumps.
I, FREDERICK NOEL MACKAY, of 242, York Road, King's Cross, in the
County of Middlesex, Engineer, do hereby declare the nature of this invention
to be as follows:-
My invention relates to improvements in packing-devices for engines and pumps..
One of the objects of my said invention is to construct a packing which can be
placed in an ordinary stuffing-box, if desired, and which will accommodate itself to
irregularities in the rod which works through it.
Another object of my said invention is to construct an improved compound
stuffing-box, particularly well adapted for use upon refrigerating machinery and
on other apparatus wherein it is not only of importance that leakage of fluid from
the interior of the apparatus to the exterior should be avoided, but is also of
importance that air or oil from the exterior should not penetrate to the interior of
the apparatus.
According to one part of this invention I construct a series of rings to embrace
the rod, and I place the said series within a bush, which is received in the cavity
of the stuffing-box and at its lower end is bevelled, packed with copper or lead wire,
or otherwise constructed or arranged so that leakage past the exterior of the bush is
prevented. Each said ring is made in segments; some of the segments serve as
guides for the others, and all are pressed towards the rod by springs which bear at
their outer ends upon the interior of the bush, and at their inner ends are received
in suitable recesses in the segments. The segments of each ring are arranged to
break joint with those of adjacent rings. One end of the bush is closed by a screw
plug, hollowed out to receive oil by which the rod is kept lubricated. The said
plug, preferably, is kept from slacking back by a set-screw, and is so constructed
that it affords a hold for a tool by which the bush can be pulled out of the stuffing-
when released by the set-screw the plug may be readily unscrewed by the
same or another tool so that the packing-rings can be got at. The rings are
arranged to have end play in the bush, and they have a clearance between their
outer peripheries and the inner periphery of the bush. The ends of each ring
are faced, as also are the inner ends of the plug and bush, and these faced surfaces,
when in contact, will not allow steam or other fluid to pass between them. A very
small passage is made in the bush to allow a little steam to pass from the cylinder
into the bush to bear on the outside of the rings, to keep them up to their work.
At the top of the stuffing-box a joint may be made with a cover-plate, or an
ordinary gland can be employed.
box;
In the compound-stuffing-box constructed according to this invention, which will
now be described, by way of example, in its application to the top end of a vertical
cylinder, the lower portion of a stuffing-box is fitted with a bush in which rings are
provided as aforesaid. A second bush in line with the first one, is screwed into the
upper end of the latter, and a third bush is similarly screwed into a second one. The
second and third bushes are each divided into separate chambers by internal flanges;;
in one chamber in each of these bushes, packing-rings of the kind herein before
described, are provided; the other chamber in each is empty. The upper end of
the third bush is closed by a screw plug, constructed so as to be readily removable ;
for example it may have holes or channels therein, into which a screwed rod or
other tool can be inserted. In the said plug are small channels which afford com-
munication between a clearance around the outside of the rings in the third bush,
and a space left around the rod where the said bush encircles it. Above the third

page_text: bush a tight joint is made between a cover and the stuffing-box, by any suitable
means, and above the said joint I may employ another stuffing-box, preferably such
äs is described in the Specification of Letters Patent No. 4645 of A.D. 1888,
granted to me.
Around the second bush in the lower stuffing-box is a clearance, which is in
communication with an oil vessel and with any other vessel (such as the cooler, in
refrigerating apparatus) in which a moderate pressure exists, that is to say a
pressure lower than that in the cylinder to which this device is applied.
Small passages are provided in the wall of the second bush and of the first bush,
to lead into the said clearance. The pressure in the clearance passes through the
openings in the second bush and keeps the rings therein up to their work. Any
fluid escaping up past the rings of the lower bush passes into the empty chamber of
the second bush, and thence into the clearance, where uniform pressure is maintained
by reason of the connection of the clearance with the cooler .or other vessel as
aforesaid. Oil which passes into the said clearance, flows into the said chamber of
the second bush, keeps the rod lubricated, and assists in maintaining the efficiency
of the packing.
Any air or oil entering the stuffing-box comes into the space around the rod, at
the point where the screw-plug encircles it, and passes into the openings in the said
plug and thence into the space at the back of the rings in the upper bush, wherein
it serves to keep the said rings against the rod so as to prevent the inflow of air or
oil into the apparatus. The rings in the second bush prevent any leakage of the
air at the lesser pressure in the clearance to the exterior of the apparatus. Thus
the three sets of rings in the bushes prevent, respectively, leakage from the cylinder
to the exterior, leakage from the clearance in stuffing-box to the exterior, and
leakage of air and influx of oil into the apparatus from the exterior.
The lowermost ring in the upper bush makes a tight joint therewith, at its lower
edge, to further prevent the passage of air. The rings in all the bushes are preferably
faced to fit each other and the contiguous faces of the bushes, and are arranged to
have lateral movement and a slight movement with the rod.
The segments of the rings in the aforesaid stuffing-boxes are kept from turning
round the rod by set-screws, screwed through the bushes to bear on the segments.
Dated this 3rd dow of October 1802
HASELTINE,. LAKE & Co.,
45, Southampton Buildings, Loudon, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Packing-devices for Engines and Pumps.
I, FREDERICK NOEL MACKAY, of 242 York Road, Kings Cross, in the County
of Middlesex, 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 :-
My invention relates to improvements in packing-devices for engines and
pumps.
The object of my said invention is to construct an improved packing which can
be placed in an ordinary stuffing-box, if desired, and which will accommodate itself
to irregularities in the rod which works through it. Two or more of the aforesaid
.packing-devices can be combined in one stuffing-box, to form what I term a
compound-packing device particularly well adapted for use upon refrigerating
machinery and on other apparatus wherein it is not only of importance that leakage
of fluid from the interior of the apparatus to the exterior should be avoided, but is
also of importance that air or oil from the exterior should not penetrate to the
interior of the apparatus.
According to one part of this invention I construct a series of rings to embrace

page_text: Figure 2 shows a stuffing-box fitted with a modified form of my improved packing

page_text: the pressure of the working fluid in the space F however is the principal agent in
maintaining the rings tight against the rod. When the machine is working, the
pressure with which the segments are pressed against the rod is greater or less
according as the pressure in the cylinder varies; by this means the resistance to
leakage accommodates itself to the requirements. Any steam escaping round the
rings of the part C passes into the empty chamber c² of the part C and thence
through the passages c into the clearance A' which surrounds the parts C¹ and C².
This clearance space is connected by pipes G with a chamber or receptacle in which
the pressure is less than it is in the cylinder, for example it may be connected with
the exhaust pipe as hereinafter described. Whatever pressure there is in the
clearance space A' acts on the rings E in the bush C' through the passages c³ and
presses them against the piston rol.
The screw plug D which as aforesaid closes the top of the part C is provided
with channels d, d which form a communication between the space F' outside the
packing rings E and the space between the plug and the rod.
Above this plug a tight joint is made between the packing and a cover H and
above the joint I may employ another stuffing-box preferably snch as is described
in the Specification of Letters Patent No. 4645 of A.D. 1888 granted to me.
It will be observed that air or oil entering the packing between the screw plug D
and the rod passes into the clearance space F' and if the rings are not tight into
the annular chamber c³, the rings E of the part C¹ prevent such oil or air from
passing further. In a similar manner steam from the cylinder may pass through
the channels and space F to the chamber and clearance A¹ but will not leak
past the rings E of the bush C₁ to the exterior. Thus the three sets of rings E
prevent respectively, leaking, from the cylinder to the exterior, leakage from
space A to the exterior, and leakage of air and influx of oil into the apparatus
from the exterior.
The pressure in the clearance space A¹ is always less than the maximum
pressure in the cylinder so that the packing the outermost part C' of the device is
not required to stand such a high pressure as the packing in the part C, moreover
any fluid which leaks past the packing in part C owing to the high pressure thereon
escapes into the clearance A¹ and is so retained in the apparatus.
The rings in all the bushes are preferably faced to fit each other and the
contiguous faces of the bushes, and are arranged to have lateral movement and a
slight movement with the rod.
In Figures 2 and 3 a modified form of packing device is shewn. The clearance
space A extends from top to bottom of the bush or outer case of the packing device
which is constructed of only two parts C, C¹ screwed together at C3 and provided
with a screw C³ as shewn in Figure 4 to prevent the same from slacking back.
The bush is bevelled and packed with lead at the top in the manner hereinbefore
described for the bottom. The two parts C, C¹ shewn in Figures 4 and 5 are
provided with internal flanges c, c' so that the interior space is divided into three
parts in each of which two packing rings such as hereinabove described with
reference to Figure 6, are placed. Between the inner faces of said rings, and the
outer faces of the flanges c, c I place washers I, I a plan view of one of which
is shewn in Figure 7. Said washers are made with radial channels i, i and longi-
tudinal channels, and slide casily upon the piston rod. Both the lower and
upper ends of the bush or casing are provided with screw plugs D, D somewhat
similar to the plug D hereinbefore described with reference to Figure 1 said plugs
being provided with annular chambers and very loosely fitting the piston rod as
shewn. I also provide in said plugs radial slots d³ in which a suitable tool may be
inserted to screw out the plugs. In the bottom plug in addition to these orifices I
make longitudinal channels d' through which the space d² in said plug commu-
nicates with the clearance space F between the innermost rings E and the part C
of the bush. These details are clearly shown in Figures 8 and 9 which are
plan views of the top and bottom plugs respectively. Screws prevent the
plugs working loose..

page_text: It will be observed that in this packing-box the spaces, c³, c shewn in Figure 1
are absent otherwise the action is precisely the same. The orifices c8 are made at
back of the outermost set of rings as shewn in Figures 3 and 4 instead of at the
back of the middle series.
Steam from the cylinder passes through the channels d³ in the lower plug to the
space and then through the passages to the annular chamber where it
presses the rings against the rod. Any steam which escapes between the upper
ring and the flange c will readily pass through the radial channels i and passages i¹
to the space behind the second set of rings E and on escaping further will reach
in a similar manner the back of the third set of rings whence it passes through
the orifices to the clearance A¹ which is connected to a low pressure chamber
by the pipe G.
Oil for lubrication is placed in the annular chamber d' in the upper plug D and
if there is any leakage will pass through the same channels as the steam from
the cylinder but in an opposite direction thereto, the rod will therefore be
lubricated at the inner peripheries of the rings I and flanges c, c.
In Figure 10 I shew a plan of part of a compound engine. J is the steam inlet,
K is the high pressure cylinder with valve chest L and exhaust pipe J', and K' the
low pressure cylinder with valve chest L' and exhaust pipe J. The waste pipe G¹
from the clearance space A' in the piston rod stuffing-box of the cylinder K is
connected to the exhaust pipe J1 of the high pressure cylinder and the pipe G' from
the valve spindle stuffing-box is connected to the low pressure steam chest L'.
In the same manner the waste pipe G³ from the stuffing-box on the low pressure
cylinder K and the pipe G* from the stuffing-box on the steam chest L' are both
connected to the exhaust J³.
In the packing devices illustrated I shew three sets of packing rings E but it
will be understood that I may use one, two or any suitable number of sets of rings
and I may provide one, two or more rings in each set.
When I use one set of rings only I prefer to call the packing device a simple
packing device those with more than one set of rings such as shewn in the drawings
I prefer to call compound packing devices.
My improved packing may be used for packing piston or pump rods or valve
spindles or any other similar moving rod.
A supplementary apparatus may be provided to lessen the pressure in the
space A and round the rings to any desired extent. For example I may use an
exhaust and compression pump or the pressure may be reduced by absorption.
In any case there is no loss of the fluid used in the machine which in the case of
refrigerating machinery is very important,
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is-
1. A stuffing-box so constructed and arranged that leakage past the packing is
caused to flow into a chamber in which the pressure is lower than in the working
chamber for the purpose specified.
2. For a stuffing-box a packing in which the parts in contact with the rod
are formed of segmented rings, which have a clearance space behind them into
which space the working fluid can enter so as to maintain the rings in contact with
the rod, substantially as described.
3. For use in a stuffing-box a segmented ring, substantially as described with
reference to Figure 6 of the drawings.
4. Stuffing-boxes constructed substantially as described and operating as
specified.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.