Improved Means for Packing Pump Plungers.
Year: 1899

page_text: Date of Application, 3rd Mar., 1899-Accepted, 5th Aug.,
1899
COMPLETE SPECIFICATION.
Improved Means for Packing Pump Plungers.
I, JOSEF SCHAEFER, Engineer, No. 4, Westwall, Crefeld, Germany, do hereby
declare the nature of my said invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:
One of the greatest difficulties in the construction of the so-called inside-plunger
pump is that of securing adequate packing for the plunger.
Hitherto for the purpose of packing the plunger, which, as is well known
works in all cases, in two pump barrels, the one of which is placed above the
other, stuffing boxes or packing collars have been used and as the use of two
stuffing boxes or packing collars has in most cases proved impracticable, since
it is impossible to tighten up the two stuffing boxes or packing collars equally,
the one stuffing box or packing collar has been discarded and the alternative
of building up the cylindrical part which serves for the reception of the cylinder
and so constructing the cylinder that it is connected with the one remaining.
stuffing box or packing collar has been adopted. In this way the cylinder-cover
of the plunger and the one pump chamber are simultaneously sealed.
This arrangement has however the disadvantage that the whole contrivance is
liable to easily get out of order in consequence of the uneven tightening of
the several stuffing boxes or packing collars. Besides, pumps of this description
are attended by the greatest difficulties in regard to their fitting.
These inconveniences are completely obviated by the process which is the object
of the present invention inasmuch as stuffing boxes or packing collars are entirely
discarded. The closure of the cylindrical part, which serves to connect the two
chambers and to receive the plunger, is effected by the provision of one or more
annular spaces which, either in consequence of the pressure produced in them or of
inserted packing rings or of both simultaneously, impede the passage of the water
from the one chamber into the other. The lengthy and difficult process of packing
the hitherto necessary stuffing boxes or packing collars is also completely obviated
as are the stoppages occasioned by the incomplete nature of the closure effected by.
the packing. This is especially the case with pumps which are used for raising
turbid liquids which, even with the best stuffing boxes or packing collars possible
have proved useless in a very short time.
A pump constructed according to the present process is illustrated in the
accompanying drawing, in
Figure 1 is a sectional view. ›
Figure 2 shews a variation in form of this contrivance.
Figures 3 & 4 shew in section and elevation a further variation and simplified
method of construction.
Figures 5 & 6 shew variations in the construction of 3 & 4.
The chambers a and b in Figure 1 which are alternately exhaust and pressure
chambers, are connected by the cylindrical part e which serves to receive the
plunger d which works in both chambers. The inner surface of this cylinder c has
à series (in the present instance 3) of annular spaces e, f and g, the conformation
of which is shewn in Figure 1.

page_text: g
A pressure has to be produced in these spaces which shall prevent the passage
of water from the chamber a to the chamber 6 or vice versa.
For this purpose
the channels are connected with the pressure chambers, a suitable arrangement
being the connection of the channel e with the chamber a and the channel with
the chamber these chambers being pressure chambers alternately, while the
middle cliannel f is connected with the chamber h which is always a pressure
chamber. The connection is suitably made by the tubes e¹, f', and g¹. For the
sake of illustration, if the plunger is moved in the direction of the arrow from left
to right, an excess of pressure is produced in the chamber and the water has a
tendency to pass into the chamber a in which a vacuum is produced. To prevent
this passage the flow is partially stopped owing to the fact that, for reasons given
more fully below a' pressure results in. g. which is greater than the pressure in
the space 6 as the equalisation of pressure in g cannot take place so quickly on
account of the smallness of the diameter. of the tube g. The water which still
passes on is stopped from forcing its way further by the pressure in the space f.
Moreover there is a pressure in the space c.which effectually stops the last forward
tendency of the water. Naturally the number of channels is regulated.by. the
size of the pump and the pressure produced. When. the plunger is withdrawn the
same procedure is repeated. It is an essential feature that the diameter or cross
section of the tubes e, g! be of such a size that the equalisation of pressure through
these tubes may not take place as quickly as does the alternation of pressure in
the chambers, a and b.
2.
In pumps of simplified construction, such as. that illustrated in Figure 2, where
the chambers are separated by a partition-wall m, the cylindrical part c, which
receives the plunger d, is firmly affixed to the wall and the spaces e and gare
provided, with holes e¹g to connect them with the chambers a and b. These
holes corresponding to the similarly lettered tubes in Figure 1. The middle
channel is in this case connected with the pressure chamber h by means of
a hole bored in the partition wall. The working of a pump of this kind is
exactly the same as that of the pump in Figure 1.
In some class of pumps, especially those which work with a lower pressure, it
is not necessary for a large series of annular spaces to be provided in the
cylinder-wall; on the contrary only one space is sufficient to prevent the flow
of water from one chamber to the other. Figures 3 and 4 illustrate a device
of this kind and in this case a packing-ring r, is inserted in the annular space f
which surrounds the plunger. This is, in the arrangement illustrated, pressed
against the plunger by means of spring. t. The annular space in this case forms
a casing, the interior of which may be easily and conveniently reached by the
removal of a cover so that it is possible to get at the packing ring at any time.
The packing ring when inserted in this way in the annular space f is quite
sufficient to check the flow of water from one chamber to the other. If, however,
greater security is desired the annular space f can, as shewn in the variation
illustrated in Figures 5 and 6, be suitably connected with the pressure chamber
of the pumps by means of the tube f¹. In this way the pressure in the annular
space and the inserted packing-ring are simultaneously used to prevent the flow
of water. There is still to be mentioned the arrangement shewn in Figures-5
and 6 where the packing ring is firmly held in position and pressed against the
plunger by means of an india-rubber band y, encircled by hempen-cords. The
casing w, which is formed by the annular space, is suitably made, in two parts,
so that on taking them apart, it is possible to get at the packing-ring easily and
conveniently.
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:
the
CLAIM.
inside luncor numa

page_text: the cylindrical part, which connects the two chambers and serves to receive the
plunger, being provided with one or more annular spaces, which either in conse-
quence of the pressure produced in them or by means of an inserted packing-ring
or by both simultaneously check the flow of water from the one pump chamber
to the other.
Dated this 2nd day of March 1899.
JOSEF SCHAEFER,
By George Barker,
Fellow of The Chartered Institute of Patent Agents,
Agent for Applicant,
77, Colmore Row, Birmingham.