IMPROVEMENTS IN SELF-LUBRICATING JOURNAL BEARINGS, AND IN THE MANUFACTURE OF COMPOUNDS FOR THE SAME.
Year: 1878

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS
IN SELF-LUBRICATING JOURNAL BEARINGS, AND IN THE MANUFACTURE OF
COMPOUNDS FOR THE SAME.' A communication from abroad by James
H. Gilbert and William H. L. Lee, both of New York, in the United States
of America.
COMPLETE SPECIFICATION filed by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 31st August 1878.
"
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN SELF-LUBRICATING JOURNAL BEARINGS, AND IN
THE MANUFACTURE OF COMPOUNDS FOR THE SAME' A communication from abroad
by James H. Gilbert and William H. L. Lee, both of New York, in the United
States of America.
Numerous compounds have heretofore been made and suggested, many of which
have been patented as a material for journal bearings calculated to supply its
own lubricant. These may be classified under two heads videlicit, those the
lubricant property of which, like tallow, is incorporated to be developed in the
use of the compound by friction or heat, and those having a lubricant property
which, like plumbago, is incorporated to afford a permanent dry antifriction
bearing.
Among the many advantages which the latter possess over the former are that
they are not so liable to wear, or by oxidization to determine those acid re-actions
which attend fatty substances.
The difficulty however heretofore experienced in making such compounds is such
that notwithstanding their great advantage no means were devised to successfully
and practically incorporate plumbago or graphite in a compound sufficiently hard to
Price B11

page_text: afford bearing surface to journals, yet so holding the particles of plumbago or
graphite as to readily yield the same for purposes of lubrication.
The object of the first part of this Invention therefore is to produce a dry and
sufficiently hard compound capable of being shaped into suitable journal bearings,
and containing a lubricant which shall not be melted out of and disintegrate the
composition in supplying a fatty matter, but one incapable of being decomposed,
unchangeable in its own properties, and therefore not affecting the ingredients with
which it is combined, or altering the character of the composition of which it is an
eliment, which lubricant shall be so embodied in the compound as to be readily
applied to the parts in friction contact.
To this end the first part of this Invention consists,―
First. As a new composition of matter, in the combination of plumbago, asbestos,
and sulphur, substantially as herein-before described.
Second. As a new composition of matter in the combination of asbestos, sulphur,,
and plumbago, in three parts of varying proportions (as to volume, or quantity, or
weight).
Third. In the method of combining asbestos, sulphur, and plumbago, by reducing
them to powder and thoroughly mixing them together, and by then subjecting the
pulverulent compound in a mould to pressure and heat.
Fourth. As a new article of manufacture of journal bearings, consisting of
plumbago, asbestos, and sulphur, moulded under pressure and heat.
Fifth. As a new article of manufacture of self-lubricating journal bearings,
consisting of a plumbago and asbestos compound united with an iron or other
metallic casing, into which it is compressed and moulded.
For spindle bearings and some other uses however it has been found that owing to
the rough usage they are often subjected to by operators, and particularly when the
spindles are lifted out of their bearings and violently replaced, it often happens that
the sharp pivots on striking. the compound chip the same off or break them. It
therefore became necessary to produce a compound possessing the same lubricating
and heat-resisting properties, but which also shall resist percussive action, to which
it may be exposed and subjected.
The object of the second part of this. Invention therefore is to make a plumbago
asbestos compound which shall be hard, lubrifiant, tough, yet capable of being
moulded to receive the finest and most delicate impression, and so that bearings for
spindles of the most delicate structure may be provided.
Another object of the said Invention is to make the journal bearings in moulds,
from which the compounds may be removed and placed in special metallic or
wooden cases, or in frames of any material adapted to receive them.
To this end the Invention further consists,-
Sixth. Of a new composition of matter, being a plumbago vulcanite, one of the
ingredients of which is asbestos.
Seventh. In the method of compounding, moulding, and shaping asbestos, plum-
bago, vulcanite compounds, as herein-after described.
Eighth. In making the same in moulds or cases, with which they are permanently
or temporarily united.
Ninth. In making the plumbago compounds with external polygonal configuration,
or by otherwise equivalently forming the same so as to prevent them from rotating
within the cases, or to fit the same directly into similar polygonally formed or
otherwise equivalently shaped receptacle in a frame or other structure.
And in order that the said Invention. may be fully understood I shall now pro-
ceed more particularly to describe the same, and for that purpose shall refer to the
several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
In the Drawings hereunto annexed I have shewn the Invention applied to the
construction of self-lubricating journal bearings for spindle steps and bolsters for silk
and cotton mills as one among its many uses:
A description of its manufacture for this purpose will indicate the necessary

page_text: processes, so that any skilled person can make and apply it to any kind of
machinery.
The spindles are placed in a frame when in use in a vertical position; the lower
end rests in a bearing called the "step;" the spindle is also passed through and
revolves in another bearing, called the "bolster," which is placed at a point about
two-thirds of its length from the lower end of the spindle.
In making the improved bearings the first step is to prepare the lubricating
compound. For this purpose asbestos, sulphur, and plumbago are taken in about
equal proportions, in volume or quantity, and reduced to a powder and thoroughly
mixed together, so that the result is a powder which is a mechanical mixture of the
three ingredients named.
By weight the composition would be as follows:-Plumbago, ten ounces;
asbestos, two ounces; sulphur, four ounces. I would however observe that I do not
confine myself to these proportions, but they are the proportions which have been
found most suitable for spindle bearings. The object then is to convert this powder
into a substance of such consistency that it can be made into a journal bearing. It
has been found most expedient to mould the powder into a case, which re-inforces
the compound, and prevents it from cracking or splitting off. An iron case has
been found suitable for this purpose.
In the manufacture of the spindle steps according to the Invention the operation
is proceeded with in the following manner:- An iron cast is taken of the form and
size indicated in the vertical section, Figure 1. This case is solid for a portion of
its length, as indicated, and has a cylindrical hole a bored in it, say, about one half-
inch in diameter and about one inch deep. The dimensions however are purely
arbitrary, and may be varied to any extent to suit the dimensions of the spindle
end. The cases used are cast and tooled. The case is now placed in a frame or
mould, shewn in section in Figure 2 and next herein-after described. This frame
consists of two parts, one, A, being a solid block, with a hole in the centre just large
enough to contain the iron case marked C, and of the same height, and another
block B of the same horizontal diameter as the block A, but having a hole b in its
centre of exactly the diameter of the hole in the iron case, but nearly twice as long.
This proportion of length is observed for convenience, for it has been found that
when they are in position the continuous tube of the block B and of the iron case
contains just enough of the powder to fill the case properly when compressed, and.
at the same time retain its lubricating quality at the best. The case is now placed
in the block A, and the block B is placed on the block A, so that the hole b in the
block B and that, a, in the case, form one continuous hole of uniform diameter. This
continuous hole is now filled with the powder, even with the top.
It is requisite that the powder should now be coinpressed in such a manner that
it shall all be crowded into the case and preserve a seat for the spindle. end to
revolve in. For this purpose a pin (shewn in elevation in Figure 3) is employed,
the main portion 'a' of which is of the same length exactly as the hole b in the
block B of the mould, and of a size to fit into it snugly. The projection 61
is of the same dimensions as the spindle end which is to revolve in the bearing, and
is intended to mould the socket in the bearing for the reception of the spindle.
This pin is now placed on the powder in the mould and forced down by strong
pressure until it is entirely within the block B of the mould, its upper end being
Bush with the top of the block B. In this manner the powder is forced into the
hole in the iron case and remains in the desired form of a journal bearing, as
indicated in Figure 4.
It has been found that the best means of compression for this purpose is hydraulic
pressure of ten tons. The powder having been thus compressed into the desired form
the next and last proceeding is to vulcanize it, which operation is carried out at a
temperature of about two hundred and sixty degrees Fahrenheit. This heat acting
upon the sulphur fuses it, and causes it to penetrate the whole mass, the result of
which is that the compound becomes a solid, firm material. The step is now ready
for use.

page_text: In vulcanizing the heat may be applied with the pin in or out at pleasure. It
has been found most convenient to remove the pin and sleeve.
The bolster is inade in a similar manner. It consists of an iron tube or case, say,
for example, about one and a half inches long, fifteen-sixteenths of an inch in diameter,
with a hole about five-eighths of an inch in diameter. In packing the powder into
the bolster the latter is placed on end, and on its upper end there is placed another
tube of the same size, but nearly twice as long, so that the holes of the two tubes
shall forin one continuous hole of uniform diameter. Into this hole there is placed
a pin of the size of the spindle, at the point where it is to turn in the bolster, and
of the length of the two tubes combined. This pin runs through the length of the
hole, and stands in a position concentric with the tubes; powder is then introduced
around the pin until the two tubes are full to the top, after which, by the same
means as before described, a sleeve is pressed upon the powder until it is all packed
into the lower tube around the pin. This sleeve is a tube of a size to fit snugly
into and fill all the space between the pin and the inner sides of the tubes. The
sleeve and upper tube and pin are then removed, and the powder remains in the
lower tube, compressed into the desired form; it is next vulcanized, and it is then
ready for use as a bolster. It has been found advantageous to leave in the lower
end of the bolster a shoulder of from one-eighth to one-sixteenth of an inch in thick-
ness, and such as to make the diameter of the tube at that point a little larger than
the diameter of the bolster hole when filled with the compressed powder, so that
the spindle shall not touch it. The reason of this is that the inill hands, when they
remove the bobbin from the spindles, pull them up with such force that the shoulder
of the spindle strikes against the lower end of the bolster, and would be liable to
break the compound if it were not protected. The shoulder in the bolster prevents
this, and does not interfere with the lubrication.
The improved journal bearing then consists of a compound, prepared as described,
which is re-inforced by a case, which may be of iron, brass, or any other desired
material. The proportions, herein-before given, are those which have been success-
fully adopted for spindle bearings actually made. It is important to ascertain
precisely what degree of solidity shall be given to the compound.
The greater the quantity of powder that is compressed into a given space the
more solid does the resulting mass become, and the less ready does it lubricate. It
therefore follows that the compression must be increased in proportion to the weight
and pressure which the bearing will have to sustain, and the amount of such
compression must be ascertained by experiment in relation to each class of bearings.
Asbestos and plumbago are non-conductors of heat, and the plumbago has an
inherent property of lubrication. These ingredients when united with the sulphur
by vulcanization form a compound which lubricates itself.
I shall now proceed to describe the manner in which the second part of this
Invention is or inay be carried into effect. Plumbago, asbestos, rubber, and sulphur
are taken in the proportions of about fourteen pounds of plumbago, eight ounces of
asbestos, four pounds of rubber, and one pound of sulphur. The plumbago and
asbestos are first finelý pulverized and mixed together with the sulphur, then the
mixture is ground in with the rübber between tlie rollers, in the manner well
known to rubber manufacturers, until all the different ingredients are thoroughly
incorporated in and taken up by the rubber, forming with it a homogeneous mass.
It is then rolled out into sheets and cut into strips of the required length, according
to the cases or article that is to be made from it. The strip is then rolled up very
close into a stick or cylinder, and with light pressure forced into a inetal case made 5
for its reception. The compound in its case is then vulcanized in the usual manner.
The hole or bearing surface may then be drilled out, according to the sizes and
forms of the spindles, or pivots, or journals. Another and perhaps more economical
plan of making the journal bearings of the compound described consists in moulding
the bearings or holes before and during vulcanization by means of a plátë having a 5
central pin, which is a counterpart of the bearing.
The case or mould being packed with the compound it is then closed by means

page_text: of the plate, the pin of which impresses the form of the bearing surface. The case
is then vulcanized, cooled, and the top plate is removed from it. Another method
consists in cutting the compound into strips of the required width to roll it on and
over a pin, which is similar to the journal, and until the space between the pin and
case is filled.
After vulcanization the pin is removed permanently, leaving the hole or journal
bearing in the compound in a perfect condition as to shape and size.
The cases or moulds may be made to separate in two or more longitudinal parts,
so as to allow of the delivery of the vulcanized compound and of its use in separate
cases.
In order to prevent such vulcanized bearings from rotating in their cases it is
preferred to make the outer surface of the moulded compound polygonal or pris-
matic, to be used in cases the interior of which are similarly or correspondingly
shaped. In lieu of the polygonal shape any other form or device may be adopted,
for example, a groove in the one end, a lug, spline, or stud on the other. Again,
the cases may be entirely dispensed with, except as moulds for the shaping and
vulcanization of the compound, and the frame may have receptacles or holes
suitably shaped for the reception of the compound, which, if made as described,
will be found sufficiently strong to resist pressure, blows, and the like, without the
aid of the metal cases, more or less necessary with other compounds.
Although the compound has been described as applied to spindle or pivoted bearings
it is obvious that it may be used in connection with other bearings, such, for example,
as bearings for journals of axles, collars, and the like. Different uses and applications
of the compound will require corresponding differences in cases, moulds, and the
like, which however will readily suggest themselves without exercise of Invention
to any competent mechanic, and need no further description or illustration.
I would remark that I have given the ingredients and proportions of the
ingredients making up the improved compound as those which, after numerous
experiments, have been found to be best, although good results have been obtained
by varying the proportions of the ingredients within certain limits, and by adding
also other foreign matter, but it is preferred, as before stated, to employ the
compound as described without admixture or adulteration, and in the proportions
named.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention is,-
First. As a new composition of matter the combination of plumbago, asbestos, and
sulphur, substantially as herein-before described.
Second. As a new composition of matter the combination of asbestos, sulphur,
and plumbago, in three equal or nearly equal parts by volume, as herein-before
described.
Third. The method of combining asbestos, sulphur, and plumbago, by reducing
them to powder and thoroughly mixing them together, and by then subjecting the
pulverulent compound in a mould first to pressure and then to heat, as herein-before
described.
Fourth. As a new article of manufacture self-lubricating journal bearings,
consisting of a plumbago, asbestos, and sulphur compound, united with an iron or
other metallic casing, into which it is compressed and moulded, substantially as
herein-before described.
Fifth. As a new composition of matter a plumbago vulcanite, one of the ingredients
of which is asbestos.
Sixth. The method herein-before described of compounding plumbago, asbestos,
sulphur, and rubber, for the purpose of making a self-lubricating journal bearing
compound by intimately mixing the same, and rolling the same into sheets previous
to being vulcanized.

page_text: Seventh. The method of moulding and vulcanizing the journal bearing compound
herein described, consisting of rubber, sulphur, plumbago, and asbestos, by forming
the same into a sheet, rolling the sheet into a cylinder, whether with or without a
temporary pin, packing the mould therewith, and subjecting the same to vulcanizing
heat, substantially as and for the purposes herein-before described.
Eighth. As a new article of manufacture the asbestos, plumbago, vulcanite
compound, prepared in the form of journal bearings, whether with or without a
metal casing, substantially as herein-before described.
In witness whereof, I, the said John Henry Johnson, have to this my Specifi-
cation set my hand and seal, this Thirty-first day of August, One thousand
eight hundred and seventy-eight.
J. HENRY JOHNSON. (L.S.)