IMPROVEMENTS IN SELF LUBRICATING BEARINGS FOR SHAFTS, LOOSE PULLEYS AND OTHER ROTATING BODIES
Year: 1885

page_text: I, JOHN GREIG Junior of the firm of John Greig & Co, Regent Works, Regent
Road Edinburgh in the County of Midlothian Engineer, do hereby declare the
nature of the said invention for "IMPROVEMENTS IN SELF LUBRICATING BEARINGS
FOR SHAFTS, LOOSE PULLEYS AND OTHER ROTATING BODIES and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
"
This invention which relates to improvements in bearings for shafts, loose
pulleys and other rotating bodies has for its object to obviate the use of oil or
other unguent as a lubricant between the fixed and rotating parts and to employ in
their stead the metal plumbago made under pressure into rings, washers, or tubes
and inserted in the bearing the said rings, washers, or tubes being jambed or held
close together by an adjustable gland or glands screwed or tightened up as occasion
requires and which glands may also have compressed plumbago so inserted as to
lubricate the ends of the bearings.
Previous to being formed into the rings, washers or tubes the plumbago in a
powdered or ground condition is mixed into a plastic state with water or preferably
with a solution of gum arabic, glycerine, glue or other gelatinous substance having
the property when set of retaining a degree of moisture and elasticity.
The plastic composition is then moulded into the shape required by hand or other
pressure and in any suitable manner the method of moulding constituting no part
of this Invention and the rings, washers or tubes produced are prior to being used
preferably left for some time to dry or set with or without the aid of heat.
When dry or sufficiently firm or set they are inserted in the bearings as before
set forth.
لي
And in order that my said Invention may be properly understood I have
hereunto appended an explanatory sheet of drawings figure 1, of which, shows
the adaptation of the Invention to a bearing for a rotating shaft A; and figure 2,
the adaptation to the boss or bearing of a loose pulley B, on a shaft.
As shown by figure 1, the bearing C, for the shaft A, is for the greater part of
its length turned or bored out to a greater diameter than that of the shaft the said
wider part of the bearing terminating at x, so as to constitute a heel or abutment
in jambing or pressing up the plumbago rings or washers y, by means of the

page_text: gland D. Or instead of the abutment x, the bearing C, may be bored the same
diameter throughout and another gland employed at that end. To diminish the
friction between the metal surfaces as much as possible the bore of the gland and
also that of the abutment x, may be slightly wider than the diameter of the shaft.
Into this space part of the plumbago will find its way and to lubricate the ends of
the bearing both at the outside of the abutment and of the gland or at either of
them a collar or projection may be formed at these parts as seen at r, figures 3,
and 4, In the said collar a series of radial and dovetailed slots u are cut into
which bars of plumbago, previously compressed, moulded and dried as before set
forth, are inserted so as to bear at their ends on the shaft or instead of being
compressed and moulded prior to insertion the plumbago composition in a plastic
state may be packed into the slots and subsequently dried.
In figure 2, the hub or boss of the loose pulley B, is formed similar to the
bearing C, figure 1, the rings or washers y, of plumbago being jambed up by a
gland F, which is tightened further upon them when through wear they become
slack, and which gland may be formed as at figures 3, and 4, if desired.
The improved bearings herein before described are very suitable where the shaft
is running exposed to great lieat and from the examples given it is obvious that
the invention may be adapted to various kinds of bearings. In some cases where
the class of bearing renders it necessary or expedient the plumbago may be
moulded in half instead of in whole rings, washers, or tubes, these half rings
abutting against each other so as to constitute complete circles when in position in
the bearing.
In all cases a gland is preferably employed at one or both ends of the bearing.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I would observe in
conclusion that I am aware that plumbago has heretofore been used in the form of
"plugs" (usually called "Metalline ") inserted in recesses or holes made at intervals
in ordinary brass and other bearings for rotating bodies. I am also aware that
plumbago has been used in bearings in a loose or powdered condition. It is
therefore to be understood that I do not claim the use of plumbago in all forms in
such bearings but I declare that what I desire to claim is
First In bearings for shafts, loose pulleys and other rotating bodies the use of
rings washers or tubes of compressed plumbago or of compressed plumbago and a
solution of gum arabic, glycerine, glue or equivalent gelatinous substance the said
rings, washers, or tubes constituting the entire or the greater part of the length of
the bearing surface as and for the purpose described.
Second Between stationary and rotating bodies a bearing consisting of rings,
washers, or tubes of plumbago held in position by an adjustable gland and a fixed
abutment at opposite ends of the bearing; or, between two adjustable glands as and
for the purposes set forth.
Third In bearings for shafts, loose pulleys and other rotating bodies a gland
or abutment having a collar formed with radial slots the said slots being filled
with compressed plumbago as and for the purposes set forth.