AN IMPROVEMENT OR IMPROVEMENTS IN BEARINGS FOR THE AXLES OF BICYCLES, AND FOR OTHER ROTATING AXLES OR SHAFTS
Year: 1877

page_text: LETTERS PATENT to James Douglas, of Coventry, in the County of Warwick,
Manufacturer, for the Invention of "AN IMPROVEMENT OR IMPROVEMENTS IN
BEARINGS FOR THE AXLES OF BICYCLES, AND FOR OTHER ROTATING AXLES OR
SHAFTS."
Sealed the 8th February 1878; and dated the 10th August 1877.
.1
PROVISIONAL SPECIFICATION left by the said James Douglas at the Office
of the Commissioners of Patents on the 10th August 1877.
JAMES, DOUGLAS, of Coventry, in the, County of Warwick, Manufacturer.
IMPROVEMENT OR IMPROVEMENTS IN BEARINGS FOR THE AXLES OF BICYCLES, AND
FOR OTHER ROTATING AXLES OR SHAFTS."
"AN
My Invention has for its object to reduce to a minimum' the friction between the
said bearings and the axles or shafts working in them, to render lubrication
unnecessary, and to reduce the wear and tear of the axles or shafts' working in the
said bearings.
In place of the ordinary brasses' made of gun metal' or other alloy of copper I
employ bearings of agate. I make them by preference in two parts, and of a form
and size resembling generally the form and size of ordinary metallic bearings.
To the working surfaces of the bearings, that is, the surfaces surrounding the
ends of the axle. or shaft, I give a high polish; the other surfaces I prefer to leave
rough or unpolished.
I'mount or support the parts of the bearings in casings and fix them therein by
means of cement. Where however there is no jarring or strain upon the bearings,
the cement may be dispensed with:
Where, as in the case of bicycles, the direction of the axle or shaft has sometimes
to be changed by pressure of the bearings on the axle or shaft, it is desirable to
mount the agate bearings in cases, which have flanges clipping the bearings on each
side, so as to prevent the displacement of the bearings in' their cases by the strain
put upon them under the circumstances referred to. Where however the bearings
have only to support' a rotating shaft or axle, without having by their pressure to
change its direction, the said flanges are unnecessary.

page_text: Although I prefer to make each bearing of two pieces of agate, yet more than
two pieces, especially in large bearings; may be employed; and in small bearings
one piece having a cylindrical or slightly conical hole made in it and highly
polished, may be employed.
The cement I prefer to employ to fix the agates in their cases is composed of
five parts of gutta percha, one part of pitch, one part of rosin, and one part of glue,
but I do not limit myself to a cement of this composition.
Owing to the small amount of friction between the axle or shaft and the agate
bearings, the rotation of the shaft or axle produces little or no heat, and there is
consequently no need for a lubricant, and the wear and tear is largely reduced.
Although my Invention is especially applicable to bicycles, yet. it is. also applicable
to shafts for driving machinery, for the fans of blowing machines, the axles of
railway carriages and engines, and other rotating, shafts or axles.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Douglas in the Great Seal Patent Office on the 9th February
1878.
JAMES DOUGLAS, of Coventry, in the County of Warwick, Manufacturer.
"AN
IMPROVEMENT OR IMPROVEMENTS IN BEARINGS FOR THE AXLES OF BICYCLES, AND
FOR OTHER ROTATING AXLES OR SHAFTS."
My Invention has for its object to reduce to a minimum the friction between the
said bearings and the axles or shafts working in them, to render lubrication
unnecessary, and to reduce the wear and tear of the axles or shafts working in the
said bearings.
In place of the ordinary brasses made of gun metal or other alloy of copper, I
employ bearings of agate. I make them by preference in two parts, and of a form
and size resembling generally the form and size of ordinary metallic bearings.
To the working surfaces of the bearings, that is, the surfaces surrounding the
ends of the axle or shaft I give a high polish. The other surfaces I prefer to leave
rough or unpolished.
I mount or support the parts of the bearings in casings, and fix them therein by
means of cement. Where however there is no jarring or strain upon the bearings,
the cement may be dispensed with.
Where, as in the case of bicycles, the direction of the axle or shaft has sometimes
to be changed by pressure of the bearings on the axle or shaft, it is desirable to
mount the agate bearings in cases which have flanges clipping the bearings on each
side, so as to prevent the displacement of the bearings in their cases by the strain
put upon them under the circumstances referred to. Where however the bearings
have only to support a rotating shaft or axle without having by their pressure to
change its direction, the said flanges are unnecessary.
Although I prefer to make each bearing of two pieces of agate, yet more than
two pieces, especially in large bearings, may be employed; and in small bearings
one piece having a cylindrical or slightly conical hole made in it, and highly
polished, may be employed.

page_text: Owing to the small amount of friction between the axle or shaft and the agate
bearings, the rotation of the shaft or axle produces little or no heat, and there is
consequently no need for a lubricant, and the wear and tear is largely reduced.
Although my Invention is especially applicable to bicycles, yet it is also applicable
to shafts for driving machinery, for the fans of blowing machines, the axles of
railway carriages and engines, and other rotating shafts or axles.
The means I employ for giving the required shape and polish to the agate
bearings are the same as are commonly employed in shaping and polishing agate for
other purposes; I therefore do not think it necessary to describe the same.
.
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,
the improvement or improvements in bearings for the axles of bicycles, and for
other rotating axles or shafts herein-before described, that is to say, making the
bearings of the said rotating axles or shafts of one or more pieces of agate mounted
or supported in metal cases, and fixed therein, by preference by cement, the said
agate bearings having a highly polished cylindrical or nearly cylindrical hole, of a
size and shape suitable for the reception of the rotating axle or shaft, substantially
as and for the purposes described.
In witness whereof, I, the said James Douglas, have hereunto set my hand
and seal, this Fifth day of February, in the year of our Lord One thousand
eight hundred and seventy-eight.
Witness,
JOHN PORTER,
Hales Street,
Coventry.
JAMES DOUGLAS. (L.S.)