IMPROVEMENTS IN BALL AND SOCKET APPARATUS, CHIEFLY DESIGNED FOR USE AS FURNITURE CASTERS, AND IN MEANS FOR THE MANUFACTURE OF GLASS BALLS FOR THE SAME AND OTHER PURPOSES."
Year: 1880

page_text: LETTERS PATENT to Gordon Donaldson Peters, of Bunhill Row, in the City
of London, for an Invention of "IMPROVEMENTS IN BALL AND SOCKET
APPARATUS, CHIEFLY DESIGNED FOR USE AS FURNITURE CASTERS, AND IN
MEANS FOR THE MANUFACTURE OF GLASS BALLS FOR THE SAME AND OTHER
PURPOSES."
PROVISIONAL SPECIFICATION left by the said Gordon Donaldson Peters at
the Office of the Commissioners of Patents on the 24th January 1880.
GORDON DONALDSON PETERS, of Bunhill Row, in the City of London. "IMPROVE-
MENTS IN BALL AND SOCKET APPARATUS, CHIEFLY DESIGNED FOR USE AS FURNITURE
CASTERS, AND IN MEANS FOR THE MANUFACTURE OF GLASS BALLS FOR THE SAME
AND OTHER PURPOSES."
My Invention relates to an improved apparatus consisting of a ball fitted within
a socket, which is provided with novel means for keeping the said ball in place,
and allowing it while subjected to pressure to rotate very freely in the said socket.
The said apparatus may be applied to any purpose, for which similar devices are
used, but is chiefly designed to serve as a caster for tables, chairs, and other
articles of household furniture, or the like; the said Invention also relates to
means for the manufacture of glass balls.
The said Invention consists chiefly in constructing or providing the socket with
three, four, or more projections which form the bearing surfaces for the ball or
roller, and which are so arranged as to support the latter in such a manner that it
will not come in contact with the top of the interior surface of the socket. By this
contrivance the friction between the ball and socket will be reduced to a very
slight amount, so that when these casters are used on a table or other heavy
article of furniture the same may be very easily moved in any direction upon the
floor.
I prefer to form the said socket with three or more arms or branches extending
from the top of the same downward far enough to include about two thirds of the
ball, each arm or branch being provided with one of the said projections or bearing
points. The aforesaid projections may be cast or otherwise formed upon the
socket, or may consist of small balls or rollers of metal or other suitable material
fitted in holes in the said socket,

page_text: In order to explain the principle upon which the action of my improved caster
is based, I will take as an example a caster which has to support a weight of
9 pounds, and whose ball is 1/4 inch in diameter. This ball may be considered as
a wheel whose opposite radii form two levers 7/8th inch long. If this ball is fitted
in a socket with three arms and projections which bear upon the ball as near the
centre of rotation as practicable, and the ball is not allowed to touch the top of
the socket, each bearing point or projection will have to bear a weight of three
pounds. One arm will act with the full leverage of 7/8th inch, and each of the
other two arms with a leverage of 7/8th inch, all of them tending to prevent the
rotation of the ball; but the whole weight of 9 pounds resting on the ball acts
through a leverage of 7/8th inch at the bottom of the ball, and tends, when the
caster is moved, to cause the rotation of the said ball. There is therefore a force
tending to produce the rotation greater than that tending to prevent the rotation
of the ball, that is to say, the two opposing forces are as 42 to 63, leaving an excess
of 21 in favour of the ball's rotation.
16
In other ball casters, in which the ball bears the weight on its top surface, the
force tending to cause its rotation is balanced by that which prevents its rotation,
therefore the ball will not rotate when the caster is moved along the floor.
In some instances I may modify my Invention by combining with the said
projections or bearing surfaces a central roller arranged to form an additional
bearing for the ball. This roller has journals of smaller diameter than its central
bearing surface, and is supported by such journals in a swivelling piece, which is
fitted in a recess in the top of the socket with freedom to rotate horizontally to
further facilitate the rolling of the ball in all directions.
This arrangement of a roller journalled in a horizontally rotating swivelling
piece is essentially different to those devices in which a ball or number of balls or
rollers without journals, or with fixed or unadjustable journals, are provided to
afford support and bearing surfaces in a ball caster.
I prefer to use balls formed of glass in my improved casters; it is very important
that these balls should be truly round or spherical, and it is very desirable that
they should be cheaply manufactured. For this purpose I use a die or mould
formed of steel or other suitable material, and whose interior form is hemispherical.
The glass of which the ball is to be made is blown in the usual or any con-
venient manner, and while adhering to the glass blower's tube is placed in the
said mould and turned therein until it assumes a spherical or globular form. The
bar or rod of glass on whose end the ball is thus formed is then separated from the
said ball by a cutter or cutters curved to suit the diameter of the said rod, and
hinged or pivoted on the mould or otherwise in a convenient position to permit
them to be adjusted into the proper position to cut the glass rod. They are then
turned back on their pivots, and the ball is removed from the mould or die, the
part to which the said rod was attached being finished off in any suitable
manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Gordon Donaldson Peters in the Great Seal Patent Office on the
23rd July 1880.
GORDON DONALDSON PETERS, of Bunhill Row, in the City of London. "IMPROVE-
MENTS IN BALL AND SOCKET APPARATUS, CHIEFLY DESIGNED FOR USE AS FURNITURE
CASTERS, AND IN MEANS FOR THE MANUFACTURE OF GLASS BALLS FOR THE SAME
AND OTHER PURPOSES."
My Invention relates to an improved apparatus consisting of a ball fitted within
a socket, which is provided with novel means for keeping the said ball in place,
while allowing it, when subjected to pressure, to rotate very freely in the said
socket. The said apparatus may be applied to any purpose for which similar
devices are used, but is chiefly designed to serve as a caster for tables, chairs, and
other articles of household furniture or the like; the said Invention also relates to
means for the manufacture of the glass balls used in the said casters.
In the accompanying Drawing,
Figure 1 is an elevation of a ball caster constructed according to my Invention,
and
Figure 2 is a central vertical section of the same.
Figure 3 is an underside view of the socket with the ball removed from the
same.
Figure 4 is an elevation shewing a modified form of my improved caster herein-
after described.
Figure 5 is a central vertical section, and
Figure 6 is an underside view of the socket of the said caster with the ball
removed from the same.
Like letters indicate the same parts throughout the Drawing.
a represents the socket, which may be provided with three, four, or more arms,
claws, or branches a¹, and b represents the ball or roller. The chief novel feature
of my Invention consists in constructing or providing the socket a with three, four,
or more projections a³, which form the bearing surfaces for the ball or roller b, and
which are so arranged as to support the latter in such a manner that it will not
come in contact with the top of the interior surface of the socket, as shewn in
Figure 2. By this contrivance the friction between the ball and socket will be
reduced to a very slight amount, so that when these casters are used on a table or
other heavy article of furniture the same may be very easily moved in any
direction upon the floor or other surface. The claws or branches a¹ of the said
socket extend from the top of the same downward far enough to include about two
thirds of the ball, each claw or branch being provided with one of the said pro-
jections or bearing points a², as shewn in Figure 3. The said projections a² may
be cast or otherwise formed upon the socket a, or may consist of small balls or
rollers of metal or other suitable material fitted in holes in the said socket. In
some cases I insert within the mould, previous to casting therein the socket and
its claws or branches, a series of pieces or bearing points of steel, bronze, or other
suitable material. These pieces are preferably stamped out of sheet metal of the
desired shape, and are provided with projections, so that when the metal for the
socket is run into the mould the said pieces will be firmly retained therein, as
shewn in Figure 2.
In order to explain the principle upon which the action of my improved caster
is based I will take as an example a caster which has to support a weight of 9
pounds, and whose ball is 13 inch in diameter. This ball may be considered as

page_text: a wheel whose opposite radii form two levers 7/8 inch long. If this ball is fitted
in a socket with three arms a' and three projections a³, which bear upon the ball
as near the centre of rotation as practicable, and the ball is not allowed to touch
the top of the socket, each bearing point or projection will have to bear a weight of
three pounds. One claw will act with the full leverage of 7, inch, and each of the
other two claws with a leverage of 7/16 inch, all of them tending to prevent the
rotation of the ball; but the whole weight of 9 pounds resting on the ball acts
through a leverage of 7/8 inch at the bottom of the ball, and tends when the caster
is moved to cause the rotation of the said ball. There is therefore a force tending
to produce the rotation greater than that tending to prevent the rotation of the
ball, that is to say, the two opposing forces are as 63 to 42, leaving an excess of 21
in favour of the ball's rotation.
In other ball-casters, in which the ball bears the weight on its top surface, the
force tending to cause its rotation is balanced by that which prevents its rotation,
therefore the ball will not rotate when the caster is moved along the floor.
In some instances I may modify my Invention, as shewn in Figures 4 to 6, by
combining with the projections or bearing surfaces a³ a central roller d arranged
to form an additional bearing for the ball b, as shewn in Figure 5. This roller d
has journals d¹ of smaller diameter than its central bearing surface, and is sup-
ported by such journals in a swivelling piece e (preferably conical in form) which
is fitted in a recess in the top of the socket, as shewn in Figures 5 and 6, with
freedom to rotate horizontally to further facilitate the rolling of the ball in all
directions. This arrangement of a roller journalled in a horizontally rotating
swivelling piece is essentially different from those devices in which a ball or number
of balls or rollers without journals, or with fixed or unadjustable journals, are
provided to afford support and bearing surfaces in a ball-caster.
If desired the socket of my improved caster, instead of being formed with claws
or branches, as shewn, may be a plain hemispherical or cup-shaped piece with ribs
or projections secured inside the same to act on the ball.
I prefer to use balls formed of glass in my improved casters; it is very important
that these balls should be truly round or spherical, and it is very desirable that
they should be cheaply manufactured. For this purpose I use a die or mould
formed of steel or other suitable material, and whose interior form is hemispherical.
The glass of which the ball is to be made is blown in the usual or any convenient
manner, and while adhering to the glass blower's tube is placed in the said mould
and turned therein until it assumes a spherical or globular form. The bar or rod
of glass on whose end the ball is thus formed is then separated from the said ball
by a cutter or cutters curved to suit the diameter of the said rod; the said cutters
are hinged or pivotted on the mould or otherwise in a convenient position to
permit them to be adjusted into the proper position to cut the glass rod. After
cutting the same they are turned back on their pivots, and the ball is removed
from the mould or die, the part to which the said rod was attached being finished
off in any suitable manner.
Having thus fully described my said Invention, and shewn how the same may
be conveniently and advantageously carried into practice, I wish it understood
that I do not claim merely the combination of a glass or other ball with a socket
to form a ball-caster, as I am aware that similar devices have been already manu-
factured, but I claim,―
First. In a ball and socket device or ball-caster in which the ball is enclosed and
held by and between three or more claws, branches, or similar portions of the
socket, the employment at the upper part of the said socket of points or projections
which bear upon the ball, and are so arranged that the force applied to cause the
rotation of the said ball will exceed the force that resists its rotation, as above set
forth.
Second. The modification of my Invention wherein I employ at the tan of the

page_text: socket, in combination with such points or projections, a central swivelling roller,
arranged and operating as and for the purpose above specified.
Third. The improved means for manufacturing the glass balls, as above set
forth.
In witness whereof, I, the said Gordon Donaldson Peters, have hereunto set
my hand and seal, this Twenty first day of July, in the year of our Lord
One thousand eight hundred and eighty.
G. D. PETERS. (L.S.)