Improvements in Ball Castors.
Year: 1891

page_text: Date of Application, 10th Mar., 1891
Complete Specification Left, 9:h July, 1891-Accepted, 15tn Aug., 1891
PROVISIONAL SPECIFICATION,
Improvements in Ball Castors.
I, WILLIAM JOHN SMITH of Chicago in the County of Cook and State of
Illinois, in the United States of America, Gentleman do hereby declare the nature
of this invention to be as follows:-
The object of this invention is to construct ball castors in such a manner as to
reduce the friction thereof to a minimum and to enable such castors to be attached
to furniture without the aid of screws.
According to this invention, I provide a lantern or skeleton frame for the ball to
work in, and round the bottom of the frame I form a groove into which is sprung a
ring of metal or other suitable material to prevent the ball from falling out of the
frame if the article to which the castor is attached is raised from the floor.
Inside the frame, and above the centre of the ball are three equi-distant swivel
bearings carrying antifriction rollers through which the weight of the article fitted
with castors is transmitted to the ball.
The bearings are so constructed as to keep the rollers clear of the frame, and
being arranged at equal distances from each other in a horizontal plane, the load on
each bearing is equal, and being also capable of rotation on an axis radial to the
ball, they enable the rollers to accomodate themselves to the direction of rotation
of the ball, so that the article furnished with castors constructed according to my
invention may be moved with equal facility in every direction.
Attached to or formed integral with the frame is a tube, which is slit at its upper
end and expanded to a slightly larger diameter than where it is attached to the
frame. The leg of the table or other piece of furniture to which the castor is
attached is bored to fit the smaller diameter of the tube, the upper end of which is
compressed till it enters the hole in the furniture and the tube forced into the said
hole, till a shoulder formed on the frame rests on the bottom of the table leg or that
portion of a piece of furniture to which the castor is applied, the elasticity of the
slit portion of the tube holding the castor firmly in its place without screws.
I
Instead of the slit tube, the castor may be provided with the ordinary socket, or
may
form a flange on the bottom of the frame, and secure the castor to the
furniture by means of screws passing through the flange, the furniture or other
article to which the castor is applied being recessed to receive the frame.
Instead of the skeleton frame above mentioned, I may form the frame with three,
or more claws, sufficiently elastic to allow the ball to be forced into its place. By
this means,
the spring retaining ring is dispensed with.
Dated the 10th day of March 1891.
ERNEST SALAMAN,
61 & 62, Chancery Lane, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Ball Castors.
I WILLIAM JOHN SMITH of Chicago in the County of Cook and State of Illinois,
United States of America Gentleman do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
The object of this invention is to construct ball castors in such a manner as to

page_text: reduce the friction thereof to a minimum and to enable such castors to be attached
to furniture without the aid of screws.
According to this invention 1 provide a lantern or skeleton frame for the ball to
work in, and round the bottom of the frame I form a groove into which is sprung a
ring of metal or other suitable material to prevent the ball from falling out of the
frame if the article to which the castor is attached is raised from the floor.
Inside the frame and above the centre of the ball are three equidistant swivel
bearings carrying antifriction rollers through which the weight of the article fitted
with castors is transmitted to the ball.
The bearings are so constructed as to keep the rollers clear of the frame and
being arranged at equal distances from each other in a horizontal plane the load on
each bearing is equal and being also capable of rotation on an axis radial to the
ball they enable the rollers to accommodate themselves to the direction of rotation of
the ball so that the article furnished with castors constructed according to my
invention may be moved with equal facility in every direction.
Attached to or formed integral with the frame is a tube which is slit at its upper
end and expanded to a slightly larger diameter than where it is attached to the
frame.
The leg of the table or other piece of furniture to which the castor is attached
is bored to fit the smaller diameter of the tube the upper end of which is compressed
till it enters the hole in the furniture and the tube forced into the said hole till a
shoulder formed on the frame rests on the bottom of the table leg or that portion
of a piece of furniture to which the castor is applied the elasticity of the slit portion
of the tube holding the castor firmly in its place without screws.
Instead of the slit tube the castor may be provided with the ordinary socket or I
may form a flange on the bottom of the frame and secure the castor to the furniture
by means of screws passing through the flange, the furniture or other article to
which the castor is applied being recessed to receive the frame.
Instead of the skeleton frame above mentioned 1 may form the frame with three
or more claws sufficiently elastic to allow the ball to be forced into its place. By
this means the spring retaining ring is dispensed with.
And in order that my said invention may be better understood I will proceed
to explain the same with reference to the accompanying sheet of drawings in which
Fig. 1 represents a ball castor constructed according to my invention.
Fig. 2. section of same.
Fig. 3. view of underside of same with ball removed.
Fig. 4. spring retaining ring.
Fig. 5. modification of Fig. 1 adapted for heavy furniture.
Fig. 6. ball castor fitted with claw frame
The same letters denote the same parts in all the figures, a is the ball, the
frame, ccc rollers d d d bearings for same, e retaining ring, split tube for
retaining castor in position g portion of leg of a table or other piece of furniture,
flange for attaching castor to furniture, i socket for same purpose k. k. k. claws
which are sufficiently elastic to allow of the ball being forced into place.
The rollers c are mounted in equidistant bearings d which are capable of
rotation round their axes 7 so as to allow of the rotation of the ball a in any
direction.
The tube which is slit at m at its upper end and slightly expanded is forced
into a hole bored in the leg g and the pressure of the upper end of the tube which
is compressed to enter the said hole holds the castor firmly in place.
Instead of the slit tube f the castor may be provided with an ordinary socket i
see Fig. 6 and attached to the furniture in the usual way or I may form a flange h.
on the frame as shewn at Fig. 5 and recess the said frame into the furniture and
secure the castor thereto by means of screws passing through the flange h.
I prefer to make the castor wholly of metal but if desired the ball may be of wood,
glass, or other suitable material.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
--
I. In a ball castor the combination of a ball and frame with three equidistant
antifriction rollers rotating in swivel bearings all substantially as described for the
purpose stated.
II. In a ball castor the slit tube fas and for the purpose stated.
III. The improved ball castors substantially as described and shewn.
t
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1001
ERNEST SALAMAN,
Registered Patent Agent, 61 & 62, Chancery Lane, London,
Agent for Applicant.