Improvements in Furniture Castors.
Year: 1893

page_text: Date of Application, 6th Feb., 1893
Complete Specification Left, 28th Feb., 1893-Accepted, 15th Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in Furniture Castors.
1 FREDERICK JOHN BURRELL of St. Nicholas Works Thetford in the County
of Norfolk Engineer do hereby declare the nature of this invention to be as
follows:-
:-
My improved castor is similar to the ordinary one in that it has a base by which
it is attached to the article of furniture either by means of the usual cup or by a
vertical screw or screws; and a lower portion which carries the roller and is pivotted
to the upper portion.
I utilize two circles or rings of balls in annular recesses formed in the upper
portion and the lower portion. One circle or ring of balls principally to take the
direct downward pressure; the other circle of balls to take the side strain resulting
from the axis of the roller being outside or away from the vertical axis of the castor.
When the two circles of balls are both upon the same plane or thereabouts, the
inner circle of balls is situated between the lower portion of the castor and the
central pin or pivot.
The balls may be arranged in various planes according as the compactness of the
design may require.
The construction of the castor is such that the balls on opposite sides of the two
sets (or circles of balls) are alternately loosened and compressed as the castor is
caused to rotate with the weight upon it. The overhanging strain compresses some
of the balls on opposite sides of the vertical centre or axis, and loosens the rest of
the balls.
The vertical central pin or pivot may be fixed in the upper or lower portions of
the castor, or may be arranged to pivot at one end, so as to admit of rocking
and thereby causing a collar upon it to press more equally on the circle of balls
surrounding it.
When one circle of balls is placed directly over the other circle or thereabouts,
the central pin may be dispensed with & the balls fitted in recesses between the
in
upper and lower portions of the castor, either of which may be formed like a cup
which the other portion works loosely, the two circles of balls forming a rolling
contact between the said portions.
Dated this 4th day of February 1893.
FREDERICK JOHN BURRELL.
COMPLETE SPECIFICATION.
Improvements in Furniture Castors.
I, FREDERICK JOHN BURRELL, of St. Nicholas Works, Thetford, in the County
of Norfolk, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:―
My invention relates to improvements in furniture castors, which is similar to the
ordinary one, in that it has a base by which it is attached to the article of furniture
either by means of the usual cup or by a vertical screw or screws and a lower
portion which carries the roller pivotted to the upper portion.
I utilize two circles or rings of balls in annular recesses formed in the upper
portion and the lower portion. One circle or ring of balls principally to take the
direct downward pressure; the other circle of balls to take the side strain resulting

page_text: from the axis of the roller being outside or away from the vertical axis of the
castor. When the two circles of balls are both upon the same plane or thereabouts
the inner circle of balls is situated between the lower portion of the castor and the
central pin or pivot.
The balls may be arranged in various planes according as the compactness of the
design may require.
And in order that my invention may be thoroughly understood, I now proceed to
describe the accompanying drawings thereof, reference being had to letters and
figures marked thereon.
Figs. 1, 2, and 3, are vertical sections of the furniture castor with the circular
rings of balls placed in various positions.
The castor consists of an upper portion a having a lower portion > pivotted to it
and carrying the roller c.
Two circular rings of balls d', d², e', and e² are utilized to save friction and are
situated in recesses formed in the upper and lower portions a and b.
The balls may be arranged in various planes according as compactness of design
may require. When the two circles of balls are both upon the same plane or there-
abouts as in Figs. 1, 2, and 3 the inner circle of balls e¹, e² is situated between the
lower portion and the central pin or pivot f.
One ring of balls d', d² principally takes the direct downward pressure; the other
ring of balls e¹, 2 take the side strain resulting from the axis of the roller c being
outside or away from the vertical axis of the castor or by any obstruction which
tends to prevent the roller from travelling in the direction in which the upper
portion of the castor a may be pushed or caused to move; such side strain becoming
considerable when the weight upon the castor causes the roller c to become embedded
in the carpet or material over which it is dragged in the direction of the arrow in
Figs. 1, 2, and 3. It will be seen that the halls on opposite sides of the two sets or
circles of balls are loosened and compressed by this side strain, viz.; the balls d'
and will be compressed and d² and e¹ will be loosened when the roller c is in the
position shewn in the drawing. The overhanging strain or side pressure causes
the ball e² to be compressed between the inner recess in the lower portion b and
the pin f.
The construction of the castor is such that there is no connection between the
portions a and b except through balls which form a rolling contact for both direct
downward pressure and side strain.
The vertical centre pin or pivot ƒ may be fixed in the upper portion a as in Fig. 1,
or in the lower portion 6 as in Fig. 2, or may be arranged to pivot at one end as in
Fig. 3, so as to admit of rocking upon the cross pin 9 and thereby causing the
collar to press more equally upon the circle of balls e', e² surrounding the pin.
When one circle of balls is placed directly over the other circle or thereabouts,
the balls may be fitted in recesses between the upper and lower portions of the
castor either of which may be formed like a cup in which the other portion works
loosely, the two circles of balls forming a rolling contact between the said
portions.
I am aware that it has been proposed to utilize two concentric rings of balls
situated in grooves beween the upper and lower portions of a castor but differing
from my invention in the arrangement of the rolling contact between the 'two
portions.
I would observe in conclusion, that I do not claim broadly in castors the use of
two concentric rings of balls.
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 1
claim is :-
1. In a castor, having the axis of the roller away from the vertical axis of the
castor and the combination of the construction wherein the two sets or circles of
balls are alternately loosened and compressed on opposite sides of the vertical

page_text: centre pin or axis of the castor as the lower portion is caused to rotate with the
weight upon it, substantially as herein described and according to Figs. 1, 2, and 3,
of the accompanying drawing.
2. In a castor, the combination of the second ring of balls situated in bearings for
the purpose of taking the side strain, substantially as herein described and according
to the accompanying drawing.
Dated this 28th day of February 1893.
J. P. BAYLY,
18, Fulham Place, W., Agent for the Applicant.