Improvements in Castors.
Year: 1897

page_text: I, JOHN WELBOURN, of Bobbin Villa, Syston, near Grantham, in the County of
Lincoln, Invalid, do hereby declare the nature of this invention to be as follows:-
The object of my invention is to construct ball castors so that they will freely
revolve centrally under the feet of the furniture to which they are attached, and
at the same time the balls upon which they revolve can be adjusted as to their
tightness or slackness without taking off or injuring the castor.
I employ a suitable bracket, plate or cup for securing to the furniture, the
bottom part of which has a flange and bush, the bush being threaded on its out-
side, and concave on its inside upper surface.
Screwed on to the thread bush is a lower bush narrowing towards the bottom,
so as to retain the large central ball.
Between the periphery of this central ball and the concave bottom of the top
bush of castor are a series of small balls, upon which the large ball works, by
screwing the lower bush to the right or left the play of the balls is reduced or
enlarged and so the large ball turns more or less freely. This can be done and the
balls all taken out, replaced, black leaded, lubricated, or renewed, without un-
screwing the top part of castor from the furniture.
JOHN E. WALSH,
Royal Exchange Chambers, Boar Lane, Leeds,
Patent Agent for Applicant.
Improvements in Castors.
I, JOHN WELBOURN, of Bobbin Villa, Syston, near Grantham, in the County of
Lincoln, Invalid, 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:—
The object of my invention is to construct ball castors for furniture and the
like so that they will freely revolve centrally under the feet of the furniture or
the like article to which they are attached, and at the same time the balls upon
which they revolve can be cleaned, lubricated, adjusted to take up any wear, or
renewed without detaching or injuring the castor.

page_text: DESCRIPTION OF DRAWINGS.
Fig. 1 is an elevation (in section) of my improved castor.
Fig. 2 is a plan (inverted) of attaching plate with bush or bearing cup.
Fig. 3 shows same with the small bearing balls in position.
I employ a suitable plate, bracket, or cup A for securing to the furniture or like
article, and on the under side of the said plate, bracket, or cup is a flange 13 with
a screwed outside surface and a concave bush or bearing cup C, preferably made
in hardened steel, in in the centre. Screwed to the flange B is a sleeve or retain-
ing bush D, narrowing towards the bottom so as to retain in position the large
central ball E, but so arranged as not to touch the said ball when the castor is
in position.
Between the periphery of the central ball E and the bush or bearing cup Care
a number of small balls upon which the large ball E bears, the said balls b
preferably working in a circulur groove or race Ground the edge of the said bush
or cup C and in two cross grooves H. connecting opposite sides of the said groove
or race G.
The radius of the bearing cup C is larger than that of the central ball E so as
to allow a free rolling contact between the balls and the ball E and prevent the
balls F from jamming in the cup. To prevent the small balls F from jamming
in the sleeve or retaining bush 1), and also to provide a smooth flat surface for
the balls in the circular radial race G to bear against, I provide a flat annular
ring K, which is inserted loosely over the large ball E. but which bears (so as not to
touch the said ball E) on a shoulder or annular ledge in the sleeve or retaining
bush D. By unscrewing the sleeve the balls can be cleaned, lubricated, black-
leaded, or renewed without having to detach the body of the castor from the
furniture. The castor can also be adjusted so as to take up any wear in the bear-
ing. The castor, or any part of it, may be made in any suitable metal or material.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. A castor for furniture or the like, consisting of an attachable plate or
bracket A having on its under side a flange B, to which is serewed a tapered sleeve
or retaining bush D enclosing (so as not to touch) a castor ball E which bears
against a series of small balls working in grooves or races G, H, II, arranged in
a concave bush or bearing cup C within the said flange B, the said balls being
retained in position, so as to be adjustable for taking up any wear of material, by
means of a flat annular ring K fitting in the said screwed sleeve or retaining bush 15,
substantially as shown and described.
2. In a ball castor for furniture or the like the employment in the bearing cup C
of an annular groove or race G and two cross grooves H, H, to enable the small
bearing balls to circulate freely in the said bearing cup, substantially as shown
and described.
1000