Improvements in Furniture Castors.
Year: 1896

page_text: Date of Application, 7th Oct., 1896-Accepted, 7th Nov., 1396
COMPLETE SPECIFICATION.
Improvements in Furniture Castors.
I WILLIBALD MERL, of 18 Karlstrasse, Berlin, in the Empire of Germany,
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 and accompanying drawings:-
My said invention refers to furniture castors and relates particularly to the anti-
Prior
frictional means introduced between the upper and lower parts of such castors.
to my invention balls have been introduced into the bearings between the upper and
lower part of the castor so as to lessen friction.
Such balls have however required to be confined and boxed in by special. means
which have militated against the perfect working of the bearings and have added to
the cost of the castors.
According to my invention I so fashion the upper and lower parts of the castor
that when the balls are introduced they also act as connections or couplings between
the upper and lower parts of the castor, no additional confining or boxing in means
being required.
The invention will he best understood by a reference to the annexed sheet of
illustrative drawings.
Fig. 1 is a vertical section and Fig. 2 a plan from the bottom, of a castor intended
for heavy articles of furniture and constructed in accordance with my invention.
Figs. 3, 4, 5 and 6 are different views of an improved castor intended to be secured
to the articles of furniture by a central screw.
Figs. 7 and 8 are sectional and plan views respectively of a castor intended to be
secured by a flat sole plate.
Figs. 9, 10 and 11 are views in section, plan and elevation respectively of a castor
intended to be secured by a sleeve or box surrounding the article of furniture.
All of these examples are fitted with my improved ball bearings and in the different
figs. similar parts are identified by similar letters.
The under part a of the castor which contains the roller r carried on the axle o is so
shaped at the top as to present an annular groove to slightly dished or cupped as shown
in Fig. 1 so as to overhang and imprison the ball k when in position. The upper
part 6 of the castor is also formed with a similarly shaped annular groove to the hollow
or concave parts of the two grooves to wo¹ being so shaped relatively to each other that
when the upper and lower parts of the castor are placed together as in the drawing
the two grooves constitute a species of annular split tube. One of the grooves (for
example the groove w) has a gate formed in its wall as shown in dotted lines at in
Fig. 1 and through this gate the balls k may be introduced into the annular cavity
formed by the grooves wow. The gate 7 may then be closed by bending it over and
the balls cannot then escape. The presence of the balls in the cavity practically locks
the upper and under part of the castor together so that they cannot come apart, while
at the same time the utmost freedom and ease of rotatory motion between the two
portions of the castor is maintained, the ring of balls k taking the whole of the
supported weight.
The different parts of the castor may be cast, spun or stamped from sheet metal or
tubing and can be produced at comparatively slight cost.
The roller r is preferably made of the oval shape indicated and its bearings with the
axle o may be furnished with balls m to reduce friction. I do not however advance
this as part of my invention. Instead of having the roller in the centre of the

page_text: castor as shown in the bulk of the figs. I might place it to one side as in Fig. 5 so
as to make the castor more sensitive in following the direction in which the article of
furniture is being pushed. When a fast central screw is used to secure the castor to
the table or other leg I might form holes or recesses in the upper part 6 of the
castor as shown in Figs. 4 and 5 so as to receive the studs of a key employed to screw
the castor to the leg.
The remaining gs. of the drawings not specifically described are self explanatory
and need not be more particularly referred to.
It will be evident that the relative positions of the grooves to wo¹ might be reversed,
the groove in the lower part a coming to the outside and the groove in the upper part 6,
coming to the inside.
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.
In furniture castors connecting the lower movable portion a containing the roller r
to the upper fixed portion 6 by means of the bearing balls k, the upper and lower
parts of the castor being formed with grooves wo, to¹ so shaped that when the balls are
in situ the upper and lower parts are held or coupled together in such a manner as to
prevent them from coming apart while permitting of rotary motion, substantially as
described and shown.
Dated the 6th day of Ontation 1000
For the Applicant,
E. K. DUTTON & Co.,
5 John Dalton Street, Manchester, Chartered Patent Agents.