Improvements in Castors for Furniture.
Year: 1887

page_text: Date of Application, 8th Mar., 1887.
Specification Accepted, 15th Apr., 1887.
COMPLETE SPECIFICATION.
Improvements in Castors for Furniture.
I HENRY BECKETT HARDING of Cannon Works Constitution Hill Birmingham in
the County of Warwick Manufacturer, do hereby declare the nature of this invention
and in what manner the same is to be perforined, to be particularly described and
ascertained in and by the following statement, reference being had to the accompanying
drawings and to the letters and figures marked thereon:-
This invention has for its object the construction of Globe Castorsand consists
of improvements upon former inventions of mine for the same purpose and which
have been described in Specifications of Patents No. 1717-1878 and No. 2877-
1881 respectively and supplies that great want for furniture a castor which
whilst it has vertical bearing and universal and uniform rotation forms an ample and
symmetrical foot for the furniture to which it may be attached and is also not liable
to break down nor get out of order. It consists of a hollow globe parily enclosed in
a circular case the inside or chamber of which has bearers and guides for the globe
and the outside has a screwed projection or pin wherewith to attach the castor.
globe is cast in two halves in metal by preference a meial of a non-porous nature.
The two halves are united by solder or other effective means of attachment.
globe is then turned and finished by suitable tools and machinery in such manner as
to insure its absolute roundness and perfect finish.
The
The
By casting it in two halves I am enabled to so regulate the thickness of the metal
as to reduce its weight to a minimum and also to save largely in the cost of casting.
Thus reducing that which has hitherto been a most difficult and costly operation to
one of simplicity and cheapness so much so that I am able to produce in the way
described at comparatively little cost a casior large enough to be an ample foot for
even the largest and heaviest furniture.
The case is cast in two pieces and in metal antifrictional to that of the globe. The
wo pieces are called respectively the Dome and the Band and are united by a screw
joint, the inside of the case or globe chamber has three seinicircular projections or
ridges running round it horizontally one at the top of the Dome one at the mouth of
he Band and the other about equidistant from each of them as shewn on the Drawings
on which drawings similar lettiers refer to similar parts. Fig. 1 being a section
hrough the globe castor when detached from furniture Fig. 2 a section through the
lome or case shewing it attached to the furniture by means of the screw plate
1

page_text: Fig. 3 the band and the globe Fig. 4 a complete castor fixed to the leg of
furniture.
(A) is the globe (B) the down case or globe chamber (C) the semi-circular projection
or ridge at the top (D) that at the mouth and (E) the intermediate one (F) is the
band shewn with the screw thread (G) to screw onto the case at (H) as shewn in
Figs. 1 and 5 (I) is the screw or pin to attach the castor to the furniture.
The projections cause the area of contact of the globe with the case to be so little
that the globe will not fail to roll under even an absurdly heavy weight, they also from
the same cause prevent matter which is apt to adhere to the globe and be carried by
it into the chamber retarding its freedom of rolling.
I form the dome of the case with perforations for the purpose of preventing noise
from the castor when in motion.
For facility in casting the domes and bands I avail myself of the split pattern and
the split mould which enables me to produce them in complete form inside and outside
and thus to greatly lessen the cost of making.
The screwed projection or pin of the dome for attaching the castor to furniture is
screwed into a cup or circular screw plate which accompanies each castor and is a
great convenience for attaching it to the articles of furniture.
The screw plates (K) and (K¹) are in two forms one placed at the end of the leg as
illustrated in Figs. 2 and 4 and the other inserted into the leg which is cupped to
receive it as illustrated at (L) Figs. 5 and 6.
I have discovered by practice that case of motion in the castor and its freedom from
derangement depend upon the due proportionment of the castor to the weight and
size of the article upon which it is used also that by proportioning the size of the
castor to the weight of the furniture overcome any tendency of the globe to indent
the floor or other surface upon which it rests and therefore I vary the size of my
castors to suit the requirements of the furniture to which they are to be applied.
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
First. The hollow globe cast in two halves and united in the manner herein
described.
Second. The dome and the band cast in split patterns and split moulds.
Third. The mode of attaching the castor to furniture as herein described and
illustrated.
Fourth. The construction of globe castors substantially as described herein and
illustrated in the accompanying drawings.
Dated this 1st day of March 1887.
HENRY BECKETT HARDING.