An Improved Furniture Castor.
Year: 1891

page_text: Date of Application, 9th Apr., 1891
Complete Specification Left, 8th Feb., 1892-Accepted, 12th Mar., 1892
PROVISIONAL SPECIFICATION.
An Improved Furniture Castor.
I ANDREW RENFREW of 68 Lumsden Street in Lanarkshire in the City of
Glasgow Engineer do hereby declare the nature of this invention to he as
follows:-
In the common castor there is a great strain on the castor on account of the
wheels or rollers not being directly under the line of pressure. To remedy this I
construct a castor with two wheels or rollers in line. place one wheel directly
under centre of spindle and the other in the usual place to make them turn whatever
way the furniture is moved the centre wheel taking all the weight.
Dated this 7th day of Annil 1801
ANDREW RENFREW.
COMPLETE SPECIFICATION.
An Improved Furniture Castor.
1. ANDREW RENFREW of 68 Lumsden Street in Lanarkshire in the City of
Glasgow, 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:-
This invention relates to furniture castors and has for its objects :-
First. To afford, therewith a centre or vertical pressure support, instead of a
bracket support to structures or furniture.
Second. To prevent side strain upon their vertical spindles.
Third. To prevent strain upon the screws which fix them upon furniture or
other structures.
In the common castor there is a great strain upon the metal work and screws
thereof when in use on account of the wheels or rollers not being directly under
the line of pressure.
To remedy this I construct a castor with two wheels, balls,
or rollers in line, one behind the other, in bicycle or tandem fashion. I place one
wheel directly under the centre of the vertical spindle and the other in the usual
place, so that the latter may act as a rudder and make the two wheels turn which-
ever way the furniture is moved; the centre wheels, beneath the said spindles,
receiving all the weight of the structures to which they are attached.
My invention will be better understood by reference to the accompanying
drawings, in which :-
Figure 1 is a broadside view in elevation of my improved castor;
Figure 2 is a front view, in elevation, of it; and
Figure 3 is a back view, in clevation, of my improved castor.
Each figure shews a different construction of the part which connects the castor
to the furniture, all of which methods of attachment are in common use. Figure 1
is fitted with a cup, A, for uniting it to the leg of a table or chair; Figure 2 has a
plate B for attachment to the underside of drawers, chests etcetera, and Figure 3 has
a centre screw C for insertion within the structure to which it is attached.
Each type is made so that the vertical spindle D may revolve within the
part A. B, E or F.
By constructing the castor with the two wheels, (balls or rollers) G and H, one
behind the other in bicycle or tandem fashion, the one marked G acts as a rudder
to the castor, for the purpose of turning it, by means of the vertical spindle D in
any direction required, this being the object for which it is designed; the weight of

page_text: the structure to which these castors are attached, is borne by the wheels H which
are placed directly beneath the spindle D.
As the balls H have all the weight of the structure to bear and those marked G
are required simply as rudders for turning the castors round as before named I
find an advantage is obtained by making only those marked H of wood, metal or
other hard material and those marked G of india rubber or other soft material;
and further, by fixing the latter within the plates J so that they (the wheels)
occupy a slightly lower horizontal plane than those marked H, as indicated by
dotted lines in the drawings.
The natural result of making the balls G of india rubber or soft material and
fixing them upon a slightly lower horizontal plane than those marked H is that the
former are compressed by the weight of the structure and are thereby prevented
from slipping when subjected to side movements; they also obtain a better grip of
the floor or its covering than they would if composed of hard material and fixed on
the same horizontal plane as those marked H, and are thereby rendered more
efficient as rudder wheels, these being the purposes which I have had in view in
thus making and placing them.
Owing to the fact that the structures which are furnished with my improved
castors are supported by central pressure, through the spindles D and the wheels H
there is no side strain either upon the said spindles or any of the screws which
ordinarily unite the castors to their superstructures.
I am aware that, previous to my invention, numerous kinds of furniture castors
have been made which have had centre-pressure wheels or balls; it will therefore
be understood that I do not claim a centre-pressure-wheel furniture castor broadly
as my invention.
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 :-
:-
First. In a furniture castor, the combination therewith of the two balls or
wheels, G and H, arranged in bicycle or tandem fashion, one behind the other, all
substantially as herein described and shewn, or any mere modification thereof, for
the purposes specified.
Second. In a furniture castor, the combination therewith of the two balls or
wheels G and H, arranged one behind the other in bicycle or tandem fashion,
whether the wheel G be made of soft or hard material, all substantially as herein
described and shewn or any mere modification thereof, for the purposes specified.
Dated this 6th day of February 1892.
JOSEPH
LOCKWOOD,
263, Argyle Street, Glasgow, Agent for the Inventor.