IMPROVEMENTS IN CASTORS
Year: 1865

page_text: aled the 1st December 1865, and dated the 24th June 1865.
PROVISIONAL SPECIFICATION left by the said Robert Eastman at the
Office of the Commissioners of Patents, with his Petition, on the 24th
June 1865.
I, ROBERT EASTMAN, of Islington, in the County of Middlesex, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN CASTORS," to be
as follows:-
I use a ball of a true spherical form, and cause it to revolve or roll loose in
a frame or socket of any suitable construction, and inside this frame or socket
I place at the top part a piece of metal or other suitable material forming a
segment of a circle or a plane flat surface, the said ball or sphere revolving
in contact with it, by which the least possible amount of friction takes place; the
bearing or point of contact being immédiately over the centre, and the smallest
portion of contact between the two surfaces occurring at the same time, thus
dispensing with the leverage and ordinary rim or edge of the wheel castor, so
very objectionable on account of their friction and breakage.
The balls or spheres may be made of glass, porcelain, metal, wood, or any
suitable metal or material; but when made of glass are peculiarly applicable
to pianofortes or other musical instruments, as they form a perfect insulator.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Eastman in the Great Seal Patent Office on the 18th
December 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
EASTMAN, of Islington, in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of June, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Robert Eastman. Her special licence that I, the said Robert Eastman,
iny executors, administrators, and assigns, or such others as I, the said
Robert Eastman, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully ight make, use.
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTз
CASTORS," upon the condition (amongst others) that I, the said Robert
Eastman, my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after the date
of the said Letters Patent.
IN
NOW KNOW YE, that I, the said Robert Eastman, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-
I use a ball of a true spherical form, and cause it to revolve or roll loose in
a frame of any suitable construction, and inside this frame I fix at the top
part a convex, or concave, or flat segment of metal or other suitable material,
the said ball or sphere revolving in contact with it, by which the least possible
amount of friction takes place; the bearing or point of contact being imme-
diately over the centre, and the smallest portion of contact between the two
surfaces occurring at the same time, thus dispensing with the leverage and
ordinary rim or edge of the wheel castor, so very objectionable on account of
their friction and breakage.
This Invention will be clearly understood by referring to the figures and
letters on the accompanying Sheet of Drawings, in which Fig. 1 is an outside

page_text: view, and Fig. 2 a section of one of my improved castors, and Figs. 3, 4, and 5,
are views of modifications of the same. In all the Figures a represents the
ball or sphere; b, the frame of the castor; and c, a convex segment of metal
constituting one form or arrangement of resisting surface with which the ball
is in contact.
In Figs. 1 and 2 the lower part of the frame b has a thread cut in it, into
which is screwed the ring or bead d for keeping the ball in its place and
acting as leverage in connection with the segment c, and the projections e,
Figs. 3 and 4, are for the same purpose. The ring or bead d and projections e
I prefer to be placed at or under the horizontal diameter of the hall or
sphere a. I prefer the convex segment c to be made of steel, hardened and
burnished, and the same system is to be adopted when instead of a convex
segment employ a concave segment. The frames of the castors can be made
of all dimensions and designs, and each formed either with a socket as shown
at f. Figs. 1 and 2, or with a plate as in Figs. 3 and 4, or with a screw cast in
the frame as in Fig. 5. The ring d, Figs. 1 and 2, can be of the same
material as the frame, but I prefer it to be made of steel or iron hardened.
The balls or spheres may be made of glass, porcelain, metal, wood, or any
suitable metal or material, but when made of glass are peculiarly applicable
to pianofortes or other musical instruments as they form a perfect insulator.
Having now fully described the nature of my said Invention. and the
manner in which the same is or may be used or carried into effect, I desire it
to be understood that I claim the fixing in the top of the interior of the frame
of each ball castor a convex or concave segment of metal or other material,
against which convex or concave segment the top of the ball is in contact
when the castor is in use: and also fixing the ring or head d, with or without
the projections e, at or under the horizontal diameter of the ball or sphere a.
In witness whereof. I, the said Robert Eastman, have hereunto set my
hand and seal, this Thirteenth day of December, in the year of our
Lord One thousand eight hundred and sixty-five.
ROBERT EASTMAN. (L.S.)