Improvements in Wheel Castors.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in Wheel Castors.
I JOHN HOLMES BLAKESLEY, Civil Engineer of 39 Victoria Street West-
minster do hereby declare the nature of this invention to be as follows:-
:-
To diminish or annihilate the strain upon the vertical pivot of the castor, I
enlarge this so as to make its circumference approach more nearly, or even enclose
the vertical line thro' the point of contact of the castor wheel & the floor, even
making this enlargemt. into a flat plate or cone bearing upwards against a similar
plate or cone; and to diminish the friction I insert between the pivot & its
bearings or between these flat plates or cones, antifriction rollers or balls as most
convenient, guided where desired by grooves cut in or guides raised upon the said
pivot or bearings plates or cones, or held by distance rings or other suitable device
as convenient.
Instances are given in Figs. 1 and 2. In the case of Fig. 2 the cones need not
be reversed; one may be hollow enclosing the other convex one.
The end of the pivot may bear up against smooth balls or rollers or one such.
The castor wheel may also have such antifriction bearings on its axle.
The foregoing & drawings are given by way of illustration, but it is unler-
stood that the form & methods of fixing, & the shapes & relative dimensions of
parts may be varied in many ways within the scope of my invention.
Dated this Fifth day of January 1895.
JOHN HOLMES BLAKESLEY of 39 Victoria Street, Westminster Civil 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 :—
To diminish or annihilate the bending strain upon the vertical pivot of the
castor, 1 enlarge this pivot, so as to make the outer limit of the points of vertical
pressure approach more nearly to, or even enclose the vertical line through the
centre of the castor wheel; even making this enlargement into a flat plate or cone
bearing upwards against another flat plate or cone; and to diminish the friction
I insert between the pivot and its bearings, or between the flat plates or cones,
antifriction rollers or balls as most convenient, guiding these where desired by
grooves cut in, or guides raised upon the said pivot or bearing plates or cones, or
holding them by radial axles, distance rings or other suitable device.
Instances are given in Figs. 1 and 2 in the drawing filed with my Provisional
Specification. In the case of Fig. 2, the cones need not be reversed-o
-one may be
hollow enclosing the convex one.
Or the end of the pivot may bear up against smooth balls or rollers, or one such.
The castor wheel may also have such antifriction bearings on its axle.

page_text: It will be noticed in the figures that the central pin does not represent the
vertical pivot in ordinary castors, inasmuch as it is not called upon normally to
supply any support requisite for the weight on the castor. In fact it is actually
free and out of contact with the lower plate when the castor is weighted, & only
serves to secure the lower plate from dropping off when the whole is raised from
the ground. In this case the lower plate represents the usual central pivot
enlarged as described, though the usual side pressures on it are obviated by the
ring of support enclosing the vertical line through the centre of the wheel.
The foregoing & drawings are given by way of illustration, but it is understood
that the form, method of fixing, or shapes & relative proportions of parts may be
varied in many ways within the scope of my invention.
Having now particularly described and ascertained the nature of my said inven-
tion, & in what manner the same is to be performed, I declare that what I
claim is:-
1. In castors the insertion between the central pivot and its bearings of rollers,
cylindrical, conical or spherical, substantially in the manner & for the purpose
herein described.
2. In castors the enlargement of the central pivot & its bearings, or the extension
of their bearing surfaces into plane, conical or other surfaces combined with the
insertion between them of rollers cylindrical, conical, or spherical, the rollers being
either free or guided as described substantially for the purpose & in the manner
herein described.
Dated this Thirtieth day of September 1895.
JOHN H. BLAKESLEY.