IMPROVEMENTS IN CASTORS PRINCIPALLY EMPLOYED TO FACILITATE THE MOVEMENTS OF FURNITURE
Year: 1877

page_text: LETTERS PATENT to George Lamb Scott, of the City of Manchester, in
the County of Lancaster, for the Invention of "IMPROVEMENTS IN CASTORS
PRINCIPALLY EMPLOYED TO FACILITATE THE MOVEMENTS OF FURNITURE."
PROVISIONAL SPECIFICATION left by the said George Lamb Scott at
the Office of the Commissioners of Patents on the 20th October 1877.
GEORGE LAMB SCOTT, of the City of Manchester, in the County of Lancaster,
Engineer. "IMPROVEMENTS IN CASTORS PRINCIPALLY EMPLOYED TO FACILITATE
THE MOVEMENTS OF FURNITURE."
My Invention relates to the castors which are applied to tables, pianos, bedsteads,
and other articles of furniture, and bodies, and loads, in order to render them capable
of being moved with greater facility, as will be well understood.
In such castors as usually constructed a wheel is fitted to revolve within a frame
or part which is arranged to swivel upon a pin or stump which is secured to the leg
of the table, or to a part of the article or body to which the castor is applied. The
axis of motion of the said wheel is outside of the central axis upon which the said
frame swivels, and which I will call the vertical axis, so that when the said frame
turns upon the said pin or stump the said axis of motion moves in a circle around
the said vertical axis.
According to the first part of my Invention I so mount the said wheel, and so
form and arrange the parts as that the axis of motion of the wheel is free to move
or is capable of moving in a straight or nearly straight line across the said vertical
axis, or of moving towards and from the said vertical axis in addition to the capa-
bility of movement around the said vertical axis.
In one arrangement the said frame is formed with two cheeks, and a slot is
formed in each cheek. The wheel is mounted upon a pin which is free to slide or
roll in the said slots, or the said pin is fixed in the said wheel, or gudgeons formed
on or fixed to the said wheel enter the said slots, or euter grooves formed in the said
cheeks in lieu of the said slots. The wheel can pass from one side to the other of

page_text: the said vertical line without necessarily moving in a circular path, the effect being
that the wheel more readily assumes the positions required to enable the article to
which the castor is applied to be moved with suitable facility.
In some cases two wheels may be employed in each castor, in which case they"
may be mounted or fixed upon an axle which passes through a slot in the part which
swivels upon the said vertical axis, or the common axis of the said wheels may be
carried by a block which is arranged to slide in the said part, or upon a rod or bar
attached to the said part.
Other modifications may be made in the arrangement, so long as the axis of
the wheel or wheels is capable of movement towards and from the said vertical
axis.
According to a second part of my Invention I form an annular, and by preference,
conically-formed bearing surface upon the part which is fixed to the body to be
moved, and a corresponding surface upon the part which swivels upon the said
vertical axis, so that the load is transmitted wholly or partly to the said part by
means of the said bearing surfaces, whereby a portion of the strain is removed from
the central pin or axle.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Lamb Scott in the Great Seal Patent Office on the 20th
April 1878.
GEORGE LAMB SCOTT, of the City of Manchester, in the County of Lancaster,
Engineer. "IMPROVEMENTS IN CASTORS PRINCIPALLY EMPLOYED TO FACILITATE
THE MOVEMENTS OF FURNITURE."
My Invention relates to the castors which are applied to tables, pianos, bedsteads
and other articles of furniture, and bodies, and loads, in order to render them capable
of being moved with greater facility, as will be well understood.
In such castors as usually constructed a wheel is fitted to revolve within a frame
or part which is arranged to swivel upon a pin or stump which is secured to the leg
of the table, or to a part of the article or body to which the castor is applied. The
axis of motion of the said wheel is outside of the central axis upon which the said
frame swivels, and which I will call the vertical axis, so that when the said frame
turns upon the said pin or stump the said axis of motion moves in a circle around
the said vertical axis.
According to the first part of my Invention I so mount the said wheel, and so
form and arrange the parts as that the axis of motion of the wheel is free to move
or is capable of moving in a straight or nearly straight line across the said vertical
axis, or of moving towards and from the said vertical axis in addition to the capa-
bility of movement around the said vertical axis.
According to a second part of my Invention I form an annular, and by preference
conically-formed bearing surface upon the part which is fixed to the body to be
moved, and a corresponding surface upon the part which swivels upon the said
vertical axis, so that the load is transmitted wholly or partly to the said part by
means of the said bearing surfaces, whereby a portion of the strain is removed from
the central axle or pin.
In order that my said Invention may be readily described and well understood,

page_text: I have appended hereunto a Sheet of Drawings of examples illustrative of some
of the methods which may be adopted in the carrying into effect of my Invention,
the said Drawings being marked with letters of reference.
In the said Drawings Figs. 1 and 2 represent a castor constructed in accordance
with my Invention.
In the said Figs. a is the bowl or wheel of the castor; b is the swivel frame; and
c is the part which is screwed or secured to the leg of the table or to the part to
which the castor is applied. The frame b is formed or provided with a pin or
shank d which is fitted to revolve in a bearing formed in the part c, so that the
wheel and frame can swivel, as is usual. The said frame is formed with two cheeks
or sides, in each of which is formed a slot. The ends of the axle of the wheel pass
through both slots. The said axle may either be fixed within the wheel or be loose,
as preferred.
In the example the ends of the said axle are reduced in diameter, and washers e, e,
are riveted upon the said ends, the axle being thereby kept in place within the
wheel and also within the said slots, but this arrangement may be varied.
It will be seen that the wheel a is retained within the frame but is free to move
to and fro within the said frame in a line at right angles to its axis of revolution,
the said to-and-fro movement being limited by the length of the said slots. When
the castor is, say, for example, applied to a table, and supposing the table to be
moved in the direction indicated by the arrow in Fig. 2, the wheel would be moved
to the other end of the frame, the axle of the wheel rolling within the slots; or, to
state the matter more exactly, the frame moves more quickly than the wheel, so
that the wheel is transferred from one side of the vertical axis A to the other
without the necessity for the frame to swivel upon the said axis, as would be the
case with an ordinary castor.
Fig. 3 illustrates a slight modification in the construction of the castor. The
pin d is secured to the part c, and the frame b is arranged to swivel upon the
said pin.
Figs. 5 to 8 illustrate further modifications.
In Fig. 5 recesses corresponding to the said slots are formed on the inner sides of
the cheeks of the frame b, and the gudgeons or ends of the axle of the wheel a are
mounted within the said recesses, and are free to roll to and fro therein, as in the
case of the axle and slots in Fig. 2.
In Fig. 6 the frame b is formed with a central projecting part in which is
formed a slot corresponding to the slots in Fig. 2, and two wheels fixed or formed
upon one axle are employed, the said axle passing through the said slot and being
free to roll to and fro therein, as in the examples previously described.
In Fig. 7 the said axle is fitted to revolve in a block which is arranged to slide
to and fro within the slot.
If preferred sliding blocks may be employed in the examples previously
described.
In Fig. 8 the part f is forked, and carries a bar or rod g upon which a
block his fitted to slide. The axle of the two wheels is fitted to revolve in
a bearing formed in the said block. In the Drawing one of the said wheels
is removed for convenience of illustration.
This method of construction may also be employed in the case of a castor
having only one wheel, in which case each of the cheeks of the frame b would
be formed in a similar manner to the part f in Fig. 8, and the gudgeons of
the wheel a would revolve in two blocks arranged to slide to and fro upon
two rods or bars.
Fig. 4 illustrates a further modification, and also illustrates the second part of my
Invention. In this example the upper part of the frame b is turned to a circular
conical form, and is fitted to revolve in contact with a correspondingly curved
surface formed upon the part c, whereby a large proportion of the strain is removed
from the central pin, and the steadiness of the castor and its ability to sustain a
heavy load are increased.

page_text: '
Having now fully set forth and indicated the nature of my said Invention and
methods whereby the same may be carried into effect, I would have it to be under-
stood that I claim,-
First. The castors formed and arranged to act substantially as and for the
purpose set forth, and indicated herein-before and in and by the accompanying
Drawings.
Secondly. Mounting the wheel axles or gudgeons of castors within slots or
recesses, so that the wheels can move from one side to the other of the vertical axis
without the necessity for the wheel frame to swivel upon the said central axis.
Thirdly. Mounting the wheel axles or gudgeons of castors within blocks arranged
to slide to and fro, substantially as and for the purpose set forth and indicated.
And, lastly. The castor formed and arranged to act substantially as set forth, and
indicated herein-before when referring to Fig. 4 of the accompanying Drawings.
-
In witness whereof, I, the said George Lamb Scott, have hereunto set my
hand and seal, this Eighteenth day of April, in the year of our Lord
One thousand eight hundred and seventy-eight.
Signed and sealed by the
said George Lamb Scott
in the presence of
HUGH GRANT,
Clerk to Edward K. Dutton,
Agent to the Patentee,
St. Ann's Churchyard,
Manchester.
GEORGE LAMB SCOTT. (L.S.)