IMPROVEMENTS IN FURNITURE CASTERS
Year: 1873

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of
"IMPROVEMENTS IN FURNITURE CASTERS." - A communication from
abroad by Cevedra Blake Sheldon, of the Oity, County, and State
of New York, United States of America.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 13th May 1873.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lanc, in the County
of Middlesex, Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN FURNITURE CASTERS," to be as follows:-
This Invention relates to ball and wheel casters for furniture, trunks,
and other articles, and comprises contrivances for the use of antifriction
balls to facilitate the turning of the caster balls or wheels.
Also contrivances for the attachment of the casters to the legs or

page_text: Also an improvement in the co
spindles.
And also an improvement in the construction of caster wheels, all of
which said improvements will be herein-after described.
"
I will first describe the application of a ball caster to a furniture leg. 5
The caster ball is placed in an inverted cup-shaped socket containing
antifriction balls. The socket may be made of cast metal, but I prefer
to strike it up from a piece of sheet metal. It is made larger than the
caster ball to contain the antifriction balls, and is turned inward at the
lower edge to confine said balls. At the top is a depression extending 1
nearly to the caster ball to prevent the antifriction balls from rising to
the top of said caster ball. An inverted cup-shaped cap is placed over
the socket piece above-mentioned, resting on an india-rubber or other
elastic ring or lining introduced between them to soften the shocks and
prevent noise. The lower edge of this cap is bent inward against the 1
socket just below the largest portion of its bulge, so as to hold it against
dropping out. The caster is fastened to the furniture leg by a screw
which passes through a countersunk hole on the top of the cap, also
through a nut which has a deep cavity at cach end, one of which bears
against the cup washer of the leg, and the other against the top of the
cap. The screw screws through this nut by a thread of fine pitch which
draws the parts rigidly together, while the wood screw thread at the
upper part, being of coarse pitch, screws into the leg: The friction
balls are arranged in numbers sufficient to cover about two-thirds of the
portion of the caster ball contained in the socket. They circulate
. around the sides of the ball, but are prevented from working up to the.
top as before stated, and thus distribute the action over a large surface,
which would be concentrated at the top if they were allowed to work
up to it.
i
"
In applying this part of the Invention to a trunk the socket cup for
the caster ball and the antifriction balls is received in a conical cavity
formed in the bottom of the trunk, and lined with a sheet metal plate
suitably struck up to fit in it. This plate may be formed together with
may be formed separately. The cup or
the bumper in one piece, or it
socket is inserted in the socket thus prepared for it, and secured by
tongues cut or punched in part out of the plate, and bent around-the-
edges of the cup, holding it firmly in place. In this arrangement-the

page_text: caster is very strong, and capable of withstanding severe concussions.
The cup and the balls. may be removed together from the plate if
desired by bending the tongues back.
According to another arrangement of the Invention to be applied to
wheel casters, but also applicable to ball casters, I attach to the top of
the standards or brackets mounted on the caster wheel a cup containing
antifriction balls, and having a conical elevation at the centre to keep
them in the annular groove or track formed thereby in the outer portion.
A cap is also rigidly attached to the head of the fastening screw by
rivets, or in any other manner. This cap is turned down at right angles,
and from the rim it is turned under, forming an annular box or recess on
the outside of the cup, in which recess antifriction balls are placed under
the top flange of the cup to sustain the lateral thrust of the latter, and
steady and guide it in turning. The head of the fastening screw also
rests on other friction balls which sustain the weight.
A further improvement relates to the application of the antifriction
balls to a wheel caster, which is connected to the leg by a socket and
spindle. The standards or brackets are mounted in the usual way on
the wheel, but in this case have a common spindle rising up from the
centre. Around the base of the spindle antifriction balls are placed and
confined by the annular recess of the washer fastened to the end of the
leg, and having a short conical tube, extending upward around the
spindle into the lower enlarged portion of the bush or socket by which
the socket of the leg is lined. These linings, which have heretofore been
made of parts or pieces made of cast metal, I now propose to make of
one piece or plate of sheet metal cut of suitable shape, and then bent,
stamped, or rolled up in the circular form necessary for the lining. This
plan I find less expensive, and the bush is more convenient, keeps its
place better, and wears better than those made in the common way. I
also make the socket open at the top, so that the spindle extends
through and takes none of the weight, which is all borne by the washer
on the balls.
I also propose to make caster wheels of sheet metal, say, of two
halves, said halves consisting essentially of a disc with a flange turned
on one side, also a centre box or bearing for the pivot formed on the
same side as the flanges, which said halves are riveted together or
secured by a tube passing through the centre tubes or boxes (enlarged

page_text: for the purpose) and milled over the ends. The flanges may be turned
back against the discs if preferred. In a modified application of the
antifriction balls to the caster wheel and spindle the said balls arė
arranged on the top of the bracket or standard around the base of the
spindle, and confined in an annular recess in the washer, but the washer
has a socketed extension for the spindle, which is short, and on the top
of said extension is a wood screw for securing the caster to the leg.
A hollow washer in the form of a truncated conè rests on the upper side
of the first-mentioned washer, and extends as high as the top of the
socketed cylinder to bear against the furniture leg when screwed in
up,
such manner as to brace the caster firmly and securely.
It will be observed that in these arrangements the cramping and
binding of the spindle in the socket, common to the ordinary casters, is
wholly avoided, and a very easy and smooth horizontal rotation of the
casters is secured.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 6th November 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of May, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alexander Melville Clark, Her special
licence that I, the said Alexander Melville Clark, my executors, adminis-
trators, and assigns, or such others as I, the said Alexander Melville
Clark, 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 might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN FURNITURE CASTERS," a communication to me from

page_text: °
abroad by Cevedra Blake Sheldon, of the Oity, County, and State of
New York, United States of America, upon the condition (amongst
others) that I, the said Alexander Melville Clark, 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.
NOW KNOW YE, that I, the said Alexander Melville Clark, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by
the following statement, reference being had to the accompanying
Sheet of Drawings, and to the letters and figures marked thereon (that
is to say) :-
This Invention relates to ball and wheel casters for furniture, trunks,
and other articles, and comprises contrivances for the use of antifriction
balls to facilitate the turning of the caster balls or wheels.
Also contrivances for the attachment of the casters to the legs or
trunks.
Also an improvement in the construction of sockets for the caster
spindles.
And also an improvement in the construction of caster wheels, all of
which said improvements I will now describe, first however referring to
the several Figures in the accompanying Drawings illustrating the said
improvements, of which Figuro 1 is a side elevation of a ball caster
applied to a furniture leg, showing one mode of carrying out the Inven-
tion; Figure 2 is a sectional elevation of Figure 1.
Figure 3 is a plan of the caster ball socket inverted, and containing
the antifriction balls; and Figure 4 is a plan view of a cup in which the
caster ball socket is fitted and secured to the attaching screw, said cup
being inverted.
Figure 1ª is a sido elevation of a ball caster applied to a trunk, showing
another mode of carrying out the Invention; Figure 2" is a sectional
elevation. of Figure 1*; and Figure 3* is a plan view of the caster repre-
sented in Figure 1ª, inverted.
•

page_text: Figure 1 is a sectional elevation of a wheel caster, showing one
arrangement for mounting it on antifriction balls; Figure 2b is a hori-
zontal section of Figure 1' on the line x, x; and Figure 3' is a section of
Figure 1' on the line y, y, looking downward.
Similar letters of reference indicate corresponding parts.
Figure 1° is a side elevation of a wheel caster attached to a furniture
leg, showing a modified arrangement of contrivances for mounting it on
antifriction balls.
Figure 2° is a sectional elevation of Figure 1°, showing besides the
mode of mounting the caster on antifriction balls a plan for constructing 1
the wheel of stamped sheet metal.
Figure 3º is a diagram of a sheet of rolled metal, of which I propose to
construct the spindle socket in one piece.
Figure 4° is a section of a caster wheel, showing modified plan for a
wheel of stamped metal.
Figure la is a sectional elevation of a wheel caster attached to a furni-
ture leg, showing another arrangement of devices for mounting it on
antifriction balls; and Figure 2ª is a horizontal section of Figure 1ª on
the line x, x.
Similar letters of reference indicate corresponding parts.
In Figures 1 and 2 A. is the caster ball; B is an inverted cup-shaped
socket for it, and the antifriction balls C; it may be made of cast metal,
but I prefer to strike it up from a piece of sheet metal. It is made so
much larger than the ball A as to contain the ball O, and is turned
inward at the lower edge F to confine said balls C. At the top is a
depression H extending nearly to the caster ball A to prevent the balls C
from rising to the top of the said ball A; D is an inverted cup-shaped
cap placed over the socket piece, and resting on an india-rubber or other
elastic ring or lining E, introduced between them to soften the shocks,
and prevent noise. The lower edge of cap D is bent inward against {
socket B, just below the largest portion of its bulge, so as to hold it
against dropping out. I is the screw which fastens the caster to the leg;
it passes through a countersunk hole on the top of cap D, also through
the nut J, which has a deep cavity at each end, one of which bears
against the cup washer L of the leg, and the other against the top of the

page_text: cap D. The screw screws through this nut by a thread K of fine pitch,
which draws the parts rigidly together, while the wood screw thread at
the upper part being of coarse pitch screws into the leg. .
Figure 3 shows the arrangement of the friction balls, which are in
numbers sufficient to cover about two-thirds of the portion of the caster
ball contained in the socket. They circulate around the sides of the ball;
.but are prevented from working up to the top, as before stated, and thus
distribute the action over a large surface, which would be concentrated
at the top if they were allowed to work up to it.
In Figures 1, 2, and 3* I have represented the application of this part
of the Invention to a trunk. A¹ represents the trunk; B' is a bumper ;
C³, the caster, of which G¹ is the caster ball; F, the antifriction balls;
and E¹, the socket cup for the caster ball and the balls F¹. A conical
cavity is formed in the bottom of the trunk, and lined with a sheet metal
plate suitably struck up to fit in it. This plate may be formed together
with the bumper B' in one piece, or it may be formed separately. The
cup or socket E' is inserted in the socket thus prepared for it, and
secured by tongues H' cut or punched in part out of the plate, and bent
around the edges of cup E¹, as more clearly shown in Figure 3*, holding
› it firmly in place. In this arrangement the caster is very strong, and
capable of withstanding severe concussions. The cup E' and the balls
may be removed together from the plate if desired by bending the
tongues H back.
In Figures 1, 2, and 3' is represented an example of the Invention
3 applied to wheel casters, but I do not limit myself thereto, for it is also
applicable to ball casters.
A' represents the standards or brackets mounted on the wheel B². To
the top of these standards I attach a cup D³, containing antifriction
balls E³, and having a conical elevation at the centre to keep them in the
) annular groove or track formed thereby in the outer portion. F is the
head of the fastening screw; G³ is a cap rigidly attached to the head of.
the screw by rivets H³, or in any other manner. This cap is turned
down at right angles, as seen at I³, and from the rim I' it is turned
under, as seen at J³, thus forming an annular box or recess L³ on the
6 outside of the cup D³, in which recess antifriction balls K² are placed
under the top flange of cup D³. The head of the fastening screw rests
on the friction balls E³, which sustain the weight, whilst the balls K³

page_text: sustain the lateral thrust of the cup D³, and steady and guide it in
turning. O represents the screw by which the caster is fastened to the
leg.
In Figures 1° and 2° I have represented the application of the anti-
friction balls to a wheel caster, which is connected to the leg by a socket
and spindle.
A³ represents the standards or brackets mounted, as in other cases, on
the wheel, but in this case having a common spindle C³ rising up from
the centre. Around the base of this spindle the antifriction balls D³.are
placed, and confined by the annular recess of the washer E³, fastened to
the end of the leg, and having a short conical tube F³ extending upward
around the spindle into the lower enlarged portion of the bush or
socket G³, by which the socket of the leg is lined. These linings, which
have heretofore been made of parts or pieces made of cast metal it is
now proposed to make of one piece or plate of sheet metal cut in the
form represented in Figure 3º, and then bent, stamped, or rolled up in the
circular form necessary for the lining. This plan is found less expensive,
and the bush is more convenient, keeps its place better, and wears better
than those made in the common way.
It will be observed that I also make the socket open at the top, so
that the spindle extends through and takes none of the weight, which is
all borne by the washer E³ on the balls D³.
.
It is also proposed to make caster wheels of sheet metal, say of two
halves, stamped or spun up in either of the forms represented in Figures 2°
and 4º, said halves consisting essentially of a disc H; with a flange I³
turned on one side, also a centre box or bearing Js for the pivot, formed
on the same side as the flanges, which said halves are rivetted together,
as in Figure 4º, or secured by a tube K' passing through the centre tubes
or boxes (enlarged for the purpose), and milled over the ends. The
flanges Is may be turned back against the discs, as at L³, if preferred.
In Figures 1ª and 2ª I represent a modification of the application of
the antifriction balls to the caster wheel and spindle, in which the said
balls D' are arranged on the top of the bracket or standard A* around the
base of the spindle C4, and confined in an annular recess J* in the
washer E, but the washer has a socketed extension F¹ for the spindle,
which is short, and on the top of said extension is a wood screw G* for
securing the caster to the leg. A hollow washer H' in the form of a

page_text: Eighth. The socket plate E³, provided with the extension F" for the
spindle, combined with the balls D³, spindle C³, bracket A³, and the
socket lining G³, substantially as represented in Figures 1° and 2°.
Ninth. The socket case or lining G³, constructed of a plate, substantially
in the form represented in Figure 3°.
Tenth. A caster wheel composed of two parts, formed up of sheet
metal, and fastened together by rivetting or by a tube K³, substantially
as represented in Figures 2º and 4°.
Eleventh. The socket E, F, provided at the top with the screw G',
and at the bottom with the annular recesses J', in combination with 1
standards A', spindle C, and balls D', substantially as represented in
Figure 14.
Twelfth. The combination of the washer H' with the socket E.,.F",
and screw G, substantially as represented in Figure 1ª.
In witness whereof, I, the said Alexander Melville Clark, have 1
hereunto set my hand and seal, this Fifth day of November, in
the year of our Lord One thousand eight hundred and seventy.
three.
Witness,
HENRY W. DEWEY,
53, Chancery Lane,
London.
A. M. CLARK. (L.S.)