IMPROVEMENTS IN BALL Casters
Year: 1874

page_text: LETTERS PATENT to Job Johnson, of Brooklyn, in the County of
Kings, and State of New York, United States of America, for the
Invention of "IMPROVEMENTS IN BALL Casters.”
Sealed the 28th April 1874, and dated the 23rd February 1874.
PROVISIONAL SPECIFICATION left by the said Job Johnson at the
Office of the Commissioners of Patents, with his Petition, on the
23rd February 1874.
I, JOB JOHNSON, of Brooklyn, in the County of Kings, and State of
New York, United States of America, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN BALL CASTERS," to be as
follows:-
:
The ball of the caster is of hard material, steel is preferred, and this
is within a cup or socket that is secured to the leg or other part of the
chair or article to which the caster is applied. A sleeve surrounding
the ball secures the same in position, but allows the ball to roll.
The socket for the ball is made with a flat bottom of hardened steel
against which the caster ball rolls, or clse there are intermediate balls
within an opening or openings in a steadying disk.

page_text: The plate at the bottom of the socket is secured by projections upon
its upper surface, and the sleeve is retained from unscrewing by inter-
locking projections or a screw pin.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Job Johnson in the Great Seal Patent Office on
the 19th August 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOB
JOHNSON, of Brooklyn, in the County of Kings, and State of New York,
United States of America, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of February, in the.
year of our Lord One thousand eight hundred and seventy-four, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Job Johnson, Her special
licence that I, the said Job Johnson, my executors, administrators, and
assigns, or such others as I, the said Job Johnson, 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 BALL CASTERS," upon the condition (amongst others) that I, the said
Job Johnson, my executors or administrators, by an instrument in
writing under my or their, or one of their hands and seals, should parti-
cularly 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 immediatelyafter the date of the said Letters Patent.
NOW KNOW YE, that I, the said Job Johnson, do hereby declare.
the nature of my 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 made to the Drawing hereunto

page_text: becoming disconnected. The central steady pin is of a sufficient size
to prevent the caster moving laterally upon the end of the leg and, thus
lessens the strain upon the attaching screws. The ordinary pin on
which the pivot of the caster turns is so much larger than this steady
pin that the leg is weakened by the hole that is bored for its reception.
The socket 6 in Figs 4 and 5 is of the proper depth for receiving the
caster ball d; the antifriction balls m, m, m, and the bearing disk e and
the ball d is retained in place by the screw sleeve 7 that screws upon the
outside of the socket b. The bearing disk e is made with projections 2, 2,
upon its upper surface, and these pass into depressions in the socket.
It is preferable to employ a disk e of hardened steel, and the projections 2
imbed themselves into the metal of the caster socket when the disk is
pressed firmly to its place in the socket. The balls m, m, m, are in an
opening or openings through the disk c so that this disk c keeps the
balls in their proper relative positions, and this disk c is sufficiently loose
to turn freely in the socket but it is kept from tipping or becoming
displaced by a small flange & made within the socket by a feather of
metal cut or pressed up so as to project from the interior surface of the
socket over the outer edge of the disk c. The disk c may have separate
holes, as shown in Fig. 7, but the central opening and ball recesses
shown in Figs. 8 and 9 are generally preferable as most easily cut out
by dies.
The sleeve is retained by indentations made around the joint or line
of division where the sleeve and socket join together, as scen in Fig. 4;
these indentations spread the metal in opposite directions so as to
corrugate and interlock the metal at the joint after the sleeve has been
screwed up tightly, thereby preventing the sleeve unscrewing.
When it is desired to obtain a small bearing for the main ball and
thereby lessen the surface exposed to friction, I make use of a ball
that is of such hard metal that the surface will not be injured, and in
the plate e I provide an opening or cavity, as seen in the section Fig. 10,
so that the bearing surface is only the annular edge, and upon this the
ball & rolls.
For trunks and articles exposed to concussion the caster may be made
with the two parts of the socket united by rivets or screws, as seen in
Figs. 11 and 12. In these the socket is flanged and united to the
base plate 6 by screws or rivets at 13, 13, and lugs or ribs 14 serve to
prevent the lateral strain coming upon the rivets.

page_text: In some cases the base plate 6 will be turned up to form an angular-
flange ¹, as seen in Fig. 11, and in other cases the base 6 and flange of
the socket will be elliptical, as seen in Fig. 12, and the small or narrow
bearing surface or edge for the ball will be either the separate plate e or
the edge of the flat or raised scat at the edges of the opening in the
base b, as seen in Figs. 11 and 12, and I remark that I prefer to make
this hole round but it might be polygonal or star-shaped.
What I claim as my Invention and desire to secure by Letters Patent
JOB JOHNSON. (L.S.)
Witnesses,
CHO. H. SMITH, 121, Nassau St. New York.
HAROLD SERRELL,
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