IMPROVEMENTS IN THE MANUFACTURE OF APPARATUS FOR EXPANDING TABLES
Year: 1868

page_text: LETTERS PATENT to James Hare, of Handsworth, in the County of
Stafford, Machinist, for the Invention of "IMPROVEMENTS IN THE
Scaled the 19th January 1869, and dated the 16th November 1868..
PROVISIONAL SPECIFICATION left by the said James Hare at the
Office of the Commissioners of Patents, with his Petition, on the
16th November 1868.
I, JAMES HARE, of Handsworth, in the County of Stafford, Machinist,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN THE MANUFACTURE OF APPARATUS FOR EXPANDING TABLES," to be as
follows:-
In the ordinary method of manufacturing the said apparatus the
hollow screws which form the essential parts of the said apparatus are
made by cutting the screw threads out of the substance of the metal
tubes from which the screws are made, by which method of manufacture
the screws so made are comparatively weak.

page_text: My Invention consists in forming the screw threads upon the tubes
employed in apparatus for expanding tables by compressing the metal
of the tube into the required form instead of turning or cutting away the
metal to produce the depressed parts of the screw. In effecting the
compression of the metal of the tube so as to produce screw threads
thercon I employ the ordinary drawing process or other suitable well-
known process of shaping metals by compression.
The screws made according to my Invention are of uniform strength
throughout, similar to the tubes known in commerce as cable or twisted
tubes.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Hare in the Great Seal Patent Office on
the 11th May 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
HARE, of Handsworth, in the County of Stafford, Machinist, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of November, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said James Hare, Her special licence that I,
the said James Hare, my executors, administrators, and assigns, or such
others as I, the said James Hare, 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 THE MANUFACTURE
OF APPARATUS FOR EXPANDING TABLES," upon the condition (amongst others)
that I, the said James Harc, 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

page_text: calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said James Hare, 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 Drawing here-
unto annexed, and to the letters and figures marked thercon (that is
to say)-
My improvements in the manufacture of apparatus for expanding
tables refer or apply to that kind of table-expanding apparatus or
machinery in which the expansion is effected by the action of screws,
and my said improvements principally consist in the method hercin-after
described in making such screws: The screws heretofore employed for
this purpose, whether tubular or solid, have been produced by turning
out or otherwise cutting away a portion of the metal to form the worm
or thread.
My Invention consists in making the screws used in table-expanding
apparatus or machines by twisting or compressing the metal into the
forms required to produce the threads instead of cutting a portion away.
I use for this purpose any of the ordinary methods of twisting or com-
pressing metal, such for example as forcing rods or tubes into and
through dies, but I prefer to carry my Invention into effect by drawing
the rods or tubes through properly constructed twisting tools, according
to the method well known and practised in the making of those kinds of
tubes called cable or twisted tubes.
In applying the method of manufacture described to the manufacturo
of screws for table expanders I employ by preference drawing or twisting
tools of such a figure that they form or impress upon the rod or tube a
twisted figure, in which the twist or thread more nearly resembles the
figure of an ordinary screw thread; that is to say, I prefer to form on
the twisted rod or tube a thread thicker and stronger and more clearly
marked or defined than is possessed by ordinary twisted rods and tubes.
By giving the twisted rods or tubes the figure described the hold of the
female screw or screw box upon the screw is firmer, and both screw and
screw box wear much longer. Although not necessary for the successful
working of my Invention it is better that the screw thread formed upon
the rod or tube should approach as nearly as possible to the figure of
an ordinary angular or square screw thread. By this method of manu-

page_text: facture screws are obtained at a cheaper rate and of more uniform
strength throughout than tubular screws made in the ordinary way.
This method of manufacture also affords great facility in making screws
with multiple threads, and by the employment of screws having three or
more threads I am enabled to produce a table expander more rapid in
its action, that is, opening and closing the table in much less time than
where screws of a single thread only are used. The method of making
the screws described, that is, by the compression of the metal into the
shape to form the worms or threads, applies equally to the making of the
female screws or screw nuts in or through which the screws work. I
make the said female screws or nuts by stamping or pressing plates of
metal, iron or steel being preferred, into dies shaped to produce half or
part screws of the form required; or I make the said female screws or
nuts by twisting strips of metal of a suitable section into the worms of
such screws. When brought into the required shape I secure the said
stamped plates, twisted strips, wires, or pressed sections in a suitable
metal collar by means of pins or by brazing or soldering, and thus form
the female screws or nuts instead of tapping out or cutting away the
metal to form the threads as has been the practice heretofore. I also
make female screws or nuts of two or more plates of metal, having holes
in them of the figure of the screw in cross section. These plates are
fixed in a tube or collar in any convenient manner. I prefer to make
them of hardened iron or steel. By this method of manufacture I am
enabled to harden the female screws of iron or steel, whereby greater
durability is given to the internal threads over the method of using
softer metal and cutting the worms or threads away. The method
described of manufacturing the female screws or nuts may also be
applied to the making of screws. When I make the internal threads
of screw nuts of iron or steel I harden them by any of the well-known
processes of hardening iron and steel. By the employment in the con-
struction of table expanders of screws with multiple threads, so readily
produced by my method of manufacture, a very rapid action is obtained,
and in the use of such screws there is a tendency in them to run back or
become loose in their screw nuts. In order to prevent such unscrewing,
and to secure the screws in the place to which they have been drawn,
I fix upon the spindle carrying the screw a wheel, in the rim of which
is cut a number of openings or teeth, and a detent or catch is forced into
these openings or teeth by a spring which locks the screw in its place
and prevents it from turning back. The detent is so arranged that upon

page_text: putting the key upon the square end of the spindle to turn the screw
the detent or catch is lifted out of the tooth, the key being made of a
tapering form. The apparatus is then free to turn. Upon withdrawing
the key the spring forces the detent into the tooth or opening in the
wheel which is opposite the said detent, and locks the said wheel and
prevents the screw from turning.
The arrangement of mechanism which I use for preventing the
unscrewing or running back of the screws in their screw nuts is repre-
sented in the accompanying Drawing, where Figure 1 represents in
vertical section the said mechanism in action, and the screw fixed or
incapable of rotating; Figure 2 represents in section, and Figure 3 in
end elevation the said mechanism out of action and the screw capable of
rotating.
a is the screw of the table expander, made according to the method
herein-before described. On the end of the spindle of the said screw a is
a wheel b, the rim of which is made into a series of teeth or openings c,
in which a detent or catch d may engage; the said detent turns on the
centre d² and is carried by the end plate i of the table expander. On
the outer end of the catch d is an antifriction roller e, upon which a
spring bears, and raising the inner wedge-shaped end of the catch
causes it to engage with one of the teeth or openings in the wheel b,
and thereby fix the screw a as illustrated in Figure 1. When it is
wished to rotate the screw a for the purpose of expanding or contracting
the table the key g (Figures 2 and 3) is placed upon the square end h
of the spindle of the said screw a. The nose end of the key g is inclined
or has a tapering form, and as the key is fitted on the square end of the
spindle it lifts the antifriction roller e, and depressing the acting end of
the catch or detent d from the teeth c of the wheel releases the said
wheel and the screw a, to the spindle of which it is connected; the
screw a is thereby at liberty to be turned by the key g, and the
expanding apparatus worked, as illustrated in Figures 2 and 3. On
withdrawing the key g the detent or catch d is reëngaged with the
wheel 6 by the action of the spring f, and the screw a again locked.
Having now described the nature of my Invention, and the manner
in which the same is to be performed, I wish it to be understood that I
do not limit myself to the precise details herein described and illustrated,
as the same may be varied without departing from the nature my

page_text: Invention; but I claim, as my Invention of improvements in the
manufacture of apparatus for expanding tables,
Firstly. Making the screws tubular or solid, and the female screws
or nuts used in the said apparatus by compressing the metal of which
the said screws and female screws or nuts are made into the shapes or
forms required to form the threads or worms thereof, either by stamping
or pressing the said metal into dics, or drawing it through twisting tools,
substantially as herein-before described.
Secondly. Hardening the said female screws or nuts when the same
are made of iron or steel, as herein-before described.
Thirdly. The arrangement or combination of parts herein-before
described and illustrated in the accompanying Drawing for preventing
quick threaded screws of table expanders from unscrewing or running
back in their female screws or nuts.
In witness whereof, I, the said James Hare, have hereunto set
my hand and seal, this Tenth day of May, in the year of our
Lord One thousand eight hundred and sixty-nine.
Witness,
RICHARD SKERRETT,
Clerk to George Shaw,
Birmingham.
JAMES HARE. (L.S.)