IMPROVE- MENTS IN MEANS OR APPARATUS FOR MANUFACTURING SCREWS OF VULCANITE OR OTHER ANALOGOUS MATERIAL FOR LIQUID METERS."
Year: 1874

page_text: LETTERS PATENT to Thomas Greenacre, of Turners' Road, Burdett
Road, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN MEANS OR APPARATUS FOR MANUFACTURING SCREWS OF VULCANITE
OR OTHER ANALOGOUS MATERIAL FOR LIQUID METERS."
PROVISIONAL SPECIFICATION left by the said Thomas Greenacre at
the Office of the Commissioners of Patents, with his Petition, on
the 24th October 1874.
I, THOMAS GREENACRE, of Turners' Road, Burdett Road, in the County
of Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN MEANS OR APPARATUS FOR MANUFACTURING SCREWS OF
VULCANITE OR OTHER ANALOGOUS MATERIAL FOR LIQUID METERS," to be as
follows:-

page_text: before described the parts may be otherwise connected by gearing, so
that the speed of the cutter shall be regulated to the rotary motion of
the vulcanite.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Greenacre in the Great Seal Patent Office
on the 24th April 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
GREENACRE, of Turners' Road, Burdett Road, in the County of Middle-
sex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of October, in the year of
our Lord One thousand oight hundred and seventy-four, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Thomas Greenacre, Her special license that I,
the said Thomas Greenacre, my executors, administrators, and assigns,
or such others as I, the said Thomas Greenacre, my executors, adminis-
trators, 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 MEANS OR
APPARATUS FOR MANUFACTURING SCREWS OF VULCANITE OR OTHER ANALOGOUS
MATERIAL FOR LIQUID METERS," upon the condition (amongst others) that
I, the said Thomas Greenacre, my exccutors or administrators, by an
instrument in writing, under my, or their, or one of their hands and
scals, 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 Scal Patent Office within six
calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Thomas Greenacre, do hereby declaro
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 thereof, that is to say :-
Heretofore in the manufacture of screws of vulcanite or other

page_text: analogous material for liquid meters moulds have been employed, but
by such mode of manufacture great difficulty was experienced in the
production of screws cither by their want of uniformity in shape or by
the variation of degrees of hardness in the substance thereof. Now
according to my Invention I propose to dispense with moulds in the
manufacture of such screws, and in licu thereof to cut them out of solid
material, whereby I can ensure uniformity in the shape and substanco
thereof. For this purpose I employ apparatus constructed somewhat in
the following manner :—I mount in two fixed standards a metal screw
of the pitch required for the vulcanite screw to be produced. This metal
screw is capable of revolving freely in bearings formed in or carried by
such standards, except as controlled in its rotation by the means herein-
after described. At one end of the metal screw is formed or fixed a
socket to receive one end of the picce of solid vulcanite or a spindle
carrying the same, the other end of which may be passed into another
socket formed to revolve freely in an adjustable standard or
"poppet
head," or it may be carried by a centre bearing. Over the metal screw
is passed a nut, to which is fixed by rigid connections properly guided a
cylindrical cutter head, which may be provided with three sets of cutters
mounted therein, in which case each set would be of a corresponding
number to the threads required in the screw, and would be fixed a short
distance in front of the other and so that the second and third sets should
bach cut a little deeper than the cutters immediately in advance of them,
the last sct of cutters being arranged to finish the desired screw, or in
some cases more sets of cutters or only one cutter may be employed, or
they may be caused to traverse more than once over the vulcanite.
The nut is by suitable means moved slowly forward so as to cause the
cutters to traverse the length of the piece of solid vulcauite to be cut
into screws, and in some cases I employ lengths of solid vulcanite suitablo
for making two screws at the same operation.
The cutters are formed with square stems to pass through corrc.
spondingly shaped holes formed in the cutter head, and are screwed
above such square portions to receive nuts which act in combination with
bridge or bearing pieces to facilite adjustment, and in order to ensure the
cutters being properly adjusted I employ a "dumb piece," against which
the cutters are set and then fixed in the position thus obtained. By these
mcans as the cutters are advanced the piece of vulcanite to be cut into
screws is rotated at the required speed to obtain the pitch of the desired

page_text: screws. Instead however of regulating the motion of the cutters and
the rotary motion of the piece of vulcanite by the means herein-before
described the parts may be otherwise connected by gearing, so that the
speed of the cutter shall be regulated to the rotary motion of the
L
..
Figure 1 is a side view; Figure 2 is an end view; Figure 3 is a cross
section on the line 1, 1, of Figure 1; and Figures 4 and 5 arc separate
views of parts of means or apparatus constructed according to my
Invention for manufacturing screws of vulcanite or other analogous
material for liquid meters. The apparatus represented in the above-
mentioned Figures is adapted to be mounted upon the bed plate of a lathe
and to operate with a single cutter.
Figure 6 is a plan; Figure 7 is an end view; and Figures 8 and 9 are
separate views of parts of apparatus constructed according to my
Invention, but arranged as a machine complete in itself and to work with
as many cutters as there are threads in the screw to be cut.
In all the Figures like parts are marked with similar letters of reference.
I will first describe the arrangement represented at Figures 1 to 5, in
which the apparatus is shown to be mounted upon the bed plate a of an
ordinary lathe. In the standard or poppet head band in the fixed
standard c is mounted a metal screw d of the pitch required for the
vulcanite screw to be produced. In this case I have shewn the screw d
to be provided with threads of different pitch to each other, so that as
required vulcanite screws may be produced by the aid of either of such
threads d, and corresponding in pitch therewith. This screw dis capable
of revolving freely in its bearings except as controlled in its rotation by
the means herein-after described. At one end of the screw d is a
socket d to carry one end of a spindle or axis e, on which the piece of
solid vulcanitef is fixed by means of a nut f¹ and filling piece f². The
other end of this spindle e is carried by a centre bearing g¹ carried by the
adjustable standards or "poppet head g. The socket d is formed with
a flat picce d³ to act in connection with a corresponding flat piece formed
25

page_text: i
nut h¹ the cutter shall be at the full depth to which it is required
to act.
For the purpose of facilitating the setting up of the cutter & after each
cut any desired depth I mark the upper surface of the nut ³ with any
suitable divisions, and I form the top bearing j as a hand or pointer, as
seen more clearly at Figure 5.
It will be understood from the foregoing description that by moving
the handle k in the one and then in the other direction the solid vulcanite f
is caused to rotate and the cutter h is. caused to advance and retreat at
the desired speed.
The cutter head j in addition to being fixed by the connections ³ to the
nuti is provided with a foot, which rests upon the bed a and assists in
grinding the cutter head j, whilst the connections are also guided by
passing through guide holes formed in the standard c.
"
In the arrangement shown at Figures 6 to 9 the bed a is especially
constructed for the machine, and is not a lathe bed as in the previous
arrangement, and the nut i and cutter head j are respectively fixed to
cross frames i*, j*, connected together by connections ³, and these cross
frames i, j, are guided in their motions by travelling in suitable
guides 1, 1, fixed to standards & bolted firmly to the bed plate a. In this
case the threads of the screw dare all of one pitch, and the piece of
vulcanite under operation is of length sufficient to produce two screws at
a time. And instead of employing only one cutter h, as in the arrange-
ment herein-before described, I employ as many cutters as there are
threads in the screw to be produced. These cutters are each provided
with a nut ', which on its outer periphery is formed into a toothed
pinion, which gears with and receives motion from a bevilled toothed
wheel or ring m fixed to the cutter bead j, but capable of revolving
thereon. This bevilled toothed ring m has a toothed wheel m¹ formed on
the periphery thereof, and receives a step-by-step rotary motion by the
aid of a tripping lever n acting thereon at each traverse of the cutter "
head, thereby simultaneously setting up all the cutters after each traverse.
In this case I also. dispense with the spindle e and with the wheel ' and
parts do, do, and I mount the piece of vulcanite ƒ direct in the socket d³,
and support it at the other end by the bearing 9', and instead of mounting
the hand lever / directly on the screwed shaft d I connect it to a
segment wheel o, which takes into and gives motion to a toothed pinion p
.

page_text: fixed on the end of the screwed shaft d; or if desired the apparatus may
be driven by continuous rotary motion by the use of a mangle wheel and
pinion, as will be well understood.
I would here remark that although I prefer to employ only a single
cutter or a single set of cutters as above described, two. or more sets of
cutters may be employed, as described in my Provisional Specification,
so that a screw may be finished at each stroke of the machine.
Having thus described the nature of my said Invention and the mode
in which I carry the same into effect, I would have it understood that I do
not confine myself to the precise details herein shown and described, but 1
what I claim as my Invention is, the employment by means or apparatus
for manfuacturing screws of vulcanite or other analogous material for
liquid meters by cutting them out of the solid instead of moulding them
as heretofore, in manner substantially as hercin shown and described.
In witness whereof, I, the said Thomas Greenacre, have hereunto 1
set my hand and seal, this Twenty-third day of April, in the year
of our Lord One thousand eight hundred and seventy-five.