MACHINERY FOR COMPRESSING AIR
Year: 1867

page_text: LETTERS PATENT to Isaac Griffith Lloyd, of Blaina, near Newport, in
the County of Monmouth, for the Invention of
MACHINERY FOR COMPRESSING AIR."
"IMPROVEMENTS IN
Sealed the 10th December 1867, and dated the 17th June 1867.
PROVISIONAL SPECIFICATION left by the said Isaac Griffith Lloyd at
the Office of the Commissioners of Patents, with his Petition, on the
17th June 1867.
I, ISAAC GRIFFITH LLOYD, of Blaina. near Newport. in the County of
Monmouth, do hereby declare the nature of the said Invention for "IMPROVE!
MENTS IN MACHINERY FOR COMPRESSING AIR," to be as follows:-
This Invention has for its object improvements in machinery for compressing
air, and consists in so arranging the gearing for transmitting motion from the
driving shaft of a steam engine to the reciprocating piston of an air pump
that whilst the driving shaft of the engine revolves at an even speed the
piston of the air pump may at the commencement of each stroke move with
a quicker motion than towards the end of the stroke, and to effect this I
In the arrangement of
employ by preference differential toothed wheels.
machinery I prefer the air pump cylinder is placed horizontally, and at one
of its ends guides are formed between which a cross head connected to
At the opposite end of the air
the piston rod of the air pump works.
pump cylinder is placed the cylinder of the steam engine employed for giving
Price 8d.1

page_text: motion to the piston of the air pump. The piston rod of the steam engine
gives motion to a shaft placed below the end of the air pump cylinder, and on
this shaft is a pinion gearing with a toothed wheel on an intermediate shaft,
on which there is fixed a differential toothed wheel gearing with another
similar wheel on a third shaft, which is opposite the end of the air pump
cylinder. On this last-mentioned shaft are cranks, which by long connecting
rods are connected with the ends of the cross head to which the piston rod of
the air pump is attached. By this arrangement the piston of the air pump
will complete one stroke for each half revolution of the differential wheels,
and these wheels are by preference so formed as to give a quick motion to
the piston of the air pump at the commencement of each stroke, and then
gradually to reduce the speed of the piston until the piston has arrived at
the point of the stroke at which the air in the cylinder will have been com-
pressed to the same pressure as the pressure in the receiver into which the
air is to be forced; the piston may then be caused to move with an uniform
motion for the completion of the stroke. At the commencement of the
following stroke the gearing will again commence to drive the piston at a
quick speed.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Isaac Griffith Lloyd in the Great Seal Patent Office on the
17th December 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ISAAC
GRIFFITH LLOYD, of Blaina, near Newport, in the County of Monmouth, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria. by Her Letters
Patent, bearing date the Seventeenth day of June, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Isaac Griffith Lloyd, Her special licence that I, the said Isaac Griffith
Lloyd, my executors, administrators, and assigns, or such others, as I, the
said Isaac Griffith Lloyd, 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 of "IMPROVE-
MENTS IN MACHINERY FOR COMPRESSING AIR," upon the condition (amongst

page_text: others) that I, the said Isaac Griffith Lloyd, my executors or adminis-
trators, 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 Isaac Griffith Lloyd, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:
This Invention has for its object improvements in machinery for com-
pressing air, and consists in so arranging the gearing for transmitting motion
from the driving shaft of a steam engine to the reciprocating piston of an
air pump that whilst the driving shaft of the engine revolves at an even speed
the piston of the air pump may at the commencement of each stroke move with
a quicker motion than towards the end of the stroke; to effect this I employ
differential toothed wheels. The arrangement of machinery which I prefer
is shown in the Drawings hereunto annexed. Figure 1 is a plan: Figure 2
is a vertical section; and Figure 3 is an end view thereof.
The air pump cylinder a is placed horizontally. and at one of its ends
guides b, b, are formed, between which works a cross head c. which is con-
nected to the piston rod of the air pump cylinder a. At the opposite end
of the air pump cylinder a is placed the cylinder e of the steam engine
employed for giving motion to the piston of the air pump. The piston rod f
of the steam engine cylinder e gives motion by a connecting rod to a shaft y
placed above the end of the air pump cylinder. and on this shaft is a pinion g'
gearing with a toothed wheel h¹ on an intermediate shaft h. on which there is
fixed a differential toothed wheel i gearing with another similar wheel k on a
third shaft which is opposite the end of the air pump cylinder a. On
this last-mentioned shaft are cranks P. 1. which by long connecting rods
m, m, are connected with the ends of the cross head c. to which the
piston rod d of the air pump cylinder a is attached. By this arrangement.
the piston of the air pump will complete one stroke for each half revolution
of the differential wheels i and k, and these wheels are so formed as nearly
as may be as to give a quick motion to the piston of the air pump at the
commencement of each stroke, and then gradually to reduce the speed of the
piston until the piston has arrived at the point of the stroke at which the
air in the cylinder will have been compressed to the same pressure as the
pressure in the receiver into which the air is to be forced; the piston may

page_text: then be caused to move with an uniform motion for the completion of the
stroke. At the commencement of the following stroke the gearing will again
commence to drive the piston at a quick speed.
In witness whereof, I, the said Isaac Griffith Lloyd, have hereunto
set my hand and seal, this Seventeenth day of December, in the
year of our Lord One thousand eight hundred and sixty-seven.
ISAAC GRIFFITH LLOYD. (L.S.)