IMPROVED MEANS FOR FACILITATING RECIPROCATING MOVEMENTS OF HEAVY PARTS OF MACHINERY
Year: 1864

page_text: LETTERS PATENT to John Gill, of Edinburgh, in the County of Mid
Lothian, North Britain, for the Invention of "IMPROVED MEANS FOR
FACILITATING RECIPROCATING MOVEMENTS OF HEAVY PARTS OF MACHINERY."
Sealed the 10th January 1865, and dated the 15th July 1864.
PROVISIONAL SPECIFICATION left by the said John Gill at the
Office of the Commissioners of Patents, with his Petition, on the
15th July 1864.
I, JOHN GILL, of Edinburgh, in the County of Mid Lothian, North Britain,
do hereby declare the nature of the said Invention of "IMPROVED MEANS POR
FACILITATING RECIPROCATING MOVEMENTS OF HEAVY PARTS OF MACHINERY," to
be as follows, that is to say:-
This Invention relates to means to be employed in connection with the
arresting and reversing of the motion of heavy reciprocating parts of machinery,
and has for object to facilitate such movements,-to convert the momentum
of the reciprocating part into a force available for the return movement,―
to prevent the injurious effects of sudden changes of motion,-and to obtain
increased speed with a saving of power, and other advantages.
The improved means consists of apparatus and arrangements with which
the movement in either direction from the centre of the line of traverse is
made to compress a quantity of air or the like elastic fluid, the compression
increasing until the movement is stopped, and the expansive reaction of the

page_text: air then inducing or assisting the return movement. The most convenient
apparatus for containing the air is a cylinder with a piston for compressing it;
but the piston and piston chamber may be of any convenient form, and either
cylinder or piston may be the stationary part, the other part being movable,
and being connected in any convenient way to the piece of machinery the
reciprocating parts of which are to be controlled. One or more cylinders may
be provided for reversing at each end of the traverse; or the movements in
both directions may be reversed by means of a single cylinder, or by means of
two or more cylinders acting together, the air being compressed towards
different ends of the cylinder or cylinder; or a cylinder or cylinders in which
the air is compressed in one directionon only may be arranged to control the
reversing in both directions by, for example, transmitting the actions through
straps passed round guide pulleys so as to act on the air cylinder in one
direction although actuated by opposite movements of the reciprocating piece.
The air cylinder or cylinders are by preference arranged to control the whole
of the reciprocating movement, each action commencing when the piece moves
from the centre of the line of traverse towards either end, and continuing until
the piece returns to such centre, so that whenever the piece is moved in either
direction from the centre it has a tendency to return thereto and to continue
oscillating until it finally rests at the centre. The improved apparatus may
be applied, amongst other things, to the piston and beam of a steam engine,
to the travelling type table of a printing machine, and to a reciprocating saw
or saw frame.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Gill in the Great Seal Patent Office on the 13th 2
January 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
GILL, of Edinburgh, in the County of Mid Lothian, North Britain, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of July, in the year of our Lord.
One thousand eight hundred and sixty-four, in the twenty-eighth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said John Gill, Her special licence that I, the said John
Gill, my executors, administrators, and assigns, or such others as I, the s
said John Gill, my executors, administrators, and assigns, should at any

page_text: 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
"IMPROVED MEANS FOR FACILITATING RECIPROCATING MOVEMENTS OF HEAVY
PARTS OF MACHINERY," upon the condition (amongst others) that I, the
said John Gill, 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 John Gill, do hereby declare the
nature of my 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 in writing, reference being had to the accompanying Drawings,
and to the letters and figures marked thereon, that is to say:
My said Invention relates to means to be employed in connection with the
arresting and reversing of the motion of heavy reciprocating parts of machinery,.
and has for object to facilitate such movements,-to convert the momentum
of the reciprocating part into a force available for the return movement,-
to prevent the injurious effects of sudden changes of motion, and to obtain
increased speed with a saving of power, and other advantages.
The improved means consist of apparatus and arrangements with which
the movement in either direction from the centre of the line of traverse is
made to compress a quantity of air or the like elastic fluid, the compression
increasing until the movement is stopped, and the expansive reaction of the
air then inducing or assisting the return movement. The most convenient
apparatus for compressing the air is a cylinder with a piston for compressing it;
but the piston and piston chamber may be of any convenient form, and either
cylinder or piston may be the stationary part, the other part being movable,
and being connected in any convenient way to the piece of machinery the
reciprocating movements of which are to be controlled. One or more cylinders.
may be provided for reversing at each end of the traverse, or the movements.
in both directions may be reversed by means of a single cylinder, or by means
of two or more cylinders acting together, the air being compressed towards
different ends of the cylinder or cylinders; or a cylinder or cylinders in which
the air is compressed in one direction only may be arranged to control the
reversing in both directions by, for example, transmitting the actions through

page_text: straps passed round guide pulleys so as to act on the air cylinder in one
direction although actuated by opposite movements of the reciprocating piece.
The air cylinder or cylinders are by preference arranged to control the whole
of the reciprocating movement, each action commencing when the piece moves
from the centre of the line of traverse towards either end, and continuing
until the piece returns to such centre, so that whenever the piece is moved in
either direction from the centre it has a tendency to return thereto and to
continue oscillating until it finally rests at the centre.
The improved appa-
ratus may be applied, amongst other things, to the piston and beam of a
steam engine, to the travelling type table of a printing machine, and to a
reciprocating saw or saw frame.
But the nature of my said Invention, and the manner in which it is or
may be practically carried out, will be clearly understood from the following
description and from the relative Sheet of explanatory Drawings hereunto
attached, such Drawings representing one of the many useful applications of
which the Invention is susceptible.
Figure 1 is a longitudinal vertical section showing the principal movements
of a cylinder printing machine with a horizontal travelling type table. The
travelling type table 1 is provided with racks on its under side which gear
with two pinions 2 mounted upon a transverse liorizontal spindle 3, and
running upon and gearing into two fixed racks 4 below, with which well-known
arrangement. the table 1. travels double the distance: that the pinions 2 do.
The pinions 2 are made to roll backwards and forwards, and so move the
table 1 by rods 5, which connect the spindle 3 to levers 6, and these levers 6
are made to vibrate by rods 7 connecting them to cranks 8 on a shaft 9 driven
at a suitable speed from the first-motion shaft 10. Beneath the level of the
table 1 there are two cylinders 11, 12, one at each end of the machine, and
these cylinders are provided with pistons which are on opposite ends of one
rod 18 fixed at its middle to the spindle 3 of the pinions 2. The outer ends
of the cylinders 11, 12, are closed, the inner ends being open, and as the
pinions 2 are moved in either direction the air in the cylinder, towards which
the movement is, is compressed and absorbs the momentum of the table 1 and
other moving parts, and reacting expansively on the return movement assists
in overcoming the inertia of the same parts. It is not desirable to compress
the air in the cylinders to an excessive degree, but for the sake of compactness
the cylinders are arranged so that their pistons enter almost up to their inner
ends, whilst lateral spaces 14, shown in transverse and horizontal section in
Figures 2 and 3, are formed in connection with each cylinder for the air to be
compressed into. The pistons may be packed with cup leathers or otherwise,

page_text: or packing may be dispensed with if they are made a good but easy fit, and of
a sufficient size to compensate for a little leakage; and a full supply of air
may be insured by valves opening inwards or by simple openings between the
middles and the open ends of the cylinders, and which openings are passed
over by the pistons when drawn towards the centre of the machine.
Figure 4 is a longitudinal section of a double-acting cylinder which may be
substituted for the two single-acting cylinders 11, 12, herein-before described.
This double-acting cylinder has both ends closed, the piston rod 13 passing
through a stuffing box at one end. The piston compresses the air when
moving towards either end, and separate chambers 14 for the compressed air
are formed in connection with each end.
My improved apparatus may also be applied to printing machinery the type
tables or forms of which move vertically, and in particular to printing
machinery of the kind described in the Specification of certain Letters Patent
granted to me, and dated 13th April 1863 (No. 925), in order to increase or
control the action due to the peculiar disposition of the parts as therein
described.
In the Drawings, the cylinders 11, 12, Figure 1, are shown of the full
length of the travel of the pinions 2, as although the compression need not
take place excepting for the latter half of the stroke of each piston towards
the closed end, still it is desirable for the other halves of each cylinder to act
as guides for the pistons. At the same time the compression may take place
during more than the half stroke, as the extra compression on one side will be
compensated for by the extra expansion on the other, and the remaining
resultant action on the type table will still only take effect thereon as it leaves
the centre in either direction, as herein-before described. It is desirable to
fit the closed ends of the cylinders with valves or stop-cocks, which can be
opened to admit air if found more convenient at starting the machine. The
relative sizes of the air cylinders and chambers may be varied, but the best
results will, I believe, be obtained when they are so proportioned as that the
compression of the air will be as nearly as possible equivalent to the entire
free momentum of the moving parts acted upon. The proper amount of
compression will vary with the speed at which the machine is driven, and this
variation may be provided for by altering the effective sizes of the chambers
in connection with the cylinders, and into which the air is compressed. One
simple way of contracting the effective size is by introducing into the chambers
any convenient liquid or solid substance.
Having thus particularly described my said Invention, and in what manner
the same is or may be performed, I have to state that I do not restrict myself

page_text: to the precise details herein described or delineated, but that what I believe to
be novel and original, and claim as the Invention secured to me by the
herein-before in part récited Letters Patent is, the facilitating or controlling
of the reciprocating movements of heavy parts of machinery by arranging
apparatus whereby air or the like elastic fluid is compressed so as to absorb
momentum and to assist the return movement by its re-expansion, and
whereby a tendency to return always to the centre is imparted, substantially
as herein-before described.
In witness whereof, I, the said John Gill, have hereunto set my hand
and seal, this Eleventh day of January, in the year of our Lord
One thousand eight hundred and sixty-five.
Witness,
EDMUND HUNT,
Patent Agent,
.
28; St. Enoch Square, Glasgow.
JOHN GILL. (L.S.)