IMPROVED MECHANISM AND TO ANGKITNING RECIPROCATING MOTIONS
Year: 1872

page_text: LETTERS PATENT to William Tighe Hamilton, of Rathmines, Dublin,
Ireland, Esquire, A.M., for the Invention of "IMPROVED MECHANISM
AND TO ANGKITNING RECIPROCATING MOTIONS "
Sealed the 11th March 1873, and dated the 6th December 1872.
.
PROVISIONAL SPECIFICATION left by the said William Tighe
Hamilton at the Office of the Commissioners of Patents, with his
Petition, on the 6th December 1872.
I, WILLIAM TIGHE HAMILTON, of Rathmines, Dublin, Ireland,
Esquire, A.M., do hereby declare the nature of the said Invention for
"IMPROVED MECHANISM OB APPARATUS FOR PRODUCING AND TRANSMITTING
RECIPROCATING MOTIONS," to be as follows:-
:-
The object of this Invention is to cause an axle to perform certain
positive motions which are required or will be found convenient in a
variety of machines. The motions which I can produce by means of my
improved mechanism or apparatus are,

page_text: Secondly. To reciprocate as it rotates, out at a umerent rate; or,
Thirdly. To reciprocate without rotation; or,
Fourthly. To oblige any link bar or other object to reciprocate without
rotation.
The improved mechanism whereby these objects are effected is thus
constructed. Upon any part of an axle (clear of it's bearings), and
which should have two opposite sides made flat, a circular disc or
boss having a hole through it corresponding with such flat shape is
fixed by a pin which passes through the centre of its thickness across
such flatted sides, and through the centre of the axle. The dise can
move with freedom on the other two sides of the hole so as to allow of
its being turned upon such pin, and fixed at any desired angle by
adjusting screws or other suitable means. A circular strap of the same
thickness as the boss is fitted so as to revolve upon it when kept in
position by two side plates which are fixed to the ends of the boss
similarly to the strap of an excentric. A rod is fixed into this strap in
the centre of its thickness and in a line through the centre of the axle
like the rod of an excentric. The outer end of this rod is round, and
passes through a like hole in a round stud which works. in a like hole in
a stationary frame. This stud is maintained in a vertical position at
right angles to the axle. Then the rod being kept from rising or falling
by its end being inserted in or passed through a slot in the frame has
freedom for a radial or twisting, or in-and-out motion, so as to answer to
the varying positions of the boss and strap.
The action as to the several motions will be this,―
.
1st. When the axle is caused to rotate by any of the usual means it
will be compelled by the inclination of the boss and the lateral leverago
of the rod acting in the stud to reciprocate as it rotates and at the same
rate with a throw proportioned to such inclination and its distance from
the stud. The mounting of this rod may be modified by placing a con-
centric hoop outside of the strap, but pivotted to it at opposite sides, so
that they may swivel on each other. The rod is fixed into this hoop
instead of into the strap in a line with such pivots. Then if its outer
end is made square instead of round, and such end be passed through a
like hole in the stud so as to prevent its twisting, the hoop will swing to
and fro in vertical planes like a door on its hinges. The motion of the
axle will remain the same as before.

page_text: 2ndly. When it is desired that the rate of the reciprocation shall differ
from that of the rotation the boss may be mounted upon a sleeve shaft
of the same external shape as that proposed for the axle, but with a
circular hole through it so as to revolve on the axle, which should in
this case be circular when kept in position by suitable collars or
shoulders. Then when this shaft is caused to rotate by independent
gearing the axle will reciprocate at the rate due to such gearing, but
will rotate at the rate due to its own separate gearing.
3rdly. When it is desired that the axle shall reciprocate without
rotation the mounting on the sleeve shaft is maintained, but the axle
is held in such suitable guides as will permit reciprocation but prevent
rotation.
Some of the above motions may be produced by mounting the disc
and its accessories on a cranked axle, or rather an axle.or stud which is
bent out of the line with the main axle.
4thly. When it is desired that this axle shall oblige any link bar or
other object to reciprocate the axle is left free to rotate, but prevented
from reciprocating by means of collars or shoulders acting against its
bearings. The skid is then attached to such other link bar or object,
which will then reciprocate as it slides in suitable bearings.
Again this
arrangement may be modified by allowing the primary stud to remain
stationary, but the axle free to reciprocate and rotate. Then if a second
rod is fixed into the strap opposite to the other it will cause any other
link bar or object which carries a like stud, into which it is inserted, to
reciprocate with a throw of increased proportions.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said William Tighe Hamilton in the Great Seal Patent
Office on the 6th June 1873..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
TIGHE HAMILTON, of Rathmines, Dublin, in the Kingdom of Ireland,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of December, in the
year of our Lord One thousand eight hundred and seventy-two, in the

page_text: ..
-
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Tighe Hamilton, Her special
· licence that I, the said William Tighe Hamilton, my executors,
administrators, and assigns, or such others as I, the said William
Tighe Hamilton, 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 "IMPROVED MECHANISM OR APPARATUS FOR PRODUCING
AND TRANSMITTING RECIPROCATING MOTIONS," upon the condition (amongst
others) that I, the said William Tighe Hamilton, 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 William Tighe Hamilton, 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 had to the Drawing here-
unto annexed, and to the letters and figures marked thereon (that is to
say):
The object of this improved mechanism or apparatus for producing
and transmitting reciprocating motions, and which may be termed a
reciprocator, is to cause an axle to have or produce certain positive
motions which are required or may be found convenient and useful
in a variety of machines.
The kinds of motion which an axle may thus be made to have or
produce are various. First, it may reciprocate as it rotates and at the
same rate; or secondly, it may reciprocate as it rotates but at a different
rate; or thirdly, it may reciprocate without rotation; or fourthly,
whilst itself having any of these motions it may cause any other axle or
sliding part of a machine to reciprocate, with or without rotation.
In its fundamental or simplest form this mechanism consists of a
circular sheave or grooved disc mounted upon an axle with-a-circular

page_text: strap free to revolve in the groove, and a short pin fixed into such strap
at the middle of its width and in line through the central line of the
axle. The component parts of the mechanism thus resemble respec-
tively the sheave or disc, the strap and the portion of the rod of an
ordinary excentric, with these differences however that the sheave or
disc is mounted on the axle concentric with it, but at an angle of
inclination to it, and the resulting motion of the rod (as the axle and
sheave revolve within the strap) will be parallel to not at right angles
to the axle. This motion of the rod will not be (as in the excentric of a
steam engine) in the direction of its length, but across that direction,
and if confined in a slot placed parallel to the axle it will have a throw
backwards and forwards proportioned to the angle of inclination of the
sheave, and the distance of the slot from the axle. The rod is round
and thus has freedom for a twisting as well as an in-and-out or radial
motion, so as to answer to the varying positions of the strap as the
sheave and axle revolve within it. But if the rod be now passed
through a round hole in a vertical stud so mounted as to admit of
turning upon its vertical axis the action will be reversed, that is to say,
the axle being caused to rotate by any of the usual means it will if so
mounted as to be free to reciprocate as well as to rotate be compelled
by the inclination of the sheave and the lateral leverage of the rod
acting in the stud to reciprocate with a throw equal to that which the
rod previously had.
The construction of the strap and sheave may be varied in several
ways.
Instead of using a grooved sheave a boss may be mounted on the
axle at the desired angle of inclination, and the strap may be made free
to revolve upon this boss when kept in position by two plates fixed to the
sides of the strap. This simply' inverts the relative positions of the
sheave and strap, but without alteration of effect, on the strap.
Or again, instead of using either of such forms the strap may be at
once made to revolve upon a portion of the axle which is so cranked at
an angle of inclination to the axle that the line of centre of the axle
and of its cranked portion shall intersect at the middle point of the
latter and of the strap revolving upon it. In this case the effect of
the cranked portion will be the same as that of the inclined sheave or
boss.

page_text: •
ways.
The mounting of the sheave or boss may also be varied in several
For instance it may be mounted either at once upon the axle
or upon an interposed sleeve shaft. It may also be mounted upon these
either at a permanent angle or so as to swivel by means of pivots or
gimbals, or trunnions upon the axle or sleeve shaft, and be thus capable
of being fixed by any convenient application of set screws at any desired
angle of inclination; or again, the sheave may be so connected by
means of clutch boxes (sliding on the axle), or by such other suitable
appliances as may give the sheave from time to time as it revolves such
varying angles of inclination as may be required for the special wants of
the machine to which it is applied.
The various arrangements of my improved mechanism whereby these
objects are effected are more particularly shewn in the accompanying
Drawings, in which Fig. 1 is a longitudinal section of one arrangement
for effecting the object of my Invention. Fig. 2 is a transverse section of
the same. Upon any part of the axle a, to which rotary motion is
communicated in any convenient manner (and which may have a portion
of its length made square in section, as shewn in the Drawing) is
mounted a circular sheave 6 (shewn detached in front and side elevation
at Figures 3 and 4) which has a hole through it corresponding with the
square shape of the axle. The circular sheave 6 is secured to the axle
by a pin c, which passes at right angles through the centre of its thick-
ness and across the squared sides and through the centre of the axle, as
shewn by dots in Fig. 2; this sheave can rock or move with freedom
on the pin c, and can be fixed at any desired angle by means of adjusting
screws d, d, Fig. 1, or by other suitable means. A circular strap e of
the same width as the groove in the sheave is fitted so as to admit of the
sheave 6 and axle a revolving within it when it is kept in position by
two side plates 6, 61, which are fixed to the ends of the sheave; this
strap e is placed in the sheave in a similar manner to the strap of an
excentric. A rod f is fixed into this strap in the centre of its thickness
and in a line through the centre of the axle a like the rod of an excentric.
The outer end of this rod f is rounded, and passes through a like hole
in a round stud g, which works in a like hole in a stationary frame g¹;
this stud is thus maintained in a vertical position at right angles to the
axle in one direction, as shewn at Fig. 2; then the rod g being kept
from rising or falling by its end being inserted in or passed through a
slot in the frame g¹ it has freedom for a radial or twisting or in-and-out

page_text: '
motion, so as to answer to the varying positions of the sheave 6 and
strap e.
The action of the moving parts as to the several motions will be as
follows:-
1st. When the axle a is caused to rotate (by any of the usual means)
it will be compelled by the inclination of the sheave 6 and the lateral
leverage of the rod f (acting in the stud g) to reciprocate or move end-
ways as it rotates, as indicated by the dotted lines in Fig. 1; it will
thus reciprocate at the same rate as it rotates, that is to say, for every
complete rotation of the shaft or axle a it will move once to and fro in
its bearing with a throw proportioned to the inclination of the rod ƒ and
the distance of the axle a from the stud 9. The mounting of the rod f
may be modified by placing a concentric hoop 1, Fig. 5, outside of the
strap e, but pivotted to it at opposite sides as at i, i, so that they may
swivel on each other. Gimbals or trunnions may be used for the same
purpose. This arrangement is shewn at Figures 5, 6, and 7.
•
The rod is fixed into this hoop & instead of into the strap e (as in
Figures 1 and 2.) This rod f is in a line with the pivots i, i. Then if
the outer end of the rod f be made square instead of round, and such
end be passed through a like hole in the stud 9 so as to prevent it from
twisting, the hoop h' will swing to and fro in vertical planes on its
pivots i, i, like a door on its hinges. The object of this arrangement is
that whereas every point on the circumference of the strap has a constant
extent of throw, now every point on the circumference of the hoop will
have an extent of throw proportionate to its angular distance from the
line of the pivots, gimbals; or trunnions; thus points are obtained as
the origin of different extents of motion, as will be hereafter explained.
2nd. When it is desired that the rate of reciprocation of the axle shall
differ from that of the rotation the sheave b may be mounted upon a
sleeve shaft of the same external shape as that proposed for the axle a,
but with a circular hole through it so as to revolve on the axle a, which
should in this case be cylindrical. This arrangement is shewn in detail
in Fig. 8, which is a front elevation of the arrangement complete.
Fig. 9 is a longitudinal vertical section, and Fig. 10 is a transverse
section. The reciprocating axle a is rotated by means of a spur wheel j¹
on the countershaft ; gearing into a pinion a¹ on the axle a. A
pinion on the same shaft j gears into and drives a wide toothed wheel k¹

page_text: on the sleeve shaft k. Then as the two shafts a and k are caused to
rotate by independent gearing the axle a will reciprocate at the rate due
to such gearing, but will rotate at the rate due to its own separate
gearing. The sheave 6 is adapted to the sleeve shaft / instead of to the
axle a as in the other instance; this axle passes through the sleeve
shaft k, and each rotates independently of the other; but as the sleeve
shaft is mounted between two collars 1, 1, (fixed on the axle a by
means of transverse pins) it follows that any endway or reciprocating
motion communicated to the sleeve shaft k (on which the sheave b and
its appendages are mounted) must be communicated to the axle a,
although it may be rotating at a different speed.
3rd. When it is desired that the axle a shall reciprocate without
rotating the mounting on the sleeve shaft is maintained, but the axle is
held in such suitable guides or bearings as will permit reciprocation or
endway motion therein, but will prevent rotation; this will be under-
stood by referring to Fig. 11, in which it will be seen that the sheave
b, b, is adapted to the sleeve shaft k by cross pins which, however, do
not enter the axle a. The sleeve shaft k rotates on the axle a between
the collars 7, 1, and is driven by a spur wheel taking into the teeth cut
at on the shaft. The ends a³, a², of the shaft a are made square, and
they move endways in square bearings or guides, so that it will not
rotate, but as the sleeve shaft k is provided with the sheave and all its
appendages (which work in the manner already explained), it follows
that the sleeve shaft / must reciprocate, and must therefore carry the
axle a with it.
Some of the above motions may be produced by mounting the sheave
and its accessories on a cranked axle, or rather upon an angular cranked
portion of an axle which is formed at an. inclination to the line of the
main axle.
4th. When it is desired that the axle a shall be made to act on any
link bar or other object so as to cause the latter to reciprocate, the axle a
is left free to rotate, but is prevented from reciprocating by means of
collars or shoulders mounted or fixed on it, and made to act against its
bearings; this arrangement is shewn at Figures 12, 13, and 14. The
axle a is provided with the collars or shoulders 1, 1, which are fixed
thereon, and rotate against the bearings, and thus prevent the axle from
moving endways. The stud g is then attached to a 'slide m or such other
object, which will then reciprocate as it slides in suitable guides. To the

page_text: upper end of the rod fis attached a link or bar n, to which a reciprocating
motion may be communicated, as indicated by dots in the Drawings.
As a modification of this arrangement the primary stud 9 may remain
stationary, but the axle a will be free to reciprocate and rotate; then
if a second rod f* be fixed into the strap e or ring h of Figures 5 and 6 the
two rods fand f (being opposite to each other) will cause any link bar
or object (which carries a like stud 92 into which it is inserted) to
reciprocate with a throw of increased proportions, as indicated in
Fig. 6.
The variable motions which have been referred to as derivable from
the reciprocator in its fundamental form, with the addition of the hoop
and square rod, are obtained in the following manner :-The axle
is prevented from reciprocating; and the square rod is now allowed
to travel to and fro in the horizontal slot without the use of the
vertical stud; then it is obvious that as the hoop swings to and fro in
vertical planes, which pass through a vertical diameter, the extremities
of this diameter become dead points or rather centres of motion, and
suitable arms or levers fixed to the hoop over such centres will then
'swing to and fro, so that their outer extremities will become suitable
points of attachment for rods or links to receive reciprocating motions
in the direction of their length as, for instance, for the travel of slide
valves. Again, if the original round rod be adopted instead of the
square rod, and the hoop be considered as composed of two rings placed
side by side, one of which carries the rod and the other a guide pin,
which turns in a hole in a suitable appendage, so as to be carried round
in the same plane by suitable means, the throw of the rod will vary in
extent and direction according as the pin is in either of the opposite
quadrants of its circuit, or at a more or less angular distance from the
vertical line.
In this way motions may be obtained in every desired direction
through the surrounding sphere, and of every desired degree from the
full throw of the rod when the pin and rod lines are at right angles, to a
cessation of all motion when they coincide.
In the preceding cases the extent of throw has been taken as dependent
on the inclination of the reciprocator sheave to the axle. But the same
effects will result by having the reciprocator fixed at a permanent angle,
and then varying the distance at which its stud is placed. For this

page_text: *purpose the stud¹may be so mounted as to be placed at fixed or variable
distances, and thus cause fixed or variable degrees of throw as may be
*required.
Having now described: my Invention of "Improved Mechanism or
Apparatus for Producing and Transmitting Reciprocating Motions," and
having explained the manner of carrying the same into effect, I would
remark that my improved mechanism or apparatus may when modified
to suit particular cases be adapted to any and all kinds of machinery in
which reciprocating and reciprocating rotary motions, such as those
above-mentioned, may be required, I therefore' claim as the Invention
secured to me by Letters Patent as aforesaid,—
First. The application (to an axle or shaft) of an inclined sheave or
boss, or angular crank, or other equivalent device in combination with a
strap revolving in the sheave, or upon the boss or crank, and with other
accessories, parts, or appendages as herein set forth for the purpose of
compelling either the axle to reciprocate as it rotates, or to cause some
other part of the mechanism to reciprocate as the axle rotates.
Second. I claim the application of the arrangement of parts berein
set forth, or any equivalent arrangement of like parts to all or any
machinery which may require such motions as those above-mentioned.
-
In witness whereof, I, the said William Tighe Hamilton, have
hereunto set my hand and seal, the Fourth day of June, in the
year of our Lord One thousand eight hundred and seventy-three.
WN. TIGHE HAMILTON. (L.S.)