AN IMPROVED MECHANICAL MOVEMENT
Year: 1881

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an Invention of "AN IMPROVED
MECHANICAL MOVEMENT." A communication from abroad by Joseph Harris,
junior, of Boston, in the County of Suffolk and State of Massachusetts,
United States of America.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 19th April 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "AN IMPROVED MECHANICAL MOVEMENT." [A communication
from abroad by Joseph Harris, junior, of Boston, in the County of Suffolk and
State of Massachusetts, United States of America.]
This Invention is an improvement upon a machine for converting reciprocating
into rotary motion, described in Letters Patent of the United States of America,
numbered 7902, dated January 14, 1851, and it has for its object to provide means
whereby the reciprocating motion is active to produce the rotary motion at every
point of the revolution.
.
This means consists principally of an auxiliary cross-head or similar device
applied to the main cross-head, which has independent forward and rearward
motion at the ends of the stroke in connection with levers pivoted to the oscillating
bar for transferring the force at the beginning of the reverse movements above or
below the plane or direction of reciprocation.
The Invention further consists of means for locking the auxiliary cross-head
with the main cross-head, of the auxiliary cross-head, the main cross-head, and the
oscillating bar or lever in combination with the hinged levers, the oscillating bar
being pivoted in the main cross-head, and also in the parts last stated in com-
bination with the revolving shaft provided with two cranks at or near right angles
to each other and connecting rods connecting the cranks with the ends of the
rocking bar, all as hereinafter fully described.
The two throw crank shaft, the connecting rods, the cross-head ways, and the
tie rod of the cranks are the same as in the Patent above mentioned, and the

page_text: oscillating bar and the main cross head are also of the same construction described
in said Patent, except that instead of the main cross head moving in contact with
the ways it is constructed to be moved within and by an auxiliary cross-head
which surrounds it, and that the oscillating bar is provided with pivoted levers at
its upper end.
The auxiliary cross-head is of such length relative to the length of the main
cross-head that the same is adapted to have an independent long stroke, that is to
say, a longitudinal movement at the ends of the stroke which is independent of
the movement of the main cross-head, and the ends of the auxiliary cross-head are
formed or provided with grooves or other suitable stops, with which the notched
ends of the levers pivoted to the upper end of the oscillating bar alternately
engage while the cross-head is performing its independent movement.
By this means the force during the independent movement of the auxiliary
cross-head is transferred through the pivoted levers to a point above the plane of
reciprocation, and applied to the cranks of the shaft through the oscillating bar
and the connecting rods at a point above the line of dead centre. It will be
understood that during this time the main cross-head remains at rest, and that
the motion of the oscillating bar is only upon its pivot. When the main cross-
head and oscillating bar begin to move, the pivoted levers are thrown out of
engagement with the notches by coming in contact with arms or projections which
are secured in proper position for that purpose upon the ways.
After sufficient motion has been obtained, so that the momentum will carry
past the dead centre, the auxiliary cross-head should be brought to its short stroke
by placing blocks between the cross-heads, thereby locking the two cross-heads
together, so that they act as a single cross-head. These blocks may be attached
to and operated by suitable levers attached to the machine, by which means
the movement of the auxiliary cross-head would be under easy and sudden
control.
Although the Invention is described as applied only to the upper end of the
oscillating bar, and adapted to revolve the shaft in one direction only, it is obvious
that by attaching levers to the lower end of the oscillating bar, and providing
spring or other suitable mechanism for causing the ends thereof to engage with
suitable notches or projections on the under side of the auxiliary cross-head, the
action of the auxiliary cross-head would be applied in like manner to the lower
end of the oscillating bar, and thus render the motion of the shaft reversible.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Melville Clark in the Great Seal Patent Office on
the 18th October 1881,
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"AN IMPROVED MECHANICAL MOVEMENT." A communication
from abroad by Joseph Harris, junior, of Boston, in the County of Suffolk and
State of Massachusetts, United States of America.
This Invention is an improvement upon a machine for converting reciprocating
into rotary motion, described in Letters Patent of the United States of America,
numbered 7902, dated the Fourteenth day of January, One thousand eight hundred
and fifty one, and it has for its object to provide means whereby the reciprocating
motion is active to produce the rotary motion at every point of the revolution.
This means consists principally of an auxiliary cross-head or similar device
applied to the main cross-head, which has independent forward and rearward
motion at the ends of the stroke in connection with levers pivoted to the oscillating
bar for transferring the force at the beginning of the reverse movements above or
below the plane or direction of reciprocation.
The Invention further consists of means for locking the auxiliary cross-head
with the main cross-head, of the auxiliary cross-head, the main cross-head, and the
oscillating bar or lever in combination with the hinged levers, the oscillating bar
being pivoted in the main cross-head, and also in the parts last stated in com-
bination with the revolving shaft provided with two cranks at or near right angles
to each other, and connecting-rods connecting the cranks with the ends of the
rocking bar, all as hereinafter fully described.
But to make the Invention communicated to me better understood, I will
proceed to describe the same by reference to the accompanying Drawing, in which
Figure 1 is a plan view of the Invention, Figure 2 is a longitudinal section of the
same taken on line x, x, of Figure 1, Figure 3 is a cross section taken on the
line y, y, of Figure 1, and Figure 4 is a transverse section of the cross-heads
shewing the auxiliary cross-head locked with the main cross-head.
Similar letters of reference indicate corresponding parts.
The ways A, A, upon which the cross-heads move, the shaft B carrying the fly-
wheel D and provided with the double cranks E, E, the connecting rods F, F, and
the tie-rod G of the cranks are of the same form and construction as described in
the Letters Patent above mentioned, and the oscillating bar C and the main cross-
head H are also of the same construction described in said Patent, except that
instead of the main cross-head moving in contact with the ways A, A, the same is
constructed to be moved within and by the auxiliary cross-head J, which surrounds
it, and that the oscillating bar is provided with the pivoted levers L, L, at its
upper end.
The auxiliary cross-head J is of such length relative to the length of the main
cross-head that the same is adapted to have an independent long stroke, that is to
say, a longitudinal movement at the ends of the stroke which is independent of
the movement of the main cross-head, and the ends of the auxiliary cross-head are
formed or provided with the grooves or other suitable stops d, d, with which the
notched ends of the levers L, L, alternately engage while the cross-head is travelling
the space of its independent movement. By this means the force during the
independent movement of the auxiliary cross-head is transferred through the
pivoted levers L, L, to a point above the plane of reciprocation, and applied to
the cranks of the shaft through the oscillating bar C and the connecting rods at a
point above the line of dead-centre. It will be understood that during this time

page_text: the main cross-head remains at rest, and that the motion of the oscillating bar is
only upon its pivot.
When the main cross-head and oscillating bar begin to move, the levers L, L,
are thrown out of engagement with the notches by coming in contact with the
arms or projections Q, Q, which are secured in proper position for that purpose
upon the ways A, A, as shewn.
After sufficient motion has been obtained, so that the momentum will carry past
the dead-centre, the auxiliary cross-head should be brought to its short stroke by
placing the blocks P, P, between the cross-heads, as shewn in Figure 4, which
lock the two cross-heads together, in which position they act as a single cross
head. These blocks may be attached to and operated by suitable levers attached
to the machine, by which means the movement of the auxiliary cross-head would
be under easy and sudden control.
Though I have shewn the Invention applied only to the upper end of the
oscillating bar, and adapted to revolve the shaft in one direction only, it is obvious
that by attaching levers to the lower end of the oscillating bar and providing
spring or other suitable mechanism for causing the ends thereof to engage with
suitable notches or projections on the under side of the auxiliary cross-head, the
action of the auxiliary cross-head would be applied in like manner to the lower
end of the oscillating bar, and thus render the shaft reversible.
Having thus fully described the Invention communicated to me, I wish it to be
understood that what is claimed as new and intended to be protected by the
herein in-part recited Letters Patent is,-
Firstly. The sliding cross-head H and the oscillating bar C in combination with
means, substantially as shewn and described, for transferring the reciprocating
force at the beginning of the reverse movements above or below the plane of
reciprocation, substantially as set forth.
Secondly. The auxiliary cross-head J having a longitudinal movement at both
ends of the stroke, independent of the main cross-head, in combination with the
levers L, L, and the oscillating bar C, substantially as and for the purpose
specified.
Thirdly. The auxiliary cross-head J and the main cross-head H in combination
with the removeable blocks P, P, substantially as and for the purpose specified.
Fourthly. The auxiliary cross-head, the main cross-head, the former having
movement independent of the latter, the oscillating bar C and the hinged levers
L, L, in combination with the shaft having the cranks E, E, and the connecting-
rods F, F, substantially as and for the purposes specified.
In witness whereof, I, the said Alexander Melville Clark, have hereto set
my hand and seal, this Seventeenth day of October, in the year of our
Lord One thousand eight hundred and eighty one.
A. M. CLARK. (L.S.)