IMPROVEMENTS IN COUPLINGS FOR RAILWAY CARRIAGES
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the
Office of the Commissioners of Patents, with his Petition, on the
2nd June 1870.-A communication from abroad by Richard
Campion and James W. Thomson, junior, both of Camden, New
Jersey, and John H. Michener and Samuel L. Ward, both of
Philadelphia, Pennsylvania, all in the United States of America.
I, WILLIAM ROBERT LAKE, of the "International Patent Office,"
Southampton Buildings, London, Consulting Engineer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN COUPLINGS FOR
RAILWAY CARRIAGES," a communication, to be as follows:-
This Invention relates to that class of couplings in which the coupling
link is automatically inserted and locked in the draw head by means of
a swinging pawl or latch which yields in one direction to admit the link,
but is unyielding in the other direction in order to retain the link in the
draw head.
The object of the first part of the said Invention is to lift the pawl
readily to uncouple the carriages and to hold it up out of the draw head

page_text: when required, and it consists in a novel method of combining with the
draw head a vertically swinging locking pawl and an oval ring attached
to the pawl in such manner that the ring forms a handle by which to
lift the pawl, and also when the pawl is raised as a stop to hold it up,
by passing the longer side of the ellipse of the ring over the pawl and
then by turning the ring half round its shorter axis comes beneath the
pawl but above the draw head and keeps the pawl from descending.
The object of the second part of the said Invention is to prevent
strain on the pivot of the pawl, and it consists in a novel method of
combining with the draw head a pawl swinging vertically on a pivot
in the said draw head, the hole through the pawl in which the pivot pin
fits being made eccentric to and larger than the pivot when the pawl is
down, so as to allow the pawl to abut against the draw head itself and
thus relieve the pivots of strain.
The said Invention further consists in a novel method of forming the
recesses above mentioned by securing a pin or stud of hard metal in the
draw head to form the partition between the two recesses. The draw
head is made of any suitable exterior form and may have lugs on its
upper surface to form bearings for the pivot of the pawl, and it has a
flaring throat. At the back of this throat are two recesses, the lower
recess being in some cases deeper than the upper one, but it is preferable,
for reasons herein-after given, to make them of equal depth, and in all
cases each of them should be in height somewhat more than the diameter
of the link to be used.
These recesses may be formed either by making the back of the throat
deeper below than above a projecting point at the back of the throat,
or by curving the back of the throat into two nearly semicircular
divisions. It is preferable to insert or cast in at this point a pin or
stud piece of steel or other metal, in either case the space between the
projecting point and the bottom of the throat and between the said
projecting point and the top of the throat being somewhat greater in
height than the diameter of the link and of sufficient depth for the point
to overlap the end of the link and hold it in a horizontal position in the
lower recess. A vertical longitudinal slot is made through the top of
the draw head and through the lugs. In the bottom of the draw head
is a curved depression shorter than the slot through the top. A pin or
bolt is passed through holes provided in the lugs on top of the draw

page_text: head and crosses the slot passing through and serving as a pivot for the
pawl. The pawl is so shaped that when in position it presents at its
front upper edge a bearing against the front end of the slot, in which
slot it is pivoted upon the bolt which passes through a hole in the
front upper end or shoulder of the pawl. From this bearing edge the
pawl curves upward and backward sufficiently to admit of its turning
freely on its pivot against the face of the slot; it then extends back a
distance greater than half the length of the said slot, the distance to
which it thus extends back being more or less beyond the middle of the
length of the slot according to the amount of lost motion which it is
desired to take up; it then turns downward in a straight line at its
back edge to a point near the floor of the draw head where it curves
downward and forward along the recess or curved depression to the
front end or face of this recess, and from this point it rises with the
front edge or face of the recess and gradually curves forward to the
bottom of the slot thus completing its outline. This pawl is of such
thickness as to insure ample strength and is adapted to swing freely in the
slot and recess upon its pivot. The hole in the pawl through which the
bolt passes is elongated so that the pawl has some play upon its pivot
lengthwise of the slot. An oval ring is attached in any suitable manner
to the top of the pawl and rests upon the draw head when the pawl is in
position; this ring serves to lift the pawl in uncoupling the carriages,
and when it is desired the pawl may be raised until its lower end comes
outside of the draw head and the ring is then passed lengthwise over the
base of the pawl and then turned so as to bring it crosswise of the slot
and under the pawl, thus shortening the axis of the ring parallel with
the pawl so that the pawl will rest upon and be supported by the ring.
Of the two recesses in the draw head the lower one serves to hold the
link (which is pressed back into the recess) by one end horizontal or
nearly so, insuring the entrance of the other end of the link into the
draw head of the approaching carriage when the draw heads of the two
carriages are in about the same horizontal plane, and the outer end of
the link thus held will also rise to any height required in coupling a
lower to a higher draw head. The upper recess is called into requisition
in coupling carriages whose draw heads are in planes so different that
their throats do not come nearly opposite each other, in which case one
end of the link being in the upper recess of the higher draw head the
deflection of its outer end would be such that it would enter the draw

page_text: head of the lower carriage and effect the coupling. The two recesses
are preferably made of equal depth, so that in all cases the depth of the
throats and recesses in the two draw heads which come together being
greater than the length of the link the draw heads will cover the link
entirely before they come together, and thus prevent any jamming or
crushing of the links.