IMPROVEMENTS IN THE CONSTRUCTION OF "POINTS" AND " CROSSINGS" FOR TRAMWAYS AND OTHER LIGHT RAILWAYS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Philip Unwin Askham at the Office
of the Commissioners of Patents on the 11th July 1883.
PHILIP UNWIN ASKHAM of Sheffield in the County of York Steel Manufacturer
"IMPROVEMENTS IN THE CONSTRUCTION OF "POINTS" AND " CROSSINGS" FOR
TRAMWAYS AND OTHER LIGHT RAILWAYS"
This Invention consists firstly in the construction of 'Points' with a locking
arrangement for the moveable tongue thereof
One method of carrying into effect this Invention consists of a Pawl or Catch
fitted to the point' by a pin on which it swivels. A cavity or recess is made in
the lower part or base of the 'point' in the centre of which the pawl or catch is
fitted, and into which it will drop clear of the moveable tongue the said cavity
or recess being double the length or thereabouts of the said pawl or catch fitted
therein. The tongue will be moved to one or the other side of the pawl or catch
according to the direction the Car or Vehicle is required to take the pawl being
in the recess at the end of the tongue whilst the tongue is being moved, its position
being then reversed it lies at the side of the tongue and prevents its lateral move-
ment, thus securely locking it. The 'point' will be reversed by raising the pawl,
dropping it into the cavity sliding the tongue and replacing the pawl in the reverse
position, when the 'point' will be securely locked
As a modification the tongue will have a projecting pin which passes through a
slot in the base of the point' and is entered into a groove in a shaft under the
said 'point; the shaft is mounted in bearings and is rotated right and left by a
lever, the shaft has a helical groove running into a concentric groove at each end;
when the tongue is in position for the car to pass in one direction the projecting pin
of the tongue is in the concentric groove at one end and the tongue is locked. To
reverse the 'point' for the car to pass in another direction the shaft is rotated, by
which the pin (and the tongue attached thereto) is forced along the helical groove
into the concentric groove at the other eud in which position the tongue is thereby
securely locked
As a further modification the tongue can have a pin (or pins) projecting from
the under side thereof and the 'point' have a corresponding hole (or holes) at each
side thereof into which the said pin, (or pins) will enter when the tongue is against
one or the other side of the 'point.' In reversing the 'point' the tongue will be

page_text: raised until the pin is clear of the hole, when the tongue will be moved across
until the pin can be entered in the hole at the other side by which the tongue will
be locked in the reverse position. The tongue will be so pivotted as to admit of a
vertical as well as a horizontal motion
This Invention consists secondly in the improved construction of 'points' and
'crossings' with movcable faces where wear takes place. As ordinarily constructed
the V and other parts of the crossing' and 'point' wear away rapidly and when
so worn the whole of the 'point' and 'crossing' has to be taken up from the
permanent way causing delay to the traffic and the loss of the bulk of the 'point'
and crossing' which is not worn. The point "and 'crossing' are made in two
or more parts the lower and non-wearing part being firmly secured in the permanent
way and the upper face of the wearing part or parts being removeable and secured
to the lower part or base of the point' and 'crossing' by bolts and nuts or
wedges, set screws or equivalent appliances so that the worn parts can be renewed
without disturbing the permanent way