IMPROVEMENTS IN LOCK-BOLTS OR PINS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Henry Frederick Hailes and Alfred
Samuel Bishop at the Office of the Commissioners of Patents on the 19th May
1881.
HENRY FREDERICK HAILES, of Hornsey, in the County of Middlesex, and ALFRED
SAMUEL BISHOP, of Gibson Square, in the same County. "IMPROVEMENTS IN
LOCK-BOLTS OR PINS."
The object of this Invention is to construct bolts or pins which will be auto-
matically locked in their sockets when pushed home.
These bolts are especially adapted to be used for rapidly and securely attaching
the draught poles of tramcars alternately to the ends of those vehicles.
The fastenings at present in use for this purpose are defective by reason of their
liability to work loose.
In constructing a bolt according to our Invention we take a solid pin or bolt of
iron or other metal, having a projecting collar or flange at one end, and bore it
longitudinally for about half its length, and we slot the remaining half of the bolt
for the purpose of inserting a metal rod or plunger fitted at its lower end with two
sets of inclined surfaces or projections.
This rod or plunger, having been placed in position within the longitudinally
drilled and slotted bolt, we insert in the slot two wings or barbs, one on either side
of the rod, and between the two sets of inclined projections. These wings or barbs
are secured in position by pivot pins, on which they are able to be rocked.
The upper end of the central rod or plunger is screwed to receive a cap or
socket to which a handle is attached, and by which handle the rod may be raised
or lowered within the bolt. On lifting up the bolt by the handle, the lower set of
inclined projections will engage with the lower ends of the wings or barbs, and
forcing them outwards will cause their upper ends to be drawn within the slot.
The bolt may then be dropped into the socket in which the end of the pole has
been inserted, the collar or tlange above mentioned serving to limit its descent.
On releasing the handle, the central rod or plunger will sink within the bolt by
its own weight, and the upper set of inclined projections with which it is furnished
will engage with the upper ends of the wings or barbs, thrusting them outwards
and causing them to project beyond the slot. These projecting ends will effectually
prevent the bolt from working up in its socket. To withdraw the bolt it will

page_text: merely be necessary to lift up the handle, whereupon the barbs will be withdrawn
within the slot of the bolt, and the bolt may be then removed.
Instead of slotting the bolt longitudinally at its lower half, it may be bored out
to the required diameter, and a rod or plunger having coned nuts screwed onto its
lower end or formed in one therewith may be inserted.
Two or more radial slots in the bolt will serve to receive the wings or barbs as
before. It is obvious that the motion of the wings or barbs may also be effected by
the use of toggles or links instead of the inclined projections.
The principle of action of this bolt will, however, be identical with that
already described.
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When the bolt is to be used in a horizontal position a locking catch standing
up from the projecting collar or flange of the bolt and overlying the base of the
handle is provided, the handle being slotted, so that when the catch and slot are in
coincidence the handle may be lifted, but not otherwise.
It is obvious that other forms of catch may be employed for this purpose, and
that our locking bolt, though chiefly intended for securing in place the poles of
vehicles, may be used for many other purposes.