IMPROVEMENTS IN MACHINERY OR APPARATUS FOR DRIVING PILES
Year: 1856

page_text: by the Act.)
PROVISIONAL SPECIFICATION left by Stewart Robertson and James
Howden at the Office of the Commissioners of Patents, with their Petition,
on the 8th February 1856.
We, STEWART ROBERTSON and JAMES HOWDEN, both of Glasgow, in the
County of Lanark, North Britain, Engineers, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN MACHINERY OR APPARATUS FOR DRIVING
PILES," to be as follows, that is to say:-
This Invention relates to various novel arrangements of mechanism or
apparatus to be used for effecting the rapid and economical driving of piles.
The general arrangement and construction of the pile engine framing resembles
that of existing machinery; the base consists of a rectangular timber platform,
on the back part of which is placed a boiler and steam engine, if steam power.
is to be employed for actuating the piling movement.
On the front edge of the platform are two tall parallel vertical timbers, stayed
at their upper ends by inclined timbers standing up from the back of the plat-
form. Between the two vertical timbers is a vertical screw-bladed shaft with
deep threads running in a footstep on the platform, and a top bearing in the
cross head of the main timbers. This screw shaft carries a bevil wheel at its
bottom end for gearing with another bevil wheel fast on the front end of the
horizontal shaft of the actuating steam engine. The ram is fitted to traverse
vertically in the ordinary way, and its upper end carries a short horizontal
sliding bar in suitable guides, one end of which bar has upon it a small pulley

page_text: or roller capable of being brought into gear, as it were, with the screw blades of
the lifting screw shaft; the other end of this sliding bar is in contact with a
weighted crank lever, so that except at the intervals when the crank lever
weight is sufficiently resisted, the pulley on the bar is kept in constant gear with
the screw threads or blades. This is the case when the ram or driving weight
is at the bottom of its stroke or resting upon the pile head, and on the engine
being set to work, the revolution of the screw spindle causes the ram to be
rapidly carried upwards by the pressure of the rotating screw threads or blades.
An adjustable throw-off' picce is fitted upon the screw at the proper height, and
when the ram attains this elevation the throw-off piece comes in contact with
the pulley on the sliding bar of the ram, and pushes the latter back in its
guides against the pressure of the weighted crank lever behind; this move-
ment causes the pulley of the sliding bar to clear the screw blades, and the ram
then drops. In this way the continuous rotation of the engine shaft causes a
rapid elevation and fall or driving action of the ram.
According to another modification of pile-driving engine, the framing carries
an upper and a lower endless chain pulley; the vertical distance between these
two pulleys being proportioned to the length of the intended driving stroke.
The engine is driven by causing the lower pulley to revolve continuously.in one
direction. The top of the ram is fitted as in the former instance with a sliding
catch bar. kept forward by a weighted crank lever, so that its overhanging end
has a constant tendency to enter the alternated; spaces in the endless chain
arising from the construction of the links. Thus, as the front side of the
endless chain traverses upwards, it carries up the ram until the, latter arrives
at the adjustable stop: or throw-off pin.. When this point is reached, a tail upon
the weighted crank lever comes against the stop, and this draws the catch bar
out of the chain link, letting fall.the.ram...
Another form of pile. engine, involves the use of hydrostatic power.. The
platform carries a pair of tall vertical water; cylinders,, from which a pair of
parallel lifting rams or plungers, pass upwards to a cross head. above. This
'cross head has a central pendant hook,link contrived for gearing; as may be
required, with a suspending eye. on the top of the ram: As the engine, shaft
revolves, it actuates a pump placed alongside, on the platform, and this pump
forces water into the two water cylinders. When the driving ram has been
lifted in this way to the necessary height, a tail upon the suspending hook comes
in contact with an adjustable stop, and, lets fall the ram; the water being dis-
charged from the lifting cylinders by a disengaging action working the stop
valve from a movement overhead.
..
"An effective pile-driving movement is also obtained by adopting a mechanical

page_text: contrivance resembling an ordinary crab winch. A horizontal' shaft set in
bearings in a winch frame carries a deeply grooved chain pulley, capable of
being driven continuously in one direction a band pulley on one end, or by
gearing. Round this chain pulley the lifting chain is passed; one end of the
chain being attached to the head of the pile being driven, whilst the other
passes over a guide pulley in the top of the vertical framing, and suspends the
ram. A transverse slot is formed in' the chain pulley near its periphery, and
in this slot there is placed a crank lever nipping contrivance. The short armi
of this lever which turns upon a stud pin in the chain pulley is in the plane of
the pulley, and it is curved upon its acting face to correspond with the curvature
of one side of. the chain groove, so that on being pressed over it nips the
chain and holds it from slipping in the groove. The other or horizontal arm
of the crank carries a pulley in contact with a stationary differentially faced
scroll disc or cam. The action of this cam, as the nipping crank traverses
round it, is such as to nip the chain firmly in the pulley groove during the
greater part of the pulley's revolution. The consequence is, that the chain is
thus for the time fast to the periphery of the pulley, and as the latter rotates
it hauls up the driving ram. As the revolution goes on, the pulley on the
crank lever arm comes down upon a smaller diameter of the stationary cam, and
this releases the nip, so that the ram falls, and the chain pulley revolves freely,
quite independent of the hauling chain. The chain being attached at one
end to the pile head, it is always kept evenly taught. As the action goes on,
the stationary cam again gives the nip in the chain groove, as before.
Instead of a common chain, a pitch chain or a rope with transverse pins may
be adopted; the fixing of the rope or chain upon the periphery of the pulley
being accomplished by a catch pin, working in the direction of the pulley's
plane, being hooked into or released from the pins of the chain or rope by a
bell-crank lever and stationary cam, as before. A short stroke steam cylinder
may also be judiciously employed in giving a direct pull to the hauling chain
of pile drivers.
In carrying out this modification, an inverted steam cylinder is disposed
vertically in the framing of the machine; the piston rod being set to work
through a stuffing box in the lower end of the cylinder. The external project-
ing end of the piston rod carries a pulley, over which the hauling chain or rope
is passed. One end of the chain is attached to the head of the pile being
driven, and it is then passed beneath a bottom fixed pulley, then over the
piston rod pulley, then beneath a second bottom fixed pulley like the first, and
finally, up and over the over-head pulley of the frame to the ram. Various
other pulley arrangements may be adopted for obtaining a long stroke of the

page_text: ram with a short stroke of the steam piston. As the piston rises it draws up the
ram, and when the latter is let fall the piston falls of itself.
By another contrivance a continually revolving cam or eccentric is made to
work in the bight of the hauling chain, one end of the chain being fast to
the pile head. As the cam comes hard up in the bend of the chain it thus
elevates the ram, and the relieving of the cam action similarly lets the ram
fall; a clutch contrivance being adopted between the driving shaft and the
cam for obtaining a sudden descent of the ram.
Various plans may be adopted for the engaging and disengaging action of
the hauling line upon the ram; the essential object of the Invention as regards
this part of the improvements being the automatic or self-acting re-engagement
of the ram after each fall.