Improvements in or connected with Colliery Winding Cages, Hoists, and the like,
Year: 1899

page_text: Date of Application, 15th May, 1899-Accepted, 24th June, 1899
COMPLETE SPECIFICATION.
Improvements in or connected with Colliery Winding Cages, Hoists,
and the like,
I, WILLIAM FOSTER, of the Collieries, Dungannon, in the County of Tyrone,
Ireland, Mechanic, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement and accompanying drawings:-
My said invention relates to colliery winding cages, hoists and the like. As is
well known the strain upon the winding rope when abruptly starting to raise
such cages or hoists is very great, weakening the rope and rendering the same
liable to breakage.
ง
The object of my invention is to provide a pneumatic arrangement whereby a
gradual starting of the cage is effected so that the strain upon the winding rope
or chain is relieved, such strain being brought to bear gradually instead of
abruptly. By these means the life of the winding rope is considerably prolonged
and à fruitful source of accident to a great extent obviated.
And in order that my invention may be fully understood I will now proceed
to describe the same, reference being had to the accompanying two sheets of
drawings.
ON SHEET 1.
Fig. 1 is an elevation, partly in section and broken in length for want of space,
of a colliery winding cage with my invention applied.
Fig. 2 is a sectional plan of the cage framing on the line A A Fig. 1.
Figs. 3 and 4 are detail views in section drawn to an enlarged scale.
ON SHEET 2.
Fig. 5 shows an enlarged view in section of my improved pneumatic device.
In carrying my invention into effect I secure a cylinder a of suitable capacity
to the cage by means of stays c.
b
The stays c embrace the cylinder a and are bolted thereto and to the
shown in Figs. 1 and 2.
cage
b as
A suitably packed piston d works fluid tight within the cylinder a as shown
more clearly in the sectional view Fig. 5 and to this piston is connected a rod e
which is capable of sliding through a packed gland formed in the cover a¹ of
the cylinder a. The outer protruding end of the piston rod e is screwed to
accommodate a ring g which is screwed upon the end of the rod and further secured
by means of a pin g¹.
The winding rope or chain (not shown) is secured to the ring upon the end
of the piston rode, bridle chains h also connecting the piston rod and cage. The
cylinder a is provided with an air inlet valve i of the non-return or back pressure
type shown in section in Fig. 4. Ports or passages jk formed in the cylinder
communicate with each other by means of a pipe 1. A brake valve m (clearly
shown in the sectional elevation Fig. 3) regulates the passage of air along the
pipe above or below the pistond. By operating the screw n the adjustment of
the valve m can be effected to a nicety.

page_text: The operation of my invention is as follows.
When the cage is at rest at the bottom of the pit shaft the piston d is at the
bottom of the buffer cylinder a as shown in sectional elevation Fig. 5. A coiled
spring secured to the bottom cover a² of the cylinder a serves as a resilient
buffer to prevent the contact of the piston with the cover. The bridle chains h
are slackened as shown in dotted lines in Fig. 1, and the space within the buffer
cylinder above the piston is filled with air. On commencing to wind up, instead
of the dead weight of the cage being suddenly brought to bear upon the winding
rope, the initial force is imparted to the piston and rod e. The piston is raised
within the cylinder a compressing the air above it. The compressed air is
gradually forced through the brake valve m and passes along the pipe to the
space in the cylinder a below the piston d. When the piston has been raised to
such a height within the cylinder, that the bridle chains h become taut as shown in
Fig. 1 the chains & bear the weight of the cage. The load on the winding rope
is thus gradually increased to its maximum. Owing to the resistance of the
compressed air above the piston d the weight of the cage is eased as the piston
is raised and the load is brought gradually to bear upon the cage. The inertia
of the cage is thus overcome before the bridle chains are taut and this without
any jerk or shock thus lessening the liability of the rope to breakage. On the
descent, when the cage comes to rest, the piston falls in the cylinder a expelling
the air below it along the pipe through the brake valve m to the upper portion
of the cylinder which again becomes charged with air, any deficiency being
supplied through the air inlet valve i.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is:
(1) As means for relieving the strain upon winding ropes when commencing.
to raise colliery cages, hoists and the like, the interposition between the winding
rope and cage of a pneumatic device substantially as described and shown.
(2) The improved pneumatic apparatus for colliery winding cages and the like
consisting of a cylinder a secured to the cage, piston d and rod e, air inlet valve i,
air passages jk in communication with each other and governed by a valve m,
the whole arranged and acting in the manner, for the purposes and substantially
as described and illustrated.