Improvements in Safety Props for Supporting Cages in the Head Gear of Pits in Cases of Overwinding.
Year: 1896

page_text: Date of Application, 11th Mar., 1896
Complete Specification Left, 21st Oct., 1896-Accepted, 5th Dec., 1896
Improvements in Safety Props for Supporting Cages in the Head
Gear of Pits in Cases of Overwinding.
I, CHARLES SEBASTIAN-SMITH, of Shipley Collieries, Derby, in the County
of Derby, Colliery Owner, do hereby declare the nature of this invention to be as
follows:-
My invention relates to an improved construction of safety prop for supporting
cages in the head gear of pits in the cases of overwinding when the detaching
hooks fail to hold the cage by reason of the supporting chains, or other suspending
tackle, breaking.
I construct such safety props as follows:-
A strong horizontal metal har or block is suspended by a taper stem, the back
side of which rises from about its middle to a pivot in a hollow frame open at the
front next the cage, and having an opening at bottom on the back side through
which opening the back of the prop can swing to and fro on its pivot. The one
face of the frame is flush with the face of the space in which the cage works, so
that the said bar and taper stem constituting the prop, when swung forward
project into such space, forming a wedge with a projection at the lower end, while
when swung back it is flush with the face of the frame. When in the latter position
it is prevented from swinging forward by a vertically sliding rod or bar carried by
the frame, the upper end of which rod or bar is bent at right angles so as to project
into the path of the cage.
The frame has a vertical passage behind the suspension bar of the prop and
extending above it, in which passage is a sliding block, by preference of wood
which, when the prop is swung back, as described, rests against the inclined
suspension bar.
.
Thus on the cage rising past the withdrawn props, it will come in contact with
and draw upward the rods or bars that hold the props back, so that the props in
being thus freed will swing forward by gravity and will project underneath the
cage first as a wedge, and at the bottom as a stop.
At the same time the blocks will slide down behind the suspension bars of the
props and will consequently lock these in the forward position, so that on the cage
falling, its speed will first be checked by the wedge-shaped face of the suspension
bars, and it will then be brought to a standstill by the projecting ends of the props
on which it will rest. On the cage being raised again, the wedging blocks are
drawn upward by a rod or chain, and the props are then swung back and locked in
position by the sliding rod or bar so that the cage can now be lowered past them.
The prop is extended backwards of the suspension bar to a sufficient extent to
give it a tendency to swing sharply forward when released from the backward
position.
In order to avoid the necessity of making the pivot of the swinging prop strong
enough to take the shock of the falling cage, I prefer to make the upper end of
the suspension bar forked and to suspend it on a fixed pivot pin in the frame by
means of a pin of copper or other soft metal passing through the fork above the
pivot. Or the first pin may be fixed in the suspension bar and rest on a spring or
other support attached to the frame which support will give way to the weight of

page_text: the cage and allow the pivot pin to drop sufficiently far in a slot in the frame so as
to allow the prop to rest on the supporting beam.
The underside of the prop when suspended is raised a slight distance above the
upper surface of the beam on which the frame of the prop is fixed.
On the cage falling on to the prop, the copper pin will be sheared through, or
the spring or other non resisting support to the pivot will give way, and the prop
will drop on to and be supported by the beam.
According to another modification, the prop bar, instead of being suspended
from a pivot as described, might be made to slide out upon an incline but I prefer
the first arrangement.
Or again, the prop with its incline may be mounted in vertical bearings so as to
revolve through an angle of 90°, and the upper end of the prop has an arm
projecting over the path of the cage. The latter has, projecting up from its top, an
incline which in rising comes in contact with the arm and turns the prop through 90°
thereby causing the incline of the prop to project underneath the cage.
Dated this 11th day of March 1896.
ABEL & IMRAY,
Agents for the Applicant.
Improvements in Safety Props for Supporting Cages in the Head
Gear of Pits in Cases of Overwinding.
I, CHARLES SEBASTIAN-SMITH, of Shipley Collieries, Derby, in the County
of Derby, Colliery Owner, 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 :-
My invention relates to an improved construction of safety props for supporting
cages in the head gear of pits in the cases of overwinding when the detaching
hooks fail to bold the cage by reason of the supporting chains or other suspending
tackle breaking.
I construct such safety props as follows:
A strong horizontal metal bar or block is suspended by a taper stem, the back
side of which rises from about its middle to a pivot in a hollow frame open at the
front next the cage, and having an opening at bottom on the back side through
which opening the back of the prop can swing to and fro on its pivot. The one
face of the frame is flush with the face of the. space in which the cage works so
that the said bar and taper stem constituting the prop when swung forward project
into such space, formning a wedge with a projection at the lower end, while when
swung back it is flush with the face of the frame. When in the latter position it
is prevented from swinging forward by a vertically sliding rod or bar having a
fork at the lower end which engages a stud on the bar of the prop the upper end
of which rod or bar, or a trigger lever attached thereto, projects into the path of
the cage.
The frame has a vertical passage behind the suspension bar of the prop and
extending above it, in the upper part of which passage is placed a sliding block, by
preference of creosoted wood which, when the prop is swung back as described,
rests against and above the inclined suspension bar. Thus on the cage rising past
the withdrawn props, it will come in contact with the triggers and thus draw
upward the rods or bars that hold the props back, so that the props in being thus
freed will swing forward by gravity and will project underneath the cage first in
the form of a wedge, and at the bottom, as a stop.

page_text: At the same time the blocks will slide down behind the suspension bars of the
props and will consequently lock these in the forward position so that on the cage
falling, its speed will first be checked, and frequently stopped, by the wedge-shaped
faces of the suspension bars and it will certainly be brought to a standstill by the
projecting ends of the props on which it will rest.
The accompanying drawings shew safety apparatus for cages, constructed
according to my above described invention.
Fig. 1 shews a sectional elevation on line X X Fig. 3 with the parts in the
position before being brought into action. Fig. 2 shews the same view with the
parts in the position when brought into action. Fig. 3 shews a plan.
On the horizontal beams A A fixed to the head gear of the pit (the other parts
of which are not shewn, for the sake of clearness) are fixed four strong hollow
frames B B, which may be conveniently built up of two trough iron standards,
suitably fixed together and to the beams A.
Within these hollow frames are strong swinging bars or props CC, supported
by pivots at their upper ends on spring bearings D on the frames, their lower ends
being clear of the beams A so that they are free to swing forward on their pins
from the position shewn at Figs. 1 and 3 into that shewn in Fig. 2, but when they
are subjected to a downward pressure, their spring bearings will yield sufficiently
to allow their lower ends to bear firmly on the beams A, so that no strain will come
on the supporting pins.
These bars constitute the before mentioned props; they consist firstly of the
horizontal part C', and secondly of the upright part C.
When the props are in the forward position at Fig. 2 the front face of the
part C projects in an inclined direction beyond the face of the frames B, and
terminates at the projecting beak of the part C, the inner face of the part C³
being then about vertical. When the props are in the backward position shewn at
Fig. 1, the beak of the part C¹ is about flush with the face of the frame B, so that
it does not interfere with the rising cage E, The props are ordinarily held in this
position by means of rods F sliding in guides on the frames B and engaged by
their forked lower ends with pins G on the props projecting through slots in the
frames B.
The upper ends of the rods F are pivotted to trigger levers H, which in their
turn are pivotted to brackets I carried by the head gear, so that when the rods
are engaged with the pins G of the props, they hold the trigger levers H in the
horizontally projecting position shewn at Fig. 1, in which position the cage E if
raised up to the dotted position shewn will come in contact with them and in
raising them upward will also raise the rods F so as to liberate the pins G
whereupon the props C will swing forward by gravity and will occupy the position
shewn at Fig. 2.
In the upper part of the frames B Fig. 1 are situated wooden blocks J
maintained in a vertical position by a transverse plate B₁ in the frame B and
resting with their lower ends upon the upper end of the sloping back surface of the
props which, when in the backward position, is inclined as shewn.
When the props swing forward as described, the blocks J, losing their support,
slide down behind the props, between these and a back plate or door K, and thus
serve as abutments holding the props firmly in the forward position. The doors K
are pivotted at K¹ to the frames B and are supported at the back by beams L tied
across by strong tie bolts M. Thus whatever may be the wedging strain put upon
the props, it is entirely taken by the tie bolts M to which it is transmitted through
the blocks J plate K and beams L.
From the above description it will be seen that if after the cage E has been
raised so as to disengage the props as described the lifting tackle should give way,
the cage, in dropping, would be caught between the inclined faces of the props as
at Fig. 2 and be effectually arrested by the wedging action of these. Should the
cage yield to the wedging force so as to descend to the bottom of the inclines, it
will then be effectually stopped and supported by the beaks of the props.

page_text: After the cage has been again attached to the lifting tackle, the nuts of the tie
bolts M are either unscrewed sufficiently to free the blocks J, so that these can be
drawn up again in the frame or the beams L can be entirely removed so as to allow
the doors to be opened for the blocks to be removed through them; the props are
then drawn back by the projecting outer end of C' into their backward position
and are secured there by the trigger rods F, and the blocks J having been replaced
in their original position as at Fig. 1 and the bolts M screwed up so as to bring the
bearers L close up to the doors the apparatus is again ready to operate.
By extending the part C of the props considerably backwards as shewn, the
centre of gravity of the prop will be brought into such a position as to cause
the prop to swing sharply forward when released from the backward position.
Instead of supporting the pivot of the prop upon spring bearings, the pivot may be
carried in fixed bearings and be made of soft meta! so that it will be sheared by
the downward pull of the falling cage so as to allow the bottom of the prop to
be supported by the beam A.
It will be evident that several other modifications of the props might be
employed whereby when released from a backward position by the ascending cage,
they are caused to move forward by gravity so as to support the cage; thus they
might be made to slide downwards and forwards upon fixed inclines within the
frames. But I prefer to employ the arrangement described.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. Safety prop apparatus for supporting cages in mines consisting of bars or
props that are ordinarily held in a backward position in fixed frames but which on
being liberated by a trigger device actuated by the cage when this is raised past
the props, move rapidly forward so as to project inwards underneath the cage and
thus stop its descent when it falls, substantially as described.
2. In safety prop apparatus such as are referred to in the first claim suspending
the props on pivots and forming them in such manner that when they swing
forward from the backward position they present inclined faces underneath the
cage so as to arrest its downward motion by a wedging action, the said props being
supported in such positions by sliding abutment blocks that are made automatically
to descend behind them substantially as described.
3. In safety props such as are referred to in the first claim, the combination of
fixed frames B props or bars C suspended by yielding pivots from the frames
trigger rods F holding the props in a backward position and adapted to release the
props when acted upon by the cage, and sliding blocks J which are supported in a
raised position by the props when these are in the backward position, but which
slide down when the props swing forward and act as abutments preventing the
forcing backward of the props by the cage, substantially as described.
4. In safety props arranged as set forth in the third claim, the provision of
beams L secured behind the blocks J by tie bolts M so as to take the wedging
strain exerted by the falling cage upon the props, substantially as described.
5. Safety prop apparatus combined and operating as herein described with
reference to the drawings.
Dated this 21st day of October 1896.
ABEL & IMRAY,
Agents for the Applicant.