Improvements in Pit Props.
Year: 1899

page_text: Date of Application, 29th June, 1899
Complete Specification Left. 29th Mar., 1900-Accepted, 12th May, 1900
Date of Application, 29th June, 1899
Complete Specification Left. 29th Mar., 1900-Accepted, 12th May, 1900
Improvements in Pit Props.
We, GEORGE SPENCER, of Stanley Lodge, West Hallam, Mining Engineer, and
FREDERICK CHAMBERS, of Heanor Road, Ilkeston, Engineer, both in the County
of Derby, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in metal props, to be used in place
of the timber props, which are usually employed for temporialy supporting the
roofs and sides of cuttings, in coal and other mines or workings.
The present invention relates more particularly to props which are of a tubular
or semi-tubular structure, and it has for its object to provide a metal prop of this
construction as light as possible, and with the metal so disposed in the prop that
it will withstand the greatest possible pressure.
According to our invention we form a semi-tubular prop, by taking a bar of H
girder section, and bend preferably by rolling, the two flanges into semi-circular
This forms a prop which
form in section, until their edges meet or nearly so.
in cross section is comprised of two semi-circular parts connected by a diametrical
web, and is not only a very strong prop but one which is convenient to handle,
and remove from the debris of the mine or working.
The ends of the prop may be either plugged, or closed by a circular plate,
preferably of the same diameter as the prop, and the whole welded together to
form solid ends, or the ends may be fitted with caps in the manner hereinafter
described in reference to tubular props, in order to prevent their ends from being
crushed in, or splayed out by the superincumberent weight.
In a tubular prop, that is, a prop formed of tubing of a suitable diameter
and strength, we either form the said props with solid ends of greater strength
than the walls of the tubing, or fit them with caps or plugs of special form.
In the former case a circular disc of metal or a solid plug of greater strength or
thickness than the wall of the tubular part, is inserted into the end of the prop,
and is welded in this position, thus forming a solid end to the prop of great
strength, to resist the tendency, which the end of the prop has to be crushed in,
by the weight the prop has to sustain.
When caps are employed for the ends of a tubular prop, we form the said
caps with either a rim to fit on the exterior of the end of the tube, or a rim or
plug to fit in the exterior of the end of the tube, or both as preferred, and
secure them by rivits or bolts which are preferably passed diametrically through
the rim of the cap, or interior lugs on the cap, and the end of the tubular part.
When a cap is formed with a rim to fit on the exterior of a tubular prop, the
edge of the rim is preferably bevelled off, in order that the prop may be more
readily withdrawn from fallen debris.
When a cap is however only provided with a rim or plug to fit in the interior
of the tubular part, the head of the cap may be of the same diameter as the
tubular part. In this case we bevel the end of the tubular part, and form a
correspondingly shaped annular recess in the head of the cap, into which the
end of the tube fits, and the latter is thus prevented from being splayed out or
by the pressure on the cap.
sulit

page_text: We may further strengthen or stiffen the prop, by securing a sleeve at about
the middle of its length. This sleeve is preferably shunk on the prop, and may
be either parallel, or tapered towards its two ends, as preferred.
Dated this 29th day of June '99.
BOULT & WADE,
Agents for the Applicants,
трготещению
We, GEORGE SPENCER, of Stanley Lodge, West Hallam, Mining Engineer, and
FREDERICK CHAMBERS, of Heanor Road, Ilkeston, Engineer, both in the County
of Derby, 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:
This invention relates to improvements in metal pit props, to be used in place
of timber props, for temporarily supporting the roofs and sides of cuttings in coal
and other mines or workings.
The present invention relates more particularly to props which are of a tubular
or semi-tubular structure, and it has for its object to provide a metal prop of
this description, as light as possible, and with the metal so disposed in the prop,
that it will withstand the greatest possible pressure without giving way.
The invention will be best understood by reference to the accompanying draw-
ings, in which
Fig. 1 is an elevation and
Fig. 2, a section of a semi-tubular pit prop constructed according to our
invention.
Figs. 3-4-5-6 and 7 are elevations partly in section showing the ends of
tubular props, strengthened according to our invention.
Like letters indicate like parts throughout the drawings.
According to our invention we form a semi-tubular prop such as that shown
in Figs. 1 and 2, by taking a bar of H girder section, and bending the two
flanges, preferably by rolling, into semi-circular form in section, until their edges
meet or nearly so.
This forms a prop, which is comprised in cross section, of two semi-circular
parts A, A, connected by a diametrical web B. This forms not only a very strong
prop, but one which is convenient to handle, and also remove from the debris
of the mine or working.
The ends of the prop may each be either plugged or closed by a circular
plate, preferably of the same diameter as the prop, and the whole welded together
to form a solid end such as C, (see Fig. 1) or the ends may be fitted with caps,
in the manner hereinafter described in reference to tubular props, in order to
prevent the said ends from being crushed in or splayed out by the super-incum-
bent weight.
In a tubular prop, that is a prop formed of tubing of a suitable diameter and
strength, we either form the said prop with solid ends of greater strength than
the walls of the tubing, or fit them with caps or plugs of special form.
In the former case a circular disc of metal, or a solid plug of greater, strength
or thickness than the walls of the tubular part D, (see Fig. 3) is inserted into
the end of the part D, and is welded in this position, thus forming a solid end E
of great strength, to resist the tendency which the end of the prop has to be
crushed in by the weight it has to sustain.
When caps are employed for the ends of tubular props, we form the said caps

page_text: ith either a rim or plug to fit in the interior of the tubular part, or a rim
the exterior of the tubular part, or both.
In the arrangement shown in Figs. 4 and 5, the cap F is provided with a
m F to fit in the interior of the end of tubular part D.
In this case the head
f the cap may be of the same diameter as the tubular part, and to prevent
he latter from being splayed out or split by the pressure on the cap, the latter
sformed with an annular recess or groove, to receive the bevelled end D¹ of the
ubular part D as shown.
The cap is secured by a cross pin C, passing through the tubular part D,
and lugs or extensions F2 of the rim F.
In the arrangement shown in Fig. 6, the cap F is formed with a rim 13 to fit
on the exterior of the tubular part D. The edge of this rim is preferably bevelled
off as shown, in order that the prop may be more readilly withdrawn from fallen
debris.
The cap Fin this case is also secured by a transverse pin G, passing through
the rim F3 of the cap, and the tubular part D.
In Fig. 7, the cap F is shown provided with a rim F to fit in the interior of
the tubular part D, and also a rim F3 to fit on the exterior thereof. The cap is
preferably secured by a cross pin G passing through the outer rim F³, and the
tubular part D, but if preferred, it may pass through the inner rim F', or both.
If desirable the lower end of a prop may be formed as shown in Fig. 6. In
this case the walls of the tubular part D are closed in at 12 as shown, so as to
form a taper part, having a rounded end.
We may further strengthen or stiffen the props, by securing a sleeve at or
about the middle of their length, either in the interior or on the exterior.
This sleeve is preferably shrunk into position, and may be either parallel, or
tapered towards the two ends as preferred.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is :-
1. A pit prop comprised in section of two approximately semi-circular parts
such as A A united by a web such as B substantially as described.
2. A pit prop comprised in section of two approximately semi-circular part
such as
A united by a web such as B and having solid or capped ends sub-
5 stantially as described.
3. A tubular pit prop having a solid end such as E welded therein of greater
strength than the walls of the tubing substantially as described.
4. In a pit prop the combination with a tubular part such as D of a cap such
as F having a rim F¹ to fit within the end of the tubular part and an annular
40) recess to receive the bevelled end D¹ of the said part substantially as described.
5. In a pit prop the combination with a tubular part such as D of a cap such
as F having a rim such as F3 to fit on the exterior of the tubular part substan-
tially as described.
6. In a pit prop the combination with a tubular part such as 1) of a cap such
45 as F having a rim F to fit in the interior of the tubular part and a rim F3 to
fit on the exterior thereof substantially as described.
7. The combination and arrangement of parts constituting the complete pi
props substantially as described and illustrated in Figs. 1 and 2 Fig. 3, Figs.
and 5, Fig. 6, and Fig. 7 of the accompanying drawings.
Mach 1000
BOULT, WADE & KILDUN
Agents for the Applicants,