Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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MINE STOPPING
Background of the Invention
This invention relates generally to mine ventilation and,
more particularly, to mine doors and mine stoppings.
So-called "stoppings" are widely used in mines to stop off
the flow of air in passageways in the mines, a "stopping"
generally being a masonry (e.g., concrete block) or metal wall
installed at the entrance of a passageway to block flow of air
therethrough. Such stoppings are typically provided with a
doorway or opening and a door therein for occasional access to
the blocked-off passageway. This arrangement is satisfactory
under usual conditions when the stopping should prevent the
passage of air through the passageway. In some conditions,
however, high pressure concussive air is forced against the
stopping.and door. This may occur, for instance, in longwall
mining where a large roof can collapse very rapidly and displace
a large amount of air, thereby creating a shock wave of high
pressure concussive air. Likewise, a mine blast will also force
high pressure concussive air against the stopping and the door.
In conventional stopping arrangements, the concussive air cannot
escape through the stopping without causing significant damage
to the stopping, the door or both.
Moreover, prior art stoppings are constructed generally
perpendicular to the direction of air flow through the
passageway. This construction is not optimal for decreasing the
stress on the stopping caused by the concussive air.
Summary of the Invention
Among the several objects and features of the present
invention may be noted the provision of an improved mine stopping
having a door which seals an opening in the stopping; the
provision of such a stopping wherein the door can swing open in
either of two directions to avoid damage to the stopping due, for
example, to concussive air generated by longwall mining or by a
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mine blast; and the provision of such a stopping which is
effective in controlling mine ventilation.
Further among the several objects and features of
the present invention may be noted the provision of a mine
stopping which may be installed in a mine passageway so as
to reduce dynamic air pressure exerted on the stopping; the
provision of such a mine stopping which is less likely to be
damaged by concussive air; and the provision of such a mine
stopping which is effective in controlling mine ventilation
and which is economical to manufacture.
This invention provides a mine stopping installed
in a mine passageway having air flowing through the
passageway in a first direction, said mine stopping
comprising: a rigid wall extending across the passageway to
close the passageway, said wall including a first wall
section extending at a first angle relative to the direction
of air flow through the passageway and a second wall section
extending at a second angle relative to the direction of air
flow such that the wall sections are arranged in a non-
coplanar, non-parallel relationship with respect to one
another, and an opening in the wall to permit the passage of
air therethrough, said second angle being oblique to the
direction of air flow whereby air flowing through said
passageway strikes the second wall section at said oblique
second angle thereby to reduce the dynamic air pressure
exerted on said wall.
In another aspect the invention provides a mine
stopping installed in a mine passageway comprises: a rigid
wall extending across the passageway to close the
passageway, said wall comprising a first wall section
extending at a first angle relative to the direction of air
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flow through the passageway and a second wall section
extending at a second angle relative to the direction of air
flow such that the wall sections are arranged in a non-
coplanar, non-parallel relationship with respect to one
another, at least one of said first and second angles being
between about 30-50 degrees with respect to the direction of
air flow through the passageway, whereby air flowing through
said passageway strikes the wall at said angle thereby to
reduce the dynamic air pressure exerted on said wall.
In a further aspect the invention provides a mine
stopping installed in a mine passageway comprises: a rigid
wall extending across the passageway to close the
passageway, said wall comprising a first wall section
extending from one side of the passageway at a first angle
and a second wall section extending from an opposite side of
the passageway at an oblique angle relative to the opposite
side such that the wall sections are arranged in a non-
coplanar, non-parallel relationship with respect to one
another and so that air flowing through said passageway
strikes the second wall section at said oblique angle
thereby to reduce the dynamic air pressure exerted on said
wall.
In a still further aspect the invention provides a
method of installing a stopping in a mine wherein the
stopping comprises a plurality of elongate extensible panels
adapted to extend from a floor to a roof of a passageway in
the mine, each panel comprising a lower panel member adapted
for engagement of its lower end with the floor and an upper
panel member adapted for engagement of its upper end with
the roof, one of said lower and upper panel members having a
telescoping sliding fit with respect to the other of the
panel members, the method comprising: positioning a first
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of said extensible panels at a first angle relative to sides
of the passageway, positioning a second of said extensible
panels at a second angle relative to sides of the
passageway, forcing the upper end of the upper panel member
of said panels into engagement with the roof and the lower
end of the lower panel member of said panels into engagement
with the floor, wherein said first and second panels are
arranged in a non-coplanar, non-parallel relationship with
respect to one another and at least one of said first and
second angles is oblique with respect to the sides of the
passageway to reduce the dynamic air pressure exerted on
said stopping.
In yet another aspect of the present invention, a
mine stopping is installed in a mine passageway having air
flowing
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through the passageway in a first direction. The mine stopping
comprises a rigid wall extending across the passageway to close
it, and an opening in the wall to permit the passage of air
therethrough for regulating the airflow. The wall extends
between the opening and one side of the passageway at an oblique
angle with respect to the direction of air flow through the
passageway whereby air flowing through the passageway strikes the
wall at the oblique angle thereby to reduce the dynamic air
pressure exerted on the wall.
Other objects and features of the present invention will be
in part apparent and in part pointed out hereinafter.
Brief Description of the 'Drawings
Fig. 1 is a front elevation of a mine stopping of the
present invention having a swinging door mounted thereon;
Fig. 2 is a horizontal cross section taken in the plane of
line 2-2 of Fig. 1;
Fig. 3 is an enlarged front elevation of the door;
Fig. 4 is an enlarged vertical cross section taken in the
plane of line 4-4 of Fig. 3;
Fig. 5 is a side elevation showing the door in a first open
position with respect to a door frame, the door being shown in
phantom lines in a second open position;
Fig. 6 is an enlarged front elevation of the swinging door
with a locking bar mounted thereon;
Fig. 7 is an enlarged vertical cross section taken in the
plane of line 7-7 of Fig. 6;
Fig. 8 is a horizontal cross section like Fig. 2 showing a
second embodiment of the invention; and
Fig. 9 is a horizontal cross section like Fig. 2 showing a
third embodiment of the invention;
Corresponding reference characters indicate corresponding
parts throughout the several views of the drawings.
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Dbtailed Description of the Preferred Embodiment
Referring now to the drawings, Figs. 1-5 show a sloped mine
stopping, generally designated 10, having a rigid wall 12
extending across a passageway 14 in a mine 15 to close the
passageway, an opening 16 in the wall, and a swinging door 18 for
closing the opening. The opening 16 is preferably defined by a
rectangular door frame, generally designated 20. The door 18 is
hinged adjacent the opening 16, the door preferably being hinged
on the door frame 20. However, it is contemplated that the door
may be hinged directly on the wall 12. The door frame 20 has
opposing top and bottom horizontal frame members, designated 22
and 23, respectively, and two opposing vertical right and left
side frame members, designated 24 and 25, respectively. The
horizontal and vertical frame members 22-25 may be formed from
channel bar stock, for example. The door 18 includes a main
panel portion 28, preferably formed from steel plate and
reinforcing box beams 29 extending along its bottom and vertical
sides. The door also includes an upper portion 30 preferably
formed by a separate steel strip secured, such as by welding, to
the main portion. The upper portion 30 is shaped to form a
sleeve 32 extending parallel to the top edge of the door for
receiving a horizontal hinge pin 34 which is secured to the top
frame member 22. The door 18 is swingable on the hinge pin 34
relative to the frame 20 between a closed position (Fig. 4)
engaging surfaces of the frame members 22-25 to inhibit the flow
of air through the opening, a first open position in which the
door is swung in one direction away from its closed position
(Fig. 5), and a second open position in which the door is swung
in an opposite direction away from its closed position (shown in
phantom lines in Fig. 5). It is to be understood that other
hinge configurations for the door 18 may be used within the scope
of this invention. For instance, while the door 18 is preferably
hinged along its top edge, it will be understood that the door
may be hinged at its bottom or at one side.
Preferably, a seal 36, such as the rubber D" seal shown in
Fig. 4, is attached to the reinforcing box beams 29 at the
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periphery of the door 18 for sealingly engaging the bottom frame
member 23'and the right and left side frame members 24, 25 of the
frame 20 to seal against the passage of air through the opening
16 when the door 18 is in its closed position. A skirt 38 is
5 attached to the main panel portion 28 at the top edge of the door
18 and extends substantially parallel to the top frame member 22
along substantially its full length. The skirt 38 is preferably
made of neoprene and is attached by a retainer in the form of a
steel channel 40 secured by screws 41 extending through the
channel, skirt and into the door 18. As shown in Fig. 4, the
skirt 38 is shaped to engage the top frame member 22 when the
door 14 is in its closed position to further seal the opening 16.
Preferably, a right corner piece 42 and a left corner piece 43
are mounted on adjacent corners of the door 18 for frictional,
sealing engagement with the frame 20. As shown, the right and
left corner pieces 42, 43 are attached, as by screws 45, near the
bottom corners of the door to engage the right and left frame
members 24, 25, respectively, and the bottom frame member 23.
The right and left corner pieces 42, 43 help to seal the opening
16 at the bottom corners where the seal 36 may leave gaps. The
right and left corner pieces 42, 43 are preferably relatively
stiff and are made of thick rubber or other suitable material.
The seal 36 and the corner pieces 42, 43 frictionally engage the
frame members 22-25 to hold the door 18 closed under most
circumstances. When the door 18 is subjected to substantial air
pressure, such as concussive air from a mine blast or longwalling
cave-in, the air pressure will overcome the friction between the
seal 36 and corner pieces 42, 43 and the frame members 22-25 to
force the door to an open position. Moreover, the air pressure
may force the door 18 to swing in either direction to its first
or second open position. The ability of the door 18 to swing in
both directions is advantageous. Whenever a large, abrupt air
displacement occurs, such as occurs in longwall mining or in a
mine blast, there is an initial expansion or push of concussive
air in a direction away from the displacement, followed by a
pulling of air in the opposite direction toward the displacement
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ais the low pressure on the displacement side of the stopping 10
is equalized with the higher pressure on the other side of the
stopping. The construction of the swinging door 18, as described
above, allows the air flow caused by the displacement to pass
through the opening 16 in both directions.
Referring to Figs. 6 and 7, the mine stopping 10 preferably
includes a mechanism for maintaining the door 18 in its closed
position. In this embodiment, the mechanism includes an elongate
locking bar 50 releasably mounted on the door 18 in a locking
position in which the bar extends laterally beyond the door for
engagement with the door frame 20 to prevent the door from moving
toward either of its first or second open positions. As shown
in Fig. 6, the bar 50 is secured to both the right and left frame
members 24, 25, although securement to only one frame member is
contemplated. Preferably, the locking bar 50 is removably
mounted on the door 18 by a plurality of generally,U-shaped wire
ties 52 (also referred to as twist clamps), each tie having a
hook 54 at each end engageable with a slot of a bracket 55
affixed to the door, and a central portion 56 adapted to be
twisted so as to deform the wire tie around the bar to hold the
bar iri engagement with the door. The bar 50 is similarly
attached to the right and left frame members 24, 25 by wire ties
52 engageable with slots (not shown) in the frame members, the
arrangement operable to prevent the door from swinging in either
direction to an open position. The bar 50 is easily removable
from its locking position simply by removing the wire ties 52.
It is to be understood that other mechanisms for maintaining the
door closed may be used within the scope of this invention.
Referring again to Figs. 1 and 2, the mine stopping 10
includes the rigid wall 12 extending across the passageway 14.
The wall 12 preferably includes a first section 62 extending
between the opening 16 and one side of the passageway, and a
second section 63 extending between the opening and the opposite
side of the passageway. At least one of the two sections 62, 63
extends at an oblique angle A (see Fig. 2) with respect to the
direction of air flow through the passageway 14. In the
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pteferred embodiment, both sections 62, 63 extend at an oblique
angle with respect to the direction of flow. It should be
apparent that the direction of air flow is generally parallel to
the walls of the passageway 14 adjacent the stopping 10.
Conventional prior stoppings are installed perpendicular to the
flow of air, which causes the stopping to experience' the full
amount of velocity pressure caused by the flow. (Note that
static pressure is neglected in this discussion.) Iri the present
invention, the angling of the wall 12 reduces the velocity
pressure exerted against the stopping by a factor of the sine of
the angle between the direction of flow and the wall. In the
prior stoppings mentioned above, the angle between the direction
of flow and the stopping is generally 90 . Since the sine of 900
is 1, the velocity pressure has its full impact on the stopping.
In the present invention, as an example, the wall 12 may be
constructed such that the angle.A between the direction of flow
and the wall is, for instance, 45 . Since the sine of 45 is
.707, the velocity pressure impact on the door would be only .707
times the full velocity pressure.
The wall 12 may be constructed of a plurality of elongate
extensible panels extending vertically in side-by-side relation
from a floor to a roof of the passageway 14. The panels are
preferably positioned substantially in a plane at an oblique
angle with respect to the direction of air flow through the
passageway 14. Installation of such panels is described in U.S.
Pat. No. Re. 32,675,
and suitable panels are available from Jack Kennedy Metal
Products, Taylorville, IL. The wall may also be constructed of
masonry blocks or other similar materials.
It is to be understood that the stopping 10 with angled wall
sections 62, 63 may be constructed without a door or other
structure to close the opening 16. It should also be understood
that the opening 16 may be positioned immediately adjacent the
passageway 14, i.e., the wall 12 may consist of only one section
extending from one side of the passageway to an opening at the
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other side of the passageway, the opening being defined in part
by the passageway and in part by the stopping 10.
Fig. 8 shows a second embodiment wherein the wall sections
162, 163 are oriented more than ninety degrees relative to the
direction of air flow shown. However, as noted above, the
direction of air flow in a mine passageway 14 is reversible.
Thus, the angled wall sections may be angled more than ninety
degrees relative to one direction of air flow, and may be angled
at less than ninety degrees to flow in the opposite direction,
but preferably the wall sections will generally be oblique to the
direction of air flow. Moreover, as shown in Fig. 8, the wall
sections 162, 163 may be angled at a shallower angle than in the
first embodiment, such as'about 30 degrees. The wall sections
may also be angled at angles greater than those shown. The exact
angle of the wall may depend upon such factors as the expected
direction of air flow, or the length of the mine passageway in
which the stopping is installed. The preferred angle for most
stoppings is in the range of 40-50 degrees.
The sloped stopping 10 is advantageous as described above
because it reduces the velocity pressure against the stopping.
It is further advantageous in that it directs the air flow more
satisfactorily toward the doorway or opening 16 in the stopping.
This is accomplished because the sloped stopping acts as a funnel
to direct the air flow toward the opening. This feature helps
to improve the ventilation of the mine in that it allows air to
flow more rapidly and efficiently through the stopping.
Referring to Fig. 9, in a less preferred embodiment, the
swinging door and frame 20 of the first embodiment is shown
installed in a conventional stopping 212 having walls installed
perpendicular to the direction of air flow. Thus, the swinging
door of this invention may be used advantageously in any mine
stopping, and is not limited to use in the angled stopping of
this invention.
In view of the above, it will be seen that the several
objects of the invention are achieved and other advantageous
results attained.
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- As various changes could be made in the above constructions
without departing from the scope of the invention, it is intended
that all matter contained in the above description or shown in
the accompanying drawings shall be interpreted as illustrative
and not in a limiting sense.
