Note: Descriptions are shown in the official language in which they were submitted.
1 ~6216()
T~IIS INVENTION relates to skips and to loading
flasks of similar basic construction to such skips.
~ ccording to the invention, there is provided a
unit in the form of a skip or loacling flask for receiving,
containing and di.scharging material, the unit comprising
a body defining a downward]y extending storage chamber and
having an integral sloping bottom beneath a part of the
chamberi a discharge opening beneath a further part of the
chamber and defined in the body adjacent to the integral
sloping bottom; and a door locatable in a closed position
beneath the further part of the chamber for closing the
discharge opening, the door being openable by pivoti.ng
downwardly to an open position to allow material to be
discharged from the chamber through the opening, the
door forming a chute beneath the opening and extending
downwardly and away from the sloping bottom in the open
position of the door, wherein the body includes at least one
pair of spaced opposed walls diverging downwardly along at
least a substantial part of the height of the chamber whereby
the storage chamber widens downwardly within the body, the
substantial part of the height of the chamber being greater
than the spacing between the opposed walls immediately
above the opening.
The body may be substantially square or
substantially rectangular in horizontal cross-section along
at least a substantial part of its height and it may then
have two opposed pairs of walls, both of which can diverge
downwardly along at least a substantial part of the height
- 2 -
~.~
.
l 162~6P `
of the chamber. The walls preferably diverge downwardly
along the whole height of the chamber as the provision of
the downwardl.y diverging wal].s and thus a downwardly
widening chamber can help to eliminate wear on side,
back and front walls of the skip or loading flasX as
material moves downwardly within the skip or flask.
- 2a -
1 l62l6n
--3--
An over-centre mechanism may be provided for holding
the door of the skip or flask closed. In one embodiment, the
skip or flask may have over-centre mechanisms with over-centre
means at opposite sides of the body and operable to open and
close the door, the mechanisms being movable to over-centre
positions to releasably lock the door in its closed condition.
With suitable over-centre mechanisms, the load on the door, the
weight of the door itself, and optionally the weight of any
operating means provided for operating the door may be used to
biased the mechanisms -to their over-centre positions.
Each mechanism may include an arm pivotally
connected to the door, a lever having one region pivotally
connected to the body and one region connected to the arm to
provide for over-centre means, and operating means pivotally
connected to the lever to move the arm and release the ovex-
centre mechanism from its closed condition and then to move the
door to its open position when the lever is pivoted in a
predetermined direction. The mechanism will then be arranged
to move the door to its closed condition and the over-centre
mechanism -to its over-centre condition when the lever is moved
in the other direction. Such a lever having a pivotal
connection to the body, a pivotal connection to an arm
connected to the door, and a connection to an operating means
such as a follower or ram, is herein referred to generically as
a bell crank lever for ease of reference, whether the bell
crank lever is, for example a single V-shaped or substantially
triangular member or comprises lever arms spaced from one
another along a pivot axis but movable together about the pivot
axis.
1 16216fl
--4--
The over-centre mean~ may be such that a line
extending between the pivotal connections of the arm to
the door and of the arm to the lever is on one side of the
pivot axis o~ the lever when the mechanism is i~ its over-
centre condition and on the opposite side when the
mechani~m i5 moving the doox to its open condition. Any
reaction forces applied to the lever from the closed door
will then extend along such line and will serve to retain
the mechanism in its over-centre condition until the arm
is pivoted.
The control of the door may be particularly
important for a moving skip, and in one embodiment the
operating means for the mechanism may include a follower
for engaging a cam track, the mechanism being operable ~y
movement of the follower along the cam track to open the
door. The cam track may be any suitable tipping path
provided in the head gear of a mine, for example, and the
follower may move into the path and engage to the cam
track as the skip moves upwardly to the head gear.
In contra~t, the mechanism for a loading flask
can be relatively ~imple and can be controlled, for
example, by a single pneumatic or hydraulic ram.
In~one embodiment, the over-centre mechanisms of
the skip may be largely arranged closer to one side of the
skip, for example towards the front of the skip closest to
the feed side. A bottom cross-head may then be arranged
21Bn
--5--
so that its weight is largely on the opposite side of the
skip and ~o that it helps to balance the loaded skip. The
skip design may be further modiEied to compensate for
normal unbalanced loads in the s]cip. If it is found that
the material in the skip adopts an angle of repose such that
more material will normally be received on the side of the
skip cloiest to the feed side, the sloping bottom may then
be aLranged on the oppo~ite side of the skip and the door
control mechanism and cross-head may be largely arranged to
help balance the loaded skip. This can help to eliminate
wear on shoes, guide rollers, and guides for guiding the
skip as it is raised and lowered.
Material is normally discharged into -the skip
from a loading flask, and loading flasks often direct
material from the feed side of the skip by providing a
feeder chute. This can result in undue wear on the
opposed wall of the ~kip.
In order to help reduce this wear, a loading
flask assembly including a loading flask according to the
invention may have its door for closing the discharge
opening movable to a fully open position to define a chute
surface extending from the opening; and a feeder chute
can be located to guide material discharged over the door,
the feeder chute preferably being at a steeper slope than
the door when the door is in its fully open position.
-6- 116216~
If the feeder chute is at a steeper angle than
the door, the material flowing from the flask is able to
follow a more natural path so that material is more likely
to fall downardly into the ski.p rather than to be
projected at the opposite side of the skip.
Embodiments of the invention will now be
described by way of example with reference to the
accompanying drawings, in which,
Figure 1 is a front view of a skip in a Job's bridle;
Figure 2 is a side view showing the skip and bridle
of Figure l;
Figure 3 is a front view of a bridle-less skip;
Figure 4 is a side view of the skip of Figure 3;
Figure 5 is a plan view of the skip of Figure 3;
Figure 6 is a front view of a loading flask;
Figure 7 i9 a side view of the loading flask of
Figure 6, schematically illustrating the position of a
feeder chute;
Figure 8 is a side view of a feeder chute for use
with the loading flask of Figure 6;
Figure 9 is a front view of the feeder chute;
Figure 10 is a front view of an alternative loading
flask;
Figure 11 is a side view of the loading flask of
Figure 10 also illustrating a discharge position with
respect to a feeder chute;
Figure 12 is a front ~iew of a further skip;
1 lB2161~
--7--
.
Figure 13 shows the skip of Figure 12 in its closed
condition;
: Figure 14 is ~ detail of a side of the skip of Figure
12;
Figure 15 is a plan view of the skip;
Figure 16 is a detailed rear view of part of the
skip;
Figure 17 is a schematic detail showing the junction
between a door and a sloping bottom with the door in its
closed condition;
Figure 18 is a view similar to that of Figure 17 but
with the door open;
Figure 19 illustrates the application of a rubber
lining to the door and bottom;
Figure 20 is a front view of a further skip in a Job's
bridle;
Figure 21 is a side view showing the skip and bridle
of Figure 20;
Figure 22 is a side view illustrating the removal of
the ~kip from its bridle;
Figure 23 is a side view illustrating the operation of
the door of the skip;
Figure 24 is a front view of a further loading flask;
Figure 25 is a side vlew of the loading flask of
Figure 24;
Figure 26 is a side view of the loading flask illustra-
ting the operatio~ of the door of the loading flask;
-8~ 21~
Figure 27 is the front view of yet another skip;
Figure 28 is a side view of the skip of Figure 27; and
Figure 29 is a detail of a side of the skip of Figure
28, illustrating the operation of the door of the skip.
Throughout the drawings, like reference numerals
are used to refer to similar parts, where practical.
Referring firstly to Figures 1 and 2, a skip 10
is mounted in a Job's bridle 12 on a pivot shaft 14 and is
prevented from swinging within the bridle by means of a
lock 16. The bridle may be of a conventional construction
and may be capable of receiving a man cage shown i,n solid
lines at 18 in place of the ~kip, in the manner illustrated.
The bridle has suitable guides 20 for co-
operating with a guide assembly in a mine shaft to guide
the bridle for movement in a vertical direction. The skip
10 is mounted relatively high in the bridle for overrun in
the head gear so that the head gear can be as low as
possible.
The skip has a body 22 comprising a front wall
24, a rear wall 26, and side walls 28, and is of substantially
rectangular cross-section in plan view along the major
part of its leng~h. At its upper end the body is provided
with a feed opening 30 for receiving material from a
loading flask 32 and a feeder chute 34 (see Figures 6 to
9) .
9 1 162I6~
Instead of being mounted in the ~ob's bridle 12,
the skip could be a bridle-less skip, as shown in Figures
3 and 4. This ski~ has a carrier 36 secured to its upper
end and is provided with guide shoes 38 secured to the
skip by suitable brackets, the guide shoes being arranged
for co-operating with the guide assembly 38.1 (Figure 5)
of a mine shaft for guiding the skip. Apart from these
differences, the skips of Figures 1 and 2 and Figures 3
and 4 are of similar construction and like reference
numerals are used to refer to like parts.
The bottom of each skip is partially closed by a
sloping bottom 40 which is inclined downwardly at a
suitable angle with respect to the walls and extends over
approximately half of the width area of the bottom of the
skip. A discharge opening is defined between the lower
region of the sloping bottom 40 and three walls of the
body and is normally closed by a door 42.. The door and
body can be provided with wear plates 44 in a suitable
manner.
The door 42 of each skip is normally held in its
closed condition by a door control mechanism 46 including
over-centre mechanisms 48 and followers SO in the form of
tipping wheels. As shown in the drawings, each over-
centre mechanism comprises an arm 52 which is fast with
the door or with a shaft 52.1 secured to the door for
movement with the door; a bell-crank lever 54 pivotally
mounted on a bracket 56 carried by the sloping bottom 40
1 1621~)
--10--
of the qkip, and a connecting link 58 pivotally connected
to the arm 52 and the bell-crank lever 54. A stop (not
shown) is provided for limiting the pivotal movement of
the levers 54 in an anti clockwise direction as seen in
Figure 4 50 that the lever cannot pivot beyond the
posi-tion shown in Figure 4. Each follower 50 is rotatably
mounted on the opposite end of the respective bell-crank
lever to the link 58.
Each over-centre mechanism is such that, with
the door in its normal closed condition shown in Figure 4,
it i9 held in an over-centre position by the weight of and
on the door and the weight of the follower 50.
Each ikip is arranyed to be used with a skip
head which includes a cam track provided in a t.ipping path
so that when the ~kip moves upwardly the follower 50 moves
into the tipping path and along the cam track. This
causes the over-centre mechanism to be moved from its
over-centre position and to allow the door to open. The
cam track is designed so that the follower will return the
over-centre mechanism to its over-centre position and
close the door when the skip moves downwardly in the shaft
after material has been discharged from the skip.
In order to feed a suitable quantity of material
into the skip of Figures 1 and 2 or 3 to 5, the loading
flask 32 and feeder chute 34 are provided. The loading
flask is of similar construction to the skip of Figures 3
1 16216n
and 4 and like reference numerals are used to refer to
like parts. The flask thus has downwardly diverging walls
and a door control mechanism including an over-centre
mechanism similar to that in Figure 3 to 5, although the
over-centre mechanism is a composite mechanism operated by
pneumatically controlled ram 60 instead of tipping wheels
because the loading rlask is not moved in the same way as
the skips.
Material can be supplied into the loading flask
from a conveyor 62 or in any other suitable manner and the
door 42 of the flask is held closed until surficient
material is received in the loading flask. Once sufficient
material is in the loading flask and a skip has been
located in a position where its feed opening 30 is beneath
the lower end of the feed chute 34, the door 42 can he
opened by means of the ram ~0 to allow material to flow
from the loading flask and down the feeder chute into the
skip.
The door moves to a fully open position
(represented in chain lines 64 in Figure 7) and supplies
material into the feeder chute. The feeder chute (Figures
8 and 9) then guides the material into the hopper, the
feeder chute being at a steeper angle than the door over
at least the major part of its length. This has the
advantage that material flowing from the loading flask and
across the door will be able to follow a relatively
natural path into the skip being filled, rather than all
-12- l 16216~
being directed by the.feeder chute against the opposed
wall o~ the skip. Rai~s 66 (Figures 8 and 9l help to
prevent undesirable-escape of material from the feeder
chute.
Instead of the loading flask of Figures 6 and 7,
the loading fla~k 70 of F.igures lO and ll may be used.
This loading flask has a body of almost identical
construction to that of Figures 6 and 7 and is filled in
the same way.
The loading flask 70 has a door 72 mounted on
door trunnions 74 to enable the edge of the door to be
located close to the sloping bottom of the flask~ thus
restricting escape of material, whether the door is in its
open or its closed condition las described in more detail
with reference to Figures 17 to l9).
Locking plates 76 are mounted on side plates 78
of the door and are engageable by locking pins 80 carried
by pi~tons in pneumatic locking cylinders 82. The door is
movable by drive cylinders 84 having pistons connected to
connecting rods 86 which are themselves connected to drive
pins 88 on the plates 78, the rods containing slots 90 to
allow limited lost motion.
The cylinders 82 have small diameter pistons
which are relatively rapidly acting, and the cylinders 84
have larger diameter pistons ~hich move relatively slowly.
-13- l~6216n
The pistons are operable by a pneumatic control valve
system (not shown) of suitable form. When the valve
system is initially- operated, the pins 80 are withdrawn
rapidly from the locking plate and the rods 86 take up the
lost motion provided by the slots 90 while this is
happeni,ng. The cylinders 84 then move the rods until the
door 72 is fully open, as shown at 92. The loading
flask thus discharges its contents into the chute 34,
where it follows a relatively natural discharge path in
the manner described above with reference to Figures 6 to
9.
When material is fed into a skip from either of
the loading flasks described above, it will adopt an angle
of repose which depends to some extent on the manner in
which it is supplied into the skip. However, its upper
surface 68 will normally be inclined to the horizontal.
This has the disadvantage that it causes the skip to try
to pivot within the guide assembly of the shaft in which
the skip is moving. This results in wear on the shoes,
guide rollers, brackets, or other parts used for guiding
the skip. To help reduce this wear, the sloping bottom 40
is arranged so that it is below the side of the material
which is lowest in the fully loaded skip, and the door
control mechanism is partly mounted below the sloping
bottom and is thus also at or below the side of the
material which is lowest in the skip. The mass of the
door control mechanism can therefore help to balance the
loaded skip and this can help to reduce unnecessary wear.
~14- l lB21~
It will be appreciated that the skip, loading
flask and feeder chute described above can therefore help
to reduce wear in the skip and in the guide assemblies for
the skip, as in the loading flasks.
Referring now to Figures 12 to 16, a skip 94 has
a body which is similar to that of Figure 4, although the
number of guide shoes 38 ma~ be different. A door 96
having side plates 98 is mounted on the bod~y by trunnions
lO0, allowing edges of the sloping bottom of the skip and
of the door to lie adjacent to one another whether the
door i5 open or closed, as described in more detail for
Figures l7 to l9. The trunnions also enable the base and
door to form a substantially continuous discharge surface
when the door is open.
The door 96 and the sloping bottom of the skip
are rubber-lined, the lining covering the junction hetween
the door and bottom.
The door is held in position by a door locking
mechanism 102 including locking arms 104 pivotally mounted
on pivot shafts 106 on each side of the skip. The arms
carry locking shoes 108 which, in operation, engage wedges
llO on the side plates 98. The shoes 108 and wedges llO
engage in generally vertical planes which are slightly
inclined to the axis of the skip to prevent jamming.
-15- ~ 182~6n
The locking arms are in the form of bell crank
levers and carry monkey wheels 112 for engaging monkey
rails 114 (Figure 14). The monkey wheels engage the
monkey rails when in the locked position and, as the skip
is raised, come to engage a curved part of the rail to
pivot the arms 104 and release the locking shoes 108 from
the wedge~ 110. The locking mechanism is thus released as
the skip moves to the position shown in Figure 14.
Tipping rollers 116 are provided on the side
plates 98 and move into tipping paths 118 when the skip is
raised sufficiently. Thus, when the locking mechanism 102
is released, the door 96 is not able to swing freely to
its open position but instead is restrained by the rollers
116 in the tipping paths.
As shown in Figure 14, the lower part of each
tipping path defines a guide 118.1 for guiding the
respective roller into the path and, after an initial
straight surfaces 118.2 corresponding to the position
where the locking mechanism is released, the inner surface
of the tipping path is curved sharply at 118.3 to allow
the door to open. By suitably curving the paths in this
way, it is possible to ensure that the door moves smoothly
to its open position. The inner surface of the tipping
path then continues straight upwards at 118.4 initially to
hold the door in place and to inhibit oscillations of the
door.
16- ~ 16216n
.
When the skip moves downwardly, the wheel 116
moves down~ardly onto a curved platform 115 of the outer
surface of the tipping path which supports the wheel 116
as the skip moves downwardlv. When the skip has moved
down to a sufficient extent the wheel 116 moves between
surfaces 118.2 so tha-t the door is closed and is held
closed by the tipping ~heels and tipping paths until the
locking mechanism serves to lock the door once more.
In order to prevent the action of the tipping
paths on the tipping wheels from,pressing the guide shoes
38 hard against the shaft guide and causing undue wear and
inaccurate operation of the skip, guide wheels 120 can be
provided on the skip body for engaging the monkey rail, or
on the shaft for engaging suitable members on the skip
body. These guide wheels serve to keep the skip aligned
in the shaft.
As with the skip of Figures 3 and 4, the
positioning of the components, including the locking
mechanism, can help to balance the skip.
In each embodiment, the bottom and the door are
mounted on trunnions and have plates 122 providing upper
supporting surfaces 124 (Figures 17 to 19) for supporting
material in the flask or skip. A trunnion 126, a door 128
and a bottom 130 are shown in Figures 17 and 19 to
exemplify this arrangement. As shown, the door and bottom
have strengthening members 132 and the trunnions at
1 l62lsn
-17-
opposite sides of the door are connected to these members
to allow the door to pivot about -the axis of rotation of
the trunnions. The adjacent edges of surfaces 124 meet at
the axis 134 so that, when the door is pivoted from the
closed position of Figure 17 to the open position of
Figure 18, the adjacent edges remain substanti.ally in
contact to prevent passage o~ material between the
surfaces 124. A liner 136 of suitable rubber can cover
the surfaces 124 and the junction between them as
illustrated in Figure 19.
The skip of Figures 20 to 23 is similar to that
of Figures 1 and 2. The skip 10 is mounted in a ~ob's bridle
12 on a pivot shaft 14 in seats 15 and is prevented from
swigning within the bridle by means of a releasable lock 16.
The bridle may be capable of receiving a man cage in place of
the skip, by pivoting the skip to bank level in the manner .
illustrated in Figure 22, lifting the shaft 14 from seats
15, and locating a man cage shaft in the seats 15 in
place of the shaft 14. The bridle may be extended down-
wardly to receive a multi-deck cage if desired.
Figures 27 to 29 show a bridle-less skip similar
to that shown in Figures 3 to 5.
The doors 42 of the skips of Figures 20 and 27
are normally held in a closed condition by composite door
con-trol mechanisms each including over-centre mechanisms
48 on opposite sides of the respective body. These mechanisms
-18- 1 16216n
each include a follower 50 in the form of a tipping wheel, an
anll 52 which is pivotally connected to a respective bracket on
the door for moving the door, and a plate forming a bell crank
lever 54 having one ena region pivotally mounted on a trunnion
138 carried by a respective side 2~ of the skip. The opposite
end portion of each lever 54 is connected to the respective arm
52 and the central portion of the lever carries the respective
follower 50.
In each of these two skips, the extent of movement of
the lever 54 once the mechanism moves to its over-centre
position may ~e limited in any suitable manner, for example by
slightly cranking the arm 52 at 140 so that, with the door in
its normal closed condition, it rests against the supporting
shaft 142 of the trunnion 138. The arm is cranked to such an
extent that an imaginary line 144 joining the pivotal connections
of the arm to the door and to the lever 54 is on the opposite
side of the pivot axis of the trunnion 138 to that which it
normally is in when the door is opening. Forces applied to the
closed door to open the door thus provide a reaction along the
imaginary line and increase the locking effect of the mechanism.
To open the door it is necessary to move the imaginary line 144
from the position of Figure 21 or 28 to the opposite side of
the pivot axis of the trunnion by pivoting the lever 54.
To pivot the levers 54, each skip is thus used with
a skip head which includes cam tracks 146 shown in chain lines
and each providing a tipping path for engagement by a respective
follower 50 so that when the skip moves upwardly the follower
-19- 1 1621~n
50 moves into the tipping path and along the cam track. This
causes the over-centre mechanisms to be moved from its over-
centre position in the direction of arrow 148 and to open the
door and the rollers follow the outside -tracks 146.1 until the
door is fully open.
The cam tracks 146 control the whole opening
operation of the door and cause the door to move from position
150 to position 152 while the followers are in the cam tracks.
The cam tracks will guide the followers to return the over-
centxe mechanisms to the over-centre position and close the
door when the skip moves downwardly in the shaft after material
has been discharged from the skip.
In order to feed a suitable quantity of
material into these two skips, the loading flask 32 of FigurPs
24 to 26 and a feeder chute 34 are provided. The loading
flask is of sim.ilar construction to that of Figures 6
and 8 and like reference numerals are used to refer to
like parts. The flask thus has downwardly diverging walls
and a door control mechanism, although the door control
mechanism is operated by a pneumatically controlled ram 154
as the loading flask is not moved in the same way as the
skip.
Material can be supplied into the loading flask
from a conveyor or in any other suitable manner and the
-20- ll621~n
door 42 of the flask is held closed until sufficient
material is received in the loading ~lask. Once su~ficient
material is in the loading flask and the skip has been
located in a position where its feed opening is between
the ]ower end of a feed chute associated with the flask,
the door 42 of the flask can be opened by means of the
door control mechanism to allow material to flow from the
loading flask and down the feeder chute into the skip.
The apexes of bell crank levers 54 at opposite
sides of the body of the flask are each pivotally mounted
on pivot pins 156 carried by brackets and a shaft 158
on the body of the flask and one end of each lever 54 is
pivotally connected to a connecting link 140 extending
from the ram 154 by a shaft 162. Each lever 54 may be a
single cranked element or a composite lever comprising a
lever arm adjacent to the side of the flask and a further
lever arm fixed on a common shaft with the first lever arm
but located closer to the centre of the flask. The door
is itself pivotally connected to the opposite ends of the
bell crank levers to the link 160 by connecting rods 164.
The rods 164 in Figure 25 are shown in an over-centre
position with a line 166 between the pivots for the rod 164
on the opposite side of the pivot axis of the lever 54 to
that which is normally adopts while the door is opening.
Load applied to the door will thus tend to increase the
locking effect of the door control mechanism~
-21- ~16216n
The ram 154 has a suitably large diameter piston
which moves relatively slowly and is operable by a
pneumatic control valve system (not shown). When the
valve system is initially operated, the ram 154 moves the
link 160 to pivot the levers 54. This initially moves the
rods 164 from their over-centre positions and line 166
moves across the axis of rotation of the levers 54 and
then continues to move the rods until the door is fully
open as shown in Figure 26. The loading flask thus
discharges itscontents into the chute which guides it into
the skip.
The basic features of the skip of Figures 27
to 29 and its operation have been described in general
terms together with reference to the skip of Figures 20
to 23. However, because the skip is bridle-less and the
over-centre mechanisms are located closer to the front 24
of the skip than to rear 26, the bottom cross-head 168 of the
skip is eccentrically mounted so that its load is applied
largely towards the rear of the skip to balance the skip.
Furthermore, in the embodiment of Figures 27 to 29,
deflectors 170 are mounted so that they extend over the
major parts of the over-centre mechanisms without
preventing the tipping wheels from entering the cam tracks
146. These deflectors can help to prevent dirt from
falling onto the mechanisms.
-22~ t 16216()
In each of the skips and flasks shown in the
drawings, the opposed pairs of walls, i.e. the opposed front
and rear walls and the opposed side walls, diverge down-
wardly so that the chamber widens dGwnwardly to facilitate
downward flow of material within the skip and to eliminate
undue wear on the walls as the material flows downwardly
within the skip to be discharged from the skip.
