Information
-
Patent Grant
-
6481933
-
Patent Number
6,481,933
-
Date Filed
Monday, November 6, 200024 years ago
-
Date Issued
Tuesday, November 19, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Shackelford; Heather
- Lagman; Frederick L.
Agents
- Cook, Alex, McFarron, Manzo, Cummings & Mehler, Ltd.
-
CPC
-
US Classifications
Field of Search
US
- 405 296
- 405 288
- 405 290
- 405 291
- 405 292
- 405 293
- 405 294
- 405 295
- 405 297
- 405 299
- 405 300
- 405 301
- 405 302
- 299 11
- 299 12
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International Classifications
-
Abstract
It is provide in a powered support frame, for large seam thicknesses with controlled gap sealing, that double acting gap cylinders (16, 27, 30) of several gap sealing elements (15) on a powered support frame are connected to a common pressure feed line (34, 37, 39) and to a common pressure return line (50) and are impacted with a uniform pressure when the gap sealing elements are to be extended.
Description
THE FIELD OF THE INVENTION
The present invention relates to a powered support frame, especially in the form of a shield support, with a roof cap, a gob shield and a linking arrangement to join the gob shield to a ground frame, whereby the powered support frame is provided on both sides on its roof cap and on its gob shield with a laterally extensible gap sealing plate element and with at least one gap cylinder, configured as a hydraulic cylinder, to extend the gap sealing plate elements.
A powered support frame with the above features is described in DE 28 22 368 A1; the powered support frame has a laterally extensible gap sealing plate arranged both on the roof cap and on the gob shield. In each case a hydraulic positioning cylinder is provided for the lateral extension of the gap sealing element concerned.
The gap sealing elements serve not only for the sealing of a gap arising between two support frames, against rock fall from the roof and from breaking out in the case of face equipment, but also for the alignment of the individual support frames normal to the stratification between the roof and the floor on the one hand, and in the direction of face advance to their halt against a face conveyor on the other hand, so that when the face conveyor connected to their advancing mechanisms moves, the support frames can follow on a preferred line.
There is the problem, especially in support frames provided for very large seam thicknesses, for instance between 3 meters and 6 meters, that the alignment of the individual support frames is difficult to handle using the individual controls for each positioning cylinder for each gap sealing element. This problem is exacerbated if saddles and troughs occur and/or the floor undulates in the direction of the mining. In difficult mining conditions of this type the adjacent support frames must be aligned on the one hand convergent, and on the other divergent, so that the support frames can have, for instance in the region of their gob shields, a substantially smaller separation from each other than in the region of their roof caps.
SUMMARY OF THE INVENTION
The present invention therefore has the aim of improving a powered support frame as previously described, such that even with very large seam thicknesses a good alignment of the support frames to the face conveyor is simple to contrive.
In accordance with the present invention, double acting gap cylinders of the gap sealing elements are connected to a common pressure feed line and to a common return line and are activated with a uniform working pressure when the gap sealing elements are to be extended, so that all the gap cylinders, joined and communicating with each other, of the gap sealing elements on a support frame for bridging a gap to an adjacent support frame, effect a floating activation of the individual gap sealing elements until they impact on the gap sealing elements of the adjacent support frame. Owing to the connection of all the gap cylinders to a uniform pressure supply with the prescribed working pressure each gap cylinder extends the gap sealing element connected to it as far to the side until, under the prescribed pressure, this abuts the adjacent support frame or its extended gap sealing element. In this manner the work requirement for the alignment of the individual regions of individual support frames is avoided, since the support frames, owing to the floating actuation of their lateral gap sealing elements, automatically assume their optimum positions with respect to each other.
In accordance with one embodiment of the invention, in the region of the linking arrangement an additional gap sealing element is provided, so that especially with large seam thicknesses, an additional sealing and alignment facility is provided.
Possibly, several gap cylinders are provided, distributed over the extent of each gap sealing element.
For very large seam thicknesses, the gaps arising between adjacent support frames can become so large when saddles and troughs occur in the direction along the face, that the working region of an individual hydraulic cylinder of conventional design is insufficient. Therefore, according to one embodiment of the invention, for the extension of each gap sealing element a gap cylinder arrangement is provided comprising two individual cylinders arranged in series with each other, with one inner cylinder and one outer cylinder with respect to the center line of the support frame. The working range of the gap cylinder arrangement is thereby increased in an advantageous manner with respect to the alignment of the support frames to each other and to the face conveyor. Possibly, on the pressure side the inner cylinder is connected to a common pressure feed line and the outer gap cylinder to a further common pressure feed line, and on the return side the inner gap cylinder and the outer gap cylinder are connected to a common return line.
With regard to especially difficult deposit conditions, this increase in the working range can also be used to reduce the normal width of an individual support frame, and to configure the working region of the two gap cylinders positioned on either side so that the inner gap cylinders in their extended position first set the normal width of a support frame. Further to this, the possibility still exists of undertaking the necessary alignment of the support frame using the working range of the outer gap cylinder.
According to one embodiment of the invention it is proposed that the inner gap cylinder and the outer gap cylinder can be actuated by the working pressure in a time sequence, whereby a non-return valve is arranged between the pressure supply and the first, inner, gap cylinder. Thereby, the inner gap cylinder can first be extended and established in the required extended condition by the non-return valve; following this the alignment of the support frame concerned can be undertaken by controlling the outer gap cylinder by means of a separate valve arrangement.
Alternatively, the inner gap cylinder and the outer gap cylinder can be simultaneously charged with the working pressure. In this case all the gap cylinders of the currently realised gap cylinder arrangements extend over their working range depending on the gap to be bridged, so that thereby even extreme convergences or divergences can be bridged.
With regard to relieving the load due to cross forces arising on individual gap cylinders, in accordance with one embodiment of the invention the gap sealing elements are guided by means of bolt guides on an associated component of the support frame. This construction of guidance of a gap sealing element on a component of a support frame carrying it is described in outline in DE 28 53 050 C2. Here, however, a longitudinal boring, carrying the guiding bolts, is arranged in the associated component of the support frame and is thus poorly accessible and difficult to assemble. It is therefore proposed that the gap sealing elements, formed in an angle-shape, have, on arms aligned to the component of the support frame carrying them, sleeving attachments with a longitudinal boring arranged in them, which engages so as to encompass a bolt arranged on the component. Additionally, in the longitudinal boring of the attachment, a pressure spring can be arranged supporting itself between the deepest parts of the longitudinal boring and the component, engaging around the outside of the bolt and guided by the bolt against buckling.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention, which is described below, is shown in the drawings, wherein:
FIG. 1
is a section of a face installation comprising several support frames arranged adjacent to each other in a front view as seen from the face;
FIG. 2
is an individual support frame in a side view;
FIG. 3
is an arrangement of two gap sealing elements on both sides of a support frame in an embodiment on a gob shield; and
FIG. 4
is a hydraulic circuit plan in a simplified representation for the control of the gap cylinder arrangement present on a support frame.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The front view, which can be seen in
FIG. 1
, of a part of a face installation, shows six adjacently arranged support frames
10
, whose ground frames
12
stand in the direction along the face (double arrow
51
) upon an undulating, i.e. with saddles and troughs, bottom wall
11
. Props
14
are supported on the ground frame
12
, which carry a roof cap
13
. Each support frame
10
is equipped on both sides with gap sealing elements
15
, which can be extended sideways, using individually arranged gap cylinder arrangements
16
, to the adjacent installation, so that an alignment of the support frame
10
, converging and diverging to the roof, can be effected.
As is more clearly seen from
FIG. 2
, a first gap sealing element
15
is arranged in the region of the roof cap
13
, shown formed in several parts in the embodiment depicted; a further gap sealing element
15
is positioned in the region of the gob shield
17
, and finally a gap sealing element
15
is also arranged on the guide bars
19
joining the ground frame
12
to the gob shield
17
. The gap sealing elements
15
are retained on the components
13
,
17
,
19
of the support frame
10
carrying them by gap cylinder arrangements
16
and can extend sideways, whereby to relieve the gap cylinder arrangements
16
from cross forces, bolt guides
20
are arranged between each gap sealing element
15
and the associated component
13
,
17
,
19
of the support frame
10
, which can be seen in detail in FIG.
3
.
On the associated component of the support frame, in this case a gob shield
17
, the gap sealing elements
15
, angularly formed with an upper abutment arm
21
and an alignment arm
22
, are arranged on both sides so as to slide, whereby the alignment arm
22
of the gap sealing element
15
has an attachment
23
extending inside it, and projecting to the gob shield
17
, and having a longitudinal boring
24
, which engages around a bolt
25
, fastened to an intermediate wall
18
of the gob shield
17
, and is guided by positive engagement on it. In the longitudinal boring
24
a pressure spring
26
is arranged, supported against the deepest part of the longitudinal boring
24
at one end and against the intermediate wall
18
at the other end, which is guided on the outer periphery of the bolt
25
and is thereby secured against buckling. As already realised in the gap sealing described in DE 28 53 050 C2, the pressure spring
26
pretensions the individual gap sealing element
15
in its extended position, so that activation of the gap cylinder, comprising double acting cylinders
27
,
30
, generates the necessary pressure against each other for the active alignment of the support frame
10
in the extending direction, whilst on controlling the gap cylinders
27
,
30
in the direction of retraction the spring force of the pressure spring
26
has always to be overcome.
FIG. 3
shows further detail of the gap cylinder arrangement
16
for extending the associated gap sealing element
15
, which comprises two individual cylinders arranged in series, namely an inner gap cylinder
27
and an outer gap cylinder
30
, which are supported against each other. The piston rod of the inner gap cylinder
27
is attached to a tongue
28
fastened by means of a fastener
29
to the gob shield
17
, whilst the piston rod
31
of the outer gap cylinder
30
, the latter firmly fixed to the inner gap cylinder
27
, is fastened to a tongue
32
on the alignment arm
22
of the gap sealing element
15
by means of a fastener
33
. The right-hand half of
FIG. 3
shows the right-hand gap sealing element
15
fully retracted, whilst the left-hand part of
FIG. 3
shows a partly extended, that is by means of the outer gap cylinder
30
, gap sealing element
15
of the gob shield
17
.
The circuit plan depicted in
FIG. 4
for the control of the gap cylinder arrangements
16
and the individual gap cylinders
27
,
30
shows the gap cylinder arrangements
16
for the left-hand side
42
of a support frame, and for its right-hand side
43
, with the gap cylinder arrangement
44
for the roof cap
13
, the gap cylinder arrangement
45
for the gob shield
17
, and the gap cylinder arrangement
46
for the region of the guide bars
19
.
All the gap cylinder arrangements are supplied from a central pressure feed
34
, which divides in a branching
36
into a pressure feed line
37
for the inner cylinders
27
in each case, and into a pressure feed line
39
for the supply to the outer cylinders
30
, whereby a valve arrangement is connected into the pressure feed line
39
, comprising pilot valves
41
and main valves
40
.
A non-return valve
48
and a ball valve
47
are connected into the pressure feed line
37
for the supply to the inner gap cylinders
27
, whereby through a second switch position of the ball valve
47
a connection between the pressure feed line
37
for the inner cylinder
27
and the pressure feed line
39
for the outer cylinder
30
can also be set up to a branching
49
and a branch line
49
a.
All the gap cylinders
27
,
30
of all the gap cylinder arrangements are connected to a common return line
50
, which leads via the valve arrangement
40
,
41
to the return. The circuit is completed by a pressure limiting valve
52
connected to the pressure feed line
37
for the inner cylinder
27
.
The circuit condition illustrated in
FIG. 4
shows the starting position, in which the gap cylinders
27
,
30
are actuated on the pressure side in the retracting direction, so that the gap cylinders
27
,
30
overcome the force of the pressure springs
26
, which are pre-tensioned in the extending direction of the gap sealing elements
15
and hold the gap sealing elements
15
always in contact with the associated components
13
,
17
,
19
of the support frame
10
. To this end the pressure feed
34
is connected via the valve arrangement
40
,
41
to the line designated return line
50
, so that through this control the side of the piston working in the direction of retraction in the individual gap cylinders
27
,
30
is impacted with pressure; in this switching condition the lines designated as pressure feed lines
37
,
39
work as return lines and are connected via the valve arrangements
40
,
41
to the return
35
. Also shown is the position of the ball valve
47
, which joins the line
37
to the line
39
, so that a common return is effected.
If the gap sealing elements
15
are now to be extended, in a first step the ball valve
47
can be switched to the position shown separately in
FIG. 4
, in which the connection between the inner gap cylinders
27
and the pressure feed line
34
is set up via the ball valve
47
and the non-return valve
48
; in this control phase the valve arrangement
40
,
41
still blocks the pressure feed line
39
to the outer gap cylinders
30
. If the inner gap cylinders
27
are extended, then they are locked in their final position by the hydraulic fluid return flow being prevented by the non-return valve
48
. In a second switching step the associated main valve
40
/
1
and
40
/
3
are brought via the pilot valve
41
/
1
and
41
/
3
into that circuit position in which the pressure feed line
39
is switched through to the outer gap cylinders
30
, and in this position the outer gap cylinders
30
are charged with the working pressure, so that they actuate the gap sealing elements correspondingly. At the same time the return line
50
common to all the gap cylinders
27
,
30
is connected via the main valve
40
/
2
and
40
/
4
to the return
35
.
If, during the control effecting the extension of the gap cylinders
27
,
30
, the position of the ball valve
47
is retained in the position shown in the circuit plan, then the inner gap cylinders
27
and the outer gap cylinders
30
are connected simultaneously and together to the central pressure source
34
, so that in each case alignment of the gap sealing elements
15
is effected by both individual cylinders of the gap cylinder arrangement. In this setting the connection between the pressure feed
34
and the pressure feed line
37
is blocked to the inner gap cylinders
27
, whereby in this setting of the ball valve
47
the pressure feed line
37
is connected to the pressure feed line
39
via the branch line
49
a
and the branching
49
. If now a suitable switching of the main valve
40
onto the pressure feed line
34
is made, then both the inner gap cylinder
27
and the outer gap cylinder
30
lie together and simultaneously on the pressure feed line
34
.
Claims
- 1. A powered support frame, especially in the form of a shield support, with a roof cap, a gob shield and a guide bar arrangement to join the gob shield to a ground frame, whereby the support frame is provided on both sides on its roof cap and on its gob shield with in each case a sideways extensible gap sealing element, and for the extension of each gap sealing element at least one gap cylinder, configured as a hydraulic cylinder and being double acting, is arranged, in which the gap cylinders of the several gap sealing elements are connected to a common pressure feed line and to a common return line and are impacted with a uniform working pressure when the gap sealing elements are to be extended, so that all the connected, mutually communicating gap cylinders of the several gap sealing elements to be found on a support frame effect a floating actuation of the individual gap sealing elements to bridge a gap to an adjacent support frame up to the abutment onto the gap sealing element of the adjacent support frame.
- 2. A powered support frame according to claim 1, in which an additional gap sealing element is provided in each case in the region of the guide bar arrangement.
- 3. A powered support frame according to claim 1, in which several gap cylinders are arranged along the extent of each gap sealing element.
- 4. A powered support frame according to claim 1, in which for the extension of each gap sealing element a gap cylinder arrangement is provided comprising two individual cylinders arranged in series with each other, being an inner gap cylinder and an outer gap cylinder, with respect to the center line of the powered support frame.
- 5. A powered support frame according to claim 4, in which on their pressure side, the inner gap cylinders are connected to a common pressure feed line and the outer cylinders to a further common pressure feed line and on their return side the inner gap cylinders and the outer gap cylinders are connected to a common return line.
- 6. A powered support frame according to claim 4, in which the inner gap cylinder and the outer gap cylinder can be impacted with the working pressure in a time sequence.
- 7. A powered support frame according to claim 6, in which a non-return valve is connected between the pressure feed and the first inner gap cylinder.
- 8. A powered support frame according to claim 4, in which the inner gap cylinder and the outer gap cylinder can be impacted with the working pressure simultaneously.
- 9. A powered support frame according to claim 1, in which the gap sealing elements are guided on the associated component of the powered support frame by means of bolt guides.
- 10. A powered support frame according to claim 9, in which the gap sealing elements are configured as angle shapes having alignment arms with attachments extending to the component of the powered support frame and having a longitudinal boring in the attachments which engages and surrounds a bolt arranged on the component.
- 11. A powered support frame according to claim 10, in which in the longitudinal boring of the attachment a pressure spring is arranged supported between the deepest part of the longitudinal boring and the component, the spring engaging the bolt on its outside and being protected against buckling by the bolt.
Priority Claims (1)
Number |
Date |
Country |
Kind |
199 53 526 |
Nov 1999 |
DE |
|
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Number |
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A |
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Sep 1974 |
A |
3911686 |
Becker et al. |
Oct 1975 |
A |
4010618 |
Walker et al. |
Mar 1977 |
A |
4092831 |
Lubojatsky et al. |
Jun 1978 |
A |
4217067 |
Lagodka et al. |
Aug 1980 |
A |
4293247 |
Rosenberg et al. |
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A |
4432673 |
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Feb 1984 |
A |
4586851 |
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A |
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Number |
Date |
Country |
2822368 |
May 1978 |
DE |