U.S. patent number 4,156,236 [Application Number 05/876,040] was granted by the patent office on 1979-05-22 for mine roof movement monitor.
Invention is credited to Ellsworth V. Conkle.
United States Patent |
4,156,236 |
Conkle |
May 22, 1979 |
Mine roof movement monitor
Abstract
Movement of the roof of a mine shaft is detected by unlatching
of a position sensing device in an elevated position causing it to
drop to a lowered position pivotally suspended by a link from a
bracket yieldably held in abutment with the roof ceiling. The
bracket is positioned on the lower end of an elongated support bolt
by a nut acting as a latch releasing member engageable with a latch
element connected to the link for latched support of the sensing
device in the elevated position.
Inventors: |
Conkle; Ellsworth V. (Paonia,
CO) |
Family
ID: |
25366864 |
Appl.
No.: |
05/876,040 |
Filed: |
February 8, 1978 |
Current U.S.
Class: |
340/690;
405/259.1; 73/784 |
Current CPC
Class: |
E21F
17/185 (20130101); E21D 21/0093 (20130101) |
Current International
Class: |
E21F
17/00 (20060101); E21D 21/00 (20060101); E21F
17/18 (20060101); E21D 021/00 (); G08B
021/00 () |
Field of
Search: |
;340/690,686 ;324/52
;200/61.53 ;73/784 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Yusko; Donald J.
Attorney, Agent or Firm: O'Brien; Clarence A. Jacobson;
Harvey B.
Claims
What is claimed as new is as follows:
1. In combination with an elongated support anchored to the roof of
a mine shaft and having a lower end portion projecting into the
mine shaft through an opening in the roof ceiling, a monitor
assembly mounted on said lower end portion of the support for
detecting displacement of the roof, comprising a bracket positioned
on said support, a position sensing device pivotally suspended from
the bracket for gravitational displacement from an elevated
position to a lowered position, latch means for holding the
position sensing device in the elevated position, and means fixed
to the lower end portion of the support for releasing the latch
means in response to displacement of the bracket relative to the
support.
2. The combination of claim 1 including indicator means connected
to the sensing device and rendered operative thereby in the lowered
position for signifying displacement of the roof.
3. The combination of claim 2 wherein said latch releasing means
comprises a latch engaging member adjustably secured to the
support, and spring means engageable with said member for yieldably
holding the bracket in abutment with said roof ceiling.
4. The combination of claim 3 wherein said position sensing device
includes a frame, a suspension link connected to said frame, pivot
means connecting the link to the bracket for pivotal displacement
of the frame about an axis substantially parallel to said roof
ceiling at the opening therein, and position responsive switch
means carried on the frame to which the indicator means is
connected.
5. The combination of claim 4 wherein said latch means includes an
elongated latch element pivotally connected to the suspension link
and a latch pin mounted on the bracket and engageable with the
latch element, said latch element having a pair of recesses formed
therein respectively receiving the latch pin in a latched condition
and the pivot means in the lowered position of the sensing device,
said link and latch element forming a triangular relationship with
the bracket in the latched condition to support the sensing device
in the elevated position, said latch pin abutting the link in the
lowered position of the sensing device to act as a one-way
stop.
6. The combination of claim 1 wherein said position sensing device
includes a frame, a suspension link connected to said frame, pivot
means connecting the link to the bracket for pivotal displacement
of the frame about an axis substantially prallel to said roof
ceiling at the opening therein, and position responsive switch
means carried on the frame to which the indicator means is
connected.
7. The combination of claim 6 wherein said latch means includes an
elongated latch element pivotally connected to the suspension link
and a latch pin mounted on the bracket an engageable with the latch
element, said latch element having a pair of recesses formed
therein respectively receiving the latch pin in a latched condition
and the pivot means in the lowered position of the sensing device,
said link and latch element forming a triangular relationship with
the bracket in the latched condition to support the sensing device
in the elevated position, said latch pin abutting the link in the
lowered position of the sensing device to act as a one-way
stop.
8. The combination of claim 1 wherein said latch releasing means
comprises a latch engaging member adjustably secured to the
support, and spring means engageable with said member for yieldably
holding the bracket in abutment with said roof ceiling.
9. In combination with an elongated support anchored to the roof of
a mine shaft and having a lower end portion projecting into the
mine shaft through an opening in the roof ceiling, a monitor
assembly mounted on said lower end portion of the support for
detecting displacement of the roof, comprising a bracket positioned
on said support, a position sensing device, a suspension link
pivotally connecting the sensing device to the bracket, latch means
connected to the link and engageable with the bracket for holding
the sensing device in an elevated position, release means fixed to
the lower end portion of the support for releasing the latch means
in response to displacement of the bracket relative to the support
to permit lowering of he sensing device to a suspended position,
and biasing means engageable with the release means for yieldably
holding the bracket in abutment with the roof ceiling.
10. The combination of claim 9 wherein said latch means includes an
elongated latch element pivotally connected to the suspension link
and a latch pin mounted on the bracket and engageable with the
latch element, said latch element having a pair of recesses formed
therein respectively receiving the latch pin in a latched condition
and the pivot means in the suspended position of the sensing
device, said link and latch element forming a triangular
relationship with the bracket in the latched condition to support
the sensing device in the elevated position, said latch pin
abutting the link in the suspended position of the sensing device
to act as a one-way stop.
11. The combination of claim 10 including indicator means connected
to the sensing device and rendered operative thereby in the
suspended position of signifying displacement of the roof.
12. The combination of claim 11 wherein said release means
comprises a latch engaging member adjustably secured to the
support, and spring means engageable with said member for yieldably
holding the bracket in abutment with said roof ceiling.
13. The combination of claim 10 wherein said release means
comprises a latch engaging member adjustably secured to the
support, and spring means engageable with said member for yieldably
holding the bracket in abutment with said roof ceiling.
Description
BACKGROUND OF THE INVENTION
This invention relates to detection of mine roof movements and is
an improvement over the movement monitoring apparatus disclosed in
my prior U.S. Pat. No. 3,646,553, issued FEB. 2, 1972.
In the movement detecting apparatus of the type disclosed in my
prior U.S. patent referred to, a sensing switch is mounted by a
housing on the roof ceiling in operative relation to a switch
actuator adjustably positioned on the lower end of the support bolt
through which the switch housing is yieldably held in abutment with
the roof ceiling. Sensitivity of the detecting apparatus depends,
therefore, in large measure, on the mounting and operating
characteristics of the sensing switch. Accordingly, the adjustment
setting of the switch actuator is not always reliable and changes
in sensitivity sometimes occurs even through no adjustment is made.
Further, replacement of the sensing switch requires readjustment
and is rather difficult without complete disassembly of the
apparatus.
It is, therefore, an important object of the present invention to
provide an improved movement detecting apparatus of the
aforementioned type which includes a sensing switch that does not
effect sensitivity adjustment and may be replaced without
disturbing such adjustment.
SUMMARY OF THE INVENTION
In accordance with the present invention, a position sensing device
is pivotally suspended by a suspension link from a bracket
yieldably held in abutment with the roof ceiling of a mine shaft by
a nut adjustably secured to the lower end of a support bolt
suspended from a bore extending upwardly into the earth from the
mine shaft. The nut acts as a latch release member engageable with
the end of a latch element which automatically latches to form a
rigid support, with the bracket and the link, for the sensing
device in its elevated position. Movement of the bracket relative
to the support bolt in excess of a preset amount thereby causes the
latch element to release. The sensing device then drops to its
lowered position rendering an indicator operative such as a
reflector or a position sensing switch closing to energize an
indicator lamp.
These together with other objects and advantages which will become
subsequently apparent reside in the details of construction and
operation as more fully hereinafter described and claimed,
reference being had to the accompanying drawings forming a part
hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF DRAWING FIGURES
FIG. 1 is a side elevation view of the detecting apparatus of the
present invention installed in a mine shaft.
FIG. 2 is an enlarged elevation view of the apparatus as seen from
a plane indicated by section line 2--2 in FIG. 1.
FIG. 3 is an enlarged partial side elevation view of the apparatus
shown in a latched or armed condition.
FIG. 4 is an elevation view of the apparatus as seen from a plane
indicated by section line 4--4 in FIG. 3.
FIG. 5 is an enlarged section view taken substantially through a
plane indicated by section line 5--5 in FIG. 4.
FIG. 6 is an enlarged section view taken substantially through a
plane indicated by section line 6--6 in FIG. 2.
FIG. 7 is a schematic view illustrating the wiring associated with
one embodiment of the invention.
FIG. 8 is a schematic view illustrating the wiring associated with
another embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings in detail, FIG. 1 illustrates an
installation for the mine roof movement monitor of the present
invention generally referred to by reference numeral 10. The
monitor is shown mounted on the ceiling surface 12 of a generally
horizontal mine shaft located below the ground surface 14. The roof
of the mine shaft is accordingly formed by a plurality of earth
formation strata through which a vertical bore 16 is drilled
upwardly from the ceiling surface for insertion therein of an
elongated support formed by one or more bolts 18. The support bolts
are externally threaded adjacent opposite longitudinal ends and
where two or more are utilized, they are interconnected by double
threaded coupling nuts 20. The uppermost support bolt 18 has at
least two anchor clips 22 sandwiched between anchor nuts 24
threadedly positioned on the support bolt. The anchor clips are
bowed in such a direction, as shown, to engage the vertical sides
of the bore 16 adjacent its upper end and anchor the support bolt
18 at a location adjacent surface 14 of substantially no roof
movement. The lowermost support bolt 18 is connected to the monitor
10, extending through a sleeve 26 connected to the monitor 10.
As more clearly seen in FIG. 5, the sleeve 26 is internally
threaded adjacent its lower end for threaded connection to a
mounting bracket of the monitor generally referred to by reference
numeral 28. The mounting bracket 28 includes externally threaded
connector portion 30 threadedly received within the sleeve 26 and a
flange portion 32 abutting the ceiling surface 12 laterally of the
bore 16. The threaded portion 30 forms a slide bearing for tubular
member 34 having a flange 36 at its upper end. A coil spring 38
reacts between the flange 36 and the upper end wall 40 of the
sleeve 26 so as to exert an upward bias on the bracket 28 to which
the sleeve is connected by the threaded portion 30. The tubular
member 34 at its lower end abuts a nut member 42 threadedly mounted
on the lower end of the bolt 18. The axial bias of the spring 38
may be adjusted by rotation of the nut member 42 which also acts as
a latch release as will be explained hereinafter.
A pair of parallel spaced arms 44 depend from the bracket flange
32. A pivot shaft 46 is supported between the arms 44 in vertically
and laterally spaced relationship to a latch pin 48 which also
extends between the arms 44. The pivot shaft establishes a pivotal
axis generally parallel to the ceiling surface at the bore opening.
A link 50 is pivotally connected to the bracket 28 by the pivot
shaft 46 for pivotal support of a position sensing device generally
referred to by reference numeral 52. As more clearly seen in FIGS.
2 and 6, the sensing device 52 includes a peripheral frame 54 to
which the link 50 is pivotally connected by a pin 56 extending at
right angles to the pivot shaft 46. Accordingly, the device 52 may
be pivotally displaced in a plane at right angles to its
displacement about the pivotal axis of pivot shaft 46. The device
52 is either pivotally suspended in a lowered vertical position as
shown in FIGS. 1, 2 and 6 or latched in a horizontal elevated
position as shown in FIGS. 3, 4 and 5 by means of a latch element
generally referred to by reference numeral 58.
The latch element 58 is pivotally connected by pivot pin 60 to the
suspension link 50 between the pivot shaft 46 and pivot pin 56. The
latch element is provided with a recess 62 in one longitudinal edge
intermediate its opposite longitudinal ends so as to receive the
pivot shaft 46 therein in the unlatched condition when the sensing
device 52 is suspended in its lowered position as shown in FIG. 6.
In the latched condition with the device 52 in its elevated
position as shown in FIG. 5, the latch element 58 engages the latch
pin 48 in a latch recess 64. The latch element in its latched
condition will thus cooperate with the link 50 and bracket 28 to
form a rigid triangular support for the sensing device 52 in the
elevated position. The latch element is disengaged by an upward
force applied to a latch disengaging end 66 projecting from the
bracket arms 44, as shown in FIG. 5, which will lift the latch
element 58 off the latch pin 48. The weight of the sensing device
52 will then swing it downwardly about the pivot shaft 46 to the
lowered position shown in FIG. 6 in which the latch pin 48 abuts
the link 50, the latch element 58 being then held generally
parallel to the link 50 by abutment of the latch element with the
pivot shaft 46 in its recess 62. It will be apparent that the latch
pin 48 will then act as a one-way stop to limit clockwise movement
of the sensing device 52 as viewed in FIG. 6.
In the latched condition of the monitor as shown in FIG. 5, the
axial position of the nut member 42 on the lower end of the support
bolt 18 is closely spaced from the latch disengaging portion 66 so
that a predetermined axial movement of the bracket 28 relative to
the support bolt reflecting mine roof movement, will release the
latch element causing the sensing device 52 to drop from its
elevated position to the lowered position shown in FIG. 6. In the
lowered position shown, the contacts of a mercury switch 68 mounted
by the sensing device will close and thereby energize an indicator
lamp 70 to signify roof movement. The mercury switch 68 and
indicator lamp 70 may be enclosed by means of a transparent cover
72 and mounted on a back wall 74 attached to the peripheral frame
54. In the horizontal elevated position of the device 52, the
contacts of the mercury sensor switch 68 will be open so that the
indicator lamp 70 will be deenergized.
In one form of the invention, as shown in FIG. 8, the mercury
switch 68 and indicator lamp 70 are connected in series across the
terminals of a DC battery 76 mounted within the housing formed by
cover 72 and wall 74. In another embodiment of the invention shown
in FIG. 7, the mercury switch and indicator lamp are connected in
series with a remotely located indicator lamp 78 and audible
alerting device 80 to a remotely located source of electrical
energy by means of wiring extending through a grommeted opening 82
in the back wall 74 of the housing. As another alternative, the
indicator lamp 70, mercury switch 68 and cover 72 may be replaced
by a lens covered reflector reflecting light from machinery
headlights and miners' headlamps to indicate roof movement.
When initially installing the monitor 10, the nut member 42 is
threaded onto the lower end of the support bolt 18 and the sensing
device 52 elevated to the horizontal position to cause latch
element 58 to become latched. The nut member 42 is then rotated to
axially adjust its position on the support bolt until it engages
the end 66 of the latch element causing it to release. The nut
member 42 may then be backed off by a certain amount to provide the
desired sensitivity for the monitor. The sensing device 52 is then
relatched in its elevated position and will be armed for detecting
any roof movement causing displacement of bracket 28 relative to
the support bolt 18 in excess of a preset amount.
The foregoing is considered as illustrative only of the principles
of the invention. Further, since numerous modifications and changes
will readily occur to those skilled in the art, it is not desired
to limit the invention to the exact construction and operation
shown and described, and accordingly all suitable modifications and
equivalents may be resorted to, falling within the scope of the
invention.
* * * * *