CA1168459A - Mine roof plate beam for a roof truss assembly - Google Patents
Mine roof plate beam for a roof truss assemblyInfo
- Publication number
- CA1168459A CA1168459A CA000375647A CA375647A CA1168459A CA 1168459 A CA1168459 A CA 1168459A CA 000375647 A CA000375647 A CA 000375647A CA 375647 A CA375647 A CA 375647A CA 1168459 A CA1168459 A CA 1168459A
- Authority
- CA
- Canada
- Prior art keywords
- roof
- plate beam
- reinforcing rib
- plate
- mine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D17/00—Caps for supporting mine roofs
- E21D17/01—Caps for supporting mine roofs characterised by the shape of the cap, e.g. of specified cross-section
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/006—Lining anchored in the rock
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D17/00—Caps for supporting mine roofs
- E21D17/02—Cantilever extension or similar protecting devices
- E21D17/03—Brackets for roof-supporting bars
Abstract
TITLE
MINE ROOF PLATE BEAM FOR A ROOF TRUSS ASSEMBLY
ABSTRACT OF THE DISCLOSURE
An elongated plate beam has a plurality of long-itudinally extending downwardly directed ribs. The ribs are positioned in parallel spaced relation to form a pair of lateral ribs and a center reinforcing rib. The plate beam has a preselected length adapted to span the width of a mine passage and includes a top surface arranged to abut a mine roof and a bottom surface. A plurality of openings are spaced the length of the plate beam and extend through the center reinforcing rib. A roof plate is positioned in abutting relation with the plate beam bottom surface in overlying relation with each opening. Roof bolts extend through the roof plates and openings into engagement with the walls of bore holes drilled in the mine roof. An enlarged end of each roof bolt bears against the respective roof plate to apply an upward force upon the plate beam to position the plate beam in roof supporting relation with the mine roof the entire width of the mine passage spanned by the plate beam. In one embodiment the roof plates each include a center rib positioned in complemen-tary interengagement with the plate beam center reinforcing rib to increase the surface to surface contact of the roof plates with the plate beam to increase the bearing force applied by the plate beam to the mine roof.
MINE ROOF PLATE BEAM FOR A ROOF TRUSS ASSEMBLY
ABSTRACT OF THE DISCLOSURE
An elongated plate beam has a plurality of long-itudinally extending downwardly directed ribs. The ribs are positioned in parallel spaced relation to form a pair of lateral ribs and a center reinforcing rib. The plate beam has a preselected length adapted to span the width of a mine passage and includes a top surface arranged to abut a mine roof and a bottom surface. A plurality of openings are spaced the length of the plate beam and extend through the center reinforcing rib. A roof plate is positioned in abutting relation with the plate beam bottom surface in overlying relation with each opening. Roof bolts extend through the roof plates and openings into engagement with the walls of bore holes drilled in the mine roof. An enlarged end of each roof bolt bears against the respective roof plate to apply an upward force upon the plate beam to position the plate beam in roof supporting relation with the mine roof the entire width of the mine passage spanned by the plate beam. In one embodiment the roof plates each include a center rib positioned in complemen-tary interengagement with the plate beam center reinforcing rib to increase the surface to surface contact of the roof plates with the plate beam to increase the bearing force applied by the plate beam to the mine roof.
Description
li BACKGROUND GF THE INVENTION
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1~ 1. Field of the Invention " , ~
This invention relates to a truss assembly for j supporting a roof of an underground mine and more particularly I
to a rib reinforced mine rooE plate beam supported by roof ¦
~ plates anchored to the mine roof and abutting the plate beam to ¦l place the plate beam in roof supporting relation with the ¦~ mine roof the width of the mine passage spanned by the plate beam.
¦ 2. Description of the Prlor Art ~` ~
In underground operations, such as mining or excavat-ing, .it is a well known practice to support the unsupported ¦¦ rock formation or roof by wooden beams or cross timbers that ~¦ are placed across the mine passage under the unsupported roofO
Vertical uprights or props are positioned at the ends of each ¦ wooden beam or cross timber and extend upwardly from the mine ¦
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. ~ ' i, i floor to support the wooden beam or cross timber against the roof. Wooden beams having a dimension of 3 inches by 8 inches and up to 16 feet in length are commonly supported in this manner to prevent roof falls or cave-ins. ~owever, the dis-advantage of this arrangement is that the vertical props are ii i positioned at the mine sidewalls and reduce the width of the mine passageway available for the passage of mine cars, locomotives, mining machines, and other equipment through the mine passage.
As an alternative to supporting a mine r-oof by vertical props and cross beams, it is known as disclosed in United States Patent 2,667,037 to eliminate the vertical props and hold the cross beams in place by anchoring the cross beams with expansion bolts. The bolts are inserted in holes drilled up into the mine roof and are tensioned to bear against the cross beams and hold them firmly against the mine roof. The above patent discloses cross beams made of either wood or structural steel with the bolts secured in the rock formation by either sn expansion shell or a quick-setting cement.
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It is also well known in the art to eliminate the ~¦ cross beams entirely and use roof plates spaced a preselect-'j, ed distance apart across the roof of the mine passage. With il this method of mine roof support, elongated bolts are inserted Il, in holes bored into the rock formation of the roof. The boltsare secured by either engagement of an expansion shell on the ~1 end of the bolt with the rock formation or adhesively bonding the bolt by a thermosetting resin injected into the bore hole.
Upon setting of the resin, the bolt is united with the rock formation. A roof plate is retained on the bolt and bears against the Eace of the rock formation.
ll In the case of the mechanical anchor method the bolt ¦1~ is rotated to expand a shell into gripping engagement with the rock formation~ Rotating the bolt having an expansion shell jl expands the shell to engage the rock formation~ The bolt is ¦¦ thus tensioned and the rock strata is compressed. By ad-hesively bonding bolts to the rock formation, the adhesiv,e ¦ penetrates into the rock to adhesively unite fissures in the rock and to firmly hold the bolt in the bore hole. The bolt, ~, however, is not tensioned when adhesively bonded to the rock ¦~ formation.
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Roof plates do not completely span the mine roof across a mine passage but are spaced a preselected distance ',¦ apart in accordance with a center plan. Therefore, gaps of Il unsupported mine roof are formed between the spaced apart roof ¦I plates. Thus the roof plate system of supportin~ a roof support does not provide the continuous span of roof support from sidewall to sidewall provided by the conventional cross ¦ beam system.
It is known to combine the roof plate system with the continuous span system by replacing the timber beam with j a galvanized steel roof mat having a preselected length and ¦ a width that generally ranges between 5 and 10 inches depending ~ on the size of the roof plate which abuts against the mat. The ¦I steel mat is generally a 14 or 16 gauge galvanized steel. Bolt ¦ holes are positioned at selected intervals along the length of ¦ the mat in accordance with a predetermined distance between bolt centers. A principal advantage of the rooE mat is that it is substantially lighter in weight than a comparable length ' of timber beam. This permits ease of installation and decreas-es the time required to complete the roof bolting process.
Steel roof mats also are not subject to aeterioration as are Il wooden beams.
¦, While it has been suggested to support a mine roof by ¦
bolting wooden and steel cross beams to the mine roof and to use steel mat with roof bol~s to provide a continuous span of jl roof support across a mine passage, the prior art roof support ¦¦ systems do not provide a non-wooden cross beam ~hat can with-stand the bending loads encountered when held in contact with the mine roof by roof plates bolted to the mine roof. There-¦~ fore, there is need to provide a mine roof truss system that ~¦ utilizes non-wooden cross beams in conjunction with roof plates and bolts to provide support of a section of the mine roof in a Il continuous span without bending under the load of the mine ¦I roof.
., , ~i SUMMARY OF T_E _ VENTION
In accordance with the present invention, there i~
llprovided a truss assembly for supporting a roof of an undergroun~
iimine that includes an elongated plate beam having a plurality of longitudinally extending down~ardly directed ribs~ ~he ribs ar~
disposed in space relation to form a pair of lateral ribs and ~center reinforcing rib positioned between the pair of latera~
ribs. A web section connects the center reinforcing rib to each of the pair of lateral ribs. The center reinforcing rib has a V-shaped configuration centered on the web section. The center ~¦reinforcing rib has a pair of angled side walls diverging outwardly ¦and upwardly at an angle from a point below the web section int~
connection with the web section such that the width of the cente~
reinforcing rib is less than the width of the web section betwee~
the respective one of the lateral ribs and the center reinforcing llrib. The plate beam has a top surface adapted to abut a mine roof i~and a bottom surface. A plurality of openings are spaced longitu-¦dinally the length of the plate beam and extend through the center ~reinforcing rib. Anchor meclr.s extend through each of the plate ~beam openings into a mine ro~f for securely engaging the plate beam top surface in abuttin3 relation with the mine roof. The ~lanchor means each have a firs~ end portion anchored within a mine ilroof and a second end portion ~earing against the plate beam botto ~surface so that the plate bearn exerts a roof supporting force upon ¦Ithe mine roof the entire length of the plate beam.
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i The center reinforcing rib is connected to the I, oppositely positioned lateral ribs by web sections of the plate !l beam. The web sections each include an upstanding panel and a ¦¦ horizontal panel of a preselected width that forms the top and ! bottom surfaces of the plate beam. Inner ends of each hor-¦ izontal panel are formed integral with the center reinforcing rib. Outer ends of each horizontal panel are connected, in turn, to upper ends of the upstanding panel that extends in a generally downwardly angled direction from the horizontal panel ~ when the plate beam is positioned in abutting relation with the ¦ mine roof. A lower end of each upstanaing panel is formed ¦ integral with a respective lateral rib.
¦ Thus the plate beam has a generally inverted U-chan-¦ nel shaped configuration. The pair of lateral ribs are ver-j tically spaced a preselected distance below the center re-¦ inforcing rib. The center reinforcing rib extends downwardly from the top surface, which is adapted to abut a mine roof, between the pair of lateral ribs.
l, l If Preferably, a roof plate is positioned in abutting i If relation with the plate beam bottom surface opposite the top f surface, which abuts the mine roof, overlying each of the i j openings in the plate beam. I'he roof plate includes a center ~i hole. A mine roof bolt comprising the anchor means extends through the aligned hole and opening in the roof plate and plate beam. The upper end of the roof bolt is secured to the rock formation of the mine roof by either an expansion shell or a quick setting resin to firmly hold the plate beam in compressive relation with the mine roof to support the mine If roof. The openings in the plate beam are spaced a pre-!l determined distance apart to provide selective spacing of the ¦
roof plates on the plate beam.
In one embodiment of the present invention the ¦
I¦ openings in the plate beam along the center reinforcing rib are ¦l elongated at least the length of a roof plate to permit the ¦ roof plate to abut in surface to surface contact the bottom sul2ace Df the plate ùeam.
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Further, in accordance with the present invention, there is provided a plate beam for supporting a mine roof that includes an elongated channel shaped member. ~ plural-ity of longitudinally extending ribs project from the channel shaped member. The ribs are disposed in spaced relation to form a pair of lateral ribs and a center reinforcing rib positioned between the pair of lateral ribs. A plurality of openings are spaced longitudinally the length of the channel shaped member and extend through the center reinforcing rib.
The channel shaped member has a top surface extending the length of the channel shaped member and is arranged to be positioned in abutting relation with a mine roof with the ribs extending downwardly from the mine roof.
Accordingly, the principal object of the present invention is to provide a mine roof truss assembly formed by a rib reinforced plate beam supported in roof engaging relation along its entire length by roof plates abutting the plate beam and anchored securely in the mine roof.
Another object of the present invention is to provide a plate beam as a substitute for wooden cross timbers to support a mine roof where the plate beam is structured to withstand bending forces applied ~hereto by the unsupported strata of a mine roof.
A further object of the present invention is to provide a mine roof plate beam having a center reinforcing rib ¦
for providing the plate beam with increased structural strength to resist bending along its length.
An additional object of the present invention is to ~
provide in a mine roof truss system a plate beam having a ¦
center reinforciny rib arranged to receive in complementary ¦
interengagement a center reinforcing rib of a mine roof plate to increase the surface to surface contact between the mine roof plate and the plate beam which is held against the mine roof by the mine roof plate.
These and other objects of the present invention will be more completely disclosed and described in the following specification, the accompanying drawings, and the appended claims.
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BRIEF DESCRIPTION OF_ THE DRAWINGS
¦~ Figure 1 is a fragmentary, schematic isometric ¦ view of a mine roof plate beam for supporting an unsupported ! section of a mine roof, illustrating a center reinforcing 1¦ rib and a pair of lateral ribs of the plate beam.
I Figure 2 is a fragmentary sectional view in elevation of the mine roof plate beam, illustrating one of the roof plates abuttins the plate beam and anchored in a mine roof to firmly hold the plate beam against the mine roof.
Figure 3 is a plan view of the mine roof plate beam connected to the mine roof by the roof plate shown in ¦ Figure 2, illustrating an elongated opening through the ¦ center reinforcing rib and plate beam for the roof bolt and the roof plate abutting the plate beam around the opening.
Figure 4 is a schematic sectional view of the mine ¦ roof plate beam,roof plate, and roof bolt taken along line IV - IV of Figure 3.
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,I Figure 5 is a fragmentary, schematic isometric view i similar to Figure 1, illustrating another embodiment of the present invention in which each roof plate is provided with a 11 complementary reinforcing rib arranged to interengage the plate , beam center reinforcing rib. I
Eigure 6 is a schematic exploded view of the assembly ¦
of the mine roof plate beam, the roof plate, and roof bolt Il shown in Figure 5.
¦~ Figure 7 i5 a plan view of the assembled mine roof plate beam, roof plate, and roof bolt shown in Figure 5.
Figure 8 is a schematic sectional vie-~ of the as-sembled mine roof plate beam, roof plate, and roof bolt taken ¦
along line VIII-VIII of Figure 7.
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and particularly to Figures 1 and 5 there is illustrated an elongated mine roof plate beam ~I generally designated by the numeral lQ that when used in li conjuction with a plurality of mine roof plates 12 and roof ¦ bolts 14 forms a roof truss assembly generally designated by numeral 16 for supporting the roof of an underground mine.
l For purposes of illustration only a single mine roof plate ¦i 12 is shown with the plate beam 10. The mine roof plate beam 10 extends transversely across a mine passage at the mine roof in ¦ a continuous span from sidewall to sidewall of the mine pas-sageO A first embodiment of the roof truss assembly 16, in accordance with the present invention, is illustrated in Figures 1-4. A second embodiment of the roof truss assembly is ¦ illustrated in Figures 5-8.
Now referrlng to Figure 1 in which like numerals refer to like parts in Figures 1-8, the plate beam 10 is elongated and has a preselected length as predetermined by the width of a mine passage, i.e. the width between the sidewalls , or ribs of a mine passage or mine entry. To this end the plate beam 10 m.y have a length for example of 16 feet.
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The plate beam 10 has a channel shaped configuration formed by a plurality of longitudinally extending ribs that include a pair of lateral ribs 18 and 20 and a center reinforc ing rib 22 positioned between the pair of lateral ribs 18 and I~ 20. The ribs 18-22 are positioned in spaced parallel relation I
i~ and extend the length of the plate beam 10. With the plate ¦
beam 10 in its operative position abutting a mine roof, the ribs 18-22 extend outwardly from the mine roof thereby formin ¦l a generally inverted U-shaped recess generally designated by Il the numeral 24 in which the recess 24 extends the length of the ¦¦ plate beam 10. The plate beam 10 includes a top surface 26 ¦~ adapted to engage in abutting relation the surface of a mine roof and a bottom surface 28 that is adapted to receive the I roof plates 12.
jl The plate beam 10 includes along its entire length a i plurality of elongated openings 30 only one of which is il-lustrated in Figures 1-3. The openings 30 or slots are spaced ¦ longitudinally the entire leng-th of the plate beam 10 and extend through the center reinforcing rib 22. The openings 30 ~j have a preselected length, as illustrated in Figure 2, to ~
1~ permit the roof plate 12 to be positioned in abutting relation i with the bottom surface 28 of the plate beam 10 ~ithout ob~
st~uction ùy tùe center reinEorcirg rib 22.
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I~ The roof plates 12 may be of either a square or rectangular configuration as shown in Figure 2, and may be of Il the donut-type as illustrated in Figures 2-4. However, it ¦I should be understood that in accordance with the present invention, any conventionally known type of mine roof support l~ or bearing plate is adaptable for use with the present inven-¦ tion.
~ I'he representative roof plate 12 shown in Figures ¦ 2-4 includes a center opening (not shown) through which the roof bolt 14 extends. As well known in the art, the roof bolt i 14 has an elongated shank 32 of a preselected length and an enlarged end portion 34 that serves to retain the bolt 14 on the roof plate 12 . I'he shank portions 32 of the bolts 14 are inserted in holes previously drilled in a rnine roof 36, illus-trated in ~igure 2, at suitable :pacing:.
,~i The upper ends of the bolt shank portions 32 are not shown, and it should be understood that in one embodiment ex-pansion shells, as disclosed in United States Patent 4,160,614, are used on the ends of the bolt shank portions to grip the wall of the drilled bore holes at the top ends of the holes.
~I The expansion shell, when after being positioned in the ¦l drilled bore hole, is expanded by rotating the bolt enlarged l1~ end portion 34. This places the roof bolt 14 in tension and ¦l thereby applies compressive forces upon the strata of the rock formation above the nline passage. Also, as illustrated in Il Figure 2, a washer 38 is positioned in abutting relation with ¦~ the bolt enlarged portion 34 between the enlarged end portion ¦¦ 34 and the recessed portion formed by a donut embossment 35 Il surrounding the center hole of the roof plate 12.
~; It should also be understood, in accordance with the ¦I present invention, that the bolt 14 may be adhesively bonded ¦~ in the bore hole drilled in the mine roof. As illustrated and ¦ described in ~niced States Patent 3,324,662 and 3,394,527 the components of the bonding material are advancea into the bore , ~
s~ l hole ahead of the roof bolt 14. When the roof bolt 14 or rod is rotated the components of the adhesive material are admixed and penetrate into the surrounding rock formation to ad-hesively unite the rock strata and to firmly hold the bolt 14 in position in the bore hole. ~he adhesive mixture fills the annulus between the bore hole and the roof bolt 14 along a substantial length of the bolt 14.
In this manner the bolt 14 is securely anchored in the mine roof but is not maintained in tension as is the case with a roof bolt mechanically anchored by an expansion shell in the mine roof. Known anchor systems that combine both expansion shells and a ~uick-setting resin are also adaptable with the present invention. However, with all the available methods of anchoring the roof bolts 14 in the mine roof 36~
the roof plate 12 bears against the plate beam bottom surface 28 to maintain the plate beam upper surface 26 in abutting relation with the mine roof 36. With this arrangement the plate beam 10 exerts a roof supportillg force upon the mine roof 36 the entire length of the plate beam 10. It should also be understood that the openings 30 in the plate beam 10 can be dimensioned to receive the roof bolt enlarged end portion 34 to secure the plate beam 10 to the mine roof 36 without the provision of a roof plate 12.
The center reinforcing rib 22 and the lateral ribs 18 and 20 are preferably positioned in spaced parallel relation where the center reinforcing rib 22 is connected to the oppo-sitely positioned lateral ribs 18 and 20 by web sections generally designated by the numerals 40 of the plate beam 10.
The web sections 40 each include an upstanding panel 42 and the substantially horizontal panel 44 that has a preselected whip that forms the top and bottom surfaces 26 and 28 of the plate beam 10. As illustrated in Figures 1 and 4, the center rein-forcing rib number 22 is generally V-shaped and extends down-wardly from the mine roof 36 when the plate beam top surface 26 is positioned in abutting relation with the mine roof 36.
The web horizontal panels 44 each include inner ends 46 formed integral with the V legs of the center reinforcing rib 22. The outer end 48 of each web horizontal panel 44 is connected to the upper end o-E the respective upstanding panel 42. ~ach of the web upstanding panels 42 extends in a general-ly downwardly angled direction from the respective horizontal panel 44 when the plate beam top surface 26 is positioned in abutting relation with the mine roof 36. The lower end of each upstanding panel 42 is formed integral with a respective lateral rib 18 and 20.
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As illustrated in Figure 4 the lateral ribs 18 and 20 are also generally U-shaped. The lateral ribs 18 and 20 include free end portions 50 that extend upwardly and outwardly from the web upstanding panels 42.
With the above described arrangement the plate beam lo has a generally inverted U-channeled shaped configuration where the pair of lateral ribs 1~ and 20 are vertically spaced a preselected distance below the center reinforcing rib 22. This facilitates positioning the bolt enlarged end portion 34 in the recess 24 to protect the bolt enlarged end portion 34 from being sheared off by contact with a piece of equipment moving through the mine passage. Also with the illustrated and described configuration of the rib reinforced, recessed plate beam 10, a low profile mine roof plate beam is provided making available more head room in the mine passage in comparison with the head room reduced by conventional wooden timbers and cross beams where the bolt end portions protrude from the bottom surface of the cross beam. An exposed bolt end portion is subject to being sheared off if contact-ed with sufficient force by equipment traveling through the mine passage beneath the c~o:s beam.
` - 21 -I~ ~L 3L$~~rj~ ' As illustrated in Figures 1-3 the openings 30 in the center reinforcing rib 22 are sufficiently elongated to perr,~it the roof plates 12 to abut in surface contact the length of the roof plate the bottom surface 28 of the plate beam 10.
In this manner a conventional roof plate can be used in con-junction with the plate beam 10 having the V-shaped center reinforcing rib 22. The anchored roof plate 12 exerts an upward force upon the plate beam 10 to urge the plate beam 10 substantially along its entire length into roof supporting relation with the mine roof 36. In this manner the plate beam 10 provides a continuous span of roo~ support across an unsup-ported section of the mine passage.
The center reinforcing rib 22 has been found to substantially increase the structural strength o$ the plate beam 10 to resist the bending stresses applied to the plate beam 10 by the unsupported mine roof. In tests conducted with a 16 foot plate beam it has been found that the plate beam 10 of the present invention having the center reinforcing rib 22 has the equivalent strength of a 3 inch x 8 inch wooden timber.
However, the plate beam 10 of the present invention has a lower profile than a 3 inch x 8 inch wooden timber and pro-tectively positions the bolt end portion 34 within the recess 24. This prevents the bolt end portion 34 from being sheared ofE.
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A further advantaye of the plate beam 10 over the conventional wooden timber and other known types of beam supports is that the plate beam 10 of the present inven-tion is designed to yield under the stresses exerted by an unsupported mine roof before it fails. A wooden timber aoes not yield before it fails, but cracks wi-thout giving advance warning that its load limit is about to be exceeded. The plate beam 10 has an ultimate strength to resist bending comparable to that of a conventional wooden timber but has a substantially greater factor of safety because it yields before it ultimately fails, thereby giving advance warning to a potential roof fall or cave-in.
As illustrated in another embodiment of the roof plate beam 10 in ~igures 5-8 the plate beam 10 is provided with a generally circular opening 52 having a dimension substantially equal to the diameter of the roof bolt 14.
In accordance with the second embodiment of the present invention, the roof plate beam 10 is wsed in conjunction 11, with a roof plate 12 having center reinforcing ribs 54 that extend along the longitudinal axis of the plate 12. The roof plate center reinforcing ribs 54 extend outwardly from a donut embossment 56 surrounding a center hole 58 in the roof plate 14.
In assembling the roof plate 12 on the roof plate beam 10, as illustrated in Figure 6, the center reinforcing ribs 54 of the roof plate 12 are positioned in parallel overlying alignment with the plate beam center reinforcing rib 22. The roof bolt 14 e~tends through the aligned opening 52 and hole 58 into the mine roof. The washer 38 on the roof bolt 14 surrounds the roof plate hole 58 and receives the bolt enlarged end portion 34.
Once the bolt 14 is securely anchored in the drilled bore hole of the mine roof, the plate beam and roof plate center reinforcing ribs 22 and 54 are urged into overlying abutting relation. Thus it will be apparent that the roof plate center reinforcing ribs 54 are constructed for complementary interengagement with the plate beam center reinforcing rib 22. This arrangement increases the surface to surface contact between the roof plate 12 and the plate beam 10.
l, l The roof plate 12 with the ribs 54 has an increased area of contact with the plate beam 10. This increases the bearing force exerted by the roof plate 12 upon the plate beam 10. By increasing the bearing force upon the plate beam 10, the plate beam 10 is maintained in greater contact with the mine roof 36. 1'he surface contact of the plate beam 10 with the mine roof 36 is substantially along the entire length of the plate beam 10. Consequently a continuous span of roof support is provided by the plate beam 10 from sidewall to sidewall of the mine passage.
By assuring that the plate beam 10 is substantially maintained in .contact with the surface of the mine roof 36 along its entire length, uniform roof support is provided along the continuous span of the plate beam 10. This enables the plate beam 10 to more effectively resist concentrated bending stresses applied at specific points by the rock strata on the plate beam 10. This feature, in addition to the provision of the plate beam center reinforcing rib 22, substantially in-creases the structural strength of the low profile plate beam I
Il , 10 to resist bending stresses applied thereto by unsupported rock strata. Thus a mine roof truss assembly 16 is formed that is easily installed to provide a mine roof control having a greater factor of safety than encountered with the conven-tionally known roof support systems and particularly cross beam and wooden timber supports which are su~ject -to deterioration by rotting and the like.
According to the provisions of the Patent Statutes, I
have explained the principle, preferred construction and mode of operation of my invention and have illustrated and described what I now consider to represent its best embodiments. How-ever, it should be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.
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1~ 1. Field of the Invention " , ~
This invention relates to a truss assembly for j supporting a roof of an underground mine and more particularly I
to a rib reinforced mine rooE plate beam supported by roof ¦
~ plates anchored to the mine roof and abutting the plate beam to ¦l place the plate beam in roof supporting relation with the ¦~ mine roof the width of the mine passage spanned by the plate beam.
¦ 2. Description of the Prlor Art ~` ~
In underground operations, such as mining or excavat-ing, .it is a well known practice to support the unsupported ¦¦ rock formation or roof by wooden beams or cross timbers that ~¦ are placed across the mine passage under the unsupported roofO
Vertical uprights or props are positioned at the ends of each ¦ wooden beam or cross timber and extend upwardly from the mine ¦
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. ~ ' i, i floor to support the wooden beam or cross timber against the roof. Wooden beams having a dimension of 3 inches by 8 inches and up to 16 feet in length are commonly supported in this manner to prevent roof falls or cave-ins. ~owever, the dis-advantage of this arrangement is that the vertical props are ii i positioned at the mine sidewalls and reduce the width of the mine passageway available for the passage of mine cars, locomotives, mining machines, and other equipment through the mine passage.
As an alternative to supporting a mine r-oof by vertical props and cross beams, it is known as disclosed in United States Patent 2,667,037 to eliminate the vertical props and hold the cross beams in place by anchoring the cross beams with expansion bolts. The bolts are inserted in holes drilled up into the mine roof and are tensioned to bear against the cross beams and hold them firmly against the mine roof. The above patent discloses cross beams made of either wood or structural steel with the bolts secured in the rock formation by either sn expansion shell or a quick-setting cement.
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It is also well known in the art to eliminate the ~¦ cross beams entirely and use roof plates spaced a preselect-'j, ed distance apart across the roof of the mine passage. With il this method of mine roof support, elongated bolts are inserted Il, in holes bored into the rock formation of the roof. The boltsare secured by either engagement of an expansion shell on the ~1 end of the bolt with the rock formation or adhesively bonding the bolt by a thermosetting resin injected into the bore hole.
Upon setting of the resin, the bolt is united with the rock formation. A roof plate is retained on the bolt and bears against the Eace of the rock formation.
ll In the case of the mechanical anchor method the bolt ¦1~ is rotated to expand a shell into gripping engagement with the rock formation~ Rotating the bolt having an expansion shell jl expands the shell to engage the rock formation~ The bolt is ¦¦ thus tensioned and the rock strata is compressed. By ad-hesively bonding bolts to the rock formation, the adhesiv,e ¦ penetrates into the rock to adhesively unite fissures in the rock and to firmly hold the bolt in the bore hole. The bolt, ~, however, is not tensioned when adhesively bonded to the rock ¦~ formation.
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Roof plates do not completely span the mine roof across a mine passage but are spaced a preselected distance ',¦ apart in accordance with a center plan. Therefore, gaps of Il unsupported mine roof are formed between the spaced apart roof ¦I plates. Thus the roof plate system of supportin~ a roof support does not provide the continuous span of roof support from sidewall to sidewall provided by the conventional cross ¦ beam system.
It is known to combine the roof plate system with the continuous span system by replacing the timber beam with j a galvanized steel roof mat having a preselected length and ¦ a width that generally ranges between 5 and 10 inches depending ~ on the size of the roof plate which abuts against the mat. The ¦I steel mat is generally a 14 or 16 gauge galvanized steel. Bolt ¦ holes are positioned at selected intervals along the length of ¦ the mat in accordance with a predetermined distance between bolt centers. A principal advantage of the rooE mat is that it is substantially lighter in weight than a comparable length ' of timber beam. This permits ease of installation and decreas-es the time required to complete the roof bolting process.
Steel roof mats also are not subject to aeterioration as are Il wooden beams.
¦, While it has been suggested to support a mine roof by ¦
bolting wooden and steel cross beams to the mine roof and to use steel mat with roof bol~s to provide a continuous span of jl roof support across a mine passage, the prior art roof support ¦¦ systems do not provide a non-wooden cross beam ~hat can with-stand the bending loads encountered when held in contact with the mine roof by roof plates bolted to the mine roof. There-¦~ fore, there is need to provide a mine roof truss system that ~¦ utilizes non-wooden cross beams in conjunction with roof plates and bolts to provide support of a section of the mine roof in a Il continuous span without bending under the load of the mine ¦I roof.
., , ~i SUMMARY OF T_E _ VENTION
In accordance with the present invention, there i~
llprovided a truss assembly for supporting a roof of an undergroun~
iimine that includes an elongated plate beam having a plurality of longitudinally extending down~ardly directed ribs~ ~he ribs ar~
disposed in space relation to form a pair of lateral ribs and ~center reinforcing rib positioned between the pair of latera~
ribs. A web section connects the center reinforcing rib to each of the pair of lateral ribs. The center reinforcing rib has a V-shaped configuration centered on the web section. The center ~¦reinforcing rib has a pair of angled side walls diverging outwardly ¦and upwardly at an angle from a point below the web section int~
connection with the web section such that the width of the cente~
reinforcing rib is less than the width of the web section betwee~
the respective one of the lateral ribs and the center reinforcing llrib. The plate beam has a top surface adapted to abut a mine roof i~and a bottom surface. A plurality of openings are spaced longitu-¦dinally the length of the plate beam and extend through the center ~reinforcing rib. Anchor meclr.s extend through each of the plate ~beam openings into a mine ro~f for securely engaging the plate beam top surface in abuttin3 relation with the mine roof. The ~lanchor means each have a firs~ end portion anchored within a mine ilroof and a second end portion ~earing against the plate beam botto ~surface so that the plate bearn exerts a roof supporting force upon ¦Ithe mine roof the entire length of the plate beam.
~ ' l l l l't ~oD~5~
i The center reinforcing rib is connected to the I, oppositely positioned lateral ribs by web sections of the plate !l beam. The web sections each include an upstanding panel and a ¦¦ horizontal panel of a preselected width that forms the top and ! bottom surfaces of the plate beam. Inner ends of each hor-¦ izontal panel are formed integral with the center reinforcing rib. Outer ends of each horizontal panel are connected, in turn, to upper ends of the upstanding panel that extends in a generally downwardly angled direction from the horizontal panel ~ when the plate beam is positioned in abutting relation with the ¦ mine roof. A lower end of each upstanaing panel is formed ¦ integral with a respective lateral rib.
¦ Thus the plate beam has a generally inverted U-chan-¦ nel shaped configuration. The pair of lateral ribs are ver-j tically spaced a preselected distance below the center re-¦ inforcing rib. The center reinforcing rib extends downwardly from the top surface, which is adapted to abut a mine roof, between the pair of lateral ribs.
l, l If Preferably, a roof plate is positioned in abutting i If relation with the plate beam bottom surface opposite the top f surface, which abuts the mine roof, overlying each of the i j openings in the plate beam. I'he roof plate includes a center ~i hole. A mine roof bolt comprising the anchor means extends through the aligned hole and opening in the roof plate and plate beam. The upper end of the roof bolt is secured to the rock formation of the mine roof by either an expansion shell or a quick setting resin to firmly hold the plate beam in compressive relation with the mine roof to support the mine If roof. The openings in the plate beam are spaced a pre-!l determined distance apart to provide selective spacing of the ¦
roof plates on the plate beam.
In one embodiment of the present invention the ¦
I¦ openings in the plate beam along the center reinforcing rib are ¦l elongated at least the length of a roof plate to permit the ¦ roof plate to abut in surface to surface contact the bottom sul2ace Df the plate ùeam.
~ f f ~v~
Further, in accordance with the present invention, there is provided a plate beam for supporting a mine roof that includes an elongated channel shaped member. ~ plural-ity of longitudinally extending ribs project from the channel shaped member. The ribs are disposed in spaced relation to form a pair of lateral ribs and a center reinforcing rib positioned between the pair of lateral ribs. A plurality of openings are spaced longitudinally the length of the channel shaped member and extend through the center reinforcing rib.
The channel shaped member has a top surface extending the length of the channel shaped member and is arranged to be positioned in abutting relation with a mine roof with the ribs extending downwardly from the mine roof.
Accordingly, the principal object of the present invention is to provide a mine roof truss assembly formed by a rib reinforced plate beam supported in roof engaging relation along its entire length by roof plates abutting the plate beam and anchored securely in the mine roof.
Another object of the present invention is to provide a plate beam as a substitute for wooden cross timbers to support a mine roof where the plate beam is structured to withstand bending forces applied ~hereto by the unsupported strata of a mine roof.
A further object of the present invention is to provide a mine roof plate beam having a center reinforcing rib ¦
for providing the plate beam with increased structural strength to resist bending along its length.
An additional object of the present invention is to ~
provide in a mine roof truss system a plate beam having a ¦
center reinforciny rib arranged to receive in complementary ¦
interengagement a center reinforcing rib of a mine roof plate to increase the surface to surface contact between the mine roof plate and the plate beam which is held against the mine roof by the mine roof plate.
These and other objects of the present invention will be more completely disclosed and described in the following specification, the accompanying drawings, and the appended claims.
l i ~a~J
BRIEF DESCRIPTION OF_ THE DRAWINGS
¦~ Figure 1 is a fragmentary, schematic isometric ¦ view of a mine roof plate beam for supporting an unsupported ! section of a mine roof, illustrating a center reinforcing 1¦ rib and a pair of lateral ribs of the plate beam.
I Figure 2 is a fragmentary sectional view in elevation of the mine roof plate beam, illustrating one of the roof plates abuttins the plate beam and anchored in a mine roof to firmly hold the plate beam against the mine roof.
Figure 3 is a plan view of the mine roof plate beam connected to the mine roof by the roof plate shown in ¦ Figure 2, illustrating an elongated opening through the ¦ center reinforcing rib and plate beam for the roof bolt and the roof plate abutting the plate beam around the opening.
Figure 4 is a schematic sectional view of the mine ¦ roof plate beam,roof plate, and roof bolt taken along line IV - IV of Figure 3.
v~
,I Figure 5 is a fragmentary, schematic isometric view i similar to Figure 1, illustrating another embodiment of the present invention in which each roof plate is provided with a 11 complementary reinforcing rib arranged to interengage the plate , beam center reinforcing rib. I
Eigure 6 is a schematic exploded view of the assembly ¦
of the mine roof plate beam, the roof plate, and roof bolt Il shown in Figure 5.
¦~ Figure 7 i5 a plan view of the assembled mine roof plate beam, roof plate, and roof bolt shown in Figure 5.
Figure 8 is a schematic sectional vie-~ of the as-sembled mine roof plate beam, roof plate, and roof bolt taken ¦
along line VIII-VIII of Figure 7.
~1 1i l' l '~
3 t , i ,, ., l.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and particularly to Figures 1 and 5 there is illustrated an elongated mine roof plate beam ~I generally designated by the numeral lQ that when used in li conjuction with a plurality of mine roof plates 12 and roof ¦ bolts 14 forms a roof truss assembly generally designated by numeral 16 for supporting the roof of an underground mine.
l For purposes of illustration only a single mine roof plate ¦i 12 is shown with the plate beam 10. The mine roof plate beam 10 extends transversely across a mine passage at the mine roof in ¦ a continuous span from sidewall to sidewall of the mine pas-sageO A first embodiment of the roof truss assembly 16, in accordance with the present invention, is illustrated in Figures 1-4. A second embodiment of the roof truss assembly is ¦ illustrated in Figures 5-8.
Now referrlng to Figure 1 in which like numerals refer to like parts in Figures 1-8, the plate beam 10 is elongated and has a preselected length as predetermined by the width of a mine passage, i.e. the width between the sidewalls , or ribs of a mine passage or mine entry. To this end the plate beam 10 m.y have a length for example of 16 feet.
-15- ~
.
1~6~56~
The plate beam 10 has a channel shaped configuration formed by a plurality of longitudinally extending ribs that include a pair of lateral ribs 18 and 20 and a center reinforc ing rib 22 positioned between the pair of lateral ribs 18 and I~ 20. The ribs 18-22 are positioned in spaced parallel relation I
i~ and extend the length of the plate beam 10. With the plate ¦
beam 10 in its operative position abutting a mine roof, the ribs 18-22 extend outwardly from the mine roof thereby formin ¦l a generally inverted U-shaped recess generally designated by Il the numeral 24 in which the recess 24 extends the length of the ¦¦ plate beam 10. The plate beam 10 includes a top surface 26 ¦~ adapted to engage in abutting relation the surface of a mine roof and a bottom surface 28 that is adapted to receive the I roof plates 12.
jl The plate beam 10 includes along its entire length a i plurality of elongated openings 30 only one of which is il-lustrated in Figures 1-3. The openings 30 or slots are spaced ¦ longitudinally the entire leng-th of the plate beam 10 and extend through the center reinforcing rib 22. The openings 30 ~j have a preselected length, as illustrated in Figure 2, to ~
1~ permit the roof plate 12 to be positioned in abutting relation i with the bottom surface 28 of the plate beam 10 ~ithout ob~
st~uction ùy tùe center reinEorcirg rib 22.
Ii ., 5~ 1 , ~
I~ The roof plates 12 may be of either a square or rectangular configuration as shown in Figure 2, and may be of Il the donut-type as illustrated in Figures 2-4. However, it ¦I should be understood that in accordance with the present invention, any conventionally known type of mine roof support l~ or bearing plate is adaptable for use with the present inven-¦ tion.
~ I'he representative roof plate 12 shown in Figures ¦ 2-4 includes a center opening (not shown) through which the roof bolt 14 extends. As well known in the art, the roof bolt i 14 has an elongated shank 32 of a preselected length and an enlarged end portion 34 that serves to retain the bolt 14 on the roof plate 12 . I'he shank portions 32 of the bolts 14 are inserted in holes previously drilled in a rnine roof 36, illus-trated in ~igure 2, at suitable :pacing:.
,~i The upper ends of the bolt shank portions 32 are not shown, and it should be understood that in one embodiment ex-pansion shells, as disclosed in United States Patent 4,160,614, are used on the ends of the bolt shank portions to grip the wall of the drilled bore holes at the top ends of the holes.
~I The expansion shell, when after being positioned in the ¦l drilled bore hole, is expanded by rotating the bolt enlarged l1~ end portion 34. This places the roof bolt 14 in tension and ¦l thereby applies compressive forces upon the strata of the rock formation above the nline passage. Also, as illustrated in Il Figure 2, a washer 38 is positioned in abutting relation with ¦~ the bolt enlarged portion 34 between the enlarged end portion ¦¦ 34 and the recessed portion formed by a donut embossment 35 Il surrounding the center hole of the roof plate 12.
~; It should also be understood, in accordance with the ¦I present invention, that the bolt 14 may be adhesively bonded ¦~ in the bore hole drilled in the mine roof. As illustrated and ¦ described in ~niced States Patent 3,324,662 and 3,394,527 the components of the bonding material are advancea into the bore , ~
s~ l hole ahead of the roof bolt 14. When the roof bolt 14 or rod is rotated the components of the adhesive material are admixed and penetrate into the surrounding rock formation to ad-hesively unite the rock strata and to firmly hold the bolt 14 in position in the bore hole. ~he adhesive mixture fills the annulus between the bore hole and the roof bolt 14 along a substantial length of the bolt 14.
In this manner the bolt 14 is securely anchored in the mine roof but is not maintained in tension as is the case with a roof bolt mechanically anchored by an expansion shell in the mine roof. Known anchor systems that combine both expansion shells and a ~uick-setting resin are also adaptable with the present invention. However, with all the available methods of anchoring the roof bolts 14 in the mine roof 36~
the roof plate 12 bears against the plate beam bottom surface 28 to maintain the plate beam upper surface 26 in abutting relation with the mine roof 36. With this arrangement the plate beam 10 exerts a roof supportillg force upon the mine roof 36 the entire length of the plate beam 10. It should also be understood that the openings 30 in the plate beam 10 can be dimensioned to receive the roof bolt enlarged end portion 34 to secure the plate beam 10 to the mine roof 36 without the provision of a roof plate 12.
The center reinforcing rib 22 and the lateral ribs 18 and 20 are preferably positioned in spaced parallel relation where the center reinforcing rib 22 is connected to the oppo-sitely positioned lateral ribs 18 and 20 by web sections generally designated by the numerals 40 of the plate beam 10.
The web sections 40 each include an upstanding panel 42 and the substantially horizontal panel 44 that has a preselected whip that forms the top and bottom surfaces 26 and 28 of the plate beam 10. As illustrated in Figures 1 and 4, the center rein-forcing rib number 22 is generally V-shaped and extends down-wardly from the mine roof 36 when the plate beam top surface 26 is positioned in abutting relation with the mine roof 36.
The web horizontal panels 44 each include inner ends 46 formed integral with the V legs of the center reinforcing rib 22. The outer end 48 of each web horizontal panel 44 is connected to the upper end o-E the respective upstanding panel 42. ~ach of the web upstanding panels 42 extends in a general-ly downwardly angled direction from the respective horizontal panel 44 when the plate beam top surface 26 is positioned in abutting relation with the mine roof 36. The lower end of each upstanding panel 42 is formed integral with a respective lateral rib 18 and 20.
Il i ;` ~
As illustrated in Figure 4 the lateral ribs 18 and 20 are also generally U-shaped. The lateral ribs 18 and 20 include free end portions 50 that extend upwardly and outwardly from the web upstanding panels 42.
With the above described arrangement the plate beam lo has a generally inverted U-channeled shaped configuration where the pair of lateral ribs 1~ and 20 are vertically spaced a preselected distance below the center reinforcing rib 22. This facilitates positioning the bolt enlarged end portion 34 in the recess 24 to protect the bolt enlarged end portion 34 from being sheared off by contact with a piece of equipment moving through the mine passage. Also with the illustrated and described configuration of the rib reinforced, recessed plate beam 10, a low profile mine roof plate beam is provided making available more head room in the mine passage in comparison with the head room reduced by conventional wooden timbers and cross beams where the bolt end portions protrude from the bottom surface of the cross beam. An exposed bolt end portion is subject to being sheared off if contact-ed with sufficient force by equipment traveling through the mine passage beneath the c~o:s beam.
` - 21 -I~ ~L 3L$~~rj~ ' As illustrated in Figures 1-3 the openings 30 in the center reinforcing rib 22 are sufficiently elongated to perr,~it the roof plates 12 to abut in surface contact the length of the roof plate the bottom surface 28 of the plate beam 10.
In this manner a conventional roof plate can be used in con-junction with the plate beam 10 having the V-shaped center reinforcing rib 22. The anchored roof plate 12 exerts an upward force upon the plate beam 10 to urge the plate beam 10 substantially along its entire length into roof supporting relation with the mine roof 36. In this manner the plate beam 10 provides a continuous span of roo~ support across an unsup-ported section of the mine passage.
The center reinforcing rib 22 has been found to substantially increase the structural strength o$ the plate beam 10 to resist the bending stresses applied to the plate beam 10 by the unsupported mine roof. In tests conducted with a 16 foot plate beam it has been found that the plate beam 10 of the present invention having the center reinforcing rib 22 has the equivalent strength of a 3 inch x 8 inch wooden timber.
However, the plate beam 10 of the present invention has a lower profile than a 3 inch x 8 inch wooden timber and pro-tectively positions the bolt end portion 34 within the recess 24. This prevents the bolt end portion 34 from being sheared ofE.
l I
~! ~
,' ~ 4r~ ' 1.
A further advantaye of the plate beam 10 over the conventional wooden timber and other known types of beam supports is that the plate beam 10 of the present inven-tion is designed to yield under the stresses exerted by an unsupported mine roof before it fails. A wooden timber aoes not yield before it fails, but cracks wi-thout giving advance warning that its load limit is about to be exceeded. The plate beam 10 has an ultimate strength to resist bending comparable to that of a conventional wooden timber but has a substantially greater factor of safety because it yields before it ultimately fails, thereby giving advance warning to a potential roof fall or cave-in.
As illustrated in another embodiment of the roof plate beam 10 in ~igures 5-8 the plate beam 10 is provided with a generally circular opening 52 having a dimension substantially equal to the diameter of the roof bolt 14.
In accordance with the second embodiment of the present invention, the roof plate beam 10 is wsed in conjunction 11, with a roof plate 12 having center reinforcing ribs 54 that extend along the longitudinal axis of the plate 12. The roof plate center reinforcing ribs 54 extend outwardly from a donut embossment 56 surrounding a center hole 58 in the roof plate 14.
In assembling the roof plate 12 on the roof plate beam 10, as illustrated in Figure 6, the center reinforcing ribs 54 of the roof plate 12 are positioned in parallel overlying alignment with the plate beam center reinforcing rib 22. The roof bolt 14 e~tends through the aligned opening 52 and hole 58 into the mine roof. The washer 38 on the roof bolt 14 surrounds the roof plate hole 58 and receives the bolt enlarged end portion 34.
Once the bolt 14 is securely anchored in the drilled bore hole of the mine roof, the plate beam and roof plate center reinforcing ribs 22 and 54 are urged into overlying abutting relation. Thus it will be apparent that the roof plate center reinforcing ribs 54 are constructed for complementary interengagement with the plate beam center reinforcing rib 22. This arrangement increases the surface to surface contact between the roof plate 12 and the plate beam 10.
l, l The roof plate 12 with the ribs 54 has an increased area of contact with the plate beam 10. This increases the bearing force exerted by the roof plate 12 upon the plate beam 10. By increasing the bearing force upon the plate beam 10, the plate beam 10 is maintained in greater contact with the mine roof 36. 1'he surface contact of the plate beam 10 with the mine roof 36 is substantially along the entire length of the plate beam 10. Consequently a continuous span of roof support is provided by the plate beam 10 from sidewall to sidewall of the mine passage.
By assuring that the plate beam 10 is substantially maintained in .contact with the surface of the mine roof 36 along its entire length, uniform roof support is provided along the continuous span of the plate beam 10. This enables the plate beam 10 to more effectively resist concentrated bending stresses applied at specific points by the rock strata on the plate beam 10. This feature, in addition to the provision of the plate beam center reinforcing rib 22, substantially in-creases the structural strength of the low profile plate beam I
Il , 10 to resist bending stresses applied thereto by unsupported rock strata. Thus a mine roof truss assembly 16 is formed that is easily installed to provide a mine roof control having a greater factor of safety than encountered with the conven-tionally known roof support systems and particularly cross beam and wooden timber supports which are su~ject -to deterioration by rotting and the like.
According to the provisions of the Patent Statutes, I
have explained the principle, preferred construction and mode of operation of my invention and have illustrated and described what I now consider to represent its best embodiments. How-ever, it should be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.
~!
ii i i ~,
Claims (14)
1. A truss assembly for supporting a roof of an underground nine comprising, an elongated plate beam having a plurality of longitudinally extending downwardly directed ribs, said ribs being disposed in spaced relation to form a pair of lateral ribs and center reinforcing rib positioned between said pair of lateral ribs, a web section for connecting said center reinforcing rib to each of said pair of lateral ribs, said center reinforcing rib having a V-shaped configuration centered on said web section, said center reinforcing rib having a pair of angled sidewalls diverging outwardly and upwardly at an angle from a point below said web section into connection with said web section such that the width of said center reinforcing rib is less than the width of said web section between said respective one of said lateral ribs and said center reinforcing rib, said plate beam having a top surface adapted to abut a mine roof and a bottom surface, a plurality of openings spaced longitudinally the length of said plate beam and extending through said center reinforcing rib, anchor means extending through each of said plate beam openings into a mine roof for securely engaging said plate beam top surface in abutting relation with a mine roof, and said anchor means each having a first end portion anchored within a mine roof and a second end portion bearing against said plate beam bottom surface so that said plate beam exerts a roof supporting force upward upon the mine roof the length of said plate beam.
2. A truss assembly as set forth in claim 1 in which, said anchor means includes a roof plate having a center hole aligned with a respective one of said openings in said plate beam, a roof bolt extending through said aligned hole and opening, and said roof bolt having an inner end anchored within a bore hole in the mine roof and an outer end abutting against said roof plate to urge said roof plate into abutting relation with said bottom surface so that said top surface bears against the mine roof to provide a continuous span of roof support the length of said plate beam.
3. A truss assembly as set forth in claim 2 which includes, a center rib positioned on said roof plate and extending on opposite sides of said center hole, and said roof plate center reinforcing rib having a configuration adapted to be positioned in complementary interengagement with said plate beam center reinforcing rib to increase the surface to surface contact between said roof plate and said plate beam.
4. A truss assembly as set forth in claim 1 which includes, a channel shaped recess extending the length of said plate beam between said pair of lateral ribs, and said center reinforcing rib being positioned within said channel shaped recess.
5. A truss assembly as set forth in claim 1 in which, said anchor means includes an elongated bolt extending through each of said openings in said plate beam and into the mine roof, said elongated bolt having an enlarged end applying an upward bearing force upon said plate beam bottom surface and an upper end positioned in the mine roof, and an expansion shell positioned on said bolt upper end and operable upon rotation of said bolt to expand into gripping engagement with the rock strata of the mine roof to thereby anchor said bolt in the mine roof.
6. A truss assembly as set forth in claim 1 in which, said anchor means includes an elongated bolt extending through each of said openings in said plate beam and into the mine roof, said elongated bolt having an enlarged end applying an upward bearing force upon said plate beam bottom surface and an upper end positioned in the mine roof, and a resin material mixed and cured in surrounding relation with said bolt enlarged end in the mine roof to anchor said bolt to the rock strata of the mine roof.
7. A truss assembly as set forth in claim 1 which includes, said web section including a horizontal panel forming said plate beam top and bottom surfaces and an upstanding panel, said hori-zontal panel being formed integral at one end with said center reinforcing rib and at the opposite end with one end of said upstanding panel, and each of said lateral ribs being formed integral with the opposite end of said respective upstanding panel so that said lateral ribs are vertically spaced a preselected distance from said center reinforcing rib.
8. A truss assembly as set forth in claim 7 in which, said upstanding panel is positioned at an angle with respect to said horizontal panel, and said upstanding panel being arranged to extend downwardly from said horizontal panel when said plate bean top surface is positioned in abutting relation with a mine roof.
9. A truss assembly as set forth in claim 1 in which, said center reinforcing rib has a V-shaped configuration extending downwardly from said plate beam bottom surface to provide a ver-tical dimension between said bottom surface and said lateral ribs greater than the vertical dimension between said bottom surface and said center reinforcing rib.
10. A plate beam for supporting a mine roof comprising, an elongated channel shaped member, a plurality of longitudinally extending ribs projecting from said channel shaped member, said ribs being disposed in spaced relation to form a pair of lateral ribs and a center reinforcing rib positioned between said pair of lateral ribs, a web section for connecting the center reinforcing rib to each of said pair of lateral ribs, said center reinforcing rib having a V-shaped configuration centered on said web section, said center reinforcing rib having a pair of angled sidewalls diverging outwardly and upwardly at an angle from a point below said web section into connection with said web section such that the width of said center reinforcing rib is less than the width of said web section between said respective one of said lateral ribs and said center reinforcing rib, a plurality of openings spaced longitudinally the length of said channel shaped member and ex-ending through said center reinforcing rib, and said channel shaped member having a top surface extending the length of said channel shaped member and arranged to be positioned in abutting relation with a mine roof with said ribs extending downwardly from the mine roof.
11. A plate beam for supporting a mine roof as set forth in claim 10 which includes, said lateral ribs being positioned in spaced parallel relation and vertically spaced from said top surface to form a channel shaped recess extending the length of said member, and said center reinforcing rib being positioned within said channel shaped recess.
12. A plate beam for supporting a mine roof as set forth in claim 10 which includes, a web section for connect-ing said center reinforcing rib to each of said pair of lateral ribs, said web section including a horizontal panel forming said channel shaped member top surface and a pair of upstanding panels, said horizontal panel being formed inte-gral at one end with said center reinforcing rib and at the opposite end with one end of each of said upstanding panels, and each of said lateral ribs being formed integral with the opposite end of said respective upstanding panels so that said lateral ribs are vertically spaced a preselected dis-tance from said center reinforcing rib.
13. A plate beam for supporting a mine roof as set forth in claim 12 in which, each of said upstanding panels is positioned at an angle with respect to said horizontal panel, and each of said upstanding panels being arranged to extend downwardly from said horizontal panel when said top surface is positioned in abutting relation with a mine roof.
14. A plate beam for supporting a mine roof as set forth in claim 10 in which, said center reinforcing rib has a V-shaped configuration extending downwardly from said top surface to provide a vertical dimension between said top surface and said lateral ribs greater than the vertical dimension between said top surface and said center reinforc-ing rib.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US14580280A | 1980-05-01 | 1980-05-01 | |
| US145,802 | 1988-01-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1168459A true CA1168459A (en) | 1984-06-05 |
Family
ID=22514621
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000375647A Expired CA1168459A (en) | 1980-05-01 | 1981-04-16 | Mine roof plate beam for a roof truss assembly |
Country Status (4)
| Country | Link |
|---|---|
| AU (1) | AU6967981A (en) |
| CA (1) | CA1168459A (en) |
| GB (1) | GB2075090B (en) |
| ZA (1) | ZA812674B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6146056A (en) * | 1998-01-14 | 2000-11-14 | Jennmar Corporation | Channel and bearing plate assembly |
| CN102518459A (en) * | 2011-12-15 | 2012-06-27 | 湖南科技大学 | High-strength anchor rope steel channel beam capable of yielding automatically for deep well coal roadways |
| CN108119173B (en) * | 2017-12-29 | 2020-04-28 | 山东里能鲁西矿业有限公司 | Self-moving type telescopic front canopy and supporting method thereof |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU585675B2 (en) * | 1985-12-03 | 1989-06-22 | Arnall's Engineering Pty. Limited | Service line roof strap |
| AU668524B2 (en) * | 1991-10-16 | 1996-05-09 | Buffier, Brian Lesley Joseph | Support device for services |
| WO1993008371A1 (en) * | 1991-10-16 | 1993-04-29 | PINK, Elizabeth, Anne | Support device for services |
| US20120034037A1 (en) * | 2010-08-06 | 2012-02-09 | Fci Holdings Delaware, Inc. | Curved Mine Roof and Rib Support |
| CN102200020A (en) * | 2011-04-26 | 2011-09-28 | 山东大学 | Yielding type special-shaped beam anchor rope truss roadway support system |
| CN108361053B (en) * | 2018-03-13 | 2019-11-05 | 山东里能鲁西矿业有限公司 | A kind of roadway support front cantilever apparatus and method |
-
1981
- 1981-04-16 CA CA000375647A patent/CA1168459A/en not_active Expired
- 1981-04-21 AU AU69679/81A patent/AU6967981A/en not_active Abandoned
- 1981-04-23 ZA ZA00812674A patent/ZA812674B/en unknown
- 1981-04-29 GB GB8113215A patent/GB2075090B/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6146056A (en) * | 1998-01-14 | 2000-11-14 | Jennmar Corporation | Channel and bearing plate assembly |
| CN102518459A (en) * | 2011-12-15 | 2012-06-27 | 湖南科技大学 | High-strength anchor rope steel channel beam capable of yielding automatically for deep well coal roadways |
| CN108119173B (en) * | 2017-12-29 | 2020-04-28 | 山东里能鲁西矿业有限公司 | Self-moving type telescopic front canopy and supporting method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| AU6967981A (en) | 1981-11-05 |
| GB2075090A (en) | 1981-11-11 |
| ZA812674B (en) | 1982-06-30 |
| GB2075090B (en) | 1984-04-18 |
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