US2726569A - Wedge bolt with slotted end of elliptical cross-section - Google Patents

Wedge bolt with slotted end of elliptical cross-section Download PDF

Info

Publication number
US2726569A
US2726569A US253128A US25312851A US2726569A US 2726569 A US2726569 A US 2726569A US 253128 A US253128 A US 253128A US 25312851 A US25312851 A US 25312851A US 2726569 A US2726569 A US 2726569A
Authority
US
United States
Prior art keywords
elliptical
slotted
rod
hole
roof
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 - Lifetime
Application number
US253128A
Inventor
Walter R Penman
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bethlehem Steel Corp
Original Assignee
Bethlehem Steel Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Bethlehem Steel Corp filed Critical Bethlehem Steel Corp
Priority to US253128A priority Critical patent/US2726569A/en
Application granted granted Critical
Publication of US2726569A publication Critical patent/US2726569A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21DSHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D21/00Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection
    • E21D21/0026Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection characterised by constructional features of the bolts

Description

Dec. 13, 1955 w. R. PENMAN WEDGE BOLT WITH SLOTTED END OF ELLIPTICAL CROSS-SECTION Filed Oct. 25, 1951 INVENTOR 9 h/zlter IZ. Penlluuv.

BY 2f@ United States Patent O WEDGE BOLT WITH SLOTTED END F ELLIPTICAL CRSS-SECTION Walter R. Penman, Lebanon, Pa., assigner to Bethlehem Steel Company, a corporation of Pennsylvania Application October 25, 1951, Serial No. 253,128

2 Claims. (Cl. 852) My invention relates to improvements in wedge bolts with slotted ends of elliptical cross-section and accessories.

By means of proper roof bolting, it is possible to eliminate at least a considerable part of the risk of sags and falls of overlying strata of rock and coal otherwise inherent in ordinary mining operations.

One object of this invention, therefore, is to provide a mine roof rod which will develop maximum grip and holding strength when in place under load.

Another object is a roof rod which will resist rotation while a nut is being threaded thereon.

Still other objects, purposes and advantages of the invention will appear hereinafter in the specification and drawings and in the appended claims.

In the annexed sheet of drawings:

Fig. 1 is a vertical cross-section of a mine entry, illustrating one application of my invention with a continuous roof support;

Fig. 2 is a broken side elevation of a mine roof rod, showing the lower end threaded to engage a nut and the upper end corrugated and slotted to receive an expansion wedge;

Fig. 3 is a top plan view of the mine roof rod of Fig. 2, and showing the generally elliptical form of the upper end of the rod;

Fig. 4 is a side detail view of the upper end of the rod, rotated 90 from the side shown in Fig. 2;

Fig. 5 is a horizontal transverse section of an ordinary round rod having a smooth outer surface on the upper end, showing the limited bearing area of a split round rod against the periphery of the round hole within which it is expanded by the wedge;

Fig. 6 is a transverse horizontal section of the expanded elliptical upper end of a rod having a limited number of rounded longitudinal corrugations, four on each side being shown, illustrating the enlarged area of peripheral contact with the same hole;

Fig. 7 is a transverse horizontal section of the unexpanded elliptical upper end of a rod having a larger number (shown as seven) of sharp-toothed longitudinal corrugations;

Fig. 8 is a transverse horizontal section of the upper end of the rod shown in Fig. 3; and

Fig. 9 is a transverse horizontal section of a rod having a smooth elliptical outer surface on its slotted upper end.

Referring more particularly to Fig. 1 of the drawings, the reference numeral 1 indicates a mine entry or other passageway through a coal vein 2 forming side walls or pillars 3 and having overlying strata 4 of rock, slate and the like which form a roof 5 for the passageway. Rails 6 on rail ties 7 are provided on the oor 8 for the movement of mine cars or machines in understood manner. Steel roof ties 9 or the like supply beam ICC strength and reinforcement to the mine roof 5, against which they are held by nuts 10 bearing against flat washers 11 or angle washers 12, said nuts 10 being threaded onto the lower ends 13 of round rods 14 rmly anchored in holes 21 somewhat larger than said lower rod ends 1?: drilled in the overlying strata.

In Fig. l a pair of rods 14 are shown as driven vertically upward through suitable holes in the roof tie 9, with two other rods extending divergingly outward and upward through similar holes at each end of the roof tie 9 into the rock above the pillars 3. Other arrangements or combinations of rods with other members Y are obviously possible, however.

The lower ends 13 of the rods 14 are externally threaded as at 15 to receive the nuts 10. The upper ends 16 of the rods are substantially elliptical in crosssection, with their hole-engaging outer surfaces having a radius of curvature substantially equal to or greater than the radius of the hole, and are longitudinally slotted as at 17 through their major axes. Said outer surfaces may be provided with longitudinal corrugations, either numerous and sharp-edged as at 18 (Fig. 7) or fewer and more rounded as at 19 (Fig. 8), o1' even without corrugations, asat 20 (Fig. 9), the last-mentioned form tending perhaps to be slightly less resistant to applied torque than the others. Comparison of Figs. 5 and 6 will illustrate the increase in bearing area against the hole made possible by an expanded rod surface which is elliptical instead of round, with rods of equal weight.

To expand the slotted upper ends 16 of the rods 14 against the peripheries of the holes 21, any of conventional flat-pointed wedge may be satisfactorily employed.

Although I have thus described my invention in considerable detail, I do not wish to be limited narrowly to the exact and specific particulars disclosed above, but I may also use such modications, substitutions, or equivalents as are included within the scope and spirit of the invention or pointed out in the appended claims.

I claim:

l. A mine roof rod, comprising a rod having an externally threaded portion at one end and an opposite end portion of substantially elliptical crossasection, said substantially elliptical portion being longitudinally slotted through its major axis and adapted to be expanded in a circular hole in the mine roof, the radius of curvature of the hole-engaging surface of said elliptical slotted end portion being at least equal to the radius of the hole,

2. A mine roof rod, comprising a rod having an externally threaded portion at one end and an opposite end portion of substantially elliptical cross-section, said substantially elliptical portion being longitudinally slotted through its major axis and adapted to be expanded in a circular hole in the mine roof; the radius of curvature of the hole-engaging surface of said elliptical slotted end portion being at least equal to the radius of the hole, said hole-engaging surface being further provided with a plurality of external corrugations; whereby said rod is characterized by great holding power and resistance to rotation when expanded in a circular hole.

References Cited in the le of this patent UNITED STATES PATENTS 419,018 King et al Jan. 7, 1890 660,566 Gage Oct. 30, 1900 710,216 Schmidt Sept. 30, 1902 1,229,287 Kennedy June 12, 1917 1,251,566 Pigott Jan. 1, 1918 1,349,998 Aylward Aug. 17, 1920

US253128A 1951-10-25 1951-10-25 Wedge bolt with slotted end of elliptical cross-section Expired - Lifetime US2726569A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US253128A US2726569A (en) 1951-10-25 1951-10-25 Wedge bolt with slotted end of elliptical cross-section

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US253128A US2726569A (en) 1951-10-25 1951-10-25 Wedge bolt with slotted end of elliptical cross-section

Publications (1)

Publication Number Publication Date
US2726569A true US2726569A (en) 1955-12-13

Family

ID=22958984

Family Applications (1)

Application Number Title Priority Date Filing Date
US253128A Expired - Lifetime US2726569A (en) 1951-10-25 1951-10-25 Wedge bolt with slotted end of elliptical cross-section

Country Status (1)

Country Link
US (1) US2726569A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1111580B (en) * 1958-11-06 1961-07-27 Becorit Grubenausbau Gmbh Expanding sleeve anchors, especially for mining operations
US3411398A (en) * 1966-03-31 1968-11-19 Vsi Corp Blind fastener
US4397595A (en) * 1977-06-06 1983-08-09 Dry Dock Industries, Inc. Anchoring retainer for threaded fasteners
US4415299A (en) * 1977-06-06 1983-11-15 Dry Dock Industries, Inc. Anchoring retainer for threaded fasteners
US4491447A (en) * 1980-05-15 1985-01-01 Dry Dock Industries, Inc. Anchoring retainer for threaded fasteners

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US419018A (en) * 1890-01-07 Fence-post
US660566A (en) * 1900-06-19 1900-10-30 Samuel E Gage Means for renewing house-walls.
US710216A (en) * 1902-06-12 1902-09-30 John M Schmidt Insulating-hanger.
US1229287A (en) * 1913-08-14 1917-06-12 Clements Company Wall-socket.
US1251566A (en) * 1916-11-21 1918-01-01 George W Pigott Railroad-spike.
US1349998A (en) * 1918-09-10 1920-08-17 Henry W Aylward Expansion-bolt

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US419018A (en) * 1890-01-07 Fence-post
US660566A (en) * 1900-06-19 1900-10-30 Samuel E Gage Means for renewing house-walls.
US710216A (en) * 1902-06-12 1902-09-30 John M Schmidt Insulating-hanger.
US1229287A (en) * 1913-08-14 1917-06-12 Clements Company Wall-socket.
US1251566A (en) * 1916-11-21 1918-01-01 George W Pigott Railroad-spike.
US1349998A (en) * 1918-09-10 1920-08-17 Henry W Aylward Expansion-bolt

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1111580B (en) * 1958-11-06 1961-07-27 Becorit Grubenausbau Gmbh Expanding sleeve anchors, especially for mining operations
US3411398A (en) * 1966-03-31 1968-11-19 Vsi Corp Blind fastener
US4397595A (en) * 1977-06-06 1983-08-09 Dry Dock Industries, Inc. Anchoring retainer for threaded fasteners
US4415299A (en) * 1977-06-06 1983-11-15 Dry Dock Industries, Inc. Anchoring retainer for threaded fasteners
US4491447A (en) * 1980-05-15 1985-01-01 Dry Dock Industries, Inc. Anchoring retainer for threaded fasteners

Similar Documents

Publication Publication Date Title
US3482492A (en) Joint seal
US4152875A (en) Ground covering with adjoining plates
US3695045A (en) Rock bolts
US4371293A (en) Mine roof bearing plate
US20190218910A1 (en) Asymmetric support structure of entry driven along gob-side under unstable roof in deep mines and construction method thereof
US3541798A (en) Method and structure for shoring a lateral face of an excavation
EP0143534B1 (en) Mine roof support system
US4666344A (en) Truss systems and components thereof
US2667037A (en) Suspension roof support
KR20090117701A (en) A deformable rock bolt
CN103061764B (en) Goaf waste rock filling coal mining method of flexible shield support in half-edge coal seam
CN105370299B (en) The buried empty roadway protection processing in high seam thin coal pillar edge of km
US5466095A (en) Underground support system and method of support
US3585771A (en) Connecting precast concrete structural members
CN102121389B (en) Method for preventing and treating roof falling and side collapsing of coal roadway surrounding rock by anchor rope truss
US3509726A (en) Roof support for underground mines and openings
US3139730A (en) Rock anchor
CN106089258A (en) Tunnel device and construction method
WO2018133493A1 (en) Unbalanced support design method for gob-side entry driving under deep unstable cover rock
CN205189893U (en) Be used for a lane coal column to wearing reinforced (rfd) supporting construction
US3139277A (en) Boat storage apparatus
CN1017465B (en) Closed supports
US3427811A (en) Mine roof support system
US5193940A (en) Mine roof support system
US3010257A (en) Prestressed girder