Movable roof support and bolter system

• US 4,710,064 A
• Filed: 09/26/1986
• Issued: 12/01/1987
• Est. Priority Date: 04/15/1985
• Status: Expired due to Fees

• Current Assignee: Frank K. Stafford, Robert C. Nasby
• Original Assignee: Frank K. Stafford, Robert C. Nasby
• Inventors: Nasby, Robert C., Stafford, Frank K.
• Primary Examiner(s): Taylor, Dennis L.
• Application Number:
  US06/912,331
• Time in Patent Office: 431 Days
• Field of Search: 405/288, 405/291-298, 405/150-152, 405/146, 405/141, 405/138, 299/11, 299/32, 299/33, 52/722-725, 52/731, 296/31 P, 175/113, 175/202, 175/203, 175/211, 175/212, 175/219, 175/220, 175/230
• US Class Current: 405/290
• CPC Class Codes: E21D 19/04 for use in drifting galleries
• CPC Class Codes: E21D 23/0086 in galleries

Abstract

A mine roof support system includes a plurality of truss members each having first and second ends which are positioned in spaced relationships one behind another. There are vertically extensible props under each end of the truss members which include stabilizer sleeves to stabilize the truss members thereabove. The vertically extensible props can be extended and retracted to adjust a vertical height of the props for supporting the truss member and for moving it into and out of engagement with the mine roof. Each of the props is supported by a ground engaging means in the form of a selectively operable propulsion unit capable of being operated to produce horizontal movement of the respective props and ends of the truss members. Connecting elements beneath the ends of the truss members connect the props in tandem relationship to permit the horizontal movement of truss members and associated props relative to each other by the propulsion units. Each of the truss members is horizontally expandable to facilitate transportation through a mine passageway prior to being positioned for movement into and out of engagement with the mine roof. The truss member can include a major portion which is fabricated of reinforced fiber glass to permit deflection without permanent deformation when supporting the mine roof to provide a warning prior to any failure of the truss member under the weight of the mine roof.

Claims

1. A mine roof support system comprising:

a plurality of truss members each having first and second ends, said truss members being positioned in spaced relationship one behind another;

each said truss member having a major portion fabricated from a fiber glass material that has an elastic limit permitting deformation of said truss member under a load when in contact with a mine roof;

a plurality of vertically extensible props each having an upper end portion and a lower end portion and including means for extending and retracting said upper end portion relative to said lower end portion to adjust a vertical height of said props;

one of said props being positioned under each of said ends of each said truss member;

said upper end portion of said prop being connected to a respective said end of said truss member so tat each said truss member is supported by a pair of said props for movement into and out of engagement with said mine roof;

ground engaging means for supporting each said prop at said lower end portion thereof for movement on a mine floor;

connecting means beneath said ends of said truss members for connecting adjacent props in tandem arrangement to permit limited horizontal movement of said truss members and associated props relative to each other; and

each said ground engaging means including a selectively operable propulsion unit capable of being operated to produce said horizontal movement of its respective said prop and said end of said truss member.

2. The mine roof support system as set forth in claim 1, wherein said propulsion unit is operable independently of each other said propulsion unit.

3. The mine roof support system as set forth in claim 1, wherein said propulsion unit is rigidly secured to said lower end portion of said prop.

4. The mine roof support system as set forth in claim 3, wherein said propulsion unit is generally aligned perpendicularly to said truss member for said horizontal movement in a direction generally perpendicular to said truss member.

5. The mine roof support system as set forth in claim 4, wherein said propulsion unit is capable of being operated in a first said direction and an opposite second said direction.

6. The mine roof support system as set forth in claim 5, wherein said propulsion unit is capable of creating frictional contact in said mine floor to be further capable of generally pivotal movement about an axis perpendicular to said mine floor and said horizontal movement in a generally curved path when being acted on by outside forces produced by movement of its associated prop relative to other said props, other said truss members, and said connecting means.

7. A mine roof support system as set forth in claim 1, wherein said propulsion unit is capable of making frictional contact with said mine floor to produce said horizontal movement and said connecting means is capable of limiting a horizontal distance between said adjacent props and said propulsion unit will make sliding contact with said mine floor when a limit of said horizontal distance is established by said connecting means.

8. The mine roof support system as set forth in claim 7, wherein said connecting means includes first and second telescoping means which are capable of relative telescoping movement to establish said horizontal distance between said adjacent props.

9. The mine roof support system as set forth in claim 8, wherein said connecting means includes stop means to limit said telescoping of said first and said second telescoping means.

10. A mine roof support beam comprising:

an elongated member having opposite end portions;

vertically extensible prop means connected to each of said end portions of each of said elongated members for raising and lowering said elongated member into and out of position for supporting a mine roof;

said elongated member having a major portion which is fabricated of reinforced fiberglass and has an elastic limit permitting deformation of said elongated member under load when in contact with said mine roof;

said elongated member being movable between a horizontal position and a position deflected from said horizontal position without failure when in abutting relationship with said mine roof to support said mine roof; and

said elongated member when deflected to a preselected position providing a warning that said elongated member is approaching said elastic limit prior to failure of said elongated member under a weight of said mine roof.

11. The mine roof support beam as set forth in claim 10, wherein said major portion of said elongated member is corrosion resistant and nonconductive.

12. The mine roof support beam as set forth in claim 10, wherein said elongated member as a molded box beam configuration of a preselected length, width and thickness.

13. The mine roof support beam as set forth in claim 10, wherein said major portion of said elongated member is fabricated of fiberglass reinforced with a thermosetting polyester resin.

14. The mine roof support beam as set forth in claim 13, wherein said major portion of said elongated member is fabricated of fiberglass reinforced with a vinyl ester resin.

15. The mine roof support beam as set forth in claim 10, wherein said elongated member includes strand support means extending the length of said elongated member in underlying relationship thereto for reinforcing said elongated member and means for securely connecting said strand support means to said elongated member opposite end portions.

16. The mine roof support beam as set forth in claim 15, wherein said strand support means includes a strand of wire rope and said wire rope forms a roof truss suspended across said mine roof to provide reinforcement for said elongated member while providing additional mine roof support.

17. The mine roof support beam as set forth in claim 16, wherein said strand of wire rope is operable to deflect with said elongated member.

18. The mine roof support beam as set forth in claim 13, wherein said elongated member is horizontally extensible to facilitate movement through a mine prior to said supporting said mine roof.

19. A method for temporarily supporting a mine roof that includes the steps of:

positioning a plurality of truss members in spaced relationship extending substantially across a width of a mine passageway so that said truss members are positioned one behind another;

supporting first and second end portions of each of said truss members by props positioned on a mine floor for independent vertical movement of said each truss member into and out of engagement with said mine roof;

connecting said props in tandem relation for movement of said truss members in said mine passageway;

raising selected said truss members into engagement with said mine roof so that said selected truss members are in position for supporting said mine roof;

permitting at least one of said truss members to move between a horizontal position and a predetermined position deflected downwardly from said horizontal position a preselected distance under a weight of said mine roof without failure of a deflected said member; and

indicating approaching failure of said truss members under said weight of said mine roof by said deflected truss member moving beyond said preselected distance to provide a warning of possible collapse of said mine roof above said deflected truss member prior to said collapse of said mine roof.

20. The method for temporarily supporting a mine roof as set forth in claim 19, further including the step of lowering said deflected truss member out of contact with said mine roof to permit said deflected truss member to move from said position deflected downwardly to said horizontal position without incurring permanent deformation of said deflected truss member.

21. The method for temporarily supporting a mine roof as set forth in claim 19, further including the step of measuring an amount of deflection as compared to said preselected distance to determine if said deflected truss member is approaching an elastic limit of said deflected truss member prior to failure thereof under said weight of said mine roof.

22. The method for temporarily supporting a mine roof as set forth in claim 19, further including the step of reinforcing each of said truss members with a supporting strand which extends a length of said truss member, is secured to said first and said second end portions of said truss members, and is positioned to support said mine roof in addition to said truss member.

23. A mine roof support system comprising:

a plurality of truss members each having first and second ends, said truss members being positioned in spaced relationship one behind another;

each said truss member having a major portion fabricated from a fiber glass material that has an elastic limit permitting deformation of said truss member under a load when in contact with a mine roof;

a plurality of vertically extensible props each having an upper end portion and lower end portion and including means for extending and retracting said upper end portion relative to said lower end portion to adjust a vertical height of said props;

one of said props being positioned under each of said ends of each of said truss members;

connecting means for connecting said upper end portion of said prop to said end to resist bending of said prop under a weight of and on said truss member as a pair of said props support said truss member for movement into and out of engagement with a mine roof;

ground engaging means for supporting each said prop for movement on a mine floor;

said connecting means including a stabilizer sleeve having an upper end connected to said end of said truss member;

said stabilizer sleeve extending downwardly from said truss member in surrounding concentric relation with said upper end portion of said prop such that said stabilizer sleeve moves with said upper end portion upon extension and retraction of said upper end portion to raise and lower said truss member;

said stabilizer sleeve having a lower end extending below said upper end portion of said prop into overlaying relation with said lower end portion of said prop; and

said stabilizer sleeve being slidable on said lower end portion to stabilize said truss member above said prop.

24. The mine roof support system as set forth in claim 23, which includes means positioned between said stabilizer sleeve and said upper end portion for rigidly connecting said stabilizer sleeve to said upper end portion for vertical stabilized movement of said stabilizer sleeve relative to said lower end portion of said prop.

25. The mine roof support system as set forth in claim 23, wherein said stabilizer sleeve is welded at said upper end to said end of said truss member and said stabilizer sleeve is connected to said upper end portion of said prop so that said stabilizer sleeve moves with said upper end portion to raise and lower said truss member.

26. The mine roof support system as set forth in claim 23, further including a cap member concentrically positioned on said upper end portion of said prop between said stabilizer sleeve and said upper end portion for stabilizing said stabilizer sleeve around said upper end portion of said cap member is welded to said upper end portion.

27. The mine roof support system as set forth in claim 23, wherein said stabilizer sleeve extends downwardly around said upper end portion of said prop, said stabilizer sleeve has an inner surface surrounding and spaced from an outer surface of a major section of said upper end portion, a cap member is mounted on said upper end portion between said inner surface of said stabilizer sleeve and said outer surface of said major section of said upper end portion, and said stabilizer sleeve, said cap member, and said major section of said upper end portion are connected in a concentric relation to rigidify said major section of upper end portion below said truss member.

28. A mine roof support system as set forth in claim 27, wherein said cap member includes an outer surface for receiving said inner surface of said stabilizer sleeve and said lower end portion of said porp has an outer surface for receiving said inner surface of said stabilizer sleeve lower end portion to therby provide stability to said stabilizer sleeve as said stabilizer sleeve moves vertically on said outer surface of said lower end portion upon extension and retraction of said upper end portion of said prop.