Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Supporting pillar for mines










Image Number 6 for United States Patent #4662796.

The invention relates to a travelling support pillar for use in underground mines.The support pillar has a link subjected to the action of a positioning jack. The positioning jack extends between a gate and the rear of the top of the pillar. The positioning jack hydraulically locks the support pillar by means of a sliding pressure-relief valve to compensate for load changes due to the movement of the floor or the roof. The link also permits the support pillar to be collapsed for transportation, and it provides a support pillar with a shorter length and a lower height in the collapsed position, and it permits the top of the support pillar to be placed closer to the working face of the mine when the pillar is in its roof supporting extended position.








 
 
  Recently Added Patents
Electrical conduit containing a fire-resisting thermoplastic composition
Buried object detection in GPR images
Pixel circuit
Method and apparatus for representing sensory effects and computer readable recording medium storing user sensory preference metadata
Switchgear and method for operating switchgear
Performing a cyclic redundancy checksum operation responsive to a user-level instruction
Mode detection for DVB receiver
  Randomly Featured Patents
Protective coatings for solid inkjet applications
Scoop shovel
System for controlling air supply pressure in a pneumatic direct fuel injected internal combustion engine
1-(4-alkylphenylethynyl)-4-(alkylphenylethynyl)-benzene
Arc tube/shroud holder for hid lamp
Method for the growth restriction of undesirable digestive system bacteria in animals and the establishment of lactobacillus lactis NRRL B-5628
Asynchronous memory refresh arbitration circuit
Safety bumper
Acid milk beverage and process for producing the same
Drive unit with brake for an elevator