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Mine Safety and Health Administration
MSHA's Accident Prevention Program
Innovative Products

Roof Bolting Machine
Outby Rocker Pad Deflector

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Safety Something YOU can live with!

J.H Fletcher & Co. has designed a machine-mounted "outby rocker pad deflector" to improve roof bolter operator safety. The device is intended to reduce roof bolter operator accidents resulting from small pieces of roof rock (roof skin failures) which fall in the area between the ATRS beam and the driller canopy.

Information about the device:
  • Steel plates are hydraulically deployed from a stowed position to parallel to the roof, individually controlled from the chassis.

  • Holes in the deflector plates allow just enough clearance for an 8" X 8" roof bolt plate to pass through.

  • When deployed, the deflector plates are approximately two inches from the roof, allowing oversized bearing plates, straps, or roof mats to be used.

  • The deflector's hole locations help ensure consistent roof bolt spacing.

  • Bolter operators don't have to mark bolt locations, allowing them to stay under the drill station canopy.

  • The outby deflector builds on the success of the inby rocker pad deflector, which has been in service since 1995.

  • Although the maximum benefit is gained on machines with inside controls; additional protection is still afforded to operators of outside control machines.

  • Current designs will work best on machines with "L"-style ATRS systems with leveling link and articulating beams, operating in mining heights above five feet.
 ATRS with outby rocker pad deflector on walk thru DDR.

Drilling through a 13
For information on manufacturers that are known to MSHA to have such products available, contact MSHA's Applied Engineering Division at 304-547-2303 or e-mail

Issued: 02/19/2009