David A Rohrbaugh

6402611, Jun 11, 2002

Jan 29, 2001

09/770622

David J Rohrbaugh - Oakland MD, 21550

E21F 114

454169, 405152, 49501

The hinged mine stopping has at least two panels joined by a hinge defining a wall adapted for forming an air tight seal in a mine passageway to improve mine ventilation. Each panel has a lower section defined by a sheet of gas impermeable material mounted on a tubular, rectangular frame, and an upper section defined by a sheet of gas impermeable material mounted on a tubular, inverted U-shaped frame. The side members of the upper section frame telescope into the side members of the lower section frame for height adjustment of the panels. Preferably the hinged mine stopping is disposed between the ribs of a mine in a V-shape, with the apex directed towards the high pressure side to reduce the load on the stopping, the perimeter of the stopping being sealed.

54236541, Jun 13, 1995

Sep 25, 1992

7/951016

David J. Rohrbaugh - Oakland MD

E02F 300

414686

Disclosed herein is a miniature, portable, self-contained power machine for handling materials, comprising, a rigid frame providing the base structure for all components of said machine, a means of electrical power supply for said machine, means for regulating the motion of said machine, two endless belts forming a belt traction system and serving as the means to move said machine over various types of terrain, means for readily receiving and rigidly securing a variety of miniature, hydraulically powered material handling implements to said machine, and a central hydraulic system which is powered by said power supply means and which supplies power to said attachable material handling implements. The machine has a diversity of applications in numerous industries. The machine accepts any of a variety of attachable implements through an assembly socket and a torque arm socket, and then links the implement to the central hydraulic system with hydraulic hoses leading to a hydraulic power manifold.

56477210, Jul 15, 1997

Jun 7, 1995

8/478517

David J. Rohrbaugh - Oakland MD

E02F 300

414686

Disclosed herein is a miniature, portable, self-contained power machine for handling materials, comprising, a rigid frame providing the base structure for all components of said machine, a means of electrical power supply for said machine, means for regulating the motion of said machine, two endless roller chains forming a traction system and serving as the means to move said machine over various types of terrain, means for readily receiving and rigidly securing a variety of miniature, hydraulically powered material handling implements to said machine, and a central hydraulic system which is powered by said power supply means and which supplies power to said attachable material handling implements. The machine has a diversity of applications in numerous industries. The machine accepts any of a variety of attachable implements through an assembly socket and a torque arm socket, and then links the implement to the central hydraulic system with hydraulic hoses leading to a hydraulic power manifold.

59040424, May 18, 1999

Aug 28, 1997

8/919216

David Rohrbaugh - Oakland MD

F01N3/00

60298

A diesel exhaust conditioning system removes harmful gaseous and particulate pollutants from the exhaust of a diesel engine, and also lowers the temperature of the emitted exhaust and of the shroud surrounding the pollution control components of the device. The system includes at least one combination catalytic converter and particulate filter, structured to operate at a sufficiently high temperature as to convert potentially harmful gaseous pollutants to innocuous substances, and which also collects and oxidizes carbon and hydrocarbon particles in the diesel exhaust to convert them to innocuous substances as well. The catalytic converter(s) is contained in an insulated canister for containing the heat generated by the catalytic reactions, with the insulation also serving to lower the outside temperature of the canister. A shroud is placed around the canister and other components, with an axial fan blowing ambient air between the canister and shroud to reduce the exterior temperature of the shroud to an acceptable level. The ambient air is mixed with the exhaust at the downstream end of the system, to lower the temperature of the exhaust gases to an acceptable level.