Abstract: A subterranean formation containing oil shale is prepared for in situ retorting by initially excavating a lower level drift adjacent a lower portion of an in situ oil shale retort site and excavating an air level void above the retort site. An undercut is excavated below a zone of unfragmented formation remaining within the retort site above the lower drift. The undercut tapers downwardly and inwardly to an opening in the lower drift for forming a draw point for withdrawing fragmented formation particles from the retort site. Formation within the remaining zone of unfragmented formation is explosively expanded downwardly in lifts for forming a fragmented permeable mass of formation particles containing oil shale within the retort site. A plurality of vertical blasting holes drilled in the remaining zone of unfragmented formation are loaded with explosive from the air level void prior to blasting each lift.

Abstract: A core is capable of being utilized within a conduit in a push-pull type remote control cable assembly. The core has a metallic wire member and includes a coating around the wire member which has an outer layer of TFE resin. An inner layer of the coating includes FEP resin which is bonded to the wire member to secure the coating thereabout.

Abstract: A two cable differential and push-pull system uses both cables simultaneously to operate a controlled device. The two cables are tensioned together or pushed together, or one cable is tensioned while the other is pushed, to operate a single device. Controls which have used separate cables for separate functions use paired cables for the multiple functions, reducing stress on individual cables without increasing the number of cables in the installation. In the illustrated transmission control a differential motion, which includes pushing and pulling forces, is applied through the cables to select a rail. A coincident pushing or pulling force is applied through both cables to shift the rail.

Abstract: A wiper which clamps on cable conduit and fits over end cup seals has an opening which loosely receives a sliding cable rod to scrape debris from the rod before portions of the rod enter the seal. The wiper is formed from a strip of spring steel pierced centrally to receive the rod. The piercing forms a slight convex shape and leaves a bow which extends toward the end of the rod to further aid the debris-removing function. The strip is bent rearwardly and then inwardly on both sides, and termini of the strip are formed with abutting semi-circular recesses to engage the conduit behind the end cup.

Abstract: A control means for automatic or semi-automatic transmissions and other devices which includes an integral lock-out means, an integrally movable control lever seal, and a direct reading indicator system. The control comprises a housing having an opening therein and a control lever movable between a selectable number of placements or control positions. The movable control lever includes a lever arm which extends through the opening above the housing and a lever actuator within the housing. The lever control is pivotally mounted within the housing by a pivot means located between the lever arm and actuator. The actuator includes at least one means adapted to mount or receive means for transferring motion, such as a push-pull cable rod from the lever control to the device such as a transmission to be controlled and preferably includes mounting means for slidably mounting a detent pin. A quadrant plate, mounted to the housing, is provided which includes a substantially arcuate opening having at least one detent.

Abstract: The present invention is addressed to a changeable gate plate means for use with lever control devices which have a mounting plate with an opening therein through which the lever arm of the control devices passes. The changeable gate plate means of the present invention comprises a cover means adapted to mount on said mounting plate of the control device and includes an opening therein substantially co-extensive with the opening in the mounting plate. The cover plate includes a gate plate receiving means located adjacent said opening for removably positioning a gate plate at said opening. The gate plate is positioned within the cover opening and receiving means and includes at least one detent in which the lever arm may travel. Means are included for mounting said cover to the mounting plate to complete the assembly in cooperation with the lever control device.

Abstract: A self-adjusting wear resistant seal assembly is provided for a cable rod slidably positioned within a cable conduit. A continuous polyethylene collar is radially compressed in close clearance around the rod by an elastomeric seal which embraces the end portion of the conduit and the collar and holds a flange on the collar against the end portion of the conduit. An integral lip on the seal engages the rod to provide a redundant seal. Corresponding serrations on the conduit and seal cooperate to secure the seal to the rod. A tapered lip may also be provided on the collar for engagement with the rod.

Abstract: A self-aligning, wear-resistant seal assembly is provided for a cable rod slidably positioned within a cable conduit. A rigid nylon ring which fits snugly around the rod is held against the end of the conduit by an elastomeric seal. The seal has an end wall which overlies the ring and has an axial bore aligned with the ring adapted for interference fit around the rod. Corresponding serrations on the conduit and seal cooperate to embracingly secure the seal to the rod.