Abstract: A pumping unit is of the type having a compressor made up of a cylinder and piston extending between a walking beam and samson post, opposite connecting end portions of the compressor clampingly engaging the walking beam and samson post, respectively, and spherical bearing members of the non-lubricating type are disposed in each of the connecting end portions to undergo universal movement in response to any lateral displacement or side loading of the walking beam.

Abstract: A novel and improved method and means have been devised for releasably bridging or isolating formations in a well. The apparatus consists of a retrievable bridge plug which can be run down into a well to the desired setting depth and a packer assembly on the plug can then be activated to set the apparatus in position. After work has been performed, a retrieving tool is run into the well in order to engage the bridge plug for its removal. If sand or other foreign matter is present on top of the plug, a circulating medium may be employed to remove the foreign matter even as the retrieving tool is being lowered into engagement with the plug. The plug is designed such that pressure can be equalized on opposite sides of the plug as a preliminary to removal from the well by the retrieving tool.