摘要:
A housing receives a printed circuit board and a plurality of daughter boards. The housing has two opposing sidewalls, a floor, and a ceiling. The sidewalls extend from opposing sides of the floor to opposing sides of the ceiling. The opposing sidewalls, the floor and the ceiling defining an opening for receiving a daughter board within slots in the floor and the ceiling. A movable ceiling member attaches to the sidewalls. The ceiling, the movable ceiling member and the sidewalls define an opening for receiving a printed circuit board, such as a backplane, when the movable ceiling member is in an unsecured position. The movable ceiling member is aligned with the ceiling when the movable ceiling member is in a secured position. The movable ceiling member includes a fastener that secures the printed circuit board. The movable ceiling member accommodates printed circuit boards having various thicknesses.
摘要:
A stiffener supports a printed circuit board during insertion and removal within a slot of a card cage having one or more electrical connectors. The stiffener has a rigid elongated member that defines an elongated channel. The elongated member is adapted to engage an edge of the printed circuit board along the channel. The member has an engagement portion for receiving an applied force, a driver portion for engaging an electrical connecting mechanism, and a translator portion for translating the force from the engagement portion to the driver portion.
摘要:
A support bracket, which can be used in a method of reinforcing a printed circuit board, secures the printed circuit board, such as a backplane having a plurality of electrical connectors that engage corresponding electrical connectors of daughter boards. The support bracket includes a cross member attachable to the printed circuit board in a direction substantially transverse to a direction of motion of the daughter boards. The support bracket also includes first and second end support members attached transversely to the cross member at corresponding ends of the cross member. The end support members are fixable to a support surface and are adapted to secure the support bracket in the direction of motion of the daughter boards.
摘要:
A fastening device attaches a printed circuit board, such as a backplane, within a support framework of an electrical cabinet. The fastening device includes two adjacent members of the support framework. A threaded stud is attached to one of the members and extends toward the adjacent member. A captive fastener is attached to the other adjacent member. The captive fastener has a thread that cooperates with the thread of the stud. The fastener is aligned with the stud, the cooperative thread of the fastener is capable of engaging the thread of the stud. The fastening device secures the printed circuit board between the adjacent members of the support framework.
摘要:
A method of preventing or treating lost circulation during the drilling of a well comprises the addition, at concentration ranging between about 0.5 and 6 pounds per barrel, of water-dispersible fibers having a length between about 10 and 25 mm, for instance glass or polymer fibers, to a pumped aqueous base-fluid including solid particles having an equivalent diameter of less than 300 μm.The base-fluid with the solid particles can be the drilling fluid or a small-volume pill specially pumped for curing lost circulation.
摘要:
A system for communicating to a motor vehicle operator the maximum safe speed at which the vehicle can be operated. The system includes receiver(s), sensor(s), processor(s) and dashboard display(s). The receiver(s) detects a legal speed limit. Sensor(s) detects environmental conditions surrounding the motor vehicle. The processor(s): receive data from the receiver(s) and sensor(s); calculates a maximum safe speed; and calculates a safe speed range based on the maximum safe speed and the legal speed limit. The dashboard display alerts the driver if the maximum safe speed is less than the legal speed limit, and displays the safe speed range if the maximum safe speed is less than the legal speed limit.
摘要:
Methods for treating a formation penetrated by a wellbore which improves fluid loss control during treatment. In some aspects, the treatments include preparing an aqueous fluid including one or more water inert polymers and an optional viscosifier, injecting the aqueous fluid into the wellbore at a pressure equal to or greater than the formation's fracture initiation pressure, and thereafter injecting into the wellbore a proppant laden fluid at a pressure equal to or greater than the formation's fracture initiation pressure. The water inert polymer may be a polymer such as an emulsion polymer or a latex polymer. Some methods of the invention use a fluid which may have a normalized leak off coefficient (Cw/sqrt(K)) equal to or less than about 0.0022, 0.0014, or 0.0010. A conventional fluid loss additive may or may not be used in conjunction with the treatment fluid and/or the proppant laden fluid. The water inert polymer may or may not substantially enter formation pores. In another aspect, methods for reducing matrix damage to a formation during a treatment operation include preparing an aqueous treatment fluid formed of at least one water inert polymer, and injecting the fluid at a pressure equal or greater than the formation's fracture initiation pressure.