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The purpose of this paper is to study the flow characteristics of damping control valve of shock absorber, and obtain the minimum driving current required under different working conditions.

Based on the simplified model of the internal structure of damping control valve and the theory of fluid mechanics, the mathematical model of the damping control valve driving current under rated load is established. The test bench was designed to study the relationship between flow characteristics and driving current of the damping control valve.

The results show that the minimum driving current of switching and flowrate show a linear relationship and the minimum current required for the 4-1 switching is the largest that means the minimum current as long as meets the 4-1 switching to meet the needs of all levels switching.

These results of the theoretical and experimental study provide a reliable guide and reference for the design and application of damping control valve.

Two years ago, Occidental Chemical Corp of Burlington, New Jersey, USA, ran into a problem in its PVC‐resin‐processing operation.

There is a tendency on the part of some engine operators to expect modern lubricating oils to solve all their maintenance difficulties. They frequently forget that badly designed engines are often the root of troubles thought to be caused by faulty lubrication. These points were emphasised in a paper presented recently to a Lubrication Group Session during the Annual Meeting of the American Petroleum Institute at Chicago, by A. T. Colwell and A. L. Pomeroy, of Thompson Products Inc.

The Westland Lynx helicopter is a particularly fine example of the use of advanced fan technology in modern aircraft applications. The firm of Airscrew Howden have come a long way from their original manufacture of the wooden ‘prop’ but they still continue to play a very essential part in all types of aircraft flying today; this takes the form of sophisticated fan designs to cover a wide variety of special air‐movement requirements that can arise in this sector.

Operating procedure synthesis (OPS) has been used to generate plant operating procedures for chemical plants. However, the application of AI planning to this domain has been rarely considered, and when it has the scope of the system used has limited it to solving “toy” problems. This paper describes the application of state‐of‐the‐art AI planning techniques to the generation of operating procedures for chemical plant as part of the INT‐OP project at the Universities of Salford and Loughborough. The CEP planner is outlined and its application to a double effect evaporator test rig is discussed in detail. Particular attention is paid to the issues involved in domain modelling, requiring the description of the domain, development of AI planning operators, the definition of safety restrictions, and the definition of the problem. There is then a presentation of the results, lessons learned and problems still remaining.

Looks at a system for diagnosing valve performance which works by measuring or inferring dynamic parameters such as valve travel, friction, seat load, seat contact and supply pressure by using sensors attached to the valve instrumentation. The system, which can be used in a factory or to taken to a valve on site, interprets the results and stores the test data. Gives application examples in the fertiliser and paper industries and continues that the next step will to embed diagnostics within the valve instrumentation itself. Concludes that the concept of “total valve management” in reducing costs helping plants operate more effectively will become increasingly important to manufacturers in coming years.

THE airframe systems division of Lucas Aerospace are involved in producing the high lift and wing sweep control unit for which the design rights are shared with Microtecnica SpA who hold the contract.

Smiths Industries is to supply the head‐up display system for the Sea Harrier. The company will design, develop and make the electronic head‐up display and weapon aiming computer system for the latest version of the HS Harrier which will operate from Royal Navy ships.

In hydraulically‐operated retractable wheels for aircraft the actuating member comprises a jack having a piston connected on one side with a motive pump and an exhaust, and on the other side with a hydro‐pneumatic pressure accumulator into which the liquid is forced by the jack during each lifting operation, the stored energy in the accumulator actuating the jack to assist the action of gravity when lowering the wheels. The retractable wheels R (Fig. 1) are each pivoted at A and connected to a fluid‐operated piston in a cylinder V pivoted at T, the wheels being drawn up into the machine through spring‐operated doors C1, D1 which are opened by fluid‐operated means G2 (Fig. 2) when the wheels are lowered. The cylinder V is connected by pipe 3 and non‐return valve 4 to a pump 1 supplied from a reservoir 2, surplus liquid being bye‐passed from the pump through a pipe 16. A pipe 5 for exhausting the cylinder V is connected through a manually‐operated valve 6 to the reservoir 5 and a branch 3a from the pipe 3 is connected to a cylinder 8 whereby pressure is applied to move valve 12 and non‐return valve 10 to place the other end of the cylinder V to discharge through pipes 3b, 3e to a pneumatic accumulator 9 supplied with air from a cylinder 14. When pressure is supplied by the pump 1 to the cylinder V to retract the wheels, a projection on the valve 12 opens the valve 10 and the liquid in the other end of the cylinder is forced into the accumulator 9, and when the wheels are to be lowered the valve 6 is opened by the lever 7 to exhaust one end of the cylinder into the reservoir 2 while the other end of the cylinder is supplied with pressure fluid from the accumulator. A pipe 17 from the pump 1 is connected to a cylinder G2 and is provided with a branch 18 and manually‐operated valve 19 whereby the cylinder may be exhausted. The cylinders G2 (Fig. 5) are connected by links to the doors C1, C2 maintained in the closed position by springs r1, r2, the doors C1, C2 being interconnected to open smaller doors D1 (Fig. 1) which remain open when the wheels R are lowered. The levers 25, 20, 7 (Fig. 2) are connected to a single control lever. In Fig. 10, the wheel arm J is pivoted at A and is connected by piston rod P to the cylinder V pivoted at T. A wire 35 connected to the arm J passes over pulleys 36, 37, and is connected to a piston in a horizontal cylinder 41 open to a pneumatic reservoir 9. When the wheel R is raised to the position R1 by the admission of fluid under the piston P, the wire 35 rapidly withdraws the piston in the cylinder 41 to compress the air in the accumulator 9, and since the effect of gravity is not so pronounced between the positions R, R1 as between R1, R2 and the fact that the air pressure on R tends to raise the wheel, the pressure applied to the piston P is mainly stored in the accumulator 9. From the position R to R1 the effect of air pressure is less and gravity greater, so that between these positions the wire 35 is adapted to lap around a pulley 43 on the axis A whereby the movement of the piston in the cylinder 41 is small and less power is stored in the accumulator 9, the pressure on the piston P being primarily expended in raising the wheel from R1 to R2. Similarly when lowering the wheel the accumulator expends the greatest power between R1, R. A device for recovering any leakage from the pump 1 when the reservoir 2 is at a higher level is shown in Fig. 9. A leakage pipe 28 is connected by a housing 29 and pipe 30 to the suction pipe 33, and the housing contains a float 31 with upper and lower needle valves. When the housing 29 is full of liquid, the pipe 28 is closed by the upper needle valve and the liquid in the housing is withdrawn through pipe 30 and when the housing is empty the float falls and closes the pipe 30.

The purpose of this paper is to analyze the roles of deals in innovations processes, based on the definition of a deal as the interaction of social-material value-creating processes with money-handing processes.

The paper is based on a study of the historical emergence of transaortic valve implantation (TAVI) as an innovative new technology in the area of thoracic surgery in a global setting. The study is based on a combination of interviews and secondary data analysis.

The authors found that deals play important roles in innovation processes as critical junctions that mark entries to different phases and generate major shifts in location as well as combination of resources, activities and actors. These shifts include radical changes in control, where actors in possession of resources necessary to bring the project through the next phase, move in to take control – thereby expanding their businesses to new growth niches. Based on the analysis of seven deals, the authors argue that the innovation process is a combined push and pull process where later stage entrepreneurial interests play very significant roles. Deals may also represent radical turning points and moves of the projects that set the project off in a different direction, usually also associated with shifting ownership control rights through the innovation and scaling process. The authors also argue that inventions in the periphery will tend to move to the areas with the most competent relevant business networks capable of adopting and expanding the innovation to a global business operation. The innovation process is not primarily about creating new resources and activities, but about recombining existing resources, competencies and activities. Supplier networks play particularly important roles in these processes.

The authors suggest that the study indicates that IMP researchers should turn more attention to studying business deals and financial flows and influences – in particular in studies of innovations and innovation processes – to investigate the mechanisms by which new innovations interact with and transform existing business networks.

This work highlights why and how an innovation that may initiate anywhere in the periphery, will tend to move to the most competent and capable networks around the globe, that are the most relevant to the needs of the innovation project. Hence, the more powerful business networks and eco-systems will tend to pull interesting inventions in from their periphery, and grow them effectively.

The paper expands the efforts in IMP theorizing to include financial/monetary interactions more explicitly into business network theory. It also aims at clarifying core IMP arguments toward entrepreneurship research, in particular research on international new ventures.