Abstract: Scroll pumping apparatus includes a first scroll element and a second scroll element; a drive mechanism operatively coupled to the second scroll element for producing orbiting motion of the second scroll element relative to the first scroll element, the drive mechanism having an axis of rotation; and an isolation element to isolate a first volume and a second volume in the scroll pumping apparatus. The isolation element includes a first resilient annular member coupled, directly or indirectly, to the first scroll element, a second resilient annular member coupled, directly or indirectly, to the second scroll element, and a tubular member coupled between the first and second annular members.

Abstract: Scroll pumping apparatus includes a first scroll element and a second scroll element; a drive mechanism operatively coupled to the second scroll element for producing orbiting motion of the second scroll element relative to the first scroll element, the drive mechanism having an axis of rotation; and an isolation element to isolate a first volume and a second volume in the scroll pumping apparatus. The isolation element includes a first resilient annular member coupled, directly or indirectly, to the first scroll element, a second resilient annular member coupled, directly or indirectly, to the second scroll element, and a tubular member coupled between the first and second annular members.

Abstract: Disclosed is a tool holding device capable of being clamped to a rail and holding a tool. The tool holding device comprises a primary body, a secondary body and a fastening mechanism. The primary body comprises a tool receiving portion configured to hold a tool; a first arm and a first plate peripherally integral with the tool receiving portion. The first arm is perpendicular to the first plate. The secondary body comprises a second plate and a second arm integral with the second plate. The second arm is perpendicular to the second plate. The fastening mechanism enables in fastening and clamping the primary body and the secondary body with the rail therebetween such that the first arm and the second arm clamps opposite sides of the rail for firmly clamping the tool holding device to the rail.

Abstract: A ladder-cart for transporting materials has a storage portion with a substantially horizontal area for placing the materials theron. It has a frame having a plurality of support members connected to the storage portion to secure the storage portion above ground level. A plurality of wheels are attached to the frame for engaging the ground and a ladder portion comprising a plurality of steps is integral with the frame.

Abstract: A device for controlling a hydraulic actuator comprises two servo loops having in common a fluid pressure operated main valve and an electrically operated pilot valve for controlling the main valve. One of the servo loops is for flow control and contains a flow transducer for producing an electrical feedback signal responsively to fluid flow to the actuator and a comparator for comparing the flow feedback signal with a first electrical input signal. The other servo loop is for force control and contains pressure transducing means for producing an electrical feedback signal responsively to the pressure drop across the actuator and a second comparator for comparing the force feedback signal with a second electrical input signal.

Abstract: A hydraulic system including a compensator connected between the service ports of the control valve and the load and arranged to restrict the flow in one or both of the service lines so as to maintain a constant pressure difference between the supply pressure and the pressure at the valve service port supplying fluid to the load. The compensator may be connected in both service lines and arranged to restrict the flow equally in each of them. Alternatively a single-sided compensator may be used, and if the load is liable to over-run it must be connected in the service line which is downstream of the load when over-running.