Abstract: A heat machine having an external heat source and an external heat sink may be configured as a Stirling engine having a hot pair of cylinder-and-displacer combinations 15 and a cold pair of cylinder-and-displacer combinations 16 though advantageously two pairs of hot combinations 15 and two pairs of cold combinations 16 are provided, arranged mutually at right angles. Mechanisms 20 associated with the hot and cold displacers controls the movement thereof to be truly sinusoidal and are contained within casings 21. The pressure in the working fluid spaces remote from the mechanisms 20 and also the pressure in the casings 21 is monitored and compared, and then is controlled such that the casing pressure is slightly less than the minimum working fluid pressure in the working fluid spaces. The relative phase of the two mechanisms 20 associated respectively with the hot displacers and the cold displacers is adjustable (28,29,30,31; and FIG. 4).

Abstract: A heat machine having an external heat source and an external heat sink may be configured as a Stirling engine having a hot pair of cylinder-and-displacer combinations 15 and a cold pair of cylinder-and-displacer combinations 16 though advantageously two pairs of hot combinations 15 and two pairs of cold combinations 16 are provided, arranged mutually at right angles. Mechanisms 20 associated with the hot and cold displacers controls the movement thereof to be truly sinusoidal and are contained within casings 21. The pressure in the working fluid spaces remote from the mechanisms 20 and also the pressure in the casings 21 is monitored and compared, and then is controlled such that the casing pressure is slightly less than the minimum working fluid pressure in the working fluid spaces. The relative phase of the two mechanisms 20 associated respectively with the hot displacers and the cold displacers is adjustable (28,29,30,31; and FIG. 4).

Abstract: A safety device (23) for a fluid hose (14) having at one end one part (19) of a separable connector (18) by means of which the hose (14) may be connected to another pipe (21) carrying the other part (20) of the connector, the connector parts separating when the connector (18) is subjected to a tensile load. The device (23) includes an elongate tether (24) having one end attached to the hose (14) at or adjacent the one connector part (19) and its other end attached to the pipe (21) at or adjacent the other connector part (20). The tether (24) is arranged to break when the connector parts has exceeded a pre-set distance, the breaking strain of the tether (24) being lower than the load required to separate the connector (18).

Abstract: An automatically operating valve for use for example in a forecourt fuel pump has a body (10) defining a flow passage (20) within which is formed a valve seat (22), the body having a weakened zone (16) around the flow passage (20) such that an impact on the body will fracture the body at the weakened zone. A valve member (30) is mounted for movement within the flow passage (20) and is engageable with the valve seat (22) to close the valve. A closing mechanism effects movement of the valve member (30) to its closed position in the event that the body (10) is fractured at the weakened zone. Further, the valve member (30) is configured to move to its closed position under the influence of excessive flow of liquid through the flow passage (20).

Abstract: A safety device (23) for a fluid hose (14) having at one end one part (19) of a separable connector (18) by means of which the hose (14) may be connected to another pipe (21) carrying the other part (20) of the connector, the connector parts separating when the connector (18) is subjected to a tensile load. The device (23) includes an elongate tether (24) having one end attached to the hose (14) at or adjacent the one connector part (19) and its other end attached to the pipe (21) at or adjacent the other connector part (20). The tether (24) is arranged to break when the connector parts has exceeded a pre-set distance, the breaking strain of the tether (24) being lower than the load required to separate the connector (18).

Abstract: An automatically operating valve for use for example in a forecourt fuel pump has a body (10) defining a flow passage (20) within which is formed a valve seat (22), the body having a weakened zone (16) around the flow passage (20) such that an impact on the body will fracture the body at the weakened zone. A valve member (30) is mounted for movement within the flow passage (20) and is engageable with the valve seat (22) to close the valve. A closing mechanism effects movement of the valve member (30) to its closed position in the event that the body (10) is fractured at the weakened zone. Further, the valve member (30) is configured to move to its closed position under the influence of excessive flow of liquid through the flow passage (20).

Abstract: A forecourt fuel pump has a casing locating means for metering and delivering to a flexible hose liquid fuel to be dispensed, and a processing unit arranged to monitor and control the delivery of fuel and the display of information concerning that delivery. The pump is provided with at least one sensor for an environmental parameter associated with the pump, such as the sensing of hydrocarbon liquids in the casing. Further sensors external of the pump may be provided to sense other parameters such as the presence of hydrocarbon vapor or liquids. Each sensor provides an output which is supplied to the processing unit which is arranged to monitor the output and provide an indication if the sensed value falls outside a pre-set range.

Abstract: A locking arrangement for a forecourt fuel pump having a nozzle (11) receivable in a holder (13) of the pump body has a bar (23) movable between free and locked positions by an actuator (28). When the bar (23) is in its locked position, the bar passes through an opening (24) in the nozzle handle, so preventing removal of the nozzle from its holder. The actuator (28) may be electrically controlled from a remote position such as a payment booth. All of the fuel pumps on a forecourt may similarly be arranged to permit simultaneous locking and unlocking of all of the pump nozzles.

Abstract: A mechanism for interconnecting a rotary component (40) and two members (25, 26) linearly reciprocable at 90.degree. to each other in respective bores (16, 18, 17, 19) in a housing (15). The first rotary component (40) has a shaft (41) with a pair of spaced toothed rings (42, 43). A second rotary component (44) has a bore (37) with internal teeth (45, 46) at the two ends thereof. The first rotary component (40) extends through the bore (37) with the respective teeth of the two components meshing. The second rotary component has external first and second eccentric surfaces (37 and 38), 180.degree. out of phase. Each reciprocable member (25) has a pair of spaced-apart pistons (26, 27) with a web (28) extending therebetween, the web having a bore (29) in which is received the first (or second) eccentric surface (38 or 39). In operation, the first and second rotary components (32 and 36) rotate in the same sense, and the first and second members (25) reciprocate linearly 90.degree. out of phase with each other.

Abstract: An automatically operating shut-off valve has a valve body (12) with a weakened zone (15) about which the body will break, in the event the valve is subjected to a shock load. A valve seat (25) is formed within the body (12) and a valve member (29) is pivoted to move between an open position and a closed position, against the valve seat. The valve member is spring-urged to its closed position but is held in its open position by a crank (34) having a pin (35) bearing on a brittle glass rod (33). The valve will close whenever the rod (33) breaks, even if the shock load is only sufficient to crack the valve body, about the weakened zone.