Abstract: In a hot gas engine of the type in which a number of working gas charges are separated from each other by an equal number of pistons each mounted slidably in a cylinder the said pistons are forming pairs each pair being connected to a common crank shaft so as be angular displaced in their movements relative pistons in adjacent cylinders. Each cylinder has a variable volume chamber connected to a variable volume chamber of an adjacent cylinder and all cylinders are interconnected.

Abstract: In a hot gas engine of the type having a regenerator surrounding each cylinder top a part of the upper cylinder wall and the regenerator have been made as a unit having low heat conductivity in axial and radial directions, the unit consisting of two interconnected wall elements leaving a gap of ring shaped cross section between them, and the regenerator being brazed to the outside of the outer wall element.

Abstract: In a hot gas engine the cold gas connection duct between the low temperature variable volume chamber of one cylinder and an adjacent cooler surrounding another cylinder is divided into several separate, parallel ducts leading to different segments of a chamber below said cooler.

Abstract: A five cylinder, double-acting hot gas engine having pistons acting on a common crankshaft has been designed with the central cylinder forming a larger V-angle relative its two neighboring cylinders and a smaller V-angle with the two remote cylinders.

Abstract: A heater head for a multi-cylinder, double-acting hot gas engine in which each cylinder is surrounded by an annular regenerator unit, and in which the tops of each cylinder and its surrounding regenerator unit are interconnected by a number of heater tubes. To provide for a single heater head for a plurality of sets of tubes connecting cylinder tops and surrounding regenerator unit tops, arcuately shaped manifolds are provided on the tops to form two complete concentrically disposed circles.

Abstract: An improved hot gas engine heater head where a thermocouple is coaxially positioned in an isolation tube having one closed end and the isolation tube is coaxially positioned in one of a plurality of heater tubes forming a part of a working gas path between two variable volume chambers and traversing a combustion gas flow path. The thermo-couple is in heat-transfer contact with the working gas and is physically isolated from the working and combustion gases. The temperature signal from the thermo-couple is conducted by a conduction wire passing through heat insulating material such that neither the thermo-couple nor the conduction wire is exposed directly to the working gas or the combustion gas.

Abstract: Apparatus for manipulating carrying bags which are initially in a planely compressed state in a storage compartment. The bags are held on a carriage which may be rolled into and out of the storage compartment. Drive means secured to the storage compartment mate with driven means on the carriage, which driven means are adapted to feed the compressed bags to an opening and raising station. The opening and raising station includes a bottom plate pivotally mounted about a horizontal axis between a substantially horizontal position in which it supports an open bag and a substantially vertical position in which grip members are adapted to grip a portion of the compressed bag in order to pull the bag into an open form, after which the bottom plate is elevated into a higher position. The movement of the bottom plate is coordinated with two spades adapted to be pushed into a partly raised bag in order to be moved apart therein to maintain the bag in its open form.