Abstract: A variable ratio drive mechanism, suitable for a bicycle for example, has at least one gear whose effective radius is variable in a stepless manner in response to applied torque and/or in response to an external force. The gear may include a helical spring (10) which is "wound up" as torque is applied, to decrease its radius. Other possibilities include a rim (20) supported by spokes in the form of compressible springs (22), or a series of outwardly biased arcuate members (30) arranged around a central hub.

Abstract: A soldering device includes a tube (1) for delivering a source of heating energy such as gas which is slidingly mounted in a chamber (52) such as a piston cylinder so that only the tube needs to be moved in order to move the heat source up and down with respect to a workpiece. Likewise, in a solder dispenser, the solder is supplied through a rigid tube (33) which may be slidingly mounted in a cylinder (52). The two may be used together in a combined soldering device/dispenser.

Abstract: A container system comprising at least two containers, wherein said at least two containers are each dimensioned to have a low external surface area to volume ratio, said system comprising connecting means between adjacent ones of the containers each comprising a tube adapted to fit within respective apertures in the containers to be connected and a sealing means surrounding said tube and adapted to be maintained in sealing engagement about the tube and apertures by compression between the containers joined by the connecting means.