Abstract: A method for automatically correcting the systematic errors in measurement machines and in manufacturing machines, in particular in machine tools, characterized by comprising the following operative steps in succession: identifying the parametric mathematical model of the machine, initially assigning, to the parameters of said parametric mathematical model, numerical values considered to be close to the effective values, to obtain a provisional mathematical model of the machine, effecting a plurality of mutually independent distance measurements within the working field of the machine, determining the differences between the experimentally measured distance values and the corresponding distance values deduced from said provisional mathematical model, to define the corresponding provisional inaccuracy index of the machine, varying said parameters in the sense of improving the predefined provisional inaccuracy index, to hence obtain a new provisional mathematical model of the machine which is closer to its defi

Abstract: A double rotatable spindle head of non-perpendicular axis type has a first half head and a second half head. The first half head is connected to the machine structure and rotates about a first axis. The second half head is coupled to the first half head on a flat surface and rotates about a second axis perpendicular to the flat surface. The rotation of the first and second half heads is achieved by a first and second direct motor, respectively.

Abstract: A seat has an inflatable seat base member, a back rest member and attachments for securing the seat to rigid structure of a vehicle in which it is installed. A top seating surface of the seat base member is further supported by support panel members attached one to each side end wall of the seat base member and extending upwardly to connect with vehicle rigid structure so that a supported seating surface is available for use when the seat base member is deflated.

Abstract: A flotation device (10) attached to a skid member (11) of an aircraft skid undercarriage comprises a flexible bag member (15) adapted for inflation from a collapsed condition to a shape in which it provides at least partial support for an aircraft when it lands on water. A source of pressurized gas for inflating the bag member comprises a pressurized gas bottle (21) housed within and surrounded by the bag member.

Abstract: An inflatable ram has an extensible wall of flexible sheet material connecting two opposed end faces to enclose a space which is divided into a plurality of interconnected compartments by diaphragms extending between opposed regions of the inner surface of the extensible wall so as to be parallel with the end faces. Restraining means, which may comprise elastic cords, are arranged to provide increasing restraint against inflation of successive compartments so that extension of the ram takes place by sequential inflation of the compartments as the restraining means are progressively overcome.