Abstract: A crossbow-type underwater gun having resilient propulsion comprising at least two bungee type side resilient cords (8), the gun being characterized in that it includes a device for stretching the resilient cords (8) comprising a moving head piece (11) to which the first fixing elements (111, 112) can be fixed, the head piece (11) being suitable for sliding along the front portion of the spear support element (2); and a lever arm (10) cooperating with a rod (12) via a thrust and retaining device (13, 14, 23, 24) in such a manner as to enable the resilient cords (8) to be stretched by performing a succession of pivoting actions of the lever arm (10) between an initial position (B1) and a thrusted position (B2).

Abstract: The present invention relates to a crossbow-type underwater gun having resilient propulsion means comprising at least two bungee type side resilient cords (8), the gun being characterized in that it includes a device for stretching said resilient cords (8) comprising:

Abstract: A device for grinding the head of a valve, especially of an internal-combustion engine, has a rigid stand, a structure for supporting the valve stem in terms of rotation that is arranged fixedly and vertically on the stand, a stop for rotational bearing against the valve tail, and a drive mechanism for driving the valve in rotation by the front face. The drive mechanism is arranged vertically below the structure for supporting the valve stem in terms of rotation with a coupling to compensate for any misalignment between the axis of rotation of the drive mechanism and the axis of rotation of the valve stem. A machining station is mounted on the stand having a machining tool mounted thereto in an orientable manner so that the machining axis may be adjusted in relation to the fixed and vertical reference system of the valve stem.

Abstract: The present invention relates to a machine for the machining of a metal bk, especially for boring and facing.The machine according to the invention comprises a laser sighting system making it possible to bring the component to be machined into coincidence with an axis (X) or a reference plane (XY). This system makes it possible, by means of removable optoelectronic sensors, to obtain a control signal allowing the holding table to be positioned in an assisted manual way or automatically, for example with a numerical control.

Abstract: The present invention relates to a tool for precision machining, for exam for the grinding of thermal-engine valve seats. The tool according to the invention comprises a housing (2), a sleeve (3) equipped with a spherical orientation plug (3a) mounted inside the housing, a one-piece machining shaft (6) mounted freely in terms of rotational and translation motion in the sleeve, and a means for adjusting the height of the shaft (6), comprising a means for fixing said shaft in terms of rotation to a bush (17) movable in terms of translational motion relative to the sleeve.

Abstract: A safety clasp which may be used in particular for a necklace or bracelet chain, comprises two pieces sliding one in the other, namely an outer sleeve and a slide element housed inside the sleeve. The sleeve has hooked thereto, at one end, the first end link of a chain. The sleeve also has a slot which defines a transverse arm opening and a connected longitudinal arm opening which extends in the direction of the end of the sleeve opposite to where the first end link is hooked. The sleeve is adapted to move longitudinally with respect to the sleeve and presenting, in its rear part, a notch for receiving the second end link of the chain. The inner slide element presents, in its front part opposite that part where a notch is provided, an elastically deformable arm terminating in a tooth engaging in a hole for locking provided in the wall of the sleeve.

Abstract: A method for determining the optimum component ratios in an exothermic process for producing polyurethane foam is described which consists of continuously measuring the temperature differential with respect to time and then determining the optimum component ratios by comparing the maximum value of each of the sequential temperature differential peaks and the times at which they occur.