Abstract: The pump includes two pistons 10 each sliding in a cylinder 11. These are fed by a screw 21 through ports 12. Upon delivery, a rotary valve 6 turning in a bearing 1A2 in succession closes off and uncovers the passages 1A1 from the cylinders. This rotary valve 6 includes an axial bore 61 and a slot 62 through which the material collected from the cylinders passes in the direction of the outlet orifice of the pump.

Abstract: The continuous mixing apparatus for preparing a rubber composition has a mixing chamber accommodating at least one rotor rotating in a stator and extending between an upstream end and a downstream end between which the material progressively passes. The base elastomers are introduced at the upstream end of the mixing chamber by means of volumetric pumps capable of delivering the said base polymers under pressure. It has members for the dosaging and forced introduction of the other components, arranged along the mixing chamber at at least two longitudinally separated positions between the upstream end and the downstream end.

Abstract: A rotary plug 1 has recesses 5 debouching on its side face 12 which are in communication with the inlet 6 and recesses 5 debouching on its side face 13 which are in communication with the outlet 7. These recesses 5 pass across a port 4 which permits passage to and from a unit consisting of cylinder 2 and piston 3.

Abstract: The dosaging device comprises a dosaging slide 1 actuated by a pivoting rocker 14 via a connecting rod 17. It slides within a groove 2. A unit volume is defined facing the dosaging slide 1 when the latter is at its bottom dead center. The dosaging slide 1 advances towards its top dead center to deliver the dosaged material into a transfer chamber 4.

Abstract: The material to be metered fills the cylinder 1 when it is in front of the admission orifice 31, whereupon the cylinder 1 moves opposite the delivery orifice 32 where the piston 2 describes a movement towards top dead center in order to eject said material out of the cylinder 1. The cylinder 1 then moves towards the admission orifice while the piston 2 remains at top dead center to avoid any return flow, whereupon the cycle starts over again.

Abstract: A volumetric pump for paste-like material, for example, unvulcanized rubber, in which a screw 21 feeds a cylinder 11 through ports 12 and in which a delivery piston 10 within the cylinder displaces the material through a non-return valve 15. A process for volumetric pumping of the material utilizing such volumetric pump.

Abstract: The apparatus concerns the manufacture of tires having at least one reinfement formed from a single thread. It is of the type comprising two coaxial crowns 1 of levers 2 the ends of which bear means 3 for retaining the thread and comprising means 5 for presenting the thread 4 to said retaining means 3. The presentation means 5 comprise a presentation head 50 carried by a flexible belt 55 mounted on two guide pulleys 51, the axes of rotation of which are perpendicular to the axis of the crowns 1, said guide pulleys 51 being arranged in the vicinity of the retaining means 3. The presentation means 5 also comprise an orifice 53 conducting said thread 4 substantially in the plane of and within the loop formed by the belt 55.

Abstract: A variable ratio transmission for a bicycle or other purposes includes an automatically controlled variable diameter sprocket 12 comprising a rotary support disc 101 carrying a number of pivoted arms 102, two of which have toothed sectors 104 while the remainder have smooth sectors 105, the arms being interlocked to move in unison inwards and outwards. They are urged outwards by mechanical spring units 109 or gas accumulators 174 and the movement is controlled either by adjustable brakes 118, which are preferably unidirectional, or by crank operated brakes 131 under the control of the foot cranks 127. The position of the chain contact elements is also controlled automatically by a ratchet detent mechanism 152 and an hydraulic damper 157 and wear in the brakes is compensated automatically by the rotary ratchet mechanism 158,159.