Abstract: A rotary positive displacement machine is formed by a male organ and a female organ that surrounds it. The male and female organs have helicoid surfaces of particular shapes and also have parallel axes. The male and female surfaces of the invention define a work chamber and the machine has n.sub.m +1 permanently existing points of contact between the male and female profiles. Furthermore, the work chambers of the machine are closed such that the male and female surfaces defining the chambers contain a single point defining a tapered closure in a section where the closure point comes into contact with the n.sub.m +1 permanently existing points of contact.

Abstract: The invention relates to a wiper system for motor vehicles or the like, comprising at least one wiper arm guided and actuated in a complex movement by a kinematic chain or mechanical linkage which comprises a first bar (2) actuated in an oscillating movement by a motor (63), a second bar (3) pivotally connected (23) to the first bar (2) and rigidly attached to the wiper arm, a third bar (4) articulated (34) to the second bar (3) and a fourth bar (5) secured to the vehicle body at one of its ends and torically connected to the third bar (4) at the other of its ends, said toric connection being materialized by a joint (45) made of an elastomer material. The kinematic chain and wiper arm are driven by a second kinematic chain or mechanical linkage which comprises a motor (63), a crank (64) and bar (65) with the bar (65) being pivotally connected to bar (62) rigidly connected to pivot shaft (61) connected to first bar (2).

Abstract: The wiper arm is fixedly connected with a rod of the five-link linkage, the transmission members of which include a frame stationarily arranged with respect to the body of the vehicle, a swinging member connected with the frame, two rods connected with one another, the first one being also connected with the swinging member, and a swinging lever connected with the frame and with the second rod, this swinging lever being driven by the pushing crank transmission. In this spatial five-link linkage, the hinges connecting the swinging member and the swinging lever with the frame are formed as pivotal connections, the hinge connecting one of the rods and one of its adjoining members is a spherical one, and the hinge between this rod and its adjoining member is formed as a pivotal connection, the axis of which is obliquely located with respect to the axis of one at least of the other pivotal connections in the linkage.

Abstract: The wiper arm is fixedly connected with a rod of the five-link linkage, the transmission members of which include a frame stationarily arranged with respect to the body of the vehicle, a swinging member connected with the frame, two rods connected with one another, the first one being also connected with the swinging member, and a swinging lever connected with the frame and with the second rod, this swinging lever being driven by the pushing crank transmission. In this spatial five-link linkage, the hinges connecting the swinging member and the swinging lever with the frame are formed as pivotal connections, the hinge connecting one of the rods and one of its adjoining members is a spherical one, and the hinge between this rod and its adjoining member is formed as a pivotal connection, the axis of which is obliquely located with respect to the axis of one at least of the other pivotal connections in the linkage.

Abstract: The invention relates to a positive displacement machine, such as a rotary pump, engine or compressor. This machine has a slotted rotor, sealing elements sliding in the slots and a tubular stator formed with a cylindrical inner surface, the contour line of which is particular. This contour line has a symmetry order s.sub.S and is composed of s.sub.S lobes belonging to a shortened hypertrochoid with a core, the symmetry order of this hypertrochoid being s.sub.H .noteq.s.sub.S, and s.sub.S sealing zones belonging to the contour line of the core of the hypertrochoid. Each lobe has a center point angle .theta..sub.H, each sealing zone a center point angle .theta..sub.c, .theta..sub.H and S.sub.H being related to .theta..sub.c and s.sub.S by the expressions:.theta..sub.H =(2.pi./s.sub.S -.theta..sub.cands.sub.H /s.sub.S =(.theta..sub.H +.theta..sub.c)/.theta..sub.H.