Abstract: This cluster of moulded gears with the helical teeth, comprising a group of coaxial pinions of which the teeth have the same helical sense and the same pitch, is characterized in that, Mrn and Mri designating the real moduli of any pinions respectively of rank n and of rank i of the group, Zn and Zi designating the numbers of teeth of the said pinions, and .beta.n and .beta.i designating their helical angles, the following relationship exists between these different parameters:sin .beta.n=sin .beta.

Abstract: The installation comprises in each panel a latch which is opened by means of an electric control device. Each of the control devices is connected in series with at least one switch actuating this device in a panel circuit. All of the panel circuits are connected in parallel to a source of current through at least one switch for locking or unlocking simultaneously all the panels. The source of current comprises, in addition to the usual battery of the vehicle, a buffer battery connected in parallel and located in the passenger compartment of the vehicle, there being provided a blocking component such as a diode for precluding a possible discharging of the buffer battery into the usual main battery.