Patent GB-927522-A (GB)
Title: Device for producing regulated rectilinear movements
IPC: F16H25/20
Filed: 1960-07-29
Abstract: 927,522. Controlling reactors. SOC. DES FORGES ET ATELIERS DU CREUSOT. July 29, 1960 [Aug. 6, 1959], No. 26478/60. Class 39 (4). [Also in Group XXIV] Means for producing rectilinear movements, e.g. of a control rod in a reactor, comprises a rotatable driving member, a driven member guided for movement along the axis of rotation of the driving member, an intermediate member which forms with the driven member a screw- and-nut assembly and which will rotate with the driving member, means for locking the intermediate member against axial movement relative to the driving member and means for releasing the locking means and resilient means biasing the intermediate member and driven member axially of the driving member to move the intermediate and driven members upon release of the locking means. In one form, the rotor 24, Fig. 1, of an electric motor having a stator 23 externally of a casing 1, drives an intermediate sleeve 11 through a splined connection 13 allowing free axial movement therebetween when locking arms 16 are pivoted from the engaged position shown. The rotor 24 turns the sleeve 11 which is in threaded engagement by means of rollers &c., Fig. 6 (not shown), with a driven sleeve or nut 8, guided for axial movement within the housing 1 by rollers 9 in grooves 10, a control rod 6 fast with the nut 8 accordingly being projected into or out of the reactor. The locking arms 16 are held in the position shown by energization of a solenoid 27 which attracts their upper ends outwardly to hold the arms against the bias of disconnecting springs, Fig. 5 (not shown), de-energization of this solenoid allowing the arms to be moved by the disconnecting springs to the position shown in Fig. 2. Release of the locking arms 16 from the intermediate sleeve 11 enables a spring 22 to project the intermediate sleeve rapidly downwards, and with it the driven nut 8, to force the control rod 6 rapidly into the reactor, thus prevented from operating. Fluid flow means, Fig. 6 (not shown), provide hydrodynamic braking to cushion the final travel of the control rod 6 &c. To restore the driven sleeve or nut 8 from the Fig. 2 position to the Fig. 1 position, the rotor 24 of the electric motor is turned to screw the intermediate sleeve 11 out of the nut, the control rod 6 being stationary. Ultimately, the intermediate sleeve 11 reaches the position shown in Fig. 3, when energization of the solenoid 27 turns the locking levers 16 to engage them with the intermediate sleeve, holding the spring 22 compressed, while the nut 8 and the control rod 6 remain in position within the reactor. Continued rotation of the rotor 24 then screws the intermediate sleeve 11 back to the position shown in Fig. 1. In a modified construction, the driven nut is in the form of a rectilinearly moving rod 8, Fig. 4, which is prevented from turning by a key 28 engaging a groove 29 therein, the rod being surrounded by the rotor 12 of the electric motor which has a stator 23 outside a housing 1. The rotor 12 is connected by a key 30 in grooves 31 for axial movement relatively to, but for rotation with, an intermediate sleeve 11 itself in threaded engagement with the driven rod 8. Locking arms 16 are, as before, controlled by a solenoid 27.