Patent GB-608508-A (GB)
Title: Improvements in or relating to resistance pile electric regulators
IPC: H02P9/22
Filed: 1945-02-17
Abstract: 608,508. Automatic voltage regulators. BENDIX AVIATION CORPORATION. Dec. 17, 1945, No. 34166. Convention date, Dec. 27, 1944. [Class 38 (iv)] In a carbon pile regulator of the kind wherein the mechanical compression of the resistance pile is carried by the current through an electromagnet acting in opposition to resilient means, the resilient means comprises a bent leaf spring connected to the armature of the electromagnet and having an end portion extending towards the electromagnet so that its extremity bears against the latter, a lateral abutment surface being provided to prevent outward movement of the extremity of the leaf spring as the armature is attracted, and instead to cause the end portion of the spring to wrap itself against the abutment surface. The electromagnet comprises a winding 5 upon a central core 4 which is screwed into a base-plate 3, and a centrally apertured cover 10 over the winding is held in position by a flanged collar 15 secured by screws 16 extending upwardly from the flanged edge of the plate 3. The armature 75 and controlling spring 70 are part of an assembly consisting of a top plate 66, spring 70, bottom plate 67 and armature 75, all secured together by bolts 76 and mounted by clamping the flat end of the spring upon the top flange of the annular cover. The other end of the spring is preformed with two gradually curving bends 91 and 92, the bend at 92 having the greater radius, and the curved end portion is bounded by the annular ring 15, while the extremity 95 bears upon a non-magnetic spacing plate 83, preferably of brass, located between the electromagnet and the armature 75. The part of the spring between the extremity 95 and bend 92 lies either tangentially along the vertical inside wall of the ring 15 or. at an angle thereto, depending upon the compressive force applied to the spring 70. Similarly, the surface between the bends 91 and 92 lies either tangentially along the underside of the plate 66 or at an angle thereto. The initial compression of the spring is determined by the initial pressure on the carbon pile 55 which is located within an insulating cylinder 45 and bears upon a bottom contact member 57 mounted in a short cylindrical contact 60 on a plate 61 insulatingly secured to the top plate 66 of the spring assembly. A lead 62 is secured to the contact plate 61. Initial setting pressure is exerted on the upper end contact 56 of the pile by a screw 40 in a cap 37 mounted on a rigid plate 21 which is held rigidly by spacing bolts 19 mounted on the flanged collar 15, the plate 21 forming the upper end of a housing 24 enclosing the pile 55. The leaf spring 70 is of a substantially rectangular area, and may be provided with an auxiliary leaf spring which is clamped upon it by the top plate 66. The end portion of the auxiliary spring is bent slightly to bear upon the end portion 90 of the spring 70, so that the resistance to movement of the armature is increased. To minimize the effect of external shocks the opposite lateral edges of the leaf spring 70 may be provided with projecting ears or lugs to which ballast weights may be secured on opposite sides.