US 2450732 A
Description (OCR text may contain errors)
1943- H. A. w. KLINKHAMER 2 MOVABLE MAGNETIC SHUNT TRANSFORMER Filed May 3, 1946 WM/aw ATTORNEY Patented Oct. 5, 1948 UNITED. STATE MOVABLE MAGNETIC SHUNT TRANSFORMER Hendrik Abraham Wijnand Klinkhamer, Eindhoven, Netherlands, assignor, by mesne assignments, to Hartford National Bank and Trust Company, Hartford, Conn., as trustee Application May 3, 1946, Serial No. 666,950
In the Netherlands September 17, 1942 Section 1, Public Law 690, August 8, 1946 Patent expires September 17, 1962 3 Claims- (Cl. 171-119) This invention relates to a transformer, which is controllable by means of movable magnetic shunts and consists of two shell transformers in Scott's arrangement and is more particularly characterized in that the transformer cores are assembled into a five-limb core having an unwound middle core and two unwound outer cores, shunts being provided solely in the two windows adjoining the middle core in a direction normal to the lamellation of the core, which shunts are movable and are so to be fastened, by means of a clamping device, as to be free from vibration.
When making use of the Scott circuit the advantage known" per se is secured of obtaining a three-phase output voltage from a two-phase input voltage, or conversely. The contruction of a 'five-iimb core having an unwound middle limb and two unwound outer limbs from two shell transformers yields a very simple contruction that can be manufactured at a low cost. The use of a magnetic shunt solely in each of the windows adjoining the middle limb by means of a total number of only two movable magnetic shunts capable of being clamped in installations not having an exaggerated control range, for instance, in cinema rectifiers or the like yields sufficient possibilities of control. Since only two shunts are shifted and clamped for simultaneous control of the three phases only a few running surfaces in the paths of--the shunts need be finished with the required precision,- whilst the devices for moving and clamping the shunts may have a simple construction.
In this respect it is still pointed out that the unwound middle core may consist of two separated parts each of which forms part of a separate shell transformer. However, it is advisable that the middle limb should be constructed as a .unit, as shown in the drawing.
The displacing device consists, in a manner known per se, .of a yoke-shaped coupling piece which is connected at its ends to the shunts and pressing piece are provided in such manner that clamping of the shunts takes place by moving the pressing piece in a longitudinal direction of the unwound middle core.
The invention will be more fully explained by reference to the accompanying drawing in which:
Fig. 1 is a plan view of a transformer according to the invention with a further feature of the invention illustrated in a sectional view; and
Fig. 2 is a section of the transformer according to the invention .taken along the line A-A of Fig. 1.
Referring more particularly to Fig. 1 of the drawing, the transformer consists of two shell transformers I and 2 whose windings 3, l and l, 8 are connected according to Scott. The transformer cores are united to form a flve-llmbed core having an unwound middle core I and two unwound outer cores 8, 9. Two movable shuntslo, H, which are so to be secured as to be free from vibration by means of a clamping device, are solely provided in the two windows I2, ll-adjoining the middle core 1.
As can be seen from Fig. 2, the shifting device consists of a handwheel with a screw spindle I5 which, by means of the nut l8 and the fastening plates I], bring the shunts l0 and II into the desired position in a direction normal to the direction of lamellation of the cores, the spindle 80 I5 resting on the housing iii of the clamping device.
The latter consists of two wedge-shaped members I9, 20 between which is provided anadjustable cuneiform pressing piece 2|. The pressing piece 2! is movable, by means of a screw spindle and handwheel or another-suitable device (for the sake of simplicity not represented in the drawing) in a longitudinal direction'of the core I, i. e., into the direction of the arrow points of the arrow 40 22, as a resultof which the wedge-shaped members l9 and 20 clamp the shunts Ill and l I against the wound limbs of the transformer in such manner as to be free from humming. Consequently the screw spindle extends parallel with the unwound middle core I and may be fastened thereto,
since sufiicient space is available here.
What I claim. is: 1.- A transformer which is controllable means of movable magnetic shunts comprising two shell transformers in Scotts arrangement, in which the transformer cores are united to form a five-leg core'having an unwound middle core and two unwound outer cores, movable magnetic shunts being provided solely in the two windows 5 adjoining the middle core in a direction normal to the lamellation of the core, and a clamping device securing said shunts to said transformer in a vibration-free manner, said clamping device comprising two wedge-shaped members bearing on said shunts, a. cuneiform pressing member between said wedge-shaped members, and means to position said cuneiform pressing member between said shunts to clamp said shunts to said transformer.
2. A transformer as claimed in claim 1, in which the wedge-shaped members and the conical'pressing piece are provided in such manner that clamping of the shunts takes place by shiftin: the pressing piece in a. longitudinal direction of the unwound middle core.
nnrmnncns ormn The following references are of record in the file of this patent:
' UNITED STATES PATENTS Name Date Klinkhamer Aug. 31, 1937 Number