wires the resilient wires are each made up of a horizontal curvilinear portion 2 e connected at one end thereof to the inner spring piece 2 a and repeating u turn and a vertical curvilinear portion 2 f connected at an opposite end thereof to the outer spring body 2 b and repeating u turn the curvilinear portion 2 e connected at one end thereof to the inner spring piece 2 a and repeating u turn and the curvilinear portion 2 f connected at the opposite end to the outer spring body and repeating u turn cross each other at an angle of 90 u00b0 for example that is with respect to one horizontal curvilinear portion 2 e the other vertical curvilinear portion 2 f is displaced 90 u00b0 and is connected in this state to the curvilinear portion 2 e further both end portions 2 g of each of the inner semicircular spring pieces 2 a are formed in a grooved hook shape for mounting thereto of terminals of coils c to be described later likewise grooved guide portions 2 h for mounting to the coil base 4 are formed in two upper and lower positions of the inner periphery of each spring piece 2 a the washer 3 is constituted by a thin film formed of an electrically insulating material as shown in fig1 and 2 the washer 3 is formed in the shape of a quadrangular frame 3 a and small arcuate recesses 3 b are formed in four outer corner portions of the frame 3 a although in this embodiment the electrically conductive springs 2 are formed in a bisected manner they may be formed as an integral construction in this case one conductive terminal is drawn.