the pump as shown in fig1 - 3 comprises a valve body 1 , which is formed integrally with two outlet pipes 11 , 12 and a supporting portion 15 ; a pair of gaskets 4 , 4 &# 39 ;, which cover the surfaces with openings of the valve portion of the valve body ; a pair of valve closure plates 3 , 3 &# 39 ; each of which is secured to one side of the valve body with one of the gasket seats between the closure plate and the valve body ; and a pair of pump diaphragm 5 , 5 &# 39 ; each of which is mounted over the one of the valve closure plates to form pump chambers 6 , 6 &# 39 ;. a pair of vibration arms 7 , 7 &# 39 ; each provided with a magnet 8 , 8 &# 39 ; at the end thereof and pivotably supported at the supporting portion 15 of the valve body are respectively secured to the center of the two pump diaphragms at their middle . in this embodiment , as seen in fig1 four fan - shaped valve chambers a , b , c and d ( designated as a whole as 2 ), are arranged in a quadrantal pattern divided by ridges . ( generally , they need not be fan - shaped .) the first chamber a and the fourth chamber d open on this side of the drawing sheet surface and the second chamber b and the third chamber c open on the back side of the drawing sheet surface , as seen well in fig2 . the first chamber a is provided with a check valve 21 , which consists of an air hole ( a set of four fan - shaped holes in this case ) and a small piece of membrane . in the same way , the second , third and fourth valve chambers ( b , c and d ) are respectively provided with check valves 22 , 23 , 24 . on the opening of the valve body , gasket seats 4 , 4 &# 39 ; are placed so that the valve chambers are closed , whereby the gasket seats have a hole respectively at the position corresponding to the outlet side of the chamber a and b and the inlet side of the chamber c and d . on each of the gasket seats 4 , 4 &# 39 ;, a valve closure plate 3 , 3 &# 39 ; is secured , whereby each valve closure plate is provided with a hole at the position corresponding to each hole of the gasket seat to which said plate is placed . the valve chamber a communicates with the atmosphere by means of a passage 25 , which is an indentation provided in the ridge of said valve chamber . in the same way , the valve chamber b communicates with the atmosphere by a passage 26 ( in fig2 ). in this case , the valve closure plate 3 , 3 &# 39 ; is a disc with a peripheral flange . although the shape of the plate is not limited to a disc , the circular form is most suitable from the view point of providing air - tight closure . over each of the valve closure seats 3 , 3 &# 39 ;, a cup shaped pump diaphragm 5 , 5 &# 39 ; is secured so as to form a pump chamber 6 , 6 &# 39 ;. as seen in fig2 the fourth valve chamber d communicates with the second outlet pipe 12 . in the same way , the third valve chamber c communicates with the first outlet pipe 11 . the front view of the valve closure plate as secured to the valve body with a gasket seat therebetween is shown in fig3 . this view corresponds to fig1 that is , the side of the pump chamber 6 is shown . from this figure , it is learned that air flows into the pump chamber 6 through the hole 13 from the second valve chamber b and flows out into the fourth valve chamber d through the hole 14 . it will be also understood that air flows into the pump chamber 6 &# 39 ; through the hole 13 &# 39 ; from the first valve chamber a and flows into the third valve chamber c through the hole 14 &# 39 ;. to the center of each pump diaphragm , a vibration arm 7 , 7 &# 39 ; is secured at its center . one end of the arm is pivotably supported on the supporting portion 15 , and to the other end thereof , a magnet 8 , 8 &# 39 ; is secured as shown in fig2 . beneath the pump , a tripolar field magnet 9 with a coil 10 wound on the central pole is placed . when alternate electric current flows through the coil , the alternation of the magnetic field takes place , and thus the vibration arms vibrate symmetrically ( not parallel ). symmetrical vibration produces less noise than parallel vibration . the pump body and the field magnet are contained and fixed in a suitable container not shown . from the above description , it will be understood that when the pump diaphragms are pulsated , air is carried from the atmosphere through the first valve chamber , the first pump chamber , and the third valve chamber to the first outlet pipe and simultaneously from the atmosphere through the second valve chamber , the second pump chamber and the fourth valve chamber to the second outlet pipe , with equal pressure . fig4 is a schematic representation of another embodiment of this invention . here the valve comprises a valve body 1 , a pair of gasket seat 4 , 4 &# 39 ;, a pair of valve elements 3a , 3a &# 39 ; provided with check valves 21 , 23 and 22 , 24 respectively and a pair of pump diaphragms 5 , 5 &# 39 ; defining pump chambers 6 , 6 &# 39 ;. in this figure , it must be understood that valve chambers b and d , and check valves 22 and 24 are on this side of the drawing sheet surface and there is another valve chamber a behind the chamber b and another valve chamber c behind the valve chamber d . also check valves 21 and 23 are behind the drawing sheet surface . in this construction , it will be understood that air flows from the atmosphere through the passage 26 , the valve chamber b , the second pump chamber 6 , and the fourth valve chamber d to the second outlet pipe 12 when the diaphragm 5 is pulsated . at the same time it will be also understood that air flows from the atmosphere through the passage 25 , the first valve chamber a , the first pump chamber 6 &# 39 ; and the third valve chamber c to the first outlet pipe in accordance with the pulsation of the diaphragm 5 &# 39 ;. the valve body and the valve element in the second embodiment are preferably made of a plastic material by injection molding . the valve closure plate of the first embodiment is preferably made of metal by press or die casting . the gasket seat and the diaphragm are made of any elastomeric material . although the invention has been explained in reference with preferred embodiments , it should be understood that various modifications are possible within the scope of the invention as defined in the attached claims .