Detergent dispensing device

An detergent dispensing device, comprising:

• a base for attaching the detergent dispensing device to a surface having a pair of opposing first fastening elements on a front side of the base;
• and
• an extrusion assembly joined to a front side of the base comprising a seat member, a volume control member, a connection member, and an engagement member;
• wherein
• the seat member comprises a pair of second fastening elements for joining to the first fastening elements of the base, two parallel troughs between the second fastening elements extending towards a front direction, a first tube and a second tube joining the first tube extending upward and forward, respectively;
• the first tube has an open top end and an open bottom end;
• and the second tube has an open front end;
• the first tube has a narrower section between the top and bottom ends having a smaller aperture;
• the volume control member is configured inside the first tube, and comprises a first spring, a first ball, a first cap, a hollow tube, a second spring, a second ball, and a second cap;
• the first spring, the first ball, the first cap, the hollow tube, and the second cap are arranged sequentially from bottom to top within the first tube;
• the second spring and the second ball are positioned inside the hollow tube;
• the first spring and the first ball are located within the narrower section of the first tube;
• the first cap has an opening blocked by the first ball;
• and the second cap has an opening blocked by the second ball;
• the connection member is joined to the open top end of the seat member and connected to the first tube;
• the engagement member is joined to the second tube of the seat member;
• the engagement member comprises a button piece on a front side with two opposing hooked arms extending backward;
• the hooked arms are received by and slidable back and forth along the troughs of the seat member;
• a push rod extends backward from a back side of the button piece between the hooked arms and is received by the second tube through the open front end;
• a third spring is configured between the engagement member and the seat member, and is sleeved over the second tube and threaded through by the push rod;
• the engagement member is moveable resiliently back and forth relatively to the second tube;
• when the engagement member is engaged, the push rod moves along and squeeze the air inside the second tube towards the first tube, and the first ball is driven downward away from the opening of the first cap;
• and
• when the engagement member is restored resiliently to its original position, a negative pressure is created in the second tube, and the second ball is drawn downward away from the opening of the second cap.