The invention relates to a discharging device for dispensing liquids, more particularly for dispensing pharmaceutical liquids, which discharging device includes a housing, control electronics, a liquid storage receptacle for storing the liquid prior to discharge thereof, a discharge orifice, a conveying device which can be operated manually by means of a first actuator and by means of which the liquid can be conveyed from the liquid storage receptacle to the discharge orifice for the purpose of dispensing the same, and a blocking device that can assume a blocked state, in which operation of the conveying device is mechanically blocked, and a released state, in which operation of the conveying device is possible, for the purpose of preventing another discharging operation from taking place during a blocking period following a discharging operation. For this purpose, the blocking device of a generic discharging device includes an interlock device that is capable of being moved relative to the housing between a first and a second position, the blocking device being configured such that a movement of the interlock device from its first position to its second position causes the blocking device to assume the released state. The interlock device is spring biased by a spring device in the direction of its second position. Furthermore, there is provided a first retaining device, by means of which the interlock device can be retained against the force of this spring device in its first position and which can be released by an electrical signal generated by the control electronics.
A generic discharging device is disclosed in DE 10 2008 064 559 A1. Provision is made in this device for the mechanical work involved in moving the blocking device between the blocked state and the released state to be imparted to the system by the user during the actuation of the device for the purpose of carrying out a discharging operation. Following the discharging operation, this mechanical work is stored in one or more spring devices held in the tensioned state by a retaining device. This retaining device is formed by a permanent magnet and an electromagnet in the embodiments disclosed in DE 10 2008 064 559 A1, the permanent magnet performing the actual retaining function, whilst it is rendered temporarily ineffective by means of the electromagnet for the purpose of transferring the blocking device to the released state, which is thus achieved. Thus the retaining device is released by activation of the electromagnet.
The interlock device of a generic discharging device need not directly serve for blocking the conveying device. Thus both the push rod 78 and the bolt 142 described in DE 10 2008 064 559 A1 are interlock devices in terms of the present invention, since the displacement thereof directly or indirectly results in achieving the released state of the blocking device.
The design of the retaining device as a permanent magnet and an electromagnet constitutes a very advantageous solution, but it also involves the problem that strong impacts, caused accidentally or willfully, may cause unwanted movement of the blocking device so as to achieve the released state before the blocking period has elapsed. This poses the risk of administration of an overdose of the active ingredient stored in the liquid storage receptacle.