Claims for Patent: 6,453,795

Summary for Patent: 6,453,795

Title:	Locking mechanism for a spring-actuated device
Abstract:	A spring-actuated output drive device is used for example in medical aerosol therapy for a miniaturised high-pressure producing device for atomising a small dose of a liquid medicament. A locking-stressing-mechanism for such an output d rive device is to be stressed with the application of a relatively small amount of force and is to be released with one hand and is to operate reliably over a prolonged period of time. The locking-stressing-mechanism comprises a force step-up transmission, for example a screw thrust transmission for stressing the spring, an annularly arranged locking member with engaging locking surfaces, two abutments for limiting the travel of the spring and a release button. It is compact, economical to produce, easy to assemble and comprises components with a low rate of wear. It can be reliably and easily handled by unskilled persons, even when high spring forces are involved. A medicament to be atomised can thus be metered with a very high degree of accuracy.
Inventor(s):	Eicher; Joachim (Dortmund, DE), Schyra; Michael (Wulfrath, DE), Forster; Richard (Fensterbach, DE)
Assignee:	Boehringer Ingelheim International GmbH (DE)
Application Number:	09/077,942
Patent Claims:	1. A locking-stressing-mechanism for a spring-actuated output drive device, the mechanism comprising: an upper housing portion; a spring housing; a cup-shaped output drive member; a spring acting on said output drive member to cause said output drive member to act as a quick-motion member, said output drive member being arranged to move a piston in a cylinder to compress fluid therein; a locking member; a first abutment touching said output drive member in its upper rest position; a second abutment touching said output drive member in its lower rest position, both of said first and second abutments serving for delimiting the travel of said output drive member; means for releasing the displaceably arranged locking member; and force step-up transmission means for stressing said spring, wherein said force step-up transmission means comprises a screw thrust transmission means including at least one sawtooth-shaped recess in a collar of said cup-shaped output drive member against which at least one sawtooth in sad upper housing portion slides, wherein said upper housing portion and said spring housing are connected with each other by way of snap-engagement projections and are rotatable relative to each other and, by rotating urge said output drive member into said spring housing against the force of said spring, and wherein positively couple to the movement of said output drive member is the movement of said locking member which snaps into alignment with a top portion of the collar of said output drive member to form said second abutment when said output drive member reaches its lower rest position holds said output drive member and said compression spring in the stressed position, and wherein said locking member is displaceable in a plane substantially perpendicular to the longitudinal axis of locking-stressing-mechanism, and wherein said means for displacing the locking member is a release button which is combined with or attached to said locking member and is operated in the lower rest position of said output drive member by pressing, whereby said locking member is moved out of the path of said output drive member, thereby releasing said output drive member from the lock position so that said compression spring pushes said output drive member to the upper rest position. 2. A mechanism according to claim 1, wherein the locking member comprises an open or closed ring which is arranged displaceably in a plane perpendicular to the axis of the locking-stressing-mechanism. 3. A mechanism according to claim 1, wherein said locking member comprises a radially deformable elastic ring, or a rigid ring with leaf springs formed thereon, or a rigid ring with a cam projection, or a rigid ring and a metal spring. 4. A mechanism according to claim 1, wherein said locking member is made of plastics or metal. 5. A device for c and atomizing fluid comprising a mechanism according to claim 1. 6. A device according to claim 5, which comprises a metered dose atomiser. 7. A device according to claim 5, which comprises a miniaturized high-pressure metered dose atomiser.