FR 88 00 454 discloses an apparatus for the optionally atomized discharge of an in particular liquid medium, in which the medium is stored in a spray cylinder and the medium can be discharged by means of a discharge channel. For this purpose the spray cylinder contains a piston, which can be actuated by a ram, the piston being manually operable. The manual operation of the ram takes place by means of an operating trigger or pusher, which is guided in a casing, which also receives the spray cylinder. On the casing and on the operating trigger are provided guide means, which limit the operation of the operating trigger in the axial direction of the spray cylinder, so that the overall stroke of the ram in the spray cylinder is subdivided into several, clearly defined partial strokes. In order to be able to perform the next partial stroke at the end of a first partial stroke, it is necessary to twist the operating trigger with respect to the spray cylinder or the casing in which the spray cylinder is located.
EP 334 349 A1 discloses an apparatus for the discharge of a medium in which the ram of a spray cylinder is operated by means of an operating trigger. The operating trigger is guided in a casing serving to receive the spray cylinder. On the casing are formed guide cams, which are guided in a slide path shaped onto the operating trigger. The slide path is shaped in such a way that the operating path of the operating trigger is subdivided into several partial strokes. This takes place either in that the slide path is stepped, so that between two partial strokes of the operating trigger it is necessary to twist the operating trigger with respect to the casing, or in that the slide path has overpressable stop or dwell points, which keep a cam guided in the slide path in an end position of a partial stroke until the operating force exceeds a retaining force. In the latter case the slide path can also be linear.
In apparatuses for the discharge of media in which it is necessary to twist the operating trigger with respect to the casing in order to perform successive partial strokes, it is disadvantageous that there is no possibility of a one-hand operation. For twisting the operating trigger with respect to the casing it is necessary to hold the apparatus with both hands. However, stepped guides have the advantage that an accidental successive performance of two partial strokes in a single movement is impossible. The construction with a linear slide path and dwell points overpressable by over-coming a retaining force for subdividing the discharge of the medium into several partial strokes admittedly gives the possibility of one-hand-operation, but the risk arises that unintentionally several partial strokes are successively performed in an uninterrupted operation.
The problem of the invention is to provide an apparatus operable with one hand for the discharge of a liquid medium in which it is ensured that partial strokes are not unintentionally performed in uninterrupted succession.
This problem is solved by apparatuses according to the independent claims.
According to a first apparatus according to the invention an operating trigger acts on the ram, which operates the piston displaceable in the spray cylinder, the operating path of the operating trigger being so limited between an operation starting and end position that the resulting piston discharge stroke corresponds to the amount required for the discharge of a partial charge.
According to advantageous developments of the apparatus a return or restoring spring is provided for returning the operating trigger from the operation end position into the operation starting position. On the ram acting on the spray cylinder piston are shaped drivers, which solely in the direction of the discharge stroke provide a non-positive connection between the operating trigger and the ram. In addition, according to an advantageous development, on the ram can also be shaped locking means, which in the operation starting position engage on a locking edge and which can be overpressed by overcoming a minimum operating force of the operating trigger. It can be particularly advantageous to construct the drivers in such a way that the drivers of one discharge stroke serve as the locking means for a following discharge stroke.
According to a development of the invention the drivers are constructed as thickenings of the ram and it is particularly advantageous to construct the ram section constructed as a driver in the form of a frustum, the imaginary apex of the frustum being located in the direction of the spray cylinder piston. Further advantageous developments of the apparatus for discharging a medium can be gathered from the further subclaims.
A second apparatus for the discharge of a medium is also formed by a spray cylinder in which is located a piston operable by means of a ram. For this purpose a sliding shoe engages on the ram in an area outside the spray cylinder and the ram has at least one collar. In the operation end position of an operating stroke corresponding to the discharge of a partial charge the collar is engaged with the sliding shoe.
According to an advantageous development of this embodiment the sliding shoe is supported on the spray cylinder in the operation end position. A further advantageous development comprises the collar being formed by a diameter enlargement of the ram. Further advantageous developments of this embodiment deal with the articulation of the sliding shoe.
Further subclaims deal with advantageous developments of both embodiments.
These and further features can be gathered from the claims, description and drawings and the individual features, either singly or in the form of sub-combinations can be implemented in an embodiment of the invention and in other fields and can represent advantageous, independently protectable constructions for which protection is hereby claimed. The subdivision of the application into individual sections and the subtitles in no way restrict the general validity of the statements made thereunder.