DE1822005U - INTERCHANGEABLE PHOTOGRAPHIC LENS WITH PRINT SCREEN. - Google Patents

Description

P h o t o g r am met r i e G. m. B. H.

Munich Photographic interchangeable lens with pressure screen.

The invention relates to an interchangeable photographic lens with a pressure diaphragm for single-lens reflex chambers.

With the latter, as is well known, the aperture should only be set shortly before the exposure the preselection position can be brought to the opening required for the recording, but otherwise always completely open to achieve the brightest possible viewfinder image be.

This results in the constructive task that is located in the lens and the shutter normally held fully open by a spring by the shutter release movement shortly before triggering against the diaphragm opening spring up to the preselection position as long as to close by the return movement of the trigger organs after Exposure of the way to the opening of the diaphragm is released again by the opening spring will.

In many cases, the coupling between the aperture and the shutter release mechanisms on the camera side can only be achieved by means of a pin, which is mounted in the lens and movable parallel to its axis, with a small total stroke (approx. 2-3 mm), of which about 1/3 remains available for the aperture actuation and The rest, which is necessary for the release of the spanking, by means of an empty running of the transmission organs to the aperture must be included. The pen movement must therefore for the actuation over the whole Aperture closing path can be translated many times over and the Friction may be the force necessary for the release of the lock do not enlarge impermissibly. The pen movement parallel to the objective axis must also be converted into a tangential movement that perpendicularly crosses the objective axis for the movement of a diaphragm actuator.

The fulfillment of these requirements is practical in each case the limited space available within the lens is extremely difficult.

According to the invention, the object is advantageously achieved through use a 2-armed lever for the translation, which is mounted axially parallel in the lens body, whose long arm encloses the radiation space approximately in a semicircle and with his The end engages a diaphragm adjustment element, while the short arm has a deflection piece is connected to the axially movable coupling pin.

By guiding the deflection piece by two successively effective Pivot points are achieved that of the total travel of the coupling pin only for the Aperture adjustment available part is deflected.

The end of the long lever is thus activated when the shutter is released each time moved by the same angular path in the closing direction of the diaphragm. the According to the invention, the aperture to be precounted is changed by rotation and latching of the visor body in the lens body in such a position that the Position of the diaphragm adjustment element at the preselected diaphragm opening in each case corresponds to the end of the constant lever path. The section on which the long lever end moves the diaphragm adjustment member, then corresponds to the achievement the preselected aperture required closing path.

Figure 1 shows schematically the arrangement with the omission of the lens parts of known design that are not required for understanding, viewed in the direction of the lens axis from the camera side. Figure 2 shows the deflection device in the same view as Figure 1, but enlarged, and Figure 3 shows a side view of it, partially cut away. Figure 4 shows the same View as in Figure 3, but in the other end position of the movable parts again. Figure 5 shows a section through the Hole (16) of the deflection piece (17).

In picture 6 is another version of the lever (10) with an annular one long lever arm (13 ") shown.

In the lens body (1) (see Fig. 1!) There is an iris diaphragm body (2) rotatably mounted around the lens axis.

A pin (3) that goes through a slot (4) in the lens body (1) engages, couples the visor body (2) with an externally mounted one in a known manner Preselection ring (6), which by means of a known locking device, for. B. a sprung Ball (5) and corresponding locking notches (7) in different positions to the lens body can be locked.

The respective position of the visor body (2) is indicated by a scale and an index on the lens body respectively. Preselection ring indicated. shows. A spring (8), with one end on the visor body (2), possibly on the pin (3), with the other on the aperture ver. adjusting pin (9) is attached, keeps the diaphragm open in every position. A two-armed lever (10) is around the axis (11) parallel to the objective axis in a bearing piece (12) which is firmly connected to the lens body (1), rotatable. Its long arm (13), encircling the radiation space in the lens in an arc shape, points at its end a hook (14) which is used for Close the iris serves against the opening spring (8). The short lever arm (15) reaches through a hole (16) with a sharpened edge (shown in section in Fig. 5) of the deflecting piece (17).

The latter has roughly the shape of a small, triangular plate with rounded corners (see Fig. 2!) and is connected to the headed bolt (18), which passes through a circular arc-shaped elongated hole (19) of the plate engages on the surface (20) of the bearing piece (12) kept sliding.

2 arc-shaped guide surfaces (21) and (22) on the bearing piece (12) perpendicular to the surface (20) serve as contact guides when the deflection piece (17) rotates, once around the head bolt (18) and another time around the center of the hole (16). A pin (23) on the deflection piece (17) engages in the groove (24) of a driver piece (25) which is attached to the coupling pin (26). The latter is mounted axially movable in the lens body (1) and in the bearing piece (12) and is moved by an organ on the camera side when the shutter is released. The movement is limited by stopping the driver piece (25) on the lens body (1) respectively. on the bearing piece (12). A coil spring (27) in the lens body pushes the clutch pin towards the camera. CD The mode of operation of the arrangement is as follows: By turning the preselection ring (6) (Fig. 1) into one of the locking positions (7), the pin (9) moves into a certain position, its preset position between the start and end position of this lever arm. When the latter moves into its end position (13 '), the pin (9) is moved either over the entire Ueg or part of it, depending on its pre-selected position, thereby closing the shutter completely or partially against the opening spring (8).

The entrainment path corresponds to the path required to close the open aperture to the preselected value, which is displayed on one of the aperture body (1) respectively. Preselection ring (6) attached scale with index can be read. The rotation of the lever arm (13) in its end position (13 ') takes place via the short lever arm (15), the deflection piece (17) and the coupling seat (26) by the movement of a coupled with this Transmission organ to the shutter release completely through the front of the Exposure falling part of the shutter movement.

This process can be seen in Figures 3 and 4, which is carried out by the spring (27) pushed into its rest position Eupplungsstift (26) rotates when it Movement to the end position (Fig. 4) with the driver piece (25) and the pin (23) the deflection piece (17) first around the head bolt (18) and thus the short arm (15) of the two-armed lever (10) to its end position, which is reached as soon as the lower (rounded) corner of the deflection piece (17) from the guide surface (21) the guide surface (22) slides over according to its circular arc shape and the circular arc shape Long hole (19) a further rotation of the deflection piece (17) around the land of the lever (15) allowed.

The coupling pin (26) then moves up to the stop of the driver piece (25) to the bearing part (12) without any further influence on the aperture position reached while the shutter is released.

After releasing the shutter release button, the spring (27) moves the Return the coupling pin (26) together with the deflection piece (17) and lever (10) to the initial position, wherein the opening spring (8) the The aperture is fully open again.

According to the invention, the long arm of the lever (10) for the purpose of larger Solidity is also the shape of a closed one that encloses the radiation space in the lens Ring (picture 6).

The invention also relates to such designs of lenses Pressure diaphragm, in which instead of the clutch pin (26) a differently shaped and mounted coupling member in connection with a deflecting part of the described Execution, in particular with 2 successively effective pivot points, the closing caused by the shutter release movement.

Claims (3)

Protection claims. ---------------- 1. Photographic interchangeable lens with pressure diaphragm for single-lens reflex chambers, in which the diaphragm is closed to a preselected value by the movement of a camera-side shutter release element shortly before the exposure from the full opening and is automatically fully opened again after the exposure, characterized in that to adjust the Diaphragm in the lens body a two-armed lever is arranged, which closes the diaphragm held open by a spring with its long arm, which encompasses the radiation space approximately in a semicircle, and whose short arm is connected via a movement deflection piece to a coupling pin that can move parallel to the lens axis, the deflection piece being by means of a circular arc Guides around two alternately effective pivot points in the? It is also rotatable that the axial movement of the coupling pin is deflected into a rotation of the lever when the coupling pin is rotated about one point, while the lever remains at rest during subsequent further movement of the coupling pin. 2. A photographic lens according to claim 1, characterized in that the long arm of the two-armed lever, instead of the semicircular shape, that of one of the rays room at "g- having space encompassing, closed ring. 3. A photographic lens according to claim 1 or 2, characterized in that instead of a coupling pin (26) movable parallel to the lens axis, a coupling member movable radially or tangentially to the axis is provided, the movement of which is deflected to close the diaphragm with the means indicated in the description, in particular with a deflecting part guided around 2 pivot points acting one after the other (17) takes place. w