DE3025610A1 - CIRCULAR DIRECTIONAL TRANSMISSION DEVICE AT EXTENSION EXTENSION AGENTS - Google Patents

Description

VEB PENTAGON DRESDEN ojf ^sden ' ^{on June 2nd , 198} °

Ksraert and cinema work « * i ^

Circular aperture transfer device on extension lengthening means __

The invention relates to a circular aperture transmission device on extension-lengthening means, such as intermediate rings and bellows close-up adjustment devices, and is used provided in photographic cameras with aperture measurement.

Known devices of this type have crescent-shaped levers mounted on one side and which are in a guide groove be guided. These sickle levers are not very rigid and cause relatively high friction losses again a correspondingly high drive force through the Require camera levers and do not guarantee a transmission that is adequate to the angle of rotation «,

The aim of the invention is to avoid the disadvantages shown in diaphragm transmission mechanisms.

The invention is based on the object of a device for the transmission of the diaphragm function with a precise angle of rotation to create from the lens via extension lengthening means to the camera.

According to the invention this is achieved in that in each intermediate ring as well as in the camera and lens standard of the Belgennaheinstellgerätes a diaphragm transmission ring is provided, on the outer circumference of two guide lugs, which are fixed in the housing in the radial recesses Direction can be moved, as well as a bearing pin for guiding

tion of the aperture transmission ring are arranged «, In Another embodiment of the invention are on the inner circumference of the aperture transmission ring as a stop for the lens aperture lever a drive lug and an angle lever bent at right angles to it, also with a drive lug provided as a transmission element for the camera operating lever, the contact surfaces of the drive lugs align in the axial direction, advantageously a guide lug of the diaphragm transfer ring has a start-up curve for transferring the movement of the lens diaphragm lever. To reduce the friction, it is also useful that the aperture transmission ring coated with a plastic varnish, preferably PTFE varnish is"

Preferably, to compensate for the weight of the Aperture transmission ring on the bearing pin arranged outside the optically free diameter is a leg spring provided, one leg of which rests against the housing and the other leg of which rests against the aperture transmission ring. In a further embodiment of the device according to the invention, an intermediate coupling is on the one hand in the area a drive lug on the diaphragm transmission ring and on the other hand on the crank arm, which can be rotated on one in the frame mounted profile shaft is axially displaceable, hinged rotatably. The swivel joints of the intermediate coupling Adjustable eccentrics are designed to compensate for tolerances a Is.

The invention is illustrated and illustrated using an exemplary embodiment

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Pig. 1 camera with extension ring set and lens in plan view

2a intermediate ring with aperture transmission ring 2b intermediate ring with pivoted aperture transmission ring

Pig. 3 perspective view of the bellows adjustment device with the standards.

A lens 2 is attached to a camera 1 with the interposition of extension lengthening means extension-lengthening means, it can be a set of spacers, consisting of the intermediate rings 3 and (see Pig. 1), or around a bellows close-up device Camera and lens standards 5 »6 (see Figo 3) act. In the intermediate rings 3 and 4 or the camera standard 5 and the lens standard 6 is in each case a substantially circular aperture transmission ring 7 mounted. The aperture transmission ring 7 has according to Pig «, 2a for the attachment of the lens aperture lever 9 am inner circumference a drive lug 8 and an angle lever 10 bent at right angles to this with a drive lug 11 as a transmission element for the camera operating lever 12 or the subsequent intermediate ring (see Figo 1) o The two drive lugs 8 and 11 are in alignment exactly in the axial direction with respect to their distance in the horizontal, horizontal direction to the optical Axis to guarantee a rotation angle & adequate aperture transmission »

In order to achieve a low friction loss, the diaphragm transmission ring 7 is preferably supported at three points. For this purpose, the diaphragm transfer ring 7 are on the outer circumference a Lagerz _a pfen 13 "in a borings

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tion 14 of the bearing groove 24 is rotatably articulated, as well as two guide lugs 15, 16, which are movably mounted in recesses 18, 19 fixed to the housing To reduce the friction, the aperture transmission ring 7 can be coated with a plastic varnish, preferably PTFE varnish, _{or the like}

In the area of the guide nose 16 there is a run-up curve 20 provided to which the lens aperture lever 9 when attaching of the lens 2 abuts the intermediate rings 3 or 4 or the lens standard 6 and thereby the Aperture transmission ring 7 automatically swings out of the path of movement of the lens aperture lever 9 (see FIG 2 B).

To compensate for the intrinsic mass of the aperture transmission ring 7, a leg spring 21 can be arranged on the bearing pin 13, one leg 22 of which rests in a bearing groove 24 and the other leg 23 of which rests on the aperture transmission ring 7 and pivots it in the closing direction of the lens aperture. In order to ensure a transfer of the diaphragm function from the camera standard 5 to the lens standard 6 at an adequate angle of rotation, an intermediate coupling 25 is rotatably hinged to the diaphragm transmission ring 7 in the area of the drive lug 8 on the one hand and on the crank arm on the other hand. The crank arm 27 is positively via an elongated hole 28 and rotationally connected to a rotatably arranged on the frame profile 26 ₈ shaft 29 but with an axial displacement is possible, "both pivot joints of the intermediate coupling 25 are for extending

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η.

designed as an adjustable eccentric equal to tolerances.

With the described constructive according to the invention Formation of a diaphragm transmission device is a high flexural rigidity with little tilt and low driving forces achieved.

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Claims (1)

Expectations 1. Circular cover transmission device on extension lengthening units Means, such as extension rings and bellows adjustment devices, for photographic Cameras with open aperture measurement, characterized in that that in each intermediate ring (3, 4) and in the camera and lens standard (5, 6) of the Bellows close-up a diaphragm transmission ring (7) is provided on the outer circumference two guide lugs (16, 17) which can be moved in the radial direction in recesses (18, 19) fixed to the housing are, as well as a bearing pin (13) for guiding the diaphragm transmission ring (7) are arranged «, 2ο circular aperture transmission device according to claim 1, characterized in that on the inner circumference of the diaphragm transmission ring (7) as a stop for the lens aperture lever (9) a drive lug (8) and one at right angles to it bent angle lever (10) with a drive lug (11) as a transmission element for the camera operating lever (12) and axially aligned contact surfaces of both drive lugs (8, 11) are provided Circular aperture transmission device according to Claim 1, characterized in that the guide nose (16) of the aperture transmission ring (7) is a Start-up curve (20) for transferring the movement of the lens aperture lever (9) owns. Circular aperture transmission device according to claim. 2, characterized in that the diaphragm transmission ring (7) to reduce the friction coated with a plastic varnish, preferably PTFE varnish is" Circular aperture transmission device according to. claim 1, characterized in that a leg spring (21) is arranged on the bearing pin (13) is, one leg (22) in a bearing groove (24) and the other leg (23) on the diaphragm transmission ring (7) is present, 6, circular aperture transmission device according to claim 2, characterized in that an intermediate coupling (25) on the one hand in the area of the drive lug (8) on the diaphragm transmission ring (7) and on the other hand on the crank arm (27), which is axially displaceable on a profile shaft (29) rotatably mounted in the frame (26) is guided, is pivoted, 7 · Circular aperture transmission device according to claim 6 _{g 3} characterized in that the two pivots of the intermediate link (25) are constructed as an adjustable eccentric, " 130021/0691