DE9411030U1 - Gap adjustment device - Google Patents

Description

Device for gap adjustment

In ophthalmology, slit projectors are used for diagnostic purposes. They project a slit into the pupil of the eye. The width and length of the slit must be adjustable manually or by motor. Their adjustment should be continuous with a sensitivity that decreases from the closed slit.

Known solutions (DD-B5 285 717) use an eccentric disc that controls the movement of the splitting group via a lever system.

This requires a relatively large number of individual parts, which increases the overall effort.

The controls for adjusting the gap width and for operating a panel for adjusting the gap length are spatially separated.

The invention is therefore based on the problem of realizing a simple device for gap adjustment, wherein the operating elements for gap adjustment and aperture actuation are located together.

This problem is solved by a device according to the first claim.

The desired gap adjustment can be easily achieved using just a few parts.

The course of the guide grooves allows for particularly sensitive adjustment when opening the gap.

A particularly advantageous feature of this type of control of the movement of the gap jaws is that a second axis of rotation for a rotatable aperture with different openings for limiting the gap, in particular in the longitudinal direction of the gap, can be arranged inside or outside the axis of rotation of the cylindrical part, so that the operating units for gap adjustment and aperture adjustment can be arranged close to one another.

Further advantages, the structure and the mode of operation of the invention are explained in more detail below using the schematic drawings.

Show it:

Fig.1 a: A top view of the device according to the invention Fig.1b: A side section along the section line A-A Fig.1c: A partially broken side view in direction B

7038 DE-GM

On a base plate 1 in a slit projector housing (not shown), slit jaws 2 and 3 are attached to slit supports 4 and 5, which can be moved in a linear ball guide 6 (see section A-A).

The gap supports 4 and 5 are pulled together by a tension spring 7.

A cam cylinder 9 is provided on a rotation axis 8 arranged coaxially on a rotation axis 19, which has curved guide grooves 10, 11, into which pin screws 12 visible in view B engage.

The pin screws 12 are attached to lever arms 13,14 which are pivotably mounted in the upper part of the base plate 1

When the cam cylinder 9 rotates, the pin screws 12 slide in the guide grooves 10, 11 and cause the lever arms 13, 14 to pivot about their pivot point.

The pivoting of the lever arms 13,14 is transmitted via driver slots 15, 16 to pin screws 17,18 attached to the gap supports 4,5, thereby causing a lateral displacement of the gap supports 4,5 carrying the gap jaws 2,3.

The shape of the guide grooves is designed in terms of their slope so that, starting from the closed state of the splitting jaws, a very sensitive adjustment can be carried out at the beginning and the slope increases as it progresses.

The rotary axis 19 can be operated independently of the rotary axis 8 and drives via a bevel gear pair 20 and a rotary axis 21 a diaphragm disk 22 behind the base plate 1, which can limit the gap length in selectable steps through openings provided in it.

To operate the slit adjustment or the aperture adjustment, rotary knobs can be provided outside the slit projector housing, arranged directly next to each other, separately for rotation axis 8 and rotation axis 19.

7038 DE-GM

Claims (1)

Expectations Device for adjusting the gap in an ophthalmological slit projector, with two gap jaws that can be moved linearly relative to one another and a rotatably mounted cylinder that has at least one guide groove, into which levers connected to the gap jaws are guided via elements that engage in the guide groove when the cylinder rotates. Device for gap adjustment according to claim 1, characterized in that the levers are pivotally mounted and are hinged to the gap jaws at a pivotable end. Device for gap adjustment according to claim 1 or 2, characterized in that the levers have the element guided in the guide grooves between their pivot axis and the end hinged to the gap jaws. Device according to one of claims 1-3, characterized in that a guide groove is provided for each splitting jaw on the cylinder. Device according to one of claims 1-4, characterized in that two levers are pivotally mounted on a base plate at one end and the other end has a fork-shaped recess into which an element connected to the respective splitting jaw engages. Device according to one of claims 1-5, characterized in that between the pivot axis and the fork-shaped recess a pin is provided on the levers, which engages in the guide groove of the cylinder. Device for gap adjustment according to one of claims 1-6, characterized in that a second axis of rotation is provided inside or outside the axis of rotation of the cylinder, on which an aperture disk for adjustable gap limitation is arranged. Device for adjusting the gap according to claim 7, characterized in that both axes of rotation carry rotary knobs and these are arranged one behind the other outside the slit projector.