GB2183864A - Adjustable devices - Google Patents

Abstract

An adjustment device has two members interconnected for relative movement via a spring (30), and a screw (37) threadably engaged with one (10) of the members and operable by way of two balls (26, 28) to separate the members, the balls being constrained for movement along respective passageways (18, 14) extending into the one member in mutually inclined communication, and the balls mutually engaging at the passageway junction. The second member may provide a support in an optical bench. <IMAGE>

Description

SPECIFICATION Adjustable devices This invention concerns adjustable devices and has been conceived in relation to optical component mounts used in optical benches and sinilar assemblies. It is accordingly appropriate to describe the invention in this optical context, but it will be appreciated that the invention is applicable to non-optical devices where similar adjustment requirements arise.

Optical benches commonly involve a modular system of reference base structures, component mounts and components, with a desired optical configuration being attained by selective interconnection of appropriate components to respectively associated mounts carried by a base structure. Optical configurations typically require a highly accurate positional interrelation of its components and, to this end, the mounts are often of an adjustable form allowing a finely controlled final positioning of the components to be made. These adjustments, in turn, typically involve screw mechanisms.

However, in order that the screw adjustment mechanisms of optical mounts may be of consistent accuracy and acceptable cost they are normally of a simple direct rectilinearly acting form. This frequently results in the mechanisms within an overall configuration being orientated in many different directions and can be disadvantageous to the extent that the configuration cannot be spacially compacted without rendering access to the mechanisms difficult. Indeed, difficulty in access often arises in respect of a single optical mount as these can involve adjustment mechanisms acting in mutually orthogonal directions.

An object of the present invention is to obviate this difficulty.

According to the present invention there is provided an adjustment device comprising two members interconnected for relative opening and closing movement, spring means acting to effect relative closing movement between said members, and a screw threadably engaged with one of said members and operable to act by way of two roller elements to effect relative opening movement between said members, said rollers elements being constrained for movement along respective ones of two passageways extending into said one member in mutually inclined communication therein, and said elements being in mutual engagement at the junction of said passageways.

The roller elements can be of equal or different diameters, and they can be movable along respective passageways which are mutually perpendicular or otherwise inclined at their junction.

The velocity ratio of the overall adjustment transmission which is effective from the screw to the other member in fact depends on the element diameters and passageway inclination, and can be derived from the relationship (R, +R2)2=X2+Y2-2XYcos() where R1 and R2 are the element diameters, X and Y are the operational and adjustment movements along the passageways, and () is the passageway inclination.

The roller element are suitably balls as the latter ar readily and economically available with sphericity of such accuracy as to facilitate attainment of a desirable consistency of adjustment for optical purposes.

The screw is conveniently threadably engaged with the first passageway of the transmission.

Also the screw can act directly on the roller element in that passageway, the other element can act directly on the other member, or in either case action can be effected by way of one or more further roller elements, a push rod, or equivalent direct transmission extending along the relevant passageway.

The two members can be interconnected for relative movement by translation or rotation, and for plural relative movement of either of both kinds in different directions and in independent manner by the provision of respective screws, roller elements and passageways. Also, common spring means can be employed to effect relative closure for each of plural movement capabilities.

In the case of application to ah optical component mount, preferably the one and other members are respectively adapted for connection with a reference base structure and an optical component.

For purposes of clarification of the invention as so far discussed above, the same is further described by way of example with reference to the accompanying drawings, in which: Figures 1 and 2 are respective front and side elevations of one member of an embodiment of the invention, Figures 3 and 4 similarly illustrate the other member of such embodiment, and Figures 5 and 6 similarly again illustrate the embodiment in operable assembly, but with the latter being a sectional view taken at VI-VI in the former.

The one member of Figs. 1 and 2 is seen to be generally of rectangular block form with a part thereof removed over one major face to leave a body 10 of L-shape in side view with a base portion 11 and an upright portion 12.

The upright portion has six bores.

Two bores 13 and pass 14 through the upright position from its rear to its front relative to the L-shape, these bores being counterbored from the front and threaded from the rear.

A stopped bore 15 is made in the front face of the upright portion to form a triangular array with the bores 13 and 14, this array being right-angled at bore 15 and the bore 15 being counterbored.

A further bore 16 passes through the upright portion similarly to bores 13 and 14, but is counterbored at the rear and is embraced by the triangular array.

Lastly, two stopped bores 17 and 18 extend into the upright position from its upper end respectively to communicate with the innermost counterbored ends of bores 13 and 14. Bores 17 and 18 are threaded over the major parts of their lengths from their entry into the upright portion.

The base portion of the body 10 is also provided with a stopped threaded bore 19 from below.

The other member of Figs. 3 and 4 is generally in the form of a rectangular body 20 similar to that notionally removed to produce the body 10 and it has four bores 21 to 24 effectively corresponding to the bore 13 to 16.

Bores 21 to 23 are of shallow stopped form in one face of the body 20, with 21 and 22 each being elongated in alignmeent with bore 23 to a slot form.

Bore 24 passes through the body 20 and is counterbored remotely from bores 21 to 23.

Assembly of the device embodying the members of Figs. 1 to 4 involves, as shown by Figs.

5 and 6, engagement of threaded plugs 25 in bores 13 and 14, from the rear of body 10, these plugs extending by a short distance into the counterbored ends. Respective balls 26 are located in bores 17 and 18, it being noted that these balls cannot pass wholly to the innermost end of the bores by virtue of the intrusion of plugs 25. Respective screws 27 are engaged in bores 17 and 18 to render the balls 26 captive. Respective balls 28 are located in the bores 13 and 14 to engage the respective balls 26, it being noted that the balls 28 cannot wholly enter their bores and cannot attain a position in which they are concentric with the bores 17 and 18 by virture of the intrusion of the plugs 25. A further ball 29 is seated in the bore 15 to project therefrom.The body 20 is located to engage the balls 28 and 29 in seated collocation with bores 21 to 23-by respective alignment of the latter with bores 13 to 15. This overall assembly is resiliently sustained by a tension spring 30 passed through the bores 15 and 24 and held by anchor pins 31 seated in and across the respective counterbores to urge the bodies 10 and 20 together.

Adjustment of the device is effected independently in two different, mutually orthogonal directions by operation of either one of the screws 27 to push its ball 26 and, in turn, its ball 28 to separate member 20 relative to member 10 by rotation about ball 29 and the other ball 28 against the spring action. Clearly reverse adjustment is possible by screw retraction, with the respective balls being moved by spring action.

The bore 19 serves for connection of the one member to a base structure, such as by securement of a post which projects from the body 10 for selective keyed engagement with the base. Connection of a component with the other member can be by way of a sliding keyed fit of the former over the side edges of the latter which are seen to project laterally beyond the body 10.

Claims (7)

1. An adjustment device comprising two members interconnected for relative opening and closing movement, spring means acting to effect relative closing movement between said mem bers, and a screw threadably engaged with one said members and operable to act by way of two roller elements to effect relative opening movement between said members, said roller elements beng constrained for movement along respective ones of two passageways extending into said one member in mutually inclined communication therein, and said elements being in mutual engagement at the junction of said passageways.

2. A device according to Claim 1 wherein said roller elements one each of ball form.

3. A device according to Claim 1 or 2 wherein said passageways are mutually perpendicular.

4. A device according to Claim 1, 2 or 3 wherein said screw is threadably engaged in said one member passageway and directly engaged with the respective one of said elements.

5. A device according to any preceding claim wherein said members are interconnected for relative opening and closing movements in a least two different directions, said one member having respectively different screws, roller elements and passageways as aforesaid to effect relative opening movement in each said direction, and said screws extending in the same direction.

6. A device according to Claim 5 comprising common spring means to effect said closing movements in each said different direction.

7. A device according to Claim 5 or 6 wherein said movements are mutually orthogonal rotations about a common pivot through which said members are interconnected.