GB1575046A - Adjustable mounting assemblies - Google Patents

Description

(54) IMPROVEMENTS RELATING TO ADJUSTABLE MOUNTING ASSEMBLIES (71) We, BRITISH AIRCRAFT COR PORATION LIMITED, a British Company, of 100 Pall Mall, London, S.W.1., do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement : This invention relates to adjustable mounting assemblies for optical components.

According to the invention an adjustable mounting assembly for an optical component includes a plate member having an aperture formed therethrough and through which projects a tiltable spigot member for carrying an optical component, said spigot member having a first shoulder pprtion lying on one side of the plate member and a second shoulder portion lying on the other side of the plate member, at least three jack members spaced around the aperture and extending between the first shoulder portion and the plate member to transmit compression loads between the two, resilient means of hard rubber or hard rubber-like material lying between the second shoulder portion and the plate member to transmit compression loads between the two, and adjusting means associated with at least some of the jack members for adjusting their individual lengths so that tilting of the spigot member can be effected about one or more axes.

Preferably there are provided three jack members lying at the apices of a 90" included angle triangle, at least those lying at the two apices associated with the 45" angles of the triangle being adjustable for length.

Conveniently, the spigot member includes a carrier member for carrying the optical component, the carrier member being capable of roational adjustment about an axis generally perpendicular to the axis or axes of tilt.

A preferred embodiment of a mounting assembly according to the invention is described with reference to the accompanying drawings in which: -Figure 1 is a pictorial view of an assembly, Figure 2 is a plan view of the assembly, and, Figure 3 is a cross-sectional view, the cross section being taken on the line III-III of Figure 2.

An optional component 1, for example a prism or mirror, having a reflecting surface la, is required to form part of an optical apparatus; it requires to be adjustable so that the apparatus can be set up to function correctly. A mounting assembly is provided which enables adjustment of the optical component to be effected without the use of packing pieces, shims, and the like. The mounting assembly includes a base plate 2 through which is formed an aperture 3. Protruding through the aperture with the ability to tilt slightly is a spigot 4 which has an axially extending bore 5, a shoulder portion 6 lying on one side of the base plate 2, and a further shoulder portion 7 lying on the other side of the base plate 2. This latter shoulder 7 cannot be seen in Figure 1 due to the extent of the base plate 2; it is however illustrated in Figure 3.

The shoulder portion 6 is in the form of a radially extending flange whilst that referenced 7 is in the form of a screw threaded annulus, the spigot itself being screw threaded at 8 to allow the annulus to be screwed onto it. In the bore 5 is located a mating optical component carrier 9. This has an annular groove 10which is engaged by screws fl. carried by the spigot to provide axial location but to allow rotation. The screws 11 have nylon groove-engaging tips to provide resilience should the assembly be used in a high vibration environment.

Rotational adjustment of the optical component, that is to say, of the carrier with respect to the spigot about an axis Z-Z, is effected by screws 12 extending generally tangentially from the spigot onto radially extending shoulders 13 formed on the carrier. The screws 12 are similar to those referenced 11.

Further adjustment of the optical component, that is to say, of the carrier and the spigot with respect to the base plate about axes referenced X-X and Y-Y normal to each other and normal to but displaced from the axis Z-Z, is effected by three jack members 14, 15, and 16 extending between the shoulder 6 and the base plate 2. These are arranged around the aperture 3 to lie at the apices of a 90" included angle triangle whose sides adajcent the 90" angle are coincident with the axes X-X and Y-Y such that those jack members referenced 14 and 16 are disposed on the axis Y-Y and those referenced 14 and 15 are disposed on the axis X-X. The reflecting surface la of the prism or mirror is set at or dose to an angle of 45" to the axes X-X and Y-Y and lies in a plane including or close to the axis Z-Z. Each jack member comprises a screw threaded rod 17 having a.ball end 17a, the screw threaded portion of each engaging with a screwed hole formed in the shoulder 6. The ball ends 17a engage in pads 18, 19, and 20 affixed to the surface of the box plate 2, that pad referenced 18 being of flat form, that referenced 19 having a conical cup, and that referenced 20 having a Vee cross-sectioned groove with axis of the Vee intersecting the centre of the pad 19.

Tilting of the spigot 4 is effected by rotating the jack members either clockwise or anticlockiwse with-respect to the shoulder and thus changing their effective length.

To effect tilting about the'X-X axis only the jack member 16 is rotated, whilst to effect tilting about the Y-Y axis only the jack member 1.5 is rotated. Essentially only the jack members 15 and 16 need to be adjustable, but that referenced 14-is made identical to the others to facilitate production and setting-up: As - before described rotation about the Z-Z axis is effected by rotating the carrier 9 with reference to the spigot. The"' 'tilting of the spigot is accommodated by a re silient 'm'e'Inbe# 21 in the form of a ring of hard rubber or rubber-like material. This forms á thigh ratespring. -To ensure that the jack members- 14; 15 and~I6, and -the resilient~ member 2r are 'always'- pbs'itively in' c"mp'iess'ion, the assembly is pre-loaded by screwing the shoulder annulus 7 along the spigot. The load path is thus from the base plate 2, through the resilient member 21 which transmits a compression load, the shoulder 7, the spigot 4, the shoulder 6, the jack members 14, 15, and 16 which transmit a compression load, and into the base plate. With this arrangement it is found that the prism or mirror can be readily adjusted in one of the three mutually perpendicular axes without causing excessive deviation in the other two axes. It is found, moreover, that the assembly remains adjusted even in high vibration environments.

WHAT WE CLAIM IS:- 1. An adjustable mounting assembly for an optical component including a plate member having an aperture formed therethrough and through which projects a tiltable spigot member for carrying an optical component, said spigot member having a first shoulder portion lying on one side of the plate member and a second shoulder portion lying on the other side of the plate member, at least three jack members spaced around the aperture and extending between the first shoulder portion and the plate member to transmit compression loads between the two, resilient means of hard rubber or a hard rubber-like material lying between the second shoulder portion and the plate member to transmit compression loads -between the two, and adjusting means associated with at least some of the jack members for adjusting their individual lengths so that tilting of the spigot member can be effected about one or more axes.

2. An adjustable mounting assembly according to claim 1 having three jack members lying at the apices of a 90" included angle triangle, at least those lying at the two apices associated with the 45" angles of the triangle being adjustable for length.

3. An adjustable mounting assembly according to any one of the previous claims wherein the spigot member includes a carrier member for carrying an optical component, the carrier member being capable of rotational adjustment about an axis genes ally perpendicular to the axis or axes of tilt.

4. An adjustable mounting assembly substantially as described with reference to the accompanying drawings.

5. An optical component and an adjustable mounting assembly, the combination - substantially as described with refe recce to the accompanying drawings;

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. Rotational adjustment of the optical component, that is to say, of the carrier with respect to the spigot about an axis Z-Z, is effected by screws 12 extending generally tangentially from the spigot onto radially extending shoulders 13 formed on the carrier. The screws 12 are similar to those referenced 11. Further adjustment of the optical component, that is to say, of the carrier and the spigot with respect to the base plate about axes referenced X-X and Y-Y normal to each other and normal to but displaced from the axis Z-Z, is effected by three jack members 14, 15, and 16 extending between the shoulder 6 and the base plate 2. These are arranged around the aperture 3 to lie at the apices of a 90" included angle triangle whose sides adajcent the 90" angle are coincident with the axes X-X and Y-Y such that those jack members referenced 14 and 16 are disposed on the axis Y-Y and those referenced 14 and 15 are disposed on the axis X-X. The reflecting surface la of the prism or mirror is set at or dose to an angle of 45" to the axes X-X and Y-Y and lies in a plane including or close to the axis Z-Z. Each jack member comprises a screw threaded rod 17 having a.ball end 17a, the screw threaded portion of each engaging with a screwed hole formed in the shoulder 6. The ball ends 17a engage in pads 18, 19, and 20 affixed to the surface of the box plate 2, that pad referenced 18 being of flat form, that referenced 19 having a conical cup, and that referenced 20 having a Vee cross-sectioned groove with axis of the Vee intersecting the centre of the pad 19. Tilting of the spigot 4 is effected by rotating the jack members either clockwise or anticlockiwse with-respect to the shoulder and thus changing their effective length. To effect tilting about the'X-X axis only the jack member 16 is rotated, whilst to effect tilting about the Y-Y axis only the jack member 1.5 is rotated. Essentially only the jack members 15 and 16 need to be adjustable, but that referenced 14-is made identical to the others to facilitate production and setting-up: As - before described rotation about the Z-Z axis is effected by rotating the carrier 9 with reference to the spigot. The"' 'tilting of the spigot is accommodated by a re silient 'm'e'Inbe# 21 in the form of a ring of hard rubber or rubber-like material. This forms á thigh ratespring. -To ensure that the jack members- 14; 15 and~I6, and -the resilient~ member 2r are 'always'- pbs'itively in' c"mp'iess'ion, the assembly is pre-loaded by screwing the shoulder annulus 7 along the spigot. The load path is thus from the base plate 2, through the resilient member 21 which transmits a compression load, the shoulder 7, the spigot 4, the shoulder 6, the jack members 14, 15, and 16 which transmit a compression load, and into the base plate. With this arrangement it is found that the prism or mirror can be readily adjusted in one of the three mutually perpendicular axes without causing excessive deviation in the other two axes. It is found, moreover, that the assembly remains adjusted even in high vibration environments. WHAT WE CLAIM IS:-

1. An adjustable mounting assembly for an optical component including a plate member having an aperture formed therethrough and through which projects a tiltable spigot member for carrying an optical component, said spigot member having a first shoulder portion lying on one side of the plate member and a second shoulder portion lying on the other side of the plate member, at least three jack members spaced around the aperture and extending between the first shoulder portion and the plate member to transmit compression loads between the two, resilient means of hard rubber or a hard rubber-like material lying between the second shoulder portion and the plate member to transmit compression loads -between the two, and adjusting means associated with at least some of the jack members for adjusting their individual lengths so that tilting of the spigot member can be effected about one or more axes.

2. An adjustable mounting assembly according to claim 1 having three jack members lying at the apices of a 90" included angle triangle, at least those lying at the two apices associated with the 45" angles of the triangle being adjustable for length.

3. An adjustable mounting assembly according to any one of the previous claims wherein the spigot member includes a carrier member for carrying an optical component, the carrier member being capable of rotational adjustment about an axis genes ally perpendicular to the axis or axes of tilt.

4. An adjustable mounting assembly substantially as described with reference to the accompanying drawings.

5. An optical component and an adjustable mounting assembly, the combination - substantially as described with refe recce to the accompanying drawings;