DEVICE FOR SETTING INCLINATION

Abstract: A device for setting the inclination of a reference object such as a minor or the like, used as a reference for lining up, levelling in etc. The minor (10) is rotatably balanced about an axle (12) and a portion thereof below said axle (12) is provided with a moveable bob (14). A displacement of the bob (14) causes the desired inclination of minor about the axle.

Description: Device for Setting Inclination The present invention is concerned with a device for setting the inclination of a reference object such as a mirror or the like, e.g. for lining up, levelling etc. For the purpose of simultaneously lining up and levelling in objects, such as pipes in a trench, it is a known practice to use leveling instru¬ ments equipped with a mirror, for example such as shown in Swedish Patent Application 7812008-6. The device shown therein comprises a cabinet, containing a mirror, which mirror is adjustable in a housing inside the cabinet by a setting means, the casing being in plumb at all times. The setting of the mirror with respect to the plumb line gives the level desi ed. The present invention proceeds in another way for setting the refer¬ ence object, such as a mirror, and is_characterized as set forth in the accompanying claims. The invention will be further described hereafter with reference to the embodiment shown in the drawing. Figure 1 shows a side elevation of an object with the setting device o-f -the invention. Figure 2 shows a front view. The drawing shows a reference object, such as a mirror 10. It is to be understood that the invention is of general application for setting the inclination of reference objects and that a mirror such as described herein is only one example of the performance of the invention. The mirror 10 is balanced by means of counterweights 22 to rotate about a schematically indicated axle 12, which may be fitted with bearings in a known manner to reduce friction. A plumb bob 14 is positioned on a portion of the mirror 10 below the axle 12, the lower portion of the mirror 10 in the embodiment illustrated. The bob 14, which is of sub¬ stantial weight in relation to the reference object, is mounted in the mirror 10 so as to be moveable and adjustable therein, being balanced about the plane of the mirror 10 when in the position indicated by un¬ broken lines. The bob 14 may, as mentioned, be oveably mounted in the mirror 10, but in the embodiment illustrated the bob 14 may also have the character of a micrometer screw which engages in screw threads 26 in a hole in the mirror 10 and can be screwed in either direction. The bob or micrometer screw 14 is provided with a suitable scale which can be read, for example, against a setting index on the mirror 10 and which directly shows the desired angle of inclination of the mirror. In another embodiment the mirror is rigidly fixed to a frame which is rotatably suspended in the same manner as described above and balanced, together with the mirror, about the axle. In this case the bob is move- ably mounted in the frame. It will be apparent from the above that a displacement of the bob 14 in either direction about the mid plane of the mirror 10 will cause a change in the balance of the mirror 10, thus tilting the mirror. Thus if the bob 14 is displaced to the right in the figure the mirror will tilt to the position indicated in the figure by dashed lines, as the centre of gravity 16 of the bob will remain the same as before. By a suitable choice of scales 18, 20 on the bob 14 the inclination of the mirror can be set and/or read directly. The calibrating ' screw 24 permits fine adjustment of the centre of gravity of the bob to a position directly below the axle. The mirror 10 is preferably suspended with its axle 12 in a mirror housing (not illustrated) and-the bearing and inclination desired are obtained by turning the mirror housing, e.g. manually, into the line of sight. Lining-up and level!ing-in are then carried out by finding the line of sight by eye or using a sighting device such as a target rod or similar in the manner described in the above-mentioned Patent Applicatio 7812008-6.

Claims: Claims 1. A device for setting the inclination of a reference object, such as a mirror or the like, e.g. for lining up, levelling in etc., charac¬ terized in that the reference object (10) is balanced rotatably about an axle (12) and that a portion of said reference object located below sai-d axle (12) is provided with a moveable bob (14) the displacement of which results in the desired inclination of the reference object about said axle. 2. A device according to Claim 1, characterized in that the bob (14) is moveably mounted in the mirror (10) on the principle of a micrometer screw. 3. A device according to Claim 2, characterized in that the mirror (10) and/or the bob (14) are provided with indices or scales to indicate the angle of inclination. 4. A device according to any of Claims 1 to 3, characterized in that the mirror (10) is set up in a mirror housing in such a manner that the movement of said mirror is damped by air resistance: 5. A device according to Claim 1, characterized in that the bob (14) is moveably mounted in a frame or fastener which is rigidly fixed to the mirror (10).

Inventors: JOHNSSON I, NORDGREN B
Applicants: JOHNSSON I, NORDGREN B
Application year: 1981
Main classification: G01C15
IPC codes: G01C15, G02B7