GB2292220A - Levelling aid - Google Patents

Abstract

The device comprises a first arm 1 linked to a second arm 2 about a pivot point 3. The second arm 2 carries a plumb weight 4 at one end and has a point 5 at the other end which can register with markings on a circular portion 6 of the first arm 1 as the two arms rotate relative to one another. In use, arm 1 is held against a wall so that the arm 2 hangs freely under gravity. The first arm 1 can then be rotated on the wall surface until the point 5 registers with one of the markings on the circular portion 6 so that, for example, a straight edge 7 on the arm 1 defines a horizontal line. This straight edge 7 is provided with ruler markings 8. If desired the arm 1 can then be rotated through 180 DEG (about a locating point 9 of the pivot 3 which presses into the wall surface) so that an extension of the line drawn can be created on the symmetrically positioned straight edge 10. A described alternative (Figs. 3, 4) includes a rule with a slot and a scale to either side of the slot. A slide runs in the slot. At one end of the rule a vertical reference dial comprises a scale and plumb needle. <IMAGE>

Description

linrovements relatina to Levellina Aids Various methods can be employed to create, for example, a horizontal line on the wall of a building so that fittings can be fixed "on the level". This can be done for example, by using a spirit level and ruler and possibly a line and making measurements at various positions, but this can be somewhat cumbersome and prone to error.

The present invention relates to a levelling aid comprising a first arm provided with a straight edge, and a second arm positioned over the first arm by means of a pivot member provided towards one end of the first arm, a plumb weight at one end of the second arm remote from the pivot point and registration marks enabling the two arms to be set at desired angular relationships with respect to one another.

With such a device the first arm is placed against the wall so that the second arm hangs down vertically, due to gravity acting on the plumb weight. The first arm can then be rotated until the registration marks indicate that the straight edge of the first arm is in a horizontal attitude (for example). The first arm can also be rotated so that it is aligned with the second arm, thus placing the straight edge of the first arm in a vertical condition. For these purposes the registration marks would ideally be provided to define angular relationships of 90 , 180e, 270 and 360g.

Ideally the other end of the second arm could, for example, carry a pointer to register with a circular portion of the one end of the first arm carrying the registration marks.

This circular portion can carry markings giving any desirable angular indications so that the straight edge of the first arm can be set at a desired angle which might, for example, correspond with the angle at which a stairway is to be mounted against a wall.

Preferably, the pivot member will extend through to a pointed locating portion at the rear of the first arm. This enables the pivot point to be held at a fixed position on the wall whilst the first arm is set at the desired angle.

Advantageously the other end portion of the first arm carries a set of ruler markings along the straight edge so that desired positions can be marked on the wall. Another possibility is that the other end portion of the first arm carries an array of holes along a line radiating from a pivot point. A writing implement inserted through one of these holes in the first arm can be rotated about the pivot to create a circle where, for example, a circular passageway is to be created through the wall.

The levelling aid could incorporate fixing means for securing the two arms in a fixed relationship, so that the device could be used in the manner of a protractor to enable lines to be drawn at desired angular relationships.

In another embodiment, the second arm may be an indicator or needle pivotally mounted within an enclosure but visible from outside. Here the registration marks preferably comprise a dial or the like within the enclosure.

In either embodiment, the first arm may be slotted and carry a slidable guide in the slot, with registration marks on the first arm for enabling the linear position of the slide to be set.

The invention also extends to a vertical reference dial for being attached to a rule or other object, said dial comprising an enclosure sealed against the ingress of dirt and containing a pivotable plumb weight indicator or needle, and defining registration marks for co-operation with said indicator or needle, and means for attaching said enclosure to a rule or other object.

The invention may be performed in various ways and two embodiments will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a first embodiment of levelling aid of this invention; Figure 2 is a side view of the levelling aid shown in Figure 1; Figure 3 is a plan view of a second embodiment of the levelling aid of this invention; and Figure 4 is a side view, in part section of the levelling aid of Figure 3.

The device shown in Figures 1 and 2 comprises a first arm 1 linked to a second arm 2 about a pivot point 3. The second arm 2 carries a plumb weight 4 at one end and has a point 5 at the other end which can register with markings on a circular portion 6 of the first arm 1 as the two arms rotate relative to one another. In use, arm 1 is held against a wall so that the arm 2 hangs freely under gravity.

The first arm 1 can then be rotated on the wall surface until the point 5 registers with one of the markings on the circular portion 6 so that, for example, a straight edge 7 on the arm 1 defines a horizontal line. This straight edge 7 is provided with ruler markings 8. If desired the arm 1 can then be rotated through 180" (about a locating point 9 of the pivot 3 which presses into the wall surface) so that an extension of the line drawn can be created on the symmetrically positioned straight edge 10.

The centres of each arm 1 and 2 carry respective lines 11 and 12 and if these are aligned (the arm 2 at least being of transparent material) the straight edge 7 will be in a vertical attitude. Other angular relationships can be achieved by rotating the arm 1 so that the point 5 registers with a desired angle marking on the circular portion 6. The arm 1 carries an array of holes 13 along its centre line 11 and these can be used for drawing circles by means of a writing implement inserted through a suitable hole whilst the arm 1 is rotated about the locating point 9 of the pivot 3.

As shown in Figure 2, a fixing nut 14 can be provided so that the two arms 1 and 2 can be locked in a desired angular relationship to enable fixed angles to be drawn.

Referring to Figures 3 and 4, the second embodiment comprises a rule 20 with a central slot 21 and a scale 22 to either side of the slot. A slide 23 with suitable markings runs in the slot 21. To one end of this rule, beyond the slot is secured a vertical reference dial 24 which comprises a scale 25, and a plumb needle 26 pivoted on a pivot 27, all covered by a transparent cover 28, which prevents the ingress of dirt etc. A centre stud 29 projects from the lower surface of the rule 20, concentric with the pivot 27.

In use, the rule 20 is rotated until the desired angle is indicated by the plumb needle 26; a line may then be drawn, or the slide 23 moved to one or more positions to make a series of marks along a desired axis.

Claims (7)

1. A levelling aid comprising a first arm provided with a straight edge, and a second arm positioned over the first arm by means of a pivot member provided toward one end of the first arm, a plumb weight at one end of the second arm remote from the pivot point and registration marks enabling the two arms to be set at desired angular relationships with respect to one another.

2. A levelling aid according to Claim 1, wherein the pivot member extends through to a pointed locating portion at the rear of the first arm.

3. A levelling aid according to Claim 1 or Claim 2, wherein the registration marks are provided to define angular relationships of at least 900, 1800, 2700 and 3600.

4. A levelling aid according to any one of Claims 1 to 3, wherein the other end of the second arm carries a pointer to register with a circular portion of the one end of the first arm carrying the registration marks.

5. A levelling aid according to any one of Claims 1 to 4, wherein the other end portion of the first arm carries an array of through holes along a line radiating from the pivot member, and/or a set of ruler markings along said straight edge.

6. A levelling aid according to any one of Claims 1 to 5, wherein the pivot member includes releasable fixing means for securing the two arms in a fixed relationship.

7. A levelling aid substantially as herein before described with reference to the accompanying drawings.