GB2226406A - Measuring instrument - Google Patents

Abstract

A measuring instrument consists of a spirit level 12 with spirit vials 14 arranged parallel to longitudinal side surfaces 16 of the level and perpendicular thereto. A member 20 is pivotally attached to the spirit level and carries an arcuate scale 24. As the member 20 is pivoted relative to the spirit level, the position of the indicia on the scale relative to a marked point 26 on the spirit level indicates the angle of inclination of the member 20 relative to the longitudinal side surface of the spirit level. A screw device 28 is provided to hold the member 20 at any selected pivotal position. The member 20 may be aligned parallel to a surface, the inclination of which is to be measured. The inclination is then read off from the scale 24 when the spirit level 12 is in a horizontal or vertical position as indicated by the bubbles in the spirit vials 14. <IMAGE>

Description

MEASURING INSTRUMENT This invention relates to a measuring instrument, more particularly a measuring instrument including means for establishing a datum level against which measurements can be made.

In construction, engineering and the like, it is oftep essential to establish the inclination of a surface relative to another surface or to some other datum.

Measuring devices such as protractors or adjustable setsquares can be used where another surface can act as the datum, but these devices cannot be used where no suitable datum surface exists.

It is well known to use a measuring device such as a spirit level to confirm that a surface is horizontal or vertical. However, basic spirit levels are of little use where a surface is inclined, because they cannot give the angle of the surface to the horizontal or vertical.

In view of this drawback, some, more sophisticated spirit levels have pivotally-mounted spirit vials provided with indicia which read against an angular scale, An edge of the spirit level is placed upon the surface concerned and the vial is turned until it is level, so that the inclination of the surface relative to the horizontal or vertical can be read off the angular scale.

The pivoting-vial arrangement allows measurement of inclination but still suffers from several drawbacks, among which the spirit level can becomesbulky, expensive, and difficult to read and operate. Moreover, pivoting dial arrangements cannot be readily fitted to existing, standard spirit levels.

An object of this invention is to overcome or mitigate the disadvantages of existing measuring devices.

In a broad sense, the measuring device of this invention has a body with at least one axis and levelling means for indicating when the axis is horizontal or vertical, wherein the device has a member movable relative to the axis for contact and alignment with a surface whose inclination is to be measured in use, and also has indicia by means of which the angle of the member to the axis may be determined.

It is preferred that the member is situated beside the body and is hingeably attached thereto. Suitably, the device is arranged such that in one, closed position the member lies parallel to a side surface of the body and in other, open positions the member is inclined relative to the surface.

The levelling means may include a number of spirit vials, some of which are preferably set parallel to the side surface of the body. The other vials are suitably perpendicular to the side surface.

In some embodiments, the device may include means for moving the member relative to the body and for holding the member in a given position. These means may include a screw device.

Embodiments and aspects of this invention will now be described, by way of example, with reference to the accompanying drawing. The drawing, Figure 1, is a side elevation of a preferred embodiment of the invention.

Referring to Figure 1, a measuring device 10 comprises a body 12 bearing spirit vials 14. The body 12 is essentially the same as that of a standard, basic spirit level, being of generally rectangular elevation and having two parallel flat surfaces denoted by reference numerals 16 and 18. As is common in the art, some of the vials 14 may lie parallel to the surfaces 16, 18 and others may be perpendicular to the surface 16, 18. This arrangement allows use of the spirit level with both horizontal and vertical surfaces.

One end of an elongate member 20 is pivotally attached to one end of surface 18 by means of a hinge 22.

The member 20 is arranged so that in one, closed position it lies parallel and adjacent to surface 18 and in other, open positions it is inclined relative to surface 18. In the preferred embodiment illustrated, the hinge 22 is arranged such that the member 20 remains spaced from the surface 18 along most of its length even when in its closed position, parallel to the surface 18. This ensures that dirt or the like adhering to either the member 20 or the surface 18 cannot prevent the member lying parallel to the surface.

Indicia are provided whereby the angle of the member 20 to surface 18 may be measured and displayed.

In the preferred embodiment, the indicia comprise an arcuate member 24 which bears an angular scale and which is attached to the member 20. The scale reads against a fixed mark 26 on the side of the body 12.

A further feature of the preferred embodiment is a screw 28 which passes through the body 12 and which is pivotally and slidably attached at one end to the member 20.

The screw 28 is threadedly engaged within the body 12 so as to move axially when turned by means of a knob 30, whereby the angle of the member 20 relative to the surface 18 can be adjusted and set.

It is envisaged that the screw 28 could be located at any of a variety of positions along the length of the body 12. A position close to the hinge 22 gives high sensitivity i.e. a relatively large angular movement of the member 20 in response to turning of the screw 28. On the other hand, a position relatively remote from the hinge 22 gives correspondingly lower sensitivity. Low sensitivity gives greater resistance to knocks, so that the member 20 is less likely to move from its set position if the device is roughly treated.

In use, the measuring device of this invention can readily be used to determine the angle of a surface to the horizontal or vertical. This is done by placing the elongate member 20 onto the surface and turning the screw 28, thereby moving the body 12 relative to the elongate member 20. By use of an appropriate spirit vial 14, the body 12 is brought into either vertical or horizontal alignment as desired. The angle of the member 20 to the body 12, and therefore also to the vertical or horizontal, may then be read by use of the indicia 24, 26.

When the member 20 is in its closed position, the measuring device may of course be used as a standard spirit level. The measuring device may also be used as an adjustable set square to determine the inclination of one surface relative to another surface. In this mode of use, the elongate member 20 is aligned with one surface, the body 12 is aligned with the other surface, and the angle between the member and the body is read using the indicia 24, 26.

As will be clear to those skilled in the art, the measuring device of this invention enjoys substantial advantages over existing arrangements. The device is simple in construction and is easy to use. Moreover, as the body of the device is substantially identical to a standard spirit level, certain embodiments may be fitted to existing spirit levels.

Claims (7)

1. A measuring device comprising a body with at least one axis, and levelling means for indicating when the axis is horizontal or vertical, wherein the device has a member movable relative to the axis for contact and alignment with a surface whose inclination is to be measured in use, the device further comprising indicia by means of which the angle of the member to the axis may be determined.

2. A device as claimed in claim 1, wherein the member is hingedly attached to the body and is movable from a position in which it lies parallel to a side surface of the body into positions inclined relative to the said side surface.

3. A device according to claim 2, wherein the levelling means comprises a number of spirit vials, at least one of which is parallel to said side surface, and another of which is arranged perpendicular to said side surface.

4. A device according to any one of the preceding claims, further comprising means for moving said member relative to said body.

5. A device according to claim 4, wherein said moving means comprises a screw passing through the said body and contacting said member.

6. A measuring device comprising a spirit level in a housing having parallel, spaced longitudinal side surfaces, and at least one spirit vial arranged parallel to said side surface and another arranged perpendicular to said side surfaces, an elongate member pivotally attached to one end of said spirit level adjacent a longitudinal side surface, an arcuate scale fixed to said member such that the position of the scale relative to a fixed mark on the spirit level indicates the inclination of said member relative to said longitudinal side surface, and means for holding said member at a selected pivotal position relative to said spirit level.

7. A measuring device substantially as herein described with reference to the accompanying drawing.