GB2252164A

GB2252164A - Adjustable level

Info

Publication number: GB2252164A
Application number: GB9101555A
Authority: GB
Inventors: Colin John Phillips
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-01-24
Filing date: 1991-01-24
Publication date: 1992-07-29
Also published as: GB9101555D0

Abstract

An adjustable level has two elongate parts 10 and 12 which are lengths of T-section material, connected by a pivot pin 14 near one end of the instrument. The instrument can be very accurately adjusted by a screw and nut arrangement 20, the screw of which extends through respective slots 22 and 24 which extend along the two main parts 10 and 12 of the instrument. Slot 22 extends along part 10 in a direction parallel to its basal flange. Slot 24 extends along part 12 in a direction making a small angle with its flange. Consequently, as the screw of the screw and nut arrangement is slid along the two slots, the two main parts of the instrument are angularly adjusted. The screw and nut arrangement 20 serves the dual purpose of clamping together the webs of the two main parts when an angular setting has been made. <IMAGE>

Description

Adjustable level The invention relates to an adjustable level for use mainly, although not exclusively, by drainage engineers, pipelayers and building inspectors.

It is a particular problem that when laying sewer pipes, for example, the amount of fall required may be very small indeed; angular variations of level may be measured in fractions of a degree. If an angular scale is provided at one end of an adjustable level for making angular variations of such a small magnitude, the scale will inevitably be difficult to read accurately and/or the instrument will need to be of excessive length in order to enlarge the size of the scale. The invention has for its object to at least alleviate this drawback.

According to the invention, an adjustable level includes an elongate basal part and an elongate part pivotally connected together at one end, the two parts having respective upstanding webs which slide one against the other during the angular adjustment of one part relative to the other, means being provided for clamping together the two webs for fixing the level in an adjusted position, and means whereby the instrument can be very accurately adjusted to a particular angle being constituted by a slidable element extending through respective slots which are formed in the webs of the two parts and which diverge from a point at which they meet when the planar surfaces of the two parts are parallel. The slidable element will preferably itself form part of the means provided for clamping together the two webs for fixing the level in an adjusted position.The slots formed in the webs of the two parts may both be straight. Alternatively, at least one of said slots may be of curved shape along at least part of its length, this being to make the adjustment of the instrument more sensitive than it otherwise would be along that part of the slot concerned.

In order that the invention may be fully understood and readily carried into effect, the same will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is a side view of an adjustable level embodying the invention, shown in a closed condition, Figure 2 is a section on the line 2-2 in Figure 1, Figure 3 is a view similar to Figure 1 but showing the instrument in use, and Figures 4 and 5 are views similar to Figure 1 and illustrating possible modifications.

Referring now to Figures 1 to 3 of the drawings, the adjustable level there illustrated has an elongate basal part 10 and an elongate adjustable part 12 pivotally connected to said basal part 10 by a pivot pin 14 near one end of the instrument.

As shown, both the basal part 10 and the adjustable part 12 are made from lengths of T-section material, the pivot pin extending through holes in the respective webs of the sections which abut together. (In Figure 2, the webs of the two sections are shown slightly spaced apart for clarity). In use of the instrument, after the instrument has been very accurately adjusted to a particular angle, the flange of the basal part can be seated on a length of pipe, for example, which needs to be laid at that particular angle and adjustments can be made to the setting of the pipe (or whatever other workpiece is being adjusted in position) to bring the adjustable part 12 to a perfectly horizontal position. As shown, the adjustable part 12 is provided with a spirit level 16 with reference to which the part 12 can be brought to the horizontal position.Also as shown, the web of the basal part is apertured at 18 so that the spirit level is visible from both sides of the instrument even when the instrument is in closed condition as shown in Figure 1 or when adjusted to measure a very small angle indeed.

Means whereby the instrument can be very accurately adjusted to a particular angle are constituted by a screw and nut arrangement 20 the screw of which extends through respective slots 22 and 24 which extend, as shown, along the two main parts 10 and 12 of the instrument. The slot 22 is shown to extend along the basal part 10 in a direction parallel to its basal flange. The slot 24 on the other hand extends along the adjustable part 12 in a direction making a small angle with its flange. Consequently, as the screw of the screw and nut arrangement is slid along the two slots the two main parts of the instrument are angularly adjusted one relative to the other. The screw and nut arrangement serves the dual purpose of clamping together the webs of the two parts when an angular setting has been made.

As shown, the slot 22 of the basal part is calibrated to indicate the angle at which the instrument is adjusted from 1:10 to 1:220 (that is to say, for obtaining a fall of 1 foot in ten feet to one foot in two hundred and twenty feet).

It will be understood that by the means just described it is a very simple matter to adjust the instrument to a very high degree of accuracy. A person making the adjustment does not need to have very good eyesight. A person with relatively poor eyesight may be able to adjust this instrument whilst being totally unable to adjust a similar type of instrument having only an adjustment scale at the end remote from the pivot pin.

The level is particularly useful for drainage engineers and building inspectors because the amount of fall required along a length of sewer pipe, for example, will sometimes by very small indeed, being measured in fractions of a degree.

However, the instrument will also be useful in other applications, for example when accurately setting the amount of slope on the face of a retaining wall (but of course the instrument will then require a further spirit level at right angles to the first).

Various modifications may be made. For example, in Figure 4 there is illustrated an instrument similar to that described above except that it is provided with an auxiliary adjustment scale, indicated 26, at the end of the instrument remote from the pivot pin 14. Such an auxiliary scale may be differently calibrated from the main scale, for example giving the fall in m.m. over a particular distance, conveniently over the length of the instrument.

In Figure 5 there is illustrated a different possible modification, this involving the provision of a slot 22 which, as shown, is curved as it extends towards the pivot pin 14. The curvature of the slot 22 is such that the sensitivity of the adjustment is maintained as the screw and nut arrangement is moved towards the pivot pin (whereas in the originally described instrument the sensitivity is reduced as a relatively small movement of the screw along the slots results in a progressively larger angular adjustment).

The means for clamping together the two webs for fixing the level in an adjusted position need not necessarily be the element slidable along the slots 22 and 24; the level could be provided with a clamping screw and nut located in auxiliary arcuate slots in the two parts.

Claims

1. An adjustable level includes an elongate basal part and an elongate part pivotally connected together at one end, the two parts having respective upstanding webs which slide one against the other during the angular adjustment of one part relative to the other.

2. An adjustable level includes means being provided for clamping together the two webs for fixing the level in an adjusted position, by means of a slidable element extending through respective slots which are formed in the webs of the two parts and which diverge from a point at which they meet when the planar surfaces of the two parts are parallel, allowing the instrument to be accurately adjusted for the smallest of angles/falls.

3. An adjustable level as claimed in Claim 2 that the slidable element will preferably itself form part of the means provided for clamping together the two webs for fixing the level in an adjusted position.

4. An adjustable level as claimed in Claim 2 has slots formed in the webs of the two elongated parts, these slots may both be straight or alternatively at least one of the said slots may be curved shape along at least part of its length, this being to make the adjustment of the instrument more sensitive than it otherwise would have been along that part of the slot concerned.

5. An adjustable level is calibrated along slot 22 to indicate the angle at which the instrument is adjusted to.

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6. An adjustable level is provided with its own bubble to level the instrument, and if required can be fitted with a second bubble at right angles to the first to enable the instrument to be used vertically.

7. An adjustable level has an apertured web around the bubble to enable the bubble to be seen from both sides when the instrument is closed or when adjusted to measure a very small angle.

8. An adjustable level as claimed in Claim 7 could be used as an ordinary level when in the closed position.

9. An adjustable level substantially as described herein with reference to Figures 1-5 of the accompanying drawings.