GB2143324A - Plumb weight assemblies - Google Patents

Abstract

A plumb weight assembly has a notch (14) cut in the right-angled corner of a right-triangular card (10) in which a plumb line in the form of a thread (21) carrying a weight (20) is attached to sweep across the face of the card. Lines (15, 16) are marked on the card extending from the notch parallel to the edges of the card so that when the thread (21) is aligned vertically with one of the lines (15, 16) the other line extends horizontally. Further arrangements are disclosed in which the plumb line is enclosed within a clear plastics blister on which a scale may be marked (Fig. 2) and the plumb line and weight may be replaced by a pivotted blade in a transparent fluid-filled chamber (Fig. 3). <IMAGE>

Description

SPECIFICATION Plumb weight assemblies This invention relates to plumb weight assemblies.

The invention provides a plumb weight assembly comprising a base panel, a plumb weight mounted from a point on the panel to swing across a face of the panel and a scale delineated on the panel extending over ninety-degrees and centred on the plumb weight mounting.

The plumb weight may comprise a plumb line attached to the base panel at said point and having a weight attached to the free end thereof to swing across said face of the panel and the base panel may be of right-angled triangular form and the plumb line is attached to the base panel at or adjacent the apex of the right angle of the card.

The right-angled apex of the card may be formed with a notch and the plumb line is attached to the card at the apex of the notch.

In the latter case further notches may be formed at the other apices of the triangular card and the right-angled line delineating the extent of the scale extend between said notches.

In any of the above arrangements a transparent enclosure may be mounted on the base panel and the plumb weight may be disposed on the panel within the enclosure.

In the latter case the base panel may be rectangu lar and the transparent enclosure mounted on the base panel may have a quarter circular profile and a channel may be formed around the curved periphery of the enclosure within which the plumb weight is confined to swing.

In a further construction the base panel may form one side of a transparent square shaped housing and the mounting for the plumb weight in the form of a metal strip may extend between opposing side walls ofthe housing adjacent a corner thereof.

The housing may contain a fluid to dampen the movement of the metal strip.

The following is a specific description of some embodiments of the invention reference being made to the accompanying drawing in which; Figure 1 is a perspective view of a plumb weight assembly; and Figures 2 to 4 are perspective views of further embodiments.

The drawing illustrates a plumb weight assembly in the form of a card level comprising a right-angled triangular card 10 the hypotenuse of which is indicated at 11 and the other two sides 12, 13 of which are of equal length. A right-angled notch 14 is formed in the right-angled corner of the card 10 and alignment lines 15 and 16 extend from the apex of the notch parallel to the edges 12 and 13 of the card to the other apices of the triangular card. Further notches 17, 18 are formed at the other apices of the card, the apices of the further notches co-inciding with the lines 15 and 16. A still further notch 19 is formed in the hypotenuse edge 11 of the card mid-way along the edge and a line is marked on the card from the apex of the notch 14to apex of the notch 19.A plumb weight formed by a folded strip of lead 20 is attached to one end of a cord 21 the other end of which is attached to the reverse side of the card 10 by a sticker not shown at the apex of the notch 14. The length of the cord 21 is approximately half that of the length of the short side 12, 13 of the card.

The card level can be used to derive a horizontal level by locating the card on a vertical surface and aligning the cord 21 suspending the plumb weight 20 with the line 16 on the card so that the line 16 and its adjacent side edge of the card extend vertically.

The top edge 12 will then extend horizontally and can be used to indicate a horizontal level.

The card is particularly suitable for use in the home for levelling items such as pictures, shelves, cupboards and the like.

Referring now to Figure 2 of the drawings there is shown a further form of plumb weight assembly comprising a square base panel 30 on which a diagonal slot 31 is formed to a length to position accurately the thread 33 of a plumb line inserted in the slot 31 where it emerges from and hangs free at the inner end 32 of the slot. The plumb line comprises a thread 33 at+.ached, as indicated above, at one end to the mounting point 32 on the base panel and having a circular profile lead weight 34 at the other end. A scale of lines 35 is printed on the card radiating outwardly over an arc of ninety degrees from the mounting point 32 for the thread, the end lines of the scale extending parallel to the adjacent edges of the panel 30. An enclosure 36 formed by a transparent plastics blister is mounted on the face of the card.The blister provides a quarter-circular enclosure and has a raised channel 37 extending around the curved edge thereof within which the plumb weight 34 is confined to swing. The assembly is used in a similar manner to the card level described above.

Figure 3 of the drawings shows a further embodiment comprising a square injection moulded frame 40 within which front and rear transparent moulded panels 41,42 are bonded to the frame spaced apart by a rib 43 encircling the inner periphery of the frame. A pivot 44 extends between the front and rear walls 41,42 adjacent a corner of the frame and a flat stiff straight metal strip 45 is formed with an eye 46 at one end thereof to encircle the pivot and support the blade for swinging movement therefrom between the front and rear walls. A ninety-degrees span scale of lines 47 is marked on the front wall 41 of the housing. The space between the front and rear walls of the housing may be filled with a liquid to dampen the swinging movement of the blade.

It will be appreciated that the blade will hang in a vertical direction from the pivot and by aligning the scale 47, the device can be used as a level gauge to indicate a horizontal level at one end of the scale when the blade hangs down in alignment with the other end of the scale 47 or to indicate any other inclination to the horizontal or vertical as delineated on the scale. The liquid contained in the enclosure damps the movement of the blade so that the latter quickly adopts a static position when the enclosure is set in position.

The plumb weight assemblies described above and in particular those of Figures 2 and 3 provide devices which are capable of measuring or "setting up" any angle to the horizontal or vertical as distinct from "bubble" spirit levels which are capable only of defining the horizontal or vertical.

Figure 4 shows a similar construction to that of Figure 2 comprising a square base panel 50 and a transparent plastics sheet 51 secured to a face of the card and formed with a raised quarter circular blister 52. A pivot 53 is mounted on the base panel 50 adjacent the apex of the blister and an indicator blade 54 is hinged on the pivot to swing under its weight within the blister. A graduated scale 55 is printed or engraved on the blister adjacent the part-circular periphery thereof so that the device can be used for aligning or measuring angles in the vertical plane as described above.

Claims (17)

1. A plumb weight assembly comprising a base panel, a plumb weight mounted from a point on the panel to swing across a face of the panel and a scale delineated on the panel extending over ninetydegrees and centred on the plumb weight mounting.

2. A plumb weight assembly as claimed in claim 1 wherein the plumb weight comprises a plumb line attached to the base panel at said point and having a weight attached to the free end thereof to swing across said face of the panel.

3. A plumb weight assembly as claimed in claim 2 wherein the base panel is of right-angled triangular form and the plumb line is attached to the base panel at or adjacent the apex of the right angle of the card.

4. A plumb weight assembly as claimed in claim 3 wherein the rig ht-ang led apex of the card is formed with a notch and the plumb line is attached to the card at the apex of the notch.

5. A plumb weight assembly as claimed in claim 4 wherein further notches are formed at the other apices of the triangular card and the right-angled line delineating the extent of the scale extend between said notches.

6. A plumb line assembly as claimed in claim 5 wherein a further notch is formed midway along the hypotenuse of the card to delineate an angle of forty-five degrees in the scale.

7. A plumb weight assembly as claimed in any of the preceding claims wherein the plumb weight comprises a strip of metal (e.g. lead) crimped to the end of the plumb line.

8. A plumb line assembly as claimed in any of the preceding claims wherein the plumb line is attached to the base panel by a sticker.

9. A plumb weight assembly as claimed in any of the preceding claims wherein a transparent enclosure is mounted on the base panel and the plumb weight is disposed on the panel within the enclosure.

10. A plumb weight assembly as claimed in claim 9 wherein the base panel is rectangular and the transparent enclosure mounted on the base panel has a quarter circular profile.

11. A plumb weight assembly as claimed in claim 10 wherein the enclosure is formed with a channel around the part circular periphery thereof in which the plumb weight is constrained to swing.

12. A plumb weight assembly as claimed in any of claims 9 and 10 wherein the plumb weight comprises a blade pivotally mounted in the enclosure to swing through an arc of movement under its own weight.

13. A plumb weight assembly as claimed in claim 1 wherein the base panel forms one side of a transparent square shaped housing and the mounting for the plumb weight extends between opposing side walls of the housing adjacent a corner thereof.

14. A plumb weight assembly as claimed in claim 12 wherein the plumb weight comprises a metal strip pivotally mounted between said opposing side walls.

15. A plumb weight assembly as claimed in claim 13 wherein the housing contains a fluid to dampen the movement of the metal strip.

16. A plumb weight assembly substantially as described with reference to and as illustrated in Figure 1, Figure 2 or Figure 3 of the accompanying drawings.

17. A plumb weight assembly substantially as described with reference to and as illustrated in Figure 4 of the accompanying drawings.