GB2156981A

GB2156981A - Level establishing device

Info

Publication number: GB2156981A
Application number: GB08508453A
Authority: GB
Inventors: Ernest Somers Andrews
Original assignee: Northern Research & Dev Compan
Current assignee: Northern Research & Dev Compan
Priority date: 1984-03-31
Filing date: 1985-04-01
Publication date: 1985-10-16
Also published as: GB8508453D0; GB8408370D0; GB2156981B

Abstract

A level establishing device comprising a flexible tube to the ends of which a pair of terminating devices (one shown) are connected, the terminating devices incorporating valve members 6, 7 and a transparent sight tube 5. To enable easy storage of the device the terminating devices are designed so that when brought together the shown C-shaped handle portions of the two terminating members can be secured together by complementary formations 3, 4 so as to define an H-shaped structure about which the tube can be wrapped. <IMAGE>

Description

SPECIFICATION Level establishing device The present invention relates to a level establishing device.

It is well known that in large and small scale construction work it is necessary to establish horizontal levels. On large construction sites levels are generally established using a dumpy level. On small sites a good quality spirit level may suffice. It is also known however to use a water filled tube to establish levels. The two ends of the tube are held up so that the tube defines a U-shape within which the water is retained, and the levels of the water in the two ends of the tube are marked on suitable supports. A line drawn between the two marks will be horizontal.

A water filled tube can be very accurate in establishing levels and in theory is easy to use. In practice however it has not found widespread acceptance. This is the result of several factors.

Firstly, care has to be taken to ensure that air bubbles are not trapped in the tube while it is filled or during subsequent use. Secondly, care has to be taken to prevent loss of water from the tube in the event of for example one end of the tube being dropped. Thirdly, the tube can becme tangled and is difficult to store neatly and safely.

In one commercially available device a water filled opaque rubber tube is terminated at each end by transparent tubes. Each transparent tube is provided with a single valve movable between a first position in which both ends of the glass tube are closed and a second position in which both ends of the glass tube are open. When the valve member is closed air trapped in the transparent tube cannot pass into the rubbertube however the device is handled. This makes it less likely that air will get into the rubber tube after it has been filled with water. The transparent tubes are however cumbersome and difficult to use as the valve member extends through them from one end to the other, obstructing a clear view of the water level. Furthermore, and most importantly, the rubber tube is easy to tangle and damage, and difficult to store.As a result the commercially available device has not found widespread acceptance.

It is an object of the present invention to provide an improved level establishing device.

According to the present invention, there is provided a level establishing device comprising a flexible tube to the ends of which are connected a pair of terminating devices, each terminating device comprising at least one valve member which is closable to prevent fluid escaping from the tube, and each end of the tube or a potion of the terminating device in communication therewith being transparent, wherein one of the terminating devices, or a combination of the terminating devices, or a further member secured to one end of the tube, defines a structure about which the tube can be wrapped.

In one arrangement, each terminating device comprises an elongate support from one side of which a C-shaped member extends, the ends of the C-shaped member being secured to the elongate member at some distance from the ends thereof.

The C-shaped members of the two terminating devices support cooperating formations which enables the two terminating devices to be secured together. When secured together thus, a generally H-shaped structure results, and a tube connected to sight glasses supported by the terminating members may be wrapped around the H-shaped structure. A manually operable valve is provided at each end of each of the sight glasses.

One of the terminating devices may define an H-shaped structure by itself, the other terminating member being simply hung from or secured to the said one terminating device after the tube is wrapped therearound.

As a further and even simpler arrangement, the tube support structure may be a simple one-piece H-shaped moulding defining clips on each of its major limbs. Each end of the tube supports a simple valve member wich may be for example a bistable mechanism which opens when pressed once and closes when pressed again. A similar mechanism to that provided in retractable ball point pens could be used. One end of the tube is permanently clipped to the moulding. The other may be clipped to the moulding when the tube is coiled up thereon, or may be separated from the moulding when the device is in use.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which; Figure 1 is a side view of a terminating device of an embodiment of the invention; Figure 2 is a section on the line 2-2 of Fig.1; F02Figure 3 shows two interconnected terminating devices in the configuration appropriate for storage; F02Figure 4 is an exploded view showing some of the parts of the terminating device of Fig. 1; and F02 Figures 5,6 and 7 show three further embodiments of the invention.

Referring to Fig. 1, the illustrated terminating device or hand set comprises an elongate support 1 o which a C-shaped member 2 is integrally connected to define a convenient handle. The handle 2 supports formations 3,4 which enable the hand set to be locked in engagement with another identical handset as shown in Fig.3. A rigid plastics sight glass 5 extends between valves 6 and 7 (Figs. 3 and 4).

Each of the valves comprises a moulding 8 (Fig. 4) into which a valve member 6 or 7 extends.

The support 1 is engaged by a transparent plastics extrusion 9 beneath which a paper or plastics scale 10 is trapped. A slider 11 may be moved along the sight glass to mark the level of any fluid visible therein.

As shown in Fig.2, the support 1 is hollow and a rod 12 is secured therein by knurled nuts 13 (Figs. 3 and 4). A hanger 14 (Fig. 4) is also provided to make it possible for the hand set to be hung on a nail for example.

The hand set comprises a base 15 which may be secured in the position shown in Figs.1 and 2 when the hand set is to stand alone on a flat surface or in the position shown in Fig. 3 when wthe device is to be stored. The base 15 defines a curved surface 16 around which a tube 17 is wrapped to avoid kinking when the device is stored. The tube 17 is of course connected to the sight glass 5 via the valve 7. It will also be noted that a hole 18 is provided in the base 15 to enable the rod 12 to pass through the base when the base is secured by knurled nut 19 in the position shown in Fig. 1.

The rod 12 may be extended from the base 15 to extend downwards into for example excavations prepared for foundations or to extent upwards to contact for example a ceiling. By extending the rods of both hand sets by an equal amount, and placing the tip of one rod in contact with for example the top of footings in a trench, the other hand set can be moved vertically until the height of the water or oher fluid in the sight glasses is the same. The tip of the other hand set will then be at the same level as the top of the footings. This means that levels can be established which are below the surrounding ground. If necessary, a longer rod can be inserted in place of rod 12 to enable levels to be established in deep excavations.

Figure 5 illustrates one terminating device of an alternative embodiment of the invention. This embodiment does not include an extension rod as in the embodiment of Figs.1 to 4 but a rod could be easily provided by clipping appropriate brackets to the straight side of the terminating device. The simple illustrated device could be cheaply manufactured by plastics moulding techniques.

Figure 6 illustrated one terminating device of an further alternative embodiment of the invention incorporating various additional features to those of the Fig.5 embodiment. The device comprises an aluminium extrusion 20 into which a C-shaped member 21 is slotted. An extension rod 27 is provided, as are foldable legs 23. A transparent tube 24 in communication with flexible tube 25 is positioned in front of a plastic rod 26 which transmit light from a battery powered torch 27 (shown in outline only). This makes it easier to see the fluid level in the tube 24 when working in poorly lit condtions. The purpose of other features of the device will be apparent by reference to equivalent parts of the device illustrated in Figs. 1 to 4.

F02Figure 7 illustrates an arrangement similar to that of Fig. 5 but with an restructured C-shaped handle portion incorporating a fluid resorvoir 28.

The two ends of the reservoir 28 communicate with the hand operated valve members 29 via tubes 30 indicated by dotted lines. The valve members 29 can be placed in any one of three positions. In the first position the tubes 30 are isolated from the sight glass tube 31 and the sight glass tube 31 is also sealed. In the second position the tube 30 from the reservoir is sealed but the ends of the sight glass tube are open. In the third position the ends of the sight glass tube are open and also communicate through the valve member with the tubes 30.

The advantage of the arrangement of Fig. 7 is that where two men are using the instrument with one man being located at each end of the main tube adjustments can be easily made to both of the tube ends as described above with reference to the earlier embodiments. However where only one man is using the instrument it is convenient for him to have his end of the tube connected to a reservoir having a cross sectional area considerably greater than that of the sight tube. This can be achieved by connecting a relatively large vessel on the top of his sight tube but this is relatively inconvenient and the same effect is easily achieved by appropriate manipulation of the valve mebers 29. There is no need to make any new connections are reconnections of the pipe work nor to add or drain off any liquid.

Claims

1. A level establishing device comprising a flexible tube to the ends of which are connected a pair of terminating devices, each terminating device comprising at least one valve member which is closable to prevent fluid escaping from the tube, and each end of the tube or a portion of the terminating device in communication therewith being transparent, wherein one of the terminating devices, or a combination of the terminating devices, or a further member secured to one end of the tube, defines a structure about which the tube can be wrapped.

2. A level establishing device according to claim 1, wherein each terminating device comprises an elongate support from one side of which a C-shaped member extends, the ends of the C-shaped member being secured to the elongate support at some distance from the ends thereof, and the C-shaped members of the two terminating devices being provided with cooperating formations which enable the two terminating devices to be secured together to define a generally H-shaped structure around which the tube may be wrapped.

3. A level establishing device according to claim 2, wherein each terminating member supports a sight glass and a manually operable valve is provided at each end of each of the sight glasses.

4. A level establishing device according to claim 1, wherein one of the terminating devices defines an H-shaped structure by itself, the other terminating member being adapted to be hung from or secured to the said one terminating device after the tube is wrapped therearound.

5. A level establishing device according to claim 1, wherein the tube support structure is a one-piece H-shaped moulding defining clips on each of its major limbs, and each end of the tube supports a valve member, one end of the tube being perma nently clipped to the moulding and the other end being removably clipped to the moulding so that it may be clipped to the moulding when the tube is wound thereon.

6. A level establishing device according to any preceding claim, wherein each valve member is a bistable mechanism which opens when pressed once and closes when pressed again.

7. A level establishing device according to any preceding claim, wherein at least one terminating device comprises a fluid reservoir and an associated valve member may be manipulated to connect the reservoir to the tube or to isolate the reservoir from the tube.

8. A level estalishing device substantially as hereinbefore described with reference to Figs. 1 to 4, Fig. 5, Fig. 6 or Fig. 7 of the accompanying drawings.