GB2041097A

GB2041097A - Turbine flow meter

Info

Publication number: GB2041097A
Application number: GB7848880A
Authority: GB
Original assignee: H Meinecke AG
Current assignee: H Meinecke AG
Priority date: 1978-07-26
Filing date: 1978-12-18
Publication date: 1980-09-03
Also published as: DE2832688A1; JPS5520494A; GB2041097B; FR2432162A1; JPH0122564B2; FR2432162B1; DE2832688C2

Abstract

A water meter comprises linked indicator pointers (4, 5), for example for decimal parts of a unit and for a unit and for units, driven by gearwheels (8, 10) from a turbine. Remote transmission of the measured values is provided by magnets (16, 17) carried by the respective gearwheels (8, 10) which cooperate with a pulse transmitter located externally of the sealed part of the meter casing in a plug 20. The pulse transmitter plug 20 can be located in a selected one of two different positions such that in each position the pulse transmitter cooperates with a different one of the two magnets (16, 17). <IMAGE>

Description

SPECIFICATION Water meters The invention relates to a water meter, particularly a turbine flow-meter with a device for the electrical remote transmission of the measured value, in which the cap screws holding the transparent cover through which the meter can be read are connected to the casing and lead sealed after the meter has been calibrated, and the small pointer is so connected to the large pointer of the metering mechanism via a reduction gearing that one gearwheel of the said transmission is connected to the spindle of the large pointer and another gearwheel of the transmission is connected to the spindle of the small pointer.

DOS 2 628 789 discloses a water meter with a device of this type, with a contact member in the form of a magnet provided on the large pointer of the metering mechanism and associated with which there is outside the transparent cover a contactlessly operating pulse transmitter linked to the connecting lead for remote transmission. If, per revolution of the large pointer, the magnet serving as a contactor passes the pulse transmitter which is constructed as a reed contact, then the contacts of this reed are closed and a pulse is initiated into the connecting lead for remote transmission, so that for a single rotation of the large pointer of the metering mechanism, in each case only a single switching operation is performed.

The object of the invention is so to improve this known device that the pulse number can be altered without intervention into the lead sealed part of the meter casing.

According to the invention, this problem is resolved in that at least one contact in the form of a magnet is provided also in the gearwheel which is kinematically connected to the small pointer and in that there is in the meter casing, separate from the lead sealed part thereof, a pocket-shaped chamber, the defining walls of which serve as a mounting for a plug connected to the connecting lead, the pulse transmitter being so located in the plug that in one position of the plug, the pulse transmitter is in the effective range of one magnet and when it is in a position rotated through 180 about its longitudinal axis, the pulse transmitter is in the effective range of the other magnet.

According to a further essential feature of the water meter according to the invention, the cross-section of the plug and of the chamber is such that its vertical and transverse axes are axes of symmetry.

Expediently, the plug has a recess on its side which is remote from the connecting lead.

In a further development of the water meter according to the invention, the recess has in plan view more or less the form of a blunt wedge, the pulse transmitter being disposed in the region of one face of the wedge.

The pulse transmitter may be constructed as a mechanical, inductive, capacitive or photoelectric pulse transmitter. According to a preferred embodiment, the pulse transmitter takes the form of a reed contact.

The construction according to the invention means that it is possible to alter the pulse number without intervention into the sealed part of the meter casing. Assuming that the reduction ratio between the small pointer and the large pointer of the metering mechanism is 10: 1, then in one position of the plug, there is only a single switching pulse per rotation of the large pointer of the metering mechanism, whule in the other position of the plug, per revolution of the small pointer of the metering mechanism of the water counter, there are ten switching pulses. The number of switching pulses can be further varied in that instead of a single magnet, it is possible to provide on the relevant gearwheel of the reduction gearing a plurality of magnets, these gearwheels having to be equipped with the necessary number of magnets prior to calibration.In this way, therefore, it becomes possible to alter the number of switching pulses accordingly.

An example of embodiment of the water meter according to the invention, with the device for remote electrical transmission of the measured value, is described in greater detail hereinafter with reference to the accompanying drawings, in which: Figure 1 is a partly sectional plan view of the water meter according to the invention; Figure 2 is a partial view in the direction of the arrow A in Fig. 1; Figure 3 shows a plan view of the plug of the device for remote electrical transmission of the measured value to the water meter according to the invention; Figure 4 is a plan view of the water meter according to the invention, with an inserted plug of the device for remote electrical transmission of the measured value;; Figure 5 is a partial partly sectional view taken on the line V-V in Fig. 4 through the water meter according to the invention, with the plug located in one position of operation, and Figure 6 is a view corresponding to that in Fig. 5, but in which the plug is in the other operating position.

Figs. 1 and 2 show a plan view, partly in section and a partial view of the water meter respectively, particularly a turbine flowmeter according to the invention, in which after calibration, the cap screws 2 which hold the transparent cover 1 through which the meter can be read are connected to the casing 3 and lead sealed.

The metering mechanism has thereby a large pointer 4 and a small pointer 5, the large pointer 4 indicating the cubic metres and the small pointer the tenths of a cubic metre of liquid to be measured. In other words, between the small pointer 5 and the large pointer 4 there is a reduction ratio of 10:1 which is achieved by a corresponding reduction gearing 6. Connected to the large pointer 4 is the rotary spindle 7 on which the gearwheel 8 is mounted, which must be regarded as one end unit of the transmission gearing 6. The small pointer 5 is mounted on the rotary spindle 9 which is connected to the gearwheel 10.

The rotary movement transmitted by the fan, not shown in greater detail in the drawing, to the rotary spindle 11 is transmitted via the pinion 1 2 to the gearwheel 10, the rotary movement of which is transmitted via the gear wheel set 1 3 to the rotary spindle 14 on which a pinion 1 5 is mounted. This pinion 1 5 meshes with the gearwheel 8 of the reduction gearing 6. Since all these elements are usually found in waters of the type in question, it is possible to dispense with the provision of further details.In the case of the embodiment shown in Figs. 1 and 4 to 6, a contact member in the form of a magnet 1 6 is mounted on the gearwheel 8; also located on the gearwheel 10 is a contact member in the form of a magnet 1 7. It is within the scope of the invention also to change the number of these contact members if required.

Reference numeral 18 (Fig. 1) denotes a pocket-shaped chamber disposed in the meter casing 3 and separated from the lead sealed part of the latter. The defining walls 19 of the chamber 18 serve thereby as a fitting for a plug 20 shown in Fig. 3 of the drawings. This plug 20 is connected to the connecting lead 21 for remote transmission of the measured value.

The cross-section of the chamber 1 8 and of the plug 20 is so constructed that the vertical axis H and transverse axis Q (Fig. 2) are axes of symmetry. In the case of the embodiment illustrated, the cross-section of the chamber 1 8 and of the plug 20 is rectangular. The invention is however by no means restricted to this particular form of embodiment. For example, the cross-sections of these two parts 1 8 and 20 may for example also be circular or elliptical, so long as the vertical axis H and transverse axis Q are axes of symmetry. It is in fact only this feature which makes it possible for the plug 20 to be inserted into the chamber 1 8 in more than one different operating position, an aspect which will be dealt with in greater detail hereinafter.

A pulse transmitter 22 is so disposed in the plug 20 that in one position of the plug 20, it lies in the range of action of the magnet 1 6 while when the plug position is rotated through 180 about the longitudinal axis L (Fig. 3), it lies in the range of effect of the other magnet 1 7.

As Fig. 3 of the drawings shows, on the side remote from the connecting lead 21, the plug 20 has a recess 23 which, in plan, has more or less the shape of a blunt wedge, the pulse transmitter 22 being disposed in the region of one face 23a of the wedge.

The pulse transmitter 22 can be constructed as a mechanical, inductive, capacitive or photoelectric pulse transmitter. In the case of the embodiment illustrated, the pulse transmitter 22 is constructed as a per se known reed-type contact. Such reed contacts consist of a protective tube in which are two switching tongues which move into the switching position when approached by a contactor, e.g. a magnet. The two switching tongues communicate with the connecting lead 21 via the contacts 24, 25 (Fig. 3).

The mode of operation of the water meter according to the invention with the device for remote electrical transmission of the measured value is as follows: On the one hand, let is be assumed that the plug 20 is inserted into the chamber 1 8 in such a position that the pulse transmitter 22 occupies the position shown in Fig. 5.In this position, the pulse transmitter 22 lies only in the range of action of the magnet 16, so that the magnet 1 7 can exert no influence on the pulse transmitter 22, Furthermore, if it is assumed that only a single magnet 1 6 is disposed on the gearwheel 8 then upon a single rotation of the large pointer 4 and thus of the gearwheel 8, only one single switching pulse takes place, namely when the magnet 1 6 reaches the immediate vicinity of the two switching tongues of the pulse transmitter 22.

If the pulse number is to be changed, then it is sufficient to withdraw the plug 20 from the pocket-shaped chamber 18, turn it through 180 about its longitudinal axis L and then insert it into the chamber 18 again, as Fig. 6 of the drawings shows. In this second operating position of the plug 20, the pulse transmitter 22 lies in the range of action of the magnet 1 7 while the magnet 1 6 has no effect on the pulse transmitter 22. Working on the premise that the rotary speed of the gearwheel 10 is ten times greater than that of the gearwheel 8, then the number of switching pulses is increased accordingly.

A further alteration in the number of switching pulses can be achieved by correspondingly carrying the number of magnets 1 6 or 1 7 on the gearwheels 8 or 10 of the number of pulse transmitters 22 in the plug 20 and/or the number of positions which the plug 20 can occupy in the chamber 1 8.

Claims

1. A water meter, particularly a turbine flowmeter with a device for the electrical remote transmission of the measured value, in which the cap screws holding the transparent cover through which the meter can be read are connected to the casing and lead sealed after the meter has been calibrated, and the small pointer is so connected to the large pointer of the metering mechanism via a reduction gearing that one gearwheel of the said transmission is connected to the spindle of the large pointer and another gearwheel of the transmission is connected to the spindle of the small pointer, and at least one contact member in the form of a magnet is kinematically connected to the large pointer and a pulse transmitter is provided which is adapted to co-operate contactlessly with the magnet, being connected to the connecting lead for remote transmission of the measure value to a metering mechanism, characterised in that at least one contact member in the form of a magnet (17) is provided on the gearwheel (10) which is kinematically connected to the small pointer and in that there is in the meter casing (3) and separate from the lead sealed part thereof, a pocket-shaped chamber (18), the defining walls (19) of which serve as a mounting for the plug (20) connected to the connecting lead (21), and in that the pulse transmitter (22) is so disposed in the plug (20) that in one position of the plug (20) the pulse transmitter (22) is in the effective range of one magnet (16) and when it is in a position rotated through 180 about its longitudinal axis (L), the pulse transmitter is in the effective range of the other magnet (17).

2. A water meter according to Claim 1, characterised in that the cross-section of the plug (20) and of the chamber (18) is so constructed that its vertical axis (h) and transverse axis (Q) are axes of symmetry.

3. A water meter according to Claim 1 and 2, characterised in that the plug (20) has a recess (23) on its side which is remote from the connecting lead (21).

4. A water meter according to Claim 3, characterised in that the recess (23) has in plan more or less the form of a blunt wedge, and in that the pulse transmitter (22) is disposed in the region on one face (23a) of the wedge.

5. A water meter according to Claim 1 to 4, characterised in that the pulse transmitter (22) is a mechanical, inductive, capacitive and photoelectric pulse transmitter.

6. A water meter according to Claim 5, characterised in that the pulse transmitter (22) is constructed as a reed-type contact.

7. A water meter according to Claim 1 to 6, characterised in that the plug (20) has more than one pulse transmitter (22), for instance for the purpose of redundance or recognition of direction of rotation.

Three sheets of drawings

8. A water meter substantially as hereinbefore described with reference to the accompanying drawings.