GB2109560A - Fluid flow alarm device - Google Patents

Abstract

A fluid flow alarm device comprises a rotor (25) connected in a fluid flow line (21,22) and driving an external sound generator such as a siren or bell (not shown). The device can be used in a coal shearing apparatus for use in a coal mine of the type comprising a shearing drum and having associated therewith a high pressure water spray together with pre-start warning water sprays which warn workers near the drum that cutting is about to start. The sound generator supplements the warning given by the water sprays, without the need for any electrical apparatus at the coal face. <IMAGE>

Description

SPECIFICATION Fluid flow alarm device This invention relates to an alarm device which is particularly useful in providing an audible warning signal to supplement the pre-start warning water sprays provided in coal shearing machine used in coal mines.

According to the invention there is provided a fluid flow alarm device comprising drive means insertable in a fluid flow line, and a soundgenerating means connected to and driven by the drive means.

Preferably the drive means is a paddle or turbine device, while the sound-generating means may be a rotary siren or bell.

The invention also provides a coal shearing apparatus for use in a coal mine, the apparatus comprising a shearing drum and at least one water spray warning device associated therewith, the device having a water supply line and an alarm device connected to the water supply line and caused to operate by a flow of water through the supply line.

The alarm device may be connected in series with the water spray or sprays, the water flowing first through the device and thence to the sprays, or it may be connected in a parallel line, the water leaving the device either discharging to waste or rejoining the line supplying the sprays.

The alarm device of the invention is simple in construction and reliable in operation. No control devices additional to those already present in the water spray warning of a coal shearing apparatus are required, supply of water to the sprays automatically producing an audible warning.

Reference is made to the drawings in which: Figure 1 is a schematic diagram of a coal shearing apparatus in accordance with one aspect of the invention; and Figure 2 is a sectional view of the alarm device of the invention, showing the drive means.

A coal shearing device 1 includes a shearing drum 2 which has cutting teeth around the periphery thereof and which is rotated to shear the coal along the coal face, from where it is conveyed by the face conveyor. During cutting, high-pressure water sprays 3 associated with the drum ensure, inter alia, that dust is suppressed.

To warn workers near the drum that cutting is about to start, and that they must move clear of the drum, pre-start warning sprays 4 are turned on for a period of 7 to 10 seconds prior to the start of the drum. It will be appreciated that electrical warning devices are undesirable in the conditions experienced at the coal face.

In accordance with the invention, the alarm device 5 is included in the water line supplying water to the pre-start sprays 4 and provides an audible warning supplementary to, but necessarily approximately simultaneously with, the water spray warning. The device is placed downstream of the pressure and time controls 6.

Referring to Figure 2, the warning device comprises a drive mechanism consisting of a block 20 with a water inlet connection 21 and a water outlet connection 22. The water inlet connection 21 leads into a nozzle 23 which is directed into a chamber 24 containing a rotor 25 having generally radial blades 26 on to which the water from the nozzle impinges causing high rotational speeds to be produced. For example, with a supply water pressure of 200 pounds per square inch (1379 kNm-2), speeds of 15000 revolutions per minute can be achieved. The supply to the warning sprays is required to be of the order of 30 to 40 p.s.i. (270--276 kNm-2).

The water flows from the chamber 24 into the outlet connection 22 and thence to the sprays, or to waste as the case may be. The inlet and outlet connections are aligned to minimise the pressure drop in the line produced by the mechanism.

The shaft 27 of the rotor is connected, via shaft seals (not shown), to an external sound-generator, such as a siren or bell. Thus, an audible alarm signal is produced without the need for any electrical devices.

Claims

1. A fluid flow alarm device comprising drive means insertable in a fluid flow line, and a sound generating means connected to and driven by the drive means.

2. A device according to Claim 1 , wherein the drive means is a paddle or turbine device.

3. A device according to Claim 2, wherein the sound generating means is a rotary siren or bell.

4. A fluid flow alarm device, substantially as described herein with reference to the drawings.

5. A coal shearing apparatus for use in a coal mine, the apparatus comprising a shearing drum and at least one water spray warning device associated therewith, the device having a water supply line, and an alarm device connected to the water supply line and caused to operate by a flow of water through the supply line.

6. An apparatus according to Claim 5, wherein the alarm device is connected in series with the water spray or sprays, the water flowing first through the device and thence to the sprays.

7. A device according to Claim 5, wherein the alarm device is connected in a parallel line to the line supplying the water spray or sprays, the water leaving the device either discharging to waste or rejoining the line supplying the spray.

8. A coal shearing apparatus for use in a coal mine, substantially as described herein with reference to, or as shown in Figure 1 of the drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Fluid flow alarm device This invention relates to an alarm device which is particularly useful in providing an audible warning signal to supplement the pre-start warning water sprays provided in coal shearing machine used in coal mines. According to the invention there is provided a fluid flow alarm device comprising drive means insertable in a fluid flow line, and a soundgenerating means connected to and driven by the drive means. Preferably the drive means is a paddle or turbine device, while the sound-generating means may be a rotary siren or bell. The invention also provides a coal shearing apparatus for use in a coal mine, the apparatus comprising a shearing drum and at least one water spray warning device associated therewith, the device having a water supply line and an alarm device connected to the water supply line and caused to operate by a flow of water through the supply line. The alarm device may be connected in series with the water spray or sprays, the water flowing first through the device and thence to the sprays, or it may be connected in a parallel line, the water leaving the device either discharging to waste or rejoining the line supplying the sprays. The alarm device of the invention is simple in construction and reliable in operation. No control devices additional to those already present in the water spray warning of a coal shearing apparatus are required, supply of water to the sprays automatically producing an audible warning. Reference is made to the drawings in which: Figure 1 is a schematic diagram of a coal shearing apparatus in accordance with one aspect of the invention; and Figure 2 is a sectional view of the alarm device of the invention, showing the drive means. A coal shearing device 1 includes a shearing drum 2 which has cutting teeth around the periphery thereof and which is rotated to shear the coal along the coal face, from where it is conveyed by the face conveyor. During cutting, high-pressure water sprays 3 associated with the drum ensure, inter alia, that dust is suppressed. To warn workers near the drum that cutting is about to start, and that they must move clear of the drum, pre-start warning sprays 4 are turned on for a period of 7 to 10 seconds prior to the start of the drum. It will be appreciated that electrical warning devices are undesirable in the conditions experienced at the coal face. In accordance with the invention, the alarm device 5 is included in the water line supplying water to the pre-start sprays 4 and provides an audible warning supplementary to, but necessarily approximately simultaneously with, the water spray warning. The device is placed downstream of the pressure and time controls 6. Referring to Figure 2, the warning device comprises a drive mechanism consisting of a block 20 with a water inlet connection 21 and a water outlet connection 22. The water inlet connection 21 leads into a nozzle 23 which is directed into a chamber 24 containing a rotor 25 having generally radial blades 26 on to which the water from the nozzle impinges causing high rotational speeds to be produced. For example, with a supply water pressure of 200 pounds per square inch (1379 kNm-2), speeds of 15000 revolutions per minute can be achieved. The supply to the warning sprays is required to be of the order of 30 to 40 p.s.i. (270--276 kNm-2). The water flows from the chamber 24 into the outlet connection 22 and thence to the sprays, or to waste as the case may be. The inlet and outlet connections are aligned to minimise the pressure drop in the line produced by the mechanism. The shaft 27 of the rotor is connected, via shaft seals (not shown), to an external sound-generator, such as a siren or bell. Thus, an audible alarm signal is produced without the need for any electrical devices. Claims

1. A fluid flow alarm device comprising drive means insertable in a fluid flow line, and a sound generating means connected to and driven by the drive means.

2. A device according to Claim 1 , wherein the drive means is a paddle or turbine device.

3. A device according to Claim 2, wherein the sound generating means is a rotary siren or bell.

4. A fluid flow alarm device, substantially as described herein with reference to the drawings.

5. A coal shearing apparatus for use in a coal mine, the apparatus comprising a shearing drum and at least one water spray warning device associated therewith, the device having a water supply line, and an alarm device connected to the water supply line and caused to operate by a flow of water through the supply line.

6. An apparatus according to Claim 5, wherein the alarm device is connected in series with the water spray or sprays, the water flowing first through the device and thence to the sprays.

7. A device according to Claim 5, wherein the alarm device is connected in a parallel line to the line supplying the water spray or sprays, the water leaving the device either discharging to waste or rejoining the line supplying the spray.

8. A coal shearing apparatus for use in a coal mine, substantially as described herein with reference to, or as shown in Figure 1 of the drawings.