GB2239822A

GB2239822A - Water spray unit for mining

Info

Publication number: GB2239822A
Application number: GB9000933A
Authority: GB
Inventors: George Albert Parrott
Original assignee: Minnovation Ltd
Current assignee: Minnovation Ltd
Priority date: 1990-01-16
Filing date: 1990-01-16
Publication date: 1991-07-17
Anticipated expiration: 2010-01-16
Also published as: GB2239822B; GB9000933D0

Abstract

A water spray unit (1) has an elongate nozzle (2) with a water inlet orifice (6) in communication with an internal water receiving chamber (5) and a water discharge orifice (13), and a fastener (3) having an external screw thread (17) and drive surfaces (18) for screwing or unscrewing. The nozzle and fastener are connected to one another in an articulated manner whereby, within limits, slight misalignment between the longitudinal axes (4 and 16) of the nozzle (2) and the fastener (3) can be accommodated, and, upon unscrewing, the fastener (3) retracts the nozzle (2) from within a mounting bore in a pick box. The articulation between the nozzle and fastener may be by way of a cupped end (40) of the nozzle crimped or swaged into a neck (39) on the fastener, or a pin fitted on the nozzle being loosely received in a groove in the fastener, or a ball and socket connection. <IMAGE>

Description

WATER SPRAY UNIT FOR MINING This invention relates to a water spray unit for installation in a pick box of a rotary cutting head of a mining machine. The latter may be a so-called roadheader machine for driving tunnels or underground roadways, or a socalled shearer for mineral (particularly coal) winning operations. The invention also includes a pick box provided with such a spray unit and a rotary cutting head provided with an array of such pick boxes.

According to a first aspect of the present invention, there is provided a water spray unit comprising a first component in the form of an elongate nozzle portion having a longitudinal axis, an internal water receiving chamber, a water inlet orifice in communication with the chamber and, at one end of the nozzle portion, a water discharge orifice in communication with the chamber, and a second component in the form of a fastener having a longitudinal axis and comprising an external screw thread and drive surfaces for screwing or unscrewing, with an articulated connection between the first and second components whereby, within limits, slight misalignment between the longitudinal axes of the nozzle portion and the fastener can be accommodated, and, upon unscrewing, the fastener retracts the nozzle portion.

According to a second aspect of the invention, there is provided a pick box to receive, releaseably, a mineral cutter pick, provided with a rear entry bore in which is housed a water spray unit in accordance with the first aspect.

According to a third aspect, there is provided a rotary mineral cutting head, provided with an array of pick boxes in accordance with the second aspect.

Conveniently, the articulated connection may be of the ball and socket type. Thus, a nose of the fastener may constitute the ball which is inserted into a cupped end of the nozzle portion distal from its discharge orifice, with the cupped end then suitably crimped or swaged over the ball, either during manufacture of the water spray unit, or in situ during fitting of the water spray unit into the sprayreceiving bore of a pick box.

Alternatively, a nose of the fastener may be provided with a circumferential groove and the end of the first component distal from its discharge orifice may be provided with a tangential hole to receive a pin e.g. a spring dowel, or two holes to receive the limbs of a "U"-shaped staple, with the pin or limbs being a loose or sloppy fit in the groove, to provide a degree of play and/or articulation.

The invention will now be described in greater detail by way of examples, with reference to the accom pany ing drawings in which: Figure 1 is a longitudinal section through a first proposed water spray unit of the Applicants; Figure -2 is a longitudinal section through a second proposed water spray unit of the Applicants; Figure 3 is a longitudinal section through a first embodiment water spray unit in accordance with the first aspect of the invention; Figure 4 is a longitudinal section through a second embodiment of water spray unit in accordance with the first aspect of the invention; Figures 4A and 4B correspond to Figure 4 but show different misaligned positions;; Figures 5 and 5A show another construction of the articulated embodiment of Figures 4 to 4B; and Figure 6 shows partly in section the water spray unit of Figure 3, located in a pick box in accordance with the second aspect, mounted on a rotary cutting head in accordance with the third aspect.

In Figures 1 - 5A, like reference numerals are used for like components.

Water spray unit 1, comprises a first component in the form of a nozzle portion 2 and a second component in the form of fastener 3.

The nozzle portion 2 is generally cylindrical, having a longiudinal axis 4. Internally, the nozzle portion 2 is provided with a water chamber 5, supplied with water via a radial orifice 6 protected by a wire mesh filter sleeve 7 retained by an 'O'-ring 8 in a circumferential groove 9.

Another 'O'-ring 1 is located in a circumferential groove 11 together with a pair of backing rings 12. At one, inner end, the nozzle portion 2 is provided with a water discharge orifice 13 co-axial with the longitudinal axis, to provide a water spray 14 (see Figure 5), while the leading or inner end of the nozzle portion 2 terminates in a frusto-conically tapered nose 15.

The fastener 3 has a longitudinal axis 16 and is provided with an external thread 17 and an internal hexagon socket 18 to receive an Allen Key.

As indicated in Figure 6, the water spray unit 1 is entered, from the rear, into a bore 19 of a pick box 2 provided with an aperture 21 to receive a shank 22 of a cutter pick 23 having a head 24 provided with a tungsten carbide tip 25. The box 2 is secured by welds 26 to a rotary cutting head 27.

In detail, the bore 19 is of internal diameter slightly greater than the external diameter of the water spray unit 1. At its outer end, the bore 19 is provided with screw threads 28 and at its inner end with a frust-conical seat 29 leading to an aperture 3 with which the discharge orifice 13 is adapted to be aligned in close proximity.

Reverting now to Figure 1, it will be observed that the fastener 3 illustrated is provided with an integral circular section nose 31, which is a tight, push fit within a counterbored extension 32 of the water chamber 5, the nose 31 serving firstly as a water plug for the end of the water chamber 5 distal from the discharge orifice 13 and secondly transmitting torque, and hence rotation, to the nozzle portion 2 during unscrewing in of the water spray unit 1 (to bring the nose 15 into tight, water-sealing engagement with the seat 29), or unscrewing of the water spray unit 1 (for cleaning etc).

In practice however, it was found that tap wander, during cutting of the threads 28, frequently resulted in the thread 28 not being aligned with sufficient accuracy with the bore 19. This resulted in difficulties, or on some occasions impossibility, of inserting water spray units in accordance with the Figure 1 embodiment, in the awkward confines of a mine environment, into the bores 19.

This problem was overcome by the development of the one-piece water spray unit of Figure 1 to the two-piece water spray unit in Figure 2, where the nozzle portion 2 is quite separate from the fastener 3. A bearing face 33 of the fastener 3 abuts an annular rib 34 of the adjacent end of the nozzle portion 2, to push, and advantageously not necessarily to rotate, the nozzle portion 2 along the bore 19 until tight seating engagement is achieved between the frusto-conical nose 31 and seat 29, while the extension 32 is tapped at 35 to receive a screw-in water plug 36 with an internal hexagon socket 37 to receive an Allen key. Whilst the Figure 2 water spray unit overcomes the non-alignment problem, it was found that upon unscrewing of the fastener 3, the nozzle portion 2 frequently remained stuck in situ, thus requiring an extraction tool, which is awkward to use in the confines of an underground environment. Also, as the fastener 3 is only some 5-18 mm in diameter, its insertion underground is awkward, it can become dropped and lost in the debris on a mine floor, or the fastener 3 and nozzle portion 2 may be provided in odd numbers numbers rather than, correctly, in pairs.

The embodiments of water spray units and depicted in Figures 3, 4, 4A, 4B, 5 and 5A in accordance with the invention overcome the potential practical difficulties envisaged with the water spray units of both Figure 1 and Figure 2.

In Figures 3, 4, 4A, 4B, 5 and 5A, the nose 31 of the fastener 3 functions as a ball of a ball and socket type articulated connection 38 between the first and second components. In detail, the nose 3i has a neck 39 and a cupped end 4 of the nozzle portion 2 is crimped or swaged towards the neck 39 with an annular clearance gap 41 (in the aligned position illustrated in Figures 3 and 4). Hence, as ,illustrated in Figure 4A, any axial misalignment of the thread 28 with the bore 19 (and hence axes 4 and 16 not being co axial as intended but being misaligned with axis 16 displaced to position 16A) is of no consequence as the cupped end 4 is deformable by the nose 31.Similarly, as illustrated in iFigure 4B, again misalignment of the thread 28 and the bore 19, whereby the axis 16 is displaced to position 16B, is again of no consequence as this likewise can be accommodated over 3600 due to the presence of the articulated connection 38.

Also, the handling and other difficulties of the Figure 2 embodiment are avoided, while advantageously the nozzle portion 2 is not rotated upon screwing or unscrewing the fastener 3.

Furthermore, upon unscrewing e.g. for cleaning or replacement, the fastener 3 via the articulated connector 38 reliably pulls any sticking nozzle portion 2 from the bore 19, and hence no extraction tool or extraction operation is necessary.

In the embodiments of Figures 4 to 5A the water plug 36 is omitted, the nose 31 is provided with a spherical outer surface 42 and the extension 32 is provided with a frustoconical sealing surface 43.

Finally, as illustrated in Figures 5 and 5A, the possibility exists of supplying the nozzle portion 2 and fastener 3 as two separate components, with the crimping or deforming of the cupped end 4 effected in situ, in the bore 19. In detail, the fastener 3 is provided with an annular skirt 44 with an inclined inner face which, together with the adjacent outer periphery of the nose 31 defined an inwardly tapering, annular gap 45. Thus, progressive unscrewing of the fastener 3 along the bore 19 forces the cupped end 4 of the nozzle portion 2 into the gap 45, gradually deforming the cupped end 4 until the position illustrated in Figure 5A is attained, in which the cupped end 40 engages behind the neck 39.

Claims

1. A water spray unit comprising a first component in the form of an elongate nozzle portion having a longitudinal axis, an internal water receiving chamber, a water inlet orifice in communication with the chamber and, at one end of the nozzle portion, a water discharge orifice in communication with the chamber, and a second component in the form of a fastener having a longitudinal axis and comprising an external screw thread and drive surfaces for screwing or unscrewing, with an articulated connection between the first and second components whereby within limits, slight misalignment between the longitudinal axes of the nozzle portion and the fastener can be accommodated, and, upon unscrewing, the fastener retracts the nozzle portion.

2. A water spray unit as claimed in Claim 1, wherein the articulated connection is of the ball and socket type.

3. Awater spray unit as claimed in Claim 2, wherein a nose of the fastener constitutes the ball which is inserted into a cupped end of the nozzle portion distal from its discharge orifice, with the cupped end then suitably crimped or swaged over the ball.

4. A water spray unit as claimed in Claim 1, wherein the articulated connection comprises a circumferential groove provided in a nose of the fastener and the end of the nozzle portion distal from its discharge orifice is provided with a tangential hole to receive a pin, being a loose or sloppy fit in the groove, to provide a degree of play and/or articulation.

5. A water spray unit as claimed in Claim 1, wherein the articulated connection comprises a circumferential groove provided in a nose of the fastener and the end of the nozzle portion distal from its discharge orifice with two holes to receive the limbs of a "U"-shaped staple, being a loose or sloppy fit in the groove, to provide a degree of play and/or articulation.

6. A water spray unit substantially as hereinbefore described with reference to Figure 3.

7. A water spray unit substantially as hereinbefore described with reference to Figures 4, 4A and 4B.

8. A water spray unit substantially as hereinbefore described with reference to Figures 5 and 5A.

9. A pick box to receive, releasably, a mineral cutter pick, provided with a rear entry bore in which is housed a water spray unit as defined in any preceding Claim.

1PI. A pick box substantially as hereinbefore described with reference to Figure 6.

11. A rotary mineral cutting head, provided with an array of pick boxes as defined in Claim 9 or Claim 10.