Mining or in situ disintegration of hard material – Cutter tooth or tooth head – Cleansing fluid passage
Reexamination Certificate
1998-07-20
2001-07-10
Lillis, Eileen D. (Department: 3673)
Mining or in situ disintegration of hard material
Cutter tooth or tooth head
Cleansing fluid passage
C239S600000
Reexamination Certificate
active
06257672
ABSTRACT:
This invention relates to various items of mining related equipment, specifically a clip, a water spray nozzle, a pick box, and a rotary cutting head.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Water spray nozzles have been used in a variety of dust and ignition suppression operations. For instance water spray nozzles have been provided in, on, or adjacent pick boxes for a variety of purposes. In coal mining such purposes are dust suppression; pre-start warning; incendive sparking suppression shrouding, and, on a so-called ventilated rotary cutting head, for air flow inducement to encourage methane dilution and dispersal. In coal transportation, such uses are on belt conveyor spray bars, chutes, and lump breakers.
2. Description of the Prior Art
In mining conditions, whether mining coal, potash or other minerals, or in tunnel driving operations, there is a propensity for nozzle blockage, particularly when a machine is idle for whatever reason. Hence removal, cleaning and refitting is essential if the nozzles are to remain effective, particularly as some machines safety systems monitor water flow and/or pressure and effect machine shut down automatically when monitored parameters signal excessive blockage. Various attempts, successful to greater or lesser extents, have been made to provide “screwless” nozzles, to overcome the known drawbacks of removing and refitting screw-in, screw-out nozzles in mine conditions. Thus, metal pins, wires and staples have been proposed. As a typical coal winning drum would typically carry some 50-70 pick boxes, nozzle removal, cleaning and replacement is a tedious and time consuming operation in the limited confines and lighting of a coal face. There is a demand for an attachment system that is both simple and rapid.
OBJECT OF THE INVENTION
A basic object of the invention is to provide an improved clip, a water spray nozzle, a pick box, and a rotary cutting head.
SUMMARY OF THE INVENTION
According to a first aspect of the invention there is provided a push-in, prise-out, clip for releasably retaining a replaceable water spray nozzle in a receiving bore, the clip comprising a plate-like member of suitable resilient material, e.g. synthetic plastics material, spring steel etc., generally of “V” or “U”-shape having “C”-shaped recess subtending an arc greater than 180° and adapted, in use, to engage a correspondingly arcuate waist portion of the water spray nozzle, the recess being defined in part by arcuate profiles on mutually facing, inner surfaces of each arm of the “V” or “U”, which arms are adapted to splay apart resiliently during the fitting and the removal of a clip on the water spray nozzle, with each arm provided with a mutually inclined surface to aid fitting, with the distance between inner ends of the inclined surfaces, in a non-splayed condition, being less than the diameter of the “C”-shaped recess, and with a portion of the clip in the base of the “V” or “U”, being provided with a clip retraction surface.
Thus, to fit and to remove a clip in accordance with the first aspect of the invention from a nozzle, the clip needs to be displaced radially with respect to the nozzle. During fitting the radial displacement force must exceed that needed to splay the arms. This may be achieved by manually pushing the clip into place, or by tapping the clip into place by a simple tool such as a hammer, with retraction by another simple tool such as a screwdriver blade.
Preferably, the clip retraction surface is provided by a wall of a slot or bore in the clip, engageable by a simple tool such as a screwdriver bit, to achieve clip retraction by prising out the clip to splay the arms apart, so as to permit nozzle removal.
According to a second aspect of the present invention of independent significance, there is provided a water spray nozzle, adapted to be received, releasably, in a bore, the nozzle comprising:
(1) a spigot portion of diameter approximating to that of its intended receiving bore;
(2) a water conveying passage extending through the spigot portion from an open, inlet end of the nozzle;
(3) a first circumferential groove located adjacent the water inlet end of the spigot portion to carry a resilient sealing ring to sealingly engage a portion of the bore;
(4) a waist defined by a second circumferential groove located downstream of the first circumferential groove and adapted, in use, to be engageable by a clip in accordance with the first aspect;
(5) a head portion of the nozzle located downstream of the waist and intended, in use, to be external to the bore; and
(6) a water discharge aperture provided in the head portion.
In one embodiment, the receiving bore, may be provided in a pick box, such bore being in fluid flow communication with a port of a water supply network.
In another embodiment, the receiving bore may be provided in a housing adapted to be welded eg into a recess in a vane of a rotary cutting head, with the bore again being in fluid flow communication with a water supply network eg of an associated vane of a rotary cutting head. Clearly, the housing needs to be welded in an orientation to provide water discharge in the required direction eg towards the tip of an adjacent mineral cutter pick.
In one embodiment, the nozzle provides for water discharge in a predetermined radial direction by having at least one flat on the head portion, and preferably provided with a pair of opposed, parallel flats on its head portion, for engagement, eg when fitted to a pick box, with a corresponding flat to ensure the required nozzle orientation and hence that of its discharge aperture. Such an embodiment is suitable for fitting into a receiving bore of a pick box, and preferably the head is enlarged or circumferentially grooved so that, to remove a nozzle, a simple tool such as a screwdriver blade is engageable beneath the enlarged head to prise the nozzle from its bore.
In another embodiment, the nozzle may provide for co-axial water discharge in the required pattern, e.g. as a solid cone, hollow cone or pencil jet.
With all embodiments of nozzle, the inlet end of the water conveying passage is peferably covered by a debris filtration gauze. Also, any water receiving chamber in an enlarged head is preferably provided with a water swirl unit, if swirled water emission, in contrast to a generally coherent jet of water, is required.
According to a third aspect of the invention of independent significance, there is provided a pick box in combination with a clip in accordance with the first aspect and a nozzle in accordance with the second aspect, the pick box comprising (i) a bore adapted to receive the spigot portion of the nozzle, (ii) at least one flat to be engaged by a nozzle flat(s), and (iii) an aperture to receive the clip, the aperture providing an abutment surface adapted to be engaged by a portion of a surface of the clip when pushed into its aperture and engaging the circumferential groove of the nozzle, which engagement prevents inadvertent nozzle removal.
Preferably, the box is provided with a pair of spaced apart flanges, extending beyond the upper end of the bore and beyond the axial length of the head portion, not only to provide damage protection for the otherwise exposed head portion from the mineral being mined, but also with opposed, parallel faces of flanges providing two flats for engagement by the preferred two flats of the nozzle head.
Preferably, the clip receiving aperture is a slot, of width slightly exceeding the thickness of the clip, provided at innermost ends of the flanges and intersecting each flange to provide an abutment surface in each flange that is orthogonal to the parallel flats of the pick box.
The spigot receiving bore is preferably provided with a frusto-conical mouth, adapted to be engaged by a frusto-conical seating surface of the nozzle at a transition portion between the spigot and the head of the nozzle. The latter may be of unitary construction.
According to a fourth aspect of the invention, of independent significance, there is provided a rotary mineral cutting head provided with
Lillis Eileen D.
Minnovation Limited
Singh Sunil
Trexler, Bushnell Giangiorgi, Blackstone & Marr, Ltd.
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