CA2048403A1

CA2048403A1 - Rotary cutting head

Info

Publication number: CA2048403A1
Application number: CA 2048403
Authority: CA
Inventors: Peter Barber
Original assignee: Individual
Current assignee: Hydra Tools International PLC
Priority date: 1990-08-17
Filing date: 1991-08-08
Publication date: 1992-02-18
Also published as: GB2247035A; DE4126406A1; GB9018095D0; PL291434A1; GB9116788D0

Abstract

ABSTRACT
ROTARY CUTTING HEAD
A rotary, mineral cutting head (1), comprising two parts being a base (2), which has means for attachment to a machine, and a dome (3), which is adapted externally to carry pick-receiving boxes (11), with a water gallery (15) defined between an external portion (17) of the base (2) and an internal portion (16) of the dome (3), and with the two parts (2, 3) releasably secured together by bolts or studs (22).

Description

ROTARY CUTTING HEAD
This invention relates to a rotary cutting head particularly, though not exclusively, for the cutting of minerals such as rock by a so-called roadheader machine for example.
With such a machine, the cutting head is usually hollow and is mounted at one end of a boom carried on a machine chassis, with the boom capable of being displaced to various positions to cut a roadway or tunnel to the desired profile. As a means of minimising the airborne dust generated, conventional practice is to provide a pressurised water supply to the cutting head for discharge from a plurality of water spray nozzles located at various points around the head, usually in the vicinity of picks with which the head is armed, and also usually in the vicinity of a terminal collar at one end of the head. In order not only to maintain water pressure but also to minimize weakening of the head, the head is provided with relatively fine ~e.g. 5 mm) distribution passageways, but inevitably in the course of manufacture/repair/refurbishing difficulties are encountered in ensuring tha~ all~ the drillings are removed from the passageways, so as to avoid their blockage o the water flow.
~; Currently, such heads are produced in~two or more; ~ , ;
parts, principally from a sold bar or castingj and machined, .
with the parts then welded together, with an internal water gallery defined between the welded parts. However, machining ~:
swarf or weld splatter cannot always be detected and/or :.

.. .: : -, - . ~ . .: : - . :

- 2 ~ r3 flushed out and conse~uently these debris might inadvertently cause blockage of water passageways. In addition, despite the use of ~ilters, "clean" water supply cannot always he guaranteed, particularly in mine conditions, and conse~uently contamination might be introduced into the head by the water supply. Furthermore, because of the welded construction, any blocked head must be returned to the surface for disassembly and re-welding, if a coal mine is involved.
On examination of used heads, it is discovered that although, as indicated previously, the water entering the head is filtered, there is a residue of sludge, possibly formed by the rusting of the internal parts of the head.
According to the present invention there is providea a rotary, mineral cutting head, comprising two parts being a lS base, which has means for attachment to a machine, and a dome, which is adapted externally to carry pick-receiving boxes, with a water gallery defined between an external portion of the base and an internal portion of the dome, and with the two parts releasably secured together by bolts or studs.
Thus, the head in accordance with the invention by avoiding welds avoids potential contamination by weld splatter but furthermore provides the advantagous possibility of disassembly underground to clear any blockage, resulting in minimum down time.
Furthermore, it has been proposed to counter the propensity to rust by plating, e.g. with nickel, internal surfaces of the head, and with the two-part construction in accordance with the invention, re-plating can if necessary be , .' ' : .

- 3 ~ 3 effected as this may be done after the pick boxes are welded externally to the dome so that the resultant temperature increase during box weldlng is not permitted to hava a deleterious effect on the nickel etc. plating.
Preferably, the dome is provided with a radially extending planar seating face adapted to abut a corresponding seating face of the base; and a deformable water sealing ring may be strategically located between the dome and base.
Securing of the two parts together may be by a plurality of bolts, e.g. eight, passing through plain holes about a common pitch circle of the base into correspondingly located, blind tapped holes in the dome, the bolt axes being parallel to the axis of rotation of the head. Preferably, the base is provided with a projecting, generally cylindrical nose which substantially fills the hollow interior of the dome and has a central water inlet bore to convey water to an annular distribution gallery in fluid flow communication with a plurality of water supply passageways leading to water distribution nozzles.
The invention will now be described in greater detail, by way of example with reference to the accompanying drawing, which is an axial sectional view through a head in accordance with the invention.
The head 1 comprises a first part, being a base 2, and a second part, being a hollow interior dome 3. The base 3 is provided with a stepped abutment surface 4 of a profile to match that of a complementary support surface of a boom (not shown), of a road header machine (not shown), to which boom ' '.
- , . .
,. , - :
: ~. ~ . -, .

- 4 - ~ r~

the head 1 is attachad by conve~tional means, to be powered about an axis of rotation 5.
The dome 3 is provided at an inner end with a radially extending, planar seatiny surface 6 leading, ~ia a chamfer 7 s to a circumferential location surface 8 of an internal mounting collar 9. At selected locations around an external surface 10 of the dome 3 are secured, by weld metal 11, a plurality of pick boxes 12 each housing a replacable pick 13.
Also welded at selected locations to the external surface 10 are a plurality of water spray nozzles 14 in fluid flow communication with a water supply passageway 15 pro~ided in the wall structure of the dome and extending to an annular water distribution gallery 16 deined between internal surfaces 17 of the dome 3 and external surfaces 18 o~ a cylindrical nose 19 integral with, and projecting from, the base 2 and substantially filling the hollow interior of the dome 3. The nose 19 is also provided with a circumferential location surface 20 of diameter such that the location surface 8 is a close fit on the surface 20, the latter terminating at a radially extending, planar seating surface 21 of the base 2, with a deformable water sealing ring 22 located between the chamfer 7 and a corner defined at the junction of surfaces 20 and 21, while a central water inlet bore 23 serves to convey water from a supply source on the boom to the passageways lS
and hence to the nozzles 14.
The dome 3 is secured to the base 2 by a plurality of studs 24 (typically eight) located about a common pitch circle and passing throtlgh plain holes 25 in the base 2 and into co-., , -: :

-~ .. . .
:
~ ' :... ... .

~ 3 axial tapped holos 26 in the dome 3, the holes 25 being countersunk to accommodate bolt heads 27, and the bolt axes 28 being parallel to the axis o rotation 5.

, :

.

. , .

~: . .. - , . . .

.;~: . ~ , : . : , . .

:: ' :' :' ,

Claims

1. A rotary, mineral cutting head, comprising two parts one of said parts being a base, which has means for attachment to a machine, and the other of said parts being a hollow interior dome, which is adapted, externally, to carry pick-receiving boxes, with a water gallery defined between an external portion of said base and an internal portion of said dome, and with said two parts secured together by releasable means.

2. A head as claimed in Claim 1, wherein said releasable means comprises a plurality of bolts.

3. A head as claimed in Claim 1, wherein internal surfaces of said head are plated after pick boxes have been welded externally to said dome.

4. A head as claimed in Claim 1, wherein a radially extending planar seating surface is provided on said dome and a corresponding seating surface is provided on said base, with said seating surfaces abutting one another, and a deformable water sealing ring located between said dome and said base.

5. A head as claimed in Claim 2, wherein said bolts pass through plain holes about a common pitch circle of said base into correspondingly located, blind tapped holes in said dome, longitudinal axes of said bolts being parallel to the axis about which said head is rotatable.

6. A head as claimed in Claim 1, wherein a projecting, generally cylindrical nose is provided on said base, which nose substantially fills said hollow interior dome, and a central water inlet bore is provided in said nose to convey water to an annular distribution gallery defined by external surfaces of said nose and internal surfaces of said dome, a plurality of water distribution nozzles provided externally on said dome, and a plurality of water supply passageways provided in wall structure of said dome and communicating said nozzles with said gallery.