Mining machine

A haulage system for a mining machine comprises a mining machine mounted on and/or guided by a conveyor and reciprocable with respect thereto, the conveyor being provided with a rack having plural rows of teeth of identical pitch, with the teeth of one row staggered with respect to an adjacent row(s), and the machine being provided with at least one power driven haulage sprocket comprising plural sets of peripherally arranged teeth of identical pitch, one set being angularly staggered with respect to an adjacent set(s), whereby one set is engageable with each row of teeth of the rack. The invention also includes a mining machine provided with such a power driven haulage sprocket, and a rack as above described and provided with end fittings for securing in articulated manner to an adjacent rack.

This invention relates to a haulage system for a mining machine of the kind 
adapted to be reciprocated along a mineral face and mounted on and/or 
guided by an armoured, scraper chain conveyor extending along the face and 
comprising a plurality of pans secured together end-to-end; to a mining 
machine adapted for use with such a haulage system; and to a rack for such 
haulage system. 
In contrast to a widely used haulage technique whereby a tensioned, round 
link chain of e.g. 200 yds. length, is staked at each end of the mineral 
face, and threaded around a powered drive sprocket carried by the machine, 
several so-called "chainless" haulage systems have been proposed in recent 
years principally with a view to eliminating the staked haulage chain and 
its attendant disadvantages whilst simultaneously providing for the 
possibility of multimachine operation on the same mineral face. Such 
chainless systems operate on the rack and pinion principle, the rack being 
in the form of toothed or pocketed elements attached to the individual 
pans of the conveyor, and the pinion being either in the form of a toothed 
sprocket or alternatively in the form of a relatively short, endless chain 
which may be employed to give multipoint engagement with the rack. In 
order to obtain a satisfactory haulage output from most chainless systems, 
it has usually been necessary firstly to replace the usual slide shoes of 
the machine underframe with rollers and secondly, in systems employing a 
haulage pinion, to duplicate the drive and employ two pinions to give 
reduced tooth loading and also to give an arrangement whereby when one 
pinion passes over a joint between adjacent racks, where optimum haulage 
conditions may not be possible, the other pinion is clear of any such 
joint. 
According to a first aspect of the present invention, a haulage system for 
a mining machine comprises at least one mining machine mounted on and/or 
guided by an armoured, scraper chain conveyor and reciprocable with 
respect thereto, the conveyor extending along a mineral face and 
comprising a plurality of individual pans secured together end-to-end, 
each pan having a face side sidewall and a goaf side sidewall 
interconnected by a deck plate, one sidewall being provided with a rack 
having plural rows of teeth of identical pitch, with one row laterally 
spaced with respect to an adjacent row(s), and also with the teeth of one 
row staggered with respect to an adjacent row(s) and the machine being 
provided with at least one power driven haulage sprocket comprising plural 
sets of peripherally arranged teeth of identical pitch, the sets being 
laterally spaced from one another and one set being angularly staggered 
with respect to an adjacent set(s), whereby one set is engageable with 
each row of teeth of the rack. 
A rack may be provided on the face side sidewall or the goaf side sidewall 
to suit particular operating conditions. 
According to a second aspect of the present invention, a mining machine, 
adapted to be mounted on and/or guided by an armoured, scraper chain 
conveyor extending along a mineral face and reciprocated with respect 
thereto, comprises at least one power driven haulage sprocket having 
plural sets of peripherally arranged teeth of identical pitch, the sets 
being laterally spaced from one another and one set being angularly 
staggered with respect to an adjacent set(s). 
The machine may be of the conveyor mounted, or "in-web" shearer type, while 
the or each haulage sprocket may be rotatable about a horizontal or a 
vertical axis. Preferably, the or each haulage sprocket incorporates two 
sets of teeth. Thus, the or each haulage sprocket may be formed from two 
individual and identical pinions secured coaxially together. The tooth 
stagger at the or each haulage sprocket is preferably a fraction of the 
tooth pitch e.g. dependent upon the number of pinions employed. It is 
further preferred for the or each haulage sprocket to be located adjacent 
a trapping shoe mounted on, and carried by, the mining machine, the 
trapping shoe incorporating a tongue or projection. The machine may be 
provided with two haulage sprockets located towards each end of the 
machine, and both on the face side or both on the goaf side of the 
machine. 
According to a third aspect of the present invention, a rack for a mining 
machine haulage system comprises plural rows of teeth of identical pitch, 
with one row laterally spaced with respect to an adjacent row, and also 
with the teeth of one row being staggered with respect to an adjacent row, 
the rack being provided at each end thereof with an end fitting whereby it 
may be secured in articulated manner to adjacent and similar rack(s). 
Preferably, each rack incorporates two rows of teeth, while the tooth 
stagger is at a fraction of the tooth pitch. Conveniently, the rack also 
provides a continuous surface extending in the direction of the rows of 
teeth whereby, in use, a tongue or projection of a trapping shoe mounted 
on, and carried by, a mining machine, may engage the continuous surface. 
Preferably, one row of teeth terminates in a convex surface, while the 
other row of teeth terminates at one end in a convex surface and at the 
other end in a complementary concave surface. 
The racks may be provided with teeth by flame cutting from plate. In 
detail, a two-row rack may comprise an inner, toothed plate carrying one 
row of teeth spaced from an outer, toothed plate carrying the other row of 
teeth by a spacer beam, both plates being welded or bolted to the spacer 
beam. Conveniently, the inner toothed plate has a lower edge projecting 
below that of the outer toothed plate to enter a recess in a trapping shoe 
of a mining machine. Conveniently, the ends of the outer row of teeth stop 
short of the ends of the inner row of teeth, to provide space for various 
elements of an upper joint between adjacent racks, with the space between 
adjacent ends being filled by a removable bridging tooth. Thus, if the 
outer rows terminate in convex ends, the bridging tooth is provided with 
complementary concave recesses. The bridging tooth is connected by 
elongated holes to the inner and outer plates in such a way as to provide 
space compensation when articulated in the vertical and horizontal planes. 
Preferably, lower joints are also provided between adjacent racks, the 
lower joints being of a type that avoids the use of bolts and incorporates 
an inverted "U" shaped connector, the downwardly directed ends of which 
engage behind abutment blocks. 
The rack may be secured e.g. by welding or bolts, to a support plate 
attached e.g. by holts, to one sidewall of a conveyor pan.

In the drawings, a shearer type mining machine 1 is mounted on, and guided 
by an armoured, scraper chain conveyor 2 (the conventional chain(s) and 
flight bars not being illustrated) seated on a mine floor 3, extending 
along a mineral face 4, and made up of a plurality of line pans 5 secured 
together end-to-end, each pan 5 having a face side sidewall 6 and a goaf 
side sidewall 7 of conventional sigma section, the sidewalls 6 and 7 being 
interconnected by a deck plate 8. Webs of mineral are extracted from the 
face 4 by a pick-carrying, rotary cutting head (not shown) mounted in the 
conventional manner at one end of a ranging arm 9 pivotally attached to 
the machine 1 and pivotable with respect to the machine 1 in the 
conventional manner under the control of a double-acting hydraulic ram 
(not shown). The webs of mineral are removed from the face 4 by 
reciprocating the machine 1 along the conveyor 2 and as is well known in 
the art. The machine 1 may be single ended (having a ranging arm 9 and 
cutting head at one end only of the machine) whereby after a cutting run 
has been effected along the face 4, the machine is reciprocated to the 
other end of the face in a non-cutting run, ready for commencement of the 
next cutting run; or alternatively the machine 1 may be double-ended 
(having a ranging arm 9 and a cutting head at both ends of the machine) 
whereby bi-directional cutting is effected. The or each cutting head is 
rotatable, through a speed reduction gearing, from an electric motor 
housed within the machine. 
Whether the machine is single or double-ended, haulage of the machine 
along, or with respect to the conveyor, is required, and in accordance 
with the present invention this is effected by a haulage system 10 
comprising basically a driven haulage sprocket 11 in engagement with a 
rack 12. 
The sprocket 11 is powered from either the same electric motor within the 
machine employed for driving the or each cutting head or from a separate 
electric motor, the power being conveyed from the motor by a mechanical or 
hydraulic transmission, in the well known manner. 
The sprocket 11 comprises two sets 13 and 14 of peripherally arranged teeth 
15 of identical pitch arranged on individual pinions 16 and 17, the sets 
13 and 14 abutting one another and hence being laterally spaced from one 
another and the teeth 15 of one set 13 being angularly staggered with 
respect to the adjacent set 14. 
In the embodiment of FIGS. 1 to 3, only one sprocket 11 is provided, 
rotatable about a horizontal axis 18, assuming the conveyor 2 is located 
in a horizontal plane, on a drive shaft 19. The machine 1 is supported 
from the conveyor by slide shoes, and as illustrated in FIG. 2, a shoe 20 
adapted to slide along the goaf side sidewall 7 is a trapping shoe serving 
to trap the machine to the conveyor by being provided with a "U"-shaped 
recess 21 defined between faces 22 and 23, and also provided with a tongue 
24. The shoe 20 is also provided with circular apertures 25 for the 
passage therethrough of a mounting shaft by which the shoe 20 is pivotally 
attached to the machine 1. 
Also in the embodiment of FIGS. 1 to 4, the rack 12 is attached to the goaf 
side sidewall 7 via plates 26, 27 and 28. In detail, the rack 12 has two 
rows 29, 30, of teeth 31, with one row 29 provided on an inner toothed 
plate 32 and the other row 30 provided on an outer toothed plate 33, with 
the plates 32 and 33 separated by an interposed spacer beam 34 and with 
teeth 31 of one row 29 staggered with respect to teeth 31 of the adjacent 
row 30, whereby one set 13 of sprocket teeth 15 is engageable with one row 
29 of rack teeth 31, while the other set 14 of sprocket teeth 15 is 
engageable with the other row 30 of rack teeth 31. The rack 12 also 
provides continuous surfaces 36 on a lower edge 37 of the inner plate 32 
to enter the recess 21 of the trapping shoe. 
As can be seen in FIGS. 1 and 2, each row 30, of teeth 31 terminates in a 
convex surface 38, while each row 29 terminates at one end in a convex 
surface 49 and at the other end in a complementary concave recess 50 (FIG. 
1) to receive, in abutting manner a convex surface 49 of an adjacent row 
32. At each end of each pan 5 the ends of the outer row 30 of teeth stop 
short of the ends of the inner row of teeth to provide space for an upper 
joint 39 between adjacent racks 12. The joint 39 includes a bridging tooth 
40 which fills the space, the bridging tooth 40 being detailed in FIG. 3 
and having concave recesses 41 to receive, convex surfaces 38 and 
elongated holes 42 for the passage of securing bolts 43 through the 
elongated holes and through coaxial holes 35 in the inner and outer plates 
32, 33. A lower joint 44 between adjacent rack bars 12 includes an 
inverted "U"-shaped connector 45, the downwardly directed ends 46 of which 
engage behind abutment blocks 47. 
The embodiment of FIG. 5 is very similar to that of FIGS. 1 to 3, but shows 
the rack 12 attached to the face side sidewall 6, and a ramp plate 48 to 
assist loading of mineral onto the conveyor 2, with the machine 1 
illustrated not being mounted on the conveyor 2, but seating on the mine 
floor beyond the ramp plate 48, being an "in-web" or buttock machine. 
The embodiment of FIG. 6 illustrates a doubleended machine 1 with a ranging 
arm 9 at each end and with two haulage sprockets 12, one located towards 
each end of the machine 1. 
The embodiment of FIG. 7, illustrates the machine 1 with a haulage sprocket 
12 rotatable about a vertical axis.