Ballast brooms

There is described a self-propelled railroad track ballast broom machine having a first broom unit operatively mounted at the rear of the machine frame and a second broom unit operatively mounted at the front of the frame. The broom units have substantially cylindrical brooms extending transversely of the railroad track and deflector boxes located forwardly of each of the brooms. The brooms have gaps sufficiently wide, and so spaced apart thereon, as to avoid broom contact with the rail heads in normal tangent track sweeping operations. When the machine enters into track curves, the first broom unit is so far behind the machine rear axle that it is transversely displaced relative to the track center. Compensating transverse movement can be applied to the first broom unit to maintain the broom gaps in line with the rail heads and the ends of the broom in operative engagement with both the track shoulder edges.

The present invention relates to railway track ballast brooms. 
Railway track brooms are used extensively on railroad tracks to sweep 
excess ballast, say deposited in a track lifting operation, from the tie 
tops into the cribs between the ties and to level the tops of the track 
shoulders. The operation keeps the spaces between the ties filled with 
excess ballast and in so doing removes excess ballast thereby preventing 
it from being sucked into the path of a fast moving train. In order to 
increase the productivity of railway ballast brooms they have, of late 
been attached to either end or both ends of a machine frame or power 
module. The brooms, which are generally cylindrical in configuration and 
are mounted transversely of the track so as to span it, normally require 
stone deflector shields in front of them to move the excess ballast from 
the center of the track to the shoulder area of the track structure. 
Clearly such deflectors require longitudinal space in front of the 
rotating brush and hence longitudinal space between at least one axle and 
the brush itself. This elongation of the working length of the machine 
creates problems for brooms remote from the machine's axles when the 
machine is operating in curves. Obviously the transverse displacement of a 
broom, relative to the track center on a long machine frame when it is 
passing through a curve, causes the outer extremeties of the transverse 
ballast broom to miss part of the shoulder ballast and possibly produce a 
wind-row effect. 
It is common practice to allow a free space between rows of straws 
(bristles, elements of the broom) just as wide as the width of a rail, to 
prevent excessive damage of broom elements hitting the rail head 
constantly. However, when the machine is obliged to work in curved track, 
the broom elements normally adjacent to the rail are displaced 
transversely with respect to the track and now beat the steel rail head 
and consequently destroy themselves in a short while. This deficiency 
leads to frequent replacements which is costly both in labour, time, 
material and lost working time of the machine. 
It has been proposed, in German patent document No. 2,928,198 to provide a 
system whereby the cylindrical track brooms are made up of transversely 
spaced concentric broom wheels individually mounted for vertical movement 
out of contact with the ballast. Thus, when a broom wheel encounters a 
rail, because of track curvature, that broom wheel is simply swung up out 
of the way while the other broom wheels making up the cylinder remain 
operative. The advantages of this arrangement are somewhat overshadowed by 
the complexity of the structure necessary to operatively mount such a 
multi-wheeled broom. 
According to the present invention a railroad track ballast broom machine 
comprises a machine frame mounted on track wheels; a ballast broom 
operatively mounted on the frame; and means to translate the broom 
laterally of the frame. 
Preferably the broom comprises a substantially cylindrical broom means 
mounted, in operation, to transversely span a railroad track. Conveniently 
the cylindrical broom means may have a pair of rail accommodating gaps 
dimensioned to clear a rail head, the gaps being spaced apart on the broom 
means by the dimension of a track rail gauge. 
The broom means may be provided with a leading deflector box, the box and 
broom means being mounted on a broom unit, the broom unit, with its broom, 
being mounted for lateral movement on the machine frame. 
The present invention also provides a railroad track ballast broom machine 
comprising a wheeled machine frame; a first broom unit operatively mounted 
on the frame and spaced rearwardly thereof; and a second broom unit 
operatively mounted on the frame forwardly thereof; said broom units 
including a substantially cylindrical broom means mounted in each unit so 
as, in operation, to transversely span the railroad track and a deflector 
box located forwardly of each broom means; and means to translate the 
first broom unit transversely of the machine frame.

Turning now to the drawings. 
A self-propelled ballast broom machine 10, has a machine frame 11 mounted 
on rail engaging sets of wheels 12 and 13, which are themselves mounted on 
axles. 
The machine 10 has a first broom unit 15 and a second broom unit 16 mounted 
on the machine frame 11 at the rear and at the front of the machine 
respectively. The machine 10 moves in the direction of the arrow, from 
left to right, as shown in FIG. 1, when in operation. 
In each broom unit 15 and 16, there is provided a cylindrical broom 20, 21 
of known configuration extending transversely of the machine frame 11 to 
span the track (see also FIG. 3). 
The brooms 20 and 21 are driven in conventional fashion in a 
counterclockwise direction and the broom units 15 and 16 are each provided 
with a leading deflector box 22, 23 which act as stone deflector shields 
to move excess ballast from the center of the track to the shoulde area of 
the track structure. 
The cylindrical brooms 20, 21 as shown are provided with two transversly 
spaced apart free spaces, or gaps, 25 at the point where the brooms 20, 
and 21 normally encounter each of the rails 26 (see FIG. 3) on tangent 
track. The cylindrical broom members 20 and 21 extend outwardly on each 
side beyond the tie ends 27 to the point 28 where the ballast shoulder 
starts to fall away from the upper plane of the track surface. 
The second, or front ballast broom 16, may, in the configuration shown, be 
transversely fixed on the frame 11 because the broom 21 and its deflector 
23 are close longitudinally to the axle of the front wheels 12. Thus when 
the machine 10 enters into a curve in the track, the broom 21, for all 
practical purposes, will follow the track. It is understood of course that 
the broom 21 and the front deflector box 23 can be raised and lowered on 
the frame 11 in usual fashion so as to be brought into operative contact 
with the ballast and to be lifted out of contact with the ballast, for 
track travel. 
The first, or rear, broom unit 15, because of the dimensions of its 
deflector box and the fact that the broom unit 15 has to be mounted so as 
to overhang the rear of the machine, poses a problem. The broom 20 of the 
unit 15 is, as can be seen, spaced rearwardly by a substantial distance 
from the axles of the rear wheels 13 and because of this long frame 
effect, when the machine 10 enters into curves the rear broom unit 15 is 
displaced relative to the track center. This displaces the gaps 25 
transversly relative to their rails. and the bristles (flails, etc.) 
laterally adjacent the gaps 25, starts to beat on the rail heads. Also, 
depending upon the sense of the track curve, one or other ballast shoulder 
edge 28 is not contacted by the broom and a wind-row of ballast may be 
formed along the top of the track adjacent that edge 28. 
In order to overcome these shortcomings, the first broom unit 15 is mounted 
so that it may be compensatingly translated transversely relative to the 
frame 11 to maintain the broom 20 aligned with the ballast shoulder edges 
28 and its spaced gaps 25 in line with the rail heads 26. To this end the 
rear broom unit 15 is provided with a couple of mounting subframes 30, 31 
(see FIG. 2) which are connected by transverse struts 32, 33 and are 
provided with hydraulic lifting cylinders 34, 35 to raise and lower the 
first broom unit 15 into and out of operative engagement with the ballast. 
The subframes 30 and 31 have hook frames 36, 37 which engage over support 
girders 38, 39, welded or bolted to the rear of the machine frame 11, so 
that the subframes 30, 31 and the unit 15 which they support, may slide 
transversly of the frame 11 on girders 38, 39. Counterclockwise rocking of 
the broom unit 15 about the girders 38, 39 is prevented by pressure pad 
frames 40, 41 which essentially are angle iron members which engage about 
transverse plates 42, 42a (pictorially represented in FIG. 2 by the 
fragments displaced to the right or left of the pad frames 40, 41 which 
will engage them). Pressure pads 48, 49 complete the anti-rocking frames 
40, 41. 
A traversing cylinder 50 is welded to the frame 11 at 51 and is connected, 
at 52, to the right hand subframe 31. When hydraulic fluid is admitted 
into the cylinder 50, depending upon its direction of admitance, the 
subframes 30, 31 are displaced transversely of the track with the hook 
frames 36, 37 sliding on the girders 38, 39 and the pressure frames 40, 
41, sliding relative to the plates 42, 42a. In this fashion the broom unit 
15 is moved to the left or to the right transversely to the track. In 
order to be effective the distance of unit transverse movement need not be 
more than about 3 inches in either direction, in the configuration shown, 
and of course is a function of the distance of the rearward displacement 
of the broom 20 from the rear axle of the machine. 
As the machine 10 moves into a track curve the rear broom unit 15 may be 
moved transversly relative to the track either manually by an operator, or 
automatically by providing sensors, to compensate for displacement 
relative to the track center. The gaps 25 can thus be maintained over the 
rail heads 26 and the broom elements adjacent the railheads continue to 
lie on either side thereof. Furthermore, the external portions of the 
broom 20 (see FIG. 3) are maintained at the correct position with respect 
to the edges 28 of the ballast. 
It is of course understood that if a configuration of a machine were 
desired which would displace the second broom unit 16 far forwardly of the 
front axle, similar arrangements could be provided to compensatingly 
translate the unit 16 relative to the track.