[0001] The present invention relates to a brush ring for cleansing machines intended, inter
alia, for airports and streets. A plurality of brush rings are mounted one after the
other on a rotor to form a roller brush.
[0002] The known brush rings can be manufactured in different ways. In one known method,
manufacture starts with a straight U-shaped bar. This is bent into a ring, and its
meeting ends are welded together. The hairpin-shaped bristle bundles form an eye at
the bent-over end and through this a metal wire is threaded so that the bundles are
strung on the wire like beads on a string. With the bristle bundles mounted on it,
the wire is subsequently wound round the ring in its U-shaped groove. The wire is
tensioned in the groove and the ends of the wire welded together. Since the bristle
bundles will be subjected to considerable centrifugal forces during rotation of the
roller brush, the metal wire will be subjected to large forces and there i.s thus
the risk that the weld at the ends of the wire will break. Should this happen, all
the bristle bundles will be cast off and can injure persons in the vicinity.
[0003] Another known brush ring of the kind in question is manufactured by bending two bars
to a circular shape and welding them together while the bristle bundles are clamped
between the rings, as illustrated in the Swedish Patent No. 186 616, for example.
The rings are kept to each other by spot welding. If one or more welds were to fail,
one or more bristle bundles will be cast off with the risk of personal injury.
[0004] The object of the present invention is therefore to provide a brush ring where the
bristle bundles are retained in a reliable manner and without the risk of rupture
in vital weld joints.
[0005] This is achieved with a brush ring which has, in accordance with the invention, the
characterizing features disclosed in the following claim.
[0006] A brush ring manufactured in accordance with the invention is schematically illustrated
on the accompanying drawings, as well as a roller brush provided with such rings.
Fig. 1 is a schematic perspective view of a U-shaped bar with openings having upstanding
side walls for the reception of hairpin-like bristle bundles,
Fig. 2 is a cross section through the bar and a bristle bundle fitted into one of
the openings,
Fig. 3 is another cross section and illustrates locating means on the underside of
the bar for a locking wire which is taken through the bent-over ends of the bristle
bundles,
Fig. 4 is a side view of the straight bar with the bristle bundles fitted and the
locking wire retaining them on the underside of the bar,
Fig. 5 is a partial end view to a reduced scale of a brush ring in accordance with
the invention and mounted on a rotor,
Fig. 6 is a cross section through a pair of brush rings mounted on a rotor,
Fig. 7 is a view from above of the joint between the ends of the bar after it has
been bent into a ring,
Fig. 8 is a side view of this joint, and
Fig. 9 illustrates the joint as seen from below.
[0007] The sheet metal bar in Fig. 1 is a U-shaped bar 10 formed with extruded openings
11 at uniform spacing. The extrusions are denoted by the numeral 12 and are intended
for providing support for the bristle bundles.
[0008] Narrow strips are stamped out and pressed downwards between the openings to form
eyelet-shaped location apertures 14 for a locking wire 15 intended for passing through
the apertures.
[0009] The hairpin-shaped bristle bundles 16 are pressed down into the openings 11 and are
downwardly provided with an elastic sleeve 17 for keeping the bundles bent double.
At the lower end 18 of the bristle bundle, these wires are bent double and leave an
axial channel through which the locking wire is inserted so that the bristle hairpins
will be cought by this wire 15 in a manner very reliably retaining the bristle bundle
in the opening 11.
[0010] Manufacture of the bar with the bristle bundles can be done by machine by the bundles
being fitted one after the other in the respective opening 11 while the locking wire
15 is advanced and passed through the wall of the sleeve 17 and through the channel
at the bent-over end of the respective bristle bundle.
[0011] The length of the bar is selected as being somewhat longer than the circumference
of the final brush ring, and this also applies to the length of the locking wire.
[0012] The bar is bent up into a ring 10C and mounted on a mandrel having an outer diameter
substantially equal to the inner diameter of the final brush ring.
[0013] One end 10A of the bar is joggled on three sides to fit the other end 10B, and the
overlapping ends are welded together.
[0014] The ends 15A, 15B of the locking wire will also overlap, and they are also welded
together to form a locking wire ring.
[0015] A number of spoke means 18 are arranged inwards of the ring 10C. Each spoke means
consists of sheet metal bent into a U-shape with two legs 18A, 18B and a web 18C innermost.
An axial slot 19 is made in the web and legs to suit axial splines 20 on the rotor
21. The upper edges of the legs are flanged out forming support for the inside of
the ring and guidance for the edges of the ring. The edges are bent upward along the
edge flanges of the bar, the raised edges of the legs being welded to said edge flanges.
[0016] The brush ring with its spoke means may now be easily mounted on the rotor and in
coaction with the axial splines to form a pack of brush rings of desired extension.
[0017] Alternatively, the bar 10 can first be bent into a ring, subsequent to which the
bristle bundles are mounted in the openings 11 and locked with the locking wire 15.
The ends of the bar are finally fastened together as well as the ends of the locking
wire.
A brush ring for roller brushes in cleansing machines, including a ring with a U-shaped
cross section and a ring of a locking wire arranged contiguous to the ring, the locking
wire extending through the radially inward, bent-over ends of a number of hairpin-like
bristle bundles, characterized in that in the bottom of the ring (10C) there are made
a plurality of uniformly spaced openings (11) with upstanding walls (12) to form support
for the bent-over ends (18) of the bristle bundles (16) inserted in the openings,
and in that the locking wire (15) is on the inside of the ring and taken through the
bent-over ends of the bundles to retain the bundles in position when they are subjected
to centrifugal forces.