Note: Descriptions are shown in the official language in which they were submitted.
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1
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Hrie~ Sua~mary of the Invention
This invention .relates generally to methods of
and apparatus for making packages, and more particularly a
method of and apparatus for making packages of the type
comprising a roll or rolls of paper, such as a paper towel
roll or rolls of toilet tissue in flexible sheet wrapping
material such as heat-sealable plastic film.
Reference may be made to the co-assigned U.S.
Patent 4,430,844 of Robert C. James, issued February 14,
1984, entitled Method of and Apparatus far Wrapping .
Articles, disclosing wrapping apparatus of a type sold by
the assignee, Hayssen Manufacturing Company of Sheboygan,
Wisconsin, under the trademark ULTRA FLOW particularly for
packaging toilet tissue rolls and paper towel rolls, for
relatively high speed production of packages each com-
prising one or more rolls enwrapped in flexible sheet
wrapping material, such as heat-sealable plastic film
(e. g. polyethylene film). As illustrated in that patent,
the package produced by that apparatus comprises two rolls
disposed side-by-side wrapped in polyethylene film with
the wrapper extending outwardly beyond the ends of the
rolls. These packages are completed by folding each
projecting end of the wrapper over the ends of the rolls
to form four closure flaps overlying each end, a first
flap constituting a first side flap, which may be referred
to as the top flap, a second flap constituting a first end
flap, a third flap constituting a second end flap, and a
fourth flap constituting a second side flap which may be
referred to as the bottom flap, the four flaps at each end
of the rolls being heat-sealed together to complete their
CA 02052736 1998-10-OS
2
formation as end closures for the package. This invention has
for its object the provision of a method of and apparatus for
efficiently folding over the stated second end flap for forma-
tion of neat end closures in a high-speed operation and capable
of handling packages of rolls of different sizes and different
numbers of rolls.
The invention provides in the production of packages
each comprising a unit of product having opposite ends and a
wrapper wrapped around the unit, the wrapper initially being
wider than the length of the unit from end-to-end and initially
extending outwardly beyond at least one of the ends of the unit
to form four closure flaps overlying said end, a first flap
constituting a first side flap, a second flap constituting a
first end flap, a third flap constituting a second end flap,
and a fourth flap constituting a second side falp, the method
of folding over the second end flap comprising: continuously
feeding packages forward one after another in a predetermined
path at a predetermined speed with the packages extending
transversely with respect to the direction of feed and with a
trailing portion of the extending end of the wrapper extending
laterally outwardly at one side of said path, and with the
packages spaced at intervals along said path, and, as the
packages are so fed forward, moving a yieldable folding member
laterally inwardly and forwardly into yielding engagement with
the trailing side of said trailing portion of the extending end
of the wrapper of each package, and moving said yieldable
folding member linearly forward in the direction of movement of
69162-6
CA 02052736 1998-10-OS
3
the package at a higher speed than the speed of the package to
fold over said trailing portion on said end of the product to
form said second end flap, and then moving said yieldable fold-
ing member forwardly and laterally outwardly away from said
folded-over second end flap.
From another aspect, the invention provides in
apparatus for the production of packages each comprising a unit
of product having opposite ends and a wrapper wrapped around
the unit, the wrapper initially being wider than the length of
the unit from end-to-end and initially extending outwardly
beyond at least one of the ends of the unit, production of the
packages comprising folding over said end of the wrapper on
said end of the unit to form four closure flaps overlying said
end, a first flap constituting a first side flap, a second flap
constituting a first end flap, a third flap constituting a
second end flap, and a fourth flap constituting a second side
flap, means for folding over the second end flap comprising:
means for continuously feeding packages forward one after
another in a predetermined path at a predetermined speed with
the packages extending transversely with respect to the direction
of feed and with a trailing portion of the extending end of the
wrapper extending laterally outwardly at one side of said path,
and with the packages spaced at intervals along said path; a
yieldable folding member, and means operable as the packages are
so fed forward for moving the yieldable folding member laterally
inwardly and forward into yielding engagement with the trailing
side of each package, and moving said yieldable folding member
69162-6
CA 02052736 1998-10-OS
3a
linearly forward in the direction of movement of the package at
a higher speed than the speed of the package to fold over said
trailing portion on said end of the product to form said second
end flap, and then moving said yieldable folding member
forwardly and laterally outwardly away from said folded-over
second end flap.
Other features will be in part apparent and in part
pointed out hereinafter.
Brief Description of the Drawings
Fig. 1 is a perspective of a package which is to be
completed by the method and apparatus of this invention, the
package as illustrated comprising two rolls of toilet tissue
disposed side-by-side with a wrapper wrapped around the rolls
and extending beyond the rolls at each end;
Fig. 2 is an end view showing the respective end of
the wrappers folded over on the respective end of the two rolls
to form a first side flap (the top flap);
Fig. 3 is an end view showing a successive stage in
the completion of the package involving folding over a second
flap to constitute a first end flap (the leading end flap);
Fig. 4 is an end view showing a further stage in the
completion of the package involving folding over a third flap
constituting a second end flap (the trailing end flap), this
stage being carried out by the method and apparatus of this
invention;
Fig. 5 is an end view showing the folding over of a
fourth flap to form a second side flap (the bottom flap);
69162-6
4
Fig. 6 is a perspective showing apparatus such
as may be used to form packages such as shown in Fig. 1
and showing the folding over of the first side flap and
the first end flap;
Fig. 7 is a continuation of Fig. s as indicated
by the arrow at 7 in Figs. 6 and "7 on a larger scale than
Fig. 6 showing apparatus of this invention for folding
over the second end flap, are also showing the folding
over ~of the second side .flap;
Fig. 8 is a plan of the apparatus shown in Fig.
7 for folding over the second end flap, illustrating the
end of the package and the flexible folding member (brush)
at the right in a first position, and the end of the .
package and the flexible folding member (brush) at the
left in a moved position;
Fig. 9 is vertical transverse section generally
on line 9--9 of Fig. 8;'
Fig. 10 is a view generally on line 10--10 of
Fig. 8;
Fig. 11 is a view in elevation from the right of
Fig. 10 with parts broken away and shown in section, and
showing certain pins in their extended position in certain
tubular pins which interconnect certain chain links of the
Fig. 7 apparatus;
Fig. 12 is a view similar to Fig. 11 showing the
first-mentioned pins retracted from the chains;
Fig. 13 is a view generally in elevation from
the left of Fig. 10 with parts broken away and shown in
section;
Fig. 14 is a view in horizontal section
. generally one line 14--14 of Fig. 10;
Fag. 15 is an enlarged fragment of Fig. 8
showing in phantom a first position of the flexible
folding member (brush) and in solid lines a moved
position; and
5
Fig. 16 is a semidiagrammatic view of certain
conveyor means of the apparatus and the driving means
therefor.
Corresponding reference characters indicate
corresponding parts throughout the several views of the
drawings.
Detailed Description
Referring to the drawings, first more
particularly to Figs. 1-5, there is indicated at P a
package comprising a unit of product indicated in its
entirety at 1 which is illustrated as a set of two rolls
each designated 3 of toilet tissue disposed side-by-side.
with their axes parallel, and a wrapper 13 wrapped around
the product (the two rolls). The wrapper is wider than
the length of each roll measured from end-to-end of the
roil and initially extends outwardly beyond each end 3e of
the unit constituted by the two-roll set of rolls. The
wrapping is completed by folding over each extending end
E of the wrapper on the respective end 3e of the unit as
packages are continuously fed forward one after another in
a predetermined path at a predetermined speed with the
packages extending transversely with respect to the direc-
tion of feed to form four closure flaps F1-F4, namely a
first side flap F1 at the top; a first end flap F2 at one
end constituting the leading end of the wrapper, a second
end flap F3 at the other end (the trailing end) of the
wrapper and a second side flap F4 at the bottom. The top
side flap, the leading end flap and the bottom side flap
are readily folded over as, for example, by means of
stationary plans in conventional manner, portions of the
projecting ends of the wrapper engaging the plows as the
6
package is fed forward for folding them over. Alterna-
tively, the top side flap may be blown down by a blast of
air. The formation o~ the trailing end flap F3 presents a
problem, however, on account of the forward movement of
the package, and this invention involves a method of and
apparatus for folding over the trailing end flap for
formation of neat end closures in a high speed operation
(e. g. 250 packages per minute) capable of handling pack-
ages of rolls and different numbers and arrangements of
rolls (e. g. the typical single-roll packs, two-roll packs
and three-roll packs).
Packages P each having wrapper 13 with its
extending ends E may be formed at relatively high speed.
(e. g. 250 packages per minute) by apparatus such as indi-
sated in its entirety at A in Fig, 6, which apparatus is
the same as that disclosed in the above-noted U.S. Patent
4,430,844 of Robert C. James, issued February 14, 1984 to
Hayssen Manufacturing Company of Sheboygan, Wisconsin,
this James patent being incorporated herein by reference.
Fig. 6 corresponds to Fig. 1 of said patent, showing web 5
of plastic film, e.g. polyethylene, being pulled from
supply roll 7, perforated as indicated at 11 at wrapper
length intervals by means 9, formed into tubing T around
two-roll units 1 fed forward by means 15, the units being
spaced lengthwise of the tubing with the lines of perfora-
tions in the spaces Daetween the units, and pulling means
29 for pulling the tubing apart at the lines of perfora-
tions to form the packages P.
Each package P as formed by the apparatus A of
Fig. 6 (the apparatus of U.S. Patent 4,430,844) is
delivered to a flight conveyor generally designated 31
which functions to feed the packages forward one after
another in a predetermined path (a horizontal path) with
the packages extending transversely with respect to the
2,~~'~~~
7
direction of feed and with the free ends E of. the wrapper
13 extending laterally outwardly from the two-roll units 1
therein at opposite sides of said path. As more or less
diagrammatically illustrated in Figs. 1, 2 and 16, the con-
s veyor 31 comprises a slotted table 33 along which packages
P are pushed by pushers or flights 35 on an endless chain
37 trained around a rear end sprocket 39 and a forward end
sprocket 41 with an upper forward-moving reach 37a of the
chain 37 just under the table and a lower return reach 37b
below the upper reach. The pushers or flights 35 are
mounted on arms 43 which, along the upper reach of the
chain, extend up through the slot 45 in the table 33.
The pushers act to push packages P forward along the
table, and are spaced a distance greater than the width W
of a package. The chain is driven_for forward movement of
its upper reach generally at a predetermined constant speed
by drive means such as indicated at 47 and its operation is
so timed in relation to the delivery of packages P by the
pulling means 29 of apparatus A that each package is
delivered onto the table adjacent the rearward end of the
table in front of an oncoming pushes or flight 35, the
flights acting to push the packages forward one after
another along the table with the packages spaced at inter-
vals corresponding to the flight spacing D, with the
wrapper ends E extending laterally outwardly from the roll
unit ends 3e toward opposite sides of the table.
As the package P are fed forward by the conveyor
31, the wrapper ends E first pass through a station A
(Fig. 6) where the top flaps F1 are folded over and down
at both ends of the package by suitable conventional means
(not shown) such as air blast means. They then pass
through a station B (Fig. 7) where the leading end flaps
F2 (the first end flaps) are folded back at both ends of
the package by suitable conventional means (not shown)
~~5~~~~~
s
such as plows, one at each side of the table. They then
pass through a station C (Fig. 7) where the trailing end
flaps F3 (the second end flaps) are folded forward or
tucked over on the ends of the roll unit 1 into position
overlying the folded-down top flap by folding or tucking
means 49 of this invention, to be described. They then
pass through a station D (Fig. 7) where the bottom flaps
F4 are folded up into position overlying the first three
flaps at both ends of the package by suitable conventional
means such as plows, one at each side of the table.
Finally, they pass through another station (not shown)
where the folded-over flaps F1-F4 are heat-sealed together
in conventional and well-known inanner,e.g. by heated
sealing rollers.
The aforesaid folding or. tucking means 49 com-
prises a left-hand unit 49L for folding or tucking the
second (trailing) end flap F3 over on the left end of the
package, i.e. folding or tucking it over to lie flat
against the previously folded-over top flap F1 on the left
end of the package, and a right-hand unit 49R for folding
or tucking the second (trailing) end flap F3 over on the
right end of the package, i.e. or folding or tucking it
over to lie flat against the previously folded over top
flap Fl at the right end of the package. Left-hand and
right-hand are as viewed in the direction of feed of the
packages. The left-hand and right-hand folding or tucking
units 49L, 49R are essentially identical (being .opposite
hand versions of one another), each comprising an endless
chain conveyor generally designated 51 at the respective
side (the left-hand side or the right-hand side as the
case may be) of the path along which the packages P are
fed forward by the package conveyor 31 having a forward
travelling linear (straight) inner reach 51a generally
parallel to said path opposed to the respective package
9
end and a rearward travelling linear outer return reach
51b. At 51c' is indicated the forward end reach of the
conveyor 51 where it moves around in a semicircular path
from the inner reach to the outer return reach, and at 51d
is indicated the rearward end reach of the conveyor 51
where it moves around in a semicircular path from the
outer to the inner reach. As to each of the units 49L,
49R, the endless chain conveyor 51 is constantly driven
at a speed somewhat higher than the speed at which the
packages P axe fed forward by the conveyor 31, and carries
a flexible folding member or tucker 53 movable forward at
said higher speed along with the inner reach 51a of con-
veyor 51 which comes into engagement with the trailing
side 55 of the trailing portion 57 of the respective end
E of the wrapper of each package,. moves linearly forward
relative to the end of the package to fold over or tuck
over said trailing portion of the end of the wrapper on
the respective end of the set of rolls in the wrapper to
form the stated second end flap F3, and then moves
laterally outwardly away from the folded-over second
end flap.
The endless conveyor 51 of each of the units
49L, 49R comprises a relatively short beam 59 mounted in
position extending horizontally at the respective side
(left or right) o.f the path, more precisely at a level
somewhat above the level of the path, along which the
packages P are fed forward by the conveyor 31. Each beam
59 has a vertical bearing 61 at one end thereof, namely,
its trailing or rearward end in respect to the direction
of travel of the packages P and a vertical bearing 63 at
its other end, which is its leading or forward end in
respect to the direction of travel of 'the packages. The
beam 59 of the left-hand unit 49L is mounted as shown in
Fig. 9 on a pedestal 65 at the left side and the beam 59
10
of the right-hand unit 45R is mounted on a pedestal 67 at
the right side. One of these pedestals is fixed. The
other is suitably mounted for adjustment in and out toward
and away from the package path for handling packages of
different length. Shafts 69 and 71 are journalled in the
bearings 61 and 63, respectively, each shaft having a
sprocket 73 at its upper end and a sprocket 75 at its
lower end. A chain 77 is trained around the upper
sprockets 73 and a chain 79 is trained around the lower
sprockets 75. The upper and lower sprockets are of equal
diameter, and thus the chains have inner reaches travel-
ling one above the other in a vertical plane delineating
the inside reach 51a of the endless conveyor 51 and outer
reaches travelling one above the other in a vertical plane
constituting the outer return reach 51b of the endless
conveyor 51, Each of the chains comprises a series of
links 81a and 81b pivotally interconnected by tubular
pivot pins 83. Backups for the inner and outer reaches of
the chains are indicated at 85 and 87, respectively. The
chains 77, 79 are driven in timed relation to the chain 37
of the package conveyor 31 by a drive such as indicated at
80 in Figs. 6 and 8 connected to shaft 71.
As herein illustrated, for operation on packages
which comprise a unit or set of two rolls of toilet tissue
arranged side by side in a wrapper extending beyond both
ends of the set of rolls (which is called a 1x2x1
arrangement), each of the aforesaid flexible folding or
tucking units 49h, 49R includes a single flexible folding
member or tucker 53 constituted by a brush adapted to
brush or '°wipe" over the respective second (rear) end flap
F3, this brush comprising a rectangular back 93 having a
pattern of bristles 95 on one face thereof, which pattern
may be as shown in Fig. 10. The brush 53 is carried by
means generally designated 97 removably pinned in the
11
upper and lower chains 77, 79 for movement of the brush
with the chains and for movement of the brush relative to
the chains with a special motion to be described. The
carrier means 97 for the brush comprises a pair of
brackets lUl and 103 extending vertically between the
upper chain 77 and the lower chain 77, the brackets being
spaced from one another along the length of the chains and
being movable with the chains in the direction of chain
movement.
The first bracket 101, which is the leading
bracket of the two brackets in relation to the direction
of movement of the chains, comprises a bar 105 which
extends vertically between the chains having a head 107
projecting laterally at its upper end and a foot 109
projecting laterally at its lower, end. Two pins each
designated 111 are vertically slidable in holes 113 in the
head between a raised extended position c~«L.ered in two
adjacent tubular pins 83 of the upper chain 77 for the
removable attachment of the bracket at its upper end to
the upper chain. and two pins each designated 115 are
vertically slidable in holes 117 in the foot between a
lower extended position entered in two adjacent tubular
pins 83 of the lower chain for the removable attachment of
the bracket at its lower end to the lower chain 79. The
upper pins 111 extend up from a finger tab 119 by means of
which they may be moved down to a retracted position with-
drawn from the tubular chain pins 83 of the upper chain
against the upward bias of a spring 12.1 (which biases the
tab upwardly toward the bottom of the head 107. The lower
pins 115 extend down from a finger tab 123 by means of
which they may be moved up to a retracted position with-
drawn from the tubular chain pins 83 of the lower chain
against the downward bias of a spring 124 (which biases
the tab 123 downwardly toward the -top of the foot).
12
The second bracket 103, which is the trailing
bracket of the two brackets in relation to the direction
of movement of the chains, comprises a bar 125 which
extends vertically between ttie chains having a head 127
projecting laterally at its upper end and a foot 129
projecting laterally at its lower end. Two pins each
designated 131 are vertically slidable in holes 133 in
the head between a raised extended position entered in
two adjacent tubular pins 83 of the upper chain 77 for
the removable attachcnent of the bracket 103 at its upper
end to the upper chain, and two pins each designated 135
are vertically slidable in holes 137 in the foot between a
lower extended position entered in two adjacent tubular
pins 83 of the lower chain 79 for the removable attachment
of the bracket 103 at its lower end to the lower chain.
The upper pins 131 extend up f rom a finger tab 139 by
means of which they may be moved down to a retracted
position withdrawn from the tubular chain pins 83 against
the upward bias of a spring 141 (which biases the tab
upwardly toward the bottom of the head 127. The lower
pins 135 extend down from a finger tab 143 by means of
which they may be moved up to a retracted position with-
drawn from the tubular chain pins 83 of the lower chain
against the downward bias of a spring 144 (which biases
the tab 143 downwardly toward the top for the foot 129.
A shaft 147 journalled in the head 107 and foot
109 of the stated first or leading bracket 101 extends
vertically downward from the bracket into a hole 149 in
the back of 93 the brush 53 adjacent the leading end of
the brush (the leading end in relation to the movement of
the brush with the chains 77, 79) for pivoting the brush
fox swinging movement about the vertical axis of the shaft.
A crank arm 151 in the form of a yoke is pivotally mounted
as indicated at 153 an a block 155 on the bar 125 of the
13
stated second or trailing bracket 103 for swinging movement
of the yoke relative to the bracket on a vertical axis. A
shaft 157 journalled at its upper end in the yoke 151 as
indicated at 159 extends vertically downward from the yoke
into a hole 161 in the back of the brush adjacent the
trailing end of the brush. The lower ends of the shafts
147 and 157 are secured as by set screws 162 in the back
of the brush, the upper end of shaft 147 being rotatable
in the bracket 101, the upper end of the shaft 157 being
rotatable in.the yoke 151 (which is pivoted at 153 on the
bracket 153).
The brush 53 is movable by and with the chains
77 and 79 in an endless path having straight inner and
outer reaches parallel to the straight inner and outer
reaches 51a, 51b of the chains. The arrangement is such
that as the brush travels along the inner and outer
reaches, it is held by the shafts 147 and 157 in a ver-
tical position with its plane parallel to the inner and
outer reaches, the yoke 151 occupying the position
relative to bracket 103 in which it appears in Fig. 14
extending outwardly generally at right angles relative to
the plane of the inner reach of the chains 77, 79. The
arrangement is also such that the brush is adapted for
swinging movement relative to the chains about the ver-
tical pivot axis of the shaft 147 in the course of its
travel with the chains 77, 79 as they travel around the
sprockets 73) 75.
In the operation of the apparatus, chain 37 of
conveyor 31 is continuously driven at a predetermined
speed so related to the delivery of packages P by pulling
means 29 of apparatus A (see also the aforesaid James U.S.
Patent 4,430,844), and in such timed relation to said
delivery that each package issuing from app aratus A is
~~~i~"~~
14
delivered onto the table 33 in front of an oncoming flight
35 of conveyor 31. Each package is then continuously fed
forward by said flight along the table in a predetermined
horizontal path at the predetermined speed of the flight.
The flights rnay be changed to accommodate packages of
different lengths. The packages so fed forward extend
transversely with respect to the direction of feed, with
the free ends E of the wrapper 13 of each package extend-
ing laterally outwardly from the product unit 1 therein
at opposite sides of the path.
As each package P is fed forward, it first
passes through station A where top flaps F1 are folded
over and down at both ends of the package and then through
station B where the leading flaps F2 are folded back at
both ends of the package, as previously described. The
package then passes between the left-hand and right-hand
folding or tucking units 49L, 49R at station C. The
endless chain conveyor 51 of each of units 49L, 49R is
continuously driven with chains 77 and 79 of the conveyor
51 of each unit 49L, 49R travelling at a speed higher than
the speed at which the packages P are fed forward along
the table 33. Travel of the brushes 53 of units 49L, 49R
is so phased with respect to the travel of packages as the
packages pass between units 49L, 49R that the brushes come
around the rearward or trailing end 51d of the endless
conveyors 51 of units 49L, 49R, and into the forward-
traveling inner reaches 51a of their paths of travel after
a package has progressed forward beyond the rearward or
trailing ends of units 49L, 49R. The bristles of the
brushes come into engagement with the trailing side 55 of
the trailing portion 57 of each end of the wrapper 13
(which already has flaps F1 and F2 folded over), flex back
as the brushes move linearly forward faster than the pack-
age, and fold or tuck over the trailing portion 57 of the
~~ i~~~
ends of the wrapper on the ends of the set of rolls in the
wrapper to form the rear end flaps F3. The brushes 53, in
effect, wipe over the rear end flaps F3, the wiping action
occurring as the package is moving forward by reason of
S the brushes moving forward at a higher speed than the
package. As the brushes move forward in engagement with
the rear end flap F3, they are in vertical position with
their vertical endwise planes parallel to the straight
inner reaches 51a of the conveyors 51. As the brushes 53
10 continue to move with the chains 77, 79 of the conveyors
51, bracket 101 for each chain starts travelling around in
the forward end 51c of its path of travel with the chains
around the forward sprockets 73,75. This change in
direction from linear (straight-line) forward travel to
15 arcuate outward travel results in each brush swinging
relative to its respective set of chains 77, 79 about the
vertical axis of the respective shaft 147 (carried by
bracket 101) with accompanying swinging of the crank arm
or yoke 51 to a position such as illustrated at the left
upper portion of Fig. 8 and in Fig. 9. The net result of
this is that as each brush is moved laterally outwardly
and forwardly away from the folded-over rear end flap F3
as it moves around in the forward end reach of its endless
path of travel, it is maintained in extended contact with
the flap during the initial phase of this movement. This
prolonged contact is advantageous in that it tends to
prevent formation of ears and expedites the formation of
neat end closures for the package. Once the rear end flap
F3 have been folded over, the package passes through
station 17 where the bottom flap F4 are folded up, as by
plows such as indicated at 163 in Fig. 7. The packages
with all four flaps F1-F4 folded up then pass through a
sealing station where they are heat-sealed together in
known manner, completing the wrapping of the set of rolls.
16
gy the use of brushes with suitably flexible
bristles, the apparatus is very forgiving of variations in
the dimension of packages transversely of the conveyor
(i.e. what may be referred to as the package length), and
is adapted to allow the brushes to remain in contact with
the folded-over flaps F3 right up to the point of over-
lapping with the plow 163.
For wrapping three-roll sets of toilet tissue in
which the three rolls are disposed side-by-side, for
example, the spacing of the flights 35 of the conveyor may
change as, for example, by removing every other flight to
double the flight spacing so as to accommodate the higher
package width. The apparatus may also be used to package
single rolls of paper toraeling, for example, adjusting the
lateral spacing of the left and right-hand units 49L, 49R
to accommodate the greater length of the paper towel pack-
age in which case it may be desirable to mount a second
brush 53 on each brush conveyor 51 spaced halfway around
the conveyor from the one brush 53. In this regard,
addition of the second brush may be easily and quickly
effected simply by retracting the pins 111 and 115 of
bracket 101 and the pins 131 and 135 of bracket 103,
positioning the bracket between the upper and lower
chains. and then releasing the pins to slide into
respective tubular chain pins 83. And with the
retractable pin mounting of the brackets, the brush
carriers 97 are readily removable for repair and~or
replacement.
In view of the above, it will be seen that the
several objects of the invention are achieved and other
advantageous results attained.
As various changes could be made in the above
constructions and methods without departing from the scope
of the invention, it is intended that all matter contained
30 in the above description or shown in the accompanying draw-
ings shall be interpreted as illustrative and not in a
limiting sense.
