Can end separator-conveyor

A conveyor system is arranged for transporting and spacing can ends by means of confronting flexible conveyor belts which are spaced apart to grip can ends at the edges, in combination with means for frictionally engaging the can ends in the space between the conveyor belts.

FIELD OF THE INVENTION 
This invention relates generally to the manufacture of metal containers and 
more particularly to the art of applying end seam compound to the 
peripheral channel of can ends. Specifically, the present invention 
relates to can end conveyor systems. 
BACKGROUND OF THE INVENTION 
In the manufacture of can ends, an elastomeric gasketing compound is 
commonly applied to the annular channel defined between the cover hook and 
the seaming panel radius prior to seaming of the end onto a can body. This 
gasketing compound is arranged to reside in the crimped end seam 
juxtaposed between the cover hook and the body hook in order to provide an 
hermetic seal. In the past, quick drying, solvent-base compounds, 
formulated with a volatile hydrocarbon diluent or thinner such as hexane, 
have been widely employed. However, solvent vapors generated upon the 
curing of these compounds result in undesirable atmospheric pollution. In 
response, water-base compounds have been developed and these produce no 
such effluvium. The latter compositions have the disadvantage, however, of 
requiring comparatively long drying times, on the order of ninety seconds 
or more; and existing can end handling equipment is arranged to stack the 
ends immediately after application of the end seam compound, thus 
confining the escaping moisture and prolonging the drying time, even with 
the use of a drying oven. 
BRIEF DESCRIPTION OF THE INVENTION 
Applicant has found that a can end conveyor, disposed downstream from the 
compound applying station, may be specially arranged to facilitate the 
drying of water-base end seam compounds. More particularly, applicant has 
invented a can end conveyor which accepts stacked can ends, separates the 
ends, and then conveys them in spaced-apart relationship through the 
drying cycle. 
It is accordingly a general object of the present invention to provide a 
new and improved can end conveyor system. 
Another object of the invention is to provide a can end conveyor which 
transports the ends in spaced relationship whereby to facilitate curing of 
end seam compound. 
These and other objects and features of the invention will become more 
apparent from a consideration of the following descriptions.

DETAILED DESCRIPTION 
Referring now in detail to the drawings, and giving first attention to FIG. 
1, a conveyor system indicated generally by the reference numeral 20 is 
constructed to include a feed section 22, an output or delivery section 24 
and a transport section 26 located between the sections 22 and 24. The 
conveyor system 20 is supported at a suitable height above a factory floor 
28 by means of a suitable number of adjustable machine legs 30; and as 
will be described more fully hereinafter, stacked can ends fresh from an 
end seam compound applying station are delivered from the feed section 22 
to be spaced apart and conveyed through the transport section 26 in the 
machine direction indicated generally by an arrow 32 in order to promote 
curing of the end seam compound. Specifically, a can end separating 
station 34 is located between the feed section 22 and the transport 
section 26; and desirably, a conventional forced-air drying oven unit 
contained within a plenum chamber 36 is arranged with the transport 
section 26 in order to pass a heated air stream between the spaced can 
ends for accelerating the curing action. The plenum 36 may also house 
equipment for distributing sterilizing vapor, such as steam, between the 
can ends. 
Turning to a consideration of FIG. 2 in conjunction with FIG. 5 for a more 
detailed description of the feed section 22, a generally V-shaped trough 
arrangement 38 is mounted atop a pair of side plates 40 and 42 in order to 
receive and support stacked can ends 44 which are of a planar, disc-like 
nature and which have freshly applied end seam compound 46 disposed in the 
annular channel defined between the cover hook and the seaming panel 
radius. The trough arrangement 38 includes a half-tubular guide 48 having 
rearwardly extending elongated finger rails 50 and abbreviated, forwardly 
extending finger rails 52, the rails 50 and 52 being laterally spaced, as 
is best seen in FIG. 5, for guidably directing movement of the can ends 44 
in the machine direction 32. A suitably positioned structural frame 
element 54 supports the guide 48. 
A can end transfer unit 56 is incorporated in the feed section 22 in order 
to advance the stacked can ends; and the transfer unit 56 includes a pair 
of laterally-spaced, stiffly flexible drive belts 58 which are positioned 
at the root of trough arrangement 38 by means of an upwardly opening 
channel 60 as is best seen in FIG. 5. The drive belts 58 are trained over 
respective guide pulleys 62 fixed on a common shaft 64 and over suitable 
idler rollers, not shown. In order to advance the can ends 44, the pulleys 
62 are driven in the rotary direction indicated generally by an arrow 66 
employing a driven sprocket 68 which is mounted on the shaft 64. Sprocket 
68 is powered by a drive sprocket 70 using an endless chain 72, best seen 
in FIG. 1. The path of drive chain 72 is further defined by an idler 
sprocket 74 and a driven sprocket 75 which supplies power to the 
separating station 34. Power is applied to the chain 72 by a motor-gear 
reducer unit 76 which includes an output shaft 78 upon which the drive 
sprocket 70 is mounted. 
Continuing now with reference to FIGS. 1 and 2, the can ends 44 are 
conveyed through the transport section 26 by means of confronting, 
flexible, upper and lower conveyor belts which are indicated respectively 
by the reference numerals 80 and 82. The conveyor belts 80 and 82 are 
guided through the can end separating station 34 by means including 
individual upper and lower idler rollers 84 and 86; and motive power is 
applied to these conveyor belts by respective upper and lower drive rolls 
88 and 90 which are located at the output or delivery section 24 of the 
conveyor system 20 as is shown in FIG. 1. A suitably energized and 
adjustable motor-gear reducer unit 92 which is securely mounted in a 
pendant frame arrangement 94 delivers rotative power to the rollers 88 and 
90 through an output sprocket 96, an endless drive chain 98 and driven 
sprockets 100 which are coupled to the rollers 88 and 90 by means of 
respective common shafts 102. The motor-gear reducer unit 92 powers the 
drive chain 98 in the general direction indicated by an arrow 104 in order 
to transport the confronting portions of the belts 80 and 82 in the 
machine direction of arrow 32 and at the same linear or longitudinal speed 
in order to maintain upright position and proper spacing of the traveling 
can ends. 
In compliance with the present invention, the confronting runs of conveyor 
belts 80 and 82 are spaced apart a predetermined distance in order to grip 
the can ends 44 at the edges thereof as is illustrated in FIG. 2. For this 
purpose, upper and lower guide plates 106 and 108 are adjustably 
positioned in the can end separating station 34 by means of machine 
brackets 110 and 112, threaded fasteners 114 and 116; and suitable lock 
nuts 118. 
According to the illustrated embodiment, at least one of the conveyor belts 
80 and 82 is formed into semicylindrical shape in order to promote secure 
gripping of the edges of the can ends 44. For this purpose, one or both of 
the guides 106 and 108, specifically the guide 106 in the illustrated 
embodiment, is fashioned into the desired configuration, as is best 
illustrated in FIG. 3. In further accord with the principles of the 
present invention, the conveyor belts 80 and 82 are preferably fabricated 
with textured outer surfaces by means of a suitable thread or patterns of 
nubs 120 shown in FIG. 6. 
The idler roller 84 and 86 for the conveyor belts 80 and 82 are mounted in 
the can end separating station 34 by means of generally U-shaped brackets 
122 and 124, a pair of yokes 126 and 128 each of which terminates in a 
threaded stem 130, and suitable locknuts 132. 
In order to impart spacing between the indvidual conveyed can ends 44 from 
the stacked condition in which the can ends are arrayed in the trough 
arrangement 38, frictional retarding of the can ends is accomplished as 
the individual can ends are picked up by the traveling conveyor belts 80 
and 82 at the separating station 34. In the illustrated embodiment, these 
frictional retarding means comprise a pair of laterally spaced, 
diploconical roller members 134 which are mounted on shafts 136 for 
rotation in the respective directions indicated by the arrows 138 and 140 
in FIG. 3. In order to present the desired frictional factor and 
resiliency to the edges of the can ends 44, the roller members 134 are 
advantageously fabricated from a cast, elastomeric polyurethane resin, 
which is resiliently deformable to grip the ends. 
In order to rotate the roller members 134 so as to produce an effective, 
differentially lesser speed in the machine direction 32 than the linear 
speed of the belts 80 and 82, the roller member shafts 136 are positively 
driven in unison from a transverse shaft 142. A pair of spaced beveled 
gears 144 are keyed or otherwise suitably affixed to the shaft 142 in 
order to mesh with companion beveled gears 146 which are secured to the 
respective roller member shafts 136. The shaft 142 is rotated in the 
direction of arrow 148 from drive chain 72 by means of the drive sprocket 
75 mounted on one end of the shaft 142 as is shown in FIG. 1. The drive 
and driven shafts for operating the rollers 134 are suitably journalled in 
the machine frame of the conveyor system 20. 
For purposes of affording a more complete understanding of the invention, 
it is advantageous now to provide a functional description of the mode in 
which the component parts operate. 
Elastomeric gasketing compound is first applied to each of the can ends 44 
in a conventional end seam compound applying machine where the 
semi-finished ends are stacked and then delivered to the feed section 22 
of the conveyor system of the present invention. The can ends 44, clearly 
shown stacked in FIG. 2, are advanced in the machine direction 32 by the 
drive belts 58, movement of the can ends through the trough arrangement 38 
being directed by the guide 48 and its component finger rails 50 and 52. 
As the can ends 44 pass from the trough arrangement 38, they are picked up 
and further advanced in the machine direction by the conveyor belts 80 and 
82; and as is well illustrated in FIG. 2, frictional engagement of the 
roller members 134 drags or retards the can ends instantaneously because 
the effective linear speed of the roller members is differentially lesser 
than the forward speed of the conveyor belts 80 and 82. This momentary 
retarding action of the roller members 134 spaces the can ends; and 
because the conveyor belts 80 and 82 are moving at a common speed and 
because the belts are arranged to grip the can ends at the edges thereof, 
the can ends are advanced in continuation of their spacing. When the 
spaced can ends pass through the oven unit contained within the plenum 
chamber 36, a heated air stream flows between the can ends and serves to 
dry and cure the end seam compound. Residual moisture or solvent is 
allowed to pass from the end seam compound as the can ends 44 are passed 
to the output or delivery section 24 of the conveyor system 20; and at 
this juncture, the can ends may be stacked in paper-wrapped rolls or 
packaged in cartons. 
It will be apparent from the foregoing descriptions, that the conveyor 
system of the present invention provides a fast and efficient scheme for 
curing end seam compounds and is applicable to either water-base or 
solvent-base gasketing compositions. 
The specific embodiment herein shown and described is to be considered as 
being primarily illustrative. Various changes in structure will, no doubt, 
occur to those skilled in the art; and such changes are to be understood 
as forming a part of this invention insofar as they fall within the spirit 
and scope of the appended claims. By way of example, while the embodiment 
illustrated involves a drying chamber, the invention may be employed in 
other types of can handling operations. More specifically, where solvent 
base compound is used, the chamber 36 could be a venting chamber for 
containment and removal of the solvent vapors for delivery to an 
incinerator unit wherein the hydrocarbons are burned off. As a final 
example, where the ends have to be sterilized, the chamber 36 could house 
a gas or thermal sterilizing operation.