Magnetic drum assembly and method for orienting side-by-side steel can bodies

A drum assembly and method for conveying magnetically susceptible can bodies from a first location where the can bodies are generally vertical to a second location where the can bodies are generally horizontal. The drum assembly includes a hollow, non-magnetic, generally cylindrical drum; an axle for rotating the drum; and a fixed magnet inside the drum. Can bodies are attached to the drum outer surface portion by magnetic attraction at the first location; rotated to the second location; and separated from the drum at the second location by limiting proximity of the fixed magnet and the drum to an arc of only approximately 90.degree.-110.degree..

TECHNICAL FIELD OF THE INVENTION 
The present invention relates generally to the mass transport of articles, 
such as can-shaped containers, from a first location at a vertical 
orientation to a second location at a horizontal orientation. This 
invention can be most advantageously employed in removing steel can bodies 
from the surface of an air conveyor and then feeding the can bodies to an 
air single filer. Can damage is minimized while the device provides for 
metering the cans in a positive controlled fashion. 
BACKGROUND OF THE INVENTION 
In many manufacturing operations, particularly in the manufacture of 
cylindrical containers, such as two-piece steel cans, it is necessary to 
mass transport such articles, either in single file or side by side. Such 
containers are characteristically unstable, particularly at present-day 
line speeds which are capable of handling up to approximately 2,500 
articles per minute. 
Present-day two-piece steel cans possess can bodies having almost 
paper-thin side walls. During processing, the can bodies are caused to 
engage a number of work areas, including washing, decorating and necking 
stations. When moving from one station to the next, the can bodies either 
travel in a moving belt, or more advantageously, upon an air conveyor 
consisting of a plenum having openings for the directional supply of air 
from the upper deck surface. Devices of this nature are described in U.S. 
Pat. No. 4,456,406, the disclosure of which is incorporated herein by 
reference. However, it is often times necessary to change the vertical 
orientation of the can bodies as well as to convert the flow of cans from 
a multi-row configuration to a single file orientation, particularly when 
the can bodies are to be decorated and necked. 
Air single filers, euphemistically known as doubling boxes, are well known 
in can processing operations. For example, one such device is disclosed in 
U.S. Pat. No. 4,182,586, the disclosure of which is hereby incorporated by 
reference. Conventionally, the input or upstream end of the air single 
filer would be fed by a waterfall which, as the name implies, simply 
consists of a curved slide which transcribes a circular drum across which 
cans travel while rotating 90.degree. to achieve horizontal orientation at 
which point they fall into the upstream end of the single filer. A curved 
top guide surface prevents the cans from tumbling due to the small 
clearance between the guide and the top of the can. 
The use of a waterfall in feeding a single filer, or in feeding any other 
device for that matter, possesses a number of inherent shortcomings. Quite 
obviously, the dropping of cans en masse from a waterfall to a lower 
collection area can and often times does result in damage being inflicted 
to the container side walls. This is a particular problem today as steel 
beverage containers have been provided with very thin side walls as a 
material saving expedient. 
When the flow of container bodies was to be interrupted, prior waterfall 
installations would employ a gate which would physically impede the 
entrance to the single filer which, itself, often times causes can damage. 
The gate regulates can flow by capturing a row of cans laterally across 
the conveyer with a pressure pad that clamps the row of cans between the 
pad and the conveyor deck surface. When the gate is closed, the pad is 
applied which clamps the cans, thus stopping the flow. When the gate is 
open, the pad is released and the cans are free to move. The clamping 
action applies a force to the can bodies which can result in their damage. 
The sliding action of the cans through a prior waterfall can cause damage 
to the open end of the can as it slides on the top guide. 
It is thus an object of the present invention to provide a drum assembly 
and its method of operation as a substitute for waterfall installations of 
the prior art. 
It is a further object of the present invention to provide a drum assembly 
and its method of operation capable of rotating steel can bodies in 
side-by-side relationship from a first to a second location over a curved 
surface while avoiding damage to the can bodies and providing a positive 
means of flow control while avoiding gate structures employed by the prior 
art. 
These and further objects will be readily apparent to persons skilled in 
the art from the following specification and claims.

SUMMARY OF THE INVENTION 
The present invention deals with a drum assembly and its method of 
operation. The drum assembly provides for the rotation of a plurality of 
steel can bodies over a curved surface from a first to a second location. 
The device comprises a hollow, rotatable, cylindrical drum, capable of 
rotation about a substantially horizontal, longitudinally extending axle. 
A magnet assembly is located within the hollow, rotatable, cylindrical 
drum, said magnet assembly being of a size and placement to adhere the 
steel can bodies to the surface of the hollow, rotatable, cylindrical drum 
only from a first to a second location. Means are also provided for 
rotating the hollow, rotatable, cylindrical drum about the substantially 
horizontal, longitudinally extending axle. 
As used herein, the terms "steel can bodies," "magnetically susceptible can 
bodies," and "ferrous can bodies" are expressions for the objects which 
are conveyed by the drum assembly of the present invention. The can bodies 
are usually hollow and generally cylindrical but may have other shapes as 
well. 
DETAILED DESCRIPTION OF THE INVENTION 
FIG. 1 illustrates the magnetic drum assembly 10 of the present invention 
in operation. Magnetically susceptible can bodies or steel can bodies or 
steel cans 11 are moved along an air conveyor 12 on its top surface 13 by 
the directional flow of air through openings 14. The cans 11 thereupon 
engage a hollow, rotatable, cylindrical drum 15 at a first location 16 and 
are adhered to an outer surface portion or outer surface 17 of the 
cylindrical drum 15 by virtue of a fixed magnet, the details of which will 
be discussed hereinafter. 
The hollow, rotatable, cylindrical drum 15 is caused to rotate about a 
substantially horizontal, longitudinal axis 18 by virtue of a variable 
speed motor (not shown). The motor drives a gear assembly 19 which, in 
turn, is coupled to a roller chain contained within a roller chain housing 
20. The roller chain engages a rotatable axle or shaft 21 (FIG. 3) causing 
rotation of hollow, rotatable, cylindrical drum 15 through bearings 22. 
It is an essential element of the present invention to provide a 
configuration whereby steel can bodies 11 are to be maintained by means of 
a magnetic assembly on the outer surface 17 of rotating, cylindrical drum 
15 only in a specific predetermined arc of rotation, such as shown in FIG. 
2. Ideally, the arc of rotation is approximately 90.degree. whereby the 
steel cans 11 are received from the top surface 13 of air conveyor 12 at a 
first location 16. 
Referring again to FIGS. 1 and 2, cans 11 are to be received from 
horizontal surface 13 having a substantially vertical axis 23. The steel 
cans 11 are then caused to adhere to the outer surface 17 of rotating 
cylindrical drum 15 until they reach a second location 24 where their 
collective longitudinal axes 25 are substantially horizontal. At that 
point, the influence of the magnetic assembly diminishes and the cans 11 
fall from the surface portion 17 of rotating drum 15. To further 
facilitate removal, an optional stripper plate 30 can be positioned 
adjacent to the outer surface portion 17 of cylindrical drum 15. The 
stripper plate 30 has a blade 31 extending tangentially to the outer 
surface portion 17 near the second location 24. Although in most 
instances, gravitational attraction applied to the steel cans 11 is 
sufficient to insure their discharge from the rotating, cylindrical drum's 
outer surface 17, the stripper plate blade 31 insures can removal 
substantially at the second location 24. 
The above-described apparatus also includes a magnetic assembly 35 as shown 
in FIGS. 2 and 3. The magnetic assembly 35 includes a fixed magnet 36 
supported by a support shaft 37 extending laterally through bearings 22 in 
an end wall 38 of the drum 15. The support shaft 37 is attached to a fixed 
stand 40 located exteriorly of the drum 15. The fixed magnet 36 extends 
proximal to an inner wall 41 of the drum 15 along an arc defined by angle 
.theta. to be between approximately 90.degree. and 110.degree.. 
It is further to be noted that the drum assembly 10 of the present 
invention can also act to regulate the flow of can-shaped objects as an 
alternative to gate structures of the prior art. As can-shaped objects 11 
move from the air conveyor 12, they are captured by magnetic attraction 
onto the surface 17 of rotatable, cylindrical drum 15. If the cylindrical 
drum 15 stops rotating, the flow of can-shaped objects 11 also stops as 
line pressure from air conveyor 12 is not generally of sufficient strength 
to override the inertia of cans 11 and to slide the cans 11 onto the 
surface 17 of rotating drum 15. As such, the present invention 
advantageously replaces the typical prior art gate and waterfall devices. 
Where gates of the prior art are either open or closed, the rate of travel 
of the present drum assembly can be adjusted over a wide range extending 
from zero to a predetermined maximum speed. 
Today's high-speed, can-handling processing lines require continuous flow 
regulation with a rapid response time. Intermittent flow produced by a 
gate is not adequate because the response time of a mass of can-shaped 
objects is slow due to the inertia of the pack. The present invention 
provides for such continuous flow regulation with a response time 
unmatched by prior art devices. 
It is an important feature of the present invention that steel cans are 
reoriented from a vertical position to a horizontal position without need 
for attachment to a moving magnetic belt conveyor, as in Dudley U.S. Pat. 
No. 3,338,374. The beltless conveyor of the present invention avoids 
problems of reliability and wear involved with moving belts, both on the 
cylindrical drum 15 and at adjacent positions. The invention also moves a 
much higher volume of steel cans per unit time by taking advantage of a 
long drum outer surface 17 accommodating a plurality of cans 11 in 
side-by-side relationship. As shown in FIG. 1, the present apparatus 
easily transports at least six and even more than ten steel cans across 
the length of the drum 15. In contrast, Dudley's conveyor carries can 
bodies in single file on moving, magnetic belt. The Dudley patent also 
fails to suggest any means for releasing can bodies from the magnetic belt 
when the can bodies are in horizontal orientation. 
While the invention has been described in terms of preferred embodiments, 
the claims appended hereto are intended to encompass all embodiments which 
fall within the spirit of the invention.