Method of and means for indexing articles

A conveyor system wherein randomly spaced articles are advanced on a conveyor at a predetermined rate of speed, and means made effective by the presence of an article in a predetermined position on said conveyor, to lift the article therefrom and advance it a predetermined distance at a greater speed than that of the conveyor so as to locate each article in uniform spaced relation to an article in advance thereof and reposition it on the conveyor.

This invention relates to the method of and means for indexing packages or 
articles of various sizes and shapes, and particularly those of a kind not 
having sufficient rigidity or firmness to be physically contacted which 
are deposited at random on a conveyor system, so as to result in their 
discharge from said system at known uniformly spaced intervals to 
facilitate advancing them from two or more conveyors (lanes) onto a single 
conveyor (lane) and/or to automatic equipment, for wrapping or boxing the 
individual packages or articles, or delivery of them to other equipment 
such as for example, a printing machine. 
Many problems exist when it is essential to rearrange articles being 
conveyed in a random fashion into a uniformly indexed manner. For example, 
when two or more "lanes" of articles are being conveyed randomly side by 
side for delivery onto a single lane there will be many instances when an 
article in one lane will be advancing alongside, or substantially 
alongside, an article in the adjacent lane. Hence in order to merge the 
two articles into a single lane it is common practice to advance or 
retract an article in one lane relative to an article in the adjacent lane 
in order to have both articles flow one behind the other onto the single 
lane. This has been and still is being done by bringing an article in one 
or both lanes to stop and then sequentially releasing the article at timed 
intervals so that an article in one lane will be ahead of or behind an 
article in the opposite lane, allowing the two articles to be merged in a 
single lane in predetermined spaced relationship. 
Similarily, to transform a line of randomly spaced articles into a line of 
uniformly spaced articles such as may be required in order to feed the 
articles into a wrapping, cartoning or other type of automatic machine, 
the articles generally must heretofore be stopped and released in timed 
sequence of one sort or another. In many instances the commonly used 
indexing means is satisfactory since it, in fact, does alter the position 
of articles on a conveyor from a random position to an indexed position 
wherein they are uniformly spaced apart. However, here also, in all known 
instances, the method used is to stop, release, push, pull the article in 
some way. 
In each of the aforesaid instances rearrangement of the articles 
necessitates applying holding means against the front, back, sides or top 
of the article. This is satisfactory if the article is of such weight, 
rigidity, and shape that will allow such physical handling but it is 
entirely unsatisfactory when dealing with an article that is irregular in 
shape, is fragile, unstable or for one reason or another will not allow 
physical contact with any surface other than the bottom side of the 
article; or articles that are not succeptible because of their 
fragibility, of having physical contact with another article such as 
occurs when the flow of articles on a conveyor is retarded physically. 
The invention has for one of its objects the incorporation, in a conveyor 
system, of means whereby articles deposited at random on the conveyor 
system are selectively advanced predetermined distances along the conveyor 
without the use of stops, pushers, or gates, etc. More particularly, the 
conveyor system of the present invention incorporates means to separate 
articles, advancing one ahead of another in a single lane, to a desired 
minimum spacing or center distance; to then elevate an article from its 
conveyor surface and advance said article a predetermined distance 
therealong so as to locate it in a specific advanced position, which 
position is also a given distance behind a preceeding article on the 
conveyor surface. This means includes a (feed) conveyor and a main 
conveyor, the main conveyor running at a sufficiently greater speed than 
the feed conveyor so as to create minimum known spacing between articles 
deposited on the main conveyor, and a spacing conveyor system associated 
with the main conveyor having lifting elements thereon which are 
controlled by photo-electric cells and switches, or other sensing means; 
said sensing means being responsive to the presence or absence of an 
article advancing along the main conveyor. When the beam of light from a 
given photo cell is interrupted by the passage of an article thereinto 
and/or a given switch is activated either singularly or in series with a 
given photo cell, means is actuated to lift the sensed article from the 
main conveyor. While lifted, the article is advanced at a speed greater 
than the speed of the main conveyor for such distance as may be required 
to locate it in the desired position, whereupon the sensing means is 
interrupted and means is actuated to redeposit the article on the main 
conveyor for delivery to the wrapping or packaging machine or onto another 
conveyor, machine, converger or system. 
Another object of the invention is to provide novel means and method for 
changing the position of articles randomly deposited on a conveyor system 
into a predetermined indexed position thereon. 
Another object is to provide a novel method and means to accomplish 
repositioning of an article on a conveyor without making physical contact 
with the article on any surface other than the bottom surface thereof and 
without stopping or slowing the rate of travel of the article. 
Another object is to provide a method and means for advancing articles 
randomly spaced on two or more conveyors onto a single conveyor at 
uniformly spaced increments without interference one with the other. 
Another object is to provide a novel method and means for effecting uniform 
spacing of randomly spaced articles which is entirely automatic in 
operation, inexpensive to operate, and one which does not impede the 
advance of or cause damage to said articles. 
Other objects and advantages of the invention will become apparent with 
reference to the following description and accompanying drawings.

Referring to the representative disclosure of a conveyor system used in 
practicing the method of the invention, the structure disclosed for 
purposes of illustration comprises a feed conveyor 11, an advancing or 
main conveyor 12 and a lifting conveyor 13 associated with the main 
conveyor operable for selective advancement of articles along the main 
conveyor at twice the speed of travel of the main conveyor. 
More particularly, the feed conveyor 11 may be of any conventional 
construction and it is operated at a speed half that of the main conveyor 
12, driven by motor 12a, so that articles "A" delivered from said feed 
conveyor to the main conveyor will be advanced therewith at a greater 
speed than the delivery speed of articles leaving the feed conveyor so as 
to obtain minimum spacing between the articles. In this instance, the 
minimum spacing is equal to one article length. 
Closely associated with and running parallel to the main conveyor 12 is the 
lift conveyor 13 comprised of an endless chain trained over sprockets 14 
and driven by motor 13a, carries a series of longitudinally spaced lift 
platforms 15. For purposes of illustration only, the main conveyor 12 is 
shown alternatly divided into "article portions" 16 (shown shaded) and 
"space portions" 17 (not shaded). Each of these portions is of a length 
equal to the length of an article "A" being conveyed thereon. Each 
platform 15 is equal in length to the combined total of one 
article-portion 16 and one space-portion 17 on the main conveyor 12, and 
the platforms are spaced apart one from the other a distance equal to one 
platform length. 
Each of these platforms 15, which are twice the length of article "A", 
normally lie below the plane of conveyor 12 (full lines-FIG. 3) and are 
each connected to chain conveyor 13 by means of a solenoid 18 having its 
core 19 secured to the lift platform so that when a solenoid is activated, 
the related lift platform 15 is elevated above the plane of conveyor 12 
(dotted lines -FIG. 3) to lift an article "A" thereover off of said 
conveyor. 
The lift conveyor 13 is operated at a speed twice the speed of the main 
conveyor 12 for a purpose to be made known in detail presently. Located 
above the main conveyor and spaced longitudinally from its article 
receiving end is a photo-cell 21, or other sensing means. If an article on 
conveyor 12 is interrupting the beam of said photo-cell at the very 
instant a pulsed switch 22 is momentarily energized by the lead edge of 
platform 15, the related solenoid 18 is actuated to lift the related lift 
platform 15 and lift the article off of the conveyor 12. Once lifted the 
solenoid 18 is sustained in energized condition by a latching switch and, 
the article A is advanced at twice the speed of conveyor 12. Further along 
the conveyor 12 is a second photocell 23 (FIG. 4) which is carried on a 
reciprocable piston rod 24 forming a part of an air-cylinder assembly 25. 
When an article A advancing along with the elevated lift platform 15 
interrupts the beam of cell 23 (FIG. 5) a signal is caused to de-energize 
through the latching switch solenoid 18 thereby lowering the lift platform 
to cause the article to be repositioned on the main conveyor 12 and be 
advanced at the speed of the main conveyor. 
The above described representative structure will best be understood upon 
reference to the following description of the method of conveying and 
specifically locating articles on the main conveyor. 
OPERATION 
In operation, the lifting conveyor 13 is running at twice the speed of main 
conveyor 12 and main conveyor 12 is running at twice the speed of feed 
conveyor 11. In the exemplary disclosure each article A of a succession of 
articles is twelve inches long and it is desired to deliver them at the 
discharge end of conveyor 12 at a specific instant and spaced 12 inches 
apart (whenever there are sufficient numbers of articles entering the 
system to so fill the system). As heretofore stated, the main conveyor 12 
is theoretically divided alternately into "space portions" 17 and "article 
portions" 16, each of the same length as the package which is, in this 
instance, twelve inches long. The specific purpose of the assembly is to 
locate an article A precisely on one of the "article portions" 16. 
Initially, if the leading edge of an article A is deposited from the feed 
conveyor anywhere within a "space portion" of the main conveyor 12 (as 
shown in FIG. 3) the following will occur:- At an instant when the leading 
edge 15a of a lifting platform 15 is in a so-called "zero" position (i.e., 
aligned with the lead edge 17a of a "space portion" 17 and below same) the 
beam of photo cell 21 is interrupted by the presence of article A in its 
beam and, with the lead edge 15a of platform 15 in contact with pulse 
switch 22 will cause the platform to rise. Specifically, as best shown in 
FIG. 3, "zero" position of lift platform 15 is that instant at which its 
leading edge 15a is in exact alignment with the leading edge 17a of its 
correlative "space portion" 17 of the main conveyor 12 and simultaneously 
the pulse switch 22 is momentarily activated to (in series with signal 
from photo cell 21) energize solenoid 18 and raise the platform into the 
elevated postion shown in dotted lines in FIG. 3. 
As previously noted, the lifting station 15 is traveling at a rate of twice 
the speed of the main conveyor 12, thus article A is carried on the 
elevated platform 15 a distance of two feet in the time that the main 
conveyor has advanced only one foot. Lift station 15 is now in position 
(FIG. 4) of "zero-plus one" (i.e., its leading edge 15a is now in exact 
alignment with the leading edge 16a of its correlative "article portion" 
16). When the lead edge 15a of platform 15 contacts a dual purpose switch 
26, the photo cell 23 will be advanced in the same direction, and at the 
same speed, as conveyor 12; that is, at one-half the speed of platform 15. 
Because article A is still seated on lift platform 15 while the platform is 
elevated and is traveling at a rate of of speed twice that of the main 
conveyor and twice the rate of speed of photo cell 23, the advancing 
article A will at some instant during the forward stroke of carrier rod 24 
enter and cause the beam of photo cell 23 to be broken. At the same 
instant this occurs (FIG. 5) photo cell 23, the leading edge of article A, 
and the leading edge 16a of the correlative "article portion" 16 will all 
be in exact alignment and the signal from photo cell 23 will cause 
solenoid 18 to de-energize and the lift platform will drop down and 
re-deposit the article A on the main conveyor. The 12 inch article is thus 
deposited in a twelve inch "article portion" 16 on the main conveyor. 
If the platform has not been thus retracted, dual purpose pulse switch 27 
(FIG. 5) will be actuated by contact of the lead edge 15a of said elevated 
platform 15 to de-energize its correlative solenoid 18 and cause lowering 
of said platform. This action of switch 27 is necessary because an empty 
platform, not raised in zero position by actuation of switch 22 and photo 
cell 21, will be lifted when contacting pulse switch 26. Thus, switch 27 
serves as a back-up to assure that all platforms are in their lowered 
position at the end of their useful run. Activation of switch 27, as noted 
above, is also necessary to cause photo-cell 23 to move in a reverse 
direction back to its initial position during the time that one "article 
portion" 16 and one "space portion" 17 of the main conveyor are passing 
beneath its line of travel. 
This sequence of operation is repeated for each succeeding article 
deposited on the main conveyor 12. However, should an article enter and 
fall (i.e., the leading edge of an article) on an "article portion" 
instead of on a "space portion", upon reaching the zero-position (FIG. 3) 
the correlative platform 15 will not be elevated, even though switch 22 is 
pulsed. The article, with its leading edge still resting on an "article 
portion" of main conveyor 12 will continue to advance with the main 
conveyor. When the article seated on the "article portion" of conveyor 12, 
reaches the zero=plus-one position (FIG. 4) the correlative empty platform 
15 (still down) contacts and causes switch 26 to be pulsed causing the 
platform to rise, whereupon the previously described action of photo-cell 
23 and/or switch 27 will be repeated. 
Although the foregoing description has been concerned with the handling of 
articles 12 inches long and correlated "space" and "article" portions on 
the conveyor are 12 inches long, the method and means is adaptable for 
handling of articles of other lengths, at difference speed relationships, 
and with varying lengths and relationships of "article" and "space" 
portions. To this end readjustment would be determined substantially as 
follows: 
The length of lift platforms 15 is equal to the combined total length of 
one "article portion" 16 and one "space portion" 17 of the main conveyor. 
For example, if it is desired to deliver 9 inch articles on 12 inch center 
distance, the main conveyor would be (for purposes of illustration) 
segmented into an endless series of 9 inch "article portions" and 3 inch 
"space portions". Hence, the length of the lift platform will be 12 
inches. 
The distance between the lift platforms 15 is directly related to their 
respective length and the speed relationship of the main conveyor 12 to 
lifting conveyor 13. If it is desired that the lifting conveyor be run at 
a speed 25% greater than that of the main conveyor, then 0.25 becomes a 
multiplier to establish distance between platforms. Further in the example 
just cited; the 12 inch platform length is multiplied by the 0.25 speed 
ratio factor, determining that the distance between platforms equals 3 
inches. The general expression stating this relationship is 
EQU x=[s.sub. 1 /s.sub.2 - 1]X 
where 
x is the distance between adjacent platforms, 
s.sub.1 is the speed of the lifting conveyor, 
s.sub.2 is the speed of the main conveyor, and 
X is the length of each platform. 
Although I have described a preferred embodiment of my invention, in 
considerable detail, it will be understood that the description thereof is 
intended to be illustrative and not restrictive, as details of the steps 
of the method and structure may be modified or changed without departing 
from the spirit or scope of the invention. Accordingly, I do not desire to 
be restricted to the exact steps of the method and the construction shown 
and described.