Feed apparatus with two feedscrews

A feed apparatus including two feedscrews for supporting flat articles as they are moved along a conveyor. The two feedscrews are mounted in parallel and are spaced apart so that each feedscrew supports the flat articles along a different edge of the articles. The flat articles are maintained in a substantially vertical alignment throughout the conveyance. A suction pickoff station removes the flat articles one at a time from the downstream end of the feed apparatus. The two feedscrews turn at equal speeds and have equal pitches which separate the flat articles into groups between consecutive projections of the helical threads of the feedscrews.

BACKGROUND OF THE INVENTION 
The present invention is directed to an automatic feed apparatus for 
transporting articles, particularly flat articles such as cartons, to a 
one-at-a-time pickoff station. 
In a continuous production process for filling and sealing boxes with 
particulate matter, such as laundry soap, the beginning of the process is 
to load the cartons to be filled onto the automated apparatus. The cartons 
come boxed with the cartons being collapsed and flat against each other. 
The boxes of flattened cartons are opened and emptied onto a conveyor 
belt. The flattened cartons stand against each other on edge. The cartons 
must be moved along to a station where they can be removed one at a time 
for further processing such as opening, filling and sealing. Moving the 
cartons along in an upright position to the removed station has been 
complicated by the inclusion of handles attached to the cartons. The 
handles interfere with flat carton against carton surface contact that was 
possible without the handles. The slack in the line of cartons that 
necessarily develops between cartons with handles tends to make it more 
likely that the cartons will be flopped over when they arrive at the 
removal station. 
It is an object of the present invention to provide a feed apparatus that 
will deliver flat articles such as cartons in a substantially upright 
position to permit easier and consistent removal. 
SUMMARY OF THE INVENTION 
The present invention is directed to a feed apparatus having two parallel 
feedscrews. The first feedscrew is positioned alongside a conveyor while 
the second feedscrew is mounted at a different vertical height from the 
conveyor. The threads of the two feedscrews project between adjacent flat 
articles on the conveyor. The two feedscrews are located along different 
edges of the flat articles in the line. The pitch of the threads on the 
feedscrews are such that a plurality of the flat articles being 
transported fit between consecutive insertions of the helical thread. 
Thus, the flat articles are transported in groups between the insertions 
of the feedscrews threads. The flat articles lined up on their edge on a 
conveyor are moved between the feedscrews towards a pickoff station. The 
conventional suction cup pickoff device works well with the feedscrew 
apparatus since the use of the two feedscrews advantageously maintains the 
flat articles in a substantially vertical position all the way up until 
they are picked off. 
The feedscrews may be advantageously mounted on adjustable arms so that the 
position of the feedscrews may be changed to accommodate the feeding of 
articles of different sizes. The drive apparatus turns the two feedscrews 
at equal speeds. The rotational speed of the feedscrews is a function of 
the speed of the conveyor so that the two are in proper relation. The feed 
apparatus of the present invention advantageously maintains flat articles 
in a substantially vertical position for pickoff by a suction cup device 
even when handles or the like are riveted to the flat articles. Other 
objects and advantages of the invention will become apparent during the 
following description of the presently preferred embodiment of the 
invention taken in conjunction with the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings, a feed apparatus 10 of the present invention 
is shown. The feed apparatus 10 is shown here transporting cartons 16 with 
plastic handles 17 riveted thereto. While the feed apparatus 10 of the 
present invention may be used for conveying any number of types of 
articles, it is especially adapted for the conveyance of substantially 
flat articles such as the handle bearing cartons shown in the drawings. A 
conveyor 12 is provided for moving the articles in a linear direction. The 
conveyor 12 shown in the drawings is a chain or pair of chains. The pair 
of chains are driven at the same speed by the same drive. Any alternative 
conveyor may be used for the chain such as a conveyor belt or other 
mechanism for providing a moving surface for the bottom edges of the flat 
articles. A restraining stand 14 is provided that may be demountably 
attached to the conveyor chain 12. The restraining stand 14 supports the 
upstream flat articles in a vertical position as they are moved along on 
the conveyor 12. The articles are placed flat against each other in a 
horizontal line with their edges on the conveyor 12. Only some of the 
cartons are shown in FIG. 1 others have been left out of the drawing to 
provide an improved view of the feed apparatus itself. The horizontal line 
of flat articles provides an intense line pressure which the feedscrews 
are designed to restrain so that the upstream cartons do not fall over. 
Two feedscrews are provided in parallel along the conveyor 12 to support 
the flat articles in a substantially vertical position and to maintain 
them in an upright position against the force of the line pressure. A 
first feedscrew 18 is mounted longitudinally in the direction of the 
conveyor movement. The first feedscrew 18 is alongside the conveyor and at 
least partially higher than the conveyor so that its threads 20 can insert 
between adjacent cartons 16. Looking from the upstream end of the conveyor 
the first feedscrew 18 in FIG. 1 has its threads inserted into or along a 
right hand edge of the cartons 16. The helical thread 20 of the first 
feedscrew 18 is pitched at an angle such that a group of several cartons 
16 fit between consecutive insertions of the thread 20. The presently 
preferred pitch angle of the helical thread is 59.04 degrees. The 
presently preferred dimensions for the feedscrew are 60 inches in length, 
5 inches outer diameter and 2 inches for the root diameter. The feedscrew 
is preferably made of steel, but any sufficiently smooth and durable 
material such as DELRIN plastic may be used. 
A second feedscrew 22 is mounted longitudinally parallel to the first 
feedscrew 18. The second feedscrew 22 is mounted at a different vertical 
height from the conveyor 12 than is the first feedscrew 18. In order to 
adequately support the flat articles in a substantially vertical position, 
the second feedscrew 22 is provided such that its threads 24 are inserted 
along a different edge of the cartons from the edge supported by the first 
feedscrew 18. Thus, in the drawings, the threads of the second feedscrew 
22 insert along the top edge of the cartons 16. The feedscrew 22 is shown 
at the upper left hand corner of the cartons opposite to the lower right 
hand corner where the first feedscrew 18 is roughly located. It is 
preferred that while the first feedscrew is to one side of an imaginary 
center line through the conveyor 12, that the second feedscrew be mounted, 
so as to be centered on the opposite side of the imaginary center line. 
The second feedscrew 22 has the identical pitch to the first feedscrew 18 
and rotates at the same speed as the first feedscrew 18. Indeed, it is 
desirable that the feedscrews are arranged identically so that their 
threads insert between the same adjacent flat articles and so that the 
same groups are carried between the consecutive threads of both 
feedscrews. 
In accordance with the presently preferred embodiment, the upstream ends of 
the feed screws are mounted in hubs 26, 28 that are idle. The drive 
mechanism is more conveniently located at the downstream end. The hubs 26 
and 28 may be supported on adjustable arms 30 and 32, respectively. The 
adjustments on the arms 30 and 32 may be simple mechanical manual 
adjustments or, alternatively, a robotic arm may be used with electronic 
control over positioning. The upstream arms 30 and 32 are preferably 
connected to the downstream arms by crossbars 34 and 36 to help keep the 
rear hub and downstream hub in alignment for proper mounting of the 
feedscrews. 
Referring now to FIG. 2, the drive mechanisms and pickoff station can be 
more easily seen. The pickoff station at the downstream end of the 
conveyor includes two swinging arms 40 each with a suction cup 42 mounted 
on its outer end. The suction cups 42 are provided for suction engagement 
with a substantially vertical flat surface of the lead article on the 
conveyor. A pickoff shaft 44 driven by pickoff drive 45 cyclically rotates 
the swinging arms 40 into contact with the lead flat article and away from 
the conveyor. The removed article is then handed off to the next apparatus 
in the processing system. In the case of detergent cartons, the procedures 
of opening the carton, filling the carton, and sealing the carton follow. 
The presently preferred invention is designed to operate at speeds of from 
40 to 100 cartons per minute. Thus, the swinging arms 44 rotate back and 
froth 40 to 100 times per minute picking off the lead flat articles as 
they arrive from the conveyor. 
Since the flat articles are arriving in groups at the downstream end, it is 
useful to provide some additional means to hold the articles in their 
substantially vertical position while awaiting the pickoff. Thus, it is 
recommended that a lower pin 46 and an upper pin 48 project slightly into 
the path of the flat articles to hold them up momentarily while the lead 
flat article is being removed to the next machine. So that the pins 46 and 
48 do not interfere with the pickoff process, it is desirable that a notch 
50 be cut out at the bottom and top portion of the lead flaps in the 
carton. Thus, as the pickoff means pulls a carton out from behind the pins 
the rear flaps on the carton easily bend backwards as they brush over the 
pins. The forward flap on the carton will not hit the pins because of the 
notches. Motor 52 turns at a constant desired speed. A sprocket 55 is 
rotated by the motor 52. A positive drive belt from the sprocket 55 turns 
gears 54 at the desired speed for moving the conveyor chains 12 at a 
constant linear speed. A tachometer 56 is mounted between the sprocket 55 
and the motor 52 for measuring the speed at which the sprocket 55 is 
rotating. A signal corresponding to the speed of the sprocket and hence 
determinative of the linear speed of the conveyor is directed to a 
controller 58. The controller 58 is used to set the speeds of the conveyor 
12, the pickoff shaft 44 and the feedscrews. The speed of the feedscrews 
and the pickoff shaft are determined as a function of the linear speed of 
the conveyor to coordinate the system components. The linear speed of the 
conveyor should equal the linear speed of feed screw thread. Thus, the 
supporting threads move along with the cartons at the same speed as the 
conveyor. The speed of the pickoff shaft is based on the linear speed of 
the conveyor and the numb of cartons per inch. This determines the number 
of cartons per minute. 
The rotational speed of the feedscrews needs to be a function of the speed 
of the conveyor. This can be accomplished electronically with the 
tachometer 56 and the controller 58. Alternatively, the speeds can be 
coupled mechanically. Gears, drive shafts and drive belts may be used to 
link the rotation of the feedscrews to the same motor used to drive the 
conveyor chains. Either mechanical or electrical coupling may be used to 
equivolently accomplish the proper relationship between conveyor speed and 
feedscrew rotational speed required. 
In accordance with electronic coupling, a separate feedscrew motor 60 is 
mounted on a horizontal beam 62 at the downstream end of the conveyor 
system. The controller 58 electronically sets the speed of the feedscrew 
motor 60. The feedscrew motor 60 drives a gear box 68. 
Positive drive timing belts 63 are used to deliver the rotational motion 
from the gear box 68 to the feedscrews. The positively engaged timing 
belts 63 ma be replaced by chains and gears or other drive means for 
turning the feedscrews. 
An adjustable arm 64 supports a hub 66 on which the first feedscrew is 
mounted. At the base of the arm 64 is a gear box 68 for providing the 
rotational motion to the first feedscrew 18. A second arm 70 is mounted 
for supporting a hub 72 in which the second feedscrew 22 is mounted. A 
gear box 74 is mounted at the base of the second adjustable arm 70. The 
gear boxes 68 and 74 are connected by a drive shaft 76. The drives of the 
feedscrews 18 and 22 are coupled through to the feedscrew motor 60. The 
first feedscrew 18 and the second feedscrew 22 are both turned at the same 
speed so that the same groups of flat articles are moved along the 
conveyor at the same speed and are equally supported through their 
conveyance until they reach the downstream end of the feed apparatus. 
The downstream adjustable arms 64 and 70 are connected by crossbars 34 and 
36 to the upstream adjustable arms so that the hubs that they support are 
maintained in alignment. As with the upstream arms, the downstream arms 
may be provided with manual mechanical adjustments for changing the 
location of the feedscrew or an electronic robotic linkage may be provided 
for automatic location adjustments. The adjustable arms provide freedom of 
movement in two dimensions relative to the conveyor so that the feedscrews 
can be arranged to best support the flat articles so that they do not flop 
over. It is recommended that the two feedscrews each be positioned for 
insertion into a different edge of the flat articles. In FIG. 2, feedscrew 
18 is inserted along the left hand edge while feedscrew 22 is inserted 
along the top edge. 
The feeding operation shall now be described. Boxes of cartons in their 
collapsed state are loaded onto the conveyor belt 12. Thus, a horizontal 
line of flat articles 16 supported on their edge are moved by the conveyor 
12. The flat sides of the flat articles face one another. The rear 
restraining stand 14 is repeatedly removed from the conveyor and pulled 
back so that additional boxes of flat cartons can be added to the 
conveyor. The conveyor 12 moves the flat articles toward the feedscrews 18 
22. As the conveyor moves the articles between the two feedscrews the 
threads of the feedscrews insert between adjacent flat articles. Groups of 
several flat articles are conveyed between consecutive insertions of the 
helical threads of the feedscrews. The rotational speeds of the feedscrews 
are equal to one another and are coordinated so as to be functionally 
related to the speed of the conveyor so that the flat articles 16 are 
smoothly moved along between the feedscrews and upon the conveyor. The 
flat articles are supported in groups between consecutive insertions of 
the helical threads of the feedscrews. At the downstream end of the 
feedscrews, the pickoff apparatus removes the flat articles one at a time 
from the conveyor. The controller 58 sets the pickoff speed in articles 
per minute to correspond to the linear speed of the conveyor and the 
number of articles per length of conveyor. The feedscrews have 
advantageously maintained the articles in substantially vertical position 
despite the line pressure exerted against these articles as they are moved 
along. The articles remain vertical long enough so that the pickoff 
apparatus with its suction cups can attach to the vertical surface of the 
articles and remove them one at a time from the downstream end of the 
conveying apparatus. 
Of course, it should be understood that various changes and modifications 
to the preferred embodiment described above will be apparent to those 
skilled in the art. For example, the feedscrews may be mechanically linked 
to the drive for the conveyor belt. The positions of the feedscrews can be 
adjusted to accommodate different size and shape articles. These and other 
changes can be made without departing from the spirit and scope of the 
invention and without diminishing its attendant advantages. It is 
therefore, intended that such changes and modifications be covered by the 
following claims.