A vacuum deadplate is provided which has a surface with a low coefficient of friction and spaced longitudinal slots through which a vacuum can be drawn. The vacuum deadplate can be used in conjunction with a vacuum transfer device or a palletizing device and the position of the vacuum plenum slot under the longitudinal slots can be varied to provide optimum results.

FIELD OF THE INVENTION 
This invention relates to a vacuum deadplate and more particularly to a 
vacuum deadplate for use in assisting in the transfer of containers from a 
mass conveyor to a vacuum transfer device or a palletizer. 
BACKGROUND ART 
Deadplates are commonly used at the transition point from a first mass 
conveyor running at one predetermined speed and a second mass conveyor 
running at a second but higher speed in order to obtain separation of the 
containers or articles on the conveyor. This is particularly necessary 
when the next conveyor which the containers will encounter is a vacuum 
conveyor which will lift the containers up and transport them to another 
station. The reason for the necessity for speed change is to provide 
longitudinal separation of the articles so that each properly oriented 
article will be drawn by the vacuum against the vacuum transfer device, 
rather than being held by adjacent cans due to the Coanda Effect, which is 
the wall attachment effect caused by a stream of fast moving air, moving 
along a surface creating a partial vacuum which tends to draw any adjacent 
articles toward that surface. While the structure just described is 
satisfactory for its intended purposes, one of the disadvantages is that 
it requires substantial room within the plant for the higher speed 
conveyor and in some plant arrangements, there is simply not enough room 
for including a second conveyor. The prior art arrangement just described 
is illustrated in U.S. Pat. No. 3,664,483 to Revaz for "Method of and 
Apparatus For Releasing Objects to a Transporting Device". 
A conventional vacuum transfer device for conveying containers from one 
elevation to another is disclosed in U.S. Pat. No. 4,136,767 to Sarovich 
entitled "Vacuum Operated Can-Conveying and Can-Uprighting Apparatus". In 
this device there is no longitudinal separation of the containers at all. 
Thus, if one of the containers is held by the other containers due to the 
Coanda Effect rather than being held by the vacuum, as the containers move 
around the drum, the weight of the container which is not held by the 
vacuum may be sufficient to dislodge other containers and cause them to 
fall off of the vacuum transfer device. 
A vacuum transfer apparatus for transferring containers which have already 
been separated longitudinally is shown in U.S. Pat. No. 4,146,467 to 
Sauer, et al., entitled "Apparatus for Detecting and Rejecting Downed and 
Damaged Containers". Thus, in order for this device to operate 
satisfactorily, there must be provided between the mass conveyor and this 
device a conveyor which accelerates the containers to provide the 
necessary longitudinal separation. 
Another vacuum transfer device is shown in my U.S. Pat. No. 4,560,060 for 
"Vacuum Belt Conveyor". In this device, the containers are supplied to the 
vacuum transfer belt from a mass conveyor in which the containers are in 
contiguous relationship. The vacuum transfer conveyor operates at a higher 
speed than the mass conveyor thereby separating the containers as they are 
moved to a downstream conveyor. The purpose of this separation is to allow 
the misaligned and damaged containers to be discharged from the apparatus. 
The device works well for its intended purpose. However, under certain 
operating conditions, and particularly when the containers are supplied 
with the open end down, it is possible for a leading container, as it is 
being drawn up to the vacuum belt, to pull with it one or more trailing 
containers because of the Coanda Effect whereupon those containers will 
not be held against the vacuum belt by the vacuum but will tend to fall 
off. If the containers have not been necked or flanged, the open mouth has 
a raw edge. When they are being fed with the open mouth down, as they are 
lifted from the conveyor belt to a faster moving transfer belt, the edge 
of the open mouth of the container may "trip" on the conveyor belt and tip 
over or jam which will cause subsequent containers also to be tipped over. 
Another vacuum conveyor is shown in my co-pending and commonly owned U.S. 
application Ser. No. 663,178 filed Oct. 22, 1984 for "Curved Vacuum 
Transfer Conveyor", now abandoned, wherein containers are transferred from 
a mass conveyor to a curved vacuum conveyor which picks up the containers 
and carries them around a curved plenum to a discharge conveyor at a 
different elevation. With this apparatus the same difficulties just 
described above can occur. As the leading containers are lifted by the 
vacuum transfer belt, the upstream containers, trailing on the mass 
conveyor belt can be drafted along with the leading containers due to the 
Coanda Effect. Thus, the leading containers are drawn tightly against the 
vacuum transfer belt, whereas the trailing containers may not. This is a 
particularly troublesome problem with highly etched bright containers 
because of the high coefficient of friction between the surfaces of the 
containers causes them to tend to stick together. As a result, as the 
containers move around the belt, the weight of the unattached trailing 
containers can cause them to fall away and pull with them additional 
containers so that they are not properly transferred to the next 
downstream station. Furthermore, if the mouths of the containers are down, 
they can trip on the conveyor belt as they are drafted forwardly causing 
them to tip over and causing other containers approaching from behind to 
be tipped over or otherwise disrupted from their normal path of travel. 
A vacuum alignment device is provided in U.S. Pat. No. 3,352,404 to Di 
Settembrini, entitled "Devices for Stabilizing Light Objects on Conveyor 
Belts" wherein articles are dropped onto a moving conveyor belt from above 
the belt and a vacuum device is provided to hold the containers in upright 
condition and to bring them into single file alignment through a guide 
means. This device is not intended to align containers on a mass conveyor 
prior to being lifted by a vacuum conveyor. 
A form of vacuum deadplate is shown in my co-pending and commonly owned 
U.S. patent application Ser. No. 700,748 filed Feb. 12, 1985, entitled 
"Vacuum Single Filer", now U.S. Pat. No. 4,669,604. However, this vacuum 
deadplate is for the purpose of helping discharge aligned diagonal rows of 
containers from a mass conveyor in a precise predetermined alignment so 
that they can be brought into single file alignment along a subsequent 
vacuum belt. The vacuum deadplate shown therein is not used to hold the 
containers in a particular alignment prior to being lifted up by a vacuum 
transfer conveyor belt. 
It is often desirable to move containers from a mass conveyor onto pallets 
in parallel nested rows in contiguous relationship. One such device for 
accomplishing this arrangement is shown in U.S. Pat. No. 3,300,065 to 
Witmer, entitled "Means for Material Handling". The containers move from a 
mass conveyor past converging sidewalls which direct the containers into a 
palletizing area. The containers move to the distal end of the palletizing 
area where they are retained by a vertical wall. Succeeding containers 
move in behind the first containers and fill up the area until the pallet 
layer is full. One of the difficulties with this arrangement is that 
sometimes all of the open areas will not be filled in and containers will 
be missing from one or more locations in a pallet layer when the last row 
has been filled in. This is caused because the containers do not readily 
move past each other into the vacant spaces, particularly when the 
containers have a bright finish which creates a lot of friction between 
the surfaces of adjacent containers. 
DISCLOSURE OF THE INVENTION 
In accordance with this invention, a vacuum deadplate is provided for 
holding articles in a predetermined pattern as they are moved from a mass 
conveyor at an upstream location to a downstream location. The vacuum 
deadplate comprises a flat metal plate extending transversely across the 
discharge end of the mass conveyor. Spaced openings are located across the 
plate and means for drawing a vacuum through the plate openings are 
provided so that the articles are held in precise fixed alignment for 
further work to be performed on them at the downstream location as they 
are pushed across the plate by other articles on the mass conveyor. The 
spaced openings may be longitudinal slots and means may be provided to 
longitudinally adjust the position of the vacuum drawing means under the 
slots. The vacuum drawing means includes a transversely mounted plenum 
under the plate and a transverse slot in the plenum extending transversely 
under a portion of each of the longitudinal slots. The plate has a surface 
whose coefficient of friction is low with respect to the articles, so that 
the articles slide easily thereacross and do not trip. 
In one form of the invention, an overhead vacuum pickup station is provided 
at the downstream location to transfer the articles from the vacuum 
deadplate. Means may be provided to longitudinally adjust the position of 
the transverse slots below the longitudinal slots to provide the optimum 
pickup point for the vacuum pickup station. 
In another form of the invention, converging side guide rails are provided 
at the deadplate for bringing the articles into contiguous nested rows. A 
palletizer can be provided at the downstream location which includes a 
slip sheet for receiving the articles and guide means above the slip sheet 
for holding the contiguous nested rows of articles together after they 
pass by the converging guide rails. 
When the present invention is used with a vacuum pickup station, the vacuum 
deadplate assures that the trailing articles do not get drafted along with 
the leading articles which are being drawn up to the vacuum deadplate 
resulting in the likelihood that they will drop off the vacuum 
transferring means, possibly stripping other containers from the vacuum 
transfer device. This drafting of the trailing articles is caused by the 
Coanda Effect and also by the movement of air in the direction of the 
movement of containers into the vacuum transfer plenum. 
When the deadplate of this invention is used with a palletizer, the 
deadplate, together with the converging side guides, serves to bring the 
mass of containers into longitudinal contiguous nested rows so that they 
are supplied to the palletizer in a tight mass so that the possibility of 
an article being absent from one of the rows is minimized. 
Additional advantages of this invention will become apparent from the 
description which follows, taken in conjunction with the accompanying 
drawings.

BEST MODE FOR CARRYING OUT THE INVENTION 
In one form of the invention, a vacuum deadplate assembly "D" is provided 
for use with a vacuum transfer device as shown in FIG. 1. Containers are 
supplied to the deadplate assembly "D" from a mass conveyor belt 10 which 
extends around a roller 12 at the discharge end thereof. The roller is 
journaled in brackets 14 mounted on a frame 16. Articles, such as 
containers 18, are pushed by conveyor belt 10 onto the surface of 
deadplate 20. The surface of deadplate 20 is made such that the 
coefficient of friction between it and the open end of containers 18 is 
very low so that the containers will slide across the deadplate without 
tending to trip. It has been found that by making the deadplate of 
stainless steel and polishing it to a high degree such a low coefficient 
of friction can be obtained. 
The deadplate includes a plurality of longitudinal slots 22 spaced 
laterally across the deadplate. Below deadplate 20 is an adjustable vacuum 
plenum 24 which includes a transverse slot 26. A vacuum is drawn in the 
vacuum plenum 24 by means of a suitable fan (not shown) as through an 
exhaust tube 28. As illustrated in FIG. 1, the vacuum plenum includes 
support pins 30 mounted in guideways 32 of deadplate 20 which support the 
plenum for longitudinal adjustment in the upstream or downstream direction 
with respect to longitudinal slots 22. The adjustment is accomplished by 
means of a threaded rod 34 which extends through a threaded sleeve 36 on 
the bottom of vacuum plenum 24 and is journaled in mounts 38 and 40, as 
shown. The threaded rod may be rotated by means of handle 42 attached to 
the extending end thereof. 
As illustrated, the overhead vacuum transfer station "T" includes a curved 
vacuum plenum 44 having spaced longitudinal slots 46 through which air is 
drawn. A transfer belt 48 extends along the surface of plenum 44 and 
around a roller 50. This belt has longitudinal rows of openings 52 through 
which air is drawn into slots 44 for lifting and holding the containers to 
transfer them from one location to another. As will be apparent, when air 
is drawn into the plenum, some of the drawn air will move across the top 
of the containers in the direction of arrows 52. Thus, in the absence of 
vacuum deadplate assembly "D" this movement of air would tend to draft the 
containers downstream. Also, because of the Bernoulli Principal, as 
leading containers are picked up by the vacuum belt, trailing containers 
also will tend to be drafted along with the leading container and held 
thereagainst due to the rapid vertical movement of air between the 
containers as illustrated by arrow 54. 
However, with the present invention, the air being drawn through 
longitudinal slots 22 in plate 20 hold the trailing containers in fixed 
position as the leading container, such as container 18a is picked up by 
transfer belt 48. Also, transfer belt 48 can run at a higher speed than 
mass conveyor belt 10 so that longitudinal spacing of the containers 
occurs to further minimize the drafting of one container against another. 
Because of the vacuum drawn by the vacuum deadplate assembly "D" and the 
constraint of vertically spaced side rails 56, the containers 18 are held 
in a tightly nested configuration, as best seen in FIG. 4, as they are 
pushed across the deadplate by conveyor belt 10. As the leading containers 
are pushed beyond slots 22, they will be lifted onto the vacuum transfer 
belt 48 in a uniform spaced pattern. 
It will also be noted that because of the air being drawn through vacuum 
transfer belt 48 along its length, the containers will tend to be moved 
toward the low pressure, which is at the center of the belt in accordance 
with the Bernoulli Principal. This can be observed in FIG. 4 wherein 
downstream containers 18b have moved inwardly away from side rails 56 as 
compared to their upstream counterparts. With this arrangement, there is 
less possibility that the leading containers will drag on the side rails 
into close proximity with the trailing containers so that they will be 
drafted against the leading containers. 
The arrangement just described is clearly distinguishable over the prior 
art arrangement shown in FIG. 3 wherein a trailing container 18c is 
depicted as being adhered to a leading container 18 due to the Bernoulli 
Principal so that its mouth is not against conveyor belt 48. Thus, as this 
container moves around plenum 44, it may be pulled away from container 18 
by the force of gravity, as indicated by arrow 57, and therefore strip 
additional containers below it from the belt as it falls. Furthermore, as 
the closely packed containers move around the curvature of belt 48, 
container 18c will pry container 18d off of the belt and cause it to fall, 
as illustrated by arrow 58. 
Although, the vacuum transfer device has been illustrated as a curved 
vacuum conveyor, it will be understood that the invention will work 
equally well with a flat vacuum transfer conveyor. 
The present invention also has utility with a palletizing assembly "P" as 
shown in FIGS. 7 and 8. For shipping, containers are placed in nested rows 
on slip sheets, such as slip sheets 60 shown in FIG. 7 for stacking and 
packaging for transportation from a container manufacturing plant to a 
canning plant. The slip sheets 60 are made of a liquid impervious material 
of low coefficient of friction, such as Teflon and provide a support for 
and a spacer between stacked pallet layers of containers. In a 
conventional palletizing apparatus, the containers are allowed to move 
onto the pallet randomly and to fill in the spaces until the pallet is 
full. Unfortunately, sometimes all of the spaces are not filled and there 
are open areas in the pallet which contain no containers. These open 
spaces result in additional packaging and transportation costs which can 
be minimized by the use of the present invention. 
As best seen in FIG. 8, with the present invention the deadplate causes the 
containers on conveyor belt 10 to be backed up and because of the spacing 
of guide rails 64, the empty spots can be filled in, such as by container 
18e moving downstream as indicated by arrow 66, whereupon the side rails 
have a converging portion 68 over deadplate 20 which brings the containers 
into tightly nested configuration whereupon they are pushed onto slip 
sheet 60 and held in the nested configuration by the pallet side guide 70 
and end rail 72 to form a full pallet layer. 
From the foregoing the advantages of this invention are readily apparent. 
In one form of the invention the vacuum deadplate is used in conjunction 
with a vacuum transfer device for holding the trailing containers so that 
they are not drafted forward by the Coanda Effect or by the flow of air 
into the vacuum transfer device, with a leading container which is being 
picked up by the vacuum transfer device. The vacuum plenum is adjustable 
under slots in the vacuum deadplate to precisely position the vacuum under 
the articles so that maximum results are obtained. In addition, the 
articles are longitudinally and laterally spaced by the differential speed 
of the belt and the nesting of the containers as they move across the 
deadplate. 
In another embodiment, the vacuum deadplate of this invention is used with 
a palletizing apparatus wherein the containers are caused to be nested by 
converging side guides above the vacuum deadplate which brings the 
containers into tightly packed contiguous rows so that the possibility of 
open spaces not being filled with containers is minimized. 
This invention has been described in detail with reference to particular 
embodiments thereof, but it will be understood that various other 
modifications can be effected within the spirit and scope of this 
invention.