U.S. patent number 3,731,782 [Application Number 05/151,218] was granted by the patent office on 1973-05-08 for magnetic flow director.
This patent grant is currently assigned to Hi-Speed Checkweigher Co., Inc.. Invention is credited to Victor Del Rosso.
United States Patent |
3,731,782 |
Del Rosso |
May 8, 1973 |
MAGNETIC FLOW DIRECTOR
Abstract
A magnetic flow director for use in combination with an article
conveyor movable along a pre-determined path and having at least
one article carrier supported by the conveyor for independent
movement thereon under the influence of magnetic attraction
transversely of the path. In a preferred form, the director
includes a permanent magnet and a selectively operable
electromagnet for deflecting the carrier transversely of the path
for attractive engagement with a guide surface of the permanent
magnet; such guide surface being characterized as including
upstream and downstream surface portions relative to the direction
of conveyor movement. The upstream portion is arranged for initial
magnetic engagement by the deflected article carrier and extends
substantially co-directionally with the path, and the downstream
surface portion extends from the upstream surface portion in a
diverging direction relative to the direction of conveyor movement.
The electromagnet includes a guide surface terminating in a
relatively downstream surface portion arranged in alignment with
the upstream surface portion of the permanent magnet guide
surface.
Inventors: |
Del Rosso; Victor (Ithaca,
NY) |
Assignee: |
Hi-Speed Checkweigher Co., Inc.
(Ithaca, NY)
|
Family
ID: |
22537811 |
Appl.
No.: |
05/151,218 |
Filed: |
June 9, 1971 |
Current U.S.
Class: |
198/439; 198/350;
198/849; 198/890.1 |
Current CPC
Class: |
B65G
17/005 (20130101); B65G 47/844 (20130101); B65G
2201/02 (20130101) |
Current International
Class: |
B65G
17/00 (20060101); B65g 047/26 (); B65g
047/00 () |
Field of
Search: |
;198/31AA,41,31R,31AN |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Aegerter; Richard E.
Assistant Examiner: Lane; Hadd S.
Claims
I claim:
1. In a mechanism comprising a conveyor movable along a
predetermined path, at least one article carrier supported by said
conveyor for independent movement thereon transversely of said
path, continuously operable magnetic means fixed adjacent said
conveyor and having an elongated guide surface arranged to extend
from adjacent one region of said conveyor in a diverging direction
relative to the direction of movement of said conveyor into another
region spaced transversely of said path from said one region, each
said carrier having a portion attractable by said magnetic means
upon engagement of said carrier therewith, and selectively operable
means for deflecting said carrier transversely of said path from a
line of travel within said one region for engagement with said
guide surface adjacent said one region, said magnetic means tending
to magnetically constrain said carrier when engaged for movement
along said guide surface from said one region to said other region
upon movement of said conveyor along said path, the improvement in
combination wherein:
said guide surface includes upstream and downstream surface
portions relative to the direction of conveyor movement, said
upstream surface portion being arranged adjacent said one region
for initial magnetic engagement by said deflected carrier and
extending substantially co-directionally with said path, the
distance between said upstream surface portion and said attractable
portion of said carrier when moving along said line of travel being
sufficient to prevent said magnetic means from magnetically
attracting said attractable portion thereto, and said downstream
surface portion extending from said upstream surface portion in a
diverging direction relative to the direction of conveyor movement
into said other region.
2. The improvement according to claim 1, wherein said magnetic
means is a permanent magnet device, said guide surface is defined
by at least one pole piece of said magnet device, and said
attractable portion is a roller journalled on said carrier and
engageable with said pole piece.
3. The improvement according to claim 1, wherein separator means is
arranged adjacent said magnet means intermediate opposite ends of
said downstream portion of said guide surface for selectively
separating said carrier from engagement therewith in at least one
further region intermediate said one and said other regions.
4. The improvement according to claim 3, wherein means are provided
to adjustably position said separator means lengthwise of said
downstream portion of said guide surface thereby to vary the
spacing of said further region from said one region in a direction
transversely of said path.
5. The improvement according to claim 3, wherein said separator
means includes a non-magnetic member and means to selectively move
said member into the path of movement of said carrier along said
guide surface thereby to disengage said carrier therefrom in said
further region.
6. In a mechanism comprising a conveyor movable along a
predetermined path, at least one article carrier supported by said
conveyor for independent movement thereon transversely of said
path, a pair of continuously operable magnetic means fixed adjacent
said conveyor and having elongated guide surfaces arranged to
extend from adjacent opposite sides of said one region of said
conveyor in directions outwardly diverging relative to the
direction of movement of said conveyor into other regions spaced
transversely of said path from said one region, means upstream of
said magnetic means in the direction of conveyor movement for
positioning said carrier for movement along a line of travel within
said one region substantially equally spaced transversely of said
path from said magnetic means, each said carrier having a portion
attractable by said magnetic means upon engagement of said carrier
therewith, and selectively operable means for deflecting said
carrier transversely of said path from said line of travel for
positioning said attractable portion thereof in engagement with
said guide surface of a selected one of said magnetic means
adjacent said one region, said selected one of said magnetic means
tending to magnetically constrain said carrier when engaged for
movement along said guide surface thereof transversely of said path
from said one region into an associated other region upon movement
of said conveyor along said path, the improvement in combination
wherein:
each of said guide surfaces include upstream and downstream surface
portions relative to the direction of conveyor movement, said
upstream surface portions being substantially parallel and arranged
adjacent opposite sides of said one region for initial magnetic
engagement by said deflected carrier and extending substantially
co-directionally with said path, the distance between each said
upstream surface portion and said attractable portion of said
carrier when moving along said line of travel being sufficient to
prevent said magnetic means from magnetically attracting said
attractable portion thereto, and said downstream surface portions
extending from said upstream surface portions associated therewith
in a relatively diverging relationship in the direction of conveyor
movement into said other regions.
7. A mechanism according to claim 6, wherein each said magnetic
means is a permanent magnet device and each said guide surface is
defined by at least one pole piece of one of said magnet
devices.
8. A flow directing mechanism comprising in combination:
a conveyor movable along a predetermined path;
at least one article carrier supported by said conveyor for
independent movement thereon transversely of said path, said
article carrier having a magnetically attractable portion;
at least one magnet device fixed adjacent said conveyor, said
device defining an elongated guide surface having upstream and
downstream surface portions relative to the direction of conveyor
movement, said upstream surface portion being arranged adjacent one
region of said conveyor and extending substantially
co-directionally with said path, said downstream portion extending
from said upstream surface portion in a diverging direction
relative to the direction of conveyor movement into another region
spaced transversely of said path from said one region, said device
attracting said portion of said article carrier upon engagement of
said carrier with said guide surface, whereby to magnetically
constrain an engaged carrier for movement along said guide surface
from said one region to said other region upon movement of said
conveyor along said path; and
at least one electromagnetic means fixed adjacent said conveyor
relatively upstream of said device, said electromagnetic means
including a guide surface, said electromagnetic means being
selectively operable to attract said portion of said article
carrier for deflecting said carrier transversely of said path into
engagement with said guide surface thereof, a relatively downstream
portion of the last said guide surface being arranged in alignment
with said upstream surface portion in the direction of conveyor
movement.
9. A mechanism according to claim 8, wherein said electromagnetic
means guide surface also includes upstream and intermediate surface
portions, said upstream and downstream surface portions of said
electromagnetic means being arranged in a spaced and substantially
parallel relationship, and said intermediate surface portion being
of double curvature configuration.
10. A mechanism according to claim 8, wherein said electromagnetic
means guide surface also includes an upstream surface portion and
an intermediate surface portion joining said upstream and
downstream surface portions thereof, said upstream and downstream
surface portions of said electromagnetic means being arranged in a
spaced substantially parallel relationship, and wherein a plurality
of article carriers are provided in combination, said article
carriers being spaced apart in the direction of conveyor movement
and the distance between said portions of adjacent article carriers
is equal to or greater than the length of said intermediate surface
portion measured in a direction aligned with said path of conveyor
movement.
11. A mechanism according to claim 8, wherein a pair of magnet
devices and a pair of electromagnetic means are provided in
combination, said upstream surface portions of said devices being
arranged in substantially parallel relationship and adjacent
opposite sides of said one region, said downstream surface portions
of said devices being arranged in relatively outwardly diverging
relationship in the direction of conveyor movement, and said pair
of electromagnetic means being selectively operable for deflecting
said carrier transversely of said path for engagement with a
selected one of said upstream surface portions of said devices.
12. A mechanism according to claim 11, wherein said guide surface
of each said electromagnetic means also includes an upstream and an
intermediate surface portion joining said upstream surface and said
downstream portions thereof, said upstream and downstream surface
portions of each said electromagnetic means being arranged in a
spaced and substantially parallel relationship, the spacing between
said downstream surface portions of said pair of electromagnetic
means being greater than the spacing between said upstream surface
portions thereof; and wherein a plurality of article carriers are
provided in combination, said article carriers being spaced apart
in the direction of conveyor movement and the distance between said
portions of adjacent article carriers is equal to or greater than
the length of said intermediate surface portion measured in a
direction aligned with said path of conveyor movement.
13. A mechanism according to claim 8, wherein at least one
separator means is arranged adjacent said magnet device
intermediate opposite ends of said guide surface downstream portion
thereof for selectively separating said carrier from engagement
therewith in at least one further region intermediate said one and
said other regions.
14. A mechanism according to claim 13, wherein said separator means
is adjustable lengthwise of said guide surface downstream portion
thereby to vary the spacing of said further region from said one
region in a direction transversely of said path.
15. A mechanism according to claim 8, wherein said magnet device is
a permanent magnet, and a plurality of groups of said magnet
devices and electromagnetic means are provided in combination and
said groups are arranged serially of said path of travel, said
downstream surface portion of a magnet device of a first of said
groups delivering into said other region, said electromagnetic
means of a second of said groups being selectively operable for
deflecting said carrier presented in said other region transversely
of said path in a direction away from said one region for
engagement with said upstream guide surface portion of its
associated magnet device.
16. A mechanism according to claim 8, wherein adjacent ends of said
upstream surface portion and said downstream portion of said last
said guide surface are spaced apart in the direction of conveyor
movement.
17. A mechanism according to claim 16, wherein said magnet device
is a permanent magnet device.
18. In a mechanism comprising a conveyor movable along a
predetermined path, at least one article carrier supported by said
conveyor for independent movement thereon transversely of said
path, magnetic means fixed adjacent said conveyor and having an
elongated guide surface arranged to extend from adjacent one region
of said conveyor in a diverging direction relative to the direction
of movement of said conveyor into another region spaced
transversely of said path from said one region, each said carrier
having a portion attractable by said magnetic means upon engagement
of said carrier therewith, whereby upon engagement of said carrier
with said guide surface adjacent said one region said magnetic
means tends to magnetically constrain said carrier for movement
along said guide surface from adjacent said one region to said
other region upon movement of said conveyor, the improvement
comprising:
at least one separator means arranged intermediate opposite ends of
said guide surface, said separator means being selectively operable
to separate said carrier from engagement with said guide surface in
a further region arranged intermediate said one and said other
regions.
19. A mechanism according to claim 18, wherein said separator means
is adjustable lengthwise of said guide surface thereby to vary the
spacing of said further region from said one region in a direction
transversely of said path.
20. A mechanism according to claim 18, wherein said separator means
includes a non-magnetic member and means to selectively move said
member into the path of movement of said carrier along said guide
surface thereby to disengage said carrier therefrom in said further
region.
21. A flow directing mechanism comprising in combination:
an endless conveyor movable along a predetermined path and having
upper and lower runs;
a plurality of article carriers spaced apart in the direction of
said path and supported by said conveyor for independent movement
thereon transversely of said path, each said carrier having a
magnetically attractable portion;
a magnet device extending along one of said runs and defining an
elongated guide surface having upstream and downstream surface
portions relative to the direction of conveyor movement, said
upstream surface portion being arranged adjacent one region of said
conveyor and extending substantially co-directionally with said
path, said downstream portion extending from said upstream surface
portion in a diverging direction relative to said path into a
discharge region spaced transversely of said one region, said
device attracting said portion of said carrier upon engagement of
said carrier with said guide surface whereby normally tending to
magnetically constrain said engaged carrier for movement along said
guide surface from adjacent said one region to said discharge
region upon movement of said conveyor along said path;
at least one separator means for separating selective ones of said
carriers from engagement with said guide surface in a further
discharge region spaced from said discharge region in a direction
transversely of said path towards said one region, whereby to
selectively establish at least two lines for travel of said
carriers along said one run of said conveyor downstream of said
magnet device; and
means including means arranged along an other of said runs for
gathering together said carriers traveling along said lines of
travel into a single line and for positioning at least some of said
carriers from said single line in engagement with said upstream
portion of said guide surface.
22. A mechanism according to claim 21, wherein said magnet means
extends along said upper run thereby to permit said mechanism to be
employed to diverge articles passing along a single input
selectively into at least two essentially parallel outputs, said
input being substantially aligned with said single line, and said
outputs being substantially aligned with said carrier lines of
travel.
23. A mechanism according to claim 21, wherein said magnet means
extends along said lower run thereby to permit said mechanism to be
employed to converge articles passing along at least two inputs
into a single output, said inputs being substantially aligned with
said carrier lines of travel and said output being substantially
aligned with said single line.
24. A mechanism according to claim 21, wherein said means for
positioning carriers in engagement with said magnet means includes
means selectively operable to displace said carriers transversely
of said conveyor path of travel from said single line for
engagement with said upstream portion of said guide surface,
carriers not displaced from said single line passing along said one
run along a third line of travel parallel to said two lines of
travel.
25. A mechanism according to claim 21, wherein said means for
positioning carriers positions all of said carriers in said single
line for engagement with said upstream portion of said guide
surface, and said separator means is arranged to separate carriers
at the junction of said upstream and downstream surface portions,
whereby said further discharge region is said one region and one of
said lines of travel is aligned with said single line.
26. A flow directing mechanism comprising in combination:
an endless conveyor movable along a predetermined path and having
upper and lower runs:
a plurality of article carriers spaced apart in the direction of
said path and supported by said conveyor for independent movement
thereon transversely of said path, each said article carrier having
a magnetically attractable portion;
means arranged along one of said runs for positioning all of said
attractable portions of said carriers in one region of said
conveyor when presented adjacent one end of said conveyor;
selectively operable electromagnetic means arranged along another
of said runs for attracting said attractable portion of selected
ones of said carriers for deflecting same from said one region
transversely of said path during passage thereof along said other
run, said electromagnetic means including a guide surface
engageable by said deflected carriers, at least a downstream end
portion of said guide surface relative to the direction of conveyor
movement being co-directional with said path of travel and being
spaced transversely of said conveyor relative to the path of travel
of non-deflected ones of said carriers; and
a magnet device extending along said other run downstream of said
electromagnetic means in the direction of conveyor movement, said
magnet device including an elongated guide surface engageable by
said deflected carriers, said guide surface of said device
including an upstream surface portion arranged in alignment with
said downstream end portion of said electromagnetic means in the
direction of conveyor movement and a downstream surface portion
extending from said upstream surface portion thereof in a diverging
direction relative to the direction of conveyor movement into an
other region spaced transversely of said path from said one region,
said magnet device attracting said attractable portion of said
deflected carriers for further deflecting same transversely of said
path away from said one region towards said other region when in
engagement with said guide surface thereof.
27. A mechanism according to claim 26, wherein said electromagnetic
means is arranged along said upper run thereby to permit said flow
directing mechanism to be employed to diverge articles passing
along a single input into at least two essentially parallel
outputs, said input delivering articles onto carriers arranged
within said one region adjacent said one end of said conveyor, and
each of said outputs receiving articles from carriers arranged
within one of said one region and said other region adjacent an
opposite end of said conveyor.
28. A mechanism according to claim 26, wherein said electromagnetic
means is arranged along said lower run thereby to permit said flow
directing mechanism to be employed to converge articles passing
from at least two essentially parallel inputs into a single output
during passage of said carriers along said upper run from an
opposite end of said conveyor towards said one end thereof, each of
said inputs being arranged to deliver articles onto carriers
presented within one of said one region and said other region
adjacent said opposite end of said conveyor, and said output being
arranged to receive articles from said carriers presented within
said one region adjacent said one end of said conveyor, each of
said inputs including gate means operable for discharging articles
onto said carriers when presented thereto, and there is further
provided in combination control means for controlling operation of
said electromagnetic means and said gate means whereby said
carriers are presented successively to said inputs and said gate
means are operated to deliver articles onto said presented
carriers.
Description
BACKGROUND OF THE INVENTION
This invention relates to flow directing mechanisms having use as
by way of example in machines of the general type disclosed by U.S.
Pat. No. 3,167,171.
In U.S. Patent 3,167,171 there is disclosed a machine for rejecting
packages determined by a checkweigher to be above or below a
prescribed weight. The machine includes an endless conveyor having
transverse guide rods on which article carriers are slideably
mounted for independent movement transversely of the path of
conveyor travel. Each of the article carriers is provided with a
roller formed of a ferro-magnetic material. At the entrance end of
the conveyor, all of the carriers are centered relative to the
conveyor for passage of their rollers between a pair of spaced or
opposing electromagnets. Whenever a package presented adjacent the
electromagnets is either underweight or overweight, an apporpriate
electromagnet is energized by a signal from the checkweigher in
order to attract the roller of such carrier and thereby deflect it
transversely of its normal path of travel into engagement with an
associated one of a pair of diagonally extending elongated
permanent magnets. When the electromagnet is deenergized, the
roller continues to follow the permanent magnet with which it had
been placed in engagement, whereby its carrier is deflected or
progressively moved away from the central region of the conveyor as
the conveyor advances.
Thus, in the machine of U.S. Pat. No. 3,167,171, articles delivered
from the checkweigher pass centrally along the machine if they are
of a correct weight, but are deflected to one side or the other if
they are of an incorrect weight. The articles are suitably removed
from the carriers adjacent the outlet end of the machine and the
empty carriers are centered relative to the conveyor during
movement thereof towards the entrance end of the machine by cam
elements arranged beneath the permanent magnets.
Tests performed on actual commercial machines manufactured in
accordance with the teachings of U.S. Pat. No. 3,167,171 reveal
that the reject mechanism thereof is only operable with any degree
of reliability when articles being transported by the carriers are
very light in weight. Repeated failures were even encountered with
unloaded carriers for conveyor speeds above about 100 feet per
minute. As will be readily appreciated, these performance
limitations are decided drawbacks in view of the varied weight and
high speed requirements of the package and article handling
industry, and appear to have prevented wide commercial acceptance
of the machine.
Repeated tests of the rejection mechanism have revealed that the
reason for its failure to perform satisfactorily is due to the gap,
which is necessarily provided between adjacent ends of the roller
guide surfaces of the electromagnet and permanent magnet in order
to prevent magnetic coupling therebetween. The gap causes a
reduction in the magnetic force available for transferring the
roller of a selected carrier to the permanent magnet at a point
where the permanent magnet is attempting to attract the roller for
movement along a path diverging relative to the path along which
the carrier is normally drawn by the conveyor. As a result, the
magnetic force availale in the area of the gap is ofttimes
insufficient to move the carrier transversely of its normal path of
travel, and the roller simply breaks away at the gap before being
positively "picked up" by the permanent magnet.
When break away occurs, the article carrier is only partially
deflected and when presented adjacent the outlet end of the machine
will likely produce an article transfer malfunction. The problem is
particularly acute when two or more adjacent carriers are employed
to support a single article. As will be apparent, if one of the
carriers is fully deflected and the other only partially deflected,
misalignment of the article relative to the direction of travel of
the conveyor or upsetting of the conveyed article will result.
Attempts to overcome the roller break away problem by increasing
the strength of the permanent magnet and/or reducing the gap as by
interfitting the pole pieces of the permanent magnet and
electromagnet have not been successful, since the resultant
coupling of the magnets produces uncontrolled deflections of
non-selected ones of the article carriers.
SUMMARY OF THE INVENTION
The present invention is directed to an improved directing
mechanism having use as by way of example in machines of the
general type described in U.S. Pat. No. 3,167,171, which insures
controlled diversion or deflection of article carriers under high
load-high speed operating conditions.
In accordance with the present invention, the above discussed
problem is eliminated by deflecting a selected article carrier into
initial engagement with a relatively upstream portion of an
elongated guide surface of the permanent magnet, which is arranged
substantially co-directionally of or parallel with the normal path
of carrier travel; the carrier being subsequently deflected during
movement along a relatively downstream surface portion of such
guide surface, which extends from the upstream surface portion in a
diverging relation to the direction of conveyor movement. This
arrangement permits the roller of the selected carrier to be
magnetically "picked up" and "locked" onto the guide surface during
a period of conveyor travel when there is no tendency to pull the
carrier away from the permanent magnet. Thereafter, the full
attractive force of the permanent magnet is available for use in
deflecting the carrier to the extent desired.
In a preferred form of the present invention, deflection of the
roller of the article carrier into engagement with the guide
surface of the permanent magnet is effected by a selectively
operable electromagnet having a novelly configured guide surface.
The guide surface of the electromagnet is arranged to be initially
engaged by a deflected carrier and terminates in a relatively
downstream surface portion arranged in alignment with the upstream
surface portion of the permanent magnet in the direction of
conveyor travel. Thus, during transfer between adjacent ends of the
guide surfaces of the electromagnet and the permanent magnet, the
carrier is merely drawn by the conveyor along a path parallel to
such guide surfaces. Accordingly, a gap of any desired width may be
provided between the adjacent ends of the guide surfaces in order
to prevent magnetic coupling of the permanent magnet and
electromagnet without adversely effecting the transfer of a carrier
therebetween.
As by way of providing a comparison, a commercially available
machine constructed in accordance with the teachings of U.S. Pat.
No. 3,167,171 was modified solely by replacing the pole pieces of
the permanent magnet and electromagnet with pole pieces configured
to define guide surfaces arranged in the manner described above.
Whereas tests with the unmodified machine showed repeated
malfunctions for unloaded article carriers at conveyor speeds over
about 100 feet per minute, no malfunctions were encountered with
the modified machine until the conveyor was driven at over 300 feet
per minute with a loading on the article carriers of up to 40
pounds per square foot.
The present invention provides for a further departure from the
machine construction disclosed in U.S. Pat. No. 3,167,171 by
arranging plural groups of electromagnets and permanent magnets
serially of the path of conveyor movement in order that a single
line of articles may be diverted into any desired number of
separate lines.
Also, division of a single line of articles into any desired number
of output lines having any desired spacing between lines may be
accomplished by a simplified form of the present construction,
wherein a plurality of selectively operable "flags" or separators
are adjustably positioned lengthwise of the permanent magnet. The
"flags," when operated, are merely projected into the path of
movement of an attracted carrier and serve to deflect such carrier
away from the guide surface of the permanent magnet.
Further, the improved construction of the present invention may be
employed in fabricating machines, which are alternatively adapted
to converge any number of separate lines into a single line by
merely inverting the machine.
DRAWINGS
The nature and mode of the present invention will be more fully
described in the following detailed description taken with the
accompanying drawings wherein:
FIG. 1 is a top plan view of a flow diverting mechanism embodying
the present invention;
FIG. 2 is an enlarged fragmentary view of the area designated as
FIG. 2 in FIG. 1 with parts removed for purposes of clarity;
FIG. 3 is a side elevational view of the mechanism shown in FIG.
1;
FIG. 4 is a sectional view taken generally along the line 4--4 in
FIG. 1;
FIG. 5 is a sectional view taken generally along line 5--5 in FIG.
1;
FIG. 6 is a view illustrating a modified construction permitting
the mechanism of FIG. 1 to divert a single line of packages into
five separate lines;
FIG. 7 is a view illustrating a modified construction permitting
the mechanism of FIG. 1 to divert a single line of packages into
four separate lines;
FIG. 8 is a view similar to FIG. 2 but illustrating a prior art
construction over which the present invention is an
improvement;
FIG. 9 is a view illustrating a modified form of the invention
employing pneumatically operated "flags" to selectively separate
diverted carriers from the permanent magnet;
FIG. 10 is an enlarged view of the area designated as FIG. 10 in
FIG. 9, but showing a solenoid operated "flag;"
FIG. 11 is a perspective view showing the mechanism of FIG. 1
inverted so as to provide a converger mechanism for bringing
together articles from two or more input lines into a single output
line of articles; and
FIG. 12 is a diagrammatic view of a control circuit having utility
in controlling the mechanism of FIG. 11.
DETAILED DESCRIPTION
For purposes of reference, the improved magnetic flow director of
the present invention, which is generally designated as 10 in the
drawings, will be described with particular reference to its use
with a checkweigher reject mechanism 12 constructed in accordance
with the teachings of U.S. Pat. No. 3,167,171. Further, for
purposes of comparison, reference will be hereinafter made to a
known flow director, which is generally designated as 10' in FIG. 8
and described in greater detail in U.S. Pat. No. 3,167,171.
Mechanism 12 is shown in the drawings as including an endless
conveyor comprising side chains 14, each of which is supported and
guided on suitable guide means 16 carried on a framework 18. As
best shown in FIGS. 1, 3 and 4, the links of chains 14 are
pivotally connected by pairs of transversely extending parallel
guide rods 20; the chains being trained over drive sprockets 22 and
idler sprockets 24 arranged at the entrance end 25a and discharge
end 25b of the conveyor, respectively. Sprockets 22 are fixedly
mounted on a transverse drive shaft 26, which is driven by any
suitable means including for instance drive sprocket 28, chain
drive 30 and an electric motor 32.
By referring specifically to FIG. 1, it will be seen that each pair
of adjacent transverse rods 20 serve to support a single article
carrier 36 for independent movement transversely of the path of
conveyor travel. While the article carriers may be of any desired
construction, they are shown as including an article supporting
plate 38 and a relatively bottom plate 40 having journaled
centrally thereon a roller 42. Roller 42 is preferably formed at
least in part of a magnetically attractable material, such as for
instance a ferro-magnetic material, which permits the roller and
thus the article carrier to be magnetically attracted to a
permanent magnet or electromagnet. While, in the arrangement
illustrated, a single carrier is employed to support an article, it
will be appreciated that ofttimes articles are of such size as to
require two or more carriers for each article.
Framework 18 is best shown in FIG. 4 as including a horizontal
partition member 46 arranged midway between the relatively upper
and lower runs of the conveyor. Fixed to the lower surface of
partition 46 in position adjacent the lower run of the conveyor are
elongated cam elements 48, which extend from the lateral
extremities of the conveyor adjacent discharge end 25b and converge
inwardly toward each other at conveyor entrance end 25a, as best
shown in FIG. 1. At the entrance end, cam elements 48 are curved
upwardly and forwardly in the direction of conveyor movement, such
as to be arranged substantially concentric with drive shaft 26, as
best shown in FIG. 5. As will be apparent, cam elements 48 are
arranged at the same elevation as rollers 42 along the lower flight
of the conveyor and adjacent the inlet end thereof. Accordingly,
each of article conveyors 36, regardless of the transverse position
in which it is disposed adjacent the discharge end of the conveyor
will be forced by engagement with the cam elements 48 to move into
the central part or region 50 of the conveyor for presentation at
the inlet end, as best shown in FIG. 1.
It will be understood that in the preferred form of the present
invention, which is illustrated in FIGS. 1, 2, 4 and 5, flow
director 10 includes a pair of continuously operable magnetic
means, such as permanent magnet devices 54, and a pair of
selectively operable electromagnets 56, which are suitably mounted
immediately below the upper run of the conveyor and on opposite
sides of region 50.
As best seen in FIGS. 4 and 5, permanent magnet devices 54 each
include an upper pole piece 62, a lower pole piece 64 and a
plurality of permanent magnets 66, which are arranged between the
pole pieces. Magnets 66 are so magnetized and oriented that one of
the pole pieces of each pair constitutes a "north" pole, while the
other constitutes a "south" pole. It will be noted that the edges
of pole pieces 62 and 64 cooperate to define a guide surface 68 for
rollers 42 and that rollers 42 are of such a length as to extend
across the edges of both pole pieces in order to complete a circuit
for maximum flux and thus achieve maximum attraction between the
parts. Thus, it will be apparent that whenever roller 42 of any of
carriers 36 is deflected or moved transversely of the conveyor into
engagement with guide surface 68 of either of permanent magnet
devices 54, the roller will be picked up and held in rolling
engagement with such guide surface during advanced movement of the
deflected carrier with the endless conveyor.
It is a particular feature of the present invention that each of
guide surfaces 68 is elongated and formed with relatively upstream
and downstream surface portions 68a and 68b, respectively. By
referring to FIGS. 1 and 2, it will be seen that upstream surface
portions 68a are arranged adjacent region 50 so as to extend
substantially co-directionally with the path of conveyor movement,
whereas downstream surface portions 68b are arranged to extend from
their associated upstream surface portions in a diverging direction
relative to the direction of conveyor movement into discharge
regions "A" and "B", which are spaced transversely of the path of
conveyor travel from central region 50. Thus, upstream surface
portions 68a are substantially parallel and the downstream portions
68b diverge relative to each other in the direction of conveyor
movement. It is to be further noted that upstream surface portions
68a are spaced apart transversely of the endless conveyor a
sufficient distance so that an article carrier positioned centrally
of the conveyor will pass therebetween without being attracted by
either sufficiently to be moved thereto. In other words, in the
absence of an additional force, the permanent magnet devices in and
of themselves cannot draw or deflect article carriers from their
central position on the endless conveyor.
Electromagnets 56 are best shown in FIG. 1 as being arranged one on
either side of central region 50 and as being disposed intermediate
conveyor inlet end 25a and permanent magnet devices 54. As will be
understood by reference to FIG. 5, each of electromagnets 56
include upper and lower pole pieces 72 and 74, respectively, which
are arranged substantially coplanar with permanent magnet device
pole pieces 62 and 64 respectively, and one or more electromagnetic
coils 76, which are arranged between each pair of pole pieces 72
and 74. As will be apparent, the edges of each pair of pole pieces
72 and 74 cooperate to define a guide surface 78 along which
rollers 42 move when magnetically deflected upon operation of their
associated coils 76.
It is also a particularly important feature of the present
invention that the electromagnet guide surfaces 78 include
relatively upstream and downstream surface portions 78a and 78b,
respectively, which are arranged parallel to one another and extend
co-directionally with the path of conveyor movement; and an
intermediate surface portion 78c formed with a double curvature
configuration. Also, by referring to FIG. 2, it will be apparent
that downstream surface portions 78b are arranged in alignment with
the upstream surface portions 68a of the permanent magnet devices,
and that the length of intermediate surface portions 78c in the
direction of conveyor travel is equal to or less than the spacing
between rollers 42 of adjacent article carriers supported for
movement by the conveyor. Preferably, upstream surface portions 78a
are parallel and arranged approximately in alignment with cam
elements 48.
In order to prevent magnetic coupling between permanent magnet
devices 54 and electromagnets 56, a gap 80 is provided between the
adjacent ends of the pole pieces, as shown in the case of pole
pieces 62 and 72 in FIG. 2.
Coils 76 may be connected to any suitable signal generating device,
not shown, so as to be energized in accordance with the signal
received. As by way of example, the signal generating device may be
associated with a checkweighing apparatus having a delivery
conveyor generally designated at 82 in FIG. 1. The checkweigher
apparatus is adapted to energize the coils of one or the other of
devices 56 in accordance with whether an article, package or the
like presented at the inlet end of the conveyor is determined to be
either overweight or underweight.
As will be obvious from the structure thus far described, articles
being delivered from the checkweigher are successively deposited on
article carriers 36 as the latter are presented adjacent the inlet
end of the conveyor and signals generated by the checkweigher
mechanism are delivered to the appropriate coil 76. For example, if
the checkweigher detects an article which is underweight, the
resultant signal will be applied to the upper or left hand
electromagnet, as viewed in FIG. 1, at the time when such article
and its carrier reaches a position between the electromagnetic
devices. As a result, pole pieces 72 and 74 of such electromagnet
are magnetized in order to draw the roller of the carriage from a
line of travel intermediate the electromagnets towards the
energized electromagnet and to hold it in engagement successively
with guide surface portions 78a, 78c and 78b, as the carrier is
advanced by the endless conveyor in order to produce an initial
deflection of the engaged roller from its normal or non-deflected
path or line of travel. The coil energizing signal is preferably
terminated immediately after the deflected roller is placed in
engagement with surface portion 78b in order to prevent the roller
of an adjacent following carrier from being unintentionally
deflected by the same signal. Even if the roller of a following
carrier is momentarily attracted by the same signal, termination of
the signal before such roller reaches intermediate portion 78c will
leave such roller located centrally of the conveyor.
After the coil energizing signal is terminated, the deflected
roller merely rolls off guide surface portion 78b and onto upstream
surface portion 68a of the associated permanent magnet device,
whereupon it is magnetically "picked up" and retained for
subsequent deflecting movement along the downstream guide surface
68b to a laterally displaced discharge region "A." It will be noted
that, due to the fact that adjacent guide surface portion 78b and
68a are in alignment and co-directional with the path of conveyor
movement, the deflected roller is transferred between such surface
portions and magnetically "locked" onto the permanent magnet,
during a period of conveyor travel wherein the deflected roller is
not subject to displacing movements in a transverse direction.
Accordingly, the presence of the necessary gap 80, which reduces
the magnetic field of permanent magnet device 54, has no influence
on the transfer of the roller.
If the article reaching the mechanism is overweight, the signal
from the checkweigher is applied to the coil of the lower or right
hand electromagnet, as viewed in FIG. 1 in order to deflect the
carrier of such overweight article to the right and to carry same
to opposite discharge region "B."
If the article reaching mechanism 12 is of a correct weight,
neither of coils 76 is energized, thereby permitting the carrier on
which the correct weight article is carried to move along a line of
travel centrally of the endless conveyor without deflection in a
transverse direction, as indicated for example at "C" in FIG.
1.
For purposes of comparison, reference is now made to FIG. 8, which
generally illustrates a magnetic flow director 10' of the type
described in U.S. Pat. No. 3,167,171. In FIG. 8, the several parts
of flow director 10', which are similar to those of flow director
10, are designated by primed numbers. By viewing FIG. 8, it will be
apparent that prior director 10' is to be distinguished from
director 10 on the basis that both of guide surfaces 78' and 68'
are configured so as to continuously diverge relative to the
direction of conveyor movement. Thus, when the signal to the coil
of an attracting electromagnet 56' is terminated, the partially
deflected roller tends to move along a path, which is parallel to
its non-deflected path or line of travel and at a small acute angle
relative to downstream end of surface 78' and thus the upstream end
of guide surface 68'. In order to maintain a minimal spacing
between rollers of adjacent carriers, it is desirable to terminate
the signal before the partially deflected roller reaches the end of
surface 78' in order to prevent unacceptable deflection of an
immediately succeeding carrier by the same signal.
When the articles being conveyed are very light in weight and the
conveyor is driven at a speed less than 100 feet per minute, the
magnetic field set up adjacent the upstream end of guide surface
68' is normally sufficient to maintain the partially deflected
roller, after it has been freed from attraction by electromagnet
56' in engagement with the downstream end of guide surface 78' for
transfer onto the upstream portion of guide surface 68'. Thus, it
will be noted that in this construction, permanent magnet 54' must
have a field strength, which is sufficiently strong to effect
transverse displacement of the roller both immediately before and
during transfer of the roller across gap 80' and onto the upstream
end of guide surface 68'. As will be apparent, the presence of gap
80' greatly reduces the field strength at the very point during
conveyor travel at which it is most needed and permits the roller
to break away at the point of transfer during high load and/or high
speed operating conditions. After a roller has broken away, it will
remain in a transversely displaced position, which is intermediate
its initial non-deflected position and its desired fully deflected
position, and will likely cause a malfunction.
Unexpectedly, the mere replacement of the pole pieces with pole
pieces shaped in accordance with the present invention results in
mechanism 12 having greatly improved operating characteristics.
Comparison tests have demonstrated that, whereas repeated
malfunctions occur in unmodified machines with unloaded carriers at
conveyor speed of over about 100 ft./min., no malfunctions are
encountered in a modified machine until the conveyor is driven at
over 300 ft./min. with a carrier loading of up to about 40 lb./sq.
ft.
FIGS. 6 and 7 illustrate modified forms of the present invention,
wherein articles from a single input line may be selectively
separated into five or four output lines, respectively. In each of
these modified forms, groups 90, 92 of electromagnets 56 and
permanent magnets 54 are arranged serially of the path of conveyor
movement such that guide surface portion 78a of the electromagnet
of a downstream group 92 is arranged immediately adjacent the path
of travel of roller 92 of a carrier when discharged in region "A"
from the downstream end of a permanent magnet 54 of an associated
upstream group 90. The operation of the electromagnet and permanent
magnets of each of groups 90 and 92 will of course be similar, such
that a carrier deflected by group 90 into region "A" or "B" may be
subsequently deflected, if desired, into region "D" or "E."
While the preferred embodiment of the present invention has been
described with reference to the use of pairs of electromagnets and
permanent magnets for diverting carriers in opposite directions
from a central region of the conveyor, it will of course be
understood that either the right or left hand group may be omitted
and articles diverted only in a single direction from adjacent
either the central region or a side region of the conveyor.
FIG. 9 illustrates a modified form of the invention, wherein
downstream magnetic diverting groups of the type shown in FIGS. 6
and 7 are replaced by one or more mechanical separators 100, which
are arranged to permit separation of carriers from a single
permanent magnet 54 selectively in one of a plurality of regions,
such as A, D, F and G. Each of separators 100 includes a
pneumatically operated cylinder 102, which is operable to
reciprocate a piston rod 104 carrying "flag" or deflector plate 106
formed of a non-magnetic material. Piston rods 104 are normally
retracted, such as to position "flags" 106 rearwardly of guide
surface 68 and permit roller 42 of a carrier, which has been
deflected from region "C," as by operation of an associated
electromagnet, not shown, to move outwardly along the guide surface
into discharge region "G." If it is desired to discharge a carrier
in an intermediate region, such as "D," the piston rod of the
associated separator is extended, as indicated in FIG. 9, so as to
move its "flag" beyond guide surface 68 and force roller 42 to
break away from magnet 54.
Preferably, each of separators 100 is removably and adjustably
mounted, so as to permit the number and distance between discharge
regions to be varied. To this end, mounting blocks 108 are suitably
fixed one to each of cylinders 102 and the blocks in turn
adjustably affixed to a mounting bar 110 having slots 112 adapted
to receive block adjustment bolts 114. Of course, cylinders 102 may
be replaced, if desired, by suitable reciprocating type
solenoids.
FIG. 10 illustrates a modified separator 100', which includes a
rotary solenoid 102' having a rod 104' for carrying an L-shaped
"flag" 106'. As will be apparent, the positioning of "flag" 106'
lengthwise of magnet 54 may be effected by moving bolts 114' of
solenoid mounting block 108' lengthwise within slot 112' of
mounting bar 110'.
It will be apparent that a single separator of the type discussed
with reference to FIGS. 9 and 10, may be employed to permit a
modification of the basic electromagnet-permanent magnet
combination. In this respect, a single electromagnet 56 and a
single permanent magnet 54, such as the left hand pair viewed in
FIG. 1, provide for two output or discharge lines of carriers, that
is, one line of non-deflected carriers passing along their initial
or non-deflected line of travel centrally of the conveyor within
central region "C" and one line of diverted carriers passing along
the conveyor within region "A." These same two output lines may
also be obtained by the utilization of a permanent magnet and a
single separator 100 or 100', and by arranging cam guides or
elements 48 to deliver rollers directly into surface engagement
with upstream surface portion 68a. By positioning a separator
immediately adjacent the junction of surface portions 68a and 68b,
a roller passing along surface portion 68a may be selectively
prevented from "turning the corner" onto surface 68b, thereby to
break away from permanent magnet 54 at this point for continued
movement centrally along the upper run of the conveyor. As will be
apparent, an advantage obtained from this modified form of the
invention is that the distance between the two discharge lines may
be readily adjusted by merely varying the positioning of the
separator lengthwise of surface portion 68b.
FIG. 11 illustrates the flow director 10 employed in combination
with a converging mechanism 200 for use in bringing together
articles from three input lines 202a-202c into a single output line
or conveyor 204.
It will be understood that converging mechanism 200 is identical in
construction to reject mechanism 12, except that the former is
inverted in order to place director 10 and cam elements 48 adjacent
the lower and upper runs of the conveyor, respectively; guides 16
of course being arranged to provide support for side chains 14.
Input lines would for instance include continuously driven, endless
conveyor belts 206a-206c, which are driven by electric motor 207,
shown only in FIG. 12, and marginally bounded by guide plates
208a-208c; upstream gates 210a-210c; and downstream gates
212a-212c. In the arrangement illustrated, input line 202b is
disposed in alignment with the path of non-diverted carriers
passing direction 10, whereas input lines 202a and 202c are
disposed in alignment with the downstream ends of each of magnets
54. The upstream and downstream gates of each input line are
synchronized to alternatively open and close, as by controls
214a-214c, such that one or more articles may be initially built up
as a group between the gates when the downstream gate is closed,
such group being thereafter fed onto carriers presented by
mechanism 200 when the downstream gate is opened. Controls
214a-214c may be of any desired form, such as for instance
electrically operated valves for controlling flow of air to and
from suitable gate operators.
A suitable memory unit 220 is provided to control operation of
director 10 and gate controls 214a-214c in time sequence. Unit 220
includes an electrical control circuit 222 and a cam timer 224,
which are illustrated in FIG. 12. For the three input lines
illustrated in FIG. 11, circuit 222 in its simplest form would
generally include five normally open micro-switches S-1 through
S-5, which are closable by contact with cams C-1 through C-5,
respectively, carried by rotatable cam shaft 226. Cam shaft 226 may
be conveniently driven by cam motor 228 or by being mechanically
coupled to conveyor drive shaft 26, if desired.
Again referring to FIG. 12, it will be seen that switches S-1
through S-3 are arranged in series with gate controls 214a-214c,
respectively, and switches S-4 and S-5 are arranged in series with
relays R7 and R8, respectively. When switches S-1 through S-3 are
closed, controls 214a-214c are energized to open their respective
downstream gates and close their respective upstream gates. When
energized by closing of switches S-4 and S-5, relays R7 and R8
serve to close switches R7-1 and R8-1, which when closed in turn
serve to establish a direct current circuit for energizing the left
or right hand electromagnets L.H. and R.H., respectively.
If it is assured that there are three sequentially operated input
lines from each of which a single group of two articles is to be
discharged during each full cycle of operation, and that it is
necessary to employ four carriers to support each article,
operation will be as follows. During each operational cycle, switch
S-4 would be closed first in order to energize left hand
electromagnet L.H. 56 (as viewed in FIGS. 11 and 12) for a time
sufficient to divert eight carriers to the left for subsequent
positioning in alignment with input line 202a; both of electro
magnets 56 would then remain deenergized (both of switches S-4 and
S-5 open) for a time sufficient to permit the next eight carriers
to pass centrally along mechanism 200; and finally switch S-5 would
be closed to energize the right hand electromagnet R.H. 56 (as
viewed in FIGS. 11 and 12) for a time sufficient to divert the next
eight carriers to the right for positioning in alignment with input
line 202c. As the groups of carriers are presented to the input
lines 202a-202c, switches S-1 through S-3 would be successively
closed, such that their associated gates would be operated to
permit feeding of their article groups onto the presented carrier
groups. Thereafter, the left and right hand groups of loaded
carriers are converged by cams 48 toward the central region of
mechanism 200, so as to form with the central group of loader
carriers a single line of carriers; articles being removed from
such single line by conveyor 204.
As will be apparent, depending upon system parameters, such as the
length and speed of the converger conveyor, groups of articles will
be deposited on the groups of carriers diverted during the same or
a preceding cycle of cam timer rotation.
* * * * *