US 2757780 A
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Description (OCR text may contain errors)
1956 D. sousA ACCUMULATING DEVICE Filed July 18, 1955 IN VEN TOR. DAN/EL 50usA with respect to some otherfeature of thepac'kage.
United States Patent 1 2,157,780 AGC-IJMULATING :DEVICE 7 Daniel Sousa, Berkeley, ICalif as'signor to The Glidden 'Company, 'Cleveiand,( )hio,.a 'corporationof Ohio AppiicationFJuly :18, ;1955,,%Serial No.522;57 7
" Claims. ,(Cl. I9'8"34) I This invention relates 'tofa device .for automatically accumulating and discharging a predetermined minimum numberofpackages carried on .a. moving conveyor.
Conveyors of the moying'be'ltftype are used widely in carrying packages of material froma position of one operation 'to a position'where a succeeding operation is performed. Sometimes ,the succeeding, operation is .geared to Work best when'the feed. ofpackag e's is either constant .or provides a predetermined minimum number of packages. .For example, automatic wrapping machines of various types currently available for commercial use generally require an element 'of synchronism between the arrival of separate packages on a'feed conveyor and the initiation of the wrapping operation. Where .the wrap- .ping material is aprintedlabe'l "or printed overwrap, it is important'that'the label or overwrap .be positioned .accurately with .respectto the edges of the package or If the label or overwrap is out of prope rrregis'tration, thepack- .age may have to be rejected, in which case the cost of removing the'label .or overwrap and again labeling or wrapping the package may exceed the value .of the con- .tents. In such case, the .rejection of a package due to improper registration of the labeled .or over=wrappedpackage represents a "totaliloss. "In other instances Jthecost of salvaging'the rejected package -may below enough *to make salvage worth while, buteventhen there is added cost'which could be .avoidedfi'f proper registration of the label or overwrap couldhave .been .achieved'in Ithe first place. .In such operation where registration islimportant, it'is usually poss'ible' to adjust'thelabeling oroverwrapping machine .tofunctionproperly.aslong as'it does notlhave to work on asingle, isolated package. Sometimes batches of 'two packages at .a time will enablezthe machine to function properly, whilein other instances at least three or four packages -should be supplied in. each batch. It Will be understood, .of course, that-the machines are vprimarily intendedto operate continuously'and that the problem of improper registration arises only when some preceding operation breaks .down or is slowed down, thereby preventinganniforrn, continuous 'flow of packages from reaching the'label or overwrap machine.
My invention, when installed onlthe conveyonfeeding packages into a. machine which does not operate satisfactorily .unless fed withapredeterrnined minimum number of packages, overcomestheproblem ,of unsatisfactory operation of the machine automatically accumulating the desired predetermined 'number oflpaizkages and then automatically discharging *the accumulated number to the intake of the-said machine. By'means o'f'my'inven- *tion," the machine can be 'operated successfully at a much lower .production rate than it would accommodate in tthC. absence of nix-accumulator. I
Accordingly, it :is object rof my :invention ttO sprovide. a novel accumulating:device .forzbelt' conveyors.
.lhis a further object tto provide an accumulating device .of simpleconstruction \involving 121 minimum-30f rmoving 4 m- 2,757,786 *Patented Aug. 7, 1956 It is another object .to provide a device .of the kind .described which .can .be adjusted to :accumulate various small numbers of ,packages before dischargingthe group.
These and other objects will be understood from the following description of my invention taken .in conjunction-with the attached drawings, in which:
Fig. lis ,a plan viewof one embodiment of my invention installed on a section o'fa continuous belt conveyor witl portions broken away for purposes of clarity.
Fig. '2 is an elevational viewof the embodiment of Fig. ,1 with portions broken away,illustrating its operation just prior'to vthe arrival of ,a package which will release the accumulated packages.
' Fig. 3 is a fragmentary elevational .view corresponding "to Fig; 2 and illustrating the function of the idling means of my invention inthe operation of the invention.
Fig. :4 is a plan view of another embodiment of my invention as applied 10 asection of .a continuous belt conveyor, pOItiOnSbCil'lg broken away for clarity.
Fig. '5 is an elevational view of the embodiment of Fig. 4.
'Fig. 6 is a sectionalview taken onthe lines .6--6 of Fig. 4.
Fig.7 is an elevational view, partly.in section, of a modification ofthe device of Figs. 1 3.
Referring nowpto Figs. 1 and '2 Which illustrate an em bodimentwhi'ch has been foundto function satisfactorily in connection with the overwrapping of packages of margarine,there isshown asection of a (conveyor installation involving a rectilinear supporting'table comprising a fiat bed "1 and legsIZ, 2 holding'the bed at a desired elevation'for matching the conveyor;belt"3 which moves thereon 'with'the 'intakeconveyor (not shown) of a conventional overwrap .machine such as Model .FF machine manufactured'by the Package Machinery'Company of Springifield, Massachusetts. It will'be understood that the sup- ;porting .table extends any desired .moderate distance .on
. both sides o'f'the section shown 'in'jFigs. 'l' and i2 and has the usual powered driving roller .at one end and anidling roller "at the other with .a continuous flexible web or belt "looped around the'table and rollers with sufficienttightness to vensurethat rotation of thedriving roll will cause the belt to move longitudinally of theLta'ble in. a rectilinear path. In Figs. 1 and'2 .the direction ,of. travel of the belt 3 is .shoWn to be from left to right. The return portion 4 of the conveyor belt 3 of fiOIlfSCil'llOVES from right to left as shown. J'Proceeding now to a description of my device, it'Wlli be seen 'in'Figs. 1 and "2 that a pair of "brackets 5, ,5 are mounted on'the sides .of the conveyor bed 1 toextend above theupper surface of the conveyor belt 3. A' pair of arms 6, 6 are ,pivotally secured by the shouldered screws 7, 17 to the brackets i5, 5, the shoulders of the screws "7, 7 being journalled in the said brackets so thatL'the arms "6,6 are free to rotate through "limited angles from a horizontal position, An end mem- 'ber',8 is rigidly securedat its end to apair of channeled members ,9, .9 which snugly fit theends of thearms 6, 6 and have a slot 1% in the side thereof whichpermit them -to'be'secured adjustably to arms J6, "6 as by screws 11, 11.
f It will be understood that the arms 6, '6, the channeled members 9 9 and the end member 8, when joined'to- 'gether, form'a frame which is pivotally mounted over the conveyor belt3. The end member '8, as is best shown in Fig. 2, has agreater width than that of arms 6, 6, 'so that a portionprotrudes'belqw the plane of the frame to=forma stopport-ion 12; 'Th'e'endmember's also'has -a pair of fingers 13, -13 which have their'bottom surfaces .coincident with the :bottom of the stop portion 12 and inclined downward therefrom. These fingers have an iidlin-g function iinithe =assen'1bly which will ,be explained .amorefully in connectionwith Fig. .:-3. :A shaft 14 extends between .the arms ;.6, 6.;at; a; position upstream from the stop portion 12. This shaft is journalled in the arms so as to rotate freely therein, the journals being provided by the shouldered screws 16, 16. The shaft can be moved to various positions closer to or farther from end member 8 by using the holes 17, 17 in the arms 6, 6. Shaft 14 carries a bifurcated member 18 rigidly secured thereto as by welding, and is balanced so that when the frame is about horizontal, the two ends 19 and 20 of the member 18 will have their lowest extremities in a plane parallel to the upper surface of the conveyor belt 3. One end of shaft 14 has a plurality of small holes 21, 21 drilled radially thereinto about its circumference. A light coil spring 22 is disposed around shaft 14 and has one end secured in a hole 23 in the adjacent arm 6 with the other secured in one of the holes 21, 21. By rotating this latter end from one hole 21 to another, its tension can be varied so as to cause shaft 14 and member 18 to be placed in an unbalanced position wherein the end 20 of member 18 will normally be closer to conveyor belt 3 than is end 19. Stop screws 24, 24 are threaded into tapped holes near the corners of member 8 and can be adjusted to hold the stop portion 12 at a desired elevation above conveyor belt 3. Brackets 25, 25 are secured to bed 1 and each carries a screw 26 threaded therein and having a hole adjacent its upper end. One end of a coiled tension spring 27 is hooked in this hole and the other end is hooked over a pin 28 extending outwardly from arm 6. It will be understood that the center of gravity of the frame and its associated members lies to the right of the pivotal axis provided by screws 7, 7. Accordingly, the weight of the assembly causes the frame to bear against the stop screws 24, 24. In order to lighten this efiective weight of the frame assembly, the tension of springs 27 can be adjusted by means of screws 26 until the frame has any desired bias causing it to bear on stop screws 24. Ordinarily, the springs should not entirely overcome the effective weight of the frame assembly since the operation of the assembly requires that it exert a light pressure on the order of about a pound on stop screws 24, 24. If the frame assembly is composed of light weight materials such as aluminum and/ or wood and is designed to eliminate excess weight wherever possible, then springs 27 can be adjusted to exert very little tension or can even be eliminated. It will be understood that counterweights carried near the upstream ends of arms 6, 6 can be used in place of or in adidtion to springs 27 if the effective weight of the frame assembly needs to be counterbalanced partially.
In Fig. 2, three packages 29, and 31 (which for purposes of illustration are assumed to be one-pound packages of margarine) are shown as having been carried by the moving conveyor belt 3 into the positions shown in the Figure. It should be carried in mind that the three packages were not originally in that juxtaposition when deposited on the conveyor belt 3. Package 29 was deposited on the conveyor belt first and was followed shortly thereafter by package 30 and then by package 31, at time intervals not being uniform. Consequently, the packages were spaced apart (but not equally spaced) as they were moved to the right on the conveyor belt. When package 29 reached the stop portion 12 (which has previously been adjusted in elevation by means of screws 24, 24 to arrest any such packages resting on the conveyor), it pressed against the stop portion 12 and remained there while the conveyor belt 3 moved forward beneath it. Since the forward movement of the conveyor belt was not impeded by the stopping of package 29, its motion in due course brought package 30 forward until its movement was arrested by package 29. In reaching this position, however, it first pressed against the spring depressed end 20 of member 18 (see Fig. 3) and as it moved forward it caused member 18 to be rotated counterclockwise against spring 22. By .the time package 30 pressed against package 29, the end 19 of member 18 had been lowered by the said counterclockwise rotation 4 until it assumed the position shown in Fig. 2. Meanwhile the forward travel of conveyor belt 3 brought package 31 into the position shown in Fig. 2, and it will be apparent that further forward movement of the package will cause it to slide under end 19 of member 18. This sliding action causes member 18 to now be rotated clockwise, but since end 20 of that member is already pressing against the top of package 30, such clockwise rotation of the member 18 causes the entire frame to be raised upwardly. By the time package 31 has moved to the right until it is about to be stopped by package 30, the frame will have been raised enough to remove stop 12 from engagement with the forward edge of package 29. Packages 29 and 30 will then no longer be restrained and all three packages will move to the right with the conveyor belt 3, thereby being discharged from the accumulator device.
During this upward motion of the frame and its attached stop member 12, there is a tendency for package 29 to be lifted along with the stop member. To overcome this, rollers 32, 32 carried on brackets 33, 33 restrain the package 29, thereby ensuring release of the package when stop 12 has been raised above its upper surface.
Referring now to Fig. 3 it will be recognized that this Figure represents the situation which prevails a short time after the stop means 12 of Fig. 2 has been raised enough to discharge the accumulated packages. The interval of time between Figs. 2 and 3 has been such that package 29 has been carried beyond the fingers 13, and such that package 30 is still supporting the frame through fingers 13. It will be noted that there is a space between packages 30 and 31, due to the fact that package 31 must always be moving forward while it is sliding under the end 20 of member18. If this motion were arrested by package 30 it may not have moved to the right far enough to cause the stop means to be raised to its out-ofpackage-stopping position. To ensure full operation of the device, the spacing betweenend 20 and stop portion 12 should be adjusted so that the stop portion will be in its out-of-package-stopping position before package 31 bears against package 30. Since the space between packages 30 and 31 is therefore an eventuality in the operation of the device, fingers 13, 13 are employed to retain the frame and its associated stop portion 12 in an out-ofpackage-stopping position for an interval of time sufficient to allow package 31 to be carried under the stop portion 12. The gap between packages 30 and 31 therefore does not permit the frame to drop down and retain package 31, but instead is held up by fingers 13, 13 until all three packages have been carried beyond the extremities of fingers 13, 13. Of course if additional packages followed closely upon package 31 with a gap between them which is less than the span of fingers 13, then the accumulating device would be idled until a gap wider than the span of the fingers occurred. The frame and stop portion could then drop dow into package-stopping position to begin accumulating a new pilot batch of three packages and stop member can still be actuated or triggered by a newly-arriving package.
It will be apparent from the foregoing description that the accumulating device of Figs. 1 and 2 can be adjusted to accumulate two or four packages instead of three by shifting shaft 14 to either of the other positions provided for it in arms 6, 6, and by adjusting the end member 8 with its attached stop portion 12 by means of slots 10, 10 and screws 11, 11. Adjustment of the gap between the package actuating discharge and the preceeding package (e. g., the gap between packages31 and 30 respectively) can be adjusted by moving end member 8 (and thus stop portion 12) closer to or farther from shaft 14.
Another embodiment of my invention is illustrated in Figs. 4, 5 and 6. In this embodiment, the accumulator assembly is mounted at one side of the conveyor belt and is actuated by having the ends of the bifurcated actuating swarms member bear on :the sides :of ipaokages harried on the conveyor. It will be understood that in the -embodiment of Figs. 1 ,and.2,-it.isdmportant.for,.proper operation that themiddle of a package 'beisu'ificiently firm to support the elfective-weight'dftheframeassembly. Packages of margarine, .butter,.shortening:and the llikef'have such firmness, but packages of other materials, such as cereals, are apt to yield so much in areas of their faces remote from the edges of the package that they will not properly support the ends 19 and 20 of the bifurcated member 18 and hence will keep the frame from being lifted by this member in the intended manner. Most packages, however, have sufficient rigidity on their narrower side faces, so that my accumulator assembly can be effectively actuated by such side faces. When the accumulator assembly is arranged for such operation, the packages need to be supported against their opposite side faces so that they will not slide across the moving conveyor belt when engaging the actuating end of the bifurcated member. To this end the conveyor, comprising a bed 40 and a moving belt 41, is provided with a side or wall panel 42 positioned close to one edge of the conveyor belt 41. A deflector 43 is provided on the opposite edge to shift the packages across the belt. The accumulator assembly is mounted on the same side of the bed 40 as is the deflector, and comprises an arm 44 journalled at one end on a vertical pin 45 and resting on a thrust bearing 46, so as to be free to rotate over the belt 41. At the opposite or downstream end of the arm 44 is secured a stop member 47 having a finger or idling portion 48 extending downstream therefrom. An angle bracket 49 is secured to the bed and can be adjusted toward and away from the belt 40 so as to provide a stop which limits the inward or counterclockwise rotation of arm 44. Another portion 50 of the bracket 49, on the opposite side of arm 44, is provided with an adjusting screw 51 which limits the rotation of arm 44 in a clockwise direction. A light compression spring 52 mounted on arm 44 can be adjusted by screw 53 working in bracket 54 so as to normally press arm 44 against stop 49.
As shown in Fig. 5, the middle portion of arm 44 is slotted and a bifurcated element 55 having package-contacting ends 56 and 57 is journalled in said slot on a pin 58. A pin 59 protruding from the upstream side of the element 53 is positioned to strike the arm 44 when the element 55 rotates a predetermined amount in a counterclockwise direction. A tension spring 60 is hooked to element 55 near its end 56 and is also hooked to a clip 61 frictionally attached to arm 44. This spring 60 normally retains element 55 in its rotated position with pin 59 hearing against an arm 44. It will be understood that when retained in this position end 57 of element 55 is able to contact the side of a package carried on the conveyor when the arm 44 is pressed against stop 49, and that stop 47 is then in its package-stopping position. End 56 of element 55 is not then in a package-contacting position and attains that position only after a package has moved between wall 42 and end 57, as shown by package 62.
The operation of the assembly of Figs. 4-6 will be understood from the description of the embodiment shown in Figs. 1 and 2, since the operation is the same as was there pointed out in detail. Element 55, like element 18 of Figs. 1 and 2, can be shifted from its present position to two other positions on the arm by removing pin 58 and shifting the whole bifurcated element assembly to rotate around the pin 58 when inserted in holes 63 or 64.
A modification of the bifurcated member 18 of Figs. 1-3 is shown in Fig. 7, but it will be evident that the corresponding member 55 of the embodiment shown in Figs. 4-6 can be similarly modified. The modification involves the use of a pair of rollers at each end of the bifurcated member to reduce friction between the bifurcate'rl memberzand the surfaces ofthe packages which actuate it.
From the-foregoing description of different embodiments of my invention, it will be clear that the princijples can be utilized in a variety of other embodiments,
.some .of which may beparticularly suited topackages of non-parallopided configuration. The principles can be applied readily to cylindrical cans and to bottles of various shapes, the embodiment illustrated in Figs. 1 and 2 being adapted for cans having fiat upper ends parallel to the conveyor, and the embodiment of Figs. 4-6 being adaptable to bottles which stand upright on the conveyor, by making minor changes in the shape of the stop member 47 and in the shape of ends 56 and 57 of member 55. Various other adaptations of the principles will occur to those skilled in the art without involving fundamental departures in structure from my invention. The motion of the frame of Figs. l-3 or of arm 44 of Figs. 4-6 can, of course, be used to actuate switches, valves, etc. of suitable devices whose operation is desirably synchronized with such motion.
I am aware that other accumulator devices have been disclosed in the art heretofore, such as that of U. S. Patent No. 2,690,832 here incorporated by references, but my invention is of particular merit in that it is of relatively simple construction and utilizes a minimum of moving parts.
Having described my invention, what I claim is:
1. In a device for accumulating a predetermined minimum number of packages having a uniform height when disposed in normal conveying position on a conveyor of the type having a moving belt supporting the packages in frictional contact with the upper face thereof, the combination of: a frame pivotally disposed adjacent said conveyor and adapted to rotate through small angles toward and away from said conveyor, said frame carrying stop means rigidly associated therewith and adapted to move into and out of package-stopping position relative to packages carried on said moving conveyor when said frame rotates respectively toward and away from said conveyor, said stop means being disposed on said frame downstream from the axis of rotation of said frame, means normally biasing said frame toward said conveyor so as normally to position said stop means in packagestopping position; bifurcated activating means pivotally mounted on said frame upstream from said stop means in a position permitting its two ends sequentially to contact and rest on corresponding selected surfaces of different packages carried by said conveyor and being adapted when said ends rest on said selected surfaces of different packages (1) to neutralize said biasing means and (2) to retain said frame in its rotated position away from said conveyor wherein said stop means are in an out-ofpackage-stopping position; yielding means normally biasing the downstream end of said bifurcated actuating means into package-contacting position so that said end is normally the first to contact the selected surface of a package carried on said conveyor; and idling means rigidly associated with said frame and extending downstream from said stop means, said idling means being adapted to retain the stop means of said frame in out-of-packagestopping position until any package which is being carried beyond said stop means by the movement of said conveyor has been carried a predetermined short distance downstream from said stop means.
2. The combination as claimed in claim 1 wherein said frame is disposed above said conveyor, and wherein the two ends of said bifurcated actuating means are adapted, when in their bias-neutralizing attitude, to rest on upper surfaces of different packages carried on said conveyor.
3. The combination as claimed in claim 2 wherein means normally biasing said frame toward said conveyor is that portion of the aggregate weight of said frame, stop means, bifurcated means, yielding means and idling means not supported by the pivotal mounting of said frame.
7 4. The combination as claimed in claim 3 wherein the the downstream end than with the upstream end of said said yielding means consists of a spring working between bifurcated means. said frame and said downstream end of said bifurcated References Cited in the mg of this patent means.
5. The combination as claimed in claim 3 wherein said 5 UNITED STATES PATENTS yielding means consists of greater weight associated with ,052,840 Nussbaum Sept. l, 1936