US 3647044 A
A bypass for production lines for diverting blanks advanced on the line, particularly polygonal blanks of fiber material or a similar light material, past a working unit incorporated in the line. The bypass comprises a diversion path extending in a vertical plane, and at least at the beginning of the diversion path a switch unit is provided for connecting the path with the production line, the switch unit being displaceable in a vertical plane.
Description (OCR text may contain errors)
United States Patent Orstam 1 Mar. 7, 1972  BYPASS FOR PRODUCTION LINES 2,540,972 2/1951 Wagner et al ..271/64 X 3,358,831 12/1967 Cothrell ...27l/64 X m] Invent Kara Oman" 3,471,142 10/1969 Bergez ..271/64  Assignee: Skandinavisk Emballage Aktieselskab, FOREIGN PATENTS R L A ON Lyngby' Denmark 820,731 9/1959 Great Britain 198/94  Filed: Oct. 8, 1969 Primary Examiner-Richard E. Aegerter 864736 Assistant Examiner-Douglas D. Watts Attorney-Pennie, Edmonds, Morton, Taylor and Adams  Foreign Application Priority Data 061. 15, 1968 Denmark ..4959/68 [571 ABSTRACT A bypass for production lines for diverting blanks advanced  US. Cl ..198/3l AC on the li particularly polygonal blanks f fib materm or a  Int. Cl ..B65g 47/26 Similar light material past a working i incorporated in the  new of Search "198/94, 31 20 line. The bypass comprises a diversion path extending in a ver- 198/35 271/64 50 tical plane, and at least at the beginning of the diversion path a switch unit is provided for connecting the path with the  References cued production line, the switch unit being displaceable in a vertical UNITED STATES PATENTS P 2,309,662 2/ 1943 Neuhart ..271/50 3 Claims, 5 Drawing Figures 23 16 24 25 I2 I 13 l 7 4 PATENTEDMAR 1 m2 3.647. 044
BY 5/, M/- W/w; ATTORNEYS PAIENTEMR F I972 38W, 044
' SHEET 2 OF 2 INVENT OR WEJZQW ATTORNEYS BYPASS FOR PRODUCTION LINES The present invention relates to a bypass for production lines, said bypass diverting blanks advanced on the lineparticularly polygonal blanks of fiber material or a similar light materialpast a working unit incorporated in the production line.
In the following the invention will be explained in detail in connection with the production of egg cartons of fiber material, comprising a bottom portion and a lid, a printing apparatus being incorporated in the production line for the egg cartons and adapted to make an imprint on the lid of the egg cartons before the cartons manufactured in the production machine by precipitation of fiber material on suction moulds are collected in stacks for transportation.
Production equipment of this kind is rather complicated and also sensitive to stoppages and should preferably work continuously 24 hours a day. On the other hand it is necessary now and then to stop the printing machine, e.g., in order to change blocks and printing ink, and there will always be a risk of operational disturbances, e.g., when blanks are inadvertently not advanced to the printing machine. Such stoppages of the printing machine or operational disturbances should rather not necessitate a stoppage of the whole manufacturing plant.
It has already been suggested to provide production plants of the present type with a bypass extending in a horizontal plane behind the printing machine, and along which the egg cartons are advanced past the printing machine when the same is out of operation. At the rear of the printing machine the egg cartons are returned to the normal production line, where they may be removed if so desired so as not to be mixed up with cartons which have been imprinted.
In the said known plants this diversion has been inexpedient, because the detour past the printing machine takes place behind the printing machine, for which reason the diverted cartons cannot be easily watched. Experience has, moreover, taught that during the diversion along the bypass which is curved in a horizontal plane the light polygonal egg carton blanks tend to stand on edge relative to the bypass and therefore get stuck therein. This causes operational disturbances at the very place in the production apparatus where stoppages by means of the bypass should be avoided.
Moreover, the known bypasses require considerable floor space.
It is the object of the invention to provide a bypass where the said disadvantages are avoided. According to the invention the object is achieved by forming the bypass as a diversion path extending in a vertical plane, said path at least at its beginning being connected to the production line by means of a switch unit displaceable in a vertical plane.
This means that the bypass according to the invention leads from the production line path upwards over the working unit, e.g., the printing machine, and back to the production line path. Thus, the bypass will be easily watchable and easily accessible, and the easy access ensures that egg cartons not having received any imprint and advanced along the bypass can be easily removed from the production line before they reach the packing station. Since it is no longer necessary during their advance along the bypass to divert the blanks in a plane parallel to their resting surfaces, the risk of being placed edgeways in the bypass and thus becoming stuck in the same has been eliminated. In the bypass according to the invention the blanks will during the diversion perform a swinging movement in a plane perpendicular to the plane of the resting surfaces, which does not result in any risky movement edgeways relative to the path of the bypass, and as the diversion takes place in a path curved in a vertical plane, also the gravity of the blanks is used to ensure a faultless advance of the blanks along the bypass. All this means that the disadvantages and the risk of operational interruptions known from the known bypasses are avoided in a bypass according to the invention. Finally, the advantage is obtained that the bypass according to the invention does not require more floor space.
According to an expedient embodiment the ascending part of the bypass is a conveyor of the band conveyor type, whereas the descending part is shaped as a chute adjustable in a vertical plane. Thus, the bypass will have no difficulties in receiving the blanks as they reach the bypass, and because the descending part is a chute a basis is present for an appropriate utilization of the weight of the blanks for the purpose of their advance.
According to the invention the bypass may have an uppermost substantially horizontal part where an accumulating unit is provided, said unit being adapted to accumulate a number of blanks advanced along the bypass before their return to the production line. The accumulating unit thus serves to collect the blanks which have not received any imprint, so that the blanks may be easily removed from the production line path before they reach the packing station. The accumulating unit together with the bypass may also be used when it is desired alternately to produce egg cartons with imprints and egg cartons without imprints without stopping the manufacturing process. Since the accumulation takes place above e.g., a printing machine owing to the proposed embodiment of the bypass, it will be easy for a person watching the printing machine also to watch the bypass, and the bypass will be easily accessible from the same working place.
According to the invention the accumulating unit may comprise a stop positioned above the forward-moving part of a band conveyor at a point between two revolving rollers thereof, the band conveyor at least constituting the upper part of the bypass, the distance from the stop to the forward moving part being smaller than the height of the blank to be conveyed, and at the same time a pressure member being provided before the stop as seen in the travelling direction and above the band conveyor, said member being displaceable from a position where the distance from the lower end of the pressure member to the forward-moving part of the band conveyor is greater than the height of the blank, and at least to a position where the lower end of the member is flush with the stop. When the pressure member is in the first-mentioned position and a blank is advanced, the movement of the blank will be arrested by the stop, whereas the conveyor band continues to move forward below the' blank. When at a preselected time the blank is to be carried further the pressure member is activated and presses the blank against the band. As the stop is placed between two revolving rollers of the conveyor band, the band will yield to said pressure, and the blank is pressed against the band to such an extent that its outermost end is released from the stop. Consequently, the blank will now be pulled away from under the stop by the conveyor band and will continue its advance, e.g., to a piling member for the piling of a number of blanks. The details of the arrangement comprising the stop and pressure member are described in the applicants prior application Ser. No. 848,260, filed Aug. I7, 1969.
According to the invention the switch unit may be a band conveyor, the foremost roller of the conveyor in the conveying direction being placed in the production line path, the conveyor being swingable in a vertical plane about the axis of said roller from a position where the free end of the conveyor is placed in the production line path to a position where said end is placed in the path of the bypass. Thus, dependent on the position of the switch unit in a very simple way either an advance ofthe blanks in the production line path is provided or a diversion of the blanks arriving at the vertically extending bypass.
A particularly expedient embodiment of the switch unit comprises a driving connection by means of .a belt drive between the revolving roller placed at the free end of the switch unit and a conveyor, e.g., a band conveyor, positioned at the rear of the bypass in the travelling direction of the production line path, the belt drive driving the-said revolving roller and a driving roller for the subsequent conveyor and passing about a tensioning roller positioned below said rollers and displaceable in a vertical plane. This arrangement ensures that the switching of the said unit from one working position to the other can be effected without changing over the driving connection, because the same belt drive will always form the driving connection between the conveyor constituting the switch unit and the subsequent conveyor, whether the switch unit occupies one working position or the other, because the tightening roller accompanies the switch unit when it is raised or lowered and keeps the belt drive tensioned all the time.
According to the invention the chute and the switch unit may be connected to cooperating control means, preferably hydraulic means, a single manipulation thus bringing both switch and chute in bypass position or in production-line position.
An embodiment of the bypass according to the invention will now be described in more detail reference being had to the drawing.
FIG. 1 is a schematical side view of the bypass placed above a printing machine incorporated in a production line,
FIG. 2 is a section along the line llIl in FIG. 1, on an increased scale,
FIG. 3 is a segment A of FIG. 1 on an increased scale, the parts being in the working position shown in FIG. 1,
FIG. 4 shows the same, the parts being in another working position and FIG. Sis a top view ofa segment B of FIG. 2.
A production line for the manufacture of egg cartons consisting of a bottom portion 1 and a lid 2, FIG. 2, and produced on a machine not shown, comprises a printing machine 3 consisting of a supply conveyor 4 in the form of a band conveyor, a coding unit 5 positioned above the conveyor for advancing arriving blanks to be imprinted at a predetermined distance from one another to the printing machine, a feed conveyor 6, a printing unit 7, counterpressure members 8 which can be raised and lowered, a band feeder 9 to advance blanks with imprints to a piling wheel 10 and a subsequent magazine 11 for piled imprinted objects to be conveyed to a packing station not shown.
A bypass 12 is arranged above the printing machine, said bypass comprising a band conveyor having an ascending part 15 defined by revolving rollers 13 and 14, and a horizontal part 17 defined by revolving rollers 14 and 16, and a chute l8 constituting the descending part of the bypass. At its receiving nected with the magazine 11 which is swingably mounted at 21 about a horizontal axis extending transversely of the longitudinal direction of the bypass, the magazine 11 and the chute 18 thus being either raised, whereby the magazine 11 is connected with a subsequent conveying path 22 as shown in full lines in FIG. 1, or lowered so that the chute 18 ends in front of the conveying path 22 as shown in dot and dash lines FIG. 1.
The bypass 12 comprises an accumulating unit for piling a number of blanks advanced along the bypass before they are passed to the chute l8 and along the same to the conveying path 22 which may e.g., lead to a packing machine. The accumulating unit comprises a piling wheel 23 and a coding unit positioned before the same in the travelling direction, said unit consisting of a stop 24 placed above the forward-moving part 17 between its revolving rollers 14 and 16, and a preceding pressure member 25.
As the distance from the stop 24 to the forward-moving part 17 is smaller than the height of the conveyed egg cartons the cartons are arrested by the stop 24 when advanced by the conveyor 15,17 which, however, continues to move under the egg carton. Only when the pressure member 25 presses the egg carton down so that the uppermost end of the carton is released from the lowermost end of the stop 24, the band conveyor 15,17 yielding to said pressure is able to pull the egg carton away from under the stop 24 and to pass it on to the piling wheel 23.
The bypass 12 also comprises a switch unit 26 consisting of a band conveyor 27 constituting a part of the production line path and being swingably mounted in a vertical plane at its end 28 facing away from the printing machine 7. At its opposite end the switch unit 26 is connected to a hydraulic mechanism 29 by means of which the unit can be switched in a vertical plane from the lower working position shown in FIG. 1 in full lines, where the unit is opposite the supply conveyor 4 for the printing machine, to the upper working position shown in the same Figure in dot and dash lines where the unit is opposite the receiving end of the band conveyor 15,!7 of the bypass.
As shown in FIGS. 3 and 4, the band conveyor 27 is driven by means of a belt drive 30 passed about the revolving roller 31 positioned at the left side end of the band conveyor 27, about the revolving roller 32 positioned at the right side end of the supply'conveyor 4, and about a tensioning roller 33 positioned below the said two rollers and mounted on an arm 34 which is swingable in a vertical plane. FIGS. 3 and 4 show that the driving connection between the revolving rollers 31 and 32 exists whether the roller 31 occupies its lower working position, FIG. 3, or its upper working position, FIG. 4.
The bypass also comprises a number of guide rails 35 extending above the band conveyor parts 15 and 17 in their longitudinal direction and formed as rods for cooperation with the bottom portions and lids of the egg cartons, FIG. 2.
The entire printing machine is driven by a single electric motor. The working cycles of the coding unit 5 and the unit 24,25 are synchronized with the feed conveyor 6, the printing units of the printing machine 3 and the piling wheels 10 and 23.
The printing process in the printing machine 3 can be stopped by lowering the counterpressure members 8, the printing cylinders and inking units of the printing machine remaining in position and continuing to rotate.
The entire plant works as follows.
It is supposed that an operational disturbance causes an interruption of the continuous supply of egg cartons on the feed conveyor 6. When a sensing member ascertains that a carton is missing, the counterpressure members 8 are lowered so that no ink is deposited on the surfaces supporting the cartons. At the same time a signal may be sounded. If necessary the opera tor can now raise the switch unit 26 and lower the members 11 and 18 by means of a common switch, thus connecting the bypass 12. The switching may also be effected in a fully automatic way. The egg cartons are then conveyed from the production machine via the bypass to the conveying path 22, and the printing machine can be examined and adjusted without stopping of the production machine.
The diversion via the bypass can also be effected at other times, e.g., when the printing machine has to be stopped for the changing of blocks or ink. The flow of blanks from the production machine to the conveying path 22 can be observed unhindered also when the bypass is connected, because according to the invention the path of the bypass leads upwards above the printing machine.
1. A bypass system for a production line, incorporating a processing unit, for diverting blanks advanced on the line, for example, polygonal blanks of fibre or similar light material, past the processing unit incorporated in the production line, said bypass system comprising a diversion path extending in a vertical plane and including a blank ascending part and a blank descending part, the ascending part comprising a conveyor and the descending part comprising a chute adjustable in a vertical plane, a substantially horizontal band conveyor means for receiving blanks from the uppermost portion of the conveyor of the ascending part, said conveyor means comprising an accumulating unit adapted to accumulate a number of blanks advanced along the bypass, and a switching unit located at the inlet of the conveyor of the ascending part connecting the production line with the diversion path for diverting blanks from the production line to the diversion path, the said switching unit being displaceable in a vertical plane.
2 A bypass system according to claim 1, wherein the accumulating unit comprises a stop for blanks positioned above the forward moving part of the band conveyor means at a point between two revolving rollers thereof, the band conveyor means at least constituting the upper part of the bypass system, the distance from the stop to the forward moving part being smaller than the height of the blank to be conveyed, a pressure member arranged in advance of the stop in the travelling direction of and above the band conveyor means, said pressure member being displaceable from a position where the distance from the lower end of the pressure member to the forward moving part of the band conveyor means is greater than the height of the blank, and at least to a position where the lower end of the member is flush with the lower end of the stop.
3. A bypass system according to claim 1, wherein the switching unit comprises a band conveyor operating on rollers, the foremost revolving roller in the conveying direction of the conveyor being located in the production line path, the switching conveyor being swingable in a vertical plane about the axis of said foremost roller from a position where the free end of the conveyor is in the production line path to a position where said free end is in the diversion path of the bypass, a band conveyor in the production line path positioned to receive blanks from the free end of the switching conveyor, a revolving drive roller at the free end of the switching conveyor and at the intake end of the production line conveyor. a tensioning roller located below said drive rollers, and a belt drive extending around said drive rollers and said tensioning roller.