US 3366221 A
Description (OCR text may contain errors)
Jam 30, 1968 R. PRElSlG- 3,366,221
CONVEYING MECHANISM IN A FOLDING MACHINE FOR FOLDED BLANKS Filed Aug. 25, 1966 2 Sheets-Sheet 1 F IG 3 /0 7,
2 ll l 8 Jam. 30, 1968 R. PREISIG CONVEYING MECHANISM IN A FOLDING MACHINE FOR FOLDED BLANKS 2 sheets -sheet 2 Filed Aug. 25, 1966 United States Patent Office 3,366,221 CONVEYING MECHANISM IN A FOLDING MACHINE FOR FOLDED BLANKS Roland Preisig, Lausanne, Switzerland, assignor to J. Bobst and Son S.A., Prilly pres Lausanne, Switzerland Filed Aug. 25, 1966, Ser. No. 574,996 Claims priority, application Switzerland, Aug. 31, 1965, 12,216/65 11 Claims. (Cl. 198-33) ABSTRACT OF THE DISCLOSURE A conveying mechanism in which a folded blank is placed on a flat outer surface of a conveying member which undergoes translational and rotational movement while supporting the folded blank, the conveying member having a suction passage in communication with the openings in the outer surface which is subjected to a vacuum during selected portions of the path of travel of the conveying member to maintain the folded blank against the outer surface of the conveying member, a guiding member being located adjacent the conveying member and extending parallel to and adjacent the outer surface of the conveying member for engaging the folded blank and maintaining the folded condition thereof while the blank undergoes movement with the conveying member.
This invention relates to a conveying mechanism and more particularly to a conveying mechanism for folded blanks such as paper or cardboard.
In forming cardboard boxes or the like, blanks are cut to a predetermined profile, after which they are folded in a folding machine along preivously upset lines.
Folding takes place in the course of the passage of the blanks through the machine.
Such folding, however, cannot always be effected without difiiculty while maintaining a rectilinear conveying direction. Sometimes it is necessary to turn the blanks crosswise during the course of folding.
As a result there are known so-called two coordinate folding machines, the frame of which has the shape of a square, making it particularly cumbersome.
To remedy this drawback, it has already been proposed, in a rectilinear machine, to turn the blanks in their plane at a given moment during translation, so as to avoid a temporary standstill which would interfere with continuous production.
The known conveying mechanisms employ a pair of coaxial rotary members disposed one above the other for gripping a blank between them and turning the blank in its plane while undergoing common translatory motion.
However, the transported blanks generally are already partially folded, and these folds tend to open due to the elasticity of the cardboard or paper, unless the folded condition of the blanks is maintained during their transport.
The known mechanisms fail to achieve the above, since a continuous guiding surface for maintaining the folded condition of the blanks cannot be provided either above or beneath the blank due to the required space for the passing of the rotary members.
An object of the invention is to provide a conveying mechanism which avoids the above deficiency.
A further object of the invention is to provide a conveying mechanism in a folding machine in which the folded condition of the transported blanks is preserved during their transport.
In accordance with one embodiment of the invention, the conveying device comprises a conveying member adapted for receiving a folded blank and for undergoing translational and rotational movement, said conveying 3,3662% Patented Jan. 39, 1968 member having an outer surface for supporting the blank in which surface are formed openings, means for establishing suction in said openings to maintain the blank against the outer surface of the conveying member, and a guiding member located adjacent the conveying member and having a surface extending parallel to and adjacent the outer surface of the conveying member for engaging the blank and maintaining the folded condition thereof while the blank undergoes movement with the conveying member.
The invention will next be described in greater detail with reference to an embodiment thereof illustrated in the attached drawing, wherein:
FIG. 1 is a diagrammatical illustration in plan view of a folding machine;
FIG. 2 shows a device according to the prior art for conveying a blank in the machine of FIG. 1;
FIG. 3 is a schematic side view of the portion of the machine corresponding to FIG. 2 in accordance with the invention.
FIG. 4 shows the conveying mechanism according to the invention in simplified fashion in perspective;
FIG. 5 is a transverse sectional view through the conveying mechanism;
FIG. 6 is a longitudinal sectional view through the conveying mechanism as taken along lines VIVI in FIG. 5;
FIG. 7 is a schematic elevation view of the overall conveying mechanism; and
FIG. 8 is a diagrammatic illustration of the conveying mechanism of FIG. 7 with supply and removal means.
In FIG. 1 of the drawing there is shown a rectangular frame 1 of a folding machine for the folding of blanks. The blanks 2 are supplied to the frame 1 at one end thereof and discharged therefrom at the other end.
The machine is divided into two working zones A and B. In zone A the blanks are disposed transversely while being advanced through the machine, while in zone B they are disposed longitudinally while being advanced through the machine. Between zones A and B each blank is rotated a quarter of a turn in its plane from the position shown at 2 to the position shown at 3'.
In the device according to the prior art, as shown in FIG. 2, the blank 2 is gripped between two coaxial rotary members 4, 5 which undergo concurrent rotation and translation in the direction of arrow 6. Generally, the blank has already undergone at least one folding operation and will present a folded flap 7 or the like. The flap 7 in the arrangement of FIG. 2 is not maintained against the blank during transport thereof and due to the elasticity of the blank, the flap will tend to unfold as shown. In addition to the elasticity of the blank, the centrifugal force developed by the rotation of the members 4, 5 and air resistance will also tend to unfold flap 7.
In FIG. 3 there is shown the arrangement according to the invention whereby the folded condition of the blank will be maintained during the rotation and translation of the blank. More particularly, as shown in FIG. 3, a conveying member 8 supports the blank 2 and holds the same thereagainst by suction as a result of connection with a vacuum pump via line 9. A plate 10 is disposed above the member 8 and engages the blank to maintain the flap 7 thereof in folded condition while the blank undergoes movement with the member 8. The plate 10 hasan absolutely smooth lower surface enabling smooth sliding movement of the partly folded blank thereagainst. Preferably, the plate 10 will be transparent in order to enable the operator to visibly establish that the blanks are properly being conveyed while their folded condition is maintained.
FIG. 4 shows in greater detail the arrangement of the mechanism of FIG. 3.
In FIG. 4 there are seen a succession of conveying members 8 which pass between two surfaces 11 and 12 located in a common plane. Each conveying member 8 comprises a rotatable member 14 centrally mounted in a support member or block 13. Each member 14 is provided with suction openings 14' for drawing thereagainst the blanks being transported on the surfaces 11 and 12. The plate 10 extends above surfaces 11 and 12 and serves as a guiding member for the blanks to maintain the folded condition thereof while the blanks are transported.
Two successive blocks 13 are shown in FIG. 4 and these form a part of an endless chain of such blocks as will be described later.
Successive blocks 13 are connected by elastic bands 16 which completely fill the spaces between surfaces 11, 12 and the successive blocks 13.
FIGS. and 6 show the construction of blocks 13 and how the rotatable members 14 are momentarily connected to a vacuum source during transport.
Each rotatable member 14 with its suction openings 14' is formed with a fiat head portion, beneath which depends a partly hollow shaft 17 which is rotatably mounted in the block 13. A nut 18 holds the member 14 axially in the block 13.
The shaft 17 is hollow and is provided with lateral apertures 17' to provide communication between the inside of the shaft and a lateral chamber 19 in the block 13. The block 13 passes, during transport, on a rail member 20 which is provided with a vacuum chamber 21. The upper face of member 20 facing chamber 19 is formed with a series of apertures. These apertures are normally closed by valve members in the form of balls 22 which are subjected to the action of springs 23. In FIG. 6, only one of these springs is shown.
A pump (not shown) creates a vacuum in the fixed lower chamber 21. The pressure exerted by each spring 23 is sufiicient to overcome the suction and normally maintains the valve member in closed position. A bar 24 is secured to each block 13 and passes on member 20 during the travel of the block.
During its passage on member 20, bar 24 contacts the balls 22 to push them into chamber 21 against the action of springs 23 and temporarily establish communication between the movable upper chamber 19 in the block and the fixed lower chamber 21 in member 20.
In FIG. 6 is clearly shown how on its passage on the member 20 the block 13 opens the valve members and thereby establishes suction in the openings 14 in rotatable member 14. The bar 24 has a forwardly projecting portion with an upwardly slanting surface 24', allowing the bar to pass over the balls and lower them.
As seen in FIG. 5, the arrangement of the block 13 is for the most part symmetrical, in the sense that the block 13 slides on a rail member 20 similar with regard to member 20 and containing a vacuum chamber and ball valves 22'. However, opposite the upper chamber 19 in the block 13, there is only a blind space or groove 19' and valve members 22' remain closed. The significance of the latter will be shown later.
Laterally secured to the members 20 and 20' are fixed plates 26 whose upper face serves as a support and a guide for chains 27 which connect successive blocks.
This connection is shown diagrammatically in FIG. 7, wherein an endless chain assembly of six blocks 13 is formed. The blocks 13 are connected by the pairs of chains 27 which pass on chain wheels 28 and 29.
At the time of passage of the blocks 13 beneath the guiding member or plate 10, the blocks 13 slide on the rail member 20 as shown in FIG. 7 in a simplified way. The blanks are fed between the blocks 13 and the plate in a manner to be described later. In the course of passage of the blocks 13 on member the ball valves are lowered and the suction effect is transmitted to the blocks and thereby to the blanks which are conveyed therewith.
The elastic bands 16 are held around the wheels 28, 29 by stretching arms 30.
The apparatus described so far serves for translational travel of the blanks. The rotation of the blanks is effected as follows:
As seen in FIGS. 5 and 7, the shaft 17 of the rotatable member 14 terminates at its lower end in a lever arm 31 having at its outer end a roller 32.
As shown in FIG. 7 two bars 33 and 34 are positioned along the path of the blocks 13 to contact rollers 32. In effect bars 33, 34 are linear cams, of which cam 33 contacts roller 32 to produce a quarter turn of the shaft 17 in one direction while the opposite cam 34 is effective to return the shaft 17 to its initial position.
Although the rotation will normally be a quarter of a turn, the cams can be replaced to produce half a turn. By removing the cams or placing the arms 31 in a position where the cams do not contact the rollers, it is also possible to displace the blanks without rotation.
Returning to FIG. 5, it has been noted that the blocks 13, slide on two similar members 20, 20', each provided with ball valves 22, 22, although only one row of balls 22 was operated by the bar 24.
It is contemplated that alternate blocks 13 will operate alternate valve members 22 and 22. Thus by selectively subjecting the chambers 21, 21 to vacuum every member 8 may be subjected to suction or every other member may be subject to suction. This allows adaptation of the device to various size blanks.
FIG. 8 shows very diagrammatically the overall conveyor mechanism, as mounted in a folding machine. Therein there are again shown the wheels 28, 29 and the chains 27 causing the conveying members 8 (not shown) to pass under the plate 10.
The partly folded blanks advance from left to right in FIG. 8 and pass firstly between accelerating rolls 35 which space the blanks from each other to enable their subsequent rotation. The speed of the blanks at the exit of rolls 35 will be for instance 1.2 times the normal conveying speed of the machine. The chains 27 are likewise displaced at that increased speed as are upper and lower conveying belts 36, 37 which receive the blanks after rotation and remove them for delivery to chain 38. This chain is provided with stops 39 which engage the blanks and deliver the same in correct position for subsequent folding by further folding members of the folding machine. The conveyor mechanism as shown in FIG. 8 is positioned between zones A and B in FIG. 1 to effect rotation of the blanks.
Numerous modifications and variations of the invention will now become apparent to those skilled in the art without departing from the scope and spirit of the invention if defined in the attached claims.
What is claimed is:
1. A conveying mechanism for folded blanks, said mechanism comprising a conveying member including a support member which is displaceable along a path which is at least in part linear, and a rotatable member mounted in said support member and adapted for receiving a folded blank and for undergoing translational and rotational movement while supporting the folded blank, and rotatable member having a flat outer surface for receiving the blank, said outer surface having openings therein, means for establishing suction in said openings on selected portions of the path of travel of the conveying member to maintain the folded blank against the outer surface of the rotatable member and a guiding member located adjacent the conveying member and having a surface extending parallel to and adjacent the outer surface of the rotatable member for engaging the folded blank and maintaining the folded condition thereof while the blank undergoes movement with the rotatable member.
2. A conveying mechanism as claimed in claim 1 wherein said support member has an outer surface which is coplanar with the outer surface of the rotatable member to define a flat outer surface for the conveying member.
3. A conveying mechanism as claimed in claim 1 comprising cam means disposed along the path of the support member for rotating the rotatable member within the support member as the latter undergoes displacement.
4. A conveying mechanism as claimed in claim 1 comprising at least one rail supporting the support member for displacement along its path of travel, said rail having a vacuum chamber and valve means for said chamber, said means for establishing suction in said openings comprising means on said support member for opening said valve means and establishing communication between the vacuum chamber and said openings in the rotatable member during the selected portions of travel of the support member along its path.
5. A conveying mechanism as claimed in claim 4 wherein said valve means comprises a plurality of successive valve members in said rail, spring means urging each of the valve members to closed position, said means for opening said valve means comprising a bar on said support member which opens successive valve members during displacement of the support member.
6. A conveying mechanism as claimed in claim 4 comprising means connecting a plurality of successive conveying members to form an endless chain.
7. A conveying mechanism as claimed in claim 6 comprising a second rail supporting the support members of the conveying members, the means on the support members for opening said valve means being arranged so that alternate conveying members are in communication with the vacuum chambers of opposite rails.
8. A conveying mechanism as claimed in claim 1 comprising elastic bands connecting a plurality of conveying members in succession, and guide members spaced apart to permit passage therebetween of the conveying members and elastic bands, and guide members having outer surfaces which are coplanar with the outer surfaces of the rotatable members.
9. A conveying mechanism as claimed in claim 1 wherein said guiding member is constituted of transparent material.
10. A conveying mechanism as claimed in claim 1 comprising means connecting a plurality of successive conveying members together to form an endless chain, means for driving said chain along a path in which at least one portion of the length of the chain is linear, said guiding member being located adjacent the linear portion of said chain, means for feeding folded blanks between the guiding member and the linear portion of the chain at one end thereof and means for receiving the blanks at the other end of the linear portion of the chain.
11. A conveying mechanism as claimed in claim 1 wherein said means for establishing suction in said openings is constituted by a suction passage in said conveying member in communication with said openings, and means on said conveying member for providing selective communication of said suction passage with a suction source during travel of the conveying member.
References Cited UNITED STATES PATENTS 1,096,075 5/1914 Traver 19833 X 2,618,207 11/1952 Hery et al. 198-33 X 2,812,079 l1/1957 Carnine et al. 198180 X 3,189,158 5/1965 Locas 198-33 3,294,216 12/1966 Girardi 198-33 X ANDRES H. NIELSEN, Primary Examiner.
' EVON c. BLUNK, Examiner.
R. I. HICKEY, Assistant Examiner.