GB1571465A - Conveyor for feeding portions of sheet material particularly preshaped or punched pieces of cardboard and the like to a user machine particularly to a machine for packaging cigarettes into hinged lid packets - Google Patents

Abstract

The continuous-belt conveyor device ensures the gradual feeding of sections of sheet material. In order to ensure a relatively high feed speed, the said belt comprises at least two endless webs (14) each wound onto two toothed wheels, one of which is a drive wheel. The belt extends on opposite sides of a beam (33), a flat upper surface of which projects above said belts. The latter are connected to one another by cross-ties (34) which extend above the beam and define a plurality of conveying drawers each designed to receive a section of sheet material (5). The installation is designed to supply intermittent cigarette wrapping/packgaging machines at extremely high operating frequencies and with precise positioning of the cardboard blanks. <IMAGE>

Description

(r4) C()NVEYC)R FOK FEEDING l'OR'I'IONS OF SHEET MATERIAL, PARTICULARLY PRESHAPED OR PUNCHED PIECES OF QARDB()ARD AND THE LIKE, TO A USER MACHINE, PARTICULARLY I '1'0 A MACHINE FOR PACKAGING CIGARETTES INTO HINGED LID PACKETS (71) We G. D. SOCIETA PER AZIONI, an Italian company of A() 133 Bologna Via Pomponia. 1 () Italy, do hereby declare the invention for which we pray that a patent man be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates tci a conveyor for feeding sheet material to a user machine.

More particularly@ the present invention relates to a continuous belt conveyor for feeding preshaped or punched pieces of cardboard or the lii from a feed and accumulation apparatus for said preshaped or punched pieces to an intermittent machine for packaging cigarettes into hinged lid pacliets.

In the aforesaid feed and accumulation apparatus. the preshaped pieces for feeding to said packaging machines are generally stacked inside a column vessel down which they descend bv gravity and from the lower end of which they are individually withdrawn bv extractor means and deposited on an inlet conveyor of a packaging machine.

A particularly effective example of such an apparatus is decribed in our British Patent Specification No. 1468757. In this apparatus. the preshaped pieces are continuouslv fed into a vertical acculnulation vessel and are extracted one by one from the bottom the by suckers. which deposit them in succession on a conveyor which feeds them in the same order to an intermittent packaging machine.

Conveying the shaped pieces by a convevor from an accumulation vessel such as that heretofore described to an intermittent packaging machine presents no substantial problem when the operating frequency of the machine is relatively low. However. considerable problems arise when a conveyor is required to feed the preshaped pieces to a packaging machine having a very high operating frequency, for example an intermittent packaging machine with an operating frequency of seven steps per second or more. In general, the technical specification which such a conveyor has to satisfy is extremely severe, in that it must not only feed the preshaped pieces stepwise at a feed frequency equal to the operating frequency of the packaging machine to be fed, but must also ensure that the preshaped pieces are positioned extremely precisely both longitudinally and transversely at the end of each step, as these latter are generally subjected during their travel both to pre-folding operations and to changes in direction. The terms "longitudinal" and "transverse" are used herein to indicate a direction parallel and a direction perpendicular respectively to the direction in which the preshaped pieces are fed along the conveyor.

Presently known conveyors for feeding intermittent packaging machines have proved incapable for satisfying the aforesaid requirements. These known conveyors are generally constituted by a continuous belt the upper branch of which slides in contact with a flat support plate, and from the outer surface of which project transverse projections defining conveying compartments for the preshaped pieces. In the aforesaid known conveyors, the width of the continuous belt is substantially equal to the transverse dimensions of the preshaped pieces conveyed.

Because of the width of the belt and the corresponding weight of the moving parts, these conveyors are unsuitable for feeding intermittent packaging machines at very high operating frequency because of the inertia forces generated during their stepwise movement. and which result in belt vibration and an unacceptable imprecision in the position of the preshaped pieces at the end of each step.

Furthermore, in the said known conveyors, the belt surface in contact with the preshaped pieces is generally rough and does not allow precise transverse position ing of the preshaped pieces by the guide elements disposed along the belt and arranged to co-operate with the transverse ends of the shaped pieces. An object of the present invention is to provide a conveyor which. in contrast to known conveyors, may be used for feeding preshaped pieces to an intermittent packaging machine and in particular a nlnchine for packaging cigarettes into hinged lid packets operating at very high speed.

According to the present invention, there is provided a continuous belt conveyor for step-feeding portions of sheet material, par ticularly preshiped or punched pieces of cardboard or the like, to a user machine; said belt conveyor being configured so as to define conveying compartments each adapted to accommodate a respective one of the pieces, and comprising at least two parallel spaced, endless toothed belts having coplanar conveying runs and each being wound around a respective pair of gear wheels; a beam extending k)ngitudinally between the or each pair of adjacent belts and having an upper flat surface arranged above said belts and defining a support for said pieces to be advanced; the tie bars connecting said belts together to define said conveying compartments, a portion of each said the bar extending over the beam(s) to bridge the same.

Further chiracteristics and advantages of the present invention will be evident from the description given hereinafter with reference to the accompanying drawings which illustrate one non-limiting embodiment thereof. and in which: Figure 1 is a three-quarter perspective view from above of a conveyor constructed in accordance with the present invention; Figure 2 is a plan view to an enlarged sclae of a detail of Figure 1; and Figure 3 is a section on the line III-III of Figure 2.

Figure 1 shows a conveyor 1 for preshaped packaging pieces 2 indicated idn the figure by dashed and dotted lines. The conveyor 1 is supported in a substantially horizontal position by a base 3 which extends between an inlet station 4 as described in our co-pending British Patent Application No. 16778/77. (Serial No. 1571716) and an outlet station 5 as described in our co-pending British Patent Application No.

1678t)'77. (Serial No. 1542018) at which the preshaped pieces 2 are transferred to a second conveyor 6 connected to an intermittent machine (not shown) for packaging cigarettes into hinged lid packets. A folding station 7 as described in our co-pending British Patent Application No. 16779/77 (Serial No. 157194()) is disposed in the path of the conveyor 1, and folds a flap constituting one of the ends of the preshaped pieces 2. The conveyor I comprises a longitudinal support and guide member 8 disposed in a substantially horizontal position above the base 3. and supporting, by its two ends. two shafts 9 and 1() disposed horizontally and transversely to the axis of the longitudinal member 8.

By way of bearings 11, two gear wheels 12 are rotatably mounted on the two ends of the shaft 9 and each supports and engages, together with a corresponding gear wheel 13 keyed on the shaft it), with a respective endless toothed belt 14 extending parallel to the axis of the longitudinal member 8. One end of the shaft 10 extends rotatably through a sleeve 15 rigid with the base 3, and comprises keyed thereon a gear wheel 16 which engages with a gear wheel 17 rigid and coaxial with a Maltese cross 18 mounted rotatably on a shaft 19 carried by the base 3.

The Maltese cross 18 is engaged by the idle rollers 2() carried by the device 21 of known type rigid with a drive shaft 22 for driving stepwise the shaft 10, the relative gear wheels 13 and the belts 14.

As shown in Figures 2 and 3. bars 23 are mounted transversely on the longitudinal member 8 and are substantiallv of U crossstation, comprising two lateral flanges 24 extending upwards from a substantially horizontal web 25 and provided with a central longitudinal rib 26. Together with the flanges 24. this latter defines two longitudinal grooves 27 disposed symmetrically about the longitudinal axis of the member 8. and along which the upper runs of the belts 14 extend.

To the tops of the flanges 24 there are connected. by screws 28 and 29 respectively. two flat plates 30 and 31 extending along the longitudinal member 8 and projecting laterally therefrom in opposite transverse directions. A longitudinal beam 33 is connected to the top of the central rib 26 by screws 32, and upperlv comprises a flat surface coplanar to the upper flat surfaces of the plates 30 and 31 to constitute with these latter two surfaces a support surface for the preshaped pieces 2.

Each of these latter is disposed inside a respective conveying compartment defined by two tie bars 34 extending transversely to the belts 14 and connected thereto.

Each tie bar 34 is configured substantially as an inverted U and comprises a web extending above the upper surface of the beam 33 and two lateral flanges extending inside the grooves 27 and each connected to one of the belts 14 by way of a guide shoe 35. This connection is made bv a pin 36 locked between the guide she 35 by a washer 37 and provided with threaded ends on which nuts are mounted for tightening together the tie bar 34, shoe 35 and belt 14.

The shoe 35 comprises laterally a flat surface in contact with a lateral flat surface of the beam 33, and a substantially rectangular lateral appendix 38 engaged slidably in a respective lateral longitudinal groove 39 in the beam 33.

The upper and lower surface of each appendix 38 are disposed in contact with the upper and lower surfaces respectively of the relative groove 39 so as to keep the respective tie bar 34 at a determined distance above the upper surface of the beam 33. The transverse position of the belts 14 and relative tie bars 34 is controlled both by the shoes 35 and by a lateral appendix 40 extending from each tie bar 34 above the plate 31 and comprising an end tooth 41 extending into a longitudinal groove 42 provided on the upper surface of the plate 31.

The transverse position of the preshaped pieces 2 in the relative conveying compartments is controlled on one side by a guide rib or shoulder 43 connected to the upper surface of the plate 30 by screws 44, and on the other side by a guide rib or shoulder 45 connected to the upper surface of the plate 31 by screws 46. Whereas the shoulder 43 extends longitudinally along the entire plate 30, the shoulder 45 is at least partially interrupted both at theinlet station 4 and the folding station 7.

At the station 4. the shoulder 45 is replaced by a control gate 47 rotatably mounted on a pin AS carried by the plate 41 lii order to prevent the preshaped pieces 2 separating vertically from the plates 30 and 31 and from the beam 33, brackets 49 are connected to the should 45 and project above the plate 31 to support a vertical guide knife St extending along the space lying between the stations 4 and 7.

At the inlet station 4, there is provided a device which comprises a horizontal shaft 51 arranged to retain the preshaped pieces 7 on the said support surface defined by the plates 30 and 31 and by the beam 33 before their insertion below the guide knife 50, the preshaped pieces 2 having been extracted in succession from the bottom of a vessel (not shown) descl-iletl in our above-mentioned British Patent Specification No. 1468757 and disposed vertically above the station 4.

The preshaped pieces are extracted from said vessel by an extractor unit (for a description of which reference should be made to British Patent Specification No.

1468757 comprising three suckers 52, visible in Figure 1, connected to a suction unit 53 and mobile upwards through holes 54 provided respectively through the plates 30 and 31 and the bean; 33. In order to allow the suckers 52 to rise before an empty con- veying compartment is positioned below said vessel, each tie bar laterally comprises a semi-circular notch 55 arranged to allow the passage of the central sucker 52. In use, the belts 14 and relative tie liars 34 are fed stepwise at a feed frequency determined by the drive unit comprising the drive shaft 22 and Maltese cross 18.

The depositing of a new preshaped piece 2 on the conveyor 1 is carried out by the suckers 52, which rise upwards as soon as the periphery of the notch 55 in the fronl tie bar 34 of said empty conveying cmpartment coincides with the periphery of the central hole 54. On adhering to the preshaped picce 2 lying at the bottom of said vessel, the stickers 52 move downwards and deposit this preshaped piece 2 on the conveyor I as soon as said empty conveying compartment is halted at the end of the feed step in a central position relative to the holes 54. i.e. in the position shown in Figure 2.

The structural characteristics of the conveyor 1 enable it not only to feed stepwise with a very high frequency (up to seven steps per second or more). but also allow the preshaped pieces 2 to be positioned extremely precisely both in the longitudinal and transverse directions at the end of each step.

In this respect. in the conveyor 1 the inertia of the moving parts is much less than that of known conveyors used up to the present time for the same purpose. as the continuous conveying belt of these latter has been replaced by the two belts 14 of much smaller cross-section. Furthermore, the belts 14 instead of sliding in contact with a flat support surface are supported by the beam 33 via the shoes 35, which reduce the friction forces acting on the mobile elements of the conveyor 1 to a minimum. In this respect it should be noted that the shoes 35 not only support the tie bars 34 in such a manner that they never come into contact with the beam 33. but also support the belts 14 inside the grooves 27 without them coming into contact with the bars 23.

This latter structural characteristic makes it possible to use toothed belts 14. In this respect it is important to note that in known conveyors, the lower surface of the conveyor belt has to slide in contact with a support surface and is therefore generally free from teeth in order to reduce friction to a minimum and guarantee a certain stability to the support surfce of the preshaped pieces. Thus. the relatively low weight of the moving parts. the relatively small friction forces acting upon these moving parts, and the use of toothed belts give the described conveyor 1 a feed precision which is much greater than that of known conveyors, and allows it to operate stepwise at the necessary frequencies of forward move mcnt for feeding modern intermittent packaging machines.

With regard to the transverse positioning precision of the preshaped pieces 2 during their feeding, this is ensured hv the relative- ly low friction between the preshaped pieces and their support surface. This latter is constitued not by the rough surface of a belt as in the case of known conveyors, but by a preferably polished or lapped metal surface.

As is evident from Figure 3, the belts 14 are supported by the shoes 35 at a level always lower than the level of the upper coplanar surfaces of the two plates 30 and 31 and of the beam 33 constituting the support surface of the preshaped pieces 2.

Consequently, these latter never come into contact with the belts 14 and may be continuously positioned transversely by guide elements constituted at least partly by the guide shoulders 43 and 45.

Numerous modifications may be made to the described conveyor 1 within the inventive idea without leaving the scope of the present invention. For example, it would be possible to use three or more parallel belts 14 by interposing between each pair of adjacent belts a guide beam similar to the beam 33.

Claims (6)

WHAT WE CLAIM IS:

1. A continuous belt conveyor for step feeding portions of sheet material, particularly preshaped or punched pieces of cardboard or the like, to a user machine; said belt conveyor being configurated so as to define conveying compartments each adapted to accommodate a respecitve one of the pieces, and comprising at least two parallel spaced, endless toothed belts having coplanar conveying runs and each being wound around a respective pair of gear wheels; a beam extending longitudinally between the or each pair of adjacent belts and having an upper flat surface arranged above said belts and defining a support for said pieces to be advanced and tie bars connecting said belts together to define said conveying compartments. a portion of each said tie bar extending over the beam(s) to bridge the same.

2. A conveyor as claimed in claim 1, wherein slide shoes extend laterally of each belt and engage slidably in a groove provided along the lateral surface of the beam or a respective one of the beams to support the respective belt relative to said beam in such a position that the belt is disposed at a level lower than that of the upper surface of said beam, and said tie bars are spaced above the beam(s).

3. A conveyor as claimed in claim 1 or 2, comprising two lateral longitudinal elements rigid with the beam(s) and extending along said belts external thereto; each of said two lateral elements being bounded upperly by a flat surface coplanar with said upper surface(s) of the beam(s) and defining with said upper surface(s) a support and sliding surface for said preshaped pieces.

4. A conveyor as claimed in claim 3, wherein said coplanar surfaces are lapped metal surfaces.

5. A conveyor as claimed in claim 3 or 4, wherein said lateral elements are provided with guide shoulders arranged to co-operate with the transverse ends of said preshaped pieces, one of said shoulders supporting a knife disposed vertically above the upper flat surface of the relative flat element and defining therewith a slide slot for said preshaped pieces.

6. A continuous belt conveyor substantially as described with reference to the accompanying drawings.