GB2395670A - Apparatus for making crackers. - Google Patents

Abstract

Apparatus for making cracker comprises three distinct sections. In the first section cracker snaps are assembled into bandoliers (Figs. 2, 3), in the second section the snaps are glued to cracker blanks (Figs. 4-6) and in a third operation the blanks are formed into cylinders (Figs. 7, 8). To assemble the snaps into a bandolier, they are laid between projections (16, Fig. 3) and sandwiched between tapes (20, 22, Fig. 3) moved round on a cylindrical carrier (13, Fig. 3). Such a bandolier is fed to another cylindrical carrier (38, Fig. 6) and the leading snap is severed to drop between fingers (40, Fig. 6) of the carrier. Each snap is brought to the bottom of the carrier where a blank is raised so that the ends of the snap adhere to the blank. The blank with its snap is moved on underneath a tubular mandrel 50 which is lowered to bend the blank into U-section. Suction through apertures 51 in the mandrel retain the edge portions of the blank to the tube as they are successively bent over by arms 61 with rollers 65 to adhere together. The mandrel is then raised and the now cylindrical blank is removed by an endless belt 55 co-operating with the glued seam.

Description

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1 2395670

Apparatus for making Crackers This invention relates to apparatus for making crackers. Crackers are quite complicated structures, and it has 5 proved difficult to mechanise the process. The custom is for a lot of the work to be done by hand, often by home workers who are supplied with the necessary materials and knowhow by the cracker manufacturing companies. However, this is not very efficient, and the costs are threatening to 10 undermine the industry.

It is an aim to mechanise the preliminary stage of cracker manufacture, turning a light cardboard blank into a cylinder with a snap glued to its interior.

A snap has two aligned tape-like elements overlapped 15 and adhered together with a material which, when the snap is pulled, parts with a bang. The free ends of the snap have to be adhered to the main cylindrical body of the cracker beyond the two necks, so that when the cracker is pulled and one of the necks parts, the two elements of the snap also 20 separate.

In order to mechanise the attachment of snaps to the blanks, it is necessary to get them into regular order so that they are susceptible to mechanical handling. But it they remain loose it is extremely difficult, if not imposs 25 ible. They tend to be flimsy structures of poor material, and they are apt to twist and bend, and to alter their stiffness, with atmospheric conditions. Therefore, a first

cle : ce. le. e' object is to bring the snaps to a cracker making machine in a regular manner and under full control.

This can be achieved with apparatus for assembling cracker snaps into a bandolier, the apparatus comprising a 5 carrier rotatable about a horizontal axis and presenting two matching co-axial annular arrays of radially projecting teeth, and two matching co-axial cylindrical surfaces of a radius at least as great as the radius to the roots of the teeth but less that the radius to the tips of the teeth, 10 and, for each cylindrical surface, two spindles for mounting sticky tape reels, a first pair below and a second pair above the axis of the carrier, the arrangement being such that, in operation, tape from the first pair is directed sticky side outwards onto the cylindrical surfaces, snaps 15 are laid parallel to the carrier axis to locate between adjacent pairs of teeth over at least part of each arc below top dead centre where the sticky tape is presented by the associated cylindrical surface, and tape from the second pair is directed sticky side down onto the parts of the tape 20 from the first pair exposed between the laid snaps, and across those snaps, in a second arc beyond top dead centre from the first mentioned arc, the carrier being rotated in correspondence with the laying of the snaps.

The rotation may be intermittent and hand or treadle 25 generated. The snaps may then be laid in groups by hand, with the carrier stationary. When the first arc is full, the carrier is rotated to shift those just laid snaps over top dead centre into the second arc where they are made

start; ele ee Àe e fully captive by the tapes from the second pair. The carrier is then stopped again and more snaps laid, and so on. The sticky tape ensures that they can be laid between the teeth and retained there even over the steep section of 5 the first arc.

Alternatively, the rotation could be substantially continuous, although its speed will generally be control-

lable by the operator. This will be slow enough for the operator to drop snaps between successive pairs of teeth as 10 they approach top dead centre.

Preferably each cylindrical surface will be between two similar co-axial sprockets, making four annular arrays of teeth. The tips of the teeth thus form two annular channels with castellated side walls which will constrain the tapes 15 to register with the cylindrical surfaces.

In case the tapes do not perfectly align and a tape from the second pair adheres by an edge to the cylindrical surface, each such surface may have an associated scraper to ensure the bandolier parts from the carrier.

20 The snaps are now in a bandolier and this is readily susceptible to an automatic feed which will deliver snaps one by one to apparatus that will adhere them to the blanks from which the cracker cylinders are formed.

A typical blank is shown in Figure 1 of the accompany 25 ing drawings. It is a generally rectangular sheet 1 of very light board or stiff paper. Out of this cut or stamped two arrays of diamond shaped apertures 2 (known henceforth as the diamonds) extending across the blank to

: cte e:: es-:: te'ecec: form end portions 3 and a central portion 4. A snap 5 is to be laid longitudinally of the blank to traverse narrow necks between two pairs of diamonds 2 and to be adhered to the end portions 3 at zones 6.

5 According to the present invention there is provided apparatus for attaching snaps to the interior face of a cracker blank, the apparatus comprising means for delivering and locating a blank of the kind described on a vertically movable support, a carrier rotatable about a horizontal axis 10 above the support with matching co-axial annular arrays of radially projecting fingers, means for moving the leading end of a bandolier of snaps downwards towards the pairs of fingers at top dead centre, means for indexing the carrier about its axis, means operable between movements of the 15 carrier for severing the leading snap from the bandolier to cause it to drop between each pair of fingers at top dead centre, means for retaining the snaps on the carrier tangential to their locus as they are indexed towards bottom dead centre, means for applying adhesive to points near the 20 ends of the snaps on the sides to face downwards at bottom dead centre, and means for raising and lowering the support between movements of the carrier to bring the blank thereon up to the snap at bottom dead centre, the ends of the fingers which have located that snap projecting through 25 diamonds of the blank and the blank being pressed against the adhesive coated portions of the snap, and then to disengage the blank with its snap from the carrier.

This may be modified by applying the adhesive to spots

Àe I on the end portions of the blank which are to be covered by the snap, rather than to the snap itself.

Preferably, the carrier has co-axial rollers aligned with the adhesive zones and of a radius such that they 5 provide a backing for each snap as the blank is brought up against it.

Also, when the snaps are severed from the bandolier, they will be supported by these rollers. The snaps will not lie on their edges; they will fall over effectively flat to 10 the cylindrical surfaces of the rollers. So these rollers form part of the means for retaining the snaps tangentially to their locus. They may be assisted by fixed guides curved about the carrier axis with a radius slightly greater than that of the rollers so that they trap and then support the 15 snaps as they are carried down towards bottom dead centre.

A further, complementary guide, horizontally movable transverse to the carrier axis, effectively extends each fixed guide. These horizontal guides of blade-like form support each snap on the final leg to the bottom dead centre 20 position at points away from the adhesive zones and they remain in place between the snap and blank while the adhesive sets. Then they are moved back out of the way to allow the blank and its snap to be progressed to the next stage. They then advance again to support the next snap as 25 it leaves the fixed guide.

The blank with its snap now has to be rolled into a cylinder and retained in that form.

There is also provided apparatus for forming a flat

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blank of stiffly flexible material into a cylinder, the apparatus comprising a hollow, horizontal, cylindrical mandrel with apertures along its length, means for raising and lowering the mandrel, a pair of arms parallel to the 5 mandrel with means for moving them successively and separ-

ately into co-operation with the upper side of the mandrel when that is lowered, means for applying suction to the mandrel when that is lowered, means for progressing and locating a flat blank underneath the mandrel when that is 10 raised and supporting the blank clear of the vertical movement of the mandrel, means for applying adhesive to one edge of the blank parallel to the mandrel, and a movable belt with a lower run parallel to the upper side of the mandrel to co-operate therewith when that is raised, the 15 arrangement being such that a presented and located blank is folded into U-section by the lowering of the mandrel, one arm is moved to curve over one edge portion of the blank, which is retained curved when that arm is removed by the suction acting through the holes, the other arm is moved to 20 curve over the other edge portion to stick that to said one edge, the mandrel is raised when the other arm is withdrawn, and the belt, co-operating with the glued seam, shifts the cylinder thus formed horizonatally off the mandrel while pressing on the seam to help confirm the adhesion.

25 Preferably the arms will be elongate rollers.

There are of course subsequent stages before the crackers are finished, such as inserting the contents of the cracker and crimping the necks between the central portion

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4 and the end portions 3, but those are not of present concern. For a better understanding of the invention, one embodiment will now be described, by way of example, with 5 reference to the remaining figures of the accompanying drawings, in which: Figure 2 is a front elevation of apparatus for forming a bandolier of snaps, Figure 3 is a side elevation of that apparatus, 10 Figure 4 is a diagrammatic side elevation of apparatus for attaching snaps to flat blanks, Figure 5 is a detail of that apparatus showing the delivery arrangement for the snaps, Figure 6 is a diagrammatic end elevation of the 15 apparatus of Figure 4, Figure 7 is a diagrammatic side elevation of apparatus for forming the blanks into cylinders, and Figure 8 is a diagrammatic end elevation of the apparatus of Figure 7.

20 The apparatus of Figures 2 and 3 is an upstanding U shaped frame 10 with a base 11 and two vertical arms 12 formed by narrow rectangular plates. A carrier 13 is journalled between these plates 12 at about the mid-height.

It comprises a spindle 14 and two matching sprocket wheels 25 15 at each end. Each sprocket wheel has two sets of teeth 16 flanking a plain cylindrical surface 17. The radius of the surface 17 is intermediate the radii of the crests and roots of the teeth 16. This carrier can be rotated by a

r rte'c; I'te handle 18 outside one of the arms 12.

Below the carrier 13 each arm 12 carries an inwardly projecting shaft 19 which provides a spindle for a reel of sticky tape 20. These reels are aligned with the surfaces 5 17. Similar shafts 21 at the tops of the arms 12 carry further reels 22 of sticky tape, similarly aligned. Below these, and just clear of the path of the teeth 16, the arms 12 are spanned by a bar 23 with bushes 24 that define gaps for the guidance of tape from the reels 22 onto the wheels 10 15.

The wheels 15 are axially adjustable on the spindle 14, and the reels 20 and 22, and the bushes 24, are correspon-

dingly axially adjustable.

For operation, sticky tape from the reels 20 is led as 15 indicated by the chain dotted line in Figure 3 onto the wheels 15, sticky side outwards. The tape lies in contact with the surfaces 17 over an arc of slightly more than 180 , including the top dead centre position. Tape from the reels 22 is guided as indicated by the broken lines to 20 traverse the rod 23, where it reverses direction to present its sticky side down towards the surfaces 17.

In use, snaps 5 are laid between the teeth 16 in the arc preceding the top dead centre position, the direction of motion being indicated by the arrow in Figure 3. Because 25 the radius of the surfaces 17 is greater than the radius to the roots of the teeth, the snaps engage the sticky surface of the tape from the reels 20, and are retained as soon as they are placed. A group of snaps may be positioned while

eeese t-e the carrier 13 is stationary, and then it is rotated on by the handle 18. This brings the snaps over the top dead centre position and just beyond that into contact with the tape from the reels 22. The snaps are thus very securely 5 trapped, and the exposed sticky parts of the tapes come together and are no longer exposed. A bandolier is thus formed and is directed away to a collecting box.

The snaps now have to be attached to blanks such as the one of Figure 1. This is done by the apparatus of Figures 10 4, 5 and 6. The bandolier is led to the top of the appar-

atus, where its leading end is directed downwards through a feed device 30 best understood from Figure 5. Directly below this there is a transfer assembly 31 which takes the snaps around and down to a succession of blanks presented on 15 a movable platform 32, where they are glued in place and then progressed onwards.

The feed device is simply a vertical guide 33 in the form of a fixed plate and two cams 34 rockable about a common horizontal axis in front of the plate and creating 20 gaps through which the bandolier is fed. Rotating the cams 34 back and forth pinches and releases the bandolier, the pinching action indexing its leading end downwardly.

Immediately below this plate and cam assembly there are cutting devices 35, synchronized with the movements of the 25 cams which sever the bandolier tapes at each side so that the leading snap falls down on to the transfer assembly 31.

Instead of cams, there could be reciprocating sprung pawls.

.e etete The assembly has a horizontal axle 36 vertically below the gaps between the plate 33 and the cams 34. At each end it carries a disc 37 and, beyond that, a roller 38. The axial spacing of the discs 37 corresponds to the longitudi 5 nal spacing of the arrays of diamonds 2. Each disc 37 has short radially projecting arms 39 equi-spaced around the axle 36, and each arm terminates in two circumferentially spaced fingers 40. The radius of each roller 38 is less than the radius to the tips of the fingers 40 but slightly 10 greater than the radius to the roots of those fingers.

Also, the circumferential spacing of the arms 39 is such that a tangent to the circle through the roots of the fingers 40 at a point mid-way between two paired fingers clears the nearest fingers 40 of the adjacent arms 39. The 15 reason for this will be apparent later. The axial spacing of the wheels 37 corresponds to the longitudinal spacing of the arrays of diamonds 2.

Associated with each disc 37 there is an arcuate guide 41 centered on the axle 36 and extending from near the top 20 dead centre position to near the bottom dead centre posi-

tion. Its inner radius is slightly less than the radius to the tips of the fingers 40. At the bottom, its guide and support function is taken over by a horizontally reciproc-

able flat blade 42. This can be moved between a retracted 25 position as shown in full lines in Figure 6 and a working position shown in broken lines where its end portion extends just beyond bottom dead centre.

Below this transfer assembly the movable platform 32

le ties tIt receives blanks when in a lowered position and then raises each blank towards the transfer assembly. It has apertures 43 which will register with the fingers 40 at bottom dead centre, those fingers penetrating into the apertures when 5 the platform is raised. The spacing of the arms 39 ensures that the adjacent fingers do not interfere. The blanks may be brought onto the platform by moving belts 44 which run over channels or gaps 45 in the platform to allow the latter to be raised without interfering with the belts. A stop 46 10 is raised to arrest each blank in the correct position as it is delivered, and is subsequently lowered to allow the blank to progress.

There are also means (not shown) for applying a spot of adhesive near each end of each snap on the side which is to 15 be presented to the blank. This could be varied by applying a spot of glue to each end portion 3 of the blank where the snap is to be attached. The adhesion zones 6 register with the two rollers 38.

The operation of this apparatus is as follows.

20 When two pairs of fingers 40 are at top dead centre another two pairs of fingers are at bottom dead centre. At this point the leading snap of the bandolier is cut off by the devices 35 and drops to be cradled by the top pairs of fingers. It will also bear on the rollers 38 and generally 25 will topple over to lie flat to those rollers. Ignoring for the time being what is happening at the bottom dead centre position, the transfer assembly 31 is then rotated through an arc corresponding to the circumferential spacing of two

: te. c; t adjacent arms 39. This brings another two pairs of fingers 40 to top dead centre where another snap is delivered between those fingers, the bandolier having been indexed on by the feed device 30. This continues, and the first snap 5 is soon brought under the arcuate guides 41. If it is still on its edge, the guides push it flat to the rollers 38. As that snap is brought round underneath the axle 36, the guides 41 keep it in place still substantially flat against the rollers 38. In due course, that snap approaches 10 bottom dead centre, and its support is transferred from the guides 41 to the blades 42. When the fingers 40 bring it to the bottom dead centre position, the blades 42 are projected to maintain support of the snap.

Meanwhile, a blank 1 has been delivered to the lowered 15 platform 32 and arrested by the stop 46. The platform is then raised so that the fingers 40 at bottom dead centre enter the apertures 43, having first penetrated through adjacent diamonds 2 of the blank. The glued zones 6 of the snap are now pinched between the rollers 38 and the end 20 portions 3 of the blank backed by the platform 32. The thin blades 42 are trapped elsewhere between blank and snap and do not affect this operation. There is a short dwell while the glue sets, and then the blades 42 are retracted and the platform 32 is lowered, bearing the blank with the snap 25 attached. The stop 46 is also retracted, and the blank is progressed on to the next stage.

While the gluing operation is in progress, there are fingers 40 at top dead centre receiving a snap from the

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:T e; '. j bandolier. The process is therefore substantially continu ous. The blank with its snap now has to be formed into a cylinder, and this is achieved by the apparatus of Figures 5 7 and 8. The heart of this is a cylindrical mandrel 50 which is horizontal, aligned with the direction of feed of the blanks, and hollow with a series of apertures 51 along its length. At its upstream end it has an elbow 52 with one leg 53 pointing downwards, and it is supported at this end 10 by a member 54 which can raise and lower it. Its downstream end is closed. In its upper position, the mandrel co-

operates closely with an endless belt 55 whose lower run moves in the direction of feed of the blanks. In its lowered position, the leg 53 enters the mouth of a suction 15 tube 56 and seals to it so that air is drawn into the mandrel through the apertures 51.

The blanks are delivered by horizontal belts 57 with a longitudinal gap 58 between them through which the mandrel 50 can pass with clearance. There is a stop 59 to register 20 each blank below the mandrel 50.

On opposite sides of the belts 57 there are rocker arms 60 and 61 that can swing about horizontal axes and which respectively carry on pivots at their upper ends subsidiary arms 62 and 63. These project towards each other and at 25 their free ends they respectively carry rollers 64 and 65 parallel to the mandrel. The rollers are constrained to move horizontally, but with the facility to lift. When the mandrel 50 is lowered, the arms 60 and 61 can be selectively

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rocked for the rollers to co-operate with the upper side of the mandrel.

There are means (not shown) for applying adhesive along one edge of each blank when delivered by the belts 57.

5 A cycle of operation begins with the mandrel 50 raised and a blank with a snap attached being delivered by the belts 57, registered by the stop 59, and having glue applied. The rollers 64 and 65 are kept swung back out of the way at this point. The mandrel is then lowered by the 10 member 54, and as it passes through the gap 58 it bends the blank into a U-shape, which is maintained by the rollers 64 and 65 as the mandrel passes between them. The mandrel stops with the elbow 52 engaged with the suction tube 56 and with its axis below the arms 62 and 63. Air is therefore 15 now being drawn in through the apertures S1. The arm 60 is then rocked to bring the roller 64 below the gap 58, which causes the non- glued side edge portion of the blank to be curved over the mandrel. The suction through the apertures 51 maintains it there while the roller 64 is withdrawn 20 again. This is immediately followed by the roller 65 being brought below the gap 58, causing the other side edge portion of the blank to be curved over the mandrel. It presses the glued edge down on to the edge held by suction.

After a short dwell for the adhesive to set, the roller 65 25 is withdrawn.

The mandrel is then raised again, breaking the connec-

tion between the elbow 52 and the suction tube 56, and as it reaches its upper position, the lower run of the belt 55

, ft . d ' it. I, engages the glued seam. This not only shoots the now completed cylinder off the mandrel, but also its pressure helps to confirm the seam.

The cycle is repeated, beginning with the delivery of 5 another blank.

Claims (8)

t; tI, t-: r' Claims

1. Apparatus for attaching snaps to the interior face of a cracker blank, the apparatus comprising means for deliver-

ing and locating a blank of the kind described onto a 5 vertically movable support, a carrier rotatable about a horizontal axis above the support with matching co-axial annular arrays of radially projecting fingers for receiving between them snaps delivered thereto parallel to said axis at a region above said axis, means for indexing the carrier 10 about its axis, means for retaining the snaps on the carrier with their flat sides tangential to their arcuate path as they are indexed towards bottom dead centre, and means for raising and lowering the support between movements of the carrier, the raising bringing a blank located on the support 15 up to the snap at bottom dead centre so that the ends of the fingers which have received that snap project through diamonds of the blank and the end portions of the blank are pressed against end zones of the snap, there being mutual adhesion between the snap and the blank at said zones, and 20 the lowering disengaging the blank with its snap from the carrier.

2. Apparatus as claimed in Claim 1, wherein there are means for applying adhesive to said zones of the snaps on the sides to face downwards at bottom dead centre.

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3. Apparatus as claimed in Claim 1, wherein there are means for applying adhesive to spots on the end portions of the blank which are to be engaged by said zones of the snap.

4. Apparatus as claimed in Claim 1, 2 or 3, and further

Àe;e cee c'e comprising means for moving the leading end of a bandolier of snaps downwards towards the pairs of fingers in the region of top dead centre of the carrier, and means operable between movements of the carrier for severing the leading

5 snap from the bandolier to cause it to drop between those fingers. 5. Apparatus as claimed in any one of Claims 1 to 4, wherein the carrier has a cylindrical surface of which the fingers are proud registering at least with the adhesive 10 zones of the snaps carried thereby, and of a radius such that it provides a support against which the snaps will lie flat upon delivery and a backing for each snap as the blank is brought up against it.

6. Apparatus as claimed in Claim 5, wherein the means for 15 retaining the snaps tangential to their arcuate path include a fixed guide curved about the carrier axis with a radius slightly greater than that of the cylindrical surface so that it traps and then supports the snaps as they are carried down towards bottom dead centre.

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7. Apparatus as claimed in Claim 6, wherein the retaining means further include lower end extensions of said guide of horizontal blade- like form which serve to support each snap on the final leg to the bottom dead centre position at points not in registry with the adhesive zones, the exten 25 signs being horizontally movable transverse to the carrier axis and being controlled to remain in place between the snap and the blank while the adhesive sets, to move back out of the way to allow the blank and its snap to be progressed

to the next stage, and then to advance again to support the next snap as it leaves the fixed guide.

8. Apparatus for attaching snaps to the interior face of a cracker blank substantially as hereinbefore described with 5 reference to Figures 1, 4, 5 and 6 of the accompanying drawings.