Method and Device for Handling Ends for Tins

The invention relates to a method of handling round flat substantially identical ends for tins wherein the ends are provided in the form of a plurality of elongated stacks of ends, each stack comprising a plurality of separate ends in abutting relationship and surrounded by a sheet of material such as paper.

When, in particular in the supply of the ends to the transport member, a gap is formed between the transported ends, they may fall over due to lack of support by preceding or following ends. This involves a disturbance in the transport of the ends.

The invention has for its object to carry out the method in a manner such that the risk of disturbances is reduced. For this purpose the invention provides the method and the device described in claims 1 and 2 respectively. The device embodying the invention preferably has one or more characteristics defined in the further claims in order to provide a particularly effective device for feeding a closing machine without interruption and with the required supply rate, in which machine the tins are provided with ends.

In general the invention provides a device combining a high transport rate with high reliability i.e. a very low sensitivity to disturbance.

To give a concrete idea reference is made to a known device for transporting ends serving to close preservation tins. It is capable of transporting at the most about 500 ends a minute. In practice it is found that this device is not sufficiently reliable so that constant supervision by the staff is necessary in order to avoid stagnation in the production.

The device according to the invention is capable of transporting about 1000 ends a minute with a considerably improved reliability.

The invention will now be described more fully with reference to the accompanying drawings showing a few embodiments. The drawings show in:

FIG. 1 a drastically simplified, schematic perspective view of a complex machine comprising a device embodying the invention,

FIG. 2 a sectional view II--II in FIG. 1,

FIG. 3 a sectional view III--III in FIG. 1,

FIG. 4 a perspective view of a further embodiment of a combined machine in accordance with the invention,

FIG. 5 a further detailed, fragmentary, perspective view of detail V of FIG. 4 on an enlarged scale,

FIG. 6 a schematic plan view of the detail of FIG. 5,

FIG. 7 a cross-sectional view VII--VII of FIG. 5,

FIG. 8 a cross-sectional view VIII--VIII in FIG. 5,

FIG. 9 on an enlarged scale detail IX of FIG. 1,

FIG. 10 a cross-sectional view of a stack supply device of a further device embodying the invention,

FIG. 11 on an enlarged scale the stack unpacking device of FIG. 10,

FIGS. 12 to 14 and 16 to 19 fragmentary longitudinal views of a stack supply device to be arranged at the inlet end of the transport device embodying the invention in consecutive operational positions,

FIG. 15 a cross-sectional view of the stack unpacking device of FIG. 10 to be arranged at the input end of the transport device embodying the invention,

FIGS. 20 and 21 schematic views of the inlet end of the transport device of FIG. 1 embodying the invention in two different positions,

FIG. 22 a fragmentary side elevation of an inlet end of a further transport device embodying the invention, with which the stack supply device of FIGS. 10 to 19 can be connected,

FIGS. 23 and 24 schematic sectional views taken on the lines XXIII--XXIII and XIV--XIV respectively in FIG. 22 and

FIG. 25 a preferred variant of the sectional view of FIG. 23 on an enlarged scale.

FIG. 1 shows a combined machine 1 for introducing stacks 4 of ends 3 to the closing devices 2, which comprise means for shutting tins by a supplied end 3.

The stacks 4 of ends 3 are successively supplied in a stack supply device 89 in the direction of the arrow 5 by means not shown in FIG. 1 to a guide chute 6 to which is adjoined a reciprocatory pestle 7 for supplying a stack 4 of ends 3 alternatively to transport devices 8 and 9 according to the invention. For this alternating supply the inlet ends of the transport devices 8, 9 are coupled and movable in the direction of the arrow 10 so that alternately the inlet end of the device 8 and that of the device 9 are located in line with the guide chute 6, which is illustrated in FIGS. 2, 20 and 21.

A stationary frame 30 carries two brackets 28 pivoted thereto with the aid of shafts 87 for the devices 8 and 9 respectively. These brackets 28 and 29 are pivotable, as shown in FIGS. 20 and 21, by means of a hydraulic ram 88 between two positions in which the devices 8 and 9 respectively adjoin the guide chute 6. Thus a stack 4 of ends 3 is alternately supplied to the devices 8 and 9. The brackets 28 carry rollers designated by 14, about which endless ropes 11, 12, 13 are passing. A stack 4 of ends 3 is indicated by a broken circle.

The devices 8 and 9 have similar structures. Therefore, only the device 8 will be further described.

This device 8 comprises a transport member having the three endless ropes 11, 12, 13. A motor 15 with a transmission 16 serves to drive the ropes 11, 12, 13 with equal speeds v.sub.2. The operative parts of the two lower ropes 11, 12 and the upper rope 13 are parallel and are spaced apart by distances such that these operative parts together are capable of retaining the end 3 to be transported by clamping and of transporting them. The ropes 11, 12, 13 are adjoined through a transition zone 17 three further endless ropes 18, 19, 20. As shown in FIG. 3 the frame 30 carries at the transition zone 17 the rollers 14, about which are passed the endless ropes 11, 12, 13 and the ropes 18, 19, 20. A motor 24 serves to drive the ropes 18, 19, 20 with a speed v.sub.1, which is about half the speed v.sub.2 of the ropes 11, 12, 13. In order to ensure that the magazine 22 always contains the same stock of ends 3, a monitoring member 25 is coupled through a connection indicated by a dot-and-dash line to the motor 24 for control. The speed v.sub.1 of the ropes 18, 19, 20 is a variable speed determined by the working rate of the closing device 2 and may be 5 ms a minute. If the speed v.sub.2 of the ropes 11, 12, 13 is equal to 10 ms/sec, the stacks 4 of ends 3 are axially introduced in the ropes 11, 12, 13 at a rate of, for example, 15 ms/sec, at least a higher rate v.sub.3 than the speed v.sub.2 of the ropes 11, 12, 13, because stepwise introduced stacks 4 are brought into contact with the end 149 of a continuous stack of ends 148 (FIG. 9). The rearmost end 3a of the continuous stack 148 is held safely and stably in its adjoining position because the ropes 11, 12, 13 exert a propelling effect at three places of the circumference of the end 3a in the direction of the speed v.sub.2, since the speed of said end 3a is equal to the lower speed v.sub.1. It is ensured that a next stack 4 of ends 3 is brought into contact with the end 149 of the continuous stack 148 before this end 149 has reached the transition zone 17 to a next set of ropes 18, 19, 20.

During the introduction of a stack 4 the foremost cover 3b is exposed along its circumference to a braking force exerted by the ropes 11, 12, 13 and pushing this end 3b towards the stack 4 so that the end 3b cannot fall off.

FIG. 4 shows a complex machine 32. It comprises a feeding device 33 for supplying stacks 38 of ends 3 to ropes 35, 36, 37 driven by a motor 34 with a speed v.sub.2. These ends 3 are taken over via a transition zone 39 by three further transport ropes 40, 41, 42 after which the ends are guided around a bend 43 by a guide disc 62.

Along two further bends 44, 45 the ends are guided further to a closing device 46, above which is located the magazine 47 for the ends 3, the contents of which are maintained between two extreme values by means of two monitors 48, 49. The latter control a motor 50, which drives the ropes 40, 41, 42 with a variable speed v.sub.1.

FIG. 5 shows in further detail the structure of the bend 45, which is similar to that of the bends 43 and 44.

It will be obvious that owing to the presence of a bend the angular speed of ropes being in different positions relative to the centre of rotation has a value such that transported ends 3 can be in an inclined position after having passed around the bend. In order to avoid this, the angular speed of the ropes in the bend must everywhere be the same, which implies that ropes lying further outwards should have a higher linear speed. Two lower ropes 52, 53 and an upper rope 54 transport covers 3 along the bend 45. The rope 52 is guided by its active part by a guide 55, the rope 53 by a guide 56 and the rope 54 by a guide 57 formed, as is shown more in detail in FIG. 8, by a U-shaped profile beam 58 in which is located a U-shaped beam 59 movable from and towards the transport space i.e. the space bounded by the active parts of the ropes 52, 53, 54. Setting of said beam can be carried out by means of screws 60. They may also be used for adjusting the spring pressure exerted by the rope 54 on the transported ends. It is noted here that the ropes 52, 53 shown in FIG. 5 have no freedom of movement so that it is necessary to use separate spring means for transporting the ends in a clamped state. The rope 52 is guided in the bend by a guide disc 61. The guide disc 61 has for this purpose on the underside a continuous groove 63. On the corresponding top side the guide disc 61 has a rope 64 formed by a fixed, circulating belt. In the zone in which the belt 64 transports the ends 3 in the bend 45 the rope 54 is put out of operation and guided straight on to follow the bend around a guide roller 65. Locally the effect of the rope 54 is taken over by a rope 66 arranged on a driven toothed belt 67.

FIG. 6 shows the construction described in a plan view in which the take-over of the functions of the respective ropes is shown more clearly. From this Figure it appears how the toothed belt 67 is guided by its active part i.e. the part facing the guide disc 62 by an arcuate guide 68.

FIG. 8 shows the construction described with reference to FIG. 5 on the inlet side of the bend 45.

The stack supply device 91 of FIGS. 10 to 19 comprises as a variant of the stack supply device 89 three rollers 92, 93 and 94 forming guide means for a stack 4 of ends 3 and extending mainly in the axial direction of the set of ropes 211, 212, 213 of the front end of the transport device 210 of FIGS. 20 to 25. The stack supply device 91 has a stock holder 95 for stacks 4 of ends 3 packed in sheets, for example, of paper, a bottom of which slopes downwards to a chain conveyor 97 bounding the stock holder and having chains 103 passed around sprockets 102 and having transverse bars 98 and a guide plate 99.

Between the transverse bars 98 there are stack receiving spaces 100 so that when the chain conveyor 97 is driven in the direction of the arrow 101 a stack 4 of ends 3 is received in each space 100 and then supplied rolling along the guide plate 99 to an unpacking device 104, which comprises three rollers 92, 93 and 94. The roller 93 co-operates with a roller 107 as a pair for conducting away a sheet 108. The rubber-coated rollers 107 and 93 are driven by a motor 110 via a chain drive 109 so that the rollers 93 and 107 and also the rollers 92 and 94 indirectly driven via the stack 4 rotate in the direction indicated by arrows 111.

The unpacking device 104 comprises a knife holder 112, which is urged by means of a leaf spring 113 in the direction of the arrow 114 towards the stack 4 until a hard steel stop 115 fastened to the knife holder 112 strikes the stack 4 in order to hold a knife 116 of the knife holder 112 along the stack 4 so that the sheet 108 forming the packing is cut off the stack 4, however, without damaging the ends. The knife holder 112 is adjustably fastened to a frame 118 by means of set screws 117 and fastening bolts 120 lying in elongate holes 119. The stop 115 co-operating with the roller 93 to form a bulging part 143 in which the preferably milled knife 116 can start cutting.

The rollers 92, 93 and 107 are rotatably journalled in the frame 121 comprising guide bars 122 for guiding a support 123 in the axial direction of ropes 211 to 213. An air cylinder 124 moves the support 123 in the direction of the arrow 125 to and fro. The support 123 has an arm 127 that can be turned by means of a cylinder 126 and that carries at the lower end a retaining support 128. The rope 213 is arranged centrally on the underside and the ropes 211 and 212 are arranged slightly above the middle of the stack 4 (see FIG. 23), so that the retaining support 128 can engage from above the stack 4 between the ropes 211 and 212. The ropes 211 and 212 are each guided in a rope guide 129, which is arranged with springs 130 in a U-profile. As shown in FIG. 25 these springs are leaf springs. Thus the stack 4 is stably enclosed between the ropes 211, 212 and 213.

In order to enhance the safety against falling over of the covers 3 the transport space between the ropes 211, 212, 213 is bounded on the underside by guide plates 218, which are outwardly and upwardly directed at an angle g of 60.degree. to the horizon. When ends 3 of a different diameter are treated, the two ropes 211 and 212 are displaced by displacing the associated U-profiles 131 connected with brackets 219 by means of setting means with respect to a frame 220, for example, into the positions indicated by broken lines. The setting means comprise fastening plates 221 and 222 being at an angle p of preferably 48.degree.30' to the horizon and being mutually displaceable by means of bolts 223 lying in slots in the direction of the arrows 224.

The length of the rollers 92, 93, 94 is such that stacks 4 of great and different lengths can be processed. The pestle 132 is fastened to a support 133, which is reciprocated by means of a motor 134 driving a screw spindle 135 in the axial direction of the ropes 211 to 213. As an alternative the pestle 132 may be reciprocated by means of a pneumatic cylinder, preferably a known air cylinder, the piston of which has a fastening arm extending through a longitudinal slot of the cylinder, whilst means are provided for sealing the cylinder slot.

The control of the unpacking device 104 is illustrated in successive stages in FIGS. 12 to 19.

In the position shown in FIG. 12 the retaining support 128 and the pestle 132 are located at the two ends of the unpacking space and the roller 94 is in the deflected position indicated by broken lines in FIG. 10 so that a packed stack 4 can roll between the rollers 92, 93 and 94 in the direction of the arrow 136. The pestle 132 then moves into the position shown in FIG. 13 in which the packed stack 4 is urged against the retaining support 128, after which the pestle 132 is moved back over a small distance of, for example, 5 mms (FIG. 14) in order to leave some clearance at both ends of the stack 4 for releasing the sheet 108.

As shown in FIG. 15 the stack 4 is rotated by driving the rollers 92, 93 and 107, whilst the knife 116 cuts up the sheet 108 and peels it off the stack 4. The sheet 108 is conducted away between the rollers 93 and 107.

As shown in FIG. 16 the unpacked stack 4 is driven by the pestle 132 with the above mentioned speed v.sub.3, which exceeds the speed v.sub.2 of the ropes 211, 212, 213, the pestle pushing in front of it the retaining support 128 together with the support 123, whilst the stack 4 is clamped tight. The air cylinder 124 then operates as a counter-pressure spring. When the stack is engaged over a sufficient length between the ropes 211 to 213, so that these ropes produce sufficient counter-pressure, the retaining support 128 is turned away by means of the cylinder 126 from between the ropes (FIG. 17).

FIG. 18 shows that the whole stack 4 is located between the ropes 211 to 213. Then the pestle 132 and the retaining support 128 move back to their initial positions (FIG. 19), whilst the stack 4 is further transported by the ropes 211 to 213. Then a next packed stack 4 of FIG. 12 can drop in between the rollers.

FIG. 22 shows that the ropes 211 to 213 can be commonly driven with the same speed v.sub.2 by a motor 137 having pulleys 139 mounted on a common horizontal shaft 138. The ropes 211 to 213 are all positioned in a vertical plane and passed along guide discs 140 and stretching discs 141.