GB2168304A - Swingable conveyor - Google Patents

Abstract

The invention relates to package handling apparatus for transferring elongate packages such as potato crisp packages onto a conveyor from a transfer station at which a package is supported generally vertically in a pocket adjacent to the end of the conveyor. The apparatus comprises three transfer arms 46 each having a suction head 16 for holding the package. Each arm is swingable about a horizontal axis 17 transverse to the conveyor between a position with its head in engagement with the package at the transfer station and a position where the package can be deposited on the conveyor. Each head is rotatable about the axis of its arm as the arm swings from the transfer station to the conveyor in order to deposit the package on the conveyor transversely thereof. <IMAGE>

Description

SPECIFICATION Package handling apparatus The invention relates to package handling apparatus for transferring elongate packages onto a conveyor. The apparatus of the present invention may be used in conjunction with apparatus for testing for leaks in a flexible package containing loosely packaged product and some air which is broadly as described in our published UK patent application 2138150. However, the apparatus of the present invention is particularly useful for use in combination with any apparatus for performing operations on the package at adjacent stations as the package passes along a conveyor with the stations so spaced that each package can occupy only one station without overlapping into another station.The length of such an apparatus increases if an increased length has to be provided for each station and this increased length results in an increased linear speed for the packages for a given number of packages per minute in the apparatus.

The increased size is inconvenient in itself and can add costs to the total apparatus and the increased linear speed can lead to unreliability.

In accordance with the present invention there is provided package handling apparatus for transferring elongate packages onto a conveyor from a transfer station at which a package is supported generally vertically adjacent the end of the conveyor, the apparatus comprising a transfer arm having a head for holding the package, the arm being swingable about a horizontal axis transverse to the conveyor between a position with its head in engagement with a package at the transfer station and a position where a package can be deposited on the conveyor, wherein the head is rotatable about the axis of the arm as the arm swings from the transfer station to the conveyor in order to deposit the package on the conveyor transversely thereof.By rotating the package about the axis of the arm during the swinging movement of the arm, any need for a separate orientation station to twist the package from a longitudinal to a lateral position with respect to the conveyor is avoided, thus saving space and a further handling operation. The swinging movement is required to position each package with a relatively short dimension longitudinally of the conveyor in order to enable the conveyor to operate at a low speed whilst passing a large number of packages and to allow stations where operations have to be carried out to be close together.

Preferably the head is a suction head.

Preferably there are three heads projecting equiangularly from a rotary support and the support is rotated through 1200 during each transfer to swing the heads through the same angle, the operative head releasing the package after 90" of this movement and the other heads remaining inoperative.

The apparatus of the invention may comprise a support rotatable about an axis transverse to the conveyor, at least one arm projecting radially from the support and having a head thereon, a bevel gear coaxial with the support and rotatable relative thereto, a brake to selectively hold the bevel gear against rotation or allow it to rotate, and a further bevel gear on the arm in engagement with the axial bevel gear whereby rotation of the support about its own axis causes the arm to swing and engagement of the bevel gears causes the arm to rotate about its own axis when the first mentioned bevel gear is held against rotation but allows the arm to be free of rotation when the brake is released.

An embodiment of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a pictorial view of part of a package handling apparatus incorporating an apparatus for transferring elongate packages to a conveyor; and Figure 2 is a cross-section through the apparatus for transferring the packages showing greater detail.

The apparatus shown in figure 1 incorporates a slightly modified version of the apparatus disclosed in our published UK Patent Application No.

2138150 and that part of the apparatus will be described only briefly. The invention will be described in relation to the handling of a series of packs of potato crisps but it should be understood that it could be used with packages of other products.

Individual packs of crisps which have just been filled arrive one at a time at a pocket 14 constituting a transfer station. A rotary transfer mechanism 15 incorporates three suction heads 16 which rotate in steps around a horizontal axis 17 in such a manner as to pick up individual packs of crisps and transfer them to a belt conveyor 18. Conveyor 18 passes under three probing stations 19, 21 and 22 at each of which a series of weighted probes are applied to the pack in such a way as to partially compress it if it incorporates a substantial air leak.

The third probing station 22 incorporates a sensing element 23 which senses the distance through which the weighted probes descend on to the pack and provides a measure as to the airtightness of the pack. Further details of the arrangement just described can be obtained from UK Patent Specification 2138150. Conveyor 18 is of course arranged to index the individual packs in steps and thus the packs leave the probing station 22 one at a time.

From conveyor 18 each individual pack is transferred to a short upwardly inclined conveyor 24 and the conveyors are operated in such a way that the pack comes to rest on this conveyor. Conveyor 24 is then pivotted downward to leave the pack supported on a weighing platform 25 at which it is checked whether the pack lies within prescribed weight limits. Any pack which is found to be unsatisfactory, either due to leakage or due to having the wrong weight, is ejected laterally from the apparatus by means not shown. Conveyor 24 thus transfers a satisfactorily tested pack to a further conveyor 26 which is of no concern to the present invention.

Figure 2 shows further details of the rotary trans fer mechanism which constitutes an embodiment of the package handling apparatus of the present invention. A fixed base member 31 is mounted to the frame 33 shown in figure 1 by a series of four horizontal bars 32. an electromagnetic brake 34 having a friction facing 35 is secured to the base member 31. Bearings 36 and 37 in the base member 31 and brake 34 support a shaft 38 for free rotation with respect to the base member. Further bearings 39 and 41 mount a rotatable support 42 for rotation with respect to the base member 31 and the shaft 38. Shaft 38 also carries a bevel gear 43 lying on the axis 17. The bevel gear 43 is secured to shaft 38. Shaft 38 also carries a brake disc 44 for rotation with the shaft.When the electromagnetic brake 34 is energised, disc 44 is drawn against friction facing 35 to bring the disc, shaft and bevel gear 43 to rest. The circumstances under which this braking is required will be described subsequently.

Support 42 incorporates three bearing bosses 45, only one of which is shown in figure 2, and these are mutually spaced at 1200 around the support.

Each boss supports a transfer arm 46 which carries at its outer end a suction head 16. Arm 46 is supported in boss 45 by two mutually spaced bearings 47 and 48 which also incorporate airtight seals.

Arm 46 is hollow and has an opening 49 communicating with the space between bearings 47 and 48.

This space also communicates as shown with a suction supply manifold 51 incorporated in the base member 31. In use, connection 52 to the manifold is connected through a pipe (not shown) to a source of vacuum. Manifold 51 has an opening 52 exposed to a face of the base member 31 which is in sliding, sealing contact with the rotary support 42. Opening 52 extends through an arc of approximately 90" so that suction is applied to the interior of the boss 45 and hence to the suction head 16 so long as vacuum is supplied through connection 52 and the suction head is in this arcuate region.

Arm 46 is in itself free to rotate within bearings 47 and 48 so that the head 16 is also rotatable.

However, the inner end of the arm 46 carries a second bevel gear 53 in mesh with the bevel gear 43.

As previously explained briefly, there are three arms corresponding to the arm 46 and each is mounted in bearings corresponding to the bear ings 47 and 48 in a boss 45 and has the same kind of air connection to a further suction head carried on the arm. The other arms also incorporate bevel gears corresponding to gear 53 which mesh with the axial bevel gear 43.

Support 38 has an end cover 54 for the bevel gear set and this end cover carries a shaft 55 by means of which the carrier 38 is rotatable.

The basic function of the apparatus shown in fig ure 2 will now be described and its effect when used in conjunction with the apparatus of figure 1 will be described subsequently.

Shaft 55 is arranged to be rotated in steps of 1200 with the result that during each such move ment, the subsequent arm 46 and suction head 16 arrives in the position shown in figure 2. During this action the arm and head shown have also swung through an angle of 1200 away from the position shown. During the first 90" of this movement, brake 34 is applied. The result is that the bevel gear 43 remains stationary and because bevel gears 43 and 53 are the same size, arm 46 is caused to rotate about its own axis at the same rate at which the carrier 38 is rotated about bevel gear 43.In order to achieve a rotation of 90" about its own axis for shaft 46 and suction head 16 as the arm swings through the first 90" of its arc, the brake 34 is applied during this period, to hold bevel gear 43 against rotation and thus cause the desired rotation of arm 46. After the first 900 of movement of the carrier 42 with respect to base member 31, the brake is released with the result that shaft 38 rotates with the carrier, its three arms and three bevel gears, thus no longer causing arms 46 to rotate about their own axes. The fact that there are three such arms and three bevel gears such as 53 is contributory to ensuring that axial bevel gear 43 does rotate with the carrier 42 in preference to there being further rotation of arms such as 46 about their own axes.

The arcuate opening 52 from manifold 51 ensures that suction is applied through opening 49 and arm 46 to suction head 16 during the angle of arcuate movement for which opening 52 is in register with the interior of the boss 45. At other angular positions of the boss 45 around the axis 17, no suction is applied.

The apparatus of figure 2 is installed in figure 1 as shown with the axis 17 horizontal and transverse to the conveyor 18. The arcuate opening 52 is so arranged that suction is applied to the heads 16 from their horizontal position adjacent to pocket 14 until immediately after 90" of rotation in an anticlockwise direction as shown in figure 1 at which stage the suction head is in register with the beginning of the conveyor 18.

In use, packs of potato crisps are fed down vertically to the pocket 14 from a crisp packing machine (not shown) which delivers the packets in a vertical orientation, that is with the longest dimension extending vertically. A suction cup 16 has suction applied to it at the location of the pocket and so takes hold of the packet. This occurs with the carrier 42 stationary. The carrier 42 is then indexed in an anticlockwise direction as shown in figure 1 through an angle of 1200. During the first 900 of this movement, brake 34 is applied so that the suction head rotates about the axis of its arm 46; also, suction is being applied throughout this arc so that the crisp packet is held positively on the suction head. Thus the packet swings from the pocket 14 to a transfer station immediately above the end of conveyor 18 after 90" of movement. During the remaining 30 of indexing of the arm 46, the suction and the brake are both released so that the crisp packet is released from the suction head and the suction head no longer rotates. The packet is thus left on the conveyor with its longest dimension extending transversely thereof as required for further processing.

Pocket 14 incorporates one pair of fixed jaws 56 and another pair of movable jaws 57 which are caused to move away from the jaws 56 during the indexing movement of the arm 46 if this is necessary to cause the packet to clear the jaws 57.

Claims (5)

1. Package handling apparatus for transferring elongate packages onto a conveyor from a transfer station at which a package is supported generally vertically adjacent to the end of the conveyor, the apparatus comprising a transfer arm having a head for holding the package, the arm being swingable about a horizontal axis transverse to the conveyor between a position with its head in engagement with the package at the transfer station and a position where the package can be deposited on the conveyor, wherein the head is rotatable about the axis of the arm as the arm swings from the transfer station to the conveyor in order to deposit the package on the conveyor transversely thereof.

2. Package handling apparatus as claimed in claim 1 wherein the head is a suction head.

3. Package handling apparatus as claimed in claim 1 or claim 2 comprising three heads projecting equiangularly from a rotary support wherein the support is rotated through 120 during each transfer to swing the heads through the same angle, the operative head releasing the package after 90 of this movement and the other heads remaining inoperative.

4. Apparatus as claimed in any one of the preceding claims comprising a support rotatable about an axis transverse to the conveyor, at least one arm projecting radially from the support and having a head thereon, a bevel gear co-axial with the support and rotatable relative thereto, a brake to selectively hold the bevel gear against rotation or allow it to rotate and a further bevel gear on the arm in engagement with the axial bevel gear whereby rotation of the support about its own axis causes the arm to swing and engagement of the bevel gears causes the arm to rotate about its own axis when the first mentioned bevel gear is held against rotation but allows the arm to be free of rotation when the brake is released.

5. Apparatus as claimed in any one of the preceding claims in combination with apparatus for performing operations on the package at adjacent stations as it passes along the conveyor, the stations being so spaced along the conveyor that each packet occupies only one station without overlapping into another station.

Apparatus for transferring elongate packages to a conveyor substantially as described with reference to and as illustrated by the accompanying drawings.