GB2028269A - An apparatus for unloading a layer or layers of crates, especially crates for bottles, from a pallet - Google Patents

Abstract

An apparatus for unloading crates from a pallet is built up from a horizontal rectangular frame (2) being displaceable as a whole. The said main frame (2) consists of an outer frame (4) and an inner frame (5), being intercoupled with one another with some play. The inner frame (5) comprises a slideably mounted auxiliary frame (8) within which a slideable sledge (14) is supported. The uppermost layer of crates can be seized between two abutment edges (17, 18) being mounted upon the auxiliary frame (8) and the sledge (14) respectively. Perpendicular hereto a plurality of pivotable hooks (20) are mounted, being able to engage below the upper edge of a crate. <IMAGE>

Description

SPECIFICATION An apparatus for unloading a layer or layers of crates, especially crates for bottles, from a pallet The present invention concerns an apparatus for unloading crates, especially crates for bottles, being arranged layerwise upon a pallet. This apparatus is composed of a main frame comprising an auxiliary frame being shiftably supported within the main frame. The auxiliary frame is provided with movable members, which cooperate with the uppermost layer of crates to be unloaded. The said movable members consist of clamping edges which can be folded down and back over an arc of 90 . When being folded down, the said edges are able to contact the lowermost region of two opposite sides of the uppermost layer of crates, especially crates for bottles, to be unloaded.

Various embodiments are known of an apparatus of the above mentioned type. The disadvantage of the known apparatus is, that crates or layers of crates resting against one another and being seized by the clamping edges are only retained by frictional force. In the known apparatus a considerable clamping force has to be exercised in order to have the relaive clamping edges retain all the crates satisfactorily. The said edges therefore operate in the lower region of the sides of crates, this crate region comprising most of the (plastic) material of crates; moreover the widest contours of bottles are to be found in said lower region. The result of the action of the edges will moreover cause the clamping forces to be transmitted appropriately to those crates located more inwardly on the pallet.

When the outside of a crate or crates will become moist or wet, however, a reduction of the coefficient of friction will occur in the known apparatus, causing the clamping edges to act insufficiently and crates to fall down, instead of being unloaded.

A so-called "high stacking" in the known apparatus, may decrease the unfavourable effect as mentioned hereinbefore, since the respective pallet is then ascended step by step and the layer or layers of crates to be unloaded is (are) only displaced horizontally. After the uppermost layer of crates has been seized, the said pallet will be descended slightly so as to release the relative layer etc. If a so-called "low stacking" method is performed, however, problems may occur, since the seized layer of crates is then not only displaced horizontally but also upwardly and downwardly, so causing the occurrence of vertical accelerating forces.

The present invention aims to obviate or alleviate the aforementioned problems and to obtain a more positive grip upon a layer, in particuiar an uppermost layer, or layers of crates, especially crates for bottles, to be unloaded, this in spite of the fact that the contours of a layer or layers of crates often do not correspond to one another, because their intitial stacking was performed in an inaccurate manner.

This aim is attained in the apparatus in accordance with the invention in that: - a sledge is slideably supported within the auxiliary frame in a direction corresponding to the direction of travel of the said auxiliary frame, the said sledge being provided with a drive; - both sledge and auxiliary frame comprise a fixed abutment edge, extending transversely towards the direction of travel of the sledge and the auxiliary frame; and in that -the auxiliary frame comprises a plurality of hooks, pivotable in a plane perpendiculartothe direction of travel of the axiliaryframe.

When actuating (energising) the drive of the sledge, its abutment edge will abut against the side of the uppermost layer of crates, especially crates for bottles, to be unloaded, causing the said sledge to come to a standstill. Then the auxiliary frame starts moving until its abutment edge abuts against the other side of the uppermost layer of crates. This creates the advantage that the auxiliary frame is directed accurately and will therefore always obtain the same position with respect to the uppermost layer of crates to be unloaded. Now the pivotally supported hooks of the auxiliary frame can be swung from an inactive to an active position and engage behind existing apertures in the crates, without impinging on, and thus damaging, any bottles in the said crates.One can determine in advance where there is sufficient space available between the bottles in order to adaptthe position of the hooks within the auxiliary frame.

Afurther important advantage of the apparatus in accordance with the invention is that a considerable reduction can be obtained in the forces by means of which the abutment edges of the frames press against the layer or layers of crates to be unloaded.

This in comparison with known apparatus, in which the seizing of crates takes place by friction through clamping forces. The present invention provides a more positive support for crates to be unloaded, in particular crates for bottles.

In a preferred embodiment of the apparatus according to the present invention the abutment edges may comprise cams, engaging below the edges of crates. These abutment edges need no longer operate in the lower, strongest region of crates to be unloaded. The said abutment edges presently function more as feel and directing means, so that the contact with the crates can take place in the upper region. The cams provide for an additional carrying capacity.

It is further observed that the use of swinging hooks for seizing a crate or crates, is known. The known hooks can, however, be employed only for a crate or crates which is or are stacked very accurately, that is to say for layers of crates now showing any differences in the manner of their being stacked, but being stacked properly and well-controlled. The said known hooks are therefore not capable of seeking a deviating position of a crate.

When applying pal lets upon which crate-packets have been stocked layerwise (mostly by a retailer) which pallets have to be unloaded aftertheircon- veyance to a different place, one has to reckon with the occurrence of small deviations in a transverse direction of the pallet and with greater deviations in the longitudinal direction of the pallet. The apparatus in accordance with the invention, is, however, able to bridge any lesser or greater deviations in the position of stacked layers of crates, in particular of crates for bottles, due to its seeking capability provided by the sledge with the auxiliary frame.

The invention will be illustrated, by way of exampie only, in the accompanying drawings, showing an embodiment of the apparatus for unloading a layer or layers of crates, especially crates for bottles, from a pallet, whilst further a view is shown of a formation of crates upon a pallet.

Figure lisa top-view of the most important part of the present apparatus; Figures 2 and3 show vertical sections according to lines ll-ll and Ill-Ill in Figure 1; Figure 4 shows a diagrammatical top-view of a pallet upon which some filled crates are arranged and a view of the frames and of the points where and the direction towards which the hooks engage in the crates.

The apparatus comprises a frame 1 shown only partially, within which a main frame 2 is slideably arranged in longitudinal direction through some rolls 3. The main frame comprises an outer frame 4 and a inner frame 5, the inner frame 5 resting with some play on the outer frame 4 through strips 6 and some vertical pins 7. Within the main frame 2 there is an auxiliary frame 8 consisting of longitudinal beams 9 and transverse beams 10. At one end the longitudinal beams 9 are provided with a roll 11, whilst the other end is provided with an eye 12. The rolls 11 are displaceable within the inner frame 5 whilst each eye 12 can slide on a short bracket 13 of the inner frame 5.

A sledge 14 is slideably supported within the auxiliary frame 8 which is built up of elements 9-12.

The sledge 14 has the same direction of travel as that of the auxiliary frame 8. For this purpose, the sledge is provided with four rolls 15 which can move along the transverse beams 10 of the auxiliary frame 8. The sledge 14 is provided with a drive 16 consisting of a pneumatic cylinder of which the cap-side rests on the auxiliary frame 8 whilst the rod-side is connected with the sledge 14. Both the auxiliary frame 8 and the sledge 14 are provided with fixed abutment edges 17, 18. Upon energising the drive 16 these abutment edges will move reciprocally. Both abutment edges 17, 18 are provided with cams 19 extending inwardly for a purpose to be described hereinafter.

As can be seen best in Figure 3, the auxiliary frame 8 comprises a plurality of hooks 20 which are pivotable around shafts 21. These shafts are positioned parallel with the transverse beams 10 so that they stand perpendicular to the abutment edges 17, 18. Each of the shafts 21 is provided with a sprocket wheel 22, on which there runs a chain 23. The ends of this chain are connected with a rod 24. This rod extends through a cylinder 25 which is fixedly secured to a longitudinal beam 9 of the auxiliary frame 8, a double acting piston secured to the rod 24, being provided within the cylinder 25. Figure 3 shows the hooks 20 in their active position, their entire inactive position being shown in broken lines.

As can be seen best in Figure 2, the shafts 21 are supported pivotally with respect to the auxiliary frame 8. From this it results that these shafts always have the same position with respect to the abutment edge 17. This constant position is important since the hooks 20 on these shafts 21 have to be directed very accurately with respect to the crates 26 shown in this Figure 2. This requirement is connected with the fact that the hooks 20 should possess a considerable length, so as to be able to grip at any time into the side-aperture 27 of the crate concerned, regardless of the inaccurate linked position of the adjacent crate (see Figure 4). The great length of these hooks, might cause their point to impinge on the bottles in the crate. The hooks should, therefore, always engage a region lying above the partitioning of the crate.This means that the plane within which each hook is pivotal (a plane located perpendicular to the direction of travel of the auxiliary frame 8) should mainly coincide with an intermediate wall of the partitioning (see Figure 2 and the arrows in Figure 4).

In connection herewith the hooks 20 are arranged adjustably on the shaft 21 so that their position may be fixed by means of a locking screw 28.

During its outgoing stroke the drive 16, to wit the pneumatic cylinder, will displace the sledge 14 or the auxiliary frame 8 until one of these elements contacts the inner frame 5 of the main frame 2. As soon as one of the elements 8 or 14 has come to a standstill, the other element will be moved by the drive 16 until same has also attained its outmost final position. These final positions are defined by distance bolts 29 which, are arranged on a longitudinal beam 9 of the auxiliary frame 8 and on the sledge 14. The head of these bolts contacts an abutment 30 of the inner frame 5. In this position of the auxiliary frame 8 and the sledge 14, a pallet loaded with crates is placed below the apparatus, however only after having positioned the frame 1 at such a height that the main frame 2, the auxiliary frame 8 and the sledge 14 are located above the uppermost layer of crates.An other solution is, however, to give frame 1 a fixed position and to adjust the pallet to be unloaded to the correct height.

After these preparations, the drive 16 is excited causing at least one ofthe abutment edges 17 or 18 to move sideways until it contacts the outmost crate or crates of the uppermost layer. The drive 16 remains activated so causing also the other abutment edge -18 or 17 to be displaced and to contact the opposite crates. At that moment the situation illustrated in Figure 2 is reached. Subsequently the pneumatic cylinder 25 is excited and the shafts 21 are turned through the chain 23, thus enabling the hooks 20 to be engaged through the side-apertures 27 of the crates 26 (see the situation shown in Figure 3). In the same Figure 2 the maximum deviation of .he position of the crates is indicated by the letters a, b and c Figure 4 gives a picture of deviations in the position of crates 26 which are bridged by means of the hooks 20. The crates are stacked on a pallet and the greatest deviations occur in the longitudinal direction of this pallet, as can be seen in Figure 4. A new pallet with stacked layers of crates to be unloaded is advanced below the apparatus in the same direction. Finally it is observed that one or more impulse senders 32 are mounted between the inner frame 5 and the outer frame 4. The actuation of these senders will switch off the drive of the main frame 2 as soon as the movement of the inner frame 5 is impeded, for example when there is an obstruction within the path of an unloaded crate.

The advantages of the present invention consist in that now a layer or layers of crates to be unloaded, can be seized positively instead of being held by a clamping (frictional) force. This is accomplished in accordance with the invention by employment of a sledge 14, enabling an accurate directing of an auxiliary frame 8 with respect to a layer or layers of crates and by employing hooks, which will engage through apertures in the crate or crates to be unloaded.

The present invention is very appropriate when irregularly (manually) stacked crates, especially crates for bottles upon a pallet, have to be properly unloaded from the said pallet, but the apparatus in accordance with the invention may, however, also be employed for loading a layer or layers of packets of crates, especially crates for bottles, upon one the other.

Claims (6)

1. An apparatus for unloading crates arranged layerwise upon a pallet, by means of a main frame with an auxiliary frame being slideably supported therein and provided with moveable members which cooperate with the uppermost layer of crates to be taken off, wherein: - a sledge (14) is slideably supported within the auxiliary frame (8) in a direction corresponding to the direction of travel of the said auxiliary frame, the said sledge being provided with a drive (16); - both sledge and auxiliary frame comprise a fixed abutment edge (17, 18), extending transversely towards the direction of travel of the sledge and the auxiliary frame, and - the auxiliary frame comprises a plurality of hooks (20), pivotable in a plane perpendicular to the direction of travel of the auxiliary frame.

2. An apparatus according to claim 1, wherein the two abutment edges (17, 18) are provided with inwardly extending cams which can engage under the edge of a crate or crates.

3. An apparatus according to claim 1 or 2, wherein the main frame (2) consists of an inner frame and an outer frame (4,5) which are jointly slideable in the frame (1) of the apparatus, the inner frame resting with some play on the outer frame by means of vertical pins (7), whilst impulse senders (32) are arranged between the inner and the outer frame which switch off the drive of the main frame (2) as soon as the movement of the inner frame (5) is impeded.

4. An apparatus according to any of the foregoing claims, wherein the hooks (20) have a length which is at least three times as much as the greatest wall-thickness of a crate whilst said hooks are arranged adjustably on a common shaft (21).

5. An apparatus according to any ofthefore- going claimsrwherein the drive (16) of the sledge (14) and of the auxiliary frame (8) and the pivoting of the hooks (20) is effected by pneumatic rrreans.

6. An apparatus for unloading crates, the apparatus being substantially as hereinbefore described with reference to the accompanying drawings.