GB1559973A

GB1559973A - Depalletizer

Info

Publication number: GB1559973A
Application number: GB2967175A
Authority: GB
Original assignee: Unilever PLC
Current assignee: Unilever PLC
Priority date: 1975-07-15
Filing date: 1975-07-15
Publication date: 1980-01-30
Also published as: FR2318089B1; FR2318089A1; BE844166A; NL7607759A; DE2631942A1

Description

(54) DEPALLETIZER (71) We, UNILEVER LIMITED, a company organised under the laws of Great Britain, of Unilever House, Blackfriars, London E/C 4, England, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to apparatus for removing from storage articles such as boxes, cases, and so on, hereinafter referred to collectively as packages. This procedure, known as depalletizing, is commonly used in warehouses containing large numbers of stacked packages from which a selection has to be made to make up individual orders for distribution.

The known methods of depalletizing display considerable disadvantages. It is known, for example, to depalletize by successively removing layers or parts of layers from the top of a stack of packages with the aid of a suction device. Apart from the relatively high cost of the apparatus required, there is the disadvantage that during removal of a number of packages at a time too much air can easily reach the suction head from underneath, as a result of which the lifting capacity greatly diminishes. Furthermore, if the packages are not completely closed the contents can easily be damaged, for example, with packages containing powders.

Another depalletizing method involves gripping the sides of a layer of packages and then lifting it from the stack. As high lateral pressures are generally required for a layer consisting of a number of packages, this leads in pratice to a limited lifting capacity, while at the same time the packages can easily be damaged.

It has also been proposed to depalletize packages by using an apparatus in a fixed location to which the stacked packages have to be brought, which apparatus comprises an extendable part of a conveyor roller system, with the leading roller contacting the stacked packages in turn and by frictional contact raising the packages to a position where they ride over the leading roller and pass to fixed conveyor rollers for removal elsewhere. This arrangement has the disadvantage of requiring the stacked packages to be brought to the depalletising apparatus and also that the apparatus cannot readily be used for depalletising stacks of different sizes of packages.

The present invention provides an improved depalletising apparatus which can be used without the danger of damaging the packages or their contents, and is suitable for depalletising different types of packages.

According to the invention a depalletising apparatus comprises a slide movable horizontally towards and away from a stack of packages, a movable driven surface defined by a roller rotatable about a horizontal axis, the roller being resiliently mounted on the slide, movement of the slide towards the stack of packages bringing the movable surface into resilient contact with a package and exerting on the package a progressively increasing frictional lifting force to lift the package, and driven conveyor means mounted on the slide for removing the lifted package.

In using the apparatus the driven surface is moved and the conveyor means is set into motion, and then the slide is moved forwards towards the packages, for example boxes, until the driven surface contacts the side of a package, and as the slide continues to move forward, increasing frictional pressure is built up between the driven surface and the package until the package is moved upwards.

When the package reaches a predetermined tilted position, the rotatable roller passes under the package, and then the package is carried over the roller on to the associated conveyor means on the slide which removes the package to a point of collection for further distribution. By using an apparatus as described in which progressively increasing frictional pressure is exerted by the driven surface on the packages, the apparatus is able to depalletise different sizes and weights of packages.

The roller can be resiliently mounted on the slide by using compression springs and can be mounted with an arm or arms to restrain its movement to a plane.

When the outer surfaces of the packages to be depalletised are not flat but are, for example, curved, the profile on the driven surface can be adapted thereto, so as to give a greater area of contact where the driven surface and the package touch each other.

Such an adapted profile is, for example, advantageous for the depalletising of bottles.

The conveyor means can conveniently comprise a conveyor belt and the belt can pass around the driven roller so that the belt forms the driven surface which contacts the packages.

The apparatus of the invention is preferably constructed so as to be suitable for depalletising packages, for example rectangular boxes, which are stacked in a plurality of adjacent lines and rows, and also in multiple layers. For packages lying behind each other, the slide on which the driven surface and associated conveyor means are mounted should be movable sufficiently far forward that after a first row of packages has been removed, a second and any subsequent rows of packages behind the first row can be reached and depalletised.

After the top layer of packages has been removed, for the removal of lower layers, it is necessary that the driven surface and associated conveyor means mounted on the slide and the packages to be depalletised should be movable vertically in relation to one another.

This can either be done by moving the stack of packages upwards on a vertically movable loading platform, or preferably by making the slide vertically movable adjacent to the stationary stack of packages.

When stacked packages are depalletised in the manner described above, it is often desirable in connection with the operations to be performed after their removal, to remove the packages at fixed time intervals. For packages stacked in a horizontal layer the movement of the slide in a horizontal direction towards the packages can be adapted to the friction occurring between the driven surface and the packages when they touch and to the speed of rotation of the driven roller in such a way that packages lying behind each other can be removed at equal time intervals.

In order to equalise the interval between package removal during the change-over to a new layer, and to make the interval the same as between the removal of two packages in the same layer, the package conveyor means can be stopped for a suitable time whilst the roller is being repositioned for the new layer.

A plurality of movable driven surfaces can be provided for lifting simultaneously a plurality of packages in different lines.

Apparatus according to the invention is illustrated by way of example with reference to the accompanying drawings, in which: Figure 1 is a schematic elevation of an apparatus according to the invention in use; Figure 2 is a schematic elevation of an alternative apparatus according to the invention in use; and Figure 3 is a schematic side view of the apparatus according to Figure 1, used for the depalletising of boxes.

In Figure 1, a roller 1 is rotatable about its axis in the direction of the arrow 2. When the roller 1 is placed in contact with a box 3 under sufficient pressure, the friction between the roller and the box 3 causes the box 3 to be lifted to assume the position 4 when the roller 1 is rotated.

The required degree of pressure between the roller I and the box 3 is obtained by moving a slide 5 in the direction of the arrow 6. The roller 1 is mounted on an arm 7, which is attached to the slide 5 through a helical spring 8. A conveyor belt 9 is also mounted on the slide 5 using guide rollers 10.

After the box 3 has been lifted up to the position 4, the roller 1 slips under the box and the box passes over the roller 1 until it lands on the conveyor belt 9 and is removed for further distribution.

In Figure 2, a smaller end guide roller 10a for the conveyor belt 9 also functions to lift the package 3, by frictional contact through a part 11 of the conveyor belt 9. The smaller end guide roller 10a is connected with a helical spring 8 to upper guide roller lOb which is mounted with the other guide rollers 10, lOc on the slide 5. The roller lOa is mounted on the slide 5 by arms so that it is resiliently mounted to move in a plane. In use the slide is moved towards the package 3 until the smaller end guide roller lOa brings the belt 9 into contact with the package and sufficient frictional lifting force is exerted to lift the package (as shown by the dotted line), which then is removed on the conveyor belt 9.

Figure 3 shows how a stack 12 of boxes is depalletised using apparatus according to the invention. Two boxes 3 have already been removed from the top layer of the stack 12, and are carried away on the conveyor belt 9.

When the slide 5, on which the conveyor belt 9 and the lifting roller 1 are mounted, moves at uniform speed in the direction indicated by the arrow 13, the intervals 14 between the removed boxes are practically the same, which is advantageous for further automatic distribution.

When one layer of boxes has been removed, the slide 5 and the assembly mounted thereon are withdrawn and then moved downwards with respect to the stack 12, by means not shown. The depalletising apparatus can thus be positioned one box-level lower to enable the next layer of the stack to be depalletised.

The whole assembly mounted on the slide 5 is preferably movable, for example on rails (not shown), along a row of stacked packages for depalletising different types of packages to order.

WHAT WE CLAIM IS: 1. A depalletising apparatus comprising a slide movable horizontally towards and away from a stack of packages, a movable driven surface defined by a roller rotatable about a horizontal axis, the roller being resiliently mounted on the slide, movement of the slide towards the stack of packages bringing the movable surface into resilient contact with a package and exerting on the package a progressively increasing frictional lifting force to lift the package, and driven conveyor means mounted on the slide for removing the lifted package.

2. An apparatus according to claim 1 in which the roller is mounted on the slide to move in a plane parallel to its axis of rotation and to the direction of movement of the slide.

3. An apparatus according to Claim 1 or Claim 2 in which the roller is resiliently mounted on the slide with compression springs.

4. An apparatus according to any one preceding Claim in which the conveyor means comprises a conveyor belt.

5. An apparatus according to Claim 4 in which the conveyor belt passes around the rotatable roller to form the movable driven surface.

5. An apparatus according to any of the preceding claims, the slide being vertically movable for lifting and removing successive layers of packages from a stationary stack thereof.

6. An apparatus according to any one of the preceding claims in which the roller and the conveyor means are movable at right angles to the direction of movement of the slide towards a stack of packages for depalletising packages in adjacent stacks.

7. An apparatus according to any one of the preceding claims comprising a plurality of movable driven surfaces for lifting simultaneously a plurality of packages.

8. A depalletising apparatus substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. packages for depalletising different types of packages to order. WHAT WE CLAIM IS:

1. A depalletising apparatus comprising a slide movable horizontally towards and away from a stack of packages, a movable driven surface defined by a roller rotatable about a horizontal axis, the roller being resiliently mounted on the slide, movement of the slide towards the stack of packages bringing the movable surface into resilient contact with a package and exerting on the package a progressively increasing frictional lifting force to lift the package, and driven conveyor means mounted on the slide for removing the lifted package.