GB1600666A

GB1600666A - Load-handling apparatus

Info

Publication number: GB1600666A
Application number: GB23472/78A
Authority: GB
Original assignee: Schaefer Foerderanlagen und Maschinenbau GmbH
Current assignee: Schaefer Foerderanlagen und Maschinenbau GmbH
Priority date: 1977-06-28
Filing date: 1978-05-26
Publication date: 1981-10-21
Also published as: DE2729139C2; FR2395925A1; SE418726B; DE2729139A1; BE868141A; FR2395925B1; SE7807252L; ATA417978A; AT359919B; CH629722A5; NL7806977A; JPS5413178A

Abstract

Drive for a gripper carriage (2) which can be moved to and fro between two fixed end positions, preferably intended for palletising bottle crates (5) in layers, using gripping elements (3) attached to the gripper carriage. In order to bring the gripper carriage in the shortest possible time from one end position precisely to the other end position, the drive (1) has a crank (12) which can be pivoted by a drive unit (11) in a plane (E) parallel to the plane of movement of the gripper carriage and is connected by its free end, via a point of engagement vibrating transversely with respect to the direction of movement of the gripper carriage, to said gripper carriage such that it moves analogously thereto. <IMAGE>

Description

(54) IMPROVEMENTS IN OR RELATING TO LOAD-HANDLING APPARATUS (71) We, H. SCHAEFER KG., Forderanlagen-Maschinenfabrik, a Kommanditgesellschaft organised under the laws of the German Federal Republic, of Dieselstrasse 3, D-8043 Unterfohring, Munchen, Germany, 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 present invention relates to loadhandling apparatus and more particularly to load-handling apparatus comprising a pickup carrier movable reciprocably between two end positions and used, for example, for handling articles arranged in layers on pallets.

In the handling of articles in this way, a pick-up engages, for example from within, bottle cases forming a layer, by means of its pick-up elements, picks up an entire layer, lifts it and then moves it horizontally by means of the pick-up carrier and deposits it on a pallel or on a layer already positioned thereon.

When the articles are to be removed from the pallets, the procedure is reversed, i.e.

each layer of bottle cases is lifted from the pallet and is deposited on a platform for the removal of the articles and splitting up of the layer.

The horizontal movement of the pick-up carrier is difficult to control in previously proposed constructions. It should be executed in the shortest possible time and should be carried out in a precise manner in the end positions, and the means for achieving the movement should be of simple construction and should function in a troublefree way.

According to the present invention, there is provided load-handling apparatus comprising a pick-up carrier reciprocable between two end positions, and a drive device for driving the carrier between the end positions, said drive device comprising a crank connected at one end to drive means for pivotal movement in a plane parallel to the plane of movement of the pick-up carriage, and connected at its other end to the carriage by means of a slide member which is movable along a shaft which extends transversely to the direction of movement of the carriage, said shaft having at each of its two ends a toothed wheel fast for rotation with the shaft, each of said wheels being in engagement with a first stationary rack mounted above the wheel and with a second rack which is on the carriage beneath the wheel.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a section, on line I-I of Figure 3 of load-handling apparatus in accordance with the invention; Figure 2 is a front view of the apparatus shown in Figure 1; Figure 3 is a plan view of the apparatus; and Figure 4 is a section similar to that of Figure 1 but showing a pick-up carrier of the apparatus in its other end position.

The load-handling apparatus comprises a drive device 1 and a pick-up carrier 2 used for handling articles arranged in layers on pallets, and which is driven by the drive device 1. On its underside, the carrier has a lifting means in the form of internal pick-ups 3 whereby an entire layer 4 of bottle cases 5 can be picked up and transported. The lifting means is indicated only schematically in Figure 1. As can be seen from other Figures, the pick-up carrier 2 is displaceably mounted in a frame 6 which has parallel side walls 7, which are each connected at their lower free edges to rails 8 which project inwardly at right angles to the walls 7 and support rollers 9 on which the pick-up carrier 2 runs.

The parallel side walls 7 of the frame 6 are inter-connected by a bridge element 10.

Provided midway along the bridge element 10 is an electric motor 11 which forms a drive unit for a crank 12 which is connected to the motor 11 at one of its ends. The crank 12 is pivotal in a plane E parallel to the plane of movement of the pick-up carrier 2.

The crank 12 which is driven by being pivoted in a stepwise manner between two oppositely directed end positions in which it is parallel with the side walls 7 serves to move the pick-up carrier 2 from the end position illustrated in Figure 1 into the end position shown in Figure 4, and back again.

At its free end, the crank 12 is connected to a sliding sleeve 13 which is mounted so as to be longitudinally displaceable on a shaft 14 extending transversely of the direction of travel V of the Pick-up carrier 2. The shaft 14 has a toothed wheel 15 at each end. Each of the toothed wheels 15 meshes at the top with a first rack 16 which is stationary and secured to the frame 6, whereas at the bottom each toothed wheel meshes with a second rack 17 which is mounted on the movable pick-up carrier 2. To avoid excessive loading of deflection of the shaft 14, the sliding sleeve 10 is of a suitably large length.

The apparatus operates in the following manner.

The electric motor 11 drives the crank 12 so that the latter is pivoted in the plane E.

When the direction in which the crank 12 lies coincides with the direction of travel V, i.e. when it is in one of the two end positions, the drive unit is stopped. The lifting means of the pick-up carrier 2 is then actuated either to place the goods on a pallet or to remove them therefrom. On completion of this operation, the electric motor 11 starts up again and pivots the crank in the direction of the arrow P to move it from one end position into the other end position, e.g.

from the position shown in Figure 1 to that shown in Figure 4. At the odder end position, the electric motor 11 is stopped by means of, for example, a limit switch which senses the crank. The pick-up carrier 2 is then located in the other end position and the lifting means is then again actuated either to deposit goods onto a pallet or to remove them therefrom.

In the apparatus described, the rotation of the drive unit is converted into a reciprocating movement imparted to the pick-up carrier, and stoppage of the drive unit in each of the dead centre positions of the crank results in the pick-up carrier being brought precisely into the end positions. The aft, provided at each of its ends with a toothed wheel, has the effect of displacing the pickup carrier in a precise manner and free from skewing. The sliding sleeve, which establishes the actual connection between the shaft and the crank, also contributes to this precise displacement, the sleeve oscillating during rotation of the crank on the shaft, with a shifting point of engagement. The movements of the toothed wheels, mounted on and rotating with the shaft, are selfsynchronizing.

The toothed wheels transmit the movement of the crank to the pick-up carrier. The arrangement of the racks above and below the toothed wheels results in what is known as an extended crank drive.

When the pick-up carrier 2 is to be moved into various different end positions, it is possible to vary the length of the crank 12 within fixed limits. The end positions can thus be pushed outwards and brought back in again in relation to the bridge member 10.

The pick-up carrier may be equipped with other types of pick-up element, e.g. elements which pick-up a complete layer of articles from the outside.

In the preferred embodiment described above, the crank drive is a mechanically simple connecting member between the drive unit and the pick-up carrier. The sinusoidal path of movement resulting from the crank drive offers the advantage that the pick-up carrier accelerates and slows down gently in the zone of the end positions, so that damage to the goods carried is reduced, while at the same time an economical speed can be achieved. Furthermore, stoppage at the end positions occurs in an extremely precise manner, since the crank passes its dead centre as this happens. The simple construction of the drive provides the further advantage that the displaced masses are extremely small.

The connection between the crank drive and the pick-up carrier, via the transverse shaft and toothed wheels, offers the advantage that the rotary movement of the crank does not have a deleterious effect upon the linear travel of the pick-up carrier. Precise linear travel of the pick-up carrier, free from skewing, is ensured even without any precise guiding of the carrier. The arrangement whereby the toothed wheels, each meshing with a rack, are solidly connected to the shaft, ensures that the toothed wheels move in synchronism.

Because of the stabilized meshing of the toothed wheels with the racks, it is also possible to arrange a plurality of pick-up carriers side-by-side and to power them by means of a common crank drive. Here again, skewing of the pick-up carriers is precluded.

WHAT WE CLAIM IS: 1. Load-handling apparatus comprising a pick-up carrier reciprocable between two end positions, and a drive device for driving the carrier between the end positions, said drive device comprising a crank connected at one end to drive means for pivotal movement in a plane parallel to the plane of movement of the pick-up carriage, and connected at its other end to the carriage by means of a slide member which is movable about a shaft which extends transversely to the direction of movement of the carriage, said shaft having at each of its two ends a

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. The crank 12 which is driven by being pivoted in a stepwise manner between two oppositely directed end positions in which it is parallel with the side walls 7 serves to move the pick-up carrier 2 from the end position illustrated in Figure 1 into the end position shown in Figure 4, and back again. At its free end, the crank 12 is connected to a sliding sleeve 13 which is mounted so as to be longitudinally displaceable on a shaft 14 extending transversely of the direction of travel V of the Pick-up carrier 2. The shaft 14 has a toothed wheel 15 at each end. Each of the toothed wheels 15 meshes at the top with a first rack 16 which is stationary and secured to the frame 6, whereas at the bottom each toothed wheel meshes with a second rack 17 which is mounted on the movable pick-up carrier 2. To avoid excessive loading of deflection of the shaft 14, the sliding sleeve 10 is of a suitably large length. The apparatus operates in the following manner. The electric motor 11 drives the crank 12 so that the latter is pivoted in the plane E. When the direction in which the crank 12 lies coincides with the direction of travel V, i.e. when it is in one of the two end positions, the drive unit is stopped. The lifting means of the pick-up carrier 2 is then actuated either to place the goods on a pallet or to remove them therefrom. On completion of this operation, the electric motor 11 starts up again and pivots the crank in the direction of the arrow P to move it from one end position into the other end position, e.g. from the position shown in Figure 1 to that shown in Figure 4. At the odder end position, the electric motor 11 is stopped by means of, for example, a limit switch which senses the crank. The pick-up carrier 2 is then located in the other end position and the lifting means is then again actuated either to deposit goods onto a pallet or to remove them therefrom. In the apparatus described, the rotation of the drive unit is converted into a reciprocating movement imparted to the pick-up carrier, and stoppage of the drive unit in each of the dead centre positions of the crank results in the pick-up carrier being brought precisely into the end positions. The aft, provided at each of its ends with a toothed wheel, has the effect of displacing the pickup carrier in a precise manner and free from skewing. The sliding sleeve, which establishes the actual connection between the shaft and the crank, also contributes to this precise displacement, the sleeve oscillating during rotation of the crank on the shaft, with a shifting point of engagement. The movements of the toothed wheels, mounted on and rotating with the shaft, are selfsynchronizing. The toothed wheels transmit the movement of the crank to the pick-up carrier. The arrangement of the racks above and below the toothed wheels results in what is known as an extended crank drive. When the pick-up carrier 2 is to be moved into various different end positions, it is possible to vary the length of the crank 12 within fixed limits. The end positions can thus be pushed outwards and brought back in again in relation to the bridge member 10. The pick-up carrier may be equipped with other types of pick-up element, e.g. elements which pick-up a complete layer of articles from the outside. In the preferred embodiment described above, the crank drive is a mechanically simple connecting member between the drive unit and the pick-up carrier. The sinusoidal path of movement resulting from the crank drive offers the advantage that the pick-up carrier accelerates and slows down gently in the zone of the end positions, so that damage to the goods carried is reduced, while at the same time an economical speed can be achieved. Furthermore, stoppage at the end positions occurs in an extremely precise manner, since the crank passes its dead centre as this happens. The simple construction of the drive provides the further advantage that the displaced masses are extremely small. The connection between the crank drive and the pick-up carrier, via the transverse shaft and toothed wheels, offers the advantage that the rotary movement of the crank does not have a deleterious effect upon the linear travel of the pick-up carrier. Precise linear travel of the pick-up carrier, free from skewing, is ensured even without any precise guiding of the carrier. The arrangement whereby the toothed wheels, each meshing with a rack, are solidly connected to the shaft, ensures that the toothed wheels move in synchronism. Because of the stabilized meshing of the toothed wheels with the racks, it is also possible to arrange a plurality of pick-up carriers side-by-side and to power them by means of a common crank drive. Here again, skewing of the pick-up carriers is precluded. WHAT WE CLAIM IS:

1. Load-handling apparatus comprising a pick-up carrier reciprocable between two end positions, and a drive device for driving the carrier between the end positions, said drive device comprising a crank connected at one end to drive means for pivotal movement in a plane parallel to the plane of movement of the pick-up carriage, and connected at its other end to the carriage by means of a slide member which is movable about a shaft which extends transversely to the direction of movement of the carriage, said shaft having at each of its two ends a

toothed wheel fast for rotation with the shaft, each of said wheels being in engagement with a first stationary rack mounted above the wheel and with a second rack which is on the carriage beneath the wheel.

2. Apparatus according to claim 1, wherein the crank is of a variable length.

3. Load-handling apparatus substantially as hereinbefore described with reference to the accompanying drawings.