DE20100794U1 - Stroke converter - Google Patents

Description

Eisenführ, Speiser & Partner '·· European Patent At«£»eys %,· • Dipl.-Ing. Günther Eisenführ Hamburg Dipl.-Ing. Dieter K. Speiser Pafcntanwait Dr.-Ing. Werner W. Rabus E^Jcjpean Patent Attorney Dipl.-Ing. Jürgen Brügge Dipl.-Phys. Frank Meier Dipl.-Ing. Jürgen Klinghardt Dipl.-Ing. Klaus G. Göken Lawyers Jochen Ehlers Rainer Boehm Dipl.-Ing. Mark Andres SiljaJ.Greischel* Dipl.-Chem. Dr. Uwe Stilkenböhmer •Master in Df oil Dipl.-Ing. Stephan Keck Dipl.-Ing. Johannes M.B. Wasiljeff Munich Patent Attorney Patent attorneys Dr.-Ing. Stefan Sasse European Patent Attorneys Dipl.-Wirt.-Ing. Rainer Fritsche Lawyers Lbm.-Chem. Gabriele Leißler-Gerstl Ulrich H. Sander Dipl.-Ing. Olaf Ungerer Christian Spintig Patent Attorney Sabine Richter Dipl.-Chem. Dr. Peter Schuler Bremen, 16 January 2001 . Martinistrasse 24 Berlin D-28195 Bremen Patent attorneys Phone +49-(0)421-36 35 0 European Patent Attorneys Our reference: D 1651 MAN/mac/il/CITlU Fax +49-(0)421-337 8788 (G3I Dipl.-Ing. Henning Christiansen Fax +49-10)421-328 8631 (G4I
mail@eisenfuhr.com Dipl.-Ing. Joachim von Oppen http://www.eisenfuhr.com Dipl.-Ing. Jutta Kaden Applicant/Owner: DENNERLEIN GMBH Dipl.-Ing. Mathias Karlhuber Official reference number: New registration Alicante European Trademark Attorney Dipl.-Ing. Jürgen Klinghardt

Dennerlein GmbH, Oppenheimerstrasse 28-30, 28307 Bremen

Lift converter

The invention relates to a lifting converter with a stationary base frame, a drive element and a lifting frame supported by the base frame and capable of being set into a substantially vertical up and down movement by the drive element.

The invention further relates to a conveyor line with a device for discharging or separating conveyed goods from a flow of conveyed goods.

Such conveyor lines and lifting converters are used, for example, to convey a stream of Euro pallets or to eject or separate Euro pallets from a stream of Euro pallets. Such a stream of Euro pallets is usually transported along a predetermined path by a chain conveyor with two parallel chains. It is often desirable to remove individual pallets from the stream at a preselected position in order to feed them to another stream (ejection), for example.

• ■ ··

or to increase the distance between successive pallets (separation). For this purpose, a lifting device is inserted into the space between the two conveyor chains, which is located below the upper edge of both conveyor chains when not in use, so that the pallets can be transported over the lifting device without hindrance. If necessary, it is possible to raise an upper part of the lifting device, the lifting frame, at a moment when a pallet is being conveyed over it, so that the pallet is lifted off the chain conveyor. Such a lifting device is known to have transport rollers that are rotatably mounted transversely to the conveying direction of the chain conveyor. This enables the pallets to be discharged transversely to the conveying direction.

In a known lifting converter, the up and down movement of the lifting frame is generated by means of four eccentrics mounted so that they can rotate around a horizontal axis. Two of the eccentrics are driven in series by a chain. This type of drive requires a high degree of setting precision, as the four eccentrics must rotate synchronously. Even the slightest asynchrony would lead to a blockage of the drive if the eccentrics were moving with almost no play. If, on the other hand, the eccentrics had sufficient play to prevent a blockage, then an asynchrony would result in the lifting frame becoming unintentionally tilted.

Another disadvantage of this well-known lifting converter is that the chain drive and the eccentrics are very expensive and require a lot of maintenance. This is due to the complex design, which consists of four separate drive modules, and also to the high demands placed on their precision, as the individual chains and sprockets must be manufactured with relatively little play in order to be able to drive the eccentrics permanently and synchronously. Furthermore, this type of drive requires regular inspection and readjustment.

Another known lifting converter has a lifting frame which is pivoted relative to a stationary roller frame by means of a single eccentric which is

vertical axis is rotatably mounted, is set in a substantially horizontal back and forth movement. The lifting frame rolls with four rollers that are rotatably mounted in the area of its corners on running surfaces attached at an angle to the lifting frame, which gives the back and forth movement an up and down component at the same time.

The drive of this known device is simpler than the first one mentioned and is therefore also more cost-effective. The disadvantage of this device, however, is that the up and down movement of the lifting truck is superimposed by an undesirable horizontal back and forth movement. The back and forth movement actually has a considerably larger amplitude than the up and down movement.

The lifting converter is usually installed in a chain conveyor line in such a way that its horizontal movement is aligned transversely to the conveying direction. Due to the relatively large stroke of the horizontal movement, it is necessary to design the lifting converter to be narrower than the available space between the two chains by at least the length of the horizontal stroke. This means that a gap forms transversely to the chain conveyor line between the end of the lifting converter and a connecting element located outside the conveyor chains, for example, for discharging the pallets. This gap is wider than the width required by the conveyor chains. This means that trouble-free transfer of the pallets from the lifting converter to the connecting element is not guaranteed. When discharging, the pallets can, for example, sink above the gap and thus hit the front of the pallet, for example on a transport roller of the connecting element, which requires more force to transfer the pallet and/or the pallet is braked abruptly and the load on the pallet can possibly slip.

f: ="· ■:■■ &eegr;&igr;

Of course, the problem mentioned does not only occur when conveying, discharging or separating Euro pallets, but generally with all goods conveyed along such conveyor lines.

The object of the invention is therefore to provide a lifting converter and a conveyor line with a lifting converter, which generates an up and down movement with simple means and thereby enables a reliable discharge or separation of the conveyed material.

The object is achieved according to the invention in a lifting converter of the type mentioned at the outset by the characterizing features of claim 1.

A significant advantage of the lifting converter according to the invention is that the lifting frame only moves vertically up and down, thus avoiding the disadvantages mentioned above. In addition, there are hardly any moving parts compared to lifting devices with chains. The construction according to the invention is therefore considerably simpler, requires less maintenance and is less expensive. A complex ¹ readjustment of individually driven or adjustable eccentrics can also be avoided according to the invention. Adjustment work is completely eliminated with the lifting converter according to the invention.

In an advantageous further development, the lifting frame is immovably positioned relative to the base frame with respect to the horizontal plane by means of a vertical guide element.

By using a carriage that performs a horizontal back and forth movement and the associated decoupling of the lifting frame from the back and forth movement with the additional use of a vertical guide element, the lifting frame is held in a fixed position with respect to the horizontal plane. This makes it possible to adjust the dimensions of the lifting frame so

large as the available space allows, i.e. for example, when used between two chains of a chain conveyor, the lifting frame can assume the maximum width of the distance between the two conveyor chains, since no additional space is required for a horizontal back and forth movement.

In an advantageous and structurally very simple embodiment of the lifting converter, the first and/or second bearing elements have bearing surfaces that are inclined relative to the horizontal in the direction of the back and forth movement. This transforms the horizontal back and forth movement of the carriage into an up and down movement of either the lifting carriage alone or the lifting carriage together with the carriage.

In an advantageous development of the lifting converter according to the invention, the first bearing elements have four horizontal bearing surfaces connected to the base frame, on which first rollers mounted on the carriage rest. Furthermore, second bearing elements have four running surfaces connected to the lifting frame, inclined from the horizontal in the direction of the back and forth movement of the carriage, which rest on second rollers mounted on the carriage. This arrangement transforms the back and forth movement of the carriage into an up and down movement of the lifting carriage, without the carriage having to move its own weight up and down.

Preferably, the bearing surfaces of the lifting frame are formed from first wedge surfaces of essentially vertically oriented wedge-shaped elements, which are attached to the underside of the lifting frame with second wedge surfaces. When using such wedge-shaped elements to generate an up and down movement, no synchronization problems occur, in contrast to a drive with four eccentrics. The solution according to the invention is also considerably more cost-effective. It is advantageous that the first wedge surfaces in the side view have sections with a blunt shape relative to the horizontal in the direction of the thickening of the elements.

and then have a more acute angle of inclination. The curved shape of the first wedge surface can also have any other shape. The translation of the back and forth movement of the carriage into an up and down movement of the lifting carriage can be easily adapted to the respective load and the respective lifting distance by exchanging the wedge elements.

It is also advantageous that the drive element consists of a motor attached to the base frame, a downstream gear and an eccentric mounted on the output shaft of the gear, which engages via a cam with a guide oriented transversely to the back and forth movement of the carriage and firmly connected to the carriage. Such an eccentric drive consists of a few, simple and inexpensive components, which do not require any increased maintenance effort, since their interaction requires few bearings and thus comparatively low precision.

In a further advantageous embodiment, the lifting frame has roller holders for supporting several transport rollers arranged horizontally one behind the other and rotatable about axes oriented perpendicular to the back and forth movement of the carriage.

Further advantages of the lifting converter according to the invention are explained with reference to the figures described below. They show:

Fig. 1 is a perspective view of a base frame of an embodiment of the lifting converter according to the invention;

Fig. 2 is a perspective view of a carriage of the same embodiment;

Fig. 3 is a perspective view of a lifting frame of the same embodiment;

Fig. 4 is a perspective view of the assembled lifting converter;

- 7-

• *

·

Fig. 5 is a side view of the assembled lifting converter;

Fig. 6 is a side view of a wedge-shaped element of a lifting converter according to the invention.

A base frame 10 according to the embodiment of Fig. 1 has a rectangular outer circumference, which is formed by two pairs of parallel U-profiles 12, 14 and 16,18. The two longer U-profile supports 12,14 define the longitudinal direction of the base frame 10. The four U-profile supports are positioned upright with their open profile side facing outwards, so that their upper legs define a flat upper side of the frame. The upper surfaces of the longitudinally oriented profile supports 12,14 each form a running surface 34, 36 for the carriage (not shown here) to be placed on top of them, see Fig. 4.

The base frame has four feet 20 projecting downwards at the corners of the rectangle perpendicular to the plane spanned by the rectangle, at the lower end of each of which there is a base plate 22 with a fastening hole 24 for fixing the lifting converter to the floor. The feet 20 have a thread at their upper end and are each attached to the base frame in a height-adjustable manner via a pair of nuts.

On the top side, also in the area of the corners of the rectangle spanned by the frame, two roller bearings 26, 28 are fastened. The roller bearings 26, 28 are upright U-profiles, each of which is perpendicular to one another with its open profile side pointing towards one of the outer sides of the frame 10, so that each edge of the base frame is assigned a pair of roller holders. In the area of the outward-facing upper corner of each roller holder 26, 28, a guide roller 30, 32 is mounted so as to be rotatable about a horizontal axis parallel to the associated edge of the base frame 10. Each guide roller 30, 32 projects beyond both the base frame 10 and each of the roller holders 26, 28 in the horizontal direction. The guide rollers 30, 32 can be simple plain or ball bearing rollers or, for example, ball or deep groove ball bearings.

-β-

The base frame 10 also has a holding device 38 with a mounting plate 40 attached thereto for flanging a drive motor. The holding device 38 is attached to the base frame 10 at a right angle in one of the corners. The mounting plate 40 is oriented vertically and parallel to the longitudinal direction of the base frame. A motor (not shown) is to be flanged to the mounting plate 40 in such a way that an output shaft of the motor or of a downstream gear is oriented vertically and thus performs a rotation in the horizontal plane.

A carriage 50 to be placed on the base frame 10 is shown in isolation in Fig. 2 in the same perspective view as the base frame 10. The carriage also has a substantially rectangular, horizontally arranged outer circumference. It is formed from two U-profile supports 52, 54 arranged in the longitudinal direction and two cross struts 56, 58. The cross strut 58 is offset slightly inwards from the front end of the carriage 50 and consists of two U-profile struts 62, 64 arranged parallel with their backs to each other and enclosing a gap 60. In the middle of both U-profile struts 62, 64, two guide tabs 68, 70 are also arranged parallel and enclosing a guide gap 66. The guide gap 66, which is arranged essentially vertically and perpendicular to the longitudinal direction of the carriage 50 and thus also of the base frame 10, serves to accommodate a cam of an eccentric connected to the motor to be fastened to the mounting plate 40 of the base frame 10.

The carriage 50 is placed on the base frame in the orientation shown. When the eccentric rotates around a vertically oriented axis of rotation, the cam describes a circular movement which leads to a back and forth movement of the carriage 50 on the base frame 10 in its longitudinal direction, marked by an arrow 71. The cam slides back and forth in the guide gap 66 transversely to the direction of movement of the carriage. The power of the rotary movement of the motor is transmitted to the carriage by means of the cam of the eccentric via the two guide tabs 68, 70.

-9-

The carriage 50 has an upper roller 72 and a lower roller 74 (only indicated) mounted in the longitudinal direction at each end of each of the U-profile struts, each of which is oriented so as to rotate about a horizontal axis and a direction transverse to the direction of movement. The total of four upper rollers 72 are arranged such that their outer circumference extends beyond the upper edge of the U-profile struts 62, 64. The total of four lower rollers 74 are arranged such that their circumference extends beyond the lower edge of both U-profile struts 62. The upper and lower rollers can also be simple plain or ball-bearing rollers or ball or deep groove ball bearings.

When the carriage 50 is placed on the base frame 10, it rests with the lower rollers 74 on the running surfaces 34, 36 of the longitudinally oriented U-profile supports 12, 14, whereby the lower rollers 74 together with the running surfaces 34, 36 form the first bearing elements.

The carriage 50 also has four guide rollers 78 on its underside, each of which is mounted in a bracket 76 connected to the U-profile supports 52, 54 about a vertical axis of rotation. The guide rollers 78 are spaced transversely to the direction of movement such that their outer circumference rests against the inside of the two U-profile supports 12, 14 of the base frame 10 when the carriage 50 is placed on the base frame 10. In this way, tilting or twisting of the carriage 50 during the back and forth movement in the horizontal plane is prevented.

A lifting frame 80, see Fig. 3 and Fig. 4, is placed on the peripheral surface of the upper rollers 72 of the carriage 50. The lifting frame 80 is essentially composed of four angle elements 82, 84, 86, 88 spanning a rectangle. These form a flush outer side and an inwardly angled upper edge 90. A total of four vertically oriented wedge-shaped elements 92 are attached to the underside of the upper edge of the two longitudinally oriented angle elements 82, 84; the two wedge-shaped

Elements on the angle element 84 are hidden from the outside of the frame and therefore not visible in the view in Fig. 3. The wedge-shaped elements 92 all have the same orientation, with the narrow side to the left in the view shown, and are spaced longitudinally such that their position coincides with the position of the lower rollers 74 on the carriage 50 when the lifting frame 80 is placed on the carriage 50. The lower wedge surfaces of the wedge-shaped elements 92 then form the bearing surfaces of the lifting frame 80 and together with the upper rollers 72 of the carriage 50 the second bearing elements, see Fig. 5.

Both the first and the second rollers 72, 74 of the carriage 50 are preferably mounted in the area of the corners of the rectangle spanned by the carriage 50 so that the lifting carriage 80 and the weight on the lifting carriage 80 have a maximum possible contact surface. The distance between the wedge-shaped elements 92 therefore results from the length of the carriage 50.

When the lifting frame 80 is placed on the base frame 10 with the carriage 50, the inside of the vertical legs of the angle elements 82, 84, 86 and 88 are in contact with the guide rollers 30, 32 attached to the base frame 10. In particular, the guide rollers 32 in conjunction with the angle elements 86, 88 hold vertical guide elements which fix the lifting carriage in a stationary, immobile position with respect to the horizontal during the back and forth movement of the carriage.

The lifting frame 80 also has roller holders 102, 104 which are attached to both sides of the upper edge 90 and are oriented in the longitudinal direction. These consist of two metal sheets which are upright and flush with the outside of the frame elements 82, 84 and which have a series of evenly spaced holes 106, each at the same height. The holes 106 serve to support transport rollers which are not shown and are oriented transversely to the longitudinal direction. There is also a roller holder which is arranged transversely to the longitudinal direction of the lifting frame and is attached to

A support 108 is provided which is attached to the lifting frame 80 and to which a flange 110 is attached for attaching a motor for driving one or more of the transport rollers.

In Fig. 6 it can be seen that the wedge-shaped elements 92 have a lower wedge surface with a first section 94, which has a more obtuse angle of inclination, as seen in the direction of the thickening of the wedge-shaped element 92, and a second section 96, which has a more acute angle of inclination. In front of the first section 94 and behind the second section 96 there is a horizontal outlet 98 and 100, respectively. Each transition between the sections is rounded.

This transmission, in conjunction with a sinusoidal, linear back and forth movement caused by the eccentric drive, results in an initially fast upward movement, followed by a slower upward movement and a longer stop at the upper peak. This means that the lifting truck is initially quickly brought up to the load to be lifted. The load is then slowly lifted off the conveyor of the conveyor line when the height of the lifting converter is adjusted accordingly and then remains in the raised position in order to be discharged, for example. The lifting frame is then lowered in the reverse order.

Claims (15)

1. Lifting converter with a stationary base frame (10), a drive element and a lifting frame (80) carried by the base frame (10) and which can be set into a substantially vertical up and down movement by the drive element, characterized in that the lifting converter has a carriage (50) connected between the base frame and the lifting frame, which is mounted on the base frame (10) by means of first bearing elements for carrying out a substantially horizontal back and forth movement and can be set into the back and forth movement by the drive element, and that the lifting frame is mounted on the carriage (50) by means of second bearing elements in such a way that it is substantially decoupled from the back and forth movement of the carriage (50) in the horizontal plane and is moved up or down when the carriage moves. 2. Lifting converter according to claim 1, characterized in that the lifting frame is immovably positioned relative to the base frame with respect to the horizontal plane by means of a vertical guide element. 3. Lifting converter according to claim 1 or 2, characterized in that the first and/or the second bearing elements have bearing surfaces inclined relative to the horizontal in the direction of the back and forth movement. 4. Lifting converter according to claim 3, characterized in that the first bearing elements have four horizontal bearing surfaces connected to the base frame, on which first rollers mounted on the carriage rest, and that the second bearing elements have four bearing surfaces connected to the lifting frame, inclined from the horizontal in the direction of the back and forth movement of the carriage, which rest on second rollers mounted on the carriage. 5. Lifting converter according to claim 4, characterized in that the bearing surfaces of the lifting frame are formed from first wedge surfaces of substantially vertically oriented wedge-shaped elements which are fastened to a bottom side of the lifting frame by second wedge surfaces. 6. Lifting converter according to claim 5, characterized in that the first wedge surfaces in the side view have sections with initially a more obtuse and then a more acute angle of inclination relative to the horizontal in the direction of the thickening of the elements. 7. Lifting converter according to claim 6, characterized in that rounded transitions are provided in front of, between and behind the sections of different inclination angles. 8. Lifting converter according to one of the preceding claims, characterized in that the base frame, the carriage and lifting frame have a substantially rectangular outer circumference and that the first and second bearing elements are preferably arranged in the region of the corners of the rectangle spanned by the carriage, taking into account the horizontal stroke of the carriage. 9. Lifting converter according to one of claims 1 to 8, characterized in that the drive element consists of a motor attached to the base frame, a downstream gear and an eccentric mounted on the output shaft of the gear, which eccentric engages via a cam with a guide oriented transversely to the back and forth movement of the carriage and firmly connected to the carriage. 10. Lifting converter at least according to claim 8, characterized in that the lifting frame is guided by four guide rollers which form the vertical guide elements and are mounted on the base frame in the area of the corners, the axes of rotation of which are oriented horizontally and perpendicularly to the back and forth movement of the carriage, and which are in contact with their peripheral surfaces on bearing surfaces connected to the lifting frame. 11. Lifting converter according to claim 10, characterized in that the lifting frame is additionally guided by four guide rollers which form vertical guide elements and are mounted on the base frame in the area of the corners, the axes of rotation of which are oriented horizontally and in the direction of the back and forth movement of the carriage, and which are in contact with their peripheral surfaces on bearing surfaces connected to the lifting frame. 12. Lifting converter according to one of the preceding claims, characterized in that the carriage has guide rollers mounted about vertical axes of rotation, which rest with their peripheral surface on bearing surfaces connected to the base frame and thus prevent tilting or twisting of the carriage during the back and forth movement in the horizontal plane. 13. Lifting converter according to one of the preceding claims, characterized in that the lifting frame has roller holders for supporting several transport rollers arranged horizontally one behind the other and rotatable about axes oriented perpendicular to the back and forth movement of the carriage. 14. Lifting converter according to claim 13, characterized in that a drive is attached to the lifting frame, which drives at least one of the transport rollers. 15. Conveyor line with a device for discharging or separating conveyed goods from a flow of conveyed goods, characterized in that the device for discharging or separating has a lifting converter with the features of at least one of the preceding claims.