FI93535B - A vacuum lifter - Google Patents

Abstract

A vacuum hoisting device for transporting loads having an adhesive surface has at least one suction head which is attached to a hoisting mechanism and has at least one annular seal projecting on its suction side, the vacuum space or vacuum spaces enclosed by the annular seal or annular seals being connected via a connecting line to a vacuum source with a vacuum generator, and a valve arrangement being provided in the connecting line, which valve arrangement can be switched over between a suction position and an air-admission position. In order to obtain a simple and reliable valve arrangement, the hoisting mechanism is connected to the suction head (5) via a connection piece (41) which is movably guided by a guide (35) in such a way that it can be lifted and lowered between two end positions, the connection piece (41) and guide (35) forming the valve arrangement in the form of a three-way axial valve which is located in the bottom end position in the suction position and in the top position in the air-admission position, the connection piece (41) and guide (35) being coupled via at least one change-over switch (58, 59, 60, 61, 68, 69) which permits an upward movement of the connection piece (41) from the air-admission position into the suction position only after the connection piece (41) is lowered twice into the bottom end position. <IMAGE>

Description

, 93535

A vacuum lifter. - Vacuum production.

The invention relates to a vacuum hoist for transferring loads having a gripping surface, the hoist having at least one suction head suspended from the hoisting device, having at least one annular seal projecting on its suction side, the vacuum space (s) surrounded by the annular seal or seals being connected to the vacuum a vacuum generator, and a valve device is arranged in the connecting line, which is switchable between the suction position and the aeration position, in which the vacuum source communicates with the vacuum space or vacancies and in which the aeration source is disconnected and the vacuum space or vacancies are vented or pressurized.

Such vacuum hoists can be used to lift and transport rolls wound from strips of material such as paper, metal, plastic or laminate. Planar cylindrical cavity bodies, such as plates, can also be moved by such vacuum elevators. In this case, the vacuum hoist can be hung to be lifted and lowered in the crane lifting device.

Suitable lifting devices are also, for example, balancing parts. manipulators, rollers or the like. Thus, in the invention described herein, the lifting device is to be generally understood as a means for moving the vacuum lifter.

A vacuum hoist according to the preamble is described, for example, in DE-GM 84 35 161.6. It has a planar suction plate at the suction end, on the lower surface of which several ring seals are arranged concentrically at a distance from each other. These sealing seals form, in each case, separate vacuum spaces surrounded by them, which form sealed annular chambers when the suction plate is lowered onto the gripping surface of the load intended to be transferred 2 93535, insofar as the load covers the annular chambers. In this case, the ring seals do not have to be circular, but can have any other shape, e.g. oval or angular, as long as they only form a closed ring. Nor is it necessary that they be nested.

The vacuum spaces are connected via openings in the suction plate and via a connecting line to a vacuum source having a vacuum generator. A valve device is arranged in the connecting line. As long as there is no suspended load in the vacuum lifter, the valve device is adjusted manually by means of two switches so that the connection to the vacuum generator is disconnected and the vacuum space or spaces are vented.

To lift the load, the vacuum lifter is lowered onto the load and the valve device is then moved to the suction position. In this way, a connection is established between the vacuum source and the vacuum space or spaces. In the case of several spaces, additional valves may also be provided which are arranged to open a connection to the vacuum source only when the vacuum space in question is completely covered by the load. After the vacuum has been arranged in the vacuum space or spaces, the load can be lifted or moved.

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After moving and lowering the load, the valve device is switched again from the suction position to the aeration position. This event is particularly prone to accidents, especially if the vacuum lift is used by a person in its business area. Inadvertently, it may happen that the valve device is adjusted too early and the load falls on the operator's feet or toes. Such faults can also occur during remote operation, with the result that persons in the area of operation of the vacuum lift can be injured due to the load falling.

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3,93535

The object of the invention is therefore to provide a vacuum lifter of the type mentioned at the beginning with a simple and reliable valve device.

According to the invention, this object is achieved in that the lifting device is connected to the suction head by means of a connector which is movably and lowerably movably controlled by a guide between two end positions, the connector and the guide forming a valve device in the form of a three-way axial valve in the upper end position. in the lower end position in the aeration position, and that the connector and the controller are connected by means of at least one changeover switch which enables or allows the connector to move upwards from the aeration position to the suction position only after the connector has been lowered to the lowest end position.

According to the invention, the suspension of the suction head in the lifting device is thus formed as a three-way axial valve which, when lowering the load, enters the aeration position due to the settling of the connector and thus aerates the vacuum space or spaces or even possibly loads it or them with compressed air. In connection with the related raising of the suction head, the invention is prevented. a change-over switch arranged between the connector and the guide The change-over switch arranged between the connector and the guide moves the connector to the upper end position and thus to the suction position. Only when the suction head has once again been lowered onto the load and then raised does the change-over switch allow the connector to be pushed up to the upper end position and thus to the suction position. A vacuum is then placed in the vacuum space or spaces, with which the load rises. Instead of a toggle switch, several toggle switches can also be arranged in parallel to transfer larger loads.

Switches of the above type are known in various embodiments and are used in particular in the internal grippers of 4 93535 roller lifts (cf. EP 0 070 950). In this proposed mode of operation of the change-over switch, together with the special design of the suction head suspension, a reliable and automatically operating connection of the valve device is provided.

In this case, it is particularly advantageous that when lowering the loads, the valve device is forcibly adjusted from the suction position to the aeration position only when the load is fully lowered, i.e. there is no longer any risk of falling and thus personal injury.

In an embodiment of the invention, it is arranged that the guide is formed as a guide sleeve, in which the connector piece is axially movably guided between the end positions.

In this case, it should be arranged that the body has a first recess which, in the upper end position, forms a connection between the connections of the connecting line and a second recess which in the lower end position comprises a connection to the outside air and a vacuum connection on the connecting line.

In this case, the first recess may be formed on the jacket surface of the connector, for example as an annular groove, while the second recess is formed as an aeration duct, the radial inlet of which in the lower end position communicates with the vacuum connection on the connecting line.

The second recess may be formed as a • aeration duct in the connector, the radial inlet of which has • in the lower end position a connection to the vacuum-side connection of the connecting line and the outlet of which is open to the outside air.

tl 5,93535

The changeover switches are retained gravity switches, as is known from EP 0 070 950. This is especially the case when each gravity switch consists of two parts on the guide on the one hand and on the connector on the other, namely a triangular baffle and a circumferentially movable clutch lever cooperating with the baffle, the baffle having a substantially circumferentially extending side bend and a directional tip at which a latch hook is arranged to guide the clutch lever when lowering the connector against the force acting on the clutch lever.

Such a gravity switch is excellent due to its compact design and reliable operation.

The clutch lever can be directed, for example, downwards in the suspension body in the guide curve in the guide, in which case it has a suitably radially projecting guide pin for leaning against the guide plate.

According to one feature of the invention, it is arranged that the clutch lever is pivotally mounted on a radially extending shaft. In this case, the force acting on the clutch lever may be gravity, for example by arranging asymmetrically arranged weights. It is also possible to provide a spring force on the clutch lever.

As an alternative to the pivoting arrangement of the clutch lever, it can also be rigidly fastened circumferentially against the spring force with a guide ring rotating.

In one embodiment of the invention, the guide cam is arranged opposite the bend of the guide plate to guide the clutch lever into the bend.

9 • «93535 6

A further improvement of the guide is achieved in that the guide plate is surrounded by a groove in which the clutch lever engages.

The latch hook is suitably formed so that the latch hook can be pushed out by pulling the connector piece and the guide away from each other by means of the clutch lever. However, it can also be formed by a flat spring projecting from one edge.

In the drawing, the invention is described in more detail by means of an application example.

Figure 1 shows a vertical section of the vacuum lifter and the load.

Figure 2 shows a vertical partial section of the top of the vacuum lift suspension.

The vacuum lifter 1 shown in the figures rests on the upper surface 2 of a vertically standing paper roll 3, the paper roll comprising an inner winding sleeve 4. The paper web is wound on this winding sleeve 4.

The vacuum lifter 1 has a flat, round suction plate 5, on the lower surface of which six circular seal seals 6, 7, 8, 9, 10, 11 formed of elastomeric material are arranged concentrically with the vertical axis in the middle of the vacuum lifter 1. Together with these ring seals 6-11, the vacuum lifter 1 rests on the upper surface 2 of the paper roll 3. The inner ring seal 6 has such a large diameter that the seal is outside the winding sleeve 4 so that air from the side cannot be absorbed through the winding sleeve 4. The outer ring seals 7, 8, 9, 10, 11 in each case enclose the vacuum spaces 12, 13, 14, 15, 16, which are separated from one another.

tl! 7 93535

A valve block 17 is arranged in the left-hand part of the suction plate 5, which is fastened with screws 18. Four sensor valves 19, 20, 21, 22 are arranged in the valve block 17, of which the sensor valve 21 is shown in vertical section. The sensor valve 21 has a sensor tip 24 projecting above the suction plate 5, which protrudes above the valve housing 25 and expands there into a valve cone 26. A guide pin 27 is arranged inside the valve housing 25, against the outer surface of which the upwardly projecting projections 28

The valve cone 26 is raised from its valve seat 29 and thus releases the suction passage 30, which passage leads to a vacuum space 15. The sensor valve 21 is thus arranged for this vacuum space 15. Respectively, a sensor valve 22 is provided for the vacuum space 16, a sensor valve 20 for the vacuum space 14 and a sensor valve 19 for the vacuum space 13. The sensor tips 24 of the sensor valves 19, 20, 21, 22 are then immediately outside the annular seal 8, 9, 10, 11 which surrounds the associated vacuum space 13, 14, 15, 16 from the outside.

In this case, the sensor tips 24 are pressed down by the springs arranged on the sensor valves 19, 20, 21, 22 and the sensor valves extend beyond the outermost plane of the ring seal 6, 7, 8, 9, 10, 11 when the vacuum lifter 1 is free, i.e. when it is not set. 'r tu on top of anything. When placed on top of the load, those sensor tips 24 - as shown in the drawing - are compressed upwards and thus the sensor valves 19, 20, 21, 22 open, the associated vacuum space 13, 14, 15, 16 being completely closed by the load. In the present case, the diameter of the paper roll 3 is so large that all the vacuum spaces 12, 13, 14, 15, 16 are covered by the effect of the upper surface 2, and thus all the sensor tips 24 are compressed.

The sensor valves 19, 20, 21, 22 are connected to the connecting line 31 via connecting channels 32 in the valve block 17.

I. ii k 9 8 93535 f k

The inner vacuum space 12 is connected without a valve directly via the suction port 33 to the connecting channel 32.

A hanger 34 protrudes from the axial center from the suction plate 5. The hanger 34 has a guide sleeve 35, the lower end of which is surrounded by a fastening flange 36 welded thereto, which flange is fastened with screws 37, 38 to the upper surface of the suction plate 5. A centering mandrel 39 is welded to the lower end of the guide sleeve 35, which extends through the central bore 40 down to the winding sleeve 4. In this way, the vacuum lifter 1 is centered on the paper roll 3, i.e. the vacuum lifter 1 is centered on the upper surface 2 of the paper roll 3.

The guide sleeve 35 has a substantially cylindrical suspension body 41 for vertical movement. It has an axially extending bottom hole 42, at the upper end of which a loop screw 43 is screwed. It allows the vacuum lifter 1 to be hung on the hook of the lifting device.

The outer shell of the hanger body 41, at its upper part, has a guide groove 44 extending in a vertical direction, to which a protrusion 45 projecting from the inside of the guide sleeve 35 engages. The protrusion 45 acts both as a response to limit the vertical movement of the hanger body 41 and also as an anti-rotation device. In the representation of Figure 1, the guide groove 44 and the projection 45 are shown rotated 90 °. In fact, both are on the back.

A connector ring 46 is welded to the outside of the central region of the guide sleeve 35, through which the opposite radial bores 47, 48 pass. The left-hand radial bore 47 is led by a connecting channel 32, while the right-hand radial bore 48 is connected via a line (not shown) as well as a vacuum generator (not shown). The hanger body 41 further has a radial bore 49 extending to the left out of the lower end of the bottom hole 42 and which in the position shown is Λ · 4 (1.

lii 9 93535 coaxial with the left radial bore 47. In addition, an upper radial bore 50 exits the bottom hole 42, which in the position shown is opposite the bore in the guide sleeve and thus provides a connection to the outside air. Below the bottom hole 42, an annular groove 51 is formed in the casing of the hanger body 41.

An annular support shoulder 52 is provided at the upper end of the hanger body 41, on which a circumferentially rotating pivot ring 53 is mounted by means of a bearing 54. From above, the pivot ring 53 is tensioned by two mutually locked groove nuts 55, 56 and a second bearing 57.

As can be seen in particular from Figure 2, a vertically downwardly directed clutch lever 58 (shown only partially in Figure 2) is rigidly attached to the pivot ring 53. The lower end of the clutch lever 58 has a radially inwardly projecting guide pin 59. It engages a guide groove 60 formed outside the guide sleeve 35 and having a substantially constant width. A substantially triangular guide plate 61 remains in the center of the guide portion 60. In the view of Figure 2, its left side 62 bends diagonally down to the left of the top tip 63, where it then changes to a circumferentially extending side 64. This side 64 has a strong bend 65 upwards.

. The associated right-hand side 66 has a protrusion above which a flat spring 68 fastened to the groove base by a screw 67 is arranged, which rises upwards from the groove base.

The clutch lever 58 is connected to the support shoulder 52 via a tension spring 69. The tension spring 69 tends to pull the clutch lever 58 and thus also the pivot ring 53 to the right in the view * shown in Fig. 2.

A cover tube 70 extends upwardly from the connecting ring 46 and extends to the groove nuts 55, 56. Overlapping it is a cover, ο 93535 si 71, which is fastened between the upper end of the hanger body 41 and the eyebolt 43 and which extends from the outside onto the cover tube 70.

The operation of the hanger 34 takes place as follows.

In the position shown, the hanger body 41 is in its lowest position placed on the paper roll 3 and before it is lifted. The connecting line 31 communicates with the bottom hole 42 and with the second radial bore 50 to the outside air via a radial bore 49. Since the sensor valves 19, 20, 21, 22 are open, all the vacuum spaces 12, 13, 14, 15, 16 are in communication with the outside air. The vacuum lifter 1 can now be raised, whereby the hanger body 41 carries the guide sleeve 35 and thus the guide pin 59 of the suction plate 5 supported in the bend 56 of the guide plate 61. The vacuum spaces 12, 13, 14, 15, 16 thus remain in contact with the outside air. The radial bore 48 leading to the vacuum generator is sealed by means of a hanger body 41.

When the vacuum lifter 1 is then lowered onto the second roll of paper, the centering mandrel 39 first enters the winding sleeve. The suction plate 5 with its annular seals 6, 7, 8, 9, 10, 11 is then placed - as long as the diameter of the paper roll is sufficient - on the paper roll. In this case, the sensor tips 24 of the sensor valves 19, 20, 21, 22 come into contact with the upper surface of this paper roll and protrude upwards - as long as the diameter of the paper roll is sufficient. Thus, the sensor valves 19, 20, 21, 22 are opened when their sensor tips 24 come into contact with the upper surface of the paper roll. Further lowering of the lifting device on which the vacuum lifter 1 hangs causes the hanger body 41 to move some further down the guide sleeve 35. As a result, ·. v that the clutch lever 58 in the guide groove 60 likewise moves downwards, so that in the representation of Fig. 2 it moves to the lower right part of the guide groove 60, because the clutch lever 58 rotates in this direction under the action of the tension spring 69. The clutch lever is set this ti.

11 93535 to the lower, right-hand part of the guide groove 60 to the rest position.

When lifting the paper roll, the lifting device is controlled accordingly. In this case, only the hanger body 41 in the guide sleeve 35 first rises. In this case, the guide pin 59 moves upwards in the right part of the guide groove 60 along the side 66 of the guide plate 61, bypasses the leaf spring 68 by squeezing down the upper, bent edge. The exit movement of the hanger body 41 is limited by a protrusion 45. When positioned against this protrusion 45, the annular groove 51 is at the height of both radial bores 47, 48, while the radial bore 49 emanating from the bottom hole 42 rests outside the radial bore 47. In this way, the annular groove 51 provides a connection between the two radial holes 47, 48, while access to the bottom hole 42 and thus to the outside air is prevented. The connecting line 31 then has a direct connection to the vacuum generator, whereby a vacuum is formed in the innermost vacuum space 12 and in all other vacuum spaces 13, 14, 15, 16, the sensor valves 19, 20, 21, 22 of which are open. As the lifting device is further raised, the vacuum lifter 1 rises together with the paper roll.

When lowering the paper roll, the individual movements of the parts of the vacuum lifter take place in the order already described, i.e. the hanger body 41 moves downwards again in the guide sleeve 35 due to its own weight. In this case, the clutch lever 58 moves downwards in the guide groove 60, whereby the leaf spring 68 prevents its guide pin 59 from getting into the right part of the guide groove 60. Due to the shape of the left side 62 of the guide plate 61, it rotates to the left under the action of the tension spring 69 and then enters the lower part of the guide groove 60. In this case, the connection between the vacuum generator and the connecting line 31 is broken, because the annular groove 51 is located below both radial bores 47, 48. The connecting line 31 again communicates with the bottom hole 42 and thus with the outside air. The air enters the vacuum spaces 12, 13, 14, 15, 16.

Claims (18)

A vacuum lifting device for moving loads with a stapling surface, said lifting device having at least one suction head suspended on the lifting device with at least one ring-ring projecting on its suction side, wherein a vacuum space (s) surrounded by a ring seal or surrounded by ring seals a connecting conduit is connected to a vacuum source with a vacuum generator, and a connecting device is provided in the connecting conduit which can be coupled between a suction position and an air passage position, in which the suction position of the vacuum source is in communication with the vacuum space or spaces and in which the air passage is connected. interrupted and the vacuum space or vacuum spaces are vented or loaded with compressed air, characterized in that the lifting device is connected to the suction head (5) through a coupling piece (41) which can be lifted and lowered movably controlled by a guide (35) between two end positions, the coupling piece (41) and guide (35) forming e n valve device in the form of an axial three-way valve, which in the upper end position is in suction position and in the lower end position is in air passage position, and that the coupling piece (41) and guide (35) are coupled by mediating at least one gear coupling (58, 59, 60, 61, 68, 69), which coupler or couplings allow for smooth movement of the coupler (41) from air passage position to suction position. · Only after the coupler (41) has dropped twice to the lowest end position. 2. A vacuum lifting device according to claim 1, characterized in that the guide is formed as a guide sleeve (35), in which the coupling piece (41) is axially movable between the end positions. Vacuum lifting device according to Claim 2, characterized in that the piece (41) has a first recess (51) which in the upper end position forms a connection between the connections (31) of a connecting line (31), and a second depression (42, 49, 50), which in the lower end position comprises a connection, partly to the outer atmosphere and partly to the connection of the connection line (31) on the vacuum space side. Vacuum lifting device according to claim 3, characterized in that the first recess (51) is made on the casing piece (41) of the clutch piece (41). A vacuum lifting device according to claim 4, characterized in that the first depression is made as a ring lock (51). Vacuum lifting device according to any of claims 3-5, characterized in that the second recess is made as an air duct (42) located in the coupling piece (41), whose radial entrance opening (49) in the lower end position communicates with the connecting line (31). connection (47) on the vacuum space side and whose exit port (50) is open to the outer atmosphere. Vacuum lifting device according to any one of claims 1-6, characterized in that the gear coupling is made as a compressive force coupling (58, 59, 60, 61, 68, 69). Vacuum lifting device according to claim 7, characterized in that the respective compressive force coupling consists of two parts, one part a triangular guide disc (61) in the guide (35) and the other part one cooperating with the guide disc (61) (58) in the coupling piece (41), wherein the guide plate (61) has a substantially circumferential nose, with a side (64) provided with a curvature (65) and a tip (63) directed in the suspension direction of the coupling rocker, (68) for the control of the clutch rocker arm (58) in connection with the lowering of the clutch piece, against the force (69) acting on the clutch rocker arm (58). 95535 9. A vacuum lifting device according to claim 8, characterized in that the respective clutch rocker arm (58) protrudes downwards from the coupling piece (41) to the guide plate (61) from the guide (35). Vacuum lifting device according to claim 8 or 9, characterized in that the clutch rocker arm (58) has a radially projecting guide pin (59) for resting against the guide plate (61). Vacuum lifting device according to claim 9 or 10, characterized in that the coupling rocker arm (58) is pivotally mounted on a radially extending shaft. Vacuum lifting device according to claim 11, characterized in that the force of the clutch rocker arm (58) is a force of gravity. Vacuum lifting device according to any of claims 8-11, characterized in that the actuating force of the clutch arm (58) is a spring force (69). Vacuum lifting device according to any of claims 8-10, characterized in that the clutch rocker arm (58) is rigidly attached to a rotary control ring (53) rotating in circumferential direction against the spring force (69). Vacuum lifting device according to any one of claims 8-14, characterized in that, opposite to the bend (65) of the guide plate (64), a guide cam is arranged for guiding the coupling rocker arm (58) to the bend (65). Vacuum lifting device according to any of claims 8-15, characterized in that the guide plate (61) is surrounded by a latch (60) in which the clutch rocker arm (58) engages. tl! 19 93535 Vacuum lifting device according to any one of claims 8-16, characterized in that the control hook (68) can be displaced by means of the clutch rocker arm (58) as the coupling piece (41) and guide (35) are detached from each other. Vacuum lifting device according to any of claims 8-17, characterized in that the control hook is designed as a leaf spring (68) rising from a corner at the upper part. *