US 3515424 A
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Description (OCR text may contain errors)
June 2, 1970 E S ,O'D.N 3,515,424-
ARRANGEMENT IN OR RELATING TO VACUUM LIFTER Filed Nov 2, 1967 United States Patent 3,515,424 ARRANGEMENT IN OR RELATING TO VACUUM LIFTER Einar Sjodin, Bergen, Norway, assignor to Mnnck International A/ S, a corporation of Norway Filed Nov. 2, 1967, Ser. No. 680,071 Claims priority, application Norway, Apr. 18, 1967, 167 780 Int. Cl. B66c 1/02 US. Cl. 294-64 2 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to an arrangement in vacuum lifters of the kind comprising one or more suction cups having a rim sealing member and being connected by means of hoses or the like to a source of vacuum and further comprising members for the suspension from a crane, boom, truck or other transport means.
It is previously known a series of embodiments of such vacuum lifters, the principle for the lifting of objects by means of vacuum being very old. It is then usual to place a suction cup against a relatively plain surface of the object to be lifted, evacuate the cup and lift the object by the securing force thereby obtained.
Concerning objects or bodies which are porous or permeable or stacks of bodies the same principle can be used provided the vacuum pump has the necessary capacity to maintain an effective vacuum in spite of the leakage through the load to be lifted or the load is provided with a wrapping of for example paper, or plastic. Such wrapping can be provided for paper rolls, cellulose bales, packaged lumber, bricks, boxes etc. The suction cup is then placed against the wrapping in which preferably is inserted a plate to provide a plane contact surface for the suction cup. In the wrapping there must, however, be holes in the area located under the suction cup, since otherwise the wrapping would be sucked to the cup and be torn off while the load itself was left.
Such holes in the wrapping are, however, undesirable for instance for long time storing before transportation. Further, it often is difiicult to have the suction cup placed exactly over the area of the wrapping in which the holes are arranged.
The invention obviates said drawbacks.
This is obtained for a vacuum lifter arrangement as mentioned above by placing over the suction opening a body which is so formed that in evacuating the suction cup the body cuts through that part of the wrapping which by the suction is pressed against the inner sruface of the suction cup and provides one or more apertures for the evacuation of the air from the interior of the wrapped load.
To have a better understanding of the invention ref- 3,515,424 Patented June 2, 1970 erence is bad to an embodiment shown as an example in the drawing, where:
FIG. 1' is a perspective view of a cutting element according to the invention,
FIG. 2 shows diagrammatically and in section the arrangement of the cutter element of FIG. 1 in a vacuum lifter and FIG. 3 shows the arrangement according to FIG. 2 after the evacuation has begun.
A metallic element or a shield plate 1 having V-formed cross section is provided with side flanges with holes for the securing at the inner surface of the suction cup 2. The element 1 is placed over the suction opening 8. The load 5, for example a paper roll, is provided with a wrapping 6 which at the upper end of the roll is reinforced by being duplicated 6', 6".
In FIG. 2 the suction cup with its sealing strip 4 is brought to rest against the outer sruface of the wrapping at the end of the paper roll. When evacuating of the inner space 3 of the cup 2 is carried out through the hose 7 the wrapping 6, 6" is sucked up against the inner surface of the suction cup 2.- The wrapping thereby is pressed against the element 1, which is as will be seen provided with downward directed, sharp pointed croners 1. When the wrapping is pressed against the element 1 said corners 1' will cut through the wrapping 6, 6" and the evacuation of the interior of the load 5 can occur as shown in FIG. 3.
When the lifting is ended the cuts of the corners 1' will substantially close themselves due to the fact that they are extending as linear cuts. Water and foreign matter thus are not inclined to penetrate.
The cutter element 1 can of course be given other form than that disclosed in the drawing and described above. Further, two or more such elements can be arranged in the vacuum lifter. It is also possible to carry out the cutter element as a part of a valve arrangement known per se, which only opens for suction when the vacuum lifter is placed in accurate position against the load.
1. A vacuum lifting device comprising a suction cup having a rim sealing member for engaging a wrapped article to be lifted, an opening from the interior of said suction cup, a hose means connected to the opening and adapted to be connected to a vacuum source, a cutting element positioned over said opening on the interior of the suction cup, said cutting element being a hollow member having opposed V-shaped ends which form cutting points facing away from the said opening, such that when the wrapped article is pulled by the vacuum toward the opening, the said points pierce the wrapping of the article and pass therethrough, such that the V-shaped ends form channels from the interior of the pierced wrapped article to the said opening.
2. A vacuum lifting device according to claim 1 wherein said cutting element is an elongated channel member with downwardly inclined ends which form said V-shaped ends to form said points, the center of the elongated channel between said downwardly inclined ends being directly across from the said opening.
References Cited UNITED STATES PATENTS 3,321,889 5/1967 Zubik 294--64 HARVEY C. HORNSBY, Primary Examiner