A GRIPPING DEVICE FOR MOVING A PRODUCT

Abstract: When moving a bundle of envelopes from a table (4) to a box in which they are to be packed, for instance, two movable jaws (2 and 3) which can be moved apart and towards each other are utilized, these jaws clamping the bundle during transfer. Clamping is avoided if one or more connecting elements (11 and 12) are arranged between the lower edges of the jaws (2 and 3), said connecting elements (11 and 12) acting as a bottom. The distance between the jaws (2 and 3) can be adjusted to correspond to the thickness of the bundle.

Description: A GRIPPING DEVICE FOR MOVING A PRODUCT The present invention relates to a gripping device for moving a product. Said gripping device is preferably intended to move a bundle of envelopes from a table on 'which they are stacked to a box. The purpose of the present invention is to produce a gripping device having two clamping jaws which can be moved apart and towards each other so that the distance between the clamping jaws corresponds to the thickness of the bundle of envelopes, i.e. the jaws define the thickness of the bundle without any clamping action. According to the invention connecting elements are also stored in the vicinity of one of the jaws in such a manner that they can be pulled out at the 0 lower edge of this jaw to the lower edge of the other jaw, to be secured there. The connecting element comprises a strip of metal, preferably ferro-magnetic metal. The gripping device cooperates with a support surface for the bundle of envelopes. Said support surface is provided with a groove giving passage to the strip. - Said groove, utilized as a passage for the connecting element, is provided with one or more permanent magnets or one or more electro-magnets so arranged that the connecting element is brought into abutment with the bottom of the groove. Additional features of the present invention are defined in the appended claims. 0 The present invention will be described in more detail with reference to the accompanying three igures in which Figure 1 shows a gripping device cooperating with a surface, Figure 2 shows part of the gripping device with the connecting element withdrawn. 5 Figure 3 shows the locking member for said connecting element on said second jaw. The drawings show a gripping device 1 provided with two jaws 2 and 3. The jaws are suspended on an arm movable in all directions. Between the jaws 2 and 3, preferably consisting of two flat panels, is a ball-bearing screw 5. Two bracing means 7 and 8 are also arranged between the jaws 2 and 3. 3aw 3 is provided with two drive packages for the strips 9 and 10. Two guides 13 and 1 are arranged for the metal strips 11 and 12. The strips protrude from the lower edge of the jaw 3, are folded around this edge and inserted into a groove 15 and 16. These grooves are of such a depth as to allow the strips free passage under the product stacked on the support surface 4. The strips can be fed out or in with the aid of motors in the drive packages 9 and 10. The two grooves 15 and 16 each contain a number of permanent magnets 17 and 18. Said magnets may consist of electro-magnets. A locking member 19 is arranged at the lower edge of the clamping jaw 2, which secures the strip 12 received. The gripping device 1 is provided with an arm 20 designed to move the gripping device 1 from a support surface for the product to a container in which it is to be packed. The present invention functions in the following manner: It is assumed initially that the gripping device is not in position at the support surface 4. It is also assumed that a bundle of envelopes has been placed on the table 4, all the envelopes standing on edge and being held together as a bundle by means of holders protruding from the table. The gripping device 1 is now moved over the bundle, the holders being simultaneously withdrawn. The jaws or panels are then drawn towards each other with the aid of the ball-bearing screw 5, so that the distance between them corresponds to the thickness of the bundle of envelopes, without the exertion of any clamping action. In fact the distance between the jaws 2 and 3 should preferably slightly exceed the thickness of the bundle of envelopes. When the gripping device 1 has assumed the correct position the strips 11 and 12 are fed through the passages 13 and 14 and on to the passage in grooves 15 and 16. Once in the grooves 15 and 16 the strips will be located below the surface of the support table. The two strips are held in contact with the bottom of the grooves 15 and 16 with the aid of permanent magnets 17 and 18. When the strips 11 and 12 encounter the locking means, the locking means for strip 12 being illustrated in Figure 3, the ends of the strips will be locked. The gripping device can now be moved with the aid of the arm 20 until the bundle of envelopes is located above the de-ϊred packaging box, without the envelopes falling down between the jaws 2 and 3 of the gripping device. The bundle can thus be held together without any clamping action, thanks to it being surrounded by retaining units on three sides, one side also serving as a bottom.

Claims: CLAIMS 1. A gripping device in equipment for moving a product such as a bundle of envelopes from one position to another position by utilizing the clamping action obtained by two units being moved apart and towards each other, said units being in the nature of two side walls, characterised in that one or more connecting elements (11 and 12) are stored in the vicinity of one unit (3) in such a manner - that they can be pulled out and joined to said other unit (2) in such a manner as to define a bottom between the two side walls (2 and 3). 2. A gripping device as claimed in claim 1, characterised in that locking members (19) for said connecting elements (11 and 12) are arranged on said second side wall (2). I - 3. A gripping device as claimed in claim 1, characterised in that each of the connecting elements (11 and 12, respectively) consists of a strip of metal, preferably ferro-magnetic metal. 4. A gripping device as claimed in claim 1, characterised in that when engaged in a gripping operation, the gripping device (1) cooperates with the - ■ - support surface (4) for a product so that said connecting elements (11 and 12) have free passage from one side wall (3) to the other (2). 5. A gripping device as claimed in claim 4, characterised in that each passage (15 and 16, respectively) consists of a groove or channel holding a connecting element (11, 12, respectively). - - 6. A gripping device as claimed in claim 5, in which each connecting element (11, 12, respectively) is ferro-magnetic, characterised in that said grooves (15 and 16) or channels are provided, preferably along their entire length, with permanent magnet(s) (17 and 18) or electro-magnet(s). 7. A gripping device as claimed in one or more of the preceding claims, -- characterised in that adjusting means (5) to set the distance between said two units (2 and 3) are of a type that the distance set between the units (2 and 3) corresponds to the thickness of the product without any clamping action.

Inventors: TONDEL EDWARD, TONDEL, EDWARD
Applicants: LJUNGDAHL STURE AB, AB STURE LJUNGDAHL
Application year: 1990
Main classification: B65H5
IPC codes: B65H5