The present invention refers to a machine to form a sling, that consists of a wire, the end portions of which each forms a loop and with its outer end portions is held each in a clamping sleeve applied on the wire.

Different types of machines have been developed to form such slings, which are used for different purposes within the load handling. Such a machine is known through SE-C-8902250-3.

Through the invention a machine has been developed, that constitutes a further development of the prior art and that exhibits advantages compared with earlier known techniques. The characterizing features of this machine will be illustrated by the following claims.

The invention will now be closer described with reference to the enclosed drawings, in which fig. 1 discloses the machine perspectively at an angle from the side, fig. 2 discloses perspectively at an angle from the top and at an enlarged scale substantial parts included in the machine in one position and in fig. 3 is shown the same view with the parts of the machine in another position and fig. 4-7 disclose different sequences of the wire feed.

In the machine a sleeve magazine 1 with a number of clamping sleeves 2 and a feeding mechanism 4 actuated by a piston cylinder 3 are included for loading these clamping sleeves 2 provided in a press device 5.

On the input side of the press device 5 is provided a guide flap 6, that is pivotable upwards-downwards. Outside the guide flap 6 are provided four feed rollers 7, between which a wire 8 is feedable, which wire is arranged on a table 9 serving as a bed.

On the opposite side of the press device 5, the output side, a duct 10 is provided, which consists of two parts 10a and 10b. The part 10a, located nearest the output side of the press device 5, can be swung away in the manner shown in fig. 3. This part 10a of the duct 10 has a hinged lateral wall 11 which can be opened. The other part 10b of the duct 10 is stationary and provided with an upper part 12 which can be folded up. The duct 10 is intended to guide the front end portion 13 of the wire 8 during the feed of the wire through the press device 5. In front of the outlet port of the drum 10 is provided a clamping device 14, that is arranged to grip the wire 8 at some distance behind its front end. The clamping device 14 preferably is constituted by a hydraulic driven tightening cylinder. The clamping device 14 is rigidly mounted to a revolving means 15, which by carrying the clamping device 14 mainly is pivotable 180 degrees by means of a revolving mechanism 16. This preferably consists of a hydraulic piston cylinder 17 with gear rack and pinion (not shown) known per se. The revolving mechanism 16 is movable together with the revolving means 15 and the clamping device 14 by means of a piston cylinder (see below) in direction to and from the press device 5. A cam also follows this reciprocating movement, which cam as seen from its front has a lower edge 19a directed backwards and obliquely downwards, the function of which will be described later. Part 10a of the duct 10 is firmly attached to a pivot arm 20, which is provided with a vertical downwards directed dowel 21, that runs in a curve shaped slot 22 in a slide 24 which is displaceable by means of a piston cylinder 23 in a direction to and from the press device 5. This slide is rigidly connected to the parts 14, 15, 16 and 18.

The function of the machine will be described in more detail in the following. A wire 8 is manually entered between the feed rollers 7, whereby the guide flap 6 is in lowered position. The feed rollers 7 feed the wire 8 under the flap 6, which guides the wire through the press device

5 and through a clamping sleeve 2 introduced from the magazine 1 and further through the parts 10a and 10b of the duct 10 towards a stop 25. An indicating device 26 detects the correct feed length of the wire 8, gives a signal to stop the driving motor of the feed wheels 7, as well as activates the clamping device 14. The pressure in this device propagates to a pressure switch not shown, which switch in turn activates the revolving mechanisms 16, 17 of the revolving means 15. The revolving means 15 now rotates round the clamping device 14 with the end por¬ tion of the wire 13 substantially half a turn for formation of a wire loop 27, which is shown in fig. 4 and 5. During the formation of the wire loop 27 the wire penetrates up from part 10b of the duct, which is possible by the fact that the upper part 12 of the part 10b of the duct is foldable upwards. The piston cylinder 23 is now activated and moves the revolving means 15 with the clamping device 14 holding the wire loop 27 and the slide 24 in direction towards the press device 5. During this movement the dowel 21 is forced to run in the curve shaped slot 22. Hereby the arm 20 is brought to swing out, carrying the part 10a of the duct, such as illustrated in fig. 3. By swinging up of the side 11, the part 10a of the duct is released from the wire 8 and gives space for the loop 27 with the equipment about this to approach the press device 5. The cam 18 follows with the movement towards the press device 5, which cam comes into contact with its inclined lower edge 19 against a guide cone 28 provided at the press device 5, which cone is moved to a position just in front of the clamping sleeve 2 by means of the lower edge 19. The guide cone 28 serves for guidance of the end portion of the wire 13 into the clamping sleeve 2, see fig. 6.

An indicating device 29, see fig. 1, detects the feed of the end portion of the wire into a correct position in the clamping sleeve 2 and gives a signal to reverse the wire feed. The wire 8 is now pulled back a distance in the direction of the arrow 30, see fig. 7. Another indicating

means 31, which is adjustable in a horizontal slot 32, detects a calculated, correct size of the loop 27 and interrupts the reverse movement. The same indicating device 31 gives a signal to the press device 5 to press together the clamping sleeve 2 for formation of a wire lock. After the pressing procedure, which ends when the set value on the manometer has been reached, the press piston goes back, and a signal is given to the hinge of the guide flap 6 for releasing the wire 8. The clamping device 14 releases its grip. Even the feed wheels 7 are separable for release of the wire 8.

As a result of the invention a machine for complete mechanized manufacturing of slings has been developed. By means of various indicating devices, mentioned as. well as not mentioned, it has been possible to completely automate the manufacture. One of the greatest advantages of the machine lies foremost therein, that it is easy adaptable to slings with different thickness of the wire 8 and different sizes of the wire loop 27. When changing from a wire of a certain thickness to another wire with a larger thickness, it is only necessary to shift the magazine with clamping sleeves 2 to another with slightly thicker clamping sleeves, and when shifting the size of wire loop it is only needed to change the set-up of the indicating device 31 to adjust the time for the reverse of the wire 8.

The invention is of course not limited to the embodiment shown and described above but can be varied in different ways within the scope of the subsequent claims. This applies as well to the type of feed wheels 7 and guidance into the press device 5 as type of revolving means 15 and clamping device 14 for holding the end portion of the wire.