EP0712365B1 - Device for closing a plastic clip in two parts - Google Patents

Abstract

A plastic clip in two parts is used for closing sausage casings, bags or the like. The first part (1) holds the end of the casing gathered together into a plait in a U-shaped cavity formed by side faces and cross-bars. The second part (2) bridges the cavity (4) of the first part and is lockingly secured to the first part. The second part (2) is linked at one of its transverse ends to the first part (1) by means of a film hinge (3) and has a locking arm (16) at its other transverse end that may engage a locking projection (22) on the other cross-bar (6) of the first part for closing the clip. A traverse (8) spaced apart from the cross-bar (6) next to the hinge interconnects the side faces (5) and is gripped in the closed state by an arm on the second part, so that a high closing pressure is exercised at the same time as the required elasticity is maintained. A device for closing such a plastic clip has two cavities (37, 39) for receiving both clip parts (33, 34). One cavity (37) is fixed and the other (39) may swivel around an axis (40) aligned with the hinge axis (35) of the clip parts (33, 34). The second reception cavity (39) is swivelled into the closed position of the clip by a mechanical drive (38, 41, 42). In an improvement of the closing device, a positioning arrangement (50) feeds the clip to be closed from a supply channel (32) to the reception cavities (37, 39) of the closing mechanism by means of a cam-controlled driver (56).

Description

The invention relates to a device for closing plastic clips of a clip chain consisting of two articulated parts, the device comprising a fixed first holder for a clip part, a second holder pivotable about the hinge axis of the clip parts for the other clip part and the pivoting movement of the second holder from an open drive leading into a closed clip position.

Plastic clips are known for example from DE-OS 41 37 478.9 and the PCT application PCT / EP92 / 02634. Another type of such two-part plastic clips, in which the two parts are connected to one another in an articulated manner by means of a film hinge, has been described in German patent application P 43 27 064.6; these can also be connected to longer chains of contiguous clips by easily separable webs. Such magazineable chains or strands of plastic clips are particularly suitable for use in machine-operated closing devices, and the subject of the present invention is such a clip closing device (for the purpose of closing sausage casing braids or the like).

• a) Eine ortsfeste erste Halterung für den einen Clipteil;
• b) eine um die Gelenkachse der Clipteile schwenkbare zweite Halterung für den anderen Clipteil; und
• c) einen die Schwenkbewegung der zweiten Halterung aus einer offenen in eine geschlossene Clip-Stellung führenden Antrieb.

In its most general form, a device for closing plastic clips of the type described above has:

• a) A stationary first holder for the one clip part;
• b) a second holder for the other clip part, which can be pivoted about the hinge axis of the clip parts; and
• c) a drive leading the pivoting movement of the second holder from an open into a closed clip position.

Typically, the brackets consist of receiving troughs, which are adapted in their configuration to the outer shape of the two clip parts, so that the closing force is uniformly introduced into the clip and the two clip parts are locked in a position firmly surrounding the braid. While the first holder for one clip part is stationary and positions this clip part in such a way that the braid can be inserted into this clip part through a correspondingly arranged and designed feed slot, the other clip part is (as soon as this has been done) by means of the movable second holder pivoted around the articulated connection of the two clip parts and made the locking.

According to the invention, the described device additionally has a feed channel for a sequence of clips opening into the brackets perpendicular to the pivot axis and an abutment which interacts with the pivotable second bracket for separating the clip to be closed from a clip chain (see also claim 1). In this way, the clip that has just been processed is, as it were, automatically removed from the strand fed through the feed channel during the closing process.

In contrast, the clips known from EP-A-0 356 850 for plastic clips have already been supplied with the clips individually. The device according to the invention thus differs from the prior art in that the pivoting movement of the second pivotable holder is used both for separating a clip from the clip chain and for closing the separated clip.

Advantageously, the drive carrying the second holder has a gearwheel which can be rotated by means of a meshing engaging drive member (toothed rack, pinion or the like) by a certain angle from the open to the closed position of the clip. A pneumatic cylinder can be used as the drive source, for example, which moves the drive member back and forth.

According to a further embodiment of the invention, a positioning device is provided, which in each case advances the clip to be closed into the holders. In particular, it has a driver, which engages in each part of the clip held in the feed channel with each feed cycle, moves it into the first holder and then moves out of the clip and back into the starting position in an arcuate way. Via the feed section of the driver movement, which runs to a certain extent tangentially from the mouth of the feed channel, there is a positive connection between the driver and the one clip part until it is positioned in its holder. Then the driver - perpendicular to the longitudinal extent of this clip part - is moved out, so that it clears the space for the bag plait to be inserted and leaves the clip untouched on its way back to the starting position.

The feed cycle of the driver is preferably cam-controlled, and advantageously in such a way that the driver sits on the piston of a pivotably mounted pressure medium cylinder and a guide pin, which is also attached to the piston, engages in a backdrop determining the driver movement.

Fig. 1

eine etwas schematisierte Seitenansicht einer Gesamtvorrichtung zum Schließen von Clips in der Ausgangsstellung, jedoch mit einem in den Schließmechanismus eingeführten Clip;

Fig. 2

eine etwas vergrößerte Seitenansicht des Schließmechanismus in derselben Stellung wie in Fig. 1;

Fig. 3

eine der Fig. 2 entsprechende Darstellung im Schließzustand des Clips;

Fig. 4

in drei verschiedenen Ansichten (a - c) das die zweite Halterung für den anderen Clipteil tragende Zahnrad;

Fig. 5

in drei Ansichten (a - c) den Schieber der in Fig. 1 gezeigten Positioniereinrichtung; und

Fig. 6

in Draufsicht und zwei Teilschnitten (a - c) die Kulissenplatte der Positioniereinrichtung.

The drawing illustrates embodiments of the invention. It shows:

Fig. 1

a somewhat schematic side view of an overall device for closing clips in the starting position, but with a clip inserted into the locking mechanism;

Fig. 2

a somewhat enlarged side view of the locking mechanism in the same position as in Fig. 1;

Fig. 3

a representation corresponding to Figure 2 in the closed state of the clip.

Fig. 4

in three different views (a - c) the gear carrying the second holder for the other clip part;

Fig. 5

in three views (a - c) the slide of the positioning device shown in Fig. 1; and

Fig. 6

in plan view and two partial sections (a - c) the link plate of the positioning device.

In the housing 31 of the device shown in FIG. 1, a feed channel 32 for plastic clips in a chain or strand-like sequence is provided, as are known from German patent application P 43 27 064.6 (FIGS. 9, 10). 2 and 3, such a (partial) strand is located in the feed channel 32; each clip consists of one part 33 and the other part 34, which are hinged together at 35 by a film hinge. Easily separable webs 36 connect adjacent plastic clips to one another.

In the illustration in FIG. 2, the positioning device - to be described further below - has inserted the foremost plastic clip of the strand into the locking mechanism, which has a holder arranged in the housing in the form of a receiving recess 37 for one clip part 33 and one on a gear wheel 38 (see also FIG. 4) arranged second holder also in the form of a receiving trough 39 for the other clip part 34. The articulated connection between the two clip parts 33, 34 in the form of the film hinge 35 lies in the axis of rotation 40 of the gear 38.

A toothed rack 41 mounted in a longitudinally displaceable manner in the housing 31 can move from its rest position shown in FIG. 2 into the working position shown in FIG. 3 are moved, with the aid of a pneumatic cylinder indicated only by the dash-dotted line 42 in FIG. 1 (the rack 41 is also only indicated with a schematic outline).

When the pneumatic cylinder 42 is actuated, the toothed rack 41 rotates the toothed wheel 38 in a clockwise direction about the axis of rotation 40. The second receiving trough 39 takes the other clip part 34 with it until it is locked in place with the one clip part 33, which remains firmly in its first receiving trough 37; this state is shown in Fig. 3.

Previously - while the parts were still in their relative position shown in FIG. 2 - the plait 43 of a packaging bag, a sausage casing or the like, shown with a black circular area in FIGS. 1-3, through the slot 44 in the housing 31 and have been guided into the opening of the clip part 33 ready for recording. A correspondingly shaped recess 45 is provided in the gear 38 so that the pigtail 43 and the packing sections adjoining in its longitudinal direction do not collide with the gear 38 when the pigtail is inserted into the plastic clip and its pivoting movement is not in the way when it is closed (FIGS c). Fig. 4b illustrates that the actual gear 38 is laterally offset to the feed channel 32 and only with a lateral shoulder 46 protrudes approximately in the form of a quadrant into the feed path of the plastic clips, of course in this feed direction the shoulder 46 with the second receiving trough 39 for aligns the clip part 34 with the receiving trough 37 for the one clip part 33.

The positioning device for the plastic clips in the receiving troughs 37, 39 can be seen in total from FIG. 1. It has a pneumatic cylinder 50 which is pivotally mounted in a pivot bearing 51 on the housing 31 about an axis running perpendicular to its longitudinal axis. The piston rod 52 continues in a slide 53, the design of which is shown in detail in FIG. 5. A guide pin 54 is attached to the side of the slide 53 (near the piston) in a protruding manner and engages (by means of a roller mounted on it) in a link 55, which is shown in more detail in FIG. 6. At its end opposite the cylinder 50, the slider 53 carries a driver 56 which laterally protrudes in the same direction as the guide pin and which actually positions the clips in the receiving troughs 37, 39.

The design of the slide 53 can be seen in FIG. 5. The piston rod 52 is fastened in the threaded bore 53a. The guide pin 54 is to be inserted into the blind hole 53b, while the blind bore 53c serves to receive the driver 56.

If the piston rod 52 of the pneumatic cylinder 50 is in its retracted initial position, which is shown in FIG. 1, the guide pin 54 (on the slide 53) engages in the link 55 in its lower left corner (FIGS. 1, 6). If the piston rod 52 is extended, the slide 53 moves to the right (in FIGS. 1, 6) and the guide pin 54 moves in the lower, largely horizontal branch of the link 55 in its lower right corner. When the piston rod 52 is then retracted into the cylinder 50, a partial depression 55a of the link 55, which acts as a chicane (which results in a shoulder 55b towards the horizontal branch of the link 55) in conjunction with a laterally outwardly directed spring preload arranged on the guide pin 54 Roller (not shown) for the fact that the guide pin 54 cannot return to the essentially horizontal branch of the link 55, but instead passes through its upper, arch-shaped branch, a type of ramp 55c leading back to the initial depth of the link 55 (FIG. 6b). The guide pin 54 must be followed by the slide 53 and, via the piston rod 52, the cylinder 50 in that it pivots about its pivot bearing 51. When the piston rod 52 has been completely retracted to its initial position (FIG. 1), the cylinder 50 has also returned to its essentially horizontal position; on the last, largely vertical piece of the backdrop 55, the return movement is favored by the greater weight acting on the right of the pivot bearing 51 in FIG. 1.

The above-described movement of the guide pin 54 in the link 55 during a working stroke of the piston rod 52 (and thus of the slide 53) must inevitably also involve the driver 56. In the starting position, it engages positively in that clip part with a mandrel 56a, which is adapted to a part 33 of the clip; this position of the driver 56 is marked "A" in FIG. 1. When the piston rod 52 extends and the guide pin 54 moves correspondingly in the (essentially) horizontal branch of the link 55, the driver 56 moves accordingly to the right in FIG. 1 and takes the clip part 33 and the other clip part 34 articulated thereon. Because in this way the one clip part 33 has the recessed receiving trough 39 must happen, a corresponding recess 55d (Fig. 6a and c) is provided in the backdrop, due to which the cylinder 50 and correspondingly slide 53 slightly down and there is no risk that the positive connection between the driver 56 and one Clip part 33 is lost. In the further course of the outward movement of the piston rod 52, the driver 56 finally presses the one clip part 33 into the stationary receiving trough 37, so that the plastic clip as a whole has then reached its initial position for the closing process; the driver is in position "B". During the subsequent return stroke of the piston rod 52, the driver 56 moves due to the pivoting of the cylinder 50, forced by the link 55, with the slide 53 through the channel 57 formed in the housing 31; for illustration purposes, the driver 56 is (only) shown there in various intermediate positions. Finally, the driver 56 returns to the starting position shown in FIG. 1, while the closing mechanism carries out the closing process described above. Insofar as the driver 56 engaging in the next clip does not form the abutment required for separating the clip in the closing process, this task is performed by the abutment 58 on the centerpiece surrounded by the channel 57.

Claims (4)

1. A device for closing plastic clips of a clip chain, which consist of two pivotally connected parts, where the device comprises a stationary first holding device (reception recess 37) for the one clip part (33), a second holding device (reception recess 39) for the other clip part (34), which can be swivelled about the hinge axis (35) of the clip parts (33, 34), and
   a drive (38, 41) guiding the swivel movement of the second holding device (39) from an open into a closed clip position, characterized by a feeding channel (32) for a sequence of clips, which opens into the holding devices (37, 39) at right angles to the swivel axis (40), and an abutment (58) cooperating with the pivotally mounted second holding device (39) for separating the clip to be closed from a clip chain.
2. The device as claimed in claim 1, characterized in that the drive guiding the second holding device (39) comprises a gearwheel (38), which by means of a meshingly engaging driving member (41) can be rotated by a certain angle from the open into the closed position.
3. The device as claimed in at least one of claims 1 to 2, characterized in that a positioning means for feeding always one clip to be closed into the holding devices (37, 39) has a carrier (56), which in every feed cycle engages in the one part (33) of the clip provided in the feeding channel (32), moves the same into the first holding device (37), and then moves out of the clip and on an arc-shaped path (57) back to the starting position.
4. The device as claimed in claim 3, characterized in that a carrier (56) is seated at the piston valve (53) of a pivotally mounted pressure-fluid cylinder (50), and a guiding pin (54) additionally mounted at the piston valve engages in a connecting link (55) determining the movement of the carrier.

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