EP0879118B1 - Press apparatus - Google Patents

Description

The invention relates to a pressing device, in particular for connecting a pipe with a press fitting, with at least two press jaws and a drive for moving the press jaws from an open position in a final pressing position.

For connecting pipes, it is known to be sleeve-shaped To use press fittings made of plastic or metal consist. The press fitting is used to produce a Pipe connection pushed over the pipe ends and then radially pressed together, both the press fitting and the Tube are plastically deformed. Such pipe connections and the associated press fittings are, for example, from the DE-C-11 87 870 and EP-B-0 361 630 are known.

The press fitting and the pipe are pressed with the help of pressing devices, as they are in different versions for example in DE-C-21 36 782, which is considered to be the closest prior art and the preambles of independent claims 1 and 2 discloses DE-A-34 23 283, EP-A-0 451 806, EP-B-0 361 630 and DE-C-42 40 427 are. The presses have at least two, some also more press jaws, of which at least a part of the Pressing process radially inwards to form a closed one Press room can be moved. As a drive to move the press jaw is often provided with a hydraulic piston, the one operated by hand or by an electric motor Hydraulic pressure can be applied to the pump.

The pipe connections described above are produced especially when installing water-bearing Lines in buildings. It is understood that it is extraordinary it is important that press fitting and pipe ends so be pressed that absolute tightness is guaranteed. The material must be formed over the circumference of the press fitting to be complete. To achieve this result move the press jaws so far that their opposite ones Pairs of face ends come to rest or at least only a slight gap between them End faces remains.

In order to achieve this, the drive is in its end position method. However, this does not necessarily make the desired one and reached the final pressing position of the press jaws. The occurring forces lead to elastic deformations on the levers on which the press jaws are seated or used to contract a press jaw ring become. In addition, the press jaws, press fittings and pipes with tolerances that are due to unfavorable summation cause the drive to reach its end position there is no sufficient compression. To still be one to be able to produce tight pipe connections Press jaws pressurized with the addition a sufficiently large safety factor is designed that in the normal case a sufficient and therefore tight compression is achieved.

Nevertheless, problems can arise that are imperfect Result in compression. So it’s difficult to keep the final force of the drive constant. For reaching the final force is in most cases a Tripping device responsible as a switching device, for example with rotating drives a torque clutch, with hydraulic Devices a pressure relief valve and electrical operated devices an overcurrent release. Because the trigger organ does not directly measure the driving force, but one converted size (torque, pressure or current) which only still represents a fraction of the size of the final force any inaccuracy in the manufacture of the release member and every wear has a big impact on the final force of the drive and thus ultimately on the press quality. It also has the ambient and operating temperature Influence. It is particularly serious that the change the final force mainly due to wear proceeds slowly and therefore usually goes unnoticed remains.

Another reason for imperfect pressure can be found in the wear of the bearings for the transmission lever between Drive and press jaws lie. Then there are shifts the pivot axes with the result that the press jaws in no longer form the desired contour in their end position, the predetermined final pressing position is no longer reached becomes. As a rule, this also goes unnoticed.

Eventually, the press fitting may become crushed the way come that material or even more adherent Dirt in the gap between the opposite End faces of the press jaws. This prevents one Close this column until the desired final pressing position despite reaching the final force in the drive. A poor one Compression with the result that no tightness is guaranteed is then the result.

The invention is therefore based on the object of a pressing device of the type mentioned in such a way that an essential in the manufacture of pipe connections can achieve higher reliability.

This object is achieved in that in Area of the press jaws at least one sensor for the detection the final pressing position of the press jaws is arranged and that the transducer is coupled to the drive in the manner is that the drive after reaching the final pressing position automatically switched off via a shutdown device becomes. With this configuration, the operator receives the information about whether the final pressing position has been reached is in such a way that the drive is automatically switched off becomes. As long as there is no automatic shutdown, the operator knows that no complete There is compression. The operator can then decide whether it continues the pressing process or stops. The latter will come into question if the drive is its Has reached final force.

The principle underlying the invention can also be used by realizing that in the area of the press jaws at least a sensor for the detection of the final pressing position the press jaws is arranged and that the transducer over a locking device in the manner coupled to the drive is that the drive can no longer be switched on if it is switched off during a pressing process without the or the transducer has or have detected the final pressing position.

In this case, the operator receives the information the degree of compression only after the drive has been switched off. The drive can easily be restarted the operator can be sure that the was carried out correctly, i.e. the Final pressing position has been reached. Otherwise it can be tried to carry out a repressing, or that If this does not work, the pressing device must be replaced. This embodiment of the invention can in turn the above-described embodiment of the invention combined in addition to the automatic control of the drive an additional security against further use to avoid a pressing device that is no longer suitable.

The locking device should preferably be an externally operable one Have unlocking device so that the pressing device - The cause of the incorrect compression should not be in the Press device itself - for the production of more Pipe connections can be used. So that possibility by the operator in cases where the faulty pressing is caused by a defect in the pressing device itself is not misused, it is appropriate train the unlocking device so that it only can be operated with the aid of a tool. The tool can then be deposited where a check of the pressing device can be carried out.

It is essential for the solution according to the invention that the Transducer the position of the respective press jaw essentially directly recorded, d. H. without the interposition of the Press jaws with levers connecting the drive or the like. For this purpose, the transducer can be moved on an immovable Part of the pressing device can be arranged such that he Position of the respectively assigned press jaw detected, and in particular their final pressing position. Alternatively or in The sensor or one of the sensors can be combined be arranged on a press jaw that he the Position of the press jaw to an adjacent press jaw detected. This can also be done in such a way that the transducer or at least one of the transducers on two neighboring ones Press jaws is arranged so that it has the position this press jaws detected relative to each other. this happens preferably so that the sensor or sensors in the area the opposite end faces of two neighboring ones Press jaws is or are arranged so that the gap between these end faces is detected. In some embodiments is it an advantage if several or all pairs of opposite end faces Sensor is assigned.

If several transducers are provided for the final pressing position To grasp the press jaws, they should be together be coupled so that they only emit a signal when all transducers have recorded the final pressing position. there can the signal to generate a display signal, to switch off the drive and / or to keep it open the locking device used for the drive become.

The basic principle according to the invention can be applied to all pressing devices apply the genus mentioned. this applies also for an embodiment in which the press jaws a press ring sitting in the area of an open Closing point coupling elements for the engagement of appropriate Coupling elements of a locking device (see EP-A-0 627 273). With the help of the locking device are the coupling elements on the compression ring side Closing the press ring movable together, the or at least one of the sensors in the area of the closing point and / or the locking device-side coupling elements is arranged. The latter arrangement is also one those in the area of the press jaws in the sense of the basic idea of the invention when the coupling elements are engaged are located.

Various embodiments come for the transducer in question and here in particular all known and useful Applicable sensors for detecting the position of the press jaws. In particular, the pickup can have a movably mounted one Have sensors that interact with a stop, against which the sensor when closing the press jaws starts. The sensor on a press jaw and the Stop to be attached to the adjacent press jaw to detect their position relative to each other. The attack can the end face of the press jaw opposite the sensor be yourself. However, a separate one is preferable Stop that is adjustable in the direction of movement of the sensor is, so that an exact adjustment is possible.

In an expedient embodiment, the sensor is included coupled to a sensor that detects the change in position of the sensor detected. In particular, sensors that come into question here the induction, eddy current, capacitance, magnet or Resistance principle based. But also optical sensors for example in the form of light barriers. Pressure sensors or displacement sensors can also be used become.

Even if the sensor is arranged on the press jaw itself is there is a possibility to use the sensor outside the Arrange press jaws if the sensor has a corresponding one Has extension. This has the advantage that any electrical lines remain on the fixed part, which for example, the exchange of the press jaws facilitated.

It can also be provided that the transducer a display device is assigned, which one from the outside perceptible display signal when reached or at Failure to reach the final pressing position. The final pressing position here too, the press jaw becomes essentially immediate recorded, that is, where falsification is practical is excluded, then the operator to a to provide information perceivable by her whether the press jaws actually reach the final press position have or not. The information is theirs most general form in that the pressing device is one for the Operator perceptible change in state depending on learns whether the press jaws the final pressing position have reached or not. The essentially direct capture the position of the press jaws and the one based thereon Information ensures that the operator knows whether the pressing was sufficient or not. Poses the operator determines that the final pressing position is not has been achieved, for example because it is too low Driving force has been generated or because in the drive and / or wear has occurred in the transmission levers is, the operator can press with a Repeat the new pressing device.

In the above-described embodiment, the operator receives the information also by a display signal. The display signal can be of any design if with him only a change of state in the display device is made perceptible. This is particularly suitable an optically perceptible display signal. Of course an acoustically perceptible display signal also comes in Question. If electrical current is available, can the sensor generates an electrical signal Sensor and the display device one with the sensor electrically have connected lamp. Instead, however a display device can be designed so that it has a mechanical display element that with is coupled to the transducer that it reaches its position when it is reached changed the final pressing position. The coupling can be purely mechanical or electro-mechanical.

The display device preferably has a display memory, of the display signal even after moving the press jaws in Maintains the open position, with the Display memory an externally operated extinguishing device having. In this way, the display signal remains independent obtained from the position of the press jaws until it is through manual intervention is deleted. This ensures that the operator the information about the press quality receives. It may be appropriate that the extinguishing device an actuation lock that can only be overcome with tools having. The tool can then be used on one person be deposited for checking the pressing device responsible for.

In the area of the press jaws can at least one locking device are provided, which after initiating the pressing process an opening of the press jaws until the open position locks until the final pressing position is reached. In this Case, the operator can determine whether the pressing device after the pressing can be opened completely again or not, recognize whether the level of compression is sufficient was, d. H. reached the final pressing position of the press jaws has been. This further locking device is expedient mechanically trained as this is a high degree of reliability guaranteed. However, also come into question electrically operated locking devices, the locking happen even via electrically operated locking bolts can.

The further locking device preferably has its own from the outside actuatable unlocking device so that the pressing device can be removed from the press station if the pressing jaws with further pressing attempts not up to let the final pressing position move. It avoids one Disassembly of the pressing device. Again, it is useful that the unlocking device is not simply activated by hand a tool is required is. In this way, by depositing the Tool secured with another person be that a Verification takes place according to the four-eyes principle.

The locking device (s) should (s) at two adjacent Press jaws may be attached, preferably in the area two opposite faces.

The locking device can be designed in a variety of ways his. A mechanical solution in question is characterized in that that the locking device on one side Locking device and on the other hand a guide device has, in which the locking member engages, locking member and / or guide device have locking elements that have a only form a backstop acting in the opening direction, and whereby the guide device has a deflection device, which only reaches the locking element when the press jaws are in the final pressing position, and then the locking member steers into a return lane that circumvents the backstop. This The principle of a locking device can be varied Realize wise. It offers a high degree of certainty that the press can only be fully opened when the press jaws have been moved to the final pressing position.

Figur 1

ein bekanntes Preßgerät in der Frontansicht mit Preßfitting und Rohrende in der Offenstellung;

Figur 2

einen Querschnitt durch das Preßgerät gemäß Figur 1 in der Ebene A-A;

Figur 3

eine Frontansicht des Preßgeräts gemäß den Figuren 1 und 2 in nahezu geschlossener Stellung mit Fehlquetschungen des Preßfittings und mit Detaildarstellung davon;

Figur 4

eine Frontansicht des Preßgeräts gemäß den Figuren 1 und 2 in einer fehlerhaften Schließstellung;

Figur 5

eine Frontansicht eines Teils eines Preßgeräts mit mechanischer Anzeigeeinrichtung in Offenstellung;

Figur 6

das Preßgerät gemäß Figur 5 in der Seitenansicht;

Figur 7

eine Frontansicht des Preßgeräts gemäß den Figuren 5 und 6 in der Endpreßstellung;

Figur 8

das Preßgerät gemäß Figur 7 in Seitenansicht;

Figur 9

eine Frontansicht eines Teils eines Preßgeräts mit einer modifizierten Anzeigeeinrichtung in der Offenstellung;

Figur 10

eine Seitenansicht des Preßgeräts gemäß Figur 9;

Figur 11

eine Draufsicht auf das Preßgerät gemäß den Figuren 9 und 10 in einer Schließstellung;

Figur 12

eine Frontansicht eines Teils eines Preßgeräts mit einem elektrischen Aufnehmer;

Figur 13

eine perspektivische Teildarstellung des Aufnehmers gemäß Figur 12;

Figur 14

eine Frontansicht eines Teils eines Preßgeräts mit einem anderen elektrischen Aufnehmer;

Figur 15

eine Teildarstellung des Aufnehmers gemäß Figur 14;

Figur 16

eine Frontansicht eines Teils eines Preßgeräts mit mechanischer Sperreinrichtung in Offenstellung;

Figur 17

eine Ansicht von unten auf das Preßgerät gemäß Figur 16 mit Teilschnittdarstellung durch die Sperreinichtung;

Figur 18

eine Frontansicht des Preßgeräts gemäß den Figuren 16 und 17 in teilgeschlossener Stellung;

Figur 19

eine Ansicht von unten auf das Preßgerät gemäß Figur 18 mit Teilschnittdarstellung durch die Sperreinrichtung;

Figur 20

eine Frontansicht des Preßgeräts gemäß den Figuren 16 bis 19 in der Endpreßstellung;

Figur 21

eine Frontansicht eines Teils eines Preßgeräts mit einer anderen mechanischen Sperreinrichtung in Offenstellung;

Figur 22

ein Längsschnitt durch die Sperreinrichtung gemäß Figur 21 in der Offenstellung;

Figur 23

eine Draufsicht auf die Sperreinrichtung gemäß Figur 22;

Figur 24

ein Längsschnitt durch die Sperreinrichtung gemäß den Figuren 21 bis 23 nach einer ersten Annäherung der Preßbacken;

Figur 25

die Sperreinrichtung gemäß Figur 24 in der Draufsicht;

Figur 26

die Sperreinrichtung gemäß den Figuren 21 bis 25 im Längsschnitt nach einer zweiten Annäherung der Preßbacken;

Figur 27

die Sperreinrichtung gemäß Figur 26 in der Draufsicht;

Figur 28

die Sperreinrichtung gemäß den Figuren 21 bis 27 nach einer dritten Annäherung der Preß backen im Längsschnitt;

Figur 29

die Sperreinrichtung gemäß Figur 28 in der Draufsicht;

Figur 30

ein Teil der Sperreinrichtung gemäß den Figuren 21 bis 29 im Längsschnitt nach Erreichen der Endpreßstellung;

Figur 31

eine Draufsicht auf die Sperreinrichtung gemäß Figur 30;

Figur 32

einen Teil der Sperreinrichtung gemäß Figuren 21 bis 31 im Längsschnitt nach einer Bewegung der Preßbacken in Richtung auf die Offenstellung;

Figur 33

eine Draufsicht auf die Sperreinrichtung gemäß Figur 32 und

Figur 34

die Frontansicht eines Preßgeräts mit Preßring und Schließeinrichtung.

In the drawing, the invention is illustrated in more detail using exemplary embodiments. Show it:

Figure 1

a known pressing device in the front view with press fitting and pipe end in the open position;

Figure 2

a cross section through the pressing device according to Figure 1 in the plane AA;

Figure 3

a front view of the pressing device according to Figures 1 and 2 in an almost closed position with incorrect squeezing of the press fitting and with a detailed representation thereof;

Figure 4

a front view of the pressing device according to Figures 1 and 2 in a faulty closed position;

Figure 5

a front view of part of a pressing device with mechanical display device in the open position;

Figure 6

the pressing device according to Figure 5 in side view;

Figure 7

a front view of the pressing device according to Figures 5 and 6 in the final pressing position;

Figure 8

the pressing device according to Figure 7 in side view;

Figure 9

a front view of part of a pressing device with a modified display device in the open position;

Figure 10

a side view of the pressing device according to Figure 9;

Figure 11

a plan view of the pressing device according to Figures 9 and 10 in a closed position;

Figure 12

a front view of part of a pressing device with an electrical pickup;

Figure 13

a partial perspective view of the sensor according to Figure 12;

Figure 14

a front view of part of a pressing device with another electrical pickup;

Figure 15

a partial view of the sensor according to Figure 14;

Figure 16

a front view of part of a pressing device with mechanical locking device in the open position;

Figure 17

a bottom view of the pressing device according to Figure 16 with a partial sectional view through the locking device;

Figure 18

a front view of the pressing device according to Figures 16 and 17 in the partially closed position;

Figure 19

a bottom view of the pressing device according to Figure 18 with a partial sectional view through the locking device;

Figure 20

a front view of the pressing device according to Figures 16 to 19 in the final pressing position;

Figure 21

a front view of part of a pressing device with another mechanical locking device in the open position;

Figure 22

a longitudinal section through the locking device according to Figure 21 in the open position;

Figure 23

a plan view of the locking device according to Figure 22;

Figure 24

a longitudinal section through the locking device according to Figures 21 to 23 after a first approach of the press jaws;

Figure 25

the locking device according to Figure 24 in plan view;

Figure 26

the locking device according to Figures 21 to 25 in longitudinal section after a second approach of the press jaws;

Figure 27

the locking device according to Figure 26 in plan view;

Figure 28

the locking device according to Figures 21 to 27 after a third approach of the press bake in longitudinal section;

Figure 29

the locking device according to Figure 28 in plan view;

Figure 30

part of the locking device according to Figures 21 to 29 in longitudinal section after reaching the final pressing position;

Figure 31

a plan view of the locking device according to Figure 30;

Figure 32

part of the locking device according to Figures 21 to 31 in longitudinal section after moving the press jaws in the direction of the open position;

Figure 33

a plan view of the locking device according to Figure 32 and

Figure 34

the front view of a pressing device with press ring and locking device.

In the figures, the different designs are the same or functionally identical parts marked with the same reference numerals.

The pressing device 1 shown in Figures 1 to 4 has two T-shaped bearing plates 2, 3 on - seen in front view - are arranged exactly one behind the other. In the lower part the bearing plates 2, 3 by a connecting bolt 4th enforced. On this connecting pin 4 are from both sides Support plates 5, 6 placed (in Figures 1 and 3 and 4, the front support plate 5 is omitted), which to the total with 7 designated drive belong. You are only with shown at the top. Is at their lower ends attached a hydraulic cylinder, not shown, from a piston rod protrudes upwards. The top of the Piston rod is fork-shaped with a top Provide drive head 8. Inside the drive head 8 are two side by side drive rollers 9, 10 around a horizontal Axle freely rotatable. With the help of the hydraulic cylinder can the drive head 8 vertically in the direction of arrow F be moved (of course also be moved back again). The connecting bolt 4 is designed to be removable, so that the entire drive 7 can be removed in a simple manner can.

In the upper area, the bearing plates 2, 3 are spaced apart bearing bolts 11, 12 arranged next to one another pass through. On each of the bearing bolts 11, 12 is a pivot lever 13, 14 between the bearing plates 2, 3 stored. The two swivel levers 13, 14 are mirror-symmetrical. You point from the Bearing pins 11, 12 down drive arms 15, 16 and cheek arms 17, 18 going up. The drive arms 15, 16 have drive surfaces 19, 20 which are opposite the horizontal are initially only slightly inclined and then into one pass steeply upwards. In each other opposite sides of the jaw arms 17, 18 are semicircular Recesses molded into the contour of the press jaws 21, 22 form.

Figures 1 and 2 show the pressing device 1 in the open position, in which the drive head 8 assumes its lowest position, in which it does not abut the drive arms 15, 16. The pressing device 1 is attached to a pipe connection so that it lies between the press jaws 21, 22. The pipe joint has a pipe end region 23 via which a press fitting 24 is partially pushed. This can be seen particularly in the figure 2 see. The press fitting 24 has a cylinder section 25 with a stop serving for the pipe end area 23, constriction in the middle 26. Points at the free ends the press fitting 24 bulges 27, 28 curved outwards; into each of which an elastomeric sealing ring 29, 30 is on the inside is inserted. The press jaws 21, 22 are at the level of the figure 2 ring beads 28 on the right.

The hydraulic cylinder, not shown, is used for the pressing process supplied with hydraulic pressure via a corresponding pump, so that the piston rod along with that attached to it Drive head 8 upwards in the direction of arrow F (figures 3 and 4) extends. The drive rollers 9, 10 come here first on the gently sloping sections of the drive surfaces 19, 20 to the system. The drive arms are activated when starting up further 15, 16 spread apart, with the result that the jaw arms 17, 18 approach each other and the press jaws 21, 22 come to rest on the annular bead 28. With the further Starting up the drive head 8 begins the actual one Pressing process, in which the annular bead 28 and immediately subsequent region of the cylinder section 25 radially after plastically deformed inside, being in the last pressing stage the tube end region 23 is plastically deformed radially inwards becomes. The drive rollers 9, 10 extend - as if 3 and 4 can be seen - in the area between the Drive arms 15, 16 where the drive surfaces 19, 20 only take a very acute angle, so very steep to each other are inclined.

In Figures 3 and 4 are incorrect closed positions and the reasons for this are presented, neither in either case perfect pressing takes place because the press jaws 21, 22 do not reach their final pressing position. In the case of FIG. 3 situation shown is material of the annular bead 28 between the opposite pairs of faces 31, 32 and 33, 34 have been squeezed, in particular the enlargement of details in the area of the lower pair of end faces 33, 34 shows. This material prevents one further pressing the press fitting 24, namely - like that Position of the drive head 8 shows - already at an early stage Time. The compression is so slight that the connection not sealed between pipe end area 23 and press fitting 24, is faulty even though the drive 7 is at its maximum force exercised.

The situation according to FIG. 4 shows the position of the press jaws 21, 22 - in this case without pipe connection - when on the bearing pin 11, 12 wear has occurred, making it an impermissible have high play. In unloaded condition (figures 1 and 2) take the bearing pin 11, 12 the dotted Position. The press jaws 21, 22 through Start up the drive head 8 moved against each other, shift the centers of the bearing bolts 11, 12 within of the given game in response to those occurring Forces to the outside in the solid position. This has the consequence that the press jaws 21, 22 with their upper end faces 31, 32 come to rest in the area of the lower End faces 33, 34, however, a gap 35 remains, such as especially the enlargement makes clear. This Gap can reach such a degree that during a pressing process insufficient compression of the Press fittings 24 takes place, so that the pipe connection in this Area is leaking.

Both types of mispressing - they can be applied to others Causes of wear are - usually not or only noticed when a large number of incorrect grouting has been made. So that this doesn't happen according to the invention additional devices are provided as they result from the figures described below. there is in most cases the drive 7 after removal of the Connecting bolt 4 omitted for reasons of clarity. In addition, the press jaws 21, 22 have no circular arc shape here open, but in the closed state a hexagon shape. However, this is for the function of the additional devices irrelevant, d. H. they are suitable for any contour the press jaws 21, 22.

In the embodiment according to Figures 5 to 8 is on the left-hand cheek arm 17 at the level of the lower end faces 33, 34 attached a guide block 36 in which a feeler pin 37 is guided axially movable. The feeler pin 37 protrudes from the guide block 36 in the region of the end face 33. In a region enlarged in diameter points the feeler pin 37 two ring webs arranged at a distance from one another 38, 39, which leave an annular groove 40 between them. The ring web 38 on the left is on the ring groove 40 facing away from a compression spring 41, the is supported on a cover 42. In the in the figures 5 and 6 shown open position of the pivot levers 13, 14th is the right-hand ring web 39 at a stop in the guide block 36 at. Above the ring webs 38, 39 or the ring groove 40 is an indicator pin 43 in a corresponding cylindrical one Channel arranged. The indicator pin 43 has at the bottom End of an annular collar 44, which is directed by a compression spring is applied to the annular groove 40. The indicator pin 43 protrudes outwards from the guide block 36 and is axially perpendicular movable to the feeler pin 37. Pointing at the outer end the indicator pin 43 on a further collar 46 over which it can be gripped by hand.

In the area of the right-hand end face 34 of the press jaw 22 a stop block 48 is arranged stationary. He corresponds with the feeler pin 37 in such a way that the feeler pin 37 when closing the press jaws 21, 22 against the stop block 48 starts.

The ring webs 38, 39 on the feeler pin 37 are arranged that the axial extent of the annular groove 40 is somewhat larger is as the diameter of the lower collar 44 of the indicator pin 43. In the open position (Figures 5 and 6) sits Ring collar 44 with its underside on the left-hand ring web 38 on so that it can not fall into the annular groove 40. In this position, the probe pin 37 protrudes the furthest the guide block 36 out. During the pressing process, they swivel Press jaws 21, 22 against one another in the closing direction (FIGS. 7 and 8). The above comes shortly before the final pressing position is reached End of the feeler pin 37 for contact with the stop block 48. When the press jaws 21, 22 move further in the closing direction the feeler pin 37 is inserted into the guide block 36 with the result that the indicator pin 43 also supports Ring web 38 is moved. This continues until the Ring web 38 slips out of the area of the collar 44 and so that the indicator pin 43 with the collar 44 in the annular groove 40 comes up. The individual parts are designed so that this only happens when the press jaws 21, 22 - like shown in Figures 7 and 8 - reached their final pressing position have and thus it is ensured that the pressing is correct. Since the indicator pin 43 is only slightly protrudes from the guide block 36, the operator immediately see whether the press jaws 21, 22 are actually the final press position reached or whether an imperfect pressing is present. In the latter case, the indicator pin 43 would remain in the starting position according to FIGS. 5 and 6.

After removal of the pressing device 1 from the pipe connection Indicator pin 43 pulled out again against the action of the compression spring 45. As a result, the sensor pin 37 is released, so that he means of the compression spring 41 back towards the opposite end face 34 against the inner stop is pressed. The press device 1 is then for another Pressing ready.

In the embodiment according to Figures 9 to 11 is the Guide block 36 arranged rotated by 90 °, so that the indicator pin 43 protrudes horizontally. Otherwise there are no changes been made.

However, there is an additional Z-shaped on the bearing plate 2 Locking plate 49 attached, the free leg 50 in the range of motion of the indicator pin 43 engages when it is is in the position pulled out of the guide block 36. This position results from FIGS. 9 and 10. The external collar 46 of the indicator pin 43 is located then immediately in front of the leg 50 of the locking plate 49.

When the pressing process is initiated from that shown in FIGS and 10 apparent open position, the collar 46 against the leg 50 moves. Since this is flexible and in addition - as can be seen in Figure 11 - on the guide block 36 facing side is wedge-shaped, the leg 50 bent away from the guide block 36 by the collar 46, so that the indicator pin 43 can pass the locking plate 49. The subsequent pressing takes place in the to Embodiment according to Figures 5 to 8 described Wise.

An opening of the press jaws 21, 22 is possible if these have reached their final pressing position. In this case the display pin 43 with its collar 44 in the ring groove 40 retracted and protrudes little from the guide block 46 out. When opening, it therefore does not collide with the thigh 50 of the locking plate 49. However, if the pressing was only imperfect, because the end press positions of the press jaws 21, 22 have not been reached, and thus the indicator pin 43 has its keep the initial position (Figure 11), the left-hand Press jaw 21 no longer pivoted into its starting position be because the leg 50 as a lock on the indicator pen 43 works. A manual intervention is then necessary be it by bending away the locking plate 49 or by pushing it in the feeler pin 37 so far that the indicator pin 43 in the annular groove 40 collapses. In this case it is the optical one Display by the indicator pin 43 combined with a locking device, the one open the press jaws 21, 22 into the Open position only allowed if either the final press position is reached or the locking effect of the locking device by manual intervention is overcome.

In the embodiment according to Figures 12 and 13 is on the right-hand cheek arm 18 at the level of the lower pair from the front sides 33, 34 a distance sensor working on an eddy current basis 51 attached. It has one in cross section U-shaped coil rail 52, in the U-legs 53, 54 each an electrical coil is installed, opposite one another (not shown in detail). The coil rail 52 extends horizontally towards the opposite end 33. In it, a sensor plate 55 is displaceable in the longitudinal direction guided. It protrudes towards the opposite End face 33 out of the coil rail 52. On the the end facing away from the end 33 is in the coil rail 52 a compression spring 56 is arranged, which strives to the sensor plate 55 to move towards the end face 33.

The sensor plate 55 has a reference slot 57, the Extension in the axial direction of the sensor plate 55 in the Order of magnitude of the smallest expected gap between the End faces 33, 34 in the case of incorrect pressing - that is, if the final pressing position is not reached - lies. In the direction the sensor plate 55 points to the pair of end faces 33, 34 at a distance from the reference slot 57, a window 58 whose the side adjacent to the reference slot 57 forms a measuring edge 59.

The sensor plate is located on the left-hand jaw arm 17 55 opposite a stop pin 60 which in one screwed to the jaw arm 17 holding block 61 screwed is. Via the threads in the through hole of the holding block 61 and on the stop pin 60, the stop pin 60 can be axial can be set. The position once found is then fixed by a lock nut 62.

In the open position, not shown here, the swivel lever 13, 14, the sensor plate 55 is extended far and protrudes the adjacent end face 34. During the pressing process comes the sensor plate 55 in a certain position to the system on the stop pin 60 and will with further pressing inserted into the guide housing 52. This happens first the reference slot 57 the eddy current coils with the Consequence that the damping caused by the sensor plate 55 is lifted and a signal amplitude arises, which is used as a reference is taken. When inserting the sensor plate further 55 damping occurs again due to the material of the sensor plate 55 between reference slot 57 and window 58. As the pressing continues, the measuring edge then also reaches 59 in the field of eddy current coils with the result that the Attenuation decreases again.

In the closed position of the press jaws reached at the end of the press 21, 22 becomes the amplitude generated by the reference slot 57 compared with the amplitude caused by the measuring edge 59. Exceeds the difference in amount between the two Amplitudes a predetermined value, the sensor plate 55 not pushed far enough into the column rail 52, d. H. the press jaws 21, 22 then do not have their final pressing position reached. In this case a signal can be generated that is made visually perceivable, for example in form a lamp. This shows the operator that an imperfect one Pressure is present. With a proper pressing then there is no visual display, so that the absence the optical display for the operator the information gives that the press jaws 21, 22 their final pressing position had reached. The signal state described above can be saved be, so that a possible visual display is deleted by manual intervention. This can still be done become more difficult - and this provokes an examination - That a deletion of the display only with the help of a special Tool (special key) can be carried out. Of course there is the possibility of the circuit too vice versa, so that a visual display only at The final pressing position is reached. Such an ad remains off, the operator knows that mispressing is present.

The result of the comparison of the damping amplitudes can also used for other purposes to the operator to prevent even more sustainable, continued mispressing perform. This can be the case with imperfect pressing Signal is given to a locking device for the drive 7, which makes it impossible to restart the drive 7. It can be provided that the locking device by manual Attack can be unlocked again. This can unlock can also be made more difficult by doing this only with the help of a special tool is possible.

In the embodiment according to FIGS. 14 and 15 comes also a distance sensor that works according to the eddy current principle 51 for use, its also in cross section U-shaped coil rail 52 on the outside of the support plate 5 the drive 7 is attached. Into the coil rail 52 protrudes the lower end of a transmission lever 63, the Transfer lever 63 in the area of the coil rail 52 in turn a reference slot 57 and a window 58 - spaced apart arranged - has.

The upper end of the transmission lever 63 is at one Feeler pin 64 attached via a tab 65 to a bearing pin 66 suspended about a horizontal axis is. In the outside. The sensor pin is part of one Compression spring 67 surrounded, which strives to the sensor pin 64 in To pivot clockwise. On the left is again a stop pin 60 which is held in an analogous manner as in the exemplary embodiment according to FIGS. 12 and 13.

In the open state of the press jaws 21, 22 (not shown) the feeler pin 64 is pivoted so far clockwise that he protrudes from the end face 34 and the Reference slot 57 on the left side of the eddy current coils in the coil rail 52 is located. The front comes when pressing the feeler pin 64 to the stop pin 60 for contact. The further pressing causes the sensor pin to pivot 64 counterclockwise with the consequence that initially the reference slot 57 on the coils in the coil rail 52 drives past and thus generates a reference signal and that in further course the window 58 of the Hesskante 59 in the area of influence the eddy current coils come. Then it can already the embodiment described in Figures 12 and 13 Comparison of the damping amplitudes are made, wherein here, too, the possibilities for use described there a signal dependent on the respective closed position can be used.

The two exemplary embodiments according to FIGS. 16 to 20 on the one hand and Figures 21 to 33 have in common that the Additional device to ensure that the press jaws 21, 22 reach their final pressing position, designed as locking devices are that an opening of the press jaws 21, 22 without manual Only allow engagement if the press jaws 21, 22 have reached their intended final pressing position.

In the exemplary embodiment according to FIGS. 16 to 20 a locking device 68 is provided, to which a ratchet strut 69, which is at the level of the lower pair of end faces 33, 34 on the left-hand jaw arm 17 about a horizontal axis 70 is pivotally suspended. The pawl strut 69 protrudes into Locking housing 71, which can be pivoted about a horizontal axis 71a is mounted on the jaw arm 18. The jack strut 69 is displaceable in a guide track 72 in the locking housing 71 guided. At the end there is over one Swivel pin 73 a pawl 74 with a protruding downward Pawl tooth 75 is pivotally mounted about a horizontal axis. At the free end of the pawl 74 there is an actuating pin on the top 76 attached, the lock housing 71 over an opening 77 there protrudes. The pawl 74 is designed to be flexible so that its free end extends over the actuating pin 76 from the guideway 72 towards the Bend opening 77 away. Otherwise is on the actuating pin 76 one indicated only schematically by dot-dash lines Tension spring 78 attached, the other end to the jaw arm 18 is attached.

The guide track 72 is straight and has in the end region a ratchet step 79. In the end is the guideway 72 raised and goes into an arcuate outgoing at right angles Umlenkbahn 80 über. A return path goes from this 81 diagonally back towards the guideway 72, the return path 81 also not being milled so deep is like the track 72.

This is in the open position (FIGS. 16 and 17) Free end of the pawl strut 69 in the entrance area of the guideway 72. The ratchet tooth 75 lies on the guideway 72 with preload. When closing the press jaws 21, 22, the pawl strut 69 is pushed further into the locking housing 71. The pawl 74 can in spite of the tension spring 78 do not move outgoing force into return path 81, because it is not as deep as the guideway 72, so that at the connection of guideway 72 and return path 81 a Stage is formed. As the jaws move closer 21, 22 the pawl tooth 75 slides over the pawl step 79 (figures 18 and 19). The pawl stage 79 then prevents the Press jaws 21, 22 after an imperfect pressing, at which the press jaws 21, 22 does not reach the end press position have to be brought back into the open position. This is only possible when the ratchet tooth 75 over the Operating pin 76 raised so far from the guideway 72 is that it can be moved back over the latch stage 79 can. So a manual intervention is necessary for this, which gives the operator the certainty that mispressing is present.

In the final pressing position of the press jaws 21, 22, the pawl reaches 74 the end of the guideway 72. There it can under the Swing the tensile force of the tension spring 78 into the deflection path 80 (FIG 20) and arrives in the return path 81 (dashed lines in FIG. 20) shown). In this case, the press jaws 21, 22 can be opened without manual intervention, the ratchet tooth 75 via the return path 81 back into the guideway 72 slides and after opening the press jaws 21, 22 again in the position shown in Figures 16 and 17 reached. After acceptance the pressing device 1 can then carry out a further pressing process become.

Figure 21 shows a pressing device 1 with another locking device 82, which bridges the gap between the end faces 33, 34. Their detailed design is based first on the figures 22 and 23 explained.

The locking device 82 has an elongated shaped piece 83, via a pivot pin 84 (Figure 21) on the right-hand side Jaw arm 18 is pivotally suspended. Towards the opposite end 33 runs the fitting 83 fork-shaped with two spaced apart, parallel fork arms 85, 86 and bridges the gap between the end faces 33, 34. On the left side Cheek arm 17 is a clamping block via a pivot pin 87 88 hung up in the free space between the fork arms 85, 86 borders under mutual guidance. In the terminal block 88 is a spring rod 89 clamped to the free end has a pawl 90 directed towards the shaped piece 83. How the top view shows the pawl 90 is wider than the spring bar 89.

In the right-hand area, the shaped piece 83 has a width the pawl 90 corresponding guide groove 91. Above the guide groove 91 a slide plate 92 is mounted, which itself is supported on the fitting 83 because it is wider than the guide groove 91. It has a holding web 93, in the one stop screw 94 (only shown in FIGS. 22 and 23) is screwed in, which extends horizontally. It passes through an opening 95 in a stop web 96, the belongs to the fitting 83. On the outside is on the stop screw 94 a stop nut 97. This stop nut 97 limits the mobility of the slide plate 92 in the direction on the pawl 90. The slide plate 92 is thereby applied two tension springs 98, 99 in this direction.

The slide plate 92 has a T-shaped slot 100. In the the area adjacent to the holding web 93 is this slot 100 as wide as the guide groove 91 and the pawl 90. In the the more distant area is the width to something reduced more than the width of the spring rod 89, the Slot 100 goes to the end of the slide plate 92.

Below the slide plate 92 is an S-shaped curved Leaf spring 101 attached to the bottom of the guide groove 91 and under tension on the underside of the slide plate 92 is present.

In the starting position with the press jaws 21, 22 open the pawl 90 is pretensioned by the spring bar 89 on the fitting 83 (Figures 22 and 23). The slide plate 92 is located at 96 from the stop bar lying position, the stop nut 97 on the stop web 96 is present. When closing the press jaws 21, 22nd push the clamping block 88 and fitting 83 into each other, whereby the pawl 90 moves against the slide plate 92 and this in the direction of arrow H shifts (Figures 24 and 25). At the further closing of the press jaws 21, 22 causes the pawl 90 to slip over the edge of the guide groove 91 there, so that the pawl 90 completely surrounds in the guide groove 91. Because above of the fitting 83 then only the spring rod 89 is located, the Width is less than that of the slot 90 in the slide plate 92, the slide plate 92 moves under the influence the tension spring 98, 99 back to its starting position (Figures 26 and 27). The pawl 90 is then in the guide groove 91 captured via the slide plate 92.

In the further course, the pawl 90 in the guide groove 91 moved and presses the leaf spring 101 down the bottom of the guide groove 91 (Figures 28 and 29) until the Jack 90 below the widened portion of the slot 100 is located. Because the width of the slot 100 is slightly larger there is stronger than that of the pawl 90 and the leaf spring 101 is as the spring rod 89, the pawl 90 by the leaf spring 101 pivoted upwards (arrow I, Figures 30 and 31). there is the position of the slide plate 92 due to the adjustment with the help of the stop nut 97 (Figures 22 and 23) so set that the pawl 90 only by the widened Section of the slot 100 are pushed up can when the press jaws 21, 22 reaches their final pressing position to have.

The press jaws 21, 22 can now be opened again, whereby the pawl 90 slides onto the outside of the slide plate 92, favored by slants at the transition of the widened Portions of the slot 100 in the narrowed portion (figures 32 and 33). When the open position of the press jaws is reached 21, 22 the pawl 90 slides again from the slide plate 92 and then takes the one shown in FIGS. 22 and 23 Position. It can then be re-grouted be performed.

If the pressing is incomplete, the pawl reaches 90 not completely the widened portion of the slot 100 in the slide plate 92. An opening of the press jaws 21, 22nd is only possible until the pawl 90 at the end of the guide groove 91 strikes. The operator then knows that there is an incorrect pressing. Open for a full one of the pressing device 1, the slide plate 92 must then be dismantled.

The pressing device 111 shown in FIG. 34 has a pressing ring 112 as a press tool, that of five arcuate press jaw carriers 113, 114, 115, 116, 117 is formed. The press jaws 113 to 117 are via hinge pins 118, 119, 120, 121 connected to each other and each carry a press jaw 122, 123, 124, 125, 126. The press jaws 122 to 126 are in Movable circumferentially on the press beam supports 113 to 117 stored.

Between the two lower die supports 113, 117 and Press jaws 122, 126 there is a closing gap 127. The Closing gap 127 is bridged by a coupling device 128, which has two coupling tabs 129, 130, the left coupling bracket 129 via a hinge pin 131 on the Free end of the lower left die holder 113 arranged is, while the right-hand clutch tab 130 over a hinge pin 132 at the free end of the lower right Press jaw carrier 117 is articulated. The coupling straps 129, 130 are articulated with one another via a coupling bolt 134 connected. The coupling pin 134 is removable, making it enables the press ring 112 in the area of the closing gap 127 wide open, so that he wrapped around a press fitting can be. After flipping the two coupling tabs 129, 130 connected again so that the press ring 112 can no longer fall down.

A locking device 135 is assigned to the press ring 112, which is only shown schematically here. The locking device 135 has two essentially spaced one behind the other T-shaped bearing plates 136, between which via hinge pins 138, 139 two locking levers 140, 141 pivotally arranged are. The locking levers 140, 141 each have lower lever sections 142, 143 and upper lever sections 144, 145. The upper lever sections 144, 145 face each other Recesses 146, 147 as coupling elements. These are adapted to the hinge pin 131, 132 on which the coupling tabs 129, 130 are articulated.

The lower lever sections 142, 143 face each other Drive surfaces 148, 149. In the space between the drive surfaces 148, 149 may be known per se Way a pair of rollers will be retracted leading to one here Not shown drive device in the form of a hydraulic cylinder are vertically movable. For this, the drive device via a bolt on the bearing plates 136, 137 attached, the bolt being insertable into the opening 150 is.

For a pressing process, the two lower lever sections 142, 143 moved together by hand so that the top two Lever sections 144, 145 are spread apart. The Locking device 135 can then be attached to the press ring 112 in this way be that the recesses 146, 147 the hinge pin 131, 132 are opposite. By retracting the rollers in the first narrow space between the lower lever sections 142, 143 these are spread. This will capture the Recesses 146, 147 the hinge pins 131, 132 and approach them each other. As a result, the press ring 112 is reduced in size of the closing gap 127 contracted so that the the pressing space enclosed by the pressing jaws 122 to 126 is reduced. This continues until the end faces of the press jaws 122 to 126 come to mutual investment. It will Press fitting and the pipe end inserted into it plastically deformed. To remove the locking device 135 from the press ring 112 is reversed.

In the area of the closing gap 127 is on the two opposite Sides of the jaw supports 113, 117 a pickup 151 attached (only shown symbolically). This is set that its two opposite parts are provided in the Butt the end press position and thereby generate electrical signal, which is then used for a display can be. The display tells the user that the final pressing position is reached. Instead of the arrangement on the press ring 112 also comes an arrangement on the locking device 135 in question, namely here in the area of the recesses 146, 147. This sensor 152 has the same function as the sensor 151.

It is understood that for the pickups 151, 152 also the embodiments come into question, which are from Figures 5 to 15 result. They can also be combined with locking devices be as they can be seen from Figures 17 to 33.

Claims (27)

1. Compression device (1), particularly for joining a pipe (23) with a press fitting (24), with at least two compression jaws (17, 18, 21, 22, 122, 123, 124, 125, 126) and a drive (7) for moving the compression jaws (17, 18, 21, 22, 122, 123, 124, 125, 126) from an open position to a final compression position, characterised in that in the region of the compression jaws (17, 18, 21, 22, 122, 126) is arranged at least one sensing element (51, 151, 152) for detecting the final compression position of the compression jaws (17, 18, 21, 22, 122, 123, 124, 125, 126) and that the sensing element (51, 151, 152) is coupled to the drive (7) in such a manner that the drive (7) is automatically switched off by means of a switching off arrangement after reaching the final compression position.
2. Compression device (1), particularly for joining a pipe (23) with a press fitting (24), with at least two compression jaws (17, 18, 21, 22, 122, 123, 124, 125, 126) and a drive (7) for moving the compression jaws (17, 18, 21, 22, 122, 123, 124, 125, 126) from an open position to a final compression position, characterised in that in the region of the compression jaws (17, 18, 21, 22, 122, 126) is arranged at least one sensing element (51, 151, 152) for detecting the final compression position of the compression jaws (17, 18, 21, 22, 122, 123, 124, 125, 126) and that the sensing element (51, 151, 152) is coupled to the drive (7) via a blocking device in such a manner that the drive (7) can no longer be switched on if it has been switched off during a compression process without the sensing element or sensing elements (51) having detected the final compression position.
3. Compression device according to Claim 2, characterised in that the blocking device has an unblocking device capable of actuation from outside.
4. Compression device according to Claim 3, characterised in that the unblocking device is capable of actuation with a tool only.
5. Compression device according to one of the claims 1 to 4, characterised in that the sensing element (36, 37, 38, 39, 40, 41, 42, 51, 151, 152) or at least one of the sensing elements is so arranged in the region of a compression jaw (21, 22, 122, 126) that it detects the position of this compression jaw (17, 21, 122) in relation to a neighbouring compression jaw (18, 22, 126).
6. Compression device according to one of the claims 1 to 5, characterised in that the sensing element (36, 37, 38, 39, 40, 41, 42, 51, 151, 152) or at least one of the sensing elements is so arranged in the region of two neighbouring compression jaws (17, 18, 21, 122, 126) that it detects the position of these compression jaws (17, 18, 21, 22, 122, 126) relative to each other.
7. Compression device according to one of the claims 1 to 6, characterised in that the sensing element or sensing elements (36, 37, 38, 39, 40, 41, 42, 51, 151, 152) is or are arranged in the region of the opposing front faces (33, 34) of two neighbouring compression jaws (21, 22, 122, 126).
8. Compression device according to Claim 7, characterised in that a sensing element is allocated to each pair of opposing front faces.
9. Compression device according to one of the claims 1 to 8, characterised in that a plurality of sensing elements is provided which only issue a signal when all sensing elements have detected a final compression position.
10. Compression device according to one of the claims 1 to 9, characterised in that the compression jaws (122, 123, 124, 125, 126) are situated on a compression ring (112) having, in the region of an open closure site (127), coupling elements (131, 132) for the engagement of corresponding coupling elements (146, 147), via which the coupling elements (131, 132) on the compression ring may be moved together for closing the compression ring (112), whereby the or at least one of the sensing elements (151, 152) are arranged in the region of the closure site (127) and/or the coupling elements (146, 147) on the closure device side.
11. Compression device according to one of the claims 1 to 10, characterised in that the sensing element (36, 37, 38, 39, 40, 41, 42, 51) has a movably mounted feeler (37, 55, 64), which interacts with a stop (48, 60), against which the feeler (37, 55, 64) moves on closure of the compression jaws (17, 18, 21, 22).
12. Compression device according to Claim 11,
    characterised in that the feeler (37, 55, 64) is mounted on a compression jaw (17, 18, 21, 22) and the stop (48, 60) is mounted on the neighbouring compression jaw (17, 18, 21, 22).
13. Compression device according to Claim 11 or 12,
    characterised in that the stop (60) is adjustable in the movement direction of the feeler (55, 64).
14. Compression device according to one of the claims 11 to 13, characterised in that the feeler (55, 64) is coupled to a sensor (52, 53, 54) which detects the length change of the feeler (55, 64).
15. Compression device according to Claim 14,
    characterised in that the sensor (52, 53, 54) is arranged outside the compression jaws (17, 18, 21, 22).
16. Compression device (1, 111) according to one of the claims 1 to 15, characterised in that assigned to the sensing element (36, 37, 38, 39, 40, 41, 42, 51, 151, 152) is a display apparatus (43), which generates a display signal perceptible from outside on reaching or on not reaching the final compression position.
17. Compression device according to Claim 16,
    characterised in that the display apparatus (43) generates an optically perceptible display signal.
18. Compression device according to Claim 17,
    characterised in that the sensing element has a feeler (55, 64) generating an electrical signal and the display apparatus has a lamp electrically connected to the feeler.
19. Compression device according to one of the claims 16 to 18, characterised in that the display apparatus has a mechanical display member (43).
20. Compression device according to one of the claims 16 to 19, characterised in that the display apparatus has a display store which sustains the display signal also after movement of the compression jaws (21, 22) in the direction of the open position, whereby the display store has a deletion apparatus capable of actuation from outside.
21. Compression device according to Claim 20,
    characterised in that the deletion apparatus has an actuation block which can only be overcome using tool.
22. Compression device according to one of the claims 1 to 21, characterised in that in the region of the compression jaws (17, 18, 21, 22), at least one further blocking apparatus (68, 82) is provided which, after commencement of the compression process, blocks opening of the compression jaws (17, 18, 21, 22) as far as the open position until the final compression position has been reached.
23. Compression device according to Claim 22,
    characterised in that the further blocking apparatus (68, 82) has its own unblocking apparatus (76) capable of actuation from outside.
24. Compression device according to Claim 23,
    characterised in that the unblocking apparatus of the further blocking apparatus (68, 82) is only capable of actuation with a tool.
25. Compression device according to one of the claims 22 to 24, characterised in that the further blocking apparatus(es) (68, 82) are each attached to two neighbouring compression jaws (17, 18, 21, 22).
26. Compression device according to Claim 25,
    characterised in that the further blocking apparatus(es) (68, 82) is or are each arranged in the region of two opposing front faces (33, 34) of compression jaws (21, 22).
27. Compression device according to one of the claims 22 to 26, characterised in that the further blocking apparatus (68, 82) has on one side a blocking member (69, 74, 75; 89, 90) and on the other side a guide apparatus (72, 91) into which the blocking member (69, 74, 75; 89, 90) engages, whereby blocking member (69, 74, 75; 89, 90) and/or guide apparatus (72, 91) have blocking elements (79, 91) which comprise a return block effective only in the opening direction, and whereby the guide apparatus (72, 91) has a deflection apparatus (78, 80; 100, 101), which only reaches the blocking member (69, 74, 75; 89, 90) if the compression jaws (17, 18, 21, 22) are in the final compression position and which then deflects the blocking member (69, 74, 75, 89, 90) into a guide track (81, 100) circumventing the return block.

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