EP1979110A1

EP1979110A1 - Hydraulically driven pressing device, and method of pressing a fitting

Info

Publication number: EP1979110A1
Application number: EP07704050A
Authority: EP
Inventors: Egbert Frenken
Original assignee: Gustav Klauke GmbH
Current assignee: Gustav Klauke GmbH
Priority date: 2006-01-23
Filing date: 2007-01-22
Publication date: 2008-10-15
Anticipated expiration: 2027-01-22
Also published as: JP2009523621A; KR20080089660A; RU2421293C2; PL1979110T3; US8245561B2; US20140123724A1; KR101490672B1; US8656574B2; EP1979110B1; US20100275672A1; CA2633777C; US9016103B2; CN101370604B; ATE548137T1; WO2007082951A1; CA2832765C; JP5066102B2; US20120073112A1; RU2008134474A; DE102006003044A1

Abstract

A method of using a hydraulically driven pressing device for pressing a fitting on a tube is provided. The pressing device includes a piston and a cylinder for acting on pressing jaws. A piston shaft is connected to rollers. The pressing device can be used to carry out pressing operations requiring different levels of pressing power, by using an adjustable stop which is provided in the direction of displacement of the piston in order to achieve different end positions for the piston during the piston return stroke.

Description

Hydraulically driven grouting device and method for pressing a fitting

The invention firstly relates to a hydraulically driven pressing device having a piston and a cylinder for acting on compression jaws, wherein in any case the piston shaft is connected to action means.

Grouting of the type in question are known. For example, reference is made to DE 19803536 A1. In this document, a pressing device is described and shown, which acts via pincer-like jaws on a grouting chain with several chain links. The piston of the pressing device for acting on the compression jaws is hydraulically displaced into the pressing position. The return stroke takes place by means of a tensioned in the course of the forward stroke spring.

From DE 10010601 Al a pressing device of the type in question is known, in which hydraulically acting on a formed from the compression jaws, interchangeable dies bearing press jaw is acted.

The action on the compression jaws generally takes place via tool-side action means, which are in any case connected to the piston shaft of the hydraulically displaceable piston.

In view of the prior art described above, a technical problem of the invention is seen in such a press device of the type in question to further improve that with the same device different press energies required compression can be performed. This problem is initially and essentially solved by the subject matter of claim 1, wherein it is pointed out that in the direction of travel of the hydraulic piston, an adjustable stop is provided to achieve different end positions of the hydraulic piston in the piston return. According to this embodiment, a pressing device of the type in question is created, by means of which different piston strokes can be driven. Also by means of the adjustable stop experiences the return of the piston, in particular after completion of pressing a limit, so that a subsequent pressing operation takes place from this limited Kolbenanschlagstel- ment out. As a result of this stop setting, pressings with different pressing energies can be carried out, with only one "shot", ie with only one actuation of the device. This is more preferably done with continuously moving piston movement. Accordingly, no idling is preferably provided with regard to the piston stroke. If low compression forces are required, the adjustable stop is moved to a position from which the piston covers a relatively small axial travel for compression. At high required Verpressenergien the stop is brought into a position corresponding to which the piston travels a longer way to final compression. Correspondingly, pressing with different pressing energies can be achieved with one and the same pressing device, wherein in general, ultimately, in conventional pressing devices, the pressing jaw sections cooperating with the action means also result in different pressing forces. However, it is also possible to achieve an equal final force in the maximum injection position despite different pressing energies. Increased injection energy is required, for example, when pressing fittings with large nominal diameters. The proposed solution can continue to be used with the pressing device usual standard compression jaws. For this purpose, a standard press jaw holder is provided on the pressing device. Namely, preferred is one in which the fork legs of the device neck on the surfaces facing each other, which basically consist of parallel planes, have a central longitudinal groove running in the direction of travel of the piston. The longitudinal groove preferably also has parallel surfaces (groove bottoms). The width of the groove bottom is preferably 36.2 to

36.4 mm. The distance of the groove bases, ie in the direction perpendicular to the surfaces forming the groove bases, is preferably 33.1 to 33.3 mm. Furthermore, the pressing jaws can be secured by a bolt passing through the device necks transversely to the direction of travel of the piston. For this purpose, the pressing jaws on tabs with holes. The diameter of the holes in the tabs or in the device necks is 14 to 14.1 mm, with a bolt diameter of

13.5 to 13.95 mm.

It is understood that the dimensions mentioned, as long as the compatibility is given with respect to the matching standard jaws, can still vary slightly.

It is essential that both the pressing jaws for pressing with high energy as well as the standard pressing jaws in one and the same press jaw receiving, just described the standard press jaw recording, can be used and secured.

The subjects of the further claims are explained below in relation to the subject matter of claim 1, but may also be significant in their independent formulation.

The adjustment of the stop can be done mechanically, such as hydraulically or electrically assisted. Preferred is an embodiment in which the stop is manually adjustable, this further preferably under Lö- sung a rest or the like from a shift, in particular shift shift. In a further preferred embodiment, the adjustable stop is provided with two stop positions which can be locked in particular. It is quite possible, the stop also with multiple positions, that is to provide the two end positions and other intermediate positions, so as to expand the range of possible piston strokes and according to the Verpressenergien. It is further proposed that the stop is adjustable by means of a handle provided radially outside of the cylinder. The handle is accordingly provided in the so-called dry area of the hydraulic system, that is to say radially outside the cylinder enclosing the hydraulically operated piston. Thus, the handle is preferably arranged in a handling-technically favorable position on the pressing device, more preferably in a local environment to the pressing jaws. The handle is preferably designed as a sleeve displaceable relative to the cylinder, so more preferably as a sleeve comprising the cylinder, which can be enclosed by the user if required. This sleeve-shaped handle is provided for example with a detent button, to cancel the locking positions locking locking or the like. On the cylinder on which the sleeve is displaceable, markings or the like, so on, for example, colored markings may be provided which illustrate the different stop positions.

Particularly advantageous is an embodiment in which also the stop is provided outside the cylinder, so on in accordance with the so-called dry area beyond the hydraulic loading of the piston. In this case, the stop preferably interacts with a section of the piston shaft connecting the piston with the action means. The piston cooperating with the stop does not necessarily have to be the piston of the hydraulic cylinder / piston combination. Rather, an arrangement is conceivable in which the injection molding advises a replacement head with a separate piston shaft and return spring has. Accordingly, in such an embodiment, the stop together with the handle part of the interchangeable device head, which is adjustable according to this different injection forces on account of this configuration.

The impact means connected to the piston shaft are rollers which act on facing cam tracks of the pressing lever or Verpressbacken to cause over the piston stroke spreading of the cam tracks having Verpressbackenenden, which at the other end of the Verpressbacken closing the molding mouth formed there result. In a preferred embodiment, the stop cooperates with these rollers. The latter drive accordingly in the course of the piston return after pressing against the stop, from which position out the next Verpress can be performed before gear.

It is also provided that the pressing device is equipped with at least two pairs of different compression jaws, which differ in the length of a cooperation region - the curved path - with the action means, with a longer range of cooperation associated with a lower slope angle of the action means associated surfaces of the interaction areas. Accordingly, the pressing device to be equipped with pairs of compression jaws, which differ in the same press jaw geometry in particular by the length of cooperating with the on-agents or rollers press jaw legs, adapted to each adjustable via the adjustable stop piston stroke. By adjusting the angle of increase of the cooperating with the rollers cam tracks of the compression jaws a change in the Verpressener- gie is achieved at preferably constant thrust of the piston of, for example, 32 kN. Accordingly, for example, for pressing gene with larger diameters and in this case preferably desired higher Verpressenergien Verpressbacken fixed with longer press jaw levers on the pressing device and the stop for the piston adjusted so that an enlarged, preferably a maximum piston stroke is achieved. By means of the angle of attack of the cam tracks co-operating with the rollers over the entire piston stroke, which is preferably lower than that of the shorter jaws, an increase of the injection energy, preferably with constant piston thrust, can be achieved, whereby in general also different pressing forces result in the press jaw. Despite different Verpressenergien a constant final force in the press jaw can be achieved.

The preferred stop-limited minimum piston stroke is, for example, 40 mm. The maximum piston stroke preferably corresponds to 1.5 to 3 times the minimum stroke, eg. 80 to 100 mm. With a preferably constant piston thrust of approximately 32 kN, injection energies of 1000 to 4000 joules can be achieved, such as, for example, 1280 joules for a short-stroke compression and 3040 joules for a long-stroke compression (theoretical values before losses).

The invention further relates to a method for pressing a fitting with a pipe by means of a Verpresskette and, a piston / cylinder stroke having, hydraulic Verpressgerät, wherein the Verpresskette has more than two chain links and the pressing is carried out with a certain injection energy.

A grouting chain is known from DE 10257613 Al. This is operated for example by means of a pressing device, for example according to DE 19944229 Al. In order to improve a method of the type in question, it is proposed that the pressing is carried out with a pressing device, the pressing energy of which is applied during pressing by changing a fixed stop, against which the piston moves to limit the piston movement, and is set for a certain compression so that the compression is carried out in the course of a continuous piston movement.

According to the proposed method, the same pressing device can be used both for pressing fittings with low pressing energy and for pressing fittings with higher injection energy. There are, according to the pressing device different piston strokes available, which are completely traversed by the piston after a single operation of the device (in a "shot"). By means of the adjustable fixed stop learns the return of the piston, in particular after completion of pressing, but possibly also by user-side engagement a limit, so that a subsequent pressing operation of this limited piston stop position takes place. If low compression forces are required, the adjustable stop is moved to a position from which the piston travels a relatively small axial travel for pressing. At high required Verpressenergien the stop is brought into a position corresponding to which the piston travels out a longer way to the end crimping out. Regardless of the different adjustable via the adjustable fixed stop pressing forces and concomitant different Kolbenhü- ben preferably the piston thrust is the same size. This can quite generally result in different compression forces in the press jaw. Increased injection energy is required, for example, when pressing fittings with large nominal widths. Below, the invention with reference to the accompanying drawings, which illustrates only exemplary embodiments, explained in more detail. It shows:

1 shows a perspective view of a pressing device in a first embodiment with pressing jaws acting on a pressing chain;

2 shows the section along the line II - II in Figure 1, concerning a long-stroke position of the tool.

3 shows the replacement device head of the pressing device in a single representation, likewise relating to the long-stroke position;

4 shows the section along the line IV - IV in Fig. 3.

5 shows the section along the line V - V in Fig. 3;

Fig. 6 is the front view against the replacement head;

FIG. 7 shows a representation corresponding to FIG. 3, but relating to an intermediate position in the course of the displacement of a stop; FIG.

8 shows the section along the line VIII - VIII in Fig. 7;

9 shows the section along the line IX - IX in Fig. 7;

FIG. 10 shows a representation corresponding to FIG. 3, but concerning the short-stroke position after displacement of the stop;

11 shows the section according to the line XI - XI in Fig. 10; 12 shows the longitudinal section through the pressing device in the long-stroke position with corresponding longer pressing jaws for acting on a press chain;

FIG. 13 shows a representation corresponding to FIG. 12, but relating to the short-stroke position with shorter pressing jaws; FIG.

FIG. 14 shows the longer compression jaws in an individual view; FIG.

Fig. 15 shows the shorter compression jaws in an individual view;

FIG. 16 is a comparative illustration of a longer and a shorter press bed; FIG.

FIG. 17 shows a perspective view of a pressing device according to the representation in FIG. 1, but a second embodiment relating to pressing jaws forming a pressing jaw; FIG.

18 shows a perspective view of a hand-operated, hydraulically acting pressing device with an adjustable stop in a further embodiment;

19 is a perspective view of the pressing device in a further embodiment.

With reference to FIG. 1, a first embodiment of a hydraulic compression device 1 driven by an electric motor is shown and described. Such a tool is known from DE 19944229 A1. The content of this patent application is hereby incorporated in full in the disclosure. gender invention included, also for the purpose of incorporating features of this patent application in claims of the present invention.

In the device 1, an electric motor is arranged. The drive of this electric motor via a, integrated in a handle 2 accumulator. Upon actuation of a finger-operable switch in the region of the handle 2, oil is pumped from a reservoir into a cylinder 4, whereby a piston 5 is moved in the direction of its working end position.

On the hydraulic cylinder 4, which includes the piston 5 provided with a radial seal 6, a replaceable device head 7 is arranged in the illustrated embodiment. This device head 7 shown in the illustrations serves to receive pressing jaws 8 to be acted upon.

The substantially cup-shaped hydraulic cylinder 4 is the device head 7 facing open formed and serves on the one hand inside the leadership of the piston 5 and the other outside to connect the Verpressgerätes 1 with the device head 7, to which the hydraulic cylinder 4 externally has an external thread 9.

The piston 5 is cup-shaped, with a coaxially aligned pot wall 10, which is supported on the inner wall of the hydraulic cylinder 4 on the outside wall.

The cup wall 10 comprises a seated on the piston 5 piston skirt 11 at a radial distance, which piston shaft 11 at the other end carrier is the interaction with the Verpressbacken serving action means 12. These are formed as rollers 13. There are two such rollers 13 provided on a shaft-end side support 14. The rollers 13 are rotatably supported on the carrier 14, wherein the arrangement is further selected so that the rollers 13 are arranged in juxtaposition on both sides of a piston shaft longitudinal axis x.

The device head 7 is fixedly connected to the pressing device 1 by means of a cylinder section 15, which is provided with an internal thread 16 for cooperation with the external thread 9. The cylinder section 15 radially outwardly forms a stop wall 17, which is penetrated by the piston shaft 11. The stop wall 17 serves to support the one end of the piston skirt 11 comprehensive cylinder compression spring 18, the other end, comprises of the pot wall 10, via a piston shaft-side centering before jump 19 acts on the piston 5. The centering projection 19 is seated in a facing recess of the piston 5 a.

In the illustrated embodiments, the action means 12 act on compression jaws 8, which serve to press a fitting by means of a pressing chain. In particular, a press chain is used in this regard, as is known from DE 10257613 A1. The content of this patent application is hereby incorporated in full into the disclosure of the present invention, also for the purpose of including features of this patent application in claims of the present invention.

The injection chain 20 has a total of four pressing members 21, which are involved in the pressing process in cooperation.

The action of the compression jaws 8 on the injection chain 20 takes place via chain-side articulated levers 22. These are equipped with force introduction elements 23 in the form of bolts. These bolts form bearing and abutment for action on the injection chain 20. The compression jaws 8 are replaceably mounted on the device head 7. For this purpose, the latter has a device neck 24. This is fork-shaped, with a transverse to the neck extension the fork legs passing through bolt Auf- takeme, in which a locking pin 25 is supported.

The locking pin 25 passes through the device side of the fork legs of the device neck 24 and on the tool side correspondingly positioned fixing openings 26, which are formed in fastening straps 27.

The fastening tabs 27 dive into the fork region of the device neck 24 with their sections having the fastening openings 26.

The fastening tabs 27 are T-shaped in plan, wherein the central T-leg has the above-described fixing opening 26 and the transverse thereto aligned T-webs each receiving holes 28 have.

Between the two attachment tabs 27, the compression jaws 8 are pivotally supported, including on both sides in the receiving holes 28 of the attachment tabs 27-mounted pivot pin 29 enforce the compression jaws 8.

The pivot axes extend on both sides perpendicular to the piston shaft longitudinal axis x.

With regard to the parts of the equipment neck 24 designed for holding the compression jaws 8 and the corresponding adapter parts on the compression jaws, that is to say in particular the fastening straps 27 mentioned, the compression jaws are designed according to a standard. For this purpose, it is provided in detail that the fork arms 24 'and 24 "of the device neck 24 have two mutually parallel planes E and E', which in turn symmetrically (as well as the planes E and E 'itself) to a transverse axis yy (see 6) have longitudinal grooves 46, 46 ', which recede in cross-section, with groove bottoms, which in turn essentially have mutually parallel opposing surfaces, The transverse spacing of the groove roots t is preferably 33.1 to 33.3 mm for the selected standard design Width b of the grooves 46, 46 'is preferably 36.2 to 36.4 mm.

The compression jaws are secured in the receptacle by means of one of the fork legs 24 'and 24 "passing through bolt 25, which also passes through the fixing openings 26 in the fastening tabs 27 (see also Fig. 12).

The bolt has this in the selected standard training a diameter of 13.5 to 13.95 mm, while said holes have a diameter of 14 to 14.1 mm.

The pressing jaws 8 are formed in the manner of a lever and, due to the above-described articulation on the fastening straps 27, are aligned like a pliers, one lever section of each pressing jaw 8 comprising a control lever 30 and the section protruding beyond the region of the fastening straps 27 in extension of this control lever 30 a pincer-like acting section 31 shaped. These are provided with adapted receptacles for the force introduction elements 23 of the injection chain 20, for example with these bolt-receiving bores or open-edged recesses.

The control levers 30 extend, starting from the attachment lugs 27, in the direction of the device-side action means 12 and form them facing, that is, on the narrow sides facing toward one another. ge control surfaces 32, along which run the roller-shaped engagement means 12 in the course of Kolbenvorverlagerung.

When the pressing device 1 is actuated, oil is pumped into a pressure chamber, as a result of which the piston 5 is moved counter to the action of the return pressure spring 18 in the direction of its working end position, that is to say in the direction of the compression jaws 8.

In this case, the action means 12 or rollers 13 which act against the control surfaces 32 of the compression jaws 8 bring about a pivoting of the control lever sections 30 of the compression jaws 8 caused by the selected raising angles of the control surfaces 32, thus moving the end-side action sections 31 of the compression jaws 8 towards each other via the pivot axes become. By means of the articulated levers 22, this causes the Verpresskette 20 to close, and consequently a compression of a fitting by means of the pressing members 21.

The return movement of the piston 5 takes place via the restoring compression spring 18 as soon as an unillustrated return valve opens due to the exceeding of a predetermined maximum pressure. In this regard, reference is made to DE 19825160 Al. The content of this patent application is hereby also incorporated in full into the disclosure of the present invention, also for the purpose of including features of this patent application in claims of the present invention.

The opening of the outlet valve is carried out automatically when a maximum pressure on the fitting is exceeded, after which the piston 5 is initially driven back automatically by pressure spring. The exhaust valve closes automatically as soon as the pressure on the oil caused by the returning piston 5 drops due to piston stop. After a compression has taken place, the piston 5, as a result of the valve opening and the resulting pressure drop on the part of the hydraulic system, moves back into a piston rest position, which is limited to a limited stop.

Starting from this piston rest position, the piston 5 moves on renewed activation over a predefined distance until reaching or exceeding the maximum pressure. With a constant piston thrust of preferably 32 kN can be varied by changing this distance, the applied pressing energy.

For this purpose, the stop defining the piston rest position can be adjusted, according to which the travel path can be adapted to the desired injection energy.

Outside the hydraulic range, that is, on the dry side of the piston 5, specifically in the illustrated embodiment in the region of the removable device head 7, an adjustable stop 33 is provided. This is the inner wall of a cylinder portion 15 of the removable device head 7 comprehensive sleeve 34 is formed.

This sleeve 34 is slidably supported in axial extension of the piston shaft 11 on the cylinder portion 15, wherein the axial displacement of the sleeve 34 is stop-limited in both directions, which two stop limited

End positions at the same time define the two positions for the adjustable stop 33. The simultaneously formed as a handle 35 sleeve 34 has a, preferably thumb-actuable push button 36. This is acted on the underside by a compression spring 37 radially outward.

The push button 36 is accommodated in an inner wall of the sleeve 34 arranged on this stop housing 38, on the receiving bottom for the push button 36, the compression spring 37 is supported.

The acting in the stop housing 38 portion of the press-button 36 has a radially enlarged collar 39. This acts on in a plane transverse to the extension of the longitudinal axis on both sides of the push button 36 arranged detent balls 40, which pushed over the collar 39 to the outside in accordance positioned Rastkugel- recordings 41 of the device head side cylinder portion 15 occur. This latching engagement forms the abovementioned fixable end stop for the sleeve 34.

In the illustrated embodiment, two positions of the sleeve 34 are latching fixed, so on the one hand viewed in the axial direction rear position according to the illustrations in Figures 2 to 5 and a front position according to the representations 10 and 11th

FIGS. 7 to 9 show a non-latched intermediate position of the sleeve 34.

The pointing in the direction of the action means 12 end face 42 of the stop housing 38 forms the adjustable stop 33 from.

In the rear engagement position of the sleeve 34 generating a longer piston stroke a, the piston 5 stops in the usual way in the piston rest position against the bottom of the hydraulic cylinder 4 accommodating the piston 5. zend on. From this position according to FIGS. 2 to 6, the piston 5 moves over its maximum travel while applying a maximum injection energy of approximately 2500 to 3200 joules. According to the rear stop position of the piston 5 and the cooperating via the piston shaft 11 with the piston 5 acting means 12 are held in a rear position. Correspondingly, in such a configuration, crimping jaws 8 are used, which are adapted to the variably adjustable distance dimension between the crimping jaw fixing in the region of the appliance-side locking bolt and the action means 12 with respect to the length of the control lever 30 via the adjustable stop 33. Thus, in a configuration with a long piston stroke, compression jaws according to the illustration in FIG. 12 are provided, which have extended control levers 30 with correspondingly longer control surfaces 32 compared with the compression jaws 8 'in FIG.

If no high injection energies are required (for example 1000 to 1500 joules), then the piston rest position is advanced in the direction of the piston advance movement, according to which the piston stroke a 'is shortened in the course of a compression process. For this purpose, the adjustable stop 33 is advanced over the sleeve 34 after previous release of the detent via the push button 36 in the piston feed direction. This until the corresponding end position in which the intended rest engages again.

This sleeve Vorversagerung for adjusting the stopper 33 in the short-stroke position is preferably carried out in the course of a previously performed Verpress- process or in the course of a corresponding piston forward displacement to thereby provide a corresponding flow of the action means 12 before the stop 33 to be adjusted , Such an intermediate position is shown for example in FIG. 9, although here without connection of the device head 7 to the pressing device 1. ter influencing the piston shaft reachable via the piston-cylinder hydraulic system.

In the front position of the stop 33 shown in Figures 10 and 11 occurs one of the action means 12 or one of the rollers 13 in the piston return movement after exceeding a maximum pressure or optionally controlled by the user against the end face 42 of the stop housing 38, according to a stop is achieved via the carrier 14 and the piston shaft 11 against the action of the force acting on the centering projection 19 of the piston skirt 11 force of the compression spring 18. Follow this

Standstill also drops the pressure in the hydraulic chamber of the hydraulic cylinder in front of the piston 5, which has a closing of the exhaust valve result.

In this front end position of the piston 5 or the action means 12, the piston stroke corresponds approximately to half the piston stroke in the long-stroke position, so for example. 40 mm at a long stroke of about 80 mm.

Although the adjustable stop 33 is shown with the sleeve 34 in the illustrated embodiments in the range of a removable device head 7, the proposed solution is quite predictable on Verpressgeräten 1, the device head is not detachably connected to the tool.

Such an arrangement with an adjustable stop 33 for varying the piston stroke in other Verpressvorsätzen than the compression shown pressing chain 20 can be used, for example, in Verpressbacken 8 "as shown in Figure 17, the other end of the control lever 30, a press jaw 43, optionally for Formation of replaceable press inserts.

The proposed arrangement can also be provided on a hand-held press device according to the illustration in FIG. 18, which can be used as a lever-actuatable armature. beitsgerät is formed. The pressure required for the displacement of the piston 5 is therefore not electromotive, but manually operated via a pump lever 44.

Furthermore, there is the possibility of the proposed arrangement on a pressing device 1 according to the illustration in FIG. 19, which is equipped as a one-hand operable device, with a grip region 45 to be encompassed by one hand, in which an electric motor is provided for hydraulic pressurization.

The provided with different length control levers 30 compression jaws 8 and 8 'are shown in Figures 14 and 15 in individual representations. Figure 16 shows a representation in which the different jaws are drawn to illustrate the differences in control lever side in superimposition, wherein the shorter control lever 30 having pressing jaws 8 'are shown in dash-dotted line style.

The compression jaws 8 shown in FIG. 14 for acting on the action means 12 starting from the long-stroke position are each provided with a control surface action length 1 adapted to the extended piston stroke.

The corresponding length 1 'of the injection molding jaws 8' designed for shorter piston stroke application corresponds to approximately half of the dimension 1 of the longer compression jaws 8.

As can be seen further from the illustration in FIG. 16, both pairs of pressing beams 8 and 8 'have the same design on the side of the impact section, correspondingly also having the same opening angle α in the rest position. The control surfaces 32 of the control lever 30 are different in terms of their angle of attack in cooperation with the action means 12. Thus, the control surfaces 32 of the elongated compression jaws 8 are convexly curved in plan, with a starting from the free end of each control lever 30 in the course of the further course of the control surface 32 decreasing radius.

Correspondingly, a relatively steep angle of attack for spreading the compression jaws 8 is achieved by being acted upon by means of the action means 12, which greatly reduces in the course of the further piston advance and corresponding action of the rollers 13 on the control surfaces 32 due to the concave configuration of the control surfaces 32.

This angle of attack is set steeper over the entire action path in the case of the shorter-shaped compression jaws 8 'in comparison to the longer compression jaws 8-with the exception of the contact surfaces formed in the region of the free ends of the control levers 30. In the rest position of the compression jaws 8 'as shown in Figure 15, the control surfaces 32 and in the plan whose edges, with the exception of the end-side approach surfaces are almost parallel, possibly with a tendency wedge-shaped inlet in the direction of the Einwirkungsabschnitte 31st

Due to the different angles of incidence of the control surfaces 32 different, acting on the fitting to be compressed Verpressenergien can be applied with constant piston thrust. The adjusting forces in the press jaw that can be set here can vary, such as with longer stroke sizes.

Also, if necessary, in addition to Kolbenhubänderung a change in the piston thrust force can be made, so for example. By adjusting the trigger point of the spring-loaded hydraulic return valve. All disclosed features are essential to the invention. The disclosure of the associated / attached priority documents (copy of the prior application) is hereby also incorporated in full in the disclosure of the application, also for the purpose of including features of these documents in claims of the present application.

Claims

1. Hydraulically driven Verpressgerät (1) with a piston (5) and a cylinder (4) for acting on Verpressbacken (8, 8 ', 8 "), wherein in any case the piston shaft (11) with impact means (12) is connected, characterized characterized in that in the direction of travel of the hydraulic piston (5) an adjustable stop (33) is provided to achieve different end positions of the hydraulic piston (5) in the piston return.

2. pressing device according to claim 1 or in particular according thereto, characterized in that the stop (33) is adjustable by hand.

3. pressing device according to one or more of the preceding claims or in particular according thereto, characterized in that the stop

(33) by means of a radially outwardly to the cylinder (4) provided handle (35) is adjustable.

4. pressing device according to one or more of the preceding claims or in particular according thereto, characterized in that the handle

(35) is designed as a relative to the cylinder (4) displaceable sleeve (34).

5. pressing device according to one or more of the preceding claims or in particular according thereto, characterized in that the stop (33) on the cylinder wall can be locked as a fixed part.

6. pressing device according to one or more of the preceding claims or in particular according thereto, characterized in that the stop (33) outside the cylinder (4) is provided.

7. pressing device according to one or more of the preceding claims or in particular according thereto, characterized in that the action means are rollers (13).

8. pressing device according to one or more of the preceding claims or in particular according thereto, characterized in that the stop (33) cooperates with the rollers (13).

9. pressing device according to one or more of the preceding claims or in particular according thereto, characterized in that the pressing device (1) with at least two pairs of different compression jaws (8, 8 ') is provided, in the length (1, 1') of a Collaboration range with the action means (12) differ, with a longer range of cooperation associated with a lower rise angle of the action means (12) associated surface of the interaction area.

10. A method for pressing a fitting with a pipe by means of a Verpresskette (20) and one, a piston / cylinder stroke having, hydraulic Verpressgerät (1), wherein the Verpresskette (20) has more than two chain links (21) and the compression is carried out with a certain injection energy, characterized in that the compression is carried out with a pressing device (1), the applied during a compression injection energy by changing a fixed stop (33) against which the piston (5) anfährt to limit the piston movement is changeable and is adjusted for a certain compression so that the compression is carried out in the course of a continuous piston movement.