EP2995426B1 - Press tool with an auxiliary bistable tensioning mechanism - Google Patents

Description

The invention relates to a pressing tool for connecting a pipe and a fitting, in particular for permanent connection, with two pivot elements for pressing the pipe and the fitting, with a receiving area formed between the pivot members for receiving the pipe and the fitting, with at least one pivot axis for rotatable Supporting the pivoting elements and having a clamping mechanism for biasing the pressing tool, wherein the pivoting elements for pressing the tube and the fitting about the at least one pivot axis are mutually pivotable, wherein the receiving area in a first closed position is narrower than in a second open position of the pivoting elements, wherein the pivotal elements are biased towards the closed position by the tensioning mechanism, and wherein at least one holding device is provided for holding the pivotal elements in the open position against the biasing force generated by the tensioning mechanism is.

Pressing tools of the type mentioned are already known and are used for example in the installation of piping systems for drinking water or gas supply and in the installation of sewage, air conditioning or fire protection systems. In practical use, the pivot elements of the pressing tool surround the circumference of the pipe to be pressed and the fitting. The pivotal elements are biased by the clamping mechanism on the outer peripheral surface of the fitting to be compressed, or to be pressed sleeve on. After the tool and the components to be pressed are positioned correctly relative to each other, the cold compression is usually performed by a force acting on the pivot elements engine.

If a user wants to use such a pressing tool, he must bring one hand, the components to be pressed in the intended position for the pressing and hold there, on the other hand press the pivot elements in a stressing the clamping mechanism manner against each other to make the pressing tool for receiving the components ready, and additionally bring the pressing tool and the associated engine in the position provided for pressing and hold there. There are thus three points on which the user has to pay attention. In practice, the user may, where appropriate, avail himself of the assistance of another person who assumes one of the three aforementioned activities. The user can continue to get rid of the first of the aforementioned activities by using technical aids, for example by fixing the components to be pressed before the pressing tool is applied. However, the user the use of a previously described pressing tool is difficult if he wants to perform the pressing without outside help or without further technical aids, in particular without separate fixation of the components.

From the DE 10 2007 061 164 a pressing tool according to the preamble of claim 1 is known in which two pivoting elements can be held relative to each other spring-biased on the one hand in a closed and on the other hand in an open position. For this purpose, a bistable clamping mechanism is provided. The advantage of this tool that with the help of the bistable clamping mechanism compressions in hard to reach places are possible in a simple way, the disadvantage that the holding or locking function in the open position prevents the user if necessary to the rapid implementation of a plurality of successive crimping , For example, some users prefer conventionally biased tools while others favor the bistable tensioning mechanism.

The present invention is therefore based on the technical problem of providing a pressing tool that is more flexible to handle and optimally serves a greater variety of different mounting situations.

The aforementioned technical problem is inventively achieved in that the holding device is switchable and that the holding device and the clamping mechanism form a switchable bistable clamping mechanism.

It has been recognized that a flexible to handle and a greater variety of different mounting situations optimally operating pressing tool can be specified by the inventive solution. The pressing tool according to the invention can consequently be used in two different ways. In a first operating mode, only the clamping mechanism acts on the pivoting elements, so that they are biased in the direction of the closed position. To hold the heavy elements in the open position, a user must actively keep the pivotal elements open against the biasing force generated by the tensioning mechanism. If there is no action by the user, the pivoting elements remain in the closed position or, due to the action of the clamping mechanism, fall back into the latter. In a second mode, the holding device is switched on and together with the clamping mechanism forms a bistable clamping mechanism. This means that the swiveling elements of the pressing tool can be pivoted into two stable states when the holding device is switched on, in which the swiveling elements remain outside from the outside without the action of a pulse or force input.

The closed position of the pivot elements may represent the first stable position, while the second stable position is the open position. In this case, the engaged holding device acts in the open position against the biasing force generated by the clamping mechanism, so that the pressing tool remains in the open position. If the pivot elements are transferred by the action of an operator from the open position to the closed position, the pivot elements are held by the clamping mechanism in the closed position.

In order to transfer the pivoting elements from one stable position to the other stable position, the momentum or external force input of the type must be dimensioned such that the pivoting elements are pivoted towards each other by the momentum or force input beyond the labile intermediate position lying between the stable positions , Wherein the pivoting elements fall after exceeding this labile intermediate position in the respective other stable position. The labile intermediate position is the relative pivotal position of the pivotal elements relative to one another in which the action of the tensioning mechanism and the support reciprocally cancel each other so that the moment about the pivotal axis is zero.

For example, a user may manually manipulate the pivot members to pivot them from the closed to the open position or vice versa. A pulse or a force input, which converts the pressing tool from the open position into the closed position or can be latched into it, can be introduced into the tool, for example, by an engine connected to the pressing tool for pressing the components. In this case, the user can readily grasp the components without pressing on the engine, after he has positioned the components to be pressed in the receiving area of the pressing tool.

The bistable clamping mechanism simplifies the handling of the pressing tool. Thus, the pressing tool can be positioned with the pivoting elements held by the holding device in the open position relative to the components to be pressed, whereby the user can concentrate solely on the proper positioning of the tool with the pressing tool preset in this way. The pressing tool can be brought together with a corresponding engine by the user, for example, with one hand in position.

The user can thus decide whether the pressing tool held in the open state before pressing the pipe and fitting over the holding device should or should not be. The pressing tool according to the invention thus combines the advantages of conventional, simply pre-stressed pressing tools with the advantages of tools that provide for fixing the pivoting elements in an open position. The respective user therefore has a flexibly usable pressing tool which has an optionally switchable holding function of the pivoting elements in the open position.

According to one embodiment of the pressing tool, the holding device in the open position of the pivot elements on a first switching position in which the clamping mechanism is released. In addition, the holding device in the open position of the pivot elements on a second switching position, in which the holding device counteracts the clamping mechanism. In the first switching position, the holding device is therefore not switched on and in this case does not act on the clamping mechanism. In the second switching position, the holding device is switched on and holds the pivoted in the open position pivoting elements against the force generated by the clamping mechanism in the open position. The pressing tool is therefore particularly easy to use, since the user only has to choose between two switching positions of the holding device to turn on or off the bistable clamping mechanism.

The holding device may be resiliently braced in the second switching position. The resilient elastic tension ensures a reliable holding function of the holding device in the open position, wherein the biasing force of the clamping mechanism can be precisely repeated a defined counterforce of the holding device, so that no unwanted decoupling takes place between holding device and clamping mechanism. In particular, both the clamping mechanism and the holding device may have a spring, wherein the springs, depending on the switching position of the holding device, are braced against each other. By interconnecting two springs, the clamping mechanism and the holding device can be produced in a particularly simple and cost-effective manner. In particular, it is possible to each for To set change between the positions of the pivot elements required actuating forces in a simple manner on the dimensioning of the springs.

According to a preferred embodiment of the pressing tool, the holding device has at least one latching element and at least one latching recess, wherein the latching element cooperates with the latching recess in the second switching position. Due to the interaction of latching element and latching recess, a defined contact area, such as e.g. a contact surface are created, over which the holding forces between the holding device and the clamping mechanism are transmitted. Thus, with the aid of the latching recess and the latching element, a defined open position can be specified, in which the pivoting elements are held by the holding means. Thus, the receiving area in this position has a predetermined intake width for introducing corresponding pipe and fitting diameter. The coupling between the locking element and the recess can be positive and / or non-positive. The mutually contacting areas of latching element and latching recess can be pressed against each other, for example, via the forces introduced into the pivoting elements by the tensioning mechanism. In this case, the locking element engage in an at least partially complementarily shaped recess.

The latching element and the latching recess may be provided on two different components, which are pivotable relative to each other about the pivot axis, wherein at least one of the components is one of the pivoting elements. In this way it can be ensured that an introduced via the clamping device in the pivot elements torque can be supported by the holding device about the pivot axis in the open position of the pivoting elements.

Thus, the latching recess and the latching element may be provided on the two pivoting elements. Also, the latching recess or the latching element may be provided on a housing or support member, wherein the housing or support member, for example, carries the pivot axis. Such Housing or support element may be required in particular when each of the pivot elements is held on a separate pivot axis, wherein the pivot axes are fixed in the housing or support member with respect to their relative position to each other. The housing or support member may be formed one or more parts for manufacturing and assembly reasons and in particular contribute to the stiffening of the pressing tool. In addition, the housing or support element can serve as a coupling point for coupling an engine to the pressing tool.

According to a first preferred embodiment of the pressing tool, the latching element may be a substantially cylindrical pin and the latching recess may be a recess formed on a leaf spring. The use of the cylindrical bolt in cooperation with a leaf spring has the advantage that these components can be integrated in a particularly space-saving manner in the pressing tool. The bolt is preferably arranged substantially parallel to the pivot axis. The leaf spring is arranged in particular between the bolt and the pivot axis. The leaf spring is in particular pointing away from the pivot axis, curved in the direction of the bolt to the outside and has a substantially rectangular basic shape. The length of the leaf spring corresponds to at least three times its width and is at least partially bent along its longitudinal side about the pivot axis. In the width direction, the leaf spring is oriented substantially parallel to the pivot axis.

According to one embodiment of the pressing tool, the bolt is displaceable in the axial direction between the first switching position and the second switching position, wherein the bolt in the first switching position has a distance from the leaf spring and rests circumferentially on the leaf spring in the second switching position. If the bolt is in the first switching position, the bolt and the leaf spring do not counteract pivoting out of the open position into the closed position, since the distance between the bolt and the leaf spring permits free pivoting of the pivoting elements. In the second switching position engages the Bolt in a form-fitting manner in the recess of the leaf spring. The contact area between the leaf spring and the bolt is in the open position of the pivot elements an abutment, against which the pivot elements are supported against a pivoting caused by the clamping mechanism from the open position to the closed position. In the second switching position, therefore, the leaf spring itself and the frictional contact between the leaf spring and the bolt counteract slipping of the bolt along the recess. In further embodiments of the invention, it is possible that the leaf spring and the bolt form a substantially point or line-shaped contact area to each other.

The bolt is thus a mechanical switch, wherein the displacement of the bolt in the axial direction corresponds to the switching of the holding device according to the invention. In addition to the switching function of the bolt in cooperation with the leaf spring simultaneously produces the coupling between the clamping mechanism and the holding device. The bolt can be guided slidingly along a bore, so that a defined, substantially play-free guidance of the bolt between the first and the second switching position is ensured. The bolt therefore combines together with the leaf spring both the switching and the coupling function. In this way, a compact, robust and cost-effective mapping of the switching and coupling function is made possible in the pressing tool. In addition, a bistable coupling of the prestressed via the clamping mechanism pivot elements can be achieved via the leaf spring.

Furthermore, the switching and coupling function can be divided into two or more separate components. Thus, a separate switch act on a bolt or a separate coupling element, wherein the switch and the coupling element can have electrical and / or electromagnetic and / or pneumatic switching and / or adjusting elements.

The bolt is preferably on a guide rail, which holds the bolt in the respective axial switching position. In this way it can be achieved that the bolt is secured in any pivoting and switching position against unwanted displacement from the respective switching position.

Preferably, the guide rail is a leaf spring. The trained as a leaf spring guide rail therefore allows a tension of the bolt in the respective switching position, so that the bolt is securely held in the respective switching position, in particular in the case of the first switching position in which there is no contact in the region of the recess.

According to a further embodiment of the pressing tool, the bolt has at the portion assigned to the guide rail two grooves arranged peripherally at a distance from each other and cooperating in the respective switching position with a guide track of the guide rail. The bolt is held in this way positively in the selected switching position.

According to a second preferred embodiment of the pressing tool, the latching element has a sliding element movably guided on the one pivoting element, wherein the sliding element is displaceable between the first switching position and the second switching position, and the latching recess is formed on the other pivoting element. The pivoting elements can be hooked into one another with the aid of the latching element and the latching recess. The locking element may in particular be designed in the manner of a clip or a clamp. Thus, the switching and coupling function are combined in a combination of locking element and recess and thus provide a robust and easy-to-use press tool. Preferably, latching element and latching recess are mounted on a side facing away from the receiving area of the pivot elements, so that the switchable holding device is arranged easily accessible.

In this case, the sliding element can be kept biased in the first switching position. On the one hand, this ensures that the sliding element rests firmly against the pressing tool when not in use and does not hinder the user when using the tool. On the other hand, the bias prevents inadvertent connection of the holding device by the user. Such a biasing force can be generated for example by a helical compression spring, which is arranged between the pivoting and sliding element. By the helical compression spring also the travel can be specified, which must be overcome by the operator against the spring force of the helical compression spring to bring the locking element with the locking recess into engagement.

According to a further preferred embodiment of the pressing tool, two sliding elements and two latching recesses are provided on the pivoting elements. Thus, the pressing tool can be symmetrically clamped in the open position. In further embodiments of the invention, the latching recesses are provided on the sliding elements themselves, so that the sliding elements of the pivoting elements mutually engage each other. This type of holding device can be easily retrofitted to an existing pressing tool.

According to a third preferred embodiment of the pressing tool, the locking element is a pressure piece. In such a pressure piece may be a conventional, resilient pressure piece, which cooperates with the latching recess in the second switching position to hold the pivoting elements in the open position. The pressure piece may in particular have a resiliently biased in the first switching position detent ball sitting in the second switching position in a recess formed as a recess. Preferably, the pressure piece is substantially relaxed in the second switching position. Thus, the holding device can be formed in a simple manner from a recess and a known per se and inexpensive available in a variety of different versions pressure piece.

In an advantageous development of this embodiment of the pressing tool, the pressure piece is fastened to one of the pivoting elements and the latching recess is provided on a supporting element carrying the pivoting axis. The pressure piece is pivotable in this case together with the pivoting element relative to the support member about the pivot axis. Thus, the switching of the pressure piece from the first to the second switching position (and vice versa) can be effected in a simple manner in that the pressure piece during pivoting of the pivot member with a spring-loaded locking body of the pressure piece, such. a detent ball, the end face along a defined outer contour of the support element is guided, which merges into the recess. In particular, this outer contour may be formed by a guide surface of the support element facing away from the pivot axis. The pressure piece may have an external thread and be screwed into a receptacle provided on the pivoting element.

Preferably, the pressure piece can therefore have a detent ball, which is resiliently clamped in the closed position of the pivot elements against the guide surface of the support element in the direction of the pivot axis resiliently. When pivoting the respective pivot member to which the pressure piece is attached, from the closed to the open position slides or rolls in the pressure piece held detent ball along the guide surface in the direction of the trough. If, during pivoting of the pivoting elements, a pivoting position defined by the transition from the guide surface to the recess is exceeded, the detent ball moves into the recess due to the spring force. The position of the detent ball engaged in the recess represents the second switching position of the holding device. In the second switching position, the pressure piece counteracts a pivoting of the swivel elements caused by the clamping mechanism into the closed position, so that the swiveling elements are held in the open position.

The switching of the holding device is therefore preferably carried out by the pivoting of the respective equipped with the pressure piece pivot member over a predetermined pivot position, the pivoting position by constructive the arrangement of the recess, or the relative arrangement of pressure piece and recess to each other, can be defined.

Preferably, the receiving area formed between the pivot elements when transferring the pivot elements from the closed to the open position before reaching the pivot position, the crossing causes an engagement of the detent ball in the trough, already opened so far that the entire spectrum of the subject at issue Pressing tool to be connected pipe cross-sections and fittings can be introduced into the receiving area to produce a permanent connection by compression. In other words, the pressing tool is already in the first switching position of the holding device unrestricted for pressing the respectively provided for this tool tube cross sections without causing a setting of the pivot elements in the open position by the pressure piece, wherein the disengaged in the open position from the recess recess position the detent ball represents the first switching position of the holding device. The respective user can therefore decide whether the pivoting elements of the pressing tool to be held in the open position by pivoting the pivot elements until the engagement of the detent ball into the trough or disregards it. The holding device can consequently be switched on in a simple manner, without it being necessary to grip around when the pivoting elements are pivoted from the closed to the open position.

In order to pivot the held by the pressure piece in the open position pivoting element from the open to the closed position, the resistance formed by the first pressure piece and the recess must be overcome. In the case of the locking ball seated in a recess described above, a restoring force is required for pivoting the pivoting element into the closed position, which causes the locking ball to slide off or roll out of the recess in the direction of the guide surface, the detent ball rising along the direction of the guide surface Surface of the trough against the spring of the pressure piece engages in the pressure piece.

So that an operator does not inadvertently fix the pressing tool during the spreading of the pivoting elements in the open position of the pivoting elements, a second pressure piece can be provided next to the first pressure piece, which counteracts a pivoting of the pivoting elements from the closed to the open position in a pivoting area, wherein in particular the open position is part of the swivel range. The second pressure piece can define in this way a pressure point by the resistance for spreading the pivot elements in a pivoting area immediately before reaching the pivot position, the crossing causes engagement of the detent ball into the trough is increased.

The second pressure piece may be provided on a pivoting element and cooperate with a supporting element carrying the pivot axis of the pivoting element. The second pressure piece can be a resilient pressure piece with a resiliently prestressed detent ball. In the closed position of the pivot elements, the second pressure piece, in particular the detent ball of the second pressure piece, is arranged at a distance from the support element. By pivoting the pivot elements from the closed in the direction of the open position, the detent ball engages in the pivoting area with the support element into engagement. In the swivel range, a second recess is preferably formed, in which the detent ball of the second pressure piece engages by the pivoting movement. Due to the interaction of the spring-loaded detent ball of the second pressure piece and the second trough an additional resistance is opposite to the pivoting of the pivot elements before reaching the pivot position, exceeding an engagement of the detent ball of the first pressure piece causes in the trough.

The first and the second pressure piece can be provided on different pivoting elements. In this case, the movement of the two pivoting elements can be coupled to the respective associated common or separate pivot axis via a transmission, so that pivoting of a pivoting element a Swiveling the other pivoting element causes. Thus, the first pressure piece may be provided on a first pivot element and the second pressure piece on a second pivot element, wherein both the first and the second pressure piece act on both pivot elements via the transmission.

Such a gear coupling the pivotal movement of the pivot elements may also be provided on one of the previously described embodiments of the pressing tool. This has the advantage that even a single, provided on one of the pivot elements holding device is sufficient to hold both pivot elements in the open position.

Fig. 1a, 1b

ein erstes Ausführungsbeispiel eines erfindungsgemäßen Presswerkzeugs in geschlossener Stellung, mit Haltevorrichtungen in einer ersten Schaltstellung, in zwei perspektivischen Ansichten;

Fig. 1c, 1d

Ausschnittvergrößerungen des Presswerkzeugs aus Fig. 1a und Fig.1b in geschlossener Stellung, mit den Haltevorrichtungen in der ersten Schaltstellung, in zwei perspektivischen Ansichten;

Fig. 2a, 2b

das Presswerkzeug aus Fig. 1 in offener Stellung, mit den Haltevorrichtungen in der ersten Schaltstellung, in zwei perspektivischen Ansichten;

Fig. 2c, 2d

Ausschnittvergrößerungen das Presswerkzeug aus Fig. 2a und 2b in offener Stellung, mit den Haltevorrichtungen in der ersten Schaltstellung in zwei perspektivischen Ansichten;

Fig. 3a, 3b

Ausschnittvergrößerung des Presswerkzeugs in offener Stellung, mit den Haltevorrichtungen in einer zweiten Schaltstellung in zwei perspektivischen Ansichten;

Fig. 4a, 4b

Ausschnittvergrößerung des Presswerkzeugs in geschlossener Stellung, mit den Haltevorrichtungen in der zweiten Schaltstellung in zwei perspektivischen Ansichten;

Fig. 5

ein zweites Ausführungsbeispiel eines erfindungsgemäßen Presswerkzeugs in geschlossener Stellung in einer perspektivischen Ansicht;

Fig. 6a

das Presswerkzeug aus Figur 5 in geschlossener Stellung, mit Haltevorrichtungen in einer ersten Schaltstellung, in einer Seitenansicht;

Fig. 6b

das Presswerkzeug aus Figur 5 in offener Stellung, mit den Haltevorrichtungen in der ersten Schaltstellung, in einer Seitenansicht;

Fig. 6c

das Presswerkzeug aus Figur 5 in offener Stellung, mit den Haltevorrichtungen in einer zweiten Schaltstellung;

Fig. 7a

eine Schnittdarstellung der Haltevorrichtungen entlang der Linie VII a - VII a aus Figur 6a;

Fig. 7b

eine Schnittdarstellung der Haltevorrichtungen entlang der Linie VII b - VII b aus Figur 6b;

Fig. 7c

eine Schnittdarstellung der Haltevorrichtungen entlang der Linie VII c - VII c aus Figur 6c;

Fig. 8a

ein drittes Ausführungsbeispiel eines erfindungsgemäßen Presswerkzeugs in geschlossener Stellung in einer Seitenansicht;

Fig. 8b

das Presswerkzeug aus Figur 8a in einer offenen Stellung in einer Seitenansicht;

Fig. 8c

das Presswerkzeug aus Figur 8a in einer offenen Stellung in einer Seitenansicht;

Fig. 9

ein viertes Ausführungsbeispiel eines erfindungsgemäßen Presswerkzeugs in geschlossener Stellung in einer Seitenansicht.

Alternatively or in addition to the second pressure piece, a marking may be provided on the pressing tool, which indicates to the respective user the pivoting position, the exceeding of which causes engagement of the detent ball of the first pressure piece into the recess or a switching of the first pressure piece.
In the following the invention will be explained in more detail with reference to embodiments shown in a drawing. In the drawing show:

Fig. 1a, 1b

a first embodiment of a pressing tool according to the invention in the closed position, with holding devices in a first switching position, in two perspective views;

Fig. 1c, 1d

Cut-out enlargements of the pressing tool Fig. 1a and 1b shows in the closed position, with the holding devices in the first switching position, in two perspective views;

Fig. 2a, 2b

the pressing tool off Fig. 1 in the open position, with the holding devices in the first switching position, in two perspective views;

Fig. 2c, 2d

Cutting enlargements out the pressing tool Fig. 2a and 2 B in the open position, with the holding devices in the first switching position in two perspective views;

Fig. 3a, 3b

Sectional enlargement of the pressing tool in the open position, with the holding devices in a second switching position in two perspective views;

Fig. 4a, 4b

Sectional enlargement of the pressing tool in the closed position, with the holding devices in the second switching position in two perspective views;

Fig. 5

A second embodiment of a pressing tool according to the invention in the closed position in a perspective view;

Fig. 6a

the pressing tool off FIG. 5 in the closed position, with holding devices in a first switching position, in a side view;

Fig. 6b

the pressing tool off FIG. 5 in the open position, with the holding devices in the first switching position, in a side view;

Fig. 6c

the pressing tool off FIG. 5 in the open position, with the holding devices in a second switching position;

Fig. 7a

a sectional view of the holding devices along the line VII a - VII a from FIG. 6a ;

Fig. 7b

a sectional view of the holding devices along the line VII b - VII b from FIG. 6b ;

Fig. 7c

a sectional view of the holding devices along the line VII c - VII c from FIG. 6c ;

Fig. 8a

a third embodiment of a pressing tool according to the invention in the closed position in a side view;

Fig. 8b

the pressing tool off FIG. 8a in an open position in a side view;

Fig. 8c

the pressing tool off FIG. 8a in an open position in a side view;

Fig. 9

A fourth embodiment of a pressing tool according to the invention in the closed position in a side view.

FIG. 1 shows an embodiment of a pressing tool 2 according to the invention for connecting a pipe (not shown) and a fitting (not shown) in the closed position, with holding devices 20a in a first switching position A, in two perspective views.

The pressing tool 2 has two pivoting elements 4 for pressing the pipe and the fitting. The pressing tool 2 has a receiving area 6 formed between the pivoting elements 4 for receiving the pipe and the fitting. The pivoting elements 4 each have a pressing section 8 and an actuating section 10. The operating portions 10 serve in practical use to initiate the pressing forces via an engine (not shown). The inner contours 12 of the pressing sections 8 form the receiving area 6. The receiving area 6 is moved from an open position during pressing (FIG. Fig. 2 ) in a closed position ( Fig.1 ), wherein the receiving area 6 in the closed position of the pivot elements 4 is narrower than in the open position of the pivot elements 4.

Between the pivoting elements 4 is an internal and a biasing spring comprehensive clamping mechanism 14 (not shown) for biasing the pressing tool 2 in the direction of the closed position. The pivot elements 4 are rotatably mounted on the pivot axes 16. The pivoting elements 4 are for pressing the tube and the fitting about the pivot axes 16 against each other. The pivot axes 16 are mounted in the support elements 18.

The pressing tool 2 has two holding devices 20a for holding the pivoting elements 4 in the open position (FIG. Fig. 3 ) against the force generated by the biasing spring, wherein the holding devices 20a are switchable. The holding devices 20a and the clamping mechanism 14 form a switchable, bistable clamping mechanism.

The respective holding device 20a has a latching element 22a and at least one latching recess 24a. The latching element 22a is a substantially cylindrical pin 22a, and the latching recess 24a is a recess 24a formed on a leaf spring 26. The leaf spring 26 is held in a form-fitting manner with its receptacle 30 of the support element 18 that is complementarily shaped at least in sections, with its end sections 28 bent over at the end substantially in a circular manner.

The respective pin 22a of one of the holding devices 20a bears against a guide rail 32, which secures the pin 22a in the axial direction along the axis a of the pin 22a against undesired displacement. The guide rail 32 is a leaf spring 32 which is fixed to the support member 18 opposite the leaf spring 26. The bolt 22a has at its the guide rail 32 associated portion 34 has two spaced apart, circumferentially encircling grooves 36a, 36b, which cooperate with a guide rail 38 of the guide rail 32. The guideway 38 is curved in the direction of the bolt 22a. The grooves 36a, 36b each have a in Substantially to the curvature of the guideway 38 complementarily shaped groove cross section. The guideway 38 and the grooves 26a, 26b engage positively in one another. The bolt 22a is secured by the guide track 38 and the grooves 36a, 36b against displacement in the axial direction. When pivoting the pivot elements 4 relative to the support element 18, the bolt 22a is therefore guided relative to the support elements 18 along the guide track 38.

FIG. 2 shows the pressing tool 2 from FIG. 1 in the open position, with the holding devices 20a in the first switching position A. FIG. 3 excerpt enlargements shows the pressing tool 2 FIG. 1 in the open position, with the holding devices 20a in a second switching position B, in two perspective views. The bolts 22a of the holding devices 20a are displaceable in the axial direction between the first switching position A and the second switching position B, wherein the bolts 22a in the first switching position A have a distance from the leaf spring 26 and rest in the second switching position B circumferentially on the leaf springs 26 ,

To the pivot elements 4 from the closed position ( Fig. 1 ) in the open position ( Fig. 2 . Fig. 3 ), a user must squeeze the pivot elements 4 in the region of the actuating portions 10 against the biasing force of the clamping mechanism 14. The operating portions 10 are approximated while the pressing portions 8 are spread and thus the receiving portion 6 is opened.

In the in FIG. 2 illustrated switching position A of the holding devices 20a, the holding devices 20a do not oppose the clamping mechanism 14 and the clamping mechanism 14 is released. If the user releases the actuating sections 10 in the open position of the swivel elements 4, the swivel elements 4 are moved back into the closed position due to the spring force of the clamping mechanism 14 ( Fig. 1 ). The respective pin 22a is additionally projecting through a in the first switching position A across the width of the leaf spring 26 Guide section 40 out, which has a on the leaf spring 26 laterally adjacent, circular circumferential web 42.

The holding devices 20a allow the user to set the pivoting elements 4 resiliently braced in the open position. For this purpose, the bolts 22a are moved in the open position along their respective axis a in the axial direction from the switching position A to the switching position B, which in FIG. 3 is shown.

The axes a of the bolts 22a and the pivot axes 16 are substantially parallel to each other. The bolts 22a are guided on the respective pivoting element 4 in the holes 44 so as to move in a sliding manner. When moving a bolt 22a from the switching position A to the switching position B, the guideway 38 in the switching position A encompassing groove 36a slides with the opposite direction of movement rising Nutinnenfläche on the guideway 38 and pushes the guide rail 32 in the direction of the support member 18. The bolt 22a is moved in the direction of the switching position B until the guide rail 32 engages with the guide track 38 in the respective other groove 36b. The bolt 22a is seated with a partial length of the portion 34 in a formed on the pivot member 4 guide trough 46, against which the bolt 22a is supported laterally during pivoting of the pivot elements 4.

The diameter of the leaf spring 26 in the switch position B ( Fig. 3 ) contacting portion 48 of the bolt 22a substantially corresponds to the diameter of the bore 44. Starting from the diameter of the bolt portion 48, the bolt 22a is tapered in the direction of the guide portion 40, so that between the bolt portion 48 and the guide portion 40 a circular circumferential chamfer 50th is provided. When moving a respective bolt 22a from the switch position A to the switch position B, the bolt with the chamfer 50 threads into the recess 24a in order to ensure the correct positioning of the bolt 22a. When pushing the bolt 22a on the leaf spring 26, the bolt 22a displaced by means of the chamfer 50 the Leaf spring 26 in the direction of the support member 18 so that the bolt 22a and the leaf spring 26 are braced against each other. The chamfer 50 slides on the bore 44 facing side edge 52 of the leaf spring 26 from.

FIG. 3 shows the pressing tool 2 with held in the open position the pivot elements 4, wherein the bolts 22a are in the switching position B. The bolts 22a abut with their leaf springs 26 associated portion 48 to the leaf springs 26 respectively. The pivot elements 4 are supported on the support elements 18 via the bolts 22a and the leaf springs 26. The leaf springs 26 are formed so stiff that they counteract a caused by the force of the clamping mechanism 14 slipping of the bolt 22 a along the leaf springs 26. In other words, the force introduced by the clamping mechanism 14 into the pivot elements 4, or the resulting moment about the pivot axes 16, is insufficient to displace the leaf springs 26 by means of the bolts 22a in the direction of the pivot axes 16 and thus the pivot elements 4 to move from the open position to the closed position. The pivot elements 4 are thus stably held in the open position.

In order to move the pivot elements 4 from the open position to the closed position, while at the same time the holding devices 20a are in the switching position B, it is necessary to initiate a pulse or actuating forces in the region of the actuating sections 10. This can be done for example by an engine (not shown), which engages between the actuating portions 10 and the operating portions 10 apart. The actuating forces introduced at the actuating sections 10 support the forces of the clamping mechanism 14. The bolts 22a displace the leaf springs 26 in the direction of the pivot axes 16.

After overcoming an unstable intermediate position, the pivot elements 4 fall back into the closed position. The labile intermediate position is the pivotal position of the pivot elements 4, in which the tensioning mechanism 14 and the holding device 20 in the pivoting elements introduced forces and moments about the pivot axes 14 cancel each other. At each change of the pivot elements 4 from the open to the closed position, or vice versa, the respective leaf spring 26 must be displaced by a force introduced from the outside with the bolt 22a in the direction of the support member 18 to the labile intermediate position of the pivot elements 4 in the direction of desired position of the pivot elements 4 to overcome.

The bolt 22 a is guided during the movement of the pivot elements 4 from the open to the closed position along the guide track 38 of the guide rail 32. The bolt 22a therefore remains during the change of the pivot elements 4 from the open to the closed position, or vice versa, in its engaged position ( Fig. 4 ). The interaction between the guide rail 32 and the grooves 36a, 36b holds the bolt 22a therefore also for the subsequent pressing operations in the respectively set switching position A or B. In the case described here, the bistable behavior of the pressing tool 2 is maintained until the user the bolt 22a again actively moved from the switching position B in the switching position A.

The Figures 5 and 6a show a further embodiment of a pressing tool 2 according to the invention in the closed position, with holding devices 20b in a first switching position A in a perspective view and a side view, wherein in the following with reference to the first embodiment, like reference numerals are assigned to like elements.

The pressing tool 2 has two pivoting elements 4 for pressing a pipe (not shown) and a fitting (not shown), with a receiving area 6 formed between the pivoting elements 4 for receiving the pipe and the fitting. The pivot elements 4 are rotatably mounted about the pivot axes 16. The pivot axes 16 are supported by the support elements 18. The pivot elements 4 are for pressing the tube and the fitting about the pivot axes 18 against each other pivotally. One between the Swivel elements 4 and the support members 18 arranged clamping mechanism 14 is used to bias the pressing tool 2 in the direction of the closed position.

The pressing tool 2 has two holding devices 20 b for holding the pivoting elements 4 in the open position against the biasing force generated by the clamping mechanism 14. The holding device 20b are switchable, wherein the holding device 20b and the clamping mechanism 14 form a switchable, bistable clamping mechanism.

The holding devices 20b each have a latching element 22b and a latching recess 24b, wherein the latching recess 24b is designed as a latching groove 24b. The latching element 22b is a sliding element 22b guided slidingly on the one pivoting element 4.

For better traceability of the following statements on the operation of the holding device 20b are in FIG. 7 respectively sectional views of related to FIG. 6 shown switching positions shown. Figure 7a shows a sectional view of the holding devices along the line VII a - VII a FIG. 6a , FIG. 7b shows a sectional view of the holding devices along the line VII b - VII b FIG. 6b , FIG. 7c shows a sectional view of the holding devices along the line VII c - VII c FIG. 6c ,

FIG. 6b shows the pressing tool 2 from FIG. 6a in the open position, with the holding devices 20b in the first switching position A. The receiving area 6 is in the open position of the pivot elements 4 according to FIG. 2b further than in the closed position of the pivot elements 4 FIG. 2a ,

In the in FIG. 6b illustrated open position of the pivot elements 4, the clamping mechanism 14 is released, since the holding devices 20 b in the first Switching position A are located. The holding devices 20b do not counteract the clamping mechanism 14 in this state.

To the pressing tool 2 from the in FIG. 6a shown closed position of the pivot elements 4 in the in FIG. 6b shown to transfer open position of the pivot elements 4, the pivot elements 4 are compressed in the area of the operating portions 10 by the user, without operating the holding devices 20b. For this purpose, the user grasps and actuates the actuating sections 10 at their respective sections 54 which are located upstream of the holding devices 20b in the direction of the receiving area 6. The sliding elements 22b remain in this case relative to the pivoting elements 4 in the in FIG FIG. 6a illustrated starting position. The sliding elements 22b engage in the in FIG. 6b shown open position of the pivot elements 4 not in the locking grooves 24b of the pivot elements 4 a. The sliding elements 22b are, as in the sectional views according to the FIGS. 7a and 7b shown biased by a helical compression spring 56 held in the first switching position A.

As long as the user presses the tool 2 actively in the FIG. 6b illustrated open position of the pivot elements 4 holds, with the holding devices 20b in the first switching position A, the pivot elements 4 remain in the open position. If the action of the user on the pressing tool 2, the pivoting elements 4 are due to the biasing force given by the clamping mechanism 14 in the in FIG. 6a swung back closed position shown.

FIG. 6c shows the pressing tool FIG. 6a in the open position, with the holding devices 20b in the second switching position B. In the second switching position B, the holding devices 20b counteract the clamping mechanism 14. The sliding elements 22b engage with their locking projections 58 in the locking grooves 24b. The respective sliding element 22b is between the first switching position A and the second shift position B slidably and on the associated pivot member 4 on two sides with a mandrel 60 in a groove 62 out.

The engaged in the switching position B holding devices 20b hold the pivot elements 4 of the pressing tool 2 in the open position. To the pressing tool 2 from the in FIG. 6a shown closed position in the in FIG. 6c shown to transfer open position, with simultaneous switching of the holding devices 20 b, the user actuates the actuating portions 10, starting from the in FIG. 6a shown position, in the region of the holding devices 20b. The user therefore compresses the operating sections 10 via the two sliding elements 22b. In addition to a pivoting of the pivot elements 4 in the open position, the sliding elements 22b are simultaneously displaced against the helical compression springs 56 in the direction of each provided on the opposite pivot elements 4 locking grooves 24b.

Likewise, the holding devices 20b may be made from the in FIG. 6b shown switching position A are transferred to the switching position B by the sliding elements 22b are shifted from each other, so that the locking projections 58 engage in the locking grooves 24b.

The pressing tool 2 is in the in FIG. 6c illustrated switching position B of the holding devices 20b resiliently clamped in the open position of the pivot elements 4. The voltage applied to the pivot elements 4, the latching projections 58 supporting bending spring portions 64 of the sliding elements 22b counteract a sliding of the inclined surfaces 66 of the locking projections 42 at the edges 68 of the locking grooves 24b. The pivot members 4 are therefore stably held in the open position.

Starting from the in FIG. 6c shown switching position, the pivot elements 4 in the in FIG. 6a shown closed position in which the operating portions 10 by means of an engine (not shown) are spread. The engine is coupled to the coupling portions 70 of the support members 18 in a known manner. By means of the engine, the actuating portions 10 are pressed apart, wherein the inclined surfaces 66 slide off at the edges 68 and thus the holding forces of the bending spring portions 64 are overcome. As soon as the latching projections 58 are no longer engaged with the latching grooves 24b, the pivoting elements 4 pivot back into the closed position due to the biasing force of the clamping mechanism 14. The sliding elements 22b are in turn, due to the helical compression springs 56, in the in FIG. 6a shown disengaged starting position moves back, in which they are held biased by the helical compression springs 56.

FIG. 8 shows a third embodiment of a pressing tool 2 according to the invention, wherein in the following with reference to the preceding embodiments, like reference numerals are assigned to the same elements.

FIG. 8a shows the pressing tool 2 in the closed position in a side view. The pressing tool 2 has a holding device 20c, which is formed by a pressure piece 22c and a trough 24c. The pressure piece 22 c has a detent ball 72 which is resiliently biased against a guide surface 74 formed on the support member 18. The pressure piece 22 c is fixed to the pivoting element 4 and the trough 24 c is provided on the support member 18 carrying the pivot axes 16. The guide surface 74 goes over without a jump in the trough 24c. The pressure piece 22 c has an external thread and is screwed into the pivoting element 4.

At the opposite of the pressure piece 22c pivot member 4, a second pressure piece 76 is provided which counteracts pivoting of the pivot elements 4 from the closed to the open position in a pivoting range, wherein in particular the open position is part of this pivoting range. The pressure piece 76 has a detent ball 78, which is formed with a latching recess 80 co. The recess formed as a recess 80 80 is designed flat compared to the trough 24c.

Hereinafter, the operation of the pressing tool 2 according to the third embodiment with reference to FIG FIGS. 8a to 8c described.

In the in FIG. 8a shown closed position of the pivot elements 4, the detent ball 72 is resiliently biased biased to the guide surface 74 at. The pressure piece 22c is therefore located in the in FIG. 8a shown position in a tensioned state. The detent ball 78 of the second pressure piece 76 has a spacing from the support element 18 and the detent recess 80 formed thereon. The pressure piece 76 is in a relaxed state. The pivot elements 4 are biased by the tensioning mechanism 14 held in the closed position.

In order to open the receiving region 6 for insertion of a pipe and a fitting (not shown), the pivoting elements 4 are pressed against each other in the region of the actuating sections 10 in order to pivot the pivoting elements 4 counter to the clamping force of the clamping mechanism 14 around the respectively associated pivot axis 16.

FIG. 8b shows the pivot elements 4 in an open position. In the in FIG. 8b shown pivot position of the pivot elements 4 is the pressure piece 22c in the first switching position A. The detent ball 72 is, as well as in the closed position of the pivot elements 4 in accordance FIG. 8a , At the side facing away from the pivot axis 16 guide surface 74 of the support member 18 at. In the switching position A, the pressure piece 22c does not substantially counteract a pivoting back of the pivot elements 4 into the closed position by the tensioning mechanism 14, since the smooth shape of the guide surface 74, which does not surround the detent ball 72, causes the detent ball 72 to slide or slide along the latching ball 72 Guide surface 74 favors.

By pivoting the pivot elements 4, the detent ball 78 of the second pressure piece 76 according to FIG. 8b engaged in the recess 80, so that the locking recess 80, the detent ball 78 at least partially surrounds. However, the pressure piece 76 is still, as well as in FIG. 8a , in a relaxed state.

The receiving area 6 is in the in FIG. 8b shown pivot position of the pivot elements 4 already open so far that the provided for pressing with the illustrated pressing tool 2 pipe sections and fittings (not shown) can be inserted into the receiving area 6.

To set the pivot elements 4 in the open position, the pivot elements 4 on the in FIG. 8b shown pivot position are pivoted out, as in FIG. 8c shown. In this pivotal position of the pivot elements 4, the pressure piece 22c takes the second switching position B, wherein the detent ball 72 is seated in the trough 24c. The detent ball 72 is engaged in the trough 24c, so that the pressure piece 22c is in the relaxed state. According to further embodiments of a pressing tool according to the invention, the detent ball may also continue to be held in the trough braced by the spring provided in the pressure piece.

By the interaction of the pressure piece 22c with the trough 24c, a pivoting of the pivotal elements 4 into the closed position caused by the tensioning mechanism 14 is prevented. In other words, the force introduced by the clamping mechanism 14 about the pivot axes 16 into the pivot elements 4 is insufficient to displace the detent ball 72 against the spring 82 of the pressure element 22c from the recess 24c or to move it out of the recess 24c ,

To the pivot elements 4 in the in FIG. 8a shown closed position to move back, it is therefore necessary, the pivot elements 4 in the region of Actuate operating portions 10 by means of an additional force to overcome the clamping force of the holding device 20 c. Such a force, for example, as described above with reference to the other embodiments, carried by an engine.

When pivoting the pivot elements 4 from the in FIG. 8b in the in FIG. 8c shown pivot position is formed by the second pressure piece 76, an additional resistance, which counteracts pivoting of the pivot elements 4. Starting from the in FIG. 8b shown position, the detent ball 80 of the second pressure piece 76 must be displaced from the recess 80 against the spring 84 of the pressure piece 76, so that the pressure piece 76 in the in FIG. 8c is shown pivoted position and rests against the support member 18.

In this way, a defined pressure point is formed by the pressure piece 76, which indicates to the user when pivoting the pivot elements 4, in which pivoting range the transition of the first pressure piece 22c and the holding device 20c from the first sound position A takes place in the second switching position B.

To pivot the pivot elements 4 in the in FIG. 8c to allow shown position while keeping the distance of the operating portions 10 in the closed state of the pivot elements 4 as low as possible, overlap the operating portions 10 of the pivot elements 4 in the in FIG. 8c position shown. The overlapping operating sections 10 provide an enlarged pivoting range of the pivoting elements 4 in comparison to the embodiments described above. This also ensures that an opening width of the receiving area 6 which usually exceeds that for the components to be pressed can be achieved in order to actuate the holding device 20c.

FIG. 9 shows a fourth embodiment of a pressing tool 2 according to the invention in the closed position in a side view. This in FIG. 9 illustrated embodiment differs from the in FIG. 8 illustrated embodiment only in that the in FIG. 8 existing second pressure piece 76 has been replaced by a second holding device 20c according to the invention. In the in FIG. 9 illustrated example, provided on the support member 18 and the pivot member 4 marks 86 to the user, in which pivot position, the transition of the holding devices 20c from the first switching position A takes place in the second switching position B. If the markings 86 lie directly above one another, the pivoting elements 4 of the pressing tool 2 are in one of the FIG. 8b comparable pivotal position, wherein the holding devices 20c are in the first switching position A.

According to further embodiments of the pressing tool according to the invention, it is also possible to provide only a single holding device in order to fix the pivoting elements in an open position. In this case, between the pivot elements preferably a the movement of the pivot elements coupling gear can be provided, so that pivoting or fixing of a pivot member causes pivoting or fixing the respective other pivot member.

Claims (16)

1. Pressing tool for joining a pipe and a fitting, particularly in an undetachable manner, comprising

   - two swivel elements (4) for pressing the pipe and the fitting,

   - a receiving region (6), formed between the swivel elements (4), for receiving the pipe and the fitting,

   - at least one swivel axis (16) for rotatably mounting the swivel elements (4), and

   - a tensioning mechanism (14) for pretensioning the pressing tool (2),

   - wherein the swivel elements (4) can be swivelled relative to one another about the at least one swivel axis (16) to press the pipe and the fitting,

   - wherein in a first closed position, the receiving region (6) is narrower than in a second open position of the swivel elements (4),

   - wherein the swivel elements (4) are pretensioned towards the closed position by the tensioning mechanism (14), and

   - wherein at least one holding device (20a, 20b, 20c) is provided for holding the swivel elements (4) in the open position against the pretensioning force generated by the tensioning mechanism (14),

   characterised in that

   - the holding device (20a, 20b, 20c) is switchable and

   - the holding device (20a, 20b, 20c) and the tensioning mechanism (14) form a switchable, bistable tensioning mechanism.
2. Pressing tool according to claim 1, characterised in that

   - the holding device (20a, 20b, 20c) has in the open position of the swivel elements (4) a first switch position (A) in which the tensioning mechanism (14) is released, and

   - the holding device (20a, 20b, 20c) has in the open position of the swivel elements (4) a second switch position (B) in which the holding device (20a, 20b, 20c) works against the tensioning mechanism (14).
3. Pressing tool according to claim 2, characterised in that the holding device (20a, 20b, 20c) is braced resiliently in the second switch position (B).
4. Pressing tool according to either claim 2 or claim 3, characterised in that the holding device (20a, 20b, 20c) has at least one locking element (22a, 22b, 22c) and at least one locking recess (24a, 24b, 24c), the locking element (22a, 22b, 22c) interacting with the locking recess (24a, 24b, 24c) in the second switch position (B).
5. Pressing tool according to claim 4, characterised in that the locking element (22a, 22b, 22c) and the locking recess (24a, 24b, 24c) of the holding device (20a, 20b, 20c) are provided on two different components (4, 18), these components (4,18) being swivellable about the swivel axis (16) relative to one another and at least one of the components (4, 18) being one of the swivel elements (4).
6. Pressing tool according to either claim 4 or claim 5, characterised in that the locking element (22a, 22b) is a substantially cylindrical bolt (22a) and the locking recess (24a, 24b) is a depression (24a) formed in a leaf spring (26).
7. Pressing tool according to claim 6, characterised in that the bolt (22a) can be displaced in an axial direction between the first switch position (A) and the second switch position (B), the bolt (22a) being at a distance from the leaf spring (26) in the first switch position (A) and resting peripherally on the leaf spring (26) in the second switch position (B).
8. Pressing tool according to either claim 6 or claim 7, characterised in that the bolt (22a) rests on a guide rail (32) which holds the bolt (22a) in the respective axial switch position (A, B).
9. Pressing tool according to claim 8, characterised in that the guide rail (32) is a leaf spring (32).
10. Pressing tool according to either claim 8 or claim 9, characterised in that the bolt (22a) has on the portion (34) associated with the guide rail (32) two mutually spaced apart, peripherally running grooves (36a, 36b) which interact with a guide path (38) of the guide rail (32) in the respective switch position (A, B).
11. Pressing tool according to either claim 4 or claim 5, characterised in that the locking element (22a, 22b) has a sliding element (22b) which is slidably guided on one swivel element (4), the sliding element (22b) being displaceable between the first switch position (A) and the second switch position (B), and the locking recess (24a, 24b) being formed in the other swivel element (4).
12. Pressing tool according to claim 11, characterised in that the sliding element (22b) is held pretensioned in the first switch position (A).
13. Pressing tool according to either claim 11 or claim 12, characterised in that the swivel elements (4) are provided with two sliding elements (22b) and two locking recesses (24b).
14. Pressing tool according to either claim 4 or claim 5, characterised in that the locking element (22a, 22b, 22c) is a pressure piece (22c), the pressure piece (22c) having in particular a locking ball (72) which is resiliently pretensioned in the first switch position (A) and sits in a locking recess (24a, 24b, 24c) formed as a depression (24c) in the second switch position (B).
15. Pressing tool according to claim 14, characterised in that the pressure piece (22c) is attached to one of the swivel elements (4) and the locking recess (22a, 22b, 22c) is provided in a support element (18) supporting the swivel axis (16).
16. Pressing tool according to claim 15, characterised in that a second pressure piece (76) is provided which counteracts a swivelling movement of the swivel elements (4) out of the closed position into the open position in a swivel range, in particular the open position being part of the swivel range.

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