EP0421107B1 - Pliers - Google Patents

Abstract

The invention relates to pliers (1) having two pliers jaws (8, 9) forming the pliers bit (M), of which one (fixed jaw 8) sits fixedly on one pliers limb (3) which, for coarse adjustment of the pliers bit (M), has a longitudinal slot guide (cutout 5) for the pivot (pivot pin 18) of the pliers limbs, and of which the other (movable jaw 9) is guided displaceably on the pliers limb (3) carrying the fixed jaw (8) and can be shifted, via a force-transmission point (27), between a shoulder (side arm 10) of the displaceable pliers jaw (9) and the jaw-side arm (joint peg 16) of the movable pliers limb (2), in order to close the pliers bit, and proposes, to obtain a solution which is advantageous in particular in terms of handling, that the force-transmission point (27), designed as a positive engagement between jaw-side arm (joint peg 16) and movable pliers jaw (9), is the junction point both for coarse longitudinal adjustment and for pliers bit closure between pliers limb (2) and movable jaw (9). <IMAGE>

Description

The invention relates to key pliers according to the features of the upper handle of claim 1.

A pair of key pliers, as is basically affected here, is known from US Pat. No. 3,534,641, the movable jaw partially engaging around the fixed leg and being displaceable in a straight line thereon. The movable pliers leg is rotatably mounted in a recess of the fixed leg provided with a toothing only on the side facing the pliers mouth by means of a pivot pin. The pivot pin extends through a window of a mounting plate of the movable jaw that grips around the fixed leg on one side, this mounting plate being assigned to the side of the fixed leg that is opposite the movable pliers leg. The pliers leg forms a stop surface at the end opposite the handle part, in the region of the axis of rotation. When the pliers legs are pressed together, this acts on a stop lug of the movable jaw and thus causes it to shift in the closing direction. In the area of the recess of the fixed leg, an engagement tooth is spring-loaded on the pivot, which is in positive engagement with the teeth of the recess, with a spring striving to hold the movable pliers leg in a basic position. In order to change the opening width of the jaws, the movable pliers leg is moved counter to the actuating direction, which displaces the engagement tooth from the toothing. The stop nose of the movable jaw is no longer acted upon by the stop surface of the movable pliers leg. The coarse longitudinal adjustment of the forceps jaw takes place in that the movable jaw by means of the on an inner wall of the pivot bearing on the window. Due to the fact that the pivot is mounted in a window of the movable jaw, this has a play that is compensated for by the resistance of the workpiece to be gripped when the jaws are closed. Furthermore, these key pliers have no limit stop in the opening direction. The open position of the key pliers is therefore not defined. Opening it too far can even result in loss of engagement from the engagement tooth into the toothing of the recess. This means that the opening width of the jaws can be changed unintentionally. Safe handling of the key pliers is not guaranteed in this embodiment.

In the case of known pliers (cf. DE-A1 31 02 390) a vertical displacement of the movable pliers leg in the longitudinal plane of the pliers relative to the fixed pliers leg is required for rough adjustment of the pliers jaw width. Furthermore, the movable pliers leg is guided on the inside of the fixed pliers leg. This leads not only to a technically disadvantageous coarse adjustability, but also to a considerable thickness of the pliers, particularly in the area of the interaction between the movable jaw leg and the movable jaw or the area of interaction between the movable jaw and the stationary jaw leg. The movable pliers jaw is accommodated with grooves on the inside on outer strips of the fixed pliers leg. However, these strips are in the area of the fork-shaped design of the fixed pliers leg. The degree of coverage between the movable jaw and the fixed jaw leg is low. All of the guiding work must be done through the internal grooves of the movable jaw.

From EP-A1 116 305 a water pump pliers is also known, which consists of two intersecting arranged pliers legs. For rough adjustment of the pliers, the hinge pin is guided in a bore in the pliers leg and can be displaced transversely to the longitudinal plane of the pliers against spring loading. In the coupled state, the hinge pin engages in a form-fitting manner with the profiled flanks of a longitudinal slot of the other pliers leg located in the intersection area.

In view of the initially mentioned prior art, a technical problem of the invention is seen in designing and developing the known key pliers in such a way that simple handling is possible with the greatest possible structural safety. This technical problem is solved in the subject matter of claim 1. The subclaims are advantageous developments of the subject matter of the invention.

In detail, the procedure is such that the force transmission point designed as a form-fitting engagement between the jaw-side arm of the movable pliers leg and the movable pliers jaw is the connection point both for the coarse longitudinal adjustment and for closing the jaws between the pliers leg and the movable jaw. The positive engagement between the movable pliers leg and the movable pliers jaw is thus maintained in every operating position. When the jaws are closed, the movable jaw is moved towards the fixed jaw via the force transmission point. The same connection point between the movable pliers leg and the movable pliers jaw also serves to roughly adjust the key pliers. The position of the movable jaw is independent of the previously set opening width of the jaws, directly dependent on the position of the movable pliers leg. The guide of the movable pliers jaw is designed as a free space next to the longitudinal slot guide, in which free space, which is a guide groove, a guide section of the movable pliers jaw projects. The guide section is designed as a frame. However, it is also conceivable to form the free space as a slot and the guide section as a bolt. This configuration of the guidance of the movable jaws proves to be an essential advantage in terms of handling. The key pliers can thus be made relatively slim, taking into account that there is always a safe guidance of the movable jaw. To the power transmission To optimize between the movable pliers leg and the displaceable pliers jaw, it is provided that the force transmission point acts essentially in the area of the free space both in the coarse longitudinal adjustment and in the closing of the pliers jaws. The result of this is that the main force component extends approximately in the axial direction of the free space and thus in the direction of movement of the movable pliers jaw when the movable jaw is displaced. This prevents the movable jaw from tilting within the area of the free space. Another advantage of this embodiment is the fact that the force transmission point is arranged in the immediate vicinity of the jaws. A torque of the movable pliers jaw that occurs under load is thus reduced to a minimum. Furthermore, it is provided that the movable jaw is caught essentially free of play beyond the axis of rotation over the entire pivoting path of a set opening width under a stop limitation on both sides by the engaging tooth of the movable jaw leg adjacent stop surfaces. The positive connection between the movable jaw and the pliers leg is realized by a hinge arrangement, wherein a hinge pin arranged on the end of the pliers leg opposite the handle part and beyond its axis of rotation engages in a joint recess of the movable jaw essentially without play. A limit stop in the open or The closed position of the pliers takes place by respective support of a stop surface adjacent to the hinge pin and likewise formed on the pliers limb on the support surface of the movable jaw which is associated with this and adjacent to the hinge shape. This also prevents fingers from jamming between the fixed leg and the pliers leg. The two legs can with one Do not touch actuation in system. An advantageous further development is that a stop shoulder is formed on the movable jaw with a lateral distance to a substantially U-shaped recess receiving the engagement tooth, which protrudes downward over a lower edge of the movable jaw running on both sides of the recess. This training offers improved support of the movable pliers leg in the open position. This prevents the hinge pin from moving out of the joint recess via any lever forces and thus releasing the movable jaw, which can lead to the loss of the latter. Another advantage of this configuration is the fact that the movable jaw is fork-shaped and is guided in outer grooves of the fixed leg running parallel to the row of teeth. This counteracts tilting of the movable jaw and ensures optimal guidance of this movable jaw. Improved handling is further achieved in that the pliers leg is fork-shaped and an engagement tooth is formed on both sides, which engages in each case a recess in the movable jaw. In this configuration, the force is not, as in the previously described prior art, supplied on one side, decentrally to the central axis of the movable jaw of this movable jaw, but on both sides, symmetrically to the central axis, which causes the movable jaw to tilt about its longitudinal axis and thus tilt is avoided. The power transmission from the movable pliers leg to the movable jaw is optimally solved due to this design. The row of teeth for changing the opening width of the jaws is formed on both sides on a recess. The articulated and adjustable tooth engages simultaneously in two opposite rows of teeth. Another essential A feature of the invention relates to the alignment of the recess, which is provided with the rows of teeth mentioned, and a guide groove of the movable jaw. The central axes of the recess and the guide groove diverge in the closing direction of the pliers mouth. When the movable jaw is moved in the closing direction of the jaws of the pliers, there is a certain amount of migration of the pivot pin downward out of the joint recess. The consequence of this is that the pliers legs can be moved further towards one another in the closed position. Conversely, when moving the movable jaw in the opening direction of the pliers mouth, the pliers legs can be moved less far towards one another in the closed position. This ensures that the distance between the lower ends of the pliers legs is approximately maintained in the two extreme positions of the movable jaw, but the angle between the pliers legs changes.

Fig. 1

eine Vorderansicht auf eine erfindungsgemäße Schlüsselzange in zusammengedrückter Stellung, gemäß einer ersten Ausführungsform,

Fig. 2

eine der Fig. 1 entsprechende Darstellung, jedoch in geöffneter Stellung,

Fig. 3

eine Seitenansicht der Schlüsselzange,

Fig. 4

eine Einzeldarstellung einer beweglichen Backe,

Fig. 5

ein perspektivisch dargestellter Ausschnitt der Schlüsselzange in geöffneter Stellung,

Fig. 6

eine Vorderansicht auf eine Schlüsselzange in zusammengedrückter Stellung, gemäß einer zweiten Ausführungsform,

Fig. 7

eine der Fig. 6 entsprechende Darstellung, jedoch in geöffneter Stellung,

Fig. 8

einen Schnitt gemäß der Linie VIII-VIII in Fig. 6,

Fig. 9

einen Schnitt gemäß der Linie IX-IX in Fig. 8,

Fig. 10

eine Vorderansicht auf eine Schlüsselzange in zusammengedrückter Stellung, gemäß einer dritten Ausführungsform,

Fig. 11

eine der Fig. 10 entsprechende Darstellung, jedoch in geöffneter Stellung,

Fig. 12

einen Schnitt gemäß Linie XII-XII in Fig. 10 und

Fig. 13

einen Schnitt gemäß der Linie XIII-XIII in Fig. 12.

Further advantages and details of the invention are explained in more detail below with the aid of three illustrative exemplary embodiments. It shows:

Fig. 1

2 shows a front view of a pair of key pliers according to the invention in the compressed position, according to a first embodiment,

Fig. 2

1 corresponding representation, but in the open position,

Fig. 3

a side view of the key pliers,

Fig. 4

an individual representation of a movable jaw,

Fig. 5

a perspective cutout of the key pliers in the open position,

Fig. 6

2 shows a front view of a pair of key pliers in the compressed position, according to a second embodiment,

Fig. 7

6 shows a representation corresponding to FIG. 6, but in the open position,

Fig. 8

6 shows a section along the line VIII-VIII in FIG. 6,

Fig. 9

8 shows a section along the line IX-IX in FIG. 8,

Fig. 10

2 shows a front view of a pair of key pliers in the compressed position, according to a third embodiment,

Fig. 11

10 shows a representation corresponding to FIG. 10, but in the open position,

Fig. 12

a section along line XII-XII in Fig. 10 and

Fig. 13

a section along the line XIII-XIII in Fig. 12.

The key pliers 1 of all exemplary embodiments have a movable pliers leg 2 and a fixed leg 3, which merges into a bearing plate 4 in the same material. This has a recess 5, which is profiled sawtooth-like on its parallel longitudinal flanks 6. Above the recess 5 and parallel to it are in the bearing plate 4 two free spaces 7, each machined on the outer surfaces, which run symmetrically to the key-pin central axis xx. In the area of the bearing plate 4 remote from the fixed leg 3, a thicker material (in comparison to the bearing plate 4) fixed jaw 8 is arranged symmetrically to the axis xx. This fixed jaw 8 is opposite a movable jaw 9, which is designed to be essentially symmetrical with respect to the fixed jaw 8. The movable jaw 9 forms in its lower region two cantilevers 10 which rest on the surfaces of the bearing plate 4 and overlap them in their upper region. On the inner sides facing the bearing plate 4, the arms 10 have guide sections 11, each of which forms a guide for the movable jaw 9 with one of the free spaces. The guide sections 11 are formed continuously. A guide section 11 is therefore also provided in the region of the joint recess 15. The joint recess 15 correspondingly extends over the thickness of the jaw as such, while the guide strip 11 is also formed underneath (see, for example, FIG. 4). In principle, such a jaw can be worked from the solid, for example forged. However, it is currently preferred to solder the guide bar 11, for example. Overall, the continuous guide strip 11 also improves the strength: the jaw 9 is considerably stiffer in the critical cross section. The neutral phase under bending stress is shifted.

The free spaces 7 are continuous, over the entire length or width of the jaw 9.

In the boom end regions 12 10 stop shoulders 13 are arranged on the arms. With a lateral distance to the stop shoulders 13 10 joint recesses 15 are provided in the arms, which are substantially U-shaped. They serve to receive pivot pins 16 of the movable pliers leg 2. This is fork-shaped in the upper part, the fork legs being arranged symmetrically to the central axis xx and resting on the surfaces of the bearing plate 4. The pliers leg 2 is supported in the recess 5 by a hinge pin 18 having a toothed segment. The design of the mounting of the pliers leg 2 and the procedure for moving the pliers leg in the recess 5 have already been disclosed in European patent 0 116 305. In this respect, reference is made in full to this extent and the corresponding disclosure is hereby incorporated.

In the first exemplary embodiment shown in FIGS. 1-5, the free spaces 7 are designed as grooves 22, in which the guide sections 11 formed as ribs 23 lie. These ribs 23 extend substantially at right angles to an inner edge 9 'of the movable jaw 9 extending over the entire length of the arm 10, the ribs 23 being shaped such that they practically completely fill the grooves 22 in cross section. The stop shoulder 13 arranged in the boom end regions 12 protrude downward over the lower edge 14 of the boom 10.

Above the hinge pin 18 there are 16 stop surfaces 19 and 20 on both fork legs 17 on both sides of the hinge pin.

The angle between the fixed leg 3 and the recess 5 having the sawtooth-like profiled longitudinal flanks 6 is approximately 15 ° in this embodiment.

1, the movable jaw 9 is displaced in the closed position via the joints composed of the joint recesses 15 and the joint pins 16. Here, the stop surfaces 19 are supported on the sections 21 of the lower edges 14 assigned to them. The closed position is thus defined and is independent of the position of the hinge pin 18 in the recess 5, since when the hinge pin 18 is displaced in the recess 5 there is a simultaneous, essentially parallel displacement of the movable jaw 9. This prevents the fingers from jamming between the tong legs 2 and 3. When the key pliers 1 according to FIG. 2 are opened, the movable jaw 9 is moved back until the stop surfaces 20 are supported on the lower edges 14 of the extension arms 10 in the region of the stop shoulders 13. The fork legs 17 act on the stop shoulders 13, which should prevent the pivot pins 16 from being moved out of the joint recesses 15 due to lever forces. This stop limitation also defines the open position and, like the closed position, regardless of the position of the hinge pin 18 in the recess 5. The closing path between the open position and the closed position thus remains the same length for each preselected opening width.

An essential feature relates to the alignment of the recess 5 and the guide grooves 22 with respect to one another. The guide grooves 22 and the recess 5 are arranged so that central axes a, a 'of the recess 5 and a guide groove 22 in the closing direction of the pliers 1, for example in Fig. 1 to the right, diverge slightly. The opening angle between the axes is approximately 1-3 °, preferably 2 °. When moving the movable jaw 9 in the closing direction of the pliers 1, the pivot pin 16 moves somewhat downward in the joint recess 15. As a result, when the pliers 1 are closed, the stop surface 19 reaches its stop position a little earlier (in relation to the path) in abutment with a partial section 21 Pliers 1 is approximately the same as in the case of a large opening width of the pliers jaw, the movable jaw 9 being displaced in the direction of an opening of the pliers jaw.

The exemplary embodiments in FIGS. 6-13 differ essentially from the first exemplary embodiment in FIGS. 1-5 in that the angle between the fixed leg 3 and the recess 5 is approximately 60 °.

Furthermore, it is also important that the joint recess 15 is arranged with a clear lateral displacement of the jaw 9, more precisely the tip region thereof. The lateral offset corresponds approximately to one to two times the thickness or width of the pivot pin 16. This lateral offset contributes significantly to being able to form the pliers in the desired slim shape.

In particular, the cap 9 according to the exemplary embodiment of FIGS. 6-13, but also the corresponding jaw of the other exemplary embodiments, can be constructed in two parts in cross section. In terms of production, two cheek parts bent from sheet steel are laid flat and riveted together in the upper cheek area. The parts can also be soldered or welded. The corresponding design is shown in Figs. 6 and 7 by the emerging outer visible edges are only indicated schematically.

With reference to FIG. 8, it is made clear that the guide sections 11, which are otherwise continuous, are designed as separate parts which are connected to the extension area 10 of the jaw 9, namely preferably soldered.

The formation of the guide of the movable jaw 9 of the second embodiment according to FIGS. 6-9 is the same as that of the first embodiment. Here, too, the bearing plate 4 has grooves 22 for receiving ribs 23, which extend on the inner sides of the movable jaw 9.

The stop shoulders 13 arranged in the boom end regions 12 are designed in the shape of a circular arc and extend into the region of the joint recess 15. On the side of the joint recess 15 opposite the stop shoulder 13, the movable jaw 9 forms partial sections 21.

7, the stop surfaces 19 are supported on the sections 21 of the movable jaw 9 assigned to them. Here, too, the closed position is defined and is independent of the position of the hinge pin 18 in the recess 5. When the key pliers 1 according to FIG. 7 are opened, the movable pliers leg 2 is supported on the displaceable jaw 9 in the same way, the stop shoulders 13 also the stop surfaces 20 form.

In the exemplary embodiment according to FIGS. 10-13, the guide of the movable jaw is composed of a slot 24 arranged in the bearing plate 4 and a bolt 25 inserted in the displaceable jaw 9. s This pin 25 is arranged in the region of the boom end regions 12 and connects them to one another.

The operation of the key pliers 1 according to FIGS. 10-13 largely corresponds to that of the second embodiment. Only the stop limitation when the key pliers are in the closed position is not carried out by supporting a stop surface on a portion of the movable jaw 9. This support is provided here by a stop pin 26 arranged in the movable pliers leg 2 in the lower region of its fork leg 17, which is in the closed position is supported on an outer edge of the bearing plate 4 facing it.

An essential feature of all the exemplary embodiments is that the positive engagement between the pivot pin 16 and the joint recess 15 forms the connection point between the movable jaw 9 and the movable pliers leg 2 both for the coarse longitudinal adjustment and for the jaw opening. The key pliers 1 have no further connection point between the movable jaw 9 and the movable pliers leg 2.

Furthermore, in all the exemplary embodiments, a force transmission from the movable pliers leg 2 to the movable jaw 9 takes place both in the coarse longitudinal adjustment and in the closing of the pliers mouth essentially in the region of the free spaces 7, that is to say in the region of the grooves 22 or the slot 24 16 cover the free spaces 7 in almost every operating position. An optimum transmission of force is thus realized, especially since the force transmission points 27 composed of the pivot pins 16 and the joint recesses 15 are arranged in the immediate vicinity of the jaws M.

The handling of the key pliers 1 can, for example, look as follows:
When loosening or tightening a screw or the like, the movable jaw 9 is brought up to the screw in that the hinge pin 18 is brought out of its positive engagement with the sawtooth-like profile of the longitudinal flanks 6 of the recess 5 and the movable pliers leg 2 is displaced while taking the movable jaw 9 with it becomes. The clear width between the jaws 8 and 9 now corresponds to the head width of the screw. By moving the pliers leg 2 into the open position, the movable jaw 9 is moved back, the clear width between the jaws 8, 9 increasing, giving the user the opportunity to remove the key pliers 1 from the screw and reattach them. Then the legs 2 and 3 are pressed together, which in turn results in the jaws 8 and 9 being closed and thus the screw being pinched again. By alternately closing, opening and reattaching the key pliers 1, the user can loosen or tighten screws or the like, for example, under conditions that are favorable in terms of handling, without losing the engagement between the movable pliers leg 2 and the movable jaw 9. Changing the width of the key is only possible with the will in mind. The disclosure content of the associated / attached priority documents (copy of the prior application) is hereby also included in full in the disclosure of the application.

Claims (11)

1. Wrench gripper (1) with two gripper jaws (8, 9) forming the gripper mouth (M), one of which (8) is mounted rigidly on a gripper handle (3) which for coarse adjustment of the gripper mouth (M) comprises a longitudinal slot guide (5) for a gripper handle pivot pin (18) and the other of which (9) is of forked construction and guided slidably on the gripper handle (3) carrying the fixed jaw (8) and displaceable via a force transmitting point (27) between a shoulder (10) of the movable gripper jaw (9) and the arm (16) of the movable gripper handle (2) on the jaw side, for closure of the gripper mouth, wherein the movable gripper handle (2) engages in the longitudinal slot guide (5) provided with toothing by means of the gripper handle pivot pin (18), and the force transmitting point (27) designed as form-locking engagement between the arm (16) on the jaw side and the movable gripper jaw (9) is the junction both for coarse adjustment and for closure at the gripper mouth (M) between the gripper handle (2) and the movable jaw (9), characterised in that the movable gripper handle (2) is of forked construction, for engaging around the stationary gripper handle (3), and in that guide sections (11) of the movable jaw (9) are guided in a guide groove (7) of the stationary gripper handle (3), wherein the fork ends cooperate with the movable jaw (9) via a toothed portion, and in that the gripper handle pivot pin is guided so as to mate in form-locking relationship in the longitudinal slot guide and for coarse adjustment of the gripper mouth (M) against spring bias is displaceable transversely to the longitudinal plane of the gripper into a release position for sliding in the longitudinal slot guide.
2. Wrench gripper according to claim 1, characterised in that the guide groove (7) is designed as a free space adjacent to the longitudinal slot guide (5).
3. Wrench gripper according to claim 1 or 2, characterised in that the guide section (11) is constructed as a rib (23).
4. Wrench gripper according to claim 1, characterised in that the guide groove (7) is constructed as a slot (24) and the guide section (11) as a pin (26).
5. Wrench gripper according to any of claims 2 to 4, characterised in that the force transmitting point (27) during both longitudinal coarse adjustment and closure of the gripper mouth acts essentially in the region of the free space (7).
6. Wrench gripper according to any of the preceding claims, characterised in that the movable jaw (9) is captive essentially without play beyond the axis of rotation over the whole pivot path of a set opening width, with lateral stop limiting by the engaging tooth (16) of the movable gripper handle (2) by adjacent stop faces (19 and 20).
7. Wrench gripper according to any of the preceding claims, characterised in that on the movable jaw (9) at a lateral distance from an essentially U-shaped recess (15) receiving the engaging tooth (16) is formed a stop shoulder (13) which projects downwardly beyond a lower edge (14) of the movable law (9) extending over a recess (15) on both sides.
8. Wrench gripper according to any of the preceding claims, characterised in that the movable jaw (9) is of forked construction and guided in grooves (7) of the fixed handle (3) extending more or less parallel to the row of teeth.
9. Wrench gripper according to any of the preceding claims, characterised in that the gripper handle (2) is of forked construction and on both sides is formed an engaging tooth (16) which in each case engages in a recess (15) in the movable jaw.
10. Wrench gripper according to any of the preceding claims, characterised in that centre axes (a, a') of the slot (5) and a guide groove (7) diverge in the direction of closure of the gripper mouth.
11. Wrench gripper according to claim 10, characterised in that the centre axes (a, a') have an opening angle of about 2°.

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