EP0116305B1 - Gripping plyers - Google Patents

Description

The invention relates to a water pump pliers according to the preamble of claim 1.

A water pump pliers of this type is known from GB-A-10.112 A.D. 1912. The articulation pin located there, which can be displaced transversely to the longitudinal plane of the pliers against the action of the spring, with its cross-sectionally smaller, flat web-like section penetrates a contour-appropriate opening of the one leading leg. The other, guided leg has a longitudinal slot, the flanks of which are profiled to form a number of step positions that determine the internal width. These are circular recesses into which the larger, cylindrical section of the hinge pin enters when coupled. To adjust the step, it is necessary to disengage the cylindrical section and to move the mentioned smaller section into the area of the longitudinal slot. The latter leaves narrow slits between the individual positions, which can overflow the web. This is disadvantageous for use. The pliers can be destroyed with their own lever ratios, if the section with a smaller cross section and web-like flattened section should unfortunately remain in the narrow intermediate section of the slot and the pliers are closed or opened. The corresponding basic position of the hinge pin cannot be clearly recognized even if there is no line of sight. On the other hand, the operator is required to "search" the narrow intermediate section of the slot by palpable feeling in order to change the jaws of the pliers by swiveling one or the other of the pliers legs accordingly. Since the cross-sectionally smaller, web-like section, which continues at one end into the bearing zone of the leading pliers leg, weakens the hinge pin, greater force interventions represent a considerable impairment of the safety of use of the tool.

The object of the present invention is to design a generic water pump pliers in a technically simple, easy-to-use and stable design in such a way that a sensitive jaw adjustment is possible and the hinge pin can still absorb high loads.

This object is achieved by the invention specified in claim 1.

The subclaims are advantageous developments of the water pump pliers according to the invention.

The positive engagement necessary for the adjustment also leads to non-rotation. This is the longitudinal slot. On the other hand, the penetrated pliers leg rests on this non-rotating hinge pin. The actuation forces flow into the mutual bearing points. The adjustment can be carried out quickly and easily, even without line of sight. Larger sections can be used for the positive engagement on the profiled flanks, for example two diametrically opposed zones of the pivot pin. The flank profiling can be chosen more narrowly. This leads to a distribution of the load forces over many flanks. Maximum loads leading to immediate wear and tear, such as occur on the flanks of niche holes in conventional tools, are also avoided. It also results in a more sensitive, i.e. H. adjustment in smaller steps. The construction effort is not greater. A favorable embodiment for maintaining the constant non-rotatability is achieved in that an intermediate section lies between the central, form-generating cross-sectional area and the cylindrical, thinner cross-sectional area provided at the opposite hinge pin end, the width of which is smaller and the length of which is greater than the clear distance between the molds final engagement profiles, the bolt always remains in the coupling-oriented alignment level. By lifting out the hinge pin, the thinner cross-sectional area designed as an intermediate section is still in the longitudinal slot. The movable pliers leg can be moved freely. With regard to the spring loading that brings about the positive engagement of the hinge pin, it proves to be favorable that this spring loading of the hinge pin originates from a leaf spring, the free end of which lies in a sector-shaped depression on the end face of the hinge pin.

This and the structural measure taken further, that the leaf spring is sunk into a groove of the pliers leg, avoids any lateral protrusion after the adjustment. This means that the spring cannot bump into protruding areas of the application area. On the other hand, it is also protected. To define the decoupling position of the hinge pin, the procedure is simple so that the end of the cylindrical cross-sectional area has an attached stop collar. This brings an enlarged actuating pressure area and can also be fixed or detachable for the purpose of possible disassembly of the tool. It is advantageously a screw-on ring, possibly with knurling. A balanced support, that is to say at both ends of the hinge pin, is further achieved in that the intermediate section in the coupled position rotatably plunges into a recess on the inner flank of the crossing region. As a result, the relevant pliers leg remains freely rotatable. There continues Another advantageous feature is that the penetrated pliers leg forms a throat lying on the handle side of the pliers hinge pin due to two angled leg sections. Due to the corresponding angular profile, the section adjoining the hinge pin on the handle side extends in parallel with that of the fixed pliers leg.

This leads to a narrow pliers neck. For example, in the case of parallel pipelines, this has the advantage that the pliers mouth can be more easily guided to the place of use. The usable swivel range of the pliers is also increased. The throat on the penetrated shaped leg also has manufacturing advantages in that the milling cutter axis can dip deeper into the widened section of the pliers leg and the milling cutter can practically mill out the entire clearance recess from one side.

In an advantageous further development, it is proposed that the pliers leg supporting the hinge pin in a minimal spreading position of the handle sections in the stop position, taking into account the finger thickness, comes to a stop flank of the other pliers leg lying on the mouth side of the longitudinal slot and the material region of this pliers leg extending between this stop flank and the longitudinal slot widened its handle-side end. Despite increasing mouth width adjustment, in which the handle sections of conventional water pump pliers practically move in parallel, a finger slot now remains between the handle sections. The fingers of the operating hand can no longer be pinched; rather, there is always a basic spread position of the handle sections which is suitable for use and is better matched to the ergonomic conditions of the operating hand. This is achieved with structurally simple means, and even without adding any components. The increasing widening directs the grip section of the one pliers leg correspondingly increasingly when adjusting the mouth width into a compensating spacing position from the grip section of the other pliers leg. It is furthermore advantageous that the stop edge of the one pliers leg is formed by a recess shoulder lying at a distance from the stop flank of the other pliers leg, the edge of which facing away from the mouth forms the stop edge for the maximum spread position. The latter has advantages above all for the targeted assignment of the tool. The corresponding maximum limitation can be selected so that the other pliers leg does not swing out of the gripping area of the operating hand.

• Fig. 1 die Wasserpumpenzange in Seitenansicht,
• Fig. 2 die Rückansicht hierzu,
• Fig. 3 den Kreuzungsbereich der Wasserpumpenzange von der anderen Seite her gesehen, und zwar unter Verdeutlichung der Blattfederzuordnung,
• Fig. 4 den Schnitt gemäß Linie IV -IV in Fig. 1, vergrößert,
• Fig. 5 den Schnitt gemäß Linie V -V in Fig. 4,
• Fig. 6 den Gelenkbolzen in Einzeldarsteliung, und zwar in Seitenansicht und wieder in natürlicher Größe,
• Fig. 7 die zugehörige Stirnansicht von links,
• Fig. 8 die zugehörige Stirnansicht von rechts,
• Fig. 9 die Wasserpumpenzange in abgewandelter Form in Seitenansicht, und zwar bei eng eingestellter Maulweite,
• Fig. 10 eine entsprechende Seitenansicht bei maximal eingestellter Maulweite,
• Fig. 11 die Rückansicht zu Fig. 10,
• Fig. 12 den Kreuzungsbereich der Wasserpumpenzange von der anderen Seite her gesehen, etwas vergrößert;
• Fig. 13 den Schnitt gemäß Linie XIII-XIII in Fig. 9 und
• Fig. 14 den Schnitt gem äß Linie XIV-XIV in Fig. 13, beide noch weiter vergrößert.

The subject matter of the invention is explained in more detail below on the basis of an illustrative embodiment. It shows

• 1 the water pump pliers in side view,
• 2 the rear view of this,
• 3 seen the crossover area of the water pump pliers from the other side, specifically showing the leaf spring assignment,
• 4 shows the section along line IV-IV in FIG. 1, enlarged,
• 5 shows the section along line V -V in Fig. 4,
• 6 the hinge pin in single representation, namely in side view and again in natural size,
• 7 is the associated front view from the left,
• 8 the associated front view from the right,
• 9 shows the water pump pliers in a modified form in a side view, with a narrow mouth width,
• 10 is a corresponding side view with the maximum set mouth width,
• 11 is the rear view of FIG. 10,
• 12 shows the crossover area of the water pump pliers seen from the other side, somewhat enlarged;
• Fig. 13 shows the section along line XIII-XIII in Fig. 9 and
• Fig. 14 shows the section along the line XIV-XIV in Fig. 13, both further enlarged.

The water pump pliers have two mutually intersecting pliers legs 1 and 2. The latter are connected to one another in the intersection area by means of a hinge pin 3. The pliers legs 1 and 2 each form a jaw 4 or 5 on the side above the crossing area and a grip section 6 or 7 on the underside of the crossing area. The joint of the pliers mouth M is inclined (approx. 45 °) to the grip sections 6 , 7th

The pliers leg 2 passes through a free space F of the pliers leg 1 corresponding to its thickness. The free space is designed as a slot lying in the pivoting plane of the leg, which has two approximately equal longitudinal leg walls 8 on both sides. The latter are of greater width than that of the handle section 6; it is almost three times the width in the actual intersection area.

The penetrating pliers leg 2 also has a width in the area of the free space F that clearly exceeds the width of the grip section 7. This passage area is designated 9. It is approximately at right angles to the jaw 5.

To change the size of the pliers mouth M, the penetrated pliers leg 1 can be gradually adjusted. The corresponding adjustment device consists of a longitudinal slot 10 penetrated by the hinge pin 3. The latter is profiled on its longitudinal slot flanks 11 running parallel to one another. It is a sawtooth-like profile. The individual tooth gaps are designated by 12 and, like the hinge pin 3, extend transversely to the pivot actuation plane of the pliers legs 1, 2.

The joint pin 3, which is guided in a bore 13, which is congruent with the longitudinal slot 10, is axially divided into several different cross-sectional areas. A cross-sectional area a. which corresponds to the toothed flank width x, has teeth 14 on both sides corresponding to the width x for positive engagement in the tooth gaps 12 of both flanks 11. The pivot pin 3, which is basically rotationally symmetrical, is flattened symmetrically on diametrically opposite sides such that with reference to the Clear dimension y of the longitudinal slot 10 between the positive engagement profiles 12/14 on both sides at least three teeth 14 are reached.

Between this cross-sectional area a, which produces the positive lock, and the cylindrical, thinner cross-sectional area b realized at the opposite hinge pin end 3 ', there is an out-of-round intermediate section 15. Its width is smaller and its length is greater than the clear distance y between the positive-locking engagement profiles, d. H. the flanks 11 having the tooth gaps. The cross-sectional area of the intermediate section 15 is designated by c. It is, like the cross-sectional area a, flattened and dimensioned in its axial extent so that it does not come out of the area of the longitudinal slot 10 after removal of the coupling engagement of teeth 14 and tooth gaps 12, thus securing the hinge pin 3 against self-rotation.

In the coupled position, the intermediate section 15 plunges into a depression 16 formed by the bore 13 receiving the hinge pin 3. This recess 16 has a diameter corresponding to the bore 13 and thus does not hinder the pivoting movement of the tong legs 1, 2 relative to one another in the coupled state. On the other hand, however, the circular wall sections 17 'which have remained standing form peripheral support or guide zones for the hinge pin 3 on the bore wall 13' which forms the recess 16 in the longitudinal leg wall 8 on the right-hand side.

In contrast, on the other side of the slot 10, that is to say the left-hand longitudinal wedge wall 8, the full cylindrical jacket wall 17 is supported and guided against the wall of the bore.

At the recess 16, the bore wall 13 'passes into a smaller, the circular diameter of the offset hinge pin end 3' adapted bore 13 ", so that a stop shoulder remains for the hinge pin 3 at the bottom of the recess 16.

The hinge pin 3 is in this direction under spring load, that is in the sense of maintaining the positive engagement of the profiles. The hinge pin 3 is acted upon by a leaf spring 18 from the free end having the full cross section. The latter is located on the outside of the longitudinal leg wall 8 there. The area of assignment of the leaf spring 18 has a channel 19 of corresponding shape for its recessed assignment. The leaf spring 18 takes a course adapted to the pliers leg 1. The depth of the channel corresponds to the material thickness of the leaf spring 18, so that its outside is flush with the outside surface of the longitudinal leg wall 8 there. As can be seen in the drawing, the free end 18 'of the leaf spring 18 overlaps a sector-shaped recess 20 on the end face 3 "of the hinge pin 3. The sector shape takes into account the swivel angle requirement of the pliers legs 1, 2, taking into account the fact that the hinge pin 3 also in the uncoupled state is rotatably held to the pliers leg 2 carrying the longitudinal slot 12. A relative movement, ie rotational movement of the hinge pin only takes place in relation to the penetrated pliers leg 1. A screw 23 or other fastening element penetrating the other end is used to fix the leaf spring 18.

The swiveling limitation of the two pliers legs 1, 2 to each other results from stop edges 21 and 22 in the area of the free jaw F on the jaw side. The stop edges are placed in such a way that the rounded end of the leaf spring lying in the sector-shaped recess 20 is not loaded. The stop edge 21 is placed in such a way that the pliers limb 1, which suitably supports the hinge pin 3, in a minimal spreading position of the handle sections 6, 7 in the stop position, taking into account the finger thickness of the operating hand H, comes to a stop flank A of the other pliers leg 2 lying on the mouth side of the longitudinal slot 10 Corresponding minimum spreading distance between the insides of the two handle sections is denoted by z and is not undercut even in the case of larger jaw widths (see FIG. 10) in such a way that, for example, the fingers of the operating hand which steer the opening of the mouth M would be trapped . In order to prevent the corresponding approximation of the grip section 6 from the grip section 7 when the mouth width is increased, the material region of this pliers leg extending between the stop flank A and the longitudinal slot 10, which extends essentially in the same direction, widens significantly towards its end on the handle side. The broadening is essentially continuous. While the material area in the mouth-side slot end has a thickness of approx. 8 mm, the thickness is in the opposite end area approx. 11 mm, this with a slot length of approx. 40 mm. The acute angle between the stop flank A and the longitudinal slot flank 11 is designated Beta and is 2.5 °. The stop flank A runs continuously into the upper corner edge 28 of the mouth, ie clearly beyond the upper end of the slot.

Instead of the milled-out free space F in the case of a leg arrangement not penetrating in the intersection area, the stop edge 21 of the pliers leg 1 can also be formed by a recess shoulder 29 of a recessed recess, which is at a distance from the stop shoulder A and is open towards the broad side. This reference symbol is used analogously with respect to the milled free space F. The expansion shoulder 29 is essentially transverse to a line L between the hinge pin 3 and the tip of the pliers jaw 4. The stop edges 21 and 22 are approximately the same distance from the intersection of the line L and the recess shoulder 29. The swivel path of the pliers leg 1, which is limited in both directions, is selected such that the stop edge 22 holds the pliers leg in such a maximum spreading distance from the other pliers leg 2 that it is still within the gripping range of the fingers of the operating hand H and does not fold away uncontrollably. With the greatest range, the shoulder 29 can also strike itself if the taper in the grip section 7 starts early (FIG. 10).

The free end of the reduced cross-sectional, cylindrical cross-sectional area b forms a stop collar 24. It can be a screw ring. This is detachably screwed onto the corresponding threaded end there. Of course, a fixed stop can also be used, for example by upsetting a federal government.

The penetrated pliers limb 1 form t, according to two thigh sections 1 and 11 that are at an angle to one another, a groove K lying on the handle side of the hinge pin 3. The corresponding configuration is such that the rear edge 25 of the throat section 1 running inward from the throat is approximately parallel or at the same level as the outer edge edge 26 of the penetrated pliers leg 2 runs. Here, the rear edge 27 extends the throat outwardly extending leg portion 11 at an angle alpha obtuse angle to the outer peripheral edge 26 and rear edge 25. The angle alpha is approximately 140 ^0th The throat K takes a concavely rounded course in the apex area.

This design makes the area behind the pliers head slimmer; which facilitates the use of the tool. In addition, this configuration results in the possibility of immersing the milling cutter creating the free space F immediately from one side to the entire depth. It is not necessary to move the tool part.

The adjustment of the water pump pliers is as follows: To cancel the mouth width previously used, it is only necessary to axially pivot the hinge pin 3 from the side having the stop collar 24, ie. H. to move transversely to the plane of movement of the pliers legs against spring action. With the impact of the stop collar 24 on the outer surface of the longitudinal leg wall 8 there, the positive engagement between the teeth 14 of the hinge pin and the tooth gaps 12 of the longitudinal slot 10 is eliminated. The hinge pin 3 can now be moved together with the pliers leg 1 supporting it in the direction of extension of the longitudinal slot 10. By releasing the stop collar 24, the spring 18 brings about the desired positive engagement of the profiles again, due to the close tooth sequence with only slight correction in the sense of achieving a congruent position of teeth and gaps. V-tooth surfaces can be of the same angle. With increasing downward displacement of the pliers limb 1, the one flank limb 1 is increasingly spread apart by the stop flank A increasing with respect to the longitudinal slot, so that there is no pure parallel displacement of the pliers limbs to one another, but rather a minimal distance z between the pliers handle sections 6, 7 to each other is achieved.

Claims (8)

1. Water pump pliers with two plier arms (1, 2), placed across each other and meeting each other, linked together by a joint bolt (3), which form the plier jaws (M) above the crossing zone and the grip sections (6, 7) below the crossing zone, and in which for altering the size of the plier jaws one plier arm (1) can be adjusted in stages in the crossing zone in relation to the other plier arm (2) by means of the fact that the plier arm that meets it (2) has a longitudinal slot (10) with profiled sides (11), with which a section of the non-slip joint bolt (3) form-lockingly engages; this joint bolt can be disengaged by only axial displacement in a direction transverse to the longitudinal plane of the pliers against spring effect in such a way that a section smaller in cross section, which, seen in the direction of its axis, is next to a cylindrical section, goes into the plane of the longiudinal slot (10) and can there be moved over the whole length of the longitudinal slot (10), characterised by the f act that the non-slip quality of the joint-bolt (3) is achieved by the form-locking engagement of a middle section, which is not round and is toothed over a part of its axial length, with the profiled sides of the longitudinal slot (10) and that on both sides of this middle section of the joint bolt (3) bearing sections for the meeting plier arm (1) are located.

2. Water pump pliers as per claim 1. characterised by the fact that between the middle, form-lock producing cross sectional zone (a) and the cylindrical, thinner cross sectional zone (b) provided at the opposite end of the joint bolt (3') an intermediate section (15) is situated, whose width is smaller and whose length is greater than the unobstructed distance (y) between the form-locking engagement profilings (12/14).

3. Water pump pliers as per one or more of the previous claims, characterised by the fact that the spring loading of the joint bolt (3) is formed by a leaf spring (18), whose free end (18') fits into a sector shaped hollow (20) on the front side (3") of the joint bolt (3).

4. Water pump pliers as per one or more of the previous claims, characterised by the fact that the leaf spring (18) is sunk into a channel (19) in the plier arm (1).

5. Water pump pliers as per one or more of the previous claims, characterised by the fact that the intermediate section (15) in the engaged position fits, free to turn, into a hollow (16) on the inner side of the crossing zone.

6. Water pump pliers as per one or more of the previous claims, characterised by the fact that the meeting plier arm (1) as a result of two arm sections (1, 11) standing at an angle to each other forms a neck (K) situated on the grip side of the joint bolt (3).

7. Water pump pliers as per one or more of the previous claims, characterised by the fact that the meeting plier arm (1) in minimum spread position of the grip sections (6, 7), taking into account the finger thickness, comes in the stop position to a stop flank (A) of the other plier arm (2) situated on the jaw side of the longitudinal slot (10) and that the material zone of this plier arm stretching between this stop flank (A) and the longitudinal slot (10) widens out to its end on the grip side (angle Beta).

8. Water pump pliers as per one or more of the previous claims, characterised by the fact that the stop edge (21) of one plier arm (1) is formed by a clearance shoulder (29), situated at a distance in front of the stop flank (A) of the other plier arm (2), and the edge of this turned away from the jaws (M) forms the stop edge (22) for the maximum spread position.

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