EP1080844B1 - Pliers - Google Patents

Abstract

The first work jaw (1) is coupled to first tong handle (2), while a swivelable fitted second work jaw (3), forming with the first one the jaw gap. A second tong handle (4) is swivelable mounted on rear end section (23) of the second jaw. A sprung coupler (7) has its one end on second handle and the other end on the first handle. A swivel axis (30) is secured on the second work jaw, while an elongated hole (33) for retention of the axis is located on the first work jaw. A tensile spring (5,6) has one end secured at the swivel axis, while its other end is secured on the jaw with the elongated hole.

Description

The invention relates to a pair of pliers according to the preamble of patent claim 1.

Such a pair of pliers is already out of the WO 95/23048 known. This known pliers includes a first working jaw and a fixed thereto first pliers handle, a pivotally mounted by means of a pivot axis on the first working jaws second working jaw, which forms a forceps jaw with the first working jaws, a second handle pivotally mounted on a pointing to the rear end of the clamp section the second working jaw is mounted, and a resilient connecting member, one end of which is attached to the second forceps handle just behind the second working jaw and the other end is attached to the first forceps handle.

With this pliers, the connecting link serves to improve the elasticity of the pliers.

Other pliers of the type mentioned are from the DE 31 09 289 C2 known. Thus, the local figure 1 shows a toggle pliers, which has both a resilient toggle link connection and a sprung pivot axis. In contrast, a toggle pliers is shown in the figures 11 and 12, in which a pivot axis is fixed to one of the working jaws and in the other working jaws a slot for receiving the pivot axis, the longitudinal direction in the forceps plane and at least approximately perpendicular to the forceps longitudinal direction, wherein a tension spring is fastened with one end to the pivot axis and with its other end to which the slot having working jaws.

The invention has the object of developing a pair of pliers of the type mentioned so that can be achieved with her better work results. In particular, it should be possible to allow a better self-adjustment of the force curve in the forceps jaw in response to the closing movement of the working jaws, even with regard to different sized and to be processed in the forceps jaws objects.

The solution of the problem is that the pivot axis is attached to one of the working jaws and in the other working jaws a slot for receiving the pivot axis is located, whose longitudinal direction in the forceps plane and at least approximately perpendicular to the forceps longitudinal direction, and that a tension spring is attached at one end to the pivot axis and with its other end to the slot having working jaws, wherein to produce a desired Force curve in the forceps jaw, the tension spring and the connecting member are formed so that over a limited by the length of the slot closing the working jaws the required mouth force is applied by the tension spring and the connecting member and is provided via an adjoining closing of the working jaws alone by the connecting member ,

The combination of tension spring and resilient connecting member, it is inventively possible to adjust the force curve in the forceps jaw in response to the closing movement of the working jaws very fine to desired conditions, even in the event that different sized objects are to be processed in the forceps jaw, so that from therefore achieve better work results. This is especially true when it is the pliers to a crimping tool with which, for example, wire end ferrules or other contact elements to be pressed onto cable ends. The force curve in the forceps jaw in response to the closing movement of the working jaws is adjusted by the fact that the respective spring characteristics of tension spring and link are combined.

If the tension spring otherwise used for the exact adjustment of the mouth force would be overstretched if the mouth jaws or the closing jaws of the working jaws are too large, the tension spring is switched off and the required jaw force is then applied only by the connecting link via a further closing path of the working jaws. As a result, the production can be over relatively large closing paths of the working jaws ensure a desired force curve in the forceps mouth.

According to one embodiment of the invention, the spring characteristics of tension spring and connecting member can be adapted to each other so that when reaching the limited by the length of the slot closing path of the working jaws and further closing movement a jump-free force curve in the forceps jaw is achieved.

This makes it possible to perform a more uniform deformation process in the forceps jaw and thus obtain an even better work result. This measure allows a particularly favorable ergonomic handling of the forceps.

In an embodiment of the invention, the connecting member may be formed so that it gives way after exceeding a predetermined forceps jaw limit force. As a result, damage especially larger parts to be machined in the forceps jaw during further closing of the forceps handles is avoided, and it is possible to bring a commonly cooperating with the forceps pawl out of engagement with a row of teeth to open the forceps jaw.

In a further embodiment of the invention, the pivot axis is preferably attached to the second working jaws, wherein the slot is located in the first working jaws. As a result, the tension spring can be fixed to the first and immovable working jaws, so that it is not pivoted during operation of the forceps and therefore does not distort their characteristic.

The tension spring itself may have any suitable shape, but preferably also be formed, for example, as a V-shaped, U-shaped or Ω-shaped leaf spring. In springs of this type, the desired characteristic can be adjusted in a particularly simple manner by selecting the appropriate dimensions or material thicknesses.

As a connecting member may preferably be a flat plate-like spring plate are used or a package of such feather plates, which can be easily predefined by appropriate material dimensions and material thicknesses in these sheets, the spring characteristic.

• Figur 1 eine perspektivische Ansicht der erfindungsgemäßen Zange ohne Griffschalen;
• Figur 2 eine Explosionsdarstellung der Zange nach Figur 1;
• Figur 3 eine Seitenansicht der Zange nach Figur 1 in geöffnetem Zustand bei abgenommenen Seitenblechen, jedoch mit eingesetzter Ω-Feder;
• Figur 4 eine Seitenansicht der Zange nach Figur 1 in geschlossenem Zustand bei abgenommenen Seitenblechen, jedoch mit eingesetzter Ω-Feder; und
• Figur 5 eine perspektivische Ansicht der erfindungsgemäßen Zange mit Griffschalen.

An embodiment of the invention will be explained below with reference to the drawing in detail. Show it:

• Figure 1 is a perspective view of the pliers according to the invention without handle shells;
• Figure 2 is an exploded view of the pliers of Figure 1;
• Figure 3 is a side view of the pliers of Figure 1 in the open state with removed side plates, but with inserted Ω spring;
• Figure 4 is a side view of the pliers of Figure 1 in the closed state with removed side plates, but with inserted Ω spring; and
• Figure 5 is a perspective view of the forceps according to the invention with handles.

According to FIG. 1, a pair of pliers according to the invention contains the following components: a first working jaw 1, a first gripper handle 2, a second working jaw 3, a second gripper handle 4, V-shaped spring plates 5 and 6 and a resilient connecting member 7, for example a compression spring.

The first working jaws 1 and the first forceps handle 2 are integrally connected to each other and consist of a total of two mutually parallel sheets 8 and 9, which are held by a plurality of spacers 10, 11 and 12 at a distance from each other. The spacers 10, 11 and 12 each have a passage opening through which a bolt 13, 14 and 15 passes, which holds the sheets 8 and 9 together.

In the front region, the first working jaw 1 has a recess pointing in the direction of the second working jaw 3 for forming a forceps jaw 16 together with a corresponding recess in the second working jaw 3.

The second forceps handle 4 is constructed in the same way as the first forceps handle 2. It also consists of two parallel plates 17 and 18, which are held by spacers 19 and 20 at a distance from each other. These spacers 19 and 20 are also hollow and receive bolts 21 and 22 which hold the sheets 17 and 18 together. In this case, the distance between the sheets 17 and 18 from one another corresponds to the spacing of the sheets 8 and 9.

In her pointing to the forceps jaw 16 front area the plates 17 and 18 are extended in their plane. They take there a rear portion 23 of the second working jaw 3 between them. This rear portion 23 of the second working jaw 3 is pivotally mounted on the front portion of the second forceps handle 4 and arranged for this purpose rotatable about an axis 24 which is held by the sheets 17 and 18 and passes through an opening 46 in the rear portion 23.

As will be described in more detail with reference to Figure 2, belonging to the second working jaw 3 two lateral jaw plates 25 and 26, which laterally nestle against a central node element 27 of the second working jaw 3 and are held at a distance from each other, which is also the distance of Sheets 17, 18 and 8, 9 corresponds to each other. For cohesion of the jaw plates 25 and 26 with the central node element 27 are screws 28 and bolts 29, which enforce these elements. The second working jaw 3, as will be explained with reference to FIG. 2, is rotatably mounted on the first working jaw 1 via a pivot axis 30. On both outer and the second working jaws 3 outwardly projecting ends of the pivot axis 30 is seated one end of the V-shaped spring plates 5 and 6, the other end is attached in each case via a bolt 31 at the upper region of the upper working jaw 1, ie above the Pivot axis 30. Here, the pivot axis 30 fits in a Recess 32 of the second working jaw 3 and on the other hand is in slots 33 which are located respectively in the sheets 8 and 9 of the first working jaw 1, wherein the longitudinal direction of the slots 33 is at least approximately perpendicular to the forceps longitudinal direction.

The resilient connecting member 7 consists of two mutually parallel spring plates 34 and 35 and is articulated at its lower end in the front region of the second forceps handle 4, to which it is pivotable about an axis 36 which passes through the connecting member 7 and the sheets 17 and 18th is held. The axis 36 is shifted relative to the axis 24 to the rear end of the tong. The other end of the resilient connecting member 7 is pivotable on an eccentrically mounted shaft 37 and mounted on it on the first handle 2. In this case, the eccentrically mounted shaft 37 is displaced with respect to the axis 36 to the rear end of the pliers. For eccentric mounting of the axle 37 serve both sides axle stub 38, which are rotatably mounted in the sheets 8 and 9. On one of these stub axles 38 sits an adjusting disc 39 with peripheral recesses which serve to lock the angular position of the adjusting disc 39 by means of a screw 40. By adjusting the adjusting disk 39, its length can be changed via the eccentric mounting of the connecting member 7, and thus the position of the working jaws 1 and 3 can be adjusted to one another.

FIG. 2 shows the more detailed construction of the pliers according to FIG. 1. The same elements are again provided with the same reference numerals and will not be described again.

In the upper part of Figure 2, the slots 33 are first clearly visible, the longitudinal direction is perpendicular to the forceps longitudinal direction. At a distance above the slots 33 are each the bolts 31 on the outside of the sheets 8 and 9, which serve to receive one end of the V-shaped spring plates 5 and 6. The respective other end of the spring plates 5 and 6 is curved and takes the pivot axis 30 shown in Figure 1 suitable.

The central region of Figure 2 shows the more detailed structure of the lower working jaw 3. The central node element 27 consists in the present case of a middle plate 41, which consists for example of plastic, and two adjacent to both sides of the middle plate 41 outer plates 42nd and 43, which are made of steel. All plates 41, 42 and 43 form an approximately U-shaped component, the free legs facing the rear end of the pliers. On this component, the two jaw plates 25 and 26 are mounted laterally in the region of the base and the lower leg, wherein the sheets are held together by the screw 28. As an anti-rotation serve the bolts 29, which are held by retaining rings. The jaw plates 25 and 26 protrude from the bottom of the U-shaped component and together with the front portions of the sheets 8 and 9, the forceps jaw 16. In the rear region of the forceps jaw 16, both the jaw plates 25 and 26 and the sheets 8 and 9 bevelled so that their opposite edges to the rear tong end away from each other. From the clamping jaw plates 25, 26 and the sheets 8 and 9 carried machining elements in the forceps jaw 16 can therefore tilt according to the closed position of the pliers, namely about respective tilting axes which are passed through openings 44 and 45 of the working jaws 1 and 3 and the processing elements in Hold pliers mouth 16.

The U-shaped component shown in the middle region of FIG. 2 has, in its remaining region of the base, the passage opening 32, which serves for the suitable accommodation of the pivot axis 30. This pivot axis 30 is, as already mentioned, taken up by the oblong holes 33, so that in this way the second working jaw 3 is pivotally mounted on the first working jaw 1. The free end of the lower leg of the U-shaped component in the central region of Figure 2 forms the said rear portion 23 of the second working jaw 3 and is provided there with a through-hole 46 through which the axis 24 passes to thus the second handle 4 to store the second working jaw 3 pivotally.

The upper leg of the U-shaped component 27 in Figure 2 has on its inside a toothing 47 which is coaxial with the through hole 46. In the toothing 47 engages a pawl 48, which can be seen in Figures 3 and 4. This pawl 48 may also be a pair of pawls, one of which engages in a toothing 47 on one of the plates 42, 43. Through it is achieved that the pliers can only be opened again after the forceps handles have reached their closed position. The pawl 48 is pivotally mounted in the front region of the lower pliers handle 4 about an axis 49, which can be seen in the lower part of Figure 2. The axis 49 is movable on a path concentric with the axis 24. Therefore, the length of the pawl 48 is greater than the distance between the axis 49 and teeth 47. Semicircular openings 50 coaxial with the axis 49 in the sheets 17 and 18 serve for manual actuation of the pawl 48 to bring it out of engagement with the teeth 47. In the front region of the second forceps handle 4 in Figure 2 are still through holes 51 and 52 can be seen in the sheets 17 and 18, which serve to receive the axes 24 and 36 in Figure 1.

On the outside of the upper leg of the central node element 27 in Figure 2 are still hook-shaped projections 53 at the rear end of the plates 42 and 43 can be seen. These lugs 53, which may also be supplemented to receive through holes, serve to receive an axle to which one end of a tension spring shown in FIGS. 3 and 4 is attached, bearing the reference numeral 54. The other end of this tension spring 54 is attached to an axis 55 in the upper region of the first working jaw 1. The tension spring 54 serves, upon reaching the closed position of the forceps handles 2, 4 to automatically open the pliers again. The closed position of the forceps handles is reached when the pawl 48 is disengaged from the teeth 47. The upper abutments 56 on the second gripping element 4 then strike later against the lower edges of the first gripping element 2.

With reference to Figures 3 and 4 it should be mentioned that the pawl 48 can rotate about the axis 49 and held by a spring 57 which is fixed in the lower region of the connecting member 7 in a zero position, which is actually achieved only when the pawl 48 is disengaged from the toothing 47. If the pawl 48 engages with the toothing 47, it can give way, for example, when the forceps jaw 16 closes and not in the opposite direction. In order to bring the pawl 48 out of engagement with the teeth 47 in an intermediate position of the pliers handles 2, 4, connected to the pawl approach 58 can be manually operated through the slots 50 therethrough. The pawl 48 itself is practically in the interior of the central node element 27, so that no additional space inside the pliers is needed for this ratchet mechanism of teeth 47 and pawl 48. The pliers can therefore be reduced relatively compact.

Below, the operation of the pliers with reference to Figures 3 and 4 will be explained in more detail.

FIG. 3 shows the pliers in the fully opened state. Here, both the total as a tension spring to be designated spring plates 5 and 6 are relieved and the connecting member. 7

If the forceps handles 2 and 4 or plates 9 and 18 in FIG. 3 are moved toward one another, then the force in the forceps jaw 16 is determined both by the spring plates 5 and 6 and by the connecting member 7. The characteristics of all springs add up and lead to a predetermined force curve in the forceps jaw 16 in response to the closing movement of the working jaws 1 and 3. The force curve in the forceps jaw is here essentially defined by the spring plates 5 and 6, with increasing closing movement of the forceps handles the pivot axis 30 is moved away in Figure 3 or from the first working jaw 1.

Is there a relatively small object to be machined in the forceps jaw 16 or between there arranged tool elements and is therefore only a relatively short working path of the working jaws 1 and 3 required, Thus, the force curve in the forceps jaw can be generated by the V-shaped spring plates 5 and 6 for this short working path, with only a relatively small support by the connecting member 7 takes place. The working path then begins after the tool elements have come into contact with the object to be processed. These spring plates can be bent only over the length of the slot 33, since only in this case ensures that they actually deliver the desired force curve. A bending of the spring plates 5 and 6 beyond would lead to a distortion of the force curve, since then change their elastic properties in an undefined manner.

On the other hand, if objects to be machined in the forceps jaw are to be deformed over a relatively long working path over which the V-shaped spring plates 5, 6 can no longer deliver the desired force curve, then the force curve in the forceps profile in the forceps profile over the first part of the path corresponding to the length of the oblong hole 16 substantially determined by the V-shaped spring plates, wherein it is influenced by the connecting member 7, while after passing through the permissible for the V-shaped spring plates 5 and 6 way the force curve in the forceps jaw for the further way essentially only by the spring properties of the connecting member 7 is determined. In this way it is ensured that over the entire path over which the element to be machined in the forceps jaw 16 must be processed or pressed, the desired force curve is actually made available.

FIG. 4 shows the pliers in the fully closed state. Here are all the spring elements 5, 6, 7 still charged and the pawl 48 out of engagement with the teeth 47, so that the forceps can be opened again, if in the forceps jaw 16 is a machined (not shown) object.

If the case occurs that the forceps handles 2, 4 are not yet closed, even after the working jaws 1, 3 go through a closing path have, beyond the closing path provided the V-shaped spring plates, so the connecting member 7 ensures due to its chosen spring characteristic that when a given forceps jaw limit force is exceeded due to the then incipient behavior of the connecting member 7, the forceps handles can still be closed, so that then the pliers can be opened again.

FIG. 5 once again shows the forceps according to the invention in a perspective view, now supplemented with grip shells 59 and 60 arranged on the metal sheets 8, 9 and 17, 18.

The inventive pliers can be present as a single tool or as an integral part of a machine tool. In the case of a single tool, according to one embodiment of the invention, the forceps handles 2, 4 may be formed so that the forceps can be connected via their forceps handles with a machine for forceps drive. Thus arise for the pliers several applications. It can thereby be operated manually or driven by a machine, in order to carry out periodically recurring work over a longer period of time. On the other hand, the pliers but also in whole or in parts may be a permanent part of a machine tool for driving the pliers. At least the forceps handles of the forceps can be parts of this machine tool. In this case, the pliers handles could be coupled to the rest of the pliers parts, which could be the pliers handles combine with each other different pliers parts of the type described above. One could thus take into account different dimensions of the material to be processed.

In FIG. 4, for example, a machine M connected to the forceps handles 2, 4 is shown with dashed lines. By the machine M is practically simulated the movement of the pliers handles 2, 4 for driving the pliers.

Claims (9)

1. Pliers having a first operating jaw (1) and a first plier handle (2) fixed thereto, having a second operating jaw (3) which is mounted pivotably by means of a pivot pin (30) and forms a plier mouth with the first operating jaw (1), having a second plier handle (4) which is mounted pivotably on a section (23) of the second operating jaw (3), said section being oriented towards the rear plier end, and having a resilient connecting element (7), of which one end is provided on the second plier handle (4), just behind the second operating jaw (3), and the other end is provided on the first plier handle (2), characterized in that

   - the pivot pin (30) is fastened on one of the operating jaws (3), and located in the other operating jaw (1) is a slot (33) for accommodating the pivot pin (30), the longitudinal direction of said slot running in the plier plane, at least more or less perpendicularly to the longitudinal direction of the pliers;

   - a tension spring (5, 6) has one end fastened on the pivot pin (30) and its other end fastened on the operating jaw (1), which has the slot (33), and in that,

   for the purpose of producing a desired force behaviour in the plier mouth (16), the tension spring (5, 6) and the connecting element (7) are designed such that, over a closing displacement of the operating jaws (1, 3) which is limited by the length of the slot (33), the necessary mouth force is applied by the tension spring (5, 6) and the connecting element (7) and, over a following closing displacement of the operating jaws (1, 3), said mouth force is provided solely by the connecting element (7).
2. Pliers according to Claim 1, characterized in that the spring characteristics of the tension spring (5, 6) and connecting element (7) are adapted to one another such that, once the closing displacement of the operating jaws (1, 3) which is limited by the length of the slot (33) and further closing movement have been achieved, the smoothest possible force behaviour in the plier mouth (16) is obtained.
3. Pliers according to Claim 1 or 2, characterized in that the connecting element (7) is designed such that it yields to a pronounced extent once it has exceeded a predetermined plier-mouth limit force.
4. Pliers according to one of Claims 1 to 3, characterized in that the pivot pin (30) is fastened on the second operating jaw (3) and the slot (33) is located in the first operating jaw (1).
5. Pliers according to one of Claims 1 to 4, characterized in that the tension spring (5, 6) is designed as a V-shaped, U-shaped or Ω-shaped leaf spring.
6. Pliers according to one of Claims 1 to 5, characterized in that the connecting element (7) has at least one flat-plate-like spring plate (34, 35).
7. Pliers according to one of Claims 1 to 6, characterized in that at least their plier handles (2, 4) are parts of a machine (M) for driving the pliers.
8. Pliers according to Claim 7, characterized in that the plier handles (2, 4) can be coupled to the rest of the parts of the pliers.
9. Pliers according to one of Claims 1 to 8, characterized in that the plier handles (2, 4) are designed such that they can be connected to a machine (M) for driving the pliers.

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