EP0940203A2 - Hand riveting tool for blind rivets - Google Patents

Abstract

The tongs have two grip levers (3,4) and traction element (10). A connecting rod drive (7) with variable transmission ratio is positioned between the traction element and the first grip lever. The ratio drops continuously from an initial position, in which the first lever is at maximum distance to the second lever, and an end position, in which the first lever is close to the second one. The drive has a pivoted intermediate lever, connected to the traction element.

Description

The invention relates to a hand rivet pliers with a Traction element that is relative along a pulling direction is displaceable to a housing, a first handle lever, which is pivotable relative to the housing about a pivot point and a second handle lever.

When inserting a blind rivet, the blind rivet is included its rivet shank inserted into an opening. Then the mandrel is pulled out. With this movement the rivet shank is deformed on the invisible side. The mandrel breaks after a certain movement off and the blind rivet is set. A similar approach takes place when setting blind rivet nuts. Indeed there is usually a pin in the Blind rivet nut screwed in after deforming do not tear off the blind rivet nut in its opening should, but is screwed out again.

In both cases it is necessary to have some traction to attach the rivet to the locking head to deform. For this purpose, the blind rivet is placed in the Blind rivet pliers inserted until the rivet head on one Abutment comes to the plant. The mandrel is used here seized by the tension element. If now the two handle levers towards each other, then the tension element moved away from the abutment so that the mandrel relative pulled to the blind rivet.

Blind rivet pliers of the type mentioned at the beginning are out DE 31 24 648 A1 known. Here is the handle lever that is used to actuate the tension element with the Thumb or the ball of the thumb operated. The handle lever itself is designed as a one-armed lever that opens another two-armed lever acts on the upper End of the tension element is attached. By the multiple Translation should be the one to be provided by the user Strength be kept small.

US 4 932 638 shows pliers for setting expansion bolts, where the handle lever on clamping plate acts, which are arranged around the tension element. When the handle lever is actuated, it wedges a clamping plate on the tension element. Another move of the handle lever then leads to a shift of the tension element.

Finally, DD 130 757 A1 shows blind rivet pliers articulated head, with its variable length Part arranged between the end points of two levers which are formed by the handles. A relatively large leverage ratio is achieved.

In all cases the setting of blind rivets and Blind rivet nuts relatively difficult with hand. If you have the Grip width increased to a sufficient stroke for To achieve the setting of the blind rivet, then the Often, blind rivet pliers can no longer be operated with one hand. This is true for the design according to DE 31 24 648 A1 defused by the fact that according to Art a ratchet a multiple actuation of the handle lever allowed in a single setting process. Arise here but sometimes considerable due to the many redirections Loss of friction, so sat the one applied by the user Hand force only incomplete to set the blind rivet is available.

In the embodiment according to US 4 932 638 a part of the stroke used up, the plate on the tension element to wedge. Again, there is a repeated one Follow-up enables. The ease of use however leaves something to be desired.

The invention has for its object the handling to simplify blind rivet pliers.

This task is the hand blind rivet pliers type mentioned solved in that between the first lever and the pulling element a connecting rod gear arranged with a variable transmission ratio is.

With this configuration, there are several advantages. By using a connecting rod gearbox, the Swiveling movement of the first handle lever in a simple way and implemented in the linear movement of the tension element become. This can usually be done relatively reach a few hinge points where losses occur can, so that the user applied Hand power can be used to a large extent To put a blind rivet. The connecting rod transmission has a variable one Transmission ratio. If the first Handle lever is pivoted through a certain angle, does this depending on the position of the handle lever different propulsion routes of the tension element result. This takes into account the knowledge that a user's hand power over his grip area is not constant. The hand force is extended Rather, the hand is smaller than when it is almost closed Hand. So the normal force is that of an average Hand applied when closing the pliers handles with an opening width of 50% almost twice as large as with an opening width of 100%. This is used to do this when the door is wide open Pliers, i.e. with a large distance between the first Handle lever and the second handle lever, only one slight displacement of the tension element per angular unit to generate when swiveling the first handle lever, what a correspondingly smaller energy requirement and therefore requires a smaller hand force than with each other approximate handle levers. This is considered by the user felt very pleasant.

Preferably, the gear ratio falls from one Starting position in which the first handle lever is the largest Has distance from the second handle lever up to an end position in which the first handle lever the second handle lever is approximated. In order to the counterforce that the user is facing increases steadily on. With the same angle adjustment of the The first handle lever places the pull piece at the beginning of the movement a smaller way back than at the end. Gaps or jumps are avoided. It results in a very pleasant working behavior with the blind rivet pliers.

The connecting rod transmission preferably has an intermediate lever on, which is articulated on the first handle lever and by one Pivot point is pivotable and with the tension element is in engagement, the site of engagement, the Pivot point and the pivot point an obtuse angle Form a triangle. Because the points mentioned If you form an obtuse-angled triangle, you reach several Advantages. First, there is the change in angle at the point of intervention relatively small, so that only very small Frictional losses occur. On the other hand you can the desired course through the obtuse-angled triangle of the gear ratio relatively precisely. The obtuse angle is preferably the result in the area of the fulcrum so that you can choose by of the angle can predetermine which component of the movement of the first handle lever for propelling the tension element is used.

The triangle advantageously remains over the entire working area of the first handle lever at an obtuse angle. This includes a right angle as the limit. At this limit, the largest component to move of the tension element used.

The intermediate lever on the tension element is preferably different Positions definable. So you can multi-stage setting of the Reach blind rivets. When the first one is pressed Handle lever, the tension element is first by a predetermined maximum distance shifted. This route In many cases it is not enough to close the blind rivet put. If the tension element remains in this position, can be done by swiveling back the first handle the intermediate lever back to its starting position move where he attacks the traction element again, this time but in a different position, namely a little further against the direction of the train. You can do the total stroke divide the tension element into many individual strokes. Accordingly is only a smaller one for each individual stroke Force required.

It is preferred that the tension element one with the Intermediate lever has interacting teeth. In order to there is a positive engagement between the intermediate lever and the tension element, via which also larger tractive forces can be transmitted. The design also has the advantage that you always defined intervention points or locations. Man does not have to be done by moving or tilting the Intermediate lever opposite the tension element for the necessary Care intervention.

A pawl is preferably detachably connected to the tension element engaged. The pawl secures against that the tension element when the intermediate lever in its Starting position is retracted, too walks back against the direction of the train.

It is preferred that the pawl on the same surface area of the tension element as the Intermediate lever acts. This has two advantages. On the one hand is a processing of the tension element, for example for training the toothing, only necessary in a single area. Secondly, it ensures that the pawl in the same way, about the same division, can act on the tension element like the intermediate lever also.

The intermediate lever is advantageously in the starting position the first handle lever on an axis, which forms the fulcrum of the first handle lever. On this way it is relatively easy to get the procedure between the intermediate lever and the tension element to solve. The first lever only has to be over his Starting position forward, i.e. against his working direction, be swung out. The distance then forms between the pivot point and the fulcrum a lever arm with which it is possible to use the intermediate lever to lift out of engagement with the tension element. The term "concern" is of course taken into account understand the usual manufacturing tolerances. A small distance can occur.

Preferably there is an axis that is the pivot point of the Forms intermediate lever on the first handle lever in the Starting position on the pawl. If the first Handle lever swung forward beyond the starting position then not only does the intermediate lever release, but also the pawl.

This is particularly advantageous if the pawl around the same pivot point as the first handle lever is pivotable. You then need for the handle lever and only one, common for the pawl Axis of rotation, which keeps the design effort small. In addition, there are clearly defined movement relationships.

The first handle lever is preferably a finger lever trained, i.e. it is placed on the side where the blind rivet is also inserted into the blind rivet pliers becomes. This corresponds more to the "pistol feeling" than actuation by the thumb or the ball of the thumb. The riveting pliers can be guided more precisely. The housing lies calm because only the fingers are moved. This will cause the housing to tilt relative to Avoided rivets. The risk that when setting the blind rivet an unwanted relocation is kept to a minimum.

The pulling element is advantageously on the connecting rod gear opposite side supported. The tension element can therefore the forces that act perpendicular to it, do not dodge, so that the engagement between the Connecting rod gear and the traction element always preserved remains.

The tension element preferably has a return spring and a jaw spring, both springs on Housing are supported. A return spring is for the traction element required so that it after setting the blind rivet is returned to its starting position can be, for example, if the Pawl and the intermediate lever out of engagement with be brought to the tension element. If the tension element in its starting position is pushed back, it is also required that the jaws release the mandrel so that it can hold a new mandrels are available. Now that both feathers are supported on the housing, both springs also serve to reset the tension element. Since both of them The corresponding supports can be supported be relatively stable.

It is preferred that the tension element has a damping ring having. Such a damping ring can be formed by an O-ring, for example surrounds the tension element at a position where it with a Internal slope of the housing comes into contact. Of the Damping ring prevents uncomfortable hitting, when the pawl and the intermediate lever unlock become.

The housing advantageously has a removable collecting container on. Torn in the collecting container Rivets are collected. The risk of accidents in Area of work is kept small because no torn rivets are lying around freely.

Fig. 1

eine Seitenansicht einer Blindnietzange mit den Griffhebeln in Ausgangsstellung,

Fig. 2

die Blindnietzange mit den Griffhebeln in Endstellung,

Fig. 3

eine schematische Darstellung zur Erläuterung der Handkraft,

Fig. 4

einen Querschnitt durch die Blindnietzange,

Fig. 5

einen Längsschnitt durch die Blindnietzange,

Fig. 6

eine vergrößerte Darstellung nach Fig. 4 und

Fig. 7

eine Darstellung wie Fig. 6 mit weiteren Bauteilen.

The invention is described below with reference to a preferred embodiment in connection with the drawing. In it show:

Fig. 1

a side view of blind rivet pliers with the handle levers in the starting position,

Fig. 2

the blind rivet pliers with the handle levers in the end position,

Fig. 3

a schematic representation to explain the hand force,

Fig. 4

a cross section through the blind rivet pliers,

Fig. 5

a longitudinal section through the blind rivet pliers,

Fig. 6

an enlarged view of Fig. 4 and

Fig. 7

a representation like Fig. 6 with other components.

A blind rivet pliers 1 is not used for setting Blind rivets or blind rivet nuts shown. To for this purpose, a blind rivet with its rivet mandrel a mouthpiece 2 of the rivet pliers inserted until it is there. The blind rivet pliers have a first movable handle lever 3 and a second handle lever 4 on, which is connected to a housing 5, on which also the mouthpiece 2 is attached. If now the first Handle lever 3 pivoted toward the second handle lever 4 the rivet mandrel is gripped and then exerted a tensile force on the mandrel that the Rivet mandrel with its thickened end a bit through the rivet shaft and this to the closing head deformed. In the illustrated embodiment this requires a force of 7,000 N. That power is of course dependent on the blind rivet used. Because of the leverage in connection with the 4 to 7 is discussed, is at the beginning of the pivoting process the first handle lever 3 a force of 190 N necessary. This force increases with increasing Swivel angle steadily on and is in 2 illustrated end position 310 N.

With this variable power transmission one carries the physiological conditions, which are shown in Fig. 3 are shown. The human hand can then if she closes her grip further, a higher force apply. Accordingly, the opening width is horizontal applied by hand in percent. Perpendicular is the normal force in Newtons (N). Out of it it can be seen that the hand is when it is its largest Has only taken up about 50% of the opening width Can exert force with an opening width of 40%. If now by a corresponding selected variable transmission ratio, i.e. a course of the translation, the force when pressed of the first handle lever rises, then for the user a very comfortable working behavior despite a largely constant traction on the mouthpiece 2nd

The internal structure of the blind rivet pliers is shown in Fig. 4 to 7.

The mouthpiece 2 is screwed into the housing 5, the again integrally connected to the second handle lever 4 is. The housing is shown closed here. However, this is not an unconditional requirement for the functionality of the blind rivet pliers 1.

The first handle lever 3 is about an axis 6 in the housing 5 pivotable. The axis 6 forms a fulcrum for the first handle lever 3. on the first handle lever 3 is an intermediate lever 7 pivotally mounted about an axis 8, which is a pivot point for the intermediate lever forms on the first handle lever 3. This Construction can also be seen in Fig. 6.

The intermediate lever 7 has at its other end, i.e. the end facing away from the axis 8, a toothing 9 with which the intermediate lever 7 with a tension element 10 is engaged. The tension element 10 points to this a toothing 11, which along in the direction of pull of the tension element 10 extends over an area which much longer than the toothing 9 on the intermediate lever 7 is. As a comparison of FIGS. 4 and 6 shows, it is therefore possible that the intermediate lever 7th along the tension element 10 at different positions comes into engagement with the tension element 10. One can therefore divide the total stroke that the tension element 10 carries out in several partial strokes, with the. for each partial stroke first handle lever 3 around its full swivel range the second handle lever 4 is pivoted.

With this pivoting movement, the first handle lever forms 3 together with the intermediate lever 7 a connecting rod gear. The pivot point of axis 6, the pivot point of axis 8 and the engagement point 9 (for the purpose of this consideration the rearmost point of the toothing 9 is the point of engagement considered) form an obtuse angle Triangle, the obtuse angle being arranged on axis 6 is. The pivot point of axis 8 leads one Circular movement around the axis 6 from the point of engagement between the teeth 9, 11 in a linear movement is implemented. Because the swivel angle is chosen is that the triangle spans the entire swivel range of the first handle lever 3 remains obtuse, the angle in the area of axis 6 always at least 90 ° is, the angular movements can no longer be simple be linearized. Rather, there is a clear one Increase in the displacement of the tension element 10 with increasing pivoting angle of the first handle lever 3. Here you come essentially with two rotary movements around axes 6 and 8 because the change in Interlocking geometry between the teeth 9, 11 stays small. There are practically no friction losses there.

The tension element 10 is on the opposite of the toothing 11 Side by a roller 12 in the housing 5 supported. Even the small ones, transverse to the direction of pull of the Tensile element 10 acting forces, so can not do so cause the tension element 10 out of its orientation is pushed out with the direction of pull.

The intermediate lever 7 is under the action of a spring 13 pressed against the tension element 10. Serves at the same time the spring 13 also for resetting the first handle lever 3. As can be seen from Fig. 6, the teeth 9, 11 designed so that almost perpendicular Standing tooth flanks interact when the tension element 10 in Fig. 6 to the right (in the direction of pull) becomes. Sloping tooth flanks face in the other direction opposite, so that the intermediate lever during a return movement the first handle lever 3 (clockwise) can slide over the teeth 11. In order to during this return movement of the intermediate lever 7, the tension element 10 stays in place is a pawl 14 (see Fig. 7) provided, which with the help of a Compression spring 15, which also abuts the housing 5, is pressed against the tension element 10. The pawl 14 is mounted on the same axis 6 as the first Handle lever 3. It has an elongated hole 16 through which the axis 8 is passed. The elongated hole is like this large that the maximum possible swivel angle of the first Handle lever 3 are passed through, for example, 25 ° can without the axis 8 with the pawl 14 in Conflict.

By the interaction of the intermediate lever 7 with the Pawl 14, both on the same toothing 11th act on the tension element 10, a ratchet effect is achieved. When the intermediate lever 7 moves backward the pawl 14 secures against it that the tension element 10 is moved back again.

To release the pawl 14 and the intermediate lever 7 the first handle lever 3 is shown in Fig. 4 Starting position swung open a little further, i.e. moved in a clockwise direction. As can be seen from FIG. 6, the intermediate lever 7 in its starting position on the axis 6 or has a very small distance from it. If the first Handle lever 3 moved further in the clockwise direction , then the intermediate lever 7, which by the axis 8 is fixed to the first handle lever 3 levered 6 around and then disengaged with the tension element 10.

In the same way, the axis 8 acts on the pawl 14, where it is on a surface 17, which is a boundary of the Elongated hole 16 forms, abuts. If the first handle lever 3 is opened, then the pawl 14 is also excluded Engagement with the toothing 11 of the tension element 10 brought.

The pawl 14 also has a toothing 18, which has correspondingly inclined teeth. The tension element 10 can be shifted to the right by it pawl 14 on the right against the Force the spring 15 down on the left side presses. If the pawl 14 in the opposite direction locks, then almost vertical tooth flanks face each other.

The tension element 10 has at its front end that is adjacent to the mouthpiece 2, a gripping mechanism 19 on that to hold a rivet mandrel during the pulling process serves. The gripping mechanism 19 has jaws 20 on that tapered forward on its outside approach. The jaws 20 are surrounded by one Jaw housing 21, which has a corresponding inner cone exhibit. When the pull mechanism is withdrawn 4 (to the right in Fig. 4), then the jaw housing exercises 21 a radially inward force the jaws 20, so that a mandrel reliably is held. This technique is known per se.

The tension element 10 has a return spring 22 which is supported on the housing 5 and the tension element 10 at unlocked pawl 14 and unlocked intermediate lever 7 pushes back into its starting position. At the same time there is a inside the tension element 10 Jaw spring 23 arranged, which is also on the housing 5 is supported. The jaw spring 23 also serves to reset the tension element 10.

The return spring 22 and the jaw spring 23 work now together in that the jaw spring 23 the jaws 20 as far as the stop on the mouthpiece 2 pushes. The return spring 22 pushes that Jaw housing 21 a little further, so that can open the jaws 20. Accordingly, the return spring 22 may be weak. She must only be able to over the jaw housing 21 to move the jaws 20 further to the left and does not act against the jaw spring 23.

The jaw housing 21 is on its circumference with a O-ring provided when the pulling element moves 10 in its starting position back to one accordingly conical inner wall 25 of the housing 5 comes to rest and dampens the stroke. Accordingly become hard knocks on the user's hand avoided.

As can be seen from FIG. 5, the intermediate lever 7 U-shaped. He takes the pawl 14 between to. This enables very stable engagement geometries realize.

At the end of the blind rivet pliers facing away from the mouthpiece 2 1, a container 26 is attached, which with a Through opening 27 in the housing communicates, which in turn connects to the hollow interior of the tension element 10 communicates. The opening 27 is in a in the housing 5 stored bolt 28 is provided, which on its front end opens conically and at the same time serves as an abutment for the jaw spring 23. When resetting the tension element 10, the opens Gripping mechanism 19. The torn rivet mandrels can then fall through the opening 27 into the container 26. It is then only necessary to the container 26 of Empty from time to time. An accident at work due to dropping mandrels falling out.

With the blind rivet pliers shown is a very comfortable one Setting blind rivets (or blind rivet nuts) possible. The one required to place a blind rivet The total stroke is divided into several partial strokes, with the first handle lever 3 around its in each partial stroke full swivel range is pivoted. Here is the Swivel range of the first handle lever 3 relative to the second handle lever 4 set so that the user can easily operate both handle levers with one hand, when the first handle lever 3 is in the starting position located. The first handle lever 3 is as Finger lever formed, i.e. with normal posture is the first handle lever 3 on the fingers of the user's hand. With increasing pivoting movement of the first Handle lever 3 increases relative to the second handle lever 4 the force necessary for moving. But this is on the comfort of the user without detrimental Influence because the user with increasing swivel angle can also exert a greater force. This course of force results with every single stroke. For example the total stroke can be divided into nine individual strokes. For example, an aluminum blind rivet with 4 mm Diameter, the breaking load of which is 3,650 N, with a Hand force from 180 - 230 N, depending on the position of the first one Bring handle lever 3 to tear. With a 5 mm aluminum rivet, whose breaking load is 5,400 N, the Hand force in the range from 220 to 270 N, depending on the position of the first handle lever 3. With conventional devices the necessary hand forces were of the order of magnitude from 300 to 340 N or 440 to 470 N.

Due to the many partial strokes, large overall stroke lengths can be achieved of about 16 mm, for example, so that long rivets or multi-range rivets are also used can process easily.

Claims (16)

Hand-held rivet pliers with a pulling element that runs along a pulling direction relative to a housing is displaceable, a first handle lever, which is relative pivotable to the housing around a pivot point and a second handle lever, characterized in that that between the first handle lever (3) and the connecting element (10) is a connecting rod gear with a variable gear ratio arranged is. Blind riveting pliers according to claim 1, characterized in that that the gear ratio of one Starting position (Fig. 1) in which the first handle lever (3) the greatest distance from the second Has handle lever (4) up to an end position (Fig. 2) in which the first handle lever (3) the second Handle lever (4) is approaching, steadily falling off. Blind riveting pliers according to claim 1 or 2, characterized in that that the connecting rod gear has an intermediate lever (7), that on the first handle lever (3) articulated and pivotable about a pivot point (8) is and with the tension element (10) in engagement stands, the point of engagement (9, 11), the Pivot point (6) and the pivot point (8) an obtuse angle Form a triangle. Blind riveting pliers according to claim 3, characterized in that the triangle spans the entire work area of the first handle lever (3) at an obtuse angle remains. Blind riveting pliers according to claim 3 or 4, characterized in that that the intermediate lever (7) on the tension element (10) definable in different positions is. Blind riveting pliers according to claim 5, characterized in that the tension element (10) one with the intermediate lever (7) interacting teeth (11) having. Blind riveting pliers according to claim 5 or 6, characterized in that that a pawl (14) releasably with the tension element (10) is engaged. Blind riveting pliers according to claim 7, characterized in that that the pawl (14) on the same Surface area (11) of the tension element (10) as the intermediate lever (7) acts. Blind riveting pliers according to one of claims 3 to 8, characterized in that the intermediate lever (7) in the starting position of the first handle lever (3) abuts on an axis (6) which is the fulcrum of the forms the first handle lever (3). Blind riveting pliers according to one of claims 7 to 9, characterized in that an axis (8) which the Pivot point of the intermediate lever (7) on the first Handle lever (3) forms in the starting position the pawl (14) rests. Blind riveting pliers according to claim 10, characterized in that that the pawl (14) around the same The pivot point (6) can be pivoted like the first handle lever (3) is. Blind riveting pliers according to one of claims 1 to 11, characterized in that the first handle lever (3) is designed as a finger lever. Blind riveting pliers according to one of claims 1 to 12, characterized in that the tension element (10) the side opposite the connecting rod gear is. Blind riveting pliers according to one of claims 1 to 13, characterized in that the tension element (10) a Return spring (22) and a jaw spring (23), with both springs on the housing (5) are supported. Blind riveting pliers according to one of claims 1 to 14, characterized in that the tension element (10) has a Has damping ring (24). Blind riveting pliers according to one of claims 1 to 15, characterized in that the housing (5) a has removable collecting container (26).

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