EP2165766A1 - Shredder - Google Patents

Abstract

The shredder has a shredder unit (1) and a supply pipe (2) for the supply of goods to the shredder unit. A switching element (5) is arranged at a fixing element (3) i.e. fixing screw (9). The switching element displaces a safety switch (4) i.e. ignition interruption switch, in the operating condition, by activation of a user, in a locked condition of the fixing element. The switching element displaces the switch in the resting condition and not in the operating condition, in a released condition of the fixing element. An electrical or combustion motor drives a shredder or cutting tool.

Description

In garden and green areas shredders are used for shredding plant clippings such as branches or the like. In a previously known design, such shredders have a lower shredding unit with a feed tube arranged above it for the supply of the shredded material to be shredded. About the feed tube, the clippings to the shredding unit with a chopper or Schnitzelmesser. There it is, for example, comminuted to kompostierfähigem material or mulch.

For maintenance and cleaning of the crushing unit, the feed tube is releasably secured so that it is adjustable between its above-described operating position and an example folded down rest position. For this purpose, a releasable fastening element is provided, for example in the form of a thumbscrew, which can be tightened or loosened manually. In the released state of the fastener, the feed tube can be folded into the rest position, whereby the cutting blades of the crushing unit can be reached.

In the unfolded rest position of the feed pipe, it must be ensured that the shredding unit with its rotating blades can not be put into operation. For this purpose, various safety precautions are known in the prior art. For example, the DE 39 29 260 C1 a fastener for the feed tube in the form of a screw with a threaded shaft, wherein the threaded shaft cooperates with a push-button. When tightening the fastener presses its threaded shank against the push-button, whereby the chopper is put into the operating state. The shredding unit can be switched on. When releasing the fastener of the key switch is released, the crushing unit can not be put into operation.

A disadvantage of the arrangement described above, that such key switch in commercial design have a short switching stroke, which is low compared to the depth of the fastening screw. The arrangement is therefore prone to adjustment errors. Depending on the mutual orientation of the key switch relative to the threaded shaft of the push-button switch may be either in the operating state, although the threaded shaft is not fully tightened, or remain in the fully de-energized screw in the off state. Incidentally, the switching state on the part of the user is not recognizable, which may make troubleshooting more difficult.

The invention has the object of developing a generic shredder such that its reliability is improved.

This object is achieved by a shredder with the features of claim 1.

For this purpose, a chopper is proposed in which a switching element is arranged on the fastening element for the feed tube, which puts the safety switch in the operating state in the closed state of the fastener by active operation on the part of the user, and which leaves the safety switch in the off position in the released state of the fastener and can not put into operation. Accordingly, in the dissolved state, the shredding unit is disabled. The open cutterbar can be easily accessed. For subsequent commissioning, the feed tube is first adjusted to its operating position and fixed with the fastener. However, the shredding unit initially remains out of operation. Rather, then an active actuation of the switching element on the fastener is required by the user, which acts on the safety switch and sets the device in operational readiness. This ensures that the crushing unit does not start accidentally before the fastener is fully tightened.

The assembly of fastener and switching element may have various suitable designs. In a preferred embodiment, the fastening element is rotatable about a longitudinal axis and in this case has a rotating opening direction and a rotating closing direction. This can for example be the case with a bayonet closure. In particular the fastening element is designed as a fastening screw. The switching element is arranged as a coaxial with the longitudinal axis of the fastener arranged, operable in the direction of this longitudinal axis push button with a coaxially guided through the fastener pressure pin, wherein the pressure pin is provided for actuating the safety switch. The coaxial design saves space, the radial adjustment of the pressure pin relative to the safety switch is maintained regardless of the angular position of the fastener.

In a preferred embodiment, the fastener comprises a rotary handle and a locking bolt, wherein the rotary handle against the locking bolt against a torsion spring is limited rotatable, wherein the push button against the biasing force of a spring against the rotary handle axially pressed, and wherein between the locking bolt and the push button a Catch device is arranged, which holds the push button in the depressed operating state and releases upon rotation of the rotary handle relative to the locking bolt.

If the user wants to fold down the feed tube, he must turn the rotary handle in the opening direction to open the fastener. As a result, however, initially no release of the locking bolt is generated. Rather, there is a limited relative rotation of the rotary handle relative to the locking bolt against the biasing force of the torsion spring. The push button, which holds the safety switch in operating position in the pressed-in operating state as part of the switching element, is in this twisted state of the locking device released and snapped by the biasing force of the spring in its rest position. In this case, the switching element with its pressure pin no longer acts on the safety switch. Only by relative rotation of the rotary handle relative to the locking bolt, the shredding unit is thereby taken out of service, even before the locking pin is actually released. Only then and by further rotation of the rotary handle in the opening direction takes this with the locking bolt, whereby the feed tube can be solved and opened.

In a suitable embodiment, the arrangement works in the same way in the same direction in the opposite direction when tightening the fastener. Normally, the fastener is tightened in the closing direction and only then pushed the push button to take the shredding unit in operation can. Although it is possible to press the push button even with a dissolved fastener, but this can not put the safety switch in the operating condition. If it is attempted to screw in the fastener with depressed twist grip in the closing direction, a rotational resistance sets in the thread, as a result, the rotary handle against the locking bolt twisted limited. Again, the locking device releases the push button, so that it is pressed by the spring acting thereon in its rest position and can not prematurely put the safety switch in the operating state. The latter is possible only when the fastener is completely tightened and applied by the user no more torque on the rotary handle becomes. Only then the user actively presses the push button, whereby the shredding unit can be put into operation. The operational safety of the device is significantly increased with simple and fault-tolerant handling.

In a preferred embodiment, the latching device has a latching plate with at least one opening, preferably with two diametrically opposite openings for receiving a latching hook of the push button, wherein the latching plate is rotatably connected to the locking bolt, wherein the opening of the latching plate has a radially protruding latching tab, which is engaged behind in the untwisted position of the rotary handle by the latching hook, and wherein the opening in the direction of rotation of the fastening element has an adjoining the latching tab clearance for releasing the latching hook.

The non-rotatably interconnected assembly of locking plate and locking bolt is centered on the torsion spring against the rotary handle in the absence of external torque in a particular central rest position. If the push button is pressed actively, the one or more locking hooks can rebound elastically, slide past the associated locking tab and finally snap behind the locking tab, wherein the push button is held in its depressed position. Also, the push button and the rotary handle are rotatably connected. When applying a torque on the rotary handle the locking hooks are rotated relative to the locking plate with the locking tabs until the latching hooks enter the free space. Here they are no longer held by the snap tabs, so that the push button is reliably pressed by the connected spring in its rest position. In a structurally simple design high reliability is given with low susceptibility.

The free space in the rotating opening direction and / or in the rotating closing direction preferably adjoins the latching tab. The desired unlocking takes place in each case when the user manually applies a torque in the respective direction of rotation on the rotary handle. An unlocking is thus brought about both when opening and when closing the fastener.

In an advantageous development, the latching plate on at least one radially outwardly projecting stop lug, which lies in the direction of rotation with play between two stop ribs of the rotary handle. The game in the direction of rotation allows the required relative rotation between the rotary handle and locking plate to cause the lock and, if necessary, the automatic release. On the other hand, it is ensured with structurally simple means that the rotary handle after passing through the rotational clearance entrains the detent plate and the locking bolt connected thereto. In this case, high torques can be transmitted by design, so that the fastener can be tightened or released with maximum manual force.

The torsion spring between the rotary handle and the locking bolt is advantageously designed as a bow spring with two legs, wherein the two legs a retaining lug of the locking plate engage around, and wherein ends of the legs against ribs, in particular against the stop ribs of the rotary handle, are supported. In particular symmetrical configuration, the latching plate is thereby centered in the resting state relative to the rotary handle in a central position, in which the push button can be pressed and latched. Starting from this central position, the bow spring allows a relative rotation in both directions of rotation to release the push button. The arrangement is reliable and easy and inexpensive.

Preferably, the safety switch has a switch button, the actuation direction is transverse to an actuating direction of the switching element. As a result, the stroke of the manually operated switching element and the stroke of the switch button can be decoupled from the safety switch in a manner that the safety switch does not act as an undesirable stop for the switch knob. Even with a very small switching stroke of the safety switch, which may be formed, for example, as a microswitch, the manually operated switching element can be moved in an ergonomic, easy to feel manner with a much larger stroke. The user receives a tactile and visually easily recognizable feedback on the switching state of the switching element. The arrangement is in particular insensitive to axial position tolerances between the fastener and the safety switch.

In a preferred embodiment, a particular elastically resilient sliding tab is arranged between the switch button of the safety switch and the manually operable switching element. By means of this sliding tab, the axial lifting movement of the push button and the pressure pin connected thereto is converted into the transverse thereto actuating direction of the safety switch. The pressure pin slides on the sliding lug without being able to get caught by the switch button of the safety switch.

Fig. 1

in einer perspektivischen Darstellung einen erfindungsgemäß ausgeführten Häcksler mit einer Zerkleinerungseinheit, mit einem gegenüber der Zerkleinerungseinheit aufklappbaren Zuführrohr und mit einem lösbaren Befestigungselement für das Zuführrohr;

Fig. 2

in einer Seitenansicht eine Ausschnittsdarstellung der Anordnung nach Fig. 1 bei gelöstem Befestigungs-element und teilweise aufgeklapptem Zuführrohr;

Fig. 3

die Anordnung nach Fig. 2 in weiter vergrößerter, geschnittener Detaildarstellung in Bereich des Befestigungselementes und eines davon betätigten Sicher heitsschalters;

Fig. 4

eine perspektivische Ansicht des erfindungsgemäßen, als Befestigungsschraube ausgeführten Befestigungs-elementes nach Fig. 3 mit einem Druckknopf in seiner Ruheposition;

Fig. 5

die Befestigungsschraube nach Fig. 4 mit eingedrück-tem Druckknopf im Zusammenspiel mit dem in den Betriebszustand gesetzten Sicherheitsschalter;

Fig. 6

eine Explosionsdarstellung der Befestigungsschraube nach den Fig. 4 und 5 mit einer Übersicht ihrer Einzelteile;

Fig. 7

in einer Längsschnittdarstellung die Befestigungsschraube nach Fig. 4 mit dem durch eine Druckfeder herausgedrückten Druckknopf;

Fig. 8

die Anordnung nach Fig. 7 mit eingedrücktem, durch Rasthaken an einem Rastblech gehaltenem Druckknopf;

Fig. 9

eine perspektivische Unteransicht der Befestigungs-schraube mit Einzelheiten zur selbsttätigen Entriegelung des Druckknopfes.

An embodiment of the invention is described below with reference to the drawing. Show it:

Fig. 1

in a perspective view of a chopper designed according to the invention with a shredding unit, with a relative to the shredding unit hinged feed tube and with a releasable fastener for the feed tube;

Fig. 2

in a side view a detail of the arrangement according to Fig. 1 with dissolved fastening element and partially unfolded feed tube;

Fig. 3

the arrangement after Fig. 2 in a further enlarged, cut detail in the region of the fastener and one of them actuated safety switch;

Fig. 4

a perspective view of the invention, designed as a fastening screw fastener after Fig. 3 with a push button in its rest position;

Fig. 5

after the fixing screw Fig. 4 with pressed-in push-button in conjunction with the safety switch set to the operating state;

Fig. 6

an exploded view of the fastening screw after the 4 and 5 with an overview of their items;

Fig. 7

in a longitudinal sectional view of the fastening screw to Fig. 4 with the pushed out by a compression spring push button;

Fig. 8

the arrangement after Fig. 7 with pressed-in, held by latching hook on a latch plate push-button;

Fig. 9

a bottom perspective view of the mounting screw with details for the automatic release of the push button.

Fig. 1 shows a perspective view of a chopper designed according to the invention with a crushing unit 1, in which an electric motor, not shown, drives a chopper or Schnitzelwerk also not shown with knife blades. Instead of an electric motor and an internal combustion engine can be provided. The shredder with the shredding unit 1 is set up in the operating position, wherein above the shredding unit 1, a feed pipe 2 for the supply of material to be shredded to the shredding unit 1 is arranged. The feed tube 2 has a top insertion opening 34 through which the material to be crushed is introduced. The shredder is parked with wheels 32 and supports 33 on the ground, but can also be moved by means of wheels 32 to another site. In the operating position shown here, the feed tube 2 is approximately vertically above on the comminution unit 1 and is fixed relative to this by means of a fastening element 3.

Fig. 2 shows a section of the arrangement in a side view Fig. 1 in the region of the fastening element 3. It can be seen that the feed tube 2 is fastened on a lateral side by means of a hinge 36 on the comminution unit 1. Opposite to the hinge 36, the fastening element 3 is arranged, which is here dissolved, so that the feed tube 2 can be pivoted relative to the shredding unit 1 according to a double arrow 37 about the axis of the hinge 36. In the swung-open rest position of the feed tube 2 shown here, an opening 38 of the comminution unit 1 is released, through which the user has free access to the chopping unit (not shown) within the comminution unit 1. This maintenance or cleaning work can be done by z. B. jammed shredded material is removed through the opening 38. Starting from the rest position shown here, the feed tube 2 according to the double arrow 37 in the operating position Fig. 1 be pivoted back, in which case the feed tube 2 is fixed by means of the fastener 3 to the crushing unit 1. For this purpose, in the illustrated embodiment, a nut 35 on the crushing unit 1 provided, in which the fastener 3 is screwed and thereby the feed tube in the operating position Fig. 1 holds.

Fig. 3 shows the arrangement after Fig. 2 The fastening element 3 is formed here as a fastening screw 9, which is held on an extension of the feed tube 2 and in the not shown here nut 35 of the crushing unit 1 (Fig. Fig. 2 ) can be screwed. Instead of training as a fastening screw 9, a training as a bayonet lock or the like may be advantageous.

The fastening screw 9 is rotatable about a longitudinal axis 6 and comprises a rotary handle 12 for manual operation by the user, wherein by means of the rotary handle 12 a coaxial with the rotary handle 12 arranged locking bolt 13 can be set in rotation. This allows an external thread 39 ( Fig. 6 ) of the locking bolt 13 in the nut 35 ( Fig. 2 ) of the shredding unit 1 are screwed, resulting in a rotating opening direction 7 and an opposite rotating closing direction 8. By rotation of the rotary handle 12 in the closing direction 8 of the locking bolt 13 in the nut 35 ( Fig. 2 ) and tightened, whereby the feed tube 2 relative to the comminution unit 1 in the operating position after Fig. 1 is held. A release takes place in the opposite direction of rotation opening. 7

The shredder has a safety switch 4 attached to the shredding unit 1, which removes a chopping unit 48 driving electric motor 47 of the shredding unit 1 in dissolved fastener 3, but allows its operation with the fastener 3 tightened. To illustrate the principle, a simplified electrical circuit is shown, according to which the electric motor 47 is connected to a voltage source 49. The safety switch 4 is connected in series with an on / off switch 46. Instead of the on / off switch 46, a switch can be provided with reversal of direction. The safety switch 4 is provided with a switch button 28 which closes the circuit in the depressed operating state. In this case, the comminuting unit 1 or the electric motor 47 can be put into operation with the chopper unit 48 by actuation of the on / off switch 46. Without external load of the switch knob 28 automatically springs in its rest state and interrupts the circuit. A commissioning of the crushing unit 1 and the electric motor 47 with the chopper 48 is not possible despite actuation of the on / off switch 46. In practice, deviating electrical circuits are used, but operate on the principle above. Comparable circuits can also be used in conjunction with an internal combustion engine as a drive motor for the chopper 48, wherein the safety switch 4 can be configured as a Zündunterbrechungsschalter.

For actuating the safety switch 4, a switching element 5 is arranged on the fastening element 3, which in the closed state of the fastening element 3 by active Operation by the user the safety switch 4 is put into the operating state, and which in the dissolved state of the fastener 3 in the manner described in more detail below leaves the safety switch 4 in the off position and can not put into operation. In the illustrated embodiment, the switching element 5 is arranged as coaxial with the longitudinal axis 6 of the fastening screw 9, actuated in the direction of the longitudinal axis 6 push button 10 and comprises a coaxially through the hollow locking pin 3 of the fastening screw 9 guided pressure pin 11. The push button 10 is including its pressure pin eleventh coaxial to the longitudinal axis 6 in an indicated by a double arrow actuating direction 30 can be pressed.

In the depressed state of the push button 10 shown here, the pressure pin 11 acts on the switch knob 28 of the safety switch 4. Its indicated by a double arrow operating direction 29 is transverse to the direction of actuation 30 of the switching element 5. Between the pressure pin 11 of the switching element 5 and the switch knob 28 of the safety switch 4th is an elastically resilient sliding tab 31 is arranged, on which the pressure pin 11 slides on impressions, and converts the actuation direction 30 thereof in the transverse thereto actuating direction 29 of the switch knob 28. Instead of an elastically resilient sliding strap can also be a pivotally suspended sliding tab 31 may be appropriate. In the depressed state of the push button 10 and the switch knob 28 of the safety switch 4 is pressed, in which case the safety switch 4 and the crushing unit total in the operating state are. This means that the comminution unit 1 or the electric motor 47 can be put into operation with the chopper unit 48 by actuation of the on / off switch 46. When axially retracted position of the pressure pin 11, the slide tab 31 and the switch knob 28 feathered automatically, in which case the crushing unit 1 is taken out of service and can not be turned on.

Details of this are in the 4 and 5 shown: In the in Fig. 4 illustrated rest position, the knob 10 projects axially beyond the upper end face of the rotary handle 12. The pressure pin 11 ( Fig. 3 ) is retracted into the interior of the locking bolt 13, so that the switching knob 28 of the safety switch 4 does not interact with it and is pressed outwardly due to its spring bias. Here, the shredder or its shredding unit 1 ( Fig. 1 ) shut off. In the depressed state of the push button 10 after Fig. 5 the pressure pin 11 protrudes axially out of the free end of the locking bolt 13 and presses over the sliding tab 31 (not shown here) (FIG. Fig. 3 ) the switch button 28, so that the safety switch 4 is in the operating state and the chopper or the shredding unit 1 ( Fig. 1 ) can be put into operation ..

Fig. 6 shows in an exploded view, the items of the mounting screw 9. The substantially cylindrically shaped push button 10 is provided on its underside with two radially opposite, axially downwardly projecting latching hooks 19. Coaxially and centrally therebetween is the integrally formed pressure pin 11. On the pressure pin 11 is a spring 15 threaded, which is designed in the embodiment shown as a helical compression spring, and which is supported on one side against the head of the push button 10 and on the other side against a threaded also on the pressure pin 11 pressure ring 44.

The rotary handle 12 is provided on its peripheral side with projections for a better grip and has an opening in the middle with two diametrically opposite, axially parallel projections 43. In the assembled state, the projections 43 engage in the two grooves 42 of the push button 10, as in the 4 and 5 is recognizable. As a result, a rotationally fixed connection between the rotary handle 12 and the push button 10 is given, but allows an axial relative displacement of the push button 10 relative to the rotary handle 12.

The fastening screw 9 further comprises the locking bolt 13, which carries at its free end an external thread 39, and which is provided at its opposite end with two lateral, opposite flats 40. In addition, a locking device 16 is provided between the locking pin 13 and the push button 10, which is formed in the embodiment shown as a latching plate 17, and which is provided with a central opening 41. The contour of the opening 41 corresponds to that of the locking bolt 13 in the region of its flats 40. In the mounted state, the locking bolt 13 engages through the opening 41 of the locking plate 17, wherein the flats 40 and the corresponding Form of the opening 41 is a rotationally fixed connection between the two components.

Radially outside the central opening 41 at least one opening 18 for receiving at least one latching hook 19 of the push button 10 is provided in the latching plate 17. In the illustrated embodiment, the latching plate 17 is provided with two diametrically opposite openings 18 for each one of the two latching hooks 19. In each case from the outer edge of the opening 18 each protrudes a locking tab 20 radially inwardly, which can be engaged behind in the mounted state of the latching hooks 19.

Another part of the fastening screw 9 is a torsion spring 14, which is formed in the illustrated embodiment as a bow spring 24 with two approximately U-shaped bent legs 25. The two legs 25 have ends 27 whose function will be described in more detail below. The latching plate 17 carries on its radial outer side a retaining lug 26, which is encompassed by the two legs 25 of the bow spring 24 in the assembled state. In addition, the locking plate 17 is still provided on its radial outer side with two diametrically opposed stop lugs 22.

Fig. 7 shows in a longitudinal sectional view of the fastening screw 9 after Fig. 6 in the assembled state. The push button 10 is in its rest position shown axially upwards by a projection amount a on the outer contour of the end face of the rotary handle 12 forth. As a result, the user is signaled to be tactile and visually recognizable that the push button 10 is in the rest position or inoperative position.

The visual recognition can be increased by a corresponding color of the push button 10, for example in signal color. In the position shown, the push button 10 is held by the biasing force of the spring 15 by the spring 15 is supported up against the push button 10 and in the opposite direction downward by means of the intermediate pressure ring 44 against the rotary handle 12. The push button 10 is held by means of its latching hooks 19 at edges 45 of the rotary handle 12, without the latching hooks 19 are in engagement with the latching plate 17. The integrally formed on the push button 10 pressure pin 11 is axially withdrawn into the hollow locking pin 13 and does not stand or only slightly beyond the free end, so that it can not act on the safety switch 4. The switch button 28 of the safety switch 4 protrudes outward. Here, the comminution unit 1 ( Fig. 1 ) of the chopper off.

Fig. 8 shows the arrangement after Fig. 7 Here, the locking hooks 19 are lifted from the edges 45 of the rotary handle 12, elastically resiliently pushed through the openings 18 of the locking plate 17 and hooked behind the locking tabs 20. As a result, the push button 10 against the biasing force of the spring 15 in the depressed operating condition after Fig. 8 held. The upper outer contour of the push button 10 is flush with the upper outer contour of the rotary handle 12. The depressed together with the push button 10 push pin 11 protrudes down over the free end of the locking pin 13 and pushes the button 28 of Safety switch 4 on the not shown here, but in Fig. 3 shown Gleitlasche 31 a. In this case, the safety switch 4 and also the comminution unit 1 of the chopper ( Fig. 1 ) is put in the ready state.

With additional and simultaneous reference to the Fig. 4, 5 and 7 can still be seen that the push button 10, starting from its rest position after the Fig. 4 and 7 as shown Fig. 5 in addition to the supernatant dimension a can be pressed by a Eindrückweg in the rotary handle 12 to ensure a secure engagement of the latching hooks 19. The transverse thereto actuating direction 29 of the safety switch 4 ( Fig. 3 This produces no obstruction of the axial movement of the push button 10 in its operating direction 30. After engagement of the latching hooks 19 and releasing the push button 10 this springs from its deep depressed position Fig. 5 in its operating position Fig. 8 ,

Fig. 9 shows in perspective bottom view the mounted fastening screw 9 after the Fig. 6 to 8 , wherein the push button 10 as shown by Fig. 8 pressed and hooked by means of its latching hooks 19 on the radially inwardly projecting locking tabs 20 of the locking plate 17.

The bell-shaped rotary handle 12 is provided on its inner side with radially inwardly projecting from the peripheral wall stop ribs 23. The trained as a bow spring 24 torsion spring 14 ( Fig. 6 ) engages with its two legs 25, the retaining lug 26 of the locking plate 17, wherein the ends of the 27th ( Fig. 6 ) support the legs 25 against two of the stop ribs 23 in the circumferential direction. But it can also be useful other ribs or support points for the bow spring 24. The geometry of the bow spring 24 is adjusted such that in the unloaded state, the stop lugs 22 in the circumferential direction between each two stop ribs 23 with game in relation to the circumferential direction in each case between two abutment ribs arranged in pairs 23 diametrically opposite stop lugs 22 of the locking plate 17 centered in the direction of rotation. It is therefore possible that the rotatably interconnected assembly of rotary handle 12 and push button 10 against the also rotatably interconnected assembly of locking bolt 13 and locking plate 17 in both directions, ie in the opening direction 7 and in the closing direction 8, against the force of the bow spring 24 can be twisted. However, this mutual relative rotatability is limited by the interaction of the stop lugs 22 with the stop ribs 23, wherein after overcoming the rotational play the stop lugs 22 come to rest depending on the direction of rotation to the associated stop rib 23.

Furthermore, the illustration is after Fig. 9 can still be seen that the openings 18 in the locking plate 17 are formed with their approximately U-shaped contour such that free spaces 21 of the openings 18 in the direction of rotation of the radially inwardly projecting locking tabs 20 follow. It may be expedient that the free spaces 21 are arranged only in the rotating opening direction 7 or in the rotating closing direction 8. In the embodiment shown are related on the circumferential direction on both sides of the locking tabs 20, that is, in the rotating opening direction 7 and in the rotating closing direction 8, a free space 21. This causes that in a relative rotation of the assembly of rotary handle 12 and push button 10 relative to the assembly of locking bolt 13 and locking plate 17 in the rotating opening direction 7 or in the rotating closing direction 8, the latching hooks 19 are no longer in overlap with the latching tabs 20, but are guided into the respective free space 21. The locking connection of the depressed push button 10 with the latching plate 17 is released, so that the push button 10 including its pressure pin 11 by the biasing force of the spring 15 from the operating position to Fig. 8 in the resting position Fig. 7 is pressed or raised.

In practical operation, the arrangement works as follows:

Starting from the operating position to Fig. 1 with push-button 10 ( Fig. 3, 5 and 8th ), the user can if necessary solve the fastening screw 9 by turning the rotary handle 12 in the rotating opening direction 7. With simultaneous reference to the Fig. 3 to 9 It follows that the tightened locking bolt 13 opposes this rotational movement a rotational resistance. The rotary handle 12 is rotated relative to the locking pin 13 in the rotating opening direction 7, as a result, the locking of the depressed push button 10 is released with the locking plate 17, and as a result, the push button 10 pops out of its operating position in the rest position, even before the locking bolt 13 is only partially solved. The shredder is already taken out of service. Only by further rotation of the rotary handle 12 advised its stop ribs 23 in abutment against the stop lugs 22 of the locking plate 17. The locking pin 13 is taken by the rotary handle 12 positively in the rotating opening direction 7 and can be completely solved. The feed tube 2 of the chopper can from its operating position Fig. 1 in the resting position Fig. 2 be moved or pivoted without the crushing unit 1 can start.

In the reverse direction of rotation, ie in the rotating closing direction 8, the arrangement operates in an analogous manner: By turning the rotary handle 12 in the rotating closing direction 8, the locking bolt 13 in the nut 35 (FIG. Fig. 2 ) are screwed. Once set during tightening a certain rotational resistance, the rotational play between the locking plate 17 and the rotary handle 12 is overcome against the biasing force of the bow spring 24 until the stop lugs 22 are pressed against the stop ribs 23. The result is a positive entrainment of the locking bolt 13 with the rotary handle 12 in the rotating closing direction 8, whereby the fastening screw 9 and the locking pin 13 can be completely tightened. However, if the push button 10 has been pressed and latched even before tightening the fastening screw 9, this locking is canceled by the relative rotation of the rotary handle 12 relative to the latching plate 17 in the rotating closing direction 8 in the manner described above. In the not yet completely tightened, dissolved or at least partially dissolved position of the fastening screw 9, it is therefore not possible to put the safety switch 4 by means of the switching element 5 in operational readiness. Rather, the safety switch 4 is left in the deactivated rest position.

A permanent locking is possible only when the fastening screw 9 tightened and then the knob 12 was released. Here, the bow spring 24 centers the rotary handle 12 in the direction of rotation such that the latching hooks 19 are in register with the latching tabs 20, so that the push button 10 can be pressed and latched. To be able to take the chopper back into operation after loosening the mounting screw 9, the user is an active operation, namely an active pressing the push button 10, required, whereby the safety switch 4 is placed in the operating state. An active unlocking of the push button 10 is not required, since this is done automatically by rotation of the rotary handle 12 in any direction. In addition, the arrangement prevents the safety switch 4 can be put in the operating state in the released state of the fastening screw 9.

Claims (10)

Chopper comprising a shredding unit (1) and a feed pipe (2) for supplying material to be comminuted to the shredding unit (1), the position of the feed pipe (2) being adjustable between an operating position and a rest position, the feed pipe (2) being adjustable in the operating position with a releasable fastening element (3) is fixed to the shredding unit (1), and wherein a safety switch (4) is provided which takes the shredder with dissolved fastener (3) out of operation,
characterized in that on the fastening element (3) a switching element (5) is arranged, which in the closed state of the fastening element (3) by active actuation by the user the safety switch (4) in the operating condition, and which in the dissolved state of the fastener ( 3) leaves the safety switch (4) in the off position and can not put into operation. Chopper according to claim 1,
characterized in that the fastening element (3) about a longitudinal axis (6) is rotatable and thereby a rotating Opening direction (7) and a rotating closing direction (8), wherein the fastening element (3) in particular as a fastening screw (9) is formed, wherein the switching element (5) arranged coaxially with the longitudinal axis (6), in the direction of the longitudinal axis (6) actuable push button (10) is formed with a coaxially through the fastener (3) guided through pressure pin (11), and wherein the pressure pin (11) for actuating the safety switch (4) is provided. Chopper according to claim 2,
characterized in that the fastening element (3) comprises a rotary handle (12) and a locking bolt (13), wherein the rotary handle (12) relative to the locking bolt (13) against a torsion spring (14) is limited rotatable, wherein the push button (10) against the biasing force of a spring (15) relative to the rotary handle (12) is axially pressed, and wherein between the locking bolt (13) and the push button (10) a latching device (16) is arranged, which holds the push button (10) in the depressed operating condition and upon rotation of the rotary handle (12) relative to the locking pin (13) releases. Chopper according to claim 3,
characterized in that the latching device (16) has a latching plate (17) with at least one opening (18), preferably with two diametrically opposed openings (18) for receiving a latching hook (19) of the push button (10), wherein the latching plate (17) rotatable with the locking bolt (13) is connected, wherein the opening (18) of the latching plate (17) has a radially protruding latching tab (20) which is engaged in the untwisted position of the rotary handle (12) by the latching hook (19), and wherein the opening ( 18) in the direction of rotation of the fastening element (3) has a free space (21) adjoining the latching lug (20) for releasing the latching hook (19). Chopper according to claim 4,
characterized in that the free space (21) in the rotating opening direction (7) adjoins the locking tab (20). Chopper according to claim 4 or 5,
characterized in that the free space (21) in the rotating closing direction (8) adjoins the locking tab (20). Chopper according to one of claims 4 to 6,
characterized in that the latching plate (17) has at least one radially outwardly projecting stop lug (22) which lies in the direction of rotation with play between two stop ribs (23) of the rotary handle (12). Chopper according to one of claims 4 to 7,
characterized in that the torsion spring (14) as a bow spring (24) with two legs (25) is formed, wherein the two legs (25) engage around a retaining lug (26) of the locking plate (17), and wherein ends (27) of the legs (25) against ribs, in particular against the stop ribs (23) of the rotary handle (12) are supported. Chopper according to one of claims 1 to 8,
characterized in that the safety switch (4) has a switching knob (28), the actuating direction (29) transverse to an actuating direction (30) of the switching element (5). Chopper according to claim 9,
characterized in that between the switching knob (28) of the safety switch (4) and the switching element (5) is arranged in particular a resiliently resilient sliding tongue (31).

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