FIELD OF THE INVENTION

The present invention relates to the technical sector of activating devices; in particular, the present invention relates to an activating device for mechanical transmissions, used for example for moving blades and mechanical arms on agricultural and industrial machines.

DESCRIPTION OF THE PRIOR ART

An activating device for mechanical transmissions of known type comprises:

- a body, formed by two metal half-shells; - an activating lever hinged to the body at a rotation axis passing through the body, such as to be rotatable about the rotation axis in two opposite directions; the lever comprises a grip, by which an operator can rotate it about the rotation axis between two end positions; there is, between the two end positions, also an intermediate stop position; - transmission means, connectable to a mechanical transmission (for example a command cable) and connected to the activating lever; the transmission means enable transfer of the motion from the activating lever to the mechanical transmission.

In particular the transmission means consist of: an element connected to the rotation axis of the lever which exhibits a cogged portion; a rack, arranged such as to be coupled to the cogged portion; a piston provided with elastic means, connected to an end of the rack and associable to the mechanical transmission.

The transmission means are arranged between the two half-shells that constitute the body.

When an operator activates the lever, rotating it about the relative rotation axis in a determined direction, the element exhibiting a cogged portion rotates in turn in the same direction, determining the translation of the rack, coupled to the cogged portion.

The rack consequently acts on the piston, which moves the mechanical transmission according to the activating direction of the lever. The device further comprises blocking means of the rotation of the lever, predisposed for safety reasons such that the lever is not accidentally activated in an undesired direction.

The lever rotation blocking means are constituted by: a body, for example having a cylindrical or polygonal shape, connected to the lever at the rotation axis of the lever and accessible from outside the body; a metal bar provided with a recess, externally coupled to the body, such as to be transversally mobile with respect thereto, between two end positions.

In particular, the bar is arranged on the body in such a way that the body is in the recess and an end of the bar projects from the volume of the body, in order to enable the grip and movement thereof by an operator.

The recess of the bar exhibits a profile such that when the bar is moved into each of the two end positions, a portion of the profile of the recess goes to abut against the body.

Further, the lever rotation blocking means comprise a plate arranged on the lever in such a way as to abut against the body; in detail, when the recess of the bar is abutting against the body, the plate abuts a portion of the bar, constraining the movement of the lever in a direction of rotation.

The known-type device however exhibits a drawback.

It can happen that the above-described bar is accidentally impacted by the operator or by objects present in the surrounding environment, since it considerably projects with respect to the outline of the body and is mobile in free translation. The involuntary impact of the bar can therefore cause the translation thereof into an undesirable position: numerous risks for the operator derive from this, as well as for the machine and any other object or person who is in the immediate vicinity. In fact, once the bar has been moved, the activating lever can be involuntarily activated in a non-desired direction, contrary to the direction in which it was previously rotated, with the risk of causing great damage to the machine, as well as constituting a serious danger for the operator.

Further, the lever can remain blocked in an activating direction, and the operator may be no longer able to return the lever into the stationary position, with the high risks attached to this.

SUMMARY OF THE INVENTION

The aim of the present invention is to obviate the above-cited drawback.

This aim is attained by providing an activating device for mechanical transmissions according to claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics of the activating device for mechanical transmissions, provided with the present invention, are set out in the following description, carried out with reference to the accompanying figures, in which: - figure 1 A is a partial front view of a device of the invention;

- figure 1 B is a section of a device according to the invention, in which some parts have been removed better to evidence others;

- figure 2 is a view from below of the device of figure 1 ;

- figure 3 is a section of a device according to the invention, in a different embodiment with respect to the embodiment of figure 1 B, in which some parts have been removed better to evidence others; - figure 4 is a view from below of the device of figure 3. DESCRIPTION OF PREFERRED EMBODIMENTS

With reference to the accompanying figures of the drawings, 1 denotes an activating device for mechanical transmissions, according to the present invention.

The device 1 comprises: a body 2; an activating lever 3 (partially illustrated) hinged to the body 2 at a rotation axis (not illustrated) passing through the body 2, such as to be rotated about the rotation axis once gripped by an operator; transmission means 4, connectable to a mechanical transmission (not illustrated) for activating the mechanical transmission, and connected to the activating lever 3 in such a way as to move the mechanical transmission following a rotation of the activating lever 3 about the rotation axis.

A special characteristic of the device 1 is to comprise rotation-blocking means 5, 6 of the activating lever 3, comprising in turn: a first element 5 provided with a projection 50 and which is coupled to the activating lever 3; and a second element 6 provided with at least a protuberance 60, 61.

The second element 6 is associated to the body 2 so as to be rotatable relative to the said body 2 and is arranged in such a way that, once rotated, the corresponding protuberance 60, 61 is located alongside and in abutment to the projection 50 of the first element 5, such as to block the rotation of the activating lever 3 in at least one rotation direction.

The rotation of the activating lever 3 can be advantageously blocked in at least one direction of rotation by turning the second element 6. This arrangement reduces the risk that the rotation-blocking means 4 of the lever 3 might be moved unintentionally, for example due to an impact, precisely because the second element 6 is movable in rotation, and not in translation. In the prior art, however, this risk was high because the bar of the rotation-blocking means was freely translatably movable and considerably projected from the outline of the body.

With the proposed invention, therefore, the activating lever 3 cannot be rotated in an undesired direction, and therefore the numerous risks for the operator, the machine and the surrounding working environment that exist in the prior art are reduced,.

The activating lever 3 is rotatable along a relative run between two end positions (for example in order to activate a control cable), between which there is an intermediate stop position.

In particular, with reference to the accompanying figures, the second element 6 is L-shaped, having a first arm 63 provided with the at least a protuberance 60, 61 , and a second arm 64.

The second element 6 is associated to the body 2 by the first arm 63 so as to be rotatable about the first arm 63 and so that the second arm 64 can be handled by an operator (see figure 1A).

In particular, the body 2 can afford a slot to allow coupling of the first arm 63 to the body 2 itself.

The L-shape of the second element 6 advantageously enables obtaining an overall dimension of the device 1 that is more limited than that of the devices of known type. In the known devices, in fact, the bar protrudes from the outline of the body so that it can be moved in translation.

In the embodiment illustrated in figures 1 B and 2, the first arm 63 of the second element 6 comprises two protuberances 60, 61 arranged on different planes (for example so as to be offset by 90 degrees) passing through the first arm 63, so that once the second element 6 has been rotated, the corresponding protuberances 60, 61 may each alternatively be flanked to and in abutment to the projection 50 of the first element 5.

In this way, by rotating the second element 6, the rotation of the first element 5 (and therefore the rotation of the activating lever 3) can be blocked alternately in one rotation direction.

Therefore, depending on needs, the rotation of the activating lever 3 in only one rotation direction can be enables, thus preventing it from being accidentally moved in an undesired direction. In the embodiment of figures 3 and 4, the first arm 63 of the second element 6 comprises two protuberances 60, 61 arranged on a same plane passing through the first arm 63, so that once the second element 6 has been rotated, the projection 50 of the first element 5 can be interposed between the two protuberances 60, 6 . This embodiment therefore enables, if necessary, the blocking of the activating lever 3 in the locked position, interposed between the two end positions.

By rotating the second element 6 in a rotation direction, the corresponding protuberances 60, 61 block the rotation of the first element 5, and therefore that of the activating lever 3 to which it is coupled.

By again rotating the second element 6 (for example by 90 degrees) the rotation of the activating lever 3 can be unblocked, which lever 3 can turn in both rotation directions. This arrangement avoids, therefore, that when the activating lever 3 is in the stop position thereof, can be unintentionally moved. Further, according to a variant, not illustrated, the first arm 63 of the second element 6 can comprise four protuberances, of which: a first and a second protuberance are arranged on a same plane passing through the first arm 63 such that once the second element 6 is rotated, the projection 50 of the first element 5 can be interposed between the first and the second protuberance; and a third and a fourth protuberance arranged respectively on a second and a third plane, different to one another and passing through the first arm 63, such that once the second element 6 is rotated, the relative protuberances 60, 61 can each be alternatively flanked to and abutting the projection 50 of the first element 5.

This embodiment advantageously enables, when necessary, both blocking the activating lever 3 in the stop position thereof, and to enable rotation thereof in a single direction, as required. In a different embodiment, not illustrated, two second elements 6 can be provided, one of which, when required, can block the activating lever in its stop position, and the other enables rotation of the lever in a single direction, depending on requirements (similarly to what is described above). At the relative first arm 63, the second element 6 can also exhibit a stabilising element 65, or a projection, so that once the second element 6 has been rotated in a rotation direction, the projection abuts the body 2 , stabilising the position of the second element 6. For this purpose, the body 2 exhibits a step 222 suitable for abuttingly receiving the stabilising element 65 (see figure 1A).

With reference to figures 1 B and 3, the first element 5 has a substantially cylindrical shape and is coupled to the activating lever 3 at the axis of rotation of the activating lever 3. Further, and again with reference to the accompanying figures of the drawings, the body 2 is constituted by two half-shells 21 , 22 exhibiting complementary profiles such as to enable a mutual joint coupling; one of the two half-shells 21, 22 also affords a through-hole (not visible in the figures). In addition, the transmission means 4 are arranged internally of the body 2, between the two half-shells 21 , 22; in particular, the first element 5 is accessible from outside the body 2 through the through-hole, and the second element 6 is associated with the half-shell 21 , 22 having the through-hole (see figure 1A). The jointed coupling of the two half-shells 21 , 22 is advantageous since it prevents possible infiltrations into the body 2, for example in the event of rain.

The device 1 further comprises a plurality of seatings 211 in the half shells 21 , 22 for insertion of fastening screws (not illustrated), with the purpose of optimising the coupling between the two half-shells.

Conversely, in the prior art the two half-shells were fixed together solely via fixing screws, and there was therefore the risk of possible infiltrations between the two half-shells.

The body 2 of the device 1 of the invention can further comprise hooking feet 300 (visible in figure 1A), arranged so as not to protrude laterally from the outline of the body (for example arranged in the lower part of the body 2), so as to enable coupling, for example, to a support of the agricultural or industrial machine for which it is destined. This arrangement is advantageous in that, in the event that a flanked plurality of devices have to be attached to the support, the overall dimensions can be optimised in comparison to the prior art.

In known devices, in fact, these support feet were provided at the sides of the body, so when they when a plurality of devices had to be arranged side by side, the overall total dimension was greater; in other words, more space had to be made available for attaching the devices compared to what is required with the devices of the present invention. With reference to the accompanying figures, the transmission means 4 comprise: a base 7, connected to the activating lever 3, a con rod 8, connected to the base 7; a piston 9, connected to the con rod 8 and associable to a mechanical transmission, elastic means (not illustrated) associated to the piston 9 and mounted on the body of the piston 9. As shown in figures 2 and 3, the base 7 has a first portion 70 arranged at the rotation axis of the activating lever 3 and a second portion 71 which is hinged to the con rod 8, which has two protuberances 72, 73.

Again with reference to the attached figures, the connecting rod 8 has two projections at relative ends thereof, through which it is connected respectively to the base 7 and the piston 9, and a central recess between the two projections.

The piston 9 is arranged in a chamber 11 conformed by the two half- shells 21 , 22 of the body 2, and a control cable for example is associable (not shown). In the illustrated embodiments, moreover, the first element 5 is connected to the base 7, and is fixed thereto at the relative first portion 70.

When an operator moves the activating lever 3 by rotating it about the rotation axis in a determined direction, the base 7 in turn rotates in the same direction; the con rod 8, hinged to the base 7, then translates in the direction in which the activating lever 3 has been rotated. The con rod 8 acts accordingly on the piston 9, which moves the mechanical transmission to which it is associated, depending on the direction in which the activating lever 3 has been rotated.

The elastic means can comprise a spring and ensure the return of the piston 9 towards the stop position of the activating lever 3. When the activating lever 3 is rotated in a rotation direction, in fact, the spring is compressed and abuts against the walls of the chamber 11 in which the piston 9 is arranged; instead, when the activating lever 3 is returned to the stop position, the spring extends and thus facilitates the return of the piston 9 and therefore of the mechanical transmission associated thereto.

When the activating lever 3 is in one of two relative end positions, one of the protuberances 72, 73 of the base 7 either abuts against the projection of the connecting rod 8, or against the body 2, which exhibits an appropriate abutment 20. In this way greater control can be obtained over the movement run of the activating lever 3.

The presence of the con rod 8 is particularly advantageous since it enables a longer run to be obtained in comparison to the prior art, in which a rack was used. The con rod 8, in fact, is able to translate up to being partially located in the chamber 11 in which the piston 9 is arranged.

Furthermore, the use of the con rod 8 avoids the jamming problems which were liable to occur in the prior art and due to the use of a rack coupled to a cogged portion. At the end positions, in fact, the cogged portion transferred stress to the rack not only in the transversal direction, but also in an oblique direction, because of its own rotational movement. The device 1 can further comprise sealing means 10, arranged internally of the chamber 1 and positioned so as to contact the elastic means, in order to prevent exit thereof from the chamber 1 during operation of the device. In particular, according to the preferred embodiment of the invention, the sealing means 10 can be constituted by two C-shaped elements (or by two half-rings), each arranged at an end of the chamber 11.

Each of the C-shaped elements and consists of two parts coupled to one another, uncouplable in case of need. In fact, in case of damage or breakage of the sealing means 10, it is sufficient to decouple the two parts that constitute the C-shaped element, thus uncoupling the element from the elastic means, and carry out the replacement. The sealing means 10 can be made of plastic material (e.g. nylon). The devices of known type, however, in replacement of the two C- elements, consisting of two sealing rings. Therefore, if as a result of the stresses incurred during operation of the device such rings were to be damaged, it would be necessary to de-assemble the majority of the device in order to be able to replace them. The device 1 according to the invention further includes the possibility of adjusting the maximum run of the activating lever 3, in each direction according to needs.

To this end one of the half-shells 21 , 22 provides, in the upper portion thereof, two threaded seatings 200 arranged such that the first element 5 is interposed between the seatings 200 (see figures 1 , 3).

The device 1 further comprises adjustment means (for example screws, not shown) that can be inserted into each threaded seating 200 in depth in the body 2 depending on how much it is required to limit the run of the activating lever 3 in each rotation direction.

In this way, in fact, once the adjustment means have been appropriately inserted and the activating lever 3 moved, the first element 5 (and therefore the lever 3) can rotate until one of the projections 72, 73 of the base 7 will be abutting against the adjustment means.

In particular, screws known as "self-blocking" can be used, that once inserted in the seating 200 do not protrude from the body, including as a result of stresses such as vibration or shock. These screws are, however, easily extractable from the seat when necessary.

The above detail is advantageous from the practical point of view in comparison with the devices of known type, which included, in the upper portion of the half shells, seatings for receiving the fastening screw and relative nuts. When it was necessary to adjust the maximum run of the activating lever, each nut had to be extracted from the device and the screw had to be adjusted on the locknut externally of the device; and only then were screw and nut inserted in the seating.

The prior art solution is certainly more expensive in terms of time taken for the adjustment of the screws with respect to the proposed device, as it makes it necessary to extract the nut and screw from the device whenever the maximum run of the activating lever is to be modified.

Additionally, this operation, necessary in prior art, proves complex, since the nut and the screw have to be operated on using various instruments; further, it does not ensure that the adjustment of the screw takes place in the desired way, as it is fastened to the locknut externally of the device. The proposed solution therefore offers a considerable advantage from the practical point of view and enables a significant reduction in the time needed for adjusting the maximum stroke of the activating lever 3.

The foregoing is understood to be purely by way of non-limiting illustration, and therefore any possible constructive variations are considered to fall within the scope of the following claims.