FR2796805A3 - MULTIFUNCTIONAL DEVICE FOR SAVING THE OPERATION OF PORTABLE PRUNER-TYPE ELECTRICAL APPARATUSES AND THE OPERATOR WHEN PRUNING - Google Patents

Abstract

Multifunctional device for safeguarding the action particularly of portable electric pruning devices and of the pruning operator, of the type comprising an electric motor, rotating with a toothed wheel (7) meshed by the pinion, pruning blades (1, 2), each movable relative to the other being joined at the ends to means (3, 4) which, by constituting the device for converting the movement, cooperate with said transmission group, said blades (1, 2), in being also electrically isolated from the motor, characterized by the fact that a body (8), connecting to the size blades (1, 2) is relatively integral with the toothed wheel (7), with drive means obtained in correspondence of at least one of the faces turned towards them, said means comprising at least one damping means (10).

Description

The present invention relates to a multifunction device for

  to safeguard the action, particularly of portable electric joker devices and of the operator

to the size.

  The innovation finds a particular application even if not exclusive in the field of the production of portable and electric devices, intended for the regulation

hedges.

STATE OF THE ART

  Among the common gardening devices, the pruner is of particular importance. Born to facilitate manual work, regulation and topping, made with traditional secateurs, the pruner, is today an essential, handy and extremely useful device. Said apparatus, essentially, is composed of a size bar supported cantilevered by a shell, inside of which there is the relative motor unit, and which, since it is provided with double handle, can to be moved by

  the operator by touching the hedge to trim the shrubs that exceed the desired shape.

  The cutting organ is essentially the bar which consists of two superimposed blades, intended to move reciprocally and longitudinally, which by

  following the interaction of the respective teeth, perform the pruning action.

  Electric pruners, or of the type supplied from the network, considered the predictable convenience have become more and more widespread. Essentially, they provide for a power unit whose shaft, with the cooperation of eccentric components, imposes, as previously observed, a rectilinear movement alternated with said

size blades.

  These devices, even if designed to withstand heavy workloads, are today quite delicate under certain conditions, especially with regard to the transmission member, since, as everyone knows, he may be interested in even considerable stresses that can damage it irreparably. These conditions, which cause the immediate blocking of the boards, are mainly due to the interception of a net or of the metallic wire, normally used for the fence or the support of Pag. The disadvantages described above have been easily resolved, for example by German patent 2,340,888 (Black and Decker), which essentially describes a friction system, interposed between the blades and the power unit. This technique makes it possible, in a condition of blocked blades, to make the transmission shaft absolutely independent, by safeguarding the transmission members and the engine itself. Similar proposals, but which from a conceptual point of view differ for the friction system adopted, also come from other German patents, among

  which we cite as reference, n. 3,001,923 (Licentia), n. 3,310,639 (Schrock), n.

  3,128,282 (Licentia), as well as n. 3,343,772 (Freund).

  Despite this, the drawbacks of the known solutions do not stop at the aspects noted above. More particularly, they can also relate to the power supply which being of the mains voltage type, can be the source of a series of drawbacks, especially accidents for the operator. Among them we can cite the fact that there is the objective possibility that the electric current arrives at the metal blades of size, by jeopardizing the safety of the operator. The circumstance is not uncommon and can be established due to a short circuit of the motor, or intrinsic faults of the motor itself. A first solution to this problem was offered by the American patent n. 3,625,292 (Lay). It consists in providing a cutting device or tracer, which comprises a movable part, an electric motor placed on the movable part and a transmission shaft, an electrical insulation element mounted on the aforementioned transmission shaft, o the element insulation in question has at least two opposite sides which define a cavity housed between a blade mounted on one side of the element

  insulation by distant fixing means.

  The applicant also heard of the problem of insulating the cutting blades. More particularly, in European patent n. 0 702 514 (Valex) a safety transmission device is described, particularly for electric pruners intended to be mounted in an electric pruner of the type comprising an electric motor placed in a shell and practically attached to a couple of sharp and superimposed blades which move reciprocally with respect to each other to perform the cutting action, and a friction device located between the motor and the blades, characterized in that said friction group has means of isolation

  suitable for electrically isolating the motor from the blades.

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  indicated to be mounted in an electric pruner of the type comprising an electric motor disposed in a hull and practically attached to a pair of sharp and superimposed blades which move reciprocally relative to each other to perform the pruning action, and a friction device located between the motor and the blades, characterized in that the said friction group has isolation means

  suitable for electrically isolating the motor from the blades.

  Although the solutions set out above give rise to certainly reliable devices, they do not contemplate some aspects which in any case appear relevant today under the profile of safety and convenience for the operator. For example, a typical case of a fortuitous event nonetheless concerns the sudden blockage of the blades, which, regardless of whether or not friction occurs, can cause the operator to become unbalanced, with possible repercussions caused by the loss of control. of the device, such, somehow, shocks with parts

  adjacent, if not the operator's own fall.

  Another drawback, not resolved by the previous solutions, concerns the executive pruning phase. The plurality of diameters of the shrubs interested in shearing, and which inevitably interest the pruning bar for its entire length, generates a distribution of forces of non-uniform size, so that there are some areas more stressed than others. This circumstance generates a persistent vibration of the device, which on the one hand tires the operator and makes the grip unstable,

  the other, excessively stresses the transmission member.

  By these introductory considerations, it is understood as the identification of devices which safeguard the device and which in any case optimize its operation.

is certainly preeminent.

  The object of the present invention is also that of overcoming the aforementioned drawbacks.

SUMMARY OF THE INVENTION

  We reach this goal and others with the present innovation by solving the problems exposed by a multifunction device to save the action, particularly of portable electric pruners and of the pruning operator, of the type comprising a Pag. 3 electric motor, rotating by a transmission group, cutting blades, each movable relative to the other being joined at the ends to eccentric means which, by constituting the movement conversion device, cooperate with said group of transmission, said blades, also being electrically isolated from the motor, o provision is made for: - a toothed wheel meshed by the pinion, called toothed wheel, being provided with at least one circumferential notch; - at least one body, even insulating and possibly decomposable, associated with the toothed wheel, which on one side has a corresponding projection introduced inside the respective circumferential notch - a damping means, introduced inside and in abutment at one end of the circumferential notch, urged by the other side, from the projection of the insulating body; - and a possible disc with emerging blades, each closing, even partial, of the

  respective circumferential notch.

1 5 ADVANTAGES

  In such a way, by the remarkable creative contribution whose effect constitutes a

  immediate technical progress we gain several advantages.

  A first goal is to preserve the optimal functioning of the device, by

  considerably reducing wear and tear on the motor shaft and transmission components.

  Another object is given by the fact that in the apparatus thus designed, the traditional vibrations caused by the pruning action are considerably reduced in intensity, essentially giving more safety to the operator in the action.

  to grasp the device, at the same time reducing fatigue.

  Finally, there are further advantages in optimizing the insulation and in general in the accident prevention function of the transmission group, which

  does not exclude from the improvement the safeguard of the operator.

  Finally, and under the structural profile, the device does not appear complex and expensive, and in addition it can be reduced in weight and dimensions, by facilitating the process of

  reproduction at an industrial level with a good relationship between quality and price.

Pag. 4

  These and other advantages will appear from the successive detailed description.

  some preferential solutions of realization using the schematic drawings below

  joints whose execution details should not be considered as limiting but

only example.

BRIEF DESCRIPTION OF THE DRAWINGS

  Figure 1., shows an exploded view of a first group of transmission of the reciprocating movement to the pruning blades of a particularly electric pruner. Figure 2., represents, still exploded, a variant to the group of

  transmission of the reciprocating movement to the cutting blades observed in Figure 1.

  Figure 3., shows a cross-sectional view of the group of

  transmission observed in Figure 1., taken along the axis a-A of Figure 4.

  Finally, Figure 4., is the plan of the movement transmission group

  alternative of which in Figures 1. and 3.

  DESCRIPTION OF SOME EXAMPLES OF EMBODIMENT

  Referring also to the figures, it can be seen that a device, particularly of the electric pruner type, is composed of a shell (not illustrated), generally obtained in plastic material, provided with two handles, near one of which is obtained from corresponding control correspondents. Inside said shell, is

  provided an electric motor, so as to present the pinion turned downwards.

  The function of the pinion is substantially that of transferring the rotary movement to an adjacent transmission group, on which depends downstream a movement and size conversion device, by imposing on a pair of blades (1, 2), a movement alternative straight. Said blades (1, 2), as parts of a cutting device, are superimposed, and the two are arranged in overhang relative to said shell, while the opposite end remains linked to said group of transmission and conversion of movement. In more detail still, on one side, the two blades provide terminations, specially shaped, which by cooperating with eccentric means (3, 4) held together by suitable end plates (5, 6) by means of the use of studs (12), participate in composing the conversion device

of movement and size.

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  The movement and size conversion device assembly is associated with a transmission group located above, which consists of a toothed wheel (7), provided, on the circumference, with three notches (71), through out , obtained on its

  flat faces; alternatively said notches (71) can also be of the blind type.

  In one of the two hypotheses, solution (to), to the toothed wheel (7), an insulating body (8) is united, provided with a central hole, essentially monolithic, consisting of two discs (81, 82) joined one to the other. 'other by a connecting collar, on the perimeter of which one obtains as many ribs (83), as notches (71) obtained on the toothed wheel (7). Said insulating body (8) integrally surrounds a socket (9) and embraces the toothed wheel (7), in such a way that the same results partially housed inside the insulating body (8), making sure that inside the notches (71) are emerging the relative ribs (83). Each of these ribs (83) occupies only part of the corresponding notch (71), while the remaining space is intended to contain elastic elements (10), such as for example coil springs or elastic buffers, which , on one side, insist in correspondence of the rib (83), on the other on the bottom of the corresponding notch (71). We observe on this subject, that the rigidity of these, is calculated in such a way that they result only

  partially compressed in the normal operation of the machine.

  With the aim of occluding the notches (71) obtained on the toothed wheel (7), so that the elastic means do not come out (10), it is observed that while in correspondence with one of the two flat faces a part of the disc is superimposed, in this case the upper (81) of the insulating body (8), the lower face is interested in the disc (82) which provides as many notches (821) through which allow the introduction of elastic means (10 ). These, therefore, are closed, providing a ring (11), of the type provided with one side of emerging blades (111), coinciding with said notches (821)

  obtained on the disc (82) of the insulating body (8).

  As regards the blocking of the transmission group assembly, movement and size conversion device, it is obtained with said socket (9), which placed coaxially with the insulating body (8), has a rod below. (91) which, by a connecting pivot (13) serves as a stacking axis of the movement conversion device and

of size.

  It ultimately results, that the assembly thus arranged rigidly integrates the Pag. 6

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  insulating body (8), the sleeve (9), the ring (1 l), the screws (12), and the elements of the movement and size conversion device. Such a global assembly rotates around the pivot (13) and has a relative movement of rotation limited with respect to the toothed wheel (7). With the starting of the device and during normal working conditions, the motor output pinion transmits the movement to the toothed wheel (7) with which engages directly, which undergoes negligible relative rotations relative to the insulating body ( 8), resulting from the balance between the resistance exerted by the pruning device and the reaction of the elastic elements (10). In case of blocking of the cutting elements, the toothed wheel (7) undergoes a further rotation, or extra rotation,

  relative, relative to the insulating body (8) also blocked.

  In a variant (B) of the solution described, the insulating body (8) and the ring (11) are replaced by only two parts, in the specific case by the disc conformation, respectively (14) and (15) , both to be superimposed on two flat faces of the toothed wheel (7), which in such a way results in an intermediate position. A first disc (14), made of electrically non-conductive material, provides a hole (140) of polygonal shape, inside which the sleeve (9) can be introduced. One of the two faces of the disc (14) is flat, while the other produces a collar (141) of diameter such as to be introduced inside the hole (72) of a toothed wheel (7) of the type analogous to the one described above. On the same side of realization of the collar (141), and along the perimeter, are provided ribs (142), perpendicular, in an amount equal to the number of

  notches (71) obtained on the two flat and emerging faces of the toothed wheel (7).

  In this way, the ribs (142) are contained inside the corresponding notches (71), partially occupying the space, while the remaining part is

  intended to accommodate the elastic elements (10).

  Finally, the opposite face of the toothed wheel (7), in this case the lower one, is interested in the second disc (15), which is essentially flat, with a central hole (151) with a polygonal edge which is counter-molded with respect to the outer lateral surface of the sleeve (9). In this hypothesis, it is noted that the disc (14) is necessarily of insulating material if the sleeve (9) is not. One of the variants, at the interaction between the lower disc (15) and the sleeve (9), consists in providing a body with a single central hole of even larger dimensions of the lateral section Pag. 7 outside of the sleeve (9). In the latter hypothesis, said body is not linked to rotation with the body (14) and the sleeve (9), but simply pressed against the toothed wheel (7) of the lower elements of the size group stacked by the screws ( 12). In the event that the blades become blocked, said body may or may not slide with the toothed wheel as a function of foreseeable friction / inertia conditions. Some of the possible variants compared to the previous solutions, can look at the position of the notches for housing the elastic elements (10). For example, said notches, instead of being obtained on the toothed wheel (7), can be provided on the insulating body (8), alternately on one or on the two parts of the bodies (14, 15), or particularly on surfaces facing one or both sides of the toothed wheel, which in the specific case will logically be provided with adequate emerging teeth. Pag. 8

Claims (20)

CLAIMS I. Multifunctional device for safeguarding the operation of portable electric joker devices and the operator during cutting, of the type comprising an electric motor rotating using a toothed wheel (7) meshed by a pinion, size blades (1, 2), each movable relative to each other being united at the ends to means (3, 4) with eccentric which, by constituting the movement conversion device, cooperate with said group of transmission, said blades (1, 2), also being electrically isolated from the motor, characterized in that a body (8), (14, 15) for connection connected to the size blades (1, 2) is integral with the wheel toothed (7), drive means cooperating with at least one of the faces facing them, said means comprising at least one damping means (10).   2. Multifunction device for safeguarding the operation of portable electric joker devices, according to claim 1., characterized in that, during the normal operation of the device, said drive means obtained in correspondence of at least one of the turned faces towards them, a body (8), (14, 15) connecting to the size blades (1, 2), being guided by at least one notch (71) provided   on the toothed wheel (7), are never in an end-of-travel condition.   3. Multifunction device to save the functioning of the devices   portable electric joggers according to claims 1. and 2., characterized in   that there is provided: - a toothed wheel (7) provided with at least one notch (71); - at least one body (8), (14, 15), associated with the toothed wheel (7), which on one side has a corresponding projection (83) (142) inserted inside the respective notch ( 71); - at least one damping means (10), inserted inside and in abutment with one end of the notch (71), biased on the other side, from the projection of the body (8), (14,) ; 4. Multifunction device to save the operation of the devices   portable electric pruners according to the preceding claims 1 to 3, characterized   in that the toothed wheel (7) is provided with notches (71), obtained on at least one of its flat faces.   o 5. Multifunction device to save the functioning of the devices   portable electric pruners according to claims 1 to 4 above, characterized   in that inside the notches (71) are housed damping means constituted by elastic means (10).   6. Multifunction device for safeguarding the operation of portable electric pruners, according to claim I above, characterized in that   that the body (8), (14, 15), electrically insulates the blades (1, 2) from the motor.   7. Multifunction device for safeguarding the operation of portable electric pruners, according to claim 1, characterized in that with the toothed wheel (7), a monolithic insulating body (8) is united, perforated in the center and consisting of two discs (81, 82) joined by a collar, on the perimeter of which is provided at least one rib (83).   8. Multifunction device to save the functioning of the devices   portable electric pruners according to the preceding claims 1 to 3, characterized   in that the insulating body (8) integrally surrounds a socket (9) and embraces the toothed wheel (7), so as to be partially housed inside the insulating body (8), so that at the inside the notches (71) can be arranged the ribs corresponding (83).   9. Multifunction device to save the functioning of the devices   portable electric pruners according to the preceding claims 1 and 7, characterized   in that each rib (83) occupies only part of the corresponding notch (71), while the remaining space is intended to contain elements elastic (10).   O. Multifunction device to save the operation of the devices   portable electric jammers, according to claims 1, 8 and 9 above,   characterized in that in correspondence with one of the two flat faces of the toothed wheel (7) the upper part (81) of the insulating body (8) is superimposed, while the lower face is interested in the part (82) which provides as many notches (821)   through which allow the introduction of elastic means (10).   11.1. Multifunctional device to save the functioning of the devices   portable electric pruners according to the preceding claims 1 and 10,   characterized in that the notches (821) of the disc (82) are closed by a ring A1 '(1 1), of the type provided with one side of emerging blades (111), coinciding with said notches (821).   12. Multifunction device to save the functioning of the devices   portable electric pruners according to claims I and 2 above,   characterized in that the blocking of the assembly is obtained with a socket (9), which, placed coaxially with the insulating body (8), has in its lower part a rod   (91) which, with a connecting pivot (13) serves as a stacking axis.   13. Multifunction device to save the operation of the devices   portable electric pruners according to claims 1 and 2 above,   characterized in that the assembly thus arranged rigidly secures the insulating body (8), the sleeve (9), the ring (11), the screws (12), and the elements of the conversion device of movement and size.   14. Multifunction device for safeguarding the operation of portable electric pruners, according to claim 6., characterized in that the body solidly joined to the toothed wheel (7) is made in two parts, (14) and (15) , each to be superimposed on each of the two flat faces of the toothed wheel (7), which is in intermediate position.   15. Multifunctional device to save the functioning of the devices   portable electric pruners according to claims 1 and 14. characterized in   that one of the two faces, on the side (14) necessarily insulating if the sleeve (9) is not, makes it possible to obtain: - a collar (141) which is introduced inside the hole (72) d 'a toothed wheel (7); - And on the periphery, ribs (142), perpendicular, obtained on the turned side towards the toothed wheel (7).   16. Multifunction device to save the functioning of the devices   portable electric pruners, according to claims 1, 14 and 15., characterized in   that the part (14) provides a counter-molded hole (140) to accommodate a socket (9).   17. Multifunction device to save the functioning of the devices   portable electric pruners, according to claims 1 and 15 characterized in that   the opposite face of the toothed wheel (7), in this case the lower face, cooperates with the   second disc (15), which is essentially in plan, with a central hole (151).   18. Multifunction device for safeguarding the operation of portable electric joker devices, according to claim I above, characterized in that   that the disc (15) is of insulating material.   19. Multifunctional device for safeguarding the operation of portable electric pruners, according to claim I above, characterized in that the elastic means (10) consist of helical springs or elastic buffers, which, on one side, act in correspondence with the rib (83) of   the other on the bottom of the corresponding notch (71).   20. Multifunction device to save the functioning of the devices   portable electric joggers according to claims I and 20 above,   characterized in that the rigidity of the elastic means (10) is calculated in such a way that they are only partially compressed in the usual operation of the machine.   21. Multifunctional device for safeguarding the operation of portable electric joker devices, according to claim I above, characterized in that the toothed wheel (7), on the circumference is provided with notches (71) opening out, obtained on its flat faces.   22. Multifunction device for safeguarding the operation of portable electric pruners, according to claim 1., characterized in that the   notches for accommodating elastic elements (10) are provided on the body (8) (14, 15).   23. Multifunction device to save the functioning of the devices   portable electric pruners according to claims 1. and 22., characterized in   that the notches for accommodating elastic elements (10) are provided on the body (8) (14, 15) in correspondence with one or both sides of the toothed wheel (7), which is   provided with teeth emerging from the surrounding surface.   24. Multifunction device to save the functioning of the devices   portable electric pruners according to claims 1, 22. and 23., characterized in   that the body (8) (14, 15) provided with notches for accommodating elastic elements (10), cooperating with a toothed wheel (7) which has one or both sides with teeth   emerging from the surrounding surface, is of the insulating type.   25. Multifunction device to save the functioning of the devices   portable electric pruners, according to claims 1 to 3, characterized in   that the notches (71) obtained on at least one of the two flat faces of the toothed wheel (7), are blind.