WO2017060849A1

WO2017060849A1 - Automatic shears

Info

Publication number: WO2017060849A1
Application number: PCT/IB2016/055991
Authority: WO
Inventors: Valter Mazzarolo
Original assignee: Lightech S.R.L.
Priority date: 2015-10-07
Filing date: 2016-10-06
Publication date: 2017-04-13

Abstract

The invention relates to automatic shears for the field of agriculture. It comprises a handle which has an elongated tubular shape only along an axis (X) and comprises a cutting recess for the stalk, a blade mounted inside the handle and movable to engage the cutting recess and to retract to clear it, an element connected to the blade and movable parallel to the axis to move the blade towards the cutting recess, an electric actuator coupled to said element to make it translate.

Description

AUTOMATIC SHEARS

The present invention relates to automatic shears for the field of agriculture, useful, for example, for cutting the stalks of grapes or fruits, or for gardening, to prune and cut flowers and small plants.

There are known manual cross-bladed scissors, operated by two handles moved manually, in various types and models, some specifically designed for grape or fruit harvesting in general.

There are also known for the pruning automatic-type shears, driven by pneumatic and electrical systems, but they have the disadvantage of being very bulky, heavy, and slow to cut, so much as to discourage the prolonged use like e.g. during the harvest.

In particular the limitation for these appliances stems from the complexity and bulk of the power-supply systems, wherein for the electrical version a large battery is adopted sometimes contained in a special backpack to be worn on the shoulders. In the pneumatic version, however, flexible rubber tubes are used for air supply and connected to an electric-type air compressor of the or operated by an agricultural tractor.

In the market there are also versions of shears servo-assisted by an electric motor with built-in rechargeable batteries, but the weight and bulk make them disadvantageous for applications such as the grape harvest. And yet, the too long cutting time greatly reduces the benefit compared to the traditional harvest with manual scissors.

The main object of the present invention is to remedy to some drawbacks and disadvantages of the prior art, allowing an operator attending e.g. the grape harvest or the fruit harvest to reduce the cutting times of the stalk and to limit the manual effort for the closing and opening of the handles.

Another object of the present invention is to speed up the cutting of the stalk thereby increasing productivity and reducing efforts for the attending operator.

These objects, and others which will appear more clearly hereinafter, are achieved by shears as in the attached main claim. The dependent claims outline particularly advantageous embodiments of the shears.

The automatic shears for a stalk of grape or fruit, comprise:

a handle which has an elongated tubular shape only along an axis and comprises a cutting recess for the stalk,

a blade mounted inside the handle and movable to engage the cutting recess and to retract to clear it,

an element connected to the blade and movable parallel to the axis to move the blade towards the cutting recess.

an electric actuator coupled to said element to make it translate.

The guillotine shears have small size compared to traditional shears, and they allow to obtain a cutting with a speed higher than the crossed displacement of the traditional manual shears' blades.

The guillotine blade moved by an electromagnet or linear solenoid has a higher cutting speed, ensuring a better result with the least effort.

Here are some advantageous variants:

- said element is comprised in or connected to a movable anchor of an electromagnet or solenoid; and/or

- the electromagnet or solenoid is placed inside the handle, for maximum compactness; and/ or

- the electromagnet or solenoid is placed in a support external to the handle, for maximum lightness; and/or

- said element is comprised in or connected to the rotary shaft of an electric rotary motor mounted inside the handle. With the rotary motor, in particular of the brushless type, one is able to develop power, and to drive the blade in two motion directions, and to make the motion of the blade very fast. One can choose a micromotor, to greatly reduce the weight of the shears. In combination with the motor it is an advantageous option that said element comprises or consists of a worm screw coupled to the electric motor. A screw- nut/ screw coupling between said element and the rotary motor allows said element to move linearly, preferably parallel to the axis, so as to effectively operate a blade while remaining inside the volume imposed by the handle; and / or - said element is a cam or a sliding runner coupled to the blade so as to slide on it to move it. By designing the shape of the cam or runner according to the blade or the sliding area on the blade one can adjust the torque imparted to a blade hinged inside the handle. It also simplifies the mechanical connection between a blade and said element; and / or

- the blade is mounted inside the handle pivoted rotatably on a pin for engaging, by rotating, the cutting recess or retract to clear it. By varying the relative position between the pin and the blade the torque imparted on the blade by the actuator can be adjusted; and/or

- inside the handle a battery is installed to power-supply the actuator and / or the electronic circuit, to make the shears independent from any power wiring; and/ or

- the handle along the axis comprises an end provided with an recessed or beak-shaped opening, the opening being directed towards the outside and constituting the cutting recess. So the stalk can be reached and chopped frontally, and with the tip of the handle, rather than having to hang it laterally. This simplifies the user's action when he works in the midst of foliage; and/ or

- in the cutting recess there is a fixed blade and the movable blade is mounted to cross the fixed one. So, this simplifies the structure of the shears, while maintaining high cutting capacity.

By way of example preferred embodiments of shears will now be described, with reference to the accompanying drawings in which:

Figure 1 shows a scheme of the shears;

Figure 2 and 3 show a diagram of a second embodiment of shears;

Figure 4 and 5 show a third embodiment of shears.

Equal numbers or symbols indicate equal parts or elements.

First shears MC are shown in Fig. 1 and used, for example, to cut the stalk of a bunch of grapes or other fruit. For the aim the shears MC comprise, inside a container or casing 4 that serves as a handle, a blade 2 for the cutting which is mechanically coupled to a thrust electromagnet or linear solenoid 3. In turn, the electromagnet or solenoid 3 is mechanically connected to a spring 5 placed in the back adapted to allow the return to the rest position of the blade 2 when the electromagnet or solenoid 3 is not activated.

The cutting blade 2 may be fixed to the electromagnet or solenoid 3 by pins, or screws, or by snapping connection, or by bayonet connection, or permit the rapid replacement thereof by a suitable small opening door.

The electromagnet or solenoid 3 is electrically connected to an electronic control unit 8, which serves to control the activation of the cutting system formed by the electromagnet or solenoid 3, the blade 2 and the spring 5.

The housing 4 comprises a cutting seat 10 which can be occupied by the stalk when it has to be cut. The cutting area or seat 10 serves for the entry of the stalk and may be of various shapes, e.g. rectangular, angled round or hook-shaped.

In the seat 10 is mounted a rotatable shutter 1, which by rotating can mechanically activate a button or a microswitch or a Hall-effect sensor 9 electrically connected to the electronic board 8. The electronic board 8 is power-supplied by a power-supply conducting cable 7, which is in turn connected through a connector 13 to a battery pack 1 1.

Note that all devices forming the guillotine shears MC, except the batteries 1 1, are housed within the container 4 which has a shape suitable for the operator's hands, also acting as a handle. It could be produced with different materials, such as e.g. plastic, aluminum, carbon fiber, or stainless steel.

For safety reasons, the shears MC comprise a safety button 6 inserted in the casing 4. At any time, if the button 6 is released, the blade 2 will return to the rest position (FIG. 1), and to reactivate it one will need to hold the safety button 6 thus enabling again an automatic cutting cycle.

The battery pack 1 1 enclosed in the suitable container comprises a main switch 14 to turn on the system, as well as a connector for allowing the charging via an AC-mains adapter.

As variants, the rotary shutter 1 may

- move also by sliding in a linear guide without the help of the pin 12, or by sliding in special seats with guillotine opening; and / or - achieve the object of activating the solenoid by a mechanical deviation with a lever system or with a metal wire, connected to a micro-switch or microswitch of the pull-type activating the cut.

The shears MC operate as follows.

When the stalk enters deeply into the cutting seat 10 it pushes backwards the rotatable shutter with a rotation movement pivoted by pin 12. The shutter thus mechanically activates a button or sensor 9.

The electronic board 8 detects such activation and initialize a timer with both a fixed delay time and adjustable (for example from 1 hundredth of a second to 50 hundredths of a second). Elapsed the time set in the timer, the control board 8 powers the solenoid or electromagnet 3, which will push the cutting blade 2 forward cutting the stalk.

The activation time of the solenoid 3 is also settable according to the constructive requirements and the type of solenoid or electromagnet used. As an example it may be from 1 hundredth of a second to one second.

Expired the time of the timer, the solenoid 3 will return to the open position, by means of the return spring 5 and the stalk is cut.

Second shears MC2 are shown in Fig. 2 and 3.

Shears MC comprises (Fig. 2), inside a casing or handle 71, a rotary blade 30 for the cutting actuated by a flexible transmission connected to a linear solenoid 44 placed in a remote container 70 (Fig. 3).

The blade 30 has not only the cutting function, but has a special blunt area 35. This area 35, in the rest position of the blade 30, partially closes a cutting area and is maintained in position by a spring 40.

The cable 60, e.g. made of steel, is kept tensioned by means of the spring

45 to counterbalance the forces and eliminate mechanical plays.

The blade 30 is hinged on a pin 42 and the unsharpened area 35 can make the blade 30 rotate by means of the pin 42, fixed by screws 44 to a blade-holder 46.

A fixed counter-blade 31 forms an edge of the cutting area, the opposite margin being occupied by the blade 30.

To the blade-holder 46 is fixed, by means of a cylindrical terminal 48, a cable 60 which slides inside a sheath 62 to arrive to a container 70. The sheath 62 acts as a guide for the cable 60 forming the transmission of the movement to the blade 30. An end-plug allows the shears MC2 to rotate by 360 degrees, without winding on itself the sheath.

A spring 45 in the container 70 allows a shaft 43 of the solenoid 44 expanding in the opposite direction. To the shaft 43 is fixed a permanent magnet 47, movable near a Hall sensor 68 connected to an electronic board 69. The magnet 47 has the function to activate the Hall sensor 68.

The electronic board 69 and the solenoid 44 are powered by rechargeable batteries 78.

The components such as the solenoid 44, the electronic board 69 and the batteries 78 are within the container 70, which in turn is inserted in one backpack, allowing the operator to move freely.

The Hall sensor 68 may also be inserted inside the casing 71, by inserting the magnet 47 in the blade-holder 46 and connecting the sensor 68 by appropriate wires to the circuit board 69. The Hall sensor 68 may also be an optical-type LED sensor.

The electromagnets or solenoids 44 may be replaced by

- a dual-action electromagnet or solenoid of the linear type (through return with permanent magnet), without the aid of the return spring 40; or

- a traction electromagnet or solenoid of the linear type, which employs levers adapted to reverse the direction thereof, or

- a double-coil linear solenoid, one coil for pushing and one for the return.

The rotatable shutter activation device 1 may be activated either with the sensors 9, 68 or mechanically by the pressure of a microswitch, by using magnetic detection, a pull-switch, an optical sensor, or a proximity sensor.

When a stalk enters the cutting area, it engages and then pushes against the blunt area 35, making the blade 30 rotate through the pin 42. This rotation loosens the traction of the steel cable 60 set by the spring 40. The permanent magnet 47 thus approaches to the sensor 88 giving the consent to the electronic board 69 to activate the solenoid 44, which will pull in the same direction the cable 60 thereby making the blade 30 rotate which will cross over the fixed counter-blade 31 cutting the stalk. The spring 40 will then return the blade 30 in rest position with the solenoid 44 de-energized.

The excitation time of solenoid 33 is set by the electronic board 69, and may be varied according to the needs.

A variant of shears MC3 is shown in Fig. 4, useful to cut the stalk of a bunch of grapes or other fruit. The shears MC3 comprise a container or housing 80 that serves as a handle and, as the previous ones, has elongated and approximately tubular shape along a longitudinal axis X.

The casing 80 comprises a cutting seat 82 (e.g. a recess) which can be occupied by the stalk when it must be cut. The cutting area or seat 82 serves for the entry of the stalk and may be of various shapes, e.g. rectangular, angled round or in the shape of hook.

Inside the casing 80 there is a blade 81 for the cutting which is mechanically coupled, e.g. with screws 94, to a threaded rod 83 engaged in a bushing or female-threaded epicyclic reduction gear 84 actuatable into rotation by a rotary motor 85. The coupling via the thread between the threaded rod 83 and the bushing or reduction gear 84 allows to translate the rod 83 back and forth along or parallel to the axis X by operating the motor 85 in a direction or in the opposite direction.

The motor 85 is electrically connected to a control electronic board 89, powered by batteries 88, for example rechargeable via an electrical socket 87 set on a side of the casing 80.

As in the previous variant, inside the casing 80 is mounted on a pin 92 a rotating shutter 91 so as to occupy the bottom of the seat 82. The shutter 91 by rotating can mechanically activate a button or a microswitch, or excite a Hall effect sensor 93, connected electrically to the electronic board 89.

Note that all of the components described forming the shears MC3 are housed within the container or casing 80, which has a form suitable for the operator's hands as well as acting as a handle. It could be produced with different materials, such as e.g. plastic, aluminum, carbon fiber, or stainless steel. For safety reasons, the shears MC3 comprise a safety button 86 inserted in the casing 80. At any time, if the button 86 is released, the blade 81 will return to the rest position (Fig. 4), and to reactivate it holding of the safety button 86 will be necessary thus enabling again an automatic cutting cycle.

The shears MC3 operates as follows.

When the stalk enters deep into the cutting seat 82 it pushes backward the rotatable shutter 91 with a rotation movement pivoted by the pin 92. The shutter 91 thus activates a button or excites the sensor 93.

The electronic board 89 detects such activation and initialize a timer with a fixed or adjustable delay time (for example from 1 hundredth of a second to 50 hundredths of a second). Elapsed the time set in the timer, the control board 89 supplies the motor 85 to rotate it in the direction that pushes the rod 83 and the blade 81 forward along axis X cutting the stalk. After a certain time, set e.g. by another timer, the control board 89 supplies the motor 85 to rotate it in the opposite direction, to bring the rod 83 and the blade 81 back and out of the cutting area 82.

The use of the rotary motor makes the cutting fast, and by using a miniaturized motor one can also light the shears.

Another variant of shears MC4 is shown in Fig. 5. This variant still uses a rotary motor but with different coupling to the blade.

The shears MC4 comprise a container or housing 180 that serves as a handle and, like the previous ones, has an elongated and approximately tubular shape along a longitudinal axis X.

The casing 180 comprises a cutting seat 172 (e.g. a recess) which can be occupied by the stalk when it must be cut. The cutting area or seat 172 is shaped like a beak or recess placed at one end of the housing 180, on the axis X. So the stalk can be reached frontally without hooking it sideways.

Inside the casing 180 there is a cutting blade 181 hinged rotatably on a pin 190. The blade 181 is also coupled to a presser cam or member 182 which is slidable on a side of the blade 181 and integral with a threaded rod 183 engaged in a bushing or female-thread planetary reducer 184 to be actuated in rotation by a rotary motor 185. The coupling via thread between the threaded rod 183 and the bushing or reducer 184 is equal to the previous one.

The motor 185 is electrically connected to an electronic control board 189, powered by batteries 188 for example rechargeable via an electrical socket 187 placed on a side of the housing 180.

The operation of the board for the motor 185 is the same as the variant MC3.

The shears MC4 comprises a button 186 inserted in the housing 180. At any time, if one presses the button 186, the electronic board 189 detects this pressure and powers the motor 185 to make it rotate in the direction that pushes the piston rod 183 and the member 182 forward parallel to the axis X towards the blade 181. Thus the member 182 slides on the edge of the blade 181 and rotates it about the pin 190 to enter in the area 172 and cut the stalk. After a certain time, set e.g. by a timer, the control board 189 powers the motor 185 to rotate it in the opposite direction, to pull the rod 183 backwards. A spring, not shown, draws the blade 181 out of the cutting area 172.

In Fig. 5 are shown two oscillating blades 181, both movable as described by the member 182. Thus the blades 181, upon moving, cross and cut the stalk on opposite sides. However it is possible to have only one blade 181 and leave the other fixed, or use only a movable blade with respect to a fixed rim, with or without cutting edge.

The member 182 may be coupled permanently to the blade(s) 181, e.g. via a guide, so as to apply a force during both opposite translation directions of the rod 183, thereby avoiding the use of a spring for the return of the blade(s) 181.

The electronic boards 8, 69, 89, 189 may be constituted by a microcontroller to perform all the functions of the timers or by analog systems with integrated circuits and transistors (discrete electronic components), or by a wired-logic electromechanical system, without electronic components but only accomplished by the microswitches alone connected in series for the solenoid's activation.

Claims

1. Automatic shears (MC, MC2, MC3, MC4) for a stalk of grape or fruit, comprising:

a handle (4; 80) which has an elongated tubular shape only along an axis (X) and comprises a cutting recess for the stalk,

a blade (2; 91) mounted inside the handle and movable to engage the cutting recess and to retract to clear it,

an element (83) connected to the blade and movable parallel to the axis to move the blade towards the cutting recess,

an electric actuator (3; 85) coupled to said element to make it translate.

2. Shears according to claim 1, wherein said element is comprised in or connected to a movable anchor of an electromagnet or solenoid (3).

3. Shears according to claim 1 or 2, wherein said element is a rigid rod

(83).

4. Shears according to claim 1 or 2, wherein said element is a flexible cable (7).

5. Shears according to claim 2 or 3 or 4, wherein the electromagnet or solenoid is placed inside the handle.

6. Shears according to claim 2 or 3 or 4, wherein the electromagnet or solenoid is placed in a support external to the handle.

7. Shears according to any one of the preceding claims 2 to 6, wherein the electromagnet or solenoid is connected to a spring (5) mounted to return said element back towards a rest position.

8. Shears according to claims 3 or 4, wherein said element is comprised in or connected to the rotary shaft of a rotary electric motor (85) mounted inside the handle.

9. Shears according to claim 8, wherein said element comprises or is consisting of a worm screw (83) coupled to the electric motor for translating linearly.

10. Shears according to any one of the preceding claims, wherein said element is connected integrally with the blade.

1 1. Shears according to claims 8 or 9, wherein said element is a cam ( 182) coupled to the blade so as to slide on it to move it.

12. Shears according to any one of the preceding claims, comprising an electronic circuit for controlling the electric actuator, and consequently the electric actuation of said element.

13. Shears according to claim 12, wherein the electronic circuit is connected to a sensor (68) for detecting the movement of said element and configured to move the blade through said actuator when the sensor emits a signal.

14. Shears as claimed in claim 12 or 13, comprising a movable member (91), mounted in proximity to or inside the cutting recess, adapted to signal to the electronic circuit the presence of a stalk in the cutting recess.

15. Shears according to claim 14, wherein the movable member is rotatably mounted on a pin (92) internal to the handle for moving in and out of the cutting recess.

16. Shears according to claim 14 and 15, comprising a sensor connected to the electronic circuit to detect the displacement of the movable member.

17. Shears according to claim 14 or 15 or 16, wherein the movable member is integral with - or part of - the blade.

18. Shears according to any one of claims 12 to 17, wherein the electronic circuit is

connected to a button (6) mounted on the handle, and

configured to move the blade through said actuator when the button emits a signal.

19. Shears according to any one of the preceding claims, comprising a spring fixed to the blade to keep it in a rest position corresponding to a greater distance from the cutting recess.

20. Shears according to any one of the preceding claims, wherein the blade is mounted inside the handle translatable parallel to the axis (X) for engaging the cutting recess and retract to clear it.

21. Shears according to any one of the preceding claims 1 to 19, wherein the blade is mounted inside the handle pivoted rotatably on a pin (92) for engaging, by rotating, the cutting recess or retract to clear it.

22. Shears according to any one of the preceding claims, wherein inside the handle there is installed a battery to power the actuator and/ or the electronic circuit.

23. Shears according to any one of the preceding claims, wherein the handle comprises along the axis an end provided with a recessed or beak- shaped opening, the opening being directed towards the outside and constituting the cutting recess.

24. Shears according to any one of the preceding claims, wherein in the cutting recess there is a fixed blade and the movable blade is mounted for crossing the fixed one.