Animal-shearing machine having direct drive

Abstract

The invention relates to an animal-shearing machine (1), in particular a high-performance animal-shearing machine having a direct drive for shearing farm animals and / or pets, comprising: a housing (10) having a holding portion (11); a shearing head (2) which can be connected to the housing (10) and has an upper blade (4) and a lower blade (5), the upper blade (4) being movable relative to the lower blade (5); a drive unit (6) having an output shaft (7); an eccentric unit (9) which is operatively connected to the output shaft (7); an oscillating assembly (20) which is operatively connected to the eccentric unit (9) and to the upper blade (3) of the shearing head (2); and a control unit (60) for controlling the drive unit (6).

Description

Technical Field of the Invention The present invention relates to an animal-shearing machine with direct drive, in particular a high-performance animal-shearing machine for farm animals, such as sheep, goats, llamas, alpacas, cattle, horses, etc., and / or pets, which is also suitable for shearing dense and thick fur or hair. State of the Art Animal-shearing machines are known in a variety of designs and for a wide range of animals, such as sheep, alpacas, llamas, cattle, as well as horses and dogs, for example. Known animal-shearing machines generally comprise a housing with a shaped grip or handle section for a user to hold the shearing machine and a shearing head with a cutting device, for example two blades, an upper blade and a lower blade, which move translationally relative to one another to achieve the cutting action. In modern animal-shearing machines, the shearing head is detachable from the handpiece and may also include a pressure control device with a rotary control knob to adjust the pressure of the upper blade against the lower blade, so that the cutting quality can be maintained consistently throughout multiple shearing operations. Known animalshearing machines comprise a drive unit, such as an electric motor, and— particularly in high-performance models—a gearing unit to drive the blades, as well as an eccentric unit to move the movable blade or blades back and forth. With the help of the eccentric unit and a swivel or swing lever, the rotational motion of the drive electric motor is converted into the desired swivel or swing motion of the shearing head’s blades. Low-power shearing and shaving devices that use a direct-drive electric motor—i.e., one without a reduction gear—are generally known. For example, British Patent No. 1161718 A discloses an electric shearing machine for hair that uses a DC motor, in which the components operatively connected to the DC motor have the lowest possible mass. However, such a shearing machine is unsuitable for a shearing procedure on thick hair and dense fur. From document US 2017203450 A1, a cordless animal shearing machine for large farm animals is known, comprising a brushless DC motor, a replaceable shearing head, and a rechargeable battery pack, wherein the shearing head is driven by the brushless DC motor via helical gearing based on a helical-to-helical motion. Accordingly, this animal shearing machine does not include an eccentric drive to drive the movable blade of the shearing head. The resulting increased friction proves to be a disadvantage, which is also noticeable through increased vibration, greater heat generation, and noise. This also negatively affects the running time of the batteries. For more powerful animal shearing machines designed for use on thick hair and / or dense fur, direct drive is generally not used; instead, these animal shearing machines employ a reduction gear in operative connection with an electric motor to provide sufficient drive torque for the oscillating blades or shears. Shearing machines with different types of gears, such as spur gears, planetary gears, or worm gears, are known, for example, from DE 11 96 994 A and DE 10 2009 017 517 A1. The use of gears, regardless of type, has the particular drawbacks of high operating noise and a large space requirement, making it difficult to design an ergonomic animal-shearing machine. Friction leads to increased wear, significant heat generation, and reduced efficiency. Furthermore, the bearing arrangement for the gears is complex. Consequently, the development of a battery-powered high-performance animal-shearing machine is complicated by the fact that the operating time of a built-in battery is often insufficient for an entire shearing process. Starting from the state of the art, the present invention is based on the objective of overcoming the aforementioned disadvantages and proposing a high-performance animal-shearing machine with direct drive for farm animals, which provides sufficient torque to enable the shearing process even with thick hair and / or dense or heavily soiled fur. Furthermore, an animal-shearing machine is to be provided which, as a cordless version, can also be used for extended periods of operation. For such a high-performance animal-shearing machine, it is also desirable that the external shape of the housing—and thus its ease of handling—be retained and that proven components from known animalshearing machines can continue to be used. Summary of Invention According to the present invention, these objects are achieved above all through the features of the independent claim. Further advantageous embodiments emerge moreover from the dependent claims and the description. More specifically, the objects of the present invention are achieved through an animal-shearing machine, in particular a high-performance animalshearing machine having direct drive for shearing farm animals and other animals, comprising - a housing with a holding portion, - a shearing head, connectible to the housing, with an upper blade and a lower blade, whereby the upper blade is movable relative to the lower blade, - a drive unit, disposed in the housing, with an output shaft, an eccentric unit in operative connection to the output shaft and an oscillating assembly, which is in operative connection to the eccentric unit and to the upper blade of the shearing head, and - a control unit for control of the drive unit. According to the invention, the animal-shearing machine can be used, for example, for shearing sheep, llamas, alpacas, cattle, horses, etc., and / or pets. The animal-shearing machine comprises a housing that includes a holding or grip section, which is connectible to the shearing head and in which the direct drive, as well as mechanical components and, if applicable, replaceable batteries or rechargeable accumulators for cordless operation, are accommodated. Furthermore, a switch or switching means for turning the device on and off is provided on the holding portion. The animal-shearing machine includes an operative connection between the drive unit—hereinafter also referred to as the electric motor—and the eccentric unit, and further between the eccentric unit and one of the blades, in order to move that blade relative to the other blade. For this purpose, the oscillating assembly may include a rocker arm that engages at its proximal end with the eccentric unit and at its distal end with the upper blade of the shearing head. In particular, the rocker arm of the oscillating assembly may be pivotally mounted between its proximal end and its distal end about a pivot point in the housing of the animal-shearing machine. High-performance operation of the animal shearing machine requires the drive unit to provide higher torque than is needed for shearing small animals. Electric motors with a rated power of approximately 40 W to 120 W are suitable as drive units, depending on the application and / or the shearing pressure. The electric motor, which can be used as a direct drive, is designed to generate a high speed in the range of approximately 2,000 rpm to 3,000 rpm and to maintain this speed largely constant. This allows the downstream mechanism, driven by the electric motor, to achieve an effective cutting action even with thick hair and dense fur. The drive unit can be a DC motor. A DC motor is based on efficient DC motor technology, and the torque it generates is so strong that there is no significant reduction in rotational speed or cutting speed, even when cutting fur that is difficult to shear. The electric motor or drive unit used in a direct-drive configuration is preferably a brushless DC motor (BLDC motor or “electronically commutated motor”). Brushless DC motors are characterized by good energy efficiency and high power density, low maintenance requirements, a compact design, and low weight, making battery operation—and thus a cordless version of the animalshearing machine—possible even with moderate power consumption. Furthermore, such a DC motor generates little heat, so that waste heat can be effectively removed, for example, using an integrated fan. This makes it comfortable for the user to hold the device directly. Such brushless DC motors exhibit high efficiency and are also capable of delivering the rotational speed of approximately 2,500 to 2,800 rpm or higher required for shearing animals with thick, dense coats. The animal-shearing machine of the invention is not only characterized by a very high-performance electric motor, such as a brushless DC motor, but, as a direct-drive system, it also does not require a gearbox to provide the necessary torque for shearing. This results in reduced weight, a compact design, a low-maintenance animal shearing machine due to the reduced number of components requiring maintenance, and / or quiet and vibration-reduced operation. In addition, the compact design of this type of electric motor allows for space-saving installation in the holding section of the animal-shearing machine. The brushless DC motor’s low-wear operation ensures a long service life with minimal maintenance requirements. The operative connection between the output shaft of the electric motor and an eccentric shaft of the eccentric unit can be direct, i.e., the eccentric shaft is directly operatively connected to the output shaft. This reduces the number of components required for the operative connection between the electric motor and the moving blade, the bearing of which becomes obsolete, thereby enabling a simplified design of the animal-shearing machine. In a preferred embodiment, coupling means are provided between the output shaft of the electric motor and the eccentric shaft of the eccentric unit, which coupling means are mounted via bearing means. Preferably, the coupling means are mounted in the shearing head by means of the bearing means. The coupling means may comprise a claw-type coupling, a spring-tab coupling, or the like. A claw-type coupling with two coupling halves, which have different drivers in the axial direction and a preferably elastic ring gear, allows for the compensation of misalignment and / or angular displacement between the eccentric shaft and the output shaft. Furthermore, the elastic material of the toothed ring—the hardness of which can be selected—and appropriate mounting of the coupling elements can reduce shocks and vibrations in the system. Such coupling means are preferably designed to dampen the load caused by the oscillating motion of the upper blade, which is generated by the phases of the load increasing and decreasing and the standstill of the upper blade. For example, at a speed of approximately 2,500 rpm, the upper blade must be accelerated from a standstill to 5,000 rpm and then braked to a standstill again, which represents a heavy load. In a preferred embodiment, the drive unit, which is designed as a brushless DC motor, is controlled by the control unit so that it can operate at at least one preset speed. The speed is preset such that a high torque is provided for the high-performance animal-shearing machine even without a reduction gear. In the animal-shearing machine according to the invention, the rotational speed of the electric motor can be kept essentially constant during operation when a load is applied, i.e., the increase in torque upon the application of a load is covered by an increase in current demand. An animal-shearing machine of this type with a preset direct drive represents a simple embodiment. In another embodiment of the invention, the electric motor can be switched to different operating states via the control unit, which differ in terms of rotational speed. The user initiates the switching of the electric motor using a switching device. In doing so, the user can continuously increase or decrease the rotational speed using a toggle switch. Alternatively, a user can select between at least a first speed D1 and a second speed D2, which is higher than the first speed D1, using a switch designed as a slide switch. In this variant, the speeds D1 and D2 may be freely preset and may cover only a portion of the electric motor’s total power range. Furthermore, it may be provided that the power consumption of the animal-shearing machine is detected by sensor means as a control parameter for the control unit. In particular, overloading of the animal-shearing machine can be prevented by limiting or interrupting the power supply in the event of an overload. The control unit is therefore designed to control or regulate the power output of the electric motor depending on its load, thereby achieving a constant speed. In a further embodiment of the animal-shearing machine, at least one Hall sensor may be provided to control the drive unit, which is designed as a brushless DC motor, in order to facilitate the starting of the electric motor, particularly at low speeds and under higher loads. Accordingly, the Hall sensor improves the starting behavior of the electric motor, in particular by providing a clear positional reference when the electric motor starts. Furthermore, the control of the electric motor can be simplified in certain cases when Hall sensors are used. Alternatively, a hybrid control system for the electric motor of the animal-shearing machine may be provided using a switchable Hall sensor. In this case, at least the Hall sensor can be activated for motor control during the start-up process and / or in an initial phase at low speeds. At higher speeds, particularly during rated operation, control without the Hall sensor is provided. This hybrid control system thus utilizes the advantages of both control variants, i.e., a smooth motor start, stabilization at low speeds with the aid of at least one Hall sensor, and low-vibration, sensorless rated operation with the Hall sensor deactivated. In the animal-shearing machine, the output shaft of the electric motor may run roughly parallel to the longitudinal axis of the housing and be directly or indirectly in operative connection with the eccentric unit. The eccentric unit comprises, for example, a ball or a cylindrical eccentric cam, the axis of which runs parallel to the output shaft of the electric motor and can be brought into engagement with a recess or a slot or groove at the proximal end of the rocker arm mounted in the housing. Preferably, the eccentric unit comprises a ball arranged thereon with substantially no play, which is in point-contact with the surfaces bounding the recess and rolls thereon. In this way, the power transmission from the drive unit to the moving upper blade can be optimized, and friction between the components in engagement with one another is minimized. Consequently, the rotational motion of the electric motor's output shaft can be converted into an oscillating motion of the rocker arm with minimal friction. As vibration-free an operation as possible of the animal-shearing machine is achieved when the electric motor is mounted in the housing via a motor flange. In this configuration, the motor flange also serves as a spacer between the electric motor and the housing. In particular, elastically deformable bearing elements may be provided, which reduce both the operating noise of the animal-shearing machine and vibrations, thereby making it easier to hold the animal-shearing machine. Such an animal-shearing machine equipped with a high-performance brushless DC motor can be powered by a battery or rechargeable accumulator, preferably one or more lithium-ion batteries, to provide the power required to operate a cordless animal-shearing machine. A cordless version of the animalshearing machine has the advantages that no power cord restricts the user’s mobility and flexibility, and that the hazard posed by the cord to the user and the animal is eliminated. According to one embodiment of the invention, a replaceable battery may be housed in the holding or handle section of the animal-shearing machine’s housing, for example, arranged in a slide that can be extended and retracted. Such a movable slide facilitates the replacement of the battery or batteries, which can then be charged in a safe location. Furthermore, the charge level can be displayed to the user via a display device. In a preferred embodiment of the invention, the heat generated by the operation of the electric motor is effectively discharged from the housing via an airflow. This prevents harmful effects caused by the heating of the mechanical and electronic components housed within the housing. The heat generated by the electric motor can be removed, at least in the area of the control unit—which may be designed as a circuit board or semiconductor module—by means of an airflow generated by an integrated fan, flowing from at least one air inlet along defined flow paths to at least one air outlet. Preferably, the fan is integrated into the motor housing of the electric motor to ensure cooling of the electric motor and mechanical and electronic components by means of through-flow ventilation. The air drawn in by the fan can be passed through a filter located at the air intake, thereby protecting the interior of the housing from hair, dust, etc. that would otherwise be drawn in along with the ambient air. Further details of the invention are set forth in the following description of the preferred embodiments of the animal-shearing machine according to the invention, which are illustrated in the accompanying drawings by way of example. The description reveals further advantages of the present invention, as well as suggestions and proposals for how the subject matter of the invention may be modified or also further developed within the scope of the claims. Brief Description of the Drawings The execution examples of the invention are described in more detail below with reference to the drawings. They show: Figure 1: a schematic perspective sectional view of an animalshearing machine according to the invention, with a brushless DC motor; Figure 2 a schematic detailed view of an operative connection of a drive unit, coupling means, and an eccentric unit; Figure 3 a schematic detailed view of an embodiment of the animalshearing machine according to the invention with a brushless DC motor without coupling means. Preferred Embodiments of the Invention Figure 1 shows a preferred animal-shearing machine 1 in a cordless version, depicted in perspective, which can therefore be used flexibly and effectively. Basically, the animal-shearing machine 1 comprises a housing 10, which can be connected to a shearing head 2 via connecting means, wherein the shearing head comprises an adjustment knob 3. The housing 10 defines a space in which a drive unit 6 can be arranged, in particular an electric motor, preferably a brushless DC motor 8. The housing 10 may be formed by a housing upper shell 10.1 and a housing lower shell 10.2 that can be connected thereto, whereby an ergonomically shaped holding or grip section 11 is provided. In the illustrated execution example, the drive unit 6 is in operative connection with an eccentric unit 9, which, via an oscillating assembly 20, is in operative connection with an upper blade 4 via a rocker arm (not shown), which can be moved translationally relative to a lower blade 5 via the adjustment knob 3. The lower blade 5 is a fixed cutting blade that is firmly but detachably connected to the housing 10. Details of the operative connection between the drive unit 6 and the movable upper blade 4 are shown below in Figure 2 and Figure 3, respectively. In the execution example shown in Figure 1, the animal-shearing machine 1 is depicted in a cordless version, i.e., to power the brushless DC motor 8, a battery pack or rechargeable batteries 40 (not shown) is housed in the housing 10, specifically in a battery compartment that is accessible via a cover 43 on the rear side of the housing 10. To replace or remove the batteries or rechargeable batteries 40, they can be taken out after opening the cover 43 and recharged, for example, in a provided charging station. Preferably, the battery pack or the rechargeable batteries 40 can be arranged on a movable slide 42 (not shown), which, when the cover 43 is open, can extend out of the housing 10 so that the battery pack or the rechargeable batteries 40 can be easily replaced. Lithium-ion batteries with a charging capacity of at least 5 Ah are suitable. The brushless DC motor 8 used in the animal-shearing machine 1 of the invention is characterized by a compact design and high energy efficiency, and the heat generated during operation by this type of electric motor is also low. To effectively remove the heat generated from the housing, particularly to protect sensitive components such as an electronic control unit 60 from overheating, a fan unit 50 is provided. The fan unit 50 may be integrally formed with a motor housing of the brushless DC motor 8 to provide active cooling during motor operation. The fan unit 50 draws air from the surrounding environment through at least one air inlet 51 and, if present, a filter 54 (not shown) at the proximal end of the housing 10 by means of a fan impeller 53, whereby the air flows through the housing 10 and exits through an air outlet 52 (not shown) at the distal end of the housing 10. If the air outlet 52 is positioned appropriately, the blades 4, 5 of the shearing head 2 are also cleaned, thereby preventing blockage by hair. Figure 2 illustrates the operative connection, or a drive train 30, comprising the drive unit 6, coupling means 12, and the eccentric unit 9. Starting from the drive unit 6, which is preferably a brushless DC motor 8 and is specifically designed as an external rotor motor, the output shaft 7 is operatively connected via coupling means 12, designed as a claw-type coupling, to an eccentric shaft 14 of the eccentric unit 9, which additionally comprises a ball 15 (not shown). The coupling means, designed as a claw-type coupling, comprise two coupling parts and an elastic ring gear, so that both vibrations are reduced and any misalignment of the output shaft 7 relative to the eccentric shaft 14 can be largely compensated for. A first coupling part is mounted on the output shaft 7, a second coupling part is mounted on the eccentric shaft 14, and the third coupling part, designed as a star or ring, is clamped between the first coupling part and the second coupling part. The eccentric unit 9 further comprises the ball 15 (not shown in Figure 2), which can be brought into engagement with a recess 24 formed at the proximal end 21 of the rocker arm. In particular, the contact surfaces between the ball 15 and the recess 24 may be shaped such that the contact is largely point-like in order to minimize friction. Furthermore, Figure 2 shows that the fan unit 50, specifically a fan impeller 53, is integrally arranged on the drive unit 6. Figure 3 illustrates another embodiment of an operative connection of the animal-shearing machine 1 according to the invention. In this embodiment, the output shaft 7 of the drive unit 6—i.e., preferably a brushless DC motor 8—is in direct operative connection with the eccentric unit 9; that is, the connection is not made via coupling means 12, as in the execution example shown in Figure 2. The corresponding animal-shearing machine 1 is a simplified variant that is lighter and thus more flexible due to a reduced number of components

Claims

1. An animal-shearing machine (1), in particular a high-performance animal-shearing machine having direct drive for shearing farm animals and / or pets, comprising- a housing (10) with a holding portion (11),- a shearing head (2), connectible to the housing (10), with an upper blade (4) and a lower blade (5), whereby the upper blade (4) is movable relative to the lower blade (5),- a drive unit (6), disposed in the housing (10), with an output shaft (7), an eccentric unit (9) in operative connection to the output shaft (7) and an oscillating assembly (20), which is in operative connection to the eccentric unit (9) and to the upper blade (4) of the shearing head (2), and- a control unit (60) for control of the drive unit (6).

2. The animal-shearing machine (1) according to claim 1, wherein the drive unit (6) is a brushless DC motor (8).

3. The animal-shearing machine (1) according to claim 1 or 2, wherein for coupling between the drive unit (6) and the eccentric unit (9), coupling means (12) are provided, which are mounted in the shearing head (2) via bearing means (18).

4. The animal-shearing machine (1) according to claim 3, wherein the coupling means (12) comprises a claw-type coupling.

5. The animal-shearing machine (1) according to one or more of the preceding claims, wherein the drive unit (6) is able to be operated at at least one preset speed under the control of the control unit (60).

6. The animal-shearing machine (1) according to one or more of the preceding claims 1 to 4, wherein the drive unit (6) is able to be operated at various preset speeds under the control of the control unit (60), which speeds are able to be selected by the user via a switching device (13).

7. The animal-shearing machine (1) according to claim 6, wherein the switching device (13) enables the speed of the drive unit (6) to be increased and decreased in a continuously variable manner.

8. The animal-shearing machine (1) according to one or more of the preceding claims, wherein at least one Hall sensor (19) is provided to control the drive unit (6).

9. The animal-shearing machine (1) according to claim 8, wherein the Hall sensor (19) is able to be selectively activated.

10. The animal-shearing machine (1) according to one or more of the preceding claims, wherein the drive unit (6) is powered by at least one rechargeable battery (40) housed within the housing (10), and the battery's state of charge can be displayed on a display device (41).

11. The animal-shearing machine (1) according to one or more of the preceding claims, wherein a fan unit (50) with a fan impeller (53) is arranged inside the housing (10) to draw in ambient air through at least one air inlet (51) provided on the holding portion (11), guide it along a flow path, and allow it to flow out through at least one air outlet (52) provided at a front end of the housing (10).

12. The animal-shearing machine (1) according to claim 11, wherein at least one filter (54) is provided in the flow path, preferably near the air inlet (51).

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