Abstract:
An electric actuator to be primarily used on an all-terrain vehicle (ATV) having implements such as snow plow is disclosed. The main purpose of the actuator is to allow the driver to rotate the blade when it is not touching the ground without having to get out of the vehicle. The actuator is composed of a stator assembly and a motor assembly. An electric motor is concealed in the motor assembly and drives a screwed or grooved part that engages the threaded or grooved inner surface of the stator assembly. Rotation of the screwed or grooved part induces a translational movement alongside the longitudinal axis of the actuator assembly. The translation movement induces the elongation or the retraction of the actuator depending on the rotating direction of the electric motor.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present patent application claims the benefits of priority of U.S. Provisional Patent Application No. 62/239,129, entitled “ELECTRIC ACTUATOR”, and filed at the United States Patent and Trademark Office on Oct. 8, 2016, the content of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention generally relates to electric actuators. More specifically, the present invention relates to electric actuators for moving implement attached to a vehicle. 
       BACKGROUND OF THE INVENTION 
       [0003]    All-terrain vehicles (“ATV” or “ATVs”), utility-terrain vehicle (“UTV” or “UTVs”), and other similar vehicles, are often equipped with implements such as plows (or plough in English spelling) to allow the vehicles to displace any type of elements or objects, such as snow, dirt, soil, gravel, etc. Such implements are typically removably mounted to the vehicles via appropriate supporting frames or supporting frame assemblies. Such implements are typically pivoting in order to change the angle of the implement to angularly push elements. In order to pivot an implement, typical systems on the market use hydraulic actuator. Such configurations are very expensive. These systems are typically bulky and support high loads. 
         [0004]    Thus, it is believed that there is a need for a new low cost system using an reduced size actuator, typically an electric actuator, to angularly turn the implement, wherein such system could comprise a mechanism to automatically trigger the turning of the implement while being user-friendly and by limiting the need of an operator to disembark from the vehicle to activate the system. Such system shall aim at having dimensions allowing to fit the actuator in current plow systems originally designed to use typical hydraulic actuators. Furthermore, a vehicle having an implement is expected to hit obstacles. Thus, the actuator shall aim at providing a very high static/impact load resistance. Such load shall be higher than what the electric motor can withstand. 
       SUMMARY OF THE INVENTION 
       [0005]    It is disclosed a fully electric actuator assembly to be used to rotate an implement such as the shovel of a snow remover. 
         [0006]    It is disclosed an electric actuator composed of two main parts, preferably cylindrical, of different size or diameter such that a smaller part, herein below referred to as a motor assembly, is able to fit inside a larger part, herein below referred to as the stator assembly. The inside wall of the stator assembly being shaped in a way to be either directly engaged by a moving counterpart, preferably attached to the motor assembly, or engaged by rolling balls configured to move inside an externally grooved part. The grooved part is either a modified part of the moving counterpart or an additional part attached to the side of the moving counterpart, facing the inner part of the stator assembly. The moving counterpart is typically activated by the drive shaft of an electric motor. The electric motor may be coupled to a gearbox to increase the torque. Rotation of the moving counterpart induces either an immediate translational movement alongside the longitudinal axis of the actuator assembly or a rotational movement of the rolling balls inside the grooved part which induces a translational movement alongside the longitudinal axis of the actuator. The translational movement induces the elongation or the retraction of the actuator. 
         [0007]    According to a preferred embodiment, an electric actuator or a system to change the orientation of an implement is disclosed. 
         [0008]    In one aspect of the invention, an electric actuator is adapted to change the orientation of an implement. The actuator comprises a mobile assembly, an electric motor connected to the mobile assembly and an engaging mean for attaching the actuator to an implement at one end of the assembly. The mobile assembly engaging the engaging mean is adapted to rotate and is configured to translate the rotational movement of the mobile assembly into a longitudinal movement along a longitudinal axis of the actuator 
         [0009]    In another aspect of the invention, the mobile assembly may comprise a mobile counterpart coupled, at one side, to a sleeve by at least one attachment mean. The sleeve is coupled to an electric motor with a drive shaft. The mobile assembly further comprises a plate trapped between the mobile counterpart and the sleeve. The plate is being attached to a second end of the actuator by at least one attachment mean. 
         [0010]    In one aspect of the invention, the mobile counterpart is adapted to engage the engaging mean with at least two communicating threaded parts. 
         [0011]    In another aspect of the invention, the mobile counterpart may be adapted to engage the engaging mean with a grooved interior wall communicating with a grooved counterpart by the mean of rolling balls. 
         [0012]    In a further aspect of the invention, the mobile counterpart may be adapted to engage the engaging mean with at least two communicating threaded parts and the movement of the rolling balls inside a grooved insert supported by the counterpart. The insert is adapted to receive a reduced friction mechanism. 
         [0013]    In another aspect of the invention, the sleeve and the mobile counterpart may be adapted to independently rotate from one end of the actuator about a longitudinal axis of the actuator. The sleeve may further comprise an aperture shaped in a way to engage a drive shaft. The sleeve and the drive shaft being coaxial. 
         [0014]    The present invention also provides a method for expanding or retracting an electric actuator through converting the rotational movement of a mobile assembly into a transitional movement alongside the longitudinal axis of the actuator with an engaging mean. The method comprises attaching a first end of the actuator to an implement at least by a mean of attachment, attaching a second end of the actuator to a vehicle at least by another mean of attachment and activating a motor to rotate a mobile assembly inside a stator assembly of the electric actuator. The rotation of the mobile assembly triggers a mobile counterpart to engage an inner part of the stator assembly of the electric actuator. The method further comprises converting the rotational movement of the mobile assembly into a transitional movement alongside the longitudinal axis of the actuator with an engaging mean. 
         [0015]    In another aspect of the invention, the step of converting the rotational movement may further comprise using a reduced friction mechanism to convert the rotational movement of the mobile assembly into a transitional movement alongside the longitudinal axis of the actuator and to improve the mechanical resistance of the actuator. 
         [0016]    In a further aspect of the invention, the motor may be connected to a gear box. 
         [0017]    The step of converting the rotational movement may further comprise converting the rotational movement of the mobile assembly into a transitional movement alongside the longitudinal axis of the actuator using an internally threaded stator assembly of the actuator and a screw attached to the mobile assembly. 
         [0018]    The step of converting the rotational movement may further comprise rolling balls engaging an internally grooved stator assembly of the actuator and an externally grooved counterpart attached to the mobile assembly to convert the rotational movement of the mobile assembly into a transitional movement alongside the longitudinal axis of the actuator and to ensure an important resistance to high loads. 
         [0019]    In a further aspect of the invention, the method may further comprise engaging a threaded portion of the stator assembly to a threaded portion of the mobile assembly and engaging rolling balls to both a grooved inner part of the stator assembly and an externally grooved insert attached to the mobile counterpart. 
         [0020]    Other and further aspects and advantages of the present invention will be obvious upon an understanding of the illustrative embodiments about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    The above and other aspects, features and advantages of the invention will become more readily apparent from the following description, reference being made to the accompanying drawings in which: 
           [0022]      FIG. 1  is a perspective view of an electric actuator in accordance with the principles of the present invention. 
           [0023]      FIG. 2  is a sectional perspective view of a motor assembly in accordance with the principles of the present invention. 
           [0024]      FIG. 3  is a perspective view of an electric motor assembly in accordance with the principles of the present invention. 
           [0025]      FIG. 4  is a sectional perspective view of an electric actuator shown in expanded position in accordance with the principles of the present invention. 
           [0026]      FIG. 5  is a close sectional perspective view of a threaded end of the motor assembly in accordance with the principles of the present invention. 
           [0027]      FIG. 6  is a sectional perspective view of the electric actuator of  FIG. 1  shown in retracted position. 
           [0028]      FIG. 7  is a perspective exploded view of two parts composing an electric actuator in accordance with the principles of the present invention. 
           [0029]      FIG. 8  is a sectional perspective view of a screw of an electric actuator in accordance with the principles of the present invention. 
           [0030]      FIG. 9  is a sectional perspective view of a plate of an electric actuator in accordance with the principles of the present invention. 
           [0031]      FIG. 10  is a sectional perspective view of a sleeve of an electric actuator in accordance with the principles of the present invention. 
           [0032]      FIG. 11  is a sectional perspective view of a second embodiment of an electric actuator shown in expanded position in accordance with the principles of the present invention. 
           [0033]      FIG. 12  is a close sectional perspective view of a threaded end of a second embodiment of the motor assembly in accordance with the principles of the present invention. 
           [0034]      FIG. 13  is a close sectional perspective view of a portion of a second embodiment of an electric actuator shown in expanded position in accordance with the principles of the present invention. 
           [0035]      FIG. 14  is a perspective view of an exemplary grooved insert attached to a screw of an electric actuator in accordance with the principles of the present invention. 
           [0036]      FIG. 15  is a perspective view of an exemplary screw having a specific grooved shape in accordance with the principles of the present invention. 
           [0037]      FIG. 16  is a perspective view of an exemplary grooved metallic insert attached to the screw in accordance with the principles of the present invention. 
           [0038]      FIG. 17  is a sectional perspective view of a third embodiment of an electric actuator shown in expanded position in accordance with the principles of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0039]    A novel electric actuator will be described hereinafter. Although the invention is described in terms of specific illustrative embodiments, it is to be understood that the embodiments described herein are by way of example only and that the scope of the invention is not intended to be limited thereby. 
         [0040]    In a preferred embodiment, the electric actuator is used to change the orientation of an implement comprising an enclosure for connecting the system to a vehicle or an implement comprising an engaging mean, such as but not limited to the enclosure being threaded or internally grooved. The electric actuator further comprises a mobile counterpart to engage the engaging mean for translating the rotational movement of the mobile counterpart into either a longitudinal movement along the longitudinal axis of the system or into a rotational movement of rolling balls inside a grooved part. In such an embodiment, a translational movement is induced by the rotational movement of the rolling balls alongside the longitudinal axis of the system. The electric actuator may further comprises an electric motor connected to the mobile counterpart for engaging the mobile counterpart and a second enclosure connected to the electric motor for connecting the system to said vehicle or said implement. 
         [0041]    In other embodiments, the electric actuator may further comprise a gear box connected to the mobile assembly and to the electric motor for increasing the torque of the electric motor. 
         [0042]    Now referring to  FIG. 1 , an embodiment of an electric actuator  10  typically used to connect a plow to a vehicle using an attachment device  12 . The actuator  10  generally allows changing orientation of the implement with respect to a generally vertical axis. However, it is understood that the electric actuator  10  is not limited to be used with a plow. It could therefore support other types of implements such as, but not limited to, a snowblower or the likes. The electric actuator  10  is composed of two main parts: the stator assembly  14  and the motor assembly  16 . 
         [0043]    Now referring to  FIGS. 2, 5, 10, 13 and 17 , preferred embodiments of an electric actuator, comprising different engaging means, are shown. The motor assembly  16  typically comprises a moving counterpart  162 , at one end of the motor assembly to be coupled to a sleeve  166  by means of fasteners  168 , such as bolts. The sleeve is then coupled to an electric motor assembly  18  by means of a drive shaft  182  to induce rotation of the moving counterpart  162 . The sleeve  166  comprises an aperture  190 . Such aperture  190  is typically shaped in a way to engage the drive shaft  182  for limiting rotational movement of the said drive shaft with regard to the sleeve  166 . The electric motor assembly  18  is substantially immobile with regard to the enclosure  164 . The moving counterpart  162 , the enclosure  164 , the sleeve  166 , and the drive shaft  182  all have a longitudinal axis. All of said axes are generally parallel. 
         [0044]    In some embodiments, the moving counterpart  162  is externally threaded, such as but not limited to a screw as shown in  FIG. 8 . 
         [0045]    Now referring to  FIGS. 14 to 16 , some preferred embodiments of the moving counterpart  162  are shown. The  FIG. 14  shows a moving counterpart  162  comprising two majors portions: preferably but not limited to, a plastic insert  201  injected on the end of a threaded part  200 . The insert  201  is adapted to host rolling balls  206  as shown on  FIG. 12 . Such a configuration aims at reducing internal friction and aims at improving the force transmitted by the motor to the actuator. The insert  201  is deformed during an impact without being damaged and without damaging the rolling balls, thus creating a resilient force. Now referring to  FIG. 16 , an embodiment of the moving counterpart  162  is shown. In such an embodiment, the counterpart  162  comprises a preferred metallic insert  202  attached to the end of a threaded portion  200 . The insert  202  is adapted to host rolling balls  206  or any other type of limited friction rolling mechanism. 
         [0046]    Now referring to the  FIG. 15 , the moving counterpart  162  is an externally grooved part  207  adapted to receive the reduced friction rolling mechanism or rolling balls  206 . Such an embodiment aims at supporting high loads. 
         [0047]    Now referring to  FIGS. 4, 11 and 17 , different shapes of the interior surface  142  of the stator assembly  14  are shown. In the presented embodiments, the interior surface  142  is adapted in a way to engage, by different possible means, the moving counterpart  162  of the motor assembly  16 . Thus, the  FIG. 4  shows the interior surface  142  engaging a totally threaded moving counterpart  162 , such as but not limited to a screw. The  FIG. 11  shows the interior surface  142  engaging a moving counterpart  162  which comprises an insert  205  grooved in a way to receive a reduced friction mechanisms such as rolling balls and attached at the end of a threaded portion  200 . Now referring to  FIG. 17 , both, the interior wall  142  and the moving counterpart  162  are grooved in a way to receive rolling balls  206 . One skilled in the art shall understand that any other way to engage the moving counterpart  162  to the interior surface  142  may be used. 
         [0048]    The powering of the electric motor  186  of the electric motor assembly  18  may be triggered using any type of interface. In a preferred embodiment, a button wired to the electric motor  186  is used to trigger the electric motor  186 . In other embodiments, the motor assembly may comprise a module to be remotely activated using any type of communication method, such as a RF remote controller and/or a portable device such as a smart phone, tablet or computer. The main advantage resides in the fact that the operator will not have to quit the vehicle to turn the implement. Also, the system is simple and only needs a small electric motor to be activated, thus reducing the weight of the system. 
         [0049]    Now referring back to  FIG. 3 , it is noted that the size of the electric motor assembly  18  is limited by the size of actuator  10 . In a preferred embodiment, a gearbox  184  could be connected to the electric motor  186  to reduce the final angular velocity of the drive shaft while significantly increasing the available torque of the electric motor assembly  18 . The gearbox  184  uses common technology known in the art such as, but not limited to, planetary gears. 
         [0050]    Now referring to  FIGS. 3, 5, 13 and 7-10 , the moving counterpart  162  is attached to the sleeve  166  to trap the plate  172  between the moving counterpart  162  and the sleeve  166 , aiming at limiting translational movement of the moving counterpart  162  with regard to the enclosure  164  alongside the longitudinal axis of the enclosure  164 . In the present embodiment, the moving counterpart  162  is attached to the sleeve  166  using fasteners  168  and the plate  172  is attached to the enclosure  164 . The fasteners  168  are screwed through holes  192  of the moving counterpart  162  and through holes  194  of the sleeve  166 . The sleeve  166  and the moving counterpart  162  are thus able to rotate independently from the enclosure  164  about its longitudinal axis. The electric motor assembly  18  is substantially static with regard to the enclosure  164 . In the present embodiment, bolts  170  are used to attach said electric motor assembly to the plate  172  but any other attachment means known in the art may be used. The bolts  170  are screwed through holes  196  of the plate  172  and through holes  198  of the electric motor assembly  18 . 
         [0051]    In a preferred embodiment, actuation of the electric motor  186  of the electric motor assembly  18  induces rotation of the drive shaft  182  thus forcing the sleeve  166  and the moving counterpart  162  to rotate inside the stator assembly  14 . The rotatory movement is then transformed in a translational movement alongside the longitudinal axis of the actuator  10 . In some embodiment, the translation movement is transformed:
       i. either by the two communicating threaded parts of  162  and  142  as shown on  FIG. 4 ;   ii. either by the grooved interior wall  142  and the rolling balls  206  hosted by a grooved counterpart  162  as shown on  FIG. 17 ;   iii. by two communicating threaded parts of  162  and  142  and the movement of the rolling balls inside a grooved insert supported by the counterpart  162 .       
 
         [0055]    The translational movement alongside the longitudinal axis of the actuator  10  causes the electric actuator  10  to expand or retract depending on the rotating direction of the electric motor  186  (see arrows on  FIG. 4 ). The fully expended and retracted actuators are illustrated in  FIGS. 4 and 6 , respectively. 
         [0056]    The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.