Patent Publication Number: US-2016227710-A1

Title: Power-driven hedge trimmer with movable power assembly

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a power-driven hedge trimmer, more particularly, to a power-driven hedge trimmer with a movable power assembly. 
     2. The Prior Arts 
     Common hedge trimmers on the market nowadays usually include a power and trimming assembly and a gripping assembly. The power and trimming assembly mainly consists of a motor and a cutting blade. The motor is able to drive the blade to reciprocate in order to achieve hedge trimming with the reciprocating motion of the cutting blade. 
     Please refer to the hedge trimmer of Taiwan Design Patent No. D112185, which is shown in  FIG. 1  of the present invention. As shown in  FIG. 1 , in order for a user to steadily hold the hedge trimmer  1   a  during the operation while the hedge trimmer  1   a  is vibrating, the gripping assembly usually consists of a front gripping portion  11   a  and a rear gripping portion  13   a,  so the user may operate the hedge trimmer  1   a  with both hands. The front gripping portion  11   a  in the conventional hedge trimmer  1   a  is attached to a front end of the rear gripping portion  13   a.  The front griping portion  11   a  is vertically aligned with the rear gripping portion  13   a;  in addition, the front gripping portion  11   a  and the rear gripping portion  13   a  are attached to a front side and a rear side of the motor  3   a  respectively. 
     Generally speaking, the front gripping portion  11   a  is disposed on a same axis as the blade to serve as a point of support for the gripping of the machine. In some examples of the conventional hedge trimmer  1   a,  the rear gripping portion  13   a  can be adjustable; however, the front gripping portion  11   a,  the motor  3   a  and the cutting blade  5   a  are permanently connected with each other. 
       FIG. 1  illustrates a front-cutting state of the hedge trimmer  1   a.  During the front-cutting operation, the rear gripping portion  13   a  is gripped by the right hand of the operator, and the front gripping portion  11   a  is gripped by the left hand of the operator (when the operator is right-handed). In addition, in order for the operator to hold the hedge trimmer  1   a  with a comfortable posture, the left hand of the operator is above the hedge trimmer  1   a  during the operation. When the hedge trimmer  1   a  is used for side-cutting, it has to be rotated by 90°. Nevertheless, such rotation is performed by using the wrists of the operator as the pivot points of the rotation, and performing the rotation in such a way may cause the left hand of the operator to deviate from the original position to the right (or left) side of the hedge trimmer  1   a.  Even though the rear gripping portion  13   a  may be adjusted before or after the rotation of the hedge trimmer  1   a,  the left hand of the operator is still turned by 90° in both cases. As a result, both hands of the operator are put in different positions with respect to the original gripping positions after the rotation of the hedge trimmer  1   a,  thus making the operation of the hedge trimmer  1   a  rather difficult and awkward. 
     During the actual operation, the hedge trimmer  1   a  needs to be rotated to switch between the front-cutting state and the side-cutting state frequently. Since the pivot points of the rotation of the hedge trimmer  1   a  are the wrists of the operator, the wrists of the operator have to be turned and twisted frequently, and the gripping positions of the left and right hand of the operator are also constantly changing in order for the operator to maintain a most effortless posture for gripping the hedge trimmer  1   a.    
     Notably, when rotating the hedge trimmer  1   a,  the center of gravity and balance thereof are also constantly changing, and the operator needs to spend extra effort to maintain the center of gravity and the balance of the hedge trimmer  1   a.  If the operator fails to hold the hedge trimmer  1   a  properly, not only can the hedge trimmer la be damaged from falling and hitting the ground, but also the safety of personnel can be endangered. In addition, since the front gripping portion  11   a  and the rear gripping portion  13   a  are connected at two opposite ends of the motor  3   a,  the operator needs to put in extra force in a horizontal direction to hold the weight of the hedge trimmer  1   a  and to maintain the center of gravity thereof. 
     Furthermore, the gripping assembly and the power and trimming assembly of conventional hedge trimmers are connected with each other with only one single rotary shaft. Such structure not only has a low rigidity, but also has a low stability due to the vibration of the motor during the operation of the hedge trimmer. 
     SUMMARY OF THE INVENTION 
     Based on the above reasons, a primary objective of the present invention is to provide a power-driven hedge trimmer with a movable power assembly, so the operator may hold the hedge trimmer with a comfortable posture during different types of operations. In addition, the gripping position of the left and right hands of the operator can stay unchanged in different operations, thus increasing comfort during prolonged operation. 
     Another objective of the present invention is to provide a power-driven hedge trimmer, in which the gripping portion and the power source are connected with each other with two rotatable rotary shafts at two opposing ends of the power source. In such a way, the rigidity of the overall structure is increased, and the stability of the hedge trimmer during operation is also enhanced. 
     Another objective of the present invention is to provide a power-driven hedge trimmer that has a lower overall weight due to a design of the suspended front arm. In this way, the gripping portion can be attached to two opposite ends of the power source without increasing the overall mass of the machine and without compromising the operability of the machine. 
     For achieving the foregoing objectives, the present invention provides a power-driven hedge trimmer with a movable power assembly. The power-driven hedge trimmer includes: a power and trimming assembly, a gripping assembly and a control unit. The power and trimming assembly includes a trimming blade and a power source. The trimming blade is connected to the power source so as to be driven to reciprocate. The gripping assembly includes a front gripping portion, a connecting portion and a rear gripping portion. The front gripping portion is attached to a first side of the power source via a front attaching portion, the rear gripping portion is attached to a second side of the power source opposite to the first side thereof via a rear attaching portion, and the connecting portion is connected with the rear mounting portion, the front gripping portion and the rear gripping portion simultaneously. The control unit is disposed on the connecting portion for controlling the power source. The front attaching portion and the rear attaching portion are two rotary shafts, and a rotation axis of the front attaching portion on the first side of the power source is aligned with a rotation axis of the rear attaching portion on the second side of the power source. A rear stop lock is disposed on the rear gripping portion for locking the front attaching portion and the rear attaching portion at fixed locations. 
     According to an embodiment of the present invention, the front gripping portion includes a suspended front arm, a front handle and a front stop lock. The front attaching portion and the connecting portion are connected to two ends of the suspended front arm respectively, the front stop lock is disposed on the suspended front arm, and an end of the front handle is pivotally connected to a front end of the suspended front arm. The front handle can be locked at at least two locking positions, which are located on two opposite sides of the suspended front arm, with the front stop lock. 
     According to an embodiment of the present invention, each of the two locking positions is located at a position with an angle of 90° between the front handle and the suspended front arm, and the front handle is able to move between the two locking positions. 
     According to an embodiment of the present invention, the rear gripping portion includes a rear handle, and an end of the rear handle is connected to the connecting portion. In addition, a contacting area between the suspended front arm and the connecting portion is equal to a cross-section area of the rear handle. The angle between the suspended front arm and the connecting portion is equal to 90°-120°. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a conventional hedge trimmer; 
         FIG. 2  is a perspective view showing a power-driven hedge trimmer according to a preferred embodiment of the present invention; 
         FIG. 3  is a side view showing the power-driven hedge trimmer according to the preferred embodiment of the present invention; 
         FIG. 4  is a rear view illustrating the rotation of a power assembly of the power-driven hedge trimmer according to the preferred embodiment of the present invention; 
         FIG. 5  is a top view illustrating the rotation of a front handle of the power-driven hedge trimmer according to the preferred embodiment of the present invention; 
         FIG. 6  is a perspective view illustrating the power-driven hedge trimmer of the present invention in a right side cutting state; and 
         FIG. 7  is a perspective view illustrating the power-driven hedge trimmer of the present invention in a left side cutting state. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
       FIG. 2  is a perspective showing a power-driven hedge trimmer according to a preferred embodiment of the present invention, and  FIG. 3  is a side view showing the power-driven hedge trimmer according to the preferred embodiment of the present invention. As shown in  FIGS. 2 and 3 , the power-driven hedge trimmer provided by the present invention includes a power and trimming assembly, a gripping assembly and a control unit. 
     The power and trimming assembly includes a trimming blade  11  and a power source  12 . As shown in  FIG. 2 , the trimming blade  11  is connected to a motor, which serves as the power source  12 , so as to be driven to reciprocate by the power source  12 . In such a way, the sharp blades disposed around the peripheral edge of the trimming blade can be used to perform hedge trimming. 
     In the preferred embodiment of the present invention, the gripping assembly includes a front gripping portion  21 , a connecting portion  22  and a rear gripping portion  23 . The front gripping portion  21  is attached to a first side of the power source  12  via a front attaching portion  24 , the rear gripping portion  25  is attached to a second side of the power source  12  opposite to the first side thereof via a rear attaching portion  25 , and the connecting portion  22  is connected with the rear mounting portion  25 , the front gripping portion  21  and the rear gripping portion  23  simultaneously. To be more specific, the front gripping portion  21  consists of a suspended front arm  211  and a front handle  212 . As shown in  FIG. 3 , the two ends of the suspended front arm  211  are connected with the front attaching portion  24  and the connection portion  22 . An end of the front handle  212  is pivotally connected to a front end of the suspended front arm  211 , so the front handle  212  can be rotated with respect to the suspended front arm  211 . A front stop lock  213  is disposed on the suspended front arm  211  at a location near the pivotal connection of the front handle  212  for locking the front handle  212 . The rear gripping portion  23  includes a rear handle  231 . An end of the rear handle  231  is connected to the connecting portion  22  at a side opposite from the suspended front arm  211 , and the main body of the rear gripping portion  23  is in connection with the rear handle  231  and the rear attaching portion  25 . 
     In the preferred embodiment of the present invention, the front attaching portion  24  and the rear attaching portion  25 , which are used for attaching the front gripping portion  21  and the rear gripping portion  23  at two opposite sides of the power source  12 , are two rotatable rotary shafts. As indicated by the dotted line shown in  FIG. 3 , the mounting positions of the front attaching portion  24  and the rear attaching portion  25  on the two opposite sides of the power source  12  are aligned so that the front attaching portion  24  and the rear attaching portion share a same rotation axis. In this way, the front gripping portion  21  and the rear gripping portion  23  can be rotated with respect to the motor, which serves as the power source  12 , in the directions indicated in  FIG. 4 . As shown in  FIG. 4 , a rear stop lock  26  is disposed on the rear gripping portion  23  for restricting the rotations of the front attaching portion  24  and the rear attaching portion  25 . 
     As shown in  FIG. 2 , the control unit  3  of the present invention is a control panel  31 . The control panel  31  is disposed on an upper surface of the connecting portion  22 , so the operator can control the power source  12  via the control unit  3 . 
     With the above structure and configuration, the operator can adjust the positions of the front handle  212  and the gripping assembly according to the gripping posture needed for a certain type of trimming tasks to be performed, such as front-cutting, right side cutting and left side cutting. Specifically, when adjusting the position of the front handle  212 , the front stop lock  213  is switched to release the front handle  212  from the locking restriction of the front stop lock  213 . Subsequently, the movable front handle  212  is rotated to a desirable position on either side of the suspended front arm  211 , and the front stop lock  213  is switched again to lock the front handle  212  at the desirable position. With the above adjustment, the operator may hold the power-driven hedge trimmer with a comfortable posture during the operation. 
     In addition, since the suspended front arm  211  is located right above the power source  12 , the operator can hold the hedge trimmer effortlessly with one hand only while keeping the balance at the same time by exerting a force in a vertical direction. In such a way, the operator can adjust the power source  12  with the other spare hand, and the operating state of the hedge trimmer can be switched promptly, thus improving the efficiency of the hedge trimming operation. 
     The present invention is characterized in that the gripping assembly is used as the pivot point of rotation for rotating the power source  12 , and the gripping assembly of the hedge trimmer only has to be held stationary by one hand of the operator. The power source  12  can be rotated as long as the pivot point of rotation is held stationary. In order to keep the gripping assembly in a stationary position, the operator has to hold the hedge trimmer steadily and properly with one hand; furthermore, the hand has to stay above the hedge trimmer at all times to ensure the safety of both the machine and the operator. 
     In the preferred embodiment of the present invention, the rotation range of the front handle  212  is between the two locking positions on two opposite sides of the suspended front arm  211 , and each of the two locking positions is located at a position with an angle of 90° between the front handle  212  and the suspended front arm  211 , as shown in  FIG. 5 . 
     When adjusting the relative position between the gripping assembly and the motor, first, the rear stop lock  26  is switched to release the front attaching portion  24  and the rear attaching portion  25  from the rotation restriction of the rear stop lock  26 . Subsequently, the front gripping portion  21  and the rear gripping portion  23  are rotated to a desirable position relative to the power source, and the rear stop lock  26  is switched again to lock the front gripping portion  21  and the rear gripping portion  23  at the desirable positions. With the above operation, the power-driven hedge trimmer of the present invention can be adjusted to suitable positions for various types of operations, and the operator may hold the power-driven hedge trimmer with a consistent and comfortable posture in different types of operations as well. 
     As shown in  FIG. 3 , in the preferred embodiment of the present invention, an angle θ between the suspended front arm  211  and the connecting portion  22  is between 90°-120°, and a contacting area between the suspended front arm  211  and the connecting arm  22  is equal to a cross-section area of the rear handle  231 . With the above features, the structures of the front gripping portion  21  and the rear gripping portion  23  are strong enough to support the power and trimming assembly; in addition, with the designs of the suspended front arm  211  and the rear handle  231  as described above, the power-driven hedge trimmer of the present invention may have a higher rigidity while maintaining a low weight of the overall structure with the suspended structure, thus increasing the operability of the power-driven hedge trimmer. 
     Due to the adjustable and movable front handle and power assembly, the power-driven hedge trimmer of the present invention may be adjusted to desirable states according to the trimming direction, such as front cutting, right side cutting or left side cutting. When using the power-driven hedge trimmer for front cutting, the operator may use his preferred hands to hold the power-driven hedge trimmer to perform hedge cutting. For example, when the hedge trimmer is in the state as shown in  FIG. 2 , the operator may hold the front handle  212  with his left hand and may hold the rear handle  231  with his right hand to operate the machine. If the operator wishes to hold the front handle  212  with his right hand, he may also adjust the position of the front handle  212  with the front stop lock  213 , as shown in  FIG. 5 . 
     When using the power-driven hedge trimmer of the present invention to perform right side cutting, the operator may release the rear stop lock  26  to rotate the front gripping portion  21  and the rear gripping portion  23  with respect to the trimming blade  11  and the power source  12  to the position shown in  FIG. 6 . The front gripping portion  21  and the rear gripping portion  23  are then locked at the positions shown in  FIG. 6  by switching the rear stop lock  26  again. As shown in  FIG. 6 , when performing the operation of right side cutting, the position of the front handle  212  is at the same position with the one shown in  FIG. 2 . Since the front handle  212  is perpendicular to the rear handle  231 , the operator may perform the right side cutting using the same posture as the posture used for front cutting; namely, the right side cutting may be performed by holding the front handle  212  with the left hand and holding the rear handle  231  with the right hand. 
     When using the power-driven hedge trimmer of the present invention to perform left side cutting, the operator may release the front stop lock  213  and the rear stop lock  26  to rotate the front handle  212 , the front gripping portion  21  and the rear gripping portion  23  relative to the trimming blade  11  and the power source  12  to the positions shown in  FIG. 7 . The front handle  212 , the front gripping portion  21  and the rear gripping portion  23  are then locked at the positions shown in  FIG. 7  by switching the front stop lock  213  and the rear stop lock  26  again. As shown in  FIG. 7 , when performing the operation of left side cutting, the position of the front handle  212  is on the right side of the rear handle  231  while still being perpendicular to the rear handle  231 . Hence, the operator may perform the left side cutting using a posture similar to the postures used for front cutting and right side cutting, i.e., the left side cutting may be performed by holding the front handle  212  with the right hand and holding the rear handle  231  with the left hand. 
     The power-driven hedge trimmer of the present invention is provided with a movable front handle and a movable power assembly. The movable front handle and the movable power assembly can be adjusted according to the types of operations to be performed, thereby allowing the operator to maintain a comfortable and consistent gripping posture throughout various types of operations. Thus, the experience of using the hedge trimmer provided by the present invention for prolonged operation is ameliorated. Furthermore, the gripping assembly and the power assembly are connected via two rotatable attaching portions. Not only are the rigidity and stability of the hedge trimmer improved by doing so, but the operability and applicability of the hedge trimmer are also enhanced with a suspended design, which lowers the overall mass of the hedge trimmer. 
     Although the present invention has been described with reference to the preferred embodiments thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.