Abstract:
A power operated pick-up tool comprises a hollow handle and a battery operated motor received in the handle for imparting a rotary motion driving force through an output gear, a gear reduction assembly reducing the speed of the rotation of the output gear before transmitting the rotational force to a nut and screw assembly which converts the rotational motion into a linear motion of the nut, an elongate hollow stalk having a distal end and a proximal end attached to the handle, and a clamping assembly attached to the distal end of the stalk and the nut of the nut and screw assembly such that the clamping assembly can be operated to grasp an object or release a grasped object upon actuation of the motor.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to a pick-up tool for reaching and fetching objects, particularly, to a pick-up tool which is driven by electricity.  
       BACKGROUND OF THE INVENTION  
       [0002]     Single-hand actuated pick-up tools are known to reach and fetch objects.  FIG. 6  shows a conventional pick-up tool, which comprises an elongate hollow stalk  501  having a distal end  502  and a proximal end  503 . Each of two outer flexible, spring fingers  504  is attached at its proximal end to the outside of the stalk  501  and is attached at its distal end to a flexible clamping cup  505 . Each of two inner flexible spring fingers  506  extends from the flexible clamping cup  505  through the interior of the stalk  501  to a trigger  507  which is pivotally mounted at the proximal end  503  of the stalk  501  and used to pull the two inner flexible spring fingers  506  backward (toward the trigger) when squeezed by a user. The backward pull of the two inner flexible spring fingers  506  will cause the two flexible clamping cups  505  to come together in order to grasp an object through the flexing and bending of the two outer flexible, spring fingers  504  toward each other.  
         [0003]     When operating this kind of conventional pick-up tool, a user must use his/her hand to squeeze the trigger in order to grasp an object. However, such an operation is laborious, especially for weak or older people and children. Hence, it needs an improved pick-up tool which is labor-saving.  
       SUMMARY OF THE INVENTION  
       [0004]     The main object of this invention is to provide a pick-up tool, which is electricity driven and thus is labor-saving for users.  
         [0005]     The present invention provides an electric powered pick-up tool comprising a hollow handle and a power means received in the handle for imparting a rotary motion driving force and having an output gear. A gear reduction assembly reduces the speed of the rotation of the output gear before transmitting the rotational force to a nut and screw assembly which converts the rotational motion into a linear motion of the nut. An elongate hollow stalk has a distal end and a proximal end attached to the handle. A pair of outer flexible, spring fingers are attached at the distal end of the stalk and have clamping elements terminating at the outer ends of the fingers for grasping an object when brought toward one another. A pair of inner flexible spring fingers extend from the clamping elements through the interior of the stalk and operably connect with the nut and screw assembly such that the pair of inner flexible spring fingers can be pulled toward the handle to bring the clamping elements toward one another or pushed toward the clamping elements to bring the clamping elements away from one another. Preferably, the power means is a battery operated motor.  
         [0006]     When operating the pick-up tool of the invention, users can just press a switch on the handle at a first position to actuate the power means to cause the two flexible clamping elements to come together for grasping an object. On the contrary, when users press the switch at a second position to actuate the power means, the two flexible clamping elements will move away from each other to release the object.  
         [0007]     The structure and advantage of the invention will become more apparent by reading the following description of the preferred embodiment with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is a perspective view of a preferred embodiment of a pick-up tool in accordance with the present invention;  
         [0009]      FIG. 2  is an exploded perspective view of the pick-up tool of  FIG. 1 ;  
         [0010]      FIG. 2A  is an enlarged drawing showing the bearing, gear box, copper sleeve, linkage rod, travel limit stop and stalk shown in  FIG. 2 , wherein the gear box, copper sleeve and linkage rod are shown in section;  
         [0011]      FIG. 3  is a longitudinal sectional view showing the pick-up tool of  FIG. 1  in a gripping condition;  
         [0012]      FIG. 4  is a longitudinal sectional view showing the pick-up tool of  FIG. 1  in a non-grasping condition;  
         [0013]      FIG. 4A  is an enlarged view showing a portion circled by dash line W in  FIG. 4 ;  
         [0014]      FIG. 5  is a schematic view showing the circuit formed by the contact switch, battery set, two travel limit switches and motor; and  
         [0015]      FIG. 6  is a perspective view of a conventional pick-up tool. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0016]     Referring to  FIGS. 1 and 2 , the pick-up tool of the present invention comprises a hollow handle  10 , an elongate hollow stalk  30  and a clamping assembly  40 . A battery set  12 , an electric motor  21  having an output gear  211 , and a transmission assembly  20  are provided within the handle  10 .  
         [0017]     Referring to  FIG. 2 , the hollow handle  10  is formed of two housing halves  11  connected together through screws  111 . The upper side of the handle  10  has an opening  13  for receiving a switch  14 , such as a contact switch, which is electrically connected to the battery set  12  and the motor  21 , although the wiring is not shown for clarity.  
         [0018]     The elongate hollow stalk  30  has a distal end  31  and a proximal end  32 , and receives a wire rod  33  therein. A proximal end of the wire rod  33  has threads  331 . At the proximal end  32 , the stalk  30  has a cut  35  provided at the upper side thereof and an elongate slot  34  extending along the bottom side thereof, opposite to the cut  35 . The slot  34  has an appropriate length depending on demands. The cut  35  and the elongate slot  34  all extend to the proximal end of the stalk  30 .  
         [0019]     Referring to  FIGS. 2 and 4 A, the transmission assembly  20  comprises a first set and a second set of planet gears ( 22 ,  23 ) mounted on gear stands  24  and  253 , respectively, and a cylindrical gear case  26 .  
         [0020]     The gear stand  24  has three radially equally located studs  241  provided at one side thereof. Each stud  241  is used for mounting thereon each planet gear of the first set of planet gears  22 . The first set of planet gears  22  engage both the output gear  211  of the motor  21  as a sun gear as well as an internal gear  262  of the cylindrical gear case  26 . A sun gear  242  is provided in the center of another side of the gear stand  24  for engaging with the second set of planet gears  23  which mounted on three studs  2531  radially equally located on the gear stand  253 . The second set of planet gears  23  also engage with the internal gear  262  of the cylindrical gear case  26 .  
         [0021]     Since the detailed structure and function of the sun and planet gear are well known to a person skilled in the art, the description therefore is omitted here.  
         [0022]     As shown in  FIGS. 2A and 4A , the cylindrical gear case  26  has a larger diameter portion  261  of which the interior surface forms the internal gear  262  as a ring gear, and a smaller diameter tube portion  263  forming an annual shoulder  266  at the bottom of the larger diameter portion  261 . The larger diameter portion  261  and the smaller diameter portion  263  have the same central axis.  
         [0023]     The smaller diameter portion  263  has two diametrically positioned lugs  264  each having a through hole  265  and provided at the outside thereof for engaging with the cuts  35  and the slot  34  of the stalk  30 , respectively, so as to mount the gear case  26  onto the proximal end  32  of said stalk  30  and also secure the gear case  26  to the inner side wall of one of the housing halves  11  via screws (not shown) extending through the holes  265  and into the receiving holes  112  on the inner side wall of the one of the housing halves  11  ( FIG. 2 ). A bearing or a bushing  255  is fitted in the smaller diameter tube portion  263 . The stalk  30 , with its proximal end  32  fitted on the smaller diameter tube portion  263 , and bearing  255  are fixed together via a set screw  268  threaded through holes ( 36 ,  267 ,  256 ) provided at the proximal end  32 , smaller diameter tube portion  263  and bearing  250 , respectively.  
         [0024]     Referring to  FIGS. 2, 2A  and  4 A, the transmission assembly  20  further includes a screw  25  having an enlarged end  252  connected to the gear stand  253 . A hollow linkage rod  27  in the stalk  30  has an enlarged end portion  271  for receiving therein a nut  28 , preferably made of copper, which engages with the screw  25 .  
         [0025]     A stop  29  is fixed at the bottom of the enlarged end portion  271  via a screw  291  extending through the stop  29 , a washer  292  and the end portion  271 . The screw  291  is also used to fix the nut  28  in the end portion  271  by extending through a recess  281  in the nut  28 .  
         [0026]     A smaller end of the hollow linkage rod  27  has internal threads  272  for engaging with the threads  331  on one end of the wire rod  33 .  
         [0027]     As shown in  FIG. 4A , the screw  25  is inserted through the gear case  26  with the gear stand  253  abutting against the shoulder  266  of the larger diameter portion  261  of the gear case  26  and the enlarged end  252  rotatably supported in the bearing  255 , and engages with the nut  28  fixed in the linkage rod  27 . The rod  27  is received in the stalk  30  with the stop  29  projecting through the slot  34  of the stalk  30  and outside of the stalk  30 .  
         [0028]     First and second travel limit switches (SW 1 , SW 2 ) are provided on the inner surface of said handle  10  near the distal end of the handle  10  and beneath the elongate slot  34  of the stalk  30  and the stop  29 . The first and the second travel switches (SW 1 , SW 2 ) are spaced apart at an appropriate distance depending on the maximum travel of the stop  29 .  
         [0029]     The clamping assembly  40  is attached to the distal end  31  of the stalk  30 , and has two outer flexible, spring fingers  41  each attached at its proximal end via rivets  413  to the outside of the stalk  30  and is attached at its distal end to a flexible clamping cup  43  via post and nut combination  44 , and two inner flexible spring fingers  42  each extending from the flexible clamping cup  43  through the interior of the stalk  30  and connected with the distal end of the wire rod  33  via rivets (not shown in the drawings).  
         [0030]     Referring to  FIGS. 3 and 5 , when a user wants to grasp an object, he/she can press the contact switch  14  in a first position A. At this time, in the contact switch  14 , contact  2  connects with contact  4 , and contact  8  connects with contact  6  such that a closed circuit is formed between the motor  21 , the travel limit switch SW 2 , contact switch  14  and battery set  12 , and the motor  21  is rotated in a counterclockwise direction (as observed from the handle toward the clamping cup) and the sun gear  211  of the motor  21  is thus rotated in a counterclockwise direction. The first set of planet gears  22  engaging with the sun gear  211  and the ring gear  262  are rotated in a clockwise direction to cause the rotation of the gear stand  24  and the sun gear  242  in a counterclockwise direction. Further, with the sun gear  242  engaging with the second set of planet gears  23  which engage with the ring gear  262 , the planet gears  23  are rotated in a clockwise direction to cause the rotation of the screw  25  in a counterclockwise direction such that the nut  28  together with linkage rod  27  and the wire rod  33  can be pulled backward as shown in arrow D 1 . The backward pull of the wire rod  33  also causes the rearward pull of the inner spring fingers  42  such that the two clamping cups  43  can come together for grasping an object by flexing and bending the outer flexible spring fingers  41 . It can be appreciated that the enlarged end portion  271  of the rod  27 , slidably fitted in the stalk  30 , serves a guide for the sliding movement of the rod  27  along the stalk  30 .  
         [0031]     During the rearward movement of the linkage rod  27 , the stop  29  attached to the linkage rod  27  will also be moved backward. When the stop  29  touches the second travel limit switch SW 2 , the second travel switch SW 2  will be switched off. At this time, the flexible clamping cups  43  are at their maximum clamping force. Of course, during the rearward movement of the inner flexible spring fingers  42 , the wire rod  33  and the linkage rod  27  to make the flexible clamping cups  43  come together, the user can release the contact switch  14  any time to switch off the circuit depending on demands.  
         [0032]     Referring to  FIGS. 4, 4A  and  5 , after the flexible clamping cups  43  have grasped the object, the user can press the contact switch  14  in a second position B in order to make the flexible clamping cups  43  move apart from each other to release the object. When the user presses the contact switch  14  in the second position B, contact  1  connects with contact  3 , and contact  7  connects with contact  5  such that a closed circuit is formed between the motor  21 , the travel limit switch SW 1 , contact switch  14  and battery set  12 . At this time, the motor  21  is rotated in a clockwise direction (as seen from the handle toward to the clamping cups) and the sun gear  211  of the motor  21  is thus rotated in a clockwise direction. Since the first set of planet gears  22  engages with the sun gear  211 , the planet gears  22  are rotated in a counterclockwise direction to cause the rotation of the gear stand  24  and the sun gear  242  in a clockwise direction. Further, since the sun gear  242  engages with the second set of planet gears  23 , the planet gears  23  are rotated in a counterclockwise direction to cause the rotation of the screw  25  rotated in a clockwise direction such that the linkage rod  27  with the wire rod  33  can be pushed forward as shown in arrow D 2 . The forward push of the wire rod  33  also causes the forward push of the inner flexible spring fingers  42  such that the flexible clamping cups  43  can move apart from each other for releasing the object.  
         [0033]     During the forward movement of the inner flexible spring fingers  42 , the wire rod  33  and the linkage rod  27 , the stop  29  will also be moved forward. When the stop  29  touch the first travel limit switch SW 1 , the first travel limit switch SW 1  will be switched off. At this time, the flexible clamping cups  43  are at their maximum opening position.  
         [0034]     In the embodiment of the invention, the numbers of the teeth of the sun gears ( 211 ,  242 ), planet gears ( 22 ,  23 ) and the ring gear  262  are 12, 15 and 42, respectively. Thus the ratio between the rotational speed of the motor and the screw is about 20.27:1. Therefore, if the rotational speed of the motor  21  is 18000 rpm, then the rotational speed of the screw  25  would be 888 rpm. The sun and planet gear can reduce the speed of the output rotation of the motor while increase the torque to perform the grasping action of the flexible clamping assembly  40 . The distance between the first and the second travel limit switches (SW 1 , SW 2 ) can determine the closing and opening range of the two flexible clamping cups  43 .  
         [0035]     The preferred embodiment described herein is depicted in order to provide an example of the present invention, and not limiting of the scope of the invention. Other embodiments and variations will be apparent to those skilled in the art and may be made without departing from the essence and scope of the invention as defined in the attached claims.