Patent Publication Number: US-2016221657-A1

Title: Handheld Propulsion Assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from Taiwanese application no. 104201568, filed on Jan. 30, 2015, the disclosure of which is incorporated in its entirety herein by reference. 
     FIELD 
     The disclosure relates to a handheld propulsion assembly, more particularly to a handheld propulsion assembly by which a watercraft can be propelled in a force-saving manner. 
     BACKGROUND 
     A conventional paddle includes an elongated shaft, a blade at a lower end of the elongated shaft, and a handle at an upper end of the elongated shaft. A paddler can use the paddle to propel a watercraft, such as a canoe, by inserting the blade into water and then pushing or pulling the blade through water in each paddle stroke. For propelling the watercraft, the paddler must exert a relatively large force. 
     SUMMARY 
     Therefore, an object of the disclosure is to provide a handheld propulsion assembly by which a paddler can propel a watercraft in a force-saving manner. 
     According to the disclosure, a handheld propulsion assembly for watercraft includes at least one propulsion subassembly which includes a floatable board, a pivot mount, a crank shaft, a crank arm, a hinge mount, and at least one blade. The floatable board member is elongated in a forward-rearward direction and has upper and lower surfaces. The pivot mount is disposed on the upper surface of the floatable board member and has a pivot bearing surface defining a pivot axis. The crank shaft has a pivoted end and a connected end opposite to the pivoted end. The pivoted end is pivotably mounted on the pivot mount about the pivot axis and is in frictional engagement with the pivot bearing surface. The crank arm extends from the connected end in a radial direction relative to the crank shaft, and has a driven portion opposite to the connected end such that when the driven portion is driven to swing back and forth, the floatable board member is correspondingly moved forward and backward due to the frictional engagement between the pivot bearing surface of the pivot mount and the pivoted end of the crank shaft. The hinge mount is disposed on the lower surface of the floatable board member and defines a hinge axis. The blade is hinged to the hinge mount and is angularly movable about the hinge axis between an unfolded position, where the blade has a maximized propelling force, and a folded position, where the blade has a minimized propelling force. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the disclosure will become apparent in the following detailed description of the embodiments with reference to the accompanying drawings, in which: 
         FIG. 1  is an exploded perspective view of a propulsion subassembly of a handheld propulsion assembly according to a first embodiment of the disclosure; 
         FIG. 2  is a fragmentary side view of the propulsion subassembly shown in  FIG. 1  in an assembled state; 
         FIG. 3  is similar to  FIG. 2  but with blades in a folded position; 
         FIGS. 4 to 6  illustrate the handheld propulsion assembly according to the first embodiment in use; 
         FIG. 7  shows a modified configuration of the propulsion subassembly according to the first embodiment; 
         FIG. 8  is an exploded perspective view of a propulsion subassembly of a handheld propulsion assembly according to a second embodiment of the disclosure; 
         FIG. 9  is a fragmentary side view of the propulsion subassembly shown in  FIG. 8  in an assembled state; 
         FIG. 10  is similar to  FIG. 9  but with blades in a folded position; 
         FIG. 11  is an exploded perspective view of a propulsion subassembly of a handheld propulsion assembly according to a third embodiment of the disclosure; 
         FIGS. 12 to 14  illustrate the handheld propulsion assembly of the third embodiment in use; 
         FIG. 15  illustrates a handheld propulsion assembly according to a fourth embodiment of the disclosure in use; 
         FIG. 16  is an exploded perspective view of a propulsion subassembly of a handheld propulsion assembly according to a fifth embodiment of the disclosure; 
         FIG. 17  is a perspective view of the propulsion subassembly shown in  FIG. 16  in an assembled state; 
         FIG. 18  is a top view of a blade of the propulsion subassembly of the fifth embodiment; and 
         FIG. 19  is similar to  FIG. 18  but with the blade in a folded position. 
     
    
    
     DETAILED DESCRIPTION 
     Before the disclosure is described in greater detail, it should be noted that like elements are denoted by the same reference numerals throughout the disclosure. 
     With reference to  FIGS. 1 and 4 , a handheld propulsion assembly according to a first embodiment of the disclosure is used for propelling a watercraft  9 , such as a canoe, and includes at least one propulsion subassembly  10 . 
     The propulsion subassembly  10  includes a floatable board member  1 , a pivot mount  20 , a crank shaft  23 , a crank arm  2 , a hinge mount  13 , and at least one blade  32 . 
     The floatable board member  1  is elongated in a forward-rearward direction (X), and has upper and lower surfaces  11 ,  12 . The pivot mount  20  is disposed on the upper surface  11  of the floatable board member  1 , and has a pivot bearing surface  201  defining a pivot axis (P). The hinge mount  13  is disposed on the lower surface  12  of the floatable board member  1 , and defines a hinge axis (H). In this embodiment, the pivot axis (P) is oriented transverse to the forward-rearward direction (X), and the hinge axis (H) is parallel to the pivot axis (P). In addition, the floatable board member  1  and the hinge mount  13  are formed in one-piece. 
     The crank shaft  23  has a pivoted end  231  and a connected end  232  which are opposite to each other. The pivoted end  231  is pivotably mounted on the pivot mount  20  about the pivot axis (P), and is in frictional engagement with the pivot bearing surface  201 . 
     The crank arm  2  extends from the connected end  232  in a radial direction relative to the crank shaft  23 , and has a driven portion  221  opposite to the connected end  232  such that when the driven portion  221  is driven to swing back and forth, the floatable board member  1  is correspondingly moved forward and rearward, due to the frictional engagement between the pivot bearing surface  201  of the pivot mount  20  and the pivoted end  231  of the crank shaft  23 . 
     In this embodiment, the driven portion  221  can serve as a handle for gripping by a paddler (see  FIG. 4 ), and the crank arm  2  has upper and lower segments  22 ,  21  which are telescopically connected to each other. The lower segment  21  is connected to the connected end  232  and has a tubular end portion  212  distal from the connected end  232 , and the upper segment  22  has a connected end portion  222  which is distal from the driven portion  221 , and which is slidably fitted into the tubular end portion  212  so as to permit telescopic connection between the connected end portion  222  and the tubular end portion  212 . The tubular end portion  212  has a plurality of through holes  214  that are linearly displaced from each other. The connected end portion  222  has a spring-loaded ball  223  configured to be snapped into a selected one of the through holes  214  for adjusting the length of the crank arm  2 . 
     The blade  32  is hinged to the hinge mount  13 , and is angularly movable about the hinge axis (H) between an unfolded position ( FIGS. 2 and 5 ), where the blade  32  has a maximized propelling force, and a folded position ( FIGS. 3 and 6 ), where the blade  32  has a minimized propelling force. 
     In this embodiment, the blade  32  is hinged to the hinge mount  13  through a hinge member  31 , and has a free side edge  323  and a hinged side edge  324  which is opposite to the free side edge  323 , and which is hinged to the hinge mount  13  about the hinge axis (H). When the blade  32  is in the unfolded position (see  FIGS. 2 and 5 ), the free side edge  323  is disposed remote from the lower surface  12  of the floatable board member  1  to permit the blade  32  to have the maximized propelling force. When the blade  32  is in the folded position (see  FIGS. 3 and 6 ), the free side edge  323  is disposed close to the lower surface  12  of the floatable board member  1  to permit the blade  32  to have a minimized propelling force. 
     Specifically, when a paddler sits in the watercraft  9  and grips the driven portion  221  (see  FIG. 4 ), the length of the crank arm  2  can be adjusted to permit the floatable board member  1  to float on water. As shown in  FIG. 5 , when the paddler drives the propulsion subassembly  10  to move the propulsion subassembly  10  rearwardly, the blade  32  is in the unfolded position and has the maximized propelling force, thereby propelling the watercraft  9  forwardly. As shown in  FIG. 6 , when the paddler drives the propulsion subassembly  10  to move the propulsion subassembly  10  forwardly, the blade  32  is in the folded position and has the minimized propelling force, thereby preventing the watercraft  9  to be propelled rearwardly. Because the floatable board member  1  floats on water, the paddler can drive the propulsion subassembly  10  in a force-saving manner. 
     As shown in  FIG. 1 , the propulsion subassembly  10  further includes a stop member  33  which is connected to the hinged side edge  324  of the blade  32 , and which extends along a lengthwise axis (L) that is oriented perpendicular to the blade  32  such that the stop member  33  abuts against the lower surface  12  of the foldable board member  1  once the blade  32  is moved to the unfolded position ( FIG. 2 ). 
     As shown in  FIGS. 1 and 4 , the handheld propulsion assembly includes two propulsion subassemblies  10  each having two blades  32 , two stop members  33 , and two hinge members  31 . The blades  32  are displaced from each other in the forward-rearward direction (X). 
     It should be noted that each propulsion subassembly  10  can be modified to be used by two or more paddlers. As shown in  FIG. 7 , two paddlers can use a modified configuration of the first embodiment to simultaneously propel the watercraft  9 . In this modified configuration, the floatable board member  1  is lengthened, and each propulsion subassembly  10  includes two hinge mounts  20 , two crank shafts  23 , two crank arms  2 , four blades  32 , four stop members  33 , and four hinge members  31 . 
       FIGS. 8 to 10  illustrate a handheld propulsion assembly according to a second embodiment of the disclosure. The second embodiment is similar to the first embodiment except that, in the second embodiment, instead of the stop member  33 , each propulsion subassembly  10  includes left and right side brackets  34 ,  35 . In each propulsion subassembly  10 , the blade  32  has left and right lateral edges  321 ,  322  which are opposite to each other in a direction of the hinge axis (H), and each of the left and right side brackets  34 ,  35  connects the lower surface  12  of the floatable board member  1  and a corresponding one of the left and right lateral edges  321 ,  322 , and is configured to be collapsible.  FIG. 9  shows the blade  32  in the unfolded position. When the blade  32  is displaced to the folded position, the left and right side brackets  34 ,  35  are displaced to a collapsed position (see  FIG. 10 ), where each of the left and right lateral edges  321 ,  322  is substantially parallel to the lower surface  12  of the floatable board member  1 . 
     In this embodiment, each of the left and right side brackets  34 ,  35  has pleats  341  to allow the left and right side brackets  34 ,  35  to be collapsible. 
       FIGS. 11 to 14  illustrate a handheld propulsion assembly according to a third embodiment of the disclosure for propelling a watercraft  9 ′ with a relatively large size. The third embodiment is similar to the first embodiment except that, in the third embodiment, each of the propulsion subassemblies  10  further includes a bearing lug  6  and an auxiliary crank member  7 . As best shown in  FIGS. 12 to 14 , the bearing lug  6  is adapted to be mounted on a gunwale  91 ′ of the watercraft  9 ′, and has a bearing lug surface  61 . The auxiliary crank member  7  has a handle segment  71 , an arm segment  72 , and an actuating segment  73 . The handle segment  71  extends in a direction of the pivot axis (P) to terminate at a grip portion  711  and a juncture portion  712 . The arm segment  72  extends from the juncture portion  712  in the radial direction to terminate at an arm end  721 . The actuating segment  73  is disposed to connect the arm end  721  and the driven portion  221  of the crank arm  2 , and is rotatably mounted on the bearing lug surface  61 . 
     In addition, in each propulsion subassembly  10 , the lower segment  21  of the crank arm  2  further has an impact absorbing portion  215  proximate to the connected end  232 , for absorbing shock or vibration of the floatable board member  1  resulting from the swinging movement of the crank arm  2 . 
       FIG. 15  illustrates a handheld propulsion assembly according to a fourth embodiment of the disclosure. The fourth embodiment is similar to the third embodiment except that, in the fourth embodiment, the handheld propulsion assembly further includes a post  52  and a bearing member  51 . The post  52  is adapted to be mounted on a deck  92 ′ of the watercraft  9 ′. The bearing member  51  is supported by the post  52  and has left and right bearing surfaces  511 ,  512 . Each of the propulsion subassemblies  10  further includes a coupling rod  4  extending from the grip portion  711  to terminate at a journal end  41  which is journaled on a corresponding one of the left and right bearing surfaces  511 ,  512 . Alternatively, the grip portions  711  of the propulsion subassemblies  10  can serve as foot pedals to allow a user to propel the watercraft  9 ′ by pushing the foot pedals with his/her feet. 
       FIGS. 16 to 19  illustrate a handheld propulsion assembly according to a fifth embodiment of the disclosure. The fifth embodiment is similar to the third embodiment except that, in the fifth embodiment, a hinge mount  13 ′ is disposed on the lower surface  12  of the floatable board member  1 , and defines a hinge axis (H) which is oriented transverse to both a direction of the pivot axis (P) and the forward-rearward direction (X). The blade  32  is hinged to the hinge mount  13 ′. Each propulsion subassembly  10  further includes a fin member  14  which extends downwardly from the lower surface  12  of the floatable board member  1 , and which extends forwardly from the hinge mount  13 ′ in the forward-rearward direction (X) to terminate at a front end edge  141 . The blade  32  has two blade halves  325  each having a free side edge  326  and a hinged side edge  327  which is opposite to the free side edge  326 , and which is hinged to the hinge mount  13 ′ about the hinge axis (H). When the blade  32  is in the unfolded position ( FIGS. 17 and 18 ), the free side edges  326  of the blade halves  325  are disposed remote from each other to permit the blade  32  to have the maximized propelling force. When the blade  32  is in the folded position ( FIG. 19 ), the free side edges  326  of the blade halves  325  are disposed close to each other to permit the blade  32  to have a minimized propelling force. 
     In the fifth embodiment, each propulsion subassembly  10  includes two fin members  14 , two blades  32 , and two hinge mounts  13 ′. The fin members  14  are adapted to be disposed in water to stabilize the motion of the floatable board member  1  while the floatable board member  1  moves on water. 
     While the disclosure has been described in connection with what are considered the exemplary embodiments, it is understood that this disclosure is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.