Patent Publication Number: US-7909049-B2

Title: Operating mechanism for umbrella

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to umbrellas and more particularly, to an operating mechanism for umbrella, which uses screw rods and screw nuts to move the telescopic umbrella shaft between the extended position and the received position, thereby moving the runner to open or close the umbrella canopy. 
     2. Description of the Related Art 
     Many automatic umbrellas are commercially available. These conventional automatic umbrellas have drawbacks as follows:
     1. When released the lock, the runner is suddenly forced by the spring force of the related spring member to push the umbrella stretchers against the umbrella ribs, opening the umbrella canopy in a rush. Sudden open of the umbrella canopy may injure other persons accidentally.   2. After the umbrella canopy is opened, the runner is not locked, and the umbrella canopy may be forced by a strong wind to collapse the umbrella stretchers and the umbrella ribs.   3. The spring member will start to deteriorate after a long use of the umbrella, affecting normal functioning of the umbrella.   

     SUMMARY OF THE INVENTION 
     The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide an operating mechanism for umbrella, which assures positive positioning and high safety when opening or closing the umbrella. It is another object of the present invention to provide an operating mechanism for umbrella, which is durable in use. 
     To achieve these and other objects of the present invention, an operating mechanism is used in an umbrella comprising a hub and rib assembly, a runner, a plurality of stretchers pivotally connected between the ribs of the hub and rib assembly and the runner, and a canopy stretched on the hub and rib assembly. The operating mechanism is operable to move the runner against the stretchers and to further force the ribs of the hub and rib assembly to open/close the canopy. The operating mechanism comprises a telescopic shaft, first and second screw nuts fixedly mounted in the telescopic shaft at different elevations, a third screw nut is fixedly mounted in the runner of the umbrella, a first screw rod threaded through the first screw nut, a second screw rod threaded through the second screw nut and axially slidably connected to and rotatable with the first screw rod, a third screw rod threaded through the third screw nut and axially slidably connected to and rotatable with the second screw rod, and a transmission mechanism connected to the first screw rod and operable to rotate the first screw rod. 
     Further, the transmission mechanism comprises a transmission gear set, and a drive member rotatable by a user to drive the transmission gear set, causing the transmission gear set to rotate the first, second and third screw rods and to further move the runner upwards or downwards. 
     In an alternate form of the present invention, a motor is provided for driving the transmission gear set to rotate the first, second and third screw rods 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is an exploded view of an operating mechanism for umbrella in accordance with a first embodiment of the present invention. 
         FIG. 2  is a schematic assembly view of the operating mechanism for umbrella in accordance with the first embodiment of the present invention. 
         FIG. 3  is a schematic sectional view of the operating mechanism for umbrella in accordance with the first embodiment of the present invention. 
         FIG. 4  is a cross sectional view of the present invention, showing the first screw rod, second screw rod and third screw rod concentrically coupled together. 
         FIG. 5  is an exploded view of the transmission mechanism of the operating mechanism for umbrella in accordance with the first embodiment of the present invention. 
         FIG. 6  is a cross sectional view of the transmission mechanism of the operating mechanism for umbrella in accordance with the first embodiment of the present invention. 
         FIG. 7  is a cross sectional view of a part of the first embodiment of the present invention, showing the gear of the first screw rod meshed with the transmission gears of the of the last gear holder of the transmission gear set. 
         FIG. 8  is a schematic drawing of the present invention, showing the runner moved upwards and the stretchers extended outwards. 
         FIG. 9  is an exploded view of an operating mechanism for umbrella in accordance with a second embodiment of the present invention. 
         FIG. 10  is a schematic sectional view of the operating mechanism for umbrella in accordance with the second embodiment of the present invention. 
         FIG. 11  is an exploded view of the transmission mechanism of the operating mechanism for umbrella in accordance with the second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1˜8 , an operating mechanism in accordance with a first embodiment is shown used in an umbrella comprising a hub and rib assembly  13 , a runner  1 , a plurality of stretchers  16  pivotally connected between the (ribs of the) hub and rib assembly  13  and the runner  1 , and a canopy  10  stretched on the hub and rib assembly  13 . When the runner  1  is moved upwards subject to the operation of the operating mechanism, the stretchers  16  are forced to move the hub and rib assembly in opening the canopy  10 . On the contrary, when the runner  1  is moved downwards, the stretchers  16  are received together, causing the hub and rib assembly  13  to close the canopy  10 . 
     The aforesaid operating mechanism comprises a plurality of hollow screw rods, i.e., the first screw rod  21 , the second screw rod  22  and the third screw rod  23 , a plurality of screw nuts, i.e., the first screw nut  31 , the second screw nut  32  and the third screw nut  15 , a telescopic shaft  4 , and a transmission mechanism  6 . 
     The first screw nut  31  and the second screw nut  32  are fixedly mounted inside the telescopic shaft  4  at different elevations. The third screw nut  15  is formed integral with or fixedly mounted in the inner diameter of the runner  1 . 
     The first screw rod  21  is threaded through the first screw nut  31  and inserted into the second screw rod  22  (see  FIG. 3 ), having a gear  211  fixedly located on its one end and meshed with the transmission mechanism  6  and a longitudinal sliding groove  212  for guiding axial movement of the longitudinal rib  221  the second screw rod  22  relative to the first screw rod  21 . The second screw rod  22  is threaded through the second screw nut  32  (see  FIG. 3 ), having a longitudinal sliding groove  222  (see  FIG. 4 ) for guiding axial movement of the third screw rod  23  relative to the second screw rod  22 . The third screw rod  23  is threaded through the inner thread  151  of the third screw nut  15  in the runner  1 , having a longitudinal rib  231  axially slidably coupled to the longitudinal sliding groove  222  of the second screw rod  22 . 
     The telescopic shaft  4  comprises a plurality of tubular shaft elements  41 ˜ 45  that slide one inside another, a cap  46 . The bottom tubular shaft element, i.e., the first tubular shaft element  41  is fixedly connected to the transmission mechanism  6 . The aforesaid first screw nut  31  is fixedly mounted in the first tubular shaft element  41  and meshed with the first screw rod  21  (see  FIG. 3 ). The aforesaid second screw nut  32  is fixedly mounted inside the top tubular shaft element, the fifth tubular shaft element  45  and meshed with the second screw rod  22 . The fifth tubular shaft element  45  is inserted through the inner diameter  12  of the runner  1 , having a longitudinal crevice  451 , which receives a longitudinal rib  121  of the runner  1 , and a top locating hole  452 . The cap  46  is fastened to the top locating hole  452  of the top tubular shaft element  45  with a fastening device  453  for stopping the top end  232  of the third screw rod  23 , having a top screw hole  462 . Further, a holding down device  14  is attached to the top side of the canopy  10  to hold down the canopy  10  on the cap  46  and the hub and rib assembly  13 , having a threaded shank  141  threaded into the top screw hole  462  of the cap  46  (see  FIGS. 1 and 3 ). 
     The transmission mechanism  6  comprises a transmission gear set  61 , a drive member  62 , a housing  64  that houses the transmission gear set  61 , a front cover  63  covered on one side of the housing  64 , and a rear cover  65  covered on the other side of the housing  64 . By means of rotating the drive member  62  clockwise or counter-clockwise, the transmission gear set  61  is driven to rotate the first screw rod  21  clockwise or counter-clockwise. 
     When the drive member  62  is rotated clockwise or counter-clockwise, the transmission gear set  61  is driven to rotate the first screw rod  21  clockwise or counter-clockwise, and the second screw rod  22  as well as the third screw rod  23  are rotated with the first screw rod  21 , thereby causing the runner  1  to move upwards or downwards along the third screw rod  23  to open or close the canopy  10 . During rotation of the first screw rod  21 , second screw rod  22  and third screw rod  23  of the operating mechanism, the third tubular shaft element  43  and the fifth tubular shaft element  45  are respectively moved with the first screw nut  31  and the second screw nut  32  to extend out or receive the telescopic shaft  4 . 
     Further, as shown in  FIGS. 5 and 6 , the drive member  62  has a circular chamber  622  (see  FIG. 6 ) and a plurality of teeth  6221  arranged around the inside wall of the circular chamber  622 . 
     The housing  64  is a tubular member having a plurality of longitudinal teeth  641  arranged around the inside wall. 
     The front cover  63  is fixedly mounted on the front side of the housing  64  with screws  66 , having a center axle hole  631  (see  FIG. 5 ), a plurality of pivot pins  632  perpendicularly extended from the front side thereof and equiangularly spaced around the center axle hole  631 , and a plurality of gears  633  respectively pivotally mounted on the pivot pins  632  and meshed with the teeth  6221  of the drive member  62 . 
     The rear cover  65  is fixedly mounted on the rear side of the housing  64  with a screw  67 , having an extension tube  652 , an axial hole  6521  defined in the extension tube  652  for the passing of the first screw rod  21 , and a locating block  6522  fastened to a retaining hole  412  of the bottom tubular shaft element  41  of the telescopic shaft  4 . 
     The transmission gear set  61  comprises a plurality of gear holders  611 ˜ 614  each supporting a plurality of transmission gears  6112 ,  6121 ,  6131  and  6141 . The gears  6112 ,  6121 ,  6131  and  6141  are meshed with the longitudinal teeth  641  of the housing  64 . The first gear holder  611  of the transmission gear set  61  further comprises an axle  610  pivotally coupled to the center axle hole  631  of the front cover  63 , a driven gear  6111  fixedly mounted on the free end of the axle  610  and meshed with the gears  633  of the front cover  63 , a front extension rod  6113  axially extended from the center of the driven gear  6111  and inserted through the drive member  62 , and a retainer ring  6114  fastened to a locating groove  6115  around the periphery of the front extension rod  6113  to secure the front extension rod  6113  to the drive member  62 . Further, the transmission gears  6141  of the last gear holder  614  are meshed with the gear  211  at the first screw rod  21  (see  FIGS. 5 and 7 ). 
     When the drive member  62  of the transmission mechanism  6  is rotated clockwise or counter-clockwise, the gears  633  of the front cover  63  are driven to rotate the driven gear  6111 , causing the transmission gears  6112  to rotate the gear holders  612 ,  613  and  614 , and therefore the transmission gears  6141  of the last gear holder  614  are forced to rotate the gear  211  and the first screw rod  21 . 
     Referring to  FIG. 3 , the tubular shaft elements  41 ˜ 45  of the telescopic shaft  4  have different diameters. Further, each of the tubular shaft element  41 ˜ 45  has a tubular shaft element body  415 ,  425 ,  435 ,  445  or  455 , and a flange  414 ,  424 ,  434 ,  444  or  454  extending around the periphery of one end of the tubular shaft element body  415 ,  425 ,  435 ,  445  or  455 . The tubular shaft elements  41 ˜ 45  are axially inserted through one another, allowing the telescopic shaft  4  to be alternatively set between the extended position and the received position. 
       FIGS. 9˜11  show an operating mechanism in accordance with a second embodiment of the present invention. According to this second embodiment, a motor  60  is used to substitute for the aforesaid drive member  62  of the transmission mechanism  6 . The motor  60  has a pinion  601  fixedly mounted on the output shaft (not shown) thereof. The transmission gear set  61  comprises a plurality of gear holders  612 ˜ 614  each supporting a plurality of transmission gears  6121 ,  6131  and  6141 . The gears  6121 ,  6131  and  6141  are meshed with the longitudinal teeth  641  of the housing  64 . The gear holder  612  of the transmission gear set  61  further comprises a plurality of driven gear  6122  meshed with the pinion  601  of the motor  60 . Further, the transmission gears  6141  of the last gear holder  614  are meshed with the gear  211  at the first screw rod  21 . Further, the motor  60 , front cover  63 , housing  64  and rear cover  65  of the transmission mechanism  6  are fixedly fastened together with a screw rod  68 . Further, a battery (not shown) is installed to provide the motor  60  with the necessary working voltage. The battery can be a regular battery or storage battery. 
     As indicated above, the invention has the following features and advantages:
     1. By means of manually rotating the drive member  62  or by means of controlling the motor  60 , the transmission mechanism  6  is driven to rotate the screw rods  21 ˜ 23 , causing the first screw nut  31  and the second screw nut  32  to move the telescopic shaft  4  and the third screw nut  15  to move the runner  1 , and therefore the umbrella is opened or closed accurately. Because the screw rods  21 ˜ 23  are disposed inside the telescopic shaft  4 , they are kept from sight and well protected against outside dust.   2. When the screw rods  21 ˜ 23  are rotated clockwise or counter-clockwise, the runner  1  is moved with the third screw nut  15  along the third screw rod  23  to close/open the umbrella. Therefore, a user can close/open the umbrella with less effort.   3. The invention assures high positioning stability and operation safety when closing/opening the umbrella.   4. The invention has high structural strength against wind force, assuring high durability for long service.   5. The operating mechanism is practical for use in a folding umbrella.