Abstract:
A winch for opening and closing an umbrella includes a winch drum mounted within an elongate support tube of the umbrella, to rotate about a longitudinal axis thereof. A threaded shaft is coaxial and rotationally fast with the drum. A line is fixed at one end to the drum and at other end to a sleeve, to which struts are pivotally connected, each strut being associated with a canopy-supporting rib. A travelling nut is engaged with the threaded shaft and blocked for rotation relative to the tube. A guide is fixed to the nut for guiding the line onto the drum, and a motor is also enclosed in the support tube and drivingly connected to the winch drum.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to umbrellas having a winch by which the umbrella is opened and closed and particularly, but not exclusively, to umbrellas having a motorised winch. 
   A typical large umbrella for use with outdoor seating, or the like, is constructed with a support rod carrying at its uppermost end a crown with radiating ribs pivotally connected thereto and a sleeve sliding over the rod with struts being interconnected between the sleeve and the ribs. Various drive mechanisms have been provided to slide the sleeve along the rod in order to cause the struts to splay the ribs attached to the crown upwardly and outwardly to erect the umbrella. 
   A winch may be employed to erect the umbrella, turning the winch tightens a line trained about a pulley at the upper end of the rod and connected to the sleeve. In tiltable umbrellas the rod includes upper and lower portions joined by a transverse pivot to allow relative angular movement. The winch likewise includes a drum mounted upon a transversely aligned axle. A sector engaging a rack or worm wheel may be provided for accurately positioning the upper portion relative to the lower portion. As a result of the above complexity these prior art designs have assumed an unattractive appearance owing to the presence of many exposed mechanical elements, and the size of these elements or their housings projecting from the support rod is a drawback, both for use and storage of these umbrellas. It is therefore an object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages, or more generally to provide an improved umbrella. 
   DISCLOSURE OF THE INVENTION 
   In one aspect the present invention provides a motorised umbrella comprising 
   a support tube; 
   a plurality of radially disposed ribs, each rib being pivotally connected at one end to an end of the tube; 
   a sleeve in external sliding relationship to the tube and moveable relative thereto between an outer extended position and a retracted position; 
   a plurality of struts pivotally connected between the sleeve and associated ones of the ribs, and 
   drive means for moving the sleeve between the extended and retracted positions, whereby the struts cause the ribs to splay outwardly of rod in response to movement of the sleeve to the extended position and the struts cause the ribs to collapse inwardly in response to movement of the sleeve to the retracted position;
 
the drive means including:
         a winch drum mounted within the support tube to rotate about a longitudinal axis of the support tube;   a threaded shaft coaxially mounted to the drum for rotation therewith;   a line fixed at one end to the drum and at other end to the sleeve;   a travelling nut engaged with the threaded shaft and blocked for rotation relative to the tube;   a guide fixed to the nut for guiding the line onto the drum, and   a motor enclosed in the support tube and drivingly connected to the winch drum.       

   Preferably the umbrella further includes: 
   driving and driven bevel gears mounted coaxially with the winch drum, the driven bevel gear being drivingly engaged with the drum; 
   a pinion connecting the driving and driven bevel gears, the pinion having means for engaging a crank handle; 
   a clutch connected between the motor and the driving gear for disconnecting drive from the motor to allow the crank handle to be used for manually rotating the winch drum. 
   The crank handle preferably comprises a socket for drivingly engaging a recess in the pinion. 
   Preferably the clutch includes an actuating member for engaging or disengaging the clutch, the actuating member protruding transversely through the support tube and having a portion which protrudes from the support tube at a position circumferentially aligned with the crank-receiving socket. 
   Preferably the umbrella further includes a joint assembly in the umbrella, joining an upper part of the support tube to a lower part of the support tube, the joint assembly comprising: 
   a transverse pivot connecting the upper and lower parts of the support tube; 
   a detent in one of the upper and lower parts for engaging one of plurality of angularly spaced features in the other of the upper and lower parts 
   to fix the upper and lower parts in respective angular positions, and 
   an interlock fixed to one of the upper and lower parts and actuated by engagement with the other of the upper and lower parts to prevent actuation of the motor when the upper part is inclined relative to the lower part 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein. 
       FIG. 1  is a central longitudinal section through a motorised umbrella according to the present invention; 
       FIG. 2  is an enlarged view of the portion B of  FIG. 1 ; 
       FIG. 2   a  is a fragmentary longitudinal section of portion D of  FIG. 2  in a plane offset from the central longitudinal axis; 
       FIG. 3  is an enlarged view of the section AA of  FIG. 1  with the clutch in an engaged position; 
       FIG. 4  is an enlargement of the clutch portion E of  FIG. 2 ; 
       FIG. 5  is an enlarged view of the portion B of  FIG. 1  with the clutch in a released position, and 
       FIGS. 6 and 7  are front and side exploded views of joint members connecting the upper and lower support tubes of the umbrella of  FIG. 1 ; 
       FIG. 8  is an enlarged view of the joint portion C of  FIG. 1  wherein one of the two flanges comprising the joint is cut away for clarity; 
       FIG. 9  is a longitudinal cross section in the central plane of a pin for locking the joint for tilting movement of the umbrella, and 
       FIG. 10  shows the section of  FIG. 9  with the upper support tube in a tilted position. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 1 , a motorised umbrella  1  includes an upright support tube assembly  2  having a crown  3  fixed at an outer end thereof. A plurality ribs  4  for supporting the umbrella canopy (not shown) are connected at one end to the crown  3  by pivots  5  to extend radially from the support tube assembly  2 . A yoke  6  is in external sliding relationship to the support tube assembly  2  received therein. The yoke  6  is moveable relative to the support tube assembly  2  between the extended (upper) position shown and a retracted position. 
   Note that the terms “inner” and “outer” are used to describe relationships relative to both of the two longitudinally opposing ends of the central tube assembly of the umbrella. References in brackets relate to the upright orientation shown in the figures and are added for clarity. 
   A plurality of struts  7  are pivotally connected to the yoke  6 , each strut  7  being connected to an associated one of the ribs  4 . When moving the yoke  6  from the retracted position to the extended position, the struts  7  cause the ribs  4  to splay outwardly of support tube assembly  2 . The struts  7  cause the ribs  4  to collapse inwardly in response to movement of the yoke  6  to the retracted position (shown in dashed outline). 
   The support tube assembly  2  includes lower support tube  2   a  which, for instance, may be received in an aperture in a table, or the like, and upper support tube  2   b  to which the crown  3  is mounted. A winch  10  mounted in the lower support tube  2   a  provides drive means for moving the sleeve between the extended and retracted positions. A line  11  engaged with the winch  10  extends longitudinally within lower support tube  2   a , around a pulley  12  and through an aperture  13  in the upper support tube  2   b , to connect to the yoke  6 . 
   As seen in  FIG. 2 , a winch drum  14  and threaded shaft  15  are integrally formed from an elongate member mounted coaxially with the central longitudinal axis  16   a  of the lower tube  2   a . A journal  17  engages a bearing block  18  fixed inside the tube  2   a , to support the drum  14  and shaft  15  for rotation about axis  16   a.    
   A nut  19  is engaged with the treaded shaft  15  and has a longitudinally aligned slot  21 . A bar  20  fixed to the inner wall of the tube  2   a  extends axially and is received in the slot  21  to block rotation of the nut  19 . The line  11  approaches the nut in the longitudinal direction, passes about a roller guide  22  fixed to the nut  19  and is fed generally transversely into the drum  14 . One end of the line  11  is fixed to the drum  14 , such that the line is wound in a helix of the same pitch as that of the screw threads. On the nut  19 , opposite the slot  21 , a pair of axially spaced wheels  23   a ,  23   b  engage the inner wall of the tube  2   a.    
   The drum  14  and shaft  15  are rotated by a motor  24 , driven through a primary gearbox  25 , a clutch  26  and then a secondary gearbox  27 . The primary gearbox  25  serves to reduce the speed and increase the torque supplied to the clutch  26 . The primary gearbox  25  is mounted within the lower tube  2   a  coaxially with the adjacent motor  24 . The clutch  26  and secondary gearbox  27  cooperate to allow the umbrella to be operated using either the motor  24  or a crank handle  28  to rotate the drum  14  and shaft  15 . 
   The secondary gearbox  27  includes opposing driving and driven bevel gears  30 ,  31  mounted coaxially with the axis  16  and connected by a pinion  32 . The pinion  32  is mounted on a transversely extending axle  33  which includes a socket  34  for receiving the crank handle  28 . The driven bevel gear  31  is connected to the winch drum  14  and threaded shaft  15  by a coupling shaft  35  mounted for rotation in a bearing sleeve  36  fixed inside the support tube assembly. 
   The clutch  26  is mounted between the output  37  from the primary gearbox  25  and the driving bevel gear  30 . As best seen in  FIG. 4 , the clutch  26  includes an actuating member extending transversely through the lower tube  2   a  and having button portions  38 ,  39  on opposing ends thereof which protrude from either side of the support tube  2   a  and are pressed to release and engage the clutch  26  respectively. A spring  40  is mounted (around a hub  41  fixed to the driving bevel gear  30 ) to bear against an axially sliding collar  42 , which through the abutting thrust plate  43  and pins  44  in turn holds balls  45  in recesses in a flange portion  39  of the rotating output  37 . In this manner the torque is transmitted through the thrust plate  43  to the hub  41  and thus to the driving bevel gear  30 . 
   When the button portion  38  is pressed ( FIG. 5 ) inclined faces (not shown) on the actuating member  30  and collar  42  cooperate to move the collar  42  axially so as to compress the spring  40 , thereby allowing the balls  45  to ride up out of the recesses in the output  37 , disengaging the drive from the primary gearbox  25 . In the released position ( FIGS. 2 and 4 ) the button portion  38  protrudes from the lower tube  2   a  at a position circumferentially aligned with the crank-receiving socket  34 . In this manner the button portion  38  projects into the path traced in use by rotation of the crank handle  28  providing a visual clue to the user that, in order to crank the handle  28 , it is necessary to press the button  38 , not only to release the clutch but to allow the handle  28  to pass the button  38 . 
   Stacked within the support tube  2   a , below the motor  24  are five rechargeable batteries for powering the motor. A socket in the support tube assembly is provided for plugging in a power supply (not shown) for charging the batteries. 
     FIGS. 6-10  illustrate a joint assembly  50  between the upper and lower support tubes  2   a ,  2   b , each of which are fixed to a respective upper an lower joint member  51 ,  52  joined by a transverse pivot  53 . Protruding from an end of the upper joint member  51  is a central tongue  56  with a semicircular edge  59 . The tongue  56  is received between flanges  57 ,  58  protruding from the end of the lower joint member  52 , the pivot  53  extending between both flanges  57 ,  58 . Three recesses  54   a ,  54   b ,  54   c  are provided in the edge of the flange  56 , recesses  54   a  and  54   c  being equally angularly spaced either side of the central recess  54   b . A detent  61  is mounted to slide longitudinally in the lower joint member  52  and includes a nub portion  55  and a button portion  60 . The button portion  60  is exposed externally and for manual release of the detent, for instance, sliding the button longitudinally against the urging of spring  62  withdraw the nub  55  from one of the recesses  54 , allowing the members to be inclined relative one another for tilting the umbrella. 
   The outer edge of the flange  58  has a convex face  64  complementary to an adjacent concave face  65  on the upper joint member  51 . A pin  66  is received in a longitudinally aligned recess in the extending through the convex face  65 . A beam spring  67  engages one end of the pin  66  to bias the opposing end outward toward the concave face  65 . A recess  68  in the concave face  65  is longitudinally aligned with the axis  16 . An interlock switch  63  is provided in the electrical circuit controlling the operation of the motor  24 , the switch  63  being mounted adjacent the pin  66  in the lower joint member  52 . An actuating lever  69  extends from the switch  63  below the beam spring  67 . 
   In use, with the upper and lower portions of the support tube aligned, as shown in  FIG. 9 , the pin  66  is received in the recess  68  and the switch is in a first state, for instance, an electrically closed position. Any rotation of the portions of the support tube, as shown in  FIG. 10 , displaces the pin  66  from the recess  68 , pushing the pin  66  against the actuating lever  69  to move the switch to a second state, for instance, an electrically open position. In this manner the switch  63  is used to prevent operation of the motor  24  when the upper and lower support tubes  2   a ,  2   b  are inclined. 
   Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof.