Patent Publication Number: US-2023148719-A1

Title: Umbrella having a cam assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application No. 63/050,812, filed Jul. 12, 2020, and titled “SPIRAL-SPOKED UMBRELLA,” the entirety of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to umbrellas. 
     BACKGROUND OF THE INVENTION 
     Umbrellas are designed to protect a user against natural elements, such as sunlight and precipitation, like rain and snow. When a conventional umbrella is open, strong wind gusts can strike the underside of the canopy, causing the stretchers to bend in an upward direction, thereby inverting the dome-like shape of the canopy. This renders the umbrella ineffective in protecting a user from the natural elements. Further, such an inversion may cause the stretchers to break and, therefore, the umbrella to become unusable. 
     SUMMARY OF THE INVENTION 
     In one aspect, the invention relates to an umbrella including a support shaft, a plurality of ribs, a rotatable cam assembly, and a canopy. The support shaft includes an upper portion, a lower portion, and a longitudinal axis. Each rib of the plurality of ribs has a proximal end portion and a distal end portion. The proximal end portion is pivotably attached to the upper portion of the support shaft to pivot the rib between an open position and a closed position. The rotatable cam assembly includes a cam configured to rotate about the longitudinal axis. The cam is engaged with each rib of the plurality of ribs such that (i) each rib moves in a direction from the closed position to the open position when the cam rotates in a first direction and (ii) each rib moves in a direction from the open position to the closed position when the cam rotates in a second direction, the second direction being opposite the first direction. The canopy has an inner edge and an outer edge attached to the distal end portion of each of the ribs. 
     In another aspect, the invention relates to an umbrella including a support shaft, a plurality of ribs, a rotatable cam assembly, a fixed handle, and a canopy. The support shaft includes an upper portion, a lower portion, and a longitudinal axis. Each rib of the plurality of ribs has a proximal end portion, a distal end portion, and a slot formed in the proximal end portion. The slot includes a proximal end and a distal end. The proximal end portion of each rib being pivotably attached to the upper portion of the support shaft to pivot the rib between an open position and a closed position. The rotatable cam assembly includes a cam, a movable handle, a rotatable shaft and a fixed handle. The cam is configured to rotate about the longitudinal axis. The cam includes a plurality of radially projecting rods. Each rod is engaged with the slot in a corresponding one of the ribs to slide in the slot. The movable handle is configured to rotate about the longitudinal axis. The rotatable shaft connects the movable handle to the cam such that, when the movable handle is rotated about the longitudinal axis, the movable handle rotates the rotatable shaft about the longitudinal axis, and the rotatable shaft rotates the cam assembly about the longitudinal axis. The fixed handle is connected to the lower portion of the support shaft. The canopy has an inner edge centrally mounted to the upper portion of the support shaft and an outer edge attached to the distal end portion of each of the ribs. When the movable handle rotates in a first direction, each rod slides in the corresponding slot from the proximal end to the distal end to move the corresponding rib from the closed position to the open position. When the movable handle rotates in a second direction, each rod slides in the corresponding slot from the distal end to the proximal end to move the corresponding rib from the open position to the closed position. 
     These and other aspects of the invention will become apparent from the following disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a side orthographic view of an umbrella according to a preferred embodiment of the invention. 
         FIG.  2    is a side orthographic view of the umbrella shown in  FIG.  1    illustrating how a canopy of the umbrella can be replaced. 
         FIGS.  3 A and  3 B  show the canopy of the umbrella shown in  FIG.  1   .  FIG.  3 A  is a top orthographic view of the canopy with certain features of the umbrella  100 , and  FIG.  3 B  is a side orthographic view of the canopy. 
         FIG.  4    is a bottom orthographic view of the umbrella shown in  FIG.  1   . 
         FIG.  5    is a perspective view of the umbrella shown in  FIG.  1    showing the underside the canopy. 
         FIG.  6    is a detail view of a hub of the umbrella shown in  FIG.  1   . 
         FIG.  7    is a perspective view of the handle of the umbrella shown in  FIG.  1   . 
         FIG.  8    is a top orthographic view of the hub and ribs of the umbrella shown in  FIG.  1   . 
         FIG.  9    is a side orthographic view of the hub and ribs shown in  FIG.  8   .  FIG.  9    also shows the handle and includes a cross section of the opening and closing features located near the handle. 
         FIG.  10    is a detail, side orthographic view of the hub and ribs shown in  FIG.  1   . 
         FIG.  11    is the view shown in  FIG.  9    illustrating an alternate connection of a movable handle to a rotatable cam assembly. 
         FIG.  12    is a cross-sectional view of a gear configuration of the movable handle taken along line  12 - 12  in  FIG.  11   . 
         FIG.  13    is a partial cross-sectional view of the handle assembly shown in  FIG.  11   . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the description of preferred embodiments of the invention, the terms “inner” and “outer” are used in relation to an inner side and an outer side of a canopy of an umbrella, respectively, and are interchangeable with the terms “interior” and “exterior,” respectively. The terms “upper” and “lower” are used in relation to an upper end and a lower end of a support shaft, respectively, when the umbrella is oriented upright, as shown in  FIG.  1   . In addition, the terms “distal” and “proximal” are used in relation to the support shaft. More specifically, “proximal” refers to a position relatively closer to the support shaft, and “distal” refers to a position relatively farther from the shaft. 
       FIG.  1    shows an umbrella  100  in accordance with a preferred embodiment of the invention.  FIG.  1    is a side orthographic view of the umbrella  100  and  FIG.  4    is a bottom orthographic view of the umbrella shown in  FIG.  1   . The umbrella  100  includes a support shaft  110  (see  FIG.  9   ) and a canopy  120  supported by a plurality of ribs  130 . The support shaft  110  includes an upper portion  112  and a lower portion  114 . Each of the ribs  130  is movable between a closed position and an open position. The broken lines in  FIG.  1    illustrate the ribs  130  in the closed position. Each of the ribs  130  includes a proximal end portion  132  and a distal end portion  134 . The proximal end portion  132  is pivotably attached to the upper portion  112  of the support shaft  110 , and the distal end portion  134  pivots upward from the closed position to the open position as illustrated in  FIG.  1   . 
       FIG.  2    is a side orthographic view of the umbrella  100  illustrating features of the canopy  120  and how the canopy  120  can be replaced.  FIGS.  3 A and  3 B  also show the canopy  120 .  FIG.  3 A  is a top orthographic view of the canopy  120  with certain features of the umbrella  100 , and  FIG.  3 B  is a side orthographic view of the canopy  120 . The canopy  120  may be formed of any suitable material, such as waterproof (or resistant) fabric or plastic, to protect the user from the natural elements, such as sunlight and precipitation, like rain and snow. Although the canopy  120  will typically be an opaque material, the canopy  120  is shown as a transparent material in  FIGS.  1  and  4    for clarity to illustrate various features of the umbrella  100 . The canopy  120  is connected to the support shaft  110  at the upper portion  112 . The canopy  120  includes an inner edge  122  and an outer edge  124 . The inner edge  122  may be, for example, the edge of a central hole  125  formed in the canopy  120 . In this embodiment, the inner  122  has the same geometric shape as the outer edge  124 . The inner edge  122  is centrally mounted to the upper portion of the support shaft  110  by a cap assembly  140 . The cap assembly  140  may include an adaptor  142  that has a central hole (bore) into which the upper portion  112  of the support shaft  110 , and more specifically the upper tip, may be inserted. The adaptor  142  may be secured to the support shaft  110  by any suitable means including, for example, a set screw  144 . The adaptor  142 , and thus the canopy  120 , of this embodiment is detachably attached to the support shaft  110  to facilitate easy replacement of the canopy  120  if the canopy  120  becomes damaged. The adaptor  142  of this embodiment has a circular outer edge to which the inner edge  122  of the canopy  120  is attached by a suitable means such as by compression in a slot and/or adhesive. In this embodiment, the cap assembly  140  includes a top cap  146  that fits over the adaptor  142 . The top cap  146  provides a decorative cover for the adaptor  142  and set screw  144 . The top cap  146  is detachably attached to the adaptor  142  by any suitable means, such as by snap engagement with the adaptor  142 . 
     The outer edge  124  of the canopy  120  is attached to the distal end portion  134  of each of the ribs  130  by any suitable connection known in the art. In this embodiment, a plurality of receivers  126  are formed on the underside of the canopy  120 . Each receiver  126  is configured to slide over the distal end portion  134 , and more specifically the distal tip, of each rib  130 . To remove the canopy  120 , the top cap  146  is first removed by disengaging the snap engagement features and lifting the top cap  146  from the adaptor  142 . The set screw  144  is then loosened to detach the adaptor  142  from the support shaft  110 . The adaptor  142  can then be moved to provide slack in the canopy  120  and allow each receiver  126  to slide off of the distal end portion  134  of each rib  130 . The process is reversed to install the canopy  120 . 
     As shown in  FIG.  1   , each rib  130  is oriented parallel to the support shaft  110  in the closed position, and the distal end portion  134  pivots upwardly and outwardly to the open position. The support shaft  110  includes a longitudinal axis  102 , which in this embodiment is also the longitudinal axis of the umbrella  100  as a whole, and each rib  130  also is oriented parallel to the longitudinal axis  102  in the closed position. With the canopy  120  attached as discussed above, the ribs  130  stretch the canopy  120  to be taut when the ribs  130  are in the open position, as can be seen in  FIGS.  4  and  5   .  FIG.  5    is a perspective view of the umbrella shown in  FIG.  1    showing the underside of the canopy. In particular, the canopy  120  includes panels  128  between each of the ribs  130  and in the open position the ribs  130  stretch the panels  128 , but in the closed position the panels  128  are slack. A strap (not shown) may be used to secure the umbrella  100  in a closed state. The strap may be secured using hook and loop fasteners, such as Velcro®. Alternatively, two straps (not shown) may be provided on the outer side of the canopy  120  to secure the canopy  120  in the closed state by tying the straps together. 
     As shown in  FIGS.  4  and  5   , the ribs  130  have a spiral arrangement, and each rib  130  moves between the open position and the closed position in a plane which does not include the longitudinal axis  102 . As will be discussed further below, the ribs  130  are pivotably attached to a fixed hub  160  and not the support shaft. The ribs  130  do not swivel or pivot in a plane or direction that coincides with a radial direction (radius r in  FIG.  3 A ) extending from the longitudinal axis  102  of the support shaft  110 , rather the ribs  130  have a spiral pattern. A radius R based on the length of the rib  130  from the pivot point of the rib  130  thus does not coincide with the radius r. For the fabric of the canopy  120  to be taut in the open position, the panels  128  are cut such that the stiches (quilt ribs) are in line with the ribs  130  instead of, for example, in the radial direction r. 
     The structure of the umbrella  100 , and more specifically the rotatable cam assembly  200  and the connection to the rib  130 , discussed herein enables a fewer number of ribs to be used as compared to traditional umbrellas. The umbrella  100  preferably includes at least three ribs  130 . In the embodiments shown and discussed herein, the umbrella  100  includes five ribs  130 , but any suitable number of ribs  130  may be used. In some embodiments, each of the panels  128  are generally triangular between the ribs  130 , with the. The canopy  120  may have a shape (e.g., the outer edge  124  of the canopy) with the same number of sides as the number of ribs  130 . In the embodiment shown in  FIGS.  4  and  5   , for example, the umbrella includes five ribs  130  and the canopy  120  has the shape of a pentagon. In other embodiments, for example, the umbrella  100  may include three ribs  130  and the canopy  120  has the shape of a triangle; may include four ribs  130  and the canopy  120  has the shape of a quadrilateral, such as a rectangle, or more specifically, a square; may include six ribs  130  and the canopy  120  has the shape of a hexagon; may include seven ribs  130  and the canopy  120  has the shape of a heptagon; or may include eight ribs  130  and the canopy  120  has the shape of an octagon. As noted above, the ribs  130  are pivotably attached to the upper portion  112  of the support shaft  110 . In this embodiment, the umbrella  100  includes a fixed hub  160  and each rib  130 , more specifically the proximal end portion  132  of each rib  130 , is pivotably attached to the fixed hub  160 .  FIG.  6    is a detail view of the fixed hub  160  shown from the perspective of  FIG.  5   . The fixed hub  160  of this embodiment is fixed (connected) to the upper portion  112  of the support shaft  110 . 
     As shown in  FIG.  1    and in more detail in  FIG.  7   , the umbrella  100  also includes a fixed handle  150 . The fixed handle  150  is connected to the lower portion  114  of the support shaft  110 .  FIG.  7    is a perspective view of the fixed handle  150 . The fixed handle  150  is preferably shaped to be held comfortably by a user such that the user can hold the umbrella  100  over his or her head. Any suitable shape may be used including generally cylindrical shapes or hooked shapes. Located above the fixed handle  150  is a movable handle  210 . As indicated by the arrows in  FIG.  1   , the movable handle  210  may be rotated about the longitudinal axis  102  in a first direction to open the umbrella  100  and rotated in a second direction, opposite the first direction, to close the umbrella  100 . 
     The movable handle  210  is part of a rotatable cam assembly  200  that is used to move the plurality of ribs  130  between the closed position and the open position. The rotatable cam assembly  200  will be described in more detail with reference to  FIGS.  8  and  9   .  FIG.  8    is a top orthographic view of the fixed hub  160  and one of the ribs  130 , and  FIG.  9    is a side orthographic view of the fixed hub  160  and one of the ribs  130  corresponding to the features shown in  FIG.  8   . In  FIG.  9   , the movable handle  210  is shown in cross section. An arm  136  is located on the proximal end portion  132  of each rib  130 . The arm  136 , and more specifically, the proximal end of the arm (and thus the rib  130 ) is pivotably attached to the fixed hub  160  by a pivot  162 . Any suitable pivot  162  may be used including a fastener extending through a hole formed in the arm  136  and fastened to the fixed hub  160  such that the arm  136  can rotate about the fastener. 
     The arm  136  includes a slot  170  formed therein. The slot  170  is elongated in a direction from the proximal end portion  132  to the distal end portion  134  of the rib  130  in which the slot is formed. The slot  170  includes a proximal end  172  and a distal end  174  defining a longitudinal axis  176  of the slot  170 . In some embodiments, the slot  170  may be linear from the proximal end  172  to the distal end  174  along the longitudinal axis  176 , but in other embodiments, the slot  170  may have a shape, such as a curve shape or a V-shape. In the embodiment shown in  FIG.  9   , the slot  170  has a V-shape and includes a portion between the proximal end  172  to the distal end  174 , which in this embodiment is a central portion  178 , that is lower than the longitudinal axis  176  of the slot  170  when the rib  130  is in the open position. The slot  170  is located in a direction toward the distal end portion  134  from the pivot  162 . 
     The rotatable cam assembly  200  also includes a rotatable shaft  220  and a cam  230 . The movable handle  210  is connected to the cam  230  and configured to rotate the cam  230  about the longitudinal axis  102  when the movable handle  210  is moved. In this embodiment, the rotatable shaft  220  connects the movable handle  210  and the cam  230 . Although indirect connections may be used, the rotatable shaft  220  directly connects the movable handle  210  to the cam  230  such that, when the movable handle  210  is rotated about the longitudinal axis  102 , the movable handle  210  rotates the rotatable shaft  220  about the longitudinal axis, and the rotatable shaft  220  rotates the cam  230  about the movable handle  210 . 
     In this embodiment, the support shaft  110  is an inner shaft and extends through each of the movable handle  210 , rotatable shaft  220 , and cam  230 . More specifically, each of the movable handle  210 , rotatable shaft  220 , and cam  230  are annular having a passage formed therein, and the support shaft  110  extends through the passage. However, other suitable arrangements may be used, for example, the support shaft  110  may be the outer shaft having the passage formed therein and the rotatable shaft  220  may be the inner shaft extending through the support shaft  110 . 
     The cam  230  is engaged with each rib  130  of the plurality of ribs  130  such that each rib  130  moves in a direction from the closed position to the open position when the cam  230  rotates in the first direction and each rib  130  moves in a direction from the open position to the closed position when the cam  230  rotates in the second direction. In this embodiment, the cam  230  includes a rotatable hub  232  having a plurality of radially projecting rods  234 . Each rod  234  engages with the slot  170  in a corresponding one of the ribs  130 . The rod  234  slides within the slot  170  as the rotatable hub  232  rotates about the longitudinal axis  102 . When the rotatable hub  232  rotates in the first direction, each rod  234  slides in the corresponding slot  170  from the proximal end  172  to the distal end  174  to move the corresponding rib  130  from the closed position to the open position. The combination of the rotatable hub  232  and the rod  234  turns the rotational movement of the rotatable hub  232  to translational movement of the rod  234 . As the rod  234  sidles (translates) in the slot  170 , the rod  234  bears upon (contacts) an upper surface of the slot  170  raising the rib  130  from the closed position to the open position. The rod  234  has a length such that the rod  234  remains engaged with the slot  170  throughout the length of travel as the cam  230  rotates. To close the umbrella  100 , the process is reversed. Each rod  234  slides in the corresponding slot  170 , from the distal end  174  to the proximal end  172  to move the corresponding rib  130  from the open position to the closed position when the rotatable hub  232  rotates in the second direction. 
     An advantage of the umbrella  100  and the rotatable cam assembly  200  described herein, is that the umbrella  100  has very good wind resistance. In a conventional umbrella, the ribs are supported by a plurality of stretchers that connect an intermediate point of the rib to the shaft. The frame and the shaft of conventional umbrellas are optimized to be lightweight, so that the user can hold and support the conventional umbrella with one hand. As a result, the stretchers of the frame tend to be relatively thin. When the conventional umbrella is open, strong wind gusts can strike the lower side of the canopy, causing the stretchers to bend in an upward direction, thereby inverting the dome-like shape of the canopy. This renders the umbrella ineffective for protection from precipitation. Further, such an inversion may cause the stretchers to break and, therefore, the umbrella to become unusable. 
       FIG.  10    is a detail view showing the ribs  130 , the fixed hub  160 , and the cam  230 . As the wind blows on the canopy  120  (not shown in  FIG.  10   ) and the ribs  130  from the underside as indicated by the arrow labeled wind, the resultant force is transmitted to the rod  234  by the lower side of the slot  170  as indicated by the arrow F. This force acts on the rod  234  in sheer and thus the strength and the cross-sectional area of the rod  234  provide strength to hold the shape of the umbrella  100  and prevent inversion. Because of the relatively large diameter of the rod  234 , the umbrella  100  can resist large amounts of wind. In view of the strength of the connection between the arm  136  of the rib  130  and the cam  230 , the rib  130  is preferably made from a strong material that resists fracture and that is also light weight. In this embodiment, a carbon fiber rod is used to form the rib  130 . The carbon fiber is strong, but also allows elastic deformation of the rib  130  during strong wind gusts. Preferably the rib  130  is more flexible than the combination of the connection between the arm  136  of the rib  130  and the cam  230 . For example, when the umbrella  100  is in the open position, the rib  130  may flex to the support shaft  110 , but the connection between the arm  136  of the rib  130  and the cam  230  is strong enough to not to fail in such conditions. The connection between the arm  136  of the rib  130  and the cam  230  is just as strong as when the wind is acting on the outer surface of the canopy  120 . To prevent the cam  230  from rotating in the second direction, a latch may be used, such as the one shown and described below with reference to  FIGS.  11 - 13   . 
       FIGS.  11 - 13    show another embodiment of the umbrella  100 . This embodiment is similar to the embodiment discussed above and like reference numerals are used to refer to the same or similar components in this embodiment. A detailed description of such components is omitted here. In the embodiment discussed above, the movable handle  210  was directly connected to the cam  230  by the rotatable shaft  220 . To improve the ease in which the movable handle  210  is rotated, the movable handle  210  is connected to the cam  230  through a gear assembly  240 .  FIG.  11    is the view shown in  FIG.  9    illustrating the connection of the movable handle  210  to the cam  230  by the gear assembly  240 .  FIG.  12    is a cross-sectional view of the gear assembly  240  of the movable handle taken along line  12 - 12  in  FIG.  11   , and  FIG.  13    is a partial cross-sectional view of the fixed handle  150  and the movable handle  210  shown in  FIG.  11   . 
     The movable handle  210  includes a driving gear  242  and the rotatable shaft  220  includes a driven gear  244 . The driving gear  242  of the movable handle  210  is configured to transmit a driving force from the movable handle  210  to the driven gear  244  of the rotatable shaft  220 . In this embodiment, the driving gear  242  and the driven gear  244  are integrally molded (formed) with the movable handle  210  and the rotatable shaft  220 , respectively. 
     The gear assembly  240  of this embodiment is a planetary gear arrangement with the driving gear  242  being a sun gear and the driven gear  244  being a ring gear. The gear assembly  240  also includes a plurality of intermediate gears  246  having teeth formed on an exterior surface thereof. Teeth are formed on the exterior of the driving gear  242  and the teeth of each of the intermediate gears  246  mesh with the teeth of the driving gear  242  such that the driving force is transmitted from the driving gear  242  to the intermediate gears  246 . As noted above, the driven gear  244  is a ring gear with teeth formed on an interior surface thereof. The teeth of the intermediate gears  246  also mesh with the teeth of the driven gear  244  to transmit the driving force from the intermediate gear  246  to the driven gear  244  and thus the rotatable shaft  220 . The driving gear  242  and the driven gear  244  are positioned coaxially with each other and the axis is the longitudinal axis  102 . Each of the driving gear  242  and the driven gear  244  are configured to rotate about the longitudinal axis  102 . 
     In this embodiment shown in  FIG.  10   , the driving gear  242  is attached to, more specifically integrally formed with, the movable handle  210 , and the driven gear  244  is attached to, more specifically integrally formed with, the rotatable shaft  220 . In other embodiments, different arrangements may be used. For example, the driving gear  242  may be attached to, more specifically integrally formed with, the rotatable shaft  220 , and the driven gear  244  may attached to, more specifically integrally formed with, the rotatable hub  232  of the cam  230 . By such an arrangement, the driving force required to rotate the handle can be reduced by the appropriate gear ratio. Where the gear ratio of the driving gear  242  to the driven gear  244  (considering the planetary arrangement of the intermediate gears  246 ) is 1:2, the driving force can be reduced by half as compared to the direct connection arrangement; although it will be appreciated that such an arrangement also results in the movable handle  210  being rotated twice as far as compared to the direct connection arrangement. 
     As noted above, a locking mechanism  180  may be used to prevent the movable handle  210  and thus the rotatable cam assembly  200  from rotating. An example of such a locking mechanism  180  is shown in  FIGS.  11  and  13   . The locking mechanism  180  of this embodiment includes a button  182  that protrudes from the fixed handle  150  and may be pressed by the user against a biasing force of a spring  184 . The locking mechanism  180  also includes an engagement portion  186  that engages with the movable handle  210 . When the button  182  is pressed, the engagement portion  186  disengages from the movable handle  210  allowing the movable handle  210  to rotate. The locking mechanism  180  may be configured to lock the movable handle  210  in discrete positions, such as the open position and the closed position, by having slots formed in an inner surface of the movable handle  210  that the engagement portion  186  engages with. 
     Although this invention has been described with respect to certain specific exemplary embodiments, many additional modifications and variations will be apparent to those skilled in the art in light of this disclosure. It is, therefore, to be understood that this invention may be practiced otherwise than as specifically described. Thus, the exemplary embodiments of the invention should be considered in all respects to be illustrative and not restrictive, and the scope of the invention to be determined by any claims supportable by this application and the equivalents thereof, rather than by the foregoing description.