Abstract:
A patio umbrella has a pole, a plurality of primary ribs extending from the pole, a hub slidably supported on the pole, and a plurality of secondary ribs, each secondary rib having a first end pivotally coupled to the hub and a second end pivotally coupled to one of the primary ribs. The patio umbrella has a ledge positioned on the pole, and a spring slidably supported on the pole between the hub and the ledge. The patio umbrella can also have at least one stretcher having a first end pivotally coupled to one of the secondary ribs, and a second end pivotally coupled to the ledge.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to outdoor and patio umbrellas, and in particular, to a spring and stretcher system for use with outdoor and patio umbrellas. 
     2. Description of the Prior Art 
     Outdoor and patio umbrellas (hereinafter referred to collectively as patio umbrellas) have become increasingly popular, due to newly found uses and applications. Patio umbrellas have traditionally provided shade from sunlight in patios, backyards, swimming pools and other play or recreation facilities. 
     Recently, hotels, resorts, and restaurants have also taken advantage of the shade protection of these umbrellas for their guests and have become major purchasers. In particular, patio umbrellas will usually see extended usage in tropical countries and other warm weather resort areas. 
     In order to be used outdoors safely, patio umbrellas must carry enough weight to provide the necessary stability against the elements. However, most patio umbrellas are typically heavy, bulky, and large in size, which makes them somewhat inconvenient to store and transport. 
     In order to be used outdoors, patio umbrellas must be durable, safe, and easy to use. Many patio umbrellas employ a pulley and cord to open and to close the umbrella. However, because the cord rubs and chafes against the pulley, the fibers of the cord eventually fray and disintegrate. In addition, with this wear and tear, even the pulley mechanisms have a tendency to wear out from the constant rubbing of the metal parts and from the force applied from the pulling of the cord. Thus, after extended normal use, both the pulley and rope mechanisms may become defective or break. 
     Given their size and weight, breakage of any part of the umbrella may compromise the stability of the entire umbrella structure. Any breakage could also possibly lead to the dangerous collapse of the umbrella upon those people who are positioned under the umbrella. 
     Even if the breakage does not compromise the stability and safety, it can still be troublesome and expensive to either ( 1 ) repair the umbrella, or ( 2 ) replace the pulley system, or ( 3 ) dispose of or replace the old umbrella with a new one, especially if the repair and replacement is required on a regular basis. 
     In addition, having to pull a cord to open and close a large and bulky patio umbrella is inconvenient and time consuming. More importantly, this task requires the exertion of a large amount of force, which is something that certain people (e.g., young children, some women, and some senior citizens) will have find great difficulty in doing. To these people, this exertion of force can even pose health dangers. 
     Thus, there remains a need to provide a patio umbrella that has increased durability, maximizes safety, and is easy to use. 
     SUMMARY OF THE DISCLOSURE 
     It is an object of the present invention to provide a patio umbrella that is convenient to open and to close. 
     It is another object of the present invention to provide a patio umbrella that minimizes the possibility of breakage of any of its components. 
     It is yet another object of the present invention to provide a patio umbrella that does not require the use of a cord and pulley system. 
     To accomplish the objects of this invention, there is provided a patio umbrella having a pole, a plurality of primary ribs extending from the pole, a hub slidably supported on the pole, and a plurality of secondary ribs, each secondary rib having a first end pivotally coupled to the hub and a second end pivotally coupled to one of the primary ribs. The patio umbrella has a ledge positioned on the pole, and a spring slidably supported on the pole between the hub and the ledge. When one of the primary ribs of the umbrella is lifted, the spring will bias the umbrella into an opened position. The umbrella can be closed by compressing the spring, and maintained in the closed position by restraining the spring in its compressed position. 
     In one embodiment of the present invention, the patio umbrella has at least one stretcher having a first end pivotally coupled to one of the secondary ribs, and a second end pivotally coupled to the ledge. 
     In another embodiment of the present invention, the patio umbrella further includes covers for the spring. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a portion of the patio umbrella according to one embodiment of the present invention shown in an open position. 
     FIG. 2 is a side view of the patio umbrella of FIG. 1 shown in a closed position. 
     FIG. 3 is a cross-sectional view of the compressed spring mechanism according to another embodiment of the patio umbrella. 
     FIG. 4 is a cross-sectional view of the spring mechanism of FIG. 3 in a non-compressed position. 
     FIG. 5 is a perspective view of a portion of the connection mechanism of one stretcher and one rib of the patio umbrella in FIG.  1 . 
     FIG. 6 is an exploded perspective view of the connection mechanism of FIG.  5 . 
     FIG. 7 is a view of the connection mechanism of one stretcher and the annular ledge of the patio umbrella in FIG.  1 . 
     FIG. 8 illustrates an annular ledge according to an alternative embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following detailed description is one of the best presently contemplated modes of carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating general principles of embodiments of the invention. The scope of the invention is best defined by the appended claims. In certain instances, detailed descriptions of well-known devices and mechanisms are omitted so as to not obscure the description of the present invention with unnecessary detail. 
     The present invention provides a novel spring and stretcher system that allows the user to open and close the umbrella without using a pulley and cord. When one of the long ribs of the umbrella is lifted, the spring will bias the umbrella into an opened position. The umbrella can be closed by compressing the spring, and maintained in the closed position by restraining the spring in its compressed position. 
     FIG. 1 illustrates the skeletal frame for a patio umbrella  20  according to the present invention. The umbrella  20  has a pole  25  having a lower end  30  that is adapted to be inserted into the bore of a conventional umbrella base (not shown). The umbrella  20  also includes a hub and runner system that is provided adjacent to the top of the pole  25 . The hub and runner system includes an upper hub  35  that is permanently fixed or secured to the top of the pole  25 , and a lower hub  40  that is adapted to slide along a portion of the vertical length of the pole  25  below the upper hub  35 . 
     The umbrella  20  further includes a plurality of long ribs  70  extending radially from the upper hub  35  for supporting an umbrella covering  60 . Additionally, there are a plurality of short ribs  75 , each of which has an inner end  80  and an outer end  85 . The inner end  80  of each short rib  75  is pivotally connected to and extends radially from the lower hub  40 . The outer end  85  of each short rib  75  is connected to a pivoting connection  90  which is positioned between the opposing ends of the long rib  70 . FIGS. 1 and 2 illustrate one non-limiting example for this connection  90 , and it will be appreciated by those skilled in the art that it is possible to provide this connection  90  using any other conventional mechanism or joint. For example, the outer end  85  of each short rib  75  can be coupled to a corresponding long rib  70  by rivets. 
     Referring to FIGS. 1 and 2, a spring  50  is positioned between the lower hub  40  and an annular ledge  45 . The pole  25  extends through the spring  50 , and the spring  50  can be left unattached, between the lower hub  40  and the annular ledge  45 . In one embodiment, the spring  50  can be composed of a durable, metallic substance. The annular ledge  45  has a plurality of generally rectangular channels  95 , which are provided in a spaced-apart manner around the annular ledge  45 . Each of these channels  95  has a connection bar  100 . The annular ledge  45  provides a lower resting surface for the lower end of the spring  50 . A handle  65  can be provided along the bottom side  67  of the ledge  45 . 
     The umbrella  20  also includes a plurality of stretchers  55 . The stretchers  55  can be made of any sturdy material, such as a metallic material. Each stretcher  55  has an inner end  105  and an outer end  110 . The outer end  110  of each stretcher  55  is pivotally coupled with the body  115  of a corresponding short rib  75 , as shown in FIGS. 5 and 6. The inner end  105  of each stretcher  55  is pivotally coupled to one connection bar  100  on the annular ledge  45 , as shown in FIG.  7 . Thus, each stretcher  55  extends radially from annular ledge  45  to the body  115  of a short rib  75 , and lifts or supports the annular ledge  45  to prevent the annular ledge  45  from sliding vertically downwardly. 
     Referring to FIGS. 5 and 6, the outer end  110  of each stretcher  55  has a closed circular loop  120 , which is adapted to fit into a rectangular slot  125  along a side  127  of the body  115  of a corresponding short rib  75 . On the two opposing sides  130  and  135  of the short rib  75  that are perpendicular to the side  127 , there are two holes  140  and  145 , respectively, which lie opposite to, but are aligned with, one another to accommodate a locking pin or rivet  150 , which is adapted to be inserted through the closed circular loop  120 . Thus, the stretcher  55  can pivot with respect to the short rib  75  at a pivot point defined by the axis created by the locking pin or rivet  150 . 
     Referring now to FIG. 7, the inner end  105  of each stretcher  55  has a generally closed circular loop  107  that loops around a corresponding connection bar  100  on the annular ledge  45 . Thus, the connection bar  100  is retained inside the opening of the loop  107 , so that the stretcher  55  can pivot with respect to the annular ledge  45  at a pivot point defined by the axis created by the connection bar  100 . 
     FIG. 8 illustrates another possible embodiment for the annular ledge  200 . The annular ledge  200  has a base plate  202  with a raised platform  204  provided about the center of the base plate  202 . A bore  206  extends through the center of the base plate  202  and the platform  204 , and the pole  25  is adapted to be slidable through the bore  206 . An annular wall  208  extends from the top surface  210  of the platform  204  at the location of the bore  206 , so that the pole  25  can slide through the annular wall  208 . Thus, the spring  50  is adapted to be seated on the top surface  210  of the platform  204 , with the annular wall  208  acting as a guide for positioning the spring  50 . In addition, a plurality of openings  212  are provided in spaced apart manner about the periphery  214  of the base plate  202 . Each opening  212  is adapted to receive the loop  107  of the inner end  105 .of a respective stretcher  55  to form a pivoting connection between the annular ledge  200  and the stretcher  55 . 
     Referring to FIGS. 1 and 2, the spring  50  and the stretcher  55  operate to open and close the umbrella  20 . First, when the umbrella  20  is in its closed position as shown in FIG. 2, the stretchers  55  are disposed in a generally vertical orientation where each stretcher  55  is generally parallel to the pole  25 . This orientation of the stretchers  55  allows the stretchers  55  to counteract or oppose the bias of the spring  50 , thereby keeping the spring  50  compressed and the umbrella  20  in the closed position. 
     To open the umbrella  20 , the user applies an upward force to the bottom side  72  of one of the long ribs  70  to cause the stretchers  55  to be moved from their vertical orientation. This releases the force that keeps the spring  50  compressed, so that the spring  50  now automatically biases the lower hub  40  upwardly along the pole  25  without any further user intervention. The bias (i.e., extension) of the spring  50  will also cause the spring  50  and the annular ledge  45  to advance vertically upwardly along the pole  25 . As the lower hub  40  moves upwardly along the pole  25 , the short ribs  75  are moved radially outwardly towards a generally horizontal orientation, thereby opening the umbrella  20  into the open position shown in FIG.  1 . 
     To close the umbrella  20 , the user applies a downward force to the top side  73  of one or more of the long ribs  70 , so as to push the short ribs  75  radially inward, which in turn causes the lower hub  40  to be pushed downward along the pole  25 . This overcomes the bias of the spring  50 , and causes the spring  50  and the annular ledge  45  to advance vertically downwardly along the pole  25 . When the long ribs  70  are pushed down until they are generally parallel with the pole  45 , the stretchers  55  are disposed in the generally vertical orientation in the closed position of FIG.  2 . To apply the downward force, the user can also employ the handle  65  to pull down on the annular ledge  45 , or pull down on the base plate  202  of the annular ledge  200 . 
     Thus, the deployment and closing of the umbrella  20  is very simple, and requires little force or strength on the user&#39;s part. A small upward force is all that is needed to open the umbrella  20 , and the user can watch as the spring  50  does the rest of the work that is needed to open the umbrella  20 . To close the umbrella  20 , the user only needs to corral the long ribs  70  and to push them down against the bias of the spring  50  (or merely pull down on the handle  65  or base plate  202 ). The vertical orientation of the stretchers  55  provides an effective self-locking mechanism which does not require any other separate locking device or mechanism to hold the umbrella  20  in the closed position. 
     Referring to FIGS. 3 and 4, another embodiment of the present invention employs covers for the spring  50 . In this embodiment, there are two overlapping covers: a lower spring cover  155 , which is attached to the annular ledge  45 , and an upper spring cover  160 , which is attached to the lower hub  40 . The lower cover  155  overlaps the upper cover  160  when the spring  50  is compressed. In other words, when the spring  50  is compressed, the lower cover  155  slides over the upper cover  160 . When the spring  50  is expanded, the lower cover  155  no longer completely overlaps the upper cover  160 . These spring covers  155  and  160  protect the spring  50  from dirt and moisture and provide a pleasing aesthetic appearance. The covers  155  can be made from any durable material, such as fabric, plastic or metal. 
     Thus, the spring and stretcher system of the present invention improves the durability, safety, and ease of use of the umbrella  20 . The user is able to open and to close a patio umbrella  20  without the use of a cord and pulley, and using a minimal amount of force. This spring and stretcher system is best applied for outdoor and patio umbrellas. 
     While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention.