shown in fig1 – 9 is a cap 10 having a brim 15 with extensible / retractable leaves 16 , 17 , each of which is pivotally mounted to a main brim member 18 . main brim member 18 is typically fixed to cap 10 in a conventional manner . extensible / retractable leaves 16 , 17 are pivotally attached to opposite ends of main brim member 18 and are rotatable around pivot pins 21 , 20 to allow the effective area of the brim to be expanded in both the length and width directions . in the fully retracted position shown in fig1 , 2 and 8 , extensible / retractable leaves 16 , 17 are completely covered and generally concealed by main brim member 18 and secondary guide member 28 , whereby the effective surface area of adjustable brim 15 is equal to the area of main brim member 18 . each of the extensible / retractable leaves 16 , 17 are pivotable into any position between a first position in which superposition of the extensible / retractable leaves with main brim member 18 is minimized ( i . e ., extension and surface area are maximized ) as shown for example in fig3 – 6 , and a second position in which superposition of extensible / retractable leaves 16 , 17 with main brim member 18 is maximized ( i . e ., leaves 16 and 17 are fully retracted to minimize surface area of brim 15 ) as shown in fig1 and 2 . movement of leaves 16 and 17 can be either independent or dependent . however , in the illustrated embodiment movement of extensible / retractable leaves 16 and 17 is coordinated ( i . e ., structure is provided to cause leaves 16 and 17 to be extended and retracted together ). this mechanism includes a guide 22 secured to the underside of main brim member 18 , a pin 23 that extends through an elongate linear slot 24 through guide 22 , an elongate arcuate slot 25 through leaf 17 , an elongate arcuate slot 26 through leaf 16 , and an elongate slot 27 through a secondary guide member 28 . pin 23 includes a head section 29 which is wider than slot 24 , and is therefore retained between main brim member 18 and guide 22 . leaves 16 , 17 and secondary guide member 28 are sandwiched between guide 22 and a flange portion 30 of an actuator 31 fastened to the shank portion of pin 23 . in the illustrated embodiment , fasteners 32 and 33 cooperate with pins 20 and 21 respectively to hold the various brim components 16 , 17 , 18 and 28 together in a layered relationship . in this illustrated embodiment , a shank portion of fasteners 32 and 33 are received in axial bores extending through pins 20 and 21 respectively . fasteners 32 and 33 may be secured to pins 20 and 21 respectively by means of an interference fit , frictional engagement , adhesives , or various other means . various alternative means for assembling the components of the brim may also be utilized , provided that each of the extensible / retractable leaves 16 and 17 may be rotated with respect to main brim member 18 to supplement the effective area of brim 15 in both the length and width directions . the effective area of brim 15 may be expanded by grasping actuator 31 and pushing outwardly toward the edge of the brim 15 in a direction coinciding with the longitudinal direction of slot 27 . this causes pin 23 attached to actuator 31 to engage the outer edge of slots 26 and 25 of extensible / retractable leaves 16 and 17 respectively , whereby leaf 16 is rotated outwardly around pin 21 and extensible / retractable leaf 17 is rotated outwardly around pin 20 . leaves 16 and 17 may be retracted by moving actuator 31 in an opposite direction away from the edge of brim 15 , or by pushing inwardly on the outward edges of extended leaves 16 and 17 . in the illustrated embodiment , leaves 16 and 17 are essentially mirror images of each other . this , along with slots 25 and 26 , guide slot 24 , and pin 23 , and optional guide slot 27 ensure that brim components 16 and 17 are extended equally to provide brim symmetry . such symmetry is generally desired for aesthetic reasons . however , the slots and guides are not essential to achieving a brim structure which may be expanded in both the length and width directions . shown in fig1 is an alternative embodiment of the invention in which the structure with extensible / retractable leaves described above with respect to fig1 – 9 is utilized with a headband , rather than with a cap . headgear 110 includes a headband 111 attached to a structure with extensible / retractable leaves as generally described above . the extensible / retractable leaves structure includes a main brim 118 , a first extensible / retractable leaf 116 , a second extensible / retractable leaf 117 , and a guide member 128 . brim structure 115 of headgear 110 may be similar to the brim structure 15 described above with respect to the embodiment illustrated in fig1 – 9 . thus , fig1 illustrates that the structure with extensible / retractable leaves may be utilized with any of a variety of different hats , caps , headbands , and various other headgear . shown in fig1 – 14 is an article of furniture 200 , such as a desk or table , having a first panel 210 which provides a horizontal support surface or work surface 212 . a second panel 216 and a third 217 are each pivotally mounted onto the underside of first panel 210 , whereby they may be rotated between a retracted position as shown in fig1 and 12 , wherein panels 216 and 217 are entirely superposed beneath first panel 210 ( i . e ., a position in which superposition is maximized ), and a second position in which panels or leaves 216 and 217 are rotated around pivot pins 221 and 220 respectively into a position in which superposition of the second and third panels 216 and 217 is substantially reduced , whereby the effective area of support surface 212 is increased in both the length and width directions . as illustrated in fig1 , extensible / retractable leaves 216 and 217 may be provided at one end of first panel 210 , and additional extensible / retractable leaves 218 and 219 may be provided at an opposite end of first panel 210 . as with the headgear illustrated in fig1 – 10 , articles of furniture and other structures employing the extensible / retractable leaves may be provided with a means for deploying leaves 216 and 217 in a symmetrical fashion . this means may be generally similar to those described for extensible / retractable visor 15 . in addition to headgear and articles of furniture , the disclosed structure with extensible / retractable leaves may be utilized for a variety of other purposes , such as for various platforms , trays , etc . the actuator used with the structure ( e . g ., actuator 31 ) may be directly or indirectly connected to the extensible / retractable leaves or panels , and can be slideably , rotationally or otherwise manipulated to effect movement of the leaves or panels . the actuators may or may not be lockable . additionally , the pivot pins can be suitably configured to function as actuators . actuators can be situated at various locations on the visor assembly . when only one fixed visor panel is used , it can be located above or below the visor extensions . fixed and rotatable visor panels can be made from cardboard , fabric , plastic , wood or any other suitable material . the structures of this invention may employ more than two extensible / retractable panels which may be deployed and retracted in a manner similar to that of the illustrated embodiments . accordingly , the claims are to be interpreted to require at least two extensible / retractable panels and encompass structures having three or more extensible / retractable panels . the above description is considered that of the preferred embodiments only . modifications of the invention will occur to those skilled in the art and to those who make or use the invention . therefore , it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and not intended to limit the scope of the invention , which is defined by the following claims as interpreted according to the principles of patent law , including the doctrine of equivalents .
a structure with extensible / retractable panels , which provides variable surface area for items such as headgear brims , furniture tops , etc ., includes a first panel , a second panel pivotally mounted to the first panel , and a third panel pivotally mounted to the first panel . the second and third panels are rotatable from a retracted position in which the second and third panels are positioned underneath the first panel , and a deployed position in which the second and third panels extend beyond both the length and width of the first panel .