Abstract:
An extendable lighting system having a main housing with a bottom wall and upwardly extending side walls. A lamp housing is retractable positioned within the main housing and a flexible diaphragm connects to the main housing above the bottom wall and connects to the lamp housing to create a substantially enclosed space between the diaphragm and the bottom wall. An air passage communicates with the enclosed space.

Description:
This application claims the benefit under 35 USC §119(e) of U.S. Provisional Application Ser. No. 60/691,886 filed Jun. 17, 2005, which is incorporated by reference herein in its entirety. 

   FIELD OF INVENTION 
   The present invention relates to extendable/retractable lighting systems and in one particular embodiment, relates to retractable landscape lights typically implanted in the ground along a path or walkway. 
   BACKGROUND 
   Retractable lighting systems, particularly landscape lights, are known in the art as can be seen in U.S. Pat. Nos. 5,628,558 to Iacono and 5,683,176 to Clendenin. These two patents disclose pneumatically operated devices which have an inner housing sliding within an outer housing. In pneumatically operated devices, O-rings are typically used to minimize airflow between the inner and outer housings. O-ring seals have the disadvantage of adding frictional resistance to the sliding action between the two housings. Additionally, O-ring seals must be kept fee of dirt and grit or they tend to fail prematurely. Of course, landscape lights being buried in the ground are subject to extremely dirty and gritty conditions, especially when combined with periodic rain. Moreover, since landscape lights may be installed in low areas, it is quite possible that they will at times be submerged during heavy rainfalls. Given these circumstances, there exists a need for improvements to the various prior art retractable lighting systems. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  illustrates an internal perspective view of one embodiment of the extendable lighting system of the present invention. 
       FIG. 2A  illustrates a sectional view of the embodiment of the extendable lighting system seen in  FIG. 1  while in the raised position. 
       FIG. 2B  is the external view of the  FIG. 2A  embodiment. 
       FIG. 3A  illustrates a sectional view of the embodiment of the extendable lighting system seen in  FIG. 1  while in the lowered position. 
       FIG. 3B  is the external view of the  FIG. 3A  embodiment. 
       FIG. 4A  illustrates a sectional view of an alternate embodiment of the extendable lighting system while in the raised position. 
       FIG. 4B  illustrates a sectional view of the  FIG. 4A  embodiment while in the lowered position. 
       FIG. 5  illustrates one embodiment of the control system for the extendable lighting system of the present invention. 
       FIG. 6  illustrates an alternate embodiment of the control system for the extendable lighting system of the present invention. 
   

   DETAILED DESCRIPTION OF INVENTION 
   One embodiment of the extendable lighting system of the present invention is seen in  FIG. 1 . This particular embodiment is in the form of landscape light  1 . Landscape light  1  generally comprises a main housing  2 , a lamp housing  15 , and a flexible diaphragm  30 . The substantially cylindrical main housing  2  seen in this embodiment will include a bottom wall  3  and sidewalls  4 . A wire aperture  5  is positioned at the bottom of main housing  2  in order to allow power cord  27  to extend into the interior of main housing  2 . A seal formed of rubber, silicone, or a similar sealant material will make wire aperture  5  water and air tight. Main housings  2  will further include a conventional air nipple  7  with conventional hose engaging ridges  8  such that when a hose or fluid line is attached to air nipple  7 , air (or another fluid) may flow into the interior of main housing  2 . The upper portion of main housing  2  may include a clamp ring shoulder  9 . As best seen in  FIG. 3A , this embodiment of claim ring shoulder  9  includes a rounded upper shoulder portion  9 A and an outer flat shoulder portion  9 B. In one preferred embodiment, main housing  2  will be constructed of an injection molded plastic such as an acrylonitrile-butadiene-styrene copolymer (ABS), but could be constructed of any number of materials having adequate corrosion resistance to outdoor conditions. 
   Again viewing  FIG. 1 , lamp housing  15  generally comprises a lamp base  20  which includes a threaded center aperture  31  extending therethrough and into which is threaded lamp socket  29  with a lamp bulb  21 . In the embodiment shown, lamp bulb  21  is a conventional incandescent bulb, but could be an LED or other suitable light emitting device. Lamp base  20  will support a clear lamp lens  18  onto which a deflector cap  16  having light directional vanes  17  will be positioned. In one embodiment, lamp base  20  may be cast or milled aluminum while lamp lens  18  may be clear cast acrylic and deflector cap  16  may be injection molded plastic. This embodiment of lamp lens  18  will have machined groves on both ends to receive o-rings  19 . After the o-rings  19  are fitted onto lamp lens  18 , the lens slips into the machined female grove in the interior of lamp base  20  and deflector cap  16  slides over the lamp lens  18  such that the bottom of direction vanes  17  may snap into the machined groves  32  in the lamp base  20  (best seen in  FIG. 2A ). 
   Lamp housing  15  will be connected to main housing  2  by way of a flexible diaphragm  30 . In the embodiment shown, flexible diaphragm  30  is formed of a 1/32″ or 1/16″ thick nylon inserted neoprene rubber which is formed into a frustum or cone shape and then glued or vulcanized along the seam. Naturally, other flexible, substantially air impermeable materials could form flexible diaphragm  30  in other embodiments of the invention. Diaphragm  30  will connect to the lamp base  20  of lamp housing  15  by way of retaining cup  22  which includes a center aperture  23 . As best seen in  FIG. 2A , one end (the “upper” end) of diaphragm  30  will be positioned between the beveled bottom of lamp base  20  and the mating retaining cup  22 . A hollow, all-thread connector tube  24  will pass through retaining cup center aperture  23  (which is not threaded) and engage the threaded center aperture  31  formed in lamp base  20 . It will be understood that the tightening of jam nut  25  against retaining cup  22  will force retaining cup  22  against lamp base  20  and hold diaphragm  30  securely in place. Because diaphragm  30  is an elastic, rubber-like material, an air-tight, water-tight seal is formed between retain cup  22  and lamp base  20 . 
   The lower end of diaphragm  30  will be connected to main housing  2  in a similar manner using clamp ring  10 , which in the embodiment shown is formed of injection molded plastic. This lower end of diaphragm  30  is placed between the clamp ring shoulder  9  on main housing  2  and the claim ring  10 . Clamp ring  10  will then be tightened against ring shoulder  9  by a series of screws  11  inserted along the perimeter of ring shoulder  9 . Although the embodiment of  FIG. 2A  employs stainless steel flat head, counter-sunk machine screws  11 , it will naturally be understood that other conventional methods of securing together ring shoulder  9  and clamp ring  10  are within the scope of the present invention. For example, a two piece tapered clamp could be utilized if the shoulder  9  and the clamp ring  10  were tapered in shape to match the clamp. As with lamp base  20  and retainer cup  22 , it will be understood that the gripping of diaphragm  30  between ring shoulder  9  and clamp ring  10  forms a substantially air-tight and water-tight seal. Although  FIG. 2A  illustrates diaphragm  30  connected to the upper edge of main housing  2 , other embodiments could have diaphragm  30  connected to any upper portion of main housing  2 , but typically above bottom wall  3 . 
   Still viewing  FIG. 2A , a further element of landscape light  1  includes a guide member/biasing weight  26 . In the embodiment shown, guide member  26  is a disk shaped steel member having a threaded center aperture  28 . The outer diameter of guide member  26  will be smaller, but sufficiently close to the inner diameter of main housing  2  such that guide member may easily slide within main housing  2  in a non-contacting, substantially frictionless and seal-less manner, but at the same time provides support to help maintain lamp housing  15  in a centered, upright orientation. Guide member  26  also acts as a biasing weight to pull lamp housing  15  downward when there is not sufficient air pressure in the interior of main housing  2  (as explained in greater detail below). In one embodiment, guide member  26  will weight between about 3 and about 8 lbs. As suggested in  FIG. 2A , guide member  26  is attached lamp housing  15  by being threaded onto connector tube  24  and fixed in place with a jam nut  25 . The power cord  27  will extend through connector tube  24  and connect to lamp socket  29 . In the embodiment shown, power cord  27  has a preformed coil which allows it to easily lengthen when lamp housing  15  is in the raised position, but is re-coiled when lamp housing  15  is in the lowered position as seen in  FIG. 3A . 
   An alternate embodiment of landscape light  1  is seen in  FIGS. 4A and 4B . In this embodiment, guide member  26  has been replaced with spring hanger  35 . Spring hanger  35  includes a top section  37  with an aperture therein and feet  38  formed at spring hanger  35 &#39;s lower end. Connector tube  24  may be passed through the aperture and secured to top section  37  with a pair on jam nuts  25 . Main housing  2  is also modified in  FIG. 4A  to include a retaining ring  39  secured to the interior of main housing  2 . A retracting spring  36  is positioned between a retaining ring  39  and feet  38 . As seen in  FIG. 4A , when lamp housing  15  is in the raised position, spring  36  will be compressed and exert a downward bias on lamp housing  15 . When the force maintaining lamp housing  2  in the raised position (e.g., air pressure within main housing  2 ) is not sufficient to overcome the force of compressed spring  36 , spring  36  will move lamp housing  15  to the lowered position as seen in  FIG. 4B . 
   Typically, a series of landscape lights  1  will be used as part of an overall lighting system to light a driveway, walking path, or the like.  FIG. 5  illustrates one embodiment of this overall lighting system. Each landscape light  1  will have its main housing  2  positioned below ground level such that in the lowered position, the deflector cap  16  extends no further than about one inch above ground level. An air line  48  will branch to each air nipple  7  and a power line  47  will branch to each power cord  27 . 
     FIG. 5  illustrates the air line  48  and the power line  47  connecting to a unitary control box  40 . In the embodiment shown, control box  40  includes an on/off switch  45 , a power transformer  41 , a low pressure air pump  44 , a solenoid activated air dump valve  42 , and a pressure relief valve  43 . The electrical components of control box  40  will be powered by conventional 120 volt power source  46  (e.g., a standard residential power outlet). On/off switch  45  may be manually activated or it may be an automatic switch such as a timer switch  45 A or a photo-activated switch  45 B. Timer switch  45 A and photo-activated switch  45 B will allow the landscape lights  1  to be automatically turned on at dusk and turned off at dawn as desired by the user. The 120 volt power source  46  will typically be stepped down to either 12 or 24 volts by transformer  41  depending on the voltage rating of the other components in control box  40 . Transformer  41  supplies low voltage power to the lamps  21 . Switch  45  will supply the required voltage to air pump  44  and air dump valve  42  via power line  4  while air line  48  is connect to the output of air pump  44 . In the embodiment shown, air pump  44  may be a low pressure (about 4 psi max), high efficiency, positive displacement pump such as, in one non-limiting example, a conventional aquarium pump manufactured by Rolf C. Hagen Corporation of Montreal, Canada under the designation “Optima”. In such an embodiment, it is preferred that the pump provide air at a rate of less than about 5000 to about 20,000 cc/min. Because a positive displacement pump may be damaged if it must pump against a pressure much higher than its rating, a pressure relief valve  43  may be placed in air line  48 . In this embodiment, pressure relief valve  43  may be in one example a “500 Series Adjustable Inline Relief Valve” manufactured by Circle Seal Controls, Inc., of Corona, Canada and set to release pressures of over about 1.5 psi. This will allow air pump  44  to operate continuously without damage. As one example, solenoid activate dump valve  42  may be a “Body-Ported Solenoid Control Valve” manufactured by Mead Fluid Dynamics of Chicago, Ill. Solenoid activated dump valve  42  will be of a type which is closed when power is supplied and open when the solenoid is not energized. 
   When switch  45  activates the system, air pump  44  will begin pumping air while at the same time solenoid valve  42  is energized causing it to move to the closed position (i.e., closing off the air dump outlet). As pressure increases in the main housing  2  of each landscape light  1 , the lamp housing  15  will move to the raised position. In the embodiment of landscape light  1  seen in  FIG. 2A , a gauge pressure (i.e., above atmospheric pressure) of about 1.5 psi acting against the interior of diaphragm  30  and the bottom of cup  22  will be sufficient to fully extend lamp housing  15 . Returning to  FIG. 5 , it can be seen how pressure relief valve  43  acts to release compressed air at any time the pressure in the system exceeds 1.5 psi. 
   At a time or under lighting conditions when switch  45  moves to the off position, power to the lamps, pump  44  and solenoid valve  42  is cut. Pump  44  will then cease to supply compressed air and solenoid valve  42  returns to the open position, thereby allowing any positive pressure in the system to equalize to atmospheric pressure. Without positive pressure within main housing  2  of landscape lights  1 , the weight of the guide member as suggested in  FIG. 3A  (or tension in the spring  36  in  FIG. 4A ), causes lamp housing  15  to sink back into main housing  2  as suggested in the lower portion of  FIG. 5 . 
   Although  FIG. 5  illustrates an integrated control box  40 , an alternate embodiment seen in  FIG. 6  demonstrates how an existing control box  40 A of a prior art lighting system could be employed with a retro-fit control box  40 B of the present invention. The control box  40 A could be the control box for an existing prior art lighting system where the landscape lights are stationary above ground lights. Existing control box  40 A would include a timer  45  and a transformer  41  supplying current to an existing power line  47  running to the stationary landscape lights (not shown). This prior art system could be retrofitted to an embodiment of the current invention by first replacing the stationary landscape lights with the landscape lights  1  positioned in the ground as described above. The existing power line  47  would be connected to landscape lights  1 . A new air supply line  48  would be connect to each landscape light  1  and supplied with pressurized air by the pump  44  in retro-fit control box  40 B. Retro-fit control box will also include solenoid dump valve  42  and pressure relief valve  43 . All components of retro-fit control box  40 B are powered by a connecting line  49  from the existing power source. It will be understood that the retro-fitted system will then operate in a manner identical to that described in reference to  FIG. 5 . 
   Although described in reference to specific embodiments, there are many variations and modifications which fall with in the scope of the present invention. As further nonlimiting examples, the landscape lights  1  could be installed in a concrete slab or side walk. Nor is the present invention limited to ground located lighting. The embodiment of  FIG. 4  could readily be employed as retractable lighting in ceilings or walls. Nor is the present invention necessarily limited to pneumatic operation, but could operate on other fluids (e.g., water). Nor is the invention limited lighting applications, but could be used whenever it is desired to have an object extended and retracted from a ground/floor, overhead, or wall area. For example, the invention could be used to raise and lower decorative items or markers such as small flags, or to raise and lower boundary markers around the perimeter of a football, soccer, or other sports field. In the case of boundary markers, the markers could collapse if a player fell on the marker. Also, the flexible diaphragm would allow the marker to bend sideways when struck by a player, but then return to an upright position. All such modifications and variations are intended to fall within the scope of the following claims.