Abstract:
A lamp having a threaded base for threadedly coupling to an electrical energy source is provided. The lamp includes a light-generating bulb replaceably coupled to the threaded base and a housing coupled to the base. The housing has an inner light-directing surface disposed about the bulb. The housing terminates at an outer rim, and defines an opening. A mounting assembly, including a lens-holding ring with a keeper and a latch hook on the sidewall, removably mounts a lens on the rim in a covering position closing the opening, whereby removal of the lens permits access to the bulb. The lens holding ring may be separable from the housing or may be pivotally coupled to a ring on the housing.

Description:
RELATED APPLICATION 
     This application is a continuation-in-part of co-pending U.S. application Ser. No. 09/289,237, filed Apr. 9, 1999, entitled “Lamp With Removable Lens.” 
    
    
     BACKGROUND 
     This invention relates to lamps, and more particularly, to lamps having threaded bases. 
     In the past, lamps used in display lighting, such as flood lighting and spot lighting, commonly include a bulb contained within a generally frustoconical glass envelope coupled to a threaded base for connection to an electrical socket. The interior of the envelope is metallized to define a reflector. To provide a whiter light throughout its life, the bulb may be filled with a gas, such as a halogen gas. When such a bulb burns out, the entire lamp is usually discarded and replaced with a new one. When used in retail stores and other commercial installations, these lamps are on for many hours of each day. Thus, they must be replaced frequently. The combination of the cost of the bulb-within an-outer-envelope construction and the frequency of replacing the lamp used in display lighting makes such lamps expensive to use. 
     Lamps have also been provided which have a threaded base detachable from the glass envelope. This allows a user access to the interior of the lamp to replace burnt out bulbs, but requires the user to first unscrew the lamp from the socket. Often, the lamps, when connected to the socket, are in tight quarters making removal from the socket difficult and often time consuming. 
     SUMMARY 
     It is a general object of the invention to provide a lamp which avoids the disadvantages of prior lamps while affording additional structural and operational advantages. 
     An important feature of the invention is the provision of a lamp which is of a relatively simple and economical construction. 
     In connection with the above feature, another feature of the invention is the provision of a lamp which provides cost reduction by providing for replacement of the bulb of the lamp, thereby permitting the reuse of the outer envelope, the lens and other elements of the lamp. 
     A further feature of the invention is the provision of a lamp of the type set forth that does not need to be removed from an attached socket to change the bulb. 
     Certain ones of these and other features of the invention maybe attained by providing a lamp comprising: a threaded base for threadedly coupling to an electrical energy source and having a pair of female terminals; a light-generating bulb having a pair of male terminals removably receivable in the female terminals; a reflective housing connected to the base and having an inner light-directing surface disposed about the bulb, the reflective housing terminating at an outer rim, and defining an opening; a lens; and a mounting assembly mounting the lens on the rim in a covering position closing the opening and accommodating movement of the lens to a non-covering position wherein at least a portion of the opening is uncovered to permit access to the bulb through the opening. 
     The invention consists of certain novel features and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawings a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, the invention, its construction and operation, and many of its advantages should be readily understood and appreciated. 
     FIG. 1 is a perspective view of the lamp of the present invention with the lens mounted in place; 
     FIG. 2 is a bottom plan view, partially broken away, of the lamp of FIG. 1; 
     FIG. 3 is a side elevational view of the lamp of FIG. 1, partially in section; 
     FIG. 4 is an enlarged fragmentary view of the circled area of FIG. 3; 
     FIG. 5 is a fragmentary, front elevational view of the lens of FIG. 1, wherein the latch has been moved to a non-engaged position; 
     FIG. 6 is an front elevational view of the lamp of FIG. 1, with the glass envelope partially broken away and the lens detached; 
     FIG. 7 is a fragmentary, front elevational view of the lug and slot of the lens mounting assembly engaged with each other; 
     FIG. 8 is a fragmentary, right-hand side elevational view of the lamp of FIG. 7; 
     FIG. 9 is an enlarged, fragmentary, front elevational view of the left-hand side of FIG. 3; 
     FIG. 10 is a fragmentary, left-hand side elevational view of the lamp of FIG. 9; 
     FIG. 11 is a bottom plan view of another lamp embodiment; 
     FIG. 12 is an enlarged, fragmentary view in vertical section taken generally along the line  12 — 12  in FIG. 11; 
     FIG. 13 is a fragmentary, side elevational view of the lamp of FIG. 12, as viewed from the left-hand side thereof; 
     FIG. 14 is an enlarged, fragmentary, top plan view of the lamp of FIG. 11; 
     FIG. 15 is a fragmentary, side elevational view of the lamp of FIG. 12, as viewed from the right-hand side thereof; 
     FIG. 16 is a fragmentary sectional view taken generally along the line  16 — 16  in FIG. 14; and 
     FIG. 17 is an enlarged, fragmentary, sectional view, taken generally along the line  17 — 17  in FIG.  11 . 
    
    
     DETAILED DESCRIPTION 
     Referring to FIGS. 1,  3  and  6 , a lamp  20  is provided. The lamp  20  includes a threaded base assembly  22  including a cup-shaped threaded end portion  24  adapted to be threadedly engaged to an associated lamp receptacle (not shown), for electrical connection thereto in a known manner. The threaded end portion  24  is integral with a flared frustoconical shoulder  26 , which terminates in a cylindrical wall portion  28 . 
     The lamp  20  also includes an envelope or housing  30  fixedly coupled to the base assembly  22  in a known manner. The envelope  30  is typically formed of glass and, as seen in FIGS. 3 and 6, has an end wall  32  and a generally frustoconical-shaped sidewall  34  having interior and exterior surfaces  36 ,  38 . 
     The interior surface  36  is provided with a reflector material to form a reflector  39  or light directing surface. The sidewall  34  terminates at a rim  40  which defines a circular opening  42  (FIG.  6 ). As seen in FIG. 4, the rim  40  has a groove  43  about its periphery. The rim  40  also defines a shoulder surface  44  which projects radially outwardly from the exterior surface  38  to an annular terminal edge  44   a  (FIGS. 3,  4  and  6 ). 
     As seen in FIGS. 3 and 6, two electrical clamps, or connectors  45 ,  46 , defining female terminals, are disposed in the end wall  32  of the envelope  30  and are respectively electrically connected to the threaded end portion  24  of the base assembly  22  by wires  48 ,  50  in a known manner. 
     As seen in FIG. 4, the lamp  20  also includes a light-generating bulb  52 , such as a halogen bulb, having a capsule  54  made of hard glass or quartz and a pair of connecting legs, or male terminals  56 ,  58 . Legs  56 ,  58  respectively have parallel end portions  60 ,  62  respectively connected to inclined portions  64 ,  66  which converge toward each other. The parallel portions  60 ,  62  are respectively removably disposable in clamps  45 ,  46 . The clamps  45 ,  46  are preferably spring loaded to maintain the parallel portions  60 ,  62  therein to maintain electrical contact. As seen in FIG. 3, the inclined portions  64 ,  66  contact the upper portion of the clamps  45 ,  46  to prevent the end portions  60 ,  62  from being inserted too deeply into the clamps  45 ,  46  and to properly align the capsule  54  at the focal point of the reflector  39  which is disposed about the capsule  54 . 
     The lamp  20  also includes a lens  68 , preferably formed of glass, to focus or direct light in a predetermined beam pattern, such as, among others, spot, flood and wide flood. 
     The lamp  20  also includes a mounting assembly  76  to mount the lens  68  in a covering position, as seen in FIGS. 1 and 3, on the rim  40  to close the opening  42  and to position the lens  68  properly to direct the light from the light generating bulb  52 . As seen best in FIG. 4, the lens  68  has interior and exterior surfaces  70 ,  72  and a raised rim  74  about the periphery of the interior surface  70 . When the lens  68  is in the covering position, the raised rim  74  is disposed in the groove  43 . 
     The mounting assembly  76  includes a ring-like lens holder  78  made of a metal, or other suitable material, which can withstand the operating temperatures of the lamp  20 . The lens holder  78  has an annular bottom wall  80  integral with, and inclined to, an upstanding cylindrical sidewall  82 . The lens holder  78  also includes a latch keeper  84  projecting up from the top of the sidewall  82  and a flange  86  also projecting up and radially inwardly from the top of the sidewall  82  and inclined with respect to the sidewall  82 . The flange  86 , as seen best in FIGS. 1,  2  and  8 , includes a centrally disposed slot  88  formed of two generally parallel sidewalls  90  and a bottom wall  92  connecting the two. The flange  86  is spaced about 180° from the keeper  84 . The lens holder  78  may be adhesively attached to the lens  68  by means of an adhesive  79  (FIG.  2 ), such as an epoxy, disposed between the bottom wall  80  and the lens  68 , or may be attached by mechanical means. The lens holder  78  can also be free from the lens  68 . 
     The mounting assembly  76  also includes a box-like lug  94  projecting from the exterior surface  38  of the envelope  30  adjacent to the rim  40 . The mounting assembly  76  also includes a latch hook assembly  96  disposed about 180° away from the lug  94  (FIG. 6) and adhesively attached to the exterior surface  38  of the envelope  30 . The hook assembly  96  includes an operating lever  98  and a latch hook  100  having a hooked end  102 . 
     When the lens  68  is in the covering position, the slot  88  of the flange  86 , as seen in FIGS.  1 ,  7  and  8 , is aligned with the lug  94 , so that lug  94  is disposed between the sidewalls  90  of the slot  88 , which prevents the lens holder  78  from rotating with respect to the envelope  30 . Additionally, portions of the radially inwardly projecting flange  86  rest on shoulder surface  44 , which aid in supporting the lens  68  on the envelope  30  (FIGS. 3,  4  and  7 ). 
     Also, when the lens  68  is in the covering position, the hooked end  102  of the latch hook  100  is engageable with the keeper  84  of the lens holder  78 , as illustrated in FIGS. 3 and 5. 
     To remove the lens  68  from the covering, the operating lever  98 , as seen in FIGS. 3 and 5, is rotated from the position shown in FIG. 3, in the direction of arrow A (FIG.  5 ), which disengages the hooked end  102  of the latch hook  100  from the keeper  84 . The operating lever  98  can then be rotated in the direction of arrow B (FIG. 5) to provide clearance between the hooked end  102  of the hook  100  and the keeper  84  so a user can pull the lens holder  78  and lens  68  away from the opening  42  (and the rim  40 ), as seen in FIG. 6, to a non-covering position, and thereby can gain access to the light-generating bulb  52  for replacement or repair. After replacement, the lens  68  (and lens holder  78 ) are returned into the covering position shown in FIGS. 1 and 3. 
     While, the mounting assembly  76  accommodates complete removal of the lens  68  from the envelope  30 , it is contemplated that the lens  68  could also remain coupled to the envelope  30  but moved to a position which leaves at least a portion of the opening  42  uncovered to provide access to the light-generating bulb  52 . More specifically, referring now to FIGS. 11-17, there is illustrated another lamp embodiment, generally designated by  120 , which is similar to the lamp  20  of FIGS. 1-10, but utilizes a different lens mounting assembly. Accordingly, parts of the lamps  20  and  120  which are the same will bear the same reference numbers. 
     The lamp  120  has an envelope or housing  130  fixedly coupled to the base  22  in the same manner as described above for the lamp  20 . The envelope  130  has a generally frustoconical-shaped side wall  132  with an exterior surface  133  and terminating at a rim  134  (FIG. 17) which defines the circular opening  42 . The rim  134  has a frustoconical outer surface portion  134   a  and a cylindrical surface portion  135  which terminates at an annular outer end surface  136  lying in a plane substantially perpendicular to the axis of the lamp  120 . An annular rib  137  projects axially forwardly from the end surface  136  and joins it to an annular inner end surface  138  substantially parallel to the outer end surface  136 . Projecting generally radially outwardly from the exterior surface  133  of the side wall  132  at diametrically opposed locations thereon are two generally prism-shaped lugs  139  (one shown in FIG.  16 ). 
     Encompassing the rim  134  and fixedly secured thereto is a housing ring, generally designated by the numeral  140 , which may be formed of a suitable plastic material. Referring, in particular, to FIGS. 12,  16  and  17 , the ring  140  has a frustoconical wall  141  integral at its upper end with a more sharply-sloped frustoconical flange  142  and integral at its lower end with a depending, cylindrical flange  143 , the ring  140  being so dimensioned that the wall  141  and the flanges  142  and  143 , respectively, lie along the outer surface  134 a of the rim  134 , the exterior surface  133  of the envelope side wall  132  and the cylindrical surface  135  of the rim  134 . At a plurality of equiangularly spaced locations therearound, the cylindrical flange  143  is provided with radially inwardly extending retaining flanges  144  (one shown in FIG. 17) which underlie and engage the outer end surface  136  of the rim  134  for fixedly retaining the ring  140  in place on the envelope  130 . The retaining flanges  144  may be formed by ultrasonic deformation of the cylindrical flange  143  or by ultrasonic attachment to that flange of separate retaining pieces, after the ring  140  is positioned in place on the rim  134 . Formed at diametrically opposed locations on the ring  140  and projecting radially outwardly therefrom are two generally prism-shaped bosses (one shown in FIGS.  14  and  16 ), respectively defining recesses  146  for receiving the lugs  139  and cooperating therewith to prevent rotation of the ring  140  relative to the envelope  130 . Projecting radially outwardly from the ring  140 , substantially midway between the bosses  145 , is a pair of generally triangular hinge flanges  147  and  148  (FIGS.  12  and  13 ). 
     The lamp  120  includes a latch mechanism, generally designated by the numeralI 50 , which includes an extension  151  of the frustoconical flange  142  of the ring  140 , disposed diametrically opposite the hinge flanges  147  and  148 . Projecting radially outwardly from the extension  151  is a short, cylindrical boss  152  which defines a cylindrical recess  153 , receiving one end of a helical compression spring  154 . Also projecting radially outwardly from the extension  151  and the adjacent portions of the ring wall  141  and flange  142 , respectively on opposite sides of the boss  152 , are two pivot flanges  155  and  156  (FIGS.  12  and  13 ). The latch mechanism  150  also includes a latch hook  160  disposed between the pivot flanges  155  and  156  and having a hub  161 . A pivot pin  162  is received through complementary openings in the hub  162  and the pivot flanges  155  and  156  for mounting the latch hook  160  for pivotal movement between latching and unlatching positions. Integral with the hub  162  at one end thereof is a stop flange  163  designed to engage the extension  151  in the latching position of the latch hook  160 , illustrated in FIGS. 12 and 13. Also integral with the hub  160  and depending therefrom is a hook flange  165  provided at its distal end with a radially outwardly projecting hook lip  166  having an inclined cam surface  167  thereon. Projecting radially outwardly from the hook flange  165  and spaced a slight distance from the hook lip  166  is a stop lug  168 . Formed in the inner surface of the hook flange  165  behind the stop lug  168  is a spring recess  169  which receives the other end of the spring  154 . Thus, it will be appreciated that the spring  154  resiliently urges the latch hook  160  to its latching position, illustrated in FIG.  12 . 
     The lamp  120  also includes an annular lens ring  170 , which may be formed of the same plastic material as the housing ring  140 , and includes a cylindrical wall  171 , integral at its forward end with a radially inwardly and forwardly projecting frustoconical flange  142 . Also projecting radially inwardly from the cylindrical wall  171  a slight distance rearwardly of the flange  172  is an annular seating rim  172 , which has radially inwardly projecting therefrom, at equiangularly spacedapart locations thereon, a plurality of retaining flanges  174  (one shown in FIG.  17 ). Extending axially rearwardly and radially inwardly from the cylindrical wall  171  is a hinge arm  175 , disposed in use between the hinge flanges  147  and  148  of the housing ring  140 . A hinge pin  176  is received through complementary openings in the hinge arm  175  and the hinge flanges  147  and  148  for accommodating pivotal movement of the lens ring  170  between a covering position, illustrated in the drawings, and an uncovering position (not shown). Also extending axially rearwardly from the cylindrical wall  171  diametrically opposite the hinge arm  175 , and forming a part of the latch mechanism  150 , is a generally trapezoidal-shaped keeper arm  177  (FIGS. 12 and 13) having a rectangular slot  178  formed therethrough and defining at its upper edge a cam surface  179 . 
     The rings  140  and  170  cooperate to form a mounting assembly for a lens  180 , similar to the lens  68  of the lamp  20 . The lens  180  has a sloping front surface  181  and stepped cylindrical rim surfaces  182  and  183 , the latter terminating at an annular rear rim surface  184 . In use, the surfaces  181 - 183 , respectively, lie along the frustoconical flange  172 , the cylindrical wall  171  and the seating rim  173  of the lens ring  170  (see FIG.  12 ), with the retaining flanges  174  disposed for engagement with the rear rim surface  184  of the lens  180  (see FIG. 17) for securely fixing it in place in the lens ring  170 . The retaining flanges  174  may be formed in the same manner as was described above for the retaining flanges  144  of the housing ring  140 , after the lens  180  has been assembled in the lens ring  170 . 
     It will be appreciated that, in use, the lens  180  pivots with the lens ring  170  between the covering and uncovering positions. In the uncovering position, the lens  180  can be moved out of alignment with the envelope opening  42  to permit access to the bulb, as described above. When the lens ring  170  is pivoted from its uncovering position to its covering position, the cam surface  179  on the keeper arm  177  engages the cam surface  167  of the latch hook  160  for pivoting the latch hook  160  in a counter-clockwise direction, as viewed in FIG. 12, against the urging of the spring  154 , to permit passage of the keeper arm  177 . As the keeper arm  177  moves past the hook lip  166 , the hook lip  166  will snap into engagement in the keeper slot  178  under the urging of the spring  154  to latch the lens ring  170  and the lens  180  in their covering position, further movement of the lens ring  170  being limited by engagement of the cam surface  179  with the stop lug  168 . In order to release the latch mechanism  150 , the user simply depresses the latch hook  160 , as by pushing on the stop lug  168 , to release the hook lip  166  from the keeper slot  178 . 
     While the rings  140  and  170  are described as formed of plastic material, it will be appreciated that other materials could be used, and other techniques could also be utilized for assembling them to the envelope  130  and the lens  180 , respectively. 
     While particular embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.