Abstract:
A lamp retaining device for holding a lamp within a housing. The lamp retaining device includes a bracket adapted to mount to a housing. The bracket includes a channel formed therein which has a portion oriented such that an end of the lamp will rest unaided thereon. To positively secure the lamp into the bracket, a retainer is coupled to the bracket. More specifically, the retainer includes a retaining portion which is configured for insertion into the channel to positively secure the end of the lamp into the oriented portion of the channel. The retainer further includes a coupler to allow selective coupling and uncoupling of the retainer and the bracket.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to ultraviolet lamp systems and, more particularly, to retainers for holding a ultraviolet lamp in a housing. 
     BACKGROUND OF THE INVENTION 
     Ultraviolet lamp systems are used for curing or drying adhesives, sealants, inks, coatings, and other similar materials. A typical ultraviolet lamp system includes a housing to which an ultraviolet lamp is detachably mounted by a pair of oppositely disposed holders. The holders receive and secure the ends of the ultraviolet lamp to the housing. In some ultraviolet lamp systems, each holder is connected to a source of electricity for energizing the ultraviolet lamp or bulb. 
     As can be appreciated, each ultraviolet lamp has a finite life after which the lamp burns out and must be replaced. Depending on the curing or drying application, several ultraviolet lamp systems may be used at one time. If, during the drying or curing process, one ultraviolet lamp burns out, the process may have to be interrupted until the ultraviolet lamp can be replaced with a new one. Such interruptions reduce production efficiency as the entire process must be stopped to install the new ultraviolet lamp. 
     When using prior ultraviolet lamp systems, the installation of a new ultraviolet lamp is relatively cumbersome and involves an unacceptably long interruption in the curing or drying process. In some instances the interruption can be as long as 30 minutes. A large portion of the time required to replace the ultraviolet lamp is consumed removing the fasteners which affix the ultraviolet lamp to the housing. Generally, several fasteners of various types must be removed using one or more hand tools, such as screwdrivers and wrenches. In addition, hand tools are needed to disconnect any electrical connections between the ultraviolet lamp and the housing. In many situations, an electrician must be employed when hand tools are required to disconnect the electrical connections. Having to call in an electrician further lengthens the down time of the production process and increases the cost of changing the ultraviolet lamp. 
     What is needed, therefore, is an ultraviolet lamp system which provides for quick and easy installation of an ultraviolet lamp. The ultraviolet lamp system should allow for installation of the ultraviolet lamp without using hand tools or requiring an electrician. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the foregoing and other shortcomings and drawbacks of prior lamp retaining devices used to hold ultraviolet lamps. The lamp retaining device of the present invention provides for quick and easy installation and/or removal of an ultraviolet lamp from a housing without requiring hand tools or the assistance of an electrician. Although the lamp retaining device of the present invention is especially suited for use with ultraviolet lamps, it is equally applicable for use with other types of lamps. 
     In accordance with the principles of the present invention, the lamp retaining device includes a bracket adapted to mount to a housing. The bracket includes a first channel formed therein having a portion oriented such that an end of the lamp will rest unaided thereon. In other words, once the lamp ends are placed into that portion of the channel, the lamp will remain therein without using any fasteners or retainers. However, to positively secure the lamp into the bracket, a retainer is coupled to the bracket. More specifically, the retainer includes a retaining portion which is adapted for insertion into the channel to positively secure the end of the lamp into the oriented portion of the channel. The retainer further includes a coupler to releaseably couple the retainer to the bracket. Preferably, the channel is L-shaped and one leg of the L-shaped channel corresponds to the oriented portion discussed above. Advantageously, the retaining portion includes a spring loaded projection which is adapted to contact the lamp end with a positively acting force. Preferably, the spring loaded projection is a spring loaded ball bearing. 
     In a further aspect of the invention, the housing includes an end member which is disposed adjacent to but not in contact with the bracket. The end member has a second channel formed therein which is similar to the first channel in the bracket. As such, the retainer not only includes a retaining portion for insertion into the first channel of the bracket, but also a filler member for insertion into the second channel in the end member. The filler member in cooperation with the end member helps block heat from the lamp from getting to portions of the housing which are not actively cooled. 
     In another aspect of the invention, the bracket includes a fastener and the coupler on the retainer includes a sliding member. The sliding member moves between latched and unlatched positions relative to the fastener to respectively couple and uncouple the retainer and the bracket. 
    
    
     Various additional advantages and features of the invention will become more readily apparent to those of ordinary skill in the art upon review of the following detailed description taken in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the invention. 
     FIG. 1 is a disassembled bottom perspective view of the ultraviolet lamp retaining device of the present invention; 
     FIG. 2 is an enlarged disassembled perspective view of the lamp retaining device of FIG. 1; 
     FIG. 3 is a cross-sectional view of the assembled lamp retaining device taken along line  3 — 3  in FIG. 2; 
     FIG. 4A is an enlarged partial perspective view of the lamp retainer of FIG. 2 shown in the unlatched position; and 
     FIG. 4B is an enlarged partial perspective view of the lamp retainer of FIG. 2 shown in the latched position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to the FIG. 1, an ultraviolet lamp system  10  incorporates a lamp retaining device  12  constructed in accordance with the principles of the present invention. It will be appreciated that the lamp retaining device  12  of the present invention is not limited to the installation and retention of only ultraviolet lamps. The invention is equally applicable to other types of elongated, tubular lamps or even single-end light bulbs. 
     The ultraviolet lamp system  10  includes a lamp housing  14  which is operatively connected to a source of chilled water and a source of electricity (not shown). The lamp housing  14  includes a water cooled manifold  16  which is operatively connected to the source of chilled water. The water cooled manifold  16  serves to cool the ultraviolet lamp system  10  while it is operational, such as during a heating or curing application. The ultraviolet lamp system further includes an ultraviolet lamp  18  which is selectively removable from the lamp retaining device  12 . Preferably, the ultraviolet lamp  18  is made from quartz. 
     The lamp retaining device  12  includes a lamp bracket  20  which is mounted to and in thermal contact with the water cooled manifold  1   6  by fasteners (not shown). As such, lamp bracket  20  is cooled by water cooled manifold  16  while the ultraviolet lamp system  10  is operative. To provide further thermal protection to the lamp bracket, a housing end member  21  is disposed adjacent lamp bracket  20 . The housing end member  21  is also in thermal contact with the water cooled manifold  16  and shields the lamp bracket  20  from the direct ultraviolet light rays emitted from the ultraviolet lamp  12 . Lamp retaining device  12  also includes a lamp retainer  22  which is selectively coupled to lamp bracket  20  to securely hold ultraviolet lamp  18  thereto. Lamp housing  14  further includes electrical connector  24  which is operatively connected to a source of electricity. 
     With reference to FIG. 2, a lamp end  26  of ultraviolet lamp  18  is shown being installed into the lamp retaining device  12 . The installation of lamp end  26  is substantially the same as that for the opposite end of the ultraviolet lamp  18  so the following discussion will be similarly applicable to that opposite lamp end. Housing end member  21  and lamp bracket  20  include channels  27 ,  28 , respectively, both of which are generally L-shaped. Lamp bracket  20  further includes a fastener  30 . The L-shaped channels  27 ,  28  include vertical portions  31 ,  32  and horizontal portions  33 ,  34 . 
     Lamp end  26  includes an end fixture  36  which is fixedly secured by cement to a terminal end  38  of ultraviolet lamp  18 . An ultraviolet lamp  18  with end fixtures  36  of the type shown in FIGS. 1 and 2 is manufactured by Primearc, a subsidiary of the assignee of the present invention. Preferably, end fixture  36  is made of a ceramic material. When the ultraviolet lamp  18  burns out, the ultraviolet lamp  18  including end fixtures  36  is removed and replaced with a new ultraviolet lamp  18  with new end fixtures  36 . 
     The end fixture  36  includes a threaded electrical member  40  for threadingly receiving a thumb nut  42 . During installation of the ultraviolet lamp  18 , electrical connector  24  is placed over threaded electrical member  40  and thumb nut  42  is threaded thereon. The thumb nut  42  is readily removed by hand from the threaded electrical member  40  without the use of hand tools. It will be appreciated that the end fixture  36  could have a female positive electrical connector into which a male positive thumb screw is inserted to secure electrical connector  24 . Alternatively, electrical connector  24  could have an electrical plug that engages a complementary electrical receptacle in end fixture  36  such that no other fasteners are required. Whichever connecting scheme is used, electrical connector  24  should be securely fastened to end fixture  36  to avoid electrical arcing during when the ultraviolet lamp system  10  is operative. 
     End fixture  36  further includes a bushing  44  which is sized to conform to the L-shaped channel  28 . The L-shaped channel  27  of housing end member  21  is sized to conform to the terminal end  38  of ultraviolet lamp  18  which has a smaller diameter than that of bushing  44 . When end fixture  36  is inserted into L-shaped channel  28 , bushing  44  rests upon the horizontal portion  34  (FIG. 3) and remains therein without any further fasteners, allowing the ultraviolet lamp  18  to be installed by only one person because there is no need for a second person to hold the other end while lamp end  26  is being installed. 
     Lamp retainer  22  includes a mounting plate  46 . Affixed to the mounting plate  46  are a filler member  48 , a retaining portion  50  and a coupler  52 . Advantageously, filler member  48  and retaining portion  50  are spaced apart from each other so that heat is not transferred from filler member  48  to retaining portion  50 . Filler member  48  is sized to substantially fill the vertical portion  31  of the L-shaped channel  27  when inserted therein. The filler member  48  in cooperation with the housing end member  21  provides further thermal shielding from the heat generated by an operational ultraviolet lamp  18 , minimizing heating of non-cooled sections of the lamp housing  14 . Advantageously, housing end member  21  and filler member  48  are constructed of a material capable of withstanding high temperatures. Retaining portion  50 , which is sized to substantially fill the vertical portion  32  of L-shaped channel  28 , includes a spring loaded ball bearing  54  which positively contacts bushing  44  when lamp retainer  22  is affixed to lamp bracket  20 . The ball bearing  54  provides a positive contact force against bushing  44  to minimize unwanted movements and vibrations of ultraviolet lamp  18  that may be experienced during a particular heating or curing application. More importantly and as shown in FIG. 3, ball bearing  54  pushes bushing  44  into contact with the end of the horizontal portion of L-shaped channel  28  so that bushing  44  and end fixture  36  is cooled by water cooled lamp bracket  20 . Vertical portions  31 ,  32  are transversely offset from one another such that when filler member  48  and retaining portion  50  are positioned in vertical portions  31 ,  32 , respectively, there is no line-of-sight gaps for ultraviolet lights rays to directly pass therethrough. This offset helps to minimize heating of non-cooled sections of the lamp housing  14 . 
     Coupler  52  includes fixed member  56  affixed to mounting plate  46  by fasteners  57 . Fixed member  56  includes a throughhole  58  aligned with a throughhole  60  in mounting plate  46 . Fixed member  56  includes folded tabs  62  which form a channel through which a sliding member  64  can slidably move therethrough. Sliding member  64  includes opposing flexible members  66  which clampingly engage fastener  30  when sliding member  64  is moved from an unlatched position to a latched position. 
     A preferred embodiment of the coupler  52  is shown in FIGS. 4A and 4B. Sliding member  64  includes outer extensions  68  along the outside edges of flexible members  66  to prevent the sliding member  64  from sliding out of the channel formed by tabs  62  when sliding member  64  is moved to the unlatched position (FIG.  4 A). Sliding member  64  also includes inner extensions  70  along the interior edges of flexible members  66  to ensure that the sliding member  66  does not move beyond the fastener  30  when the sliding member  66  is moved to the latched position (FIG.  4 B). 
     To install ultraviolet lamp  18  into the lamp housing  1   4 , the terminal ends  38  and bushing  44  of a new ultraviolet lamp  18  are slid upwardly into vertical portions  31 ,  32  and then over into horizontal portions  33 ,  34 . At this point, the ultraviolet lamp  18 , and more specifically bushing  44 , rests unaided upon horizontal portion  34  without needing any fasteners to hold the ultraviolet lamp  18  in place. Electrical connector  24  is then affixed to threaded electrical member  40  by thumb nut  42 . Lamp retainer  22  is then coupled to lamp bracket  20 . More specifically, filler member  48  and retaining portion  50  are inserted respectively into vertical portions  31 ,  32  of L-shaped channels  27 ,  28  and fastener  30  is inserted through throughholes  60 ,  58 . Once the lamp retainer  22  is in place, sliding member  64  is moved by a hand or finger  72  from an unlatched position (FIG. 4A) to a latched position (FIG. 4B) such that flexible members  66  engage and surround fastener  30  to positively secure lamp retainer  22  to lamp bracket  20 . The entire installation procedure can be conducted without the use of any hand tools or the assistance of an electrician. The ultraviolet lamp  18  can be removed from the lamp housing  14  by simply reversing the installation process. 
     While the present invention has been illustrated by a description of various embodiments and while these embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant&#39;s general inventive concept.