Watertight LED lamp

Disclosed is a three-piece light emitting diode lamp. The lamp comprises a lamp holder that encapsulates and seals various connectors and connections. A removable light emitting diode is inserted into contact sockets so that the light emitting diode can be easily replaced. Various techniques are used to provide proper polarity for placement of the light emitting diode in the contact sockets. A lens cover is engaged in a ring cavity between an inner annular wall and an outer annular wall that seal and hold the lens cover to the lamp holder and provide a watertight seal.

BACKGROUND OF THE INVENTION

Light emitting diodes have been widely implemented as an alternative to traditional incandescent and fluorescent lamps, especially for decorative light strings. Light emitting diodes have high efficiency, a long lifetime and a low cost. Christmas light strings need to operate in both an indoor and outdoor environment. As such, watertight light strings are required for safety reasons and to provide an extended lifetime.

SUMMARY OF THE INVENTION

An embodiment of the present invention comprises a watertight, light emitting diode lamp comprising: a lens cover having an annular neck that forms a lens cover opening; a light emitting diode having at least two light emitting diode leads, the leads having a crimp formed therein so as to create contact surfaces on the light emitting diode leads; a lamp holder comprising: at least two light emitting diode sockets that have conductive socket contact surfaces that are releasably engaged by the contact surfaces on the light emitting diode leads, so that the light emitting diode can be replaced; at least two wire connectors that are conductively connected to the light emitting diode socket conductors and to at least two power leads; a housing comprising a plastic insulating material that surrounds and encloses the light emitting diode sockets, the light emitting diode socket conductors and the wire connectors to seal the light emitting diode sockets, the light emitting diode socket conductors and the wire connectors from moisture and provide electrical isolation between the light emitting diode sockets, the light emitting diode socket conductors and the wire connectors, the plastic insulating material formed to provide an inner annular wall and an outer annular wall that create a ring cavity having a size that substantially matches the annular neck of the lens cover to form a watertight seal between the lens cover and the lamp holder.

Another embodiment of the present invention comprises a method of manufacturing an light emitting diode lamp comprising: molding an insulating plastic housing around at least two light emitting diode sockets that have conductive socket contact surfaces, at least two light emitting diode socket conductors that are conductively connected to the light emitting diode sockets and at least two wire connectors that are conductively connected to the light emitting diode socket connectors and to at least two power leads, to provide an insulated housing that seals the light emitting diode sockets, the light emitting diode socket conductors and the wire connectors from moisture and provides electrical isolation between the light emitting diode sockets, the light emitting diode socket conductors and the wire connectors; forming an inner annular wall in the housing; forming an outer annular wall in the housing that creates a ring cavity between the inner annular wall and the outer annular wall that has a pre-selected size; providing an light emitting diode that has at least two light emitting diode leads; forming a crimp in the light emitting diode leads that create contact surfaces on the light emitting diode leads; inserting the light emitting diode leads into the light emitting diode sockets such that the contact surfaces of the light emitting diode leads slidingly and releasably engage the light emitting diode sockets to provide a conductive contact between the light emitting diode leads and the light emitting diode sockets while allowing the light emitting diode to be removed and replaced with another light emitting diode; inserting a lens having an annular neck into the ring cavity such that at least one contact surface of the neck forms a watertight seal with the housing.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1is an assembly diagram of one embodiment of a light emitting diode lamp100. As shown inFIG. 1, the light emitting diode lamp100is comprised of three primary parts: a lamp holder102, a light emitting diode104and a lens cover106. These three primary elements are assembled to provide a watertight lamp100that is suitable for use on either indoor or outdoor light strings. The lamp holder102includes an insulating, waterproof over-molded housing116that covers all of the electrical components and wire connections of the lamp holder102. The housing116can be made from a plastic or rubberized type material that can be molded directly over the other components in the lamp holder102. The over-molded housing116provides a waterproof package that securely holds all of the components of the lamp holder102. The over-molded housing116also covers the power leads110and prevents moisture from entering the lamp holder102. The power leads110are connected by wire connectors112to the light emitting diode contact sockets114. A portion of the insulating, waterproof over-molded housing116separates each of the light emitting diode contact sockets114and provides electrical insulation between the sockets114. The insulating, waterproof over-molded housing116is formed with an inner annular wall120and an outer annular wall122that provide an annular ring cavity134. The light emitting diode104has two light emitting diode leads108that fit into the light emitting diode contact sockets114in the lamp holder102. The lens cover106has a neck142with an opening136that fits over the light emitting diode104. The neck142fits into the ring cavity134and provides a tight waterproof seal between the neck142of the lens cover106by forming a seal between the neck14and the inner annular wall120and the outer annular wall122.

The three primary components of the light emitting diode lamp100, comprising the lamp holder102, the light emitting diode104and the lens cover106, can be easily assembled and disassembled by hand. The assembled light emitting diode lamp100provides a watertight package that allows replacement of the light emitting diode104in cases where the light emitting diode104burns out, or the user desires to replace the light emitting diode104with a different color light emitting diode or a different wattage light emitting diode. The neck142of the lens cover106fits tightly in the ring cavity134such that the elasticity of the over-molded plastic material116tightly holds the lens cover106to the lamp holder102with a force that is sufficient to prevent the disassembly of the lens cover106from the lamp holder102during normal usage of the light emitting diode lamp100. Alternatively, as disclosed below, with respect toFIGS. 17A and 17B, the lens cover106can be threaded into threads in the ring cavity134to securely hold the lens cover106to the lamp holder102.

FIG. 2is a schematic diagram of two light emitting diode contact sockets114connected to two power leads110. As shown inFIG. 2, contact socket124is conductively connected to the wire conductor112via conductor128. Similarly, contact socket126is connected to another one of the wire connectors112via conductor130. Contact socket124includes a socket contact surface125that engages a contact surface138on one of the light emitting diode leads108, as disclosed below with respect toFIG. 4. Similarly, contact socket126has a socket contact surface127that engages a contact surface139on the other light emitting diode lead108, as explained in more detail below with respect toFIG. 4.

FIG. 3discloses a lamp holder102. Lamp holder102has an insulating waterproof molded housing116that surrounds and encapsulates light emitting diode contact sockets114, wire connectors112and conductors128,130. Power leads110are also surrounded by the insulating, waterproof over-molded housing116that are sealed in the housing116to prevent leakage of moisture that could cause corrosion. The insulating, waterproof over-molded housing116is also disposed between the light emitting diode contact sockets114, the conductors128,130and the wire connectors112to provide an insulating layer between these components. An outer annular wall122is formed in an outer portion at one end of the insulating, waterproof over-molded housing116. An inner annular wall120is created inside of the outer annular wall122and protrudes from the housing116to form a ring cavity134in the housing116. A polarity indicator132is also provided on the outside of the lamp holder102to indicate the proper polarity for the light emitting diode104.

FIG. 4is an assembly diagram illustrating assembly of a lamp holder102with a light emitting diode104. As shown inFIG. 4, light emitting diode104has two light emitting diode leads108. Crimps140,142are formed in the light emitting diode leads108to create contact surfaces138,139, respectively. The contact surfaces138,139are adapted to engage contact surfaces128,130, respectively, when the diode104is inserted into the light emitting diode contact sockets114. The light emitting diode leads108have sufficient elasticity to create a force between the contact surfaces138,139and the contact surfaces128,130to ensure sufficient electrical conduction to drive an adequate current through the light emitting diode leads108to light the light emitting diode104.

FIG. 5is an assembly diagram illustrating the manner in which a lamp holder102can be assembled with lens cover106. As shown inFIG. 5, the light emitting diode104is inserted into the light emitting diode contact sockets114, such that the light emitting diode lead contact surfaces138,139engage the socket contact surfaces128,130, respectively. Lens cover106, as shown inFIG. 5, includes a neck142having an opening136, which is large enough to accommodate the light emitting diode104. The neck142is substantially the same size as the ring cavity134and fits tightly into the ring cavity134. The outer surface of the neck145creates a seal with the inner surface of the outer annular wall122. Similarly, the inner surface of the neck143creates a seal with the outer surface of the inner annular wall120. Opening136covers the light emitting diode104. An annular indentation150may also engage an optional ring134that is connected to the outer annular wall122. The ring140causes the neck142of the lens cover106to snap into place so that the annular indentation150engages the ring140. Ring140can be formed as part of the structure of the outer annular wall122.

FIG. 6is a diagram of an assembled light emitting diode lamp100. As shown inFIG. 6, the lens cover106is inserted into the ring cavity134between the inner annular wall120and the outer annular wall122. Neck142forms a seal with the outer annular wall122and the inner annular wall120. The inner annular wall120extends outwardly from the lamp holder122to engage a larger portion of the neck142of the lens cover106to increase the sealing surface that is created between the lens cover106and the lamp holder102. A waterproof latch118may be used to increase the pressure between the inside surface of the outer annular wall122and the neck142to increase the sealing properties between neck142and outer annular wall122.

FIGS. 7A-7Cshow another embodiment of lamp holder152.FIG. 7Ais a side cutaway view of lamp holder152. As shown inFIG. 7B, the embossment154provides a label to label the polarity of the contacts156,158.FIG. 7Cis a side view of the lamp holder152illustrating the manner in which the embossment154is disposed on the lamp holder152.

FIGS. 8A and 8Bdisclose another embodiment of a lamp holder160. As shown inFIG. 8A, light emitting diode contact socket166is placed in a rearward position from the light emitting diode contact socket164. The light emitting diode contact sockets164,166are displaced by a distance162.FIG. 8Bis an end view showing the contact sockets164,166in the lamp holder160. Light emitting diodes (not shown) having different length leads can then be used with the lamp holder160to ensure proper polarity when the light emitting diode is inserted into the light emitting diode contact sockets164,166.

FIGS. 9A and 9Billustrate an alternative embodiment of a lamp holder168. As shown inFIG. 9A, lamp holder168includes a light emitting diode contact socket170and a light emitting diode contact socket172. As shown inFIG. 9B, openings174,176are provided in the lamp holder168that are different sizes. The leads of a light emitting diode (not shown) can be made to have different sizes to fit the openings174,176to ensure proper polarity when inserting the light emitting diode. Alternatively, the light emitting diode sockets170,172can be made different sizes to ensure the proper polarity.

FIGS. 10A and 10Bshow another embodiment of a lamp holder178. As shown inFIG. 10A, lamp holder178includes light emitting diode sockets180,182. As shown inFIG. 10B, openings184,186can be of a square shape and a round shape, respectively. The leads of a light emitting diode (not shown) can then be formed to match the openings184,186to ensure proper polarity upon insertion of the light emitting diode. Alternatively, the light emitting diode sockets180,182can be made in the shape of the openings184,186.

FIGS. 11A and 11Bdisclose another embodiment of a lamp holder188. As shown inFIGS. 11A and 11B, a notch192is provided in the inner annular wall190. A protrusion extending from a light emitting diode (not shown) can be used to match the notch192to ensure the proper polarity when inserting the light emitting diode.

FIGS. 12A and 12Billustrate another embodiment of a lamp holder194. As shown inFIGS. 12A and 12B, a tab196is provided on a portion of the inner annular wall198. A light emitting diode (not shown) can have a notch that matches the tab196to ensure that the light emitting diode is inserted with the proper polarity.

FIG. 13illustrates another embodiment of a lamp holder200. In traditional light emitting diode lighting strings, light emitting diodes are normally collected in series. If one light emitting diode in the string burns out or is broken, the entire string will fail. To improve the light emitting diode string reliability, bypass components, such as bypass component202, can be connected between the leads of the light emitting diode that are burned out or broken to provide a bypass around the light emitting diode214. Bypass component leads208,210can be connected to conductors204,206at contact points212. In this manner, a bypass component202can be disposed between the conductors204,206of the light emitting diode contact sockets and provide an inexpensive and compact manner of providing a bypass component202. The bypass component may comprise a resistor, a diode or a resistor-like component. This is disclosed in more detail in U.S. patent application Ser. No. 11/461,293, filed Jul. 31, 2006, by Jing Jing Yu, entitled “Parallel Serial LED Light String,” which is specifically incorporated herein by reference for all that it discloses and teaches.

FIG. 14is a schematic illustration of the manner in which a lamp holder216can be connected in a parallel fashion to lamp holder218. As illustrated inFIG. 14, power lead220as well as power lead222are connected to a first wire holder228of lamp holder216. Power lead222is then connected to a first wire connector232of lamp holder218. Power lead224is connected to a second wire connector230of lamp holder216. Power leads224,226are connected to wire connector234so that lamp holder216,218are effectively wired in parallel. This is more fully disclosed in U.S. patent application Ser. No. 10/767,820, filed Jan. 30, 2004, by Mingzhu Li, et al., entitled “LED Light Module and Lighting String” and U.S. patent application Ser. No. 11/716,788, filed Mar. 12, 2007, by Jing Jing Yu, entitled “A Half-Wave Rectification Circuit with a Low-Pass Filter for LED Light Strings,” which applications are specifically incorporated herein by reference for all that they disclose and teach. The advantage of the parallel wiring scheme illustrated inFIG. 14is that if a light emitting diode of either lamp holder216or218burns out, the remaining lights in the string will not burn. Wire connectors228,230,232and234are capable of engaging either one or two wires so that the parallel wiring scheme ofFIG. 14can be achieved.

FIG. 15is another diagram of the lamp holder216showing the manner in which power leads220,222are connected to wire connector228, and power lead224is connected to wire connector230.

FIGS. 16A and 16Billustrate two different methods for attaching lens covers to lamp holders. As shown inFIG. 16A, lamp holder236includes screw threads238in the annular ring which match the screw threads242that are formed in the neck of the lens cover240. In this manner, the lens cover240can be screwed into the lamp holder236and held securely in the lamp holder236.

As shown inFIG. 16B, the lamp holder244includes a ring246in the ring cavity that matches the indentation250in the neck of the lens cover248. When the lens cover248is inserted into the ring cavity, the ring246engages the indentation250to securely hold the lens cover248in the lamp holder244.

FIGS. 17A,17B and17C show three different embodiments of lamp holders. As shown inFIG. 17A, lamp holder252has an inner wall254that protrudes outwardly from the lamp holder252beyond the outer wall256by a distance258. The extended portion of the inner wall254engages the inner surface of the lens cover to provide an additional sealing surface on the interior portion of the neck of the lens cover.

As shown inFIG. 17B, lamp holder260has an outer wall262that protrudes beyond the inner wall264by a distance266. The outer wall262engages the outer surface of the neck of the lens cover to provide an additional extended sealing surface266on the outer portion of the neck of the lens cover.

FIG. 17Cillustrates another embodiment of a lamp holder268. Lamp holder268has an outer wall272that extends the same distance as the inner wall270. Both the inner wall270and the outer wall272engage and seal on the inner and outer surfaces, respectively, of the neck of the lens cover.

FIGS. 18A and 18Bshow the use of a waterproof o-ring seal274that is disposed in the ring cavity134. As shown inFIG. 18B, the waterproof o-ring seal is placed at the end of the ring cavity134and fits tightly within the ring cavity134. As shown inFIG. 18A, the lens cover106fits tightly down over the waterproof o-ring seal, and the end of the neck of the lens cover106forces the o-ring seal into the bottom of the ring cavity134to form a seal that tightly seals the lens cover106to the lampholder102.

The present invention therefore provides a unique three-piece light emitting diode lamp that is watertight and allows the lens cover and light emitting diode to be easily replaced. The lamp holder102provides a waterproof housing that encapsulates the electrical components and connections so that moisture cannot penetrate the housing and corrode the various connections.