Through-insulation strip light connector

A connector for light-emitting diode (LED) strip light is disclosed. The connector has a cavity with conductive longitudinal and transverse pins that, when the connector is assembled with an LED strip light in a cavity within the housing of the connector, penetrate the insulation of the strip light to make electrical contact with the strip light's conductors. The connector also includes gasket seals and a removable portion that exposes the cavity. The removable portion may include a window to expose any LEDs that may be within the housing of the connector.

BACKGROUND OF THE INVENTION

1. Field of the Invention

In general, the invention relates to electrical connectors, and more particularly, to electrical connectors for light-emitting diode (LED) strip lights.

2. Description of Related Art

Over the last decade, light-emitting diode (LED)-based lighting has become popular in both residential and commercial lighting applications because of its efficiency, adaptability, and wide range of color and color temperature options. One of the most popular forms of LED light is the strip light—a long, flexible printed circuit board (PCB) with LED light engines connected to the PCB at a regular interval along its length. Strip light can be placed in long extrusions to provide the same sort of form factor that a traditional fluorescent or incandescent fixture might and has a plethora of other uses. Backed by adhesive, strip light can adhere to essentially any surface, and is sometimes referred to as tape light.

Strip light typically experiences a voltage drop per unit length, which limits its maximum length. In order to overcome that voltage drop, strip light can be made to operate at higher voltages. For example, a 12V strip light might have a maximum effective length of about 16 feet (4.9 meters), while a 24V strip light might have a maximum effective length of about 40 feet (12.2 meters). The use of low voltage—depending on the authority one consults, anything under about 50 V—is advantageous because it poses less of a safety hazard and is less strictly regulated under electrical and fire codes and regulations.

Higher-voltage strip light is available on the market, and has significant advantages in terms of maximum length. For example, a strip light operating at 120V may have a maximum effective length on the order of 150 feet (45.7 meters). For this type of high-voltage strip light, a pair of wires run the entire length of the PCB, usually one wire positioned on each side of the PCB, to provide power. The wires are connected to the PCB at intervals, essentially connecting segments of the PCB in parallel with one another. The entire PCB and its power-conducting wires are typically coated or wrapped in a transparent or translucent insulative and waterproof coating, e.g., made of vinyl or another appropriate material.

Making electrical connections to strip light typically involves soldering wires to the strip light or connecting the existing wires with mechanical crimps. These processes include a number of delicate steps and may require extra equipment to perform. Especially when soldering is necessary, it can be difficult to ensure that a good connection has been made. Moreover, because most strip light is designed to be cut to desired lengths in the field, connections are often made under less-than-ideal conditions by installers whose training and ability can vary greatly. A more robust and reliable solution for connecting strip light to power would be useful.

SUMMARY OF THE INVENTION

One aspect of the invention relates to a through-insulation strip light connector. A connector housing includes a cavity sized to accept the cut or free end of a light-emitting diode (LED) strip light. The cavity includes two or more sets of pins arranged in different orientations from one another that extend upward from the floor of the cavity and are sharpened and otherwise adapted to penetrate the insulation of the strip light to make electrical contact with its conductors when the strip light is fully installed in the housing. The sets of pins each include a transverse pair of pins positioned to cradle the conductor and make electrical contact in a first orientation and location and a longitudinal group of pins positioned to make electrical contact in a second orientation and direction. The sets of pins are contiguous parts of a pair of strip conductors disposed beneath the floor of the cavity. The hidden ends of the strip conductors are arranged and adapted to make electrical contact with power conductors from a power cable. A removable portion of the housing that is placed overtop the strip light may include a window to allow the last LED or LEDs on the strip light to be seen. The through-insulation strip light connector thus provides a robust, redundant electrical connection with a strip light without the need to solder or place connectors on wire.

Other aspects, features, and advantages of the invention will be set forth in the description that follows.

DETAILED DESCRIPTION

FIG. 1is a perspective view of a connector, generally indicated at10, that connects a strip light12with a traditional power cable14. The connector10includes molded strain relief16where the cable14meets the connector10.

The strip light12itself comprises a printed circuit board (PCB)18on which light-emitting diode (LED) light engines20are disposed at a regular interval. The interval is usually constant over the entire length of the strip light, but may vary in some cases. The PCB may include other circuits, including LED driver circuits, and it may be either flexible or rigid. A flexible PCB may, for example, use mylar as a basic substrate, while a rigid PCB may use a material such as FR4 glass-fiber composite. In addition to the PCB18and the LEDs20, the strip light has a pair of power conductors22,24, typically braided wires, that extend along its length, periodically connecting to the PCB18to provide power. The conductors22,24themselves are usually without their own electrical insulation; the entire strip light12is enclosed in a transparent or translucent electrically insulating covering26, such as a vinyl polymer.

Externally, the connector10has a housing28that, in the illustrated embodiment, is generally rectilinear in shape. The housing28would typically be made of a plastic, such as ABS plastic, although other materials may also be used. The housing28has a removable portion30that extends along its top and along portions of the left, right, and forward sidewalls of the housing28. The housing28and its removable portion30may be specifically adapted for the strip light12; in the illustrated embodiment, the removable portion30has a window in its top surface. The window32allows light from the last LED or LEDs20on the PCB18to be seen, and in some embodiments and installations, may prevent “dark spots” or breaks in the light generated by the strip light12. The window32may be defined by a transparent or translucent material, such as glass or plastic, or it may simply be open.

FIG. 2is an exploded view of the connector10ofFIG. 1. As shown, the housing has a depressed cavity34surrounded on three sides by a raised wall36. Both the cavity34and the wall36are open toward the forward sidewall38of the housing28, as is the housing28itself. Abutting the wall36around its perimeter and extending out from it is a recessed channel40.

On the floor of the cavity34are a number of electrical contact and retaining features. Two sets of conductive longitudinal pins42, one on each side of the cavity34, extend upward from the floor of the cavity34and are parallel to the long axis of the housing38. Two sets of conductive transverse pins44, one on each side of the cavity34, also extend upward from the floor of the cavity34. Thus, one set of longitudinal pins42and one set of transverse pins44lie close to each other on each side of the cavity34. Relative to the locations of the longitudinal pins42in each grouping, the transverse pins44in the illustrated embodiment are closer to the forward sidewall38of the housing28. The transverse pins44are also orthogonal in orientation relative to the longitudinal pins42.

In addition to the pins,42,44, the floor of the cavity34also has several rows of teeth46,48. The forward sidewall38of the housing28defines an opening50, the floor of which also includes a row of teeth52. The purpose of the pins42,44and teeth46,48,52will be explained below in more detail.

A lower seal52is contoured to rest in the recessed channel40, and has a thickness about equal to the depth of the channel40and contours that cause it to dip into and rest on the floor of the opening50and its teeth52as well. The lower seal52would typically be made of a resilient, water-resistant material, such as a silicone polymer. The strip light12is placed overtop the lower seal52, such that it rests on the floor of the cavity34and extends out the opening50. The resting position of the strip light12within the housing28is defined and delineated by the cavity34and the wall36around it—that space is typically dimensioned to be just larger than the strip light12itself, so as to provide for a tight fit.

An upper seal54rests overtop the strip light12. The shape of the upper seal54is similar to that of the lower seal52, except that the upper seal54has a rounder, thinner cross-section and accommodates the upper half of the opening50. The upper seal54may rest in a groove or depression defined in the underside of the removable portion30(not shown inFIG. 2). Fixing the entire housing together are fasteners56, four screws in the illustrated embodiment, that extend through aligned holes defined in the various components. Of course, the manner of closure and fastening is not critical, and many variations are possible.

The cavity34, wall36, and opening50are dimensioned and adapted to place the strip light12in a known and relatively precise location relative to the housing28. When the connector10is assembled with the strip light12present and the fasteners56are tightened, the housing28compresses the strip light12and causes the longitudinal and transverse pins42,44to penetrate the relatively soft insulative covering26of the strip light12. The resulting positioning of the components is shown in the schematic end-elevational view ofFIG. 3, as well as in the longitudinal cross-section ofFIG. 4.

As shown inFIGS. 3 and 4, both the longitudinal and transverse pins42,44are positioned to penetrate the insulative covering26in order to make contact with the power conductors22,24. The individual transverse pins44in each pair are spaced from each other with angled side edges that terminate in upper points. The transverse pins44also diverge slightly from one another. The side edges and divergence of the pins44create a V-shaped space between them, such that they receive and cradle the respective conductors22,24in the transverse plane, as shown inFIG. 3.

Meanwhile, the longitudinal pins42penetrate the insulation in alignment with the lengths of the conductors22,24, contacting the conductors22,24several times along their lengths. As can be seen in the view ofFIG. 4, there are four longitudinal pins42in each set. The first and last pins43of the set are mirror images of one another and include one vertical long side, one slightly inwardly canted long side, and a single angled edge that connects the two long sides, forming an off-center point. The middle pins45of the set are wider than the first and last pins43(in the illustrated embodiment, approximately double the width), and are also mirror images of one another. The include two long, vertical sides that are slightly off-vertical, canted toward one another, and a pair of top angled edges that connect between the two long sides, forming an off-center point. The pins43,45reach the same height, but the different shapes provide for different types and degrees of penetration and provide an overall “serrated” edge.

Ideally, both the longitudinal and transverse pins42,44penetrate the insulation26sufficiently to make electrical contact, and the amount of contact allows for redundancy and more power-carrying capacity. Additionally, the transverse pins44, because of the cradling function they provide, may have the effect of holding the conductors22,24in place.

As was described briefly above, the floor of the cavity34and the opening50include teeth46,48,52in addition to the sets of pins42,44. The general purpose of the teeth46,48,52is to create enough friction on the covering26to hold the strip light12in place within the housing28. In contrast to the pins42,44, which would typically be made of a conductive material and adapted to penetrate the insulation26fully, the teeth46,48,52would typically be made of a nonconductive material and either would not be adapted to penetrate the insulation26at all, or would be adapted to penetrate only to a very shallow depth to hold the strip light12in place. For example, the teeth46,48,52could be molded features of the housing. Moreover, while the term “teeth” is used, the teeth46,48,52need not be pointed or particularly sharp; rather, any feature that tends to increase friction on the strip light12could be used.

As shown inFIG. 4, the longitudinal and transverse pins42,44on each side of the cavity34are integral parts of a strip conductor56that is placed below the floor of the cavity34.FIG. 5is a perspective view of one end of the strip light12, showing its connection with a pair of the strip conductors56in isolation. As can be seen in both figures, the pins42,44are actually the divided, pointed ends of a pair of tabs58,60on the strip conductor56that are bent to extend upwardly.

At their proximal ends, the two strip conductors56take an upward step62to contact and connect with respective power and ground conductors64from the power cable14. The connection between the strip conductors56and the wires54from the power cable14may be a soldered connection, a crimped connection, or a connection that relies on any sort of hardware. The upward step62allows the cable14to align with the horizontal centerline of the housing28.

In some cases, the housing28may be made of a molded plastic, and the strip conductors56may be molded into the plastic (e.g., by overmolding). In other cases, the housing and its components may simply be assembled. In either case, final installation of the strip light12is relatively simple: the cut or free end of a strip light12is placed in the cavity34and the removable portion30of the housing28is placed atop it. Once pressure is exerted, either manually or by tightening of fasteners56, the pins42,44penetrate the insulation26of the strip light12and make electrical contact with its conductors22,24at multiple, redundant points, with the transverse pins44and teeth46,48,52helping to hold the conductors22,24in the desired position. This process may be simpler, more repeatable, and more mechanically and electrically robust than a classic process of soldering or making other types of connections with spade connectors or other hardware. Moreover, it can be performed quickly on field-cut lengths of strip light12. Depending on the gauges of conductors42,44,56and other factors, the connector10may be used with either low-voltage or high-voltage strip light12, although the strip light12enclosed in insulation is more commonly seen with high-voltage strip light.

Of course, the pins42,44need not be part of the same physical structure as long as they are electrically connected together. Thus, the pins42,44may in some cases be individual pins that are connected together with wires, printed circuit board (PCB) contact traces, or any other suitable type of electrical connection.

While the invention has been described with respect to certain embodiments, the description is intended to be exemplary, rather than limiting. Modifications and changes may be made within the scope of the invention, which is defined by the appended claims.