GB2071837A

GB2071837A - A rope light

Info

Publication number: GB2071837A
Application number: GB8008325A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-03-12
Filing date: 1980-03-12
Publication date: 1981-09-23

Abstract

An element for constructing a rope light, comprising two moulded sections 12 and 13 hinged together at 14 and provided with a lock 16, 17 to hold the two sections together in a tubular shape. At least a portion of one section is transparent and the sections are provided with a pair of electrical connectors 19,20 to allow the connection of a lamp to appropriate conductors. One end of the tubular member defined by the two sections is formed as a head and the other end has a socket to receive a head of another like member. By interconnecting a plurality of such tubular members with conductors extending therethrough and interconnecting lamps within each member, a complete modular rope light can be constructed. <IMAGE>

Description

SPECIFICATION A rope light This invention relates to a lighting system in which a plurality of lamps are arranged in a row along a flexible carrier, the lamps being appropriately inter-connected by wires wired either for simultaneous illumination in some predetermined sequence. Such a lighting system is generally known, and will hereinafter be referred to, as "rope light". In particular, this invention relates to an element for use in the construction of a rope light, as well as to rope light constructed from a plurality of such elements.

The usual technique for manufacturing a rope light is to make up a string of lamps wired in series from a plurality of separate coloured lamps and wires cut to appropriate lengths so that the lamps are spaced by typically 20 cm. Typically four such strings are then twisted together with the lamps arranged in sequence, one from each string in turn, the lamps being equi-spaced at about 5 cm intervals. The group of intertwined strings are then threaded into a flexible tube of translucent plastics material and the wires appropriately terminated to allow connection to an electricity supply. The length of such a rope light is typically 8 metres for an assem bly having four strings each of forty 6v filament lamps, so that the light can be operated on a 240v mains supply.The rope light can be connected to an electric control module, which serves to distribute the supply of electric current to each of the four assemblies in such a way as to give the effect of a light appearing to "run" along the length of the rope light. Of course, other power supply arrangements could be used; for instance all the lamps could be flashed on and off together, or ali could simply be illuminated at the same time. Moreover other numbers of strings could be intertwined.

Rope lights as have just been described find wide applications. For example, they are frequently used in the retail and advertising trades, to attract attention to a particular display-for instance in a shop window. Rope lights also are used extensively in light shows, such as in places of entertainment and especially in discotheques.

The rope light manufacturing technique described above is most difficult reliably to perform. Each lamp of each string separately has to be connected to the wires which carry the electric current, and to reduce the manufacturing cost, it is usual simply to twist the wire "tails" of each lamp to the appropriate wire, the twisted joint then being protected with an insulating sleeve. Subsequently, on pulling the group of intertwined strings through the relatively long plastics material tube, there is a high risk that at least one of the twisted connections will separate-and a break at some point in any one string will prevent operation of that entire string.Even if a connection does not break, there is the risk that the insulating sleeve at a connection will become dislodged, leading to the possibility of a short circuit and hence premature failure of the rope light. A further disadvantage is that the replacement of a failed bulb by another is very difficult, requiring at least partial extraction of the group of strings from the tube.

This problem can be reduced by providing filament lamps which short-circuit internally when the filament breaks, thus ailowing the remainder of the lamps in that assembly to continue working, but nevertheless should two or more lamps fail the remaining lamps willl be subjected to a considerable overvoltage, leading to a reduction in the life thereof.

In addition to the disadvantages mentioned above, the actual assembly of the known type of rope light discussed above is particularly difficult and requires a considerably long assembly bench, allowing each string of lamps to be laid out lengthwise. Moreover, it is found that unless the plastics material tube is stretched out substantially linearly, the threading of the group of strings therethrough is virtually impossible, without damaging either lamps or their connections to the associated wires.

In view of the very considerable disadvantages of the known rope lights and the manufacturing thereof, as discussed above, this invention seeks to allow the manufacture of an improved rope light by providing an element, a plurality of which are used end-to-end in the construction of a rope light.

Accordingly, this invention provides an element for use in the construction of a rope light which element comprises a generally tubular member formed of or having a window of a transparent or translucent material, the member being adapted to allow the opening and closing thereof and being provided with locking means to restrain opening once closed, the member having at least one pair of electrical connectors accessible when the member is open and by means of which a lamp positioned within the element can be connected to electric conductors, one end of the tubular member being in the shape of a head and the other end being formed as a socket to receive the head of a second like element.

It will be appreciated that a rope light can be constructed from a plurality of elements of this invention, by arranging the elements endto-end with the head of one element fitted into the socket of the next adjacent element.

A lamp is positioned within each element and connected to appropriate conductors by means of the electrical connectors within the element, the conductors extending axially through the conjoined elements. By appropriately interwiring the conductors, as many separate strings of lamps can be provided as are required, from one string (that is, the lamp of every element being in the same electrical circuit) up to a number of strings dictated by the number of wires which conveniently can be accommodated within the elements.

The element of this invention preferably is made in one piece by a plastics moulding technique, the element being adapted to allow the opening and closing thereof by providing a split parallel to the length of the tubular member from one end thereof to the other end and a hinge line opposed to the split which hinge line is defined by a region of reduced wall thickness. For a tubular member of circular cross-section, the member thus preferably has two semi-circular sections with the hinge line interconnecting the two sections; by relatively hinging the two sections the member may be opened and closed to allow access to the interior thereof.

For an arrangement as just described, the locking means conveniently comprises at least one barb provided on one of the sections and adapted to interengage a slot provided on the other section as the two sections are moved towards each other to close the member.

In the element of this invention, each electrical connector of the pair thereof preferably comprises an upstanding boss appropriately configured to receive the conductors to be connected together - and usually this will be one wire extending lengthwise of the element and one of the tails of the lamp to be located within the element. Advantageously, such a boss is in the form of a peg provided internally on one of the wall sections of the element at such a position that on closing the element the peg can be received in a socket provided on the other wall section. In this way, the socket may serve to clamp together the conductors received within the peg and to restrain withdrawal thereof.Conveniently, the peg is provided with slots extending from the free end thereof towards the base thereof, into which slots the wires may be positioned so as to be driven together towards the base of the peg by the socket as the member is closed.

For a case where an electrical connection of great reliability is required, each electrical connector could be provided with an improved clamping arrangement to ensure the two wires to be connected are positively mechanically and electrically joined - for example, a screwthreaded arrangement could be used. This would however increase the cost of the element.

Though each element may in itself possess a degree of flexibility, so that a rope light assembled from a plurality of such elements may be flexed in a manner similar to that of the known form of rope lights described above, it is preferred for each element to be made of a substantially rigid plastics material but to form the head and socket at the two ends respectively of the element in such a way that when the head of one element is fitted into the socket of another element, a degree of freedom is permitted therebetween.

The preferred head is of part-spherical shape with a socket correspondingly formed, so that the axis of one element may be moved through a conical angle with respect to the axis of the next adjacent element. In this way, the interfitting head and socket are similar to a conventional ball and socket joint. However, if required, means could be provided within the head and socket to prevent relative rotation therebetween, so as to prevent excess strains being placed on the conductors extending therethrough should one element be subjected to a rotational torque.

To increase the intensity of light emitted from an element with a lamp into a rope light, two or more lamps could be wired into the same pair of connectors within the element, depending upon the space available and the size of the lamps used. Moreover, depending upon the physical size and length of the element, more than one pair of electrical connectors could be provided therewith in, to allow the connection of more than one bulb to more than one separate channel or string of lamps.

This invention extends to a rope light comprising a plurality of elements of this invention as hereinbefore defined, which elements are conjoined end-to-end by the head of one element being received within the socket of the next adjacent element, each element having a lamp positioned therewith in to radiate illumination through the transparent or translucent material of the element, the lamp being wired to the pair of electrical connectors within the element and electrical conductors extending from the connectors of one element to the connectors of other elements thereby to complete electrical circuits including the lamps located within the elements.

The lamps used in a rope light of this invention could be incandescent filament bulbs, light-emitting diodes or even other electrically-operated light sources such as gas discharge tubes. In general, however, it is contemplated that the lamps will be filament bulbs, in view of the relatively high light output which can be obtained from such a lamp, despite a small physical envelope.

By way of example only, one specific embodiment of this invention will now be described, reference being made to the accompanying drawings, in which: Figure 1 is a longitudinal sectional view through a rope light constructed from a plurality of elements of this invention arranged endto-end, but with the bulbs and wires removed for clarity; Figure 2 is a sectional view through an element of this invention, with a lamp located therewith in; and Figure 3 is a lateral cross-section on an enlarged scale through an element of this invention, when open.

Referring to the drawings, it can be seen that a light rope of this invention is constructed from a plurality of elements 10 conjoined end-to-end, each element containing a lamp 11 having associated wiring extending axially within the elements. Each element is made by an injection moulding technique using a transparent or translucent plastics material, such as polypropylene, though other polymers having good heat resistant properties as well as being at least translucent could be used.

The element is moulded to have a crosssectional shape as shown in Fig. 3: thus, the moulding can be considered as having two sections 1 2 and 1 3 each of semi-circular cross-sectional shape which sections are linked together by means of a hinge portion 14, the wall thickness of which is considerably less than the wall thickness of the sections 1 2 and 1 3. The long edge 1 5 of section 1 2 carries a pair of spaced barbs 1 6 which barbs are inter-engageable in corresponding slots 1 7 formed in the long edge 1 8 of section 13, when the sections 1 2 and 1 3 are hinged together about the hinge portion 1 4.

When so hinged together with the barbs 1 6 interengaged with the slots 17, the two sections 1 2 and 1 3 define a generally tubular member of circular cross-sectional shape.

Axially spaced within the element 10 is a pair of electrical connectors each of which comprises a socket 1 9 upstanding from the internal wall of section 1 2 and a corresponding peg 20 upstanding from the internal wall of section 1 3. The dispositions of a socket 1 9 and its corresponding peg 20 in the two sections 1 2 and 1 3 respectively are such that as the sections 1 2 and 1 3 are hinged together to form the tubular member, the peg 20 enters the socket 1 9. Each peg 20 has a diametral slot 21 the width of which reduces away from the free end of the peg, and adjacent the base of the slot 21 there is formed a conical portion 22 the diameter of which also increases further from the free end of the peg 20. The conical portion 22 conjoins a cylindrical portion 23 formed integrally with the wall of section 1 3.

The socket 1 9 defines a bore 24 the diameter of which is such that the peg 20 is a sliding fit therewithin, the free end of the bore 24 being flared at 25 to receive the conical portion 22 of the peg 20.

One free end of each section 1 2 and 1 3 is so shaped that when the sections 1 2 and 1 3 have been hinged together to form the tubular member, the one free ends together define a head 26 generally of part-spherical shape, the head 26 being conjoined to the main body part of the sections 1 2 and 1 3 by means of a waisted zone 27. The other free ends of the sections 1 2 and 1 3 are shaped as to define a socket 28 (when the sections are hinged together) the internal configuration of which is such that a head 26 of another member may be received therewithin.

A rope light is constructed from a plurality of elements as described above, in the following manner. For the case of a rope light to have four separate channels - that is, four separate strings of lamps each of which separately can be energised - typically 6 elements are placed end-to-end, in the open state as shown in Fig. 3. The elements are so arranged that the one free ends of the sections 1 2 and 1 3 together defining the head 26 of one element are located over the other free ends of the next adjacent element which other free ends together define the socket 28 of the next element.Insulated flexible wire is prepared by cutting lengths 30 thereof suitable for connection between the electrical connectors of one element spaced by four other elements from the said one element, the insulation being stripped back for a short length at each end of the prepared wire length. Then, the bared end 31 of one length of wire is inserted into the slot 21 of one peg 20 of the leading element of the aligned group thereof, and the bared end of a second length of wire 30 is inserted into the slot 21 of the other peg 20 of the same element. A miniature capless filament bulb 11 having a pair of wire "tails" 33 is positioned between the two electrical connectors of that element and the tails 33 are bent round so that the two tails are located one in the slot 21 of each peg 20 respectively.Next, the element is closed by relative hinging movement of the sections 1 2 and 1 3 until the barbs 1 6 engage in the slots 17; thereafter, the next adjacent element is prepared and wired in the manner described above and when that element also is closed, the socket 28 thus formed closes around the head 27 of the previously-assembled element.

In this way, a complete rope light made up from interengaged elements can be produced and the number of channels will be defined by the lengths of the prepared wires 30.

Moreover, because the lengths of wire are specifically cut to a length appropriate for the number of channels, the assembler does not have to keep count of the elements to ensure that the wiring of the rope light correctly is completed, for the pre-prepared lengths prevent connection of one lamp to an incorrect channel.

Once the rope light has been constructed to have the required length (for example, in a case in which 6v bulbs are used and the rope light has four channels intended for operation on 240v A.C. mains, 1 60 such elements should be assembled together) the wires can be terminated by employing a terminal ele ment (not shown) which is generally similar to the elements 10 described above but is not provided with the electrical connectors therewith in; instead, the terminal element has a plurality of sockets to which a multi-pin plug may be connected, the sockets each extending parallel to the axis of the terminal element. Moreover, the plug member should be provided with a suitable key, so as to ensure correct orientation of the plug member with respect to the sockets of the terminal element.

Depending upon the precise intended manner of use of the rope light described above, the circuit for each channel of the rope light may be completed by providing a further conductor extending axially within the elements, which conductor is laid in place as the rope light is assembled. This further conductor should be connected to the electrical connector of the last element for each channel and thus should interconnect one connector of each of the first four elements assembled, and thereafter should run uninterrupted for the full length of the rope light, up to the terminal element. There, the further conductor should be terminated on one of the sockets of the terminal element. In this way, a return path can be provided for each channel, back to the terminal element.

Claims

1. An element for use in the construction of a rope light which element comprises a generally tubular member formed of or having a window of a transparent or translucent material, the member being adapted to allow the opening and closing thereof and being provided with locking means to restrain opening once closed, the member having at least one pair of electrical connectors accessible when th3 member is open and by means of which a lamp positioned within the element can be connected to electric conductors, one end of the tubular member being in the shape of a head and the other end being formd as a socket to receive the head of a second like element.

2. An element as claimed in claim 1, wherein the element is in the form of a onepiece moulding of a plastics material.

3. An element as claimed in claim 2, wherein the tubular member defined by the eiement is provided with a split parallel to the length of the tubular member from one end thereof to the other end, there being a hinge line in the member opposed to the split which hinge line is defined by a region of reduced wall thickness.

4. An element as claimed in claim 3, wherein the locking means comprises at least one barb provided on one of the sections and adapted to interengage a slot provided on the other section as the two sections are moved towards each other to close the element thereby defining the tubular member.

5. An element as claimed in any of the preceding claims, wherein each electrical connector of the pair thereof comprises an upstanding boss appropriately configured to receive the conductors to be connected together.

6. An element as claimed in claim 5, wherein each boss is in the form of a peg provided internally on one of the wall sections of the element at such a position that on closing the element the peg can be received in a socket provided on the other wall section.

7. An element as claimed in claim 6, wherein the peg is provided with slots extending from the free end thereof towards the base thereof, into which slots the wires may be positioned so as to be driven together towards the base of the peg by the socket as the member is closed.

8. An element as claimed in any of the preceding claims, wherein each element is made of a substantially rigid plastics material and the head and the socket at the two ends respectively of the element are so formed that when the head of one element is fitted into the socket of another element, a degree of freedom is permitted therebetween.

9. An element as claimed in claim 8, wherein the head is of part-spherical shape with a socket correspondingly formed, so that the axis of one element may be moved through a conical angle with respect to the axis of the next adjacent interconnected element.

10. An element for use in the construction of a rope light and substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.

11. A rope light comprising a plurality of elements as claimed in any of the preceding claims, which elements are conjoined end-toend by the head of one element being received within the socket of the next adjacent element, each element having a lamp positioned therewithin to radiate illumination through the transparent or translucent material of the element, the lamp being wired to the pair of electrical connectors within the element and electrical conductors extending from the connectors of one element to the connectors of other elements thereby to complete electrical circuits including the lamps located within the elements.

12. A rope light as claimed in claim 11, wherein each lamp comprises an incandescent filament bulb.

1 3. A rope light as claimed in claim 11 and substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.