GB2392900A - A storage device for cabling. - Google Patents

Abstract

A storage device for cabling used to connect a computer to telephone equipment comprises a spool 12 rotatably mounted within a casing 1 about which are wound two cables, each of which is connected at one end to a respective terminal of a circuit board which is mounted upon the spool and rotates therewith. The casing may comprise a base, a cover 3 and an upstanding wall 4, with the spool being located within a housing 5 defined by the casing. The housing may contain a spring biassed so as to rewind the cables upon the spool. In addition to storing cable, device may protect against voltage transients and/or act as a filter to enhance signal quality.

Description

PORTABLE CABLE SPOOL APPARATUS

This invention relates to portable cable spool apparatus for placing computer equipment in communication with telephonic equipment.

There is an increasing requirement for portable cables which enable businessmen and others to communicate via modems of computers (e.g. laptops) and telephone equipment with more sophisticated office or homebased computer equipment when travelling in this country and overseas. Presently available portable cables tend to be cumbersome and not easily installable between wall-mounted telephone sockets and laptop computers inter alla because of inadequate lengths of cable supplied. To overcome this particular problem, additional and separate cable lengths need to be carried by the traveller.

Alternatively, spool mounted cables are known; however, these tend to be even more cumbersome and can suffer from operational difficulties because of the need to incorporate slip rings or the like to maintain electrical integrity between the cable spools and associated circuitry as cable is withdrawn from or rewound onto the spool.

Data transmitted by conventional telephone equipment is often or poor quality.

Furthermore, conventional cable spools frequently lack protection against potentially destructive voltage transients, direct contact with mains power and accidental connection to digital telephone lines. This lack of protection can seriously damage or at least impair the performance of equipment connected by the cables of the spool.

The present invention sets out to provide a readily transportable compact cable spool which does not suffer from, or at least alleviates, many of the disadvantages present in existing cable spools.

Typically, a portable cable spool in accordance with the invention is of a size which enables it to fit into a pocket or handbag of a traveller. Furthermore, preferred

embodiments of portable cable spools in accordance with the invention include filters to enhance signal quality and/or power surge protective devices and/or current limiting devices to provide protection against direct contact with mains power and accidental connection to digital telephone lines.

In one aspect, the invention provides a portable cable spool comprising a casing which houses a spool mounted for rotation relative to the casing and about which are wound two cables each connected at one end to a terminal of a printed circuit-board and each carrying at its other end a connection for placing computer equipment in electronic communication with telephone equipment, the printed circuit-board being carried by the spool and rotating therewith as cable is extracted from or rewound onto the spool.

In one embodiment, the casing comprises a base and a cover joined by an upstanding integral wall which extends over only a minor part of the peripheries of the base and cover.

The spool may be located within a spool housing positioned between the cover and base of the casing. When assembled, the inner face of the integral wall lies in contact with an opposed face of the spool housing.

The spool housing may comprise a base bordered by an upstanding wall to define a well in which is retained a coiled rewind spring.

The casing may be produced from a metallic material, e.g. aluminium, and the spool housing and spool may be produced from a plastics material.

lithe spool may rotate about a spindle upstanding from the base of the spool housing. The printed circuit board may be permanently secured to the underside of the base of the spool.

The invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is an exploded view of a portable cable spools in accordance with the invention; Figures 2, 3 and 4 are plan, side and rear views of a casing of the cable spools shown in Figure 1; Figure 5 is a plan view from above of a spool housing of the cable spools shown in Figure 1; Figure 6 is a section along line VI-VI of Figure 5; Figure 7 is a plan view from above of a spool of the modem shown in Figure 1; Figure 8 is a side view of the spool shown in Figure 7; Figure 9 is a plan view from above of the illustrated cable spools but with the casing top removed; and Figures 10 and 11 are sections taken through the cable spools illustrated in Figure 9. As illustrated in the drawings, a portable cable spool in accordance with a preferred embodiment of the invention includes an outer casing 1 shown in greater detail in Figures 2 to 4 which includes a base 2 and a cover 3 joined by an upstanding integral wall 4 which extends over only a minor part of the peripheries of the base and cover. As shown, the casing 1 is generally circular in plan view with one side extended by a straight edged flange. Other shapes of casing may, however, be employed. The wall 4 and its fold lines with the base and cover provide sufficient resilience to enable the base and cover to be moved towards and away from one another for ease of assembly. Typically, the length of

the casing is between 65 and 75mm, the width between 50 and 60mm and the depth between 14 and 18mm. In a preferred embodiment, the casing length is 71mm, its width 55.20mm and its depth 16.40mm.

Located between the base and cover is a spool housing 5 formed with a base 6 bordered by an upstanding wall 7 to define a well in which is retained a coiled rewind spring 8 (see Figures 10 and 11). The spool housing is shaped to complement that of the casing and is shown in greater detail in Figures 5 and 6. A spindle 10 of less height than that of the wall 7 is upstanding from a central region of the base 6 and the coiled spring is wound about the spindle 10 with one end held within a slot formed in the spindle.

The casing and the spool housing are secured together at their ends remote from the wall 4 by screws or the like which pass through apertures 11 formed in the flanged extension of the casing and spool. When so secured, the inner surface of the wall 4 lies in contact with the opposed face of the spool housing.

The casing 1 is typically produced from a metallic material, e.g. aluminium, and the spool housing from a plastics material. Other suitable materials may, however, be employed. Positioned above the housing 5 and seated partially therein is a rotatable spool 12.

The spool is shown in greater detail in Figures 7 and 8 and includes a central collar 14 which locates over the spindle 10 to enable the spool 12 to rotate relative to the spindle and, therefore, the housing 5. The spool 12 has an outer flange 15 whose peripheral rim lies close to the inner surface of wall 7. The flange is formed with radial cut-outs 16 which extend across the full width of the flange and through holes 17. A generally circular wall 18 is upstanding from a central generally circular portion of the upper surface of the spool 12 to define an annular retainer above the flange 15 for receiving wound cables 21 (see Figure 9) which, in use of the cable spools, provide the required connection between a wall-mounted telephone outlet and an inlet port of electronic equipment, for example a lap-top computer. Typically, a cable length of around three metres is wound onto the spool. The wall 18 has openings 23 positioned alongside the radial cut-outs 16.

A leg 24 projects downwardly through the floor of the spool and includes a foot 25 for attachment to the end of the coiled spring 8 remote from its attachment to the spindle 10.

The generally circular central portion of the under surface of the spool is recessed to receive a printed circuit board 26. The printed circuit board includes a central opening which complements the position of the central collar 14 and is secured to the undersurface of the spool. Thus, the circuit board rotates on rotation of the spool.

On assembly, the spool 12 and therefore the circuit board 26 locate over the spindle 9 of the spool housing.

One end of each cable 21 is soldered or otherwise connected to a terminal of the printed circuit board 26 and the other ends of the cables carry connectors for connection to a wall-mounted telephone outlet port and a computer inlet port. The connectors may be colour coded for ease of reference. Each connector-carrying cable end passes through one of the cut-outs 16 and leaves the spool through openings of a cable assembly 29 positioned within the end of the wall 7 of the housing remote from the wall 4 of the casing. In use, the connectors carried by the cables prevent total retraction of the cables onto the spool.

When extended cable lengths are required, the connectors are simply pulled against the action of the rewind spring 8 to draw from the spool the required cable lengths. A ratchet mechanism is provided to retain the spool in position during the time that the cable spools provides the required connection between the telephone equipment and the user's laptop computer. When the connections have been terminated, a button 30 set in the cover of casing 1 is moved downwardly against the action of a coil spring 31 to operate a release mechanism to cause the spool to rotate under the action of the rewind spring to cause the cables automatically to be rewound onto the spool.

Positioned around the button 30 is a mounting 32 for two spaced light emitting diodes 33, 34 connected electrically to the printed circuit board 26. Diode 33 is illuminated when there is a live connection between a telephone line and a computer; and diode 34 is illuminated when the connection is in order. The diodes are covered by a ring shaped transparent hood

The exposed upper surface of the cover 3 may be selectively protected by a hinged cover. The printed circuit of the board 26 includes a toroidal filter, thermistors or polyswitch, silicon surge protection device, resistor and diode pairs.

An important function of the cable spools is to protect equipment connected to telephone lines against potentially destructive voltage transients.

Normal mode transient protection is provided by the silicon surge protective device 42. This component uses fast thyristor technology to suppress tip-to-ring voltage spikes down to a level which the connected equipment can withstand. Device 42 exhibits a short-

circuit failure mode; when damaged by surge current above its rated limit it fails to short-

circuit. Since the cable spool is connected between the two line wires, this failure mode prevents further surges from passing to the connected equipment.

The thermistors 41 operate as current limiter devices. The thermistors exhibit open-circuit failure mode. Being series connected, the thermistors isolate the equipment should a failure occur.

A further important feature of the cable spool is filtering of electrical "noise" on a telephone line. This feature provides more reliable, and sometimes faster, data communication. To achieve this feature low-pass filtered is used to suppress high frequency interference and, hence, "clean" the signal.

In particular the toroidal filter 40 provides around SdB attenuation at 300kHz and over lOdB at lMHz. At these levels, the filter will not affect normal analogue and fax signals which operate within the normal voice bandwidth of the telephone line up to around 4kHz. The connectors of the cables of the spool are typically FCC-68 compliant RJ11 plugs and are wired to standard US configurations.

It will be appreciated that the foregoing is merely exemplary of portable cable spools in accordance with the invention and that various modifications can be made without departing from the scope of the invention.

Claims (10)

1. A portable cable spool comprising a casing which houses a spool mounted for rotation relative to the casing and about which are wound two cables each connected at one end to a terminal of a printed circuit-board and each carrying at its other end a connection for placing computer equipment in electronic communication with telephone equipment, the printed circuit-board being carried by the spool and rotating therewith as cable is extracted from or rewound onto the spool.

2. A cable spool as claimed in claim I wherein the casing comprises a base and a cover joined by an upstanding integral wall which extends over only a minor part of the peripheries of the base and cover.

3. A cable spool as claimed in claim 1 or claim 2 wherein the spool is located within a spool housing positioned between the cover and base of the casing.

4. A cable spool as claimed in claim 3 wherein, when assembled, the inner face of the integral wall lies in contact with an opposed face of the spool housing.

5. A cable spool as claimed in any one of the preceding claims wherein the spool housing comprises a base bordered by an upstanding wall to define a well in which is retained a coiled rewind spring.

6. A cable spool as claimed in any one of the preceding claims wherein the casing is produced from a metallic material and the spool housing and spool may be produced from a plastics material.

7. A cable spool as claimed in claim 6 wherein the casing is produced from . alummum.

8. A cable spool as claimed in any one of the preceding claims wherein, in use, the

spool rotates about a spindle upstanding from the base of the spool housing.

9. A cable spool as claimed in any one of the preceding claims wherein the printed circuit board is permanently secured to the underside of the base of the spool.

10. A cable spool substantially as herein described and as described with reference to the accompanying diagrammatic drawings.