GB2206439A - A multi-conductor electrical cable of controlled electrical performance - Google Patents

Description

2f.206439 1 A MULTI-CONDUCTOR ELECTRICAL CABLE OF CONTROLLED ELECTRICAL

PERFORMANCE The present invention relates to a multi-conductor cable construction, in particular of miniature size, for transmission of data signals which has been designed to have a controlled electrical performance. More particularly the conductor-to-conductor and the cable can be controlled impedance and capacitance conductor-to-shield within Modern digital data processing and computing systems and other electronic apparatus have become increasingly miniaturized, the apparatus of many kinds are linked together in systems which may work together sometimes at a distance from the source of signal generation, and among which signals of less and less uniformity of shape and spacing are transmitted at higher and higher speeds. Significant problems of clarity and accuracy of data transmission increasingly arise from faulty signal synchronization, recognition, and assembly and impedance matching where transmission cables offer less uniform or less controlled attenuation, impedance, and capacitance cpabilities to the systems.

2 According to the present invention there is provided a multi-conductor electrical cable having controlled impedance and capacitance conductor to conductor and conductor to shield., comprising an inner core of an insulative material around which a plurality of evenly-spaced electrical conductors are located, a layer of dielectric material surrounding said conductors and said inner core of insulation, and an outer insulating jacket.

In particular, the present invention provides a cable which controls impedances and capacitances signal to signal and signal to shield in small gauge wire applications such as, for example, those utilizing AWG 40 to AWG 44 wire. Existing tape wrap technologies require too narrow a slit width at these gauge sizes.

The invention will now be particularly described, by way of example, with reference to the accompanying drawings in which: - Figure 1 shows a cross-section of a cable according to the invention, not to scale, with four conductors distributed about a central core; 1 1 3 Figure 2 is a side view of the cable with each layer exposed to view; Figure 3 is a cross-section of an alternative embodiment of a cable according to the invention wherein the central core has a conductor down its centre.

In the embodiment of the invention shown in Figure 1, metal conductors 1 are spiraled about a central core 2 of insulation material by a wire serving machine or other means. Although the invention is not confined to any particular size or range of sizes or composition of wire, the preferred range of wire size is AWG 20 - AWG 44. A capstan can be used to pull insulation 2 at the required rate such that wires 1 can be spiraled or served on to it to achieve the desired spiral. Optionally conductor preferably polyester, expanded materials centre core insulation 2 may contain a centre 6, as shown in Figure 3. Insulation core 2 comprises MIL-ENE (Registered trade mark) polytetrafluoroethylene (PM), or porous PTFE (EPTFE), although other polymeric of suitable tensile strength and dielectric constant could be used. The most preferred core is porous EPTFE. A closing die on the serving machine may be used in some instances to embed the wires 1 partially 4 into insulation 2 to ensure positional stability of wires 1 under stress when the cable is in use.

The desired thickness of insulation 3 is now placed over the cable by winding, serving or extrusion. Typical insulative materials would be MILENE (Registered Trade Mark) polyester, full density PTFE, or most preferably, EPTFE. If desired, as for instance in making a coaxial cable, a shielding layer 4 can be braided, served or wound around the insulation layer 3. This can be aluminized foil, copper alloy braid, or served metal foil.

To protect the cable, a final jacket layer 5 of protective insulation, usually of rugge material to resist damage from the environment, is placed or extruded on to the cable. This jacket is suitably polyvinyl chloride (PVC), fluorinated ethylene -propylene (FEP) polymer, or polyfluoroalkyl vinyl ether (PFA).

The cable, when containing small gauge conductors 1 (36 to 44 AWG), will provide strain relief to tension placed on the conductors, by distributing the majority of the load to the inner dielectric 2 rather than the conductors themselves since the conductors are spirally wrapped around the inner dielectric material 2. Since I P,smun Prticle of clothing is hunan.n a hgnzer (Fizs.; and 6) nni then onto the rail in the cabinet. The i",em is then tensi-Ined ty me.-.ns i.f tensimincr aids (Fig.) x.nich are he-me.s'ed ti the bidr of the cgbinet by insertirg the protrusions into the oles or the rid?es of the inner si.- les of the inleriir or the cabinet (Fie. 7). if additional cr%!7-es ere re,,7.,tirei in s,.,,eeific zLreas of the articlem., thp5e -:r. be tersiored Specifically, for example sleeve../.:-olisi-rs (FiT.

lhe 1-opd is etermine, by the actx,.?! am.31Lnt to be proce!!-ed and the R"oiint an! tfies of febtic5 ti be prece-sed 81.

E'l= z-+ric '.net...tinr -JS th-?n nsed P. soeci--fiel of iicrj.o;pvee lr r-c-,o fre-uency w_.ves t) loa.d) are frm the -na;rnetr.:,i or rp--4--) fre-liencv soun.i. -The cloth---L? can then be left until the reruired time 4-s zaRsed for the waves t-) hc-ve erualised (tine by loed) or until the cl..tn-o. i: here be no f=ther jroceseLIR of the.in!Rss more waves are e!,.itted. The cl-ot-ing can then be release,'.' frm tensior and, hur.R i. the-i.- usupl jl--,ce.

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Claims (1)

1. A drying/iranihd cabinet, in the body of a box any dimensions shape) which is controllable from the outside using microwaves radio frequency waves.

   -A drying/ironing cabinet as claimed in claim 1 whereby the wazz can either be static or moving.

   An ironing/drying cabinet as claimed in Claim 1. wherein the door i---. opened from either side or from the top or the bottom.

   An ironing/drying cabinet as claimed in claim 1 wherein the cwor l--:i part glazed (as in the drawings), fully glazed or not glazed at all An ironing/drying cabinet as claimed in Claim 1 wherein the artiei,::-f is hung and tensioned although not necessarily an a hanger.

   An ironing/drying cabinet as claimed in Claim 1 wherein the grinwer-, F rods are substantially similar to those in the accompanying cram c An ircning/drying cabinet substantially as described herein reference to figs 1 - 4 of the accompanying drawings.

   1 1 W An ironing/drying cabinet as claimed in claim 1 where it is connected to a 13 amp plug socket. mains power er similar memos e. power connection.

   i 1 1 1 1 Amendments to the claims have been filed as follows - 7 - 1.

   221 043 The apparatus, designed for domestic use, will bombard articles of damp laundry, whilst under tension, with microwaves or radio waves according to a pre-determined cycle for a period of time dependent upon the nature of the fabric and the volume of water to be removed from it in order to eliminate creases caused by washing processes and also for enhancing those creases inherent to the fabric to substantiate the style of the article.

   Whilst carrying out the above process, water will be simultaneously removed from the article so that on completion of the cycle, the article is ready for immediate use.

   The apparatus consists of a cabinet of unspecified shape and size which can be either 'free-standing' or 'built-in' to accommodate any domestic requirement.

   The construction of the cabinet will be compatible with the requirements for the safe containment of microwaves or radio waves.

   Access to the processing area of the cabinet will be through an external opening which, when closed, affords the same degree of protection from radiation as the remainder of the cabinet.

   Constructed within the cabinet are facilities for the extraction of water vapour created during the process, a ridged side surface and an upper support onto which tension rods specified in the main patent are attached and a device for generating microwaves or radio frequency waves as appropriate.

   A% 22104 %JP 2. The apparatus according to claim 1 wherein the device for generating microwaves or radio frequency waves is either static or non-static in order to evenly bombard the articles within the cabinet.

   The apparatus according to claim 1, wherein access to the processing area is via a door which-can be hinged from the top or the bottom, either left or right hand side, rolled back, slid or removed.

   The apparatus according to claim 1, wherein the door is part glazed ( as in the drawings), fully glazed or not glazed at all, and is constructed to provide the same degree of protection from radiation as the remainder of the cabinet.

   5. The apparatus according to claim 1, wherein the pre-determined processing cycle will automatically'cease when the door is opened.

   6. The apparatus according to claim 1, wherein the article is hung and tensioned, although not necessarily on a hanger as described in the main patent.

   8. The apparatus according to claim 1, wherein the method of applying to the article is substantially similar to those shown in the accompanying drawings.

   The apparatus according to claim 1, wherein the gripper rods are substantially similar to those shown in the accompanying drawings.

   9. The apparatus according to claim 1, wherein the cabinet is connected to a power supply through a domestic power outlet.

   22 10439 10. The apparatus according to claim 9, wherein the cabinet is either- portable or in a fixed location according to the power outlet available.

   Pued 1988 at rhe Patert Office. State Emat. %?j H1ih Ho'berr. Und= WC1R 4TP. Par.Cor copies maybe obed cv, Th#Patcn%OMce. wee Branall. a C omn. am = pmtad by M tachn It& at M07 Cray. Kent. CM I.C7.