Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
  • H04R1/00—Details of transducers, loudspeakers or microphones
  • H04R1/12—Sanitary or hygienic devices for mouthpieces or earpieces, e.g. for protecting against infection

Definitions

• the present invention relates to a set of bactericidal shields for use on telephone handsets.
• British Patent Application No.8523521 discloses a set of bactericidal shields for use on telephone handsets, the set comprising a pair of plastic shields designed to clip over or into the telephone mouthpiece or earpiece respectively, each shield being impregnated with a bactericidal agent which is able to leech out of the shield over a period of time.
• the shields of the prior art have the disadvantage that, because the bactericidal agent is impregnated, their time of action is relatively short, for instance about 3 days, even though any odour imparted by a perfume may last longer, and they are relatively complicated to manufacture.
• a set of bactericidal shields for use on telephone handsets comprising a pair of rigid polyvinylchloride or rigid polystryrene shields designed to fit over or into the telephone mouthpiece and earpiece respectively, each shield having a bactericidal agent incorporated into its molecular structure.
• the present invention provides a method of producing a set of bactericidal shields for use on telephone handset, comprising: preparing a rigid polyvinylchloride or rigid polystyrene formulation containing a bactericidal agent; and moulding the formulation to produce the shields.
• the formulation is converted to the shields by vacuum forming or injection moulding.
• the formulation containing the bactericidal agent prior to moulding, for instance by vacuum forming or injection moulding, has substantially no bactericidal activity, even though the bactericidal agent is merely mixed in the formulation.
• the bactericidal agent is apparently incorporated into the molecular structure of the plastic and is activated.
• the shields of the present invention have good bactericidal properties which can last up to 30 days or more and which extends not only to the immediate area of the shield but also to a "halo" area around it.
• bactericidal agent In addition to the bactericidal agent, one or more of a germicidal agent, an algaecidal agent, a fungicidal agent, a biocidal agent, an anti-dandruff agent or a perfume may be included in the shields. These are preferably mixed into the formulation.
• a perfume such as a lemon, pine or rose aroma be included in the shields.
• the bactericidal agents are halogenated cyclic and heterocyclic compounds which are known as bactericides.
• a particularly preferred source for the bactericide is Actifresh (Registered Trade Mark) supplied by British Sanitized Limited, which also contains the optional agents referred to above.
• the amount of bactericidal agent will depend on the particular agent used, but will generally comprise between 2 and 7, preferably 3 and 5, percent by weight of the formulation.
• the shields will generally be between 0.25 and 0.50, preferably 0.30 and 0.38, millimetres in thickness.
• the shields will be shaped as appropriate so as to be able to fit over or into the mouthpiece and earpiece respectively, and also to be readily removable when the bactericidal activity of the shield has been substantially exhausted.
• the shields will thus be disposable.
• the shields may be perforated to match the perforations of the mouthpiece and earpiece respectively of the telephone handset.
• holes in the shields may be offset with respect to the holes in the handset so as to reduce further the ingress or collection of dirt and/or germs. It is not necessary for the shields to be perforated since the shields without perforations are able to transmit sound without significant distortion.
• the shields may come in many different shapes and sizes so as to be able to fit any type of telephone handset.
• a plurality of sets of shields are provided for sale packed in a suitable moisture-­proof carton, with each set being individually sealed in an evacuated, sterile plastic or foil container.
• the carton could be kept by a telephone handset, thereby allowing the telephone user to change the set at will.
• the shields could be supplied in packages to cleaning contractors who could merely change the shields, for instance, at monthly intervals. This would represent a considerable cost and manpower saving compared to the normal cleaning operation, which needs to be carried out at least weekly.
• the shields include a substance which changes colour when a predetermined reduction in the activity of the agents in the shield has occurred, or after the lapse of a predetermined time, thereby providing a ready indication as to when the shields should be changed.
• the colour indicator is in the form of a micro dot or a micro dot matrix affixed to, applied to or incorporated in the shield.
• the colour indicator could, for instance, change to red or could make visible a word such as "now" when the colour change occurs.
• the substance which changes colour is a substance which is sensitive to ultraviolet or visible light.
• the shields of the present invention differ from prior art shields in that they have no catches, flanges, ribs, clips or other mounting means or moving parts, nor do they include any lint, gauze, paper, card, filters or cloth. Moreover, they are not impregnated, dipped, coated, laminated or glued. They are therefore very simple. Nonetheless, they are highly effective, and produce a bactericidal effect not only on their immediate surface, but also in a "halo" area around them.
• a formulation comprising rigid polyvinyl chloride (containing 7% plasticiser) and Actifresh PL-149 (which contains halogenated cyclic and heterocyclic compounds as the bactericidal agents) was prepared by mixing the components in a conventional plastics mixer.
• the formulation contained 5% Actifresh.
• the rigid polyvinylchloride is supplied by Wardle-Storeys plc of Earby, Colne, Lancashire under their designation DURA HIA.
• the formulation thus produced was tested for bactericidal properties but was found to be substantially inactive.
• the formulation was injection moulded at a temperature of 1000°C for 8 seconds to form sets of shields 0.30 millimetres thick and shaped so as to be able to fit over the mouthpiece and earpiece of a conventional GPO telephone handset. When tested, it was found that these sets were highly bactericidal and retained their activity for at least 30 days. The bactericidal activity was not limited to the immediate area of the shields, but extended also to a "halo" area around the shields.

Landscapes

• Health & Medical Sciences (AREA)
• Public Health (AREA)
• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Acoustics & Sound (AREA)
• Signal Processing (AREA)
• Telephone Set Structure (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=10605006

Family Applications (1)

Country Status (2)

Cited By (4)

Family Cites Families (5)

• 1986
  • 1986-09-30 GB GB868623447A patent/GB8623447D0/en active Pending
• 1987
  • 1987-09-29 EP EP87308611A patent/EP0262921A3/en not_active Withdrawn

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