Patent GB-1280928-A (GB)
Title: Apparatus for the comparison of coded pressure pulse registrations for use in filing systems in space to improve the efficiency of the international patent system and application to the recognition of "voice prints" to operate devices by words of command
Inventor: PEDRICK ARTHUR PAUL
IPC: G10L15/24
Filed: 1971-01-12
Abstract: 1280928 Fluid-pressure actuated switches A P PEDRICK 12 Jan 1971 41015/70 Heading H1N [Also in Division G4] In an apparatus for comparing a permanent record of information represented by patterns of selectively-made electric contacts with a request for information represented in a similar manner, the essential components are a pair of fluid-pressure-operated multi-contact switches. In use, the condition of the contacts of one such switch in the information store is compared with the condition of a similar switch operated by the information-seeking signal, an output being given if the same pattern of made contacts is exhibited by both switches. The principal application disclosed is patent searching: it is envisaged that a global store of technical information, especially that contained in Patent Specifications, will be located in an artificial earth satellite to which information, coded in accordance with an internationally agreed classification system, will be sent by radio for registration by switches of the above-mentioned form. A search request, e.g. from a national Patent Office, can be transmitted in like manner and registered in another such switch. An automatic comparison of the state of the two switches will identify existing documents conforming to the search request and the result can be transmitted back to earth. An alternative application of the system is to make the store contain switching patterns representative of " voice prints " and for the request-responsive switch to reproduce a voice-print from a person verbally addressing the apparatus. In this way, it is suggested that an automatically-controlled apparatus responsive to verbal commands, e.g. of a disabled person, may be made responsive only to the commands of a particular person and so not be accidentally operated by other sounds. The construction of the switching elements of the system is shown in Fig. 2. The " permanentinformation " switch consists of a series of compressible capsules 15 of insulating material located in a tubular housing 14 which also contains a particulate solid conducting medium 27, e.g. lead shot. Normally, the capsules are in the state shown at the two ends of the series, i.e. they do not contact the walls of the housing and an electric current can flow through the conducting particles in the space between the edges of the capsules and the wall of the housing. However, each capsule can be deformed by pressure to expand radially until it touches the housing wall and thereby create an insulating barrier to current flow through the particles (see for example the barrier constituted by the sixth capsule from the right in Fig. 2). The information-seeking switching means operates in a like manner but employs pistons in place of capsules. Each piston 23 is spring biased into a lower position, namely the position shown at the two ends of the series shown in Fig. 2, but under pressure a piston will be raised (as for example the sixth piston from the right in Fig. 2 has been raised) and an electric contact is made when it is so raised. In use, a train of pressure pulses representing a search request is applied to the right hand end of the space beneath the pistons 23 and it is arranged that when the leading pulse reaches the left hand end of that space means (not shown) are operated to clamp all raised pistons in their raised position. Thus, a particular pattern of pulses will cause some pistons to be held in their raised positions, the pattern of raised pistons reproducing the pulse pattern. If a like pattern of pressure pulses, representing the information content of an existing document, has previously been applied to the series of capsules, the insulating barriers in the series will correspond in position to the contacts made by the pistons so that each piston-made contact will by-pass the capsule-broken contact and so create a through-flow path for electric current (represented by the arrow-headed line running in a labyrinthine path from right to leftin Fig. 2). Thus, identity of search request and stored information produce an output, non-identity does not.  In Fig. 19 (not shown), the " permanentinformation" and "information-seeking" switches are both of the piston type and magnets are employed as the means to hold the pistons in the positions to which they are displaced by pressure pulses.