A patent was obtained for improvement in the destructive distillation of shale, and co., and in apparatus therefor. The specification stated that the invention ‘has for its object the economical and satisfactory obtainment and application of the heat required for the destructive distillation of shale, and co., and it comprises improved arrangements for the utilisation of the spent shale, and co., itself as fuel for supplying the heat or a portion thereof.’
The claim in the specification was for ‘(1) the conducting of the destructive distillation of shale, and co., substantially according to and by means of the arrangements and apparatus hereinbefore described; (2) the arranging of two or more retorts in one oven, but with a separate passage or space for the transference of the contents of each retort directly into a common fire-chamber substantially as hereinbefore described; (3) the applying of a valve in the passage or space through which the contents of each retort are transferred to the common fire-chamber, such valve being in addition to the door or cover which closes the discharge-opening of the retort substantially as and for the purpose hereinbefore described.’
The object of the invention was to utilise the spent shale as fuel without loss of heat, by passing it after distillation from the retort into the furnace without exposure to the air. This was accomplished by means of an arrangement of the doors of the retorts in relation to corresponding doors in the roof of the fire-chamber, which prevented the heat in the retorts from becoming too great, and also the door opening out of the retorts from being destroyed by excessive heat.
In a question of infringement of patent- held ( aff. judgment of Second Division) that what the specification described and the patent was obtained for was a certain novel and useful arrangement of apparatus for the purpose of managing the heat for distillation, and utilising for that purpose the spent shale, the essence of which arrangement was the placing and working of the doors in the retort and fire-chamber in a certain manner; (2) that the use of the common fire-chamber was on a proper construction of the specification not claimed as essential to the invention, but was only an incident of it, and therefore, (3) that an arrangement of apparatus which was substantially the same as that patented except that no common fire-chamber was used, was merely a colourable imitation of that of the patentee, as described by him and claimed under the first clause of his claim.
Judges:
Lord Chancellor, Lords Watson, Bramwell, and Fitzgerald
Citations:
[1883] UKHL 423, 20 SLR 423
Links:
Jurisdiction:
Scotland
Intellectual Property
Updated: 30 June 2022; Ref: scu.636758