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British Vacuum Company Ld. v. Exton Hotels Company Ld.

"interposed between the said implement and pump, substantially as and for the purpose specified. 2. In apparatus of the type claimed in the first Claim a "valve controlling the communication between the extracting instrument and "the impurity collectors and suction pump, said valve being so arranged that "it normally assumes a closed position, substantially as described and for the 5 purpose specified 3. In apparatus such as is claimed in the first Claim a "hollow extracting implement having a transverse vibratory porous diaphragm, "an inlet orifice closed by a valve on one side of said diaphragm, and an outlet "suction pipe on the other side of said diaphragm, substantially as described, "for the purpose specified. 4. In apparatus such as is claimed in the first 10 "Claim an impurity collector provided with a dome-shaped porous partition "having beneath it a deflecting cap upon which impure air is discharged, and "having an outlet for cleansed air above said partition, substantially as described "for the purpose specified. 5. In apparatus such as is claimed in the first Claim "an impurity collector containing liquid, in which are arranged perforated 15 "reticulated partitions for distributing the impure air, and having baffle plates arranged above the level of said liquid to cause the air to flow in a circuitous "course before leaving the collector, substantially as described for the purpose "specified. 6. An impurity extracting implement constructed arranged and "adapted to operate substantially as described with reference to Figures 2 20 "and 3, or to Figures 4 and 5, or to Figures 6 and 7, or to Figures 8 and 9 of "the accompanying Drawings for the purpose specified. 7. An impurity "collecting implement constructed, arranged and adapted to operate substantially as described with reference to Figure 10 or to Figure 11 or to Figure 12 of the accompaning Drawings for the purpose specified. 8. Apparatus having its 25 "members constructed and arranged to co-operate substantially as described "with reference to the accompanying Drawings for the purpose specified."

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On the 23rd of May 1907 the British Vacuum Cleaner Company Ld. commenced an action for infringement of the Patent against the Exton Hotels Company Ld., claiming the usual relief, but with costs as between solicitor and 30 client,

British Vacuum Company Ld. v. Exton Hotels Company Ld.

The Plaintiffs by their Statement of Claim alleged that they were the owners of the Patent; that the Patent was valid; that the Defendants had infringed, and threatened and intended to continue to do so unless restrained; and that in an action in which the Plaintiffs in the action here reported were Plaintiffs 5 and Suction Cleaners Ld. and others Defendants, Mr. Justice Farwell had certified that the validity of the Patent had come into question.*

By their Particulars of Breaches the Plaintiffs alleged that the Defendants had imported into, and used in, this country apparatus, machines or mechanism for the extraction of dust from carpets and other materials in infringement of all 10 the claiming clauses of the Patent; and that, in particular, the Defendants, on divers occasions, had at the Linden Hall Hydropathic at Boscombe, Bournemouth, in the County of Hants, used one or more machines in infringement of the said claiming clauses.

The Defendants by their Defence denied that they had infringed. 15 On the 4th of May 1908 the Defendants made an application to Mr. Justice Parker for leave to amend their Defence by giving Particulars of prior knowledge. No Order was made on the application, except that the costs occasioned thereby should be the Plaintiffs' costs in any event.

The Drawing given below was used by the Plaintiffs at the trial as showing 20 the general arrangement of the Vacuum Cleaner plant used by the Defendants at the Linden Hall establishment.

The Drawing given below was used at the trial as showing the action of the Defendants' sweeper.

The action came on for trial on the 11th of May 1908 before Mr. Justice 25 WARRINGTON.

T. Terrell K.C., Colefax and Moulton (instructed by Hasties) appeared for the Plaintiffs; Bousfield K.C., W. Neill, and W. E. Bousfield (instructed by G. and W. Webb) appeared for the Defendants.

British Vacuum Company Ld. v. Exton Hotels Company Ld.

Terrell K.C. opened the Plaintiffs' case.-The substance of the invention is a combination of three things-a vacuum of about 5 lbs. to the square inch, that is, about 10 inches of mercury; a direct-action pump capable of giving such a vacuum; and an intermediate filter, either wet or dry or both. The Defendants have, for some purpose not material to the Patent, formed in their dust- 5 extracting implement a slot in addition to that in the Plaintiffs' implement ; and they have used a dry filter like the Plaintiffs', and have also made the dust-laden air bubble through water in a wet filter. They have fixed piping throughout the hotel, and connected it to the filters and pump in the cellar. An inspection made by the Plaintiffs' adviser, Professor Boys, was unsatisfactory, 10 because the Plaintiffs were told that, as the armature of the motor was being repaired, the apparatus could not be shown working.

Evidence was given in support of the Plaintiffs' case. Professor C. V. Boys said that he was present at the inspection of the Defendants' apparatus, which was substantially as shown in the Drawing given ante, page 621. The pipe 15 from the hotel first entered what appeared to be similar to the cyclone of a flour mill. From the appearance of the motor and pump, the apparatus seemed as powerful as an ordinary vacuum cleaning apparatus; a gauge on it showed a pressure of 5 lbs. at the pump, and a representative of the Defendants said, in the presence of a representative of the Defendants' solicitors, that when the instru- 20 ment was working the gauge showed that pressure. The witness was shown four extracting implements. In one of them there was a wide slot in connection with the pipe; there was a second slot, exposed to the open air, and between them there was a rib B that was set back about and of an inch; in another instrument the rib was set back about th of an inch; of the two others, one was a 25 brush instrument and the other a mere round tube. The purpose of the second slot was not apparent. The setting back would become less as the implement became worn; it was too slight to have any effect with an ordinary carpet. It was not evident from the outside whether, in the wet filter, the air entered below the water; the question whether it did or not might be material as to 30 the Claim for the filter. In the Plaintiffs' Fig. 8 there was a practical similarity of vacuum between the point 30 and the underside of the filtering medium 32. The fall of pressure towards the instrument would depend upon the length of the pipe and the size of it-upon the volume of air passing through the pipe, and the volume of air would depend upon the tightness of the closure of the 35 orifice by the carpet. Before the date of the Plaintiffs' Patent there were two classes of instruments, some that swept down upon the surface of the carpet and up into the instrument, and others that pulled the air through the carpet. The Plaintiffs' apparatus belonged to the latter class, and in the Defendants' apparatus practically the whole of the air that entered the implement would 40 have come through the carpet. With any ordinary carpet there would be contact at the rib B, and there would not be any free way into the instrument. The apparatus shown in the Drawing would draw up chalk and flour from under the carpet in the same way as the Plaintiffs' did. If the maximum vacuum obtained at the filter was only 3 lbs. the apparatus would work less 45 well. An extractor, dust-collector, and pump had been used together, but not the Booth power pump in combination with a filter and extracting instrument of the Plaintiffs' type. In the earlier instruments a fan was used that would produce a vacuum of only a few ounces to the inch. With 5 lbs. there was an exceedingly good result; with less than 5 lbs. there was a less good result, but 50 the apparatus was not useless. A power-driven pump was necessary.

Frederick A'Beckett said that he was employed at the Linden Hall establishment, from March 1905 to December 1907, as an engineer. He used to work the Defendants' apparatus. There was a tank in which the fine and the heavy dust were separated, and a water tank in which the fine dust was collected. 55 The instrument used was as shown in the Drawing. It was worked generally at a pressure of 15 inches on the gauge, but sometimes at 10 or less, when the

British Vacuum Company Ld. v. Exton Hotels Company Ld.

pipes were choked. It was installed in November 1906. The pipe leading into the wet filter dipped under the surface of the water.

Seymour Booth (one of the engineers to the Plaintiffs) and F. C. Carter (a member of the firm of John Carter & Sons of Southampton) said that they saw 5 the Defendants' apparatus in operation at the Linden Hall establishment on the 19th of February 1907. The gauge showed 15 inches. The extracting instrument shown in the Drawing was being used on a carpet with a considerable pile. It sat firmly upon the pile.

Evidence was given in support of the Defendants' case. W. E. Clifton 10 (a member of the firm of Clifton, Son and Smith, of Nottingham, solicitors), said that he had had experience in mechanical engineering, and had tested the Defendants' apparatus with Mr. Haddan. The pressure was 15 inches near the pump, and 2 inches at the slot of the instrument when sweeping; and when a man of 12 stones weight stood on the instrument, which 15 was on an Axminster carpet, the pressure was 5 inches. With a pressure near the pump of 8 to 10 inches, and the instrument on a new Axminster carpet, the pressure was under 1 inch when sweeping, and about 1 inches when pressed down. Experiments with older carpets gave higher pressures at the instrument -with 10 inches at the pump the pressure was 2 to 4 inches sweeping, and 20 4 to 5 inches pressed down; with 15 inches at the pump the pressure was 5 inches, sweeping, and up to 10 inches pressed down. The pressure at the dry dust separator, when that at the pump was 10, was 4 inches when the sweeper was off the carpet, 5 to 6 when sweeping a close old Wilton carpet. The fall of pressure, as compared with the Plaintiffs' arrangement, was attributable 25 to the inrush of air. The Defendants' apparatus depended more on the beating action of the inrushing air than on the suction, because good results were obtained with 4-inch of pressure. The smaller slot was considerably less in area than the vacuum slot, with the result that the rush of air through the former slot opened the pile of the carpet immediately underneath it, and 30 carried off the surface dust, without sucking up the dust from beneath the carpet. The apparatus mainly operated on the principle of apparatus using compressed air and suction, but the air jet was produced by the suction. It was not an instrument that sat tightly upon the carpet so as to give a practical similarity of vacuum at the instrument end and the filter end. It was not 35 necessary to maintain a vacuum of 5 lbs. in the cyclone. There was no filtering medium, unless the water used could be so called. The witness had had, for his firm, the conduct of the correspondence in the action, and had suggested that, if the Sanitary Cleaning Manufacturing Company of New York and San Francisco, the makers of the Defendants' apparatus, were unwilling to vindicate 40 their right to manufacture it, the Defendants should accept the Plaintiffs' offer to grant them a licence. His firm, on finding from the Defendants' solicitors that the makers did not admit infringement, wrote to the Plaintiffs stating their doubts as to the validity of the Patent, and their suspicions that the action in which it was declared valid was collusive. The Plaintiffs' solicitors had written 45 that if the Defendants admitted validity and infringement they would be allowed to continue to use the machine for a payment of 607. There was no filter in the Defendants' apparatus-there was a dust separating tank. For the efficient working of a vacuum cleaner it was necessary that there should be a certain difference of vacuum in the sweeper from what there was in the filter; 50 Booth attempted to get the required effect with as little difference as possible. The Defendants had a regulating valve between the pump and the gauge to keep the vacuum at the filter constant. The Defendants' apparatus would work best at 10 inches pressure.

R. Haddan (Patent Agent) said that he had conducted the Defendants' 55 experiments with the previous witness, and was in agreement with him as to the results. Booth's sweeper was very effective, but would wear out the carpets if used as frequently as the Defendants' apparatus was used at the

British Vacuum Company Ld. v. Exton Hotels Company Ld.

Bournemouth establishment. The most effective difference between the vacuum in the tool and that in the pump would depend on the work to be done; if it was desired to sweep the surface of the carpet, high velocity would be the first object, but if it was desired to drag the dust up through the carpet high vacuum with low velocity would be best. The wear of the carpet would 5 be greater with Booth's tight joint than with the Defendants' sweeper. Having regard to the fact that in Fig. 8 the pressures at the opening 30 and at the filter 32 were practically identical, the efficiency did not depend upon any particular difference between the vacuum at the opening and that at the filter. There was an inrush of air at the top of the slot in the Defendants' sweeper. L. Exton said that his Company had an indemnity against their failure in the action. If their apparatus was worked at a pressure of 15 inches that was against their instructions, which were, at first, that the pressure was to be usually 12, and never higher than 15, and, later, that it was to be 10 inches. Neither it nor the Plaintiffs' apparatus obviated the necessity for occasionally 15 taking up the carpets for cleaning.

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Bousfield K.C. summed up the Defendants' case.-In the former action it was with some difficulty that the learned Judge came to the conclusion that the Patent was valid even for a very narrow Claim. The case is similar to Curtis v. Platt (L.R. 3 C.D. 135n); the Claim is only for the particular combination 20 of extractor, dust-collector, and pump. It does not cover every combination with a power pump. It only relates to extractors working with a considerable vacuum. It is a question of degree; all that had been done before, but not to a degree that the learned Judge thought was anything like the degree of the Plaintiffs' vacuum. The Report of the former action contains enough evidence 25 to justify the present Defendants' argument. The statement in the Specification as to the pressure is essential for the purpose of marking out the limits of the invention, and the Patentee is bound to that. Anybody is entitled to do what the Plaintiffs do if he can do it with less than 5 lb. pressure, even though he exactly copies their apparatus. It is not as if the Patentee merely defined the 30 best pressure to work at; he stated the limit of pressure to distinguish his apparatus from what had gone before. The condition for having a considerable vacuum at the extractor is that there shall be at least 5 lbs. at the filter. That is a vital condition. Directly one gets down to a vacuum of 3 or 4 lbs., one can obtain it without the use of a power pump. With a vacuum of 15 inches at the 35 pump, that at the cyclone would be 8 or 9, but when that vacuum was used the motor became over-heated, showing that the apparatus was not constructed to work at that pressure. The Defendants' apparatus acts mainly by drawing air over, not through, the carpet. The fact that the rim is nd of an inch back will prevent the existence of a tight joint at the rim, however hard the sweeper is 40 pressed down on the carpet. The apparatus will remove the dust from the surface of a carpet with a vacuum of only half a pound at the extractor. That shows a difference of principle from the Plaintiffs' apparatus. The Defendants' apparatus has no filtering medium, in the sense of a filtering material or strainer; it was merely a cyclone that separates all but very fine dust, and then 45 the air and dust are forced into water without any kind of strainer.

Terrell K.C. replied.-The alleged difference of action between the Plaintiffs' and Defendants' apparatus, as regards the velocity and volume of the current of air, is merely one of degree, and in each apparatus will depend upon the tightness of the joint made by the sweeper and the carpet. It is said that it is 50 a Curtis v. Platt type of case; but the invention has created a new and important industry. There are three elements of novelty-(1) a tight joint at the carpet, and that means high velocity and small volume; (2) a small orifice to the cleaning instrument-that is copied by the Defendants; and (3) a considerable vacuum-there must be a practical relation of vacuum. There is a 55 power-driven pump; in previous instruments a fan or similar means had been used; and with a fan it is not necessary to remove the dust from the air before