Introduction
The case of Gillette Safety Razor Company versus Anglo-American Trading Company stands as a classic illustration of how courts interpret patent specifications and distinguish true invention from mere imitation of existing ideas.
Decided by the House of Lords in 1913, this dispute revolved around the famous Gillette safety razor and whether a rival product called the “Duplex” razor infringed the patent.
The judgment remains relevant today because it explains two fundamental principles of patent law:
- First, that a patent is only valid if it shows real inventive merit over what was already known; and
- Second, that even a valid patent is not infringed unless the accused product falls squarely within the scope of what the patentee actually claimed and described.
The decision shows how the highest court carefully balanced the rights of the inventor with the right of the public to use ideas that were already in the public domain.
Factual Background
King Camp Gillette invented a safety razor that used a very thin, flexible blade instead of the thick, rigid blades common at the time.
The blade was held in a special holder with:
- A curved backing; and
- A curved guard.
When the parts were screwed together, the thin blade bent into a gentle curve. This bending gave the blade the stiffness needed for shaving and also allowed the user to adjust how close the cutting edge came to the guard. The inventor explained that this curvature was an important feature of his design.
The defendants sold a safety razor under the name “Duplex.” In their razor:
- The backing and guard were completely flat;
- There was no curvature; and
- The thin blade was simply clamped flat between the two flat surfaces.
The blade was held firmly enough to shave, but it did not bend or offer the same kind of adjustment as the Gillette razor. The defendants argued that their product was different because it lacked the bending mechanism that Gillette had described as central to his invention.
Procedural Background
The Gillette company had earlier faced challenges to its patent in other cases, leading to an amendment of the specification to limit it strictly to safety razors.
In the present action, the company sued the Anglo-American Trading Company and its manufacturer for infringement.
Stages of Litigation:
| Stage | Court | Outcome |
|---|---|---|
| Trial | Before Mr Justice Parker | Patent held valid; Duplex razor held to infringe |
| Appeal | Court of Appeal | Decision reversed; no infringement |
| Final Appeal | House of Lords | Appeal heard by Lords Kinnear, Atkinson, Shaw, and Moulton |
Reasoning And Decision Of Court
The House of Lords carefully examined what Gillette had actually invented and what he had told the public in his specification.
Lord Moulton delivered the leading speech.
Examination Of Prior Art
He first looked at an earlier American specification by John Butler, published before Gillette’s patent.
Butler had shown a safety razor in which:
- A blade was clamped between two flat cheeks at the end of a handle; and
- One cheek was shaped to act as a guard.
Lord Moulton explained that this was a simple and well-understood way of fixing a blade transversely to a handle.
The only real difference between Butler’s razor and the defendants’ Duplex razor was that the defendants used a thin blade while Butler had shown a thicker one. But thin blades for razors were already known from other earlier designs. Therefore, the defendants’ razor involved no new inventive step beyond what Butler had already made public.
Interpretation Of Gillette’s Patent
Turning to Gillette’s patent, the court held that the patent was valid because it required the special curved holder that bent the thin blade.
The words “substantially as described” in the main claim tied the invention to this bending feature.
The defendants’ flat holder did not bend the blade in the way Gillette had described, so it did not infringe the patent.
In short:
- The patent protected the clever idea of using curvature to give rigidity and adjustability to a thin blade; but
- It did not prevent anyone from making a safety razor that simply clamped a thin blade flat between two flat surfaces.
Point Of Law Settled In The Case
This case settled an important principle that continues to guide patent law:
- If the accused product is, in substance, the same as something already described in a prior publication and differs only in non-inventive ways, then either the patent is invalid for lack of novelty or the product does not infringe.
- When a patentee says his invention is “substantially as described,” the claim must be read in the light of the whole specification, including the drawings and the features the inventor treated as important.
Optional features may be ignored, but essential features that the inventor highlighted cannot be stripped away to widen the claim.
The judgment reminds inventors that they must describe their invention clearly and cannot later argue for a broader monopoly than what they actually disclosed to the public.
Case Details
| Case Title | Gillette Safety Razor Company v. Anglo-American Trading Company Ltd. |
|---|---|
| Date Of Order | 30 June 1913 |
| Case Number | Letters Patent No. 28,763 of 1902 |
| Neutral Citation | (1913) 30 R.P.C. 465 |
| Name Of Court | House of Lords |
| Name Of Hon’ble Judge | Delivered by Lord Moulton (with concurring opinions by Viscount Haldane L.C., Lord Shaw of Dunfermline, Lord Kinnear and Lord Atkinson) |


