The case discussed in this article is not a real case, and the patent at issue and the alleged infringing product involved in the case are all discussed on a hypothetical basis. The purpose of discussing this hypothetical case is to illustrate issues that may exist in the determination of literal infringement and equivalent infringement as well as the consequences that the said issues may lead to. Given that the preciseness of legal provisions and the flexibility of law implementation seem to contradict each other, this article does not involve much of the analysis of the ways to solve the said issues.

Key words: literal infringement, equivalent infringement, technical problem

Case Introduction

Patent at Issue

The patent at issue involves a kind of travel suitcase, and a division plate is installed within the travel suitcase, which divides the space inside the suitcase into two parts from top to bottom. In addition to the function of space division, the other important function of the division plate is that it firmly supports the suitcase, making the suitcase stronger. The division plate plays the role of reinforcing the suitcase, but it also adds weight to the suitcase. The purpose of the patent at issue is to provide a division plate with the same firmness but lighter weight.

Claim 1 of the patent at issue reads as follows: "a division plate of a box, characterized in that eight holes are drilled in the division plate, and the connection of the centres of the eight holes forms a square. The centre of the square and the centre of the said division plate overlap each other, and there are two holes on each side of the square." The division plate for which patent protection is being requested under Claim 1 of the patent at issue can be illustrated in the following Figure 1 (top view): 

The black circles in Figure 1 represent the holes, and the dotted lines do not actually exist in the division plate, but are drawn solely for the purpose of indicating the relative positions of the eight holes. The specification of the patent at issue describes the technical effects as follows: the weight of the division plate is reduced because of the drilling of holes, and experiments show that the way of drilling holes in the division plate will not weaken the supporting effect provided by the division plate to the travel suitcase.

Alleged Infringing Product

The alleged infringing product is a kind of box publicly sold for containing chemicals. There is also a division plate within the box, which divides the box into two parts from top to bottom. The two parts are used to contain two different kinds of chemicals namely A and B. In order to stabilize A and B, a kind of stabilizer C is placed within the box. C is placed in the upper part of the box, and in order to enable C to volatilize to reach the lower part of the box and to stabilize A and B placed therein, some holes are drilled in the division plate of the box; the way of setting out the holes is exactly the same as that in Figure 1. It is described in the operation instruction of the alleged infringing box that the purpose of drilling holes in the division plate is to enable the stabilizer C to volatilize to reach the lower part of the box, but other effects which can be brought about by the division plate are not mentioned. What should be emphasized here is that although it is true that the division plate can bring about the effect of supporting the box, the manufacturer of the alleged infringing product does not realize that the division plate with the use of holes enables it to reduce its weight without weakening its effect of supporting the box. This is because the holes are made solely for the purpose of enabling the stabilizer to reach the lower part of the box.

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