Mechanical patents, which mainly involve the structure of objects, contain a large number of names of devices and parts, as well as phrases describing the positional relationship, connection relationship, and operational relationship of the devices and parts. The way of accurately translating these terminologies is a key point and also a tricky point in the translation of mechanical patents. Moreover, unlike the fields of communications and chemistry where most terminologies have definite and common names, in the field of machinery, many objects do not have universal names. In addition, the Chinese language itself includes numberless polysemants and synonyms: different names may refer to the same object, and sometimes the same name may refer to different objects. Let’s see some examples that illustrate several common issues in translation.

I. Same terminology referring to different objects

1. “机身”

The Chinese terminology “机身” generally refers to the central body of an airplane that is designed to accommodate the crew and passengers (or cargo), and in this case, the terminology should be translated to be “fuselage”. However, in other cases, for example, when “机身” is used in a text describing unmanned aerial vehicles, the translation “fuselage” does not make sense because an unmanned aerial vehicle does not have a fuselage. In this case, “机身”refers to the whole vehicle, and should be translated into “body”.

2. “踏板”

The Chinese terminology “踏板” can be used to describe a brake pedal, an accelerator pedal, or a piano pedal and refers to a device operated by foot to transmit a force.


“踏板” can also be used to describe a plate or a platform for allowing feet to be placed thereon or a person to stand thereon, for example, the deck of a scooter.


3. “顶针”

When used to describe sewing supplies, the Chinese terminology “顶针” refers to a thimble; and when the terminology is used to describe mold accessories, it refers to an “ejector pin” in an injection mold.

4. “钩扣”

The Chinese terminology “钩扣” can be used to describe a hook-and-eye closure which is used for fastening garments together.


The terminology can also be used to describe a snap hook which includes a closed loop with a spring-loaded opening and is usually used for connecting ropes.

II. When to avoid literal translation

Certain terminologies should not be translated just according to the literal Chinese meaning, but as the object actually referred to. Here, a corresponding English terminology should be used.

For example, in the field of electronic cigarettes, the Chinese terminology “烟油” does not refer to oil, but a special liquid, and should be translated into “e-liquid”; and the Chinese terminology “烟雾” does not refer to “smoke”, but vapor generated from an e-liquid, and should be translated as “vapor”.

Another example is the Chinese terminology “气膜建筑”, which actually refers to a structure which supports a building housing using pressurised air and has a common English name “air supported structure”. Thus this terminology should not be translated into “air film structure” or “air membrane structure” simply according to the Chinese text.

III. Homophonic Chinese terminologies

By way of illustration, the Chinese terminologies “滚筒” and “辊筒”. The Chinese terminology “滚筒” generally refers to a “drum”: for example, a washing machine has a drum. The Chinese terminology “辊筒” generally refers to a roller: for example, a belt conveying system has a conveyor roller. However, in actual translation practice, sometimes“辊筒” and “滚筒” are interchanged, and “滚筒”may be used to describe a “roller”. Therefore, the actual meaning of the terminology should be analyzed during translation.

It can be concluded from the discussion above that to translate terminologies referring to mechanical structures, the real meanings of the terminologies, rather than simply the literal Chinese meanings, should be understood. Otherwise mistranslation may easily occur and even the whole article may not make sense. This requires a translator to grasp the true meaning of the terminologies according to the context and drawings, and to find and check the corresponding English terminologies according to drawings, so as to accurately determine the translation of each terminology.