The complete specification
To get an idea of the look and feel of a complete specification let’s have a look at a short extract from the body of the Kreepy Krauly patent referred to earlier. First, one of the drawings (below); the numbers are used to assist the description which is given in the body of the complete specification.
Then, how the apparatus moves randomly over the floor of the pool is explained in the section following the drawing.
The flow of water through the head chamber 26, past the valve 16, and into the passage 14.1 acts on the valve 16 and causes it to be displaced away from the valve seat 30 for the passage 14.1. The flow of water in this passage 14.1 is suddenly stopped. However, the water flowing in the passage 14.1 had kinetic energy, which is transferred to the body member, 18, and thus the apparatus 10, via the valve 16. This kinetic energy will be transferred as a force directed along the axis of the passage, and will thus have a vertical component and a horizontal component in the direction of the arrow 50. Further, as the flow rate of the water into the head chamber 26 is decreased, due to the inertia of the water in the passage 14.2, the suction grip of the head 12 on the floor decreases. As a result, the apparatus 10 is slightly displaced in the direction of arrow 50. As the flow rate of the water increases, the apparatus 10 will tend to experience a downward force in the opposite direction to the previous force. As this force will tend to increase the frictional grip between the head 12 and the floor and as the sectional grip is increased, the apparatus will not be displaced in the reverse direction to the arrow 50. The flow of water through the head chamber 26 causes the valve 16 to be displaced to open the passage 14.1 and closes the passage 14.2. This again causes the apparatus 10 to be displaced in the direction of the arrow 50. It will be noted that during this phase of the operation, as the valve seat 30 for the passage 14.2, is disposed substantially vertically, when it is struck by the valve 16, a force is exerted on the head 12 whose major component is in the direction of the arrow 50. This causes the apparatus 10 to be displaced further than when the passage 14.1 is closed, as in the latter case the action of the valve 16 opposes displacement of the apparatus 10. By this means, the apparatus 10 migrates across the floor of the swimming pool.
The claims are a very important part of the complete specification. Using only words, claims define the entire scope of the protection that you claim in the patent. Here is the main claim of the same Kreepy Krauly patent:
A cleaning apparatus for automatically cleaning a surface submerged in a liquid, the apparatus including a cleaning head, having a peripheral region releasably engageable with the surface to be cleaned; two suction passages; in suction communication with the head through communication openings therein; and means for automatically transferring liquid flow through passages, from the head alternatively and repeatedly from one of the passages to the other.
It may be no surprise to learn that even experienced judges have complained about the language used in patent documents. However, there is purpose to this. We return to look more closely at this particular claim when dealing with infringement.
Specifications, including claims, can be amended. However, the monopoly cannot be broadened if the patent has already been granted.
Read section 51 of the Patents Act.
Moreover, where an improvement or modification of the invention is developed, a ‘patent of addition’ can be obtained.
Read section 39 of the Patents Act.