Appeal No. 1997-3892
Application 08/421,379
providing water;
admixing with the water an effective amount of active zinc, the latter being present in the water in
an amount sufficient to inhibit the growth of biological fouling in irrigation lines and emitters in the
irrigation system through which water is pumped; and
pumping the water admixed with the active zinc through the irrigation lines and emitters to inhibit
biological fouling.
The appealed claims as represented by claim 1 are drawn to a method for treating an irrigation
system to inhibit the formation of biological fouling comprising at least the step of mixing with the
irrigating water an amount of active zinc sufficient to inhibit the growth of biological fouling in the
irrigation system. Claim 2 specifies that the active zinc is provided by zinc sulfate while claim 5 specifies
that the active zinc is chelated with 1-hydroxy ethane 1,1-diphosphonic acid (HEDPA). Claim 9
specifies that the water-active zinc mixture is continuously pumped through the system while claim 11
specifies that such a mixture is pumped through at least one time each week. Claims 3, 7, 10 and 12
specify that about 0.1 to about 10.0 ppm of active zinc is present in the mixture.
The references relied on by the examiner are:
Alexander 4,108,772 Aug. 22, 1978
Geiger et al. (Geiger) 0 017 373 Oct. 15, 1980
(published Eur. Pat. Application)
The examiner has rejected all of the appealed claims under 35 U.S.C. § 103 as being
unpatentable over Geiger in view of Alexander. We reverse.
Under the provisions of 37 CFR § 1.196(b) (1997), we enter a new ground of rejection of
claims 1 through 4 and 9 through 12 under 35 U.S.C. § 103 as being unpatentable over the knowledge
of the problem of biological fouling of irrigation systems in the art as acknowledged by appellants in the
specification combined with the teachings of Alexander.
Rather than reiterate the respective positions advanced by the examiner and appellants, we refer
to the examiner’s answer and to appellants’ brief and reply brief for a complete exposition thereof.
Opinion
The appealed claims are drawn to methods for treating an irrigation system to inhibit the
formation of biological fouling comprising at least the step of mixing active zinc with the irrigating water
- 2 -
Page: Previous 1 2 3 4 5 6 7 8 9 Next
Last modified: November 3, 2007