If anybody knows patent(s) that are having multiple colons in the first claim, please share. Also, please let me know how many colons we can use in the first claim. Thank you in advance. Best regards, Ram
Claim 1 of US 7346650 contains two colons. There is nothing particularly special or notable about this patent, it's just the first one I came across.
Using multiple colons in a claim is not especially rare. There is no formal limit to the number of colons usable in a claim, as long as their use does not affect the clarity of the claim.
Looking internationally, I would say it's particularly common in European patents, given the requirement for two-part form. You would typically have one colon after the introductory phrase ("A method comprising:"), then one after the characterising wording ("characterised in that the method further comprises:").