Seven life terms for the nurse who raped and killed; He used memory-loss drug to attack women in hospital.
He killed a ward sister and raped two patients during his campaign of sex terror in hospitals.
Cobb showed no emotion as Judge Martin Stephens QC branded him a "serious danger to women and the public at large".
Cobb was found guilty in May of manslaughter, two charges of rape and four of adminstering a drug with intent to rape between November 1996 and January 1999.
He still maintained his innocence, the judge was told.
Detectives feared there could be dozens more victims because the drug the pervert used causes the victim memory loss .
Judge Stephens told Cobb: "You caused anguish to your victims and feelings of shock and disgust to the general public. It is difficult to imagine what could constitute a greater breach of trust than what you did."
The women were "violated" by him in hospital "with all the anguish and distress that involves".
He had disgraced the nursing profession which was "probably held in higher respect and affection than any other."
He praised the courage and determination of rape victim, Janine Cuddington, 33, who went to the police and this led to him being caught.
She was at the Old Bailey to see him being sentenced.
The judge said that the most poignant and tragic case was that of Susan Annis, saying, "she was a delightful young woman with outstanding qualitites as a human being and a nurse."
He accepted that Cobb did not intend to kill her but he had been intent on raping her.
The fact that Cobb then went on to attack three other patients showed how callous he was.
"You did it in order to satisfy your perverted sexual demands", and described the effects of the drug Cobb used, midazolam, as "devastating".
The judge also said that Cobb would not be consider for parole for almost nine years and ordered that Cobb be on the sexual offenders register for life.
He said: "I have good cause to believe you will remain a great danger to the public for a period that cannot be determined."
Cobb's GP wife Anita, who he has a two-year-old son with, was standing by him.
She even came to court to give evidence on his behalf. She said: "I trust him. I know he could not have done these things."
Cobb, of Yateley, Hampshire, had no previous convictions .
Susan Annis, 31, died in November 1996 after Cobb spiked cans of cider she was drinking from. She suffered from a mild heart condition and the drink and drug cocktail caused fatal complications.
But the shock of her death did not stop Cobb. He callously went on to rape or sexually abuse the three patients after injecting them with the drug in the casualty department of St Peter's Hospital in Chertsey, Surrey.
Cobb had worked at the Royal London Hospital, Whitechapel, East London, Ashford Hospital in Staines, Frimley Park Hospital as well as St Peter's. He began his nursing career in 1983.
Police have set up a hotline and appealed to any woman who felt something odd or unpleasant had happened to them while they were in hospital - especially if they were cared for by Kevin Cobb - to come forward.
As a member of staff Cobb had free access to midazolam. He did not even have to sign a register indicating that he had taken the drug. Hospital proceedures on the use of the drug have since been tightened up.
Cobb's second rape victim was also aged 33 and a professional woman with three children. She went into the A & E department of St Peter's Hospital on December 14 1998 complaining of stomach pains.
Cobb isolated her in a small theatre room and there injected her. She said that it left her feeling like a rag doll.
The third woman was attacked on January 7 1999, also at St Peter's. She went for treatment at the casualty department following an asthma attack
The 34-year-old mother of two said that she fell into a deep sleep after Cobb injected her.
"I felt as though someone was having their wicked way with me," she told the jury.
All three were badly traumatised by their experiences at the hands of Cobb, suffering nightmares and flashbacks.
Police said that one of the things that disturbed them most is they were attacked when they were totally helpless and vunerable and in a place where they should have been safe.
Police - there could be many more victims
THE detective who led the investigation into Kevin Cobb's horrific crimes has revealed details of further allegations of sexual assault against the disgraced nurse.
Detective Superintendent Dave Cook, of Surrey Police, said a number of women had come forward following Cobb's conviction.
The claims of one victim would be pursued and Cobb interviewed in prison.
She told officers she was sexually assaulted by Cobb, 38, at St Peter's two years ago. The nature of Cobb's crimes meant that most women could only remember hazy details of what he did to them.
But Det Supt Cook said: "The inquiry will go on as victims come forward. We have got one woman who, if we had known of her existence over a year ago, I'm sure Cobb would have been charged with an offence against her as well.
"It is for the CPS to decide if it's in the public interest to proceed."
Cobb still denied his crimes but Det Supt Cook said he may come to accept what he had done while he was in prison.
Asked his personal view of Cobb, he said: "He's a person who's abused his position of trust. Devious and evil - calculatingly evil because he's selected his victims and put them under the influence of drugs.
"He picked out young, attractive, professional women, the sort of woman who would show no interest in him as a man.
"We are convinced there may have been other victims but the truth is we just do not know for sure - it's impossible to put a figure on it."