Rodney Nziza, 25, of Browning Avenue, pleaded guilty and was sentenced to a total of ten years and eight months at Kingston Crown Court on June 8, according to a police statement.
On January 27 last year, at 7.15am, at Sainsbury's, Rayners Lane, Harrow, a security officer from a private security company was making a cash drop for the ATM machine, police said.
As he was taking a cash box from the security van to the store, Nziza approached him, said police, grabbed his arm and pulled on the box. A brief struggle ensued but Nziza managed to prise the box away before making his escape.
The second robbery is said to have happened at around 3pm on April 8 last year, when once again a security officer from a private security company was making a cash drop for the ATM machine at Sainsbury's, in Churchfield Road, Acton.
As he removed a cash box from the security van, Nziza ran up to the security officer and, before he could get the box back into the van, he was threatened and pushed in the chest, police said. Nziza managed to grab the cash box and escape down Alfred Road before fleeing in a car.
In both incidents no one was injured.
The cash boxes were forced open in an underground garage in Copley Close, Hanwell, close to Nziza's home address. No cash has been recovered.
Detective Constable Phelim Redmond from the Met's Flying Squad said: "When Nziza was faced with the forensic evidence we had managed to obtain at the scenes of his crimes, coupled with other evidence, he really had no option but to plead guilty.
"I am glad that another criminal of this type has been jailed for a long time."