Pervert Baher Elabady groped the woman when he offered her assistance after she injured her back.
After being arrested and released on bail the 42-year-old went on to sexually assault a teenage girl.
Elabady, 42, of Meadow Court, Castleford, appeared via video link from custody at Leeds Crown Court where he pleaded guilty to two counts of sexual assault.
Rupert Doswell, prosecuting, said the first assault took place when the woman hurt herself while tending to a machine.
Elabady was asked to take her to a first aid room.
He first touched her hip and grabbed her thighs as he asked her to sit.
The defendant then put his hand underneath her bra strap.
Beeston murder trial: 'Brothers abandoned attempt to flee country hours after 'revenge' killing as one did not have a passport'Mr Doswell said the victim tried to move but was restricted by the injury to her back.
The victim broke down in tears and reported the incident.
Mr Doswell said the ordeal had left the victim frightened and it had affected her life.
Elabady was then arrested again for sexually assaulting a girl and held on remand.
Satpal Roth-Sharma, mitigating, said her client had no previous convictions.
"He is keen to be rehabilitated."
Judge Robin Mairs jailed Elabady for six years and one month.
He also made him the subject of a restraining order and a sexual harm prevention order (SHPO), which allows his behaviour to be monitored.
Both orders will last until further notice.