Staff at Michael Jones Jeweller in Northampton feared for their lives when five masked men armed with hammers, axes and machetes stormed into the store in the run-up to Christmas in 2018.
They entered after a car was used to ram the front of the shop, which injured a member of the Michael Jones team and a customer.
Other members of the team were said in court to still be suffering from post trauma anxiety and other health issues.
The gang the smashed their way into cabinets displaying high-value Rolex watches and diamond jewellery before dashing out to a getaway car in broad daylight.
Two of the gang, father and son Elliot Burton (above left) and Connor Burton (above right) were caught, charged and this week convicted of the robbery.
“The planning of this offence was detailed. The staff and customers inside the shop were frightened, terrified – you injured them physically and psychologically and you have fought the matter at every stage, showing no remorse for your actions,” His Honour Judge Michael Fowler said at the sentencing hearing at Northampton Crown Court.
Elliot Burton received the longer sentence because, the judge said, he has an appalling record of offending and took a leading role in the offences.