Less than a year since it secured new financing partners, Robbins Bros., World’s Biggest Engagement Ring Store, has opened its first store outside California. The new location in Houston will be followed by two more Houston locations, the company said. Robbins Bros., which launched in its current format in 1995, last December secured equity investment financing from Weston Presidio and Dorset Capital in order to proceed with its expansion plans. The Glendale-based retailer operates seven stores in Southern California.