A U.S. appeals court on Friday showed few signs that it was prepared to support a request by Apple Inc to block immediately the sale of some Samsung Electronics smartphones and tablets.

In a high-stakes patent dispute, the court heard arguments about whether a federal trial judge acted correctly in December when she ruled that Apple failed to provide enough evidence to support an injunction of Samsung's Galaxy pro duct line.

The court's judges reacted with skepticism to a premise put forward by Apple's lawyer that for the purpose of getting an injunction, Apple does not need to show that patent infringement would directly cause a loss of customers.

Apple's lawyer, Michael Jacobs, said it is enough to show that Samsung likely infringed on Apple's patents used in products such as the iPhone, and that Apple is likely to be hurt. The trial judge found both those things but not enough evidence of a causal link.

Judge William Bryson on Friday asked about a hypothetical case in which an automaker copied the design of a cupholder from a second automaker. Under Apple's argument, if the second automaker later lost market share, it could ask for an injunction against sales by the first automaker, Bryson said.

"Can that possibly be right?" he asked. Bryson is one of three judges who heard the case before the U.S. Court of Appeals for the Federal Circuit.

Apple and Samsung are scheduled to go to trial in July in federal court in California. An order to stop Galaxy sales would have the potential to affect settlement considerations.

(Reporting by David Ingram; Editing by Padraic Cassidy and Richard Chang)