Patent ID: 8177522

Claim:
A mode changing apparatus for a scroll compressor, the mode changing apparatus comprising: at least one low pressure passage configured to communicate with a low pressure area of the scroll compressor; at least one intermediate pressure passage configured to communicate with an intermediate pressure area of a plurality of compression pockets of the scroll compressor; and a mode changing assembly configured to selectively allow communication between the at least one low pressure passage and the at least one intermediate pressure passage based on a selected mode, wherein the mode changing assembly comprises: a communication member; a block assembly having a chamber configured to receive the communication member therein and a passage that allows communication between the at least one low pressure passage and the at least one intermediate pressure passage; and a pressure control device that supplies a high or low pressure to the chamber, wherein the communication member comprises a piston, and wherein the piston has a passage formed in a groove shape on an outer surface thereof, which extends therethrough and is configured to allow communication between the at least one low pressure passage and the at least one intermediate pressure passage when aligned with the passage of the block assembly.