Abstract: A scroll-type machine having a control arrangement which acts to disable the machine when there is an abnormal pressure in one of the scroll fluid pockets, thereby preventing damage to the machine upon reverse rotation or low system charge.

Abstract: There is disclosed a scroll-type machine specifically suited for use as a gaseous fluid compressor. The machine incorporates an improved rotation controlling mechanism which is extremely simple in construction, several embodiments of which are disclosed. This mechanism does not eliminate relative rotation between the scrolls but limits it to a relatively small predetermined amount. Several novel techniques for contouring the profiles of the scroll wrap flanks to give good flank sealing with the aforesaid rotation controlling mechanism are also disclosed, as are two embodiments of an improved scroll drive mechanism and an improved thrust bearing arrangement. A novel method of machining a scroll is also disclosed.

Abstract: There is disclosed a scroll-type machine specifically suited for use as a gaseous fluid compressor. The machine has intermediate relief valve means providing variable pressure ratio characteristics to thereby improve efficiency, as well as protect against overcompression.

Abstract: Disclosed is an apparatus and process for indicating or measuring the frequency of an incoming signal of unknown frequency. The system includes a plurality of processing channels, each of said channels including a pair of oscillators offset in frequency coupled to a pair of harmonic generators for producing respective output signals harmonically related, wherein the fundamental frequency of said harmonic generators are correspondingly offset. A combination of mixers, filters, amplifiers, and frequency-to-voltage convertors are utilized in combination with logic comparator means for producing analog voltage signals representative of the unknown frequency. Examples of utilization and display of these analog signals are illustrated.