Abstract: An improved security mailbox having a combination mail receiving and outgoing mail portion, securely held within an opening formed in a wall of a rectangular housing. The combination mail receiving and outgoing mail portion includes a top chamber which holds outgoing mail, and a bottom slot which connects to an inner chamber formed in the rectangular housing. Mail collects on a shelf secured in the inner chamber, and is accessible from a lockable door either in the front or rear wall. The shelf may be bare or have tiles thereon for easy cleaning, and the top of the housing is securely capped, while the base of the housing may be secured to the ground in any desired manner, or to a concrete support base. A plurality of combination mail receiving and outgoing mail portions may be secured in the housing, and an equal number of shelves and lockable doors may be provided.

Abstract: In an optical pattern follower, of the rotating scanning type, in which co-ordinated drive signals are produced by sampling two co-ordinate sinusoids, an adjustable kerf off-set is provided by selectably delaying the sampling pulse.

Abstract: The present invention applies to a circular scanning optical pattern tracer of the non-steering type. The scanner includes the normal circular scanning mirror and sensor and in addition a further circular scanning mirror and sensor to produce a scan of greater diameter than the normal scan. The signal from the second scan is used to indicate rapid changes of direction of the pattern by gating the produced signal through a gate produced from the normal scan.

Abstract: A pattern tracer having provision for recognizing special markings on the pattern termed "command marks" and for recognizing at least two different kinds of commands to enable special control of the machine tool controlled by the pattern tracer.