Photoelectric limit sensing assembly and system

Claim 2

In a a photoelectric limit sensing assembly and system, a source of light, means forming a pattern lying in a plane through which light from the source can pass, the pattern being characterized in that it is encompassed by a continuous line to define an acceptable region for movement, means carrying a plurality of photoelectric elements, said photoelectric elements being arranged so that there is at least one row of photoelectric elements with at least two elements in each row, means for causing relative movement between the means forming a pattern and said means carrying said photoelectric elements, and logic circuitry connected to said photoelectric elements for preventing movement beyond said acceptable region and for permitting movement only into said acceptable region after movement beyond the acceptable region has occurred.

Claim 3

In a photoelectric limit sensing assembly and system, a source of light, means forming a pattern lying in a plane through which light from the source can pass, the pattern being characterized in that it is encompassed by a continuous line to define an acceptable region for movement, means carrying a plurality of photoelectric elements, said photoelectric elements being arranged so that there are two rows of said photoelectric elements which intersect with three photoelectric elements in each row with two of the photoelectric elements representing directions, means for causing relative movement between the means forming a pattern and said means carrying said photoelectric elements for preventing movement beyond said acceptable region and for permitting movement only into said acceptable region after movement beyond the acceptable region has occurred.

Claim 4

In a photoelectric limit sensing assembly and system, a source of light, means forming a pattern lying in a plane through which light from the source can pass, the pattern being characterized in that it is encompassed by a continuous line to define an acceptable region for movement, means carrying a plurality of photoelectric elements, said photoelectric elements being arranged so that there are two rows of said photoelectric elements which intersect with three photoelectric elements in each row with two of the photoelectric elements representing directions, means for causing relative movement between the means forming a pattern and said means carrying said photoelectric elements for preventing movement beyond said acceptable region and for permitting movement only into said acceptable region after movement beyond the acceptable region has occurred.

Claim 5

An assembly and system as in claim 1 wherein said acceptable region is in the form of a circle.

Claim 6

An assembly and system as in claim 1 wherein said means carrying said plurality of photoelectric elements includes a planar member and wherein said photoelectric elements are mounted on said planar member.

Claim 7

An assembly and system as in claim 2 wherein said photoelectric elements are capable of assuming first and second conditions in response to receiving light or not receiving light and wherein said logic circuitry includes gate means for permitting movement in only those directions which are represented by photoelectric elements which are in one condition after movement beyond the acceptable region.

Claim 8

An assembly and system as in claim 5 wherein said logic circuitry also includes means for comparing the commanded direction of movemeNt with actual direction of movement.

Claim 9

An assembly and system as in claim 5 wherein said logic circuitry includes means for preventing stopping of movement until the rate of movement is below a predetermined speed.