US 5,079,981 A · Cutter mechanism

Abstract

Apparatus for cutting the leading and trailing edges of an opaque sheet angling initially at an offset angle with respect to a cutting blade includes a pair of light sources and a pair of light sensors opposite said light sources. An opaque sheet to be cut is moved at right angles to a line extending between said pairs of light source and sensors to bring said article edges to and past said pairs of light sources and sensors. The sensors produce article edge angle indicating signals which indicate the time difference each edge reaches said pair of sensors. Means are provided responsive to said signals which adjust the blade angle to be parallel to each article edge so the blade cuts parallel to each edge. The angle indicating could be signals which are a direct measure of the difference in times each edge reaches the sensors. However, they are preferably derived from sensors measuring the relative amounts of light at a snapshot time passing through slots partially covered to different degrees by the sheet edge portion involved when the edge being measured is at an angle to said line.

Claims8

Dependent claims

Article position control apparatus responsive to an offset angle between an straight edge of an article and a first reference line comprising:

a pair of spaced apart sensing means located along a second line;
moving means for moving the article in a direction at right angles to said reference line to bring said article straight edge to and past said pair of sensing means, whereby said article straight edge will reach said pair of sensing means at the same time when said article straight edge is parallel to said second line and will reach said pair of sensing means sequentially if said straight edge is at an angle to said second line;
means responsive to the sequence in time when said straight edge of said sheet initially reaches said pair of sensing means for producing an article straight edge angle indicating signal which varies with the time sequence;
and adjusting means responsive to said article straight edge angle indicating signal for adjusting the relative positions of said article straight edge and said reference line so that said straight edge and said reference line have a substantially constant predetermined relationship.

1 more element

Apparatus responsive to the offset angle between a straight edge of an article and a first reference line:

means forming a pair of similar slots spaced along a second line, said slots being transparent to a given radiation and said means beyond said slots being opaque to said radiation;
radiation source means on one side of said slots for directing said radiation through said slots;
a pair of radiation sensing means on the opposite side of said slots for generating output analog signals proportional to the overall amount of the radiation passing through said slots and received by each of said sensing means;
moving means for moving said article straight edge toward and beyond said pair of slots in a direction transverse to said second line so that the article progressively decreases to zero the amount of radiation received by said radiation sensing means;
comparison means for comparing the signals indicative of the amplitudes of said output analog signals generated by said radiation sensing means at an instant of time when said straight edge intercepts the radiation passing through both of said slots and generating a comparison signal indicative of said compared signals;
and
adjusting means responsive to said comparison signal for adjusting the relative positions of said article straight edge and said reference line to a given predetermined relationship.

4 more elements

Dependencies are inferred from the claim text.

Cutter mechanism

Life of this patent

Cutter mechanism

Life of this patent

Abstract

Claims8