Safety sensor for screen printing flash cure unit
OwnerCasimira Marie Dunsoninventor
Life of this patent
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Abstract
Disclosed herein is a safety device for a manual cure unit for use during screen printing. The present safety device includes a proximity sensor, a timer, and a voltage reduction mechanism. A programmable logic controller is used to control the device. The safety device is constructed and designed so that the power supply to the radiation source of the manual cure unit is automatically reduced when an object is detected in the scorch zone of the cure unit for a pre-selected duration of time.
Claims18
A safety device for use with a manual cure unit during a screen printing process, wherein the cure unit includes a radiation source that is powered by a continuous supply of electric current having a voltage, and wherein the radiation source emits a constant stream of radiation defining a scorch zone, said safety device comprising:
- a) a proximity sensor positionable at a location proximate the scorch zone, said proximity sensor having a capability to detect the presence of an object disposed in the scorch zone when positioned at said location, and wherein said proximity sensor is adapted to provide a continuous current through an output line while detecting an object, in the scorch zone;
- b) a voltage reduction mechanism interruptably connectable to the continuous supply of electric current of the cure unit and adapted to reduce said voltage upon actuation, wherein said mechanism actuates upon receiving current through an input line to said mechanism;
- and
- c) a timer receivably connected to said output line of said proximity sensor and providingly connected to said input line of said voltage reduction mechanism, wherein said timer is adapted to measure the duration of time that current is continuously received from said output line of said proximity sensor and, upon measuring the current output from the proximity sensor for a pre-selected maximum safe cure time, to provide a current to said input line of said voltage reduction means, thereby causing said voltage to be reduced.
A safety device for use with a manual cure unit during a screen printing process, wherein the cure unit includes a radiation source that is powered by a continuous supply of electric current having a voltage, and wherein the radiation source emits a constant stream of radiation defining a scorch zone, said safety device comprising:
- a) a proximity sensor positionable at a location proximate the scorch zone, said proximity sensor having a capability to detect the presence of an object disposed in the scorch zone when positioned at said location, and wherein said proximity sensor is adapted to provide a continuous current through an output line while detecting an object in the scorch zone;
- b) an alarm that operates upon receiving current through an alarm input line;
- and
- c) a timer receivably connected to said output line of said proximity sensor and providingly connected to said alarm input line, said timer adapted to measure the duration of time that current is continuously received from said output line of said proximity sensor, said timer adapted to provide a current to said alarm upon measuring the electric current from said proximity sensor for a pre-selected warning time.
A manual cure unit for use during screen printing comprising:
- a) a radiation source powered by a continuous supply of electric current having a voltage, and wherein said radiation source emits a constant stream of radiation defining a scorch zone;
- b) a proximity sensor positioned proximate said radiation source and directed toward said scorch zone, said proximity sensor having a capability to detect the presence of an object disposed in the scorch zone, and wherein said proximity sensor is adapted to provide a continuous current through an output line while detecting an object in the scorch zone;
- c) a voltage reduction mechanism interruptably connected to the continuous supply of electric current of said radiation source and adapted to reduce said voltage upon actuation, wherein said mechanism actuates upon receiving current through an input line to said mechanism;
- and
- d) a timer receivably connected to said output line of said proximity sensor and providingly connected to said input line of said voltage reduction mechanism, wherein said timer is adapted to measure the duration of time that current is continuously received from said output line of said proximity sensor and, upon measuring the current output from the proximity sensor for a pre-selected maximum safe cure time, to provide a current to said input line of said voltage reduction means, thereby causing said voltage to be reduced.
In a process for curing ink deposited on a flammable substrate disposed on a screen printing apparatus including a step of providing a cure unit including a radiation source emitting a continuous stream of radiation defining a scorch zone having a size, wherein the radiation source is powered by a continuous supply of electric current having a voltage, and a step of positioning the substrate in the scorch zone by sufficiently aligning the cure unit and the screen printing apparatus with each other, the improvement which comprises:
- (a) detecting the presence of the substrate in the scorch zone with a proximity sensor;
- (b) measuring the duration of time that the substrate is continually detected in the scorch zone;
- and
- (c) upon measuring a predetermined maximum safe duration of time, drawing the scorch zone away from the object by sufficiently reducing the voltage of the electric current supplying the radiation source with a voltage reduction mechanism.
Dependencies are inferred from the claim text.