Dual-servo control for conveyor induction systems

In a conveyor system including an induction subsystem adapted to merging packages from at least two conveyor lines discharging packages with desired spacing between packages and control means for controlling said induction subsystem, the improvement comprising:

• said induction subsystem including at least two induct control conveyors and an initial gap control conveyor associated with each induct control conveyor upstream of that induct control conveyor.
• said control means including means for controlling the speed of said induct control conveyors in a manner that will merge packages from said induct control conveyors with desired spacing between packages and for controlling the speed of each said initial gap control conveyor in a manner that will provide controlled spacing between packages on the associated said induct control conveyor;
• and
• wherein each of said induct control conveyors includes speed control means for responding to said control means to vary the speed of the associated said induct control conveyor between a low-speed and at least one speed that is greater than said low-speed and wherein said control means provides said controlled spacing between packages on each said induct control conveyor as a function of the time it takes said speed control means to cause that said induct control conveyor to switch from a particular speed to said low-speed.

In a conveyor system including a sortation subsystem adapted to sorting packages onto selected spurs, an induction subsystem adapted to discharging packages to said sortation subsystem with desired spacing between packages and control means for controlling said induction subsystem, the improvement comprising:

• said induction subsystem including at least one induct control conveyor and an associated initial gap control conveyor upstream of said induct control conveyor;
• said control means including means for controlling the speed of said induct control conveyor in a manner that will create said desired spacing between packages on said sortation subsystem and for controlling the ratio of the speed of said induct control conveyor to the speed of said initial gap control conveyor in a manner that will provide controlled spacing between packages on said induct control conveyor;
• said control means including a first variable speed motor operatively connected with said at least one induct control conveyor, a second variable speed motor operatively connected with said associated initial gap control conveyor and means for controlling the speed of said second variable speed motor as a function of the speed of said first variable speed motor;
• and
• said control means further including first selection means for selecting a speed of said first variable speed motor, second selection means for selecting a ratio of speed between said first and second variable speed motors and wherein said means for controlling the speed of said second variable speed motor is responsive to said first and second selection means.

In a conveyor system including an induction subsystem adapted to merging packages from at least two conveyor lines and to discharging packages with desired spacing between packages and control means for controlling said induction subsystem, the improvement comprising:

• said induction subsystem including at least two induct control conveyors and an initial gap control conveyor associates with each induct control conveyor upstream of that induct control conveyor;
• said control means including means for controlling the speed of said induct control conveyors in a manner that will merge packages from both said induct control conveyors with desired spacing between packages and for controlling the ratio of the speed of each induct control conveyor to the speed of the associated initial gap control conveyor in a manner that will provide controlled spacing between packages on each said induct control conveyor;
• said control means including first and second variable speed motors operatively connected one with each of said two induct control conveyors, third and fourth variable speed motors operatively connected one with each of the initial gap control conveyors associated with the two induct control conveyors and means for controlling the speed of each of said third and fourth variable speed motors as a function of the speed of the one of said first and second variable speed motors operatively connected with the associated induct control conveyor;
• and
• said control means further including first and second selection means for selecting speeds of said first and second variable speed motors, third and fourth selection means for selecting speed ratios respectively between said first and third variable speed motors and between said second and fourth variable speed motors and wherein said means for controlling the speed of each of said third and fourth variable speed motors is responsive to said first, second, third and fourth selection means.

In a conveyor system including an induction subsystem adapted to merging packages from at least two conveyor lines and discharging packages with desired spacing between packages and control means for controlling said induction subsystem, the improvement comprising:

• said induction subsystem including at least two induct control conveyors and an initial gap control conveyor associated with each induct control conveyor upstream of that induct control conveyor;
• said control means including means for controlling said induct control conveyors in a manner that will merge packages from both said induct control conveyors with desired edge-to-edge spacing between packages and for controlling each associated initial gap control conveyor in a manner that will produce controlled center-to-center spacing between packages on each said induct control conveyor;
• and
• each of said induct control conveyors including speed control means for responding to said control means to vary the speed of the associated said induct control conveyor between a low-speed and at least one speed that is greater than said low-speed and wherein said control means provides said controlled center-to-center spacing between packages on said induct control conveyor as a function of the time it takes said speed control means to cause each said induct control conveyor to switch from a particular speed to said low-speed.

In a conveyor system including an induction subsystem having at least two conveyor lines, a sortation subsystem which receives packages from said induction subsystem and discharges packages selectively to take-away lines and control means for controlling said conveyor lines, the improvement comprising:

• said induction subsystem having first conveying means operative to convey packages at a first predetermined speed;
• said sortation subsystem having second conveying means operative to convey packages at a second predetermined speed that is different from said first speed;
• and
• said control means including means for controlling said induction subsystem in a manner that will cause desired gaps between packages after the packages are received on said sortation subsystem, wherein said means for controlling is responsive at least to the ratio between said first and second speeds.

A conveyor system including a sortation subsystem adapted to sorting packages onto selected spurs, an induction subsystem adapted to discharging packages to said sortation subsystem with desired spacing between packages and control means for controlling said induction subsystem, the improvement comprising:

• said induction subsystem including at least two induction lines, each of said induction lines having an induct control conveyor and an associated initial gap control conveyor upstream of said induct control conveyor;
• said control means including first means for controlling the speed of each said induct control conveyor in a manner that will merge packages from both said induction lines and provide desired spacing between packages on said sortation subsystem, said control means further including second means for controlling the speed of each said initial gap control conveyor in a manner that will provide controlled spacing between packages on the associated said induct control conveyor;
• said first means including first and second variable speed motors operative connected respectively with each of said induct control conveyors and first and second selection means for selecting a speed respectively of said first and second variable speed motors;
• and
• said second means including third and fourth variable speed motors operatively connected respectively with each of said associated initial gap control conveyors, third and fourth selection means for selecting a ratio of speeds respectively between said first and third variable speed motors and said second and fourth variable speed motors and means responsive to said first, second, third and fourth selection means for establishing a speed of said third and fourth variable speed motors.