Failsafe decelerating system

Claim 2

A decelerating system for a conveyor comprising: drive assembly means for driving a conveyor, said drive assembly means having a motor coupled to a drive train of said conveyor, said drive assembly means having a flywheel coupled to said drive train to keep said conveyor moving through the inertia of said flywheel for a limited period of time after said motor ceases to drive said drive train; signal generating means connected to said drive assembly means, said signal generating means generating a first signal proportional to the speed of said conveyor; reference signal generating means for generating a second signal to be compared with said first signal when power to said motor is cut off; said second signal declining in amplitude as a function of time; brake means for retarding movement of said drive assembly; and comparing means for comparing said first and second signals and regulating said brake means in accordance with said comparison so as to retard the movement of said drive assembly in a predetermined manner.

Claim 3

In the decelerating system of claim 1: said brake means being pressure actuated and said comparing means regulating pressure in said brake means.

Claim 4

In the decelerating system of claim 2: said signal generating means being a first pump, and said reference signal generating means being a second pump having a capacity equal to said first pump for a given speed.

Claim 5

In the decelerating system of claim 3: holdback means for effecting actuation of said brake means when said conveyor moves backward.

Claim 6

In the decelerating system of claim 4: said holdback means having a dump valve connected to said brake means, said dump valve being actuated by pressure and connected to said first pump, and said first pump being reversible whereby backward movement of said conveyor effects actuation of said dump valve and a reduction of pressure in said brake means.

Claim 7

In the decelerating system of claim 3: an outlet port of said second pump and an inlet port of said first pump being interconnected by a first hydraulic line, said outlet port of said second pump and said brake means being interconnected by a second hydraulic line, valve means for isolating said inlet port of said first pump from said outlet port of said second pump and said brake means when power is supplied to said motor and said conveyor is in operation, said valve means interconnecting said inlet port of said first pump with said outlet port of said second pump and said brake means when power to said motor is cut off whereby a differential in the flow rates of said first and second pumps will affect the regulating pressure in said brake means.

Claim 8

In the decelerating system of claim 6: holdback means for effecting actuation of said brake means, when said conveyor moves backward.

Claim 9

In the decelerating system of claim 7: said holdback means having a dump valve connected to said brake means, said dump valve being actuated by pressure and connected to said first pump, and said first pump being reversible whereby backward movement of said conveyor effects actuation of said dump valve.

Claim 10

In the decelerating system of claim 2: said first signal being a voltage generated by a tachometer generator coupled to said conveyor drive train and driven by said conveyor, said second signal being a voltage generated by a ramp generator, said comparing means comparing said voltages and issuing a control signal for regulating the pressure in said brake means.

Claim 11

In the decelerating system of claim 9: holdback means for effecting actuation of said brake means when said conveyor moves backward.

Claim 12

A decelerating system for a conveyor comprising: drive assembly means for driving a conveyor, said drive assembly means having a first motor coupled to a drive train of said conveyor, said drive assembly means having a flywheel coupled to said drive train to keep said conveyor moving through the inertia of said flywheel for a limited period of time after said first motor ceases to drive said drive train: signal generating means associated with said drive assembly means, said signal generating means being a first pump coupled to said drive train whereby said first pump is driven at a rate of speed proportional to the speed of said conveyor and has a flow rate proportional to the speed of said conveyor; reference signal generating means, said reference signal generating means being a second pump having a capacity equivalent to said first pump for a given speed, said second pump being coupled to a second flywheel and a second motor, said second pump being driven by said second motor during the normal operation of said system to maintain a source of pressure within said system, said second pump being driven by said second flywheel for a limited period after said second motor ceases to drive said second flywheel and said second pump to provide a reference signal, said second pump having a flow rate proportional to the speed of said second flywheel which declines in amplitude as said second flywheel decelerates; comparing means for comparing said flow rates and regulating the pressure within the decelerating system in accordance with said flow rates; and brake means for retarding the movement of said conveyor, said brake means being regulated by the pressure in said system whereby the retarding of the movement of said conveyor by said brake means is governed by the relative flow rates of said first and second pumps.

Claim 13

A decelerating system for a conveyor comprising: drive assembly means for driving a conveyor, said drive assembly means having a first motor coupled to a drive train of said conveyor, said drive assembly means having a flywheel coupled to said drive train to keep said conveyor moving through the inertia of said flywheel for a limited period of time after said first motor ceases to drive said drive train: signal generating means associated with said drive assembly means, said signal generating means being a first pump coupled to said drive train whereby said first pump is driven at a rate of speed proportional to the speed of said conveyor and has a flow rate proportional to the speed of said conveyor; reference signal generating means, said reference signal generating means being a second pump having a capacity equivalent to said first pump for a given speed, said second pump being coupled to a second flywheel and a second motor, said second pump being driven by said second motor during the normal operation of said system to maintain a source of pressure within said system, said second pump being driven by said second flywheel for a limited period after said second motor ceases to drive said second flywheel and said second pump to provide a reference signal, said second pump having a flow rate proportional to the speed of said second flywheel which declines in amplitude as said second flywheel decelerates; comparing means for comparing said flow rates and regulating the pressure within the decelerating system in accordance with said flow rates; and brake means for retarding the movement of said conveyor, said brake means being regulated by the pressure in said system whereby the retarding of the movement of said conveyor by said brake means is governed by the relative flow rates of said first and second pumps.

Claim 14

In the decelerating system of claim 11: holdback means for effecting actuation of said brake means when said conveyor moves backward.

Claim 15

In the decelerating system of claim 12: said holdback means having a dump valve connected to said brake means, said dump valve being actuated by pressure and connected to said first pump, and said first pump being reversible whereby backward movement of Said conveyor effects actuation of said dump valve and a reduction of pressure in said brake means.

Claim 16

In the decelerating system of claim 11: an outlet port of said second pump and an inlet port of said first pump being interconnected by a first hydraulic line, said outlet port of said second pump and said brake means being interconnected by a second hydraulic line, valve means for isolating said inlet port of said first pump from said outlet port of said second pump and said brake means when power is supplied to said first motor and said conveyor is in operation, said valve means interconnecting said inlet port of said first pump with said outlet port of said second pump and with said brake means when power to said first motor is cut off whereby a differential in the flow rates of said first and second pumps will affect the regulating pressure in said brake means.

Claim 17

In the decelerating system of claim 14: holdback means for effecting actuation of said brake means when said conveyor moves backward.

Claim 18

In the decelerating system of claim 15: said holdback means having a dump valve connected to said brake means, said dump valve being actuated by pressure and connected to said first pump, and said first pump being reversible whereby backward movement of said conveyor effects actuation of said dump valve.