Back to results
US 4,406,605 AGranted
Apparatus for forming concrete pipe of uniform density including control means to vary feed rate of concrete/aggregate as function of packerhead torque
AssigneeKerr Concrete Pipe Company
InventorGeorge E. Hand
Life of this patent
Estimating the term…
Abstract
In order to form concrete pipe of uniform density in apparatus where a packer head packs concrete into a mold to form the pipe, the horsepower of the drive motor driving the packer is sensed and used to adjust the rate of concrete supply such as to insure a constant horsepower as the packer is moved from one end of the pipe mold to the other.
Claims24
An apparatus for forming concrete pipe of uniform density comprising:
- (a) means for forming concrete into the form of said pipe comprising a mold having an inner wall, a packing head for packing concrete against said inner wall, a shaft centrally mounted on said packing head, a packing head motor for revolving said packing head through the mold and means for raising said packing head only at a fixed rate and for lowering said packing head in at least one pass;
- (b) means for feeding concrete to said forming means;
- (c) a feed motor for driving said concrete feeding means;
- (d) means for sensing and measuring the components of the actual power being used by said packing head motor said power being a function of torque generated in said packing head;
- (e) means for selecting a desired power;
- (f) means for comparing said actual power to said desired power;
- and
- (g) means for controlling the speed of said feed motor responsive to said means for comparing.
5 more elements
A control system for use with apparatus for making a concrete pipe, said apparatus including a mold;
- a conveyor for feeding concrete to said mold;
- a motor for driving said conveyor;
- a packing head for rotating within said mold to distribute and pack concrete supplied by said conveyor;
- a drive motor for driving said packing head;
- and means for controllably raising and lower said packing head in first and second passes, comprising:
- (a) a speed control for said conveyor motor having a reference speed input and actual speed input and driving said motor such as to minimize the error therebetween;
- (b) a tachometer generator for generating a signal representative of the actual speed;
- (c) first means for supplying to said speed controller a first signal representative of a desired speed during the first pass;
- and
- (d) second means for supplying a second signal representing a desired speed during the second pass.
7 more elements
An electronic control system for an apparatus for forming concrete pipe of uniform density which includes:
- a mold having an inner wall, a packing head for packing concrete against the inner wall, a shaft centrally mounted on the packing head, a packing head motor for revolving the packing head through the mold;
- means for feeding concrete to the mold;
- a feed motor for driving the concrete feeding means;
- means for raising said packing head only at a fixed rate and lowering the packing head in at least one pass, comprising:
- (a) means for sensing and measuring the components of the actual power being used by the packing head motor said power being a function of torque generated in said packing head;
- (b) means for selecting a desired power;
- (c) means for zeroing out the portion of actual power which represents drive train and other losses at no load to obtain corrected power;
- (d) means for comparing said corrected power to said desired power;
- and
- (e) means for controlling the speed of said feed motor responsive to said means for comparing, such as to cause said actual power to be only constant and thereby said torque to also be constant, whereby said packing head will evenly pack concrete in said mold.
7 more elements
A control system for an apparatus for forming concrete pipe of uniform density which includes:
- a mold having an inner wall;
- a packing head for packing concrete against the innner wall;
- a shaft centrally mounted on the packing head;
- a packing head motor for revolving the packing head through the mold;
- means for feeding concrete to the mold;
- a feed motor for driving the concrete feeding means;
- and means for raising said packing head only at a fixed rate and lowering said packing head in at least one pass, comprising:
- (a) means for sensing and measuring the components of the actual power being used by the packing head motor said power being a function of torque generated in said packing head;
- (b) means for selecting a desired power;
- (c) an operational amplifier having a summing junction at its input, said amplifier having a variable resistor in its feedback path, for comparing said actual power to said desired power;
- and
- (d) means for controlling the speed of said feed motor responsive to the output of said operational amplifier, such as to cause said actual power to be only constant and thereby said torque to also be constant, whereby said packing head will evenly pack concrete in said mold.
9 more elements
An apparatus for forming concrete pipe of uniform density comprising:
- (a) means for forming concrete into the form of said pipe comprising a mold having an inner wall, a packing head for packing concrete against said inner wall, a shaft centrally mounted on said packing head, a packing head motor for revolving said packing head through the mold and means for raising said packing head only at a fixed rate and lowering said packing head in at least one pass;
- (b) means for feeding concrete to said forming means;
- (c) a feed motor for driving said concrete feeding means;
- (d) means for sensing and measuring the components of the actual power being used by said packing head motor said power being a function of torque generated in said packing head;
- (e) means for selecting a desired power;
- (f) an operational amplifier having a summing junction at its input, said amplifier having a variable resistor in its feedback path for comparing said actual power to said desired power;
- and
- (g) means for controlling the speed of said feed motor responsive to the output of said operational amplifier.
5 more elements
An apparatus for forming concrete pipe of uniform density comprising:
- (a) means for forming concrete into the form of said pipe comprising a mold having an inner wall, a packing head for packing concrete against said inner wall, a shaft centrally mounted on said packing head, a packing head motor for revolving said packing head through the mold and means for raising said packing head only at a fixed rate and lowering said packing head in at least one pass;
- (b) means for feeding concrete to said forming means;
- (c) a feed motor for driving said concrete feeding means;
- (d) means for sensing and measuring the components of the actual power being used by said packing head motor said power being a function of torque generated in said packing head;
- (e) means for selecting a desired power;
- (f) means for zeroing out the portion of actual power which represents drive train and other losses at no load to obtain corrected power;
- (g) means for comparing said corrected power to said desired power;
- and
- (h) means for controlling the speed of said feed motor responsive to said means for comparing.
6 more elements
An electronic control system for an apparatus for forming concrete pipe of uniform density which includes a mold having an inner wall, a packing head for packing concrete against the inner wall, a shaft centrally mounted on the packing head, a packing head motor for revolving the packing head through the mold;
- means for feeding concrete to the mold;
- a feed motor for driving the concrete feeding means;
- and means for raising said packing head only at a fixed rate and for lowering said packing head in at least one pass, comprising:
- (a) means for sensing and measuring the components of the actual power being used by the packing head motor said power being a function of torque generated in said packing head;
- (b) means for selecting a desired power;
- (c) means for comparing said sensed power to said desired power;
- and
- (d) means for controlling the speed of said feed motor responsive to said means for comparing, such as to cause said actual power to be only constant and thereby said torque to also be constant, whereby said packing head will evenly pack concrete in said mold.
5 more elements
Dependencies are inferred from the claim text.