The present disclosure relates to a dowel bar inserter apparatus for inserting dowel bars in a freshly placed concrete slab, and to methods of operation of such an apparatus.
A dowel bar inserter apparatus includes a bottom pan assembly, sometimes referred to as a bottom-group assembly. The bottom pan assembly is the structure that slides across the top of the freshly placed concrete slab, and from which the dowel bars are inserted into the concrete slab. Modern slip form pavers and the associated dowel bar inserters must span large widths, up to as much as 50 feet. To insure that the bottom pan assembly properly glides over the top surface of the concrete slab, and does not dig into the slab, the bottom pan assembly is supported from the structure of the dowel bar inserter which in turn is typically supported from the main frame of the associated slip form paver. This support is typically proved by a series of threaded rods which must be manually adjusted during the set-up of the dowel bar inserter for a given paving job. If height corrections of the bottom pan assembly are necessary during the paving operation, again these adjustments are typically made by further manual adjustment of the threaded support rods.
Such height corrections of the bottom pan assembly are often necessitated by changes which may occur in the consistency of the concrete during the paving operation. Such changes in consistency may occur across the working width of the dowel bar inserter and/or in the paving direction. When such manual corrections of the height of the bottom pan assembly are needed they often can only be carried out by a human operator stepping onto the freshly paved concrete surface to adjust the threaded support rods, and access to those mechanical components is often difficult. But it is very undesirable for the operator to step onto the concrete surface because that may influence the position of dowel bars that have already been inserted.
There is a need for improved dowel bar inserters that avoid the need for such manual height adjustments of the bottom pan assembly.
In one embodiment a dowel bar inserter apparatus includes first and second end carriages, a bottom pan assembly configured to engage a top surface of a freshly placed concrete slab, an insertion beam having a plurality of insertion forks attached to the insertion beam, and first and second insertion actuators supporting the insertion beam from the first and second end carriages, respectively, for raising and lowering the insertion beam and the insertion forks relative to the end carriages. At least one first suspension actuator supports the bottom pan assembly from the first end carriage independent of the raising and lowering of the insertion beam relative to the first end carriage. At least one second suspension actuator supports the bottom pan assembly from the second end carriage independent of the raising and lowering of the insertion beam relative to the second end carriage. Each of the suspension actuators includes associated therewith a suspension actuator extension sensor configured to detect an amount of extension of the respective suspension actuator.
The at least one first end suspension actuator may include a forward first end suspension actuator and a rear first end suspension actuator. The at least one second end suspension actuator may include a forward second end suspension actuator and a rear second end suspension actuator.
In any of the above embodiments each of the suspension actuators may be a hydraulic cylinder.
In any of the above embodiments each of the suspension actuators may comprise a hydraulic smart cylinder, and the suspension actuator extension sensor associated with each suspension actuator may be an integral part of the hydraulic smart cylinder.
In any of the above embodiments the dowel bar inserter may include a plurality of deflection compensation actuators configured to support a plurality of intermediate locations of the bottom pan assembly, the deflection compensation actuators being located between the first and second suspension actuators.
In any of the above embodiments each of the deflection compensation actuators may include a hydraulic cylinder and a flexible connector connecting the hydraulic cylinder to the bottom pan assembly such that the deflection compensation actuators can support the bottom pan assembly in tension loading but not compression loading of the flexible connectors.
In any of the above embodiments each of the hydraulic cylinders of the deflection compensation actuators may comprise a hydraulic smart cylinder including an integral deflection compensation actuator extension sensor.
In any of the above embodiments each of the deflection compensation actuators may be connected to the insertion beam so that the plurality of intermediate locations of the bottom pan assembly are supported from the insertion beam.
In any of the above embodiments each of the deflection compensation actuators may be connected to a support structure fixed to the first and second end carriages so that the plurality of intermediate locations of the bottom pan assembly are supported from the support structure.
In any of the above embodiments the deflection compensation actuators may be arranged in pairs of deflection compensation actuators, each pair including a front deflection compensation actuator and a rear deflection compensation actuator.
In any of the above embodiments the dowel bar inserter may include a chain conveyor configured to carry dowel bars to the bottom pan assembly and a hydraulic chain tensioning cylinder configured to maintain a tension in the chain conveyor.
In any of the above embodiments each of the suspension actuator extension sensors may be configured to generate a suspension actuator extension signal corresponding to the amount of extension of the respective suspension actuator, and the dowel bar inserter may further include a controller configured to receive the suspension actuator extension signals and to send control signals to the respective suspension actuators, at least in part in response to the suspension actuator extension signals for the respective suspension actuators.
In any of the above embodiments the dowel bar inserter may include a plurality of deflection compensation actuators configured to support a plurality of intermediate locations of the bottom pan assembly from the insertion beam, each of the deflection compensation actuators including a hydraulic smart cylinder including an integral deflection compensation actuator extension sensor, and the controller may be further configured to receive deflection compensation actuator extension signals from the deflection compensation actuator extension sensors corresponding to an extension of the respective deflection compensation actuators, and to send control signals to the respective deflection compensation actuators, at least in part in response to the deflection compensation actuator extension signals for the respective deflection compensation actuators.
In any of the above embodiments the dowel bar inserter may include at least one dowel bar storage bin located above the first end carriage, a chain conveyor configured to carry dowel bars from the at least one dowel bar storage bin to the bottom pan assembly, and an adjustable height support supporting the at least one dowel bar storage bin at an adjustable height above the first end carriage such that adjustment of the height of the at least one dowel bar storage bin above the first end carriage provides an initial adjustment of a chain tension in the chain conveyor during setup of the dowel bar inserter apparatus.
In any of the above embodiments the dowel bar inserter may include at least one hydraulic chain tensioning cylinder or other tensioning device extending between the first end carriage and the chain conveyor and configured to provide a further adjustment of chain tension in the chain conveyor during operation of the dowel bar inserter apparatus. Similar hydraulic chain tensioning cylinders may extend between the second end carriage and the chain conveyor.
In any of the above embodiments the dowel bar inserter may include at least one chain conveyor configured to carry dowel bars to the bottom pan assembly, a chain tensioning actuator configured to maintain a tension in the chain conveyor, a chain tensioning sensor, and a controller configured to receive a chain tension signal from the chain tensioning sensor and to send a control signal to the chain tensioning actuator, at least in part in response to the chain tension signal.
In any of the above embodiments the at least one first end suspension actuator may include a forward first end suspension actuator and a rear first end suspension actuator, and the at least one second end suspension actuator may include a forward second end suspension actuator and a rear second end suspension actuator. The controller may be configured to adjust the amount of extension of the forward first end suspension actuator and the forward second end suspension actuator relative to the amount of extension of the rear first end suspension actuator and the rear second end suspension actuator, respectively, to adjust a front to rear slope of the bottom pan assembly.
In any of the above embodiments the dowel bar inserter may include a plurality of deflection compensation actuators configured to support a plurality of intermediate locations of the bottom pan assembly, the deflection compensation actuators being located between the first and second suspension actuators, the deflection compensation actuators being arranged in pairs of deflection compensation actuators, each pair including a front deflection compensation actuator and a rear deflection compensation actuator, and the controller may be further configured to adjust an amount of extension of the front deflection compensation actuators relative to an amount of extension of the rear deflection compensation actuators to adjust the front to rear slope of the bottom pan assembly.
In any of the above embodiments the dowel bar inserter may include a swelling sensor configured to detect a swelling of the concrete slab and the controller may be configured to receive a signal from the swelling sensor corresponding to the swelling of the concrete slab, and to adjust the front to rear slope of the bottom pan assembly at least in part in response to the signal from the swelling sensor. The swelling sensor may be mounted on the dowel bar inserter itself or it may be mounted on other associated structures such as the paving mold which is a part of the paving apparatus located ahead of the dowel bar inserter.
In any of the above embodiments the controller may be further configured to adjust all of the suspension actuators to raise the entire bottom pan assembly at least in part in response to the signal from the swelling sensor.
In any of the above embodiments the controller may be configured to have a transport mode in which all of the suspension actuators are adjusted to raise the bottom pan assembly to a transport position.
A method of operating the dowel bar inserter of any of the above embodiments may include steps of:
receiving suspension actuator extension signals from the suspension actuator extension sensors with a controller; and
sending control signals from the controller to the suspension actuators at least in part in response to the suspension actuator extension signals for the respective suspension actuators.
The above method may further include:
receiving deflection compensation actuator extension signals from the deflection compensation actuator extension sensors corresponding to an extension of the respective deflection compensation actuators; and
sending control signals to the respective deflection compensation actuators, at least in part in response to the deflection compensation actuator extension signals for the respective deflection compensation actuators.
Any of the above methods may further include:
receiving a chain tension signal from the chain tensioning sensor with the controller; and
sending a control signal from the controller to the chain tensioning actuator, at least in part in response to the chain tension signal.
Any of the above methods may further include:
sending control signals from the controller to adjust the amount of extension of the forward first end suspension actuator and the forward second end suspension actuator relative to the amount of extension of the rear first end suspension actuator and the rear second end suspension actuator, respectively, thereby adjusting a front to rear slope of the bottom pan assembly.
Any of the above methods may further include:
sending control signals from the controller to adjust an amount of extension of the front deflection compensation actuators relative to an amount of extension of the rear deflection compensation actuators to adjust the front to rear slope of the bottom pan assembly.
Any of the above methods may further include:
detecting a swelling of the concrete slab with a swelling sensor;
receiving with the controller a signal from the swelling sensor corresponding to the swelling of the concrete slab; and
sending control signals from the controller to adjust the front to rear slope of the bottom pan assembly at least in part in response to the signal from the swelling sensor.
Any of the above methods may further include:
sending control signals from the controller to retract all of the suspension actuators and thereby raising the entire bottom pan assembly at least in part in response to the signal from the swelling sensor.
Any of the above methods may further include:
sending control signals from the controller to retract all of the suspension actuators to raise the bottom pan assembly to a transport position.
Numerous objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon a review of following description in conjunction with the accompanying drawings.
The embodiments of the present disclosure described below are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present disclosure.
Referring now to the drawings and particularly to
The slip form paver apparatus 10 includes a main frame 22 and a slip form paver mold 24 supported from the main frame 22. Left and right side form assemblies 26 are connected to the slip form paver mold 24 to close the slip form paver mold 24 on the left and right sides to form the lateral concrete sides such as 20 of the finished concrete structure 16. The slip form paver apparatus 10 shown in
The main frame 22 is supported from the ground surface by a plurality of ground engaging units such as 30, which in the illustrated embodiment are tracked ground engaging units 30. Wheeled ground engaging units may also be used. Each of the ground engaging units 30 is connected to the main frame 22 by a lifting column such as 32 which is attached to a swing arm such as 34. An operator's station 36 is located on the main frame 22. A plow or spreader device 38 is supported from the main frame 22 ahead of the slip form paver mold 24. Behind the slip form paver mold 24 a dowel bar inserter apparatus 40 may be provided. Behind the dowel bar inserter apparatus 40 an oscillating beam 41 and a super smoother apparatus 42 may be provided.
The present disclosure is focused on the construction of the dowel bar inserter 40.
The dowel bar inserter 40 includes first and second end carriages 44 and 46. As can be seen in
The dowel bar inserter 40 includes bottom pan assembly 52 which slides across the top surface 18 of the concrete slab 16 during the paving operation. The bottom pan assembly 52 includes a forward pan beam 54, a rearward pan beam 56, and a series of pan sections 58 attached to the pan beams and having spaces 60 between adjacent pan sections. Alternatively, the pan section 58 may extend in one or more segments across the width of the dowel bar inserter 40 and the spaces 60 may be formed in the pan section 58 itself. As further described below the dowel bars are pushed downward through the spaces 60 into the freshly poured concrete slab 16.
As will be understood by those skilled in the art the dowel bar inserter 40 slides forward and backward on the rails 48 during the dowel bar insertion operation. The slip form paver 10 moves forward continuously. When the dowel bar inserter 40 reaches a location where a group of dowel bars 79 are to be inserted the dowel bar inserter 40 is held stationary relative to the ground surface 14 and the slab 16 while the slip form paver 10 continues to move forward. This temporary stopping of the dowel bar inserter 40 is achieved by sliding the dowel bar inserter rearward on rails 48 at the same speed at which the slip form paver 10 is advancing. While the dowel bar inserter 40 is stationary over the slab 16 a set of dowel bars is inserted. Then the dowel bar inserter 40 is moved forward on the rails 48 back to its initial forward position and it is ready to perform the next insertion cycle.
An insertion beam 62 is supported from the left and right end carriages 44, 46, respectively.
A plurality of insertion forks 78 are attached to the insertion beam 62. When the insertion beam 62 is lowered from the position of
In an embodiment the first and second insertion actuators 64 and 66 may be hydraulic “smart” cylinders such as are further described below with reference to
In
The bottom pan assembly 52 is supported from the support legs such as 82 of the left and right end carriages 44, 46 by four suspension actuators 84, 86, 88 and 90. In
In an embodiment each of the suspension actuators 84, 86, 88 and 90 is independently controllable. Thus, all the suspension actuators may be simultaneously or separately retracted or extended. In one embodiment all the suspension actuators may be simultaneously retracted or extended to raise or lower the bottom pan assembly 52. In another embodiment the front suspension actuators 88 and 90 may be raised more than the rear suspension actuators 84 and 86 to adjust a front to rear slope of the bottom pan assembly 52. In a further embodiment the left end suspension actuators 84 and 88 may be extended differently from the right end suspension actuators 86 and 90 to provide a cross slope of the bottom pan assembly 52.
In an embodiment the dowel bar inserter 40 may be described as having at least one first end suspension actuator 84 and/or 88 for supporting the bottom pan assembly 52 from the first end carriage 44 independent of the raising and lowering of the insertion beam 62 relative to the first end carriage 44. Similarly, the dowel bar inserter 40 may be described as having at least one second end suspension actuator 86 and/or 90 for supporting the bottom pan assembly 52 from the second end carriage 46 independent of the raising and lowering of the insertion beam 62 relative to the second end carriage 46.
In an embodiment the suspension actuators 84, 86, 88 and 90 may each have associated therewith a suspension actuator extension sensor 84S, 86S, 88S and 90S, respectively, configured to detect an amount of extension of the respective suspension actuator. In an embodiment each of the suspension actuators may be a hydraulic cylinder. In a further embodiment the hydraulic cylinders may each be a hydraulic smart cylinder and the suspension actuator extension sensors associated with each suspension actuator may be an integral part of the hydraulic smart cylinder, as is further described below with reference to
Due to the substantial width of the bottom pan assembly 52 it may be desirable to provide further support for the weight of the bottom pan assembly 52 in between the left and right end suspension actuators 44 and 46. This further support may be provided by a plurality of deflection compensation actuators 92. In an embodiment as seen in
In the embodiment shown in
In an embodiment each of the hydraulic cylinders 94 may be a hydraulic “smart” cylinder including an integral deflection compensation actuator extension sensor 94S as further described below with regard to
As best seen in
Like the suspension actuators 84, 86, 88 and 90, each of the deflection compensation actuators 92 may be independently controllable. Thus, all of the deflection compensation actuators 92 may be simultaneously retracted or extended in synchronicity with the suspension actuators 84, 86, 88 and 90 to raise or lower the bottom pan assembly 52. Also, the front deflection compensation actuators may be raised more than the rear deflection compensation actuators to adjust a front to rear slope of the bottom pan assembly 52. Further, in rare cases, the front deflection actuators may even be set lower than the rear deflection compensation actuators. And along the length of the dowel bar inserter 40 from left to right the deflection compensation actuators may be extended different distances to provide a cross slope or a crown to the bottom pan assembly 52.
In the embodiment illustrated in
Alternatively, in another embodiment as schematically shown in
The dowel bar inserter 40 may include left and right dowel bar storage bins 100 and 102 located above the left and right end carriages 44 and 46, respectively. The details of the left dowel bar storage bin 100 are best shown in
A hydraulic chain tensioning cylinder 110 may have one end 112 pivotally connected to a support arm 114 attached to the end carriage 44. A second end 116 of the hydraulic chain tensioning cylinder 110 may be connected to a pivotable arm 118 carrying sprockets 120 and 122 which apply tension to the chain conveyor 108. The hydraulic chain tensioning cylinder 110 may be configured to provide a further adjustment of chain tension in the chain conveyor 108 during operation of the dowel bar inserter 40.
In an embodiment there may be a front and a rear chain conveyor 108 and a front and a rear chain conveyor hydraulic chain tensioning cylinder 110 associated with the dowel bar storage bin 100.
The chain tensioning cylinders 110 may each be described as a chain tensioning actuator 110 configured to maintain a tension in the chain conveyor 108.
The chain conveyor 108 may have associated therewith a chain tensioning sensor 124 configured to detect a tension in the chain conveyor 108. In one embodiment the chain tensioning sensor 124 may be a pressure sensor associated with the chain tensioning cylinder 110 to detect a hydraulic pressure within the hydraulic cylinder 110 as seen in
In an embodiment each of the hydraulic cylinders 110 may be a hydraulic “smart” cylinder including an integral extension sensor 1105 as further described below with regard to
As is schematically shown in
In an embodiment the crown adjustment actuator 130 may be a hydraulic cylinder. In another embodiment the hydraulic cylinder 130 may be a hydraulic smart cylinder 130 having an integral hydraulic cylinder extension sensor 130S associated therewith as further described below with reference to
As previously noted, the first and second insertion actuators 64 and 66, the suspension actuators 84, 86, 88 and 90, the hydraulic cylinders 94 of the deflection compensation actuators 92, the hydraulic chain tensioning cylinders 110 and the crown actuators 130 may be “smart” hydraulic cylinders having integral extension sensors associated therewith. In the control system schematic of
A representative construction of such a “smart” hydraulic cylinder is shown in
The sensor 84S includes a position sensor electronics housing 136 and a position sensor coil element 138.
The piston portion 132 of actuator 84 includes a piston 140 and a rod 142. The piston 140 and rod 142 have a bore 144 defined therein, within which is received the position sensor coil element 138.
The actuator 84 is constructed such that a signal is provided at connector 146 representative of the position of the piston 140 relative to the position sensor coil element 138.
Such smart cylinders may operate on several different physical principles. Examples of such smart cylinders include but are not limited to magneto-strictive sensing, magneto-resistive sensing, resistive (potentiometric) sensing, Hall effect sensing, sensing using linear variable differential transformers, and sensing using linear variable inductance transducers.
As schematically illustrated in
For example, extension signals from the extension sensors such as 84S will be received so that the controller can monitor the extension of the suspension actuators such as 84.
Similarly, the controller 202 will generate control signals for controlling the operation of the various actuators discussed above, which control signals are indicated schematically in
In
Controller 202 includes or may be associated with a processor 204, a computer readable medium 206, a data base 208 and an input/output module or control panel 210 having a display 212. An input/output device 214, such as a keyboard, joystick or other user interface, is provided so that the human operator may input instructions to the controller. It is understood that the controller 202 described herein may be a single controller having all of the described functionality, or it may include multiple controllers wherein the described functionality is distributed among the multiple controllers.
Various operations, steps or algorithms as described in connection with the controller 202 can be embodied directly in hardware, in a computer program product 216 such as a software module executed by the processor 204, or in a combination of the two. The computer program product 216 can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, or any other form of computer-readable medium 206 known in the art. An exemplary computer-readable medium 206 can be coupled to the processor 204 such that the processor can read information from, and write information to, the memory/storage medium. In the alternative, the medium can be integral to the processor. The processor and the medium can reside in an application specific integrated circuit (ASIC). The ASIC can reside in a user terminal. In the alternative, the processor and the medium can reside as discrete components in a user terminal.
The term “processor” as used herein may refer to at least general-purpose or specific-purpose processing devices and/or logic as may be understood by one of skill in the art, including but not limited to a microprocessor, a microcontroller, a state machine, and the like. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
Particularly the controller 202 may be programmed to receive extension signals from each of the extension sensors of the various hydraulic smart cylinders and to send control signals to control the extension of those hydraulic smart cylinders at least in part in response to the respective extension signals.
In one embodiment each of the suspension actuator extension sensors 84S, 86S, 88S and 90S may be configured to generate a suspension actuator extension signal corresponding to the amount of extension of the respective suspension actuator. And the controller 202 may be configured to receive the suspension actuator extension signals to send control signals to the respective suspension actuators, at least in part in response to the suspension actuator extension signals for the respective suspension actuators.
In a further embodiment the controller 202 may be configured to adjust the amount of extension of the forward suspension actuators 88 and 90 relative to the amount of extension of the rear suspension actuators 84 and 86 to adjust a front to rear slope of the bottom pan assembly 52. As will be understood by those skilled in the art the forward edge of the bottom pan assembly is typically held slightly higher that the rear edge so as to prevent the accumulation of a ridge of concrete material in front of the bottom pan assembly 52 as the bottom pan assembly slides forward over the surface 18 of the freshly formed concrete slab 16.
Another phenomenon which must be dealt with when operating a slip form paver 10 including a dowel bar inserter 40 is that of swelling of the concrete layer 16 behind the slip form paver mold 24 and ahead of the bottom pan assembly 52. In a further embodiment a swelling sensor 220 may be provided to detect such swelling. The swelling sensor 220 generates a swelling signal which is received by the controller 202. The controller 202, in response to the swelling signal, may send control signals to all of the suspension actuators 84, 86, 88 and 90 to raise the entire bottom pan assembly 52 and/or to adjust the front to rear slope of the bottom pan assembly 52 so as to accommodate the detected swelling. The control signals are at least in part in response to the signal from the swelling sensor 220.
In one embodiment if a relative small amount of swelling is detected the swelling may be accommodated by an adjustment of the front to rear slope of the bottom pan assembly 52, but if a relatively large amount of swelling is detected the swelling may be accommodated by raising the entire bottom pan assembly 52 in addition to possibly adjusting the front to rear slope of the bottom pan assembly 52.
In one embodiment schematically shown in
In another embodiment as seen in
Although only a single swelling sensor 220 is shown in the schematic illustrations, it will be understood that multiple swelling sensors 220 may be placed across the width of the slip form paver apparatus 10. The concrete swelling may not be uniform across the width of the concrete slab and thus it may be desirable to make variable adjustments in the deflection compensation actuators 92 across the width of the concrete slab. Also, it will be understood that in rare cases the “swelling” of the concrete slab may even be negative, that is the concrete slab may shrink, and that also can be accommodated by the systems described above.
A still further alternative type of swelling sensor 220 may be a pressure sensor 220P placed in the concrete near the bottom of the concrete mold 24 at its forward edge as schematically illustrated in
In another embodiment each of the deflection compensation actuators 92 may comprise a hydraulic smart cylinder 94 including an integral deflection compensation actuator extension sensor 92S configured to generate a deflection compensation actuator extension signal corresponding to the amount of extension of the respective deflection compensation actuator 92. The controller 202 may be configured to receive the deflection compensation actuator extension signals from the deflection compensation actuator extension sensors 92S, and to send control signals to hydraulic cylinders 94 of the respective deflection compensation actuators 92, at least in part in response to the deflection compensation actuator extension signals for the respective deflection compensation actuators 92.
In an embodiment the deflection compensation actuators 92 may be adjusted simultaneously with the suspension actuators 84, 86, 88 and 90 to assist in the adjustment of front to rear slope of the bottom pan assembly 52 and/or to assist in height adjustment of the bottom pan assembly 52. Such adjustments of the deflection compensation actuators 92 may be at least in part in response to the signals from the swelling sensor 220 similar to that described above for the suspension actuators.
In another embodiment the controller 202 may be configured to have a transport mode in which all of the suspension actuators 84, 86, 88 and 90 and all of the deflection compensation actuators 92 are retracted in unison to raise the bottom pan assembly 52 to a transport position in which the bottom pan assembly 52 is located a substantial distance 91 above either the ground surface or the paving slab 16 as necessary. Such a transport position is schematically illustrated in
Additionally at the end of a paving day the controller 202 may save the extension data for all of the suspension actuators 84, 86, 88 and 90 and for the deflection compensation actuators 92, thereby defining the vertical location of the bottom pan assembly 52 in engagement with the concrete slab 16. Then the bottom pan assembly may be raised above the slab 16 as in the transport mode. Then at the beginning of the next paving day the controller 202 may return the bottom pan assembly 52 to the exact same vertical position to resume paving. Similarly, any of the other actuators having associated extension sensors may be returned to their previous positions after any break in the paving operation.
In another embodiment each of the chain tensioning actuators 110 may have associated therewith a chain tensioning sensor 124. The controller 202 may be configured to receive a chain tensioning signal from the chain tensioning sensor 124 and to send a control signal to the chain tensioning actuator 110, at least in part in response to the chain tension signal. The human operator may input or set a desired chain tension to the controller 202 via the input 214 and the controller 202 may control the chain tension to that set point.
Thus, it is seen that the apparatus and methods of the present disclosure readily achieve the ends and advantages mentioned as well as those inherent therein. While certain preferred embodiments of the disclosure have been illustrated and described for present purposes, numerous changes in the arrangement and construction of parts and steps may be made by those skilled in the art, which changes are encompassed within the scope and spirit of the present disclosure as defined by the appended claims Each disclosed feature or embodiment may be combined with any of the other disclosed features or embodiments.