US20160102439A1

US20160102439A1 - Operator platform adjusting mechanism for machines

Info

Publication number: US20160102439A1
Application number: US14/972,109
Authority: US
Inventors: John E. Jorgensen; Gianluca Lombardi
Original assignee: Caterpillar Paving Products Inc
Current assignee: Caterpillar Paving Products Inc
Priority date: 2015-12-17
Filing date: 2015-12-17
Publication date: 2016-04-14

Abstract

A paving machine is disclosed that includes a tractor, a screed, and an operator platform. The screed is coupled to the tractor and is located behind the tractor. The operator platform is movably coupled to the tractor and has a first position and a second position. In the first position, the operator platform is located at least partially above the screed, and in the second position, the operator platform is located behind the screed.

Description

TECHNICAL FIELD

The present disclosure relates generally to operator platforms in paving machines. More specifically, the present disclosure relates to operator platforms that are switchable between a first position and a second position relative to paving machines.

BACKGROUND

Paving machines are commonly used to lay road forming materials such as asphalt, bitumen, or concrete, on roads, bridges, parking lots, and other similar construction sites. Commonly, paving machines include apparatuses such as screeds that are applied to smoothen and provide minor compaction to a laid quantity of road forming material, to form a mat. During operations, screeds may be extended, retracted, panned, and manipulated, in a generally two dimensional plane, so as to form a desired mat width. Asphalt paving machines also include operator platforms to allow operators to be stationed relative to the screeds and monitor a quality and pace of the paving operation. In typically small commercial pavers of capacity less than 7 tons, such platforms are generally positioned behind the screed, rearwardly to the direction of movement of the paving machine. As a result, in instances when the paving machine needs to pave-up to an obstacle, such as a wall, a railing, or a pavement, the operator platform is retracted to a home position and is temporarily stacked away until the screed is able to effectively pave a non-paved surface adjacent to the obstacle.
In conventional operational practice, a retraction of the operator platform operator is performed with the platform being manipulated from a generally horizontal plane to a generally vertical plane. As a result, operators stationed on the platform are inevitably required to vacate the platform, prior to the retraction process, and be posted outside the paving machine to monitor the paving operation. Such a practice may limit the operators to control one or more functions of the operator platform or of the screed owing to their posting outside. Such limitations arise since the control panels positioned locally on the paving machine become inaccessible to operators from the ground. Furthermore, such a practice is generally time consuming and involves unwarranted effort. Further, a frequent encounter with obstacles requires the operators to vacate the platform on an equivalent number of occasions, leading to increased lead time and a generally counter-productive work schedule.
Japanese Patent Publication JP H07156657 relates to a cab device for a cab seat of a construction machine such as an asphalt paver. The cab device allows the cab seat to be manipulated so as to keep the visibility of an operator of the construction machine relatively unaffected. However, the '657 reference does not provide a solution for operators stationed on operator platforms of asphalt pavers from mitigating repeated climbing and alighting (or vacating) procedures whenever, for example, there is a need for the paving machine to pave-up to an obstacle.
Accordingly, the system and method of the present disclosure solves one or more problems set forth above and other problems in the art.

SUMMARY OF THE INVENTION

Various aspects of the present disclosure illustrate a paving machine that has a tractor, a screed, and an operator platform. The screed is coupled to the tractor and located behind the tractor. The operator platform is movably coupled to the tractor. The operator platform includes a first position and a second position. In the first position, the operator platform is located at least partially above the screed. In the second position, the operator platform is located behind the screed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an exemplary paving machine incorporated with an operator platform that is positioned in an extended state relative to the paving machine, in accordance with the concepts of the present disclosure;

FIG. 2 is a perspective view of the paving machine of FIG. 1, with the operator platform being positioned in the extended position, in accordance with the concepts of the present disclosure; and

FIG. 3 is a perspective view of the paving machine of FIG. 1, with the operator platform being positioned in a retracted position relative to the paving machine, in accordance with the concepts of the present disclosure.

DETAILED DESCRIPTION

Referring to FIG. 1, there is shown an exemplary paving machine 10, which operates over a non-paved surface 12 and paves the non-paved surface 12. The paving machine 10 may be an asphalt paver. To perform the paving operation, the paving machine 10 includes a variety of components, such as an auger 14, an end gate 16, a screed 18, an operator platform 20, and a hopper assembly 22. Each of these components is suitably connected to a tractor frame 24 of the paving machine 10. The tractor frame 24 may be interchangeably referred to as a tractor 24. The paving machine 10 also provides relative compaction to a road forming material that is delivered to the non-paved surface 12. The road forming material may be one of asphalt, bitumen, or concrete, or a mixture of these, although other known materials may also be contemplated. A fully formed paved surface may be referred to as a mat 26. Further, a machine movement may be executed along a direction, A, as shown. Additionally, the paving machine 10 may include an operator cab portion 28, which in certain implementations forms the same region as has been defined by the operator platform 20, from where the paving machine 10 is controlled and operated. Wherever possible, same reference numbers may be used throughout the drawings to refer to the same or like parts.
The auger 14 is adapted to receive and lay the road forming material on the non-paved surface 12. The auger 14 may embody a screw conveyor, which may include a mechanism that uses a helically shaped screw blade known as flighting. A rotation of such a screw conveyor may dump the road forming material as a stockpile over the non-paved surface 12.
The screed 18 is connected with the tractor 24 and is controllable to evenly spread the dumped stockpile over the non-paved surface 12, depending on a desired width of the mat 20. The screed 18 may provide at least a minimal compaction to the underlying stockpile to form the mat 26. In that way, the screed 18 addresses a preliminary compaction requirement of the mat 26. A disposal of the stockpile may be such that a flattened, planer layer of the stockpile is substantially uniformly laid-out on the non-paved surface 12, as the paving machine 10 proceeds in the direction, A.
The end gate 16 may be fixedly engaged along the ends of the screed 18. As the screed 18 assists in the formation of the mat 26, the end gate 16 may restrict the unrequited spread of the stockpile beyond the specified limits, and may comply to form a desired mat width. The end gate 16 is generally attached to the screed 18 and moves with the screed 18 to prevent undesirable spillage of the road forming material over an adjacent, unpaved surface. Such movement of the end gate 16 with the screed 18 generally results in the formation of an edged margin between the mat 26 and an adjacent unpaved surface, along an expanse of the associated roadway.
Referring to FIG. 2, the paving machine 10 with the extended operator platform 20 is viewable from a perspective standpoint. The operator platform 20 is installed behind the tractor 24, adjacent to the screed 18, and rearward to the direction of motion A (FIG. 1) of the paving machine 10. The operator platform 20 functions as a walkway that enables an operator 30 (FIG. 3) to be stationed and observe a progress of the paving process. While being positioned on the operator platform 20, the operator 30 (FIG. 3) may also monitor various aspects of the mat 26, such as a leveling, surface finish and width of the mat 26. The operator platform 20 includes a proximal rail portion 32, a distal rail portion 34, a walkway portion 36, a four-bar linkage assembly 38, and an actuator 40.
The walkway portion 36 is a generally steel base structure, which is a flattened member that is substantially horizontally laid out to effectuate operator stationing. The walkway portion 36 may be manufactured from a sheet metal characterized with a sufficient quantity of bends, corners, and stiffeners, to attain a relatively robust structure that is able to withstand the weight of the operator 30 (FIG. 3). While being robust, the operator platform 20 is also considerably lightweight so as to be relatively easily and effortlessly manipulated to either of an extended or a retracted position (discussed later) relative to the paving machine 10. The walkway portion 36 may be integrally formed with the proximal rail portion 32 and the distal rail portion 34. However, it is also contemplated that the walkway portion 36 is formed separately relative to the proximal rail portion 32 and the distal rail portion 34, and assembled through conventional methods of fastening and welding.
The proximal rail portion 32 and the distal rail portion 34 portion are two fence (or rail) portions structured and arranged on the operator platform 20. It should be noted that the terms “proximal” and “distal,” as used herein, are intended to respectively refer to positions of a device, component, or a feature, for example, relative to the paving machine 10. The proximal rail portion 32 corresponds to the rail portion among the two fence (or rail) portions of the operator platform 20 that is closer to the paving machine 10. Conversely, the fence (or rail) portion being relatively farther away from the paving machine 10 is referred to as the distal rail portion 34. Collectively, the proximal rail portion 32 and the distal rail portion 34 may be referred to as rail portions 32 and 34.
Generally, a disposal of the rail portions 32 and 34 are in manner such that the proximal rail portion 32 is substantially closer to the paving machine 10, as noted supra. Further, the proximal rail portion 32 is substantially laterally disposed relative to a length, L, of the paving machine 10 (FIG. 1). Similarly, the distal rail portion 34 is disposed substantially laterally relative to the length, L, of the paving machine 10, but further away from the paving machine 10, than the proximal rail portion 32. The disposal of the distal rail portion 34 is nearly parallel to the proximal rail portion 32, with the walkway portion 36 being defined between the proximal rail portion 32 and the distal rail portion 34. When viewed from the side, as shown in FIG. 1, the operator platform 20 conforms to an almost U-shaped profile, which allows operators and personnel to be positioned within the space formed by the rail portions 32 and 34 and the walkway portion 36. As shown, similar rail portions are absent on either sides (or the laterally opposite sides) of the operator platform, relative to a length, L, of the paving machine 10. Therefore, a generally easy ingress and egress for the operator 30 (FIG. 3) is assumed.
Referring to FIGS. 2 and 3, the four-bar linkage assembly 38 forms a connection interface between the paving machine 10 and the operator platform 20. The four-bar linkage assembly 38 includes a first four-bar linkage 42 and a second four-bar linkage 44, with each of the first four-bar linkage 42 and the second four-bar linkage 44 respectively forming individual connection interface portions between the operator platform 20 and the either sides (laterally opposed sides) of the paving machine 10, as shown. A forthcoming description will be focused towards the first four-bar linkage 42 alone. However, it is understood that a description for the first four-bar linkage 42 is equivalently applicable for the second four-bar linkage 44, as well.
The first four-bar linkage 42 includes a first shaft member 46 and a second shaft member 48. The first shaft member 46 is a generally elongated structural member, which is substantially rigid in construction. The first shaft member 46 is pivotally connected with a portion of the tractor 24 of the paving machine 10 at a first end 50 of the first shaft member 46. At an opposed second end 52 of the first shaft member 46, the first shaft member 46 is pivotally connected with the proximal rail portion 32.
The second shaft member 48 assumes a position below the first shaft member 46, in a substantially parallel fashion relative to the first shaft member 46, as shown. As with the first end 50 and the second end 52 of the first shaft member 46, the second shaft member 48 includes a machine end 54 and a platform end 56. The machine end 54 corresponds alongside the first end 50 of the first shaft member 46, while the platform end 56 corresponds alongside the second end 52 of the first shaft member 46. The second shaft member 48 is also pivotally connected to the tractor 24 at the machine end 54, while at the platform end 56 the second shaft member 48 is pivotally connected to the proximal rail portion 32, as well.
Effectively, each of the first shaft member 46 and the second shaft member 48 are pivotally connected to the tractor 24, while also being pivotally connected to the proximal rail portion 32. As a result, a parallelogram-linkage is formed between the operator platform 20 and the tractor 24. Which enables the first four-bar linkage 42 to movably engage the operator platform 20 with the tractor 24. Therefore, a restricted rotatable manipulation is possible between the tractor 24 of the paving machine 10 and the operator platform 20. This rotatable manipulation allows the operator platform 20 to be positioned relative to the paving machine 10 in at least one of a first position and a second position. The first position of the operator platform 20 corresponds to the deployment of the operator platform 20 relatively and at least partially above the screed 18 (FIG. 3), along an elevation (or height) of the paving machine 10. In the second position, the operator platform 20 is located behind the screed 18 or the tractor 24 (FIG. 2), when viewed along the length, L, of the paving machine 10. In effect, the first position corresponds to a retracted position of the operator platform 20, while the second position corresponds to an extended position of the operator platform 20 relative to the paving machine 10.
As may be seen by way of the above description, the first four-bar linkage 42 includes a fixed ground link, which is the tractor 24. Since the first shaft member 46 and the second shaft member 48 are pivotally connected to the tractor 24, the first shaft member 46 and the second shaft member 48 are grounded links. Lastly, the proximal rail portion 32 is a floating link, which is abled for manipulation in relation to the tractor 24. An exemplary manipulation of the first four-bar linkage 42, with pivotal connections at each of the first end 50, the second end 52, the machine end 54, and the platform end 56, is envisioned to be executed substantially planarly.
The actuator 40 is adapted to power the movement of the operator platform 20 from the first position to the second position. The actuator 40 is a linear actuator, which is incorporated into the first four-bar linkage 42. The actuator 40 has a first actuator end 58 and a second actuator end 60. The first actuator end 58 is connected to the machine end 54 of the second shaft member 48, while the second actuator end 60 is connected substantially midway to the first shaft member 46. Although the point of connection described above, it is envisioned that the first actuator end 58 may be connectable to other portions of the tractor 24 or frame of the paving machine 10. In addition, it is possible that the connection of the second actuator end 60 is away from the midway point of the first shaft member 46. For example, the second actuator end 60 may he connected to either of the second end 52 or the platform end 56 respectively of the first shaft member 46 and the second shaft member 48. As the actuator 40 is linearly manipulable, a retraction and an extension of the actuator 40 is possible. In turn, such a provision facilitates the possibility to tiltably or rotatably lift the first shaft member 46 generally arcuately (see arrow, B, in FIG. 3) along a height of the paving machine 10, with the first actuator end 58 forming a rigid reference point from where an associated upward component of force is applicable.
In an embodiment, the actuator 40 is a screw actuator operable by electrical activation. However, other actuator types may be contemplated, such as those that are hydraulically or pneumatically activated. Controls for the activation and deactivation of the actuator 40 may be provided within or adjacent to the operator cab portion 28 (or the operator platform 20), which remains accessible to an operator stationed on the paving machine 10.
Further, the second four-bar linkage 44 assumes a similar role, form, and function, as has been described for the first four-bar linkage 42. Accordingly, it may he assumed that the second four-bar linkage 44 is abled to move planarly as well. This movement is also envisioned along a height of the paving machine 10. As a result, the first four-bar linkage 42 and the second four-bar linkage 44 is manipulable along parallel planes. However, configuration where a manipulation is affected along non-parallel planes may be contemplated as well. Additionally, as with the connection, form, and function, of the actuator 40 with the first four-bar linkage 42, an auxiliary actuator (not shown) is assembled and incorporated with the second four-bar linkage 44, as well.

INDUSTRIAL APPLICABILITY

During road laying operations, it is typically desired to accomplish the mat 26 that is characterized by an end-to-end smoothened, planar surface. However, this is a challenge as a starting point, an end point, or any intermediate point, along an expanse of the associated non-paved roadway is typically beset with the presence of one or more obstacles.
During operations, the operator 30 within the operator cab portion 28 (if present) or from the operator platform 20 may initiate a paving operation from or adjacent an obstacle. As it requires to appropriately lay and provide initial compaction and smoothening to the delivered stockpile, the operator 30 activates the actuator 40 and effectuates a retraction of the operator platform 20 from a supposed default extended position, as shown in FIG. 2, to a retracted position. To this end, the actuator 40 is linearly manipulated and extended upwards along the direction indicated by the arrow, B (FIG. 3). Simultaneously, the four- bar linkages 42 and 44 are manipulated along parallel planes. The operator 30 may continue with the upward extension of the actuator 40 until the operator platform 20 has reached a position where an outermost rearward point on the operator platform 20 is at least in line with an outermost point on the screed 18. In that way, protruded portions beyond the screed 18 are drawn back and the screed 18 is rendered free to pave-up to an obstacle.
With the four- bar linkages 42 and 44 in place, it is possible for the walkway portion 36 to remain horizontally aligned even when the operator platform 20 is moved to the retracted position (first position) from the extended position (second position). As a result, the operator 30 (FIG. 3) positioned on the operator platform 20 may avoid frequent alighting from the paving machine 10. Moreover, it is possible that a switch between the extended position and the retracted position is executed even during a movement of the paving machine 10, such as when there is an early detection of an obstacle ahead, during an on-going paving process. Such a provision mitigates the consumption of time, which is conventionally wasted on frequent operator movement relative to the paving machine 10. Depending upon need, the operator platform 20 may be positioned infinitely or in multiple positions in-between a fully retracted position (first position) and a fully extended position (second position), as well.
Advantageously, the retracted position of the operator platform 20 is suited to comply with other situations as well. For example, during shipping or local transportation, it may be desirable to have the operator platform 20 in the retracted position and conformed to enclosure requirements of an associated mode of transportation. Further, as the retracted position of the operator platform 20 also corresponds to an elevated walkway portion 36, it is contemplated that the operator 30 (FIG. 3) stationed on the operator platform 20 may tap into a line of sight acquirable in this position, thus freeing the way to view the contents (road forming materials) of the hopper assembly 22, even while the paving machine 10 is in motion and in operation.
It should be understood that the above description is intended for illustrative purposes only and is not intended to limit the scope of the present disclosure in any way. Thus, one skilled in the art will appreciate that other aspects of the disclosure may be obtained from a study of the drawings, the disclosure, and the appended claim.

Claims

What is claimed is:

1. A paving machine comprising:

a tractor,

a screed coupled to the tractor and located behind the tractor; and

an operator platform movably coupled to the tractor and having a first position and a second position;

wherein in the first position, the operator platform is located at least partially above the screed, and in the second position, the operator platform is located behind the screed.

2. The paving machine of claim 1, further comprising a four-bar linkage that movably couples the operator platform to the tractor.

3. The paving machine of claim 2, further comprising an actuator to move the operator platform between the first position and the second position.