Quick-Attach System for Screed Plates

Description

TECHNICAL FIELD

The present disclosure generally relates to paving machines, and more particularly relates to systems for attaching screed plates to paving machines.

BACKGROUND

Paving machines are well known devices for laying asphalt to make roads, highways, parking lots and other surfaces needing a smooth, durable surface on which cars, trucks and other vehicles can travel. An asphalt paving machine typically includes a powered tractor or the like to which is attached a hopper for receiving hot asphalt. A conveyor carries material from the hopper to an auger which rotates to distribute the asphalt across the width of the machine as the paving machine moves forward.

In order to tamp down the asphalt and provide the asphalt with a uniform thickness and appearance, a screed plate is employed. Most specifically, a screed plate or plate are attached to a screed frame. The screed can be raised and lowered depending on the desired thickness of the roadway, the topography of the underlying ground, and other considerations. As the screed plate is the component which actively engages and smooths out the asphalt, it is subjected to significant wear and tear. Over time, the screed plates therefore need to be removed and replaced with new screed plates.

To remove and replace a screed plate, however, takes significant effort and time. Perhaps more importantly, any time the screed plate is being replaced is time that the paving machine is not in operation, thus detrimentally affecting performance, efficiency and profitability. Conventionally, such screed plates are attached to the screed frames by way of a series of bolts, washers and nuts which all need to be loosened and removed in order for the old screed plate to be removed. The new screed plate then needs to be installed in a reverse fashion. Moreover, given the environment in which such paving machines operate, those nuts and bolts are subject to sever degradation, rust and seizure.

U.S. Pat. No. 10,156,049 discloses one system for attaching a screed plate to a screed frame, but does so using retaining locks and fasteners in a manner similar to that mentioned above. It can therefore be seen that a need exists for a system to attach a screed plate to a screed frame in a more efficient manner so that it can be removed and replaced more easily and rapidly.

SUMMARY OF THE DISCLOSURE

In accordance with one aspect of the disclosure, a paving machine is disclosed which may include a frame, an engine mounted on the frame, a plurality of ground engaging members supporting the frame, a drive train operatively associated between the engine and the plurality of ground engaging members, a screed pivotably attached to the frame, and a screed plate attached to the screed frame, one of the screed frame and screed plate including a locking structure, the other of the screed frame and screed plate including a complementarily shaped cavity, the locking structure and cavity being locked together by friction.

In accordance with another aspect of the disclosure, method of attaching a screed plate to a screed frame of a paving machine is disclosed. The method may include providing a paving machine having a frame, an engine supported by the frame, a plurality of ground engaging members supporting the frame, and a drive train operatively connecting the engine and plurality of wheels, pivotably attaching a screed to the paving machine frame, and attaching a screed plate to the screed frame by frictionally engaging a locking structure provided on one of the screed frame and screed plate with a complementarily shaped cavity provided in the other of the screed frame and screed plate.

In accordance with another aspect of the disclosure, a quick-attach system for a screed plate of a paving machine is disclosed which may include a screed plate, a screed frame, a locking structure provided on one of the screed plate and the screed frame, and a cavity provided in the other of the screed plate and screed frame, the cavity being complementarily shaped to the locking structure such that the locking structure is adapted to nest within the cavity.

These and other aspects and features of the present disclosure will be better understood based on the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a paving machine constructed in accordance with the teachings of the present disclosure.

FIG. 2 is a side view of a paving machine in accordance with the teachings of the present disclosure.

FIG. 3 is a perspective view of a hopper of a paving machine showing an internal conveyor.

FIG. 4 is a schematic top view of the screed plate and screed frame with nested locking mechanism and cavity.

FIG. 5 is a schematic exploded view of FIG. 4.

FIG. 6 is a perspective view of a locking mechanism.

FIG. 7 is a perspective view of a cavity within a screed frame.

FIG. 8 is a perspective view of the locking mechanism of FIG. 6 nested within the cavity of FIG. 7.

FIG. 9 is a flowchart depicting a sample sequence of steps according to a method of the present disclosure.

While the depicted embodiments convey some exemplary approaches encompassing portions of the present invention, it is to be understood such embodiments are not exhaustive and can be extended to additional embodiments as would be understood by one of ordinary skill in the art.

DETAILED DESCRIPTION

Referring now to the drawings, and with specific reference to FIG. 1, a paving machine constructed in accordance with the present disclosure is generally referred to by reference numeral 10. While the following detailed description will be provided with specific reference to the paving machine 10, it is to be understood that the teachings of the present disclosure can be applied to any other work machine for conducting earth-moving, construction, or agricultural activities.

As shown in FIG. 1, the paving machine 10 includes a frame 12 which supports an engine or other prime mover 14. The frame is supported for movement by a plurality of ground engaging elements 16. As depicted, the plurality of ground engaging elements 16 are provided in the form of wheels 17, but the ground engaging elements 16 may be provided in the form of continuous tracks 18 as shown in FIG. 2 as well. Also supported by the frame 12 is an operator seat 20.

At a front end 22 of the paving machine 12 is provided a hopper 24. The hopper 24 includes an open top end 26 for receipt of hot paving material such as asphalt. The hot paving material may be deposited into the hopper 24 by a dump truck, wheel loader or the like (not shown). To deliver the hot paving material from the hopper 24 to the roadway 28, a conveyor 30 or other facilitating mechanism is mounted in a base 32 of the hopper 24 as shown best in FIG. 3. When the conveyor 30 is operated hot asphalt moves along the hopper and through a feeding slot 36 at the rear of the paving machine and is distributed to an auger 33, which rotates and spreads the asphalt evenly in front of a screed 25 as described in further detail below.

So as to produce a uniformly dense and properly dimensioned layer of pavement 40 for use as the needed roadway, parking lot, or the like, one or more screed plates 42 are mounted to a screed frame 38. Moreover, it will be noted that the screed 25 is adapted to be raised and lowered (as by hydraulic cylinder 39) relative to the roadway so as to so control the thickness of the pavement 40 laid down. While the screed plate 42 is described herein as a singular plate 42 it is to be understood that multiplate screed plates 42′ may be employed on a paving machine 10, depending on the desired width of the pavement being laid. It is common to provide three (3) screed plates with flanking plated 42′ on either side of main plate 42, but other numbers of plates are possible.

However, since the screed plate 42 is the component of the paving machine 10 is most contact with the pavement 40 as the paving machine 10 navigates forward (arrow 45) to continue to lay more pavement, the screed plate 42 is subjected to significant wear and tear. Over time, the screed plate 42 therefore degrades and eventually needs to be replaced. With conventional screed systems, this replacement was very labor intensive and time consuming. Perhaps even more important though was that given the time-consuming nature of conventional screed plate replacement, this meant that the paving machine 10 was out of service, not producing pavement, and thus not being profitable.

Conventionally, the screed plate 42 was attached to the screed frame 38 with a series of nuts, bolts, washers, and similar fasteners. Not only were suitable tools needed to remove these fasteners, but given the harsh environment in which the screed plate 42 operated, the fasteners themselves were subjected to significant degradation, rust, and seizure, thus adding to the time needed to remove same.

The present disclosure therefore greatly improves upon this prior approach. As shown in FIG. 4, it does so by providing a quick-attach system 44 for the screed plate 42 without the need for any convention nuts, bolts, or similar fasteners. Referring now to FIGS. 4-5, the screed plate 42 is shown removably attached to the screed frame 38. It is able to do so without any conventional fasteners through the use of its novel quick attach system 44. The quick attach system 44 includes a locking structure 46 and a complementarily shaped cavity 48. One of the locking structure 46 and cavity 48 is provided in the screed frame 38, and the other of the locking structure 46 and cavity 48 is provided in the screed plate 42. In the depicted embodiment, the locking structure 46 is provided in the screed plate 42, and the cavity 48 is provided in the screed frame 38, but it is to be understood that they can be provided in the opposite orientation as well.

As shown best in FIG. 5, the locking structure 46 may be provided in a wedge shape, with the cavity 48 being provided in a complementary shape so that the locking structure 46 may nest within the cavity 48. More specifically, it will be noted that the locking structure 46 has a first wall 50 and second wall 51 arranged in a V formation. First wall 50 and second wall 51 are connected by a forward wall 52 and a rearward wall 53 so that in total the locking structure 46 forms a trapezoidal shape. In addition, the locking structure 46 includes a first width 54 at a forward end 56, and a second width 58 at a rearward end 59, with the first width 54 being less than the second width 58.

Similarly, the cavity 48 includes a first recess 60 and a second recess 61 forming the V shaped cavity 48. The first recess 60 and second recess 61 may be connected by a third recess 62, with the space 64 opposite the third recess 62 being open. In addition, the cavity 48 includes a first width 65 at a forward end 66, and second width 68 at a rearward end 70, with the first width 65 being less than the second width 68.

While the locking structure 46 and complementarily shaped cavity 48 are described as wedge or V-shaped it is to be understood that other shapes are certainly possible such as trapezoidal, triangular, pentagonal, hexagonal, u-shaped, teardrop, dovetail and the like. As the locking structure 46 and complementarily shaped cavity 48 are held together by friction, shapes which increase the overall surface areas in frictional engagement are most desirable.

Referring now to FIGS. 6-8, the manner of nesting the locking structure 46 within the cavity 48 is depicted in sequence. More specifically, the locking structure 46 as described above is shown in FIG. 6, and the cavity 48 as described above is shown in FIG. 7 and provided within the screed frame 38. It is to be understood that for purposes of ease of illustration and understanding, the locking structure 46 is not shown in FIG. 6 as attached to the screed plate 42. The screed plate 42 is attached to the screed frame 38 by sliding the locking structure 46 into the cavity 48 as shown in FIG. 8.

By orienting the forward ends 56 and 66 in the direction of paving machine travel, the locking structure 46 moves into the cavity 48, with the locking structure forward end 56 nesting within the cavity forward end 66, and the locking structure rearward end 58 nesting within the cavity rearward end 70. To secure the components together, they may be tapped as by a hammer or the like. Further forward movement of the paving machine 10 causes sufficient frictional interference between the locking structure 46 and the cavity 48 to lock the screed plate 42 to the screed frame 38. No external fasteners are required, although a retaining pin, such as a cotter pin, may be employed if desired. Moreover, it will be noted in FIGS. 6-8, that the walls 50 and 51, as well as recesses 60 and 61 may be beveled or chamfered to facilitate retention.

When sufficient wear occurs such that the screed plate 42 needs to be replaced, the screed plate 42 can be removed from the screed frame 38 simply by providing sufficient force in the opposite direction, as by hammer or the like, to overcome the frictional interference. In so doing, the time for replacement of the screed plate 42, and down time for the paving machine 10 as a whole is reduced by an order of magnitude relative to the prior art.

INDUSTRIAL APPLICABILITY

From the foregoing, it can be seen that the technology disclosed herein has industrial applicability in a variety of settings such as, but not limited to paving machines, or any work machine having replaceable parts. More specifically, the present disclosure has industrial applicability in providing a system by which screed plates can be quickly attached and detached from a paving machine.

In operation, and in reference to FIG. 9, a method of attaching a screed plate 42 to a paving machine 10 is generally referred to by reference numeral 100. In a first step 102, the paving machine 10 is provided. The paving machine 10 may include the frame 12 to which is mounted the engine 14. The frame 12 may be supported by the plurality of ground engaging elements 16, with a drivetrain operatively connecting the engine 14 to the plurality of ground engaging elements 16.

In a second step 104, the screed frame 38 is pivotably attached to the paving machine frame 12. This provides a structure to which the screed plate or plates 42 can be removably attached.

In a third step 106, the screed plate 42 is attached to the screed frame 38 by frictionally engaging the locking structure on one of the screed frame 38 and screed plate 42 with the complementarily shaped cavity provided in the other of the screed frame 38 and screed plate 42. This may be done by aligning the complementarily shaped cavity 48 with the locking structure 46 and sliding the two components together such that the locking structure 46 nests with the cavity 48, and then using a hammer or similar tool to tap the components together.

While the foregoing descriptions and depictions capture some embodiments of the present disclosure, it is to be understood that the scope of the invention is not limited to such embodiments, but rather are captured by the following claims and their equivalents.