Patent Application
20080083431
Turning now to the drawing figures,
The fan 14 is powered by the motor 16. An intake 30 of the fan 14 pulls air from the hopper 22, pushes the air through a hood entry and passes the air through the hood 18 back through the return 28 into the hopper 22. Within the hopper 22, a filter filters the air prior to passing the air through the intake. In this manner, the air that enters the fan 14 is filtered from small debris which may have been picked up through the air if the intake was vented to atmosphere. The motor 16 is configured to power the re-circulating air sweeper system, but is not responsible for propulsion of the sweeper 10. However, fluid reservoirs meant to supply both the motor 16 and the engine of the sweeper 10 may be shared between these two components.
Turning now to
The central mating section 34 attaches the left and right sections 30 and 32 to each other through the central mating section 34. The central mating section 34 allows for each side section 30 and 32 to be removed individually from the hood 18. In a single piece hood, the entire hood would need to be removed to repair any damage to a section.
The central mating section 34 is configured to overlay portions of the side sections 30 and 32. The central mating section 34 and the side sections 30 and 32 are connected so that the hood 18 is structurally stiff. However, the connectors 50 between the central mating section 34 and the side sections 30 and 32 may be configured to shear so that forces exerted on the side sections 30 and 32 do not damage the side sections 30 and 32, instead damaging a simple connector. The sections, then, are relatively flexible to direct impacts while maintaining stiffness in normal operating conditions.
If a side section 30 or 32 is damaged, then repair may be achieved quicker and more cost effectively by having to only replace a single side portion 30 or 32. Access to a single side portion 30 or 32 is less labor intensive than fully removing the entire hood. In addition, replacing only a single side section 30 or 32 does not require removing additional connections between the hood 18 and the sweeper. Moreover, the lower costs associated with shipping smaller parts at less weight also reduce the total cost of maintenance.
The front flap 36 of the hood 18 extends over the elongated top surface 40 of the left and right portions 30 and 32 and the central mating section 34 and extends perpendicularly downward as deep as the end skirt 42. An outer edge 50 of the front flap 36 abuts the end skirt 42. The end skirt 42 and the front flap 36 are the lower extension of the hood 18. Together with a back flap (discussed with reference to
The plenum is ideally a constant volume chamber. When the end skirts 42 abut the ground, the volume of the plenum is approximately the product of the length and width of the elongated top surfaces 40 and the depth of the end skirts 42. A constant volume chamber allows for a constant airflow through the plenum. As air enters the plenum from the fan 14, an equal amount of air exits the plenum through the flexible hose 28. At each cross section parallel to the end skirt 42 through the plenum, an equal amount of air travels. If the cross section parallel to the end skirt 42 is reduced in size, then in order to move the same amount of air that enters through the fan requires an increased velocity of the air as it flows through the plenum. Bernoulli's principle requires that as the air moves faster, the pressure drops. A drop in pressure limits the size and weight of the debris removed from the paved surface.
The front flap 36 and the end skirts 42 also must abut the paved surface so that air does not flow out from under the hood 18. The front flap 36 and the end skirts 42 direct flow of air from the fan to the flexible hose 28. If the front flap does not reach the pavement, then air may escape under the hood 18 over the paved surface. Escaping air may push debris away from the hood 18 and also limits the ability of the air to push the debris under the hood 18 through the flexible hose 28.
The front flap 36 is flexible such that debris that hits the front flap 36 lifts the flap 36 so that the debris may enter the plenum for collection. However, as the front flap 36 hits the pavement, wear removes parts of the front flap 36 so that the flap does not touch the pavement. The front flap 36 is configured so that the flap may be lowered relative to the hood 18. Slotted connectors 60 attach the front flap 36 to the hood 18. The slotted connectors 60 are received through a slot (as shown in
Similar to the front flap 36, the purpose of the rear cartridge flap 64 is to maintain the depth of the hood 18 and maintain contact between the hood 18 and the pavement. As the rear cartridge flap 64 is worn away from contact with the pavement, the rear connectors 70 may be advanced so that the bottom edge of the rear cartridge flap 64 may maintain contact with the pavement without having to drop the hood 18 downward.
The cartridge flap 64 includes a rigid member to attach to the rear connectors 70. The rigid member is formed from an upper U-shaped member 66 and a downward projecting straight support member 68. The upper U-shaped member 66 is inverted such that the horizontal part of the U-shaped member may receive the rear connectors 70. The U-shaped member 66 is rigidly attached to the straight member 68. The straight member 68 extends downward to shorten the distance to the flexible portion of the flap. In the rear of the hood, it may be beneficial to have a slightly stiffer flap than in the front of the hood. While debris is meant to push under the front flap, the debris is not meant to roll out from underneath the hood at the rear.
The interior flap 76 is located behind the front flap 36. The interior flap 76 acts as a check valve for the plenum. As debris passes the front flap 36, the circulating air under the hood may not escape because the air flows between the interior flap 76 and the rear cartridge flap 64. As the debris passes the front flap 36, the interior flap 76 maintains contact with the pavement. Once the debris passes the front flap 36, then the front flap 36 falls back into contact with the pavement. As the debris passes the interior flap 76, the front flap 36 maintains contact with the pavement and the plenum under the hood 18.
The slots 80 in the flap 36 also allows for more of the flap 36 to be used prior to removing the flap 36. The flap 36 may be lowered a distance equal to the length of the slot 80. Thus, the edge 82 of the flap 36 may be worn away for a distance equal to the length of the slot 80. This reduces the environmental impact of the wasted portion of the front flap 36.
Increasing the total length of the flap 36 may also increase the life of the front flap 36. As debris contacts the front flap, the additional rubber that is flexed over the upper surface of the hood may absorb some of the impact from the debris. Thus, more of the flap 36 may be used and the wear of the flap 36 may be reduced.
As the cartridge flap 64 is lowered, the rubber member 88 maintains contact with the pavement. The use of the cartridge 86 allows for minimal rubber use in the rubber member 88. Because the cartridge 86 (and thus the rubber member 88) may be lowered to the depth of the rear connectors 70, the waste rubber in the rubber member 88 is minimized.
The cartridge 86 is coupled to the rubber member 88 through a plurality of connectors 89 located along the length of the cartridge flap 86 and the rubber member 88. In another embodiment, the cartridge 86 may slidably receive the rubber member 88 laterally, for example through a dove tail joint between the cartridge 86 and the rubber member 88. The rubber member 88, then, would be supported in the hood by the cartridge 86 and held in place laterally by the end skirts of the hood. In another embodiment, the rubber member 88 may be attached to the cartridge 86 by a compression member exerting a force to squeeze the rubber member 88 to the cartridge 86. The compression member is configured to fixedly attach the rubber member 88 to the cartridge 86. Because the rear flap 64 may be more rigid than a front flap, the length of the cartridge may be elongated to increase stiffness. Increased stiffness may come at the expense of more frequent replacement, as the rubber member 88 is likely to wear faster and the amount the flap may be lowered is limited to the depth of the rubber member 88.
Turning now to
The connecting arms are also pinned to the sweeper. The connecting arms are shaped such that forces that lift and drop the hood 18 are appropriately transmitted through the connecting arms. The connecting arms are also formed to deform when forces are exerted on the hood 18 that attempt to rotate the hood 18 over the pavement. The connecting arms, then, are the portion of the sweeper that is most deformable to impacts from debris to the hood 18. This allows a simple connecting arm, instead of the hood portions, to be replaced.
The hood 18 is also connected to the sweeper through a piston 96. The piston 96 attaches to two pulleys 98 through guide wires 100. Mounting brackets 102 attach the pulleys to the sweeper. The guide wires 100 are attached to the hood 18 through a pair of eye bolts 110. The piston 96 is configured to quickly lift the hood off the pavement. The controls for the piston 96 are located within the cab of the sweeper so that the operator may lift and lower the hood from within the cab while operating the sweeper. By popping the hood up, the operator may be able to clear larger, lighter debris that is unable to be swept under the front flap 36 of the hood 18. Lighter, larger debris may not be pushed under the hood 18 like most debris because the larger debris requires more force to be pushed under the hood 18. When the debris is not pushed under the hood, the debris may build up in front of the hood 18. A build up in front of the hood limits the effectiveness of the sweeper in sweeping debris.
When the operator engages the piston, the piston length shortens and the hood 18 is raised. The operator may keep the hood 18 raised as the operator drives over the debris so that the debris is swept under the hood 18. When the hood 18 is simply kicked up, then the debris is funneled between the interior flap and back flap of the hood 18 and may be removed from the paved surface into the hopper. This saves time and labor where an operator previously would be required to push debris from the front of the hood 18 after stopping the sweeper and laboring in front of the hood 18 to remove the debris.
While the piston 96 has been attached to the hood 18 through guide wires, it may be possible to directly couple the piston 96 to the hood 18. Moreover, it may be possible to provide the same effect through other means besides a piston. For example, a four bar linkage, a motor, or a screw drive may raise the hood 18 in order to clear debris from the front of the hood 18.
As will be apparent to one skilled in the art, various modifications can be made within the scope of the aforesaid description. Such modifications being within the ability of one skilled in the art form a part of the present invention and are embraced by the claims below.
