US RE38973 E1
A sweeper includes a support structure having parallel arms which may be moved apart to allow a brush held between the arms to be replaced. Each of the arms has a hub mounted thereon by a universal joint which provides automatic alignment of the two hubs to provide a single axis of rotation for the brush. One of the hubs is connected to a hydraulic drive motor and includes a plurality of slots, one of which receives a drive lug on the interior of the brush which is preferably of the type having a core of a thin metal tube. A raising and lowering mechanism comprises a parallelogram having a hydraulic cylinder in the center for controlling the configuration of the parallelogram. As the brush is raised its support mechanism remains parallel to the vehicle and moves closer to it. A unique stop element is mounted to the hydraulic cylinder to provide a minimum height for the sweeper.
1. Sweeping apparatus comprising support means for supporting a brush for rotation about a generally horizontal axis and means for mounting said support means on a vehicle, wherein said support means comprises first and second arms, means for moving said first second arm with respect to said second first arm between a first position wherein said first second arm is spaced from said second first arm by a distance such that said brush is received between said arms and a second position wherein said first second arm is spaced from said second first arm such that said brush is released from between said arms, drive means mounted on said first arm by universal joint means for engaging one end of said brush and for rotating said brush about an axis extending between said first and second arms, and idler means mounted on said second arm by universal joint means for engaging an opposite end of said brush.
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This invention relates to the art of sweepers. In particular, the invention relates to sweepers used for large areas, such streets and which use replaceable brushes.
Street sweepers of the type having an elongate, essentially cylindrical brush which rotates about a horizontal axis are known. These sweepers are useful for cleaning large areas, such as parking lots or streets, and are typically mounted on the front of a vehicle to be pushed ahead of it. The brush is driven such that the bristles move away from the vehicle as they engage the surface being swept.
As the bristles become worn, it is necessary to replace the brush by removing it from a support structure and installing a new brush. In some prior art sweepers, it is necessary that drive or idler brackets be disassembled to permit the brush to be removed. This is difficult and requires a substantial amount of time.
The sweeper shown in U.S. Pat. No. 3,284,830 (Kroll) has a drive hub mounted to a door which forms the side of a compartment which supports the brush. When the door is opened, the brush may be removed from the compartment and a new brush installed.
Other U.S. Pat. Nos. showing sweepers of interest are: 3,310,825 (Tamny); 3,276,109 (Mortensen); 3,812,551 (Mortensen); and 3,879,786 (Larkin).
The prior art sweepers do not facilitate the installation of new brushes and generally do not permit the use of brushes having a core formed of a thin metal tube. For example, the sweeper shown in the Kroll patent uses a brush comprising a thick tube with tufts in rows running from one end of the tube to the other. Spaces between the strips of bristles have drive slots for receiving lugs on a drive hub. Because the Kroll sweeper has no arrangement providing for exact alignment of the drive and idler hubs, use of a brush having a thin walled metal core is not possible.
In accordance with the invention, a sweeper includes a support structure which is generally U-shaped when the brush is held in an operative position. The ends of the arms of the support structure have idler and drive structures, respectively, for receiving opposite ends of the brush. One arm of the support structure is pivotally mounted to permit removal of the idler end from the brush and to allow the brush to be disengaged from the opposite, drive end. A new brush may then be inserted easily and the pivotal arm rotated to a position parallel to the other arm to engage the broom.
The idler and drive hubs are mounted to the arms by universal joints, thus providing for automatic alignment of the idler and drive hubs to provide a single axis of rotation for the brush. This permits the use of a brush having a thin metal tube without the necessity of providing a solid shaft passing through the center of the tube and connecting the drive and idler ends.
A drive lug is welded to the interior of the metal tube and engages a slot in the drive hub. Preferably, the drive hub has a plurality of slots whereby a subsequent slot may the used when the first slot has become worn. This increases the life of a drive hub.
The pivotal arm is preferably controlled by a hydraulic cylinder, and the cylinder may have a safety strap secured across its ends when the pivotal arm is in the operational position to prevent accidental rotation of the arm.
A raising and lowering mechanism is connected between the support structure and the vehicle. This mechanism is preferably a parallelogram comprised of a mounting bracket on the vehicle, a mounting bracket on the support structure, and upper and lower parallel arms. A hydraulic cylinder is located within the parallelogram for raising or lowering the brush. A stop mechanism is arranged parallel to the hydraulic cylinder to adjust the lowermost position of the brush.
An object of this invention is to provide a sweeper wherein removal or installation of a brush are facilitated.
Another object of this invention is to provide a sweeper having a raising and lowering mechanism which maintains a brush mechanism parallel and closer to the vehicle as it is raised.
With reference to
A plurality of slots 30 is provided such that the drive lug 28 may be engaged in another of the slots when a first slot becomes worn. Thus, the drive hub need be replaced only after all of the slots are worn, and the lifetime of the drive hub is increased. The drive end preferably includes a removable bumper (not shown) which attaches to part 6 and extends over the motor to protect it.
The opposite end of the metal tube 26 receives an idler hub 34 which is attached to arm 8 by a universal joint which will be described in more detail with respect to FIG. 4. With reference to
The dimensions of the hub, the universal joint, and the arm are preferably such that the hub 34 is aligned with the axis of rotation of the brush throughout the pivotal movement of arm 8. When arm 8 is pivoted inwardly, after installation of a new brush, hub 34 engages tube 26 and automatically aligns itself with the axis of rotation of the brush such that it may be easily slid into the tube. Hub 34 is shown in
With reference to
The parallelogram arrangement 18 is shown more clearly in
The parallelogram arrangement for raising and lowering the brush is particularly useful with the sweeper of the invention. As the cylinder is lengthened, the brush and its associated support parts 6 and 8 remain parallel to the ground and move closer to the vehicle as they move upward. This allows the vehicle to be driven up ramps (not shown) leading to a trailer (not shown) without bumping the brush against the ramps. Known sweepers simply pivotally mount a brush mechanism to the front of the vehicle resulting in an orientation wherein the brush ordinarily bumps into the ramps when being driven onto the trailer ramps.
With reference to
a mounted on the first part of the support structure. Drive lug 28 engages a slot 30 such that activation of drive motor 56 to rotate drive hub 32 drives the brush accordingly.
The provision of universal joints 46 and 52 causes drive hub 32 and idler hub 34 to automatically align to provide a common axis of rotation for the brush.
With reference to
As shown in
Modifications of the invention within the scope of the appended claims will be apparent to those skilled in the art.