Pickup truck mounted sweeper - Patent Review 4660248

Claims

What is claimed is:

1. A sweeper for roads, parking lots or like surfaces which is particularly adapted to be mounted upon a bed of a mobile vehicle comprising means for defining a hopper into which debris is adapted to be discharged, said hopper having spaced front and rear walls and a pair of spaced side walls each having upper and lower side wall portions, a fore-aft axis disposed generally in transverse relationship to said front and rear walls to thereby coincide with the direction of travel of said associated mobile vehicle, a pick-up head, means for supporting said pick-up head from said associated mobile vehicle in transverse relationship to the fore-aft axis of said hopper, said hopper and pick-up head each including an inlet and an outlet, first conduit means between said pick-up head outlet and said hopper inlet for conducting air-entrained debris from said pick-up head into said hopper, second conduit means between said hopper outlet and said pick-up head inlet for conducting air from said hopper to said pick-up head, means for generating a continuous recirculating stream of air along a closed path of travel including successively said pick-up head, said pick-up head outlet, said first conduit means, said hopper inlet, said hopper, said hopper outlet, said second conduit means, and said pick-up head inlet, means for centrifugally removing debris from the air stream during the travel thereof between said hopper inlet and said hopper outlet about an axis disposed generally parallel to said hopper fore-aft axis, said hopper including a longitudinal center line between said side walls and generally parallel to said fore-aft axis, said centrifugal removing means being disposed adjacent one of said side walls and remote from the other of said side walls, the axis of said centrifugal removing means being in transversely spaced relationship to said hopper longitudinal center line, said hopper inlet and hopper outlet being on opposite sides of said hopper longitudinal centerline adjacent respective ones of said side walls, and said inlet being on the side of said centerline opposite said centrifugal removing means to enhance separation from the airstream of larger particles of debris.

2. The sweeper as defined in claim 1 including means between said hopper inlet and said centrifugal removing means for separating debris from the air stream.

3. The sweeper as defined in claim 2 wherein said air stream generating means includes a rotating blade, and said rotating blade has an axis which is generally coincident to an axis of said centrifugal removing means.

4. The sweeper as defined in claim 2 wherein said centrifugal removing means includes a generally cylindrical wall defining a centrifugal chamber, an air inlet in said cylindrical wall through which the air stream enters from the hopper, an air outlet for conducting the air stream from said centrifugal chamber to said air stream generating means, and a debris outlet in said cylindrical wall through which debris centrifugally removed from the air stream enters into said hopper.

5. The sweeper as defined in claim 1 wherein said air stream generating means includes a rotating blade.

6. The sweeper as defined in claim 1 wherein said air stream generating means at least in part defined by a rotating blade.

7. The sweeper as defined in claim 6 wherein said centrifugal removing means includes a generally cylindrical wall defining a centrifugal chamber, an air inlet in said cylindrical wall through which the air stream enters from the hopper, an air outlet for conducting the air stream from said centrifugal chamber to said air stream generating means, and a debris outlet in said cylindrical wall through which debris centrifugally removed from the air stream enters into said hopper.

8. The sweeper as defined in claim 6 including means between said hopper inlet and said centrifugal removing means for separating debris from the air stream, and means for allowing removal of said separating means at least partially from said hopper.

9. The sweeper as defined in claim 6 including screen means between said hopper inlet and said centrifugal removing means and in the path of said air stream for separating debris therefrom prior to the air entering said centrifugal removing means.

10. The sweeper as defined in claim 6 including screen means between said hopper inlet and said centrifugal removing means and in the path of said air stream for separating debris therefrom prior to the air entering said centrifugal removing means, and means for removing said screen means at least partially from said hopper.

11. The sweeper as defined in claim 1 wherein said air stream generating means includes a rotating blade, and said rotating blade has an axis which is generally coincident to said axis of said centrifugal removing means.

12. The sweeper as defined in claim 11 wherein said centrifugal removing means includes a generally cylindrical wall defining a centrifugal chamber, an air inlet in said cylindrical wall through which the air stream enters from the hopper, an air outlet for conducting the air stream from said centrifugal chamber to said air stream generating means, and a debris outlet in said cylindrical wall through which debris centrifugally removed from the air stream enters into said hopper.

13. The sweeper as defined in claim 11 including means between said hopper inlet and said centrifugal removing means for separating debris from the air stream, and means for allowing removal of said separating means at least partially from said hopper.

14. The sweeper as defined in claim 11 including screen means between said hopper inlet and said centrifugal removing means and in the path of said air stream for separating debris therefrom prior to the air entering said centrifugal removing means.

15. The sweeper as defined in claim 11 including screen means between said hopper inlet and said centrifugal removing means and in the path of said air stream for separating debris therefrom prior to the air entering said centrifugal removing means, and means for allowing removal of said screen means at least partially from said hopper.

16. The sweeper as defined in claim 1 wherein said hopper inlet and outlet have parallel axes.

17. The sweeper as defined in claim 1 including means for moving said pick-up head between upper inoperative and lower operative positions, and means for stabilizing said pick-up head in said upper inoperative position.

18. The sweeper as defined in claim 1 wherein said hopper includes top and bottom walls; and said rear wall includes a pair of doors.

19. The sweeper as defined in claim 1 wherein said hopper includes top and bottom walls; said rear wall includes a pair of doors, and means for pivoting at least one of said doors about a generally vertical axis.

20. The sweeper as defined in claim 1 including an internal combustion engine having an output drive shaft, means for connecting said output drive shaft to said air stream generating means, means for throttling said internal combustion engine, and means adjacent said throttling means for moving said pick-up head between upper inoperative and lower operative positions.

21. A sweeper for roads, parking lots or like surfaces which is particularly adapted to be mounted upon a bed of a mobile vehicle comprising means for defining a hopper into which debris is adapted to be discharged, said hopper having a fore-aft axis to coincide to the direction of travel of said associated mobile vehicle, a pick-up head, means for supporting said pick-up head from said associated mobile vehicle in transverse relationship to the fore-aft axis of said hopper, said hopper and pick-up head each including an inlet and an outlet, first conduit means between said pick-up head outlet and said hopper inlet for conducting air-entrained debris from said pick-up head into said hopper, second conduit means between said hopper outlet and said pick-up head inlet for conducting air from said hopper to said pick-up head, means for generating a continuous recirculating stream of air along a closed path of travel including successively said pick-up head, said pick-up head outlet, said first conduit means, said hopper inlet, said hopper, said hopper outlet, said second conduit means, and said pick-up head inlet, means for centrifugally removing debris from the air stream during the travel thereof between said hopper inlet and said hopper outlet about an axis disposed generally parallel to said hopper fore-aft axis, said hopper being defined at least in part by a pair of side walls having upper and lower side wall portions, said lower side wall portions being in generally upstanding relationship, one of said upper side wall portions being of a curved configuration and projecting laterally beyond its associated lower side wall portion, and said centrifugal removing means being at least in part defined by said curved upper side wall portion.

22. The sweeper as defined in claim 1 wherein said centrifugal removing means includes a generally cylindrical wall defining a centrifugal chamber, an air inlet in said cylindrical wall through which the air stream enters from the hopper, an air outlet for conducting the air stream from said centrifugal chamber to said air stream generating means, and a debris outlet in said cylindrical wall through which debris centrifugally removed from the air stream enters into said hopper.

23. The sweeper as defined in claim 1 including means between said hopper inlet and said centrifugal removing means for separating debris from the air stream, and means for allowing removal of said separating means at least partially from said hopper.

24. The sweeper as defined in claim 1 including screen means between said hopper inlet and said centrifugal removing means and in the path of said air stream for separating debris therefrom prior to the air entering said centrifugal removing means.

25. The sweeper as defined in claim 1 including screen means between said hopper inlet and said centrifugal removing means and in the path of said air stream for separating debris therefrom prior to the air entering said centrifugal removing means, and means for removing said screen means at least partially from said hopper.

26. The sweeper as defined in claim 1 wherein said pick-up head includes a top wall, front and rear walls and opposite side walls; said pick-up head inlet and outlet being located one each at a removed portion of the intersection of an associated top and side wall, said first and second conduits having respective rigid first and second conduits secured to said pick-up head at the outlet and inlet thereof respectively, and said first and second rigid conduits each having an axis disposed at an angle of generally 60 degrees to the horizontal.

27. The sweeper as defined in claim 1 wherein said pick-up head includes a top wall, front and rear walls and opposite side walls, a side plate disposed in generally face-to-face relationship with each side wall, and means for vertically selectively adjusting each side plate relative to its assocaited side wall.

28. A sweeper for roads, parking lots or like surfaces which is particularly adapted to be mounted upon a bed of a mobile vehicle comprising means for defining a hopper into which debris is adapted to be discharged, said hopper having a fore-aft axis to coincide to the direction of travel of said associated mobile vehicle, a pick-up head, means for supporting said pick-up head from said associated mobile vehicle in transverse relationship to the fore-aft axis of said hopper, said hopper and pick-up head each including an inlet and an outlet, first conduit means between said pick-up head outlet and said hopper inlet for conducting air-entrained debris from said pick-up head into said hopper, second conduit means between said hopper outlet and said pick-up head inlet for conducting air from said hopper to said pick-up head, means for generating a continuous recirculating stream of air along a closed path of travel including successively said pick-up head, said pick-up head outlet, said first conduit means, said hopper inlet, said hopper, said hopper outlet, said second conduit means, and said pick-up head inlet, means for centrifugally removing debris from the air stream during the travel thereof between said hopper inlet and said hopper outlet about an axis disposed generally parallel to said hopper fore-aft axis, means between said hopper inlet and said centrifugal removing means for separating debris from the air stream, said hopper being defined at least in part by a pair of side walls having upper and lower side wall portions, said lower side wall portions being in generally upstanding relationship, one of said upper side wall portions being of a curved configuration and projecting laterally beyond its associated lower side wall portion, and said centrifugal removing means being at least in part defined by said curved upper side wall portion.

29. A sweeper for roads, parking lots or like surfaces which is particularly adapted to be mounted upon a bed of a mobile vehicle comprising means for defining a hopper into which debris is adapted to be discharged, said hopper having a fore-aft axis to coincide to the direction of travel of said associated mobile vehicle, a pick-up head, means for supporting said pick-up head from said associated mobile vehicle in transverse relationship to the fore-aft axis of said hopper, said hopper and pick-up head each including an inlet and an outlet, first conduit means between said pick-up head outlet and said hopper inlet for conducting air-entrained debris from said pick-up head into said hopper, second conduit means between said hopper outlet and said pick-up head inlet for conducting air from said hopper to said pick-up head, means for generating a continuous recirculating stream of air along a closed path of travel including successively said pick-up head, said pick-up head outlet, said first conduit means, said hopper inlet, said hopper, said hopper outlet, said second conduit means, and said pick-up head inlet, means for centrifugally removing debris from the air stream during the travel thereof between said hopper inlet and said hopper outlet about an axis disposed generally parallel to said hopper fore-aft axis, said air stream generating means being at least in part defined by a rotary blade, said hopper being defined at least in part by a pair of side walls having upper and lower side wall portions, said lower side wall portions being in generally upstanding relationship, one of said upper side wall portions being of a curved configuration and projecting laterally beyond its associated lower side wall portion, and said centrifugal removing means being at least in part defined by said curved upper side wall portion.

30. A sweeper for roads, parking lots or like surfaces which is particularly adapted to be mounted upon a bed of a mobile vehicle comprising means for defining a hopper into which debris is adapted to be discharged, said hopper having a fore-aft axis to coincide to the direction of travel of said associated mobile vehicle, a pick-up head, means for supporting said pick-up head from said associated mobile vehicle in transverse relationship to the fore-aft axis of said hopper, said hopper and pick-up head each including an inlet and an outlet, first conduit means between said pick-up head outlet and said hopper inlet for conducting air-entrained debris from said pick-up head into said hopper, second conduit means between said hopper outlet and said pick-up head inlet for conducting air from said hopper to said pick-up head, means for generating a continuous recirculating stream of air along a closed path of travel including successively said pick-up head, said pick-up head outlet, said first conduit means, said hopper inlet, said hopper, said hopper outlet, said second conduit means, and said pick-up head inlet, means for centrifugally removing debris from the air stream during the travel thereof between said hopper inlet and said hopper outlet about an axis disposed generally parallel to said hopper fore-aft axis, said air stream generating means includes a rotary blade, said rotating blade having an axis which is generally coincident to said axis of said centrifugal removing means, said hopper being defined at least in part by a pair of side walls having upper and lower side wall portions, said lower side wall portions being in generally upstanding relationship, one of said upper side wall portions being of a curved configuration and projecting laterally beyond its associated lower side wall portion, and said centrifugal removing means being at least in part defined by said curved upper side wall portion.

31. A sweeper for roads, parking lots or like surfaces which is particularly adapted to be mounted upon a bed of a mobile vehicle comprising means for defining a hopper into which debris is adapted to be discharged, said hopper having a fore-aft axis to coincide to the direction of travel of said associated mobile vehicle, a pick-up head, means for supporting said pick-up head from said associated mobile vehicle in transverse relationship to the fore-aft axis of said hopper, said hopper and pick-up head each including an inlet and an outlet, first conduit means between said pick-up head outlet and said hopper inlet for conducting air-entrained debris from said pick-up head into said hopper, second conduit means between said hopper outlet and said pick-up head inlet for conducting air from said hopper to said pick-up head, means for generating a continuous recirculating stream of air along a closed path of travel including successively said pick-up head, said pick-up head outlet, said first conduit means, said hopper inlet, said hopper, said hopper outlet, said second conduit means, and said pick-up head inlet, means for centrifugally removing debris from the air stream during the travel thereof between said hopper inlet and said hopper outlet about an axis disposed generally parallel to said hopper fore-aft axis, said hopper being defined at least in part by a pair of side walls having upper and lower side wall portions, said lower side wall portions being in generally upstanding relationship, at least one of said upper side wall portions being of a curved configuration, and said centrifugal removing means being at least in part defined by said curved upper side wall portion.

32. A sweeper for roads, parking lots or like surfaces which is particularly adapted to be mounted upon a bed of a mobile vehicle comprising means for defining a hopper into which debris is adapted to be discharged, said hopper having a fore-aft axis to coincide to the direction of travel of said associated mobile vehicle, a pick-up head, means for supporting said pick-up head from said associated mobile vehicle in transverse relationship to the fore-aft axis of said hopper, said hopper and pick-up head each including an inlet and an outlet, first conduit means between said pick-up head outlet and said hopper inlet for conducting air-entrained debris from said pick-up head into said hopper, second conduit means between said hopper outlet and said pick-up head inlet for conducting air from said hopper to said pick-up head, means for generating a continuous recirculating stream of air along a closed path of travel including successively said pick-up head, said pick-up head outlet, said first conduit means, said hopper inlet, said hopper, said hopper outlet, said second conduit means, and said pick-up head inlet, means for centrifugally removing debris from the air stream during the travel thereof between said hopper inlet and said hopper outlet about an axis disposed generally parallel to said hopper fore-aft axis, means between said hopper inlet and said centrifugal removing means for separating debris from the air stream, said hopper being defined at least in part by a pair of side walls having upper and lower side wall portions, said lower side wall portions being in generally upstanding relationship, at least one of said upper side wall portions being of a curved configuration, and said centrifugal removing means being at least in part defined by said curved upper side wall portion.

Tymco, the assignee of the subject matter of this disclosure is the recognized leader and originator of REGENERATIVE AIR.TM. sweepers since the mid-1960's. Reference is made to U.S. Pat. Nos. 3,545,181; 3,512,206 and 3,790,981 for details of such REGENERATIVE AIR.TM. sweepers of Tymco which are relatively heavy-duty, high capacity models designed for cleaning airport runways, roadways, and other such relatively large expanses over which the sweeper is moved. While such REGENERATIVE AIR.TM. sweepers are highly efficient for sweeping large areas, the capital investement precludes the efficient use thereof for relatively small areas, such as small parking lots, parking areas at shopping malls, etc. Such lesser size surface areas dictate a minimum capital investment even though this reflects a proportionate reduction in overall hopper capacity. However, since a lesser surface area is being cleaned a reduction in hopper capacity is not detrimental but is actually economically desirable both from the initial capital investment (cost of the sweeper) and the day-to-day cost of operation, maintenance and the like.

In keeping with the foregoing, it is a primary object of the present invention to provide a novel REGENERATIVE AIR.TM. sweeper of relatively low-volume/capacity for sweeping relatively small parking lots, parking areas, roads or like surfaces and which is particularly adapted to be removably supported upon the bed of a pickup truck, the sweeper including a hopper into which debris is adapted to be discharged, the hopper having a fore-aft axis which coincides with the direction of travel of the pickup truck, a pickup head, the pickup head being supported in transverse relationship to the fore-aft axis of the hopper, the hopper and pickup head each including an inlet and an outlet, first and second conduits for conducting air-entrained debris from the pickup head to the hopper and from the hopper outlet to the pickup head inlet, respectively, means for generating a continuous recirculating stream of air along a closed path of travel including successively the pickup head, the pickup head outlet, the first conduit, the hopper inlet, the hopper outlet, the second conduit, and the pickup inlet, and means for centrifugally filtering the air stream during the travel thereof between the hopper inlet and the hopper outlet about an axis disposed generally parallel to the hopper fore-aft axis.

Still another object of this invention is to provide a novel sweeper as heretofore described including a removable screen between the hopper inlet and the centrifugal filtering means for separating debris from the air stream prior to the introduction of the air into the centrifugal separating means.

Still another object of the invention is to provide a novel sweeper wherein the means for generating the stream of air is a turbine, and the turbine has an axis which is generally coincident to an axis of the centrifugal filtering means.

Yet another object of this invention is to provide a novel filter of the type heretofore set forth wherein the hopper includes top and bottom walls, spaced side walls therebetween, and front and rear walls; the side walls having upper and lower side wall portions, the lower side wall portions being in generally upstanding relationship, one of the upper side wall portions being of a curved configuration and projecting laterally beyond its associated lower side wall portion, and the centrifugal filtering means is at least in part defined by the latter-noted curved upper side wall portion.

A further object of this invention is to provide a novel sweeper as latter defined wherein the centrifugal filtering means includes a generally cylindrical wall defining a centrifugal chamber, an air inlet at an uppermost portion of the cylindrical wall defined in part by the curved side wall portion through which the air stream enters from the hopper, and a debris outlet in the cylindrical wall at generally a lower portion thereof through which debris departs the centrifugal filtering means and enters the hopper.

Still another object of this invention is to provide a novel sweeper as aforesaid wherein the pickup head includes a top wall, front and rear walls and opposite side walls; the pickup head inlet and outlet being located one each at a removed portion of the intersection of an associated top and side wall, the first and second conduits having respective rigid first and second conduits secured to the pickup head at the outlet and inlet thereof, respectively, and the first and second rigid conduits each having an axis disposed at an angle of 60.degree. to the horizontal.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings.

IN THE DRAWINGS

FIG. 1 is a rear perspective view of a REGENERATIVE AIR.TM. sweeper constructed in accordance with this invention, and illustrates the sweeper mounted upon a bed of an associated pick-up truck.

FIG. 2 is an enlarged cross-sectional view taken generally along line 2--2 of FIG. 1, and illustrates details of a hopper and a pickup head of the sweeper and associated conduits establishing a continuous recirculating air stream flowing into the hopper through a hopper inlet, through a debris-separating screen, into a centrifugal separator or filter whose axis is parallel to the fore-aft axis of the hopper, an outlet from a turbine through a conduit into the pickup head transversely spanning the pickup truck and another conduit leading back to the hopper.

FIG. 3 is an exploded view of the sweeper of FIGS. 1 and 2, and illustrates several of the major components thereof, including a mechanism for raising and lowering the pickup head and details of the hopper construction.

FIG. 4 is an enlarged fragmentary top plan view of the sweeper with a top wall of the hopper housing and the turbine housing removed for clarity, and illustrates the air flow by unnumbered headed arrows from the pickup head outlet into the hopper, through the screen, into and through the centrifugal separator, through the turbine housing and back to the pickup head.

FIG. 5 is a fragmentary sectional view taken generally along line 5--5 of FIG. 4 with an auxiliary engine for the turbine and other components removed for clarity, and illustrates the manner in which the pickup head is mounted for pivoting movement transversly of the pickup truck between upper inoperative and lower operative positions.

FIG. 6 is a cross-sectional view taken generally along line 6--6 of FIG. 5, and illustrates details of a mechanism for lifting and lowering the pickup head.

FIG. 7 is a side elevational view of the pickup head, and illustrates a rigid conduit, a side wall seal and/or deflector and a vertically adjustable skid associated therewith.

FIG. 8 is a bottom plan view of the pickup head taken generally along line 8--8 of FIG. 7, and illustrates rigid conduits opening into a chamber of the pickup head through top and side walls thereof.

FIG. 9 is an enlarged cross-sectional view taken generally long line 9--9 of FIG. 8, and illustrates a partition panel within the pickup head chamber.

FIG. 10 is a cross-sectional view taken generally along line 10--10 of FIG. 9, and illustrates the manner in which the conduit opens into the pickup head chamber through an outlet opening in the top and end walls thereof.

FIG. 11 which appears on the sheet of drawing containing FIG. 1 is a fragmentary cross-sectional view taken generally along line 11--11 of FIG. 7, and illustrates the bent or twisted configuration of the side wall deflector.

A novel REGENERATIVE AIR.TM. sweeper constructed in accordance with this invention is generally designated by the reference numeral 10 (FIGS. 1 through 4), and is illustrated mounted upon or within a bed B (FIG. 2) of a pickup truck T having a conventional cab C, outer side walls or panels So (FIGS. 1 and 2), upper longitudinal edges E thereof, inner side walls or panels Si, and wheel wells W (FIG. 2). Normally, the pickup truck T includes a tailgate, but the unillustrated tailgate has been removed incident to the positioning of the sweeper 10 upon the bed B. The pickup truck T can be most any 1967 or later American-made styleside pickup, as, for example, the Ford Ranger for light sweeping, the Ford F-150 for medium sweeping, and the Ford F-250 for heavy sweeping.

The sweeper 10 includes a hopper 20 defined by a bottom wall 21 (FIGS. 2 and 3) which rests upon the bed or floor B, side walls 22, 23, a forwardmost and lowermost top wall 24 (FIG. 3), an intermediate top wall 25, and an uppermost and rearmost top wall 26; a forwardmost front wall 27, an intermediate front wall 28, and a rearmost front wall 30; and a rear wall 31 (FIG. 1). The bottom wall 21 of the hopper 20 is of a generally rectangular configuration and is of a width and length so as to be accommodated within the bed B of the truck T, as is most evident from FIG. 2 of the drawings.

The side walls 22, 23 are each identical, and each includes lower wall portions (unnumbered) defined by identical upwardly diverging walls or panels 32, 33 (FIG. 2), walls or panels 34, 35 which are in greater divergent relationship to each other than the walls 32, 33 (FIG. 2), generally parallel walls 36, 37 which are upright and normal to the bottom wall 21, and opposing inwardly directed walls 38, 39. Thus, the lower portion of the side wall 22 is defined by the walls 32, 34, 36 and 38 (FIG. 2), while the lower portion of the side wall 23 is defined by the walls 33, 35, 37, and 39. The walls 32, 34 and 33, 35 merge with and are welded or otherwise secured to the forwardmost front wall 27 (FIG. 3). However, the walls 36, 38 and 37, 39 terminate at the intermediate front wall 28 and are welded or are otherwise secured thereto and to the intermediate top wall 25.

The uppermost top wall 26 is formed of two generally identical top wall panels 41, 42, each having respective downwardly directed flanges 43, 44 which lie along the fore-aft center line plane of the hopper 20 and, of course, also of the pickup truck T and its bed B, as is most evident from FIG. 2 of the drawings. The flanges 43, 44 are secured to each other by appropriate bolts. Outboardmost portions 45, 46 of the respective top wall panels 41, 42 are each of a generally semi-cylindrical configuration and progressively curve outwardly, downwardly and inwardly terminating at inwardly opposing edge portions 47, 48, respectively (FIG. 2). The edge portions 47, 48 overlie and are bolted to the uppermost walls 39, 38, respectively, of the side walls 23, 22, respectively. Thus, part of the curved portions 45, 46 and the lower end portions 47, 48, respectively, thereof form continuations of the side walls 23, 22 and, of course, the upper portions of the wall portions 45, 46 also form portions of the top walls 41, 42. Thus, though there is no specific line of demarcation between the side walls 22, 23 and the top wall 26, at least a portion of each of the side walls 22, 23 is in part defined by lower portions of the curved wall portions or panels 46, 45, respectively. The same semi-cylindrical portions 45, 46 have a maximum outboard extent generally corresponding to that of the plane of the outer side panel So (FIG. 2) thereby optimizing the total space available between the side panels So for any particular pickup truck T with which the sweeper 10 is associated. Forwardmost edges (unnumbered) of the top wall panels 41, 42 are bolted to an uppermost edge (unnumbered) of the upstanding rearmost front wall 30, as is most evident from FIGS. 2 and 3 of the drawings. The flanges 43, 44 are not only secured to each other, but are also received in a notch 49 (FIGS. 2 and 3) formed in the flange of the front wall 30. Two other front walls or panels 51, 52 of somewhat greater than a semi-circular configuration are bolted to the top wall panels 41, 42, respectively, and to opposite lateral upstanding edges (unnumbered) of the front wall 30 and are generally coplanar therewith. The front walls or panels 51, 52 are provided with respective air outlet and air inlet openings 53, 54.

The rear wall 31 (FIG. 1) is defined by a pair of doors 56, 57 (FIG. 1), each mounted for pivotal opening along a vertical hinge or pivot 58. A seal or gasket 59 of a semi-circular configuration is carried by the door 56. The hinge 58 is secured along one side of a rigid rectangular rear frame 60 formed by an upper rail 61, a lower rail 62, a side rail 63, and another side rail 64. Handles 65 carried by each of the doors 56, 57 secure these doors closed in the manner clearly shown in FIG. 4. In addition to the doors 56, 57, the rear wall 31 of the hopper 20 is also defined by two generally semi-circular rear wall panels 71, 72 longitudinally opposite the panels 51, 52 and two generally rectangular rear wall panels 73, 74 which generally extend between the uppermost walls 39, 38, respectively, and the bottom wall 21 (FIG. 1).

One purpose of the hopper 20 of the sweeper 10 is, of course, to collect debris D (FIG. 2) conducted therein after having been picked up by a pickup head 80 (FIGS. 2 and 4) which will be described more fully hereinafter. However, with the pickup head 80 in its lowermost operative position (FIGS. 1 and 2) traversing the pickup truck T means in the form of a six bladed stainless steel rotating blade or turbine 90 generates a high pressure recirculating stream of air along a closed path of travel including successively the turbine or blower 90, an outlet 91 of a housing 92 of the turbine 90, conduit means 93 in the form of a flexible conduit, a rigid inlet conduit 94 opening into the pickup head 80, across the pickup head 80, a rigid outlet conduit or pipe 95 of the pickup head 80, second conduit means in the form of a flexible conduit 96, another rigid inlet conduit or pipe 97 bolted to the front wall portion 52, the inlet opening 54 of the latter, the interior of the hopper 20 generally along the top wall 26 thereof (FIG. 2) and back to the turbine 90 through means 100 for centrifugally separating, removing or filtering dust and relatively fine debris from the debris-entrained air stream prior to the introduction thereof once again and continuously into the turbine 90 through the opening 53.

The housing 92 includes a flange 69 (FIGS. 2, 3 and 4) which lies flush against and is bolted to the front wall or panel 51 by a plurality of bolts (not shown). The bolts pass through openings 79 formed in the flange 69 and in the periphery of the panel 51 adjacent the air inlet opening 53. There are six equally spaced openings 79 in the flange 69 of the housing 92 and twelve equally spaced openings 79 in the panel 51. Due to the latter relationship, the housing 92 can be rotated clockwise, as viewed in FIG. 2, from the position illustrated to another position approximately 20.degree. to the right thereof which positions an outlet 91 of the housing 92 at a more downwardly directed vertical position than that shown in FIG. 2. Due to the latter adjustment, the same hopper 20 and housing 92 can be used on vehicles having narrower beds widthwise than the bed B illustrated as measured between the outer side panels So. Similarly, a like flange 69 associated with an inlet conduit 97 is also provided with similar openings 79, as is the front panel 52 to angularly adjust the conduit 97 for narrower vehicle beds.

During the movement of the debris-entrained air stream from the inlet 54 to the outlet 53 (FIG. 4), the heavier or larger pieces of debris D, such as large pieces of paper, cans, etc., tend simply to drop toward and accumulate upon the bottom wall 21. However, in order to prevent such heavier debris from being drawn into the centrifugal separator 100 means 110 (FIGS. 1 through 4) in the form of a generally rectangular screen are provided for separating heavier debris during the air flow along the top wall 26 of the hopper 20 between the inlet 54 and the centrifugal separating means 100. The screen or separating means 110 includes a screen 111 (FIGS. 3 and 4) of suitable mesh supported by a relatively rigid rectangular frame 112 having longitudinal frame members 113, 114. The distance between the frame members 113, 114 corresponds generally to the distance between a pair of channel members 115, 116 which generally extend the entire distance between the uppermost front wall 30 and the rear wall 31 (FIGS. 3 and 4). The channel member 115 is welded or otherwise secured to a generally semi-cylindrical wall 101 which extends between the semi-circular front wall portion 51 and the semi-circular rear wall portion 71 of the hopper 20. The channel member 116 is simply bolted or welded to the top wall panel 42 of the top wall 26, as is most evident from FIG. 2 of the drawings. The screen means or separating means 110 is thus inclined to the horizontal, as is best shown in FIG. 2, and as heavier or larger debris is drawn by the turbine 90 from the inlet 54 toward the outlet 53, it will contact the screen means 110 of specifically the screen 111 thereof and/or any of a number of chains 117 or like elongated elements suspended therefrom. The screen 110 and/or the chains 117 thereby prevent the heavier or larger debris from being drawn into the centrifugal separator 100, the outlet 53 and into the turbine 90 which might otherwise damage or adversely affect the air flow heretofore noted. Thus, the only debris which will enter the centrifugal separator 100 and/or the turbine 90 is debris of a size which will pass through the relatively small openings of the screen 111, and the latter openings are selected so as not to adversely affect the turbine 90 or the air flow created thereby. At any such time as the screen means 110 becomes undesirably clogged with debris, it can simply be slid partially or entirely outwardly of the hopper 20, as is generally indicated in FIG. 1, and can be cleaned and slid back to is operative position. The screen means 110 is essentially self-cleaning at any time that the turbine 90 is inoperative since any material lodged upon the underside of the screen 110 or the chains 117 will tend simply to drop thereform and accumulate upon the bottom wall 21.