Walk behind floor maintenance machine

0001"The present invention relates to a forward throw sweeping machine, comprising a mobile body portion, a main rotatable driven cylindrical brush on the body portion for propelling material forwardly from a surface to be cleaned, a debris hopper mounted on the body portion ahead of the brush with an inlet opening for receiving debris propelled by the brush, the hopper being movably mounted on the body portion so that it can be moved for dumping, a movably mounted filter housing with an inlet opening and a filter therein, and a vacuum fan assembly on the body portion to create an air current through the hopper and the filter housing to prevent dusting when the hopper and the filter housing are in operative position for sweeping".

0002In a floor maintenance machine as known from US-A-4 173 052, the filter housing is pivotably mounted with a hinge in the interior of a hopper, which in turn is pivotable via an arm on a part of the frame around an axis. The filter housing, in its operative position, does not engage the hopper. The filter housing forms a separate chamber within the hopper and is provided with a separated dust collector having a connecting opening towards the interior of the hopper. Lifting cylinders engage the arms in order to tilt the hopper together with the filter housing. Then the dust from the filter chamber has first to be dumped through an opening into the hopper before the filter housing tilts away to clear the outlet of the hopper to dump the debris in an inverted position of the hopper. The manipulation of the machine for dumping is complicated since opposing tilting motions between the filter housing and the hopper itself have to be precisely matched. A relatively long period of time is necessary for the dumping cycle because the dust from the filter chamber has first to be dumped in the hopper before the contents of the hopper can be dumped. No free access is possible to the interior of the hopper to clean it quickly at the end of a dumping cycle.

0003Another floor maintenance machine as known from CH-A-416 974 comprises a hopper positioned in a front part of the machine. The filter housing is provided in a rear part of the machine and has no direct contact or connection with the hopper. Furthermore, the vacuum fan is provided between the hopper and the filter housing, so that the dusty air stream has to pass the fan first, before the dust can be cllected. With this principle, the fan assembly underlies a constant contamination. A further serious disadvantage of said machine is a relatively bulky design which results from the separated and spaced arrangement of the different working components within the frame of the machine. Furthermore, due to the remote position of the filter housing, a separate dust collecting chamber must be provided beneath the filter housing which has to be emptied regularly.

0004Furthermore, in a floor maintenance machine as known from US-A-4 328 014, the filter itself is positioned in the interior of the hopper and is pivotally mounted in hinges and held in position by brackets. When the top cover of the hopper is open, the filter may be removed and replaced. For dumping the contents of the hopper, the whole and relatively heavy, contaminated filter assembly has to be moved with the hopper. Access to the filter assembly and manipulation of the filter components is complicated since the filter assembly is hidden within the hopper.

0005It is a task of the invention to create a floor maintenance machine as disclosed having an improved and facilitated handling for dumping "the contents of the hopper and maintaining good dust control.

0006This is achieved with the features according to the characterizing part of claim 1 in that the filter housing is mounted directly on the body portion above the hopper, that the hopper has an outlet opening in its upper wall , that the filter housing is constructed and arranged to be moved on the body portion between an operative position where it engages the hopper with the inlet opening mating with the outlet opening and an inoperative position where it is remote from the hopper so that the hopper may be moved and dumped, that a resilient seal surrounds the aligned openings and engages the hopper in the operative position, and that the hopper is so mounted on the body portion that it is allowed to rock during normal operation around a shaft to allow obstacles to pass underneath".

0007As soon as it becomes desirable to empty the hopper of collected dirt and debris, the filter housing is pivoted into its inoperative position. Then the hopper can be easily brought into its dumping position. The weight of the filter housing with its components is supported by the body portion, and must not be moved with the hopper during the dumping cycle. With the filter housing in its in operative position and spaced apart from the hopper, any dusty air from the dumping step does not contaminate the filter. For each dumping cycle, only a relatively short period of time is necessary since with the lifted filter housing and with lowforces, the hopper can be moved quickly in its dumping position. After dumping, and with the hopper in its operative position, the filter housing has only to be moved back into its operative position so that the machine can immediately continue working.

0008"Since the filter housing in the operative position engages the hopper with the inlet and outlet openings mating, the dust-laden air is closely controlled and remains entirely within a restricted flow path including the filter. In a direct forward throw machine the debris hopper must be positioned closely to the floor, resulting in an increased risk of obstacles being clamped between thefloorand the hopper. This problem is overcome by the invention by mounting the hopper pivotally, thereby permitting of a rocking movement of the hopper while obstacles are passing underneath. Further, a resilient annular seal is placed between the hopper and the filter housing which surrounds and seals the controlled air path during normal sweeping operation but still on occasion permits the said rocking movement of the hopper.

0009Preferred embodiments of the invention are contained in tme dependent claims. <ul id="ul0001" list-style="none"><li>Figure I is a perspective view from the left front of the present invention;</li><li>Figure II is a side elevational view of the embodiment of Figure I;</li><li>Figure III is a perspective view of the present invention with the filter housing pivoted to its uppermost position;</li><li>Figure IV shows a lower front portion of the invention including a hopper support member;</li><li>Figures V and VI show the upper side supports of the hopper;</li><li>Figure VII shows the present invention with the filter housing pivoted to its uppermost position and the hopper lifted out of its supported position;</li><li>Figure VIII shows the present invention with the hopper pivoted to a dumping position;</li><li>Figure IX hows a side view of the present invention with housing portions removed to expose underlying structure;</li><li>Figure X is an exploded view of the filter assembly on the present floor maintenance machine;</li><li>Figure XI is a cross sectional view of the filter assembly; and</li><li>Figure XII is a schematic view of an alternate embodiment.</li></ul>

0010In Figures I-XI a floor maintenance machine 10 includes a body portion 11 with a steering bar 13 and shifting lever 14 supported on wheels 12. A side brush 16 may be disposed at the forward portion of machine 10. A housing overlies the internal structural portions of the machine. The machine 10 has a rotatably driven cylindrical brush 17 which may be encased within a suitable dust housing 18 which minimizes dusting around the machine.

0011In Figure III various housing portions are removed to disclose the underlying structure, including a hopper 19 and a filter housing 21. As shown in Figures III, IV and VII, the hopper 19 includes a bottom wall 22, a pair of sidewalls 23 and 24, an upper wall 26 and a front wall 27. The bottom wall 22 includes a ramp 28, for example, of a resilient elastomeric material. The hopper 19 partially is enclosed to the rear by wall 25 thus providing an opening 31 for receipt of swept material. The upper wall 26 has a rectangular opening 32 therein for purposes hereinafter described. A pair of upwardly extending arms 33 and 34 is mounted on the upperwall 26. Arm 33 includes an upwardly extending portion 33a and a rearwardly extending portion 33b. Portion 33b has an outwardly extending stub shaft 36 which assists in supporting the hopperwith respect to body portion 11. Arm 34 is similarly constructed. A pair of L-shaped bars 37 and 38 serve as suitable handles for lifting and carrying the hopper 19. Bar 37 is welded at one end to upper wall 26 and secured by a bolt 39 atthe otherend. The hopper 19 has a lever and grip 41 rotatably secured at one end to the bar 37. The lever and grip 41 is of a length slightly less than the width of the hopper 19 to permit stowing. The lever 41 may be rotated from the position shown in Figure VII to the position shown in Figure VIII. A small lock 42 secures handle 41 when rotated to the position shown in Figure VIII.

0012The sidewalls 23 and 24 each have an outwardly extending stub shaft 43. The stub shafts 36 and 43 serve to support the hopper 19 with respect to the body 11. The stub shaft 36 is located rearwardly of the center of mass of hopper 19 whereas the stub shaft 43 is located slightly forwardly of the center of mass. The body portion 11 has a forwardly extending arm 44 adjacent each side for supporting engagement with the stub shaft 43. The arm 44 as illustrated in Figure X has an upwardly facing recess in which the stub shaft 43 is held. The body portion 11 (Figures V and VI) has a pair of side members 46, one on either side, on which is located a channel-like support45 for reception of the stub shaft 36.

0013The filter assembly 21 as illustrated in Figures III, VII and IX, includes a housing 47 having a lower portion 48 and cover 59. Housing 47 is supported with respect to the body 11 by hinges 49 (Figure VII) and by stop 50. A panel filter 51 (Figure X) is supported in the housing 47 and sealed with respect to such housing such that any air passing through the housing 47 must pass through the filter. The filter thus divides the housing into a dusty air zone beneath the filter and a clean air zone above the filter. The housing 47 (Figures Vll, VIII and X) has an inlet 52 with a suitable resilient seal 53 therearound. The inlet 52 mates with hopper opening 32 to receive airfrom the hopper. The housing 47 (Figures III and X) further includes an outlet 54 which communicates with a vacuum fan 56. The outlet 54 may include a short tube 57 which slides into a rubber boot 58 when the filter housing is in the lowered operating position, and yet slips out of such boot when the housing is raised, as illustrated in Figure III. The filter housing 47 has a cover portion 59 which may be removed by the removal of screws 61 (Figures VII and X) from the threaded openings 62 in the housing support brackets 63. Panel filter 51 may be then lifted out and removed.

0014The machine 10 is illustrated using a panel filter however other types of filters may be used such as bag filters, canister filters and the like. Further, the tube 57 and boot 58 may be replaced with an accordion-type tube which is secured at one end to a fan duct and secured at the other end to the filter housing 47.

0015According to Figure III, an electrically powered eccentric weight device 64 is provided to vibrate the entire housing 47 and panel filter 51. Since the device 64 is located outside the filter housing 47 it is protected from the abrasive dusty environment of such housing and thus has an extended life. In the absence of such a vibrating device, the housing and filter may be vibrated by merely striking the housing with one's fist to dislodge dust from the filter. The lower wall 48a of housing 47 may slope downwardly and may act as a vibratory conveyor to move the dislodged dust to the hopper.

0016In operation, the machine 10 is powered by any suitable power source, such as an electric motor or a gasoline powered engine. The power source drives the wheels 12 and the brushes 16 and 17. The brush 16 serves to sweep dirt and debris from the side of the sweeper path into the center portion wherein the main brush 17 picks up the dirt and debris, sweeping it into the hopper 19. The dirt and debris enters the hopper opening 31 and generally is retained therein. The vacuum fan 56 serves to draw an airstream through the hopper 19 moving light debris forwardly. The filter assembly 21 serves to remove dust-laden air from the airstream, thus protecting the fan motor 56 from abrasion. This also protects the operator from breathing dust-laden air. The panel filter 51 serves to trap such dust. During normal operation, the filter assembly 21 engages at its lower end the hopper 19 with the opening 52 of assembly 21 communicating with the opening 32 of hopper 19. The weight of the filter assembly 21 is supported on stop 50. The resilient seal 53 prevents entrance of ambient air, thus requiring all airstream to pass through the hopper. One may activate the eccentric vibrator 64 periodically to shake the dust collected from panel filter 51. The low- erwall of the filter housing 47 is also vibrated and the dust slides therealong to drop into the hopper 19. If one wishes to replace the panel filter 51, screws 61 are removed and the cover 59 is removed providing access to such filter.

0017When the operator desires to empty the hopper 19 of collected dirt and debris, the filter assembly 21 is pivoted upwardly as shown in Figure III. To facilitate this operation, an air spring 60 may be provided to counterbalance the weight of such assembly. Alternatively, suitable releasable bracing may be provided. The operator grasps the handles 37 and 38 and lifts the hopper 19 from its position on sweeper 10. The hopper may be carried to a suitable dump area and emptied. Alternatively, if the operator merely wishes to dump the hopper 19 at the location of the machine 10, the handle 41 is pivoted to the position shown in Figure IV and the hopper is elevated to the position shown in Figure VIII with the hopper pivoting on stub shaft 36. The pair of stub shaft supports 43 at each side of hopper 19 permit the hopper to rock over obstacles. For example, as an obstacle such as a can or brick moves beneath the rear portion of hopper 19 and resilient lip 28, the hopper 19 may pivot upwardly resting on shafts 43.

0018An alternative embodiment is illustrated in Figure XII. Machine 110 is identical in structure except that it includes a power dump for the hopper 119. The power dump may be an electrically driven screw 141 which is mounted on body portion 111. The screw 141 acts to rotate hopper 119 in a clockwise direction as viewed in Figure XII to an elevated dump position. The upper stub shafts 136 may be locked in channel 145 by a solenoid 146 but only during the dumping operation. The machine 110 has suitable controls for activating the solenoid 146 and the screw 141 for dumping and includes a lockout mechanism which prevents activation of screw 141 unless the operator has first raised the filter housing 121. The operator may, if desired, manually lift and carry the hopper 119 to a dump site.