WO2008079944A2

WO2008079944A2 - Brush mount for floor scrubber

Info

Publication number: WO2008079944A2
Application number: PCT/US2007/088312
Authority: WO
Inventors: James C. Polites; Timothy J. Larson; Jesse V. Mondigo; Richard Thompson; Shay Shalmon; Jeffrey W. Pollack
Original assignee: Minuteman International, Inc.
Priority date: 2006-12-21
Filing date: 2007-12-20
Publication date: 2008-07-03
Also published as: WO2008079944A3

Abstract

A floor scrubber includes a motor coupled to a drive member having at least two drive lobes. The drive member is received in a receptacle of the brush having a sector for each lobe. Each sector includes a drive zone and a release zone with a retainer member between each drive and release zone. A controller (circuitry) prevents the brush from being driven in the raised position under normal conditions to prevent accidental release of the brush. When it is desired to unload the brush, it is raised, and the operator actuates a keyswitch to energize the motor momentarily. Subsequently, when the keyswitch is released in the unload mode, the motor is abruptly stopped, permitting the drive lobes to override the retainer members, and to place the drive lobes in associated release zones, thereby releasing the brush.

Description

BRUSH MOUNT FOR FLOOR SCRUBBER

Cross Reference To Related Applications

This application claims priority from U.S. Provisional Application No.

60/876,332 filed on December 21, 2006 and U.S. Provisional Application No. 60/973,305 filed on September 18, 2007.

Field of the Invention

The present invention relates to floor scrubbing machines; and, in particular, it relates to improvements in the system for driving and releasing the scrub brush used in a floor scrubbing machine.

Background of the Invention

Floor scrubbing machines of the type with which the present invention is concerned typically include at least one scrub brush mounted beneath the machine and capable of being moved by an operator (either manually, as by foot pedal, or power- assisted) between a lowered use position and a raised, transport/storage position. The brush is driven by a motor energized typically, by batteries. A source of cleaning fluid supplies the fluid to the floor or directly on the brush for scrubbing and cleaning the floor. The dirty or "spent" solution is collected by a squeegee following behind the brush and removed by suction. The spent solution is stored in the machine until it is discarded, normally in a janitor's closet or the like, and the solution tank is refilled with clean solution.

Although the instant invention is not so limited, the disclosed embodiment is directed to a machine with only one brush, and for simplicity, the rear squeegee is not shown, nor are the details for delivering the clean solution and storing the spent solution because these subsystems may be conventional and do not form an essential part of the improvement of the present invention. Such conventional machines may include a circular scrub brush which is operated (typically, mechanically, by the operator's stepping on a foot pedal) between a raised (storage or transport) position, and a lowered use position. When the brush is lowered to the use position, a "Run" Enable switch is actuated to permit the operator to actuate a second, control device to energize a drive motor coupled to the brush for scrubbing action.

The brush is coupled to the drive motor by a drive hub assembly (or simply "hub assembly") which includes a drive lug having a plurality of drive lobes spaced at equal angular increments about the axis of rotation of the hub. This type of drive lug, referred to herein as "tri-lobular", in the case where three lobes are provided, has a tendency to uncouple the brush unintentionally when the motor is shut off. The rotational inertia of the brush is sufficient to cause the brush to overrun the drive lug so that the drive lugs come to rest in a position on the brush plate to align with the removal openings, which permits the brush to fall away from the drive hub under gravity.

The unintentional occurrence of uncoupling the scrub brush from the drive hub creates an inconvenience to the operator of the machine since this type of machine is frequently moved manually; and the operator, in the course of operation, shuts down the drive brush, thereby creating the possibility that the drive brush would be inadvertently uncoupled from the drive hub, even to the point of falling to the floor.

Summary of the Invention

One embodiment of the present invention overcomes the above-referenced problem of inadvertently uncoupling the scrub brush from the drive hub, by incorporating improvements in the electrical control system energizing the brush, and by incorporating retention members (or detents) in the receptacle of the brush in which the drive lug is mounted.

When the brush is located in the normal use position (i.e. the brush rests on the floor), the retention members retain the drive lug in the drive zone of the brush so that it cannot be removed. The drive system (or controller) includes two switches which are mounted to the machine in such a manner as to be actuated only when the brush is raised to the transport/storage position. One of these switches, referred to as the Unload Enable switch, is connected in the control circuit with a relay that energizes the brush drive motor upon operator action. Thus, when the brush is in the raised position, the brush drive relay is disabled and the brush motor cannot be energized by the Operator Run switch (that is, the switch which is normally-open and actuated by manual or hand operation of the operator during normal operation). wants to scrub a floor ). The Run Enable switch is connected in series with the Operator Run switch. Thus, in order for the brush to be driven in rotation under normal use conditions by the brush drive motor, two conditions must occur. First, the brush must be in the lowered or use position so that the brush engages the floor and the Run Enable switch is actuated; and secondly, the operator must actuate the Operator Run switch by a hand lever, which must be held in the operating position by the operator or the scrubbing action will stop.

To release the brush, the controller includes an Unload Enable switch, a normally-open switch which is closed or actuated when the brush is in the raised position, is connected in circuit with the brush motor and a Keyswitch, which is a spring-loaded rotary switch, operated by the operator and actuated (i.e. closed) only so long as the operator holds the Keyswitch in the unload position.

When the brush is in the raised position and the operator rotates the Keyswitch to the unload position, the brush relay is actuated to drive the motor. When, however, the operator releases the Keyswitch from the Brush Unload position, the brush relay is de-energized, and normally-closed contacts on the "off" position of the Keyswitch short the terminals of the brush motor, generating a dynamic load on the motor and bringing the brush to a very quick stop. The rotational inertia of the brush then overrides the drive hub, and carries the brush beyond the drive hub to a release position; thereby permitting the brush to be removed manually. Thus, in normal use conditions when the brush rests on the floor, the brush is prevented by the retention members from being release from the drive lug. But when the brush is raised to the storage/transport height, the controller permits the operator to drive the brush for a short time, then abruptly brakes the motor, causing the brush to continue to rotate and the retention member on the brush override the drive lobes, placing the brush in a release or removal position, but only when intentionally caused by explicit operator action.

In a first embodiment, a receptacle in the brush plate is provided with three centrally extending retention members. These retention members may be in the form of detents integral with the brush plate and extending centrally into the receptacle formed in the brush plate for the drive lug. The detents of the first embodiment are in the form of protrusions which act to engage the outermost rounded points of the drive lobes of the drive lug to prevent dislodgement of the brush during normal operation while permitting the brush to be dislodged under operator action. That is, the receptacle has a "sector" for each lobe of the drive lug. Moving in the direction of normal brush rotation, forward of each of the retention members and up to an associated driven surface on the receptacle of the brush, there is a "drive" or engagement zone, in which the brush is not dislodged from the drive hub even in conditions of rough use, as is common. Rearward of each retention member to a limit or "release" surface on the receptacle, for each sector, there is a "release" zone in which the brush may be easily dislodged from the drive hub. In a second embodiment, the detent (or "retention member") is in the form of a segment of a rod of synthetic material, such as polyurethane.

To release the brush the motor is raised, and the operator actuates the Keyswitch, to the Brush Unload position, the brush is thereby driven by the motor. When the operator releases the Keyswitch, the motor is disconnected from the power source, and the terminals of the motor are shorted together (by the control circuit) to load the motor dynamically and thus stop it quickly. The rotational inertia of the brush causes the retention members of the brush to override the three drive lobes of the drive lug, moving the drive lug from the captive or drive zone to the release zone and placing the drive lug in register with an exit opening position in the brush receptacle, thereby permitting the brush to be removed for cleaning, repair or replacement.

In the embodiment in which the retention member is a cylindrical segment of synthetic material, the synthetic material reduced wear on the drive lug, thus prolonging the life of the drive lug.

In another embodiment, the brush plate is provided, in the illustrated embodiment, with three circumferential drive channels, and the drive lug includes three metal drive members which are received in associated ones of said drive channels. The drive members each have a leading drive surface, which may be flat, but not necessarily so, and each drive member engages an associated driven surface in one of the drive channels to drive the brush in operation. This type of drive system may act alone (i.e. without the drive lug) to drive the brush, or it may act in cooperation with the drive lug to drive the brush. In either case, wear on the drive lug is reduced, and it will be appreciated that the drive lug is subjected to considerable stress in operation.

Other features and advantages of the present invention will be apparent to those skilled in the art from the following detailed description of the illustrated embodiment, accompanied by the attached driving wherein identical reference numerals will refer to like parts in the various views.

Brief Description of the Drawing

FIG. 1 is a side view of a floor scrubbing machine incorporating the present invention but otherwise simplified, with the brush shown in vertical cross section, and with the brush in the raised or transport position;

FIG. 2 is a view similar to FIG. 1 , with the brush in the lowered or use position;

FIG. 3 is a vertical sectional view showing the motor, drive hub and brush in vertical cross section (along a plane through the axis of rotation of the brush extending in the direction of travel) and with the motor shown diagrammatically;

FIG. 4 is an upper perspective cross section view of the drive hub assembly;

FIG. 5 is a view similar to FIG. 4, taken from a lower perspective of the drive hub;

FIG. 6 is a bottom view of the lower section of the drive lug;

FIG. 7 is a side view of the drive lug seen in FIG. 6; FIG. 8 is a bottom view of the drive hub assembly;

FIG. 9 is a side view of the drive hub assembly;

FIG. 10 is a lower perspective view of the drive hub assembly;

FIG. 11 is an upper perspective view of the brush;

FIG. 12 is a vertical cross sectional view of the brush taken through the axis of rotation;

FIG. 13 is a top view of the drive hub assembly assembled to the brush with the outer portions of the brush cut away to permit the hub to be seen in greater detail;

FIGS. 14 and 15 are bottom views of the drive lug, shown in relation to the mounting receptacle of the brush, with the drive lug respectively in the release position and in the drive position;

FIG. 16 is a circuit schematic diagram of the electrical control circuit for the machine of FIG. 1 in the Transport Mode;

FIG.17 is an upper perspective view of an alternative embodiment of the brush with a cylindrical insert providing the interference detent or retention member between the drive and release zones of the brush plate;

FIG.18 is a view similar to FIG. 17 with the cylindrical insert shown in exploded relation to the brush plate;

FIG. 19 is a vertical cross section view of the brush of FIG. 18 in a plane passing through the axis of rotation of the brush;

FIG. 20 is a composite, perspective view of the brush and drive assembly for a second embodiment of the invention, with the drive lug assembly rotated to view the underside; and FIGS. 21-22 are bottom, cut away views of the drive lug assembly and central portion of the brush for the embodiment of FIG. 20 with the components in the load position and the drive position respectively.

Detailed Description

Referring first to FIG. 1, reference numeral 10 generally designates a floor scrubbing machine incorporating one embodiment of the present invention. The machine includes an outer housing or casing 11 and is supported by forward wheels 12, as well as a central rear caster wheel 13.

Within the housing 11 are batteries for powering the machine, a reservoir of cleaning fluid for application either to the scrub brush or directly to the floor, with a rear suction device for recovering spent solution and a storage tank for the spent solution, all of which are conventional and not shown in detail.

An operator's handle 16 is rigidly mounted to the frame permitting the operator to maneuver the machine. Forward of the handle 16 is an actuator 17, controlled by the operator, which closes an Operator Run switch 17A (See the schematic of FIG. 16) when actuated. Actuator 17 may be a manually operated bail-type control adjacent the operator's hand, and pivotally connected to the machine so that the operator can simply squeeze the pivoting actuator handle 17 toward the fixed handle 16 to actuate the Operator Run switch (to be further described within) and power the scrub brush in the lowered position of FIG. 2.

Also mounted on the operator's console, adjacent the handle 16 (so as to be conveniently accessible to the operator) is a Keys witch 18 (diagrammatically shown and designated 124 in the electrical schematic, FIG. 16), which is a rotary switch temporarily actuated by a key and spring-biased to an "off position, to be described further within. It will be appreciated, however, that the Keyswitch 18 is readily accessible to the operator when he or she is positioned at the operator's station behind the machine (to the right in FIG. 1).

Turning now to the lower forward portion of the machine, a scrub brush generally designated 20, is mounted to a drive shaft connected to a motor 22. At the lower end of the drive shaft (designated 34 in FIG. 3) there is mounted a hub assembly generally designated 24. The motor 22 is mounted above a deck 26 which houses the brush 20. The motor and deck are carried by the frame of the machine 10 by means of a lift linkage in the form of a four-bar or parallel linkage partially shown and generally designated 28 in FIG. 1.. A lever 29 provided with an actuating foot pedal 30 immediately in front of the operator's station is pivotally connected at 32 to the frame of the machine 10. The forward end of the lever 29 forms the lower link of the four bar linkage 28 so that when the operator depresses the foot pedal 30, the motor 22, brush 20 and deck 26 are lifted to the raised position shown in FIG. 1 for storage or transport.

When the foot pedal 30 is released as seen in FIG. 2, the motor and brush are lowered by the four-bar linkage 28 to the operating position, with the bristles of the brush contacting the floor F (FIG. 2) for scrubbing. The mechanical aspects of the raise and lower mechanism, which permits the brush to be set in the raised position indefinitely, are conventional.

A Run Enable switch 33 and Brush Unload Enable switch 35 may be mounted to the frame of the machine. The functions of these switches will be described in connection with the schematic diagram, FIG. 16. The Unload Enable switch 35 is actuated by lever 29 and Run Enable switch 33 is actuated by a strike plate (designated 31 in FIGS. 1 and 2) when the brush is raised, as in FIG. 1. The strike plate 31 is mounted to an extension of the lever 29 which extends forwardly of the pivot 32 and which forms the lower link of the parallel linkage 28. Briefly, the Run Enable switch allows the brush to be driven by the motor when the brush is lowered for use (FIG. 2), and the Brush Unload Enable switch allows the brush to be driven for unload when the brush is in the raised position (FIG. 1).

Turning now to FIG. 3, the motor 22 (and associated gearing, if any) is conventional and need not be described in further detail. The motor 22 drives a shaft 34 which extends in a vertical direction for driving the brush 20. The hub assembly 24 is connected to the drive shaft 34 and mounts the brush 20 as will be described in further detail.

The brush 20 includes a brush plate 36, the lower portion of which is provided with bristles 37. The center of the brush plate 36 is increased in thickness, as at 38, thus providing strength, and defining a receptacle generally designated 39 for receiving and releasably coupling to the hub assembly 24, as will be described in more detail within.

Briefly, the hub assembly 24 includes an upper hub member 42, and a lower hub member (or "drive lug") 43. As will be described, the upper hub member 42 is placed respectively on the top of the central portion 38 of the brush 20, and the lower hub member 43 of the hub assembly 24 is located beneath the upper hub member and attached to it by means of bolts 45 (FIGS. 4 and 5). The hub assembly is fastened together by fasteners 45, and when fastened together, the hub assembly grips and secures the brush plate 36 as seen in FIG. 3. The hub assembly is secure to the shaft 34 of the motor by fastener 41. As will be described, the upper hub member 24 applies the downward force on the brush 20, and the lower hub member or drive lug 43 is received in the lower, central receptacle 39 of the brush plate 36. The upper and lower hub members 42, 43 form the hub assembly 24; and they cooperate to provide an annular, circumferential retention groove or channel 48 (FIG. 9) for securing the brush 20 in the driving position of FIG. 3.

Turning now to FIGS. 4 and 5, there are shown, respectively, an upper perspective view and a lower perspective view of the drive hub assembly 24 in cross section. When the two hub members 42, 43 are secured together, by the fasteners 45, they provide the retention grove or channel 48 for removably securing the brush, as will be described further within.

Turning then to the upper hub member 42 (FIG. 9), it includes a central collar 51 which receives fastener 41 of FIG. 3, and which includes an axially extending key way 52 for coupling to the drive shaft 34 of the motor 22. The drive shaft 34 is provided with a matching keyway providing a driving engagement for the drive hub assembly when the upper and lower hub members are secured together as described above.

The upper hub member 42 also includes an outwardly extending circular flange 54 including a horizontally extending lower, generally flat lower surface 55 which extends horizontally when the hub assembly is connected to the drive shaft 34. The lower horizontal surface 55 of the upper hub member 42 rests on the upper cylindrical surface of the raised central portion 38 of the brush plate 36, and provides a means through which the upper hub member 42 exerts a downward force on the brush 20 when it is lowered to the operating position. The force may be provided by the weight of the motor 22 and the associated linkage assembly for positioning the drive motor. Additional force may be added by other means if necessary or desired.

Referring to FIG. 6 and 7, the lower hub member 43, sometimes referred to as the drive lug, is seen from the top and side respectively. It includes a cylindrical wall 61 which includes three equally angularly spaced mounting apertures 62 which receive bolts 45 for mounting the lower hub member 43 to the upper hub member 42 as seen in FIG. 3.

The lower portion of the lower hub member 43 includes a peripheral drive surface 68. The lower surface of the drive lug 43 has a tapered shape as seen at 69 in FIGS. 4, 5 and 7 adapted to engage a similarly shaped dished surface 91 (FIGS. 11, 12) on the upper surface of the raised, central portion of the brush 20 for centering the brush beneath the drive lug during loading. The lower hub member 43 has a central opening 66 which is shaped to receive the upper hub member, in a snug fit. The upper surface 64 of sidewall 61 is annular and engages the lower surface 55 of the flange 54 of the upper hub member when the two are assembled to form the drive hub assembly, as seen in FIGS. 4, 8, 9 and 10.

Still referring to both FIGS. 6 and 7, beneath the cylindrical sidewall 61, the lower hub member 43 forms a peripheral drive flange 67. The upper surface 74 of drive flange 67 is flat, as best seen in FIG. 7, for supporting and lifting the brush when raised. The drive flange 67 extends peripherally beyond the outer surface 76 of the cylindrical sidewall 61 to define drive surface 68.

The drive surface 68 defines three outwardly-protruding portions having curved outer extremities and equally angularly spaced are designated respectively 77, 78 and 79 in FIG. 6. The formed protuberances 77, 78 and 79 are sometimes referred to herein as "lobes" (thus, the term "tri-lobular" describes the drive lug 43).

In summary, the drive flange 67 defines a peripheral drive surface 68 which extends about the lower hub member and defines the three drive lobes 77, 78 and 79. Each of the drive lobes 77, 78 and 79 is symmetrical about a center line passing between the center of opening 66 of the lower hub member and the "peak" of the associated lobe.

As seen in FIG. 6, the portion of drive surface 68 which is located clockwise relative to the curved peak of a lobe or distal portion of a lobe (when viewed from above) is a drive surface (these are designated 77A, 78A, and 79A for lobes 77, 78 and 79 respectively). The trailing surfaces (i.e. extending counterclockwise from the peaks) are limit or release surfaces designated 77B, 78B and 79B. These drive and release surfaces may be symmetrical about the radial center of the associated "peak". It will be observed that when viewed from the top, the direction of drive is clockwise (FIG. 6), but counterclockwise when viewed from the bottom (FIGS. 14, 15).

Turning to FIGS. 3, 4, 11-13, as described, reference number 20 designates the brush and 36 is the brush plate which holds the bristles. The brush plate 36 includes the upper central raised portion 38 defining an upper central opening 92 which has the tri-lobular shape shown in solid line in FIG. 13 and corresponds to, but is slightly larger than the shape of the peripheral drive surface 68 of the lower hub member 43 (i.e. the drive lug) to permit the lower hub member 43 to pass through the correspondingly shaped opening in the raised portion 38 of the brush plate 36 in assembling the brush to the tri-lobular drive hub assembly 40. Thus, the drive hub assembly can be removed from, or assembled to the brush when the drive surface 68 of the drive lug is aligned with upper opening 92 of the brush, and the motor 22 is raised.

The raised central portion 38 of brush plate 36 defines a lower central opening 102 formed by interior sidewall 101. The shape of the sidewall 101 of the raised central portion 38 (which forms receptacle 39 for the drive lug 43), is seen in dashed line in FIG. 13 and generally designated 101. Moving in a clockwise (the direction of drive) about surface 101 in FIG. 13, beginning at drive lobe 79, the surface 101 (sometimes referred to as an intermediate surface because it lies between a release zone partially defined by the release surface of each sector, and a drive or captive zone associated with the driven surface of each sector extends outwardly from the drive axis. Portion 96A serves as a driven surface of the brush when engaged by a corresponding drive surface 79A on the peripheral surface 68 of the lower hub member 43. The wall 101 of the hub receptacle 39 formed by the brush plate 36 has similar release (or limit), intermediate and driven surfaces for each of the other two lobes 77 and 78, as will be understood, and retention detents 108, 109, 110 are formed in the intermediate zones between each pair of release and drive zones. The lobes 77-79 of the drive lug (i.e. lower hub member), in the drive position, extend beneath an overhead or undercut surface 115 (FIG. 12) which is formed in the raised central portion 38 of the brush plate 36. The drive lobes are received in the groove 48 of the drive hub assembly (FIGS. 4 and 9) to retain the brush on the drive hub assembly in the raised position (see also FIG. 3) and when the machine is placed in the drive mode.

Turning now to the bottom views in FIGS. 14 and 15, the drive lug 43 is in the drive position in FIG. 15 - that is, the drive lobes are forward (in the counterclockwise direction of drive) of their associated retention lugs and in driving engagement with the associated driven surfaces of the side wall 100 of the receptacle 39 of the brush 20. Drive lug 43 is in the release position in FIG 14. The region between the retention detent and the driven surface for each drive sector (i.e. forward of the retention detent in the direction of drive) is referred to as the "drive zone", and the region in which the drive lug engages or is immediately adjacent the associated limit or release surface is referred to as the "release zone".

FIG. 13 is a top view. The drive shaft of the motor rotates in a clockwise direction in the driving mode (that is, when the motor is energized). As seen in FIG. 13, then, the drive hub assembly is in the removal or release position. The surface extending counterclockwise of the peak of the drive lobe 77, designated 77B in FIG. 13, engages a corresponding release or limit surface 87 A of the receptacle 39 for the lower hub member 43. Surface 87 A thus defines a limit or release position for removing the brush (by raising the motor and thus the drive hub assembly 24). Corresponding limit or release surfaces of the receptacle 39 are shown at 87B and 87C for drive lobes 79 and 78.

Referring to FIGS. 14 and 15 (which are bottom views so the direction of driving is counterclockwise), the drive hub assembly is shown in the release and the drive positions respectively, for better understanding. Thus, in the driving position, (FIG. 15), the forward drive surfaces 77A, 78A and 79A of the three drive lobes 77-79 of the drive lug engage and drive corresponding driven surfaces 94, 95, 96 of the side wall 100 of the receptacle 39. In doing so, the three drive lobes 77, 78 and 79 of the drive hub assembly pass over retention detents (or retention members) 108, 109 and 110 formed on the inner surface 101 of the side wall 100 of the receptacle 39 for the lower hub member 43. As seen in FIG. 14, the drive hub assembly is in the release or removal position. That is, the opening 92 of the central portion 90 of the brush plate 36 is aligned with the correspondingly shaped sidewall 75 of the lower hub member, and enough clearance is provided to permit the drive hub to be raised and removed from the brush.

Turning now to FIGS. 17 and 18, there is shown an alternate embodiment of the brush plate, designed 211. Brush plate 211 is similar to previously described brush plate 36, providing a receptacle for the trilobular drive, lug 43, as described above. Specifically, brush plate 211 has three separate sections, each including a driven surface, a release or limit surface and a detent between them for retaining the drive lug in the forward or drive zone except during a "Brush Unload" procedure, as described.

In the embodiment of FIGS. 17, 18, and 19 (which works the same as the first embodiment already described), the retention member or detent is an insert designated 208; and it is formed from a rod or cylindrical length (providing a controlling facing, curved retention surface) of synthetic material such as polyurethane which has durability but also a controlled flexibility, provided by its durometer rating. Thus, the force required for the transition of the drive lug between the drive zone and the release zone may be better controlled while having improved wear characteristics.

The section of the material forming the retention detent insert 208 is received in a corresponding opening 210 in the brush plate 211. Opening 210 forms a receptacle and has a fixed lower limit surface 212 to position the detent 208 in the vertical direction, and a cylindrical side wall 215 sized to snuggly receive and hold the insert 208. Cylindrical sidewall 215 of the retention member extends more than 180°, and preferably about 210° about the receptacle to insure retention of the insert during operation. The cylindrical sidewall 215 provides an inner curved retention surface for engaging the lower hub member.

Turning now to the embodiment of FIGS. 20-21, the drive hub assembly is designated 224, and it may be as described in relation to the drive hub assembly except the drive hub assembly 224 has three metal drive members 227, 228 and 229 secured (preferably by threaded fasteners) to the lower surface 230 of the upper drive member. The drive members 227, 228, 229 are spaced apart at equal angular spacing; and they are designed, sized and arranged to be received respectively in slots 221 A, 228A and 229A. The slots 227A, 228A and 229A are curved and shaped to permit the associated drive members 227, 228 and 229 to freely move within the slots between a release zone (designated 227B for slot 227A) as shown in FIG. 21, and a drive zone or position 227C for slot 227A, as shown in FIG. 22. The drive end of each slot 227 A- 229A is provided with a driven surface, such as that designated 227D for slot 227 which is shaped (preferably flat) to correspond to the drive surface (227E) of the associated drive member (227).

Description of the Control Circuitry

Turning now to FIG. 16, there is shown an electrical schematic of the control circuit for operating the scrubber as has been described above. Reference numeral 120 generally designates a battery which supplies power to the unit. The battery 120 may be comprised of one or more deep cycle batteries. A battery charger 121 (operating normally-closed contacts 125) is connected across the terminals of the battery, to be plugged into a wall outlet when it is desired to charge the battery. When the battery charger is in operation, the Keyswitch 124 is prevented from operating the system because contacts 125 are open. A double-pole connector has two contacts 123, 123 connected respectively in the battery supply leads for manually disconnecting the battery for safety or testing of the circuit. Contacts 2 of a Keyswitch 124 (which is shown in electrical schematic form for switch 18) in FIG. 1, battery charger contact 125, and circuit breaker 128 are connected between junctions 157 and 148.

A brush relay designated 122 is connected in series with the normally-closed (i.e. when the brush is in the lowered position) Run Enable switch 33 and the normally-open Operator Run switch 17 A (shown in FIG. 16 in electrical schematic form). These three components are connected in a series circuit starting at node 148 to the negative battery terminal. One terminal of the Operator Run switch 17A is connected to a junction 152. Two normally-open contacts 131, 131 of main relay 130 are connected respectively in the positive and negative battery leads. Keyswitch 124, which enables the operator to turn the system "on" or "off" and provides other functions to be described, as shown. Keyswitch 124 is a spring biased, multiple contact switch. Briefly, switch 162 of Keyswitch 124 is connected between junction 148 and the positive terminal of the battery. Switch 161 of Keyswitch 124 is connected in series with normally-open Unload Enable switch 35; switch 160 of Keyswitch 124 is connected to junction 148, and switch 155 (which operated with switch 160) is connected to junction 152. Contacts 125 of an internal relay of battery charger 121 are connected in series with a circuit breaker 128 and Keyswitch 124 . A main relay 130 is connected between junction 148 and battery negative. Keyswitch 124 has three positions: Off (designated 0); On (designated 2); and Brush Unload (designated 1 in the drawing). When the contact (which is actuated by turning the key) moves to the numbered position, the similarly numbered contacts are actuated, (i.e. reversed from the quiescent state shown in FIG. 16), as will be further described. In the Brush Unload position, Keyswitch 124 is spring-biased to the off position and returns to that position if released by the operator.

The of normally-open contacts 131 of the main relay 130 couple battery power, when closed, to a junction 156. A vacuum switch 145 is connected between junction 148 and a vacuum relay 146, thus energizing a vacuum motor 132 via contacts 140 when switch 145 is closed by the operator and junction 148 is energized.

In series with the circuit containing the brush motor 135 are normally-open contacts 136 actuated by a brush relay 122. A circuit breaker 137 is connected in series with the normally-open contacts 136 of the Brush Relay 122. For reasons which will become clear, the terminals of brush motor 135 are terminals designated 138 and 139 (which is connected to the battery negative supply line 153 when the system is in operation).

Normally-open contacts 140 (actuated by the vacuum relay 146) are connected in circuit with a circuit breaker 141 and the vacuum motor 132 for actuating the vacuum recovery system.

Vacuum switch 145, normally closed, is connected in series with the vacuum relay 146, this circuit being connected to the junction 148, as seen. A battery gauge 149 is also connected to the junction 148.

Turning to the right side of FIG. 16, the previously described Operator Run switch 17A, (bail-operated and having normally-open contacts) is connected in series with the normally-closed contacts of the Run Enable switch 33. The Run Enable switch 33 is actuated to the closed position by the strike plate 31 being in the lowered position, as seen in FIG. 2. When the Run Enable switch 33 is closed (the strike plate 31 being lowered with the brush by action of the operator), the operator may then operate the machine by actuating (via the bail 17) the Operator Run switch 17A. Junction 152 is a common junction for: (1) switch 155 of the Keyswitch 124; (2) the circuit comprising the Run Enable switch 33 and the Operator Run switch 17A just described; (3) the brush relay 122; and (4) a series circuit comprising a water solenoid switch 129 and solenoid 126 for opening a valve to the water supply when switch 129 is closed by the operator's release of foot pedal 30.

The Keyswitch 124 includes a set of normally-open contacts 155 (actuated in position 1) which are connected to the junction 152. Normally-closed contacts 161 of the Keyswitch 124 are connected in circuit with the normally-open Unload Enable switch 35 (shown in FIG. 16 in the closed position because FIG. 16 represents the system in the Transport Mode) which is connected to brush motor terminal 138, and normally-closed contacts 159 of the brush relay 122, which are connected to brush motor terminal 139.

Operation of the Circuitry Normal Running Operation

The electrical schematic of FIG. 16 is shown in the transport mode. Thus, for example, the normally closed Run Enable switch 33 is shown as open in FIG. 16 and normally open Unload Enable switch 35 is shown as closed. Assuming the battery 120 is connected (contacts 123 closed), when a key is inserted in switch 124 and turned by the operator to position "2", switch 162 closes, and the battery 120 is connected through the circuit breaker 128, normally-closed contacts 125 of battery charger 121 (since battery charger 121 is not in operation) and contacts 162 of the Keyswitch 124 to the junction 148. This operates the battery gauge 149 for operator observation, and it also actuates the main relay 130. When the main relay 130 is energized, contacts 131, 131 close, supplying power to nodes 153 and 156. If the vacuum switch 145 is closed (manually), the vacuum relay 146 is energized, thereby closing the contacts 140 and energizing the vacuum motor (i.e., pump) 132.

Assuming that the brush is in the lowered or operating position, the Run Enable switch 33 is closed (i.e. actuated). This then couples power from junction 148 through the Run Enable switch 33 and the Operator Run switch 17A (when bail or actuator 17 is moved by the operator) to the junction 152. This actuates the brush relay 122 which, in turn, closes contacts 136 to energize the brush motor 135 to drive the brush 20. At the same time, the water solenoid 126 (optional) may be energized to supply water to the brush 20 because switch 129 is normally closed.

Operation continues until the operator releases the bail handle 17 which then opens the Operator Run switch 17A, thereby opening the contacts of switch 17A in FIG. 16 to de-energize the brush relay 122 and thereby de-energize the brush motor 135.

Transport and Brush Unload

For transport, storage or brush unload (to clean, store or charge, for example), the foot pedal 30 is depressed by the operator. This raises the brush 20 to the raised position shown in FIG.l, and the control circuit is in the Transport mode — i.e. as shown in FIG. 16. To unload the brush, the operator turns the Key switch 124 to position "1", which is spring biased to return to the "OFF" or "0" position when the key is released. If it is desired to remove the brush the operator depresses the foot pedal 30, elevating the brush to the raised position which, in turn, closes or actuates the Unload Enable switch 35. This opens contacts 33 and closes contacts 35 of the Unload Enable switch, thereby permitting brush removal because the brush is raised.

When the circuit is in this condition, if the operator turns the Keyswitch 124 to the "Brush Unload" position, the contacts 155 and 160 close. This causes the main relay 130 and brush relay 122 to be momentarily energized, thereby enabling the brush motor 135 to be energized through contacts 136 (contacts 161 being open). When the operator then releases the Keyswitch 124, it returns to position "0" under spring bias. Contacts 155 and 160 open, de-energizing the brush relay 122 and main relay 130 via junction 148, thereby opening contacts 136. This action shorts out the terminals 138, 139 of brush motor 135 via the circuit comprising: terminal 138, Unload Enable switch 35 (actuated to the closed position by virtue of manually raising the brush); closed contacts 161 (switch position "0"); and brush relay contacts 159 to motor terminal 139. At the same time, contacts 161 of the Keyswitch 124 are closed, as is the Unload Enable switch 35 , thereby shorting the terminals of the brush motor 135 and placing a load to decelerate motor 135 and bringing the motor to a quick stop due to the load. This permits the rotating brush to override the stopped drive lug (due to the rotational inertia of the brush) and be disengaged, and to fall freely from the brush drive assembly, or to be removed manually.

During brush unload, as the motor comes to an abrupt stop when the operator releases Keyswitch 124, the distal curved end portions of the drive lobes of the drive lug 43 pass over the retention members 108, 109 and 110 (FIGS. 13, 15) on the wall 101 of the hub receptacle 39, to the positions shown in FIG. 14 (it will be realized that FIG. 14 is a bottom view, the direction of rotation for driving the brush is counterclockwise). Thus, the brush continues to rotate clockwise toward the release position (i.e. the release zone), with the non-driving surface of the drive lobes engaging the limit surfaces of the wall 101 thereby freeing the brush for removal.

Having disclosed several embodiments of the invention, persons skilled in the art will appreciate that equivalents may be substituted for those elements disclosed; and it is therefore intended that all such modifications be covered as they are embraced within the spirit and scope of the appended claims.

Claims

The Claims 1. A floor scrubber comprising:

a motor,

a drive member coupled to said motor and including at least two drive lobes;

a brush including a brush plate defining a receptacle for receiving the drive member and including a circumferential recess for receiving said drive member in driving engagement, said receptacle defining a section for receiving each of said drive lobes of said drive member, each section of said receptacle having a drive zone including a drive surface for engagement with one of said lobes of said drive member and a release zone having a limit surface for positioning said brush for removal from said drive member; and

a retention member for each of said sections of said receptacle of said brush plate, each retention member being constructed and arranged to retain a lobe of said drive member in an associated drive section of said brush plate during operation, while permitting a drive lobe to pass over an associated retention member and enter the release zone when said brush is raised and said motor is abruptly stopped.

2. The scrubber of claim 1 wherein each retention member includes a surface facing the center of said receptacle for engaging an associated retention member of the drive lug.

3. The scrubber of claim 1 wherein each retention member is formed integrally with said brush plate.

4. The scrubber of claim 1 wherein each retention member comprises an insert of synthetic material received in an opening in said brush plate.

5. The scrubber of claim 4 wherein each insert is a generally cylindrical member removeably received in an associated cylindrical opening of said brush plate and has an axis substantially parallel to an axis of revolution of said brush.

6. The scrubber of claim 1 comprising three lobes on said drive member, each associated with a retention member, each lobe having a generally triangular shape and a curved distal surface for engaging an associated retention member, each lobe having a center line extending radially of the axis of rotation of said drive lobe, said center lines of said lobes being separated approximately 120°.

7. The scrubber of claim 1 further including a controller for operating the brush; said controller including a Run Enable switch connected in circuit with an operator actuatable control device for permitting said brush to be driven when said brush is in a floor-engaging position; and a Brush unload switch connected in circuit with a key-operated switch controlled by an operator, said controller permitting said brush to be driven by said motor in a raised position to release said brush when an operator actuates said key-operated switch and said brush is in a raised position, said controller including circuitry operable after the operator releases said key-operated switch to produce a load on said motor to stop said motor, whereupon the brush continues to rotate and the retention members of the brush override the lobes of the drive member enter the release zone of their associated sectors to place said brush in a removal position.

8. A brush for a floor scrubber having a brush plate and bristles extending from one side of said brush plate; said brush plate defining a receptacle for receiving in driving engagement, a drive member having a plurality of drive lobes; said receptacle of said brush including a sector for receiving each associated lobe of the drive member, each sector having a drive zone including a driven surface, a release zone in communication with an associated drive zone, and including a limit surface for positioning said brush relative to said drive lobe for removal, and a retention member for each sector, said retention member located between the drive zone and a release zone of a sector and adapted to releasably retain an associated drive lobe in a drive zone, while permitting the drive lobe to move to an associated release when the brush is raised and the motor is abruptly stopped.

9. The brush of claim 8 wherein each retention member includes a protuberance extending toward the center of said brush for engaging a distal portion of an associated lobe of the drive member for releasably impeding the drive lobe from moving to an associated release zone of said brush relative to said drive lug in operation, thereby to maintain said brush in an operating position during normal operation.

10. The brush of claim 9 comprising three retention members spaced circumferentially about said brush at approximately 120° apart.

11. The brush of claim 9 wherein each retention member comprises a cylindrical member of synthetic material.

12. The brush of claim 11 wherein each retention member is polyurethane having a compression rating of 70-90 on the Shore A scale.

13. The brush of claim 12 wherein said brush plate includes three cylindrical openings for receiving and securing an associated retention member in the form of a cylinder.

14. A floor scrubber having a motor coupled to a drive member having a plurality of drive lobes spaced at equal angular spacings about an axis of revolution, each drive lobe having a generally triangular shape with a rounded distal portion;

a brush having a receptacle for receiving said drive member in driving engagement, said receptacle having a sector for receiving each of said drive lobes; each sector defining a forward drive zone and a rear release zone; and a retention member for each sector located between an associated drive zone and release zone, whereby, said retention member releasably retains said drive member in said drive zone; and

a controller for actuating said motor, said controller including an actuatable device for energizing said motor in a forward rotary motion when said brush engages a floor for scrubbing, thereby placing said drive lobes in associated drive zones of said sectors;

said control device further including an actuator for driving said motor in a forward direction only when said brush is placed in a raised position, such that when said actuator is released, said controller imposes a load on said motor to brake it, whereby said motor abruptly stops and said brush overrides said retention members and each lobe of said drive member enters an associated release zone, wherein said brush is free from engagement with said driving member.

15. The scrubber of claim 14 wherein said controller includes a Run Enable switch connected in circuit with an operator- controlled key-actuated switch and an Unload Enable switch; said key-operated switch energizing said motor, when actuated, to drive said brush in a forward, scrubbing direction and when said brush is raised to a non-scrubbing position, said key-operated switch, connected in circuit with said motor and said Unload Enable switch operates to short the terminals of said motor upon Operator Action, thereby causing said motor to stop abruptly and said brush to continue to operate in a forward rotational direction such that said retention members override their associated drive lobes and said brush is placed in a release zone for removal.

16. The floor scrubber of claim 14, wherein said brush plate includes a plurality of grooves, each extending circumferentially about the axis of revolution of said brush and arranged to extend serially about the axis of rotation; and a plurality of drive members on said drive member, and for each of said grooves, said drive members and grooves constructed and arranged such one of said drive members is received in an associated groove in driving engagement therewith when said brush is driven in normal operation, and when said brush overrides said drive member, said drive member disengages.