GB2336991A

GB2336991A - Quick-change brushes for sweeping machines

Info

Publication number: GB2336991A
Application number: GB9809944A
Authority: GB
Inventors: Alan Bryson Riach; Douglas Watson
Original assignee: Applied Sweepers Ltd
Current assignee: Applied Sweepers Ltd
Priority date: 1998-05-08
Filing date: 1998-05-08
Publication date: 1999-11-10
Anticipated expiration: 2018-05-08
Also published as: GB9809944D0; GB2336991B

Abstract

A drive mechanism for the front brushes of a sweeping machine with a quick-change brush engagement for the two contra-rotating brushes. Each brush head is drivingly engaged with a drive hub 7 driven by electric motor 1 via shaft 5. The drive hub has at least three drive teeth (15, Fig. 4) engaging sockets (17, Fig. 7) in the brush head. The brush head is secured to the drive hub by a lock cam 33 supported on the drive hub by studs 31 through arcuate slots (35, Fig.6) permitting rotation of the lock cam relative to the drive hub through an arc. The lock cam has cams (37, Fig. 6) which are no larger than the teeth (15) and which butt against lands between the sockets of the brush head following rotation of the lock cam relative to the drive hub and thus secure the brush head.

Description

1 QUICK-CHANGE BRUSHES 2336991 This invention relates to a drive mechanism

for the front brushes of a suction sweeping machine with a quick-change brush system and to a suction sweeping machine fitted 5 with such a mechanism.

Quick-change brushes on factory polishers and cleaners are commonplace, but these are not able to accommodate contra-relating brushes, as are used on suction sweeping machines such as that marketed by us under the Registered Trade Mark THE GREEN 10 MACIUNETM.

The object of the present invention is to provide a quick-change brush system for the front brushes of a suction sweeping machine, which does not require spanners or other tools and which allows the operator of the machine to replace the rotary brushes when 15 they become worn with the minimum of effort.

Prior art quick-change systems normally use some type of bayonet attachment arrangement, but such an arrangement is not satisfactory for contra-rotating brushes, unless the bayonet systems are of "opposite hand". Such an arrangement is unsatisfactory because it requires a first set of lefl-handed components and a second set of right-handed components. The system of the present invention permits cornmon components for each brush, i.e. the same components can be used for the brushes, regardless of their direction of rotation.

According to the present invention, we provide a drive mechanism for the front brushes of a suction sweeping machine with a quick-change brush system, comprising two contra-rotating drive hubs, adapted to be driven by the machine, each drive hub being provided with a plurality of drive teeth spaced around the rotational axis of the hubs and a lock cam supported on each drive hub for rotation therewith about the same rotational axis, but being relatively rotatable about the same axis, relative thereto through a predetermined arc, each lock cam having a plurality of cams thereon and being no greater in size than the teeth and wherein each brush has a central aperture therein with a plurality of sockets in the periphery thereof, each socket being designed matingly to 2 receive a drive tooth of its respective drive hub, there being a plurality of lands located between adjacent pairs of sockets so that when the teeth are in engagement with their sockets, the lock cam can be rotated, relative to the drive teeth to engage the cams thereof behind the lands, there being suitable means on the lands and teeth so as to lock 5 the brush heads on their respective drive hubs.

Preferably, the means comprise a detent on each land on the brush head with which a projection on the lock cam can engage.

Preferably, three circumferentially equally spaced dog teeth drive teeth are provided on the drive hub, which matingly engage with three similarlyshaped sockets on the inner face of the brush head.

Preferably, the lock cam is attached to the drive hub, by means of three studs which 15 threadedly engage with three circumferentially equally spaced threaded apertures formed in the outer face of the drive hub, there being arcuate slots formed in the lock cam through which the studs pass, said slots permitting the relative rotation between the lock cam and drive hub.

Preferably, the outer face of the lock cam is provided with one or more projecting ribs, extending generally radially, by means of which the operator can grip the lock cam to disengage it from the drive hub with a pressing and twisting movement.

A drive mechanism for the front brushes of a suction sweeping machine with a quick25 change brush system according to the present invention is now described by way of example with reference to the accompanying drawings in which:- is a vertical section, on the line I-1 in Figure 2 through the drive mechanism, Figure 2 is an underside view of the mechanism of Figure 1 with part of the brush head having been omitted, 3 Figure 3 is a vertical section, on the line III-III in Figure 4 through a drive hub of the mechanism, Figure 4 is an underneath view of the drive hub of Figure 3, Figure 5 is a vertical section through a lock cam of the mechanism, Figure 6 is an underneath view of the lock cam of Figure 5, Figure 7 is an underneath view of a brush head with the brushes and brush apertures omitted, and Figure 8 is a vertical section through the brush head of Figure 7.

Referring to Figure 1 of the drawings, a rotating front brush of a suction sweeping machine is driven by a drive motor (1) supported on a motor bracket (3), the motor (1) having a drive shaft (5) on which a drive hub (7) is secured for rotation therewith by means of a fixing stud (9). The drive hub (7) has a central axial aperture (11) therein counterbore at (13) to receive the drive shaft (5) of the motor (1) (see Figure 3).

On its underside, the drive hub (7) has three circumferentially equally spaced radially extending drive teeth (15) (see Figure 3) which engage within three mating sockets (17) on a back face (19) of a brush head (21) (see Figure 7), on the opposite face of which are a plurality of sockets (23) to receive brush bristles (25). Also located on the underneath face of the drive hub (7) are three equally spaced protrusions (27) having threaded apertures (29) formed therein, each equally radially spaced from the centre of the drive hub to receive fixing studs (3 1) (see Figure 1) by means of which a lock cam (33) (see Figures 5 and 6) is secured to the drive hub (7), but for relative rotational movement thereto. As can be seen in Figure 5, the lock cam. (33) has three equally circumferentially spaced arcuate slots (35) formed therein for this purpose, the slots being wide enough to receive the threaded shanks of the fixing studs (3 1), but not allowing the heads thereof to pass therethrough. As can also be seen in Figure 5, each 4 lock cam (33) has three equally circumferentially spaced radially extending locking lugs (37) thereon which are of the same shape but no larger than the drive teeth (15) on the drive hub (7) and which can pass wholly through the sockets (17) on the brush head (21) when the brush head is offered up into driving engagement with the drive hub (7).

The arrangement is such that the back face (39) of each locking lug (37) will be substantially flush with an underneath face (41) of the brush head (21) when the brush head is in driving engagement with the drive hub (7), whereupon the lock cam (33) can be twisted relative to the drive hub (7) through a predetermined angle, the extent of which is controlled by the length of the arcuate slots (35), so as to move the locking lugs into locking engagement with the underneath face (41) of the brush head so that a projection (43) on the rear face (39) of the lock cam can move into locking engagement with a detent (45) on the underneath face (41) of the brush head (21). The brush head (2 1) will now be firmly located on the drive hub (7) with the drive teeth (15) thereof in driving engagement with the sockets (17) on the brush head.

is To remove a worn-out brush head (21) from the drive mechanism, the lock cam (33) is rotated so as to bring its three locking lugs (3 7) into line with the three sockets (17) in the brush head (21), whereupon the brush head can simply be dropped off the drive mechanism. To assist in rotating the lock cam (33) relative to the brush head (21) and the drive hub (7), a plurality of radially extending ribs (47) and (49) are provided on an underneath face (5 1) of the lock cam (3 3).

By virtue of the fact that the drive to the rotary brushes is permanently engaged, i.e.

there are three dog tooth drive teeth of the drive hub (7) in driving engagement with the sockets (17) on the brush head, drive to the brushes either in a clockwise direction, or an anticlockwise direction can be achieved without any risk of the brush head becoming disconnected from the drive hub (7), because the lock cam (33) is totally separate from and relatively rotatable relative thereto at all times. This means that identical component parts can be provided for the brush heads (21), regardless of their direction of rotation.

Instead of providing three protrusions (27) on the underside of the drive hub (7) to receive the threaded apertures (29), alternative means for securing the locking cam on the drive hub could be provided. Furthermore, the number of drive teeth (15) and mating sockets (17) could also be changed, although it is envisaged that at least three of each would have to be provided. It is also envisaged that there need not be the same number of locking lugs (37) as drive teeth (15).

It is preferred that the brush head (21) be moulded from polypropylene or the like, whereas the lock cam (33) could be moulded either from polypropylene or nylon. On the other hand, it is preferred that the drive hub (7) be formed of diecast aluminium.

It will, of course, be understood that the present invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.

6

Claims

1. A drive mechanism for the front brushes of a suction sweeping machine with a quick-change brush system, comprising two contra-rotating drive hubs, adapted to be driven by the machine, each drive hub being provided with a plurality of drive teeth spaced around the rotational axis of the hubs and a lock cam supported on each drive hub for rotation therewith about the same rotational axis, but being relatively rotatable about the same axis, relative thereto through a predetermined arc, each lock cam having a plurality of cams thereon and being no greater in size than the teeth and wherein each brush has a central aperture therein with a plurality of sockets in the periphery thereof, each socket being designed matingly to receive a drive tooth of its respective drive hub, there being a plurality of lands located between adjacent pairs of sockets so that when the teeth are in engagement with their sockets, the lock cam can be rotated, relative to the drive teeth to engage the cams thereof behind the lands, there being suitable means on the lands and teeth so as to lock the brush heads on their respective drive hubs.

2. A drive mechanism according to claim 1 wherein the means comprise a detent on each land on the brush head with which a projection on the lock cam can engage.

3. A drive mechanism according to claim 1, 2 or 3 wherein three circumferentially equally spaced dog teeth drive teeth are provided on the drive hub, which matingly engage with three similarly-shaped sockets on the inner face of the brush head.

4. A drive mechanism according to claim 1, 2 or 3 wherein the lock cam is attached to the drive hub, by means of three studs which threadedly engage with three circumferentially equally spaced threaded apertures formed in the outer face of the drive hub, there being arcuate slots formed in the lock cam through which the studs pass, said slots permitting the relative rotation between the lock cam and drive hub.

5. A drive mechanism according to any one of claims 1-4 wherein the outer face of the lock cam is provided with one or more projecting ribs, extending generally radially, by means of which the operator can grip the lock cam to disengage it from the drive hub with a pressing and twisting movement.

7

6. A drive mechanism for the front brushes of a suction sweeping machine with a quick-change brush system, substantially as hereinbefore described with reference to the accompanying drawings.

7. A suction sweeping machine fitted with a front brush drive mechanism as claimed in any one of claims 1-6.

Amendments to the claims have been filed as follows 1. A drive mechanism for the front brushes of a suction sweeping machine with a quick-change brush system, comprising two contra-rotating drive hubs, adapted to be driven by the machine, each drive hub being provided with a plurality of drive teeth spaced around the rotational axis of the hubs and a lock cam supported on each drive hub for rotation therewith about the same rotational axis, but being relatively rotatable about the same axis, relative thereto through a predetermined arc, each lock cam having a plurality of cams thereon and being no greater in size than the teeth and wherein each brush has a central aperture therein with a plurality of sockets in the periphery thereof, each socket being designed matingly to receive a drive tooth of its respective drive hub, there being a plurality of lands located between adjacent pairs of sockets so that when the teeth are in engagement with their sockets, the lock cam can be rotated, relative to the drive teeth to engage the cams thereof behind the lands. there being suitable means on the lands and teeth so as to lock the brush heads on their respective chive hubs.

6. A drive mechanism for the front brushes of a suction sweep'ng mach'ne ",'th a quick-change brush system, substantially as herclinbefore described with reference to the accompanying drawings.

1 7. A suction sweeping machine fitted with a front brush drive mechanism as W claimed in any one of claims 1-6.

8. A brush for a suction sweeping machine having a quick-change brush system, the brush having a central aperture therein with a plurality of sockets in the periphery thereof, each socket being designed matingly to receive a drive tooth of a drive hub on 0 It> the machine, there being a plurality of lands located between adjacent pairs of sockets so that when, in use of the brush, the teeth on the drive hub are in engagement with their sockets, a lock cam having a plurality of cams thereon, each beina no areater in size than each tooth and supported on the drive hub for rotation therewith about the same rotational axis, but being relatively rotatable about the same axis, relative thereto through a predetermined arc, can be rotated, relative to the drive teeth to engage the 0 W t> cams thereof behind the lands, there being suitable means on the lands and teeth so as to lock the brush head on its respective drive hub.

9. A brush according to claim 8 wherein the means comprise a detent on each land on the brush head with which a projection on the lock cam can engage.

10. A brush according to claim 8 or 9 wherein three similarly-shaped sockets are provided on the wall of the aperture in the brush head adapted matingly to be engaged 0 by three circumferentially equally spaced drive teeth provided on the drive hub.

A brush for a suction sweeping machine, substantially as hereinbefore described with reference to the accompanying drawings.